• Title/Summary/Keyword: construction mechanism

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Application of Parameters-Free Adaptive Clonal Selection in Optimization of Construction Site Utilization Planning

  • Wang, Xi;Deshpande, Abhijeet S.;Dadi, Gabriel B.
    • Journal of Construction Engineering and Project Management
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    • v.7 no.2
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    • pp.1-10
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    • 2017
  • The Clonal Selection Algorithm (CSA) is an algorithm inspired by the human immune system mechanism. In CSA, several parameters needs to be optimized by large amount of sensitivity analysis for the optimal results. They limit the accuracy of the results due to the uncertainty and subjectivity. Adaptive Clonal Selection (ACS), a modified version of CSA, is developed as an algorithm without controls by pre-defined parameters in terms of selection process and mutation strength. In this paper, we discuss the ACS in detail and present its implementation in construction site utilization planning (CSUP). When applied to a developed model published in research literature, it proves that the ACS are capable of searching the optimal layout of temporary facilities on construction site based on the result of objective function, especially when the parameterization process is considered. Although the ACS still needs some improvements, obtaining a promising result when working on a same case study computed by Genetic Algorithm and Electimze algorithm prove its potential in solving more complex construction optimization problems in the future.

DEVELOPMENT OF A FRONT END PLANNING TOOL FOR SUSTAINABILITY

  • Sang-Hoon Lee;Spencer Howard;Lingguang Song;Kyungrai Kim
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.506-513
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    • 2009
  • The Construction Industry Institute (CII) developed the Project Definition Rating Index (PDRI), as a part of their Front End Planning best practices, which helps project managers assess and measure project scope definition risk elements. U.S. Green Building Council are seeing the benefits of sustainable building and Leadership in Energy and Environmental Design certification by positively impacting life cycle costs, building marketability, and organizational productivity. However, there have been no efforts to integrate these two planning tools in construction industry. By applying a supplemental tool which combines the PDRI with the LEED rating system, construction industry can develop and implement a tailored instrument that leads to total project success in sustainability. The objective of this research is to assemble a new front end planning mechanism for green buildings by incorporating the current PDRI and LEED systems.

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DEVELOPMENT PROCESS OF INFORMATION FLOW RETRIEVAL SYSTEM FOR LARGE-SCALE CONSTRUCTION PROJECTS

  • Jinho Shin;Hyun-soo Lee ;Moonseo Park;Jung-ho Yu;Jungseok Kim
    • International conference on construction engineering and project management
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    • 2011.02a
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    • pp.556-560
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    • 2011
  • Players of construction projects proceed with each work process by information gathering, modification and communication. Due to the complex and long-span lifecycle projects increased, it became more important to grasp this mechanism for the successful project performance in construction project. Hence, most project information management systems or knowledge management systems equip information retrieval system. There are two logic to infer the meaning of retrieval target; inductive reasoning and deductive reasoning. The former is based on metadata explaining the target and the later is based on relation between data. To infer the information flow, it is necessary to define the correlation between players and work processes. However, most established information retrieval systems are based on index search system and it is not focused on correlation between data but data itself. Thus, this research aims to research on process of information flow retrieval system for large-scale construction projects.

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Production Mechanism of Residual Stress Generated by Multi-Pass Welding of the steel Pipe (강관 적층용접부 잔류응력의 생성기구)

  • Chang, Kyong Ho;Yang, Sung Chul;Kang, Jae Hoon
    • Journal of Korean Society of Steel Construction
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    • v.13 no.4
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    • pp.327-335
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    • 2001
  • The characteristics and production mechanism of residual stress generated by multi-pass welding of the steel pipe were elucidated from the results of three-dimensional thermal elastic-plastic FEM analysis. When the steel pipe was jointed by multi-pass welding, the stress components of circumferential direction and radial direction near welded joints on the inner surface and the outer surface of the pope were tensile. The stress component of axial direction on the inner surface was tensile and on the outer surface was compressive. On the other hands, the production mechanism of residual stress generated by multi-pass welding of the steel pipe was investigated. Residual stress generated by welding of the steel pipe was investigated not only by the thermal history but also by geometrical shape. Then, the generality of the production mechanism of residual stress generated by multi-pass welding was confirmed.

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Personal Broadcasting System Using mOBCP-based Overlay Multicast Tree Construction Method (개인 방송 시스템을 위한 mOBCP 기반의 오버레이 멀티캐스트 트리 구성 방안)

  • Nam, Ji-Seung;Kang, Mi-Young;Jeon, Jin-Han;Son, Seung-Chul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.8B
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    • pp.539-546
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    • 2007
  • For better performance and to avoid member service annoyance that results due to joining-clients' waiting durations and time-outs when there are more than one client wanting to join concurrently for Personal Broadcasting System service, there is a need for improving concurrent member joining mechanism. For a more efficient and better performing, this paper apply Overlay Multicast based mini-Overlay Broadcasting Control Protocol(mOBCP) Algorithm on Personal Broadcasting System. mOBCP proposed is performance-effective mechanism, since it considers the case of how fast will children, concurrently, find and join new parents when paths to existing parents are in Failure. The performance comparison, in terms of tree construction time variation and Latency are done through simulations and the results conclude in favour of the Proposed mOBCP.

