• 조명전기설비학회논문지
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• 제21권9호
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• pp.87-94
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• 2007

This paper presents new criteria for DGA(Dissolved Gases Analysis) using CDF(Cumulative Distribution Function) obtained from the data from the diagnosis of transformers operated in KEPCO over a period of 16 years. Because of differences in operating environments, construction type, oil volume, and other factors, the interpretative criteria of DGA at KEPCO differs from other standards such as IEC-60599, or Rogers and Doernenburg. To suggest the most appropriate criteria, the DGA data from transformers under normal conditions as well as from developing fault transformers were collected. Using these data, this study suggests the limitative gas level of transformers under normal operating conditions and verifies the suitability of the criteria. Because the application of this new criterion to transformers at KEPCO increases the detectable ratio of incipient faults and reduces unnecessary follow-up sampling and analysis, the new criteria yields a more reliable prediction of transformer condition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1096-1098
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• 2003

In this paper, the control algorithm and control methods for a combined system of shunt passive filter and series active filter in 3-phase 4-wire system are discussed. Moreover, the 3-phase 4-wire system is widely employed in distributing electric energy to several office building and manufacturing plants. In such systems, the third harmonic and odd multiples of $3^{rd}$($9^{th}$, $15^{th}$, etc.) are termed as triple and zero sequence components that do not cancel each other in the system neutral. As a result, the triple harmonics add together creating a primary source of excessive neutral current. Regarding this concern, this paper presents a new control scheme for a series hybrid active system. This series active power filter acts not only as a harmonic compensator but also as a harmonic isolator. Hence the required rating of the series active filter is much smaller than that of a conventional shunt active filter. However, the performance of the combined system is greatly influenced by the filtering algorithm employed in the active power filter. This paper proposes a series active power filter scheme based on performance function. Some experiments was executed and experimental results from a prototype active power filter confirm the suitability of the proposed approach.

• 한국지리정보학회지
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• 제8권2호
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• pp.103-116
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• 2005

최근 GIS를 이용한 관망 DB화가 빈번히 이루어지고 있으나 관망해석 모형과의 연계는 미흡한 실정이다. 그 주된 이유는 이들 DB가 관망해석 모형에서 요구하는 전문적인 공간정보의 작성에 어려움이 있기 때문이다. 그로 인해, 배수관망도의 작성과 이의 정확도 향상을 위하여 공간자료를 구축할 수 있는 GIS 기법 적용이 요구되고 있다. 본 연구에서는 배수관망 수리해석 모형구축에 필요한 제반 공간자료를 GIS를 이용하여 손쉽게 작성할 수 있는 방법을 제시하였다. 또한, 관망해석모형의 계산결과를 활용하여 상수관로 위치의 공간적인 적정성(노후도 분석, 표고별 수압분포, 수용가 관리를 위한 유량공급의 분석 등)을 판단할 수 있도록 하였다.

• 환경영향평가
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• 제14권6호
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• pp.403-413
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• 2005

The environmental conservation-targeted zoning in urban planning process has been functioned as securing a ecological core in urban green spaces management. Hence, the designation of conservation zones in land use planning is considered as a key task to achieve the sustainability of urban planning. The recently introduced pre-environmental review system for the proposed urban plan, by which the conservative measures for urban ecosystem and landscape are suggested in aspect of environmental impact mitigation, has played an active role in enhancing the environmental performance degraded by wide range of development pressure. This study is aimed at drawing out of objective criteria for designation of environmental conservation zones, which can be applied to urban planning establishment and also to environmental assessment process. To achieve this goal, the study adopted the following methods; pre-study review, analysis of existing official opinion statements released by the Ministry of Environment, contents analysis of related laws, and experts' panel discussions on the finally arranged criteria. The results of this research can be summarized as follows: First, the total criteria of 48 are drown out with categorizing into environment-ecological and socio-cultural sectosr. Second, the environment-ecological part is composed of 33 criteria such as vegetation, animal, geomorphology, watershed, environmental land suitability, and etc. Here, the Degree of Ecological Function, Degree of Environmental Land Suitability, and Vegetation Map are mainly utilized. Third, the 15 socio-cultural criteria relating to the history, social ecology and landscape have such components as forest around relics, Seo-won(school), castle, tomb, landmark, skyline, natural landscape, and etc. Forth, these individual criteria can be applied to designation of each conservation zones among total of 11 conservation areas(or districts).

