• Title/Summary/Keyword: Performance Evaluations

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A Study of Dry-Wall Performance Evaluation - An Alternative to Korean Traditional Mud Walling - (전통주택 흙벽을 대신할 수 있는 건식벽체 성능평가에 관한 연구)

  • Hwang, Yong-Woon
    • Journal of the Korean housing association
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    • v.22 no.6
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    • pp.61-69
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    • 2011
  • Korea's traditional house type, the Hanok, has been the essence of Korean domestic culture for hundreds of years. However, Hanok, have begun to disappear as result of urbanization. Because mud walls are crude and weak in water walls are also easily broken by impact. There are further problems in that construction cost is expensive and takes more time than modern house construction, and that the maintenance of Hanok is more difficult than people sometimes predict. Despite much interest in Hanok construction, there is a lack of in younger generation. Thus seeking new ways of maintaining Korea's traditional housing culture and extending Korean traditional houses is important. This study proposes directions for creating new residential environments for the future generation of Korea. A Dry-wall alternative to the Korean traditional mud wall is particularly needed. Dry-walling, made by sustainable materials such as mud board and wood, can strengthen the advantages and make up for the weaknesses of the Korea traditional mud wall. In this study, both wall types underwent various evaluations in terms of their performance in insulation testing, freezing and thawing testing, impacting testing and weight measuring (the size of material in this experiment was $69cm{\times}105cm$). On all of these tests, findings revealed that the dry-wall alternative performed better than traditional mud wall.

Change of stochastic properties of MEMS structure in terms of dimensional variations using function approximation moment method (함수 근사 모멘트 기법을 활용한 치수 분포에 따른 MEMS 구조물의 통계적 특성치 변화에 관한 연구)

  • Huh J.S.;Kwak B.M.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.602-606
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    • 2005
  • A systematic procedure of probability analysis for general distributions is developed based on the first four moments estimated from polynomial interpolation of the system response function and the Pearson system. The function approximation is based on a specially selected experimental region for accuracy and the number of function evaluations is taken equal to that of the unknown coefficient for efficiency. For this purpose, three error-minimizing conditions are proposed and corresponding canonical experimental regions are formed for popular probability. This approach is applied to study the stochastic properties of the performance functions of a MEMS structure, which has quite large fabrication errors compared to other structures. Especially, the vibratory micro-gyroscope is studied using the statistical moments and probability density function (PDF) of the performance function to be the difference between resonant frequencies corresponding to sensing and driving mode. The results show that it is very sensitive to the fabrication errors and that the types of PDF of each variable also affect the stochastic properties of the performance function although they have same the mean and variance.

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A Study on RFID Cell Planning Schemes for Indoor Location-awareness (실내 위치 인식을 고려한 RFID 기반 셀 구성 방안에 관한 연구)

  • Kim, Taehoon;Tak, Sungwoo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.9
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    • pp.2191-2198
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    • 2013
  • This paper proposes a RFID cell planning scheme for indoor location-awareness. We theoretically develop four objective functions that yield objective goals significant to the optimal design of a RFID cell topology and simulation is conducted to evaluate the performance of the proposed RFID cell planning scheme. We also evaluate the performance of the proposed technique after practically installing RFID readers in an indoor space to configure a RFID cell topology. Performance evaluations are conducted in terms of the following objective goals: minimal number of RFID readers for configuring a RFID cell topology, maximal RFID cell coverage areas for indoor location-awareness, minimal overlapping cells, and maximal indoor location-awareness accuracy.

