• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.391-394
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• 2005

A theoretical model was developed to predict the shear strength of slender reinforced concrete beams. The shear force applied to a cross-section of the beam was assumed to be resisted primarily by the compressive zone of intact concrete rather than by the tensile zone. The shear capacity of the cross section was defined based on the material failure criteria of concrete: failure controlled by compression and failure controlled by tension. In the evaluation of the shear capacity, interaction with the normal stresses developed by the flexural moment in the cross section was considered. In the proposed strength model, the shear strength of the beam and the location of the critical section were determined at the intersection between the shear capacity and shear demand curves. The proposed strength model was verified by the comparisons to prior experimental results.

• 대한건축학회논문집:구조계
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• 제34권10호
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• pp.11-18
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• 2018

In this study, the cross-sectional image has been acquired to evaluate the aggregate distribution affecting quality of lightweight aggregate concrete, and through the binarization method, the study is to calculate the aggregate area of upper and lower sections to develop the method to assess the aggregate distribution of concrete. The acquisition of cross-section image of concrete for the above was available from the cross-sectional photography of cleavage tension of a normal test specimen, and an easily accessible and convenient image analysis software was used for image analysis. As a result, through such image analyses, the proportion of aggregate distribution of upper and lower sections of the test specien could be calculated, and the proportion of aggregate area U/L value of the upper and lower regions of concrete cross-section was calculated, revealing that it could be used as the comprehensive index of aggregate distribution. Moreover, through such method, relatively easy image acquisition methods and analytic methods have been proposed, and this indicated that the development of modeling to assess aggregate distribution quantitatively is available. Based on these methods, it is expected that the extraction of fundamental data to reconsider the connectivity with processes in concrete will be available through quality assessment of quantitative concrete.

• 한국지리정보학회지
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• 제14권4호
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• pp.116-127
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• 2011

본 논문에서는 로지스틱 회귀분석 기법을 이용하여 산사태 취약성 분석을 수행하였다. 예측모델의 성능은 모델의 적합도 검증을 통해 사용된 데이터가 모델에 얼마나 잘 반영되어 구축되었는지에 대한 적합도 평가뿐만 아니라 예측성능에 대한 평가가 필요하다. 따라서 이 논문에서는 모델에 대한 객관적인 결과를 얻기 위해 이와 같은 두 가지 측면에 대하여 예측성능 평가를 적용하였다. 연구지역은 2006년도 집중 호우로 많은 산사태가 발생한 강원도 인제 일대를 대상으로 하였다. 산사태 관련인자들은 지형도, 토양도, 임상도로부터 추출하였다. 예측모델에 대한 평가는 누적이득차트 곡선의 하부영역을 계산하였다. 예측모델의 적합도 평가에서는 87.9% 교차검증을 통한 예측정확도 평가 결과 84.8%로 두 평가 결과간의 큰 차이를 보이지 않으며 좋은 성능의 결과를 산출하였다. 이는 산사태와 관련성이 높은 유발인자와 예측모델 성능에서 기인된 결과로 해석 될 수 있다.

• 한국식품영양학회지
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• 제29권5호
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• pp.605-609
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• 2016

This study aimed to find the optimum instrumental test conditions for the Texture Profile Analysis (TPA) of cooked rice in order to predict the sensory texture attributes (hardness, adhesiveness, chewiness). Sensory evaluation was performed for three kinds of instant cooked rice with university students in their twenties and the results of the sensory evaluation were compared to instrumental TPA patterns. Using partial least squares regression, the instrumental TPA results at a cross-head speed of 1.0 mm/sec and a compression ratio of 70% proved to be an excellent predictor of the sensory attributes of hardness ($R^2=0.99$) and chewiness ($R^2=0.99$). The results at a cross-head speed of 0.5 mm/sec and compression ratio of 30% provided an excellent model for the prediction of sensory adhesiveness ($R^2=0.83$). In this experimental range, sensory hardness and chewiness showed a high correlation with instrumental TPA parameters (hardness, cohesiveness, adhesiveness, springiness, chewiness) with a high cross-head speed and compression ratio, while sensory adhesiveness showed a high correlation with the TPA parameters with a low cross-head speed and compression ratio.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권11호
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• pp.3935-3949
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• 2021

With the rapid development of Internet and big data technology, various online social network platforms have been established, producing massive information every day. Hot topic discovery aims to dig out meaningful content that users commonly concern about from the massive information on the Internet. Most of the existing hot topic discovery methods focus on a single network data source, and can hardly grasp hot spots as a whole, nor meet the challenges of text sparsity and topic hotness evaluation in cross-network scenarios. This paper proposes a novel hot topic discovery method across social network based on an im-proved LDA model, which first integrates the text information from multiple social network platforms into a unified data set, then obtains the potential topic distribution in the text through the improved LDA model. Finally, it adopts a heat evaluation method based on the word frequency of topic label words to take the latent topic with the highest heat value as a hot topic. This paper obtains data from the online social networks and constructs a cross-network topic discovery data set. The experimental results demonstrate the superiority of the proposed method compared to baseline methods.

