• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.19-38
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• 2002

To evaluate the effects of transportation system operation, usually measures of effectiveness(MOE) such as travel time, space mean speed, stop/delay ratio have been used. But, energy consumption as well as the existing MOE in transportation receives more attention as an alternative MOE in transportation operation. The purpose of this study is a development of procedure, which could measure the relative energy consumption for each alternative and compare the results. A mesoscopic simulator called INTEGRATION is used to evaluate the operation of high occupancy vehicle lane, signal optimization, lane expansion, and the application of ITS. Among those, the application of ITS shows the greatest effectiveness in energy reduction, and then lane expansion, signal optimization, and the operation of high occupancy vehicle lane in the order named. Because we don't consider the characteristics of vehicle class, Potential demand and the simulation time is just for an hour. it is recommended that a procedure for precise economic analysis and an improvement in methodology are needed in the future for the expanded application of this study.

• Journal of Hydrogen and New Energy
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• v.28 no.4
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• pp.345-351
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• 2017

Single stage water-gas shift reaction has been carried out at a gas hourly space velocity of $150,494h^{-1}$ over $Cu-Ce_{0.8}Zr_{0.2}O_2$ catalysts prepared by a co-precipitation method. Cu loading was optimized to obtain highly active co-precipitated $Cu-Ce_{0.8}Zr_{0.2}O_2$ catalysts for single stage water-gas shift reaction. 80 wt.% $Cu-Ce_{0.8}Zr_{0.2}O_2$ exhibited the excellent catalytic performance as well as 100% $CO_2$ selectivity (CO conversion = 27% at $240^{\circ}C$ for 50 h). The high activity and stability of 80 wt.% $Cu-Ce_{0.8}Zr_{0.2}O_2$ are correlated to low activation energy and large amount of surface Cu atoms.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.2
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• pp.94-102
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• 2013

In this study, numerical modeling was performed to investigate influence of the apron shape on the discharge performance of the sluice for tidal power plant. The numerical modeling was carried out for comparison of the difference in the discharge coefficient when the apron width, slope, and the length of the horizontal section were different, without considering change in the shape of the sluice caisson itself. The modeling result showed that significant discrepancy in terms of the overall discharge performance appeared according to the apron geometry. In order to achieve maximum discharge performance of the sluice caisson, it is desirable to make the design by putting a space equivalent to the width of the sluice caisson on its both sides, by making the apron slope be 1:5, and by keeping length of the horizontal section to be 50 m that is corresponding to the streamwise length of the sluice caisson.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1729-1735
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• 2009

The hierarchical routing could cause a lot of energy consumption for transferring data by assigning hierarchical routes although actual nodes could be located in physically near spots. Also, when Node Failure or Association Error occurs, the Hierarchical routing could waste more energy to deliver the control messages. This paper evaluate performance of SHP(Shortest Hop Routing) algorithm that suggests short-cut routing algorithm using NL(Neighbor List) and Redirect_ACK message to improve problem of hierarchical routing algorithm. We do a computer simulation by the size of network, deployment of sensor nodes, sink position and POS. As a result of simulation, SHP has better performance than Zigbee Hierarchical routing and HiLow.

• Tunnel and Underground Space
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• v.21 no.4
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• pp.287-296
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• 2011

We performed a numerical modeling study of thermodynamic and multiphase fluid flow processes associated with underground compressed air energy storage (CAES) in a lined rock cavern (LRC). We investigated air tightness performance by calculating air leakage rate of the underground storage cavern with concrete linings at a comparatively shallow depth of 100 m. Our air-mass balance analysis showed that the key parameter to assure the long-term air tightness of such a system was the permeability of both concrete linings and surrounding rock mass. It was noted that concrete linings with a permeability of less than $1.0{\times}10^{-18}\;m^2$ would result in an acceptable air leakage rate of less than 1% with the operational pressure range between 5 and 8 MPa. We also found that air leakage could be effectively prevented and the air tightness performance of underground lined rock cavern is enhanced if the concrete lining is kept at a higher moisture content.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.46-52
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• 2009

Hydrogen can extend the lean misfire limit to a large extent when it is mixed with conventional fuels for an internal combustion engine. This study is about fuel reforming to produce hydrogen enriched gas as a fuel for engine. Especially gasoline, which consists of numerous hydrocarbon fuels, considered as source of reformed gas. Various hydrocarbons, including commercial fuel were reformed and potentialities of reformed gas on vehicles were accessed. The reforming efficiency and hydrogen yield were observed. Maximum hydrogen yield were found with different gas hourly space velocity(GHSV) and O2/C ratio of reforming conditions.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1726-1733
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• 2015

