• Bulletin of the Korean Mathematical Society
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• v.48 no.6
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• pp.1315-1327
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• 2011

Let M be a real hypersurface of a complex space form with almost contact metric structure (${\phi}$, ${\xi}$, ${\eta}$, g). In this paper, we study real hypersurfaces in a complex space form whose structure Jacobi operator $R_{\xi}=R({\cdot},\;{\xi}){\xi}$ is ${\xi}$-parallel. In particular, we prove that the condition ${\nabla}_{\xi}R_{\xi}=0$ characterizes the homogeneous real hypersurfaces of type A in a complex projective space or a complex hyperbolic space when $R_{\xi}{\phi}S=R_{\xi}S{\phi}$ holds on M, where S denotes the Ricci tensor of type (1,1) on M.

• Journal of Korean Association for Spatial Structures
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• v.20 no.1
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• pp.95-102
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• 2020

The structural design of arch roofs or bridges requires the analysis of their unstable behaviors depending on certain parameters defined in the arch shape. Their maintenance should estimate the parameters from observed data. However, since the critical parameters exist in the equilibrium paths of the arch, and a small change in such the parameters causes a significant change in their behaviors. Thus, estimation to find the critical ones should be carried out using a global search algorithm. In this paper we study the parameter estimation for a shallow arch by a quantum-inspired evolution algorithm. A cost functional to estimate the system parameters included in the arch consists of the difference between the observed signal and the estimated signal of the arch system. The design variables are shape, external load and damping constant in the arch system. We provide theoretical and numerical examples for estimation of the parameters from both contaminated data and pure data.

• Journal of the Chungcheong Mathematical Society
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• v.22 no.3
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• pp.481-495
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• 2009

Huffman, Park and Skoug introduced various results for the $L_{p}$ analytic Fourier-Feynman transform and the convolution for functionals on classical Wiener space which belong to some Banach algebra $\mathcal{S}$ introduced by Cameron and Storvick. Also Chang, Kim and Yoo extended the above results to an abstract Wiener space for functionals in the Fresnel class $\mathcal{F}(B)$ which corresponds to $\mathcal{S}$. Moreover they introduced the $L_{p}$ analytic Fourier-Feynman transform for functionals on a product abstract Wiener space and then established the above results for functionals in the generalized Fresnel class $\mathcal{F}_{A1,A2}$ containing $\mathcal{F}(B)$. In this paper, we investigate more generalized relationships, between the Fourier-Feynman transform and the convolution product for functionals in $\mathcal{F}_{A1,A2}$, than the above results.

• Journal of the Chungcheong Mathematical Society
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• v.30 no.1
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• pp.77-102
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• 2017

As an analogy of $Poincar{\acute{e}}$ series in the space of modular forms, T. Ono associated a module $M_c/P_c$ for ${\gamma}=[c]{\in}H^1(G,R^{\times})$ where finite group G is acting on a ring R. $M_c/P_c$ is regarded as the 0-dimensional twisted Tate cohomology ${\hat{H}}^0(G,R^+)_{\gamma}$. In the case that G is the Galois group of a Galois extension K of a number field k and R is the ring of integers of K, the vanishing properties of $M_c/P_c$ are related to the ramification of K/k. We generalize this to arbitrary n-dimensional twisted cohomology of the ring of integers and obtain the extended version of theorems. Moreover, some explicit examples on quadratic and biquadratic number fields are given.

• Architectural research
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• v.1 no.1
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• pp.1-10
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• 1999

During the first twenty-six years of its existence from 1954 to 1980, Keimyung University established on its Daemyung Campus a unique community of Western period-style buildings which recalls an old liberal arts college in America. During the first fifteen years, Keimyung built basically in the neo-Georgian style in accordance with the visions of the first two presidents, both of American nationality. During the next eleven years when Keimyung considerably expanded its facilities, it built in the neo-Classical style. The architecture of the Daemyung Campus is not without dynamism as it shows some efforts to integrate the expressions of the historical and the modern, culminating in the Main Library. The Daemyung Campus thus presents an interesting case study of how Western period-style architecture was assimilated in a provincial Korean city with a sense of an on-going building tradition.

