• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.21-26
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• 2013

In recent study, infiltration analysis considering rainfall intensity is more economical and practical than existing analysis method. Revised construction slope design standard is also stated to full-fill infiltration analysis considering rainfall for practical stability review. Infiltration analysis considering rainfall for practical stability review. But, to infiltration analysis, the process is complicated by ground impermeability and rainfall intensity. In this study, we perform infiltration analysis to charge infiltration conditions, soil type and rainfall characteristics, for more pratical stability review. Using the result, we can suggest construable condition on the assumption that soil is saturated up to surface zone.

• Environmental Engineering Research
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• v.25 no.4
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• pp.498-505
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• 2020

This study analyzes the velocity and pressure incurred by protruding shapes installed within the inlet part of a pressurized membrane module during operation to determine the fluid flow distribution. In this paper, to find the flow distribution within a module, it investigates the velocity and pressure values at cross-sectional and outlet planes, and 9 sections classified on outlet plane using computational fluid dynamics. From the Reynolds number (Re), the fluid flow was estimated to be turbulent when the Re exceeded 4,000. In the vertical cross-sectional plane, shape 4 and 6 (round-type protrusion) showed the relatively high velocity of 0.535 m/s and 0.558 m/s, respectively, indicating a uniform flow distribution. From the velocity and pressure at the outlet, shape 4 also displayed a relatively uniform fluid velocity and pressure, indicating that fluid from the inlet rapidly and uniformly reached the outlet, however, from detailed data of velocity, pressure and flowrate obtained from 9 sections at the outlet, shape 6 revealed the low standard deviations for each section. Therefore, shape 6 was deemed to induce the ideal flow, since it maintained a uniform pressure, velocity and flowrate distribution.

• Journal of Korean Society of Rural Planning
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• v.15 no.4
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• pp.135-146
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• 2009

Urban forest area in South Korea has been increased up to 20.8% of national land as of 2007 by the mergence of municipalities and counties. The rate of park and green tract among urban forest averages out to about 4% nationally but the Capital, Seoul, almost 105% level, not easy to split the two. Park and green has positive management system because of its infrastructure attribute and relevant security obligation standard while urban forest left alone with no such concerns. The most important reason of the negligence comes from institutional inertia although it is possible to be managed functionally by forest laws as like forests of park, landscape, wind and noise protection, and timber product. As a results, it reaches below than 92.64% of the national average level of the timber stockpile especially in the metropolitan areas and loses broad acres rapidly due to the easy conversion system to the urban land usage. Therefore, there must be required some alternative methodologies to conserve and foster it. The paper proposes the four urban forest management types and their control methods. The four types divide into conservation, foster, development, and reservation ones. Also it suggests the five furtherance tract types with the combination among the four earlier types, optionally having one of the six aim climaxes and recommends the standardization of operation design. The total green quantity index of urban forest also suggested by the weight method according to location and DBH class. The case study of the suggested model was executed on the Daejon Metropolitan area and its index calculated as 110.4% level compared with the acreage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.370-378
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• 2008

The CEDA(Certified E-Document Authority) is a reliable third party that deposit electronic document having legal effects securely, and verify contents of document or transmission. This paper focuses on a function of secure transmission among several important functions, and implements public key encryption system for secure transmission when server and user communicate for image transmission. This paper follows a standard fundamental rule of X.509 in ITU-T, and it uses symmetric encryption algorithm to raise speed of a large data operation. A key of symmetric encryption algorithm is encrypted by private key in public key system, it protects to be modified using digital signature for data integrity. Also it uses certificates for mutual authentication.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.455-461
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• 2008

Enhanced Distributed Channel Access (EDCA) is a channel access scheme adopted by the IEEE 802.11e draft standard for QoS-enabled wireless local area networks. It classifies traffic into separate Access Categories (ACs) and achieves service differentiation by allowing each AC to have its own values of channel access parameters. This paper proposes a scheme to dynamically adapt the EDCA parameters to traffic environment so that they both maximize the throughput of non real-time traffics and meet the delay and throughput constraints of real-time traffics. For this purpose, we develop a design algorithm for efficient exploration of the EDCA parameter space. Using the algorithm, we derive a Pareto curve fur delay-throughput trade-off in each anticipated traffic environment. The Pareto database can then be used to optimally adjust the parameter according to the traffic environment and administrative policies. Simulation results show that compared with the default parameter configuration, the proposed scheme is better for delay, throughput guarantee and can improve the throughput of non real-time traffics by 12% on average.

