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Safety Research :

 

Safety, Risk, Reliability and Quality:

 

Statistic, Probability and Uncertainty :

 

 

 

 

 

 

 

 

MY WAY TO RELIABILITY AND SAFETY

 

M. Yastrebenetsky

 

I was born in Moscow on September 10, 1934. I wrote about my family and previous generations of Yastrebenetsky (a soldier under Emperor Nicholas I, a businessman, a doctor, a chemical engineer) in my book "Generations of Yastrebenetsky” [1]. After finishing the institute and postgraduate studies, 2/3 years of my life were connected with activity in the fields of reliability and safety of technical systems. This activity is the subject of the article. 

 

 

Cite: M. Yastrebenetsky MY WAY TO RELIABILITY AND SAFETY. Reliability: Theory & Applications. 2024, September 3(79): 27-40, DOI: https://doi.org/10.24412/1932-2321-2024-379-27-40


27-40

 

 

 

 

 

 

 

ALGORITHMS FOR APPROXIMATING A FUNCTION BASED ON INACCURATE OBSERVATIONS

 

G.Sh. Tsitsiashvili, M.A. Osipova

 

This paper is devoted to the approximation of a function by a trigonometric polynomial based on its inaccurate values at selected points. Two methods of observation are considered. The first method is to make observations at points evenly distributed on the segment where the function is specified. The second method is to take observations at the points of division into a finite number of equal parts of the neighbourhoods of the selected points. Upper estimates of the standard deviation of the function from trigonometric polynomials are constructed and the rate of their convergence is estimated. Differences were found in the computational complexity of these approximations and in the number of observations of the function values at the selected points. Thus, the problem of approximating a function from inaccurate observations of their values at selected points is a multi-criteria one and its solution depends on the choice of observation points. 

 

 

Cite: G.Sh. Tsitsiashvili, M.A. Osipova ALGORITHMS FOR APPROXIMATING A FUNCTION BASED ON INACCURATE OBSERVATIONS. Reliability: Theory & Applications. 2024, September 3(79):  41-46, DOI: https://doi.org/10.24412/1932-2321-2024-379-41-46


41-46

 

 

 

 

 

 

 

AVAILABILITY AND PROFIT OPTIMIZATION OF CONTINUOUS CASTING SYSTEM OF THE STEEL INDUSTRY USING ARTIFICIAL NEURAL NETWORK TECHNIQUE

 

Shikha Bansal, Sohan Lal Tyagi, Urvashi

 

The main purpose of this study was to optimize the performance parameters of the casting process using a neural network approach. The casting process is molten or liquefied metal is poured into the mould cavity, after solidification it takes the near net shape of the cavity. The entire manufacturing process goes through six stations viz Pouring turret "ladle", "Tundish", "Mould", "Water spray chamber", "Support roller" and "Torch cutter". The Artificial Neural Network (ANN) technique is used in this paper to analyze the casting system’s availability, profitability, and state probability variation. An effort has been made to identify the most critical component of the system. The outcomes of the analysis will help the practitioners in deciding effective maintenance strategies.

 

 

Cite: Shikha Bansal, Sohan Lal Tyagi, Urvashi AVAILABILITY AND PROFIT OPTIMIZATION OF CONTINUOUS CASTING SYSTEM OF THE STEEL INDUSTRY USING ARTIFICIAL NEURAL NETWORK TECHNIQUE. Reliability: Theory & Applications. 2024, September 3(79):  47-58, DOI: https://doi.org/10.24412/1932-2321-2024-379-47-58


47-58

 

 

 

 

 

 

 

TOPP-LEONE EXPONENTIATED GOMPERTZ INVERSE RAYLEIGH DISTRIBUTION: PROPERTIES AND APPLICATIONS

 

Sule Omeiza Bashiru, Alaa Abdulrahman Khalaf, Alhaji Modu Isa

 

This paper focused on deriving a new lifetime distribution having five parameters by compounding the Gompertz inverse Rayleigh model and the Topp-Leone exponentiated-G family of distributions. The new model is called Topp-Leone exponentiated Gompertz inverse Rayleigh (TLEGoIRa) distribution. The new model is very flexible and the shape of its pdf can be positively or negatively skewed and symmetric. Some statistical characteristics of the new model, such as the moments, incomplete moments, quantile function, rényi entropy and order statistics are derived and investigated. The pdf of the minimum and maximum order statistics of the new model were derived and studied. The model’s parameters are estimated using the maximum likelihood approach. A simulation study was conducted to investigate the consistency of the newly proposed model, using the average bias and root mean square error (RMSE) as metrics. The outcome of the simulation suggested that as sample sizes increase, both the average bias and root mean square error (RMSE) decrease, indicating that the distribution is consistent. Finally, two real-life datasets were used to explore the new model’s importance and adaptability in comparison to other competing models The results of the application revealed that the new distribution out performs its competitors.

 

 

Cite: Sule Omeiza Bashiru, Alaa Abdulrahman Khalaf, Alhaji Modu Isa TOPP-LEONE EXPONENTIATED GOMPERTZ INVERSE RAYLEIGH DISTRIBUTION: PROPERTIES AND APPLICATIONS. Reliability: Theory & Applications. 2024, September 3(79):  59-77, DOI: https://doi.org/10.24412/1932-2321-2024-379-59-77


59-77

 

 

 

 

 

 

 

A PROBABILITY MODEL FOR SURVIVAL ANALYSIS OF CANCER PATIENTS

 

Mousumi Ray, Rama Shanker

 

It has been observed by statistician that to find a suitable model for the survival analysis of cancer patients is really challenging. The main reasons for that is the highly positively skewed nature of datasets. During recent decades several statistician tried to propose one parameter, two-parameter, three-parameter, four-parameter and five-parameter probability models but due to either theoretical or applied point of view the goodness of fit provided by these distributions are not very satisfactory. In this paper a compound probability model called gamma-Sujatha distribution, which is a compound of gamma and Sujatha distribution, has been proposed for the modeling of survival times of cancer patients. dolor Many important properties of the suggested distribution including its shape, moments (negative), hazard function, reversed hazard function, quantile function have been discussed. Method of maximum likelihood has been used to estimate its parameters. A simulation study has been conducted to know the consistency of maximum likelihood estimators. Two real datasets, one relating to acute bone cancer and the other relating to head and neck cancer, has been considered to examine the applicability, suitability and flexibility of the proposed distribution. The goodness of fit of the proposed distribution shows quite satisfactory fit over other considered distributions.

 

 

Cite: Mousumi Ray, Rama Shanker A PROBABILITY MODEL FOR SURVIVAL ANALYSIS OF CANCER PATIENTS. Reliability: Theory & Applications. 2024, September 3(79):  78-94, DOI: https://doi.org/10.24412/1932-2321-2024-379-78-94


78-94

 

 

 

 

 

 

 

ON A DISCRETE TIME SHOCK MODEL IN CRITICAL SITUATION

 

Reza Farhadian, Habib Jafari

 

In this paper, we study a discrete time shock model which is defined based on the length of the time between successive shocks. For a system that is exposed to a sequence of random shocks over time under this model, if the interarrival time between two successive shocks is equal to a prefixed critical time point such as δ, the system fails, and the system is not damaged otherwise. We have considered two situations for the system, which are regular situation and critical situation, then we investigate the statistical behavior of the systemŠs lifetime under these situations. More precisely, we obtain the probability generating function of the system’s lifetime, the mean time to failure, the variance of the system’s lifetime, the Laplace transform of the system’s lifetime, and some other related results. We end the paper with an example including numerical comparisons of the results.

 

 

Cite: Reza Farhadian, Habib Jafari ON A DISCRETE TIME SHOCK MODEL IN CRITICAL SITUATION. Reliability: Theory & Applications. 2024, September 3(79):  95-106, DOI: https://doi.org/10.24412/1932-2321-2024-379-95-106


95-106

 

 

 

 

 

 

 

ENHANCED METHODS UNDER EXPONENTIAL DISTRIBUTION CONCERN WITH EWMA AND DEWMA METHODS

 

Dr. V. Kaviyarasu and M. Inbarasi

 

Statistical Process Control plays a crucial part in improving the quality and lowering the fluctuation in the production process environment. In SPC, the most popularly used methods are Shewhart control chart techniques and EWMA techniques which distinguish itself for its quick identification of minute process deviations, which makes it an essential tool for guaranteeing product. EWMA methods detect variances in quality of the product as well as services, measure process mean shifts with control charts, and track manufacturing process parameters to find deviations and make necessary adjustments. The exponential distribution was employed in this study because it may reflect vast and bulk production in everyday life. Exponentially distributed data, evaluate it alongside the EWMA function. This paper’s objective is to study the impact of EWMA & DEWMA parameters within the EWMA control chart’s performance using exponential distribution. Further, A few tables are provided with suitable illustrations that can be available with parameters with the help of these findings. The study also examines how the EWMA parameter affects the shape of the distribution.

 

 

Cite: Dr. V. Kaviyarasu and M. Inbarasi ENHANCED METHODS UNDER EXPONENTIAL DISTRIBUTION CONCERN WITH EWMA AND DEWMA METHODS. Reliability: Theory & Applications. 2024, September 3(79):  107-119, DOI: https://doi.org/10.24412/1932-2321-2024-379-107-119


107-119

 

 

 

 

 

 

 

RELIABILITY SAMPLING PLAN FOR GENERALIZED INVERTED EXPONENTIALLY DISTRIBUTED UNDER PROGRESSIVE TYPE-II CENSORED DATA

 

S. Singh, A. Kaushik

 

This article aims to explore a sampling strategy designed to assess the reliability of products that exhibit lifetimes following a GIED. Considered sampling approach has been specially constructed for a Type-II progressive censoring scheme, which includes binomial removals as part of its methodology. Its core objectives is to find out acceptance constant and the optimum sample size. To facilitate practical implementation, the article presents a tabulated form of the sampling plan for the selected specification, as per the considered censoring scheme. To validate the dependability and precision of the suggested sampling approach, we perform a Monte Carlo experiment under various scenarios.

 

 

Cite: S. Singh, A. Kaushik RELIABILITY SAMPLING PLAN FOR GENERALIZED INVERTED EXPONENTIALLY DISTRIBUTED UNDER PROGRESSIVE TYPE-II CENSORED DATA. Reliability: Theory & Applications. 2024, September 3(79):  120-131, DOI: https://doi.org/10.24412/1932-2321-2024-379-120-131


120-131

 

 

 

 

 

 

 

ROLE OF AGEING METRICS TO ANALYSE THE SURVIVAL DATA OF TONGUE CANCER PATIENTS

 

B. Elina, Pulak Swain, Satya Kr. Misra, Subarna Bhattacharjee

 

The paper vividly describes the non-parametric estimation of basic quantities for right censored data of times to death for patients with tongue cancer. Here we compare patients with two different sets of DNA profile using several parameters like reliability function, cumulative hazard rate function, smoothed hazard rate function and ageing intensity function. With the help of graphical representations of these functions, we analyse which DNA profile patients have better prognosis.

