• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.1-6
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• 2020

In this study, we propose an association inference model based on data bias optimization for road hazard detection. This is a mining model based on association analysis to collect user's personal characteristics and surrounding environment data and provide traffic accident prevention services. This creates transaction data composed of various context variables. Based on the generated information, a meaningful correlation of variables in each transaction is derived through correlation pattern analysis. Considering the bias of classified categorical data, pruning is performed with optimized support and reliability values. Based on the extracted high-level association rules, a risk detection model for personal characteristics and driving road conditions is provided to users. This enables traffic services that overcome the data bias problem and prevent potential road accidents by considering the association between data. In the performance evaluation, the proposed method is excellently evaluated as 0.778 in accuracy and 0.743 in the Kappa coefficient.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.177-186
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• 2009

Rumble strip was introduced in highway pavement for driver's safety in Korea on 2000. With proving its effectiveness, total length of highway with rumble strip has increased. This research team suggested a modified form of the existing rumble strip, which was placed on new concrete pavement during construction. The modified construction equipment was applied on test section at PyungTeak-Eumsung highway with some performance experiments. Through the equation of stopping sight distance proposed AASHTO, the modified form is safer than the existing one due to 0.65m of extra width. The indoor noise test showed that the modified form $3.5{\sim}9dB(A)$ noisier than the main pavement, which wasn't applied by rumble method. Therefore, it was one of alternatives to prevent sleeping. The modified form made the frequency effected on man's eye. There were no differences of the noise and vibration between modified form and existing one. However, that driver who participated on operating test on that section felt that the former was safer than the latter. It can be concluded that modified form can be applied to the new concrete pavement, that will decrease traffic accident.

• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.564-574
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• 2015

As shown by the popularity of the rapid train in the Seoul Metro Line No. 9, the demand for the rapidization of the metro transit has been continuously increased. However, it needs tremendous cost to construct new additional infrastructures to the existing line for the rapidization. In order to overcome the problem, utilizing the existing infrastructures such as crossing tracks as railroad sidetracks can be considered to be a good method of reducing the cost. In this case, there is a way exploiting the existing train as an express train and the advanced train, which increases both acceleration and deceleration, as a local train, but achievable acceleration and deceleration have not been analyzed rigorously. In this paper, we analyze feasible ranges and optimal values of both acceleration and deceleration of the advanced train analytically when we consider the rapidization of the metro transit utilizing the existing infrastructures and verify the results in Seoul Metro Line No. 3. Simulation results show ranges and optimal values of achievable acceleration and deceleration exist when minimum gap between an express train and a local train is smaller than 40 seconds.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.141-153
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• 2010

The study is about the development of operating speed prediction models aimed for an evaluation of design consistency of four lane rural roads. The main differences of this study relative to previous research are the method of data collection and classification of road alignments. The previous studies collected speed data at several points in the horizontal curve and approaching tangent. This method of collection is based on the assumption that acceleration and deceleration only occurs at horizontal tangents and the speed is kept constant at horizontal curves. However, this assumption leads to an unreliable speed estimation, so drivers' behavior is not well represented. Contrary to the previous approach, speed data were collected with one and data analysis using a speed profile is made for data selection before building final models. A total of six speed prediction models were made according to the combination of horizontal and vertical alignments. The study predicts that the speed data analysis and selection for model building employed in this study can improve the prediction accuracy of models and be useful to analyze drivers' speed behavior in a more detailed way. Furthermore, it is expected that the operating speed prediction models can help complement the current design-speed-based guidelines, so more benefits to drivers as real road users, rather than engineers or decision makers, can be achieved.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.4
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• pp.16-36
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• 2024

This study, developed a dynamic hard shoulder running(HSR) algorithm that includes ending speed and minimum operation time in addition to the starting speed for HSR, and presented an operation plan. The first stage of the algorithm was red, which means vehicles are prohibited from HSR. The second stage is red/amber, in which drivers are notified of HSR, and operators are given time to check whether there is any obstacle to HSR. Stage 3 is green, which vehicles are permitted for HSR. Stage 4 is amber, in which a signal is given to drivers that the end of HSR is imminent. In addition, a minimum time is applied to green and red, but if congestion is severe, red is terminated early to prevent congestion from worsening. The upstream and downstream traffic flow is managed stably through main line ramp metering and lane number matching. The operating standard speed reflects the characteristics of vehicles and drivers, and based on simulation results, 7090 was selected as the optimal operating standard speed considering traffic flow and safety aspects. Therefore it is desirable to apply the travel time divided by the minimum speed of the HSR link as the minimum operating time in order to ensure continuity of traffic flow

