• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.470-477
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• 2009

Modular reconfigurable robots with physical docking capability easily adapt to a new environment and many studies are necessary for the modular robots. In this paper, we propose a vision-based fuzzy autonomous docking controller for the modular docking robots. A modular docking robot platform which performs real-time image processing is designed and color-based object recognition method is implemented on the embedded system. The docking robot can navigate to a subgoal near a target robot while avoiding obstacles. Both a fuzzy obstacle avoidance controller and a fuzzy navigation controller for subgoal tracking are designed. We propose an autonomous docking controller using the fuzzy obstacle avoidance and navigation controllers, absolute distance information and direction informations of robots from PSD sensors and a compass sensor. We verify the proposed docking control method by docking experiments of the developed modular robots in the various environments with different distances and directions between robots.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1090-1097
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• 1999

the multi computers operated in harsh environments should be designed to guarantee normal operations in the presence of the component faults. One solution for this is a fault-tolerant routing. In the paper, we consider n-dimensional meshed network for the basic topology and propose a simple fault-tolerant routing algorithm that can transfer messages to their destination as desired in the presence of some component faults. the built algorithms basically adopts a WormHole(WH) routing method and uses the virtual channels sharing a physical channel for deadlock-freedom. Consequently, we show that the suggested algorithm has a higher performance than the X-Y routing algorithm through simulation results.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.419-428
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• 2013

The objectives of this research were to determine ecological characteristics and chemical gradients in two different loach populations-Misgurnus anguillicaudatus ($M_a$) and Koreocobitis rotundicaudata ($K_r$). Eight chemical parameters were compared to test the chemical preferences between the two species. The population of Kr occurred more in better water quality, compared to the $M_a$-population. The $M_a$-population co-occurred more with tolerant species (TS) and omnivores, whereas the $K_r$-population co-occurred more with sensitive species (SS) and insectivores. The differences in the tolerance and trophic composition matched well with the result of stream health assessment, based on the multi-metric model of Index of Biological Integrity (IBI). The IBI value in habitat with the $M_a$-population was "19.6" (range: 8~40) indicating a fair condition, and the IBI values of $K_r$-population was 29.4 (range: 12~40) indicating good condition. Similar results were found in physical habitat health analysis (QHEI). Overall, data analysis showed that the $M_a$-population belong to the tolerant species and $K_r$-population belong to sensitive species in the tolerance classification.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11c
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• pp.2029-2032
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• 2003

IT 시스템 평가과정은 시스템의 보안기능과 이에 적용된 보증수단이 요구사항들을 만족하는지에 대한 신뢰도를 확인하는 것이며, 평가결과는 소비자가 IT 제품이나 시스템이 주어진 환경에 적응하기에 충분히 안전한지, 사용상 내재하는 보안위험이 허용가능한지를 결정하는데 도움이 될 수 있다. 공통평가기준(정보통신부 고시 제2002-40호)에 기반한 평가를 통하여 평가보증등급(EAL) 3 이상의 등급을 인증받기 위해서는 ALC_DVS 패밀리의 요구사항을 고려하여야 하며, 국가기관에서 요구하고 있는 EAL 3+ 등급을 획득하기 위해서는 ALC_DVS.1 컴포넌트의 요구사항을 만족하여야 한다. ALC_DVS.1 컴포넌트의 요구사항 만족 여부를 확인하기 위해서는 개발현장에 대한 실사가 필요할 수 있으나, 공통평가 기준에는 이에 관하여 세부적인 요구사항이 명시되어 있지 않다. 본 논문에서는 평가자 및 개발자가 ALC_DVS.1 컴포넌트에서 요구하는 인적, 물리적, 절차적 보안 요소를 확인하는 데 도움을 줄 수 있는 점검항목들을 도출하였다.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.45-49
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• 2001

Wideband code division multiple access (WCDMA) is the most widely adopted third generation air interface. The physical layer of the air interface is the main discussion topic during standardization processes. This paper aims to investigate the performance of uplink WCDMA over many conceivable transmission scenarios in realistic operating conditions. The focus of the study is placed on the performance under frequency selective fading channel conditions with multiple access interference (MAI) in mixed services environments. For the investigation, a simulator has been developed and it encompasses a variety of WCDMA air interface features. The results show that the performance is greatly affected by MAI and is further aggravated with the presence of frequency selective fading, thereby necessitating a suitable compensation measure.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.55-61
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• 2020

In this paper, we present a novel approach to efficiently control the location of NPC(Non-playable characters) in the interactive virtual world such as game, virtual reality. To control the NPC's movement path, we first calculate the main trajectory based on the user's path, and then move the NPC based on the weight map. Our method constructs automatically a navigation mesh that provides new paths for NPC by referencing the user trajectories. Our method enables adaptive changes to the virtual world over time and provides user-preferred path weights for smartagent path planning. We have tested the usefulness of our algorithm with several example scenarios from interactive worlds such as video games, virtual reality. In practice, our framework can be applied easily to any type of navigation in an interactive world.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.2 s.314
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• pp.63-73
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• 2007

This paper proposes an illuminant-adaptive reproduction method using light adaptation and flare conditions for a mobile display. Displayed images in daylight are perceived as quite dark due to the light adaptation of the human visual system, as the luminance of a mobile display is considerably lower than that of an outdoor environment. In addition, flare phenomena decrease the color gamut of a mobile display and de-saturating the chroma. Therefore, this paper presents an enhancement method composed of lightness enhancement and chroma compensation. First, the ambient light intensity is measured using a lux-sensor, then the flare is calculated based on the reflection ratio of the display device and the ambient light intensity. To improve the perceived image, the image's luminance is transformed by linearization of the response to the input luminance according to the ambient light intensity. Next, the displayed image is compensated according to the physically reduced chroma, resulting from flare phenomena. This study presents a color reproduction method based on an inverse cone response curve and flare condition. Consequently, the proposed algorithm improves the quality of the perceived image adaptive to an outdoor environment.

