• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.647-652
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• 2001

A noise reduction of noise barrier for high speed train was measured by using scale down model test. A selected types of noise barriers were simple vertical barrier, interference type barrier with plate, interference type barrier with cylindrical pipes. On experiment, in order to make similar present test lane condition, reduced train model and multiple noise sources were considered. As a result. interference type noise barrier with cylindrical pipes is most effective than other barriers. A present height of noise barrier which is established in a test lane is not high enough for reducing patograph noise.

• Journal of Auto-vehicle Safety Association
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• v.8 no.3
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• pp.5-9
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• 2016

The objective of this study was to find the factors affecting the results of full frontal barrier impact test for the NCAP (New Car Assessment Program). To find the factors, the frontal NCAP test results of the NHTSA (National Highway Traffic Safety Administration) were utilized. The three tested vehicle were same model year. It was observed the second peak value of barrier force affected the occupant injury risk. As the second peak value of the barrier force increases, the injury risk of the driver side occupant increases as well.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.98-104
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• 2012

Current [Guideline for Installation and Management of Sidewalks and Safety Facilities on Roads] suggests that the types of curbs should be Barrier curb ($85^{\circ}$). Although Barrier curbs ($90^{\circ}$) were not specified in the guideline. The curbs installed on the roads currently are Barrier curbs ($90^{\circ}$) which are not specified in the installation standard. Therefore, it is critical to prepare for the installation standard of curbs by researching types of curbs and driving safety. This research have assessed the driving safety throughout Full Scale Crash Test according to type of curbs (Barrier curbs ($85^{\circ}$) and Barrier curbs ($90^{\circ}$)). Barrier curbs ($90^{\circ}$) showed higher figure in Theoretical head Impact Velocity, Post-impact Head Deceleration, Vehicle Damage when Crash, Passenger's Wounds Severity, and every other items than Barrier curbs ($85^{\circ}$). Barrier curbs ($85^{\circ}$) were found to have better Occupant Safety Index. Analysis of Behavior Using Full-Scale Crash Test showed difference depending on the Impact Condition between Barrier curbs ($85^{\circ}$) and Barrier curbs ($90^{\circ}$). Generally, Barrier curbs ($85^{\circ}$) were superior than Barrier curbs ($90^{\circ}$) in terms of protecting the passengers and vehicle damages. When an impact angle increases, Acceleration of Vehicle, Variations of Speed, and Contact Relationship between Wheels and Curbs, two types of curb showed similarity. However, if an impact of an angle decreases, Barrier Curbs ($85^{\circ}$) showed excellence in Driving Safety such as Acceleration of Vehicle, Variations of Speed, and Contact Relationship between Wheels and Curbs.

• International Journal of Concrete Structures and Materials
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• v.2 no.1
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• pp.57-62
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• 2008

When the yield line theory is used to estimate the ultimate strength of a concrete barrier, it is of primary importance that the correct assumption is made for the failure mode of the barrier. In this study, a static test was performed on two full-scale concrete barrier specimens of Korean standard shape that simulate the actual behavior of a longitudinally continuous barrier. This was conducted in order to verify the failure mode presented in the AASHTO LRFD specification. The resulting shape of the yield lines differed from that presented in AASHTO when subjected to an equivalent crash load. Furthermore, the ultimate strengths of the specimens were lower than the theoretical prediction. The main causes of these differences can be attributed to the characteristics of the barrier shape and to a number of limitations associated with the classical yield line theory. Therefore, a revised failure mode with corresponding prediction equations of the strength were proposed based on the yield lines observed in the test. As a result, a strength that was more comparable to that of the test could be obtained. The proposed procedure can be used to establish more realistic test levels for barriers that have a similar shape.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.113-124
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• 2012

