• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.867-879
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• 2016

Since the 1970s, the region of its own pedestrian center and environmental pollution caused by exhaust gases have been reduced gradually in a continuous increase of the vehicle, school route the central business district, around the school, the sidewalk where the vehicle do not pass, facilities of minimum for the safety of pedestrians and systematic management of an area where an unspecified number and alleys impassable is insufficient. Recently, in response to the "Law for convenience enhancing safety and walking" is enforced in Korea, research on Pedestrian only Street has been actively about the government, the standard for calculating the weights of evaluation associated with it. it is a actuality, however, there are insufficient, evaluation for business promotion is being conducted evaluation polite manner by using, for example, scale residence time and purpose of the passengers as there is no car that has been carried out on a voluntary basis through the municipality have. In this study, by suggesting a method for the selection of the street without a car, make a survey by placing a purpose in the selection method presentation of the street with no car to be construction future, was researching. F.G.I (Focus Group Interview) survey, professors, staff in urban, traffic field of experts in order to present the weights for the evaluation of the Pedestrian only Street by using the evaluation index by type of Pedestrian only Street, was interviewed about the evaluation index for the conducted for professionals engaged in the engineering company, and randomly selected 200 peoples, weighted evaluation of the street with Pedestrian only Street was proposed. By classifying the items purpose and goals of the evaluation type by this by applying the weight, and present the weight of the detailed indicators each corresponding to each item, and scored on the basis of the result, in this paper it can be so that one methodology for the selection standard for the construction as Pedestrian only Street, and the weight of the evaluation of the type that has been derived, the selection and evaluation methods and then added to these criteria to settle careful study of the reference should be performed further.

• Journal of Ginseng Research
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• v.30 no.3
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• pp.112-116
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• 2006

To investigate the protective effect of saponin from red ginseng extract, 2,3,7,8-tetrachlorodibenzo--dioxin (TCDD) was exposed to female guinea pigs and then femur weights was measured. Forty eight female guinea pigs ($820{\pm}25\;g$) were divided into 6 groups. Normal control group (NC) received vehicle and saline; only TCDD-treated group (TT) received TCDD ($5.0\;{\mu}g/kg$, single dose) intraperitoneally; pretreated group of saponin 10 (PE 10) received 10 mg/kg of saponin i.p. for 4 weeks from 1 week before TCDD-exposure; pretreated group of saponin 20 (PE 20) also received 20 mg/kg of saponin i.p. for 4 weeks from 1 week before TCDD-exposure. While, post-treated group of saponin 10 (CE 10) received 10 mg/kg of saponin i.p for 3 weeks after TCDD-exposure. Post-treated group of saponin 20 (CE 20) received 20 mg/kg saponin i.p for 3 weeks after TCDD-exposure. Body weight of TT group was significantly decreased after TCDD-exposure. However, body weight in all saponin-treated groups increased throughout the experimental period, although the increasing rate was slower than that of NC group. Body weights of PE 10 and 20 groups showed more higher increase than those of CE groups during the experimental period. Decrease of femur weights in female guinea pigs by TCDD intoxification was significantly recovered by the saponin treatment. Decrease of $Ca^{2+}$ level of femurs in female guinea pigs exposed TCDD also recovered by the treatment of saponin from red ginseng extract. Especially, PE20 group showed the highest increase of the $Ca^{2+}$ level in femur among the saponin treated groups. These results suggest that ginseng saponin might be a useful protective agent against femur damage caused to decrease of $Ca^{2+}$ by TCDD.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.320-325
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• 2009

