• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.21-26
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• 2005

Two-dimensional (2-D) inversion of magnetotelluric (MT) data for two survey lines having south-north direction from Jeiu Island has been carried out. The 2-D models show a thick layer having around 10 ohm-m in the depth of a few hundred meters throughout the survey area, which can be considered as the unconsolidated sedimentary layer. And they also show a conductive anomaly at the central part of each survey lines. But unfortunately by now, we do not have any further information about the anomaly. Comparison of the 2-D inversion model using MT band only and that using both AMT and MT bands said that it is helpful for us to include AMT band as well as MT band in the inversion to interpret not only the shallow part but also the deep structures.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.11
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• pp.974-980
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• 2014

A power supply of cathode has been developed for hall-effect thruster for small satellite. A microwave cathode has been applied to the electric propulsion system and cathode power is necessary in oder to work securely. Anode current is varied by a flow rate controlled by anode tank pressure. Then cathode current has to be controled in proportion by anode current. So cathode power supply has been designed to offer a current proportional to anode current. Also cathode power has been tuned to work securely for cathode to emit more electron than anode within 0.03A. The function test of cathode power was performed by constructing an equivalent load for anode and cathode. It has been tested in a vacuum chamber in order to ensure a stable operation of the thruster. And it was confirmed that thruster normally has been operated in the space environment after the launch.

• Journal of the Korean housing association
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• v.26 no.6
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• pp.17-25
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• 2015

Since 1997, Dr. Shin-ya Nishimura has been developing an actual town planning project named the "Gangi Project". Students, inhabitants and local professionals walk around Omotemachi, examine the characteristics of the environment and the inhabitants' way of life, discuss plans and designs for traditional wooden arcades called locally "gangi". Students and inhabitants build the gangi together every year. The purpose of this study is to clarify how an experimental project aiming to preserve a living environment obtains sustainability as an actual town planning exercise. The research hypothesizes that sustainable town planning should include strategies for financial autonomy, active participation of inhabitants, supports from local professionals, an acceptance of changing environments, and responsible construction. The project has been carried out as a part of actual town planning, and continues to create a daily living environment based on the recent economical and industrial situation of the town. By focusing on the influences of the project on the town and inhabitants, the study has revealed the possibility of an actual town planning with small budget, and importance of a collaborative relationship with various participants in order to foster a sense of responsibility regarding the construction. The project also highlights the implication that sustainable town planning creates not only a participatory system but also a collaborative one in which participants take responsibility for the issues involved in the construction process.

• Journal of the Korean GEO-environmental Society
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• v.9 no.7
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• pp.13-23
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• 2008

In this study, the centrifuge tests and numerical analyses were performed to investigate the lateral flow behavior and stability of abutment when high filling was applied on the soft ground improved by SCP. The centrifuge model tests and numerical analyses were fulfilled in the case of the back of abutment filled by EPS (case 1) and soil (case 2), and the potentiometer was installed on the abutment and fill to measure the vertical and horizontal displacement at the top of abutment. As a result of the centrifugal tests, the horizontal displacement of abutment in the case 1 was 1.4cm that is almost coincide with the results of numerical and satisfy the allowable standard. On the other hand, the horizontal displacement of abutment in the case 2 was 12 cm that is 18% greater than that of numerical analysis and exceed the allowable standard. As a result of analysis, the maximum horizontal displacement of pile was 1.26 cm in case 1 that satisfies the criterion of allowable horizontal displacement (1.5 cm). In contrast, the maximum horizontal displacement of pile was 1.005 m in case 2 that greatly exceeds the allowable horizontal displacement.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.161-169
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• 2018

This study presents a time synchronization system in decentralized structure by using the blockchain, a core technology of Bitcoin introduced by Satoshi Nakamoto in 2008. In this study, Getting away from existing time synchronization system in centralized structure, A blockchain network has completely decentralized structure using public blockchain. In decentralized structure, Only certain peers among the peers that participate in a blockchain network access the NTP server. Therefore, others can synchronize time without having to go to public network. Furthermore if appropriate time synchronization cycles are established for each peer, time synchronization can be maintained even when connection to public network is completely lost. A time synchronization system in this study has advantages of p2p system and can be also guaranteed reliability and stability because it used digital signature, merkle tree, consensus algorithm which are core characteristics of block chains.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.350-356
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• 2020

