• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.45-52
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• 2004

There are many cities installing ITS(Intelligent Transportation Systems) and running TMC(Trafnc Management Center) to improve mobility and safety of roadway transportation by providing roadway information to drivers. There are many devices in ITS which collect real-time traffic data. We can obtain many valuable traffic data from the devices. But it's impossible to avoid missing traffic data for many reasons such as roadway condition, adversary weather, communication shutdown and problems of the devices itself. We couldn't do any secondary process such as travel time forecasting and other transportation related research due to the missing data. If we use the traffic data to produce AADT and DHV, essential data in roadway planning and design, We might get skewed data that could make big loss. Therefore, He study have explored some imputation techniques such as heuristic methods, regression model, EM algorithm and time-series analysis for the missing traffic volume data using some evaluating indices such as MAPE, RMSE, and Inequality coefficient. We could get the best result from time-series model generating 5.0$\%$, 0.03 and 110 as MAPE, Inequality coefficient and RMSE, respectively. Other techniques produce a little different results, but the results were very encouraging.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.560-569
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• 2003

Background : A large number of pollutants such as sulfur dioxide, nitric oxide, carbon monoxide, particulate matter, and ozone influence on the body. These pollutants put a burden on the lung and the sequelae resulting from the oxidative stress are thought to contribute to the development of fibrotic lung disease, emphysema, chronic bronchitis and lung cancer. Also, carbon monoxide generated from the incomplete combustion of carbon-containing compounds is an important component of air pollution caused by traffic exhaust fumes and has the toxic effect of tissue hypoxia and produce various systemic and neurologic complications. The objective of this study is to compare the difference of pulmonary function and serum carboxyhemoglobin(CO-Hb) level between the traffic policemen and clerk policemen. Method : Three hundred and twenty-nine of traffic policemen, and one hundred and thirty clerk policemen were included between 2001 May and 2002 August. The policemen who took part in this study were asked to fill out a questionnaire which included questions on age, smoking, drinking, years of working, work-related symptoms and past medical history. The serum CO-Hb level was measured by using carboxyoximeter. Pulmonary function test was done by using automated spirometer. Additional tests, such as elecrocardiogram, urinalysis, chest radiography, blood chemistry, and CBC, were also done. Results : $FEV_1(%)$ was $97.1{\pm}0.85%$, and $105.7{\pm}1.21%$(p<0.05). FVC(%) was $94.6{\pm}0.67%$, and $102.1{\pm}1.09%$, respectively(p<0.05). Serum CO-Hb level was $2.4{\pm}0.06%$, and $1.8{\pm}0.08%$(p<0.05). After correction of confounding factors (age, smoking), significant variables were FVC(%), $FEV_1(%)$ and serum CO-Hb level(%)(p<0.05). Conclusion : Long exposure to air pollution may influence the pulmonary function and serum CO-Hb level. But, further prospective cohort study will be needed to elucidate detailed influences of specific pollutants on pulmonary function and serum carboxyhemoglobin level.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.192-196
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• 2005

도시를 중심으로 지속적으로 발생하고 있는 초고속 네트워크서비스의 안정성을 확보하기 위해 KT는 경제적이고 안정된 구조의 직경 1,000mm 이하의 무인통신구를 건설하고 있다. 도심지에서 무인통신구 공사 허가시 점용면적은 민감한 문제가 되며 교통혼잡 발생으로 민원을 유발하는 요인이 된다. 본 연구는 복잡한 도심지에서 사용할 수 있는 소형의 크기와 무인통신구 건설을 위한 처리용량을 갖춘 도심형 디샌더의 개발과 그 동안 정성적으로 평가하고 조절하던 디샌더의 처리용량을 나타내는 성능계수에 관한 것으로 이를 통해 공사 설계 단계에서부터 이수처리량을 추정할 수 있는 근거를 제안하고자 한다.

• Journal of Navigation and Port Research
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• v.30 no.10 s.116
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• pp.825-831
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• 2006

This research does by purpose that present safe navigation plan for ships during doing dredging construction with dredger crossing waterway of Gadeok Dredging operations need to build sunken tunnel that cross the bottom of the sea under waterway of Gadeok for access road construction between Busan- Geoje. Accordingly, dredger must cross and dredge waterway of Gadeok fatally. There is possibility of marine accident of collision for latent danger situation of ships to navigate waterway of Gadeok relatively. Therefore, safe navigation plan of ship is groped in reply and its countermeasure is presented. Firstly, navigating traffic in daytime was forecasted less than 20% of its maximum capacity through estimating the traffic volume and traffic congestion The proposal was presented to execute dredging operations in three-step and to establish temporary waterway after reviewing waterway design principles. The role of VTS center was emphasized in the new Busan Port, lastly.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.400-409
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• 2013

In this paper, considering the characteristics of the driver at roundabouts by investigating the critical gap acceptance on various traffic conditions, multi-legged roundabouts were evaluated. The gap acceptance and rejection of 4-legged, 5-legged, 6-legged, and 7-legged roundabout were surveyed on real fields, and the critical gap acceptance was estimated using Raff's methods. Derived the critical gap acceptance was processed calibration and validation for micro-simulation, and then multi-legged roundabouts under variable conditions such as variations of traffic volume, turning ratio, and size of inscribed circle diameter were evaluated to verify operating conditions of roundabouts. As the results, according to the operating traffic volume and turning ratio, the inscribed circle diameters were proposed at each level of service. These inscribed circle diameters were able to reflect the guideline of geometric design for multi-legged roundabouts.

