• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.280-282
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• 2000

지금까지 인터넷에서 단말기의 이동성을 보장하기 위한 연구 방향은 계층적 망 구조에 따라 메크로 이동성과 마이크로 이동성을 분리하는 것이다. 핸드오프가 적은 매크로 이동성의 경우 Mobile IP 로 수렴되는 반면 이동성이 잦은 마이크로 이동성의 경우 HA 로 보내지는 제어 메시지를 어떻게 줄일 것인가에 대하여 서로 다른 방안이 제시되고 있다. 현재까지 제시된 연구의 공통적인 문제는 게이트웨이 라우터의 집중화로 발생할 수 있는 부하이다. 본 논문에서는 단말기의 이동의 지역성 및 분산된 지역 에이전트 개념을 도입하여 이러한 문제를 개선한 분산 지역 기반 이동프로토콜인 DRMIP를 제안한다. 또 DRMIP 의 특성 및 적용성을 검증하기 위하여 인터넷 프로토콜과의 호환성, QoS 지원성, 시스템 안정성, 광역단위로의 확장성 등의 측면에서 타 프로토콜과 비교 분석하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.11-17
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• 2022

In this study, we address the development of a floating platform system based on a unmanned surface vessel for wide-area sensing and monitoring of hazardous and noxious substances (HNSs). For long endurance, a movable floating platform with no mooring lines was used and modified for HNS sensing and monitoring. The floating platform was equipped with various sensors such as optical and thermal imaging cameras, marine radar, and sensors for detecting HNSs in water and air. Additionally, for experiment validation in real outdoor environments, a portable gas-exposure system (PGS) was built and installed on the monitoring system. The software for carrying out the mission was integrated with the Robot Operating System (ROS) framework. The practical feasibility of the developed system was verified through experimental tests conducted in inland water and real-sea environments.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.309-310
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• 2003

입자상물질에 대한 연구는 광역적인 대기 오염정도의 평가 및 오염물질의 이동에 대한 유용한 정보를 제공해 주므로 이와 같은 오염원의 크기에 대한 배경농도를 파악하는 것이 무엇보다 중요하다. 또한 입자상물질은 대기중에서 기류를 타고 이동할 수 있기 때문에 오염농도 변화는 지역적인 영향을 받는 대도시 지역보다 오염원으로부터 격리된 청정지역에서의 측정이 필요하다(신혜정 등, 2002). 본 연구에서는 국내 배경농도 측정지점 중 하나인 강화에서 2000년부터 2002년까지 측정한 입자상 물질의 농도 특성을 파악하고자 한다. (중략)

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.12
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• pp.455-462
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• 2016

Wireless sensor networks have been researched to gather data about events on sensor fields from sources at sinks. Multipath routing is one of attractive approaches to reliably send data against the problem of frequent breakages on paths from sources to sinks due to node and link failures. As mobile events such as humans, animals, and vehicles are considered, sources may be continuously generated according to the movement of the mobile event. Thus, mobile events provide new challenging issue in multipath routing. However, the research on multipath routing mainly focus on both efficient multipath construction from sources to static sinks and fast multipath reconstruction against path breakages. Accordingly, the previous multipath routing protocols request each source continuously generated by a mobile event to construct individual multipath from the source to sinks. This induces the increase of multipath construction cost in the previous protocols in proportion to the number of source. Therefore, we propose efficient multipath routing protocol for supporting continuous sources generated by mobile events. In the proposed protocol, new source efficiently reconstructs its multipath by exploiting the existing multipath of previous sources. To do this, the proposed protocol selects one among three reconstruction methods: a local reconstruction, a global partial one, and a global full one. For a selection decision, we provide an analytical energy consumption cost model that calculates the summation of both the multipath reconstruction cost and the data forwarding cost. Simulation results show that the proposed protocol has better performance than the previous protocol to provide multipath routing for mobile events.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.5
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• pp.639-650
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• 2023

Economic development has resulted in the concentration of population and industry in the metropolitan area. Additionally, the Republic of Korea is experiencing this phenomenon, with more than half of the population living in the Seoul capital area. To alleviate this concentration of population, the Korean government implemented the new town development policy. Unfortunately, this has led to an increase in the commuting population, causing an imbalance in transportation services due to financial and policy differences in each region. This paper analyzes the level of user satisfaction with mega commuting in three aspects: mobility, accessibility, and connectivity. To objectively assess the level of user satisfaction, which is qualitative data, the Rasch Model is used to analyze the collinearity of user data. The results indicate that the level of user satisfaction differs by region, and service satisfaction with mobility is lower than that with accessibility and connectivity. Therefore, prior to the introduction of new town policies, it is necessary to develop metropolitan transportation infrastructure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.79-87
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• 2010

