• 전기학회논문지
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• 제61권12호
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• pp.1964-1969
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• 2012

This paper presents to verify the selective grounding fault protective relaying technique for the ungrounded DC traction power supply system. This system selectively blocks fault section when grounding fault occurred. In order to perform this verification, field test facilities have been installed on Oesam substation and Worldcup-Stadium substation, and field test process has been suggested. Also, selective grounding fault protective relaying components and rail voltage reduction device have been tested with the various trial examinations. In order to compare and evaluate performance of the selective grounding fault protective relaying function, field test system was modeled and the system fault simulation results were compared and evaluated with the field test result. Performance of selective grounding fault protective relaying function was evaluated with the above-mentioned process, and the fact that the system recognizes fault section irrespective of insulation between rail and ground and fault resistance from grounding fault.

• ETRI Journal
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• 제30권4호
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• pp.576-586
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• 2008

In most parallel loops of embedded applications, every iteration executes the exact same sequence of instructions while manipulating different data. This fact motivates a new compiler-hardware orchestrated execution framework in which all parallel threads share one fetch unit and one decode unit but have their own execution, memory, and write-back units. This resource sharing enables parallel threads to execute in lockstep with minimal hardware extension and compiler support. Our proposed architecture, called multithreaded lockstep execution processor (MLEP), is a compromise between the single-instruction multiple-data (SIMD) and symmetric multithreading/chip multiprocessor (SMT/CMP) solutions. The proposed approach is more favorable than a typical SIMD execution in terms of degree of parallelism, range of applicability, and code generation, and can save more power and chip area than the SMT/CMP approach without significant performance degradation. For the architecture verification, we extend a commercial 32-bit embedded core AE32000C and synthesize it on Xilinx FPGA. Compared to the original architecture, our approach is 13.5% faster with a 2-way MLEP and 33.7% faster with a 4-way MLEP in EEMBC benchmarks which are automatically parallelized by the Intel compiler.

• 복식문화연구
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• 제22권6호
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• pp.899-910
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• 2014

The purpose of this study was to analyze high school students' school uniform wearing attitude by group according to clothing attitude targeting Gyeongnam area. This study aims to provide preliminary data in the field of school uniform and marketing that clothing propensity by groups is considered. This study conducted a survey targeting 762 high school students in Gyeongnam. For statistical analysis, SPSS for Window 14.0 was used for frequency analysis, factor analysis, reliability analysis, multiple sponse analysis, cluster analysis, ANOVA analysis and Duncan's ex-post analysis method. As a result of cluster analysis on the clothing attitude, students were divided into 4 segmentation of fashion seeking group, fashion indifference group, conformity group and modesty group. As a result of verification on the difference in perception toward wearing school uniform by groups which were classified according to the propensity of clothing attitude, activity, stability, and practicality were all varied according to the propensity of clothing attitude. 4 groups were significant differences in the degree of consent to wearing school uniform, price of school uniforms, tendency to prefer famous brand when purchasing school uniform, experience of transforming school uniform, opinion about school uniform modification and reason for school uniform modification. While low graders were many in 'modesty group', upper graders were many in 'fashion seeking group', which means that more segmentalized satisfaction of clothing by group may be raised if such a fact is considered when planning clothing for high school students segmentalized by age.

• 한국주거학회논문집
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• 제23권4호
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• pp.69-76
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• 2012

This study conducted an analysis of importance levels and also an AHP analysis based on the results of the monitoring (from Aug 2011 through Feb 2012) carried out in the Sajik 2-dong in the City of Cheong-ju. By quantitatively eliciting the effects that the urban regeneration projects that use art programs have on the changes in the perception of community housings and by analyzing the results of objective verification, this study was able to ascertain that local resident festivals had the greatest impacts on the change in the perception of community housings in the Sajik 2-dong in the City of Cheong-ju. This is deemed to be attributable to the fact that programs such as local resident festivals, in which various age groups participated, - amidst the unmitigated circumstance of Sajik 2-dong in the City of Cheong-ju (conflicts among the residents on account of redevelopment project) - exerted significant influences in the perceptional change of the community and in the resolution of conflicts.

