scholarly journals A copula-based approach to accommodate intra-household interaction in workers’ daily maintenance activity stop generation modeling

2021 ◽  
Author(s):  
You-Lian Chu
Keyword(s):  
Maintenance Activity ◽  
Household Interaction

scholarly journals Influence of height on endothelial maintenance activity: a narrative review

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Yuji Shimizu ◽  
Takahiro Maeda
Keyword(s):  
Risk Factors ◽  
Cardiovascular Disease ◽  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Inverse Association ◽  
Hematopoietic Stem ◽  
Genetic Characteristics ◽  
Maintenance Activity ◽  
Marrow Activity

AbstractRecent studies have revealed an inverse association between height and cardiovascular disease. However, the background mechanism of this association has not yet been clarified. Height has also been reported to be positively associated with cancer. Therefore, well-known cardiovascular risk factors, such as increased oxidative stress and chronic inflammation, are not the best explanations for this inverse association because these risk factors are also related to cancer. However, impaired blood flow is the main pathological problem in cardiovascular disease, while glowing feeding vessels (angiogenesis) are the main characteristic of cancer pathologies. Therefore, endothelial maintenance activity, especially for the productivity of hematopoietic stem cells such as CD34-positive cells, could be associated with the height of an individual because this cell contributes not only to the progression of atherosclerosis but also to the development of angiogenesis. In addition, recent studies have also revealed a close connection between bone marrow activity and endothelial maintenance; bone marrow-derived hematopoietic stem cells contribute towards endothelial maintenance. Since the absolute volume of bone marrow is positively associated with height, height could influence endothelial maintenance activity. Based on these hypotheses, we performed several studies. The aim of this review is not only to discuss the association between height and bone marrow activity, but also to describe the potential mechanism underlying endothelial maintenance. In addition, this review also aims to explain some of the reasons that implicate hypertension as a major risk factor for stroke among the Japanese population. The review also aims to clarify the anthropological reasons behind the high risk of atherosclerosis progression in Japanese individuals with acquired genetic characteristics.

Unrelated Parallel-Machine Scheduling with Controllable Processing Times and Impact of Deteriorating Maintenance Activities under Consideration

2016 ◽  
Vol 33 (01) ◽  
pp. 1650001 ◽  
Author(s):  
Chun-Lai Liu ◽  
Jian-Jun Wang
Keyword(s):  
Processing Time ◽  
Machine Scheduling ◽  
Parallel Machine Scheduling ◽  
Parallel Machine ◽  
Controllable Processing Times ◽  
Maintenance Activity ◽  
Processing Times ◽  
Unrelated Parallel Machine Scheduling ◽  
Deteriorating Maintenance ◽  
Maintenance Activities

In this paper, we study the problem of unrelated parallel machine scheduling with controllable processing times and deteriorating maintenance activity. The jobs are nonresumable. The processing time of each job is a linear function of the amount of a continuously divisible resource allocated to the job. During the planning horizon, there is at most one maintenance activity scheduled on each machine. Additionally, if the starting time of maintenance activity is delayed, the length of the maintenance activity required to perform will increase. Considering the total completion times of all jobs, the impact of maintenance activity in the form of the variation in machine load and the amounts of compression, we need to determine the job sequence on each machine, the location of maintenance activities and processing time compression of each job simultaneously. Accordingly, a polynomial time solution to the problem is provided.

Slack Due-Window Assignment Scheduling Problem with Deterioration Effects and a Deteriorating Maintenance Activity

2022 ◽  
Author(s):  
Xue Jia ◽  
Dan-Yang Lv ◽  
Yang Hu ◽  
Ji-Bo Wang ◽  
Zhi Wang ◽  
...  
Keyword(s):  
Polynomial Time Algorithm ◽  
Time Algorithm ◽  
Machining Process ◽  
Scheduling Problem ◽  
Maintenance Activity ◽  
Starting Time ◽  
Weighted Number ◽  
Deteriorating Maintenance ◽  
Due Window ◽  
Due Window Assignment

This paper studies the slack due-window assignment scheduling problem with deterioration effects and a deterioration maintenance activity on a single-machine. The machine deteriorates during the machining process, and at a certain moment performs a deterioration maintenance activity, that is, the duration time of the maintenance activity is a linear function of the maintenance starting time. It is needed to make a decision on when to schedule the deteriorating maintenance activity, the optimal common flow allowances and the sequence of jobs to minimize the weighted penalties for the sum of earliness and tardiness, weighted number of early and delayed, and weighted due-window starting time and size. This paper proposes a polynomial time algorithm to solve this problem.

scholarly journals Inspeksi Overhaul Motor Induksi 3 Fasa 1000 KW di PT. Mesindo Tekninesia