PURPOSES : In This study two different concrete barrier systems have been proposed to be established at the small vehicle driveway. One is for median barrier, and the other is for roadside barrier. METHODS : In order to determine the suitable shape of barrier, the impact parameters including vehicle weight, impact angle, impact velocity and impact level have been analyzed. The real crash test has been carried out with 0.9 ton and 2.5 ton vehicles, respectively by using the 2m segment type concrete barriers connected by steel plates that are totally 40m barrier systems. RESULTS : The numerical results obtained by LS/DYNA-3D software are compared with real crash tests from the viewpoints of vehicle stability, vehicle trajectory, occupant risk, etc. CONCLUSIONS : From the above results, the dynamic performance of proposed barrier systems satisfies the specification of Korean Code for roadside safety structures.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.21-26
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• 2022

Commercial use of autonomous vehicles is to come soon. So far most of responsibility of the accident is on the human driver with conventional vehicles whereas that will be on the car OEM and transportation related organizations with autonomous vehicles, which asks car OEM's and government to do vast study of car crash in various conditions. Test protocols need amendment and to be newly enacted to reflect new findings from the study aforementioned. Rigid stationary barrier and moving or stationary deformable barrier as well as car to car test which is same as actual accident can be utilized to simulate the crash happening on the road. Among those 3 test methods, rigid stationary barrier is most economic and has good repeatability. Limitation as well as advantage of the rigid stationary barrier is studied through comparison between car to car crash and oblique rigid barrier crash.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.938-945
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• 2004

Intrinsic safety is generally considered the safest method of operating electrical instrumention in potentially explosive atmospheres. The method of intrinsic safety limits the energy passing into the hazardus area. The energy limitation is provided by the use of safety barriers which are mounted in the safe area. Because of the energy limitation, regardless of the fault in the hazardous area, sufficient energy cannot be released to ignite the explosive atmosphere. The following industries are known to have hazardous locations: chemical. munitions, petrochemical, auto(paint spray booths), grain, waste water, printing, distillers, pharmaceutical. breweries, cosmetics, and utilities. In this paper, a isolator type barrier for ship(LNG, LPG, etc,) and test equipment confidence are proposed. The test equipments are designed for mechanical electrical life time test and vibration. All of test results satisfy the goal and the studied barrier shows the improved confidence.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.33-36
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• 2004

The current Korea bridge design specifications have no provisions about concrete Barrier. And there are no test results of registence strength of the concrete barrier at the vehicle collision sites. This paper reports experimental results of concrete barrier on bridge deck conctructed by standard drawing of SB5 grade. Eight specimens were tested under static test. The specimens are divided by two groups (D-series and B-series). D-series is to show failure pattern of bridge deck. B-series is to show failure pattern of concrete Barrier. The test results compared with calculation results using Yield-Line theory of AASHTO LRFD Bridge Design Specifications.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.163-163
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• 2012

차세대 모바일용 전자디스플레이로 각광받고 있는 FOLED (flexible organic light emitting display)의 연구에서 display의 신뢰성과 수명은 매우 중요한 연구 테마이다. OLED의 수명단축에 영향을 미치는 요소는 수분에 의한 열화가 가장 치명적이다. Barrier layer를 통한 수분의 주요 침투경로는 pin-hole과 void 등과 같은 defect에 의한 것으로 보인다. 수분의 침투 경로를 제어하는 OLED용 barrier layer의 요구조건은 WVTR (water vapor transmission rate)이 $10^{-6}g/m^2{\cdot}day$ 이하로 낮아야 한다. Barrier layer가 가져야 할 핵심적인 조건은 유연성을 가지면서 동시에 WVTR 값이 매우 낮아야 하는데, 아직까지 이를 만족하는 barrier layer의 개발은 아직 덜된 실정이다. 본 연구에서는 PET (polyethylene terephthalate) 기판에 sputtering법으로 barrier layer를 제조하였다. 증착에 이용한 타겟은 두가지 종류인 Al과 $Al_2O_3$를 사용하였으며, 다층박막으로 제조하였다. 제조된 barrier layer의 수분침투 특성은 WVTR의 측정으로, 유연성의 평가는 in-situ fatigue test를 수행하여 측정하였다. 종합적인 특성 평가를 위하여 SEM과 AFM (atomic force microscope) 관찰도 하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.547-548
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• 2012