• Title/Summary/Keyword: Rework

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A Study on Security Measure of Step-Wise Project (단계별 프로젝트 보안 방안에 대한 연구)

  • Shin, Seong-Yoon;Jang, Dai-Hyun;Kim, Hyeong-Jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.11
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    • pp.2459-2464
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    • 2012
  • Many companies has led to the damage case being leaked to personal information by taking cyber attack. Also, planned hacking cases continues to increase for the purpose of acquiring monetary gain or causing social disruption induction, etc. Approximately 75% of the Web site attacks exploit the vulnerability of the application. Major security issue is to strengthen the S/W development security according to the legal basis. The members of the project team is the fact that the lack of recognition of application development security. In addition, passive response and security validation/testing, etc. throughout the SDLC to the entire area is insufficient. Therefore, rework due to the belated discovery of a defect has occurs. In this paper, we examine the case of the project step-by-step security activities by performing IT services companies. And, through this, we present security measures that can be applied to the step-wise real-world projects.

Impacts of Contract types on Construction Project Performance - Cost Reimbursable and Lump Sum - (계약방식에 따른 건설프로젝트 성과의 비교분석 연구 - 실비정산방식과 총액계약방식을 중심으로 -)

  • Lee, Yoo-Seob;Hwang, Bon-Gang
    • Korean Journal of Construction Engineering and Management
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    • v.8 no.2
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    • pp.155-163
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    • 2007
  • Multiple parties-owners, engineering and construction contractors, and suppliers involve the delivery process of capital facility projects in the construction industry, and each party obtains or provides their workforce, material, equipment, or service tied into specific contracts. Considering that construction projects are based on the contracted relationship between the parties and that contract types are one of the significant factors determining project success. it is critical for project stakeholder to select appropriate contract types for successful deliveries of projects. With these considerations, this paper assesses impacts of different contract types on project cost, schedule, safety, change, or rework. Analyzing data from real construction projects, the differences in project performance between two contract types, Cost Reimbursable and Lump Sum are measured and statistically tested to investigate if the differences are significant. For this analysis, performance metrics developed by Benchmarking and Metrics program, the Construction Industry Institute are used.

DEVELOPMENT OF BUILDING INFORMATION MODEL FOR RESOURCES OPTIMIZATION IN CONSTRUCTION PROJECT

  • Gopal M. Naik;Rokhsareh Badamahgan
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.634-639
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    • 2013
  • The aim of the study is to develop the 3D visualization of Building Information Model and integrated 4D model for optimization of resources in the construction project. This study discuss the process of methodology and creation of 4D model of the project and simulate it to monitor the workflow at the site. Different stages of the construction process and activities are generated by using Revit and MS Project. MS project has been used for creation of the schedules and these are linked with the Revit for 3D modeling. The time used as the fourth dimension and 4D model created by using Navisworks Time liner software. Narges shopping center is presented as a case study to realize the actual uses and benefits of Building Information Model (BIM). Narges shopping mall is located in Tehran, Iran. As a part of Hekmat master plan, Narges shopping center is an 11 stores building with a total area of 30000 Sq.m. This shopping and entertainment center is comprised of 150 retails and two multi-use public halls with a capacity of 400 persons each and underground parking with total 400 parking space. The main purpose of architecture was to create an urban public center along with its revolving, spiral like form and an ever changing continuous façade by means of different colors, materials, which is in harmony with the other building of the master plan. The approximate cost of the project is $17 million and duration of the project schedule is 30 months. The developed Building Information Model enabled us to identify the potential collisions or clashes between various structural and architectural systems. 4D model has been used for limiting the interaction between subcontractors installing the different systems so rework could be avoided and productivity maximized. It is also observed that the utility of BIM for construction stimulation and clash detection is the best suitable method. Clash detection before the implementation of work is highly recommended to avoid rework.

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Minimization of Inspection Cost in an Inspection System Using a Time-based Flow Analysis

  • Yang, Moon-Hee;Kim, Sun-Uk
    • Journal of Korean Institute of Industrial Engineers
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    • v.35 no.3
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    • pp.194-202
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    • 2009
  • In this paper, we address an optimization problem and a case study for minimizing the cost of inspections incurred throughout an inspection system, which includes a K-stage inspection system, a source inspection shop, and a re-inspection shop. In order to formulate the inspection cost function, we make a time-based flow analysis between nodes (or shops), and derive the limiting sizes of flows between nodes and limiting defective rates by solving a set of nonlinear balance equations. It turns out that the number of items reworked throughout the inspection system is invariant irrespective of the defective rate of items moved through the K-stage inspection system. Hence we define the inspection cost as the total number of items inspected, and we provide an enumeration method for determining an optimal value of K which minimizes the number of items inspected.

