• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.1-6
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• 2004

This paper suggests an evaluation of risk level for damage of marine accidents in SRRs. Qualitative analyses in words is sometimes priorior to quantative analyses in numeric symbols. This paper intoduces a concept of fuzzy theory with the plenty of related literature review and AHP in the Korean SRRs of RCC and RSC. The methodology of this paper is max . min composition of fuzzy extensive principle, defuzzifiation is centroid of gravity methods. At the result, the evaluation of risk level is especially over Serious for smarine accident of Taean, Gunsan, Mokpo, Yosu, Tongyoung, Busan SRR. This paper recommends that many Rescue Vessels and Equipments need to the reduction of risk level about those.

• 한국사회정책
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• v.20 no.2
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• pp.35-68
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• 2013

Class has been the factor that affects welfare attitudes in western societies. But the results of the studies on affects of class in Korea are not consistent. This Study focuses on the relations between three class variables-income, status in employment, occupation-and the Korean attitudes on welfare policy and examines the regulating effects of education on that. Attitudes on welfare policy consist of 'reinforcement of established welfare programs', 'expansion into new welfare area' and 'universalism in welfare policy.' The result shows that all three class variables, education and age do not affect the attitudes to 'reinforcement of established welfare programs.' Age and class variables affects the attitudes to 'expansion into new welfare area' statistically, but education does not. Education explains largest parts of the attitudes to 'universalism in welfare policy.'

• Communications of Mathematical Education
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• v.25 no.2
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• pp.323-339
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• 2011

The expansion of exponential law as the law of calculation of integer numbers can be a good material for the students to experience an extended configuration which is based on an algebraic principle of the performance of equivalent forms. While current textbooks described that exponential law can be expanded from natural number to integer, rational number and real number, most teachers force students to accept intuitively that the exponential law is valid although exponent is expanded into real number. However most teachers overlook explaining the value of exponent of rational number or exponent of irrational number so most students have a lot of questions whether this value is a rational number or a irrational number. Related to students' questions, most teacher said that it is out of the current curriculum and students will learn it after going to college instead of detailed answers. In this paper, we will present several examples and the values about irrational exponents of a positive rational and irrational exponents of a positive irrational number, and study the recognition and fallacy of would-be teachers about the cases of irrational exponents of a positive rational and irrational exponents of a positive irrational number at the expansion of exponential law.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.4
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• pp.379-386
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• 2010

In conceptual design stage it is important to develop structural forms freely. However, structural engineers are prompt to consider types of structural systems following load paths rather than to imagine various forms. This study attempts to expand the limit of imagination that was blocked within engineering approach newly from geometric perspective view. First of all, existing bridge structures are reviewed in terms of geometric vocabulary. Some bridge forms showing apparent geometric features are regenerated through the geometric approach proposed in this study. This study is not to develop geometric principle to build new structural forms, but to propose the geometric approach to generate design alternatives using the well established geometry concepts.

• Journal of The Korean Association of Information Education
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• v.20 no.1
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• pp.39-46
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• 2016

Unplugged has been widely used as an instrument for teaching the basic principles of Computer Science. We'll present 'the binary system teaching contents for the characters' developed for the elementary. And they will successfully guide the student to understand the characters using in computer system. The activity-based learning is provided for describing characters with coding and decoding rules, and the using will be found out in everyday life. To check the adequacy of these materials they were tested to the elementary classroom, and the results showed effectively at Knowledge, Attitude, Generalization levels.

• Computational Structural Engineering
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• v.7 no.4
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• pp.85-101
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• 1994

A family of variational principles governing the dynamics of laminated plate has been derived using a variationally consistent shear deformable discrete laminated plate theory with particular reference to finite element procedures. The theoretical basis for the derivation is Sandhu's generalized procedure for the variational formulation of linear coupled boundary value problem. As the bilinear mapping to write the operator matrix of the field equations in self-adjoint form, convolution product was employed. Boundary conditions, initial conditions and probable internal discontinuity were explicitly included in the governing functionals. Some interesting extensions and specializations of the general variational principle were presented, which can provide many different finite element formulations for the problem.

