美国运筹学期刊(英文)最新文献

{"title":"A Software Reliability Model for OSS Including Various Fault Data Based on Proportional Hazard-Rate Model","authors":"T. Yanagisawa, Y. Tamura, Adarsh Anand, S. Yamada","doi":"10.4236/ajor.2022.121001","DOIUrl":"https://doi.org/10.4236/ajor.2022.121001","url":null,"abstract":"The software reliability model is the stochastic model to measure the software reliability quantitatively. A Hazard-Rate Model is the well-known one as the typical software reliability model. We propose Hazard-Rate Models Considering Fault Severity Levels (CFSL) for Open Source Software (OSS). The purpose of this research is to make the Hazard-Rate Model considering CFSL adapt to baseline hazard function and 2 kinds of faults data in Bug Tracking System (BTS), i.e., we use the covariate vectors in Cox proportional Hazard-Rate Model. Also, we show the numerical examples by evaluating the performance of our proposed model. As the result, we compare the performance of our model with the Ha-zard-Rate Model CFSL.","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70519087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploiting Virtual Elasticity of Production Systems to Respect OTD—Part 3: Basic Considerations for Modelling CPPS Characterized by Non-Ergodic Order Entry and Non-Deterministic Product-Mix for Fully Flexible Addressable Workstations","authors":"B. Rüttimann, Martin T. Stöckli","doi":"10.4236/ajor.2022.122003","DOIUrl":"https://doi.org/10.4236/ajor.2022.122003","url":null,"abstract":"","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70519103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unsupervised Methods to Classify Real Data from Offshore Wells","authors":"Antonio Orestes de Salvo Castro, M. D. J. R. Santos, F. R. Leta, C. Lima, G. B. A. Lima","doi":"10.4236/ajor.2021.115014","DOIUrl":"https://doi.org/10.4236/ajor.2021.115014","url":null,"abstract":"In the petroleum industry, sensor data and information are valuable. It \u0000can detect, predict and help to understand processes during oil production. \u0000Offshore wells require more attention. Once workovers, maintenance, and \u0000intervention are more costly than onshore wells. Coupling data-driven methods for \u0000well-monitoring applications, two unsupervised classification methods, one \u0000statistical and one machine learning-based, are proposed to detect anomalies in \u0000well data. The novelty is presented by applying a Control Chart using a 3 standard deviations window for the \u0000Permanent Downhole Gauge Pressure \u0000sensor (P-PDG), and a Fuzzy C-means algorithm to classify data from pressure \u0000and temperature sensors in an offshore field. The main goal in structuring a \u0000classified data set is using it to train machine learning models to monitor and \u0000manage petroleum production. Modeling applications for early fault detection \u0000systems in offshore production, based on real-time data from production sensors, \u0000require classified data sets. Then, labeling two target classes: “normal” and “fault” is a key step to be implemented in order to train the \u0000machine learning models. Therefore, this paper applies two methodologies to \u0000classify a real-time data set to create a training data set divided into \u0000“normal” and “fault” classes. Thus, it is possible \u0000to visualize the abnormal events pointed out by the methodologies and \u0000compare how sensible is each method. In addition, it is proposed a random forest application to test the performance of the \u0000classified data sets from both methods. The results have shown that the control chart method presents higher sensibility than \u0000fuzzy c-means, however, the differences \u0000between are insignificant. The random forest performance displayed \u0000sensitivity and specificity values of 99.91% and 100% for the data set classified \u0000by the control chart method and 94.01% and 99.98% for the data set classified \u0000by fuzzy c-means algorithm.","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41934965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NEW PERT and CPM in Project Management with Practical Examples","authors":"K. B. Bagshaw","doi":"10.4236/ajor.2021.114013","DOIUrl":"https://doi.org/10.4236/ajor.2021.114013","url":null,"abstract":"This paper reviewed the concepts of Project \u0000Evaluation Review Technique and Critical \u0000Path Method in project management with practical examples. The methods and \u0000success of quantitative decision-making approaches in project management \u0000through the use of project evaluation review technique and the critical \u0000path method as regards project duration and critical activities of a