Performance Evaluations of the Computer Networks for the Voice/Data Coexisted Network Design (음성/데이터 통합망 설계를 위한 이행 단계별 성능평가)

  • Eom, Ki-Bok;Yoe, Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.4
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    • pp.678-683
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    • 2003
  • This study presents a result of performance with the design of network topology for voice and data integration under computer network. This network is consisted of FastEthernet, other LANs and ATM WAN(wide area network), and performance evaluation of delay in a PBX+IP network, delay in a VoIP network and delay in a IP+ATM network will be shown. We use parameters including network bandwidth, number of packet, routing protocol(IGRP, OSPF). We simulate integrated of voice and data used PBX. we will study further about the case of integrated of voice and data environments using PBX. and, evaluate IP+ATM WAN average measured network delay and average delay of VoIP network.

Analysis and Design considerations of Energy Absorbing Steering System Using Orthogonal Arrays (직교배열표를 이용한 에너지흡수 조향계의 해석 및 설계)

  • 임재문;한선규;전원기;우덕현;박경진
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.6
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    • pp.144-155
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    • 1999
  • An occupant analysis code SAFE (Safety Analysis For occupant crash Environment) is utilized to simulate and improve the crash performance of an energy absorbing steering system. The safety standard FMVSS 203 is simulated and used for design evaluations . Segments and contact elliposids are utilized to model the bod blocks and the components of the steering system with SAFE. Spring-damper elements and force-deflection characteristics are utilized to model the energy absorbing components such as the plate and the polyacetal molding. The plate absorbs the impact energy through tensile deformation . Whereas, the polyacetal molding absorbs the impact energy through compression. the body block test is carried out to validate tie simulation model, and real component tests are performed to extract the force-deflection curves . After the model is validated , the parameter study is carried out to evaluate the crash performance of the energy absorbing components. A performance measure is defined for the parameter study. Using the results of the parameter study and managing the orthogonal arrays, optimum design values of energy absorbing components are determined to minize the occupant injury.

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Thermal effect on dynamic performance of high-speed maglev train/guideway system

  • Zhang, Long;Huang, JingYu
    • Structural Engineering and Mechanics
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    • v.68 no.4
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    • pp.459-473
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    • 2018
  • Temperature fields and temperature deformations induced by time-varying solar radiation, shadow, and heat exchange are of great importance for the ride safety and quality of the maglev system. Accurate evaluations of their effects on the dynamic performances are necessary to avoid unexpected loss of service performance. This paper presents a numerical approach to determine temperature effects on the maglev train/guideway interaction system. Heat flux density and heat transfer coefficient of different components of a 25 m simply supported concrete guideway on Shanghai High-speed Maglev Commercial Operation Line is calculated, and an appropriate section mesh is used to consider the time-varying shadow on guideway surfaces. Based on the heat-stress coupled technology, temperature distributions and deformation fields of the guideway are then computed via Finite Element method. Combining guideway irregularities and thermal deformations as the external excitations, a numerical maglev train/guideway interaction model is proposed to analyze the temperature effect. The responses comparison including and excluding temperature effect indicates that the temperature deformation plays an important role in amplifying the response of a running maglev, and the parameter analysis results suggest that climatic and environmental factors significantly affect the temperature effects on the coupled maglev system.

TSM Strategies and Evaluation of Traffic Performance - Special Reference to a Case Study of Reversible Lane Technique. (TSM전략과 효율측정-일례연구를 중심으로)

  • 도철웅
    • Journal of Korean Society of Transportation
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    • v.4 no.1
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    • pp.3-11
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    • 1986
  • One important element of a systematic approach to the management and control of the flow of people over an urban street network is the monitoring and evaluation of system performance. The nature of TSM strategies that, in part, differentiates them from traditional long-range transportation improvement alternatives is that they are less costly, are more quickly implemented and modified, and are often oriented toward sub-area problems which must be addressed at a more microscopic level of analysis. These factors suggest that pre-implementation evaluations of alternative TSM actions will often have to rely on quick-turn around, manual methods of analysis to guide the choice of which management action should be implemented. This paper was prepared to focus on the definition and importance of TSM, specifically associated with monitoring and evaluating traffic performance in the context of TSM startegies. A simple case study of reversible lane technique was presented. The purposes of the case study is to illustrate the methodology of evaluating TSM strategies and demonstrate to identify the benefit from the reversible lane technique, which may otherwise be overlooked in real world. Applying the reversible lane technique to Sam-Il elevate highway, it was found to be a very promising low cost alternative to reduce total travel time(or delay) and fuel consumption.

