• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2021-2026
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• 2008

Recently, a high speed rail consists of many train coaches and power cars. For keeping the reliable train communication system with train coaches and power cars, train uses the OSI model(Open Systems Interconnection Basic Reference Model) and KTX(Korea Train eXpress) only uses the Physical to Transport layer of OSI model. This paper describes the analysis of CLNP(Connectionless Network Protocol) and ES-IS(End System to Intermediate System) protocols used in KTX for the network layer. CLNP is used to send data to other system and ES-IS protocol is used to route and send information between end systems and intermediate systems. Also this paper presents the protocol parsing program and implementation of Network layer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.915-917
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• 1998

Optimal routing of distribution networks can be attained by keeping the line power capacity limit to handle load requirements, acceptable voltage at customer loads, and the reliability indices such as SAIFI, SAIDI, CAIDI, and ASAI limits. This method is composed of optimal loss reduction and optimal reliability cost reduction. The former is solved relating to the conductor resistance of all alternative routes, and the latter is solved relating to the failure rate and duration of each alternative route. The routing considering optimal loss only and both optimal loss and optimal reliability cost are compared in this paper. The results showed that reliability cost should be considered as well as loss reduction to achieve the optimal routing in the distribution networks.

• Strategy21
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• 통권39호
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• pp.140-162
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• 2016

The construction of Jeju Naval Base was finally completed and donated to the Republic of Korea Navy on February 26th this year. There is no doubt that the new base will contribute to the substantial augmentation of Korea's naval power and maritime security. However, we should note that the new naval base took a long and hard twenty-three years to be completed. In the 21st century, Korea should adopt a new strategy that can fulfill the security requirements of Korea for the new age of international relations. The 21st century is characterized by globalization, and in the world of globalization, a national boarder has become meaningless. In the late 20th century, after the Cold War, trade between countries have greatly increased and so did the importance of the seas. Having transformed from an agricultural country into a commercial country, Korea went from a continental state to a maritime state. Korea has become the 9th largest trading state, and obviously, the importance of the sea has become significant. Korea's national strategic focus needs to be on the sea for national survival. Thus, since the 1990s, the Korean Navy has planned to build the Jeju Naval Base. Jeju, due to its geopolitical characteristics, is extremely important to the 21st century Korea's economy and national security. Jeju is the starting point of the sea route that reaches out to the world, and at the same time, the ending point of the sea route that heads towards Korea. Jeju is located in the center of Northeast Asia and thus, Jeju Naval Base is extremely important for the area's security and order. Jeju Naval Base will be very useful not only for the maritime security of Korea, but also for keeping peace and order in Northeast Asia. Jeju Naval Base was the minimal effort against the six sea route security threats towards Korea. The six sea route threats are: 1) Threat from North Korea; 2) China's Threat towards Korea's sovereignty; 3) China's treat towards Korea's fishery; 4) Threat from Japan; 5) Threat towards Korea's sea routes; 6) Threat from recent phenomena of isolationism of the United States. Jeju Naval Base is built for both warships and civilian ships--such as cruise ships--to use. Just like the United States' Pearl Harbor, Jeju Naval Base will become not only the largest military base, but a beautiful tourist site.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.485-486
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• 2007

Wireless Sensor Networking is state of the art technology that has a wide range of potential applications. Sensor network generally consists of a large number of distributed nodes that organize themselves into a multi-hop wireless network. Each node has one or more sensors, embedded processors and low-power radios, and is normally battery operated because of small size. In this paper wireless sensor networking technology applies to the environment monitoring system in the underground. This system can monitor a pollution level of the underground in realtime for keeping up a comfortable environment.

