• Journal of Electrical Engineering and Technology
• /
• 제9권4호
• /
• pp.1188-1195
• /
• 2014

This paper presents an analytical technique for reliability evaluation of electrical distribution network (EDN) containing distributed generation (DG). Based on hierarchical levels of circuit breaker controlling zones and feeder sections, a directed-relation-graph (DRG) for an END is formed to describe the hierarchical structure of the EDN. The reliability indices of EDN and load points can be evaluated directly using the formed DRG, and the reliability evaluation of an EDN containing DGs can also be done without re-forming the DRG. The proposed technique incorporates multi-state models of photovoltaic and diesel generations, as well as weather factors. The IEEE-RBTS Bus 6 EDN is used to validate the proposed technique; and a practical campus EDN containing DG was also analyzed using the proposed technique.

• 대한기계학회논문집
• /
• 제19권5호
• /
• pp.1202-1210
• /
• 1995

Aiming at nondestructive evaluation of defect with high accuracy and resolution, ICFPD(Induced Current Focusing Potential Drop) technique was newly developed. This technique can be applied for locating and sizing of defects in components with not only simple shape such as plain surface but also more complex shape and geometry such as curved surface and dissimilar joing. This paper describes the principle of ICFPD technique and also the results of 2-dimensional surface crack in ferromagnetic metal(A508 Cl. III steel) and paramagnetic metal (pure aluminum and stainless 304 steel) measured by this technique. Results are that surface defects in each specimen are detected with the difference of potential drop, and potential drops are distributed a similar shape for each metal and each depth. The normalized potential drop ( $V_{\delta}$2/$^{t}$ / $V_{{\delta} 2}$$^{-1}$) max. in the vicinity of defect is varied with the depth of defect. Therefore, ICFPD technique can be used for the evaluation of defect not only in ferromagnetic metal but also in paramagnetic steel..

• 한국습지학회지
• /
• 제17권3호
• /
• pp.209-220
• /
• 2015

본 연구에서는 기존의 물리적 하천교란 평가방법을 개선하고 적용성을 분석하였다. 개선한 교란평가 기법은 정성적 항목을 정량적인 항목으로 제시하고 이의 근거와 평가 산정식을 제시하였고, 이에 상응하는 평가영역 내 점수를 보다 세분화 하고 수리특성과 지형 변화를 수치모의에 의한 결과를 이용할 수 있도록 개선하였다. 개선된 교란평가방법은 적용성을 확인하기 위해 비정비하천, 도시관류하천, 산지계류하천의 특성을 가지는 6개의 하천에 적용하여 기존의 평가방법과 개선된 평가방법의 결과를 비교 분석하였다. 하상서식환경과 하상재료를 제외한 8가지 평가항목은 HEC-RAS 수치모의 결과를 직접 입력하여 간편하게 수행할 수 있었다. 또한 정량적 평가방법의 적용 결과 기존의 평가방법보다 민감한 평가 결과를 나타냈으나, 전반적으로 기존의 평가방법과 비슷한 결과를 나타내어 적용성이 있음을 확인하였다.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제18권2호
• /
• pp.161-172
• /
• 2018

Purpose: Test & Evaluation items are main contents which verify performance of the development system and they are deduced going through project management system stages. However, there is no systematic or standardized framework for Test & Evaluation items, so a lot of differences occur between projects and people are questioning whether verification items are selected for the optimization of the development system. In this regard, this research proposes the process of deducing Test & Evaluation items in a systematic way during a development stage by applying QFD (Quality Function Deployment) technique which reflects customers' requirements. Methods: Test & Evaluation items are recognized as customers' requirements, and QFD technique which refines and gathers various requirements of customers effectively during general products' development stage is applied to complete HOQ (House of Quality) Conclusion: There is no specific methodology for Test & Evaluation items, so currently, they are selected by including items which are given by similar projects or higher authorities. However, by utilizing QFD technique, selection of evaluation items which goes through more systematic process is expected to be possible.

• 한국생산제조학회지
• /
• 제5권4호
• /
• pp.38-46
• /
• 1996

This paper discusses the feasibility of Ultrasonic Nondestructive Evaluation (UNDE) technique for sport weld quality. Ultrasonic c-scan image assisted by image processing technique was used for Nondestructive Evaluation(NDE) of spot weld quality. Ultrasonic testing results obtained were confirmed and compared by Optical Microscope and SAM(Scanning Acoustic Mircroscope) observation of the spot-weld cross section, The results show that the nugget dinameter can be successfully measured with the accuracy of 0.5mm. It was ascertained that ultrasonic c-scan technique is very effective method for the sake of the approach to the quantitative measurement of nugget diameter and the discrimination of the corona bond from nugget. Additional support for the above conclusions is provided by the results for galvanized steel. The ultrasonic results for galvanized welds generally correspond to the results for uncoated steel. Finally, it was found that the above-mentioned technique can be sufficiently applied to NDE method for securing the Quality Assurance(QA) of spot welded products in production line.

