• Kyungpook Mathematical Journal
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• 제59권2호
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• pp.225-231
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• 2019

In a previous paper, the authors of this paper studied $2{\times}2$ matrices in upper triangular form, whose entries are operators on Hilbert spaces, and in which the the (1, 1) entry has a nontrivial hyperinvariant subspace. We were able to show, in certain cases, that the $2{\times}2$ matrix itself has a nontrivial hyperinvariant subspace. This generalized two earlier nice theorems of H. J. Kim from 2011 and 2012, and made some progress toward a solution of a problem that has been open for 45 years. In this paper we continue our investigation of such $2{\times}2$ operator matrices, and we improve our earlier results, perhaps bringing us closer to the resolution of the long-standing open problem, as mentioned above.

• Journal of Multimedia Information System
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• 제8권4호
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• pp.243-250
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• 2021

Instructional contents are used to demonstrate a technical process to teach and walkthrough certain procedures to carry out a task. This type of informational content is widely used for teaching and lectures in form of tutorial videos and training videos. Since there are questions and uncertainties for what could be the killer application for the novel wearables, we propose a self-instruction training application on a smart glass to utilize already-available instruction videos as well as public open data in creative ways. We design and implement a prototype application to help users train by wearing smart glasses specifically designed for two concrete and hand-constrained use cases where the user's hands need to be free to operate. To increase the efficiency and feasibility of the self-instruction training, we contribute to the development of a wearable killer application by integrating a voice-based user interface using speech recognizer, public open data APIs, and timestamp-based procedural content navigation structure into our proof-of-concept application.

• 한국환경농학회지
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• 제11권3호
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• pp.225-234
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• 1992

Thermal decomposition was conducted to investigate the influence of the various factors on stability of a new insecticide, [O, O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl) thiophosphoric acid ester : KH-502], in view of those informations applicable for industrial exploitation. In the thermal decomposition experiment, KH-502 was, after mixing with Fe, Cu and adjustment of moisture and pH conditions, subjected to three temperatures, 25, 50, and $100^{\circ}C$. Results for stability, and degradation pattern of KH-502 from the above experiment can be summarized as follows: 1. Main products of the thermal decomposition when this was conducted in the closed system were identified as following five compounds:O, O, O-Triethylthiophosphoric acid(TEPA), 1-Phenyl-3-trifluoromethyl-5-ethoxypyrazole(PTMEP), 1-Phenyl-2-ethyl-3-trifluoromethyl-5-hydroxypyrazole(PETMHP), O, O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phosphoric acid ester(KH-502 oxo form), O, S-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phospho rothiolate(S-ethyl KH-502). However, compounds such as oxo form and S-ethyl KH-502 were not identified when the thermal decomposition was proceeded in the open system. 2. KH-502 was stable at 25 and 50$^{\circ}C$, but it was decomposed at 100$^{\circ}C$ following the first-order kinetics at the early stages of decomposition. 3. Rate constants for the thermal decomposition of KH-502 at 100$^{\circ}C$ were in the orders of Cu powder addition 0.344>Cu plate addition 0.21>moisture addition 0.05>closed system=open system=iron addition=pH 5.5 adjustment 0.04>pH 8.5 adjustment 0.027 day$^{-1}$, representing KH-502 was decomposed fast at Cu powder treatment and slow at pH 8.5 adjustment. 4. Half-life for the thermal decomposition of KH-502 at 100$^{\circ}C$ was in the orders of Cu powder addition 2.02

• 한국문헌정보학회지
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• 제13권
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• pp.39-71
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• 1986