 

 

Cite: B. Elina, Pulak Swain, Satya Kr. Misra, Subarna Bhattacharjee ROLE OF AGEING METRICS TO ANALYSE THE SURVIVAL DATA OF TONGUE CANCER PATIENTS. Reliability: Theory & Applications. 2024, September 3(79):  132-143, DOI: https://doi.org/10.24412/1932-2321-2024-379-132-143


132-143

 

 

 

 

 

 

 

STATISTICAL PROPERTIES AND APPLICATIONS OF TRANSMUTED SKEW STUDENT t DISTRIBUTION

 

David Ikwuoche John, Mathew Stephen

 

In this study, a modified 2-parameter skew t distribution called the transmuted skew student t distribution (TSStD) was presented. Some statistical and reliability properties of TSStD such as the quantile function, the raw moments, and the moment generating function (among others), were derived. Through the method of maximum likelihood, the two parameters of the model were estimated. The stability of the model was studied via Montecarlo simulations utilizing bias, mean square error, and root mean square error as metrics. The results from the stability study revealed that the TSStD was well-behaved. Four datasets were modeled with the transmuted skewed student t distribution and four other probability density models. On the basis of information criteria, the results revealed that the transmuted skew student t distribution provides a better fit for all the datasets compared to the other competing models.

 

 

Cite: David Ikwuoche John, Mathew Stephen STATISTICAL PROPERTIES AND APPLICATIONS OF TRANSMUTED SKEW STUDENT t DISTRIBUTION. Reliability: Theory & Applications. 2024, September 3(79):  144-156, DOI: https://doi.org/10.24412/1932-2321-2024-379-144-156


144-156

 

 

 

 

 

 

 

SINE-TOPP-LEONE EXPONENTIATED G FAMILY OF DISTRIBUTIONS: PROPERTIES, SURVIVAL REGRESSION AND APPLICATION

 

A. M. Isa, S. I. Doguwa, B. B. Alhaji, H. G. Dikko

 

In this research article, we have introduced a new class of continuous probability distributions known as the Sine Topp-Leone Exponentiated-G family of distributions. This newly proposed family exhibits a higher degree of flexibility compared to some of the established distribution families. The various models within this family find wide-ranging applications in fields such as physics, engineering, and medicine. Some statistical properties of the Sine Topp-Leone Exponentiated-G family of distributions such as moments, moment generating function, quantile function and order statistics are derived. Two special models were also presented and studies. Maximum likelihood estimation method was used to estimate parameters of the models. The consistency of the proposed family was determine using simulation studies. Two real life datasets were analyzed to show the flexibility of the proposed model and the results of the analysis showed that, the proposed model was more efficient and best fit the data sets than its competitors.

 

 

Cite: A. M. Isa, S. I. Doguwa, B. B. Alhaji, H. G. Dikko SINE-TOPP-LEONE EXPONENTIATED G FAMILY OF DISTRIBUTIONS: PROPERTIES, SURVIVAL REGRESSION AND APPLICATION. Reliability: Theory & Applications. 2024, September 3(79):  157-172, DOI: https://doi.org/10.24412/1932-2321-2024-379-157-172


157-172

 

 

 

 

 

 

 

ANALYSIS OF RELIABILITY OF TYPICAL POWER SUPPLY CIRCUITS

 

S.V. Rzayeva, N.M. Piriyeva, I.A. Guseynova

 

This article is devoted to the analysis of the reliability of typical power supply circuits. The question of what factors have the greatest impact on the reliability of power supply circuits, as well as what methods and tools are used to analyze and improve their reliability is considered. Particular attention is paid to the comparative analysis of various types of power supply schemes and the determination of their advantages and disadvantages in terms of reliability. The article also discusses current trends and developments in the field of increasing the reliability of power supply and possible ways to optimize existing circuits. The results obtained can be useful for specialists in the field of power engineering and electrical engineering in the design, maintenance and modernization of power supply systems.

 

 

Cite: S.V. Rzayeva, N.M. Piriyeva, I.A. Guseynova ANALYSIS OF RELIABILITY OF TYPICAL POWER SUPPLY CIRCUITS. Reliability: Theory & Applications. 2024, September 3(79):  173-178, DOI: https://doi.org/10.24412/1932-2321-2024-379-173-178


173-178

 

 

 

 

 

 

 

FUZZY LOGIC RELIABILITY BLOCK DIAGRAM APPROACH FOR PATIENT HEALTH MONITORING USING R PROGRAMMING 

 

Liji Sebastian, Rita S, Vennila J

 

In this research, a new approach using fuzzy logic and reliability block diagram (RBD) techniques is used to ensure the reliability of patient health monitoring systems. This technique handles uncertainties in health information, while RBD assesses system reliability by displaying factor relations. The RBD model construct for system components and measure reliability using probabilistic models. Fuzzy logic identifies the effect of uncertainties on overall reliability. Using this approach in a simulated health monitoring scenario, using R, we demonstrate its effectiveness and potential to increase reliable health monitoring for improved patient outcomes and healthcare efficiency. Furthermore, the awareness gained from this study can be directed beyond healthcare such as modern process control and environmental sensing. 

 

 

Cite: Liji Sebastian, Rita S, Vennila J FUZZY LOGIC RELIABILITY BLOCK DIAGRAM APPROACH FOR PATIENT HEALTH MONITORING USING R PROGRAMMING . Reliability: Theory & Applications. 2024, September 3(79):  179-185, DOI: https://doi.org/10.24412/1932-2321-2024-379-179-185


179-185

 

 

 

 

 

 

 

RELIABILITY ANALYSIS OF AN ANTI-DRONE SYSTEM BY CONSIDERING RANDOM ENVIRONMENTAL FACTORS

 

Dharmaraja Selvamuthua, Harshita Badiyasara, Smrati Tripathia, Priyanka Kalitab, Raina Rajc

 

In today’s security landscape, the proliferation of unauthorized drones in restricted airspace has emerged as a significant threat. These drones pose various risks, from potential surveillance and espionage to more sinister possibilities such as physical attacks. Consequently, the development of effective anti-drone laser systems has become increasingly vital. Our study focuses on three main objectives: modeling internal reliability, identifying critical components, and studying the factors affecting the reliability of anti-drone systems. We aim to enhance the overall performance and effectiveness of anti-drone laser systems by analyzing the reliability of critical components and understanding how system parameters influence system reliability. To this end, reliability block diagram (RBD) methodology has been employed to compute the reliability of the laser subsystem in the anti-drone system. Additionally, we conduct a comprehensive review of component-wise reliability to identify vulnerable points within the system, thus enabling targeted improvements and optimizations. To capture the realistic scenario of system failure behavior, different distributions have been used to compute the reliability of the system, ensuring a thorough understanding of its operational reliability in diverse conditions. Finally, the energy values and probability of hitting are obtained for the anti-drone laser system to effectively mitigate environmental challenges.

 

 

Cite: Dharmaraja Selvamuthua, Harshita Badiyasara, Smrati Tripathia, Priyanka Kalitab, Raina Rajc RELIABILITY ANALYSIS OF AN ANTI-DRONE SYSTEM BY CONSIDERING RANDOM ENVIRONMENTAL FACTORS. Reliability: Theory & Applications. 2024, September 3(79):  186-205, DOI: https://doi.org/10.24412/1932-2321-2024-379-186-205


186-205

 

 

 

 

 

 

 

STRATEGIES FOR REPLACEMENT IN WORKFORCE SCHEDULING RELIABILITY MODELS

 

Iyappan. M, Balaji. M, R. Saranraj, G. Sathya Priyanka

 

It is a typical occurrence to replace some industrial equipment or components, such as electronic chips, bulbs, etc. It deals with the ideas of dependability theory, in which the likelihood of an equipment malfunctioning instantly is calculated assuming that it has operated normally for a given amount of time, 't'. In reliability, it's known as the hazard rate. The rate of hazard may be rising, falling, or staying the same. However, replacement tactics are employed to maintain output. Basically, two distinct approaches are employed. 1. Replacing a broken item; 2. Replacing items on a regular basis. Since it is a preventive measure to maintain production, the effective administration of maintaining system functionality depends on the application of both reliability concepts in addition to replacement theory. One may envision a similar issue with the personnel system as well. To determine the best manpower policies in this situation, replacement methods and dependability theory can also be coupled. This theory's application to labor systems is examined, and appropriate methods for employee replacement and advancement are covered in order to ensure the system's successful upkeep. In order to obtain the best fit, manpower planning is a dynamic process that controls the movement of workers into, through, and out of the organization. In order to determine appropriate manpower replacement policies for promotion and replacement of personnel for the successful maintenance of the system, this study discusses the application of dependability theory and the renewal process.

 

 

Cite: Iyappan. M, Balaji. M, R. Saranraj, G. Sathya Priyanka STRATEGIES FOR REPLACEMENT IN WORKFORCE SCHEDULING RELIABILITY MODELS. Reliability: Theory & Applications. 2024, September 3(79):  206-214, DOI: https://doi.org/10.24412/1932-2321-2024-379-206-214


206-214

 

 

 

 

 

 

 

PERFORMANCE ANALYSIS OF M[X]/GB/1 FEEDBACK RETRIAL QUEUE WITH VARIABLE SERVER MODEL

 

N. Micheal Mathavavisakan, K. Indhira

 

In this article, a working vacation policy-based on bulk arrival feedback retrial queueing system with variable server capacity has been analyzed. The server can serve a minimum of one customer and a maximum of B customers in a batch in accordance with the variable server capacity bulk service rule. As soon as the orbit becomes empty at the time of service completion, the server goes for a working vacation. The server works at a lower speed during a working vacation period. In addition, the steady state probability generating function for system size and orbit size is generated by incorporating the supplementary variables technique (SVT). Further, the conditional decomposition law is shown for this retrial queueing system. Moreover, system performance metrics, and significant special instances are discussed. Finally, the effects of various parameters on the system performance are analyzed numerically.

 

 

Cite: N. Micheal Mathavavisakan, K. Indhira PERFORMANCE ANALYSIS OF M[X]/GB/1 FEEDBACK RETRIAL QUEUE WITH VARIABLE SERVER MODEL. Reliability: Theory & Applications. 2024, September 3(79):  215-229, DOI: https://doi.org/10.24412/1932-2321-2024-379-215-229


215-229

 

 

 

 

 

 

 

STOCHASTIC MODELING AND PERFORMABILITY ANALYSIS OF REPAIRABLE SYSTEM OF A PLYWOOD INDUSTRY

 

Mr. Amit Kumar Singh, Dr. P. C. Tewari

 

The current paper analyzes the performance behavior concerning the performability of the Veneer layup system in a plywood industry. A Markovian Approach is utilized to develop a process model for the system and enhance to evaluate system performability i.e. the function of system availability. The study investigates the impact of varying failure and repair rates on the availability of system, variation in the availability is also determined by varying available repair facilities, using a licensed software package. Particle Swarm Optimization (PSO) method has been employed to optimize the results. Additionally, a Decision Support System (DSS) has been proposed for making strategic decisions regarding financial investments and maintenance order priorities. The findings of the paper will aid the practitioners in deciding the maintenance order priorities among various subsystems.

 

 

Cite: Mr. Amit Kumar Singh, Dr. P. C. Tewari STOCHASTIC MODELING AND PERFORMABILITY ANALYSIS OF REPAIRABLE SYSTEM OF A PLYWOOD INDUSTRY. Reliability: Theory & Applications. 2024, September 3(79):  230-241, DOI: https://doi.org/10.24412/1932-2321-2024-379-230-241


230-241

 

 

 

 

 

 

 

E-BAYESIAN ESTIMATION FOR BATHTUB-SHAPED LIFETIME DISTRIBUTION BASED ON UPPER RECORD VALUES

 

Sana, M. Faizan

 

In this research paper, we presents the expected Bayesian (E-Bayesian) estimation of bathtub-shaped lifetime (BSL) distribution for scale parameter based on upper record values (URV) using a conjugate prior distribution. Also, we are considered different prior distributions for the E-Bayesian estimators. Some properties of the E-Bayesian estimators are discussed. A simulation study is given to compare the performance of the E-Bayesian estimators with Bayesian estimator. we notice that the E-Bayesian estimators are perform better than the Bayesian estimators. Moreover, the performance of the Bayesian estimators and E-Bayesian estimators for Prior II are better than Prior I. Also, we observe that if we increase the sample size n then the estimators are showing lesser mean square error (MSE).

