• Journal of Welding and Joining
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• 제13권4호
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• pp.122-131
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• 1995

An automatic welding equipment for thick plates requires the capability of the seam tracking of the weld line which often includes misalignment of the workpiece and variation of groove width. In this study, an automatic welding equipment and control algorithms based on the arc sensor were proposed for the GMA welding of thick plates which had misalignment and gap variation. The developed system being constituted with 5 axis can be automatically controlled by computer and also automnatically set the welding conditions such as welding current, and voltage. The proposed algorithms for the seam tracking in multi-pass welding of the thick plates were constituted as follows : the detection of weaving-end point for findng the variation of groove width, the control of welding velocity for acquiring a constant thickness deposition of weld metal, and the calculation of groove width and height of an arbitrary pass in the multi-pass weld. As results of the application of the system, it was revealed that the system had a good capability in seam tracking and made an excellent weld quality in V groove butt joint.

• 기술혁신연구
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• 제13권2호
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• pp.45-70
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• 2005

Much work on innovation has focused on the manufacturing sector. In this paper, we propose a framework for analyzing innovation in services centred on capability and technology integration. We illustrate the theoretical points made by conducting a case study on an international telephone communications provider Brastel, which introduced significant innovations in international calling services, in the form of rechargeable pre-paid calling card, through effective application of standard IT. Brastel is situated against its main competitors, considering two dimensions of price and service breadth and convenience. A novel technique for measuring competitiveness based on price and service index is introduced. The following competitors were selected: NTT, KDDI, Japan Telecom, Fusion Communications, J-Call / World Link, G-Call, ASP Check, Primus, QuickPhone, and MCI. To create the service index, factors such as ease of use, convenience, number of languages in which the services are available, and additional features were taken into account. The company itself and the rechargeable card innovation were analyzed through in-depth interviews and data collection. It was shown that a competitive advantage was maintained through internal and external capabilities.

• 한국해양공학회지
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• 제32권1호
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• pp.43-50
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• 2018

Recently, various efforts have been made to develop oil and gas in the Arctic Ocean. It is very important to consider the load caused by ice in designing floating structures in the area. The magnitude of the ice load and its impact on a structure should be considered. In this paper, we analyze ice parameters affecting the DP performance of FPSO with a DP-assisted mooring system. Several ice characteristics are selected, and the resulting ice load is calculated using GEM software. Numerous simulations are conducted while changing the values of the parameters, and DP capability plots are generated to visualize the effects of changing these parameters. It is shown that the ice drift speed and thickness are the major properties to be considered in DP system design. The limitations of the analysis and future work are discussed in the conclusion.

• 한국정보처리학회논문지
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• 제3권5호
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• pp.1138-1146
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• 1996

퍼지 논리는 추론과정에서 일부의 정보가 무시되어 적절하지 못한 추론 결과를 초래할 수 있다. 한편, 신경망은 패턴 처리에는 적합하지만 인간의 지식을 모델링하기 위해서 필요한 논리적인 추론에는 부적합하다. 그러나 신경망의 변형인 신경논리망 (neural logic network)을 이용하면 논리적인 추론이 가능하다. 따라서 본 논문에서는 기존의 신경논리망을 기반으로 하는 추론 네트워크를 확장하여 퍼지추론 네트워크(fuzzy inference network)를 구성한다. 그리고 기존의 추론 네트워크에서 사용되는 전파규칙 (propagation rule)을 보완하여 적용한다. 퍼지추론 네트워크 상에서 퍼지 규칙의 실행부에 해당하는 명제의 믿음값을 결정하기 위해서는 추론하고자 하는 명제에 연결된 노드들을 탐색해야 한다. 이를 위해서 연결된 모든 노드들의 링크를 따라 순차적인 탐색을 하는 경우와 링크에 부여된 우선순위에 의해 탐색을 하는 경우의 탐색비용에 대하여 실험을 통해 비교·평가한다.

• 한국수소및신에너지학회논문집
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• 제8권1호
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• pp.11-21
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• 1997

$ZrV_{0.7}Mn_{0.5}Ni_{1.2}$ alloy is attractive for anode material in Ni/MH secondary battery because of its large hydrogen storage capacity in gas-solid reaction and long cycling durability in KOH electrolyte. In this work, in order to further improve the discharge performance of this alloy electrode, the alloy was annealed by optimal condition which is for 12 hours at $1000^{\circ}C$. The alloy annealed under optimal condition had higher rate capability and discharge capacity than as-cast one. The microstructure of the as-cast and annealed alloy was investigated by scanning electron microscopy and energy dispersive spectroscopy. Ni content in the matrix was increased, being this homogenized after annealing. Additionally, The measurement of the surface area by B.E.T. analysis showed that there was little difference as-cast and annealed alloy. Therefore, improvement in the rate capability of the annealed alloy is due to increase of Ni content in the matrix.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권12호
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• pp.725-731
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• 2004

