• Title/Summary/Keyword: scheduling management

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Integer Programming-based Operation Sequencing for Multi-operation on Single Machine (정수계획법을 통한 다중작업 수행 단일기계에서의 작업순서 결정)

  • Park, Seonyeong;Shin, Moonsoo
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.3
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    • pp.261-270
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    • 2019
  • With the advent of the Fourth Industrial Revolution, multi-variety production in the up-to-date manufacturing environment is proceeding more rapidly whereby production planning and management have been getting more complicated. Moreover, the need to improve production efficiency through effective operation sequencing is further heightened. Fundamentally, the effective operation sequencing can reduce the set-up of the equipment, efficiently utilize the equipment, shorten the set-up time, and ultimately contribute to productivity improvement. This study deals with the problem of efficient operation sequencing in a situation where a single machine performs multiple operations. The complexity of the problem is very high when compared to the case where only one operation is performed on one machine, which is covered in most existing studies. In this paper, we propose an integer programming model to minimize the number of setups. This study aims at minimizing the number of mold replacement times in the process of processing a given production order for the wiring harness manufacturing process, which is one of the components of automobile electric field. In addition, brief case studies are presented to verify the validity of the proposed mathematical model.

Design Information Management System Core Development Using Industry Foundation Classes (IFC를 이용한 설계정보관리시스템 핵심부 구축)

  • Lee Keun-hyung;Chin Sang-yoon;Kim Jae-jun
    • Korean Journal of Construction Engineering and Management
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    • v.1 no.2 s.2
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    • pp.98-107
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    • 2000
  • Increased use of computers in AEC (Architecture, Engineering and Construction) has expanded the amount of information gained from CAD (Computer Aided Design), PMIS (Project Management Information System), Structural Analysis Program, and Scheduling Program as well as making it more complex. And the productivity of AEC industry is largely dependent on well management and efficient reuse of this information. Accordingly, such trend incited much research and development on ITC (Information Technology in Construction) and CIC (Computer Integrated Construction) to be conducted. In exemplifying such effort, many researchers studied and researched on IFC (Industry Foundation Classes) since its development by IAI (International Alliance for Interoperability) for the product based information sharing. However, in spite of some valuable outputs, these researches are yet in the preliminary stage and deal mainly with conceptual ideas and trial implementations. Research on unveiling the process of the IFC application development, the core of the Design Information management system, and its applicable plan still need be done. Thus, the purpose of this paper is to determine the technologies needed for Design Information management system using IFC, and to present the key roles and the process of the IFC application development and its applicable plan. This system play a role to integrate the architectural information and the structural information into the product model and to group many each product items with various levels and aspects. To make the process model, we defined two activities, 'Product Modeling', 'Application Development', at the initial level. Then we decomposed the Application Development activity into five activities, 'IFC Schema Compile', 'Class Compile', 'Make Project Database Schema', 'Development of Product Frameworker', 'Make Project Database'. These activities are carried out by C++ Compiler, CAD, ObjectStore, ST-Developer, and ST-ObjectStore. Finally, we proposed the applicable process with six stages, '3D Modeling', 'Creation of Product Information', 'Creation and Update of Database', 'Reformation of Model's Structure with Multiple Hierarchies', 'Integration of Drawings and Specifications', and 'Creation of Quantity Information'. The IFCs, including the other classes which are going to be updated and developed newly on the construction, civil/structure, and facility management, will be used by the experts through the internet distribution technologies including CORBA and DCOM.

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Design and Implementation of XML based Global Peer-to-Peer Engine (XML기반 전역 Peer-to-Peer 엔진 설계 및 구현)

  • Kwon Tae-suk;Lee Il-su;Lee Sung-young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1B
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    • pp.73-85
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    • 2004
  • SIn this paper, we introduce our experience for designing and implementing new concept of a global XML-based Peer-to-Peer (P2P) engine to support various P2P applications, and interconnection among PC, Web and mobile computing environments. The proposed P2P engine can support to heterogeneous data exchanges and web interconnection by facilitating with the text-base XML while message exchange are necessary. It is also to provide multi-level security functions as well as to apply different types of security algorithms. The system consist of four modules; a message dispatcher to scheduling and filtering the message, a SecureNet to providing security services and data transmission, a Discovery Manager to constructing peer-to-peer networking, and a Repository Manager to processing data management including XML documents. As a feasibility test, we implement various P2P services such as chatting as a communication service, white-board as an authoring tool set during collaborative working, and a file system as a file sharing service. We also compared the proposed system to a Gnutella in order to measure performance of the systems.