The present study was carried out to investigate the acute oral toxicity and anti-obesity effects of a diglyceride preparation containing conjugated linoleic acid (DG+CLA). To test its acute oral toxicity, the DG+CLA was injected into 30 rats (15 males and 15 females) at dosage of 2,000 mg/kg and 5,000 mg/kg. Mortality rates, clinical signs, and body weight changes were monitored for 14 days following administration. According to the results, the lethal dose ($LD_50$) of DG+CLA was determined as >5,000 mg/kg in both sexes. There were no significant changes in general conditions, clinical signs, body weight, and gross lesions between the vehicle control and DG+CLA groups. For the anti-obesity studies, obese Zucker rats were randomly divided into 4 groups and fed saline, soybean oil, diglyceride, and DG+CLA, respectively, for 8 weeks. The DG+CLA groups presented significant differences in body weight, food efficiency ratio, serum lipid levels, and fat weight. Overall, the results showed that the DG+CLA did not have acute oral toxicity and reduced body weight, serum lipid levels, and fat gain.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.365-373
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• 2014

This study is to analyze the physical environment and conduct spatial data for bicycle road system in changwon. Index for evaluation index was developed based on literatures. Then the level of importance and weight have been modified through experts review. Finally, index with eight categories such as greenness(40% over), bicycle road connectivity(1.8, 9.8%), road type bike(bicycle lane, 24.4%), pave type(asphalt 72.5%), illegal parking(none, 93.9%), bike road surface visibility(exist, 46.8%), vehicle speed limits(30km, under), vehicle traffic(500/hr under, 44.3%) have been applied to empirical investigation. Collected data has been hierarchically classification by ArcGIS Program. The Highest grades(score 31-35, level 1) occupied 35% of target destination. High level of greenness and load type has contributed to high score. In addition, average level of greenness of those destination was 35% and higher, which provide high degree of security and freshness for bicycle riding. Meanwhile, lowest level(level 5, which earned 15 point or less) occupied 24.5%. illegal parking, low level of greenness, and no surface sign caused low score.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1413-1420
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• 2012

To predict the dynamics behavior, running stability, etc. of a railway vehicle and to understand its physical characteristics, analytical methods are used for the testing and manufacturing of a scale model along with numerical simulations in developed countries (England, France, Japan, etc.). The test of the dynamics characteristics of full-scale models is problematic in that it is expensive and time-consuming because an entire large-scale test plant needs to be constructed, difficulties are involved in the test configuration, etc. To overcome these problems, an analytical study involving dynamics tests and computer simulations using a scaled bogie model that applies the laws of similarity was carried out. In this study, we performed stability analysis on a 1/5 small scaled bogie for parameters such as the running speed and carbody weight by using an analysis model. Furthermore, we verified the reliability by using a small-scaled derailment simulator and examined the dynamic characteristic of the 1/5 small scaled bogie.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.802-809
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• 2017

3D printing technology is a manufacturing process for products, in which polymer and metal materials are laminated to form structures. It is advantageous for manufacturing parts requiring a high degree of design freedom and functionality. In addition, it would be a suitable technology for the production of parts for railway vehicles in the future, due to the need to produce parts in small quantities. In order to fully exploit the advantages of 3D printing technology, it is necessary to consider the process characteristics during the design of the product. In this study, the redesign and manufacturing technology of the product considering the performance and process conditions were studied for the heat exchanger in the air compressor of railway vehicles, as a trial application of the 3D printing technique. First of all, the design concept to improve the performance of the heat exchanger was defined, and the design range was specified to satisfy the performance of the present heat exchanger analyzed experimentally. Then, the detailed design was revised considering the characteristics of the metal 3D printing process, such as the manufacturing restrictions and production time. Based on the final design, the product was fabricated by the 3D printing process using aluminum material, and it was confirmed that the dimensional accuracy was satisfied. The weight of the final product was reduced by 41% compared with the existing products. The results of this study will make it possible to develop an efficient product design process for 3D printing technology.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.4
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• pp.1-13
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• 2014

