• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.152.1-152.1
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• 2011

This study analyzes transitions to a green path in transportation system in South Korea. We develop transportation system model with four new technology options, green cars; Hybrid electric vehicle, plug-in hybrid vehicle, electric vehicle and fuel cell vehicle. Among those technologies fuel cell vehicle is the best option assuming no GHG emissions when driving. We use MESSAGE model to get an optimal solution of pathway for high deployment of fuel cell vehicles under the Korea BAU transportation model. Among hydrogen production sources, off gas hydrogen is most economic since it is hardly used to other chemical sources or emits in South Korea. According to off gas hydrogen projection it can run 1.8 million fuel cell vehicles in 2040 which corresponds to 10% of all passenger cars expected in Korea in 2040. However, there are concerns associated with technology maturity, cost uncertainty which has contradictions. But clean pathway with off gas and renewable sources may provide a strong driving force for energy transition in transportation in South Korea.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1639-1644
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• 2018

Unlike internal combustion engines, electric cars have little engine sound and very quiet, causing the following problems to occur. First of all, pedestrians are a threat to safety because they can't feel the car approaching. The driver is also unable to recognize how fast his car is driving at a certain speed. To solve these problems, electric cars should be artificially created and reused. This paper examines the problems of the Sampling engine sound currently being used and uses the engine sound to produce a sound engine sound for the solution. The sampling engine sound has some limitations in making natural engine sounds. To overcome this problem, we studied two methods of using software synthesizers. They found subtractive synthsizing and wavetable synthsizing, which compared wavetabe synthsizing with actual engine, sampling and subtractive methods to find the most similar to real engine sound. We found that data usage and production cost are more advantageous than sampling method and subtractive syndication method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.3
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• pp.335-344
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• 2008

In recent years, public complaints against railroad noise by KTX and Ordinary train have been rising. Regulation of railways noise uses same standard without distinguishing the type of railroad cars. According to the type of railroad cars, the frequency characteristics of emitting noise is different. Therefore it is requested to know how the public response vary to each types of railroad cars. The noise annoyance from three types of trains(KTX, electric train, diesel train) was analyzed by jury evaluation test for assessing the effect of frequency characteristics. The numerical results by a semantic differential method showed that annoyance response to three type of trains depended on the frequency characteristics. As a result, this study proposed that the KTX could have a bonus level of maximum 2.9 dB(A) compared to ordinary train.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.61-66
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• 2016

This paper presents the implementation for a network structure of railway cars using a point to point communication. Most of network's representative specifications for a train are the FIP (Field Bus), MVB (Multifunction Vehicle Bus), CAN and WTB (Wire Train Bus) which is used by ALSOM, SIEMENS and BOMBADIER as major in this field. These networks in a physical layer use a multi-drop method, connected from $1^{st}$ car to $n^{th}$ car of a train through a cable without any extra services such as an electric part, amplifier. However waveforms which is passed through a long cable in the multi-drop are distorted by a capacitance or resistance of the cable or environments. Also since using a cable connected directly from $1^{st}$ car to $n^{th}$ car, if over two trains make double head, it isn't easy to distinguish ID for each railway cars. So by using the point to point network per each car, it is able to reduce a distortion. Also since reducing distortion, this communication speed can be been higher and transmit and receive any packets more stably. Using proposed token in a packet, this can make ID per each railway car automatically. Finally experimental results show the good performance and effectiveness of the proposed method.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.896-899
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• 2003

The electric railway has been widely used as a transportation all over the world. It also was opened in 1973 in korea and it has been steadily proceeded in making electric railway network for a big city and building Keongbu high speed , electric railway. That's why the system of electric railway is able to solve the environmental pollution and operate the useful energy in environmental ways, it helps to increase the ability of transportation and to decrease the cost. Because of the advantage of making the economic situation better, the system of electric railway is trying to do their best in developing technique of electric railway. Because of the increasing of transportation and the high speed operation, cars with regenerative braking system was adapted. Therefore, unbalanced voltage and current of three phase system and the drop and rise of voltage of feeding circuit is expected. Now that building the substation, newly spends lots of costs and time, it is a very difficult situation to solve the problem. We can guess that electric railway line can't receive power from the power system of bigger size in building newly electric railway. In this paper, it was proved that series voltage compensator was suitable as a solution according to voltage drop and voltage fluctuating through computer simulation.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.947_948
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• 2009

In an attempt to minimize the air pollution caused by CO2, $NO_X$x, and $SO_X$ and the fuel cost, the auto industries and researchers recently are looking into replacing the diesel and gasoline cars with hybrid electric vehicles, plug-in electric vehicles, or battery powered electrical vehicles. This paper reports the technical status of the primary components such as batteries, motors, power control units and auxiliary parts to be used for electric vehicles.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.1-6
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• 2019

Recently, as electric vehicles and hybrid vehicles are widely used, the use of rechargeable batteries is increasing. Electric and hybrid cars are made up of hundreds to thousands of electric cells depending on the car model. And the assembly process of the cells and modules requires a variety of bonding process. Meanwhile, in order to connect several cells in series, Cu used as a cathode and Al of an anode must be bonded. In this paper, the characteristics of Al and Cu metals, laser types, characteristics and principles of welding lasers for welding of Cu and Al electrodes are introduced.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.281-287
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• 2006

Subway line becomes an important way of transportation as road traffic goes to limit. Recently the large number of passengers of the subway lines near metropolitan area, In-Cheon, Su-Won, Pyung-Teak and Chon-An, is rapidly increasing. The electric cars of the No. 1 subway line in the suburbs are now running fast compared to the downtown area. However, the fast electric car can be uncomfortable to ride in, because there are so much noise and vibration. In this research, the running characteristics of the electric car of the No. 1 subway line in the suburbs is investigated through the measurements of the noise and vibration at running condition.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.738-745
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• 2014

Recently, various measures have been discussed for overcoming depletion of fossil fuels and environmental pollution. One of the measures is electric vehicles. But electric vehicles has some limitations from high cost of battery and low efficiency, so operation distance of electric cars is limited. Also there are difficulties that charging lines should be connected by an electric car whenever it charges. Thus, many studies have been conducted to overcome the limitation using conventional batteries of electric vehicles. As a result, the OLEV(On-Line Electric Vehicle) was developed. But the OLEV system is some limitations. The OLEV system causes power quality problems when it charges. Power quality problem cannot be ignored because OLEV systems are closely connected by distribution grids. In this paper, the OLEV system is designed by using PSCAD/EMTDC, and the power quality is measured and evaluated. Power quality is divided by two cases; harmonics and high-frequency. Harmonics were evaluated according to IEEE Std. 519-1992. But the evaluation of High-frequency could not take it because there was no standard. For this reason, the data measured by OLEV system was compared with the EN50065 regulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.589-593
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• 2014

Recently, the market has been released a lot of excellent NVH performance cars such as hybrid, electric and luxury cars. Therefore, the consumer is a tendency of many sensitive of the noise inside the vehicle than in the past. In order to match the propensity of such consumers, the automotive industry defines the standard of product related to noise generation of a single product. However, it is difficult to reduce the noise of the product to automobile part suppliers to follow these standards. In this paper, we propose a method for evaluating several necessary in order to find a way to reduce the noise.