• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.711-718
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• 2001

The tyre/road noise becomes aggravated due to the rapid increase of motor vehicles. It has a great effect on the dwelling environment. Therefore we investigate the characteristics and sources of the tyre/road noise through grasping the status of the tyre/road noise. Traffic noise results from the collective contribution of the noise produced by individual motor vehicles. The tyre/road noise varies enormously depending upon its type and mode of operation.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.631-636
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• 2009

This study has its intention to investigate the water quality of non-point source which is runoff from roads. We have classified and selected twelve sites as city road, industrial road, national road and mountain road by considering their traffic volume and surroundings. Water quality was analyzed based on BOD, COD, SS, T-N and T-P and the concentrations were measured by sampling after rainfall with the interval of 10 minutes, 20 minutes, and 30 minutes. BOD was the highest in city road with 57.6 mg/L and the lowest in mountain road with 45.0 mg/L. For COD, the highest concentration in industrial road was 146.5 mg/L and the lowest was in mountain road with 98.0 mg/L. The run off concentration of SS was up to maximum 630.0 mg/L (average 280.4 mg/L) which was remarkable compared to other types of road. It showed its lowest concentration in national road with 76.0 mg/L. T-N and T-P were the highest in industrial road and the lowest in mountain road. We found out that the runoff concentration was high with large amount of traffic volume and it seemed to be high in city road and industrial road where they were largely affected by their surroundings. Relatively, national road and mountain road seemed to show low concentration as they have less traffic volume and less affected by their surroundings.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.5
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• pp.274-278
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• 2016

A road energy harvester was designed and fabricated to convert mechanical energy from the vehicle load to electrical energy. The road energy harvester is composed of 20 piezoelectric materials. This study attempted to evaluate output depending on pavement materials when paving road piezoelectric energy harvester in the road. Harvester is the bender type and is the method of supporting the both ends of piezoelectric material and applying the load in the middle part. Harvester was paved in the type paved with asphalt, type paved with cement and in the exposed type not covering the top of harvester. The output characteristics were compared and evaluated depending on changes in vehicle load and vehicle speed changes. As vehicles, truck (11.9 ton), SUV(1.6 ton) and sedan (1.5 ton) were used and the output characteristics when driving at the interval of 10 km/h from 10 km/h to 100 km/h were evaluated.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.6
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• pp.595-603
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• 2015

With the advances of the big-data process technology, acquiring the real-time information from the massive image data taken by a mobile device inside a vehicle will be possible in the near future. Among the information that can be found around the vehicle, the route information is needed for safe driving. In this study, the automatic extraction of route information from the road sign imagery was dealt with. The scope of the route information in this study included the route number, route type, and their relationship with the driving direction. For the recognition of the route number, the modified Tesseract OCR (Optical Character Recognition) engine was used after extracting the rectangular-road-sign area with the Freeman chain code tracing algorithm. The route types (expressway, highway, rural highway, and municipal road) are recognized using the proposed algorithms, which are acquired from colour space analysis. Those road signs provide information about the route number as well as the roads that may be encountered along the way. In this study, such information was called “OTW (on the way)” or “TTW (to the way)” which between the two should be indicated is determined using direction information. Finally, the route number is matched with the direction information. Experiments are carried out with the road sign imagery taken inside a car. As a result, route numbers, route number type, OTW or TTW are successfully recognized, however some errors occurred in the process of matching TTW number with the direction.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.37-45
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• 2015

PURPOSES : The purpose of this study is to validate the design criteria of the concrete modular road system, which is a new semi-bridge-type concept road, through a comparison of numerical analysis results and actual loading test results under static axial loads. METHODS : To design the semi-bridge-type modular road, both the bridge design code and the concrete structural design code were adopted. The standard truck load (KL-510) was applied as the major traffic vehicle for the design loading condition. The dimension of the modular slab was designed in consideration of self-weight, axial load, environmental load, and combined loads, with ultimate limit state coefficients. The ANSYS APDL (2010) program was used for case studies of center and edge loading, and the analysis results were compared with the actual mock-up test results. RESULTS : A full-scale mock-up test was successfully conducted. The maximum longitudinal steel strains were measured as about 35 and 83.5 micro-strain (within elastic range) at center and edge loading locations, respectively, under a 100 kN dual-wheel loading condition by accelerating pavement tester. CONCLUSIONS : Based on the results of the comparison between the numerical analysis and the full-scale test, the maximum converted stress range at the edge location is 32~51% of the required standard flexural strength under the two times over-weight loading condition. In the case of edge loading, the maximum converted stresses from the Westergaard equation, the ANSYS APDL analysis, and the mock-up test are 1.95, 1.7, and 2.3 times of that of the center loading case, respectively. The primary reason for this difference is related to the assumption of the boundary conditions of the vertical connection between the slab module and the crossbeam module. Even though more research is required to fully define the boundary conditions, the proposed design criteria for the concrete modular road finally seems to be reasonable.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.7 s.196
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• pp.106-111
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• 2007