• International Journal of Highway Engineering
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• v.10 no.1
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• pp.155-164
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• 2008

It is critical to develop a core ITS technology such as real-time travel time estimation in order that the efficient use of the ITS implementation can be achieved as the ITS infrastructure and relevant facilities are broadly installed in recent years. The provision of travel time information in real-time allows travellers to make informed decisions and hence not only the traveller's travel utilities but also the road utilization can be maximized. In this paper, a hybrid model is proposed to combine VDS and AVI which have different characteristics in terms of space and time dimensions. The proposed model can incorporate the immediacy of VDS data and the reality of AVI data into one single framework simultaneously. In addition, the solution algorithm is made to have no significant computational burden so that the model can be deployable in real world. A set of real field data is used to analyze the reliability and applicability of the proposed model. The analysis results suggest that the proposed model is very efficient computationally and improves the accuracy of the information provided, which demonstrates the real-time applicability of the proposed model. In particular, the data fusion methodology developed in this paper is expected to be used more widely when a new type of traffic data becomes available.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.99-106
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• 2004

This paper presents some comparisons between Cournot-Nash and Stackelberg game in bi-level program, composed of both upper level program and lower level one. The upper level can be formulated to optimize a specific objective function, while the lower formulated to express travelers' behavior patterns corresponding to the design parameter of upper level problem. This kind of hi-level program is to determine a design parameter, which leads the road network to an optimal state. Bi-level program includes traffic signal control, traffic information provision, congestion charge and new transportation mode introduction as well as road expansion. From the view point of game theory, many existing algorithms for bi-level program such as IOA (Iterative Optimization Assignment) or IEA (Iterative Estimation Assignment) belong to Cournot-Nash game. But sensitivity-based algorithms belongs to Stackelberg one because they consider the reaction of the lower level program. These two game models would be compared by using an example network and show some results that there is no superiority between the models in deterministic case, but in stochastic case Stackelberg approach is better than that of Cournot-Nash one as we expect.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.36-50
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• 2015

The purpose of this study is to assign emission source profiles of volatile organic compounds (VOCs) and particulate matters (PMs) for chemical speciation, and to correct the temporal allocation factor and the chemical speciation of source profiles according to the source classification code within the sparse matrix operator kernel emission system (SMOKE) in the Seoul metropolitan area. The chemical speciation from the source profiles of VOCs such as gasoline, diesel vapor, coating, dry cleaning and LPG include 12 and 34 species for the carbon bond IV (CBIV) chemical mechanism and the statewide air pollution research center 99 (SAPRC99) chemical mechanism, respectively. Also, the chemical speciation of PM2.5 such as soil, road dust, gasoline and diesel vehicles, industrial source, municipal incinerator, coal fired, power plant, biomass burning and marine was allocated to 5 species of fine PM, organic carbon, elementary carbon, $NO_3{^-}$, and $SO_4{^2-}$. In addition, temporal profiles for point and line sources were obtained by using the stack telemetry system (TMS) and hourly traffic flows in the Seoul metropolitan area for 2007. In particular, the temporal allocation factor for the ozone modeling at point sources was estimated based on $NO_X$ emission inventories of the stack TMS data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.3
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• pp.273-282
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• 1999

For appling the GSIS on a air environment division, first of all, spatial-distribution of environmental factor which has distinction of continuous surface such as air-pollutant and a factor of weather must be able to be drawn. So we should estimate a distribution of whole area with point observation value which is observed on several restricted point. On this study, we investigate and study the application of GSIS technique which can be visible emission characteristic by regions, items, and time using data such as traffic quantity data, digital map for GIS-T and emission factor of each pollutant of vehicles about whole area of Seoul surveyed by traffic sensus of Seoul to air environment division.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.407-413
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• 2022

In this study, the empirical formula for evaluating cable tension based on long-term measurement for about 3 years according to temperature change was proposed by proving the correlation between the expansion joint displacement of the upper road bridge and the cable tension of the lower railway bridge. The tension prediction results using the empirical formula for tension evaluation each cables proposed in this study were found to be in good agreement with the cable tension using the vibration method within 3%. Therefore, it was analyzed that it could be applied together with the vibration method that was an experimental technique, to predict and evaluate the cable tension in serviced railway steel composite bridge. As a result of applying the estimated temperature calculated by the empirical formula for expansion proposed in this study to the empirical formula, it was analyzed that a high level of reliability could be secured when compared with the vibration method. Therefore, it is judged that the empirical formula for cable tension evaluation reflecting the estimated temperature proposed in this study can be used to predict the tension of cables according to climate change in the future and establish a maintenance plan.