• The Optical Journal
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• s.143
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• pp.30-45
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• 2013

미국 QED Technologies(이하 QED)가 세계 최초로 상용화한 자기유동유체연마장치(이하 MRF$^{(R)}$-Magnetorheological (Fluid) Finishing)는 역시 QED가 개발한 간섭계 응용장비인 SSI$^{(R)}$(Subaperture stitching interferometer)와 같이 운용하면 1um 이하의 나노광학산업에서 ${\lambda}/10$ 또는 ${\lambda}/100$ 이상 더 정밀한 영역을 손 쉽게 제조할 수 있는 획기적인 공정을 가능하게 한다. 이러한 능력 때문에 미국, 유럽 및 일본 등의 첨단광학회사들은 96년 상업화된 이후 MRF$^{(R)}$와 SSI$^{(R)}$ 공정을 앞다투어 도입하며 기존공정이 지니고 있던 많은 한계들을 극복했다. 우리나라의 MRF와 SSI의 도입은 선진국에 비해 10년 이상 늦어진 2008년에 이르러서야 최초의 장비가 도입되었으며 이후 꾸준히 그 응용분야가 확장되어 가고 있다. 2012년에는 한국천문연구원과 그린광학에 SSI의 최신장비인 ASI(Aspheric Stitching Interferometer)와 MRF가 각각 도입됐다. 이를 계기로 해서 한국사무소에서 제안을 하여 QED사의 총괄대표이사인 Dr. Andrew Kulawiec, 응용기술부장인 Paul Dumas, QED 한국사무소의 오한석 박사와 신지식 박사가 그간의 기술동향을 발표하는 기술강연회가 지난 2012년 10월 23일 개최되었다. 한국천문연구원, 그린광학과 한국광학기기산업협회의 후원으로 한국천문연구원 은하수홀에서 개최된 이번 강연회에서는 다음과 같은 세가지 주제를 다루었다. 1. MRF의 원리 및 응용분야의 현황과 장비개발 현황 2. SSI의 원리 및 응용분야의 현황과 장비개발 현황 3. 광학설계와 가공실현성에 도움이 되는 비구면을 표현하는 새로운 식 Q-Polynominal 이번 강연회는 특히 QED의 공정 및 장비개발자들이 직접 참가한 기술강연회로 지난 2004년 및 2008년에 열린 기술강연회와 차별화되며, 25개 업체 약 50여 명이 참석하여 성황리에 마무리되었다. 향후 국내의 사용자 그룹에 대한 세미나를 정기적으로 개최해 QED의 첨단광학기술에 대한 정보교환의 장을 확대할 예정이며, 기술강연회도 가능한 한 정기화할 예정이다. 이번 강연회의 주제 중 우선 MRF와 SSI에 대한 논의를 광학세계 1월호에 소개하고자 한다.

• Geophysics and Geophysical Exploration
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• v.6 no.3
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• pp.153-159
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• 2003

Using reciprocity theorem, one direction aperture of seismogram can be extended to full aperture seismogram. Modified seismogram is applied to reverse time migration only to acquire improved migration image. In this paper, we tested reverse time migration with the Marmousi velocity data to examine efficiency of modified seismogram. And linearly increasing velocity model is selected and examined for a case where velocity data is insufficient. When true velocity is applied, using modified seismogram enhances the reverse time migration image more than using original seismogram. In the case of using linearly increasing velocity model, migration image is distorted. So low frequency source is brought in migration process. Reverse time migration image with low frequency source and linearly increasing velocity model is improved when modified seismogram is used. From the result of study, seismogram modification by reciprocity theorem is useful and migration image can be enhanced.

• Journal of the Korean Society for Library and Information Science
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• v.51 no.1
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• pp.5-27
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• 2017

The goal of this study is to suggest various improvements and expanding strategies of the public library ecosystem. For this goal, researcher reviewed and analyzed the realistic landscapes and social recognitions about the public library ecosystem as local public goods, and discoursed the basic principles and structural terrain of public library ecosystem based on natural ecosystem. As a result, researcher proposed multifaceted alternatives (ensure library's identity and publicity applying Law of Karma, strengthen librarian's professionalism on the premise of overcoming the Minerva's syndrome, optimize the library service and collection management based on the Pareto principle, reduce reading room and differentiated program through resolution of Halo effect, eliminate usage bias by life cycle based on the Gauss distribution, acceptance of the digital paradigm and use-friendly spatialization that ruminates the Icarus paradox, incorporate small library into public library system through a clear understanding of the Gresham's law, and enforce communication and spread social and cultural value through the practice of the Pompeii paradox).

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.2
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• pp.115-124
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• 2001

In this paper, authors propose a new nonlinear rotor flux observer for rotor field oriented control of an induction motor which is designed based on the extended Luenberger Observer theory. Extended Luenberger Observer requires minimal solution of nonlinear partial differential equation on its coordinate transformation and linearization needed on a nonlinear observer design in general. The proposed rotor flux observer is derived from the 2 phase model of induction motor on the orthogonal coordination and it has the reduce gain matrix. Simulation and experimentation were performed under the conventional indirect vector control and direct vector control with the proposed observer at different rotor resistance. Simulation results show that the convergence of the proposed observer is influenced by the chosen eigenvalues. Experimentation results on load operation show the direct vector control with the proposed observer is better than the indirect vector control to maintain the characteristics of the vector control.