• Journal of electromagnetic engineering and science
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• 제12권4호
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• pp.240-246
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• 2012

This paper presents a novel modeling technique for traces that cross a defected ground structure. A simple and accurate equivalent circuit model provides clear insight into the coupling mechanism between a microstrip line and a slot or split. The circuit models consist of a transformer as the coupling mechanism and LC resonators as the ground with a slot or split structure. Resistors, capacitors, and inductors are added to the model to increase accuracy and equivalence at high frequency. Simulated and measured S-parameters are presented for defected ground structures. The accuracy and validity of the proposed equivalent circuit model is verified by evaluation of the S-parameter characteristics of the defected ground structures and comparison with measured results.

• 대한수학회논문집
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• 제34권1호
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• pp.279-286
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• 2019

Complex Grassmann manifolds $G_{n,k}$ are a generalization of complex projective spaces and have many important features some of which are captured by the $Pl{\ddot{u}}cker$ embedding $f:G_{n,k}{\rightarrow}{\mathbb{C}}P^{N-1}$ where $N=\(^n_k\)$. The problem of existence of cross sections of fibrations can be studied using the Gottlieb group. In a more generalized context one can use the relative evaluation subgroup of a map to describe the cohomology of smooth fiber bundles with fiber the (complex) Grassmann manifold $G_{n,k}$. Our interest lies in making use of techniques of rational homotopy theory to address problems and questions involving applications of Gottlieb groups in general. In this paper, we construct the Sullivan minimal model of the (complex) Grassmann manifold $G_{n,k}$ for $2{\leq}k<n$, and we compute the rational evaluation subgroup of the embedding $f:G_{n,k}{\rightarrow}{\mathbb{C}}P^{N-1}$. We show that, for the Sullivan model ${\phi}:A{\rightarrow}B$, where A and B are the Sullivan minimal models of ${\mathbb{C}}P^{N-1}$ and $G_{n,k}$ respectively, the evaluation subgroup $G_n(A,B;{\phi})$ of ${\phi}$ is generated by a single element and the relative evaluation subgroup $G^{rel}_n(A,B;{\phi})$ is zero. The triviality of the relative evaluation subgroup has its application in studying fibrations with fibre the (complex) Grassmann manifold.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2001년도 추계학술대회 논문집
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• pp.242-245
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• 2001

This study is aimed to design a priority setting algorithm necessary for evaluating and selecting interdependent R&D planning system alternatives. In case that the relationship of technology alternatives is interdependent, a relative importance as occurrence or nonoccurrence of the technology alternatives viewed from the future time varies. So, we are subject to design the evaluation process considering a cross- impact of future technology alternatives. Thus, we apply the cross impact analysis (CIA) model to consider the cross-impact among interdependent system alternatives. Also, the analytic hierarchy process(AHP) model is applied to determine the priority of alternatives by taking the pair-wise comparison among factors.

• 산업경영시스템학회지
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• 제35권1호
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• pp.188-197
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• 2012

DEA 모델중 널리 사용되는 교차평가모델(cross efficiency model)은 가중치에 제한을 두지 않고 어떤 특정분야에 탁월한 성과를 내는 DMU(Decision Making Unit)보다는 보다 전반적인 분야에서 두각을 나타내는 DMU를 선발함으로써 많은 연구자들이 DEA문헌에서 적용하여 왔다. 본 연구에서는 이러한 교차평가모델이 실제에 있어서는 암묵적으로 고정 가중치를 사용한다는 것과 동일한 결과를 나타낸다는 것을 분석적으로 밝혔다(one input, multi output case). 또한 multi-input, multi-output case의 경우에도 overall performer의 cluster에 근접한 대다수 DMU의 경우에는 고정 가중치를 사용한 경우와 거의 차이가 없음을 보였다. 교차평가 모델에 적용된 변수의 가중치를 보다 명확히 함으로써 연구자들이 모델의 평가결과를 이해하는데 도움이 될 수 있을 것이다. 또한 교차 평가의 가중치 도식을 더 명확히 보여주기 위해 biplot을 제안한다.

• 한국콘텐츠학회논문지
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• 제6권3호
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• pp.93-101
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• 2006

본 연구는 미국의 토론 모형인 CEDA (Cross Examination Debate Association)방식을 인터넷 토론학습에 적용하는 새로운 시도를 통하여 향후 인터넷 수업에 응용할 수 있는 CEDA형 인터넷 토론수업 모델을 설계하는데 그 목적이 있다. 먼저 본 연구는 미국의 CEDA토론 기법의 기본 요소를 인터넷 토론학습모델에 적용한 수업설계를 통하여 1,2차에 걸쳐 각각 200명의 학습자들에게 인터넷 CEDA토론을 실시하고 그 결과와 토론에 대한 의견을 분석하였다. 연구결과 학생들은 인터넷 CEDA토론학습에 대해 긍정적인 반응을 나타냈으며, 기존의 개방형 토론방법보다 찬반형의 CEDA토론방법을 선호하는 것으로 밝혀졌다. 하지만 2차 연구에서는 토론에서 튜터의 중요성이 강조되며 튜터의 전략에 따라 토론결과가 달라 질 수 있음을 보여주었다. 이는 대부분의 학습자들이 스스로 토론에 대한 경험이 부족함을 보완하기 위해 튜터의 지원을 원하는 것으로 판단된다. 결론으로 본 연구는 CEDA형 인터넷 토론학습 모델이 학교현장에 폭넓게 활용될 수 있도록 교과목별, 학습자별 다양한 토론학습 모델이 개발되어야 하며 학습자 입장에서 토론수업을 지원할 수 있는 전략이 필요함을 강조한다.