• 한국수학교육학회지시리즈C:초등수학교육
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• 제11권1호
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• pp.39-57
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• 2008

본 연구에서는 현실주의 수학교육 이론을 바탕으로 '비율그래프' 단원을 재구성한 수업이 학생들의 수학 학업성취도와 수학적 성향에 어떤 영향을 주는지를 알아봄으로써 교실 수업을 개선하기 위한 것이다. 연구 대상은 6학년 학생 68명(실험반 34명, 비교반 34명)이었으며, 수업은 MiC 교재를 참고하여 재구성한 프로그램을 8차시에 걸쳐 실시하였다. 본 연구를 통해 얻은 결론은 다음과 같다. 첫째, 현실주의 수학교육론에 근거하여 재구성한 교재를 활용한 수업이 학습자의 수학 학업성취도 향상에 긍정적인 영향을 미치는 것으로 확인되었다. 둘째, 현실주의 수학교육론에 근거하여 재구성한 교재를 활용한 수업이 학습자의 수학적 성향에 긍정적인 영향을 미치는 것으로 확인되었다.

• Journal of Korea Trade
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• 제23권5호
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• pp.118-128
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• 2019

Purpose - This paper examines the international R&D contest in which the extent of intellectual property right (IPR) affects both the size of prize for the winning firm and the extent of positive spillover through cost of firms. Recognizing the possibility of incomplete protection of IPR, the present paper analyzes the effect of changes in the extent of IPR on payoffs to firms and social welfare. Design/methodology - This paper examines coordination of IPRs by countries in economic integration. The paper then develops a general model of international R&D contest with incomplete protection of IPR. An increase in the extent of IPR augments the share of the prize the winning firm can appropriate, while decreasing the positive cost externality. To derive sharper results, the paper considers the cases of linear and fixed spillovers. Findings - Under plausible assumptions, an increase in the IPR augments the payoff to each firm and the aggregate payoffs as well. The paper also shows that the number of firms participating in the R&D contest can be endogenously determined in the two-stage R&D contest. The higher the extent of cost spillover, and the larger the effective prize, the more firms participate in the international R&D contest. Originality/value - Existing studies assume that firms winning the R&D contest enjoy perfect IPR to the output of their R&D activities. This is a very restrictive assumption in that other firms can copy the new products or processes. By allowing for the incompleteness of the IPR, the present paper develops a more realistic model of R&D contest. The novelty of the present paper is to allow for the possibility that the higher extent of IPR increases the prize and decreases positive cost externality at the same time. The findings of the present paper can serve as a basis for government policy toward R&D activities of firms and protection of IPRs.

• 한국전산유체공학회지
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• 제13권4호
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• pp.114-125
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• 2008

Current state and perspective of DNS of turbulence and turbulent combustion are discussed with feature trend of the fastest supercomputer in the world. Based on the perspective of DNS of turbulent combustion, possibility of perfect simulations of IC engine is shown. In 2020, the perfect simulation will be realized with 30 billion grid points by 1EXAFlops supercomputer, which requires 4 months CPU time. The CPU time will be reduced to about 4 days if several developments were achieved in the current fundamental researches. To shorten CPU time required for DNS of turbulent combustion, two numerical methods are introduced to full-explicit full-compressible DNS code. One is compact finite difference filter to reduce spatial resolution requirements and numerical oscillations in small scales, and another is well-known point-implicit scheme to avoid quite small time integration of the order of nanosecond for fully explicit DNS. Availability and accuracy of these numerical methods have been confirmed carefully for auto-ignition, planar laminar flame and turbulent premixed flames. To realize DNS of IC engine with realistic kinetic mechanism, several DNS of elemental combustion process in IC engines has been conducted.

• 제어로봇시스템학회논문지
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• 제19권8호
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• pp.718-724
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• 2013

In today's automotive industry, there exist several systems that help drivers reduce the possibility of accidents, such as the ADAS (Advanced Driver Assistance System). The ADAS helps drivers make correct and quick decisions during dangerous situations. This study analyzed the performance of the IMM (Interacting Multiple Model) method based on multiple Kalman filters using the data acquired from a driving simulator. An IMM algorithm is developed to identify the current discrete state of neighboring vehicles using the sensor data and the vehicle dynamics. In particular, the driving modes of the neighboring vehicles are classified by the cruising and maneuvering modes, and the transition between the states is modeled using a Markovian switching coefficient. The performance of the IMM algorithm is analyzed through realistic simulations where a target vehicle executes sudden lane change or acceleration maneuver.

• International journal of advanced smart convergence
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• 제6권4호
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• pp.80-87
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• 2017

Mixed Reality (MR) shows a composite image of a virtual object in the real world. It has been applied to various fields by the introduction of head mounted display (HMD) such as Microsoft's Hololens [1-3]. The virtual studio in broadcasting combines the contents created by computer graphics with the actual set to reproduce the 3D image screen. This requires physical space such as a set of chroma keys. It also requires professional knowledge and manpower and costly equipment to post-process the graphics and information for long periods of time. Therefore, in this paper, we aim to study the implementation of virtual studio based on Mixed Reality using Microsoft Hololens. Through the implementation of 'Holo-studio' application, realistic and virtual objects of broadcasting camera viewpoint were acquired at the same time. Using Microsoft's spectator view library, the frame rate is degraded in objects with high polygons (100,000 polygons). The proposed method maintains 60 fps image transmission in high polygon objects. The results of this paper show the possibility of using virtual studio at low cost which does not need separate physical space.

