• 대한전자공학회논문지TC
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• 제45권3호
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• pp.46-52
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• 2008

BGP는 인터넷에서 망사업자 및 대규모 네트워크에서 네트워크간에 라우팅 정보를 교환하는 라우팅 프로토콜이다. 라우터가 end-to-end 트래픽에 대해 트래픽 엔지니어링을 위한 정책을 설정할 때 neighbor AS 이외의 AS들에게는 원하는 정책이 영향을 미치지 않기 때문에 원하는 트래픽 엔지니어링을 할 수 없는 한계가 있다. 본 논문에서는 global 정책의 설정을 통해 원하는 트래픽 엔지니어링의 특성을 반영시킬 수 있도록 함으로써 BGP에서 End-to-End간 트래픽 엔지니어링을 위한 라우팅이 실현될 수 있도록 하는 확장된 BGP 라우팅 알고리즘을 제안한다. 새로운 BGP 라우팅 알고리즘은 전통적인 BGP 라우팅 테이블의 구조적인 변경을 하지 않고 새로운 메시지 형식을 추가하지 않으며 기존의 UPDATE message를 이용하여 global 정책 설정을 하게 한다. 또한 새로운 BGP 라우터가 전통적인 BGP 라우팅 알고리즘으로 동작하는 BGP 라우터들과 함께 망을 구성하고 있는 경우에도 확장성 문제를 야기하지 않는다. 새로운 BGP 알고리즘과 전통적인 BGP 알고리즘의 성능을 비교하기 위해 패킷 loss와 평균 delay를 시뮬레이션을 통해 비교 분석하여 그 결과를 확인하였다.

• 한국안전학회지
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• 제33권1호
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• pp.148-161
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• 2018

A traffic fatality by young people marked average annual decrease of 4.5% since 2011. Meanwhile, a traffic fatality by senior over 65 years old marked average annual increase of 7.9% for the last five years which means that the annual increase of traffic fatality by senior will be a serious problem. This study started questioning that senior drivers over 65 years old did not retain the same causal factor of fatal traffic accidents and thus extensively analyzed a risk of it by age group quantitatively, dividing the senior driver group into the early, middle and latter stages. Depending on the aging level, the risk of traffic fatality showed a wide difference in seven different types of traffic accidents generally, and happened to increase with latter and middle parts of the senior driver more than the early part. Therefore, this study proposes four policy suggestions: 1) The senior driver need to be offered customized driving educations and the improvement of road environment is also recommended. 2) Political assistance is needed to support and guide a safety related technology installation for the new or existing car. 3) Renewal of driving license and an aptitude test(physical examination, cognitive test) for drivers over 75 years old should take in a less than 3 years and an additional road test is needed as occasion demands. 4) Like the United States and Europe, development and extension of customized treatment guidebook for medical teams who examine senior drivers is needed and establishment of education and administration system that a supervisor of driving license renewal can impose safety restriction and American anonymity reporting system is considered to institutionalize in the medium to longer term.

• 항공우주정책ㆍ법학회지
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• 제32권2호
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• pp.67-100
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• 2017

항공산업이 비약적으로 발달을 함에 따라, 항공기사고의 위험성도 커지고 있다. 본 논문에서는 항공기사고의 인적요인 중 하나인 항공교통관제사 불법행위를 중심으로 다루었다. 현재 우리나라의 법령상 항공교통관제사의 불법행위 대한 책임을 규정한 명문은 없다. 따라서 국가공무원으로서의 항공교통관제사의 법적책임에 대하여 헌법제 29조1항과 국가배상법의 적용 여부를 살펴보았다. 실제로 우리나라는 항공사고의 원인이 항공관제사 과실에 의한 것이라는 유일한 판례가 1971년에 선고된 이후, 항공사고조사결과 관제사의 과실이 사고의 주요요인이었다고 함에도 불구하고 추가판례가 없는 상황이다. 본 논문은 항공사고에 있어서 관제사와 조종사간 요인 뿐만 아니라, 관제사에 대한 실제로 법령의 적용가능성을 해외사례를 통해 살펴보았다. 항공교통관제라는 특수한 업무가 고강도의 업무스트레스를 갖는 업무라 할지라도, 항공교통관제의 최종목적인 항공기의 안전한 운항을 책임지고 있는 전문가로서 항공기사고의 원인이 되었다면, 그에 따른 법적 책임은 져야 한다는 내용을 다루었다.

