• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.85-92
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• 2010

There is an authentication method for participants with an encrypted ID and password as a symmetric-key in multilateral video conferencing. It is hard to manage when the security-keys makes many while the transportation processing for the encryption and decryption get complicated when the video conferencing involves a number of participants and the third party as an attackers to gain unauthorized symmetric-key to access video conference which makes a problem less secrecy. This study suggests three ways to enhance security in video conference: first, we present PKI-based X.509 certificate for authenticating the participants of multilateral conferencing and we suggest to encode and decode the video conference media data using a secrecy key created by each of the conference participants; second, a more secured multilateral video conferencing can be expected in a group communication by using the participants secrecy key in creating and distributing group keys, where the group key will be renewed whenever there is change in the group member; and finally, we suggest to encode the RTP payload of the media data before transmission.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1113-1119
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• 2006

For a multi-user OFDM system in mobile channels which requires low-complexity in adaptive resource allocations, resource allocation algorithm using multi-threshold is proposed. The allocation scheme, which is performed by the multi-threshold values in descending order, considers only subcarriers over each threshold level. Moreover, some subcarriers with the lowest channel gain can be· removed in the present threshold level within the constraint of satisfaction of the required data rate, in order to allocate them to the other users when the allocation process of next threshold is executed. As a result, the proposed bandwidth and subcarrier algorithm has better system performances than the conventional allocation schemes in terms of required power and processing time, which is expected as a technique that improves the spectral efficiency of OFDM systems in a mobile environment.

• The KIPS Transactions:PartD
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• v.13D no.3 s.106
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• pp.325-336
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• 2006

For supporting LBS service, recent studies on spatial network databases (SNDB) have been done actively. In order to gain good performance on query processing in SNDB, we, in this paper. design efficient storage and index structures for spatial network data, point of interests (POIs), and moving objects on spatial networks. First, we design a spatial network file organization for maintaining the spatial network data itself consisting of both node and edges. Secondly, we design a POI storage and index structure which is used for gaining fast accesses to POIs, like restaurant, hotel, and gas station. Thirdly, we design a signature-based storage and index structure for efficiently maintaining past, current, and expected future trajectory information of moving objects. Finally, we show that the storage and index structures designed in this paper outperform the existing storage structures for spatial networks as well as the conventional trajectory index structures for moving objects.

• Journal of the Korean Applied Science and Technology
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• v.4 no.1
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• pp.91-97
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• 1987

Because of its more complete hydrolysis and rapid absorption, MCT is expected its usefulness in the diets of patients with malabsorption syndrom. Also, several authors reported that serum cholesterol level was lower after MCT feedings. In this study, rate of each experimental group were fed for 4weeks with 20％ MCT, 20％ corn oil, mixed diet of 10％ MCT and 10％ corn oil, mixed diet of 17％ corn oil and 3％ shortening. After experimental diet, it was measured to growth rate and serum cholesterol, triglyceride and phospholipid level. The results were as follows; 1. The body weight gain was the lowest in MCT group and others were lower than control group. 2. Serum total cholesterol level was the lowest in corn oil group and others were significantly lower than control group. Free cholesterol level was lower in all experimental groups than control group too. 3. Serum HDL-cholesterol level was significantly higher in all experimental groups than control group. 4. The ratio of VLDL, LDL-Cholesterol to HDL-Cholesterol was significantly lower in all experimental groups than control group. 5. Serum triglyceride level was higher in all experimental groups than control group. Serum phospholipid level was significantly in only mixed diet group of corn oil and shortening than control group. 6. The ratio of total cholesterol to phospholipid was significantly lower in corn oil diet group than control group.

• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.143-152
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• 2019

In this study, the author seeks to identify the status of the online job information service market and present strategic guidelines to maintain the market ecosystem based on it. The research method was carried out as a descriptive study to identify the online job information service market by utilizing various secondary data. Specifically, the market analysis identified the high potential growth rate of the job information service market and key issues. Industry trend analysis analyzed key service features, job seeker types and features, service use trends, promotion and marketing methods. Finally, through SWOT analysis of the market, strategic guidelines were proposed to lead the market ecosystem into a virtuous circle. In the first place, these findings will help us gain a comprehensive view of the market by identifying the status of the job information service market with a focus on the main issues. It may also provide companies in the industry with the necessary clues to their continued survival within the industry. Furthermore, the government and public organizations are expected to contribute to boosting the job information service market with the aim of creating and improving jobs.

• Smart Structures and Systems
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• v.2 no.2
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• pp.115-126
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• 2006

The Terra-Scope system is an affordable 4-D down-hole seismic monitoring system based on independent, microprocessor-controlled sensor Pods. The Pods are nominally 50 mm in diameter, and about 120 mm long. They are expected to cost approximately $6000 each. An internal 16-bit, extremely low power MCU controls all aspects of instrumentation, eight programmable gain amplifiers, and local signal storage. Each Pod measures 3-D acceleration, tilt, azimuth, temperature, and other parametric variables such as pore water pressure and pH. Each Pod communicates over a standard digital bus (RS-485) through a completely web-based GUI interface, and has a power consumption of less than 400 mW. Three-dimensional acceleration is measured by pure digital force-balance MEMS-based accelerometers. These accelerometers have a dynamic range of more than 115 dB and a frequency response from DC to 1000 Hz with a noise floor of less than $30ng_{rms}/{\surd}Hz$. Accelerations above 0.2 g are measured by a second set of MEMS-based accelerometers, giving a full 160 dB dynamic range. This paper describes the system design and the cooperative shared-time scheduler implemented for this project. Restraints accounted for include multiple data streams, integration of multiple free agents, interaction with the asynchronous world, and hardened time stamping of accelerometer data. The prototype of the device is currently undergoing evaluation. The first array will be installed in the spring of 2006.