 

 

Cite: Sana, M. Faizan E-BAYESIAN ESTIMATION FOR BATHTUB-SHAPED LIFETIME DISTRIBUTION BASED ON UPPER RECORD VALUES. Reliability: Theory & Applications. 2024, September 3(79):  242-247, DOI: https://doi.org/10.24412/1932-2321-2024-379-242-247


242-247

 

 

 

 

 

 

 

A CLASS OF LOGARITHMIC-CUM-EXPONENTIAL ESTIMATORS FOR POPULATION MEAN WITH RISK ANALYSIS USING DOUBLE SAMPLING

 

Diwakar Shukla, Astha Jain

 

In order to improve upon the efficiency of an estimate in double sampling for estimating population mean of character under study using an auxiliary variable, a part of survey resources are used to collect the information on auxiliary variable. Some authors have suggested exponential-type estimators and some others advocated for log-type estimators. But combination of such is required for specific situation. This paper presents a class of logarithmic-cum-exponential ratio estimators in double sampling setup. The expressions for the mean squared error and bias of the proposed class of estimators are derived for two different cases(sub-sample and independent sample). Sometimes the persons involved in the sample survey have to undergo for risk on life. For example, data collection in naxalites area, working in intense forest, interview during spread of epidemic or data collection in politically disturbed region. Such risk may affect the accuracy, efficiency of estimation. A linear Risk function is used for the proposed class of estimators. Two cases of double sampling are compared in terms of relative efficiency in view to risk aspect.It is found that the proposed class of estimators has a lower mean squared error than the simple mean estimator, usual ratio, usual exponential, usual log estimators in the double sampling setup. In addition, these theoretical results are supported by a numerical example. Risk function based simulated study is performed for the support of findings of the content. Optimal sample sizes under risk are derived and compared under two cases.

 

 

Cite: Diwakar Shukla, Astha Jain A CLASS OF LOGARITHMIC-CUM-EXPONENTIAL ESTIMATORS FOR POPULATION MEAN WITH RISK ANALYSIS USING DOUBLE SAMPLING. Reliability: Theory & Applications. 2024, September 3(79):  248-262, DOI: https://doi.org/10.24412/1932-2321-2024-379-248-262


248-262

 

 

 

 

 

 

 

STOCHASTIC ANALYSIS OF A GAS TURBINE SYSTEM WITH PRIORITY AND RANDOM INSPECTION BY SINGLE SERVER UNDER DIFFERENT HUMID CONDITIONS

 

Pinki, Vijeta Kumari, Dalip Singh

 

In this study, we investigated the impact of two different humid levels on the reliability measures of a stochastic model for a gas turbine system composed of a gas turbine and a steam turbine. To enhance the system’s overall performance, we prioritize gas turbine repair over steam turbine repair in addition to a combined inspection and preventative maintenance approach. To find some reliability measures, such as the mean time to system failure, availability, etc., semi-Markov process and regenerating point technique are utilized. These measures are analysed graphically based on the data obtained from a gas turbine power plant in Delhi, India.

 

 

Cite: Pinki, Vijeta Kumari, Dalip Singh STOCHASTIC ANALYSIS OF A GAS TURBINE SYSTEM WITH PRIORITY AND RANDOM INSPECTION BY SINGLE SERVER UNDER DIFFERENT HUMID CONDITIONS. Reliability: Theory & Applications. 2024, September 3(79):  263-274, DOI: https://doi.org/10.24412/1932-2321-2024-379-263-274


263-274

 

 

 

 

 

 

 

PYTHON IMPLEMENTATION OF FUZZY LOGIC FOR ZERO-INFLATED POISSON SINGLE SAMPLING PLANS

 

Kavithanjali S, Sheik Abdullah A

 

Acceptance sampling is used in Statistical Quality Control (SQC) to conduct lot quality evaluations through sample inspections which involve probability theory and fuzzy sets. It aims to optimize quality, costs, and productivity, frequently applying linguistic variables when accurate parameter values are not good enough which is handled using fuzzy set theory. This research analyses single sampling plans (SSP) in the presence of fuzzy number non-conformities, modelling them with the Zero-inflated Poisson (ZIP) distribution structure. This study presents a unique method to single sampling plans (SSP) inside the Zero-inflated Poisson (ZIP) distribution framework that makes use of fuzzy logic approaches. In addition, we show how to apply this method using a Python programme, providing practical suggestions for real-world quality control complications.

 

 

Cite: Kavithanjali S, Sheik Abdullah A PYTHON IMPLEMENTATION OF FUZZY LOGIC FOR ZERO-INFLATED POISSON SINGLE SAMPLING PLANS. Reliability: Theory & Applications. 2024, September 3(79):  275-281, DOI: https://doi.org/10.24412/1932-2321-2024-379-275-281


275-281

 

 

 

 

 

 

 

ANALYSIS OF NON-MARKOVIAN BATCH ARRIVAL RETRIAL QUEUE WITH PRIORITY SERVICES, IMMEDIATE FEEDBACK, PUSH OUT, DIFFERENTIATED BREAKDOWNS, DELAYED REPAIR, RANDOMIZED VACATION

 

G. Ayyappan, S. Nithya

 

Priority and ordinary customers arrive according to Poisson processes, and their service time based on the general distribution. The server constantly offers a single service for both priority and ordinary customers. We compute the Laplace transforms of the time-dependent probabilities of system states using the probability generating function and supplementary variable technique. Numerical results are obtained which are also examined to facilitate the sensitivity analysis of system descriptions.

 

 

Cite: G. Ayyappan, S. Nithya ANALYSIS OF NON-MARKOVIAN BATCH ARRIVAL RETRIAL QUEUE WITH PRIORITY SERVICES, IMMEDIATE FEEDBACK, PUSH OUT, DIFFERENTIATED BREAKDOWNS, DELAYED REPAIR, RANDOMIZED VACATION. Reliability: Theory & Applications. 2024, September 3(79):  282-297, DOI: https://doi.org/10.24412/1932-2321-2024-379-282-297


282-297

 

 

 

 

 

 

 

PERSONALIZED FEATURES-BASED STRESS DETECTION WITH HYPERPARAMETER TUNING USING GENETIC ALGORITHM

 

Jigna Jadav, Uttam Chauhan

 

In recent years, there have been considerable improvements in how we keep track of mental health, especially with devices you can wear, which give us a better chance of spotting and dealing with problems like stress before they become serious. This research paper presents an innovative approach. Experimental validation uses a comprehensive dataset of 15 subjects working as multinational company employees. Heart Rate Variability(HRV) was obtained from wearable sensors using Apple Watch during working hours. We have calculated time, frequency and non-linear domains as well and added personalized features like a person's age, height, weight, etc. Recurrent Neural Network( RNN )and Long Short-Term Memory ( LSTM )models are applied and get an accuracy of 87% and 90%, respectively. To enhance stress detection accuracy by optimizing hyperparameters using a genetic algorithm (GA) explicitly targeting the configuration of LSTM models. Key hyperparameters, including the number of units in the LSTM layer and the number of training epochs, are optimized to maximize stress detection accuracy. Model Through 5 generations of evolution, the GA identifies optimal hyperparameter settings of 45 units in the LSTM layer 49 epochs, significantly improving stress detection accuracy compared to baseline configurations. It gives 92 % accuracy with optimized hyperparameters. Analyzing recorded data, we observe that the time per training step decreases gradually, indicating efficient convergence during optimization. Simultaneously, stress detection accuracy steadily improves over epochs, showcasing the model's effectiveness in learning patterns from physiological data. So, This study provides insights into the practical application of genetic algorithms for hyperparameter optimization in healthcare contexts, contributing to advancements in personalized monitoring and intervention strategies for mental well-being.

 

 

Cite: Jigna Jadav, Uttam Chauhan PERSONALIZED FEATURES-BASED STRESS DETECTION WITH HYPERPARAMETER TUNING USING GENETIC ALGORITHM. Reliability: Theory & Applications. 2024, September 3(79):  298-309, DOI: https://doi.org/10.24412/1932-2321-2024-379-298-309


298-309

 

 

 

 

 

 

 

ANALYSIS OF SINGLE SERVER FEEDBACK RETRIAL QUEUE WITH BERNOULLI WORKING VACATION AND STARTING FAILURE

 

Keerthiga S, Indhira K

 

The suggested queueing model describes a single-server feedback retrial queueing system with starting failure, Bernoulli working vacation and vacation interruptions. The server departs on a working vacation as soon as orbit is empty. During the working vacation period, the server provides a slower level of service. The supplementary variable method was utilized to determine the steady-state probability-generating functions for the system and its orbit. If there are consumers in the system at the end of each vacation, the server becomes idle and ready to serve new customers. The average busy time and the average busy cycle are presented as important system performance indicators. Additionally, the adaptive neuro-fuzzy interface system has compared the numerical results with the neuro-fuzzy results. Finally, particle swarm optimization (PSO) were utilized to obtain the best (optimal) cost for the system in this study. We have examined the convergence of these optimization strategies.

 

 

Cite: Keerthiga S, Indhira K ANALYSIS OF SINGLE SERVER FEEDBACK RETRIAL QUEUE WITH BERNOULLI WORKING VACATION AND STARTING FAILURE. Reliability: Theory & Applications. 2024, September 3(79):  310-326, DOI: https://doi.org/10.24412/1932-2321-2024-379-310-326


310-326

 

 

 

 

 

 

 

IMPROVING THE SPECTRAL EFFICIENCY IN DOWNLINK MULTIPLE USER MULTIPLE INPUT MULTIPLE OUTPUT TRANSMISSION FOR FIFTH GENERATION AND BEYOND WIRELESS COMMUNICATIONS

 

Abdulmujeeb Akajewole Masud, Donatus Uchechukwu Onyishi

 

This research presents a solution in Multiple Input Multiple Output (MIMO) wireless systems to meet the growing demand for high data rates in cellular networks. Although MIMO systems offer greater capacity, the higher frequencies used have caused interference problems, especially for mobile User Equipment (UE). This research aims to reduce interference problems in the downlink of Multi-user MIMO (MU-MIMO) systems, with a specific focus on improving Quality of Service (QoS) metrics, such as outage probability and Signal-to-Interference plus Noise Ratio (SINR). Existing solutions to these challenges are complex due to the dynamic nature of the factors involved in modelling real-world scenarios. As such, an Improved Downlink MU-MIMO (ID-MU-MIMO) algorithm is developed as a solution to these problems. The ID-MU-MIMO method employs both single antenna users and multiple transmitter antennas. The performance of the suggested algorithm is compared to the IEEE 802.11ax standard specification and a previous research work for validation and evaluation. Performance measures considered to aid validation included outage probability, spectrum efficiency, and communication connection reliability. On this premise, the outcomes showed that the proposed ID-MU-MIMO scheme outperforms both the IEEE 802.11ax standard and current MD-MU-MIMO systems. In particular, compared to IEEE 802.11ax, the ID- MU-MIMO technique achieved a 7.71% reduction in interference. When compared to the performance of the random and uniform MD-MU-MIMO algorithms, the proposed ID-MU- MIMO scheme showed a reduction in interference in percentages of 8.90% and 2.28%, respectively. The ID-MU-MIMO scheme outpermed the random and uniform MD-MU-MIMO algorithms in terms of Signal-to-Interference Noise Ratio (SINR), outperforming them by 4.27% and 2.75%, respectively, and resource block use, outperforming them by 20.05% and 3.89%, respectively.

