• Journal of Astronomy and Space Sciences
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• v.12 no.1
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• pp.112-122
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• 1995

We assume that the KOREASAT fails the entry of the geostationary orbit due to the error at the apogee kick motor firing. A simulation is done for the satellite that has a geosynochronous orbit with a non-zero degree inclination angle due to the failure at the apogee kick motor firing caused by the unbalance of the fuel storage and the spin of the thrust vector, etc. We analyzed the evolution of the orbit using the perturbation theory and calculated the changes of the eccentricity and the inclination. WHen a communication satellite has the figure eight trajectory, the beam point also traces the satellite. In this paper, We develope an algorithm to attack the above problem by stabilizing the beam point using the adjustment of the roll angle of the satellite. The spin action on the polarization plane that occurs when a satellite passes the ascending node and descending node affects the efficiency of the communication a lot, so we did another simulation for the better yaw angle adjustment for the KOREASAT to reduce the spin actino on the polarization plane.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.4
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• pp.387-401
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• 2007

Recently, because of the restriction of land for construction and interference of adjacent structure, parallel tunnels with small clearance have been planned and constructed in many sites. In this case, the stability of pillar at center part is very important factor to satisfy the stability of tunnel structure under the construction. In this paper, numerical analyses for the asymmetry parallel tunnels with a narrow width of pillar have been carried out to search for the optimum reinforcement measure for rock pillar and verify the stability of tunnel. Rock pillar between each single tunnel is supposed to be under heavy load by rock mass. The analysis of stress state at rock pillar at various cases for construction conditions is required to investigate the structural behaviour of tunnels and stability of the pillar. Strength-stress ratio is calculated based on the failure theory of rock and the safety factor of tunnel is computed with strength reduction technique. Through these numerical results, reasonable reinforcement measures for rock pillar at parallel tunnel were established and recommended.

• Architectural research
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• v.16 no.2
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• pp.37-44
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• 2014

Utilizing spaces for awareness could be superficially noble. However, the typology of spaces played an important role in addressing the awareness of translating the messages through tangible forms, which in this context are sculptures. Assuring the efficacy of the typology of the spaces that is compatible with the content is important to ensure its timelessness to the dynamic demographical change of viewers. Therefore, the study proposes an investigation of the efficacy of typology of public urban space; garden that accommodates memorial sculptures. The study intends to analyze the features and flaws of ASEAN Sculpture Garden, as a mediatory role of ASEAN in instilling awareness of unity between ASEAN members to the public. The objective of the study is to analyze the efficacy of the garden to accommodate the rich memorial sculptures. The body of the research is formed by theoretical and case study research. It is projected by three methods; archival research, semi structured interviews and site documentation; direct observations and site visit. The qualitative data then will be analysed using Actor Network theory, keyword coding and site findings. Findings showed that as the main objective of the garden is to exhibit the sculptures, it could be summed up that it has failed to meet the apparent intention based on the site analysis conducted by the researcher. The typology of the space should be able to communicate the project's aims continuously rather than serving the function temporarily. The variables, which are space and time factors are debatable, as the neighboring tourist spot, National Monument residing the wide square managed to attract public attention due to its great efficacy of typological space regardless the time factor. As a conclusion, the typology of space is a huge factor to ensure the park's success.

• The Journal of Art Theory & Practice
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• no.2
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• pp.121-146
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• 2004

Compared to the influences of Korean art journalism, the researches on them are rarely conducted. This study aims to examine the influence of art journalism in art magazines in Korea. Although it is essential to consider media, journalism, public opinion altogether, I focused only on the media due to the absence of previous studies I have analyzed the current conditions of korean art journalism, types of feature articles, sponsors, their relations with articles and the comparison with foreign art journalism in terms of production conditions. There have been about one hundred art magazines published in previous sixty years and currently there are twenty three. Monthly periodicals are the majority: the publishers are sorted out as publishing houses, galleries, newspaper company in order specialized art magazines developed from the eighties. Through an examination of feature articles in these art magazines, I found that they repeated similar art issues and covered the same artists sponsors and articles. Moreover, when the magazines went through the conflicts between managers and editors, the ascendency of managers obstructed the development of art journalism regarding journal quality. These days, art journalism have been comparatively regressed compared to other art systems such as art museums, curatorship, international aft festivals, distributions and art promotion policies. The main causes for failure were the lack of professional management, the limited effort to diversify sponsors, and the repetition of the same informants and events without making an effort to be specialized Magazines are published media which contribute to the creation of culture, distribution, and preservation. Therefore art magazines can be said the most influential media in forming art culture and distributing it. It is quite necessary to reform the problems of repeating of information and the lack of speciality in conjunction with the commitment of management and editorialship.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.8
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• pp.949-956
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• 1999