project, \u0000were discussed. The review found that while both methods are effective in \u0000achieving success in project management, the relationship and connectivity of \u0000activities involved in a project life cycle are key aspects. The paper \u0000concludes that the project evaluation review technique is more effective when \u0000the duration of the project is uncertain, while the critical path method is \u0000effective when the project’s end time is certain. The paper, therefore, \u0000recommends that to achieve maximum operative efficiency in utilizing resources \u0000in project management, prior to commencing the execution of a project, all \u0000required resources to cover every activity must be assembled and prioritized to \u0000eliminate interruptions that could bring delay and unnecessary cost \u0000implications. Again, policies focused on improving project execution should be \u0000implemented in developing nations to minimize the many cases of failed and \u0000delayed projects. Subsequently, stakeholders in projects must be given the \u0000right, under the law, to prosecute the government, its agencies and/or the \u0000executors of projects for failure to execute a project on schedule.","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46226559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of an Inventory System for Items with Price-Dependent Demand and Time Dependent Three-Parameter Weibull Deterioration Function","authors":"O. Pius, I. E. Chukwu Walford, S. M. Olaniyi","doi":"10.4236/ajor.2021.114012","DOIUrl":"https://doi.org/10.4236/ajor.2021.114012","url":null,"abstract":"In this research work we propose a \u0000mathematical model of an inventory system with time dependent three-parameter \u0000Weibull deterioration and price-dependent \u0000demand rate. The model incorporates shortages and deteriorating items are \u0000considered in which inventory is depleted not only by demand but also by decay, \u0000such as, direct spoilage as in fruits, vegetables and food products, or deterioration \u0000as in obsolete electronic components. Furthermore, the rate of deterioration is \u0000taken to be time-proportional, and a power law form of the price dependence of \u0000demand is considered. This price-dependence of the demand function is \u0000nonlinear, and is such that when price of a commodity increases, demand \u0000decreases and when price of a commodity decreases, demand increases. The \u0000objective of the model is to minimize \u0000the total inventory costs. From the numerical example presented to \u0000illustrate the solution procedure of the model, we obtain meaningful results. \u0000We then proceed to perform sensitivity analysis of our model. The sensitivity \u0000analysis illustrates the extent to which the optimal solution of the model is \u0000affected by slight changes or errors in its input parameter values.","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41770471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploiting Virtual Elasticity of Manufacturing Systems to Respect OTD—Part 2: Post-Optimality Conditions for the Cases of Ergodic and Non-Ergodic Order Rate with Deterministic Product-Mix","authors":"B. Rüttimann, Martin T. Stöckli","doi":"10.4236/AJOR.2021.113009","DOIUrl":"https://doi.org/10.4236/AJOR.2021.113009","url":null,"abstract":"Respecting the on-time delivery (OTD) for manufacturing orders is \u0000mandatory. However, for non-JIT Batch & Queue Push-manufacturing systems, \u0000the compliance of OTD is not intrinsically guaranteed. As an OTD related manufacturing theory is largely missing it is crucial \u0000to understand and formalize the necessary conditions of OTD compliance for \u0000complex production environments for maximum exploitation of the production \u0000capacity. This paper evaluates the conditions of post-optimality while being \u0000OTD compliant for production systems, which are characterized by stochastic order rate and a deterministic product-mix. Instead of applying \u0000discrete event simulation to explore the real case-by-case order scheduling \u0000optimization for OTD compliance, a Cartesian approach is followed. This enables \u0000to define theoretically the solution space of order backlog for OTD, which \u0000contributes to developing further manufacturing theory. At the base stands the recently defined \u0000new concept of virtual manufacturing elasticity by reducing lead-time to \u0000increase virtually production capacity. The result has led to defining additional two corollaries to the OTD theorem, which sets up basic OTD \u0000theory. Apart from defining the post-optimal requirements to guarantee for \u0000orders at least a weak solution