• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 춘계학술논문 발표대회
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• pp.147-150
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• 2007

As recent buildings often use low-quality concrete materials, are constructed defectively, and are put in extreme environmental conditions, many of them show the shortening of life resulting from the corrosion of reinforcing rods by salt damage, carbonization, freezing and thawing, cracking. This in turn raises the cost of repair and maintenance, so it is required to extend the life of structures through enhancing the durability of concrete. In response to the demand, researches on high-durability concrete are being made actively focused on the maximum water-cement ratio, the maximum unit quantity, the minimum cover thickness, the addition of mineral admixtures, etc. With this background, the present study examined the basic physical properties of concrete containing admixtures for enhancing the durability of concrete.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권12호
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• pp.527-531
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• 2005

Because of increasing demand for safety of the power transformer, the seismic qualification process in accordance with the standard of IEEE Std 693-1997 is essentially required by customer. Dynamic analysis method and static analysis method were used to qualify the seismic withstanding of the power transformer at high seismic level. Maximum stress was detected at the connection between the main structure and appendages, and maximum displacement was detected at the point of appendage's end tip. Load path and substructure system can be considered as important elements to prevent over stress and over displacement.

• 전기학회논문지
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• 제59권7호
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• pp.1187-1193
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• 2010

This paper provides the methods for enhancing the stability with normal or emergency operating conditions in real power systems and copes with the unbalance of demand of reactive power due to the loss of facility, such as 765kV transmission line. In this paper, we focused on the maximum allowable transmission power(hereafter, MAXTP) in the metropolitan area. In order to increase the MAXTP, the application of reactive power compensators, SVC, and Shunt compensator and reactor, is analyzed as an enhancing method of stability and MAXTP. Particularly, the f-V analysis was performed for the postulated contingency, in order to evaluate the effects on SVC. Conclusively, the stability of power systems could be enhanced and the MAXTP is increased effectively with Dongseoul SVC which has the capacity 200MVAr.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.254-259
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• 2006

It is increased electrical energy consumption with the development of intelligence society in the subway station and thus an energy conservation through efficient use of electricity became more important. This paper shows a reasonable design load density in subway stations, that was made by the systematic and statistical way considering actual conditions, such as investigated electric equipment capacity, peak power consumption, demand factor, etc., for 34 subway stations and 10 electrical design offices. In this dissertation, it is necessary to analyse the key features and general trend from the investigated data. It made an analysis of the feature parameters, such as average, standard deviation, median, maximum, maximum and thus it was carried linear and nonlinear regression analysis.

• 한국산학기술학회논문지
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• 제14권3호
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• pp.1011-1015
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• 2013

최근 친환경 이동수단으로 자전거 수요가 증가하고 있으나, 국내 생산기반은 전무한 실정이다. 본 연구에서는 경량 마그네슘 소재로 대중교통기관과 연계가능한 신개념 자전거로 제안된 모델에 대해 수평프레임과 수직프레임 설계 해석을 수행하였다. 연구결과, 주조용 마그네슘 합금을 사용하는 도심형 자전거의 주요 프레임에 대한 구조해석을 실시하여 150kg 수직하중시 최대응력이 70 MPa이하를 나타내는 설계기술을 확보하였다.

• 한국시뮬레이션학회논문지
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• 제10권3호
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• pp.71-82
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• 2001

Considering material handling delay which occurs between storage and processing stations, we propose an algorithm to estimate the required storage capacity, i.e., number of aisles and number of openings in vertical and horizontal directions in each aisle, of an automated storage/retrieval(AS/R) system. Due to the random nature of storage and retrieval requests, proportion of single and dual commands is not known in advance. Two design criteria, maximum permissible overflow probability and maximum allowable storage/retrieval(S/R) machine utilization, are used to compute the storage capacity. Most of studies assume that storage capacity of AS/R systems is given, although it is a very important decision variable in the design phase. Therefore, the proposed model can be effectively used in the design phase of new AS/R systems.