A Design of the Intelligent Motor Control Center Using the Graphic Editor (그래픽 에디터를 이용한 지능형 전동기 제어반 설계)

  • Lee, Sung-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.55 no.3
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    • pp.128-132
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    • 2006
  • The previous MCCs(Motor Control Centers) have the demerits of high cost and much manhour for rework because it is impossible for us to standardize the previous MCCs and they have many manual connections. The customers require the products which can operate with the SCADA system by digitalizing the functions of the current MCCs and the systematized products with capability of remote control. To solve these disadvantages and requirements, we developed the Intelligent Motor Control Center. This system has the various functions such as protection, measuring, and communication. Using these functions, we can monitor motor status through communication with the upper system and define the circuit for lowering connection costs according tn starting type and shortening the manufactural period by the graphic editor. The development of this system results in establishment of the competitive structure with domestic area and Perfect automatic monitoring through linkage with the SCADA system.

Determination of Target Value under Automatic Vision Inspection Systems (자동시각검사환경하에서 공정 목표치의 설정)

  • 서순근;이성재
    • Journal of Korean Society for Quality Management
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    • v.29 no.3
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    • pp.66-78
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    • 2001
  • This paper deals with problem of determining process target value under automated visual inspection(AVI) system. Three independent error sources - digitizing error, illumination error, and positional error - which have a close relationship with the performance of the AVI system, are considered. Assuming that digitizing error is uniformly or normally distributed and illumination and positional errors are normally distributed, respectively, the distribution function for the error of measured lengths is derived when the length of a product is measured by the AVI system. Then, Optimal target values under two error models of AVI system are obtained by minimizing the total expected cost function which consists of give away, rework and penalty cost. To validate two process setting models, AVI system for drinks filling process is made up and test results are discussed.

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An integrated production-inventory model with rework and inspection in serial production system (재가공과 검사를 고려한 통합 생산-재고 모형)

  • Kim, Seong-Tae;Kim, Jae-Ryeon
    • Journal of Korean Society for Quality Management
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    • v.17 no.2
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    • pp.158-167
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    • 1989
  • In this paper, a model is presented which incoporates the possibility of quality control at each of the production stages. We consider the TYPE I error and the TYPE II error in inspection procedures. In addition to alternative quality control configurations, the model integrates the carrying costs of in-process and finished inventory, quality of production process, reprocessing including fixed and variable cost. Our policy determines the value of optimal lot-size and reprocessing batch size in reducing the total costs. A numerical example illustrates the model framework and highlights the role of the decision variables.

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The Optimization of LCD Color Filter Coating Method

  • Cho, Moon-Chul;Bae, Dong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.177-177
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    • 2009
  • We examine the process to enhance the productivity of the thin-film transistor-addressed liquid-crystal display (TFT LCD) panels with the objective of optimizing the relation between the Type of color PR dispense nozzle and the amount of dispensing of color PR consumption, directly affecting a spectroscopic analysis. Most manufacturers of the panels have been utilizing a spin-type coater. We show that we successfully optimize the spectral values by controlling the color PR dispense type(Static dispense or Dynamic dispense) and the amount of color PR. From this study, we accomplished to decrease 43% in color PR consumption and to decrease 30% in color PR Stained, to decrease 30% rework rate.

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Comparative Analysis of Rework Policies in Multistage Production System (다단계 생산시스템에서 재작업 정책의 비교분석)

  • Sin, Jae-Seon;Han, Ju-Yun;Jeong, Bong-Ju
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.707-714
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    • 2005
  • 최근 개별 제품의 가격이 상승하고 품질의 중요성이 강조됨에 따라, 생산현장에서 제품의 불량을 검사하고, 불량품을 즉시 재작업하는 공정이 많아지고 있다. 따라서 본 연구에서는 불량품의 재작업 과정을 고려하여 생산라인에서 비용을 최소화 하는 최적 배치사이즈와 재작업 정책을 결정하는 모델을 제안하였다. 제안된 모델은 다수의 기계가 연속적으로 연결된 다단계생산시스템을 가정하고 있으며, 검사 공정의 위치 변화에 따른 두 가지 재작업 정책과 두 정책으로부터 변형된 정책을 반영할 수 있다. 제안된 모델을 통해 생산 환경에 따라 비용을 최소화하는 재작업 정책과 최적의 생산 배치사이즈를 결정할 수 있으며, 생산 환경요인들의 변화에 따른 배치사이즈와 비용의 변화를 정책 별로 비교 분석할 수 있다.

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Economic Selection of Specification Limits for a Given Target Value (공정평균(工程平均)의 목표치(目標値)가 주어진 경우 규격한계(規格限界)의 경제적(經濟的) 선정(選定))

  • Riew, Moon-Charn
    • Journal of Korean Institute of Industrial Engineers
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    • v.15 no.2
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    • pp.57-64
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    • 1989
  • An Economic selection of specification limits is considered for a given target value in a complete inspection plan. Each item is inspected, and if it meets the specification, it is accepted. Items less than the lower specification limit are scrapped or sold at a reduced price, and those greater than the upper specification limit are reworked. Cost factors to be considered are economic loss caused by quality deviations, rework cost and scrapping cost. Methods for finding the optimal specification limits are given for the cases of piecewise linear loss function and quadratic loss function with illustrative examples.

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