• International Journal of Highway Engineering
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• v.13 no.2
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• pp.49-56
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• 2011

Understanding various casual factors affecting the occurrence of freeway traffic crash is a backbone of deriving effective countermeasures. The first step toward understanding such factors is to identify crash risks on freeways. Unlike existing studies, this study focused on the unsafe vehicle maneuvering that can be detected by in-vehicle sensors. The recent advancement of sensor technologies allows us to gather and analyze detailed microscopic events leading to crash occurrence such as the abrupt change in acceleration. This study used an accelerometer to capture the unsafe events. A set of candidate variables representing unsafe events were derived from analyzing acceleration data obtained by the accelerometer. Then, the crash risk was modeled by the binary logistic regression technique. The probabilistic outcome of crash risk can be provided by the proposed model. An application of the methodology assessing crash risk was presented, and further research items for the successful field implementation were also discussed.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.187-196
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• 2010

The purpose of this study is to develop the calibration method for temperature effects to improve the accuracy of the Weigh-In-Motion(WIM) system for collecting long-term truck weight data. WIM system was installed at a location where the truck traffic volume is high and weight data has been collected from January 2010. In this study, as a calibration measure, the first axle weight of Truck Type 10, the semi tractor-trailer is used based on the fact that the first axle weight is relatively constant, independent of the cargo weight. From this fact, calibration equations are developed from the relationship between the axle weight and the temperature(daily mean, maximum and minimum). Analysis on calibrated weight data shows adequacy of the proposed calibration method. Results of this study can be used to improve the accuracy of the WIM system and to carry out more rational design of pavement and bridge structures.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.197-202
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• 2010

Post release mechanism is generally used to reduce the severity of the occupant of an errant vehicle impacting a roadside posts. The 820kg-50km/h head-on impact simulations were made using LS-DYNA program for the posts of 101.6mm Dia(t=4.0mm) with and without clip-type release mechanism. The simulation result was compared with impact test result to enhance the credibility of simulation model. The study shows that the high impact severity (THIV, PHD) and excessive deformation threatens the safety of the occupant when a car impacts a rigidly connected posts, while a post with clip-type slip base reduce the impact severity to a safe level.

• Journal of Korean Society of Transportation
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• v.23 no.4 s.82
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• pp.37-45
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• 2005

This paper presents a relationship between Nash bargaining game and Wardrop user equilibrium, which has been widely used in transportation modeling for route choice problem. Wardrop user equilibrium assumes that drivers in road network have perfect information on the traffic conditions and they choose their optimal paths without cooperation each other. In this regards, if the bargaining game process is introduced in route choice modeling, we may avoid the strong assumptions to some extent. For such purpose, this paper derives a theorem that Nash bargaining solution is equivalent to Wardrop user equilibrium as the barging process continues and prove it with some numerical examples. The model is formulated based on two-person bargaining game. and n-person game is remained for next work.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.167-177
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• 2010

This study proposes a methodology for assessing the improvement of network connectivity of transport hubs. Extending a previously developed model that measures the connectivity of a node in transportation networks, we define two quantities called the supplied connectivity and the experienced connectivity. Using these quantities, we provide a systematic procedure for analyzing the network connectivity of a transport hub and also suggest criteria for determining whether a given project is effective in improving the network connectivity of the transport hub. The application of the methodology to a test site produces reasonable results, and as such it is expected that the methodology can be used for various transport hubs in the national road network. Once enough data from the application of the methodology are accumulated, a further study on the level of service in terms of network connectivity needs to be followed.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.654-663
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• 2010

Attention has increasingly focused on the pollutant load discharged from rural area since the enforcement of total maximum daily loads (TMDLs) in korea. As one of the methods to control the inflow of pollutant load during wet weather events, local governments are attempting to apply non-point source control facility. To design those facilities appropriately, it is essential to understand the runoff characteristics of pollutants such as TSS, $BOD_5$, $COD_{Cr}$, TP and TN. In the paper, the quantitative analyses for pollutant runoff characteristics were examined in a small rural watershed with the area of about 53 hectares. For a dry weather day and wet weather events, variation patterns of dry weather flow and runoff characteristics of wet weather flows were monitored and investigated. The runoff model using XP-SWMM reflecting the landuse types of the watershed in detail was simulated to perform the sensitivity analyses for several factors influencing on their hydrograph and pollutographs. As a result, for the case of medium and small rainfall events (i. e. total rainfall of 35.8 and 17.5 mm), the impervious area including green house, roof and road which covers relatively low portion of total area (i. e. 16%) caused substantial first flush and the majority of total runoff load. Therefore, it has been concluded that the runoff characteristics of each pollutant and distribution of impervious area should be considered for the establishment of the control strategy of non-point pollutant runoff at a rural area.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.2
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• pp.66-81
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• 1989

