• 한국인터넷방송통신학회논문지
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• 제14권6호
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• pp.113-117
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• 2014

본 논문에서는 레이더 시스템에서 탐지 거리 추정에 영향을 미치는 레이더 단면적의 크기에 대한 집적 방식을 비교 분석한다. 본 논문에서는 레이더 단면적의 크기에 따라 크기가 작을 경우 스웰링 케이스 1, 클 경우에는 스웰링 케이스 3의 탐지 확률을 레이더 방정식에 적용하여 탐지 거리를 추정하였다. 모의실험을 통해서 스웰링 케이스의 차이에 따른 코히런트 집적과 비 코히런트 집적을 비교 분석하였다. 비교 분석 결과, 비 코히런트 집적 방식이 추정 거리가 가장 우수하였고 코히런트 집적 방식은 스웰링 케이스를 적용한 탐지 거리 추정에 적합하지 않음을 알 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.862-870
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• 2010

This thesis has been researched on optimized design method for the total cross section of embankment considering the fact that the size of embankment cross section is directly related with economic efficiency when dam designing. In general, embankment cross section of fill dam is either determined by cohesion and angle of internal friction, a strength parameter of embankment materials or by permeability of embankment. Therefore the size of embankment cross section depending on strength parameter of embankment materials was determined by using MIDAS-GTS program through stress-seepage coupled analysis at the time of fill dam design. As a result, determination of embankment cross section was more affected by the size of central core and permeability rather than by slope stability by shear strength and it was revealed that in case of embankment height being over 20m, stability against infiltration and slope action could be secured only when embankment slope is at least over 1:2.5. In addition, it was also revealed that in case of making the size of central core exceeding specification standard, total cross section of embankment could be reduced considerably and at the time of embankment design, adequate size and appropriateness of embankment cross section could be determined with referring the table suggested by this study.

• 항공우주시스템공학회지
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• 제18권1호
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• pp.21-28
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• 2024

본 논문에서는 회전익 블레이드의 단면 구조 정보를 통해 블레이드의 단면 강성을 예측하고, 재료 정보를 이용하여 단면 강성을 예측할 수 있는 심층 신경망 기반 네트워크 예측 모델의 설계 및 적절성 검토를 수행하였다. 재료 정보를 네트워크 입력으로 갖는 예측 모델의 경우, 블레이드 단면 부재 재료의 탄성 계수를 네트워크의 입력으로 고려하여 단면 강성을 예측하도록 설계하였다. 또한, 단면 구조 정보를 네트워크 입력으로 갖는 예측 모델의 경우, 블레이드의 단면을 구성하는 단면 부재의 위치와 두께 정보를 네트워크 입력으로 고려하여 단면 강성을 예측하도록 설계하였다. 각 예측 모델은 심층신경망 구조를 기반으로 설계하였으며, 단면 해석 프로그램인 KSAC2D를 통한 단면 해석 결과를 네트워크의 훈련 및 검증 데이터로 사용하였다.

• Journal of the Korean Data and Information Science Society
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• 제9권2호
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• pp.119-138
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• 1998

The case of proportional cell frequencies for the two-way cross-classification with interaction is considered. Several types of hypotheses for the general unbalanced data that are commonly used in the literature are shown, and they are written out for this particular case. A reparameterized form of the cell means model is defined to establish the reparameterized model, and orthogonal property of the model is shown using the augmented matrix and the numerator sums of squares are computed. Different ways of producing the same analysis of variance tables are shown in both orthogonal and nonorthogonal situations.

• International Journal of Fluid Machinery and Systems
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• 제9권2호
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• pp.169-174
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• 2016

A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio. Therefore, it is a good candidate for use as a self-starting turbine. Furthermore, it has low noise and excellent stability; therefore, it has attracted attention from the viewpoint of applications as a small wind turbine for an urban district. However, its maximum power coefficient is extremely low (10 %) as compared to that of other small wind turbines. In order to improve the performance and flow condition of the cross-flow rotor, the symmetrical casing with a nozzle and a diffuser are proposed and the experimental research with the symmetrical casing is conducted. The maximum power coefficient is obtained as $C_{pmax}=0.17$ in the case with the casing and $C_{pmax}=0.098$ in the case without the casing. In the present study, the power characteristics of the cross-flow rotor and those of the symmetrical casing with the nozzle and diffuser are investigated. Then, the performance and internal flow patterns of the cross-flow wind turbine with the symmetrical casings are clarified. After that, the effect of the side boards set on the symmetrical casing is discussed on the basis of the analysis results.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제26권2호
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• pp.63-82
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• 2023