• 대한지리학회지
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• 제49권3호
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• pp.423-437
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• 2014

구획화는 인간 활동에 영향을 미치는 새로운 지역적 틀을 만들어내는 공간 의사결정 과정이다. 그러나 구역 내 포함되어 있는 자연적 장애물은 재조직화된 구역 내에서 이루어지는 인간 활동의 효율성을 떨어뜨릴 수 있다. 이는 구획화 과정에서 경계의 특성, 즉 고도와 같은 자연적 특성, 상호작용과 같은 관계적 특성을 고려할 필요가 있음을 의미한다. 본 연구의 목적은 이러한 경계 특성을 반영하는 새로운 구획모델을 고안하는 것이다. 경계를 '결합' 혹은 '분리'와 같이 이분법적으로 간주하기 보다는 인접한 두 공간 단위 사이의 길이, 고도 편차, 상호작용과 같은 여러 경계 특성을 바탕으로 평가된 결합의 가능성을 나타내는 연속적 함수로 간주하고 목적함수 형태로 모델에 반영한다. 모델은 인구, 면적과 같은 수요 균형을 부여하는 제약조건뿐만 아니라 명시적인 연접성 제약조건을 갖는다. 경계 속성을 자연적 특성과 관계적 특성으로 구분하고, 이와 관련된 다양한 요인들에 대하여 적합도 분석을 수행하여 인접한 두 기본 공간 단위 사이의 결합 가능성을 평가한다. 행정구역 재설정문제에 고안된 모델 및 경계 특성 분석 방법을 적용한다. 분석 결과는 혼합정수계획법의 틀로 다양한 경계 특성을 고려한 구획화가 가능함을 보여준다.

• 복식
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• 제63권1호
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• pp.81-96
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• 2013

We interviewed and surveyed parents of 3 to 6-year-old boys in order to determine designs for indoor apparel that appealed to toddlers. In addition, on the basis of the behavioral characteristics of such boys, improvements in the development of indoor apparels were suggested. Parents preferred indoor apparels because it could be worn as underwear when the kid is outdoors and as outerwear when indoors. These apparels were popular with toddlers. Therefore, indoor apparel that gives the impression of outerwear while performing the function of underwear was designed. Underwear fabric was used, but outerwear apparel design was partially adopted. In order to improve the activity, fabric that could be stretched in any direction was used for the sleeves and pant legs, while organic fabric with soft texture was used for the trunk part of the apparel. Dark-colored material was used for the chest and elbow parts of the clothes in order to prevent contamination in these parts. In particular, a bib was used to prevent contamination in the chest part. Given that toddlers engage in many activities, the fabric needed to be durable, so this led to thick materials being used for the knee part. As certain parents complained about the short length for tops, we increased the length of the tops by 5cm. In the survey items that investigated overall wearability, ease, and suitability for toddlers' activities, the test apparel obtained a higher score than existing apparel did. This indicates that the overall suitability of the newly designed apparel was improved.

• 한국항공우주학회지
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• 제49권6호
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• pp.521-528
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• 2021

위협평가가 끝난 공중항적에 대해 적절한 대응무기를 할당하기 위해서는 교전예상지점을 고려하여 교전적합성을 평가하는 것이 필요하다. 논문에서는 공중항적이 교전공간을 통과할 때 공중항적의 상대거리, 접근방위각 및 고도 등 다변량 속성정보를 가지고 베이지안 정리를 적용하여 교전공간내 위치에 따른 격추확률을 계산하는 방법을 제시하였다. 계산결과 교전공간내에서의 각 지점별 격추확률값의 분포형태는 최적의 예상요격지점을 기준으로 다변량 정규분포를 따르고 있음을 확인하였고, 계산된 격추확률값은 교전공간을 통과하는 공중항적의 교전가능성 평가에 적용가능할 것으로 기대된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.844-847
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• 1997

