• Journal of the Korean Regional Science Association
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• v.15 no.2
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• pp.117-130
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• 1999

Northeast Asia's burgeoning mage- cities have an extraordinarily economic vitality. While national statistics disguies how economic activity is concentrated, much of the region's robust growth of recent decades has centered around large cities, such as Tokyo, Seoul, Beijing, Shaghia, Hongkong. These cities are also at the heart of the Northeast Asia's emerging reional economy. This paper aims to compare the advantages and disad- vantages of these selected Northeast Asia cities in various categories of urban competitiveness and cooperation. Above all, the paper compares the individual cities with one another, and analyzes relations and linkages among them. Then, strengths that can be reinforced and weakness that can be overcome are identified for each city. Finally, an urban development strategy for Seoul in the context development strategy for Seoul in the context of Northeast Asian cities is provided : I) Seoul should strive to be an effective regional capital of Northeast Asia ; ii) Seoul should be a focal point for the intermingling of Chinese, Japanese and Western cultures.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.3
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• pp.126-131
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• 1998

In computer vision system of modern industry precise measuring has lots of dfficulties because of measurement error due to distortion phenomenon. Among the difficulties, the distortion of edge is regraded as a dominent problem. which is caused by the vlurred image. The blurred image apperar when camera can not discriminate its precise focus. So. it is very important to decide focus of lens and to develop algorithm in order to correct distortion phenomenon. Thus. discrimination criteria obtained by image information of precise focus must be fixed in advance. The gray level histogram of image acquired from blurred edge tends to show a uniform distribution. Bimodal intensity histogram is related with condition of focus, and it is possible to find good condition of focus by using bimodal histogram of entropy.

• New & Renewable Energy
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• v.2 no.4 s.8
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• pp.39-45
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• 2006

This paper introduces a preliminary work for the design of a mini-dish cluster system for power generation. Each mini-dish [typically has a 20 to 30 cm in diameter] is designed with a simple parabolic profile concentrating sun light [after the glass glazing cover to avoid dust deposition on the reflector and facilitate cleaning] onto a centrally located small plane[or concave] mirror which is placed on the bottom side of a transparent glass cover. The mirror with a mini-dish concentrator is designed to focus beam radiation onto a focal point before it enters a bundle of optical fibers connected to a remote receiver for power generation. Different options are considered in designing a mini-dish concentrator to maximize its effectiveness for the collection and use of solar energy.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.161-162
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• 2000

We propose multi-layer aspheric lenticular lens for rear projection screen to provide wide viewing angle. Each pitch of lenticular lens sheet is divided by three region and image light from projection optical system is propagated widely on each region due to different focal point. Besides, to improve vertical viewing angle of screen, we propose glass bead embedded screen on observer side of lenticular lens.

• Journal of the Optical Society of Korea
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• v.8 no.3
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• pp.127-131
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• 2004

This paper investigates applications of femtosecond lasers for the micromachining of transparent materials and fabrication of optical devices. We show commercial micromachining examples of transparent materials which have been fabricated for various applications. Near infrared femtosecond laser processing is an attractive method to fabricate three-dimensional optical waveguides into various transparent materials. Focused femtosecond laser pulses induce a permanent refractive-index change only near the focal point. We also demonstrate a Y coupler with the splitting ratio of 1:1 written by femtosecond laser pulses into a fused silica glass. The minimum propagation loss of 0.8 ㏈/㎝ awl the refractive-index change of 0.006-0.01 at the wavelength of 1550 ㎚ were achieved by optimization of the laser fluence.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.429-430
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• 2007