 

 

Cite: Abdulmujeeb Akajewole Masud, Donatus Uchechukwu Onyishi IMPROVING THE SPECTRAL EFFICIENCY IN DOWNLINK MULTIPLE USER MULTIPLE INPUT MULTIPLE OUTPUT TRANSMISSION FOR FIFTH GENERATION AND BEYOND WIRELESS COMMUNICATIONS. Reliability: Theory & Applications. 2024, September 3(79):  327-342, DOI: https://doi.org/10.24412/1932-2321-2024-379-327-342


327-342

 

 

 

 

 

 

 

ENHANCING PROCESS CAPABILITY ANALYSIS FOR LOGNORMAL DATA UTILIZING BOX COX TRANSFORMATION AND GOODNESS OF FIT TESTS

 

J. Krishnan, R. Vijayaraghavan

 

Process capability analysis is a valuable tool in quality assurance, but deviations from normal distribution necessitate adjustments to basic process capability indices. Process control literature offers solutions for non-normality, with data transformation being a common approach. The Box- Cox transformation (BCT) is often used to normalize non-normal data, relying on maximum likelihood estimation (MLE) to determine the transformation parameter, lambda. Alternative methods exist for estimating the single transformation parameter lamda, employing goodness-of-fit tests instead of the MLE method. This study explores two expressions within the Box-Cox transformation (BCT), encompassing both optimal and rounded values of lambda. The primary goal is to identify an effective method for transforming non-normal data into a distribution closer to normality through goodness-of-fit tests, aiming to obtain accurate estimates for process capability analysis in alignment with six sigma standards. Furthermore, this study focuses on the influence of utilizing both optimal and rounded values of lambda when transforming non-normal data to normal, and how these lambda values impact the estimates of process capability analysis. The findings reveal that methods such as Shapiro-Wilk's (SW) and Artificial Covariate (AC) outperform the MLE method. Moreover, employing the optimal lambda value during data transformation leads to improved estimates of process capability. Data simulation and analysis were conducted using Minitab software and the R programming language.

 

 

Cite: J. Krishnan, R. Vijayaraghavan ENHANCING PROCESS CAPABILITY ANALYSIS FOR LOGNORMAL DATA UTILIZING BOX COX TRANSFORMATION AND GOODNESS OF FIT TESTS. Reliability: Theory & Applications. 2024, September 3(79):  343-355, DOI: https://doi.org/10.24412/1932-2321-2024-379-343-355


343-355

 

 

 

 

 

 

 

INFERENCE ON THE INVERSE POWER BURR-HATKE DISTRIBUTION UNDER TYPE II CENSORING

 

Pavitra Kumari, Vinay Kumar

 

There are many real-life situations, where data require probability distribution function which have decreasing or upside-down bathtub (UBT) shaped failure rate function. The inverse power burr hatke distribution consists both decreasing and UBT shaped failure rate functions. Here, we address the different estimation methods of the parameter and reliability characteristics of the inverse Pareto distribution from both classical and Bayesian approaches. We consider classical estimation procedures to estimate the unknown parameter of inverse power burr-hatke distribution, such as maximum likelihood. Also, we consider Bayesian estimation using squared error loss function based joint priors. The Monte Carlo simulations are performed to compare the performances of the obtained estimators in mean square error sense. Finally, the flexibility of the proposed distribution is illustrated empirically using one real-life datasets. The analyzed data shows that the introduced distribution provides a superior fit than some important competing distributions such as the Weibull, inverse Pareto and Burr-Hatke distributions.

 

 

Cite: Pavitra Kumari, Vinay Kumar INFERENCE ON THE INVERSE POWER BURR-HATKE DISTRIBUTION UNDER TYPE II CENSORING. Reliability: Theory & Applications. 2024, September 3(79):  356-363, DOI: https://doi.org/10.24412/1932-2321-2024-379-356-363


356-363

 

 

 

 

 

 

 

ANALYSIS OF TWO NON-IDENTICAL UNIT SYSTEM HAVING SAFE AND UNSAFE FAILURES WITH REBOOTING AND PARAMETRIC ESTIMATION IN CLASSICAL AND BAYESIAN PARADIGMS

 

Poonam Sharma, Pawan Kumar

 

The present paper aims at the study of a two non-identical system model having safe and unsafe failures and rebooting. The focus centers on the analysis w.r.t important reliability measures and estimation of parameters in Classical and Bayesian paradigms. At first one of the units is operational whereas other one is confined to standby mode. Any unit may suffer safe or unsafe failure. A safe failure is immediately taken up for remedial action by a repairman available with the system all the time, while the case of unsafe failure cannot be dealt directly but first rebooting is performed to convert the unsafe failure to safe failure mode so as to start repair normally. A switching device is used to make the repaired and standby units operational. The lifetime of both the units and switching device are taken to be exponentially distributed random variables whereas the distribution of repair times are assumed to be general. Regenerative point technique is employed to derive assosciated measures of effectiveness. To make the study more elaborative and visually attractive, some of the derived characteristics have been studied graphically too. A simulation study has also been undertaken to exhibit the behaviour of obtained characteristics in Classical and Bayesian setup. Valuable inferences about MLE and Bayes estimates have been drawn from the tables and graphs for varying values of failure and repair parameters.

 

 

Cite: Poonam Sharma, Pawan Kumar ANALYSIS OF TWO NON-IDENTICAL UNIT SYSTEM HAVING SAFE AND UNSAFE FAILURES WITH REBOOTING AND PARAMETRIC ESTIMATION IN CLASSICAL AND BAYESIAN PARADIGMS. Reliability: Theory & Applications. 2024, September 3(79):  364-379, DOI: https://doi.org/10.24412/1932-2321-2024-379-364-379


364-379

 

 

 

 

 

 

 

RELIABILITY ESTIMATION OF STRESS-STRENGTH MODEL USING FUZZY DISTORTION FUNCTION UNDER UNCERTAINTY IN ENVIRONMENTAL FACTORS

 

K Sruthi, M Kumar

 

In the reliability estimation of stress-strength models, external factors such as temperature, humidity, etc. may influence the distribution of stress and strength random variables. In traditional reliability analysis, these external factors are accounted for by introducing a real-valued distortion function, which replaces the original distribution with a distorted one. However, it’s important to note that the effect of these external factors is not always adequately represented by a single real-valued function. To address this issue, we propose the use of fuzzy numbers within the distortion function. In this paper, we introduce the concept of a "fuzzy distortion function" to incorporate the uncertainty stemming from external factors when estimating the reliability of stress-strength relationships. We present a methodology for estimating fuzzy reliability by employing this fuzzy distortion function. Through an illustrative example, we demonstrate how this approach to estimating fuzzy reliability offers a wider range of possibilities for system reliability and provides more comprehensive insights into the system’s behaviour. Throughout our exploration, we have delved into the diverse properties inherent in fuzzy distortion functions. These properties highlight the versatility and adaptability of such functions in capturing uncertainty within data sets. Moreover, we have scrutinized several methods for constructing fuzzy distortion functions from pre-existing ones. By examining these methods, we gain valuable insights into how fuzzy distortion functions can be tailored to specific contexts and applications, thereby enhancing the accuracy and robustness of reliability analysis in complex systems. Additionally, in the conventional stress-strength model, reliability is determined without considering the uncertainty in the parameters of the distribution function. The drawback of existing methods in the literature is that they do not consider the uncertainty or fuzziness in the parameters of the distribution. Therefore, we estimate the system reliability in the presence of fuzzy parameters in the distribution function of corresponding random variables. The method we discuss in this paper provides a reliability estimate of the given system under realistic situations. A sensitivity analysis study is carried out to examine the behaviour of mean square errors (MSE) of estimated system reliability under various scenarios. It is observed that MSE can be significantly reduced by a suitable choice of parameters in the membership function of fuzzy parameters.

 

 

Cite: K Sruthi, M Kumar RELIABILITY ESTIMATION OF STRESS-STRENGTH MODEL USING FUZZY DISTORTION FUNCTION UNDER UNCERTAINTY IN ENVIRONMENTAL FACTORS. Reliability: Theory & Applications. 2024, September 3(79):  380-392, DOI: https://doi.org/10.24412/1932-2321-2024-379-380-392


380-392

 

 

 

 

 

 

 

ANALYTICAL AND COMPUTATIONAL ASPECTS OF A MULTI-SERVER QUEUE WITH IMPATIENCE UNDER DIFFERENTIATED WORKING VACATIONS POLICY

 

Aimen Dehimi, Mohamed Boualem, Amina Angelika Bouchentouf, Sofiane Ziani, Louiza Berdjoudj

 

A multi-server queueing system with synchronous differentiated working vacation policy, Bernoulli schedule vacation interruption, and customer impatience (balking and reneging) is studied. The system consists of c servers and a finite capacity N, where customers arrive according to a Poisson process and are served in the chronological order of their arrival. When the system becomes empty, servers wait for a random duration before entering a type-1 working vacation, during which service is provided at a reduced rate. If customers are present in the system at the moment of service achievement during this period, the vacation is interrupted. With a certain probability, servers return to the regular busy period; otherwise, they continue the working vacation. Upon completion of the working vacation, if the system is still empty, servers can take another working vacation of shorter duration, named type-2 working vacation; otherwise, they switch to the regular busy period. Customer impatience is considered during both the normal busy period and working vacations. A recursive analysis method is used to find the steady-state probabilities of the system. Then, some important performance measures are obtained. Furthermore, an optimal operational policy for the model is developed to minimize the total expected cost. The Grey Wolf Optimization (GWO) meta-heuristic approach is employed to determine the optimal service rates for both working vacations and normal busy periods. Finally, several numerical examples are provided to validate and support the theoretical findings.

 

 

Cite: Aimen Dehimi, Mohamed Boualem, Amina Angelika Bouchentouf, Sofiane Ziani, Louiza Berdjoudj ANALYTICAL AND COMPUTATIONAL ASPECTS OF A MULTI-SERVER QUEUE WITH IMPATIENCE UNDER DIFFERENTIATED WORKING VACATIONS POLICY. Reliability: Theory & Applications. 2024, September 3(79):  393-407, DOI: https://doi.org/10.24412/1932-2321-2024-379-393-407


393-407

 

 

 

 

 

 

 

COSINE MARSHAL-OLKIN-G FAMILY OF DISTRIBUTION: PROPERTIES AND APPLICATIONS

 

Akeem Ajibola Adepoju, Alhaji Modu Isa, Olalekan Akanji Bello

 

Trigonometric distributions have recently been emphasized due to it applicability and relevance for modeling different phenomena. This article contributes to the existing literature on trigonometric family by introducing and investigating new trigonometric family of distribution which is developed by compounding the cosine family of distribution with Marshall-olkin family of distribution to form a new Cosine Marshall-Olkin family of distribution (CMO). Graphical, numerical and analytical approach was explored to study the properties and applicability of the new CMO family of distribution. Special representations and important reliability properties and other statistical properties were defined. Simulation study was conducted in order to have an insight on the estimates of the three parameters model using maximum products of spacing (MPS). Emphases on the greater flexibility of the new CMO family of distribution beyond the cosine-G family and other top models of the Cosine related family was made through Weibull distribution. The results revealed the superiority of the Cosine Marshall-Olkin Weibull model (CMO-W) over others via two data sets.

