• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1196-1202
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• 2007

In construction of high speed railway, the fan shape is limited to achieve reduction of required travel time and concrete railway which has structural stability and induces small maintenance cost with allowable ground settlement is recently applied. So construction of concrete railway on soft ground in which considerable ground settlement occurs increases and settlement management in soft ground section is required. Field monitoring on ground movement and integrated geotechnical information system which manages construction, design, and field monitoring data are essential for settlement management of concrete railway subgrade. Site investigation data are also required due to future repair work. Therefore in this study, integrated geotechnical information system for construction and maintenance of concrete railway is developed. The developed system consists of a database and an application program. The database contains site investigation, construction, design, and field monitoring data throughout a railway. Application program performs various functions on managing and utilizing information in the database with graphic visualization of output. And by providing integrating information with comprehensible visual displays, the applicability and effectiveness of the developed system for construction and maintenance management were confirmed.

• 한국도로학회논문집
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• 제14권6호
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• pp.167-173
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• 2012

PURPOSES : This study is to develop speed correction factor for more realistic Level-of-Service(LOS) at multilane highway. METHODS : In this study, we compared speed difference the degree of speed reductions in actual multilane road conditions with speed reduction considering speed correction factor presented in highway capacity manual using statistical techniques. And also we presents new speed correction factor analyzing collected data at national highway No.1 (Goyang~Wolrung). RESULTS : The result of analyzing and comparing new suggested speed correction factor with speed correction factor in Korea Highway Capacity Manual (KHCM) shows RMSE (Root Mean Square Error) in new speed correction factor (RMSE 1.5) is much lower than existing speed correction factor (RMSE 13.4). New suggested speed correction can be used for analyzing Level-of-Service at multilane highway. And also we suggests improvements for analysis procedure in analyzing Level-of-Service at multilane highway CONCLUSIONS : As a result of comparing differences, we draw the causes that effect the differences in speed and suggest new speed correction factor that consider traffic volumes. It can be more rational because it uses speed correction factor which can consider more realistic traffic conditions, etc.

• 한국물환경학회지
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• 제21권6호
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• pp.609-616
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• 2005

A high ammonia nitrogen ($NH_3-N$) concentration has been recursively observed every winter season in Geum River, which hindered chemical treatment processes at a water treatment plant. A flushing discharge from Daecheong Dam was often considered to dilute $NH_3-N$, but information on the quantitative effect of flushing on the downstream water quality was limited. In this study, the impact of a short-term reservoir flushing on the downstream water quality was investigated through field experiments and unsteady water quality modeling. On November 22, 2003, the reservoir discharge was increased from $30m^3/sec$ to $200m^3/sec$ within 6 hours for the purpose of the experiment. The results showed that flushing flow tends to reduce downstream $NH_3-N$ concentrations considerably, but the effectiveness was limited by flushing amount and time. An unsteady river water quality model was applied to simulate the changes of nitrogen concentrations in response to reservoir flushing. The model showed very good performance in predicting the travel time of flushing flow and the effect of flushing discharge on the reduction of downstream $NH_3-N$ concentrations at Maepo and Geumnam site, but a significant discrepancy was observed at Gongju site.

• 한국도로학회논문집
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• 제19권6호
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• pp.175-182
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• 2017

PURPOSES : Road sectors contribute approximately 16 % of total GHG emission rates in South Korea. Engineers and experts expend significant efforts to identify countermeasures for the reduction of carbon emission. This study aims to determine how total carbon emission rates change depending on whether or not there is speed limit enforcement. METHODS : In this study, Lamm's travel speed profile theory is first adopted to select the hazard road, which sections are designated as speed limit enforcement. Second, Motor Vehicle Emission Simulator (MOVES) was used to simulate the carbon emission on the road. RESULTS : The total carbon emission rate under speed limit enforcement was 10,773 g higher than the condition without speed limit enforcement in the designated road. This might affect acceleration, which can lead to increased emissions. CONCLUSIONS : There would be no researches about proving the relationship how speed limit enforcement has an effect on carbon emission. The result of our study can provide valuable guidelines regarding road safety and eco-friendly roads.

• 유통과학연구
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• 제11권7호
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• pp.15-22
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• 2013

Purpose - The study investigates the influence of tourism and hospitality industry on economic growth and CO2 emissions. Research design, data, and methodology - In the empirical analysis, unit root tests, cointegration test and vector error correction model regression using time series data of South Korea from the first quarter of 1970 to the third quarter of 2010 are performed to examine the long-run equilibrium relationship and short-run dynamics among the tourism and hospitality industry, CO2 emissions, economic growth and other industry sectors. Results - Results indicate that a long-run equilibrium relationship exists among these variables. Furthermore, the tourism and hospitality industry and CO2 emissions have high significant positive effect on economic growth. The tourism and hospitality industry in Korea, in turns, shows a high significant positive impact on economic growth while the industry sector incursa high significant negative impact on CO2 emissions. Conclusions - The tourism and hospitality industry in Korea may havebeen prompted by several factors such as accelerated process of technological innovation or energy and environmental policies. These findings suggest that the effectively managed tourism and hospitality sector in Korea has resulted in both economic growth and a reduction in CO2 emissions.