Buffer Sizing Method of CCPM Technique Using Statistical Analysis (통계분석을 이용한 CCPM 기법에서의 버퍼 산정방법)

  • Liu, Jing-Chao;WhangBo, Taeg-Keun
    • The Journal of the Korea Contents Association
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    • v.12 no.8
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    • pp.29-36
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    • 2012
  • In CCPM Technique, as the buffer size calculation method, the Cut and Paste(C&P) method and the Root Square Error (RSE) method for all tasks carried out the same treatment, without considering the actual situation and characteristics of the task, the lack of reasonable judgment, is too simple and hasty. In this paper, taking into account the limitations of existing methods, a new method of buffer sizing method based on statistical analysis was introduced. It makes statistical analysis for the relationship between each worker and a variety of tasks, and use the information to predict the next task time. In order to verify the effectiveness of the new method, according to different task difficulty and the number of tasks set up the project. Use C&P, RSE method and new methods to predict the time of the project. Through Monte Carlo Simulation to simulate the project time, a comparison of three methods of performance. The results show that the new method can achieve the managers expect the probability of completion, and for those tasks can be completed ahead of schedule, the new method can save project time.

An study on selecting the restricted area of timber harvesting using Geographic Information Systems (GIS를 이용한 대채제한지(代採制限地) 선정(選定)에 관한 연구(硏究))

  • Woo, Jong-Choon;Choi, Jo-Ryong;Won, Hyun-kyu
    • Journal of Forest and Environmental Science
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    • v.16 no.1
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    • pp.119-123
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    • 2000
  • This paper studies the methods to support decision making for forest management Using GIS. Specially, most important is selecting restrict area to timber harvest suitable on scheduling its harvest in experimental forest of kangwon national university. Because timber harvesting causes water pollution, land sliding and soil erosion, it is necessary to restrict area to be harvest. The study is analyzed with Buffering modules and overlay modules which are an function of Arcinfo 7.1. As a result, restricted area is 52.64ha in total area. Of which Hardwood stand 13.21ha, pinus Pinus koraiensis stand 26.44ha, Larix leptolepis stand 12.38ha and Pinus rigida stand 0.61ha.

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Dynamic Memory Allocation for Scientific Workflows in Containers (컨테이너 환경에서의 과학 워크플로우를 위한 동적 메모리 할당)

  • Adufu, Theodora;Choi, Jieun;Kim, Yoonhee
    • Journal of KIISE
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    • v.44 no.5
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    • pp.439-448
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    • 2017
  • The workloads of large high-performance computing (HPC) scientific applications are steadily becoming "bursty" due to variable resource demands throughout their execution life-cycles. However, the over-provisioning of virtual resources for optimal performance during execution remains a key challenge in the scheduling of scientific HPC applications. While over-provisioning of virtual resources guarantees peak performance of scientific application in virtualized environments, it results in increased amounts of idle resources that are unavailable for use by other applications. Herein, we proposed a memory resource reconfiguration approach that allows the quick release of idle memory resources for new applications in OS-level virtualized systems, based on the applications resource-usage pattern profile data. We deployed a scientific workflow application in Docker, a light-weight OS-level virtualized system. In the proposed approach, memory allocation is fine-tuned to containers at each stage of the workflows execution life-cycle. Thus, overall memory resource utilization is improved.

An Efficient Caching Strategy in Data Broadcasting (데이터 방송 환경에서의 효율적인 캐슁 정책)

  • Kim, Su-Yeon;Choe, Yang-Hui
    • Journal of KIISE:Computer Systems and Theory
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    • v.26 no.12
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    • pp.1476-1484
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    • 1999
  • TV 방송 분야에서 다양한 정보와 상호 작용성을 제공하기 위해서 최근 기존 방송 내용인 A/V 스트림 외 부가정보 방송이 시도되고 있다. 데이타 방송에 대한 기존 연구는 대부분 고정된 내용의 데이타를 방송하는 환경을 가정하고 있어서 그 결과가 방송 내용의 변화가 많은 환경에 부적합하다. 본 논문에서는 데이타에 대한 접근이 반복되지 않을 가능성이 높고 사용자 접근 확률을 예상하기 어려운 상황에서 응답 시간을 개선하는 방안으로 수신 데이타를 무조건 캐쉬에 반입하고 교체가 필요한 경우 다음 방송 시각이 가장 가까운 페이지를 축출하는 사용자 단말 시스템에서의 캐슁 정책을 제안하였다. 제안된 캐쉬 관리 정책은 평균적인 캐쉬 접근 실패 비용을 줄임으로써 사용자 응답 시간을 개선하며, 서로 다른 스케줄링 기법을 사용하는 다양한 방송 제공자가 공존하는 환경에서 보편적으로 효과를 가져올 수 있다.Abstract Recently, many television broadcasters have tried to disseminate digital multimedia data in addition to the traditional content (audio-visual stream). The broadcast data need to be cached by a client system, to provide a reasonable response time for a user request. Previous studies assumed the dissemination of a fixed set of items, and the results are not suitable when broadcast items are frequently changed. In this paper, we propose a novel cache management scheme that chooses the replacement victim based on the remaining time to the next broadcast instance. The proposed scheme reduces response time, where it is hard to predict the probability distribution of user accesses. The caching policy we present here significantly reduces expected response time by minimizing expected cache miss penalty, and can be applied without difficulty to different scheduling algorithms.

