Impatient Customers in an M/M/1 Working Vacation Queue with a Waiting Server and Setup Time

2019 ◽  
Vol 10 (5) ◽  
pp. 1189-1196
Author(s):  
P. Manoharan ◽  
T. Jeeva
Keyword(s):  
Setup Time ◽  
Impatient Customers ◽  
Working Vacation

scholarly journals Phase-Type Arrivals and Impatient Customers in Multiserver Queue with Multiple Working Vacations

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Cosmika Goswami ◽  
N. Selvaraju
Keyword(s):  
Blocking Probability ◽  
Death Process ◽  
Impatient Customers ◽  
Working Vacation ◽  
Multiple Working Vacations ◽  
Phase Type ◽  
Working Vacations ◽  
The One ◽  
Vacation Period ◽  
Stationary Probability Vector

We consider a PH/M/c queue with multiple working vacations where the customers waiting in queue for service are impatient. The working vacation policy is the one in which the servers serve at a lower rate during the vacation period rather than completely ceasing the service. Customer’s impatience is due to its arrival during the period where all the servers are in working vacations and the arriving customer has to join the queue. We formulate the system as a nonhomogeneous quasi-birth-death process and use finite truncation method to find the stationary probability vector. Various performance measures like the average number of busy servers in the system during a vacation as well as during a nonvacation period, server availability, blocking probability, and average number of lost customers are given. Numerical examples are provided to illustrate the effects of various parameters and interarrival distributions on system performance.

Designing an Energy Efficient Scheme in MANET using Reconfigurable Directional (RDA) Algorithm

2018 ◽  
Vol 8 (4) ◽  
pp. 92
Author(s):  
Rinkle Chhabra ◽  
Anuradha Saini
Keyword(s):  
Ad Hoc ◽  
Energy Savings ◽  
Setup Time ◽  
Directional Antennas ◽  
Directional Antenna ◽  
Efficient Scheme ◽  
Primary Focus ◽  
Hoc Networks ◽  
Energy Gains ◽  
Insight Into

Mobile Ad Hoc Networks (MANET) are autonomous, infrastructure less and self-configuring networks. MANETs has gained lots of popularity due to on the fly deployment i.e. small network setup time and ability to provide communication in obstreperous terrains. Major challenges in MANETs include routing, energy efficiency, network topology control, security etc. Primary focus in this article is to provide method and algorithm to ensure significant energy savings using re-configurable directional antennas. Significant energy gains can be clinched using directional antenna. Key challenges while using directional antenna are to find destination location, antenna focusing, signal power and distance calculations. Re-configurable directional antenna can ensure significant energy gains if used intelligently. This article provides a brief insight into improved energy savings using re-configurable directional antennas and an associated algorithm

MINIMALISASI BIAYA SIMPAN DAN BIAYA SETUP PADA MULTIPLE PRODUK: SIMULASI DENGAN CAPACITATED LOT SIZING PROBLEM

2019 ◽  
Vol 4 (2) ◽  
pp. 205-214
Author(s):  
Erika Fatma
Keyword(s):  
Production Cost ◽  
Lot Sizing ◽  
Setup Time ◽  
Production Costs ◽  
Total Production ◽  
Product Cycle ◽  
Lot Size ◽  
Setup Costs ◽  
Lot Sizing Problem ◽  
Capacitated Lot Sizing

Lot sizing problem in production planning aims to optimize production costs (processing, setup and holding cost) by fulfilling demand and resources capacity costraint. The Capacitated Lot sizing Problem (CLSP) model aims to balance the setup costs and inventory costs to obtain optimal total costs. The object of this study was a plastic component manufacturing company. This study use CLSP model, considering process costs, holding costs and setup costs, by calculating product cycle and setup time. The constraint of this model is the production time capacity and the storage capacity of the finished product. CLSP can reduce the total production cost by 4.05% and can reduce setup time by 46.75%.  Keyword: Lot size, CLSP, Total production cost.

scholarly journals Extraperitoneal Robotic Laparo-Endoscopic Single-Site Plus1-Port Radical Prostatectomy Using the da Vinci Single-Site Platform

2021 ◽  
Vol 10 (8) ◽  
pp. 1563
Author(s):  
Ching-Chia Li ◽  
Tsu-Ming Chien ◽  
Ming-Ru Lee ◽  
Hsiang-Ying Lee ◽  
Hung-Lung Ke ◽  
...  
Keyword(s):  
Radical Prostatectomy ◽  
Da Vinci ◽  
Specific Antigen ◽  
Operation Time ◽  
Setup Time ◽  
Single Site ◽  
University Hospital ◽  
Da Vinci Surgical System ◽  
Free Survival ◽  
The Aesthetic

Currently, over 80% of radical prostatectomies have been performed with the da Vinci Surgical System. In order to improve the aesthetic outlook and decrease the morbidity of the operation, the new da Vinci Single Port (SP) system was developed in 2018. However, one major problem is the SP system is still not available in most countries. We aim to present our initial experience and show the safety and feasibility of the single-site robotic-assisted radical prostatectomy (LESS-RP) using the da Vinci Single-Site platform. From June 2017 to January 2020, 120 patients with localized prostate cancer (stage T1–T3b) at Kaohsiung Medical University Hospital were included in this study. We describe our technique and report our initial results of LESS-RP using the da Vinci Si robotic system. Preoperative, intraoperative and postoperative patient variables were recorded. Prostate-specific antigen (PSA)-free survival was also analyzed. A total of 120 patients were enrolled in the study. The median age of patients was 68 years (IQR 63–71), with a median body mass index of 25 kg/m2 (IQR 23–27). The median PSA value before operation was 10.7 ng/mL (IQR 7.9–21.1). The median setup time for creat-ing the extraperitoneal space and ports document was 25 min (IQR 18–34). The median robotic console time and operation time were 135 min (IQR 110–161) and 225 min (IQR 197–274), respectively. Median blood loss was 365 mL (IQR 200–600). There were 11 (9.2%) patients who experienced complications (Clavien–Dindo classification Gr II). The me-dian catheter duration was 8 days (IQR 7–9), with a median of 10 days (IQR 7–11) of hospital stay. The PSA free-survival rate was 86% at a median 19 months (IQR 6–28) of follow up. Robotic radical prostatectomy using the da Vinci Single-Site platform system is safe and feasible, with acceptable outcomes.

scholarly journals Mathematical Modeling and Discrete Firefly Algorithm to Optimize Scheduling Problem with Release Date, Sequence-Dependent Setup Time, and Periodic Maintenance

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Mustafa A. Qamhan ◽  
Ammar A. Qamhan ◽  
Ibrahim M. Al-Harkan ◽  
Yousef A. Alotaibi
Keyword(s):  
Firefly Algorithm ◽  
Programming Model ◽  
Setup Time ◽  
Mixed Integer ◽  
Release Date ◽  
Sequence Dependent ◽  
Sequence Dependent Setup Time ◽  
Periodic Maintenance ◽  
Discrete Firefly Algorithm ◽  
Sequence Dependent Setup

An evolutionary discrete firefly algorithm (EDFA) is presented herein to solve a real-world manufacturing system problem of scheduling a set of jobs on a single machine subject to nonzero release date, sequence-dependent setup time, and periodic maintenance with the objective of minimizing the maximum completion time “makespan.” To evaluate the performance of the proposed EDFA, a new mixed-integer linear programming model is also proposed for small-sized instances. Furthermore, the parameters of the EDFA are regulated using full factorial analysis. Finally, numerical experiments are performed to demonstrate the efficiency and capability of the EDFA in solving the abovementioned problem.

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