• 한국수자원학회논문집
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• 제54권5호
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• pp.289-299
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• 2021

본 연구에서는 수원 유역 혹은 한계지지면적의 변동성 규모에 따른 하천망의 형상 변화를 추출하여 설마천 시험유역의 분기 특성에 대한 해석을 수행하였다. 수원 유역의 면적이 감소함에 따라 대상 유역의 내부에는 하천망의 분기 현상이 발생하며, 그 결과로서 하천망의 신장(총 하천 길이의 증가)과 함께 하천망의 확장(수원의 개수 증가)이 동시에 나타남을 볼 수 있었다. 하천망이 신장되는 경우 하천 구간의 길이가 증가하는 경향이 새로운 수원이 생성되는 경향보다 우세하게 나타나는 반면, 하천망이 확장되는 경우 반대 거동에 따라 배수망이 유역 내부의 공간을 채워가는 과정으로 나타남을 확인할 수 있었다. 이로부터 자연 유역의 하천망들이 가지는 규모 불변성은 수원 유역의 규모가 감소함에 따라 나타나는 하천망의 신장 특성과 하천망의 확장 특성이 상호 균형을 이루면서 발현되는 지형학적 특성으로 기술될 수 있었다. 설마천 시험유역의 분기 구조는 하천망의 신장 특성과 규모 불변성이 공존하는 형태로 판단되며 강우로 인한 유출 현상에 보다 지배적인 역할을 하는 요인에 대한 후속 연구가 필요한 것으로 판단된다.

• 이베로아메리카
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• 제23권2호
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• pp.93-134
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• 2021

2019년 보우소나루 정부가 출범하면서 브라질은 국내·대외적으로 눈에 띄는 정책노선의 변화를 경험하였다. 이러한 변화를 외교분야로 한정해서 살펴보면 보우소나루 정부 들어 기존 정권의 전통중립외교와 명확히 구분되는 친미·반중 외교행보가 본격화되었다는 점을 지적할 수 있다. 그럼에도 불구하고 보우소나루의 친미·반중 외교노선에 대한 선행연구는 제한적이며, 주로 기성언론을 통한 시론적 보도 정도에 그치고 있는 실정이다. 본 논문은 이러한 문제의식을 기반으로 보우소나루의 친미·반중 외교노선의 결정요인을 도출하는 것을 주요 연구목적으로 하였으며, 특히 정치지도자(보우소나루)의 개인적 수준을 주요 변수로 상정하여 파악하였다. 본 연구는 보우소나루의 생애사를 통해 축적된 개인적 경험과 이러한 요소들에 의해 형성된 그의 이념, 신념 및 세계관, 그리고 자신의 국내적 정치와 외교노선 간의 연계를 통해 자신의 국내정치적 지지기반을 공고히 하는 일종의 정치적 계산이 궁극적으로 보우소나루 정부의 친미·반중외교에 영향을 끼쳤음을 주장하였다. 본 연구는 정치지도자(대통령) 수준에 대한 개인적 특성 분석을 통해 브라질의 친미·반중외교의 요인을 설명함으로써 외교정책결정요인 이론뿐만 아니라 브라질의 외교정책을 이해하는 데 개인적 수준의 분석이 가지는 이론적 함의를 제고했다는 점에서 의의가 있다고 사료된다.

• 복식문화연구
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• 제23권4호
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• pp.554-568
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• 2015

Technological change leads to a value shift in human society. Various cultural experiences through the digital paradigm influence the expression of fashion. This article considers fashion film as a new form for presenting fashion and explores the distinctiveness of expression in digital fashion film. For the methodology, a literature review was conducted to examine the concepts and features of digital fashion film and metareality. Empirical research was also performed by drawing from Nick Knight's digital films, "Sans Couture", "#asif", and "The Elegant Universe" and by specifically analyzing the classification of the themes, visuals, and auditory expression. The results are as follows. The proliferation of fashion film has accelerated in the internet environment. New media in the digital era allows images to become more realistic and variable through immaterial conversion. Metareality is the notion of a reality beyond existence. A metarealistic image maintains the metaphysical nature of an object and transcends empirical appearance. It possesses immaterial, transboundary, and multidimensional features, and the image is realized by digital technology. The expression analysis identifies the metareality expressed in contemporary fashion film appearing as atypical forms, irrational combinations, and the playfulness of motion. It shows a positive attitude, transcending the immaterial limit of reality toward fashion. This study indicates how fashion as products challenges the metaphysical transformation in the digital era. The exploration of metareality in digital fashion film promotes a wider perspective and understanding of the concept of fashion.