• Structural Monitoring and Maintenance
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• 제6권1호
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• pp.47-66
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• 2019

One method of retrofitting concrete structures is to use fiber reinforced polymers (FRP). In this research, the shear, torsional and flexural strengthening of self-compacting reinforced concrete (RC) girders are fulfilled with glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) materials. At first, for verification, the experimental results were compared with numerical modeling results obtained from ABAQUS software version 6.10. Then the reinforcing sheets were attached to concrete girders in one and two layers. Studying numerical results obtained from ABAQUS software showed that the girders stiffness decreased with the propagations of cracks in them, and then the extra stresses were tolerated by adhesive layers and GFRP and CFRP sheets, which resulted in increasing the bearing capacity of the studied girders. In fact, shear, torsion and bending strengths of the girders increased by reinforcing girders with adding GFRP and CFRP sheets. The samples including two layers of CFRP had the maximum efficiencies that were 90, 76 and 60 percent of improvement in shear, torsion and bending strengths, respectively. It is worth noting that the bearing capacity of concrete girders with adding one layer of CFRP was slightly higher than the ones having two layers of GFRP in all circumstances; therefore, despite the lower initial cost of GFRP, using CFRP can be more economical in some conditions.

• 대한수학회보
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• 제60권1호
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• pp.1-22
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• 2023

Let L(s, χ) be the Dirichlet L-series associated with an f-periodic complex function χ. Let P(X) ∈ ℂ[X]. We give an expression for ∑^f_n=1 χ(n)P(n) as a linear combination of the L(-n, χ)'s for 0 ≤ n < deg P(X). We deduce some consequences pertaining to the Chowla hypothesis implying that L(s, χ) > 0 for s > 0 for real Dirichlet characters χ. To date no extended numerical computation on this hypothesis is available. In fact by a result of R. C. Baker and H. L. Montgomery we know that it does not hold for almost all fundamental discriminants. Our present numerical computation shows that surprisingly it holds true for at least 65% of the real, even and primitive Dirichlet characters of conductors less than 10⁶. We also show that a generalized Chowla hypothesis holds true for at least 72% of the real, even and primitive Dirichlet characters of conductors less than 10⁶. Since checking this generalized Chowla's hypothesis is easy to program and relies only on exact computation with rational integers, we do think that it should be part of any numerical computation verifying that L(s, χ) > 0 for s > 0 for real Dirichlet characters χ. To date, this verification for real, even and primitive Dirichlet characters has been done only for conductors less than 2·10⁵.

• Geomechanics and Engineering
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• 제35권6호
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• pp.637-646
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• 2023

At present, the research on wave propagation in graphene platelet reinforced composite plates focuses on the propagation behavior of bulk waves, in which the effect of boundary condition is ignored, there is no literature report on propagation behaviors of guided waves in graphene platelet reinforced metal foams (GPLRMF) plates. In fact, wave propagation is affected by boundary conditions, so it is necessary to study the propagation characteristics of guided waves. The aim of this paper is to solve this problem. The effective performance of the material was calculated using the mixing law. Equations of motion of GPLRMF plate is derived by using Hamilton's principle. Then, the eigenvalue method is used to obtain the expressions of bending wave, shear wave and longitudinal wave, and the degradation verification is carried out. Finally, the effects of graphene platelets (GPLs) volume fraction, elastic foundation, porosity coefficient, GPLs distribution types and porosity distribution types on the dispersion relations are studied. We find that these factors play an important role in the propagation characteristics and phase velocity of guided waves.

• 디지털융복합연구
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• 제15권6호
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• pp.361-368
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• 2017

최근, 유명 연예인과 인사들의 우리나라 위인에 대한 망언과 실언이 방송에 나감으로써 국민들에게 질타를 받는 안 좋은 이슈를 일으켰다. 반면에, 유명 예능 프로그램에서 특집 편성한 일련의 방송으로 인해 국민들의 역사의식이 높아지고 있다. 이렇게 국민들이 우리나라 역사에 대한 생각이 깊어졌을 때 반드시 짚고 넘어가야 할 점은 바로 역사의 사실성이다. 매체에는 '몰입'이라는 강력한 힘이 존재하기 때문에 수용자 즉, 플레이어가 그 게임에 흥미만 갖게 하는 것이 중요하다. 따라서 역사 사실을 바탕으로 제작된 게임들이 플레이어의 흥미 유발과 관심을 끌기 위해 또는 게임과 캐릭터의 특징을 만들기 위해 역사적 사실과 맞지 않게 제작하는 상황이 발생한다. 그래서 본 연구자는 플레이어들이 올바른 역사의식을 가질 수 있도록 역사 사실을 바탕으로 제작된 'HQ team'사에서 개발한 '천년의 신화'라는 게임을 선정해서 게임 속에 등장하는 '광개토대왕', '근초고왕', '무열왕'의 디자인과 역사적 사실을 비교 분석하고자 한다. 그 결과 역사적인 사실과 게임 속 캐릭터의 디자인이 일치하지 않는 것으로 나타났다.

