• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.835-839
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• 2012

In recent decades, a lot of noise barriers have been installed along paved road in order to reduce the road induced noise, which increases as traffic volume grows. For better range of sight, transparent noise barriers are widely installed despite of reflecting noise. In this study, the effect of surface shape and pattern of noise barriers on the reduction of reflecting noise was analyzed to maximize the noise reduction. According to the number of shape and pattern, it was observed that there were noise reduction effect as of 0.9~1.5 dB(A). It was found that the spatial field where the noise concentrates or disperses changes according to the width of blocks on the barriers as well. It suggests that there might be possibility of surface shape modification to optimize the noise reduction technology.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.4
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• pp.759-770
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• 2014

The aim of this study is to examine how time-use and activities are affected by work hours. To achieve this, we focused on the weekday time-use of full-time workers in Seoul Metropolitan Area(SMA). The long 'work hours' are under active discussions since it is related to the quality of life. However, many Social researcher thought that problem of Korean working hours is linked to quality of life in the abstract. Because activity connects time-use and quality of life, the key point is activity under time constraints. Therefore, travel patterns should be understood by time-use and activity patterns. This study composes trip-chains from travel data of 2010 Household Travel Survey(HTS). Grouping trip-chains by activity patterns, we could make sure that a few of activities after work is affected by a short free time. This study has potential implications for the policy of work hours and traffic problems in the evening, and will provide new geographical perspective related to measuring quality of life.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.861-866
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• 2022

Seoul introduced the shared bicycle system, "Seoul Public Bike" in 2015 to help reduce traffic volume and air pollution. Hence, to solve various problems according to the supply and demand of the shared bicycle system, "Seoul Public Bike," several studies are being conducted. Most of the research is a strategic "Bicycle Rearrangement" in regard to the imbalance between supply and demand. Moreover, most of these studies predict demand by grouping features such as weather or season. In previous studies, demand was predicted by time-series-analysis. However, recently, studies that predict demand using deep learning or machine learning are emerging. In this paper, we can show that demand prediction can be made a little better by discovering new features or ordering the importance of various features based on well-known feature-patterns. In this study, by ordering the selection of new features or the importance of the features, a better coefficient of determination can be obtained even if the well-known deep learning or machine learning or time-series-analysis is exploited as it is. Therefore, we could be a better one for demand prediction.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1976.06a
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• pp.86.2-86
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• 1976

Authors have performed the audiological analysis in accordance with age, sex, site, duration, cause, ear drums, curve pattern, and hearing level taken from 165 patients (Male; 101, Female; 64) with non-perforated ear drums who had complained hearing impairment. The results are as follows. 1. The audiographic pattern has classified into Normal (30 cases, 18.18%), Flat form (46 cases, 20.6%), Ascending form (5 cases, 3%), Mountain form (9 cases, 5.4%), Basin form (7 cases, 4.2%), Total deaf (24 cases, 14.55%) and Others (10 cases, 6%). 2. In age distribution, the highest is in 3rd decade (50 cases, 30.3%), and the next is in 2nd (43 cases, 26%), 4th (27 cases, 16.3%) in order. 3. Male (101 cases) is more than female (64 cases) giving ratio of 1.9 : 1 4. Bilateral involvement is in 58 cases and unilateral is in 77 5. 45 cases (27.3%) in duration of hearing loss is as short as 3 months and the next is overs; 28 cases (16.9%) 6 to 10 years; 21 cases (12. 7%). And in cases of total deaf, nearly all cases is over 10 years. 6. The suspected cause of the hearing loss is unknown (99 cases, 60%) and the next is following head trauma by traffic accidents in 31 cases (18.8 %) and is related to the middle ear diseased in 12. cases (7.3%). Other causes like senile, noise etc. are in few. 7. The most common findings in ear drums is normal in 177 ears (79.4%) and the next is retracted drums in 28 ears (12.6%). 8. The average hearing level is widely distributed from mild to profound hearing loss which was not related to the audigraphic pattern.

• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.781-786
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• 2010

In this study, a new concept of ocean transport system, called the mobile harbor serving for a short distance transport of containers with cargo handling cranes between mother containerships and coastal ports, is introduced. Instead of direct berthing a very large containership at the coastal port, Mobile Harbor is moving to the offshore mooring basin with enough water depth condition. Therefore, investigation of the coastal environment, technical condition and limitation of the domestic trade ports for the application of Mobile Harbor, is essential process. To figure out the accessibility of mobile harbor, the environmental conditions, the cargo handling capacity and marine traffic volume and flow pattern has been analyzed with the tools for marine traffic simulation and virtual navigation aids system. The most proper Mobile Harbor mooring areas among trade ports of the south and east coast are selected by analyzing the obtained information and evaluating its application: (1) Under natural environmental conditions such as air and sea weather, three candidate areas are selected such as Masan port, Ulsan port, and Busan(New port) port. (2) Under marine traffic and appropriateness of water facilities, three candidate areas are selected as Mokpo port, Busan(New port) port, and Donghae & Mookho port (3) For a region-based analysis considering handling capacity and the local managed trade ports in vicinity, three candidate areas are selected as Busan region, Yosu & KwangYang region, and Mokpo region. Through this study, the basic guideline for selection of optimum trade port and offshore mooring basin for mothership and Mobile Harbor is recommended. In order to apply the Mobile Harbor to the real water, navigaton aids as the virtual route identification with AIS must be introduced for maritime safety in the vicinity of Mobile Harbor area which berthing and cargo handling is being conducted.

• Archives of Plastic Surgery
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• v.34 no.3
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• pp.365-370
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• 2007

Purpose: There are many reports about facial bone fractures, but limited to retrospective data of a single hospital. Etiology and severity of the facial bone fracture have been changed and treatment method and materials have been advanced. In order to reflect those changes and provide up-to-date data of the facial bone fractures in Daegu, we gathered the data and analyzed the epidemiologic study. Methods: The medical records of 1058 fractures in 895 patients were gathered from 5 general hospitals in Daegu during last year and these data were analyzed by following parameters: age, sex, place of residence, occupation, cause of injury, time of injury, location of fracture, length of in-hospital stay, time of operation, treatment method, associated injury, complication. Statistical analysis was performed using the Chi-square test. Results: Most commonly involved age group was 20s(26%) and the sex ratio was 3.4:1(male predominance). Fractures were occurred more in unban and white-color workers. Among variable etiology of injury, traffic accident was the most common cause. Time of injury was heighest at 6 to 7 P.M., on Sunday, in July. Locations of fractures were following sequence: nasal, zygoma, mandible, orbit, maxilla. Mean length of in-hospital stay and time of operation after injury were 6.3 and 3.2 days, respectively. In treatment methods, operative methods were dominant than conservative management and general anesthesia were favored than local anesthesia. Associated injuries were noticed in 188 cases(21.2%) and complications were in 94 cases(8.9%) and among them, ocular problem were common. Conclusion: Compared to previous studies, mean age of occurrence was lowered and the etiologies showed age-specific pattern and reflected the change of lifestyle. In young age groups, sports injury, violence were more dominant and the other hand, traffic accident and fall were dominant in older groups.

• Journal of Environmental Impact Assessment
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• v.29 no.4
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• pp.252-271
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• 2020