• 한국운동역학회지
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• 제25권1호
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• pp.1-10
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• 2015

Objective : The purpose of this study was to find some kinetic variable's relationships between personal records and low records in female high jump. Methods : Collected data of the subjects(N=8, ages: $25.5{\pm}1.85$, height: $173{\pm}5.83$, mass: $54.75{\pm}6.36$ personal record: $1.71{\pm}0.04$, low record: $1.62{\pm}0.03$) were used for the last three strides and take-off phase. Five video cameras set in 30frames/s were used for recording. After digitizing motion, the Direct Linear Transformation(DLT) technique was employed to obtain 3-D position coordinates. The kinematic and kinetic factors of distance, velocity, angle, impulse, jerk variables were calculated. A paired t-test was applied for the difference of variables between personal records and lower records and for correlation with performances and variables. The significance level was accepted at p<.05. Results : There was no relationship between pattern of stride and performance. However, rate of change of velocity was related with cental of mass height(CMH) at peak point(PP). Knee, hip, backward lean, foot plant, approach and take off angle showed no difference between best record and low record. Vertical impulse momentum also showed no difference between performances. Conclusion : According to a t-test result, there were significant differences in CMH at PP and jerk at touch down between best record and low record.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2595-2618
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• 2018

In this paper, we investigate secure communication with the presence of multiple eavesdroppers (Eves) in a two-tier downlink dense heterogeneous network, wherein there is a macrocell base station (MBS) and multiple femtocell base stations (FBSs). Each base station (BS) has multiple users. And Eves attempt to wiretap a macrocell user (MU). To keep Eves ignorant of the confidential message, we propose a physical-layer security scheme based on cross-layer cooperation to exploit interference in the considered network. Under the constraints on the quality of service (QoS) of other legitimate users and transmit power, the secrecy rate of system can be maximized through jointly optimizing the beamforming vectors of MBS and cooperative FBSs. We explore the problem of maximizing secrecy rate in both non-colluding and colluding Eves scenarios, respectively. Firstly, in non-colluding Eves scenario, we approximate the original non-convex problem into a few semi-definite programs (SDPs) by employing the semi-definite relaxation (SDR) technique and conservative convex approximation under perfect channel state information (CSI) case. Furthermore, we extend the frame to imperfect CSI case and use the Lagrangian dual theory to cope with uncertain constraints on CSI. Secondly, in colluding Eves scenario, we transform the original problem into a two-tier optimization problem equivalently. Among them, the outer layer problem is a single variable optimization problem and can be solved by one-dimensional linear search. While the inner-layer optimization problem is transformed into a convex SDP problem with SDR technique and Charnes-Cooper transformation. In the perfect CSI case of both non-colluding and colluding Eves scenarios, we prove that the relaxation of SDR is tight and analyze the complexity of proposed algorithms. Finally, simulation results validate the effectiveness and robustness of proposed scheme.

• International Journal of Oral Biology
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• 제32권3호
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• pp.93-101
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• 2007

Cell behavior of the transformed cells is known to affect by interaction with extracellular matrix (ECM) proteins and integrin. To investigate the alterations of both integrin expression and cell-matrix interaction during neoplastic conversion of human oral kerationcytes, we studied expression levels of integrin subunits by flow cytometry and cellular responses to the ECM proteins in normal human oral keratinocytes (NHOKs), HPV-immortalized HOK-16B line, and three oral cancer cell lines established from HOK-16B line, CTHOK-16B-BaP, CTHOK-16B-DMBA, and CTHOK-16B-Dexa lines. The expression levels of ${\alpha}\;and\;{\beta}$ integrin subunits were shown decreased tendency in human oral keratinocytes undergoing immortalization and tumorigenic transformation except CTHOK-16B-DMBA line tested. Although ${\alpha}v{\beta}6$ integrin is known to be highly expressed in squamous cell carcinomas, and the altered integrin expression is suspected to be associated with cellular carcinogenesis, ${\alpha}v$ integrin subunit and ${\alpha}v{\beta}6$ integrin did not express in oral cancer cell lines tested. Cell behavior to the ECM proteins in HOK-16B line was generally similar to that of exponentially proliferating NHOKs. The adhesion activity profiles of type I collagen were very similar to that of its laminin counterparts, but fibronectin showed minimal adhesion activity under our conditions compared to the BSA control. The ability of the CTHOK-16B-BaP line to spread upon type I collagen and laminin markedly decreased, but migration was notably increased on type I collagen. In contrast, CTHOK-16B-DMBA and CTHOK-16B-Dexa lines spread less but migrated more upon type I collagen than immortalized HOK-16B line. These data indicate that downregulation of integrin subunits causes the changes of cellular responses to the ECM proteins during neoplastic conversion of human oral keratinocytes, and that cellular responses to the ECM proteins in oral cancer cell lines established by exposing different carcinogens are variable according to chemical carcinogens treatment.

