• Title/Summary/Keyword: construction mechanism

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Investment Decisions for Clean Development Mechanism under Uncertain Energy Policies using Real Option

  • Taeil Park;Changyoon Kim;Hyoungkwan Kim
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.107-110
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    • 2013
  • Recently, Korea parliament legislated the Low Carbon Green Growth Act (April, 2012) and approved a bill (May, 2012) to start carbon emission trading system in 2015. It means that for the first time, government would regulate the amounts of carbon emission in private entities, and private entities should attain predefined emission reduction goals by implementing clean development mechanism (CDM) project or buy the Certified Emission Reductions (CERs) from the trading market to avoid penalty. Under these circumstances, it is not easy for them to determine when or how to implement the CDM project because the governmental energy policies about the level of governmental subsidies, periods for free emission allocation, etc. are still under discussion and the future price of the CERs is quite uncertain. Thus, this study presents a real-option based model to assess the financial viability of the CDM project which switches bunker-C oil to liquefied natural gas (LNG). The proposed model is expected to assist private entities in establishing the investment strategy for CDM project under uncertain government energy policies.

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Research on three-point bending fatigue life and damage mechanism of aluminum foam sandwich panel

  • Wei Xiao;Huihui Wang;Xuding Song
    • Steel and Composite Structures
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    • v.51 no.1
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    • pp.53-61
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    • 2024
  • Aluminum foams sandwich panel (AFSP) has been used in engineering field, where cyclic loading is used in most of the applications. In this paper, the fatigue life of AFSP prepared by the bonding method was investigated through a three-point bending test. The mathematical statistics method was used to analyze the influence of different plate thicknesses and core densities on the bending fatigue life. The macroscopic fatigue failure modes and damage mechanisms were observed by scanning electron microscopy (SEM). The results indicate that panel thickness and core layer density have a significant influence on the bending fatigue life of AFSP and their dispersion. The damage mechanism of fatigue failure to cells in aluminum foam is that the initial fatigue crack begins the cell wall, the thinnest position of the cell wall or the intersection of the cell wall and the cell ridge, where stress concentrations are more likely to occur. The fatigue failure of aluminum foam core usually starts from the semi-closed unit of the lower layer, and the fatigue crack propagates layer by layer along the direction of the maximum shear stress. The results can provide a reference for the practical engineering design and application of AFSP.

An Theoretical study on Spalling Mechanism of Concrete (콘크리트 폭렬발생 메카니즘에 관한 이론적 고찰)

  • Kim, Hyung-Jun;Kim, Heung-Youl;Kim, Gyeong-Ok
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.422-427
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    • 2008
  • The major cause of Concrete Spalling at high temperatures can be divided into the Vapor Pressure Rising, caused by the increase in free water temperature within the concrete, and Pore Pressure Rising induced by the vapor moving into dense pores within the concrete. Although the occurrence of spalling within concrete caused by these pressure increases can be assessed experimentally, a close examination into Mechanistic influence against various spalling factors shall be carried out first by using Mathematical Modeling and Theoretical Equations. The Spalling Prospect Process by theoretical mechanism is expedited in order of the following; selection of heating condition (fire strength and flame heating direction), a selection of constituent elements, an analysis of heat transmission, an analysis of moisture movement, distribution of water content, an analysis of pore/vapor pressure, and assessment of spalling occurrence.

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A Study on Load Transfer between Soil and Nail Using In-situ Pull-out Tests (현장인발시험을 통한 흙-네일의 하중 전이특성에 대한 연구)

  • Kim, Jong-Soo;Yi, Chang-Tok;Min, Kyong-Jun;Lee, Song
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.167-174
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    • 1999
  • A Land slide in Granitic Gneiss weathered soil was stabilized successfully with soil nailing using 929mm steel bar. To understand the behavior of load transfer between soil and nail, in-situ pdl-out tests were carried out. The strains of steel bars were measured using strain gauges during pull-out tests. Forces-strain data from laboratory tension tests on steel bar and grouted steel bar were examined to compare with those of the pull-out tests. Comparisons were made between the pull-out test results and laboratory test result to understand load transfer mechanism.

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Development of Modeling and control Methods for Multi-DOF dielectric polymer actuator

  • Jung, M.Y.;Jung, K.M.;Koo, J.C.;Choi, H.R.;Nam, J.D.;Lee, Y.K.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1225-1228
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    • 2004
  • Principles and mechanism of energy transduction of dielectric polymer materials are well known from the various smart material related publications. However their introduction to industrial actuator applications is limited mainly due to difficulties guarantee controllability and reliability. Most of the previous publications have elaborates energy transduction physics of chunk of polymer while development of construction methods for feasible actuators made of the material is rarely proposed. In the present article, a conceptual design of multi-DOF linear polymer actuator construction that is to be controllable with moderate level of control work os introduced. In addition, numerical models that are developed with a unified energy based approach are presented not only for basic working mechanism analysis of the polymetric soft actuator but for providing analytical foundation to expend the concept toward design of multi-DOF actuator controls.

