• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.40-46
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• 1990

This paper describes a design and an implementation of a machine-independent global optimizer which is a required module of RISC compiler system designs. It receives a triple as input and performs data flow analysis, common subexpression elimination and code motion and finally generates the optimized code. Since the implemented optimizer operates on the machine-independent intermediate code, its portability is good for many high level languages and target machines. It performs the effective optimizations to improve the execution time of programs.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1217-1220
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• 2005

정보통신 기술의 발달이 가져온 가장 큰 변화중의 하나로 글로벌 커뮤니케이션을 들 수 있을 것이다. 각 지역별 사업장을 운영하는 기업체들은 대부분 사업장들을 연결하는 광역 통신망을 구축하여 사용하고 있지만, 이를 운영하는데 드는 막대한 비용과 보안문제에 많은 어려움을 겪고 있는 실정이다. 본 논문에서는 사업장의 이동이 빈번한 기업의 광역 통신망을 구축함에 있어 비용 절감을 위해 재 활용된 개인용 컴퓨터를 이용하여 리눅스 기반의 VPN 게이트웨이를 만들어 사용하고 포트스캔 기술과 패킷 스니퍼를 이용한 네트워크의 모니터링을 통해 보다 안전하고 효율적으로 통신망을 운영한 사례를 제시하고자 한다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.468-471
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• 2012

본 연구는 삼척시를 중심으로 행정구역별(읍 면 동) 산불발생 현황과 삼척시 지역에 필요한 산불감시카메라의 적정대수 산정에 관하여 연구를 수행하였으며 결과는, 이미 설치되어 있는 개별 카메라는 중첩되는 곳이 있어 가시권이 확보된 곳으로 이동해야 할 것으로 판단하였다. 또한, 감시가 취약한 지역에 신규로 설치할 경우에는 인접한 기관(지자체 및 지방산림청)간의 감시시설과 감시지역 중복여부, 감시시설 위치의 타당성 등은 물론 어디에 우선하여 설치할 것인지를 광역적이고 과학적으로 판단하며 설치해야하며, 삼척시의 경우 설치 적정대수를 산정한 바, 최소한 32대 이상은 되어야 가장 효율적인 산불감시체계가 가능할 것으로 분석되었다.

• Journal of the Korean earth science society
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• v.27 no.6
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• pp.643-652
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• 2006

Data of the carbon monoxide concentration observed in Mt. Waliguan in China (WLG), Ulaan Uul in Mongolia (UUM), Tae-ahn Peninsula in Korea (TAP), and Ryori in Japan (RYO) were analyzed for a long period between 1991 and 2004. The annual average concentration of carbon monoxide was the highest at TAP $(233{\pm}41ppb)$ followed by $RYO(171{\pm}36ppb),\;UUM(155{\pm}26ppb),\;and\;WLG(135{\pm}22ppb)$. The seasonal variations being high in spring and low in summer were observed in other areas of Eastern Asia except WLG. TAP was high in carbon monoxide concentration in all seasons compared to WLG, UUM and RYO and shows wide distribution of concentration in the histogram, which is caused by the influence of large-scale air pollution due to its downwind location close to the East Asian continent, China in particular. Also, our data was compared with data measured at Mauna Loa (MLO) in Hawaii. According to the origin of the isentropic backward trajectory and its transport passage, carbon monoxide concentration observed in TAP was analyzed as follows: continental background airflows (CBG) were $216{\pm}47ppb$; regionally polluted continental airflows (RPC) were $316{\pm}56ppb$; Oceanic background airflows (OBG) were $108{\pm}41ppb$; and Partly perturbed oceanic airflows (PPO) were $161{\pm}6ppb$. The high concentration of carbon monoxide in TAP is due to the airflow from East Asian continent origin rather than that from the North Pacific origin. Especially, RPC which passes through the eastern China appeared to be the highest in concentration in spring, fall, and winter. However, OBG was affected by the North Pacific air mass with a low carbon monoxide concentration in summer. The NOAA satellite images and GEOS-CHEM model simulation confirmed a large-scale air pollution event that was in the course of expansion from southeastern China bound to the Korean Peninsula and the Korea East Sea by way of the Yellow Sea.

• Journal of the Korean Geographical Society
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• v.50 no.2
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• pp.203-216
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• 2015

This paper examined the changes of urban system through the network and the flow pattern reflected in daily movement in Korea. Because daily movement reflects trip pattern, urban system formed by inter-city linkages can be recognized in terms of living sphere. While population movements between cities have the number of linkage systems of city network and the number of traffic regions composed of the origin and destination has increased respectively. Nevertheless, spatial extent of Capital region and Busan region has been expanded. In Gangwon-do in which Seoul-oriented high-speed transportation network has developed, separation of living sphere between Yeongdong area and the Soyanggang cultural region formed around Chuncheon was intensified. Living sphere that includes Daejeon and the surrounding cities has been expanded to the southern Gyeonggi-do. The existing living sphere formed in Jeollanam-do was fragmented into the east and west around Mokpo and Suncheon due to the weakened centrality of Gwangju. Living spheres formed by spatial interaction were consistent with regional administrative boundary. Considering the increased interaction between Seoul and its surrounding cities, the development of global city-region centered on Seoul is expected.