이 논문에서는 ATM (Asynchronous Transfer Mode) 방식의 초고속망의 장애 발생 시 이용자 연결의 QoS (Quality of Service)를 고려하여 복구할 수 있게 하는 보호 망 설계 방안을 제시한다. 제시한 설계 방안에 기초한 비용과 복구 특성을 분석과 모의 실험을 통해 알아본다. 제안하는 망에서의 복구는 분리 VP 그룹 (Disjoint Virtual Path Group, DVPG) 을 사용하는 상태 독립적 (State- independent) 방식으로 복구된다. ATM 망의 운용 및 보호 VP 할당과 용량 배정 문제를 정의하고 이를 바탕으로 최소의 비용을 갖는 VP 망을 설계한다. 망의 고장 시 기존 노드간의 VP 연결은 미리 할당된 링크 또는 노드 분리 보호 VP 경로를 따라 간단한 복구 알고리즘에 의해 빠르게 복구된다. QoS의 고려는 추가 비용을 필요로 하지만 정확한 이용자 연결의 복구를 실현하며, 분리 VP 그룹의 적용은 비용을 상승시키지만, 빠른 복구와 복수의 고장에 대처할 수 있는 방안이 된다.Abstract A cost evaluation of protection scheme for VP-based ATM network is presented here and its related characteristics are evaluated. The proposed and evaluated scheme is a state-independent restoration scheme using a disjoint path group. For fast and simple restoration of failed connections, link disjoint or node disjoint VP groups (DVPG) were utilized in this paper. A VP assignment and capacity planning problem is formulated. When failure occurs, the failed working VPs are switched to the protection VPs of disjoint path groups with a simple restoration scheme. And, cost evaluation and restoration characteristics are presented. The consideration of multiple QoS (Quality of Service) levels and disjoint path group protection scheme require additional network cost but acquire fit and fast restoration.

• Knowledge Management Research
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• v.13 no.4
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• pp.101-116
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• 2012

Knowledge management system is crucial for increasing organizational performance. However, despite this importance of knowledge management system, many companies fail to facilitate individual employees' knowledge sharing. One of reasons for this failure is the lack of consideration of how individual employees' characteristics and their interpersonal relationship influence on individual-level knowledge sharing. To explain individual-level knowledge sharing, this study investigates the mechanism that employees engage in knowledge sharing activities with their coworkers from the social exchange perspective. We have two purposes of study. First, we examine whether coworker's task-related help seeking affects employee's knowledge sharing with them. Second, we investigate the influence of help-seeker' characteristics as moderators on the relationship between task-related help seeking and knowledge sharing. Specifically, we considered coworker's maladjustment, LMX, and ability as moderators. Our analysis of 192 employees shows that the main effect of coworker's task-related help seeking on knowledge sharing is not significant. However, coworker's maladjustment and LMX moderate the relationship between task-related help seeking and knowledge sharing. The positive relationship between task-related help seeking and knowledge sharing is stronger when help seeker's maladjustment is high than when it is low. And the positive relationship between task-related help seeking and knowledge sharing is weaker when help seeker's LMX is high than when LMX is low. The results of this study have theoretical implications that enrich our understanding of individual-level knowledge sharing, and managerial implications that suggest employees' appropriate attitudes to facilitate knowledge sharing in a coworker relationship.

