• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1261-1266
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• 2008

Experimental study was performed to understand the operations of a showcase working in a discount store. Temperatures of evaporation, condenser were measured and also electric power consumption of compressor were measured. The purpose of this study is to application use of cold-heat storage systems operated the showcase. At the condition using ice storage system, the ice making process was operated during midnight being not needed the cooling of the showcase through the continuous running of the condenser unit. And then, the refrigerant was sub-cooled using stored cold-heat after being discharged from the air cooling condenser during the day time. The cooling performance was increased owing to the sub-cooling of refrigerant during day time, hence the running time of the compressor was effectively decreased. In other words, this study showed that power consumption during daytime can be transferred to the midnight for making use of the refrigerant sub-cooling. So the operating characteristics of the showcase system under various working conditions were analyzed and discussed.

• Steel and Composite Structures
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• v.29 no.5
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• pp.669-680
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• 2018

The rapidly decreasing natural resources and the global variation of the climate push us to find intelligent and efficient structural systems to provide more people with fewer resources. This paper proposed a kinematic cable-strut system to realize sustainable structures in responding to changing environmental conditions. At first, the concept of the kinematic system based on crystal-cell pyramid (CP) cable-strut unit was given. Then the deployment of the structure was studied experimentally. After that, the static behaviors in the fully deployed state under the symmetric and asymmetric load cases were investigated. Moreover, the effects of thermal loading and the initial prestress distribution were also discussed. Comparative studies between the proposed structure and other deployable cable-strut system under three times of design load cases were carried out. Finally, the robustness of the system was studied by removal of one passive cable at one time.

• Journal of the Korean Geotechnical Society
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• v.21 no.1
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• pp.93-103
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• 2005

Both static pile load test with load transfer measuring system and the pile dynamic load test are performed to estimate the skin friction and behavior characteristics of a large drilled shaft. And the numerical modeling of large drilled shaft is performed by applying the FDM program. Since the magnitude of friction resistance depends on the relative displacement between soil and shaft, load and displacement at the arbitrary depth along the large drilled shaft are estimated to analyze the correlation. According to the measuring results of load transfer, unit skin friction along the large drilled shaft was fully mobilized at gravel layer in the middle of shaft and the frictional resistance transmitted to bedrock was relatively small. Also, even for the same drilled shaft, the results of PDA and static load test are different with each other and the difference is discussed.

• Wind and Structures
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• v.18 no.6
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• pp.669-691
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• 2014

Since low-rise residential buildings are the most common and vulnerable structures in coastal areas, a reliable prediction of their performance under hurricanes is necessary. The present study focuses on developing a refined finite element model that is able to more rigorously represent the load distributions or redistributions when the building behaves as a unit or any portion is overloaded. A typical 5:12 sloped low-rise residential building is chosen as the prototype and analyzed under wind pressures measured in the wind tunnel. The structural connections, including the frame-to-frame connections and sheathing-to-frame connections, are modeled extensively to represent the critical structural details that secure the load paths for the entire building system as well as the boundary conditions provided to the building envelope. The nail withdrawal, the excessive displacement of sheathing, the nail head pull-through, the sheathing in-plane shear, and the nail load-slip are found to be responsible for the building envelope damage. The uses of the nail type with a high withdrawal capacity, a thicker sheathing panel, and an optimized nail edge distance are observed to efficiently enhance the building envelope performance based on the present numerical damage predictions.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.73-77
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• 2022

Recently, as the number of years of operation has increased for more than 30 years, interest in evaluating the remaining life of major power facilities such as transformers and ultra-high voltage cables is increasing. In particular, the risk of failure is increasing because the underground transmission XLPE cable has been built since 1980 and has been operating in excess of 30 years of design life or close proximity. Therefore, it is necessary to develop an algorithm to evaluate the residual life of the XLPE cable considering the load to determine the risk of failure. Since load data is large amount of data, it is necessary to make the variable load information equivalent to the time unit first in order to calculate the remaining life of the system quickly. In overseas literature, transformers are reported to be standardized for variable load equivalent conversion formulas, but they have not been reported for ultra-high voltage cables. Therefore, in this paper, whether the equivalent conversion formula of a transformer can be applied to XLPE cables was reviewed through accelerated degradation tests under equivalent and variable temperature conditions, and considerations were studied when evaluating the remaining operating life of XLPE cables based on the experimental results.