This study was conducted to investigate the antioxidant compounds and activities of Prunus yedoensis Matsumura bark (PYMB) ethanol extracts (EE) and various other fractions. Among them, the highest total phenol content was 496.80 mg gallic acid equivalent/g in the ethyl acetate fractions (EAF). The flavonoid contents were 7.26-265.52 rutin equivalent mg/g, with the EAF showing the highest levels. The highest proanthocyanidin content was determined to be 326.31 catechin equivalent mg/g in the EAF and the remaining values in descending order were as follows: n-butanol, ethanol, dichloromethane, water, and n-hexane. EAF exhibited the highest DPPH, ABTS⁺, superoxide^- radical scavenging activities, and reducing power, whereas the nitrite scavenging activities were the highest in the case of the EE. The n-hexane and water fraction antioxidant compounds and activities were lower than those of the other fractions. In summary, these results suggest that the PYMB EAF is a potential source of natural antioxidants.

• Journal of Internet Computing and Services
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• v.11 no.2
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• pp.49-60
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• 2010

H.264/AVC offers a better encoding efficiency than conventional video standards by adopting many new encoding techniques. However, the advanced coding techniques also add to the overall complexity for H.264/AVC encoder. Accordingly, it is necessary to perform optimization to alleviate the level of complexity for the video encoder. The amount of computation for motion estimation is of particular importance. In this paper, we propose a diamond web-grid search algorithm combined with efficient stationary block skip method which employs full diamond and dodecagon search patterns, and the variable thresholds are used for performing an effective skip of stationary blocks. The experimental results indicate that the proposed technique reduces the computations of the unsymmetrical-cross multi-hexagon-grid search algorithm by up to 12% while maintaining a similar PSNR performance.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.85-94
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• 2004

In the companion paper, a constitutive model was proposed in order to represent brittleness and dilatancy for cohesionless soils. An optimized design methodology was proposed on the basis of real-coded genetic algorithm in order to determine parameters fir the proposed model systematically. The material parameters were then determined by that algorithm. In order to verify the proposed model, triaxial tests were peformed under $K_0$ conditions for weathered soils. In addition, the results of istropic compressed triaxial tests for granular materials verified the proposed model. For those results the brittle stress-strain relationship and the dilatancy could be modeled reasonably by the proposed model. As a result it was found that the proposed model can appropriately represent the behavior on weathered soil and granular soil.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.501-510
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• 1992

Lipid prooxidants in sardine skin was characterized. Prooxidants in the sardine skin extract with 0.05M phosphate buffer was purified by successive chromatography on Sephadex G-200, DEAE-Sephadex A-50 and CM-Sephadex A-50. Prooxidants of sardine skin exist mainly in the intermediate molecular weight fractions. Observations of the thermounstability and optimum pH(pH 7.0) suggest that the major prooxidants are enzymes and hemoproteins. They can oxidize well both free and esterified linoleic acid and form conjugated hydroperoxides. From these results, the major prooxidants in sardine skin are assumed to be lipoxygenase-like enzymes.

• The Journal of the Korea Contents Association
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• v.8 no.5
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• pp.237-245
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• 2008

Characteristics of Japanese public library recently has been changed to mutual networking between libraries, complex use of data, and long stay of users. Such change requires new service and contents. Also, in Korea, it is circumstance that interest of library's contents rise politically. And under government leading by BTL project, various libraries are increasing all over the country fast such as public library, extension of existing school library and the small library, etc. In this research, space composition of library, automatic check-out & bookshelf system, and mutual networking between libraries was analyzed by selected 3 libraries (central library of Chiba city, Tomisato and Ichigawa city library) of Chiba area and find applicable contents to our library system.