In this study, the three type hybrid interrupters according to the arrangement of the thermal expansion chamber and the puffer cylinder(they are called 'serial type', 'parallel/exchanged type', and 'parallel/separated type' respectively in this work) were designed and manufactured. This paper presents the tested results of the thermal recovery characteristics on the interrupters using a simplified synthetic test facility. The 'serial type' hybrid interrupter which is to obtain more easily the pressure rise for the thermal recovery compared with the others has the best capability in the thermal recovery characteristics. In order to investigate the stress on the operating mechanism, the distortion of the stroke wave in on-load test was examined to the stroke curve in no-load test. The biggest distortion was occurred in the 'parallel/exchanged type' hybrid interrupter. Finally, the small interruption capability on the three type interrupters was estimated by a theoretical form and the 'parallel/separated type' hybrid interrupter has the advantage of the others in the view of structure.

• Journal of Information Technology Applications and Management
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• 제21권1호
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• pp.107-136
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• 2014

This study aims to suggest research implications that may contribute to preventing turnover of personnel in small and medium sized software companies. A research model is developed based on the Bergiel, et al. (2009) and Woo and Hwang (2010). This model describes how human resource management (HRM) practices (compensation, recognition, job autonomy, technical capability development, work-life conflict) affect turnover intention, through the mediating effects of job satisfaction and job embeddedness. 177 questionnaires are collected and analyzed. Validity and reliability of measures, and appropriateness of the structural model are verified. Results of the hypotheses testing are somewhat different from the expected ones: Only compensation and technical capability development are significant, but the remaining variables are not significant in affecting job satisfaction and job embeddedness. As for turnover intention, job embeddedness and job satisfaction are proved to be significant predictors. From the analyses of data, subsequent interview with several respondents and additional data analyses, more research implications are derived. The study has a limitation of not including more diverse variables that might affect job embeddedness and job satisfaction of so called road warriors.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.20-30
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• 2013

An intelligent grid computing architecture is proposed and developed for transient stability constrained total transfer capability evaluation of future smart grid. In the proposed intelligent grid computing architecture, a model of generalized compute nodes with 'able person should do more work' feature is presented and implemented to make full use of each node. A timeout handling strategy called conditional resource preemption is designed to improve the whole system computing performance further. The architecture can intelligently and effectively integrate heterogeneous distributed computing resources around Intranet/Internet and implement the dynamic load balancing. Furthermore, the robustness of the architecture is analyzed and developed as well. The case studies have been carried out on the IEEE New England 39-bus system and a real-sized Chinese power system, and results demonstrate the practicability and effectiveness of the intelligent grid computing architecture.

• 한국정보시스템학회지:정보시스템연구
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• 제12권2호
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• pp.189-208
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• 2003

The purpose of this study was to survey current status of information technology literacy in Korean teachers and to give some suggestions for the preparation of prospective teachers in Korea. To achieve the purpose, data were collected using on- and off-line surveys containing questionnaires developed by the researchers. The survey items were categorized into 11 groups such as operation capability, computer use and communication, word processing, ethics, computer fundamentals, understanding of educational IT, information instruments use, application s/w use, work processing with computer, and internet use capability. Major findings were as follows: (1) Female teachers rated their IT literacy level higher than male teachers. (2) Teachers with longer teaching experience rated their IT literacy level lower than those of shorter experience. (3) There were no signigicant differences among sex, school, job grade of teachers at the present level of literacy, but there were significant differences among sex, age, carreer, job grade, and subject matter at the expectation level except for school grade.

• Applied Science and Convergence Technology
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• 제24권6호
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• pp.250-253
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• 2015

High contrast grating (HCG) is the structure made up of the sub-wavelength grating of high-index and the surrounding layer of low-index, which reveals high contrast between two materials. Its advantages include high reflectivity over a broad bandwidth, polarization and wavelength selectivity, optical high-Q resonator, and phase modulation. In this work, the HCG structure comprising of indium tin oxide (ITO) and Silicon (Si), for the surrounding layer and the grating layer respectively, was studied. Its theoretical model was established, and transmittance, phase and optical behavior were calculated by rigorous coupled-wave analysis and finite element method. Furthermore, the established structure was fabricated to validate its feasibility. The fabricated structure shows the focusing capability whose length is about $10{\mu}m$, and the feasibility of the structure was demonstrated. It is also meaningful that ITO layer can contribute to the fabrication of the HCG structure, leading to enable the structure to be electrical-driven.