• Journal of Auto-vehicle Safety Association
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• v.10 no.1
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• pp.45-51
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• 2018

There are some ambiguities of the information on the fuel economy provided to the consumers because the standard and the detailed regulations for the fuel economy of the two-wheeled vehicle have not been established in Korea. Since Korea has been a signatory of World Forum for Harmonization of Vehicle Regulations since 1998, it is possible to remove the ambiguities by adopting the WMTC (Worldwide-harmonized Motorcycle Test Cycle) measurement method for the fuel economy of the two-wheel vehicle. As a preliminary study on the WMTC mode fuel economy, road loads measured by coast down method and table method were compared for the two types of two-wheeled motorcycles on sales in domestic market. In the same model, it was confirmed that the deviation of WMTC mode fuel efficiency was below -5% between products. On the other hand, the difference of WMTC fuel economy exceeded 5% between the coast down method and table method.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1542-1549
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• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.3
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• pp.29-35
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• 2022

When a vehicle is driven off a road surface, the deformations of the road surface and tire are combined. Consequently, the dynamic behavior of wheel movement becomes difficult to predict and control. Herein, we propose a tire test bed to capture the dynamic behavior of tires moving on sand and soil. Based on this study, it is discovered that the slip rate can be controlled, and the vertical force can be measured using a load cell. The test results show that this test bed can be useful for capturing the dynamic behavior of the tire and validating dynamic simulations. In fact, the tire test bed developed in this study can be used to verify the results of computer simulations. In addition, it can be used for basic experiments pertaining to the speed control of unmanned autonomous vehicles.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.04a
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• pp.11-16
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• 1989

This paper presents a fatigue reliability model for the reliability-based evaluation of remaining fatigue life of existing rail-road bridges. It is demonstrated that the simple fatigue reliability model based on the Weibull distribution of fatigue life can be extended by incorporating various effects due to the rate of the train-traffic increase and in-service Inspections. The paper also suggests the system fatigue reliability analysis using an approximate formulation and 2nd-order bound solutions. The application of the proposed model to existing rail-road brdiges based on field load tests shows that it may be practically used for the assessment of fatigue reliability, remaining life, and in-service inspection scheduling of existing rail-road bridges.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.2
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• pp.40-45
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• 2009

This study is analyzed by stress contour of automotive tire at contact on road surface. Maximum equivalent stress as 61200Pa is shown on the lower mid part in case of tire contacted on road surface. As the air pressure of tire increases, maximum total deformation as 5mm is shown on the side part of tire. It can be shown that the side part of tire is unstabilized. There is no load effect on tire at its upper and lower directions. When the moment applied on the side of tire is increased 1.4 times as its value, the value of maximum principal stress is increased 1.4 times. The stress at the tire is in proportion to the moment applied on the its side. The tire tends to incline toward its side by this moment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.266-269
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• 2006

Tire is in charge of a lot of function, which is supporting vehicle load, transferring traction and. brake, absorbing impact by road etc. As the silence of vehicle increase more important, the importance of tire noise is more raised. In recent, the study on reduction of tire noise is generally processed. Tire noise is divided in structure home noise and all borne noise. Tire tread properties have a lot of multiplicity. Rubber properties are caused by changing or tread hardness. That change Elastic Modulus and Loss Modulus, which is related by tire noise. In the study, we found that road noise is affected by tread hardness

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.197-203
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• 2003

Korea Highway Corporation(KHC) began the ambitious KHC Test Road construction project from 1997. It is 7.7km long two-lane highway next to the mainline of Jungbu Inland Expressway. The KHC Test Road construction was completed at the December 2002. It is composed of twenty-five PCC test pavement sections. Section design parameters are (1) concrete slab thickness, (2) base type, (3) base thickness (12, 15, and 18cm), and (4) pavement type. Twenty-five PCC test pavement sections contain 1241 sensors to evaluate the behavior of pavement system under traffic load and environmental change. The behavior of pavement systems will be identified by the observation of sensor measurement and pavement distress survey from test pavement sections. The Test Road research outcome will validate the Korean Pavement Design Guide which is develop by on-going funded research from the Ministry of Construction and Transportation.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.31-35
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• 2006

Cement stabilisation is a common method for stabilising recycled road base material and provides a longer pavement life. With cement effect, the increment of stiffness in the stabilised layer would provide better load transfer to the pavement foundation. The recycling method provides an environmentally option as the existing road base materials will not be removed. This paper presents a case study of a trial section along the North-South Expressway in West Malaysia, where the Falling Weight Deflectometer (FWD) was implemented to evaluate the compressive strength and in-situ stiffness of the cement stabilised road base material. The improvement in stiffness of the cement stabilised base layer was monitored, and samples were tested during the trial. FWD was found to be useful for the structural assessment of the cement-stabilised base layer prior to placement of asphalt layers. Results from the FWD were applied to verify the assumed design parameters for the pavement. Using the FWD, an empirical correlation between the deflection and the stiffness modulus of the pavement foundation is proposed.

• Korean Journal of Ecology and Environment
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• v.38 no.spc
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• pp.58-61
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• 2005

Environmental polluting materials from road surface drainage are a significant nonpoint source influenced to the eutrophication of lake and ecosystems with a transport development in recent years. To elucidate the discharge characteristics, the changing patterns in concentrations of polluting materials such as suspended solid (SS), chemical oxygen demand (COD), nitrogenous and phosphorus nutrients in drainage waters, were investigated during rainfall. Load variation of COD concentration in drainage water samples was closely related to that of SS concentration. This indicates that SS contained a greater part of organic matter. A quite difference between the past pavement and the new well-drainage pavement system was observed in the concentrations of SS and COD in drainage waters. Appreciable concentrations of nitrite and nitrate were determined in drainage waters. The present results indicate that the drainage water from road surfaces is a significant nonpoint source, and that the well-drainage pavement system introduced to skid prevention has an effect on the decreases of pollutants.

• Journal of the Society of Disaster Information
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• v.4 no.2
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• pp.68-91
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• 2008

Our country is consuming huge source of revenue to improve geometric structure of road with a view to improve safety of the road. However, it is more efficient to provide high-quality pavement markings to the road users. For this purpose, in this study, it is considered the optical theory related to retroreflectivity of pavement marking along with the our country's study literature and foreign. And also considered ur country standard related to pavement marking, made pavement marking sample and measured retroreflectivety. For the experiment, it is selected colors of normal temperature-type paints, grading and content of glass bead as experiment factors. After it is made the same conditions like construction spot, measured retroreflectivity according to the combination of factors and analyzed the optimization of factors.