Queuing Time Computation Algorithm for Sensor Data Processing in Real-time Ubiquitous Environment (실시간 유비쿼터스 환경에서 센서 데이터 처리를 위한 대기시간 산출 알고리즘)

  • Kang, Kyung-Woo;Kwon, Oh-Byung
    • Journal of Intelligence and Information Systems
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    • v.17 no.1
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    • pp.1-16
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    • 2011
  • The real-time ubiquitous environment is required to be able to process a series of sensor data within limited time. The whole sensor data processing consists of several phases : getting data out of sensor, acquiring context and responding to users. The ubiquitous computing middleware is aware of the context using the input sensor data and a series of data from database or knowledge-base, makes a decision suitable for the context and shows a response according to the decision. When the real-time ubiquitous environment gets a set of sensor data as its input, it needs to be able to estimate the delay-time of the sensor data considering the available resource and the priority of it for scheduling a series of sensor data. Also the sensor data of higher priority can stop the processing of proceeding sensor data. The research field for such a decision making is not yet vibrant. In this paper, we propose a queuing time computation algorithm for sensor data processing in real-time ubiquitous environment.

Distributed BS Transmit Power Control for Utility Maximization in Small-Cell Networks (소형 셀 환경에서 유틸리티 최대화를 위한 분산화된 방법의 기지국 전송 전력 제어)

  • Lee, Changsik;Kim, Jihwan;Kwak, Jeongho;Kim, Eunkyung;Chong, Song
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.12
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    • pp.1125-1134
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    • 2013
  • Small cells such as pico or femto cells are promising as a solution to cope with higher traffic explosion and the large number of users. However, the users within small cells are likely to suffer severe inter-cell interference (ICI) from neighboring base stations (BSs). To tackle this, several papers suggest BS transmit power on/off control algorithms which increase edge user throughput. However, these algorithms require centralized coordinator and have high computational complexity. This paper makes a contribution towards presenting fully distributed and low complex joint BS on/off control and user scheduling algorithm (FDA) by selecting on/off pattern of BSs. Throughput the extensive simulations, we verify the performance of our algorithm as follows: (i) Our FDA provides better throughput performance of cell edge users by 170% than the algorithm without the ICI management. (ii) Our FDA catches up with the performance of optimal algorithm by 88-96% in geometric average throughput and sufficiently small gap in edge user throughput.

Designing of a Global Logistics System for the ICGCPS under Considering Overseas Markets

  • Hiraki, Shusaku;Ichimura, Takaya;Ishii, Kazuyoshi
    • Industrial Engineering and Management Systems
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    • v.7 no.3
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    • pp.189-196
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    • 2008
  • This paper proposes a way of designing of a global logistics system for "the international cooperative global complementary production system" (ICGCPS) constructed in ASEAN region. ICGCPS is a global production system with several production bases located in a number of countries. In order to assemble the final products and sell them in the domestic market, each production base produces only special kinds of components and parts with the total demand required all the participating countries, and supplies them to the other production bases each other. In the ICGCPS, there are a number of important decision-making problems such as identifying which countries are suitable to produce specified components and parts, and deciding how to transport components and parts between the production bases. In the initial period of this system, each production base focused on its domestic market so that the final products it produced were sold only in the country where the base was located. Recently, some production bases have expanded sales to overseas markets. Taking this fact into account, we propose a production and transportation planning model in this paper that takes into account the export quantity of the final products, formulating it into a mathematical programming problem. Using this, we propose a way for managing the supply chain processes of the ICGCPS in order to improve performance measurements such as the total lead-time, the inventory quantity at the depot and the average rate of loading. A numerical example is presented to clarify the procedure proposed in this paper.