• 한국기계가공학회지
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• 제19권9호
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• pp.100-106
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• 2020

This study analyzes the residual stress of AISI 1536V for an engine shaft of the shipbuilding industry and AISI A387 for a reactor shell of the chemical refining industry by the hole drilling method with a strain gauge rosette, which transforms fine mechanical changes into electrical signals. Tensile residual stress is generated in the forging and heat treatment process because specimens are affected by thermal stress and metal transformation stress. In the heat treatment process, the residual stress of AISI A387 is almost 170% the yield strength at 402 MPa. Since during the machining process, variable physical loads are applied to the material, compressive residual stress is generated. Under the same condition, the mechanical properties greatly affect the residual stress during the machining process. After the stress-relieving heat treatment process, the residual stress of AISI A387 is reduced below the yield strength at 182 MPa. Therefore, it is necessary to control the temperature, avoid rapid heat change, and select machining conditions depending on the mechanical properties of materials during manufacturing processes. In addition, to sufficiently reduce the residual stress, it is necessary to study the optimum condition of the stress-relieving heat treatment process for each material.

• 한국운동역학회지
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• 제15권2호
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• pp.129-138
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• 2005

The purpose of this study was to investigate the techniques used by long jumpers who recorded over 8meters in 2002 Busan Asian Game and 2003 Daegu Universiade. The kinematic characteristics from the last three stride to takeoff at the takeoff board were analyzed such as velocities, heights and angles. The real-life three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation procedure. The conclusion were as follows; 1. The height variation who recorded over 8 meters of center of gravity of the jumpers at the last stride was under 8cm. In order to record over 8meters the national long jumpers should have under 10cm height variation. 2. In the approach phase the horizontal velocity of the jumpers should reach to 10.5m/s in last three strides and 9.79m/s in touch down at take off board. 3. The horizontal velocity at take off board must have over 8.51m/s and the vertical velocity must have 3.75m/s simultaneously in order to record 8meters. 4. The forward body lean angle should have over 20degrees with pushing the take off board in forwarding movement. The appropriate body variation range ratio between take off and touch down should be 1.2 vs 1 and the trunk angle at touch down on the board should be close to the erect posture for higher body flight.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권1호
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• pp.20-28
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• 2004

소프트웨어 개발 초기에 개발비용, 소묘인력과 기간을 추정하는 것은 소프트웨어공학 분야의 중요하면서도 어려운 문제이다. 기존 모델은 개발업체의 생산성 수준을 고려하지 않고 단순히 기능점수와 노력, 노력과 개발기간 관계에 대한 회귀분석을 통해 개발노력과 기간을 추정하는 모델을 제시하였다. 그러나 동일한 규모의 소프트웨어라도 개발업체의 생산성 수준에 따라 다른 노력의 양이 투입되며, 동일한 노력이 투입되더라도 생산성에 따라 개발기간이 달라진다. 생산성 수준을 고려하지 않은 제안된 모델들은 실제 개발될 프로젝트 적용에 제한점을 갖고 있다. 본 논문은 기존 모텔의 단점을 보완하기 위해 생산성을 고려하여 개발기간을 추정할 수 있는 모델들을 제안한다. 생산성에 기반 하여 다양한 방법으로 개발기간을 추정할 수 있는 모델을 제안하고 모델들의 성능을 비교하였다. 모델 성능 비교 결과 생산성에 기반 하여 소프트웨어 규모로부터 개발기간을 추정하는 모델이 단순하면서도 가장 좋은 결과를 얻었다. 본 모델은 사업 초기에 프로젝트 관리자에게 소프트웨어 개발 기간 의사결정 정보를 제공한다.

• 생물정신의학
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• 제16권4호
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• pp.238-245
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• 2009

Objectives : Mild Alzheimer's disease(AD) is uncertain to be related to visuospatial working memory subsystem dysfunction. We used the self ordered pointing test(SOPT) to find the characteristics of visuospatial working memory in mild AD. Methods : We compared the visuospatial working memory abilities of 20 patients with mild AD and 20 normal elderly controls(NC) using SOPT, of which stimuli consisted of two stimuli types(A : abstract, C : concrete) and two stimuli numbers(8 and 12). Therefore, working memory was tested using C8, C12, A8, and A12 stimuli conditions in SOPT. Mixed-model ANOVA was conducted with the AD and NC groups as between-subjects factor, with stimuli types and stimuli numbers as the within-subjects factors and with SOPT error rates as the dependent variable. Results : The AD group showed higher error rates in SOPT than the NC group. The NC group showed low error rates in concrete stimuli than in abstract stimuli and in small stimuli numbers than in large stimuli numbers. And the AD group showed no differences between stimuli types or stimuli numbers. Conclusion : AD patients showed a poor performance in visuospatial working memory using concrete stimuli. The result suggests that there is a non-transformation from visual input to phonological working memory in AD. Patients with AD showed a poor performance although in small stimuli number condition of SOPT. It suggests that in AD, visuospatial working memory is not working well although in low central executive loads.