FPA (Focal Plane Arrary)를 이용한 적외선 영상 획득 시스템에서 발생하는 주요 잡음 중 하나는 영상에 존재하는 공간적 고정 패턴 잡음(SFPN, Spatial Fixed Pattern Noise)이다. 이것이 발생하는 주된 요인은 배열을 이루고 있는 각 검출기들과, FPA 출력단에 있는 증폭기의 입출력 응답이 균일하지 않고, 시간이 흐름에 따라 그 응답특성이 변화하기 때문이다. 이 문제를 극복하기 위하여 일반적으로 교정기반 불균일 보정 방법(CBNUC, Calibration Based Nonuniformity Correction)과 장면기반 불균일 보정방법(SBNUC, Scene Based Nonuniformity Correction)이 사용된다. 본 논문은 CBNUC를 사용하는 시스템의 FPA 출력단 회로에 구성된 복수의 증폭기에 존재하는 이득의 차이 및 잡음에 의한 불균일을 보정하기 위한 보간 기법을 제안한다. 실험을 통하여 제안한 기법이 CBNUC 기반 적외선 영상 시스템에서 발생하는 규칙적인 패턴의 SFPN을 효율적으로 제거하는 것을 확인하였다. 또한, 제안한 기법은 CBNUC 기반 적외선 영상 시스템에서 주기적으로 수행해야하는 단일점보정 (OPC, One Point Correction)의 수행횟수를 줄이고, 연산량도 적어 실시간 시스템 구현이 가능하다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1986.04a
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• pp.184-188
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• 1986

The gain variations of paraboloid reflector antenna with an axially and perpendicularly defocused feed are investigated using the Huygens-Fresnel Principle. The theoretical calculations and the experimental for the reflector antenna with an axially defocused feed are compared. Although there were about 3dB difference between two results in a range from focal point to 2.0 wave-length, we could know that it was property approached to theoretical results. However, when the magnitude of defocusing is increased, the differences are also increased because of the influence by a weak received signal and interference of external noises. In addition, it can be shown that gain variations are acutely decreased more in perpendicular defocusing than in axial defocusing in the paraboloid reflector antenna.

• English Language & Literature Teaching
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• v.10 no.1
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• pp.1-22
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• 2004

The primary purpose of this study is to investigate the applicability of content and formal schemata for processing the scientific texts which encompass the human knowledge of the physical world. In general, schema theory is based on the culture-oriented background of a text. From this point of view, the problem as to whether both content and formal schemata are applicable to the comprehension of a scientific text deserves a focal attention in terms of information processing modes. The results of empirical study indicate that whereas the universality of general knowledge content about the natural world attenuates the tenets of schema theory, the rhetorical organization of scientific texts encourages the application of the schema-based approach; the reader's familiarity with the structural patterns of a text facilitates his reading comprehension.

• Journal of the Korean Institute of Rural Architecture
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• v.2 no.3
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• pp.25-36
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• 2000

The purpose of this study is to understand and explain the traditional housing-culture in South East Asia, focused on the traditional Malay houses. The research objectives are : 1) to obtain informations related to the traditional Malay houses in West Malaysia. 2) to survey the traditional Malay houses in the selected area. 3) to understand their characteristics. It is expected that the traditional Malay houses were a major focal point of traditional Malay village society. The Malay houses provided the basic needs of shelter to the villagers. They were designed and built by villagers themselves, thus, manifestation of the creative and aesthetic skills of the community. Further, these houses reflect those factors including climate, geographical features, history of the region.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.6
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• pp.637-642
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• 2002

An arc-shaped line array slit has been used for the laser generation of focused Lamb waves. The spatially expanded Nd:YAG pulse laser was illuminated through the arc-shaped line array slit on the surface of a sample plate to generate the Lamb waves of the same pattern as the slit. Then the generated Lamb waves were focused at the focal point of which distance from the slit position is dependent on the curvature of slit arc. The proposed method showed better spatial resolution than the conventional linear array slit in the detection of laser machined linear defect and drill machined circular defect on aluminum plates of 2mm thickness. Using the focused waves, we could detect the linear defect and the circular defect with the improvement of spatial resolution. The method can also be combined with the scanning mechanism to get an image just like by the scanning acoustic microscope(SAM).