In order to study the effect of the high-altitude and dusty weather in northwest of China on the corona characteristics of transmission lines, a corona caged based experimental system with sandy and dusty flow condition is numerically investigated and designed. This system overcomes the difficulties caused by harsh environment and offers easy usage for off-site tests. The design parameters are mainly determined by the characteristics of strong sandstorm in northwest region and test requirements. By the comparison of numerical simulation of the particle diffusion in four programs with rectangular or circular air-duct, a practical technology, which introduces swirl to control the particle diffusion length, is obtained. Accordingly, the structure of round air-duct with swirl elbow in inlet and outlet of high level segment is selected as final program. Systems of control and measurement are designed at the same time. Field tuning results show that the test system could ensure the range of sandy and dusty coverage. The wind speed, sandy and dusty concentration could be controlled and meet the requirements of accuracy. The experimental system has many features, such as simple structure, easy to be assembled, disassembled, transported and operated, small space occupied.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1996.05a
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• pp.1-10
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• 1996

Factory-style plant production systems of various kinds are the final goal of greenhouse production systems. These systems facilitate planning for constant productivity per unit area and labor under various outside weather conditions, although energy consumption is intensive. Physical environmental control in combination with biological control can replace the use of agricultural chemicals such as insecticides, herbicides and hormones to regulate plants. In this way, closed systems which do not use such agricultural chemicals are ideal for environmental conservation for the future. Nutrient components in plants can be regulafied by physical environmental control including nutrient solution control in hydroponics. Therefore, specific contents of nutrients for particular plants can be listed on the container and be used as the basis of customer choice in the future. Plant production systems can be classified into three types based on the type of lighting: natural lighting, supplemental lighting and completely artificial lighting (Plant Factory). The amount of energy consumption increases in this order, although the degree of weather effects is in the reverse order. In the addition to lighting, factory-style plant production systems consist of mechanized and automated systems for transplanting, environmental control, hydroponics, transporting within the facility, and harvesting. Space farming and development of pharmaceutical in bio-reactors are other applications of these types of plant production systems. Various kinds of state-of-art factory-style plant production systems are discussed in the present paper. These systems are, in general, rather sophisticated and mechaized, and energy consumption is intensive. Factory-style plant production is the final goal of greenhouse production systems and the possibilities for the future are infinte but not clear.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2003.05a
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• pp.413-425
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• 2003

Information Technology is the kernel technology deciding the industrial standard of one nation, and biotechnology will be the main technology of next generation. Based on this fact, a lot of efforts were made to industrialize them. Nano Technology is beginning to position itself as the kernel fusion technology, and its usage and popularity is expanding. Environmental and Energy Technology is a must-have strategic technology considering the increase demand of new energy development, the international environment correspondence, the environment-friendly production, and so forth. Space Technology is the field, which will contribute to raise the domestic component and system technology to the next level. In 2001, new technology research development costs total of 1 trillion 32 billion won in the following fields; 437.82 billion won in IT, 88.457 billion won in BT, 46.799 billion won in NT, 315.682 billion won in ET, and 112 billion won in ST. from component ratio, IT forms 42% which is the most, 31% for ET and in order of BT, ST and NT. ETRI and KISTI are concentrating on IT, KIBB is on BT, KAERI, KIER, KERI and KBSI are focusing on ET, and KIMM, KRISS, KRICT and KORDI is participating together in 4∼5 new technology such as IT, BT, NT and ET. Funds for research development costs in 5 new technology fields of 13 contribution (year) are consisted as follows; The Office for Government Policy Coordination has contributed 131 billion won (13%), 387 billion won (37%) by MOST, 256 billion won (25%) by Ministry of Information and Communication, 67 billion won (6%) by Ministry of Commerce, Industry and Energy, 19% by others and the industrial world. < Strategy for Technology Advancing > o Promotion of comprehensive contributing (year) new technology development research plan project o Increase research efficiency by promoting new technology development project connected with peculiar projects of organization by contribution (year) o Formation of superior research group by technology and introduction of operation system for research accumulation are needed. o Technology demand-oriented assignment deduction and promotion of research development project connected with intermediate long term objective o National will and investment extension of research development costs, training and popularization of professionals, commercialization promotion with efficient control for research plan and result.

• Journal of Korea Multimedia Society
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• v.17 no.3
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• pp.287-293
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• 2014

Early fire detection is very important to avoid loss of lives and material damage. The conventional smoke detector sensors have difficulties in detecting smoke in large outdoor areas. The video-based smoke detection can overcome these drawbacks. This paper proposes a new smoke detection method in video sequences. It uses the ratio of variation rate of subband energy in the wavelet transform domain. In order to reduce the false alarm, candidate smoke blocks are detected by using motion, decrease of chromaticity and the average intensity of block in the YUV color space. Finally, it decides whether the candidate smoke blocks are smokes or not by using their temporal changes of subband energies in the wavelet transform domain. Experimental results show that the proposed method noticeably increases the accuracy of smoke detection and reduces false alarm compared with the conventional smoke detection methods using wavelets.