 

 

Cite: Akeem Ajibola Adepoju, Alhaji Modu Isa, Olalekan Akanji Bello COSINE MARSHAL-OLKIN-G FAMILY OF DISTRIBUTION: PROPERTIES AND APPLICATIONS. Reliability: Theory & Applications. 2024, September 3(79):  408-422, DOI: https://doi.org/10.24412/1932-2321-2024-379-408-422


408-422

 

 

 

 

 

 

 

ANALYSIS OF MMAP/PH1,PH2/1 PREEMPTIVE PRIORITY INVENTORY RETRIAL QUEUEING SYSTEM WITH SINGLE VACATION, WORKING BREAKDOWN, REPAIR AND CLOSEDOWN

 

G. Ayyappan, S. Meena

 

This paper analyzes preemptive priority inventory retrial queueing system with a single vacation, working breakdown, repair, and closedown. We assume that an arrival follows the Marked Markovian arrival process and that the server will provide them with phase-type services. The (s, S) policy to replenish the items and the replenishing duration follow an exponential distribution. In this paper, we consider two types of customers: high-priority(HP) customers and low-priority(LP) customers. Arriving HP customers should get the service if the server is idle and has a positive inventory level; otherwise, they should wait in front of the service station. Arriving LP customers get service only if there is a positive inventory level and there are no high-priority customers in the system; otherwise, go for the finite capacity size of the orbit. After the completion of service, if no one is present in the high-priority queue and orbit, the server will close down the system and then go on a single vacation. The server is idle when the vacation period ends. When the server breaks down, it only serves the present customer and operates in slow mode while it is being repaired. The number of high-priority customers in the system, the number of low-priority customers in the orbit, the inventory level, and server status may all be determined in a steady state. Numerous key performance indicators are defined, and a cost analysis is obtained. To make our mathematical concept clearer, a few numerical examples are provided.

 

 

Cite: G. Ayyappan, S. Meena ANALYSIS OF MMAP/PH1,PH2/1 PREEMPTIVE PRIORITY INVENTORY RETRIAL QUEUEING SYSTEM WITH SINGLE VACATION, WORKING BREAKDOWN, REPAIR AND CLOSEDOWN. Reliability: Theory & Applications. 2024, September 3(79):  423-441, DOI: https://doi.org/10.24412/1932-2321-2024-379-423-441


423-441

 

 

 

 

 

 

 

OPTIMIZATION OF AN INVENTORY MODEL FOR DETERIORATING ITEMS ASSUMING DETERIORATION DURING CARRYING WITH TWO-WAREHOUSE FACILITY

 

Krishan Kumar Yadav, Ajay Singh Yadav, Shikha Bansal

 

A common topic in the context of its application in today’s business contexts is inventory modelling and management. It is well-known that deterioration has a big impact on inventory management. One of the most frequent supply chain concerns is the deterioration of items during transit from a supplier’s storehouse to a retailer’s storehouse. In light of this, a two-level supply chain inventory model for decaying goods is developed with two warehouse (storehouse) facilities for retailers, namely Owned Warehouse (OW) and Rented Warehouse (RW), assuming deterioration both during carrying from a supplier’s storehouse to a retailer’s storehouses and in the retailer’s storehouses themselves. Also, we are assuming the selling price and time sensitive demand. We are developed this model under inflation. Shortages are not allowed. The main objective of this study is to determine the optimal ordering policy in order to maximizes the retailer’s profit per unit of time. The applicability of our suggested model is investigated using a numerical example and with the support of MATLAB programming software (version: R2021b). Sensitivity analysis is used to examine the effects of changing the values of system parameters. Graphical representations are also shown in this paper.

 

 

Cite: Krishan Kumar Yadav, Ajay Singh Yadav, Shikha Bansal OPTIMIZATION OF AN INVENTORY MODEL FOR DETERIORATING ITEMS ASSUMING DETERIORATION DURING CARRYING WITH TWO-WAREHOUSE FACILITY. Reliability: Theory & Applications. 2024, September 3(79):  442-459, DOI: https://doi.org/10.24412/1932-2321-2024-379-442-459


442-459

 

 

 

 

 

 

 

ON MODELING OF BIOMEDICAL DATA WITH EXPONENTIATED GOMPERTZ INVERSE RAYLEIGH DISTRIBUTION

 

Sule Omeiza Bashiru, Alaa Abdulrahman Khalaf, Alhaji Modu Isa, Aishatu Kaigama

 

This paper introduces and thoroughly examines the Exponentiated Gompertz Inverse Rayleigh (EtGoIr) Distribution, a four-parameter extension of the Gompertz Inverse Rayleigh distribution. The primary focus is on its application to biomedical datasets, shedding light on its mathematical and statistical properties. Some properties of the distribution that were derived include the quantile function, median, moments, incomplete moments, Rényi entropy, and probability weighted moments. The model parameters were estimated using the method of maximum likelihood. A simulation study was conducted to investigate the consistency of the proposed model. The outcome of the investigation revealed that the model demonstrates consistency, as evidenced by the reduction in both root mean square error (RMSE) and bias as sample sizes increase. To showcase the practical relevance of the EtGoIr distribution, the paper applies the model to three distinct biomedical datasets. The results highlight its enhanced flexibility, demonstrating superior fit compared to its counterpart.

 

 

Cite: Sule Omeiza Bashiru, Alaa Abdulrahman Khalaf, Alhaji Modu Isa, Aishatu Kaigama ON MODELING OF BIOMEDICAL DATA WITH EXPONENTIATED GOMPERTZ INVERSE RAYLEIGH DISTRIBUTION. Reliability: Theory & Applications. 2024, September 3(79):  460-475, DOI: https://doi.org/10.24412/1932-2321-2024-379-460-475


460-475

 

 

 

 

 

 

 

BEHAVIOR ANALYSIS PRESENTED SYSYEM WITH FAILURE AND MAINTENANCE RATE WITH USING DEEP LEARNING ALGORITHMS 

 

Shakuntla Singla, Shilpa Rani, Diksha Mangla, Umar Muhammad Modibbo 

 

The paper discusses the behavioral analysis and dependability of a three-unit system utilizing RPGT for system parameters. Since all three units P, Q and R include parallel subcomponents, in the event that one of them fails, the system continues to operate although at a reduced capacity, but it is not profitable to run the system when two units are in reduced state hence considered failed state. The rates of failures are exponentially distributed, but the rates of repair are generalized, independent, and differ based on the operational unit. Fuzzy concept is used to declare/ determine whether the system is in failed/ reduced/ failed state. Graphs and tables are drawn to compare failure/repair effect on the parameters values. The system parameters are modelled using Regenerative Point graphical Technique (RPGT) and optimized using Deep learning methods such as Adam, SGD, RMS prop. The results of the optimization may be used to validate and challenge existing models and assumptions about the systems. 

 

 

Cite: Shakuntla Singla, Shilpa Rani, Diksha Mangla, Umar Muhammad Modibbo  BEHAVIOR ANALYSIS PRESENTED SYSYEM WITH FAILURE AND MAINTENANCE RATE WITH USING DEEP LEARNING ALGORITHMS . Reliability: Theory & Applications. 2024, September 3(79):  476-485, DOI: https://doi.org/10.24412/1932-2321-2024-379-476-485


476-485

 

 

 

 

 

 

 

OPTIMIZING INVENTORY CONTROL THROUGH A GRADIENT-BASED MULTILEVEL APPROACH IN THE FACE OF DEMAND AND LEAD TIME UNCERTAINTIES

 

Muragesh Math, D.Gopinath, B. S.Biradar

 

Systems of two-level assembly with unknown timing of leads are taken into consideration while arranging supplies. Probably, the final product's demand and its deadline are known. When all required parts are on hand, each level's assembly process gets underway. To address these problems, we have developed a model for the control of inventories for an uncapitatedwarehousing space in a manufacturing plant with unpredictable demand and lead times. The goal is to choose orders in a way that minimizes the overall system's cost. We present a multilevel optimization model including a rotating horizon that utilizes gradients to handle unknown lead time and demand, irrespective of the distributions at the core of them. Furthermore, a precise algorithm is created to solve the model. In a case study, we compare our approach with the current model. Our computational results indicate that while the new gradient-based multi-level optimization model nearly continuously yields the least expensive overall across all parameter settings. These models' performances are either systematically worse or extremely sensitive to cost parameters (holding cost, shortfall cost, etc.).

 

 

Cite: Muragesh Math, D.Gopinath, B. S.Biradar OPTIMIZING INVENTORY CONTROL THROUGH A GRADIENT-BASED MULTILEVEL APPROACH IN THE FACE OF DEMAND AND LEAD TIME UNCERTAINTIES. Reliability: Theory & Applications. 2024, September 3(79):  486-496, DOI: https://doi.org/10.24412/1932-2321-2024-379-486-496


486-496

 

 

 

 

 

 

 

THE EXPONENTIATED SKEW LAPLACE DISTRIBUTION: PROPERTIES AND APPLICATIONS

 

Timothy Kayode Samson, Christian Elendu Onwukwe, Ekaette Inyang Enang

 

In this paper, a 4-parameter Exponentiated Skew Laplace distribution is defined and studied. Various statistical properties including its moment generating function, characteristics function, hazard function, and reliability function of the proposed ESLD were derived. The estimation of its parameters was carried out using the maximum likelihood method of estimation. The performance of the proposed ESLD compared with other similar distributions was demonstrated empirically with daily returns of S & P 500 between 2/02/24 and 28/03/2024 and daily returns of Bitcoin between 2/02/24 and 1/04/24 as obtained from Yahoo Finance. The fitness performance of the proposed distribution was evaluated based on log-likelihood, AIC, and BIC. Results obtained show that the proposed ESLD reported the highest log likelihood as well as the lowest AIC and BIC in the two data sets. This study therefore underscores the superiority of the proposed distribution over the some of the similar existing distributions.

 

 

Cite: Timothy Kayode Samson, Christian Elendu Onwukwe, Ekaette Inyang Enang THE EXPONENTIATED SKEW LAPLACE DISTRIBUTION: PROPERTIES AND APPLICATIONS. Reliability: Theory & Applications. 2024, September 3(79):  497-509, DOI: https://doi.org/10.24412/1932-2321-2024-379-497-509


497-509

 

 

 

 

 

 

 

A NOVEL ASYMMETRIC COMPOUND CLASS OF DISTRIBUTIONS WITH ESTIMATION AND APPLICATION

 

A.G. Al-Kilany, Amal S. Hassan, L.S. Diab, E.S. El-Atfy

 

This paper introduces and discusses the novel asymmetric class of distributions that have the name inverse power Lomax power series (IPLPS). This class of distributions is produced by combining the inverse power Lomax with the power series distributions. This combined approach provides an opportunity for the creation of flexible distributions with significant physical implications in many fields, like biology and engineering. The IPLPS distributions encompass several new compound distributions as sub-models along with a new class of compound distributions. Many statistical features, including moments, quantile function, conditional moments, inverse moments, uncertainty measures, and probability-weighted moments, are obtained. As a special model of the generated class, the parameters of the inverse power Lomax Poisson distribution are estimated by different methods, including least squares, Cramér von Mises, maximum likelihood, and weighted least squares. Through an extensive simulation analysis, the execution of different parameter estimation techniques for the inverse power Lomax Poisson model is performed to show its validity based on its mean squared error and absolute bias. Two real datasets are utilized to show the practicality of the newly generated model. Results show that the inverse power Lomax Poisson distribution provides the most fitted model for these datasets in comparison to other distributions such as power Lomax, Marshall- Olkin power Lomax, power Lomax Poisson, and Topp-Leone Lomax distributions.

