Mathematics最新文献_第9页

Sojourn Time Analysis of a Single-Server Queue with Single- and Batch-Service Customers 具有单个和批量服务客户的单服务器队列的停留时间分析

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-11 DOI: 10.3390/math12182820

Yusei Koyama, Ayane Nakamura, Tuan Phung-Duc

{"title":"Sojourn Time Analysis of a Single-Server Queue with Single- and Batch-Service Customers","authors":"Yusei Koyama, Ayane Nakamura, Tuan Phung-Duc","doi":"10.3390/math12182820","DOIUrl":"https://doi.org/10.3390/math12182820","url":null,"abstract":"There are various types of sharing economy services, such as ride-sharing and shared-taxi rides. Motivated by these services, we consider a single-server queue in which customers probabilistically select the type of service, that is, the single service or batch service, or other services (e.g., train). In the proposed model, which is denoted by the M+M(K)/M/1 queue, we assume that the arrival process of all the customers follows a Poisson distribution, the batch size is constant, and the common service time (for the single- and batch-service customers) follows an exponential distribution. In this model, the derivation of the sojourn time distribution is challenging because the sojourn time of a batch-service customer is not determined upon arrival but depends on single customers who arrive later. This results in a two-dimensional recursion, which is not generally solvable, but we made it possible by utilizing a special structure of our model. We present an analysis using a quasi-birth-and-death process, deriving the exact and approximated sojourn time distributions (for the single-service customers, batch-service customers, and all the customers). Through numerical experiments, we demonstrate that the approximated sojourn time distribution is sufficiently accurate compared to the exact sojourn time distributions. We also present a reasonable approximation for the distribution of the total number of customers in the system, which would be challenging with a direct-conventional method. Furthermore, we presented an accurate approximation method for a more general model where the service time of single-service customers and that of batch-service customers follow two distinct distributions, based on our original model.","PeriodicalId":18303,"journal":{"name":"Mathematics","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance Evaluation of the Taiwanese Banking Industry before and after the COVID-19 Pandemic 台湾银行业在 COVID-19 大流行前后的绩效评估

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-11 DOI: 10.3390/math12182817

Chuan-Feng Lee, Fu-Chiang Yang

{"title":"Performance Evaluation of the Taiwanese Banking Industry before and after the COVID-19 Pandemic","authors":"Chuan-Feng Lee, Fu-Chiang Yang","doi":"10.3390/math12182817","DOIUrl":"https://doi.org/10.3390/math12182817","url":null,"abstract":"This study aimed to explore efficiency changes in Taiwan’s banking industry before and after the outbreak of coronavirus disease 2019 (COVID-19) by using the maximum slacks-based measure approach. The data, spanning from 2018 to 2021, categorized banks into three systems: state-owned, private, and foreign. Bank performance was measured from two perspectives: single-period evaluation (assessing bank performance in each year individually) and cross-period evaluation (assessing bank performance from 2018 to 2021 collectively). Inter-temporal changes in bank performance across the three banking systems were analyzed. The results indicated that only foreign banks rebounded rapidly after the COVID-19 outbreak, while the average performance of private banks remained stagnant, and state-owned banks performed worse than before the outbreak. Therefore, it is recommended that state-owned banks develop effective and rapid improvement policies to address major emergencies. Additionally, the study found that inefficiencies in banks were due to excessive input resources and/or failure to achieve the output targets. The input–output gap of inefficient banks was also analyzed, providing learning benchmarks and clear improvement targets that can help these banks formulate practical actions to improve their performance.","PeriodicalId":18303,"journal":{"name":"Mathematics","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Correction: Muniyappan et al. Stability and Numerical Solutions of Second Wave Mathematical Modeling on COVID-19 and Omicron Outbreak Strategy of Pandemic: Analytical and Error Analysis of Approximate Series Solutions by Using HPM. Mathematics 2022, 10, 343 更正：Muniyappan 等人.关于 COVID-19 和大流行病 Omicron 爆发策略的第二波数学模型的稳定性和数值解：使用 HPM 的近似数列解的分析和误差分析.数学 2022，10，343

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-11 DOI: 10.3390/math12182816

Ashwin Muniyappan, Balamuralitharan Sundarappan, Poongodi Manoharan, Mounir Hamdi, Kaamran Raahemifar, Sami Bourouis, Vijayakumar Varadarajan

引用次数: 0

An Outlier Detection Approach to Recognize the Sources of a Process Failure within a Multivariate Poisson Process 在多变量泊松过程中识别过程故障源的离群值检测方法

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-11 DOI: 10.3390/math12182813

