• Title/Summary/Keyword: Design Change Structure

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Case Study and Standard Process Analysis of Change Order in Design for Road Tunnel Project (터널공사 사례분석에 의한 설계변경 표준프로세스 구성방안)

  • Kang Leen-Seok;Kim Dong-Kwang;Jung Won-Myoung;Lee Seung-Ryul;Kim Hyun-Soo
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.1149-1152
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    • 2005
  • Recently, tunnel structure is being widely used in railway or roadway construction projects because earthwork causes large cutting and damages in environmental factors. However, there are many changes of design by different items comparing with design phase in tunnel structure by uncertain drawings. This study develops a standard process for the change of design to reduce change orders in construction phase.

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The Optimum Modification of Dynamic Characteristics of Stiffened Plate Structure Including the Number of Stiffener (보강재의 수를 포함한 보강판 구조물의 동특성의 최적변경)

  • 박성현;고재용
    • Journal of the Korean Institute of Navigation
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    • v.25 no.4
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    • pp.461-469
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    • 2001
  • The purpose of this paper is the optimum modification of dynamic characteristics of stiffened plate structure including the number of stiffener. This paper shows the optimum structural modification method by dynamic sensitivity analysis and quasi-least squares method and considers it's validity. In the method of the optimization, finite element method, sensitivity analysis and optimum structural modification method are used. The change of natural frequency and total weight are made to be an objective function. Thickness of plate, the number of stiffener and cross section moment of stiffener become a design variable. The dynamic characteristics of stiffened plate structure is analyzed using finite element method. Next, rate of change of dynamic characteristics by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using optimum structural modification method. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure including the number of stiffener.

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Study on the Optimum Modification and Modal Analysis of Stiffened Plate of Ship Hull Structure (신체의 Stiffened Plate 구조물의 모우드해석과 최적변경법에 관한 연구)

  • 박성현;박석주;고재용
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.10b
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    • pp.51-58
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    • 2000
  • The purpose of this study is the optimum modification of dynamic characteristics of stiffened plate structure. In the method of the optimization ,finite element method (FEM), sensitivity analysis and optimum structural modification method are used. To begin with, using FEM, the dynamic characteristics of stiffened plate structure is analyzed. Next, rate of change of dynamic characteristic by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of plate and cross section moment become a design variable. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure.

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The appearance change and heat·moisture transfer properties of knitted fabric by yarn shrinkage (원사의 수축에 따른 다공성 편성물의 형태변화와 열·수분 전달특성)

  • Sang, Jeong-Seon;Park, Juhyun;Lee, Mee-Sik;Oh, Kyung Wha
    • The Research Journal of the Costume Culture
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    • v.25 no.6
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    • pp.880-892
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    • 2017
  • In this study, the appearance change and the heat moisture transfer properties of knitted fabric by yarn shrinkage were examined to obtain useful data on the development of thermo-sensitive functional materials. Eleven types of knitted fabric were knitted using highly bulky acrylic-blended yarn. After shrinking the specimens using dry heat treatment, the appearance change and thickness were measured. An HEC simulator was adopted for measuring the heat moisture transfer properties of specimens by yarn shrinkage. When holes were arranged vertically in the mesh structure, the specimens with 2,500 and 5,000 holes showed high percent change of hole area, appearance, and thickness. When holes were diagonally arranged in the mesh structure, the percent change of hole area in the specimen with 1,250 holes was larger than the one with 2,500 holes. However, the dimensional stability of the specimen with 2,500 holes was better because of its smaller appearance and thickness change. In the tuck structure, the percent change of hole area in the specimen with 625 and 416 holes was relatively large compared with the appearance and thickness change. Furthermore, the hole size in the tuck structure was smaller than that in the mesh structure but the percent change of hole area was larger. Therefore, it was proved that the tuck structure is more suitable than the mesh structure for developing thermo-sensitive functional materials. Heat moisture transfer property test verified that the change of hole area by yarn shrinkage enabled obtaining the thermal effect due to the distinct temperature difference in the inner layer.