• Archives of design research
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• v.15 no.1
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• pp.181-190
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• 2002

Every object's patterns is the balancing-relationship between the object's inner-energy and outer-stress. To see this as a balancing-relationship between an organism, inner-energy would be the occurrence of thermodynamic entropy which is for its existing maintenance. Outer-stress would be the friction that comes from the surrounding environment. Namely, we can see that object's figure exists in the balance between an extort to survive and fiction that disturb it. However, it is fourth that these figures are consisted of a curve and curved-surface which is not a straight line. So, it is impossible to find a figure made up of straight lines and surfaces in the existing object's world. It's true that we have regarded only a curve as the beautiful. Here, we have presented that in a curve, there exists an important function which protect our survival from the ancient humanity. And by closely observing the function in a physical dynamic-pattern sight, we've searched what is important in the design's origin that handle curve-patterns. Of course it would be more reasonable to analyze it in the standpoint of Mathematics, Chemistry, or Biology, and synthesize the points. However, due to the limitation of the researchability, we will concern about the physical structure in the design. Deficient details will be replenished through the study between educational systems. As a result, we have confirmed that, devoting the curve's physical structure-phenomenon (occurred in nature) to the design, is more beautiful in our eyes, too.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.7-12
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• 2008

근래에 들어 급속한 산업화에 따라 하천 고유의 특성을 간과한 채 개발 위주의 하천 정비사업이 시행되고 있으며 이는 하천의 인공화 및 생태계의 교란 등 많은 문제점을 낳고 있다. 이에 따라 하천 및 하도 환경에 미치는 영향이 심각할 뿐만 아니라 홍수 피해 또한 급격히 증가하고 있다. 지금까지의 치수 위주의 하천 정비를 벗어나 친환경적인 하천으로의 복원 사업이 필요한 실정이며, 이는 새로운 하천 관리 기술의 도입이 필요함을 의미한다. 따라서 본 연구에서는 항공사진과 GIS기반의 하천 시계열 분석을 수행하여 새로운 하천 관리 기술 도입에 응용할 수 있는 방안을 제시하고자 하였다. 분석을 위하여 댐 하류의 하천교란 및 적응현장 시범지역을 선정한 후 대상 지역의 항공사진을 GIS화하여 하천 교란 실태를 분석하는 데에 필요한 저수로와 제방 및 기타 자료를 shape 파일 형태로 생성하였다. 생성된 자료를 바탕으로 하천의 사행도 및 유로 변동 현황 분석을 실시함에 따라 하천의 변화 양상을 확인하였으며 대상 하천의 사행도 및 저수의 구체적인 제반 수치를 제시할 수 있었다. 또한 분석 결과를 바탕으로 현재 이루어지고 있는 하천의 정비 및 복원 사업이 하천의 흐름에 어떠한 영향을 미치는 지 예측을 가능하게 하였다. 본 연구에서 규명된 경년별 하천 형태의 변화 추세와 하천 부지의 물리적 특성 변화 양상을 기본 자료로 한다면 하천 관리에 있어 수리 수문학적 분석이 용이하리라 사료된다. 향후 연구에서는 GIS기반의 하천 관리 방안 수립에 대한 심층 연구가 뒤따라야 할 것이다.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.1-20
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• 2000

There are increasing evidences of climate change in the Antarctic and Arctic Oceans, especially elevated temperature due to the continuous burning of the fossil fuels and ultraviolet B(UV-B) flux within the ozone hole. Light-dependent, temperature-sensitive, and fast-growing organisms respond to these physical and biogeochemical changes. Polar marine phytoplankton, which are pioneer endemic species and important carbon contributors in the polar waters, are therefore highly suitable biological indicators of such changes. By virtue of light requirement, the primary producers are exposed to extreme seasonal fluctuations in temperature, photosynthetically active radiation, and UV radiation. Local environmental warming and increased UV-B radiation during ozone depletion may have profound effects on the primary producers that are primary carbon producers in the polar water. Small changes in climate temperature and solar radiation may have profound effects on the activity threshold of the polar phytoplanktion. To demonstrate biological response to the environmental changes, standardized representative natural and biological parameters are needed so that replicate samples (including controls) can be taken over extended periods of time. In this paper, we review general characteristics of polar phytoplankton, their environment, environmental changes in the polar waters, the effects on the environmental changes to the polar phytoplankton, and the importance of the polar phytoplankton to understand the global environmental changes. [Biological indicators, Global environmental change, Polar phytoplankton, UV].