 

 

Cite: A.G. Al-Kilany, Amal S. Hassan, L.S. Diab, E.S. El-Atfy A NOVEL ASYMMETRIC COMPOUND CLASS OF DISTRIBUTIONS WITH ESTIMATION AND APPLICATION. Reliability: Theory & Applications. 2024, September 3(79):  510-529, DOI: https://doi.org/10.24412/1932-2321-2024-379-510-529


510-529

 

 

 

 

 

 

 

EXPLORING LENGTH BIASED QUASI SUJA DISTRIBUTION: PROPERTIES AND APPLICATIONS

 

Vidya Yerneni, Aafaq A. Rather

 

This paper introduces a new statistical distribution called length biased quasi suja distribution (LBQS). It explores its properties, including moments, moment generating function(MGF), characteristic function(CF), harmonic mean, reliability, hazard rate and reverse hazard rate. Order statistics of the above distribution is obtained. Furthermore, the paper also examines various entropy which measures the randomness of system, like Renyi entropy and Tsalli’s entropy. It also evaluates Bonferroni and Lorenz curves which are useful in measuring the inequality. It also discusses parameter estimation techniques specifically maximum likelihood estimation and likelihood ratio testing. Moreover, a simulation study has been conducted to demonstrate how well the distribution would perform in real-life situation. The validity of the distribution is also demonstrated with real-world data example of failure data, highlighting its potential for practical applications in data analysis.

 

 

Cite: Vidya Yerneni, Aafaq A. Rather EXPLORING LENGTH BIASED QUASI SUJA DISTRIBUTION: PROPERTIES AND APPLICATIONS. Reliability: Theory & Applications. 2024, September 3(79):  530-544, DOI: https://doi.org/10.24412/1932-2321-2024-379-530-544


530-544

 

 

 

 

 

 

 

A NEW GENERALIZATION OF SABUR DISTRIBUTION

 

Suvarna Ranade, Aafaq A. Rather

 

When the weight function depends on the lengths of the units of interest, the resulting distribution is called length biased. Length biased distribution is thus a special case of the more general form, known as weighted distribution. In this study, we introduce a novel probability distribution named the Length- Biased Sabur distribution (LBSD). This new distribution enhances the traditional Sabur distribution by incorporating a weighted transformation approach. The paper investigates the probability density function (pdf) and the cumulative distribution function (cdf) associated with the LBSD. A thorough examination of the distinctive structural properties of the proposed model is conducted, covering the survival function, conditional survival function, hazard function, cumulative hazard function, mean residual life, moments, moment generating function, characteristic function, likelihood ratio test, ordered statistics, entropy measures, and Bonferroni and Lorenz curve.

 

 

Cite: Suvarna Ranade, Aafaq A. Rather A NEW GENERALIZATION OF SABUR DISTRIBUTION. Reliability: Theory & Applications. 2024, September 3(79):  545-553, DOI: https://doi.org/10.24412/1932-2321-2024-379-545-553


545-553

 

 

 

 

 

 

 

MODELING THE INTERCONNECTED OPERATION OF ENERGY SYSTEMS FOR ENERGY SECURITY STUDY IN TODAY’S CONTEXT

 

Dmitry Krupenev, Natalia Pyatkova

 

The paper shows the need for comprehensive research into energy security problems to assess the possibilities of interconnected operation of all energy industries with the view to identifying the implications for consumers of energy resources in the event of emergencies in one or several industries at the same time. The paper presents a methodological framework and features of modeling the interrelated operation of the industries in current context and a model developed for these studies. The results of experimental studies using the developed methodology are shown through the analysis of several critical situations (threats to energy security) of various nature.

 

 

Cite: Dmitry Krupenev, Natalia Pyatkova MODELING THE INTERCONNECTED OPERATION OF ENERGY SYSTEMS FOR ENERGY SECURITY STUDY IN TODAY’S CONTEXT. Reliability: Theory & Applications. 2024, September 3(79):  554-566, DOI: https://doi.org/10.24412/1932-2321-2024-379-554-566


554-566

 

 

 

 

 

 

 

ESTIMATION OF PARAMETERS FOR KUMARASWAMY EXPONENTIAL DISTRIBUTION BASED ON PROGRESSIVE TYPE-I INTERVAL CENSORED SAMPLE

 

Manoj Chacko, Shilpa S Dev

 

In this paper, we consider the problem of estimation of parameters of the Kumaraswamy exponential distribution using progressive type-I interval censored data. The maximum likelihood estimators (MLEs) of the parameters are obtained. As it is observed that there is no closed-form solutions for the MLEs, we implement the Expectation-Maximization (EM) algorithm for the computation of MLEs. Bayes estimators are also obtained using different loss functions such as the squared error loss function and the LINEX loss function. For the Bayesian estimation, Lindley’s approximation method has been applied. To evaluate the performance of the various estimators developed, we conduct an extensive simulation study. The different estimators and censoring schemes are compared based on average bias and mean squared error. A real data set is also taken into consideration for illustration.

 

 

Cite: Manoj Chacko, Shilpa S Dev ESTIMATION OF PARAMETERS FOR KUMARASWAMY EXPONENTIAL DISTRIBUTION BASED ON PROGRESSIVE TYPE-I INTERVAL CENSORED SAMPLE. Reliability: Theory & Applications. 2024, September 3(79):  567-582, DOI: https://doi.org/10.24412/1932-2321-2024-379-567-582


567-582

 

 

 

 

 

 

 

ANALYSIS OF MX/G/1 QUEUE WITH OPTIONAL SECOND SERVICE, FEEDBACK AND BERNOULLI VACATION

 

S. Karpagam, B. Somasundaram, A. Kavin Sagana Mary, R. Lokesh,

 

In this article the single-server queue situation described with batch arrivals, a mandatory first service and a choice of second service are provided to the customers. A general distribution governs the service times, whereas a compound Poisson distribution follows customer arrivals. Although each new customer requests the first mandatory service, only some of them choose the optional second service. Customers who are dissatisfied with mandatory service are more likely to get the required services later on. After every service is finished, the server might choose to go on Bernoulli vacation. Time dependent probability generating functions are constructed in terms of Laplace transforms using the supplementary variable approach, and explicit results are obtained for the steady state. Additionally, mean waiting time and mean queue length expressions are examined. The graphical and numerical representations improve comprehension of the results even further.

 

 

Cite: S. Karpagam, B. Somasundaram, A. Kavin Sagana Mary, R. Lokesh, ANALYSIS OF MX/G/1 QUEUE WITH OPTIONAL SECOND SERVICE, FEEDBACK AND BERNOULLI VACATION. Reliability: Theory & Applications. 2024, September 3(79):  583-594, DOI: https://doi.org/10.24412/1932-2321-2024-379-583-594


583-594

 

 

 

 

 

 

 

INVERTED DAGUM DISTRIBUTION: PROPERTIES AND APPLICATION TO LIFETIME DATASET

 

Abdulhameed A. Osi, Shamsuddeen A. Sabo, Ibrahim Z. Musa

 

This article presents the introduction of a novel univariate probability distribution termed the inverted Dagum distribution. Extensive analysis of the statistical properties of this distribution, including the hazard function, survival function, Renyi’s entropy, quantile function, and the distribution of the order statistics, was conducted. Parameter estimation of the model was performed utilizing the maximum likelihood method, with the consistency of the estimates validated through Monte Carlo simulation. Furthermore, the applicability of the proposed distribution was demonstrated through the analysis of two real datasets.

 

 

Cite: Abdulhameed A. Osi, Shamsuddeen A. Sabo, Ibrahim Z. Musa INVERTED DAGUM DISTRIBUTION: PROPERTIES AND APPLICATION TO LIFETIME DATASET. Reliability: Theory & Applications. 2024, September 3(79):  595-604, DOI: https://doi.org/10.24412/1932-2321-2024-379-595-604


595-604

 

 

 

 

 

 

 

A NOVEL HYBRID DISTRIBUTED INNOVATION EGARCH MODEL FOR INVESTIGATING THE VOLATILITY OF THE STOCK MARKET

 

Mubarak M.T., Adubisi O.D., Abbas U.F.

 

When calculating risk and making decisions, investors and financial institutions heavily rely on the modeling of asset return volatility. For the exponentiated generalized autoregressive conditional heteroscedasticity (EGARCH) model, we created a unique innovation distribution in this study called the type-II-Topp-Leone-exponentiated-Gumbel (TIITLEGU) distribution. The key mathematical characteristics of the distribution were determined, and Monte Carlo experiments were used to estimate the parameters of the novel distribution using maximum likelihood estimation (MLE) procedure. The performance of the EGARCH (1,1) model with TIITLEGU distributed innovation density in relation to other innovation densities in terms of volatility modeling is examined through applications using two Nigerian shock returns. The results of the diagnostic tests indicated that, with the exception of the EGARCH (1,1)-Johnson (SU) reparametrized (JSU) innovation density, the fitted models have been sufficiently specified. The parameters for the EGARCH (1,1) model with different innovation densities are significant at various levels. Furthermore, in out-of-sample prediction, the fitted EGARCH (1,1)-TIITLEGU innovation density performed better than the EGARCH (1,1)- existing innovation densities. As a result, it is decided that the EGARCH-TIITLEGU model is the most effective for analyzing Nigerian stock market volatility.

 

 

Cite: Mubarak M.T., Adubisi O.D., Abbas U.F. A NOVEL HYBRID DISTRIBUTED INNOVATION EGARCH MODEL FOR INVESTIGATING THE VOLATILITY OF THE STOCK MARKET. Reliability: Theory & Applications. 2024, September 3(79):  605-618, DOI: https://doi.org/10.24412/1932-2321-2024-379-605-618


605-618

 

 

 

 

 

 

 

SINGLE AND DOUBLE ACCEPTANCE SAMPLING PLAN FOR TRUNCATED LIFE TESTS BASED ON GAMMA LINDLEY DISTRIBUTION

 

Sriramachandran G. V.

 

For  time-truncated  life  tests,  this work defines single  acceptance  and  double  acceptance sampling plans   assuming   that the product's lifespan   follows the Gamma   Lindley distribution. The minimum sample size needed in a single acceptance sampling plan for lot approval is calculated for a range of parameter combinations and a fixed test termination time. This ensures the given average product life and the corresponding number of failures. Operational characteristic and producer risk values are also tabulated for these parameter values. Using a double acceptance sampling  plan,  the best first  and  second  samples are  obtained to ensure that  the products specified average  with a certain level of  customer trust.  Finally,  under  the  same conditions, the  minimum  sample  size  obtained using  these  strategies  are compared  with other acceptance sampling plans.

 

 

Cite: Sriramachandran G. V. SINGLE AND DOUBLE ACCEPTANCE SAMPLING PLAN FOR TRUNCATED LIFE TESTS BASED ON GAMMA LINDLEY DISTRIBUTION. Reliability: Theory & Applications. 2024, September 3(79):  619-629, DOI: https://doi.org/10.24412/1932-2321-2024-379-619-629


619-629

 

 

 

 

 

 

 

FUZZY VARIABLE LINEAR PROGRAMMING PROBLEMS USING A FUZZY DUAL SIMPLEX ALGORITHM

 

Srinivasa Rao Kolli, U.V. Adinarayana Rao, Taviti Naidu Gongada

 

In modern research, several brilliant minds investigate linear programming problems involving fuzzy variable quantities. Many researchers have turned to linear programming by fuzzy variables to address this problem. Various fuzzy simplex approaches have been developed, using ranking functions to handle fuzzy numbers. Results from this research suggest that linear ranking functions can provide a straightforward interpretation of problems involving linear programming by fuzzy variable quantities. To solve these types of problems, the Fuzzy Dual Simplex Tableau method is often applied, which proves useful for sensitivity analysis when modifications are made to the activity vectors of the fundamental columns. In this study, a numerical case is presented to demonstrate the potential benefits of this approach for future technologies.

