• 한국전산유체공학회지
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• 제14권3호
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• pp.33-48
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• 2009

In the present study, a fast grid deformation technique has been incorporated into the unsteady compressible and incompressible viscous flow solvers on unstructured hybrid meshes. An algebraic method based on the basis decomposition of normal edge vector was used for the deformation of viscous elements, and a ball-vertex spring analogy was adopted for inviscid elements among several spring analogy methods due to its robustness. The present method was validated by comparing the results obtained from the grid deformation and the rigid motion of entire grids. Fish swimming motion of an NACA0012 airfoil and flapping wing motion of a generic fighter were also simulated to demonstrate the robustness of the present grid deformation technique.

• 한국소음진동공학회논문집
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• 제13권3호
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• pp.180-185
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• 2003

The equivalent electroacoustic circuit approach has been conventionally used for the analysis of the multiple layer perforated plate system. However, it is found that an analogy error has been involved in the equivalent electroacoustic approach proposed by previous researchers for the element of straight pipe. Although the pipe between the perforated layers is a distributed element in the analogy, it has been treated as a parallel element by previous investigators. The analogy error is demonstrated by comparing the calculated absorption coefficients based on the parallel circuit and the distributed circuit, respectively, with the measured values by the two-microphone impedance tube method.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.31-34
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• 2003

가압방식 로켓추진기관시스템의 작동점 변화 추적을 위하여 각 추진제 탱크의 압력, 수위 및 비행 가속도로부터 각 추진제질유량, 연소실압력을 계산할 수 있는 직접상사모델을 만들었다. KSR-III의 비행시험결과 예로 분석하였으며, 이 계산모델을 통하여 가압방식 로켓추진시스템의 작동점 변화의 경향성을 파악할 수 있음을 보였다.

• Architectural research
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• 제2권1호
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• pp.47-54
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• 2000

The critical load of a continuous compression member was determined by the beam-analogy method. The proposed method utilizes the stress-analysis results of the analogous continuous beam, where imaginary concentrated lateral load changing its direction is applied at each midspan. The proposed method gives a lower bound error of critical load and can predict the span that buckles first. The effective length factors for braced frame columns can be easily determined by the present method, but result in the upper bound errors in all cases, which can lead to a conservative structural design.

• 한국조경학회지
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• 제25권3호
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• pp.210-221
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• 1997

This study was conducted to investigte the visual preference and response between introduced and native trees for utilization of the south native trees in interior space. 1. The intensity of illumination was below 500lux at 24 buildings of interior spaces surveyed. Generally the temperature was 24~$26^{\circ}C$, and humidity was 60~70%. 2. Total number of introduced tree species were 9 familiar, 16 genus, 18 species, especially palm genus were the largest tree among them at these surveyed interior spaces, but native trees were only 2 species. The introduced tree of 2 to 3m in height was 46 percent, and the case of 1.2 to 2m was 42 percent. 3. The mean of visual preference was the highest at Rhapis excelsa and howeia belmoreana, and followed with Neolitsea sericea, Daphniphllum macropodum, Listsea japonicum. In the mean of visual preference for selected tree groups, native tree was not different as compared with introduced tree. 4. Visual image factor of the native and introduced trees at interior spaces was classified by individual factor and emotional factor. These 2 factors were shown 66.5% total variance. The native tree was strongly recognized on individual factor, as , and introduced tree was also strongly recognized on emotional factor. 5. In the analysis of visual preference and image, a difference between the selected groups of the introduced and native trees were not shown significant, and the introduced trees were similar to the native trees on the visual image. This result was as follow There was an analogy between Cinnamomum camphora, Ligustrum japonicum and Ficus retusa, Ficus benjamina. There is an analogy between Castanopsis cuspidata var. sieboldii, Cinnamomum japonicum and Ficus retusa, Ficus benjamina. There was an analogy between Elaeocarpus sylvestris var. ellipticus, Fatsia japonica and Rhapis excelsa, Howeia belmoreana. There was an analogy between Neolitsea sericea, Daphniphyllum macropo여, Listsea japonica and Rhapis excelsa, Howeia belmoreana. There was an analogy between Elaeocarpus sylvestris var. ellipticus, Fatsia japonica and Dracaena fragranse, Ficus elastica, Monstera deliciosa.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.502-507
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• 2000