Non-linear Analysis of Full Scaled CFT Column to H-Beam Connections with T-Stiffeners (T 스티프너를 이용한 CFT기둥-H 형강보 실대형 접합부의 비선형 해석)

  • Lee, Seung Woo;Kim, Young Joo;Shin, Kyung Jae;Oh, Young Suk;Moon, Tae Sup
    • Journal of Korean Society of Steel Construction
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    • v.14 no.6
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    • pp.835-843
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    • 2002
  • The goal of this paper is to understand the stress-transfer mechanism of concrete-filled tubular column to H-beam connection with external T stiffener through the elasto-plastic finite element method and to offer basic data for the design of T stiffener. For the accuracy, analysis results are compared with experimental results. It makes use of several stress and strain indices to understand the stress-transfer mechanism of connection. An alternative plan that decreases the stress concentration of beam flange to horizontal stiffener connection is proposed through the elasto-plastic finite element method.

Design Case Study of Permanent Excavation Wall Using Soil Nailing System (쏘일네일링 공법을 적용한 영구 지하굴착 벽체의 설계사례 연구)

  • Park, Si-Sam;Lee, Je-Man;Yoo, Chan-Ho;Kim, Hong-Taek
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.10a
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    • pp.84-91
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    • 2005
  • In case of soil nailing system, there have been many attempts to expand into slope and temporary earth retaining system stabilization method since the first ground excavation earth retaining system construction in 1993. Recently, jointing wall, underground wall of buildings and excavation earth retaining wall, construction were increasingly applied for effective utilization of the limited underground space and land application maximized. However, the application of joining wall into retaining wall or building by temporary soil nailing system and design of permanent wall were performed by using Rankine earth pressure theory without considering the distribution of earth pressure in the soil nailing. In this study was performed to introduce the design case by 'Two-Body Translation mechanism (TBTM)' to be able to consider distribution of earth pressure in the soil nailing when designing the permanent jointing wall using soil nailing system for effective utilization of ground space. Also, this study attempts to evaluate the earth pressure change, decreasing effect of wall displacement and increasing effect of stability when advanced soil nailing system is constructed using $FLAC^{2D}$ ${\nu}er.$ 3.30 program and 'Two-Body Translation mechanism'.

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A study on the Properties for Structural Behavior of High-Performance Concrete Filled Square Steel Tube Columns -The Behavior Properties by Loading Conditions- (고성능 콘크리트를 충전한 각형강관 기둥의 구조적 거동 특성에 관한 연구 -재하조건별 거동특성-)

  • Park, Jung Min;Lee, Sung Jo;Kim, Wha Jung
    • Journal of Korean Society of Steel Construction
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    • v.10 no.2 s.35
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    • pp.177-186
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    • 1998
  • The concrete filled steel tubular column have to superior in compressive load carrying capacity, compared with same section typed hollow steel tube column, and have many excellent structural properties, such as stiffness improvement by filled concrete, improvement of ductility by reinforced effect of local buckling, and the like. However, it has not clear the effect of interaction between steel tube and filled concrete, stress portion ratio and fracture mechanism of concrete. This study investigated to structural properties for high strength concrete filled steel tube column by loading conditions through a series of experiments. Especially, this study investigated the properties of structural behaviors for concrete filled steel tube column stress ratio by loading conditions and failure mechanism of filled concrete.

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Analysis of Temperature Reduction and Reflection Spectrum of Steel Plate according to Differential Thermal Mechanism of Solar Heat Paint (태양열 차단 도료의 차열 메카니즘에 따른 강판재의 온도저감 및 반사스펙트럼 분석)

  • Mun, Dong-Hwan;Lee, Kwang-Soo;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.37-38
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    • 2017
  • In Infrared rays, which are 50% of sunlight, act as heat rays to heat buildings. Solar heat paint is widely used to protect buildings from sunlight. Solar heat coatings are used to block buildings form sunlight. Solar heat paints are classified as heat-reflective paints and heat-insulating paints according to the differential thermal mechanism. In this study, we study the thermal differential mechanism by analyzing the temperature change of the coated steel plate and the solar reflection spectrum on the surface. In this experiment, exposed steel plate, heat-reflective coated steel plate, heat-insulating coated steel plate, and general paint coated steel plate were used. As a result, when the infrared rays of 780nm ~ 1400nm were irradiated, the heat reflective paint had a temperature lower by 10 degrees than other paints. Analysis of the reflection spectrum of the paint shows that the heat paint is lower in heat than other paints because it has higher reflectance of light and absorbs much of the infrared rays.

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Simplified Failure Mechanism for the Prediction of Tunnel Crown and Excavation Front Displacements

  • Moghaddam, Rozbeh B.;Kim, Mintae
    • Magazine of korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.101-112
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    • 2019
  • This case study presented a simplified failure mechanism approach used as a preliminary deformation prediction for the Mexico City's metro system expansion. Because of the Mexico City's difficult subsoils, Line 12 project was considered one of the most challenging projects in Mexico. Mexico City's subsurface conditions can be described as a multilayered stratigraphy changing from soft high plastic clays to dense to very dense cemented sands. The Line 12 trajectory crossed all three main geotechnical Zones in Mexico City. Starting from to west of the City, Line 12 was projected to pass through very dense cemented sands corresponding to the Foothills zone changing to the Transition zone and finalizing in the Lake zone. Due to the change in the subsurface conditions, different constructions methods were implemented including the use of TBM (Tunnel Boring Machine), the NATM (New Austrian Tunneling Method), and cut-and-cover using braced Diaphragm walls for the underground section of the project. Preliminary crown and excavation front deformations were determined using a simplified failure mechanism prior to performing finite element modeling and analysis. Results showed corresponding deformations for the crown and the excavation front to be 3.5cm (1.4in) and 6cm (2.4in), respectively. Considering the complexity of Mexico City's difficult subsoil formation, construction method selection becomes a challenge to overcome. The use of a preliminary results in order to have a notion of possible deformations prior to advanced modeling and analysis could be beneficial and helpful to select possible construction procedures.