• 한국강구조학회 논문집
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• 제19권1호
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• pp.79-86
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• 2007

도장, 용사 및 도금 등의 강교용 방청법의 장기내구성 평가에는 대기노출실험법이 사용되고 있으나, 노화데이터를 얻기까지는 수년에서 수십 년이라는 장기간의 실험기간을 필요로 한다. 본 연구에서는 기존의 방청법을 포함하여 최근에 개발, 사용되고 있는 강교용 방청법의 장기내구성의 단기간 평가를 위한 기초단계로서 무도장 강재의 부식내구성 평가를 위한 부식환경 촉진실험법의 활용에 대해 검토하였다. 본 실험에는 일본공업규격(JIS)에 규정되어 있는 S6-cycle 부식환경 촉진실험조건을 이용하여, 30, 60, 90, 120, 150일간의 무도장 강재의 부식 중량감소량 및 두께감소량의 경시변화를 정량적으로 평가하였다. 그리고 기존의 대기노출실험과 본 실험으로부터 구한 중량감소량을 이용하여 촉진배율을 산출하고, 대기노출실험지의 지역환경구분, 해안선으로부터 거리, 아황산가스량 및 비래(飛來)염분량과의 관계를 검토하였다. 그 결과, 촉진배율을 비래염분량으로 정식화하였으며, S6-cycle 부식촉진실험결과의 대기노출환경에의 활용 가능성을 제시하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.394-399
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• 2009

Since some decades ago, there has been a concern for resource depletion and environmental pollution associated with building properties. In addressing such impact of the built environment, there is a recognition of the existence of alternative building materials, fuels for energy supply as well as technologies for waste handling and disposal. Nevertheless, for long time, the choice between such alternatives was dictated by factors such as differences in prices and aesthetic values. A new important dimension in discriminating between different options is the environmental dimension. This aspect is important since buildings are one of the spatially big new additions to the natural environment that consume a lot of materials and energy during their long lifetime. Thus, with the environmental dimension kept in mind, a existing cost estimation needs to be changed. A new cost assessment method, Life Cycle Cost, should calculate overall costs with dimensional factors: investment and utility costs as well as maintenance costs over the lifetime of the building. Aiming to give an overview of the present status of Building Life Cycle Assessment(LCA) tools as a basis for further research and development including economic performance, this paper describes and compares 3 different tools for Life Cycle Assessment(LCA) and economic analysis of the green buildings. This paper compared these approaches based on various aspects. These include economic analysis method, evaluation duration, data of results(index). Use of the comparison analysis is to produce a better picture and indicate profits and shortcomings for the tools as a group; thus providing important direction improvement of LCA tool as well as further research and development of this group of tools.

• 동력기계공학회지
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• 제18권5호
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• pp.122-128
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• 2014

Generally, the mechanical components and structures are joined by many welding techniques, and therefore the welded joints are inevitable in the construction of structures. The Alloy 617 was initially developed for high temperature applications above $800^{\circ}C$. It is often considered for use in aircraft and gas turbines, chemical manufacturing components, and power generation structures. Especially, the Alloy 617 is the primary candidate for construction of intermediate heat exchanger (IHX) on a very high temperature reactor (VHTR) system. In the present paper, the low cycle fatigue (LCF) life of Alloy 617 base metal (BM) and the gas tungsten arc welded (GTAWed) weld joints (WJ) are evaluated by using the previous experimental results under strain controlled LCF tests. The LCF tests have been performed at room temperature with total strain ranges of 0.6, 0.9, 1.2 and 1.5%. The LCF lives for the BM and WJ have been evaluated from the Coffin-Manson and strain energy based life methods. For both the BM and WJ, the LCF lives predicted by both Coffin-Manson and strain energy based life methods was found to well coincide with the experimental data.

• 한국전자통신학회논문지
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• 제10권11호
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• pp.1265-1270
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• 2015

무선 센서 네트워크에서 배터리로 동작하는 센서 노드 또는 수집 노드를 위한 에너지 효율을 개선한 MAC 프로토콜은 중요한 성능 요소이다. 본 논문에서는 무선 센서 네트워크를 위한 MAC 프로토콜에서 활성구간과 수면구간을 반복하여 수행하는 Duty Cycle 기법의 고정적인 활성 구간에 따른 제한적인 성능을 개선하기 위해 수신 예측 기반의 주기 적응적 웨이크업 제어 기법을 제안한다. 제안된 기법은 CC2500 RF 트랜시버 및 C8051F330 마이크로컨트롤러 기반의 무선 노드를 이용한 성능평가를 통해 최소의 활성구간을 분석하였고, 주기 변화에 따라 적응적으로 수면구간을 증가시켜 에너지 성능을 향상시킬 수 있음을 확인하였다.

• 시스템엔지니어링학술지
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• 제14권2호
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• pp.49-57
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• 2018

The main objective of this paper is come up with methodology approach for FPGA-based system in verification and validation lifecycle regarding software reliability using system engineering approach. The steps of both reverse engineering and re-engineering are carried out to implement an FPGA-based of safety critical system in Nuclear Power Plant. The reverse engineering methodology is applied to elicit the requirements of the system as well as gain understanding of the current life cycle and V&V activities of FPGA based-system. The re-engineering method is carried out to get a new methodology approach of software reliability, particularly Software Reliability Growth Model. For measure the software reliability of a given FPGA-based system, the following steps are executed as; requirements definition and measurement, evaluation of candidate reliability model, and the validation of the selected system. As conclusion, a new methodology approach for software reliability measurement using software reliability growth model is developed.