• Pediatric Infection and Vaccine
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• 제4권2호
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• pp.282-287
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• 1997

Malaria due to Plasmodium vivax had been known as an indigenous protozoan disease in Korea. However, massive use of insecticides and improvement of sanitation for several decades have led to rapid reduction of malaria incidence, then it was recognized to have been almost eradicated in recent years. However in 1993, one case was reported in Phajoo, Kyungki-do, and then, reported cases have been increasing annually. Recently we encountered one case of malaria in a 3 year old male child living in Dorim-dong, Seoul, who had never been abroad and had no history of transfusion, drug abuse, and travel to endemic area in Korea. He had characteristic fever, chill and splenomegaly and was confirmed as Plasmodium vivax malaria with peripheral blood smear finding. He was successfully treated with hydroxy chloroquine and primaquine. We report this case with brief review of related literature.

• 한국철도학회논문집
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• 제16권3호
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• pp.226-232
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• 2013

최근 지속가능한 개발(ESSD: Environmentally Sound And Sustainable Development) 정책의 일환으로 하여 탄소저감형 정책이 다양하게 추진되고 있다. 이에 노면전차, 모노레일 등 신교통수단이 이에 대한 대안으로 대두되면서 많은 지방자치단체에서 관심을 보이고 있다. 본 연구에서는 불확실성을 내재하고 있는 관광수요를 합리적으로 반영하기 위하여 대전 보문산 지역의 모노레일의 적용성을 검토하고자 하였다. 관광수요의 장래 불확실성에 대한 대비 차원에서 모노레일 도입에 대한 여러 가지 대안 시나리오를 구성하여 경제적 타당성 분석결과를 제시하였다.

• Asian Journal of Business Environment
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• 제11권4호
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• pp.5-16
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• 2021

Purpose: This study aims to investigate the impact of auditor-client traffic convenience on accrual -based and real earnings management of the client firms. Research design, data and methodology: Using a sample of firms listed in Shanghai and Shenzhen Stock Exchanges over the period of 2007 to 2018, this paper empirically investigates the association between auditor-client traffic convenience and earnings management. We use three measures of auditor-client traffic convenience: railway traffic convenience, expressway traffic convenience, and air traffic convenience. The accrual-based earnings management is measured by abnormal accruals estimated by industry and year using the Modified Jones Model. Results: Findings indicate that traffic convenience is conducive to detecting and restraining positive accrual earnings management and real earnings management. After changing the measurement of independent variable and dependent variable, including potential omitted variables, the results are statistically unchanged. Further, the research shows that traffic convenience can not only improve audit quality, but also lead to higher fee premiums. Auditors didn't share with clients the cost reduction benefits caused by traffic convenience. Conclusions: Traffic convenience provides auditors with easy access to the client firms, alleviating the information asymmetry and improving corporate earnings quality. The findings have implications for regulators, audit practitioners and stakeholders.

• 한국ITS학회 논문지
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• 제22권1호
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• pp.93-102
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• 2023

본 연구는 운전자에게 차량속도와 횡단보도 인근 보행자 존재 유무에 대한 정보를 제공하는 차량정보안내시스템의 설치 전·후에 대한 효과평가를 수행했다. 시나리오는 운전자에게 정보를 제공하지 않는 경우(S1), 차량주행속도만 제공하였을 경우(S2), 횡단보도에 보행자의 존재 유무와 차량주행속도를 모두 제공하였을 경우(S3) 등 3가지로 구성했다. 조사결과 시나리오 S1보다 운전자에게 정보를 제공하는 S2, S3에서 차량의 속도감속률이 약 0.4~0.7km 큰 것으로 나타났다. 또한 시나리오 S3에서 횡단보도 인근에 보행자가 있는 경우에 없는 경우보다 속도 감속률이 0.2km 높아 차량 속도를 더 줄이는 것으로 나타났다. 통계분석 결과에서도 시나리오 3개에 대한 평균 차량의 속도감속률에 차이가 있는 것으로 분석됐고, 보행자가 있는 경우 속도 감속률이 큰 것으로 나타났다.

• 대한교통학회지
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• 제24권7호
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• pp.101-114
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• 2006

버스는 대중교통의 대표적인 수단으로 지하철보다 운영이 저렴하고 접근성이 뛰어나다는 장점을 가지고 있음에도 불구하고 일반차량과 도로를 공유하여 사용하기 때문에 도로혼잡의 직접적인 영향을 받고 있다. 이러한 버스의 정시성, 신속성, 쾌적성 등 버스서비스의 개선을 위해 버스우선신호의 도입이 요구되고 있다. 버스우선신호의 필요성 증대와 관련하여 서울시에서 운영되고 있는 실시간 신호제어시스템(COSMOS)은 버스우전신호에 대한 제어전략이 구축되어 있지 않은 실정이다. 이에 본 연구에서는 교통상황에 대응하여 신호시간을 결정하는 실시간신호제어시스템에서 대중교통, 특히 버스의 효율성을 높이는 버스우선신호 알고리즘을 정립하여 그것의 효과를 평가하였다. 본 연구에서 제안한 알고리즘은 실시간 교통대응제어를 기반으로 버스우선신호를 제공하기 때문에 기존 버스우선신호에 비해 부도로의 교통상황을 고려할 수 있다는 장점이 있다. 도심의 신호운영에서 중요시되는 연동을 유지하면서 우선신호를 제공하기 위해 수정주기 개념을 도입하였다 모의실험 결과 실시간 신호제어시스템하의 버스우선신호를 실행한 경우 그렇지 않은 경우와 비교하여 총지체는 증가하나 이는 기존 버스우선신호보다는 비교적 총지체를 감소시킨 것으로 나타났다. 버스통행시간의 감소로 버스서비스의 개선이 예상된다. 또한 버스의 재차인원을 고려할 경우, 차량이 아닌 사람을 기준으로 지체를 계산하기 때문의 본 알고리즘의 효율성을 인정받을 수 있다.