• STI Policy Review
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• v.6 no.2
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• pp.54-86
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• 2015

The study examines the U.S. Small Business Innovation Research (SBIR) program, with a focus on the recent Reauthorization, and compares, in the political context, the U.S. and East Asian countries-Japan, Korea and Taiwan-that adopted the U.S. SBIR program. For the systematic analysis and cross-country comparison, the study employs Kingdon (2003)'s framework-his political theory and Garbage Can Model-to identify political participants and processes underlying the SBIR Reauthorization and to analyze the differences in problem, policy, and politics streams between the U.S. and East Asian countries. For the cross-country comparison, specifically, the study uses various data sources such as OECD, Global Entrepreneurship Monitor, Hofstede's Cultural Dimensions, and World Value Survey. Based on the analysis outcomes, implications of U.S. practices on East Asian countries are extracted as follows. East Asian countries tend to: Have higher entrepreneurial aspiration while lower entrepreneurial activity and attitude than the U.S.; bear higher long term orientation and uncertainty avoidance while lower individualism than the U.S.; and have greater expectations of technology development and higher confidence in political parties while participating less in political action than the U.S. Drawing on the differences, the following policy recommendations are suggested. East Asian countries should: Improve entrepreneurs' access to resources (in particular, financial resource) in order to link their high entrepreneurial aspiration to actual entrepreneurial activities; cultivate failure-tolerating culture and risk-taking entrepreneurs, for instance, by providing a second chance to SBIR-participating businesses that failed to materialize their innovative ideas; and leverage their high expectations of new technology in order to take bold actions regarding their SBIR programs, and update the programs by drawing out constructive dialogues between SBIR stakeholders.

• Journal of Korean Society of Steel Construction
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• v.24 no.2
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• pp.207-215
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• 2012

The 45-degree cone failure theory has been used in concrete anchor bolts design under shear loading, but the CCD (Concrete Capacity Design) method was adopted as a new design method since 2000. However, the method was allowed only for anchor diameters of less than 50mm because it is based on the experimental results of small size anchor bolts. Therefore, it is necessary to develop a rational concrete breakout capacity equation for medium-to-large size anchor bolts with large edge distance. In this study, shear tests on M56 cast-in-place single anchor bolt with edge distance of 350mm were performed using four test specimens. Based on the test results and findings of existing studies, a new equation for the breakout capacity of anchor bolts under shear loading with edge distance of up to 750mm was proposed.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1144-1154
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• 2008

In this paper, the behaviour of shell foundation was studied. In order to perform this study, three studies such as theoretical, numerical and experimental programs were performed. In the theoretical program, the general shallow foundation theories and failure mechanism developed by Terzaghi, Mayerhof and others were reviewed and compared. Based on the previous shallow foundation behaviour, the shell foundation theory was developed using the upper boundary theorem. In the numerical study, the 2 and 3 dimensional FEM simulations were carried out using an uncoupled-analysis approach. From the analysis results, the adequate depth of shell foundation was evaluated. It was also evaluated the bearing capacity according to the shell angle ($120^{\circ}$, $90^{\circ}$, $60^{\circ}$). In the experimental study, the laboratory model tests were carried out for five cases of different foundation shapes including the rectangular and circular foundation in order to verify the theoretical and nemerical study. According to the results of this study, the bearing capacity of shell foundation was theoretically about 15% larger than that of general foundation. However, in the model test, the bearing capacity of shell foundation was about 25 to 30% larger than that of general foundation. In the case of shell angle, the maximum bearing capacity of shell foundation shows when the shell angle of foundation was $60^{\circ}$. In addition, Even if the shell foundation has the various advantages compared with the general foundations as described above, the practical verifications in full scale size will be necessary to use in the field and will be helpful in the technical development of other special foundations.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.194-203
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• 2008

Construction companies require management system to increase efficiency and profit because of receiving competition and globalizing business environment. Since 1990s, construction companies have made various attempts to innovate business structure both internally and externally by means of BPR, 6 Sigma, PI, and Workflow. Some improvements were made, but most of them were temporary, and insufficient to provide the much-needed promptness of business process in responding to the changes. Furthermore, the recent methods of applying BPM and practical using are limited to the theory and method of other industries, and also the attempts of applying BPM in construction industry are at the stage of theoretical approaching and examining in a few construction companies. Accordingly, this study deduces the necessity of adopting BPM based on change of business paradigm for construction companies and limits of current researches, failure causes and problems of application attempts of BPM and process management. And also, we analyze Advance of BPM and suggest the application method of business process management model for construction companies.