• Journal of Environmental Impact Assessment
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• v.9 no.4
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• pp.277-290
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• 2000

The purpose of this study is to identify the problems of environmental impact assessment(EIA) and to suggest new EIA technology. The problems of EIA in Korea can be summarized as follows. First, the EIA does not reflect the impact of policy, plan and program on environment. Second, the project EIA does not consider the cumulative impacts such as additive impacts, synergistic impacts, threshold/saturation impacts, induced and indirect impacts, time-crowded impacts, and space-crowded impacts. Third, the EIA techniques in Korea are not standardized. Finally, the present EIA suggests only alternatives to reduce adverse impacts. To solve above-mentioned problems, the development of new EIA technology is essential. First, the new EIA technology should be developed toward pollution prevention technology and comprehensive and integrated environmental management technology. Second, new fields of EIA for pollution prevention contain strategic environmental assessment, cumulative impacts assessment, socio-economic impact assessment, cyber EIA and EIA technology necessary after the reunification of Korean Peninsula. Third, EIA technology for integrated environmental management contains the development of integated environment assessment system and the development of packaged EIA technology. The EIA technology for integrated environmental assessment system contains (1) development of integrated impact assessment technology combining air/water quality model, GIS and remote sensing, (2) integrated impact assessment of EIA, traffic impact assessment, population impact assessment and disaster impact assessment. (3) development of integrated technology combining risk assessment and EIA (4) development of integrated technology of life cycle assessment and EIA, (5) development of integrated technology of spatial planning and EIA, (6) EIA technology for biodiversity towards sustainable development, (7) mathematical model and GIS based location decision techniques, and (8) environmental monitoring and audit. Furthermore, there are some fields which need packaged EIA technology. In case of dam development, urban or industrial complex development, tourist development, landfill or combustion facilities construction, electric power plant development, development of port, road/rail/air port, is necessary the standardized and packaged EIA technology which considers the common characteristics of the same kind of development project.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.6
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• pp.407-413
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• 2013

In the conventional towing tank, the ordinary towing carriage has a speed barrier which caused not only by the limitation of the length of towing tank but also the limitation of acceleration. Therefore the length of the towing tank should be decided carefully from the planning stage of the towing tank construction. Consequently the acceleration of the towing carriage should be taken less than 0.06g practically to avoid the slip of the wheel on rail. Due to the increasing demand of the high speed experiments on the development of special novel ship, the requirement of the high speed towing carriage is continuously increased recently. When the minimum measuring time of the towing experiment is prescribed as five seconds, the carriage should be accelerated with higher than 0.12 g to get the speed of 18 m/sec even in the towing tank having a length of 400m in length approximately. This means that the requirement of acceleration is bigger than twice of the ordinary practices of carriage acceleration. In such a condition the exerted total power of motor could not converted to traction force for the acceleration of the carriage without slip. To over come these difficulties a pair of horizontal traction wheels are reinforced to each of the ordinary vertical carrier wheel and appropriate suspension system has been devised for the towing tank of super high speed operation. It is believed that the design of novel suspension system adaptable for the high speed acceleration of towing carriage will play a important role as a reference for the remodeling of the towing tank for high speed experiment.

• Journal of IKEEE
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• v.18 no.1
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• pp.152-158
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• 2014

It is very important to supply the diesel fuel from fuel tank to combustion chamber in case of cold start procedure. the paraffin hydrocarbons are easily solidified at low fuel temperature and it can be blocking the fuel supply to the high pressure fuel pump. In order to reduce the fuel crystallization (Waxing), it have been used to develop not only cold flow additives but also the proper mounting design of fuel filter. Block heater in the fuel filter assembly have been also contained to improve the cold start and prevent blocking the fuel supply in Common Rail Direct Injection System. we can obtain the fuel pressure drop and fuel flow rate, power consumption of fuel heater to have the cold flow evaluation test with the saperated and composited fuel heater at the low ambient temperature, Due to evaluating cold flow performance of two block heater, we knew that composited package fuel heater was the excellent cold flow performance compared to separated type and obtained the parameters of cold flow.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.161-170
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• 2017

The balise is a device for the railroad signal control systems, which is installed between both rail. The balise sends fixed or variable data, named telegram, to the train with wireless method. The telegram includes the position information, the movable distance under the signal status, the gradient, the speed, the temporary speed limit, etc. This research is on a design of the DBPL encoder for the balise. Normally the DBPL encoder for the balise is with the ASIC or FPGA technology. In this research, the DBPL encoder is designed with commercial low power operable micro-controller. The firmware(logic level encode) and the SPI Bus function block(physical level output) of the micro-controller are used for the DBPL encode. Under the european standard, the required working speed of the DBPL encoder is 564.48Kbps. The DBPL encoder of this research is tested under the speed of 564.48Kbps, and it worked properly.

