• Journal of the Korean Magnetics Society
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• v.20 no.5
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• pp.173-177
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• 2010

The electronic structure of charge-density-wave (CDW) system $CeTe_2$ has been investigated by using angle-resolved photoemission spectroscopy (ARPES). The clearly dispersive band structures are observed in the measured ARPES spectra, indicating the good quality of the single-crystalline sample employed in this study. The four-fold symmetric patterns are observed in the constant energy (CE) mappings, indicating the $2{\times}2$ lattice deformation in the Te(1) sheets. The observed CE images are similar to those of $LaTe_2$, suggesting that Ce 4f states have the minor contribution to the CDW formation in $CeTe_2$. This study reveals that the carriers near the Fermi level should have mainly the Te(1) 5p and Ce 5d character, that the Te(1) 5p bands contribute to the CDW formation, and that the Ce 5d bands cross the Fermi level even in the CDW state.

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.1-7
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• 2017

Virtual reality(VR) is known as immersive multimedia or computer-simulated reality, is a computer technology that replicates an environment, real or imagined, and simulates a user's physical presence and environment to allow for user interaction. Virtual realities artificially create sensory experience including sight, touch, hearing, and smell. Owing to the use of a single device in most VR contents, user have difficulty in manipulating user interface and game object. And also immersion of the game goes down because they can't see the mouse and keyboard in virtual space. In this paper, we design and implement the chess game to easily and accurately control user interface to improve the immersion in game.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.1
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• pp.22-29
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• 2010

A real-time detection and tracking of moving objects in video sequences is very important for smart surveillance systems. In this paper, we propose a novel algorithm for the detection of moving objects that is the entropy-based adaptive Gaussian mixture model (AGMM). First, the increment of entropy generally means the increment of complexity, and objects in unstable conditions cause higher entropy variations. Hence, if we apply these properties to the motion segmentation, pixels with large changes in entropy in moments have a higher chance in belonging to moving objects. Therefore, we apply the Clausius entropy theory to convert the pixel value in an image domain into the amount of energy change in an entropy domain. Second, we use an adaptive background subtraction method to detect moving objects. This models entropy variations from backgrounds as a mixture of Gaussians. Experiment results demonstrate that our method can detect motion object effectively and reliably.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.1-7
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• 2011

Terrain, building location and area, and building shape information is in need of implementing 3D map. This paper proposes a method of extracting a building area by an improved semi-automatic snake algorithm. The method consists of 3-stage: pre-processing, initializing control points, and applying an improved snake algorithm. In the first stage, after transforming a satellite image to a gray image and detecting the approximate edge of the gray image, the method combines the gray image and the edge. In the second stage, the user looks for the center point of a building and the system sets the circular or rectangular initial control points by an procedural method. In the third stage, the enhanced snake algorithm extracts the building area. In particular, this paper sets the one tenn of the snake in a new way in order to use the proposed method for specializing building area extraction. Finally, this paper evaluated the performance of the proposed method using sky view satellite image and it showed that the matching percentage to the exact building area is 75%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.165-173
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• 2008

In this paper, we propose a new reliable broadcast protocol referred to as timer-based reliable broadcast (TRB) for wireless sensor networks (WSNs). The proposed TRB scheme exploits (1) bitmap based explicit ACK to effectively reduce the unnecessary error control messages and (2) randomized timer for ACK transmission to substantially reduce the possibility of contentions. Although it has been argued that 100% reliability is not necessary in WSNs, there should be messages (such as mission-critical message, task assignment, software updates, etc.) that need to be reliably delivered to the entire sensor field. We propose to use the TRB algorithm for such cases. Performance evaluation shows that the TRB scheme achieves 100 % reliability significantly better than other schemes with expense of slightly increased energy consumption.

• The Journal of Society for e-Business Studies
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• v.17 no.2
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• pp.39-62
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• 2012

Green IT is a necessary technology to solve the energy and environmental problems and to increase the productivity of corporations. However, till now there were not the specific policies for individual industries so we have to establish several strategies for spread of Green IT and building green growing environment. In this paper, we proposed the road map for spread of green IT and deducing the strategic directions for domestic industries. Four types of green IT direction was identified and in each direction, several action plans were discovered. We formed an expert-committee to choose new green IT business models and selected some demonstration projects by measures of necessity, urgency and extensibility. The object, scope, classification and policy effect are wrote out and it will be helpful information to disseminate green IT.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.167-185
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• 2016