• Korean Chemical Engineering Research
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• 제51권3호
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• pp.403-406
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• 2013

이 논문에서는 6-aminohexanoic acid (AHA)를 사용해서 물에 분산이 잘되는 균일한 maghemite 나노입자를 제조하는 방법을 설명한다. 물에 분산되는 maghemite 나노입자는 $195^{\circ}C$의 octyl ether와 AHA의 혼합물에 $Fe(CO)_5$를 넣어주는 방법으로 제조하였다. 제조된 나노입자는 좋은 결정성과 자성을 띄고 있으며 물에서 상당한 안정성을 보여주었다. 또한 ligand-exchange 방식으로 물에 분산되는 maghemite 나노입자를 제조하는 방법도 가능함을 확인하였다. 본 연구에서는 AHA를 이용하여 물에 분산된 금속 산화물 나노입자를 제조하는 새로운 대안을 제시하였다.

• 정보처리학회논문지C
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• 제12C권5호
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• pp.623-632
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• 2005

애드혹 네트워크는 기존의 유무선 네트워크의 고정된 기반시설(infrastructure) 없이 이동 호스트들만으로 구성된 무선 환경의 네트워크이다. 애드혹 네트워크의 기본 특성, 즉, 링크의 불안정성, 각 노드의 물리적 보호의 한계, 노드간 연결의 산재성, 토폴로지의 동적인 변화 뿐 아니라 악의적인 노드의 활동으로 인해 라우팅 보안에 대한 위험성은 매우 높다 따라서 본 논문에서는 애드혹 네트워크에서 경로 탐색이나 설정 과정중 악의적인 노드가 라우팅 메시지를 변조, 위조하거나 다른 노드를 가장하여 잘못된 라우팅 정보를 네트워크에 주입시키는 공격을 방지하기 위하여 일방향 해쉬 함수를 기초로 한 one-time 전자 서명을 이용한 라우팅 보안 메커니즘을 제안한다. 제안하는 메커니즘에서 노드들은 라우팅 메시지를 서명하기 위하여 공개키 요소의 첫 세트를 반복적으로 해쉬 함수에 적용함으로써 해쉬 체인을 생성하고, 생성된 해쉬 체인으로부터 공개키 요소들을 여러 세트 유도하여 해쉬 테이블을 생성한다. 해쉬 테이블 생성 후, 노드들은 자신의 공개키 요소를 다른 노드들에게 공표하고 라우팅 메시지를 전송할 경우 one-time 전자 서명을 포함한다. 이러한 one-time 전자 서명은 라우팅 메시지를 인증하고 메시지에 무결성을 제공한다. 제안하는 라우팅 보안 메커니즘은 이동성이 높은 네트워크 환경에서는 보안을 고려하지 않은 라우팅 메커니즘에 비해 라우팅 오버헤드가 좀더 높아지지만, 경로를 탐색하고 설정하는 과정에서 악의적인 노드의 공격에 대하여 훨씬 높은 안전성을 제공함을 시뮬레이션을 통해서 확인할 수 있다.

• 한국산학기술학회논문지
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• 제12권2호
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• pp.821-828
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• 2011

본 논문은 자동항로 추적(Track keeping control), 자동조타(Automatic steering), 자동 접이안(Automatic mooring control) 등으로 구성된 자동운항 시스템 중 자동조타장치의 성능 개선 알고리즘 개발에 대해 다루고 있다. 자동조타는 풍력 또는 조력 등의 영향으로부터 선박의 설정 항로와 실제 침로와의 차이를 계산하여 설정된 항로를 유지하며 항해하므로, 조타에 소요되는 선원의 지속적인 항해로 인한 운전 부담을 경감시키고 불필요한 타조작에 의한 항로 이탈을 줄임으로써 항해거리 단축과 연료비용을 절약할 수 있는 시스템이다. 선박의 모델링을 위하여 Nomoto 모델에 근거하여 전달함수를 구하고, 조종성능(Manoeuvirng) 편리성을 고려하여 타각 입력에 대한 선수각 응답으로 표시된 선박의 4자유도만을 고려한 선형 모델을 제안하고 선박 자동조타장치의 최대각과 타각율을 고려하여 Fuzzy제어기를 설계 하였고 PID제어기로 성능을 비교 분석하였다.

