• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.282-288
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• 2023

In this study, we analyzed the amount of roadside fine dust generated from newly constructed specially modified asphalt pavement and general asphalt pavement from existing roads. We collected the 1,000 g (100 g/day) of dust samples from the roadside of the express bus terminal and commercial facility area in Chungcheongnam-do's C site at three-day intervals during the summer of 2022 and 2023. The collected samples were separated from fine dust according to size in the 75-150 ㎛ range and, were separated only from Tire and Road Wear Particles through density separation. No.1-3 are general asphalt pavement section as an existing road. Fine dust and Tire and Road Wear Particles in No.1-3 were 24.27 g, 24.36 g, 0.53 g, and 0.53 g, respectively, and the quantitative results for 2022 and 2023 were similar. On the other hand, No.4-6 are newly constructed specially modified asphalt pavement section. Fine dust decreased by 14.8 % and tire and road wear particles decreased by 29.6 % in 2023 compared to 2022 in No.4-6. In addition, according to the results of thermogravimetric analysis, Tire and road wear particles in No.1-3 are tire and road components at 30 % and 70 %, respectively. And Tire and road wear particles in No.4-6 are tire and road components at 35 % and 65 % in 2023, respectively. From these results, it was confirmed that the newly constructed specially modified asphalt pavement can be effective in reducing roadside fine dust and Tire and Road Wear Particles. However, there may be some shortcomings in conclusive research results due to limited space and sample collection period. In the future, we plan to conduct various case studies.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.12
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• pp.1131-1138
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• 2007

This paper studies experimentally on the building-up process for the amplitude of a commercial truck vibration induced by brake judder. A front axle drum equipped with a drum brake system is utilized for this experiment. A brake dynamo test, a real vehicle ride test and a real vehicle braking test are performed for the analysis of brake judder. The brake dynamo test measures judder by applying brake chamber pressures of 1, 2 and 3 bar at initial brake pad temperatures of $100^{\circ}C$ and $150^{\circ}C$. In order to assess the vertical acceleration at the front axle, the real vehicle ride test on a straight test road with velocities of 20, 40, 60 and 80 km/h is performed. The real vehicle braking test is carried out at the deceleration rate of 0.2g from a velocity of 90km/h for evaluating the vertical, lateral and longitudinal accelerations both at the front axle and at the cab floor under the driver's seat. The magnitudes and frequencies of the measured peak accelerations from the brake dynamo test, the real vehicle ride test and the real vehicle braking test are comparatively analyzed. This paper shows that the vibration produced by brake judder is built up due to the brake system's peak acceleration frequency being close to the vehicle ride mode's frequency.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.1
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• pp.22-30
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• 1990

The contents of benzo(a)pyrene (Bap.), Pyrene(Py) and Perylene(Pery) were determined by one-dimensional dual band thinlayer chromatogragphy and spectrofluorophotometer in soil samples from road at 36 places of Ulsan and 6 places of Seoul from April to May, 1984. The concents were as follows: 1. Ulsan city : Bap. 0.05-3.66 $\mu$g/g ; mean 1.07 $\mu$g/g Py. 0.60-11.01 $\mu$g/g ; mean 4.34 $\mu$g/g Pery. 0.94-5.48 $\mu$g/g ; mean 1.83 $\mu$g/g 1) Industrial area : Bap. 0.03-3.66 $\mu$g/g ; mean 5.28 $\mu$g/g Py. 2.34-9.07 $\mu$g/g ; mean 5.28 $\mu$g/g Pery. 1.01-3.69 $\mu$g/g ; mean 2.09 $\mu$g/g 2) Commercial area : Bap. 0.15-2.27 $\mu$g/g ; mean 0.29 $\mu$g/g Py. 0.06-11.0 $\mu$g/g ; mean 4.04 $\mu$g/g Pery. 1.03-5.48 $\mu$g/g ; mean 1.84 $\mu$g/g 3) Residential area : Bap. 0.05-0.05 $\mu$g/g ; mean 0.29 $\mu$g/g Py. 1.34-5.53 $\mu$g/g ; mean 2.74 $\mu$g/g Pery. 0.94-2.15 $\mu$g/g ; mean 1.18 $\mu$g/g 2. Commerical area in Seoul : Bap. 0.35-1.01 $\mu$g/g ; mean 0.74 $\mu$g/g Py. 9.37-24,44 $\mu$g/g ; mean 18.64 $\mu$g/g Peay. 1.47-2.24 $\mu$g/g ; mean 1.87 $\mu$g/g 3. The areas that had high contents of Benzo(a)pyrene had also high contents of Pyrene and Perylene. 4. The industrial area had the highest contents of polynuclear aromatic hydrocarbons, followed by commercial area and residential area. 5. The contents of Bap. and Pery. in the commercial area were similar in Seoul and Ulsan, while the content of Py. in Seoul was 4 times higher than in Ulsan.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.1-10
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• 2015