for OTD compliance, this paper reveals that for \u0000a deterministic product-mix a non-ergodic order arrival rate can be rescheduled \u0000into an ergodic order input rate to the shopfloor if the virtual elasticity T is large enough, hence \u0000the importance of having fast and flexible production lines.","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49308662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of M/M/s/N Queueing Model with Reneging in a Fuzzy Environment","authors":"Ananda Prasad Panta, R. Ghimire, D. Panthi, S. Pant","doi":"10.4236/AJOR.2021.113008","DOIUrl":"https://doi.org/10.4236/AJOR.2021.113008","url":null,"abstract":"This paper deals with the study of multi-server queueing model in a fuzzy \u0000environment with imposition of reneging of customers. Entry of the customers in \u0000the system is assumed to be Poisson process and exponential service time distribution \u0000under first-come-first-served basis. Specific of this investigation is to derive the \u0000various fuzzy performance measures such as fuzzy queue length, fuzzy waiting \u0000time in queue, fuzzy response time and fuzzy optimal number of servers in \u0000explicit form for the finite capacity multi-server queueing system by using \u0000recursive method. For the validity of the model we have obtained the numerical \u0000illustrations in tabular form which shows that fuzzy-queue can be more \u0000realistic than crisp queue.","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":"11 1","pages":"121-140"},"PeriodicalIF":0.0,"publicationDate":"2021-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42741024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interdependence of Software and Progress of Mathematics in OR: Some Illustrative Cases and Challenges","authors":"Santosh Kumar, E. Munapo","doi":"10.4236/AJOR.2021.112007","DOIUrl":"https://doi.org/10.4236/AJOR.2021.112007","url":null,"abstract":"This paper points out that delayed or no supply of software can kill potential benefits associated with new mathematical ideas that have led to development of new mathematics in OR. It also points out that it is a self-created situation by the scientific community. This situation needs attention and should be resolved urgently. Many illustrative examples have been given to justify the claim.","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":"11 1","pages":"110-119"},"PeriodicalIF":0.0,"publicationDate":"2021-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49455631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum to “An Inventory Model for Deteriorating Items with Generalised Exponential Decreasing Demand, Constant Holding Cost and Time-Varying Deterioration Rate” [American Journal of Operations Research 8 (2018) 1-16]","authors":"I. Aliyu, B. Sani","doi":"10.4236/AJOR.2021.112006","DOIUrl":"https://doi.org/10.4236/AJOR.2021.112006","url":null,"abstract":"The original online version of this \u0000article (Isiyaku Aliyu, Babangida Sani (2018) [18] An Inventory Model for Deteriorating Items with Generalised Exponential \u0000Decreasing Demand, Constant Holding Cost and Time-Varying Deterioration Rate. AJOR, 8, 1-16. doi: 10.4236/ajor.2018.81001.) was published as some results data reported mistakenly. The author wishes \u0000to correct the errors to:","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":"11 1","pages":"100-109"},"PeriodicalIF":0.0,"publicationDate":"2021-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41806491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling Complete Power Outage Data Using Reliability","authors":"N. P. Akpan, N. Bassey","doi":"10.4236/AJOR.2021.112005","DOIUrl":"https://doi.org/10.4236/AJOR.2021.112005","url":null,"abstract":"Data on \u0000time between complete power outages, Time between Failure (TBF) in Uyo were \u0000considered. Trend test and serial correlation test were conducted graphically \u0000for the data. The tests proved that the data were identically and independently \u0000distributed (iid). Summary statistics of the data showed that complete power \u0000outage occurred 416 times between the year 2014 and 2018. The maximum \u0000likelihood estimation method was used to estimate the parameters of Weibull \u00002-parameter, Normal, Lognormal 2-parameter and exponential distributions. The \u0000values of Kolmogorov-Smirnov, Anderson Darling and Chi-Square statistics were \u0000used to determine the best fit distributions. A model for the \u0000computation of reliability of electric power was then proposed.","PeriodicalId":61329,"journal":{"name":"美国运筹学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49289419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}