• Information and Communications Magazine
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• v.27 no.7
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• pp.16-20
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• 2010

이동통신망을 활용하여 사물과 사물간의 연결(Connectivity)을 제공하는 사물통신 서비스를 M2M이라 하며, 이는 인구수의 제약을 넘어서는 신규 가입자시장이다. M2M은 원격측정, 감시, 제어, 관제 등의 기능을 제공하며, 사물과 현장의 정보를 수집하는 센싱부와 이를 전달하는 광역통신망 및 수집정보의 가공, 처리, 통제하는 서버시스템의 3요소로 구성된다. 이를 위해서 기기, 센서, 통신모듈, 통신 및 IT등 다양한 전문Player의 협업을 필요로 하는 Value Chain을 가지고 있다. M2M 시장은 고정물, 이동물, 차량 및 대인시장으로 구분할 수 있으며, 전력, 수도 등 검침, 보안방범, 재난재해관리, 환경감시, 차량관제, 대인 위치추적 등 다양한 분야에서 적용되고 있다. 국내 M2M 시장은 지난 10년간 지속적인 성장을 계속하고 있으나 급속성장 및 활성화를 위하여는 소규모 세분시장의 한계를 극복하고 규모의 경제를 달성할 수 있는 방안의 모색, Value Chain내 다양한 Player간 Win-Win 협업체계의 강화, 높은 QoS에 의한 서비스 안정성 및 도입운영의 용이성 제고, 초기도입 비용장벽의 완화 등이 필요한 것으로 분석된다. 향후 높은 성장 잠재력을 가지고 있는 M2M 시장은 참여자들의 창의적인 대상시장 발굴과 가치의 제공을 통하여 상생 발전의 선순환을 도모할 필요가 있다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.71-77
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• 2001

현재 급속히 발전하는 정보통신시스템은 산업계에 전형적인 중대한 변화를 가져왔다. 새롭고 향상된 하드웨어에 의해 진행된 클라이언트/서버 환경의 혁명적인 변화는 정보의 공유와 저장, 이동이 비약적으로 발전하고 있다. 광역 네트워크(WAN)는 그 대역폭의 제한을 풀고 무제한의 대역폭으로 넓혀가고 있다. 이제 곧 10배나 빠른 LAN 속도로 상호 연결된 수백만의 서버가 존재하는 네트워크가 지구상에 구축될 것이다. (중략)

• Journal of the Economic Geographical Society of Korea
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• v.9 no.3
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• pp.341-357
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• 2006

Recently new periodic markets formed in large apartment areas where consumers live. Before, in the case of peasant periodic markets travelling merchants, consumers and producers met in specific places on decided dates. Closing time of apartment's new periodic markets is later than that of peasant periodic markets, and the number of travelling merchants is fewer than that of peasant periodic markets. The average number of apartment and household for a new periodic market is about ten and 920 respectively, and if neighboring apartment household are included, the number is larger. Apartment's new periodic markets in Cheongju city is included in Daejeon market area. The types of regional trip of travelling merchants can be divided into one round trip of two or three neighboring dongs and larger sphere of more than 4 dongs. The larger sphere round trip consists of one type combining the southeastern, southern and southwestern regions, and the other type combining southeastern and southwestern regions. About 85 percent of travelling merchants visit the periodic market 5 days in a week; about 12 percent of travelling merchants choose to visit on Saturday; only 2 percent of travelling merchants visit 4 days in a week.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.694-701
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• 2004

In this paper, we proposed a feature-based tracking system that traces moving objects with a pan-tilt camera after separating the global motion of an active camera and the local motion of moving objects. The tracking system traces only the local motion of the comer features in the foreground objects by finding the block motions between two consecutive frames using a block-based motion estimation and eliminating the global motion from the block motions. For the robust estimation of the camera motion using only the background motion, we suggest a dominant motion extraction to classify the background motions from the block motions. We also propose an efficient clustering algorithm based on the attributes of motion trajectories of corner features to remove the motions of noise objects from the separated local motion. The proposed tracking system has demonstrated good performance for several test video sequences.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.1-18
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• 2009

A series of three-dimensional numerical simulations using a generalized multidimensional hydrodynamic dispersion numerical model is performed to simulate effectively and to evaluate quantitatively impacts of urbanization on density-dependent groundwater flow and salt transport in a coastal aquifer system, Suyeong-Gu, Busan, Korea. A series of steady-state numerical simulations of groundwater flow and salt transport before urbanization with material properties of geologic formations, which are established by numerical modeling calibrations considering all the urbanization factors, is performed first without considering all the urbanization factors. A series of transient-state numerical simulations of groundwater flow and salt transport after urbanization is then performed considering the urbanization factors individually and all together. Finally, the results of both numerical simulations are compared with each other and analyzed. The results of the numerical simulations show that density-dependent groundwater flow, salt transport, and seawater intrusion in the coastal aquifer system are intensively and extensively impacted by the urbanization factors. Especially, these urbanization factors result in the changes of the total groundwater volume and salt mass in the coastal aquifer system. However, such impacts of each urbanization factor are not spatially uniform but locally different.