This paper presents the numerical prediction of airflow-induced sound in DVD drives. Computational fluid dynamics (CFD) is first conducted to evaluate flow field characteristics due to the high-speed disk rotation, and to support the acoustic analysis. The acoustic analogy based on Ffowcs Williams-Hawkings (FW-H) equation is adopted to predict aeroacoustic noise patterns. The integral solution for quadrupole volume source is included to identify the turbulence noise generated inside the DVD tray. Near-field noise is strongly affected by the flow field characteristic, which is caused by the complex shape of the tray. For a mid-field, the quadrupole noise play as a counterpart of thickness noise or loading noise, resulting in a different pattern compared with those in the near field.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.457-460
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• 1988

We present here a numerical solution for obtaining propagation characteristics including lossess for various modes of an multi-layered optical waveguide structure. The method is based on transmission line analogy. A comparison with other method shows the our results are accurate and simple.

• 한국과학교육학회지
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• 제27권9호
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• pp.778-786
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• 2007

이 연구에서는 비유를 사용한 화학 개념 학습에서 대응 오류 분석 활동의 효과를 개념 이해도,대응 관계 이해도,수업에 대한 인식 측면에서 조사하였다. 2개 중학교의 1학년 121명을 비교 집단과 처치 집단으로 배치한 후,'물질의 상태와 분자 배열'에 대하여 수업을 실시하였다. 비교 집단에서는 TWA 모형에 기초한 비유 수업을 하였고,처치 집단에서는 TWA 모형의 '유사성 대응' 및 '차이점 지적'을 '대응 오류 분석 활동'으로 대체한 수업을 하였다. 연구 결과,학생들의 장의존성 장독립성에 관계없이 개념 이해도 검사와 대응 관계 이해도 검사에서 처치 집단의 점수가 비교 집단보다 높았으며,그 차이가 통계적으로 유의미하였다. 수업에 대한 인식 검사 결과에서는 대부분의 학생들이 비유를 사용하는 수업에 대해 긍정적으로 인식하였으나,처치 집단의 학생들은 대응 오류 분석 활동을 어려워하는 것으로 나타났다. 이에 대한 교육적 함의를 논의하였다.

• 설비공학논문집
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• 제24권4호
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• pp.306-314
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• 2012

Several numerical or analytical models have been proposed to analyze the thermal response of vertical ground heat exchangers (GHEX). However, most models are valid only after several hours of operation since they neglect the heat capacity of the borehole. Recently, the short time response of the GHEX became important in system simulation to improve efficiency. In this paper, a simple new method to evaluate the short time response of the GHEX by using an analogy model of electric circuit transient analysis was presented. The new transient heat exchanger model adopting the concept of thermal capacitance of the borehole as well as the steady-state thermal resistance showed the transient thermal resistance of the borehole. The model was validated by in-situ thermal response test and then compared with the DST model of the TRNSYS program.

• 한국정보처리학회논문지
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• 제6권4호
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• pp.916-931
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• 1999

소프트웨어 재사용에서 코드 재사용은 다른 개발자에 의해 작성된 재사용 코드의 이해와 검색의 어려움 등 한계점을 갖는다. 코드 재사용 한계를 극복하기 위해서는 코딩 단계 이전의 설계 단계나 분석 단계의 산물을 재사용 할 수 있어야 한다. 본 연구에서는 객체 모델링 단계에서 이전의 경험을 재사용할 수 있는 환경을 제공하기 위해 질의와 컴포넌트에 대한 analogy를 판단하여 라이브러리의 모델과 패턴을 재사용 할 수 있는 방법을 제안하였다. Analogy 매칭 기법은 설계 패턴의 검색, 이해 그리고 조합 등에 적용되며 본 논문에서 연구된 내용은 다음과 같다. 1. 재사용 라이브러리로부터 유사 컴포넌트 검색 및 추출을 위한 analogical 매칭 함수 제안 2. analogical 매칭을 위해 라이브러리 내에 저장될 재사용 컴포넌트 표현 및 정의 3. 특정 도메인에 대한 의미적 정보의 라이브러리 설계 4. 사용자를 위한 analogical 매칭 에이전트 구축