In this paper, the transient brake time was studied on the van type vehicle with accelerometer. Experiments were carried out on the asphalt(new and polished), unpacked road(earth and gravel) and on wet or dry road conditions. The transient brake time is not effected bzy the vehicle speed. The transient brake time is about 0.41$\sim$0.43second on the asphalt road surface and the error range is within 0.1$\sim$0.16second. For the asphalt road condition, the transient brake time is not effected by both new asphalt road surface and the polished asphalt road surface. With compared by dry and wet road surface condition, the transient brake time of wet condition is longer than dry road condition and compared with unpacked road condition and packed road condition, unpacked road condition is shorter than packed road condition. It is considered that the transient brake time is effected by the road surface fraction coefficient. In other words, the transients brake time increases as friction coefficient decreases.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.165-173
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• 2017

PURPOSES : The current practice in car headlight visibility performance evaluation is based on the luminous intensity and illuminance of headlight. Such practice can be inappropriate from a visibility point of view where visibility indicates abilities to perceive an object ahead on the road. This study aimed at evaluating the appropriateness of current headlight evaluation method. METHODS : This study measured the luminance of object and road surface at unlit roadways. The variables were measured by vehicle type and by headlight lamp type. Based on the measurements, the distance where drivers can perceive an object ahead was calculated and then compared against such distance obtained by conventional visibility performance evaluation. RESULTS : The evaluation method based on illuminance of headlight is not appropriate when viewed from the visibility concept that is based on object-perceivable distance. Further, the results indicated a shorter object-perceiving distance even when road surface luminance is higher, thereby suggesting that illuminance of headlight and luminance of road surface are not the representative indices of nighttime visibility. CONCLUSIONS : Considering that this study utilized limited vehicle types and that road surface (background) luminance can vary depending on the characteristics of the given road surface, it would likely go too far to argue that this study's visibility performance evaluation results can get generalized to other conditions. Regardless, there is little doubt that the current performance evaluation criterion which is based on illuminance, is unreasonable. There should be future endeavors on the current subject which will need to explore study conditions further, under which more experiments should be conducted and effective methodologies developed for evaluating automotive headlight visibility performance. Needs are recognized particularly in the development of headlight visibility performance evaluation methodology which will take into account road surface (background) luminance and luminance contrast from various perspectives as the former indicates the driver's perception of the front road alignment and the latter being indicative of object perception performance.

• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.46-53
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• 2010

The purpose of this study is to provide a database for the reduction of road-kills in the Odaesan National Park. To accomplish this task, investigations were conducted on the road-kills that occurred in the period from 2003 to 2007. The results of investigations are as follows: 427 road-kill cases were reported during the period, and the road-kill victims turned out to be mostly small mammals. Among mammals and reptiles the road-kill occurrence rate of squirrels and garters was higher than that of other species, and in the case of birds, the road-kill occurrence rate of yellow-throated bunting was the highest. The road-kill accidents of mammals and reptiles took place more frequently during the summer and autumn, while those of birds during the spring and summer. The increase of road-kill occurrence rate was found to be related to the activity and breeding period of wild animals, as well as to the increase of vehicles. The occurrence rate of road-kills was also found to be influenced by the type of land use on the roadside. Furthermore, the occurrence rate increased significantly when the roads passed through dry fields.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.166-173
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• 2002

The wheel bearing hub unit is developed type of wheel bearing unified with the hub parts. It has advantage of reducing the weight and the number of components. And, it also improves uniformity of manufacturing quality, In order to design the wheel bearing hub units, many techniques are used such as load analysis, structure analysis and bearing characteristics analysis and so forth. These techniques need highly accurate load conditions founded on service conditions. In this study, to design the wheel bearing hub units used widespread in passenger cars, the service load was measured through driving tests on the public roads and in the special events. The public roads are classified into highway, intercity road, rural road, urban road, and unpaved road so as to know what the characteristics of the road loads are. The results of the tests showed that the wheel force was relative to the lateral acceleration, and also could be calculated from the lateral acceleration. The lateral acceleration was measured from 0.0G to 0.6G in general driving on the public roads, with different distributions in each road type. In special events, the maximum lateral acceleration was measured from 0.8G to 1.3G.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.11-20
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• 2011

This study aimed to devise the method to construct safe and convenient bicycle road by considering the peripheral environmental factor related to using bicycle. Analyzing the existing design of bicycle road and construction case, this study established the method to design bicycle road that reflects site condition and presented the optimal design method for each type of bicycle road to construct safe and convenient bicycle road by analyzing the type of traffic accident for each type of bicycle road, surveying present situation and local survey. It was found that the optimum design of bicycle road for specification, width, curve radius, ascending slope, etc in consideration of peripheral environment and separating traffic between users of traffic means should be done by installing safety sign, safe facilities and separation facilities to design safe bicycle road. Further, the minimum traffic space of bicycle users and connection between bicycle roads should be ensured to design safe bicycle road. It is judged that information related to safety and convenience of bicycle road such as slope, route information, location of convenience facilities, information to the public traffic should be provided so as to activate the users of bicycle.