• 품질경영학회지
• /
• 제27권3호
• /
• pp.94-112
• /
• 1999

It is booming to use computer and information owing to the information society. As software applications have grown, so too has the importance of software quality. Therefore, software quality measurement and evaluation are necessary to satisfy the users who are using computers. The ISO/IEC 9126 defines six quality characteristics and twenty-one subcharacteristics including forty inter quality characteristics. We developed software measurement and evaluation technique using the check list in accordance with the ISO/IEC 9126 in design phase. We applied idea and concept of Total Quality Management in order to evaluate and measure the quality of software. Namely, it is the concept such as "you should do it right the first time." or "you have to build quality in the process." We executed the quantitative evaluation of software, also had shown the distinctive result in order that users and developers can find the errors easily. We evaluated the quality of academic softwares in order to verify developing technique at S college. As a result of the evaluation, this college has found it necessary to maintain the software as soon as possible because academic systems are not adequate for users at this present time.

• 정보과학회지
• /
• 제5권2호
• /
• pp.41-48
• /
• 1987

어느 기관이 컴퓨터 씨스템을 처음 도입하고자 할때, 어떤 씨스템이 그 기관의 고유 업무를 수행하는데 가장 적합한지를 결정하는 일은 무엇보다도 중요 하다. 이와 같은 씨스템 능력 측정의 주요한 목적은 임대료와 컴퓨터 씨스템 구 성이 비슷한 경우 능력 측정을 하고자 하는 기관 고유 업무의 각 기종에 대한 상 대적인 thruput을 알아 보는데 있다.

• 한국환경복원기술학회지
• /
• 제17권6호
• /
• pp.1-15
• /
• 2014

A dredging on erosion control dam has been enforced without evaluation the factors that affect the dredging. In addition, there is the negative effect much more than positive effect by dredging on erosion control dam. Therefore, this study was carried out to develop evaluation indicators and to suggest fieldbook in order to determine whether sand deposits at erosion control dam should be dredged up or not. The most important six evaluation indicators that can decide to dredge up at erosion control dam were obtained from three round delphi technique and were selected in the following order: the current sand deposit ratio(0.339), existence of cultivated land and house downstream(0.276), the slope of streambed(0.162), the amount of movable soil and gravel(0.118), the history of any disasters(0.063), the basin area(0.043). The weighted score for each evaluation indicator were acquired from AHP analysis with respect to the degree of importance and then the modified weighted score for actual measurements were classified as three categories: large(2.53), medium(1.60) and small(1.01). Based on delphi technique, erosion control dam dredging evaluation fieldbook introduced the four evaluation indicators out of the total six evaluation indicators and two low effected evaluation indicators were excluded. This results showed that the values for reliability analysis and consistency ratio were acceptable.

• International Journal of Advanced Culture Technology
• /
• 제8권1호
• /
• pp.113-119
• /
• 2020

Development of forest garden for city dwellers utilizing green space within urban area is nowadays highly regarded as a means to invigorate city and to raise living standard for city dwellers. Thus, development of forest garden has become pressing and important agenda for city governments. Promoting forest garden to solve many environmental and social issues city governments face today requires evaluation criteria to determine whether target green space is suitable to serve as forest garden. In this respect, we believe that evaluation of values of forest garden from previous studies can serve as foundation for developing evaluation index for forest garden. Thus, we aimed to develop evaluation criteria for values of forest garden. First, various evaluation criteria collected from previous studies were assessed by expert groups. Then, the result was studied through AHP technique and we developed evaluation criteria for forest garden based on such result. Especially, evaluation criteria were divided into main and sub-levels for more detailed and precise evaluation system.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1995년도 추계학술대회 논문집
• /
• pp.1005-1008
• /
• 1995

The spindle is a very important part of machine tool. The evaluation of spindle motion is required for improving the performance of machine tools. The evaluation tools have been developed for precison spindle by the reversal technique, and 3D error map motion of spindle is proposed. This technique makes us understand the total movement of spindle more easily. The proposed technique has been successfully applied to practical machine tools, giving high potentials for the spindle performance measurement.