• Pallet News
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• s.51
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• pp.3-10
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• 2008

아시아 물류선진화를 위해서는 현대물류에 있어 가장 효율적 시스템인 유닛로드 시스템(Unit Load System ULS)의 구축과 보급 확산이 시급한 과제다. ULS는 일관파렛트화와 컨테이너화가 그 핵심이며, 일관파렛트화와 컨테이너화는 파렛트와 컨테이너의 표준화로 가능하다. 본 협회는 아시아 유닛로드시스템의 중요성과 구축방안에 대한 한 중 일 아시아 유닛로드시스템 컨퍼런스를 개최하였으며 또한 제5회 한국파렛트컨테이너산업대상 시상식을 갖고 개최하여 산업물류 혁신을 위해 표준파렛트와 컨테이너 생산 및 사용에 있어 가장 모범이 되는 우수한 업체와 이러한 활동에 헌신한 개인 또는 단체를 발굴, 시상하였다.

• Pallet News
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• s.72
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• pp.5-15
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• 2014

물류에 있어 가장 효율적 시스템인 유닛로드 시스템(Unit Load System, ULS)의 구축과 보급 확산은 국내 물류시장의 시급한 과제로 ULS는 일관파렛트화와 컨테이너화가 그 핵심이며, 일관파렛트화와 컨테이너화는 파렛트와 컨테이너의 표준화로 가능하다. 10회째를 맞이하는 한국파렛트컨테이너산업대상은 물류의 기본 핵심인 표준파렛트와 컨테이너의 생산 및 사용에 있어 가장 모범이 되는 우수한 업체와 이러한 활동에 헌신한 개인 또는 단체를 발굴, 시상함으로써 유닛로드 시스템의 보급 확산을 촉진하기 위해 제정된 국내 유일의 시상식이다. 또한 유닛로드시스텀 컨퍼런스를 통하여 국내 우수기업의 유닛로드 시스템 개선사례 및 성공사례를 발표하는 시간을 가졌다.

• Journal of the Korean Operations Research and Management Science Society
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• v.13 no.2
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• pp.34-46
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• 1988

This paper deals with design problem of unit load automated storage/retrieval systems (AS/RS). We propose an optimal design model in which the investment and maintenance costs of AS/RS, operating under dual command model is minimized over a time horizon satisfying the warehouse dimensional constraints. The model is formulated as an integer nonlinear program and an algorithm is proposed to find an optimum solution. The valididty of the solution algorithm is illustrated through an example.

• Journal of Korean Institute of Industrial Engineers
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• v.16 no.2
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• pp.23-36
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• 1990

A unit-load automated guided vehicle system is considered in which a single vehicle is operated on a unidirectional path in a closed loop. The vehicle serves a manufacturing cell moving pallets from one station to another based on the "First-Encountered-First-Serve" dispatching rule. An approximation method is developed to compute the mean waiting time of an arbitrary pallet at each station. Extensive numerical experiments, performed for various problems, yield fairly good results in most of the cases compared with those obtained by simulation method.

• Pallet News
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• s.60
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• pp.5-14
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• 2011

현대물류에 있어 가장 효율적 시스템인 유닛로드 시스템(Unit load System ULS)의 구축과 보급 확산은 국내 물류시장에 시급한 과제다. ULS는 일관파렛트화와 컨테이너화가 그 핵심이며, 일관파렛트화와 컨테이너화는 파렛트와 컨테이너의 표준화로 가능하다. 올해는 APSF 아시아 유닛로드시스템 컨퍼런스를 개최하여 APSF 회원국들 및 국내 우수기업의 유닛로드시스템 개선사례를 소개하였다. 한편, 같은 시기에 한국파렛트컨테이너산업대상을 함께 개최하여 산업 물류 혁신을 위해 표준파렛트와 컨테이너 생산 및 사용에 있어 가장 모범이 되는 우수한 업체와 이러한 활동에 헌신한 개인 또는 단체를 발굴, 시상하였다.