Interlibrary loan has been a very common library service in the developed countries but it is yet to be actualized formerly in Korea. As Korea is moving toward an information society where all the individual user's request in the library should be met, we need to understand, in detail, the theory and practice of interlibrary loan service. As various information technology has been applied to the libraries, the libraries became the open system. Thus, the libraries become more cooperative, form networks, and make interlibrary loan service available. This study is based on the following three hypothesis formulated from the systems theory. 1. If libraries cooperate each other and form some kind of networks by mail, computers or telecommunications, they become the open system. 2. If a library develops as the open system, interlibrary loan becomes available in the library. 3. If the interlibrary loan system works, the role of the librarians will be changed. The research was carried out by analyzing the various studies about interlibrary loan service and by examining the interlibrary loan systerns presently working in the U.S.. The conclusions are reached deductively from the data. Some of the terminology used are defined as follows: System: a network of interrelated procedures that are joined together to perform an activity or to accomplish a specific objective. It is, in effect, all the ingredient which make up the whole. Cooperation: Working together to benefit participant libraries. Network: a much more structured type of cooperation in which definite regions or areas are connected by electronic or other means to promote interlibrary loaning of materials, in-service traing & other sharing of resources. Interlibrary loan: the lending of books between libraries. The model of cooperation or networks was used to be (1) a star type, (2) a hieranchical type, (3) a distributed type or (4) the combination of aforementioned three. However, the development of the telecommunications and computers enables all kinds of libraires cooperate together. Interlibrary loan service starts with the needs of user's information. The information have to be logically accessed through bibliographies, computers, electronic mails and satellite communications. And the logical access requires the information technology and the libraries become cooperative. The physical access to the information follows next but only traditional method of mail and some commercial service are currently available for this purpose. Therefore, researches are needed to develop this physical access. If the libraries form networks, the microaspect of library changes accordingly as the macroaspect changes. If the libraries . cooperate to become one large world library, the librarians plan, organize, control library operations and report the results. And the librarians work inside and outside of the library to cooperate with other libraries. Only the cooperation of the libraries will enhance interlibrary loan and the Korean librarians have to be prepared to accept the new role of librarianship for the interlibrary loan service.

• 한국정보과학회논문지:시스템및이론
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• 제37권4호
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• pp.226-238
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• 2010

OpenSSL은 보안 통신 프로토콜인 SSL을 구현한 공개 소스 기반의 라이브러리이다. 하지만, 이 라이브러리는 리눅스 혹은 유닉스 운영체제에서 공유 라이브러리 형식으로 사용될 때 보안 정보를 쉽게 노출할 수 있다는 취약점이 있다. 본 논문은 이런 취약점을 공격하는 기법을 제안한다. 이 기법은 실행중인 클라이언트 프로그램에 공격 코드를 주입하여 SSL 핸드셰이크 단계에서 보안 취약점을 다음과 같이 공격한다. 첫째, 클라이언트가 서버에게 지원 가능한 암호 알고리즘의 목록을 전송할 때 그 목록의 모든 알고리즘을 임의로 지정한 알고리즘으로 교체한다. 이 교체는 암호 알고리즘의 목록을 수신한 서버로 하여금 지정한 암호 알고리즘을 선택하도록 한다. 둘째, 암복호화에 사용되는 암호 키를 생성 과정에서 가로채고, 그 암호 키를 외부 공격자에게 전송한다. 그 후 외부 공격자는 지정한 암호 알고리즘과 가로챈 암호키를 사용하여 송수신된 암호 데이터를 복호화한다. 제안하는 기법의 실현성을 보이기 위해 본 논문은 리눅스에서 OpenSSL 공유 라이브러리를 사용하는 ftp 클라이언트가 서버로 전송하는 암호화된 로그인(login) 정보를 가로채 복호화하는 실험을 수행하였다.

• 한국의상디자인학회지
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• 제16권1호
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• pp.105-115
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• 2014

The costumes (including mask) of the first World Master series of The National Changguk Company of Korea, Achim Freyer's 'Mr. Rabbit & Dragon king' is directly designed by Achim Freyer who was in charge of direction and stage design. The new form called Pansori opera is proposed for modernization of Korean traditional opera, it maintained the original form of music yet introduced play form of opera. The costumes and stage also promoted modernistic transformation while maintaining the original Korean form. The overall concept of 'Mr. Rabbit & Dragon king' costumes emphasizes comical effect by abstractness like childlike scribble. It expressed characteristic of characters diversely through exaggeration and expansion while maintaining original form of Hanbok, used surface of costumes as a drawing board, and created flat and geometrically transformed silhouette. The complicated characters was caricatured like everyone is doing mask play by using masks, and it still maintained sophisticated oriental color with modern application of five cardinal colors. It may seems it just mixed our traditional elements like a hint of humor, however, it could be known that it introduced various techniques in it to deliver new subject while maintaining the original form of 'Mr. Rabbit & Dragon king'. From this study, open mind for our tradition and need for diverse attempt could be rediscovered and could also see the possibility to contribute on creating a Nation Brand of traditional performing art.