The paper gives an overview of the concepts, basic requirements, and trends regarding packaging technologies of power modules in hybrid (HEV) and electric vehicles (EV). Power electronics is gaining more and more importance in the automotive sector due to the slow but steady progress of introducing partially or even fully electric powered vehicles. The demands for power electronic devices and systems are manifold, and concerns besides aspects such as energy efficiency, cooling and costs especially robustness and lifetime issues. Higher operation temperatures and the current density increase of new IGBT (Insulated Gate Bipolar Transistor) generations make it more and more complicated to meet the quality requirements for power electronic modules. Especially the increasing heat dissipation inside the silicon (Si) leads to maximum operation temperatures of nearly $200^{\circ}C$. As a result new packaging technologies are needed to face the demands of power modules in the future. Wide-band gap (WBG) semiconductors such as silicon carbide (SiC) or gallium nitride (GaN) have the potential to considerably enhance the energy efficiency and to reduce the weight of power electronic systems in EVs due to their improved electrical and thermal properties in comparison to Si based solutions. In this paper, we will introduce various package materials, advanced packaging technologies, heat dissipation and thermal management of advanced power modules with extended reliability for EV applications. In addition, SiC and GaN based WBG power modules will be introduced.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.632-637
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• 2017

The vehicle lubricant occupies upto 35% in a total lubricant market and engine oil occupies upto 77% in the vehicle lubricant market in Korea. A suitable quality management of the circulating engine oil is necessary for driver and engine protection. But, KS and synthetic engine oil products (involved over 30% synthetic oil) are exempt to any quality management under Petroleum and Alternative Fuel Business Act. It is also known that synthetic oils such as PAO (poly alpha olefin) have excellent properties and performance like anti-wear, varnish control and oxidation stability than those of mineral oils. For this reason, PAO has been used for an engine oil, rotary screw and reciprocating compressor in addition to heavy duty and other extreme service applications. In this study, our research group analyzed the chromatogram pattern for the mineral oil, PAO and mineral oil involved a typical ratio of PAO using SIMDIST (simulated distillation). In the SIMDIST chromatogram, the mineral oil showed a broad peak, while PAO showed a sharp typical peak. Also the oil with a large viscosity grade exhibited a long retention time due to the heavy molecular weight and high boiling point. In particular, the blended mineral oil with 20% PAO sample showed a distinctly different pattern compared to that of using the conventional mineral oil. For monitoring PAO contents in distributing engine oils, we analyzed the SIMDIST for 27 kinds of engine oils which were popularly sold in Korea. The analytic results indicate that all kinds of engine oils showed that PAO contents were below 20% in engine oil products. Moreover, the PAO titled product was found to have a small amount of PAO. Thus, we conclude that the related laws for the proper quality management of synthetic oils are needed to be established.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.123-128
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• 2014

This paper presents the study about MGV(Magnetic guidance vehicle) with up-and-down rotating type differential drive unit. Previous MGV needs the landmarks to get the driving information and additional sensor to recognize the landmarks except for localization sensor. Previous MGV requires at least 2 drive units when common fixed differential drive unit is used because it occurs the problems with driving control and localization error from imbalance of the MGV's weight. To solve such problems, we propose the MGV using up-and-down rotating type differential drive unit. Proposed MGV recognizes the driving information from the pattern which is consisted of both pole of magnet without landmarks and additional sensors, and it control the backward movement using up-and-down rotating type differential drive unit instead of common drive units. Proposed MGV considers KF(Kalman filter) to improve the localization accuracy. To verify the performance of proposed method, we designed MGV for the experiment. As the results, we can confirm the performance of propoesed method to recognize the pattern and to control the backward movement. With respect to localization, proposed method has the less RMSE about 5.6904 mm than previous method.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.827-836
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• 2018

In this study, we developed a PC - based motorcycle simulator based on the development technology of a virtual patrol motorcycle training system. This simulator has been developed to be applied to a variety of fields such as driving training for beginners, driver factor research, and system development such as ABS, which can be seen in advanced models. The weight of the motorcycle operated by the patrol guards is more than 400Kg. There is a lot of risk due to the nature of work without prior practice. Therefore, we implemented a study on the untilization of physical stress and temporal pressure in emergency situations. In order to get a feeling that the motorcycle simulator is operating in real-life, it is important that the mutual reliable signal transmission and operation feel between the driver and the simulator. In order to achieve this, we developed a system that can apply the sub-systems of the actual vehicle to the motorcycle simulator in order to generate the same operation feeling as the actual vehicle. Based on these results, we have developed a method of generating a feedback queue.