• 예술경영연구
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• 제53호
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• pp.207-247
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• 2020

<인생나눔교실>은 인문학적 소양을 갖춘 은퇴세대가 멘토가 되어 후속 세대인 멘티에게 삶의 지혜와 방향을 제시하고 소통의 장을 만들어가는 사업이다. 이와 같은 사업의 평가들은 사업이 진행되는 단기간을 기준으로 하여 정량적, 정성적 평가를 수행하는 것이 일반적이다. 그러나 단기간의 평가는 실제 의미있는 효과를 예측하고 판단하기 어렵다는 한계를 가지고 있다. 이에 <인생나눔교실>에서는 2017년과 2018년 영상추적조사를 통해 본 사업의 핵심 참여자의 질적 변화 추이를 살펴보고자 했다. 이를 위해 연구주제에 적합한 조사방법으로 인터뷰 영상 촬영, 촬영 현장 관찰, 가치부호화를 통한 질적연구방법론을 채택하였다. 결과 분석을 위해서는 인터뷰 내용에서 키워드를 추출, 가치부호화 작업을 진행한다. 이후 인문정신가치를 매칭시켜 변화양상을 확인하고 그 의미를 도출하는 이론적 방법을 활용하였다. 실질적으로 본 연구에서 진행한 연구가 추적조사임에도 불구하고 2년이라는 다소 짧은 시간 동안 변화된 양상을 분석했다는 점이 여전히 한계로 남는다. 하지만 국내외 문화예술교육 사업 분야의 추적조사를 위한 모형을 거의 찾아볼 수 없는 현 시점에 추적조사를 위해서 연구자들이 진행해야하는 방법론을 체계화하고 구체적인 적용 사례를 함께 제시했다는 점에서 유의미성을 찾을 수 있다.

• 통상정보연구
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• 제13권3호
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• pp.377-401
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• 2011

본 연구는 우리나라 수출보험이 대기업 및 중소기업의 수출촉진에 효과적으로 작용하고 있는지를 분석하는 데에 초점을 두었다. 이를 위하여 대기업과 중소기업의 수출공급함수 모형을 각각 설정하여 수출보험이 수출공급에 미치는 영향에 대하여 실증분석 하였다. 실증분석 결과를 요약하면 다음과 같다. 1992년부터 2009년까지 연도별 자료를 이용하여 대기업과 중소기업의 수출보험인수액이 수출공급에 미치는 영향에 대하여 통상최소자승법으로 분석한 결과, 대기업과 중소기업의 수출보험인수액은 우리나라의 수출촉진에 긍정적 영향을 미치는 것으로 나타났다. 하지만 실증분석을 하기 위해서는 분석에 사용되어지는 자료들의 안정성 여부가 중요하다. 특히 불안정한 시계열을 적용할 경우 통계분석의 결과가 무의미해질 수 있기 때문이다. 따라서 자료들의 안정성 여부를 파악하기 위해 ADF 방식을 이용하여 검정을 시행한 결과 모든 변수들이 I(1)인 시계열임을 알 수 있었다. 이에 따라 I(1)인 변수들의 장기적 균형관계를 살펴보기 위해 Johansen 검정에 의해 공적분 검정을 실시하였다. 공적분 검정결과, 대기업의 수출공급과 수출보험인 수액 간에서는 5% 유의수준에서 공적분벡터가 존재하는 것으로 나타났다. 반면 중소기업의 수출공급과 수출보험 간에는 공적분벡터가 존재하지 않는 것으로 분석결과 나타났다. 따라서 대기업의 경우 수출보험이 수출공급에 영향을 주는 것으로 해석할 수 있지만, 중소기업의 수출공급에는 수출보험이 영향을 미치지 않고 있다 할 수 있다. 이를 통해서 대기업의 수출은 중소기업의 수출보다 수출보험의 영향력이 더 큼을 알 수 있다.