• 경영과정보연구
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• 제2권
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• pp.169-193
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• 1998

Case- based reasoning(CBR) offers a new approach for developing knowledge based systems. Unlike the rule-based paradigm, in which domain knowledge is encoded in the form of production rules, in the case-based approach the problem solving experience of the domain expert is encoded in the form of cases stored in a casebase(CB). CBR allows a reasoner (1) to propose solutions in domains that are not completely understood by the reasoner, (2) to evaluate solutions when no algorithmic method is available for evaluation, and (3) to interprete open-ended and ill-defined concepts. CBR also helps reasoner (4) take actions to avoid repeating past mistakes, and (5) focus its reasoning on important parts of a problem. Owing to the above advantages, CBR has successfully been applied to many kinds of problems such as design, planning, diagnosis and instruction. In this paper, I propose case-based DSS(CBDSS). CBDSS is an intelligent DSS using CBR technique. CBDSS consists of interface, case-based reasoner, maintainer, casebase management system, domain dependent CB, domain independent CB, and so on.

• 대한수학회지
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• 제33권3호
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• pp.625-639
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• 1996

A convex $RP^n$-structure on a smooth anifold M is a representation of M as a quotient of a convex domain $\Omega \subset RP^n$ by a discrete group $\Gamma$ of collineations of $RP^n$ acting properly on $\Omega$. When M is a closed surface of genus g > 1, then the equivalence classes of such structures form a moduli space $B(M)$ homeomorphic to an open cell of dimension 16(g-1) (Goldman [2]). This cell contains the Teichmuller space $T(M)$ of M and it is of interest to know what of the rich geometric structure extends to $B(M)$. In [3], a symplectic structure on $B(M)$ is defined, which extends the symplectic structure on $T(M)$ defined by the Weil-Petersson Kahler form.

• 한국환경과학회지
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• 제4권2호
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• pp.245-251
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• 1995

Generally, It is Introduced to well-known other models without considering tidal current of the field. The paper presents field measurements and numerical model solving velocity field of Cheonsu Bay by two-dimensional tidal model. It was proved that this scheme is easy to handle complex topography. Computed results is represented characteristics of tidal current for Cheonsu Bay. The results of the study can be summarized as follows ; 1. Tide form number has 0.21 value. Tidal range estimated 630.3 cm on spring, 454.1 cm on mean and 277.9 cm on neap, respectively 2. Tidal current has semi-diurnal form. Distance of traveling observed 16.6 km on flood and 15.5 km on ebb. 3. Tidal velocity showed reversing current. It was found that tidal velocity above 100 cm/sec is about 20 %. 4. Computed results are in good agreement with the observed data. Applying the algorithm to Cheonsu Bay, velocity fields and dry bank phenomena are simulated well in spite of complex topography. 5. An advanced study on the effects of open boundary conditions should be continuously performed.

• 한국의류학회지
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• 제18권5호
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• pp.727-738
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• 1994

It has been representing the delicate changes which express new sentiments through the floating, fluid, free look with the transparent, sheer material in fashion during the early 1990's. The concept of lightness is selected to describe the phenomenon of recent fashion. The purpose of this study is to identify the distinctive characteristics of lightness as external forms and internal meaning in fashion of the early 1990's. The data were collected from fashion magazines such as American Vogue, Italian Vogue from 1987 to 1994. The characteristics of lightness of fashion in the early 1990's are as follows; The external forms are consisted of the material such as the transparent, sheer, soft material, of slim and bell silhouette which occupying the more space in bottom, of the drapery, pleats to shape the unfitted look and is identified as the open, whole, indeterminate and planar intergration form according to the category of clothing form suggested by Belong. It is also the reflection of the social changes which is getting out of the modernity. It is the results of the dominant social state which are diffused the sensual pleasures, transitoriness.