Promising onshore wind farm sites in Gangwon province of Korea were investigated in this study. Gangwon province was divided into twenty five simulation regions and a commercial program based on Reynolds averaged Navier-Stokes equation was used to find out wind resource maps of the regions. The national wind atlas with a period 2007-2009 developed by Korea institute of energy research was used as climatologies. The wind resource maps were combined to construct a wind resource map of Gangwon province with a horizontal spatial resolution of 100m. In addition to the wind resource, national environmental zoning map, distance from substation, residence and automobile road, Beakdudaegan mountain range, terrain slope, airport and military reservation district were considered to find out promising wind farm sites. A commercial wind farm design program was used to find out developable wind farm capacities in promising wind farm site with and without excluding environmental protection regions. The total wind farm capacities with and without excluding the protection regions were estimated to be 46MW and 598MW, respectively, when a 2MW commercial wind turbine was employed.

• International Journal of Automotive Technology
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• v.6 no.1
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• pp.29-35
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• 2005

The structural integrity of either a passenger car or a light truck is one of the basic requirements for a full vehicle engineering and development program. The results of the vehicle product performance are measured in terms of ride and handling, durability, Noise/Vibration/Harshness (NVH), crashworthiness, and occupant safety. The level of performance of a vehicle directly affects the marketability, profitability and, most importantly, the future of the automobile manufacturer. In this study, the Virtual Proving Ground (VPG) approach has been developed to simulate dynamic nonlinear events as applied to automotive ride & handling. The finite element analysis technique provides a unique method to create and analyze vehicle system models, capable of including vehicle suspensions, powertrains, and body structures in a single simulation. Through the development of this methodology, event-based simulations of vehicle performance over a given three-dimensional road surface can be performed. To verify the predicted dynamic results, a single lane change test was performed. The predicted results were compared with the experimental test results, and the feasibility of the integrated CAE analysis methodology was verified.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.915-923
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• 2011

Our country is promoting the introduction of new means of transportation due to insufficient supply according to the existing demand of road traffic. Among them, manless light railroad transit is settled down as the most definite alternative. However, new traffic systems such as manless light railroad have certain difference between characteristics of hardware and software and subway system. Therefore, there will be many differences compared to the existing contingency system when accidents occur. Railway management organization has to establish railway contingency plan and acquire permission from the minister of the Ministry of Land, Transport, and Maritime Affairs. However, as commercial transportation is available, a new traffic system also should establish contingency plan. Therefore, the establishment of systematic contingency plan is suggested in order to analyze characteristics of manless light railroad in the beginning of introduction and to make contingency response available.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.1
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• pp.45-50
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• 2015

This study performed a finite element crash analysis of support structures made of various composite materials for road facilities. The effects of different material properties of composites for various parameters are studied using the finite element commercial package for this study. In this study, the existing finite element analysis of composite post structures using the LS-DYNA program is further extended to compare dynamic behaviors against car crash of the structures made of various composite materials. The several numerical examples show the comparison of the nonlinear dynamic effects for different materials.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.154-160
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• 1998

Ride quality of medium truck became a very important factor in the suspension design, to the demand of more comfortable ride of passengers. This study describes how to determine and evaluate design parameters related to the chassis suspension system with time and frequency analysis. The spring stiffness and damping force of the chassis suspension system were obtained by observing the vertical acceleration PSD. The simulation was carried out on various road profiles, which was suggested by ISO. The pitching motion of the medium size truck was observed to improve the ride quality. A computer simulated truck model was constructed using DADS, a commercial dynamic analysis software, in order to simulate the truck motions. From the analyzed process of suspension parameters, it was concluded that the spring and the shock absorbers affect the pitching of the vehicle. In order to validate the computer simulated truck model, a physical prototype was constructed and tested.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.882-886
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• 2007

People living in the large cities are exposed to high level noise due to road-traffic, railway-traffic and aircraft. Nowadays, some researches are ongoing to reduce the noise by using noise map. However it has to be decided which prediction model is the most suitable in Korea. In this study, it has been focused on railway noise prediction models which are employed in a commercial software(Sound Plan) and developed by Korea Railroad Research Institute, and comparative study of the prediction models has been made.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.251-252
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• 2015

본 연구는 국방규격서의 전문어, 오용어, 어문규정 및 순화어 미(未)준수 어휘를 추출, 정의 또는 순화어로 정제하는 맵핑구조를 제시, 민 군규격용어 표준화를 위한 정보업무 로드맵을 구축하여 민간용어와의 호환성 및 일관성을 유지할 수 있는 지원체계를 연구하였다. 대상 규격용어는 KS용어표준 원칙을 기본으로 한 신뢰도 평가와 텍스트 마이닝 (text mining)빈도분석을 이용하여 선정하였으며, 시소러스(thesaurus) 체계를 삽입, 개념기반 서비스의 확장성을 제시하였다. 이를 기반으로 산출된 규격용어 DB는 민간 및 국방 관련분야의 용어표준관리 정보체계에 검색 및 용어설명에 활용될 수 있다.