• 환경영향평가
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• 제21권6호
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• pp.927-939
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• 2012

Cool roofs are currently being emerged as one of important mechanism to save energy in relation to the building. Although green roof has already gained nation-wide recognition as a typical method of energy saving in the roof, this approach did not provide a realistic evidence that is economically feasible in terms of installation cost. This research is primarily intended to compare installation cost between the two techniques. This research proposes a comparative evaluation framework in a more objective and quantitative way for an installation cost between the two techniques. Kyungpook National University (KNU) was selected as a survey objective and an exhaustive and realistic comparison of installation cost between the two techniques was conducted, based on Life Cycle Cost analysis (initial investment cost, maintenance cost, dismantling and waste disposal expense). It was possible to identify that installation cost of cool roofs is 4.7 times cheaper than that of green roof. Also present value based on probabilistic approach was identified as 0.25 (4.95) higher than the installation cost on the assumption of constant price and interest. It is expected that much more installation cost for the large scale green roof will be required since small-size green roof selected as a survey objective in this study could be operated under less initial installation and maintenance condition.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.273-274
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• 2023

Although there are many old school buildings that is more than 40 years in Korea, it is difficult to rebuild all of them due to limitations in budget management. Therefore, objective feasibility evaluation criteria are necessary to determine which school buildings should be rebuilt preferentially among the numerous old school buildings. One of the rebuilding feasibility evaluation items, economic evaluation generally requires documents such as construction statements and facility drawings. However, because most buildings older than 40 years do not have these documents, an economic analysis model that requires only basic building information should be developed. In this study, the economic analysis model that can be used for evaluating the rebuilding feasibility only with the number of years, total floor area, and structural information of school buildings was established. This model can contribute to the objective feasibility evaluation of old school buildings because it can evaluate numerous buildings on the same criteria based on basic building information.

• 한국컴퓨터정보학회논문지
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• 제9권3호
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• pp.135-141
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• 2004

소프트웨어의 종류가 다양하고, 커짐에 따라서 유지 보수 문제는 더욱 복잡하고 어렵게 되고, 프로그램 에러의 교정이나 요구 사항의 변경, 사용자에 대한 요구가 점차 증가되면서 소프트웨어의 유지 보수가 소프트웨어 생명 주기에서 가장 비용을 많이 차지하는 부분이 되었다. 본 논문에서는 객체지향 시스템에서 소프트웨어 재구성 환경을 위한 역공학 도구를 설계, 구현하였다. 이 도구는 클래스 정보를 이용한 규칙기반 역공학 도구이다. 프로그램 유지보수자가 프롤로그를 이용한 시스템 쿼리를 사용할 수 있도록 하였다. 대부분의 유사한 클래스를 추출하기 위한 재구조화 방법과 변수와 함수 사이의 관계에 근거를 둔 방법을 사용하였다. 추출된 클래스의 가시성이 자동적으로 산출되고, 논리언어를 이용한 쿼리를 사용함으로서 실질적인 유지보수가 이루어지도록 하였다. 또한 이 도구를 평가하는 방법을 제안하였다.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.190-195
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• 1996

Texture-modifying and freeze-thaw stabilizing effects of different wheat gluten and modified starches on surimi based-product were evaluated. The different incorporation manners of wheat gluten and modified wheat starch in surimi gel were also examined to evaluate their effects of textural properties on surimi gel. The addition of wheat gluten reduced the gel strength of surimi, but after freeze-thaw cycle it significantly improved freeze-thaw stability by reducing freexe-thaw expressible moisture and also by preventing rubbery texture development, Gluten-1 incorporated surimi gel showed higher functionality in forming cohesive gel determined by compressive and penetration force as wall as expressible moisture after freeze-thaw cycle. Surimi gel containing modified wheat starch showed better freeze-thaw stability that of modified potato starch. When a preblended mixture of wheat gluten and starch are incorporated into surimi gel, it made gel texture significantly softer as so in high sensory score. The compertition for moisture between gluten and starch is a main reason to show different way of textural modification.

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.66-72
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• 2008

In this study, the ground source heat pump was installed at a research center in Jeju Island to verify the performance of the system and to give an information for a economic feasibility. The performance test was conducted until the heat storage tank temperature reached at $5^{\circ}C$ from $50^{\circ}C$ in the cooling operation, and until the storage temperature goes up to $50^{\circ}C$ from $10^{\circ}C$ in the heating mode. As results, the system performance shows that $2.2{\sim}3.5$ for the cooling operation and $2.5{\sim}3.5$ for heating operation. It is found that the underground is good heat source for the heat pump with $3{\sim}10^{\circ}C$ variation range. The ground source heat pump could be connected one of air conditioning system without any problem in system performance. Based on the economic analysis, the initial cost for the ground source heat pump will be compensated after 4 years operation. If the system runs 20 years, approximately 300 million Won will be saved when the air conditioning system adapt the ground source heat pump based on Life Cycle Cost analysis.