• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4108-4122
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• 2016

To address challenges of an unprecedented growth in mobile data traffic, the ultra-dense network deployment is a cost efficient solution to off-load the traffic over other small cells. However, the real traffic is often much lower than the peak-hour traffic and certain small cells are superfluous, which will not only introduce extra energy consumption, but also impose extra interference onto the radio environment. In this paper, an elastic energy efficient cell management scheme is proposed based on flow scheduling among multi-layer ultra-dense cells by a SDN controller. A significant power saving was achieved by a cell-level energy manager. The scheme is elastic for energy saving, adaptive to the dynamic traffic distribution in the office or campus environment. In the end, the performance is evaluated and demonstrated. The results show substantial improvements over the conventional method in terms of the number of active BSs, the handover times, and the switches of BSs.

• KIEAE Journal
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• 제3권2호
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• pp.33-36
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• 2003

The influence of the visual information on the sound perception would be considerable. Furthermore, if the sound perception ranges in noisiness or annoyance beyond the loudness, it will depend much more on the shape of the visual information. This paper aims to estimate the influence of the several kinds of visual information on the perception of road traffic noise by means of the psycho-acoustic test method. The findings of present study on the influence of visual information on subjective noise perception are summarized as follows: Presenting visual images of mild and comfortable scenery reduced the noise perception reaction at the less noisy environments not exceeding 65 dB(A). At highly noisy environments exceeding 65 dB(A), however, the noise perception can be reduced by strong image of waterfall. Even eliminating the road traffic image may be helpful. Visual image of waterfall reduced the noise perception at all levels. It is inferred that the road traffic noise perception can be effectively ameliorated by presenting strong and real landscape images at any noisy environment.

• 대한교통학회지
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• 제25권3호
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• pp.7-17
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• 2007

단순한 배기가스의 양적 감소를 위한 노력에서 벗어나 환경정의와 같은 새로운 이론적 체계 속에서 교통 운영 개선과 대기오염 개선을 함께 살펴보았다. 즉, 환경정의의 관점에서 새로운 목표를 설정하고. 설정된 목표를 달성하기 위한 교통운영 대안들을 마련한 후, 교통 및 환경차원에서 동시에 적용 평가하는 틀을 마련하였다. 이러한 이론적 틀은 교통개선을 통한 환경정의 구현 목표 설정, 교통운영전략 시나리오 수립, 시나리오별 결과 산출, 결과 분석 및 시사점 도출의 과정으로 구성된다. 본 연구를 통해 환경적 요구가 뚜렷하게 강조되어야 하는 경우에는 환경정의가 우선되는 교통운영 개선전략을 마련하고 평가하여 시행할 수 있는 도구를 마련하였다.

• 대한전자공학회논문지TC
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• 제43권9호
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• pp.25-31
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• 2006

본 논문에서는 데이터 마이닝을 이용한 차량 사고 사망확률 모형을 제안하였다. 본 논문의 목표는 제안된 모델을 이용하여 기술적, 환경적 개선을 통해 교통사고를 줄이는 것으로 교통사고 데이터를 수집하여 데이터 마이닝 알고리즘을 적용하여 사망 원인에 대한 분석을 통해 사망확률 모형을 개발하였다. 이를 위해서 훈련 데이터와 테스트 데이터를 이용하여 최적의 모형을 개발하였다. 이모형을 통해 교통 사망사고에 대한 사망확률을 구할 수 있고 사망 사고의 원인이 되는 중요한 요인을 알아낼 수 있다. 교통사고의 원인이 되는 요인을 기술 개발과 교통 환경 개선에 활용한다면 향후 교통사고를 줄이는데 기여할 것이다.

• Asian Journal of Atmospheric Environment
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• 제1권1호
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• pp.1-8
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• 2007

Vehicle exhaust is a dominant source of air pollutants in urban areas. Since people are easily exposed to vehicle exhaust particles while driving a car and/or traveling via public transportation, air pollution near traffic has been extensively studied in developed countries. In this paper, investigations on vehicle-related fine particulate air pollution at roadsides and on roads in Seoul, Korea were reviewed to understand air pollution near traffic. Comparison of $PM_{10}$ concentrations in Seoul showed that roadside air is more contaminated than urban air, implying that exposure levels near vehicular emissions are more critical to sensitive persons. Concentrations of ultrafine particles and BC (black carbon) at roadsides of Seoul fluctuate highly for short durations, responding to traffic situations. Diurnal variations of ultrafine particles and BC concentrations at roadsides seem to be affected by traffic volume, mixing layer height, and wind speed. Concentrations of ultrafine particles and BC decrease as distance from the road increases due to dilution during transport. On-road air pollution seems to be more severe than roadside air pollution in Seoul. Since nearby traffic air pollution has not been well understood in Seoul, further studies including various vehicular air pollutants and representative locations are needed.

• 한국컴퓨터정보학회논문지
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• 제10권4호
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• pp.173-179
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• 2005

컴퓨팅 기술과 네트워크 기술의 지속적인 발전은 인터넷의 폭발적인 성장을 가져왔으며, 사회 전반에 걸친 기반시설 및 공공 인프라, 산업 인프라 및 문화 환경을 인터넷 기반으로 변화시키는 중요한 역할을 수행했다. 최근 정보통신의 급속한 발전으로 인터넷을 이루는 컴퓨터 및 네트워크 환경은 초유의 성장과 발전을 거듭했지만, 잠재적인 취약점을 많이 가지고 있다. 이러한 취약점을 이용한 웜 및 해킹으로 인한 피해는 날로 심각하다. 본 논문에서는 이런 문제점들을 해결하기 위하여 유해 트래픽 분석 시스템을 설계하여 새로운 공격에 대한 방어와 네트워크의 트래픽을 분석함으로써 침입 및 유해 정보 여부를 판단하여 실시간으로 대응한다.

