• Title/Summary/Keyword: Utility Work

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Sequencing the Mixed Model Assembly Line with Multiple Stations to Minimize the Total Utility Work and Idle Time

  • Kim, Yearnmin;Choi, Won-Joon
    • Industrial Engineering and Management Systems
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    • v.15 no.1
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    • pp.1-10
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    • 2016
  • This paper presents a fast sequencing algorithm for a mixed model assembly line with multiple workstations which minimize the total utility work and idle time. We compare the proposed algorithms with another heuristic, the Tsai-based heuristic, for a sequencing problem that minimizes the total utility works. Numerical experiments are used to evaluate the performance and effectiveness of the proposed algorithm. The Tsai-based heuristic performs best in terms of utility work, but the fast sequencing algorithm performs well for both utility work and idle time. However, the computational complexity of the fast sequencing algorithm is O (KN) while the Tsai-based algorithm is O (KNlogN). Actual computational time of the fast sequencing heuristic is 2-6 times faster than that of the Tsai-based heuristic.

Sequencing to Minimize the Total Utility Work in Car Assembly Lines (자동차 조립라인에서 총 가외작업을 최소로 하는 투입순서 결정)

  • 현철주
    • Journal of the Korea Safety Management & Science
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    • v.5 no.1
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    • pp.69-82
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    • 2003
  • The sequence which minimizes overall utility work in car assembly lines reduces the cycle time, the number of utility workers, and the risk of conveyor stopping. This study suggests mathematical formulation of the sequencing problem to minimize overall utility work, and present a genetic algorithm which can provide a near optimal solution in real time. To apply a genetic algorithm to the sequencing problem in car assembly lines, the representation, selection methods, and genetic parameters are studied. Experiments are carried out to compare selection methods such as roullette wheel selection, tournament selection and ranking selection. Experimental results show that ranking selection method outperforms the others in solution quality, whereas tournament selection provides the best performance in computation time.

Antioxidant Activity of Some Yogurt Starter Cultures

  • Kim, H.S.;Chae, H.S.;Jeong, S.G.;Ham, J.S.;Im, S.K.;Ahn, C.N.;Lee, J.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.2
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    • pp.255-258
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    • 2005
  • Several commercial yogurt starter cultures (L. acidophilus LA5, L. casei 01, L. acidophilus LA100, L. bulgaricus LB207 and L. rhamnosus GG744) were investigated for antioxidant activity by using in vitro assays. From the results of the present work, all strains tested showed varying degrees of antioxidant activity. L. bulgaricus LB207 showed the highest antioxidant activity, with a linoleic acid peroxidation inhibition of 81.3%. Hydroxy radical scavenging activity, ferrous iron chelating activity, reducing power and superoxide dismutase (SOD) activity were also studied. L. bulgaricus LB207 showed the highest hydroxy radical scavenging activity and L. casei 01 showed the highest chelating activity. L. bulgaricus LB207 and L. acidophilus LA100 showed good reducing power. All the strains in this study showed low SOD activity. The results of the present work suggest that antioxidant activity of L. bulgaricus LB207 due to its strong hydroxy radical scavenging activity and reducing power.

Utility Bounds of Joint Congestion and Medium Access Control for CSMA based Wireless Networks

  • Wang, Tao;Yao, Zheng;Zhang, Baoxian;Li, Cheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.1
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    • pp.193-214
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    • 2017
  • In this paper, we study the problem of network utility maximization in a CSMA based multi-hop wireless network. Existing work in this aspect typically adopted continuous time Markov model for performance modelling, which fails to consider the channel conflict impact in actual CSMA networks. To maximize the utility of a CSMA based wireless network with channel conflict, in this paper, we first model its weighted network capacity (i.e., network capacity weighted by link queue length) and then propose a distributed link scheduling algorithm, called CSMA based Maximal-Weight Scheduling (C-MWS), to maximize the weighted network capacity. We derive the upper and lower bounds of network utility based on C-MWS. The derived bounds can help us to tune the C-MWS parameters for C-MWS to work in a distributed wireless network. Simulation results show that the joint optimization based on C-MWS can achieve near-optimal network utility when appropriate algorithm parameters are chosen and also show that the derived utility upper bound is very tight.

A study on students′ utility cognition of Home Economics course (가정과 교육내용의 유용성 인지에 관한 연구 -중학교 ‘가족과 일의 이해’ 단원을 중심으로 -)

  • 지금수;이진숙
    • Journal of Korean Home Economics Education Association
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    • v.14 no.3
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    • pp.77-88
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    • 2002
  • This study was designed to examine students' utility cognition and related variables on the ‘understanding of family and work’ in the Home Economics course. The subjects were 503 middle and high school students, and university students in Jeonju city. The results are as follows : 1) The level of utility cognition on the ‘attitude of sexuality’ was found to be relatively high in the Home Economics course. 2) There were gender difference in the evaluation of learning environment. and grade differences in the evaluation of learning environment, participation in class of Home Economics, needs for Home Economics, evaluation of learning environment. 3) The utility cognition of Home Economics course significantly differed by gender, participation in class of Home Economics. needs for Home Economics, evaluation of learning environment. and Perception of Home Economics. 4) The needs for Home Economics emerged as the most important variable in the utility cognition of Home Economics course.