In the context of Korean educational research, the number of qualitative research studies has gradually increased since 2000. It has become one of the most important research methods today. The field of math education is no exception to this trend, and qualitative approaches are now becoming one of the main research methods. This increase in qualitative research has contributed to the provision of detailed information about educational practice, but at the same time, the overall level of credibility in the results of qualitative research seems to be lower than that of quantitative research. This study started with the problem consciousness that the number of qualitative studies is increasing in the field of mathematical education, but there is a lack of discussion on the methodology of applying qualitative research methods. In this study, among the papers published in the journal related to mathematical education, papers using a qualitative approach are analyzed focusing on cross-case analysis. Based on the analysis results, the tendency to use qualitative approaches is diagnosed, ways of improving the validity and trustworthiness of qualitative research results in the field of mathematical education are examined, and implications and suggestions are presented.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.694-700
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• 1998

PSC box bridge by MSS construction method may not be set at cross section at one step. Web and bottom flange(U member) would be set at first, top flange will be set later with a time lag. In this case, U member and top flange concrete have different strain history. As two different aged section behaves as the composite section, there would happen the redistribution of stress. This is come from time-dependent strain characteristics of concrete itself. In this study, two models are considered, one with considering the set time of cross section and the other without. By performing longitudinal analysis of two models on considering construction stage, the stress differences of two are compared. As the analysis results show a considerable differences in the stresses of cross section between two models, the set time of cross section is needed for rational design f PSC box girder bridge.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2008년도 추계학술대회 및 정기총회
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• pp.8-23
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• 2008

The purpose of this study is to develop a Cross Impact System Alternatives Tree(CISAT) model necessary for selecting the interdependent R&D planning system alternatives. This model modifies System Alternatives Tree(SAT) model developed by Kwon et al.. The SAT model is composed of several functions necessary for the achievement of a final goal and several subsystems for satisfying each function. In case that the relationship of technology alternatives is interdependent, this model overlooked a relative importance derived from occurrence or nonoccurrence of the technology alternatives in the future time varience. However, a complex evaluation process within the ballot system is another disadvantage of the SAT. To solve such problems, the Cross Impact Analysis(CIA) model is applied in the SAT model so as to consider the cross impact among interdependent system alternatives.

• Asia Marketing Journal
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• 제18권1호
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• pp.1-22
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• 2016

Studies in key account management (KAM) have identified the importance of cross-functional coordination in firms to effectively implement KAM. However, these studies have ignored how companies integrate KAM and other customer management (non-KAM). This paper explores coordination design between KAM units and non-KAM units by analyzing a case study through three dimensions: front-end coordination, back-end-coordination, and organizational translation at the beginning of research. The case study shows that non-KAM conditions can require a modification of the coordination design. This research performs an in-depth analysis of changes in the implementation of sales reforms for an IT-related machinery and system vendor in Japan. Data sources include interviews with KAM units and non-KAM sales units and an analysis of secondary data. This paper suggests that studying the coordination between KAM units and non-KAM units will further our understanding of internal coordination in KAM research.

• 한국국방경영분석학회지
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• 제33권2호
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• pp.61-73
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• 2007

본 연구의 목적은 미래 기술예측에 사용되는 TFDEA(Technological Forecasting with Data Envelopment Analysis)의 문제점을 살펴보고 이의 개선방향을 찾아 주력전차의 기술예측 문제에 적용해 보는 것이다. 기존의 TFDEA는 복수의 DMU(Decison Making Unit)를 효율적 DMU로 판정하는 DEA(Data Envelopment Analysis)의 특성상 실제로는 그다지 효율적이지 않은 DMU까지 포함해서 기슬예측을 수행함으로써 예측 결과의 정확도가 저하될 수 있다. 본 연구에서는 DEA의 확장된 개념을 적용하여 평가 대상 DMU에 대한 순위를 산정한 후 이를 토대로 기술 예측을 시행하는 방법을 검토해 보았다. 이를 위해 일반적인 DEA기반의 순위선정 방법 중 대표적인 Super-efficiency, Cross-efficiency, CCCA(Constrained Canonical Correlation Analysis)을 TFDEA에 결합 적용하고 이들을 비교해 보았다. 제시된 방법을 주력 전차의 미래 기술 예측 문제에 적용한 결과 CCCA를 이용한 순위선정방법이 실제 실현된 기술 수준과 비교했을 때 통계적으로 가장 작은 오차율을 보였다.