2020 ◽  
Vol 21 (2) ◽  
pp. 100
Author(s):  
Akmal Radiansyah ◽  
Albert Gifson
Keyword(s):  
Electrical Measurement ◽  
Mechanical Action ◽  
Load Test ◽  
Electric Motors ◽  
Mechanical Measurement ◽  
Electrical Measurements ◽  
Maintenance And Repair ◽  
Maintenance Activity ◽  
Polarization Index ◽  
Standard Value

An electric motor that is used continuously will experience a decline in performance and even be damaged, maintenance and repair of electric motors must be done based on standards so that all existing specifications can be met and repairs deserve to be accepted. Where in this case motor repair is done by overhauling, where overhaul is a comprehensive repair or maintenance activity by repairing or replacing parts of electric motors that are damaged. Based on visual data and electrical measurements the decrease in the value of the polarization index (PI) of the induction motor is caused by dirty and moist winding conditions. Overhaul is done in 8 stages, namely; planning, dismantling, electrical measurement, mechanical measurement, electrical action, mechanical action, assembling and no load test running. After overhauling, the result shows that the value of the polarization index (PI) increased by 1.4 from 1.8 to 3.2, which is above the standard value set by IEEE 43.ABSTRAK:Suatu motor listrik yang digunakan terus menerus akan mengalami penurunan performa bahkan rusak, perawatan dan perbaikan motor listrik harus dilakukan berdasarkan standar supaya semua spesifikasi yang ada dapat terpenuhi dan perbaikan layak untuk diterima. Dimana pada kasus ini perbaikan motor diakukan dengan cara overhaul, dimana overhaul merupakan kegiatan perbaikan atau perawatan secara menyeluruh dengan cara memperbaiki atau mengganti bagian dari motor listrik yang mengalami kerusakan. Berdasarkan data visual dan pengukuran elektrik penurunan nilai polarization index (PI) motor induksi disebabkan oleh kondisi winding yang kotor dan lembab. Overhaul dilakukan dengan 8 tahapan, yaitu; planning, dismantling, pengukuran elektrik, pengukuran mekanik, tindakan elektrik, tindakan mekanik, assembling dan running test no load. Setelah overhaul didapatkan hasil bahwa nilai polarization index (PI) meningkat sebesar 1.4 dari sebelumnya 1.8 menjadi 3.2, berada diatas nilai standar yang ditetapkan oleh IEEE 43

Single-Machine Scheduling to Minimize Makespan with Deterioration Jobs and Multi-Maintenance Activities

2013 ◽  
Vol 690-693 ◽  
pp. 3007-3013
Author(s):  
Chou Jung Hsu ◽  
Hung Chi Chen
Keyword(s):  
Lower Bound ◽  
Single Machine ◽  
Machine Scheduling ◽  
Single Machine Scheduling ◽  
Initial Condition ◽  
Computational Results ◽  
Maintenance Activity ◽  
Deterioration Jobs ◽  
Deterioration Effect ◽  
Maintenance Activities

This paper explored a single-machine scheduling deterioration jobs with multi-maintenance activities. The non-resumable case and simple linear deterioration effect were taken into account as well. We assumed that after a maintenance activity, the machine will revert to its initial condition and the deterioration effect will start anew. The objective was to minimize the makespan in the system. The problem was proven to be NP-hard in the strong sense. Therefore, a heuristic and a lower bound were introduced and tested numerically. Computational results showed that the proposed algorithm performed well.

A Bicriteria Approach for Single Machine Scheduling with Resource Allocation, Learning Effect and a Deteriorating Maintenance Activity

2017 ◽  
Vol 34 (04) ◽  
pp. 1750011 ◽  
Author(s):  
Zhusong Liu ◽  
Zhenyou Wang ◽  
Yuan-Yuan Lu
Keyword(s):  
Resource Allocation ◽  
Single Machine ◽  
Learning Effect ◽  
Machine Scheduling ◽  
Single Machine Scheduling ◽  
Maintenance Activity ◽  
Optimal Resource ◽  
Deteriorating Maintenance ◽  
Polynomially Solvable ◽  
Completion Times

This paper considers the single machine scheduling with learning effect, resource allocation and deteriorating maintenance activity simultaneously. For the convex resource allocation consumption function, we provide a bicriteria analysis where the first (schedule) criterion is to minimize the total weighted sum of makespan, total completion time and total absolute differences in completion times, and the second (resource) criterion is to minimize the total weighted resource consumption. Our aim is to find the optimal resource allocations and job sequence that minimize the three different models of considering the two criterion. We show that these three models are polynomially solvable respectively.

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