• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.4
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• pp.70-75
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• 2009

According to the aviation statistics, tail strike incidents and accidents are cyclic. Although many tail strikes occurred during takeoff, these are less than during landing cases. Many cases are related on human factors. In my opinion it is possible to analyze the causes of takeoff tail strikes to some extent. There are major casual factors of tail strike during takeoff such as; (1) Mis-trimmed horizontal stabilizer (2) premature rotation prior to $V_R$ (3) Excessive pitch up rate during rotation (4) Improper use of the flight director. Among these causes improper use of flight director is excluded in this paper because it is recommended that pilot should use flight director after airborne. So I analyzed the other three causes as following. Firstly, because mis-trimmed stabilizer is related to center of gravity(CG), the relationship between stabilizer and CG is reviewed. Secondly, concerned premature rotation prior to $V_R$ I reviewed the background of rotation speed($V_R$) establishment and analyzed theoretically what speed leads to tail strikes. Thirdly, concerning excessive pitch up rate during rotation I analyzed what excessive pitch up rate can decrease ground clearance while using FDR data.

• Journal of The Geomorphological Association of Korea
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• v.20 no.1
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• pp.57-74
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• 2013

Coastal terrace was developed at 8.3m height near Waon village in Suncheon-si. Due to the sandgravel layer deposited in a different today's environments, rounded gravel(4.3m, 5.8m, 6.3m) sequentially in a cross-section of coastal terrace, so it provides a good example which understand Holocene sea level changes to determine the effect on the various climatic-environments traits. For the purpose of identifying the morphogenetic process, Profile description, Grain size, XRD, Thin section analysis was attempted. As a result, coastal terrace are more likely to have been formed by the more recent period rather than the last interglacial(MIS 5 period), and at that time, various pedological features are considered to be formed.

• Informatization Policy
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• v.28 no.2
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• pp.3-33
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• 2021

The purpose of this study is to analyze the research trends in the field of Blockchain that is one of the core technologies of the 4^th Industry, and present future research orientation. In this study, (1) Blockchain technologies in business perspective are summarized; (2) analysis criteria of Blockchain fields are established; and (3) results of analysis are presented and future research orientation is proposed. Major findings are as follows: (1) related research is being activate with the advent of the 3rd generation blockchain which aims for distributed applications. (2) major concerns of the technology (engineering) field is blockchain scalability and of the business (application) field is blockchain-based supply chain traceability. (3) Compared to overseas, domestic research results are very poor. (4) to catchup the gap, the spreading of awareness that blockchain is not a technology but a business means is required.

• Korean Journal of Cognitive Science
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• v.18 no.3
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• pp.223-244
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• 2007

Two well known mis-localization effects, flash-lag effect (FLE) and the Pulfrich effect, have similar phenomena and theoretical explanations. In order to directly compare two phenomena, thereby examining the possibility that two phenomena have a common mechanism, the magnitudes of two effects were measured under the same experimental settings and stimuli. The Pulfrich depth was measured from each of four different brightness ratios of two moving stimuli, each of which was projected to each eye. The magnitude of FLE was measured from each of five different brightness levels, which were the same levels used in the Pulfrich experiment. The Pulfrich depth was increased with the increase of brightness ratio, whereas similar pattern was not found in the magnitude of FLE. Furthermore, actual Pulfrich depths were greatly different from those predicted from the difference of two FLEs. These results suggest that two phenomena may not have a common mechanism.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.63-81
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• 2017

Objectives of this study are to analyze the previous research perfomed in the Bus Information System (BIS) area and to suggest future research directions. This is a very meaningful and important work. To accomplish this, this study (1) summarizes the concepts of BIS, (2) establishes a research framework to be used to analyze the previous studies in the area, and (3) identifies and suggest trends and future directions of the BIS research. This study has identified total of 68 article (22 foreign and 46 domestic) using 'Google Scholoar' search engine. Major research results include (1) since non-empirical research is dominant, more explanatory empirical research is needed in the future, (2) research that provides consistent and comprehensive measures for BIS related constructs (e.g., BIS quality) is needed, and (3) impacts on the stakeholders of BIS not reflected in the current research (e.g., bus drivers, administrative agencies) should be analyzed in the future research.