In this paper, scheduling problem is dealt for the minimization of due date penalty for the customer order. Multiproduct batch processes have been dealt with for their suitability for high value added low volume products. Their scheduling problems take minimization of process operation for objective function, which is not enough to meet the customer satisfaction and the process efficiency simultaneously because of increasing requirement of fast adaptation for rapid changing market condition. So new target function has been suggested by other researches to meet two goals. Penalty function minimization is one of them. To present more precisely production scheduling, we develop new scheduling model with penalty function of earliness and tardiness We can find many real cases that penalty parameters are divergent by the difference between the completion time of operation and due date. That is to say, the penalty parameter values for the product change by the customer demand condition. If the order charges different value for due date, we can solve it with the due date period. The period means the time scope where penalty parameter value is 0. If we make use of the due date period, the optimal sequence of our model is not always same with that of fixed due date point. And if every product have due date period, due date of them are overlapped which needs optimization for the maximum profit and minimum penalty. Due date period extension can be enlarged to makespan minimization if every product has the same abundant due date period and same penalty parameter. We solve this new scheduling model by simulated annealing method. We also develop the program, which can calculate the optimal sequence and display the Gantt chart showing the unit progress and time allocation only with processing data.

• 한국도로학회논문집
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• 제16권3호
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• pp.35-41
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• 2014

PURPOSES : The dynamic modulus for a specimen can be determined by using either the non-destructed or destructed testing method. The Impact Resonance Testing (IRT) is the one of the non-destructed testing methods. The MTS has proved the source credibility and has the disadvantages which indicate the expensive equipment to operate and need a lot of manpower to manufacture the specimens because of the low repeatability with an experiment. To overcome these shortcomings from MTS, the objective of this paper is to compare the dynamic modulus obtained from IRT with MTS result and prove the source credibility. METHODS : The dynamic modulus obtained from IRT could be determined by using the Resonance Frequency (RF) from the Frequency Response Function (FRF) that derived from the Fourier Transform based on the Frequency Analysis of the Digital Signal Processing (DSP)(S. O. Oyadigi; 1985). The RF values are verified from the Coherence Function (CF). To estimate the error, the Root Mean Squared Error (RMSE) method could be used. RESULTS : The dynamic modulus data obtained from IRT have the maximum error of 8%, and RMSE of 2,000MPa compared to the dynamic modulus measured by the Dynamic Modulus Testing (DMT) of MTS testing machine. CONCLUSIONS : The IRT testing method needs the prediction model of the dynamic modulus for a Linear Visco-Elastic (LVE) specimen to improve the suitability.

• 정보처리학회논문지D
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• 제11D권4호
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• pp.885-892
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• 2004

소프트웨어 시험단계에 투입되는 노력의 분포를 추정하는 대표적인 모델로 Weibull 분포(Rayleigh와 지수분포 포함)가 있다. 이 모델은 시험 시작시점에서 실제로 많은 노력이 투입되는 점을 표현하지 못한다. 또한 다양한 형태를 갖고 있는 실제 시험 노력의 분포를 적절히 표현하지 못하고 있다. 이러한 문제점을 해결하기 위해 본 논문은 시그모이드 모델을 제안하였다. 신경망 분야에서 적용되고 있는 시그모이드 함수로부터 소프트웨어 시험 노력을 적절히 표현할 수 있도록 함수 형태를 변형시켰다 제안된 모델은 다양한 분포 형태를 보이고 있는 실제 수행된 소프트웨어 프로젝트로부터 얻어진 6개의 시험 노력 데이터에 적용하여 적합성을 검증하였다. 제안된 시그모이드 모델은 기존의 Weibull 모델보다 성능이 우수하여 소프트웨어 시험노력을 추정하는데 있어 와이블 모델의 대안으로 채택될 수 있을 것이다.