• Journal of Information Processing Systems
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• v.12 no.3
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• pp.381-391
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• 2016

The Joint Bayesian (JB) method has been used in most state-of-the-art methods for face verification. However, since the publication of the original JB method in 2012, no improved verification method has been proposed. A lot of studies on face verification have been focused on extracting good features to improve the performance in the challenging Labeled Faces in the Wild (LFW) database. In this paper, we propose an improved version of the JB method, called the two-dimensional Joint Bayesian (2D-JB) method. It is very simple but effective in both the training and test phases. We separated two symmetric terms from the three terms of the JB log likelihood ratio function. Using the two terms as a two-dimensional vector, we learned a decision line to classify same and not-same cases. Our experimental results show that the proposed 2D-JB method significantly outperforms the original JB method by more than 1% in the LFW database.

• Journal of environmental and Sanitary engineering
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• v.24 no.2
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• pp.9-16
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• 2009

The purpose of this study is to investigate the effect on the university student' attitude toward environmental problem with PBL. The controlled group consisted of 80 students who was applied PBL and experimental group was applied a traditional teaching method was consisted with 80 students. The results is as follows ; First, there was a statistically meaningful differences in attitudes toward environment between two group(F=52.789, p<0.1). It shows that PBL is very effective in attitude toward environment. Second, there was a more meaningful increasing effect of student' consciousness of environmental problems before and after environmental education on the controlled group which was applied PBL than experimental group which was applied a traditional teaching method. Finally, in the literacy education of university student' related with environment problems recommend that PBL is more effective than that of traditional teaching method.

• ETRI Journal
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• v.32 no.4
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• pp.503-511
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• 2010

WiBro radio frequency (RF) repeater is used for solving the problem of partial shadow areas in the wireless communication field that uses time-division duplexing (TDD) mode. In this paper, a method to efficiently generate TDD signals for WiBro RF repeater is proposed and its digital circuit is implemented. A TDD signal is detected from RF signals transmitted/received to/from RF repeater and then inputted again into the RF repeater, so that it can operate normally. First, the envelope of downlink signals is detected and then clamped to extract the basic form of a TDD signal using an operational amplifier circuit. Next, the TDD signal is generated by restoring and filtering the shape which has been distorted by the wireless channel. The algorithm and system to acquire TDD signal are developed with a goal to have simple but powerful functions with as little cost as possible. The proposed method is implemented as an RF-digital integrated system and verified through the experiments under the same condition as actual WiBro service environment.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.207-210
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• 2006

자동차 추돌 방지용 레이더는 도로 사정이나 기후에 따른 운전자의 인지 및 판단이 불가능한 상황에서도 차량 간의 추돌을 예방할 수 있는 시스템이다. 현재까지 연구 개발된 차량용 레이더는 초음파나 밀리미터 웨이브 등을 이용하므로 가격이나 크기 등에서 경쟁력을 갖추지 못하고 있는 실정이다. 따라서 본 논문에서는 적외선 레이저 다이오드를 매트릭스 형태로 배열한 다중 파장 구조 방식을 제안하였다. 이는 악천후에서의 탐지 능력을 개선시킬 수 있다. 또한 의사 잡음 수열의 상관 특성을 이용하여 인접 차량의 레이저 신호에 의한 간섭 영향을 최소화시킬 수 있기 때문에 차세대 ITS 기술 선점 및 산업 경쟁력을 확보 등의 효과를 기대할 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.179-182
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• 2012

기존의 원격 교육 시스템은 대부분 데스크탑 컴퓨터를 기반으로 하고 있다. 그러나 최근에 PDA, 스마트폰, 태블릿 등의 다양한 모바일 기기들이 개발되고, 그 사용자가 점점 늘어남에 따라서 모바일 기기 기반의 원격교육 시스템에 대한 필요성이 증대되고 있다. 따라서 본 논문에서는 u-캠퍼스 환경기반에서의 모바일 러닝 서비스 시스템을 구현하였다. 모바일 러닝 서비스 시스템은 u-캠퍼스 환경기반에서 교육 수요자들인 학생들에게 시공간의 제약 및 디바이스에 제약이 없는 학습 환경 시스템을 제공하고 모바일 캠퍼스 플랫폼 기반의 m-러닝 시스템을 구현한 것이다.