• Korean Journal of Environment and Ecology
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• v.23 no.2
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• pp.187-193
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• 2009

To investigate the roadkill of amphibians in Korea National parks, we conducted a survey from 2006 to 2008. As a result, our count of road-killed amphibians included 1,748 individuals from 9 species over three years, and the ratio of road-killed amphibians decreased in 2007, 2008 as compared to 2006. Additionally, many amphibians, including Rana dybawskii, Bufo gargarizans, and Bufo stejnegeri were road-killed by vehicles in "Forest-Stream" or "Forest-Forest" environments, and between March and June. In the risk analysis by frequency, 4 lines including national line 37 (Deogyusan), provincial line 517 (Songnisan), national line 6 (Odaesan) and provincial line 597 (Woraksan) were classed as RISK V category. This designation involves species considered to be extremely important, such as Rana dybowskii and Bufo stejnegeri. Therefore, a conservation plan is needed to protect important species located near RISK V lines.

• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.286-294
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• 2017

Development of transportation is rapidly reducing the barriers between countries, but this is causing the easier migration of species than the past. Typically, exotic species are imported for the purpose of food, leather, and pets. However, it has been introduced into the wild through artificially or naturally paths, and recently they are become a main cause of ecosystem disturbance. In this study, we investigated exotic turtle species introduced into the wild and analyzed their distribution characteristics. As a result of filed surveys, totally 4 genus 8 species 62 individuals of exotic turtles were found from 126 reservoirs in Gangwon-do and Gyeongsangnam-do, South Korea. In particular, Trachemys scripta elegans showed relatively high frequency than other turtle species and the natural reproduction of T. s. elegans was confirmed in some areas. On the other hand, the frequency of discovery of exotic turtles except T. s. elegans was relatively low, and the range of the areas was limited. Especially, exotic turtles except T. s. elegans were mainly found in public places such as reservoirs in the park. As a result of analyzing the distribution characteristics of exotic turtles using geographic information system, the turtles' distribution showed a high correlation with the artificial factor such as "urban". In this study, we identified the distribution characteristics of exotic turtles in the Korean wild, and these results will be important data for understanding status the and establishing effective management methods for exotic species.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.2
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• pp.225-242
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• 2006

This study aims to analyze the spatial distribution pattern of international trade. The method is to analyze the principal components by changing interaction attribute matrix of four dimensions (hinterland, gateway, foreland and commodities) into two dimension matrix. The study area is the territory region of Cheongju clearance depot in inland. The result are as follows : Major spatial patterns of regional connections by hinterland, gateway and foreland are, in the case of exports, ten patterns and in the case of imports come to nine. Composition of major export and import commodities in Cheongju clearance depot are similar, but precision instrument manufactured commodity and nonmetal mineral are remarkable in export and mineral manufactured commodity machinery and electronic manufactured commodity are remarkable in import. Gateway are similar to export and import, but Incheon international airport is used more in the case of import. And Cheongiu international airport is used for some commodities and is remarkable as a foreland of import for the areas outside of Chungcheongbuk-do.

• Investigative Magnetic Resonance Imaging
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• v.17 no.2
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• pp.149-153
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• 2013

Detection of cerebrospinal fluid leakage or exact localization of leakage site after spinal surgery is difficult on conventional imaging studies. We report two patients with surgery-related spinal CSF leakage detected on magnetic resonance (MR) myelography. They presented with severe headache after spinal surgeries, lumbar discectomy and excision of spinal meningioma, respectively. The sites of spinal CSF leakage in the patients were detected accurately on MR myelography, and the patients recovered from the postoperative CSF leakage after being treated with an epidural blood patch or reoperation. MR myelography may be effective in demonstrating the exact site of surgery-related spinal CSF leakage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2335-2342
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• 2014

If you want to use the unmanned quad rotor for emergency information provision and information about the traffic situation of real-time and moving information is included in the car to help in emergency vehicle operation of the city and in the distribution future innovation the need to consider to have enough safety of the use of silent quad rotor. Therefore, in this study, the unmanned quad rotor system research of safe landing control from the center for the improvement of safety of unmanned quad rotor system you have a motor of four, has taken a good structural balance system based on the dynamic model and motion considering the nonlinear characteristics, and attempts to proceed via non-linearity and system disturbances, tough Fuzzy controller, and analyzed through a computer simulation result.