• Journal of Korea Port Economic Association
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• v.23 no.1
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• pp.95-113
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• 2007

Recently, International institution such as IMO and major maritime countries have introduced various regulations and steps to reduce port pollution. However, recognition of environmental pollution from ports is not sufficient for Korean policy makers and port communities. The purpose of this paper is to examine solutions to port pollution problems and suggests some implications to Korean ports to become a green port. To this aim, necessity of regulation on environmental pollution from port operation; literature survey on port's environmental pollution; current conditions of international port pollution; various regulations and policies governing major ports are conducted in this paper. Our main findings are as follows; first, air pollution from ship can be reduced by providing electric power at docks while at berth, Second, in case of cargo-handling equipment, retire old equipment and switch to cleaner fuel such as low-sulfur fuel and diesel emulsions. Third, offering incentives for the installation of pollution controls and minimizing idling by enforcing idling limits or by installing idle shutoff controls can be recommended for reduction of air pollution of truck and rail at ports.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.9
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• pp.869-874
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• 2011

In a CNG/diesel dual-fuel engine, CNG is used as the main fuel and a small amount of diesel is injected into the cylinder to provide ignition priming. In this study, a remodeling of the existing diesel engine into a CNG/diesel dual-fuel engine is proposed. In this engine, diesel is injected at a high pressure by common rail direct injection (CRDI) and CNG is injected at the intake port for premixing. The CNG/diesel dual-fuel engine had an equally satisfactory coordinate torque and power as the conventional diesel engine. Moreover, the CNG alternation rate is over 89% throughout the operating range of the CNG/diesel dual-fuel engine. PM emission by the dual-fuel engine is 94% lower than that by the diesel engine; however, NOx emission by the dual-fuel engine is higher than that by the diesel engine.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.3
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• pp.189-196
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• 2018

Propeller performance measurement system for high altitude UAV was designed and applied to the wind tunnel test for 2 propeller models with a diameter around 1 m. Mechanical power of the propeller was directly measured by using the torque sensor installed on the rotating axis. The thrust of whole operation body including the propeller was measured by thrust road cell. The guide rail system was suggested to reduce the weight influence of operation body on the thrust road cell. The influence of each measured variables on the aerodynamic coefficients was studied with the repeatability and uncertainty analysis. This analysis result shows that the accuracies of the road cell and the wind velocity were major factors for the thrust coefficient. Propeller performance with typical RPM was measured with various wind speeds and the test results was summarized by performance coefficients for 5 different RPM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1110-1116
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• 2017

Depending on the operating characteristics, track circuit is installed for the purpose of direct or indirect control of the signal device, point switch machine and other security device. These are mainly used for train detection, transmission of information, broken rail detection and transmission of return current. Especially, the return current is related to signal system, power system and catenary line, and track circuit systems. It is one of the most important component shall be dealt for the safety of track side staff and for the protection of railway-related electrical system according to electrification. Therefore, an accurate analysis of the return current is needed to prevent the return current unbalance and the system induced disorder and failure due to an over current condition. Also, if the malfunction occurred by the return current harmonics, it can cause problems including train operation interruption. In this paper, we presented measurement and analysis method at return current and it's harmonics by high speed train operation on the honam high speed line.

• Journal of the Korean Society of Industry Convergence
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• v.17 no.4
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• pp.234-244
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• 2014

Recently it has been focused that the automobile engine has developed in a strong upward tendency for the use of the high viscosity and poorer quality fuels in achieving the high performance, fuel economy, and emission reduction. Therefore it is not easy to solve the problems between low specific fuel consumption and exhaust emission control at motor cars. In this study, it is designed and used the engine test bed which is installed with turbocharger and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and exhaust emission as operating parameters, and they were engine speeds(rpm), injection timing(bTDC), and engine load(%). From the result of an experimental analysis, peak cylinder pressure and the rate of pressure rise were increased, and the location of it was closer toward top dead center according to the increasing of engine speed and load, and with advancing injection timing. The combustion characteristics are effected by fuel injection timing due to be enhanced the mass burned fraction. Using the engine dynamometer for analyzing the engine performance, the engine torque and power have been enhanced according to advancing the fuel injection timing. In analyzing of exhaust emission, there has been a trade-off between PM and NOx with increasing of engine speed and load, and with advanced injection timing. The experimental data are shown that the formation of NOx has increased and PM, vice versa.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.3
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• pp.228-236
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• 2016

Extraordinarily the establishment of towing tank has been initiated after the allocation of space at the basement floor of existing building through remodeling procedure. Therefore the asymmetric tank should be unavoidably determined by compromising with the allowable space and existing building structure. Consequently the shape of towing carriage ought to be selected as a cantilever type to match with the given environmental conditions. Finally the major role of the towing tank has been configured on the fundamental research work for the high speed marine vehicles. Due to the limited length of towing tank, it is appeared that the carriage should accelerated with 1.2m/sec² which is equivalent to twice of the maximum acceleration in ordinary practices on design application of carriage. In such a condition the exerted total power of motor could not be converted to traction force of the carriage without slip for the acceleration. To overcome these difficulties the contact pressure of a horizontal traction wheel to rail has been reinforced by the elastic recovery force of springs on supporting rollers. It is believed that the design experience of the high speed towing carriage under unusual circumferential condition and acceleration barrier could be utilized not only on the design of high speed towing carriage but also on the improvement of existing facilities.