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Implementation of MPEG-21 DIA Utility Software for Stereoscopic Video Adaptation

  • Kwon Hyukmin;Kim Manbae
    • Journal of Broadcast Engineering
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    • v.10 no.2
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    • pp.139-148
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    • 2005
  • This paper presents recent works of the development of MPEG-21 DIA utility software as one of MPEG-21 activities. The main purpose of this work is to make integrated utility software for DIA C/C++ modules in a Java framework. To do this, JNI plays a role of the interface of a main module with C/C++ DIA adaptation modules. Furthermore, DIA and DID parsers are integrated to the utility software. Our software is designed such that all DIA modules are easily integrated. A variety of adaptation modules have been adopted in MPEG-21 standard. Among them, stereoscopic video conversion that is one of DIA adaptation modules is chosen and we show that our utility software is correctly implemented based on experiments.

A Study on Automatic Switch Control System for Systematic Control and History Management of Underground Utility Tunnel Work (지하공동구의 체계적인 통제 및 이력관리를 위한 자동개폐시스템에 대한 연구)

  • Oh, Am-suk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.6
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    • pp.1443-1448
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    • 2015
  • Most of access control systems for underground utility tunnel work through wired network between central system and the automatic switch control unit. However, there are several issues regarding the absence of network infrastructure and an outdoor reader in a relatively unique environment. To solve these issues we propose an authenticated key based smart phone control system for secure access to the underground utility tunnel and this scheme is anticipated providing us with crucial information about a systemic entrance history and effective management procedures of utility tunnel. In addition, the proposed scheme enables to access to secured control system in smart phone based bluetooth network and it provides information about systemic control and history management for the switch controls through smart phone applications.

Evaluation of Nursing Outcomes among Advanced Practice Nurses in a Tertiary Hospital (분야별 전문간호사의 전문간호업무에 대한 성과 평가: 일개 병원을 중심으로)

  • Seol, Miee;Yi, Myoung Sun
    • Journal of Korean Critical Care Nursing
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    • v.5 no.2
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    • pp.37-48
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    • 2012
  • Purpose: The purpose of the study was to evaluate how advanced practice nurses (APNs) recognized their work by analyzing nursing outcomes. The ultimate goal was to examine the utility of APNs by connecting their work to the outcomes. Methods: Cross-sectional survey was conducted to collect the data from 59 APNs in a tertiary hospital lovated in Seoul, Korea. The questionnaire with 84 outcome indicators for advanced practice nurses was used. Descriptive statistics were used to analyze the data. Results: Among 84 outcome indicators, 11 indicators were associated with the work of APNs. Majority of these findings were included in the categories of clinical results and satisfaction. Items identified to be associated with the work of APNs were different among oncology nursing area, surgical speciality area, emergency care area, and critical care area. Conclusion: The results of the study indicated that the works of APNs were relevant to education/counseling/training and interpersonal relationship with other health professionals. The results of the study could be helpful to delineate the work characteristics of APNs and increase the utility of APNs in Korea where roles of APNs are not yet clearly delineated in most clinical settings.

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Use-Utility of Kitchen Center and Cooking Equipments - Comparison between U.S.A. and Korea - (주방의 조리 공간 및 조리 기구의 사용자-만족도 측정 - 한.미 비교를 중심으로 -)

  • Chung, Young-Sook;Park, Young-Sun
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.6
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    • pp.1039-1048
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    • 2009
  • The purpose of this study was to establish a model of the use-utility of cooking equipments and kitchen centers using survey data and to compare U.S.A. with Korea. The survey was conducted to identify attributes that were related to the efficiency of kitchen centers as well as equipments. Indices for the most important attributes were developed and used to compare different selections of equipment. The impact of adding an equipment item was found to vary with the attributes of the item, the degree of importance ascribed to the attributes of the work center and specific functions performed there. Similarities and differences between the U.S.A. and Korea are discussed, and implications for those who have interest in the use-utility model of cooking equipment and kitchen centers are provided.

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Development of Decision Model and Management System to minimize Pavement Utility Cut for Road Facility (도로시설 재굴착 방지를 위한 의사결정모델 및 관리시스템 개발)

  • Cho, Jin-Young;Jang, Oun-Sung;Lee, Min-Jae
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.4
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    • pp.164-171
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    • 2013
  • In urban planning, road facility is used not only for the transportation purpose but also for the utility line space purpose such as electrical, gas, tele communication, heating, water, sewer, and so on. However, since these utilities are built by many different groups, it becomes very difficult to communicate each other. Delay in one party can cause another party's schedule delay but they don't commuicate often. Also, some delay in utility work can cause frequent pavement cut. And, this will impact on construction cost, schedule delay, low quality, user complain and cost. This study developed spatiotemporal decision model to prevent prequent utility cut for mega project such as new urban development project. In addition, this study developed utility cut management system to manage utility cut schedule under pavement. Finally, developed system was applied to new urban development project and verified there effectiveness.