The characteristics of resilient modulus(Mr) which dominates the life of pavement and the design of pavement were investigated on the test specimens which were cement treated and non-treated of the three different soil types. The results are summarized as follows : 1. The resilient modulus was decreased by increasing the cyclic deviator stress ($\sigma$d) , especially the resilient modulus was gradually decreased or sometimes increased when the value of ad was greater than 0.75- 1. 0kg/cm$^2$. 2. The resilient modulus was increased by increasing the homogeneous confined stress ($\sigma$do) and such phenomena were distinct on the coarse soils. 3. The resilient modulus was increased by increasing the ratio of confined stress(Kc), and this phenomena were eminent on the coarse soils too, and the higher permanent strain was showed by increasing the value of Kc. 4. In the drained cyclic triaxial compression test, the value of ad, Kc, and (Oho) was introduced by the following interrelated equations which were similar to the Mr model of Cole. Kcn/Mr=K1(J$_2$/ $\tau$oct)K2 ............. (coarse soli) Mcn/Mr=K3($\sigma$dp/ $\tau$f)k4 ...............(fine soils) 5. The stress path was not much affected by the value of Mr, however, moisture content, dry desity, and contant of fines affected the value of Mr. 6. In the soil-cement specimens, the resilient compression strain($\varepsilon$d) was decreased by the increment of the $\sigma$ho, and Mr was decreased by increasing the $\sigma$d 7. In the flexible pavement. the cement treated layer should be designed not to fail by the fatigue before the designed traffic load, and actually the pavement could cover the traffic load to a certain extent under the post-crack phase, therefore farther studies on this phenomena' are required in the design analysis. 8. The finite element computer program (ANALYS) was used for displacement analysis of pavement containing the cement-treated layer, The result showed that the program used for this analysis was proved to be usable.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.423-426
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• 2002

The foundation for developing a cost estimation system based on historical data has been being prepared in Korea. Historical data is a priori of developing a cost estimation model. Cost Index, one of the historical data, is used to estimate construction cost and to adjust the amount of contract money in the foreign country, whereas it is not used in domestic except for the road construction project in Korea. Construction cost indices can be used by an estimator in tender analysis, pricing, price adjustment, cost planning, and forecasting. In this regards, this paper identified the problems in developing Cost Index evaluation process by comparing the standard of framing Cost Index used in British to the one used in Korea. Then, the scheme for improving a Cost Index required for Site Developing Construction was proposed. Twenty-two cases of engineering estimate data were used to compare the domestic standard to the foreign one in deriving a Cost Index.

• Journal of Korean Society of Rural Planning
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• v.13 no.2
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• pp.133-142
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• 2007

Tourism and recreation spots in Korea have been developed metropolitan cities-oriented that facility construction has too much importance in local tourist site development more than satisfaction and experience. Tourism hardly seems to play its role as a motive power even in locals where tourism occupies much in their economic development. Therefore, the ministry of culture & tourism has introduced a plan to discover cultural and tourism resources as a development alternative which handles theme-ability and specialization. However, most projects of local tourism resources developed since 1999 have resulted similar features comparing to previous and existing tourist spots. And the main objectives of this paper have not been realized very well. This research hence forth suggests a program-based model development in tourism resources, with a case study of Gokun-gugok, one of the historical and cultural sites and is located in Hwachon-gun, Gangwon Province. Main points include: Since the Gokun-gugok landscape has been undermined and been loosed the traditional cultural value due to the road development, this study intends to plan to make the adventure of tourism destination including restoring the site as a cultural place. The Gokun-gugok site needs to develop combining various types of tours and adventures with instructive and educational programs to meet the visitors' needs. This research also intends to precede a development plan based on harmonizing natural, historical and cultural assets of the Gokun-gugok with facility maintains and tourism development. Meanwhile, the study stresses on realizing development of tourism resources categorizing programs by seasonality, visitor's economic class, and visit duration. Asa consequence, the research presents a "Culture & Tourism Academy" which deals with these types of adventure programs and informative educations. To assess feasibility of the development plan in terms of economy, environment and policy, the research conducted the site inspection and examined the site's surroundings, land properties and inundation. 145,000 square meters have been extracted as a feasible development area out of total 392,500 square meters. Finally, the study segmentizes target markets basedon the result of the survey on visitors and local residents. The more segmentized markets employ facilities according to their traditional characters.

• Korean Institute of Interior Design Journal
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• no.12
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• pp.40-49
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• 1997

What's the direction of INTERIOR ARCHITECTURAL DESIGN in 21 Century High Tech\ulcorner The purpose of this research is to show not only practical use of Computer Graphic(CG) as simple tool function, but offering conversation with computer and other ways of method. When we consider poor CG market, investment on the research of VR(Virtual Reality) is the most urgent. The investment on VR will solve various problems. Firstly. It will solve the problems drived from Interior design process by making spatial images like reality. Secondly, It will solve high wages and financial difficulties caused by raise cost funds. Thirdly, It prevents in a road from foreign company that will bring enormous program, caused by opening the domestic market. Also, It help interior designer check in advance the problems in constructure through showing him a supposed imagination including the system and location of equipments. But it is reality that even ordinary American can't offer VR(Virtual Reality) System. We should have noted that it is normal to spend 10 billion won for such presentation as Model House in the large corporation. We must acknowledge that it is such a waist of money nationally. Therefore, investment on CG & VR System is essential in order to save cost more effective presentation & interior design. We will see great result within a year. As we can see, there is huge area we have make develop. One of them is specific technical plan on VR System and study of flow chart. We close with simple methodological way to use VR System and will study Computer System. Which is fitting to CG that we have to solve the link of hardware and software on VR System\ulcorner We know from the cases in other countries that continuous research on this subject has great value for Interior Architectural Design and its effective use. When we try hard not only for methodological use but practical use, the purpose of CG and VR System will be a factor to contribute on this subject for better Interior design & presentation.