• 한국산업융합학회 논문집
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• 제22권4호
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• pp.395-403
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• 2019

The excessive need of power is creating an unbalance situation in power sector, where solar energy is one of the best solutions among other energy sources to mitigate this demand. It is globally accepted because of its flexibility and long life compared to others. A lot research is going on to enhance the energy efficiency by introducing photovoltaic (PV) power generation technology, but still irradiation of PV power is the major problem. In this manuscript, we have designed PV module using single diode methodology and also the solar conversion efficiency was boosted with maximum power point tracking (MPPT) by using perturb and observe (P&O) algorithm. The simulation was done for $1000W/m^2$ and $800W/m^2$ at solar irradiance in cell temperature of 25C and 40C degree levels in PSIM tool.

• 조명전기설비학회논문지
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• 제19권3호
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• pp.111-118
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• 2005

사무소용 빌딩과 같은 전력다소비 건물에서는 전력의 효율적 이용에 의한 에너지절감을 위해서 설계 단계부터 합리적인 전기설비 설계가 요청되고 있다. 본 연구에서는 사무소용 빌딩을 중심으로 부하종류별 전력소비특성을 조사 분석하였고, 전기설계사무소의 설계단계에서 적용하는 수용률값을 조사하였다. 조사된 자료의 전체 특징과 중심적인 경향을 알아보기 위해서 평균값, 표준편차, 최대값, 최소값, 중앙값 등의 특징파라메터를 분석하였고, 회귀분석을 통한 선형적인 방법과 비선형적인 방법으로 그 경향을 확인하였다. 그 결과 합성 수용률/부등률 평균값은 $46.4[\%]$로 나타나 전력용변압기는 용량에 있어서 많은 여유를 가지고 있는 것으로 나타났다. 이를 토대로 변전설비 용량의 합리적인 설계를 위하여 부하종별 수용률 기준(안)을 제시하였고, 변전설비용량 산정에 필요한 자료를 데이터 베이스화하였다.

• 조명전기설비학회논문지
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• 제21권6호
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• pp.77-84
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• 2007

병원용 건물과 같은 전력다소비 건물에서는 전력의 효율적 이용에 의한 에너지절감을 위해서 설계 단계부터 합리적인 전기설비 설계가 요청되고 있다. 본 연구에서는 병원용 건물 32개소를 선정하여 부하종류별 전력소비특성을 조사 분석하였고, 9개소의 전기설계사무소로부터 설계단계에서 적용하는 수용률값을 조사하였다. 조사된 자료의 전체 특징과 중심적인 경향을 알아 보기 위해서 평균값, 표준편차, 최대값, 최소값, 중앙값 등의 특징파라메터를 분석하였고, 회귀분석을 통한 선형적인 방법과 비선형적인 방법으로 그 경향을 확인하였다. 그 결과 합성 수용률 평균값은 47.5[%]이었으며, 전력용변압기는 용량에 있어서 많은 여유를 가지고 있는 것으로 나타났다. 이를 토대로 변전 설비용량의 합리적인 설계를 위하여 부하종별 수용률 기준(안)을 제시하였고, 변전설비용량 산정에 필요한 자료를 데이터베이스화하였다.

• Structural Engineering and Mechanics
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• 제78권3호
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• pp.351-368
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• 2021

This paper, by applying a reliability-based framework, develops seismic vulnerability macrozonation maps for Tehran, the capital and one of the most earthquake-vulnerable city of Iran. Seismic performance assessment of 3-, 4- and 5-story steel moment resisting frames (SMRFs), designed according to ASCE/SEI 41-17 and Iranian Code of Practice for Seismic Resistant Design of Buildings (2800 Standard), is investigated in terms of overall maximum inter-story drift ratio (MIDR) and unit repair cost ratio which is hereafter known as "damage ratio". To this end, Tehran city is first meshed into a network of 66 points to numerically locate low- to mid-rise SMRFs. Active faults around Tehran are next modeled explicitly. Two different combination of faults, based on available seismological data, are then developed to explore the impact of choosing a proper seismic scenario. In addition, soil effect is exclusively addressed. After building analytical models, reliability methods in combination with structure-specific probabilistic models are applied to predict demand and damage ratio of structures in a cost-effective paradigm. Due to capability of proposed methodology incorporating both aleatory and epistemic uncertainties explicitly, this framework which is centered on the regional demand and damage ratio estimation via structure-specific characteristics can efficiently pave the way for decision makers to find the most vulnerable area in a regional scale. This technical basis can also be adapted to any other structures which the demand and/or damage ratio prediction models are developed.