 

 

Cite: Srinivasa Rao Kolli, U.V. Adinarayana Rao, Taviti Naidu Gongada FUZZY VARIABLE LINEAR PROGRAMMING PROBLEMS USING A FUZZY DUAL SIMPLEX ALGORITHM. Reliability: Theory & Applications. 2024, September 3(79):  630-637, DOI: https://doi.org/10.24412/1932-2321-2024-379-630-637


630-637

 

 

 

 

 

 

 

A MODIFIED AILAMUJIA DISTRIBUTION: PROPERTIES AND APPLICATION

 

David Ikwuoche John, Okeke Evelyn Nkiru, Franklin Lilian

 

This study presents a modified one-parameter Ailamujia distribution called the Entropy Transformed Ailamujia distribution (ETAD) is introduced to handle both symmetric and asymmetric lifetime data sets. The ETAD properties like order and reliability statistics, entropy, moment and moment generating function, quantile function, and its variability measures were derived. The maximum likelihood estimation (MLE) method was used in estimating the parameter of ETAD and through simulation at different sample sizes, the MLE was found to be consistent, efficient, and unbiased for estimating the ETAD parameter. The flexibility of ETAD was shown by fitting it to six different real lifetime data sets and compared it alongside seven competing one- parameter distributions. The goodness of fit (GOF) results from Akaike information criteria, Bayesian information criteria, corrected Akaike information criteria, and Hannan-Quinn information criteria show that the ETAD was the best fit amongst all the seven competing distributions across all the six data sets.

 

 

Cite: David Ikwuoche John, Okeke Evelyn Nkiru, Franklin Lilian A MODIFIED AILAMUJIA DISTRIBUTION: PROPERTIES AND APPLICATION. Reliability: Theory & Applications. 2024, September 3(79):  638-652, DOI: https://doi.org/10.24412/1932-2321-2024-379-638-652


638-652

 

 

 

 

 

 

 

MODIFIED GROUP RUNS CONTROL CHART FOR MONITORING PROCESS DISPERSION

 

Chandrakant G. Gardi, Vikas B. Ghute

 

Due to a rise in competitiveness, it has become an intense concern to the manufacturers to monitor process dispersion to avoid low quality production. To ensure quality production, the control chart that gives early detection of change in the dispersion is always encouraged. Researchers have suggested various control charts based on different estimators of process dispersion. Recently, many synthetic control charts based on such estimators are put forth by researchers to effectively monitor the dispersion in the process. Modified Group Runs (MGR) control chart is an extension of synthetic charts with further enhancement in the detection ability. In this paper, we propose a MGR control chart based on Downton’s estimator (D). Comparison of MGR control chart with synthetic chart based on estimator D reveals the enhanced performance of MGR-D chart.

 

 

Cite: Chandrakant G. Gardi, Vikas B. Ghute MODIFIED GROUP RUNS CONTROL CHART FOR MONITORING PROCESS DISPERSION. Reliability: Theory & Applications. 2024, September 3(79):  653-659, DOI: https://doi.org/10.24412/1932-2321-2024-379-653-659


653-659

 

 

 

 

 

 

 

ON THE FLEXIBILITY OF TYPE I HALF LOGISTIC EXPONENTIATED FRECHET DISTRIBUTION

 

Olalekan Akanji Bello, Sani Ibrahim Doguwa, Abukakar Yahaya, Haruna Mohammed Jibril,

 

In this article, we delve into the modeling and analysis of lifetimes, which hold substantial importance across various scientific and industrial fields. Our focus is on introducing a novel distribution termed the Type I Half-Logistic Exponentiated Frechet (TIHLEtF) Distribution, which is an extension of the Frechet distribution. We have derived a crucial representation of the density function for this distribution. Furthermore, we explore several statistical properties associated with the TIHLEtF distribution. These properties encompass explicit expressions for the quantile function, probability-weighted moments, moments, moments generating function, reliability function, hazard function, and order statistics. To estimate the model parameters, we employ the maximum likelihood estimation technique and present the results of a simulation study. To emphasize the superiority of our newly introduced distribution, we apply it to two real datasets. The outcomes of our analysis reveal that the TIHLEtF distribution outperforms the other considered distributions in terms of fitting the data in these real-world cases.

 

 

Cite: Olalekan Akanji Bello, Sani Ibrahim Doguwa, Abukakar Yahaya, Haruna Mohammed Jibril, ON THE FLEXIBILITY OF TYPE I HALF LOGISTIC EXPONENTIATED FRECHET DISTRIBUTION. Reliability: Theory & Applications. 2024, September 3(79):  660-674, DOI: https://doi.org/10.24412/1932-2321-2024-379-660-674


660-674

 

 

 

 

 

 

 

BAYESIAN ANALYSIS OF EXTENDED MAXWELL-BOLTZMANN DISTRIBUTION USING SIMULATED AND REAL-LIFE DATA SETS

 

Nuzhat Ahad, S.P.Ahmad, J.A.R eshi

 

The objective of the study is to use Bayesian techniques to estimate the scale parameter of the 2Kth order weighted Maxwell-Boltzmann distribution(KWMBD). This involved using various prior assumptions such as extended Jeffrey’s, Hartigan’s , Inverse-gamma and Inverse-exponential, as well as different loss functions including squared error loss function (SELF), precautionary loss function (PLF), Al Bayyati’s loss function (ALBF), and Stein’s Loss Function (SLF).The maximum likelihood estimation (MLE) is also obtained. We compared the performances of MLE and bayesian estimation under each prior and its associated loss functions. And demonstrated the effectiveness of Bayesian estimation through simulation studies and analyzing real-life datasets.

 

 

Cite: Nuzhat Ahad, S.P.Ahmad, J.A.R eshi BAYESIAN ANALYSIS OF EXTENDED MAXWELL-BOLTZMANN DISTRIBUTION USING SIMULATED AND REAL-LIFE DATA SETS. Reliability: Theory & Applications. 2024, September 3(79):  675-688, DOI: https://doi.org/10.24412/1932-2321-2024-379-675-688


675-688

 

 

 

 

 

 

 

BAYESIAN NON-INFERIORITY TEST BETWEEN TWO BINOMIAL PROPORTIONS

 

W. B. Yahya, C. P. Ezenweke, O. R. Olaniran, I. A. Adeniyi, K. Jimoh, R. B. Afolayan, M. K. Garba, I. Ahmed

 

The paper aimed to propose a new Bayesian test method for establishing a non-inferiority measure between an active treatment (drug) and a new (cheaper) treatment using two independent binomial samples. A Bayesian test statistic was developed for testing non-inferiority between two independent binomial proportions. Conjugate Beta prior was assumed for the binomial proportions to elicit posterior from the same Beta family of distributions. The efficiency of this test method was established via power analysis and its ability to yield the nominal Type I error rate (alpha) in a detailed Monte-Carlo study. Results from this study showed that the proposed test method yielded higher powers and good estimates of the Type I error rate at the chosen sample sizes and varying non-inferiority margins (effect sizes). Thus, the new Bayesian test method is very efficient at detecting the significance of the non-inferiority margin between two independent binomial proportions when such is not negligible at all sample sizes. Further results showed that the size of the two population proportions being tested influences the power and the estimated nominal Type I error rate with an increase in power and a good estimate of Type I error rate achieved when both population proportions being tested are less than 0.5. It is therefore concluded that the new Bayesian test method can be employed whenever it is desirable to establish the existence of non- inferiority or otherwise between a pair of (clinical) treatments (drugs). All the simulations and analyses were performed with the R statistical package.

 

 

Cite: W. B. Yahya, C. P. Ezenweke, O. R. Olaniran, I. A. Adeniyi, K. Jimoh, R. B. Afolayan, M. K. Garba, I. Ahmed BAYESIAN NON-INFERIORITY TEST BETWEEN TWO BINOMIAL PROPORTIONS. Reliability: Theory & Applications. 2024, September 3(79):  689-703, DOI: https://doi.org/10.24412/1932-2321-2024-379-689-703


689-703

 

 

 

 

 

 

 

BAYESIAN AND E-BAYESIAN ESTIMATION OF EXPONENTIATED INVERSE RAYLEIGH DISTRIBUTION USING CONJUGATE PRIOR 

 

Ramesh Kumar, Hemani Sharma, Rahul Gupta, Ableen Kaur

 

This study explores the application of Bayesian and E-Bayesian techniques to estimate the scale parameter of the Exponentiated Inverse Rayleigh distribution. Bayesian estimates for the parameter are derived using an informative Gamma prior and evaluated under three distinct loss functions: De- Groot, Squared Error, and Al-Bayyati loss functions. Various Properties of the E-Bayesian estimators under different loss functions have also been studied. To compare the effectiveness of E-Bayesian estimates against the Bayesian counterpart, a simulation study is conducted using MatLab. The various derived estimators were compared in terms of their Mean Squared Error. The results of a simulation study reveal that E-Bayesian estimates exhibit a smaller Mean Squared Error in comparison to Bayesian estimates, thereby demonstrating their enhanced efficiency. Among the E- Bayesian estimates, the third one stands out as the most effective. Moreover, the analysis highlights that the Squared Error loss function outperforms the Al-Bayyati and De-Groot loss functions, exhibiting a smaller MSE. Furthermore, the efficacy of these estimators is demonstrated through an analysis of a real-life dataset.

 

 

Cite: Ramesh Kumar, Hemani Sharma, Rahul Gupta, Ableen Kaur BAYESIAN AND E-BAYESIAN ESTIMATION OF EXPONENTIATED INVERSE RAYLEIGH DISTRIBUTION USING CONJUGATE PRIOR . Reliability: Theory & Applications. 2024, September 3(79):  704-716, DOI: https://doi.org/10.24412/1932-2321-2024-379-704-716


704-716

 

 

 

 

 

 

 

AVAILABILITY ANALYSIS FOR IDENTIFICATION OF CRITICAL FACTOR OF A THERMAL POWER PLANT

 

Pardeep Kumar, Vipin Kumar Sharma, Dinesh Kumar

 

In the present stimulated business environment, power sector is playing a major role in the economic growth of India. During the last 20 years, the country had been facing a poor supply of energy and this supply-demand gap is increasing continuously. So, it is important for power plants to improve its power generation capacity drastically by reducing the failure rate. In the present paper, to analyze the causes of poor availability, thermal power plant has divided into six different systems and a system comprising of waste gases heating system has been considered. With the help of transition diagram, mathematical equations have been used to find out the availability. After analyzing, it was found that the value of availability is very low and boiler tube failure is one of the most critical factors for this low availability of system. Economizer zone has identified having long existence time of failures and frequency of occurrence is very high. So, minimizing the failure rate with the help of a proper maintenance schedule will result in decreasing the shutdown period of the plant and increasing the system availability.

 

 

Cite: Pardeep Kumar, Vipin Kumar Sharma, Dinesh Kumar AVAILABILITY ANALYSIS FOR IDENTIFICATION OF CRITICAL FACTOR OF A THERMAL POWER PLANT. Reliability: Theory & Applications. 2024, September 3(79):  717-724, DOI: https://doi.org/10.24412/1932-2321-2024-379-717-724


717-724

 

 

 

 

 

 

 

WEIGHTED R-NORM ENTROPY FOR LIFETIME DISTRIBUTIONS: PROPERTIES AND APPLICATION

 

Bilal Ahmad Bhat, M.A.K Baig

 

In the field of information theory, different uncertainty measures have been introduced by various researchers. These measures are widely used in reliability and survival studies. In this article, we introduce two new weighted uncertainty measures which are known as weighted R-Norm entropy (WRNE) and weighted R-Norm residual entropy (WRNRE). WRNE and WRNRE are “length- biased” shift-dependent uncertainty measures in which higher weight is assigned to large values of the observed random variable. Several important properties of these measures are studied. Some significant characterization results and the relationships of WRNRE with other reliability measures are presented. We also show that the survival function is uniquely determined by the WRNRE. Finally, based on a real life data set of bladder cancer patients, we illustrate the importance of WRNE and WRNRE.