The urban street has been escaped from functional and uniformed arrangement for merely movement to the space which can take the role of cozy and familiar culture. Therefore I tried to prepare a plan for the wide roads having streetscape which reveal area's identity as well as coziness and convenience by grasping the problem and its solution through analysing and deducing various elements with the subject of streetscape among urban landscape components, especially composing wide road's streetscape. First of all, this study made a simulation by deducing components of wide road's streetscape and controlling them with theoretical review of streetscape and consideration of wide road's local characteristic. With the evaluation on the base of them, that following four components could be the representative things of entrance part was confirmed by this study. They were familiar streetscape,symbolic scene as as an entrance gate, continuous and dynamic streetscape, and interesting and pleasant streetscape. And for the middle part, those four components could represent the wide road's streetscapeI were confirmed. They were familiar streetscape, safe and tender streetscape, pleasant and dynamic streetscape, and symbolic streetscape. It seems that the components of the streetscape obtained from the analysis of this study are utilized as reference data in the case of a future streetscape design conclusively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.05a
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• pp.187-192
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• 1998

IMT (International Mobile Telecommunications)-2000은, ITU (International Telecommunication Union)를 중심으로 추진되는 차세대 무선 이동 통신 시스템의 표준안으로서, 현재 각 국가별로 추진되는 다양한 무선 이동 통신 시스템의 규격을 단일화하여 항상 전 세계 어디에서도 동일한 단말기로 서비스를 이용할 수 있는 것을 목적으로 한다. 그리고, 광대역 다중 접속 기법을 통해 2 Mbps까지의 대역폭을 제공함으로써 무선망에서 멀티미디어 전송이 가능하도록 한다. 또한 지상의 무선망과 인공 위성 망을 통합함으로써 다양한 사용자 분포를 갖는 광역적인 지역에 대해 서비스를 제공한다. 본 논문에서는 IMT-2000이 갖는 특징과 진행 방향에 대해 조사하고, 가장 큰 부분을 차지하는 광대역 다중 접속기법과 인공 위성 통신망의 개요에 대해 기술한다.

• Korea journal of population studies
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• v.11 no.1
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• pp.185-196
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• 1988

This study considers inter-jurisdictional fiscal externalities between a central city and suburbs, rigorously examines. and empirically tests the suburban-exploitation-of-central-cities hypothesis. Using micro-migra4ion data, house-holds 'intra-metropolitan migration between 1985 and 1990 Is examined based on a random utility model. It is found that efficient population distribution between a central city and suburbs can be achieved when local government stake into account inter-jurisdictional externalities. External aids from the federal and state governments should be given to public services such as education, welfare, health, and employee retirement services, if they intend to arrest central city decline. Regional tax sharifs can be another way of dealing with these externalities.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.959-970
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• 2004

It has become more difficult to correspond an cyber attack quickly as patterns of attack become various and complex. However, current so curity mechanisms just have passive defense functionalities. In this paper, we propose new network suity architecture to respond various cyber attacks rapidly and to chase and isolate the attackers through cooperation between security zones. The proposed architecture makes it possible to deal effectively with cyber attacks such as IP spoofing or DDoS(Distributed Denial of Service), by using active packet technology including a mobile code on active network. Also, it is designed to have more active correspondent than that of existing mechanisms. We im-plemented these mechanisms in Linux routers and experimented on a testbed to verify realization possibility of attacker response framework using mobile code. The experimentation results are analyzed.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.408-408
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• 2011

수자원관리와 수문모형에 있어 강수, 증발산, 침투, 침루 등의 물 순환과정에 대한 실질적인 이해와 분석연구의 중요도가 높아지고 있는 실정이며, 그중에서도 토양수분은 강수의 침투, 유출 등의 지표면과 대기사이의 질량 및 에너지이동에 관여하는 중요한 요소로서 수자원 및 수문현상에 직접적인 영향을 미친다. 이를 위해 강수, 증발산, 토양수분과 같은 수문변수에 대한 다양한 관측이 실시되어야 하지만 국내에서는 지속적이고 안정적으로 지상관측을 할 수 없는 실정이며 관련 기반기술도 매우 취약하다. 따라서 이를 극복하기 위해서는 위성영상자료를 이용함으로써 한반도 전체에 대한 광역적인 토양수분자료의 획득을 용이하게 한다. 본 연구의 연구유역은 수자원 연구를 위해서 지정된 용담댐 시험유역으로 하였으며, 토양수분 관측지점의 지상관측 수문자료인 각 지점별 강수량, 지면온도, 인공위성자료인 MODIS 정규식생지수 등의 가용자료를 수집하고 신경망모형을 활용한 토양수분자료 생산 모형을 개발하여, 개선된 시공간 분해능과 공간정보 대표성을 가진 광역 토양수분자료를 생산하고 적용타당성을 분석하였다. 산정된 토양수분모형의 적용가능성을 파악하고자 용담댐 유역의 각 지점별 토양수분 관측데이터와 추정데이터를 비교한 결과 추천, 부귀, 상정 지점의 경우 평균 약 0.9257의 상관계수와 약 1.2917의 평균제곱근오차를 보였고, 검증지점인 천천2의 경우 약 0.8982의 상관계수와 약 5.1361의 평균제곱근오차의 결과를 보여주었으며 토양수분 추정모형의 적용가능성이 높음을 확인할 수 있었다.