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Compatibility-Guaranteeing Software Component Evolution based on Composition Rules (안정적 확장이 보장되는 소프트웨어를 위한 정형적 조합 법칙)

  • Lee, Sunae;Lee, Joon-Sang;Bae, Doo-Hwan
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.04c
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    • pp.10-12
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    • 2003
  • Since building large-scale software is usually bi9 burden to most developers, it has been an important issue for many researchers. In this paper, we suggest a mechanism that can be used to support such large-scale development. Through composition rules via subtyping within Statecharts, incremental construction of software can be achieved. Among the composition rules (i.e. delegation rule and mixin rule), we mainly focus on the delegation rule in our work. Not only we can check the subtype property. but also can verify the behavior compatibility of composite results that are available by composition rules. This new mechanism is helpful for analysts as well as designers, and it can be used as a guideline for incremental and compatible construction of component based software.

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A Study on the Creation of Slope Instability Map Using Geographic Information Systems. (GIS를 이용한 사면위험도 작성기법 연구)

  • 유명환
    • Economic and Environmental Geology
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    • v.33 no.2
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    • pp.129-138
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    • 2000
  • The various types of geohazards like landslides resulted from civil construction (i.e. highway construction) must of analysed considering all the possible influential factor systematically. Thus, by using GIS, slope stability can be evaluated, and it can be used as a data for further detailed investigation. So the aim of this study is to present a data for decision making in selecting suitable point for remediation. For analysing slope instability, through appropriate definition and classification, landslide mechanism must be understood. In building GIS model, the selection of appropriate factors and their rating system should be made. For this, the characteristics and the mechanism of landslide have to be understood. And suitable coverage should be chosen for the model considering the slope conditions. In this study, field investigation in lst and 2nd Section, Chung-ang highway was carried out. From the field data, GIS model on slope instability was created. 5 coverages were used for it. From the result of this study, 12 unstable sections were found out and more detailed investigation is needed there.

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A Study on the Security Vulnerabilities and Defense Mechanism for SET-based Electronic Commerce (SET기반 전자상거래의 보안위협요소 분석 및 대응 방안에 관한 연구)

  • 김상균;강성호
    • The Journal of Society for e-Business Studies
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    • v.4 no.2
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    • pp.59-79
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    • 1999
  • In order to construct a successful electronic commerce system, three main essential factors must be satisfied to obtain the best effective outcomes. The three main essential factors are as follows : economic factor, effectiveness factor and convenient factor. In order to understand the role of these three factors, one must have some insight knowledge about security to assist him to implement these three factors in his construction of an electronic commerce system. This paper analyses a implementation mechanism of security systems based on the SET 1.0 standard for electronic commerce systems, thus providing an effective plan for the construction of a security system in the SET-based electronic commerce field. This paper helps to analyse the elements of security vulnerabilities in the SET 1.0 standard implementation and also helps to understand the SET 1.0 protocol.

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Development of Gondola-type Building Management Robot Platform and Mechanism for Moving/Tasking on Building Outer-wall (곤돌라형 외벽 유지관리 로봇의 이동/작업 메커니즘 및 플랫폼 개발)

  • Ham, Young-Bog;Park, Soung Jea
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.4
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    • pp.375-382
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    • 2013
  • Down through the years, human needs and desires have required a robot system to work at hazardous environments instead. Current painting task is costly and laborious, and it exposes workers to significant health and safety risks. Automation system offers potential improvement in this area and is especially well suited to the outer-wall painting tasks in concrete structures. This paper introduces the result of gondola-type building management robot(G-BMR) platform and mechanism for moving/tasking on building outer-wall for the outer-wall painting. Its technical and economic feasibility are conducted, and it is concluded that developing G-BMR is physically and economically feasible in this research. And we discuss about the future of G-BMR and automation in construction field.

Clamping force control of injection molding machine using 2-way cartridge valve based logic circuit (2-방향 카트리지 밸브 기반 로직회로에 의한 사출성형기의 형체력 제어)

  • Cho, Seung Ho
    • Journal of Drive and Control
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    • v.13 no.2
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    • pp.51-58
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    • 2016
  • The present study deals with the issue of clamping force control of an injection molding machine using 2-way cartridge valve based logic circuit. The operating principle for the cartridge valve is described with its construction and static opening behavior. Basic module circuits are designed first and analysed according to the basic functions. Then they are combined with a virtual design model for the clamping mechanism to simulate the control performance of the overall system. The backlash inherent in the mechanism is considered while evaluating the time-delay in the process of clamping force build-up. The effects of a couple of design parameters in backlash, i.e., interval and stiffness have been demonstrated in the time-domain.