• 대한안전경영과학회지
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• 제11권4호
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• pp.201-211
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• 2009

The types and quantities of Hazmat and Hazmat transportation are gradually increasing, keeping pace with industrialization and urbanization. At present the safety management for Hazmat transportation only considers reducing accident probability, but even when an accident involving Hazmat-carrying vehicles occurs, that is not regarded as a Hazmat-related accident if the Hazmats do not leak out from the containers carrying them. Thus the methods to reduce risk (Risk=Probability$\times$Consequence) have to be developed by incorporating accident probability and consequence. By using Geographic Information System (GIS), a technical method is invented and is automatically able to evaluate the consequence by different types of Hazmat. Thus this study analyzed the degree of risk on the links classified by the Hazmat transport pathways. In order to mitigate the degree of risk, a method of 7-step risk management on Hazmat transportation in railway industries can be suggested. (1st step: building up GIS DB, 2nd step: calculating accident probability on each link, 3rd step: calculating consequence by Hazmat types, 4th step: determination of risk, 5th step: analysis of alternative plans for mitigating the risk, 6th: measure of effectiveness against each alternative, and 7th step: action plans to be weak probability and consequence by the range recommended from ALARP). In conclusion, those 7 steps are used as a standardization method of optimum transportation routing. And to increase the efficiency of optimum transportation routing, optional route can be revise by verification.

• 한국콘텐츠학회논문지
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• 제15권9호
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• pp.118-125
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• 2015

아동안전지킴이 제도는 아동의 범죄피해 방지를 위해 경찰청 주관으로 전국에서 운영되고 있는 협력치안 프로그램이다. 아동안전지킴이 제도는 2009년 시행된 이래 아동범죄 예방효과에 긍정적 영향을 미쳤을 것으로 기대되고 있으나 구체적 효과성은 불분명하다. 운영현황에 대한 실증적 연구와 제도발전을 위한 학술적 검토가 충분하지 못했기 때문이다. 이러한 배경에서 본 연구는 아동안전지킴이 제도의 운영실태를 파악하고 실효성 향상방안을 탐색하기 위한 목적에서 수행되었다. 연구목적 달성을 위해 16개 지역 지방경찰청에 배치된 전체 아동안전지킴이에 대해 할당표본을 추출하여 설문조사를 실시했다. 설문결과는 빈도분석, 티검증, 아노바, 다중회귀분석을 실시했다. 분석결과 제도발전을 위해 아동안전지킴이집과의 연계강화, 아동안전지킴이의 순찰노선에 대한 참여적 편성, 교육관리 감독체계의 개선, 활동비의 적정성, 성공적 직무인식 증진을 위한 아동접촉근무 강화방안 등의 중요성이 검증되었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.6.2-6.2
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• 2010

Stainless steel is widely known to have superior corrosion properties. However, in some harsh conditions it still suffers various kinds of corrosions such as galvanic corrosion, pitting corrosion, intergranular corrosion, chloride stress corrosion cracking, and etc. For the corrosion protection of stainless steel, the ceramic coatings such as protective silica film can be used. The sol-gel coating technique for the silica film has been extensively studied especially because of the cost effectiveness. It has been proved that silica can improve the oxidation and the acidic corrosion resistance of metal surface in a wide range of temperatures due to its high heat and chemical resistance. However, in the sol-gel coating process there used to engage a heat treatment at an elevated temperature like $500^{\circ}C{\sim}600^{\circ}C$ where cracks in the silica film would be formed because of the thermal expansion mismatch with the metal. The cracks and pores of the film would deteriorate the corrosion resistance. When the heat treatment temperature is reduced while keeping the adhesion and the density of the film, it could possibly give the enhanced corrosion resistance. In this respect, inorganic protective silica film was tried on the surface of stainless steel using a sol-gel chemical route where silica nanoparticles, tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) were used. Silica nanoparticles with different sizes were mixed and then the film was deposited on the stainless steel substrate. It was intended by mixing the small and the large particles at the same time a sufficient consolidation of the film is possible because of the high surface activity of the small nanoparticles and a modest silica film is obtained with a low temperature heat treatment at as low as $200^{\circ}C$. The prepared film showed enhanced adhesion when compared with a silica film without nanoparticle addition. The films also showed improved protect ability against corrosion.