Propagation of Engineering Changes for Supporting Consistent Product Data View (일관된 제품자료관점을 지원하는 설계변경 전달에 관한 연구)

  • 도남철
    • Korean Journal of Computational Design and Engineering
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    • v.8 no.2
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    • pp.90-100
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    • 2003
  • Engineering change (EC) objects are the data structure and related operations that can support applications for EC procedures or processes. Their functionalities include controlling management data, specifying related product structure, and archiving a history of product structure changes for EC management. In this paper we introduce a systematic approach to support the propagation of changes between different product structure views using the history of structure changes in EC objects. The change propagations supported by EC objects enable designers to maintain the consistency of multiple product structure views for engineering, manufacturing or even customer support applications. This paper also includes EC examples and experimental implementations for the proposed EC objects.

The design load factor of road structure considering long-term coastal geographic change (해안지형의 장기적 변화에 따른 도로 구조물 설계하중 고려 요소에 관한 연구)

  • Bae, Sun-Hak;Kang, Sang Hyeok
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.1
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    • pp.75-83
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    • 2013
  • Human-induced modifications in coastal area may cause strong geomorphic responses by disturbing sediment supply, transport and deposition regimes. Morever, engineering structure have been built to stabilize coastal change, these effort impact on other morphologic change. In case of coastal area, there are lack of sediment yield data. This study focus on the tendency of long-term shoreline change, estimate method od sediment discharge which is a major factor of coastal change and adduced to way for considering design load influenced to coastal road.

A Study on the Design Change of High-Risk Temporary Structures (재해 위험도가 높은 가설구조물의 설계변경에 관한 연구)

  • Oh, T.K.;Kim, Y.G.;Lee, M.G.;Paik, S.W.;Woo, I.S.;Song, C.G.
    • Journal of the Korean Society of Safety
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    • v.29 no.1
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    • pp.37-40
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    • 2014
  • Article 29(3) of Occupational Safety And Health Act, which states a contractor can request a design change to an employer of businesses under the risk condition of construction of temporary structure, was established. Accordingly, in this study, recent fatal accidents caused by temporary structures were analyzed, and the level of inclusion of temporary structures in the design document were examined, and high risk temporary structures were classified. In addition, the requirements of design change of temporary structures were presented, and the qualifications of expert to certify the design change were proposed.

A Study on the Optimum Modification of Dynamic Characteristics of Stiffened Plate Structure of Ship (선박의 보강판 구조물의 동특성의 최적 변경법에 관한 연구)

  • 박성현;박석주;고재용
    • Journal of the Korean Institute of Navigation
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    • v.25 no.1
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    • pp.45-52
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    • 2001
  • The purpose of this study is the optimum modification of dynamic characteristics of stiffened plate structure. In the method of the optimization, finite element method(FEM), sensitivity analysis and optimum structural modification method are used. To begin with, using FEM, the dynamic characteristics of stiffened plate structure is analyzed. Next, rate of change of dynamic characteristics by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of plate and cross section moment become a design variable. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure.

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Optimizing the Exhaustion of Inventory for Design Changes: Focusing on Concrete Pump Truck Outrigger Process (설계변경 재고 소진 최적화: E사(社) 펌프카 아우트리거 공정 중심으로)

  • Chan-Woong Park
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.45 no.4
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    • pp.174-179
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    • 2022
  • Companies are making design changes by improving product quality and function to succeed while meeting customer requirements continuously. Design changes are changing the product BOM's amount, item, specification, and shape while causing a change in the product's structure. At this time, the problem of inventory exhaustion of parts before design change is a big topic. If the inventory exhaustion fails, the pieces before the design change become unused and are discarded, resulting in a decrease in asset value, and the quality cost of the design change affects the company's profits. Therefore, it is necessary to decide to minimize quality costs while minimizing waste inventory costs at the time of application of design changes. According to the analysis, priorities should be prioritized according to urgency because the quantity of items before the design change affects the applied lead time.