In this study, we investigated physical and chemical properties such as grain size, heavy metal pollution, magnetic properties, and their environmental impacts of road dusts (RD) collected from 14 sampling points in Daebul industrial Complex. Heavy metal concentrations in RD were in the order of Fe>Zn>Cu>Pb>Cr>Ni>As>Cd>Hg, and this pollution pattern was related to major industries and traffic activities in this area. The results of the correlation analysis between heavy metal elements and particle size in RD showed that Fe and all of analyzed heavy metals had a significant correlation with each other and metal concentrations had a significantly negative correlation (p<0.05). However, due to the input of large metal particles some heavy metal concentrations in the particle fraction of >1000 ㎛ were highest. Pollution load per unit area of this fraction was the highest among the grain size fractions. Cr, Ni, Cu, Zn, Cd, Pb levels in RD decreased and the levels of Cr, Ni, Cu, Zn, Cd, and Pb were reduced to 85 (As) -22 (Ni)% of the whole after removal of MFs fraction from RD. The mean heavy metal levels in the study area did not exceed the soil contamination guide value of Korea, indicating that heavy metal levels in RD were not a concern. However, at some sampling points, Zn concentrations were exceeded the soil contamination guide value for the 3rd areas of Korea and this result indicated that further studies of the impact of RD on the surrounding environment through re-suspension or non-point pollution, and of effective management methods are required.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.2
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• pp.58-71
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• 2021

The number of elderly people worldwide is rapidly increasing and the mobility handicapped suffering from inconvenient public transportation service is also increasing. In Korea and abroad, various policies are being implemented to provide high-quality transportation services for the mobility handicapped, and budget support and investment related to mobility facilities are being expanded. The mobility handicapped spends more time for transit transfer than normal users and their satisfaction with transit service is also lower. There exist transfer inconvenience points of the mobility handicapped due to various factors such as long transfer distances, absence of transportation facilities like elevators, escalators, etc. The purpose of this study is to find transfer inconvenience points for convenient transit transfer of the mobility handicapped using Smart card Big data. This study process traffic card transaction data and construct transfer travel data by user groups using smart card big data and analysis of the transfer characteristics for each user group ; normal, children, elderly, etc. Finally, find transfer inconveniences points by comparing transfer patterns between normal users and the mobility handicapped. This study is significant in that it can find transfer inconvenience points for convenient transit transfer of the mobility handicapped using Smart card Big data. In addition, it can be applicated of Smart card Big data for developing public transportation polices in the future. It is expected that the result of this study be used to improve the accessibility of transit transportation for mobility handicapped.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.115-126
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• 2009

The lane-change behavior usually consists of discretionary lane-change and mandatory lane-change types. For the first type, drivers change lanes selectively to maintain their own driving condition and the second type is the case that the drivers must change the current lane, which can occur in recurrent congestion sections like merging and weaving sections. The mandatory lane-change behavior have a great effect on the operation condition of freeway. In this paper, we first generate data such as traffic volumes, speeds, densities, and the number of lane-change within the merging and weaving sections using the data of individual vehicle collected from time-lapse aerial photography. And then, the data is divided into the stable and congested flow by analyzing the speed variation pattern of individual vehicles. In addition, the number of lane-changing from ramp to mainline within every 30-meter interval is investigated before and after traffic congestion at study sites and the distribution of lane-changing at each 30-meter point is analyzed to identify the variation of lane-changing ratio depending on the stable and congested flows. To recognize the effect of mainline flow influenced by ramp flow, this study also analyzes the characteristics of the lane-changing distributions within the lanes of mainline. The purpose of this paper is to present the basic theory to be used in developing a lane-changing model at the merging and weaving sections on freeways.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.7-14
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• 2005

Traffic congestion causes enormous social costs as well as loss of travel time and waste of energy. Though the Seoul metropolitan government implemented various forms of transportation policies such as urban road pricing and public transportation reform, traffic volume which across the Seoul metropolitan borders have greatly increased because of housing land development in suburban area. The purpose of this study is to estimate individual's willingness-to-pay(WTP) for extensive implementation of congestion pricing through policy-mix with bus rapid transit(BRT) system. So the field survey interviews carried out. The empirical analysis was done with priority given to the following two topics; derivation of individual WTP and prior evaluation of policy effect from the equity aspect. To estimate individual WTP, we adopted contingent valuation method (CVM). The former is to estimate individual WTP for respondent's maintaining his/her transit pattern when he/she is faced with congestion pricing by using compensating variation(CV) concept. And, the latter aims at evaluating policy effect from the equity aspect by calculating the Proportion of WTP to average income using WTP in income bracket for policy scenarios.