• 한국초전도ㆍ저온공학회논문지
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• 제13권1호
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• pp.12-16
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• 2011

In this paper, the prototype of the HTS motor with an on-board cryocooler, is fabricated and tested. The overall system is composed of the stator with conventional copper winding, the rotor with superconductor, and the rotating cryocooler designed from the on-board concept. The rotor is fabricated as the race-track coil with 2G, YBCO tape and contacts with the on-board cryocooler while being rotated together. An inline-type pulse tube refrigerator is used as the on-board cryocooler. The cryocooler is fabricated from optimal process to satisfy the structure and thermal stability of the on-board system. Each component is integrated according to carefully defined sequence. Specially, a combining method of torque tubes is an important part for sustaining stability of the rotor and the cryocooler. In the rotating test, the HTS motor is successfully operated with 240 rpm of rotating speed when 75 A current is supplied to the superconducting rotor. In this paper, potential problems of the HTS motor system using the on-board cryocooler are proposed and solved, and realistic possibility of this concept is also confirmed.

• 전기학회논문지
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• 제59권1호
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• pp.26-32
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• 2010

This paper proposes a new effective installed reserve rate in order to evaluate reliability of power system considering renewable generators, which include uncertainty of resource supply. It is called EIRR(effective installed reserve rate) in this paper. It is developed with considering capacity credit based on ELCC by using LOLE reliability criterion. While the conventional installed reserve rate index yields over-evaluation reliability of renewable generators, the proposed EIRR describes actual effective installed reserve rate. However, it is not the probabilistic reliability index as like as LOLE or EENS but another deterministic effective reliability index. The proposed EIRR is able to evaluate the realistic contribution to the reliability level for power system considering wind turbine generators and solar cell generators with high uncertainty in resource supply. The case study in model system as like as Jeju power system size presents a possibility that the proposed EIRR can be used practically as a new deterministic reliability index for generation expansion planning or operational planning in future.

• 한국실내디자인학회논문집
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• 제20권3호
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• pp.119-126
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• 2011

Recently, in the fields of fashion, advertisement, film, literature, philosophy, etc., the word, 'Nomad', is being used frequently across the overall society. The contemporary society is actively incorporating "nomadic thinking" as a new social phenomenon across the boundaries of conventional fields. This is not an exception in the field of space design. This study, via the contemporary nomadic thinking, examined the relationship between space design's application possibility as a new trend and flexible space; then categorized the characteristics of flexible space into flexibility, temporariness, changeability, and correlation; and then analyzed expression characteristics of flexible space. As for unrestricted expression of scene, it was recognized that separation of scene and space leads space to meet the needs of surrounding environment and users; formation of changeable space enables uses of space from various perspectives; and combining external factors (energy, media technologies) with space leads space to self-evolution. Space is perceived as an living organism that is flexibly corresponding, via realistic movement and virtual movement, to the indefinite, diversified thinking of the contemporary society. Therefore, this study illuminates that nomadic thinking has significance as basic thinking to predict development and characteristics of design thinking through understanding the contemporary society with the basic thinking system that has been inherent without restrictions of being fixed to the present, past, and future.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1070-1077
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• 2013

Owing to the consistent increase in energy efficiency issues, studies for improving regenerative energy utilization have been receiving attention in the Urban DC railway systems, where currently, the utilization of regenerative energy is low due to the lack of a specific plan for using this energy. The regenerative energy in railway systems has a low efficiency problem which results in the increase of the catenary voltage and a possibility to create problems to the electrical devices connected to the system. This paper deals with the power integration of large urban railway subsystems to improve regenerative energy utilization where the railway subsystems are integrated with other railway subsystems to improve the energy efficiency. Through the case studies, to find the realistic effect of integrated operation, the Seoul Metro subsystems, namely Line 5 and Line 7, has been applied. Also, evaluation for the electricity cost saving has been performed by using KEPCO electricity cost table.

• 한국실내디자인학회논문집
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• 제23권3호
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• pp.108-116
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• 2014

Postmodernism, a cultural movement which occurred in the mid-20th century, avoided functional form, one of the features of modernism, and pursued post-rational and post-centric pluralistic thought which puts human emotions in importance. Postmodernism set a high value on emotional instincts of humans and focused on creation of empathy. It includes scepticism of rationalism and indicates the significance of emotional and psychological instincts of humans, or 'emotions'. Along with the big change in that time, more dynamic and unprecedented indoor spaces had appeared. Nigel Coates, who had taken various kinds of artistic activity from the early 1980s to the late 1990s, had tried to make a new approach of objet-focused emotional spaces. Such an approach made in the time when science and technology had rapidly developed and social structure had changed was considerably fresh, liberal, and futuristic. He interpreted spaces by escaping from realistic intentions and communicating with drawings, and designed object-focused emotional spaces by actively employing objets on the basis of ideas. He tried to make emotional sharing between the public and spaces through objet, and showed unique spaces in his own way by reinterpreting the meanings of spaces and stimulating human emotion. This study was intended to look into his artworks to show his way of approaching objets, and to find an application plan and the future possibility of the plan.