• Journal of Fashion Business
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• v.17 no.5
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• pp.14-30
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• 2013

The purpose of this research is to identify the differences in appearance satisfaction, self-esteem and the feeling of happiness according to the demographic variables of teenagers. The conclusion of this research indicate that appearance satisfaction has significant impacts on the self-esteem and the feelings of happiness for adolescence. Teenage students who attend vocational schools get more Allowances than students who attend general high schools, and those who have parents with lower education level also get more Allowances. But the higher the economic standard and grades the students have, the more self-esteem and the feelings of happiness they possess. Thus, the students who attend general high schools have higher self-esteems and feelings of happiness than those in vocational schools. Additionally, the students who have higher economic standards and parents with better'- education levels show more appearance satisfactions for their face, skin and body. Therefore, the level of appearance satisfaction according to the types of school, economic standards, amount of Allowances and parents' education level is an important variable, which can also affect the self-esteem and the feelings of happiness. Teenagers' appearance satisfaction have a significant impact for determining the level of self-esteem and the feeling of happiness.

• Journal of Information Management
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• v.23 no.1
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• pp.1-21
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• 1992

The importance of factual database is becoming larger and larger as the application of computer in design and processing is increasing. To follow up and support this demand and tendency, construction of factual database is necessary. The goal of this research project is to construct a factual database about the creep properties of high temperature materials. A factual database on the creep properties of 25 kinds of high temperature materials was constructed. Domestically produced data which were appeared in journals, theses, reports, etc., were collected and used as a input data source. Evaluation on these collected data will be done during the 2nd year of this project. In addition to this database construction, an experimental facility to produce creep crack propagation data was set up.

• The Journal of the Acoustical Society of Korea
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• v.24 no.4
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• pp.186-193
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• 2005

The Terrestrial Digital Multimedia Broadcasting (T-DMB) system supplies high quality audio comparable with VCD in 7 inch display and high quality audio comparable CD at the mobile reception environment T-DMB will launch commercial service at the middle of 2005. However the bandwidth for audio data and the number of channels are restricted to 128 kbps and 2 respectively in the current T-DMB standard because of the limitation of available bandwidth for multimedia data. This Paper Proposes a novel media processor structure for providing multi-channel audio contents oyer T-DMB system allowing backward compatibility with the legacy T-DMB receiver. Furthermore. we also Propose an adaptive receiver structure to supply optimal audio contents on various speaker configuration in T-DMB receiver. To provide multi-channel audio contents allowing backward comaptilbity with the legacy T-DMB receiver, the additional data for multi-channel audio are defined as a dependent stream of main audio stream. The OD strucure for control an additional multi-channel audio elementary stream is proposed without changing the BIFS of the legacy T-DMB system.

• Journal of the Korea Society of Computer and Information
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• v.10 no.1 s.33
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• pp.73-84
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• 2005

An increasing in quantity of multimedia data brought a new problem that expected data should be retrieved fast and exactly. The adequate representation is a key element for the efficient retrieval For this reason, the MPEG-7 standard was established for description of multimedia contents in 2001. Recently, the new metadata were developed to represent characteristics of movie information resources by Korea Federation of Film Archives. In this paper. we designed and implemented a movie information retrieval system. This system used XML schema to accept movie information metada. This system offers a keyword retrieval using high-level metadata based on movie information and similarity retrieval using low-level metadata based on MPEG-7. As a result, that ill be Possible more efficient movie information interchange . movie information metadata reuse and fast retrieve.

• The Journal of the Acoustical Society of Korea
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• v.18 no.6
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• pp.77-83
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• 1999

H.263 is an international standard of ITU-T that can makes the service such as video phone, video conference in the transmission line less than 64Kbps. This recommendation draft has used motion estimation/compensation, transform coding and quantizing methods. TMN5 used for the performance estimation of H.263 has fundamentally used DCT in transform coding method and presented quantizer for quantizing the DCT transform coefficient. This paper is presenting adaptive quantizer effectively able to quantize DCT coefficient considering the human visual sensitivity while the structure of TMN5 is maintaining. As quantizer that proposed DCT-based H.263 could make transmit more frame than TMN5 in a same transfer speed, it could lower the frame drop effect. And the luminance signal appeared the difference of -0.3 ～ +0.7dB in the average PSNR for the estimation of objective image quality and the chrominance signal appeared the improvement in about 1.5dB in comparision with TMN5. As a result it can attain the better image quality compared to TMN5 in the estimation of subjective image quality.