• Korean Journal of Materials Research
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• v.9 no.8
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• pp.825-830
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• 1999

Characteristics of SiOF films deposited by a FTES/$O_2$-plasma enhanced chemical vapor deposition method have been investigated using Fourier transform infrared spectroscopy, X-ray photoelectro spectroscopy, and ellipsometry. Electrical properties such as dielectric constant, dielectric breakdown and leakage current density are investigated using C-V and I-V measurements with MIS(Au/SiOF/p-Si) capacitor structure. Stepcoverage of the films have been also characterized using scanning electron microscopy and ellipsometry. A high quality SiOF film was formed on that the flow rates of FTES and $O_2$were 300sccm, respectively. The dielectric constant of the deposited SiOF film was about 3.1. This value is lower than that of the oxide films obtained using other method. The dielectric breakdown field and leakage current are more than 10MV/cm and about $8[\times}10^{9}A/\textrm{cm}^2$, respectively. The deposited SiOF film with thickness as $2500{\AA}$ on the $0.3{\mu}{\textrm}{m}$ metal pattern shows a high step-coverage without a void.

• Journal of Intelligence and Information Systems
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• v.28 no.2
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• pp.207-235
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• 2022

In a knowledge-based society where knowledge and information industries are the main pillars of the economy, knowledge sharing and diffusion and its systematic management are recognized as essential strategies for improving national competitiveness and sustainable social development. In the field of Information Systems (IS) research, where the convergence of information technology and management takes place in various ways, the evolution of knowledge occurs only when researchers cooperate in turning old knowledge into new knowledge from the perspective of the scientific knowledge network. In particular, it is possible to derive new insights by identifying topics of interest in the relevant research field, applied methodologies, and research trends through network-based interdisciplinary graftings such as citations, co-authorships, and keywords. In previous studies, various attempts have been made to understand the structure of the knowledge system and the research trends of the relevant community by revealing the relationship between research topics, methodologies, and co-authors. However, most studies have compared two or more journals and been limited to a certain period; hence, there is a lack of research that looked at research trends covering the entire history of IS research. Therefore, this study was conducted in the following order for all the papers (from its first issue in 1977 to the first quarter of 2022) published in the MIS Quarterly (MISQ) Journal, which plays a leading role in revealing knowledge in the IS research field: (1) After extracting keywords, (2) classifying the extracted keywords into research topics, methodologies, and theories, and (3) using topic modeling and keyword network analysis in order to identify the changes from the beginning to the present of the IS research in a chronological manner. Through this study, it is expected that by examining the changes in IS research published in MISQ, the developing patterns of IS research can be revealed, and a new research direction can be presented to IS researchers, nurturing the sustainability of future research.

• Journal of Digital Convergence
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• v.6 no.3
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• pp.85-91
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• 2008

본 연구는 프로젝트 선정 및 포트폴리오 관리에 관한 고찰이다. 첫 번째 부분은 프로젝트 선정에 관한 세 가지 방법 (AHP, 경제학적 방법, Microsoft's Enterprise 프로젝트 관리 방법)의 장 단점에 대한 간단한 견해를 제시하였다. 두 번째 부분은 프로젝트 포트폴리오 관리에 관한 기법 등을 소개하였고, 6개의 질문을 통해 프로젝트 포트폴리오 관리 시스템에 대해 어떻게 조직화하고 활용할 것인가를 고찰하였다.

• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.65-70
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• 2011

Recently, audio-visual speech recognition (AVSR) has been studied to cope with noise problems in speech recognition. In this paper we propose a novel method of deciding weighting factors for audio-visual information fusion. We adopt the particle swarm optimization (PSO) to weighting factor determination. The AVSR experiments show that PSO-based normalized confidence measures (NCM) improve the rejection performance of mis-recognized words by 33%.

• Journal of the Korean Operations Research and Management Science Society
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• v.3 no.2
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• pp.25-28
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• 1978

근간에 큰 기업체의 대부분은 컴퓨터를 갖추어 관리 정보체제(MIS)의 효율적인 운용을 시도하고 있다. OR/SA 분석으로 과학적인 정책수립 및 경영정책으로 무국적의 기업경쟁에 도전하고 있다. 그러나 실제 실무에 있어서 OR/SA 기법활용이 기대하고 있는 만큼 활발하지 못하며 높이 평가되고 있지 않다. 그 원인의 하나로는 제통계자료의 불충분으로 데타베스시스템이 빈약하여 OR/SA의 결론에 자신이 적어 막상 실제적용에 조심스러운 학문이라는 것과 또 하나로는 공공기관 및 기업체의 의사결정이 장기적인 안정의 시야에서가 아니라 단기적인 편법위주의 수단으로 검토되고 있는 경향이 있기 때문이다. 다소 안정된 선진국가에 있어서도 경제 및 과학발전에 따른 갖가지 사회적 위기에 대하여 미해결인 체 고심하고 있다.(중략)