 

 

Cite: Bilal Ahmad Bhat, M.A.K Baig WEIGHTED R-NORM ENTROPY FOR LIFETIME DISTRIBUTIONS: PROPERTIES AND APPLICATION. Reliability: Theory & Applications. 2024, September 3(79):  725-735, DOI: https://doi.org/10.24412/1932-2321-2024-379-725-735


725-735

 

 

 

 

 

 

 

AN IMPROVED ESTIMATOR OF FINITE POPULATION MEAN UNDER RANKED SET SAMPLING

 

Francis Delali Baeta, Dioggban Jakperik, Michael Jackson Adjabui

 

To obtain reliable estimates of population parameters, data that is sampled for estimation must accurately represent the underlying population. Sampled data that is representative of the underlying population depends also on the sampling technique that was used in obtaining them. This is very important since sampling bias could lead to over or under estimation of parameters. Ranked Set Sampling is considered to be a better alternative to the classical sampling designs in obtaining such data. Ranked Set Sampling is designed to minimize the number of measured observations required to achieve a desired precision in making inferences, and thus it is more economical to use for the purposes of estimation, compared to the classical sampling designs. This is also an added advantage in cases where it is difficult to obtain data. Many estimators have been developed recently for the estimation of finite population mean under ranked set sampling. This paper aims to improve estimation by modifying an existing estimator using a simple linear combination of the known population mean, square root of the known coefficient of variation, and the known median of an auxiliary variable. The theoretical properties of the proposed estimator, such as the bias and mean squared error were derived up to the first order of approximation, using Taylor’s expansion. The bias, mean squared error, absolute relative bias, and the relative efficiency were used as means of evaluation and comparison between the proposed modified estimator and its competitors. The R software was used to aid computations. Empirical applications to real data showed that the proposed modified estimator is superior to the competing estimators that were compared since it has least bias, the least mean squared error, the least absolute relative bias, and the highest relative efficiency in all sample sizes that were considered. The bias and mean squared error of the modified estimator under Ranked Set Sampling was found to be smaller than those of the existing estimators that were compared. Hence it is more efficient and capable of providing reliable estimates than the existing estimators that were compared and so we recommend that it should be used in survey estimations.

 

 

Cite: Francis Delali Baeta, Dioggban Jakperik, Michael Jackson Adjabui AN IMPROVED ESTIMATOR OF FINITE POPULATION MEAN UNDER RANKED SET SAMPLING. Reliability: Theory & Applications. 2024, September 3(79):  736-743, DOI: https://doi.org/10.24412/1932-2321-2024-379-736-743


736-743

 

 

 

 

 

 

 

BAYESIAN ESTIMATION OF PARAMETERS AND RELIABILITY CHARACTERISTICS IN THE INVERSE GOMPERTZ DISTRIBUTION

 

Taiwo. M. Adegoke, Latifat A. Abimbola, Oladapo M. Oladoja, Oyindamola. R. Oyebanjo, K.O. Obisesan

 

In this study, we derive Bayes’ estimators for the unknown parameters of the Inverse Gompertz Distribution (IGD) using three alternative loss functions: the Squared Error Loss Function (SELF), the Entropy Loss Function (ELF), and the Linex Loss Function. Closed-form formulas for Bayes estimators are not possible when both parameters are unknown, hence Lindley’s approximation (L-Approximation) is used for computation. We examine the performance of these estimators using their simulated hazards and assess their effectiveness in parameter estimation. It was discovered that as the sample size increases, parameter estimations became more precise and accurate across all functions. However, ELF consistently has lower MSE values than SELF and LINEX, indicating better parameter estimation. This pattern was also seen in the estimation of the hazard function, where ELF regularly beat SELF and LINEX, implying more efficient parameter estimation overall.

 

 

Cite: Taiwo. M. Adegoke, Latifat A. Abimbola, Oladapo M. Oladoja, Oyindamola. R. Oyebanjo, K.O. Obisesan BAYESIAN ESTIMATION OF PARAMETERS AND RELIABILITY CHARACTERISTICS IN THE INVERSE GOMPERTZ DISTRIBUTION. Reliability: Theory & Applications. 2024, September 3(79):  744-756, DOI: https://doi.org/10.24412/1932-2321-2024-379-744-756


744-756

 

 

 

 

 

 

 

A TWO-PARAMETER ARADHANA DISTRIBUTION WITH APPLICATIONS TO RELIABILITY ENGINEERING

 

Ravi Shanker, Nitesh Kumar Soni, Rama Shanker, Mousumi Ray, Hosenur Rahman Prodhani

 

The search for a statistical distribution for modelling the reliability data from reliability engineering is challenging and the main cause is the stochastic nature of the data and the presence of skewness, kurtosis and over-dispersion. During recent decades several one and two-parameter statistical distributions have been proposed in statistics literature, but all these distributions were unable to capture the nature of data due to the presence of skewness, kurtosis and over-dispersion in the data. In the present paper, two-parameter Aradhana distribution, which includes one parameter Aradhana distribution as a particular case, has been proposed. Using convex combination approach of deriving a new statistical distribution, a two- parameter Aradhana distribution has been proposed. Various interesting and useful statistical properties including survival function, hazard function, reverse hazard function, mean residual life function, stochastic ordering, deviation from mean and median, stress-strength reliability, Bonferroni and Lorenz curve and their indices have been discussed. The raw moments, central moments and descriptive measures based on moments of the proposed distribution have been obtained. The estimation of parameters using the maximum likelihood method has been explained. The simulation study has been presented to know the performance in terms of consistency of maximum likelihood estimators as the sample size increases and. The goodness of test of the proposed distributions has been tested using the values of Akaike Information criterion and Kolmogorov-Smirnov statistics. Finally, two examples of real lifetime datasets from reliability engineering have been presented to demonstrate its applications and the goodness of fit, and it shows a better fit over two-parameter generalized Aradhana distribution, quasi Aradhana distribution, new quasi Aradhana distribution, Power Aradhana distribution, weighted Aradhana distribution, gamma distribution and Weibull distribution. The flexibility, tractability and usefulness of the proposed distribution show that it is very much useful for modelling reliability data from reliability engineering. As this is a new distribution and it has wide applications, it will draw the attention of researchers in reliability engineering and biomedical sciences to search many more applications in the future.

 

 

Cite: Ravi Shanker, Nitesh Kumar Soni, Rama Shanker, Mousumi Ray, Hosenur Rahman Prodhani A TWO-PARAMETER ARADHANA DISTRIBUTION WITH APPLICATIONS TO RELIABILITY ENGINEERING. Reliability: Theory & Applications. 2024, September 3(79):  757-774, DOI: https://doi.org/10.24412/1932-2321-2024-379-757-774


757-774

 

 

 

 

 

 

 

STATISTICAL DESIGN OF CONDITIONAL REPETITIVE GROUP SAMPLING PLAN BASED ON TRUNCATED LIFE TEST FOR PERCENTILE LIFETIME USING EXPONENTIATED GENERALIZED FRECHET DISTRIBUTION

 

S. Jayalakshmi, S. Vijilamery

 

Reliability Acceptance sampling plan is used to assess whether to accept or reject a product depending on its lifetime. An inspection carried out for the purpose of determining if lifetime inspections are performing properly can be tested by submitting a truncated lifetime test. In this paper describes a new approach on Conditional Repetitive Group Sampling Plan based on Truncated life test is proposed and the lifetime follows an Exponentiated Generalized Frechet Distribution. For each consumer risk, it is determined whether minimum sample sizes are required to assert a percentile life. It is calculated that the operating characteristic function values of the sampling plans as well as the producer’s risk ratio corresponding to the sampling plans. The results are illustrated with numerical examples and a real-world data set is used to demonstrate the impact and performance of the suggested acceptance sampling plans.

 

 

Cite: S. Jayalakshmi, S. Vijilamery STATISTICAL DESIGN OF CONDITIONAL REPETITIVE GROUP SAMPLING PLAN BASED ON TRUNCATED LIFE TEST FOR PERCENTILE LIFETIME USING EXPONENTIATED GENERALIZED FRECHET DISTRIBUTION. Reliability: Theory & Applications. 2024, September 3(79):  775-787, DOI: https://doi.org/10.24412/1932-2321-2024-379-775-787


775-787

 

 

 

 

 

 

 

NEW EXTENSION OF INVERTED MODIFIED LINDLEY DISTRIBUTION WITH APPLICATIONS

 

Devendra Kumara, Anju Goyalb, P. Pareekc, M. Sahaa

 

In this article we, proposed a new two parameter distribution called inverted power modified Lindley distribution. The main objective is to introduce an extension to inverted modified Lindley distribution as an alternative to the inverted exponential, inverted gamma and inverted modified Lindley distributions, respectively. The proposed distribution is more flexible than the above mentioned distributions in terms of its hazard rate function. In the part of estimation of the proposed model, we first utilize the maximum likelihood (ML) estimator and parametric bootstrap confidence intervals, viz., standard bootstrap, percentile bootstrap, bias-corrected percentile (BCPB), bias-corrected accelerated bootstrap (BCAB) from the classical point of view as well the Bayesian estimation under different loss functions, squared error loss function, modified squared error loss function, and Bayes credible interval as to obtain the model parameter based on order statistics. A simulation study is carried out to check the efficiency of the classical and the Bayes estimators in terms of mean squared errors and posterior risks, respectively. Two real life data sets, have been analyzed for order statistics to demonstrate how the proposed methods may work in practice.

 

 

Cite: Devendra Kumara, Anju Goyalb, P. Pareekc, M. Sahaa NEW EXTENSION OF INVERTED MODIFIED LINDLEY DISTRIBUTION WITH APPLICATIONS. Reliability: Theory & Applications. 2024, September 3(79):  788-804, DOI: https://doi.org/10.24412/1932-2321-2024-379-788-804


788-804

 

 

 

 

 

 

 

A MAP/PH1, PH2/2 INVENTORY QUEUEING SYSTEM WITH TWO COMMODITY, MULTIPLE VACATION, SERVER FEEDBACK, WORKING BREAKDOWN, REPAIR AND EMERGENCY REPLENISHMENT

 

G. Ayyappan, N. Arulmozhi

 

We investigate a continuous review inventory queuing system in the present study that has two heterogeneous servers: Server-2, which is reliable, and Server-1, which is unreliable. An exponentially distributed random time is used to describe the repair process when server-1 has an interruption. On the other hand, server-2 is completely dependable, but it goes on vacation when the system is empty. These two goods can be reordered under ordering regulations. To ensure customer satisfaction, an emergency replenishment of one item with no lead time occurs when the on-hand inventory level falls to zero. We use the matrix analytic approach for the QBD process under a steady-state probability vector. We also take into account the overall cost and the busy time. Furthermore, numerical data shows the benefits of the suggested approach in a range of random circumstances.

 

 

Cite: G. Ayyappan, N. Arulmozhi A MAP/PH1, PH2/2 INVENTORY QUEUEING SYSTEM WITH TWO COMMODITY, MULTIPLE VACATION, SERVER FEEDBACK, WORKING BREAKDOWN, REPAIR AND EMERGENCY REPLENISHMENT. Reliability: Theory & Applications. 2024, September 3(79):  805-823, DOI: https://doi.org/10.24412/1932-2321-2024-379-805-823


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