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Development of Concrete Material Models for Performance-Based Design Code (성능기반 설계기준 작성을 위한 콘크리트 재료모델의 개발)

  • Kim, Jee-Sang;Lee, Kwang-Myung;Choi, Yeon-Wang;Jung, Sang-Hwa;Moon, Jae-Heum
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.975-978
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    • 2008
  • To strengthen the technological competitiveness of the construction market in Korea, researches have been performed to replace the prescriptive design codes (PD) to the performance-based ones (PBD). As one of the basic requirements for PBDs, development of the optimized concrete material models for domestic applications have been tried by comparing and verifying the pre-existing models with the observations and quality evaluations of ready mixed concretes that are used in the domestic market. This paper shows the summary of the present state of the research progress in the areas of compressive strength and elastic modulus.

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Performance Evaluations of Mock-up Tests for ALC Panel Curtain Wall in Building Exterior (ALC 패널을 활용한 건축물 외장 커튼월에 대한 Mock-up Test 성능 평가 연구)

  • Kim, Young-Ho;Lee, Yong-Soo
    • Journal of The Korean Digital Architecture Interior Association
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    • v.13 no.4
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    • pp.25-32
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    • 2013
  • The green building is one of biggest factors to go the goal of energy saving and environmental conservation, reduction of energy consumption, friendly energy technology, recycling of resource, and environmental pollution reduction technology. The purpose of these green buildings realized by the energy-saving technology such as the exterior materials or curtain wall system. The curtain wall system is a element that come to insulated portions of building envelope that results in heat loss. The purpose of this paper is to carried out mock-up tests for exterior wall used in autoclaved lightweight concrete panels in green building practices. Mock-up test execute a mixed process between standard test procedure and complex test procedure based on AAMA 501(American Society for Testing and Materials) and ASTM 283, ASTM 330(American Society for Testing and Materials). In results, tests meet the requirements that grant values in steps of procedures provided on ASTM and AAMA. ALC panel is suitable for a exterior wall product to be gratified thermal cycling performance and structural capacity, deflection(H/200) and lateral displacement(H/50), for curtain walls.

Performance Analysis of the XMESH Topology for the Massively Parallel Computer Architecture (대규모 병렬컴퓨터를 위한 교차메쉬구조 및 그의 성능해석)

  • 김종진;최흥문
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.5
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    • pp.720-729
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    • 1995
  • We proposed a XMESH(crossed-mesh) topology as a suitable interconnection for the massively parallel computer architectures, and presented performance analysis of the proposed interconnection topology. Horizontally, the XMESH has the same links as those of the toroidal mesh(TMESH) or toroid, but vertically, it has diagonal cross links instead of the vertical links. It reveals desirable interconnection characteristics for the massively parallel computers as the number of nodes increases, while retaining the same structural advantages of the TMESH such as the symmetric structure, periodic placement of subsystems, and constant degree, which are highly recommended features for VLSI/WSI implementations. Furthermore, n*k XMESH can be easily expanded without increasing the diameter as long as n.leq.k.leq.n+4. Analytical performance evaluations show that the XMESH has a shorter diameter, a shorter mean internode distance, and a higher message completion rate than the TMESH or the diagonal mesh(DMESH). To confirm these results, an optimal self-routing algorithm for the proposed topology is developed and is used to simulate the average delay, the maximum delay, and the throughput in the presence of contention. In all cases, the XMESH is shown to outperform the TMESH and the DMESH regardless of the communication load conditions or the number of nodes of the networks, and can provide an attractive alternative to those networks in implementing massively parallel computers.

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