$CO_2$ 지중저장 기술은 가장 유력한 대용량 온실가스 감축기술의 하나이다. 이 기술을 적용하여 국제적으로 노르웨이, 알제리, 캐나다, 미국 등에서 이미 대규모 실증 및 상용화 사업이 수행되고 있으며, 호주, 일본, 네덜란드, 독일 등 그 밖의 여러 나라에서 다양한 내용과 규모를 갖는 중소규모 실증사업이 진행되고 있다. 한국도 소규모 육상 파일럿 저장 프로젝트와 중규모 해상 저장실증 프로젝트가 추진되어 착실하게 기술개발과 경험확보를 위해 노력하고 있다. $CO_2$ 지중저장 사업은 화석연료의 사용이 다른 에너지원으로 대체되기 전까지 지속적으로 확장될 것으로 예측되고 있으나, 온실가스 감축시장의 불안전성, 사업의 수익구조와 관련된 경제성, 누출에 대한 안전성 등의 위협요소를 갖고 있다. 따라서 이러한 위협을 극복하기 위해 많은 국가와 기업들이 저비용-고효율 지중저장 기술과 안전한 지중저장 기술의 확보를 목표로 연구개발 및 실증사업을 추진하고 있다. 한국의 경우에 저장소가 주요 포집원으로부터 상당한 거리를 갖고 있는 해저에 발달하고 있기 때문에 지중저장 사업의 경제성 확보가 매우 불리한 조건이다. 따라서 정부나 기업이 CCS 기술을 주요 온실가스 감축수단으로 채택하여 대규모 지중저장 사업을 본격적으로 착수하는 것을 주저하고 있다. 한국과 같은 불리한 조건을 갖는 국가의 경우에 특히 대규모 저장소의 확보를 포함한 저비용-고효율 지중저장 기술의 실용화가 절실하게 필요하다. 결론적으로 한국의 $CO_2$ 지중저장 사업의 성공적인 추진을 위해서는 대규모 저장소의 확보, 저비용-고효율 지중저장 기술의 개발과 실증을 통한 실용화, 중소규모 지중저장 실증사업으로 축적한 기술과 경험으로 대규모 지중저장 사업의 효율화 달성이 요구된다. 이를 위한 실천적인 로드맵과 프로그램의 작성과 착실한 이행 역시 중요하다. 이러한 기반이 착실하게 다져질 경우에 한국에서 대규모 CCS 통합실증과 $CO_2$ 지중저장 사업이 본격적으로 개시될 수 있을 것이다.

• The KIPS Transactions:PartD
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• v.16D no.2
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• pp.191-200
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• 2009

Location based services (LBSs) have drawn huge attention as the growing number mobile devices and wireless technology demand more pervasive information access. In LBSs, Constraint nearest neighbor queries are one of the important queries of human to fulfill his desired quickly through wireless technology. We propose new query processing of constrained nearest neighbor query on the air to support mobile clients which demand optimal uses of wireless broadcast channel and using minimum battery power of client. First we proposed NN query processing with constrained region and then explain the novel NN query processing with various types of constraints. We have proposed novel algorithms to support Constrained Nearest Neighbor queries on the air based on Distributed Spatial Index and Bitmap-based Spatial Index.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.114-114
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• 2016

토양유실에 영향을 미치는 기후 인자로는 강우, 기온, 바람, 습도 및 태양열 복사 등이 있다. 이들 중 강우는 토양침식에 직접적인 영향을 미치는 인자로 토립장의 이탈로 인한 토양침식을 유발한다. 토양침식을 예측하는데 있어 강우의 영향을 나타내는 지표의 설정은 매우 중요하다. 이러한 강우침식인자는 각 강우사상에 대한 강우에너지와 30분 최대 강우강도의 곱의 합으로 정의된다. 강우침식도를 정확하게 계산하기 위해서는 다년간 측정된 분단위 강우자료가 필요하며, 강우자료 획득의 제한과 강우의 분류 및 계산과정 등이 복잡하여 실무적으로 산정하기 어려운 점이 있다. 본 연구에서는 1분 상세강우자료를 이용하여 개정범용토양유실공식(RUSLE)의 강우침식도 R의 추정을 위해 2001년부터 2015년까지 15년간 전국 61개 기상청 관측소의 강우 자료를 수집하여 지점별로 새롭게 계산한 연 강우침식도 및 경험식을 산정하였으며 남한전체($99,720km^2$)를 대상으로 연 강우침식량의 공간분포맵을 작성하였다. 지점별 산정된 경험식은 연평균 강우량과 1분 강우자료로부터 산정된 강우침식도와의 상관관계로 회귀식을 도출하였다. 1분 강우자료로 계산된 강우침식도와 연평균 강우량의 상관관계로부터 도출된 경험식과의 결정계수($R^2$, determination coefficient)는 0.70 ~ 0.98로 높은 상관관계를 나타냈으며 또한, 기존의 국내에서 적용된 경험식과 비교하여 평균 $R^2$가 0.59에서 0.80로 실측값과의 정확성이 높게 개선됨을 알 수 있다.

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.323-334
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• 2019

The purpose of this study is to propose agenda concerning the direction of agricultural science convergence research and development (R&D) under the fourth industrial revolution. For this study, we apply the Analytic Hierarchy Process (AHP) targeted at experts in the fields of agricultural academia and research operating R&D currently. Results suggest the following agendas; first, human resource training toward future is more emphasized rather than fragmentary technology innovation. Second, a flexible road map for agricultural science R&D need to be made for responding to short and long term issues relevant to the innovation. Third, mutual exchange and cooperative system need to be constructed between academia and research in order to create synergy effects. Finally, both institutional improvement and humanistic literacy should be emphasized for rapidly changing conditions and better human life under the fourth industrial revolution.