• 한국대기환경학회지
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• 제32권6호
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• pp.575-582
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• 2016

Seoul city has high population density as well as high traffic congestion, which are vulnerable to exposure of environmental pollutions caused by car traffic. However, recent studies are only on local regions about road traffic and air pollution or health effect of road traffic on residents. Thus, comprehensive study data are needed in terms of overall Seoul regions. In this study utilized the nitrogen dioxide concentration through the national air pollution monitoring network data, 2012 to 2013. It also divided regions into high and low exposure districts via the Origin destination data developed by the Korea transport institute to quantify and evaluate the effect of transport policies and analyzed a correlation of asthma symptoms with high and low exposure districts through raw data of community health survey from the Korea centers for disease control and prevention. Based on the collected data, the pearson's correlation analysis was conducted between air pollution substance concentration and high exposure district and multiple logistic regression analysis was conducted to determine the effect of traffic environment and factors on asthma symptoms of residents. Accordingly, the following results were derived. First, the high exposure district was higher concentrations of nitrogen dioxide ($NO_2$) as per time compared to those of the low exposure district (p<0.01). Second, analysis on correlation between average daily environmental concentration in the air pollution monitoring network and road traffic showed that nitrogen dioxide had a significant positive correlation (p<0.01) with car traffic and total traffic as well as with truck traffic (p<0.05) statistically. Third, an adjusted odds ratio about asthma doctor's diagnosis in the high and low exposure districts was analyzed through the logistic regression analysis. With regard to an adjusted model 2 (adjusted gender, age, health behavior characteristics, and demographic characteristics) odds ratio of asthma doctor's diagnosis in the high exposure district was 1.624 (95% CI: 1.269~2.077) compared to that of the low exposure district, which was significant statistically (p<0.001).

• 대한건축학회논문집:계획계
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• 제34권1호
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• pp.71-81
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• 2018

The purpose of this study is to develop neighborhood assessment tools from the perspective of women in order to evaluate neighborhood environments and suggest better policies and planning practices for women-friendly neighborhood environments. To do so, we analyze correlations between women's quality of life and the neighborhood environment. Specifically, we gave female participants a mapping survey, interview, and questionnaire to collect data targeting women living in Onyang 2-dong and 5-dong in Asan city. First, we developed a neighborhood assessment tool derived from an extensive literature review and particular case studies. The mapping and interview surveys indicated that specific aspects neighborhood life needed to be improved in a similar area. In particular, women complained about Onyangoncheon station, a commercial area, and detached house area. Second, analysis of the neighborhood environmental factors affecting women's neighborhood satisfaction, crime safety, traffic and walking environment, accessibility of living facilities, green and public spaces and childcare environment were statistically significant. Of these, the inclusion of green and public spaces was the most influential factor. Third, the neighborhood environmental factors affecting women's neighborhood attachment, crime safety, traffic and walking environment, accessibility of living facilities, green and public spaces and childcare environment were statistically significant. Of these, accessibility of living facilities appeared to be the most influential factor. Fourth, the neighborhood environmental factors affecting women's housing mobility decisions, crime safety, traffic and walking environment, accessibility of living facilities, green and public spaces and childcare environment were statistically significant. Of these, childcare environment was the most influential factor.

• 해양환경안전학회지
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• 제21권4호
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• pp.397-402
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• 2015

본 연구는 관측일수에 따른 교통량의 신뢰성을 검증하고자 한다. 목포항의 1년간 선박자동식별장치(AIS) 자료를 사용하여 월별, 요일별, 시간별 변화지수를 비교한 후, 각 관측일수에 따른 최대표준오차를 산출하였다. 월별변화지수를 비교한 결과 9월달 1.11, 2월달 0.84로 나타나 9월달이 2월달 교통량 보다 약 32.1 % 많은 것으로 나타났다. 요일변화지수는 화요일 1.05, 일요일 0.92로 나타나 화요일이 일요일 교통량보다 약 14.1 % 많았다. 해상교통조사는 요일변화지수를 고려하여 최소 1주일 이상 실시하면 최대표준오차를 21 % 이내로 산출할 수 있다. 따라서 해상교통조사 관측시기에 따라 각 변화지수를 적용하여 교통량의 흐름을 반영한 연구가 뒷받침 되어야 하겠다.

• 한국항행학회논문지
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• 제14권2호
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• pp.161-169
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• 2010

최근 항공교통량의 증가에 따라 보다 효율적인 항공교통흐름제어가 요구되고 있다. 이에 본 논문에서는 효율적인 항공관제를 위하여 항공기의 흐름을 유연하게 하기 위한 알고리즘 기법을 연구하였다. 항공교통 환경은 일반 교통 환경과는 다르게 항공기 기종에 따른 수평 및 수직 분리 간격이 존재한다. 빈센티 공식을 이용하여 항로의 거리를 산출하고 다익스트라 알고리즘을 이용하여 항로의 거리에 교통량을 적용하여 가중치를 생성하고 이를 이용하여 항공기가 연료 및 시간의 낭비를 최소화하는 항로를 선택하도록 하였다. 성능평가 결과 기존의 항로 연산 알고리즘의 단순한 최단항로 산출과는 달리 제안된 알고리즘은 교통량 파악을 통한 최적항로를 선택함으로써 효율적으로 항공교통관제를 할 수 있음을 확인하였다.