Chia-Ding Hou, Rung-Hung Su

引用次数: 0

Unified Gas Kinetic Simulations of Lid-Driven Cavity Flows: Effect of Compressibility and Rarefaction on Vortex Structures 盖驱动空腔流的统一气体动力学模拟：可压缩性和稀膨胀对涡旋结构的影响

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-11 DOI: 10.3390/math12182807

Vishnu Venugopal, Haneesha Iphineni, Divya Sri Praturi, Sharath S. Girimaji

{"title":"Unified Gas Kinetic Simulations of Lid-Driven Cavity Flows: Effect of Compressibility and Rarefaction on Vortex Structures","authors":"Vishnu Venugopal, Haneesha Iphineni, Divya Sri Praturi, Sharath S. Girimaji","doi":"10.3390/math12182807","DOIUrl":"https://doi.org/10.3390/math12182807","url":null,"abstract":"We investigate and characterize the effect of compressibility and rarefaction on vortex structures in the benchmark lid-driven cavity flow. Direct numerical simulations are performed, employing the unified gas kinetic scheme to examine the changes in vortex generation mechanisms and the resulting flow structures at different Mach and Knudsen numbers. At high degrees of rarefaction, where inter-molecular interactions are minimal, the molecules mainly collide with the walls. Consequently, the dominant flow structure is a single vortex in the shape of the cavity. It is shown that increasing compressibility or decreasing rarefaction lead to higher molecular density in the cavity corners, due to more frequent inter-molecular collisions. This results in lower flow velocities, creating conditions conducive to the development of secondary and corner vortices. The physical processes underlying vortex formations at different Knudsen numbers, Mach numbers, and cavity shapes are explicated. A parametric map that classifies different regimes of vortex structures as a function of compressibility, rarefaction, and cavity shape is developed.","PeriodicalId":18303,"journal":{"name":"Mathematics","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Some Equations in Rings Involving Semiprime Ideals and Multiplicative Generalized Semiderivations 环中涉及半等式和乘法广义半等式的一些方程

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-11 DOI: 10.3390/math12182818

Ali Yahya Hummdi, Öznur Gölbaşı, Emine Koç Sögütcü, Nadeem ur Rehman

引用次数: 0

Singularity, Observability, and Independence: Unveiling Lorenz’s Cryptographic Potential 奇异性、可观测性和独立性：揭示洛伦兹的密码学潜力

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-10 DOI: 10.3390/math12182798

Alexandru Dinu

引用次数: 0

A Novel Hybrid Model (EMD-TI-LSTM) for Enhanced Financial Forecasting with Machine Learning 利用机器学习增强金融预测的新型混合模型（EMD-TI-LSTM）

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-09 DOI: 10.3390/math12172794

Olcay Ozupek, Reyat Yilmaz, Bita Ghasemkhani, Derya Birant, Recep Alp Kut

引用次数: 0

Some Fractional Integral and Derivative Formulas Revisited 一些分式积分和导数公式再探讨

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-09 DOI: 10.3390/math12172786

Juan Luis González-Santander, Francesco Mainardi

引用次数: 0

Quantitative and Qualitative Analysis of Aircraft Round-Trip Times Using Phase Type Distributions 利用相位类型分布对飞机往返时间进行定量和定性分析

IF 2.4 3区数学

Mathematics Pub Date : 2024-09-09 DOI: 10.3390/math12172795

Srinivas R. Chakravarthy

{"title":"Quantitative and Qualitative Analysis of Aircraft Round-Trip Times Using Phase Type Distributions","authors":"Srinivas R. Chakravarthy","doi":"10.3390/math12172795","DOIUrl":"https://doi.org/10.3390/math12172795","url":null,"abstract":"One of the major issues facing commercial airlines is the time that it takes to board passengers. Further, most airlines wish to increase the number of trips that an aircraft can make between two or more cities. Thus, reducing the overall boarding times by a few minutes will have a significant impact on the number of trips made by an aircraft, as well as enabling improvements in key measures such as the median and 75th and 95th percentiles. Looking at such measures other than the mean is critical as it is well known that the mean can under- or overestimate the performance of any model. While there is considerable literature on the study of strategies to decrease boarding times, the same cannot be said about the study of the boarding time given a particular strategy for boarding. Thus, the focus of this paper is to study analytically (using suitable stochastic models) and numerically the impact of reducing the average time on the key measures to help the system to plan accordingly. This is achieved using a well-known probability distribution, namely the phase type distribution, to model various events involved in the boarding process. Illustrative numerical results show a reduction in the percentile values when the average boarding times are decreased. Understanding the percentiles of the boarding times, as opposed to relying only on the average boarding times, will help management to adopt a better boarding strategy that in turn will lead to an increase in the number of trips that an aircraft can make.","PeriodicalId":18303,"journal":{"name":"Mathematics","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0