• 한국안전학회지
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• 제21권2호
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• pp.128-137
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• 2006

Traffic accidents occur due to complex influences of transportation companies, drivers, and road environment. This study found that education and surroundings for transportation companies, driving habits of drivers, and road safety facilities and accessory facilities were main factors that affected strongly traffic accidents. Also, it found that driving habits of drivers could affect accidents heavily more than two other factors. Road safety and accessory facilities were analysed that they affected traffic accidents independently with transportation companies and their own drivers. Therefore, in order to achieve a traffic accident prevention as our main target, those companies need to produce atmosphere that their own drivers can have safety awareness, and related institutions for the above target should run parallel with policy assistance and strict traffic enforcement. In the end, this study suggests that transportation companies should secure manpower wholly being charged with traffic safety and financial resources investing in it.

• 한국통신학회논문지
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• 제21권1호
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• pp.175-186
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• 1996

An optimal channel input-traffic control (OCIC) policy is proposed for slotted frequency-hopped spread-spectrum multiple access communication systems. When the number of channel input packets is set to the optimal number, the conditional throughput for the OCIC policy is analyzed. The state transition probability is derived, the steady state performance is analyzed, and the mean pracket delay is obtained. It is shown that the mean packet delay decreases considerably when the priority of transmission is given to backlogged users. The smaller is the number of requency slots, the larger are the differences between the preformance of the OCIC policy and that of the other policies.

• ETRI Journal
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• 제28권6호
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• pp.815-818
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• 2006

In the global Internet, a constraint-based routing algorithm performs the function of selecting a routing path while satisfying some given constraints rather than selecting the shortest path based on physical topology. It is necessary for constraint-based routing to disseminate and update link state information. The triggering policy of link state updates significantly affects the volume of update traffic and the quality of services (QoS). In this letter, we propose an adaptive triggering policy based on link-usage statistics in order to reduce the volume of link state update traffic without deterioration of QoS. Also, we evaluate the performance of the proposed policy via simulations.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.91-98
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• 2007

Community noise has been serious social issues in Korea. This paper reviews current statistics and status on railway noise, with practical engineering tools in order to reduce the noise level from railway traffic noise sources. At the beginning, guidelines of the current environmental policy are discussed, with the new policy on railway noise to be enforced beginning in 2007 with 5 year schedule. Then, a noise reducer is proposed as a tool to reduce noise levels protecting people living near at the railway. Details on the acoustic effect in field test are discussed with the result of implementation in the street. We propose noise reducers as an effective and practical tool for the people who are exposed to rail traffic noise in cities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2379-2397
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• 2017

Content distribution technology, which routes content to the cache servers, is considered as an effective method to reduce the response time of the user requests. However, due to the exponential increases of content traffic, traditional content routing methods suffer from high delay and consequent inefficient delivery. In this paper, a content selection policy is proposed, which combines the histories of cache hit and cache hit rate to collaboratively determine the content popularity. Specifically, the CGM policy promotes the probability of possible superior paths considering the storage cost and transmission cost of content network. Then, the content routing table is updated with the proportion of the distribution on the paths. Extensive simulation results show that our proposed scheme improves the content routing and outperforms existing routing schemes in terms of Internet traffic and access latency.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.364-367
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• 2008

Many different types of network equipments are deployed in a large-scale IP network. In this operating environment, network service providers suffer from difficulty in controlling various equipments simultaneously in case network faults happen in their overall or regional network due to physical link failure or abnormal traffic. This paper presents a policy-based methodology to control many different types of network equipments at the same time in abnormal cases. The key idea is that NMS(Network Management System) keeps vendor-neutral control policies in normal times and that when an abnormal case occurs in network, NMS transforms the selected policy into vendor-specific control commands and enforces them to various equipments simultaneously.

• 한국경제지리학회지
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• 제15권4호
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• pp.615-627
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• 2012

본 연구는 교통카드 데이터를 이용하여 대중교통 이용과 관련하여 통행패턴을 분석하였으며 교통정책에 활용할 수 있는 방안을 제시하였다. 교통카드 데이터는 경기도권역을 대상으로 하였고 활용방안으로 교통정책 의사결정자가 버스정류소 시설을 개선할 때 교통카드데이터에서 얻어질 수 있는 여러 변수를 이용하여 대상지를 선정한다는 시나리오를 설정하여 분석하였다. 분석결과, 의사결정방법론인 K평균 군집분석과 CHAID(Chi-squared automatic interaction detection)를 이용하였으며, 유의수준 p<0.01에서 정책에 유용하게 이용될 수 있는 결과를 얻었다. 또한 본 연구에서는 이러한 결과들을 근거로 교통카드데이터를 실제로 정책에 활용되기 위해서 개선되어야 할 정책적 함의를 제시하였다.