• Journal of Convergence for Information Technology
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• v.7 no.2
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• pp.137-142
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• 2017

The purpose of this study tried theoretical review on the current Transfer Income Tax system, and review on current Korean Transfer Income Tax system, to derive the inherent problems in Korean Transfer Income Tax system. This study presents the improving measures thereto.The transfer income earned by any individual person is taxed as the Transfer Income Tax pursuant to the Income Tax Act, and the transfer income earned by any legal person is taxed as the transfer income on transfer gain on land etc, pursuant to the Corporate Tax Act. In case of the Transfer Income Taxes earned by individual persons, land and buildings comprise most of the taxable items of the Transfer Income Tax. This study limits the scope of study to the Transfer Income Tax on land and building as the major taxable item, rather than all the Transfer Income Tax taxed to individual taxpayers. The outcomes of this are expected to rationly improvement the real estate taxation in accordance with the principle of tax law.

• Journal of Korean Society for Quality Management
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• v.49 no.3
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• pp.433-446
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• 2021

Purpose: The main purpose of this study is to analyze the case of the transparent PET bottle resource circulation project of BYN Black Yak Co., Ltd., present implications, and propose ways to spread it in the future. Methods: In this study, the logic of the Double Diamond Model is applied to analyze the development process of sustainable fashion made from BYN Black Yak Co., Ltd.'s PET Bottle Resource Circulation System. Results: The K-rPET Resource Circulation Project of BYN Black Yak Co., Ltd. is recognized as a best example for its contribution to eco-friendly activities, solving social problems, raising consumer awareness, and sharing recycling habits. Before the plastic bottle becomes a garment, five steps are taken (discharge of PET bottle → collection of PET bottle → recycling of PET bottle → fabrication of yarn → production of the finished product out of the fabric). BYN Black Yak Co., Ltd. has successfully commercialized it by recycling reverse-recovery PET bottles by making solutions to problems that have not been solved at each stage. Conclusion: In addition to efforts to find and strengthen weak links presented in the Theory of Constrains (TOC), it appears to have systematically carried out activities to convert stakeholder discomforts into a package of gain points. As shown in the slogan "We are all in!" the proposal and implementation for the completion of a true environmental system is judged to have truly performed ESG management well for the company's business. ESG management activities at BYN Black Yak Co., Ltd. are expected to continue.

• The Korean Journal of Food And Nutrition
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• v.34 no.5
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• pp.526-536
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• 2021

This study was conducted to investigate the anti-obesity effect of Discorea Japonica Thunb. fermented with Monascus After inducing obesity by feeding hight fat diet (diet induced obesity model: DIO) for four weeks, each 8 rats were assigned to normal (Nor), high fat diet (HF), high fat diet containing orlistat (PC), high fat diet containing different concentration of Discorea Japonica Thunb. fermented with Monascus (UPDM_L, UPDM_H) and Discorea Japonica Thunb. (UPD) extract. Although the UPD, UPDM_L (ultrafine pulverized Discorea Japonica Thunb. fermented with Monascus: 400 mg/kg) and UPDM_H (DIO oral administration ultrafine pulverized Discorea Japonica Thunb. fermented with Monascus: 800 mg/kg) showed weight gain inhibition effects, the results of poor obesity inhibition rather than PC were confirmed. However, it showed a more effective weight loss effect in UPDM_H than UPD, and significantly reduced the weight of epididymal fat and subcutaneous fat. Furthermore, the possibility of anti-obesity effects of Discorea Japonica Thunb. fermented with Monascus can be confirmed by observing the effects of reducing serum total cholesterol, triglyceride and LDL concentrations, reducing ALT and AST levels, and inhibiting fat build-up in liver tissue. It is believed that Discorea Japonica Thunb. fermented with Monascus can be expected to utilize as a functional material that is important to improve anti-obesity and metabolic syndrome.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.390-396
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• 2021

In this research, design and fabrication of marine repeater capable to extend communication coverage in monitoring system of fishing gear automatic identification, which is one of implementation method of the real-name electric fishing gear system declared by Ministry of Oceans and Fisheries in 2016, is reported. The proposed marine repeater is fabricated in a form of RF repeater with interference cancellation system (ICS), which can cancel the oscillation due to feedback signal between service antenna and link antenna. In design process, we secure the isolation of 30 dB between service antenna and link antenna. It is confirmed that when the level of feedback signal into repeater input be lower of 15 dB than repeater gain, error vector magnitude due to oscillation can be lower than the performance criterion of 6%, from the test verification. It is expected that the service coverage will be extended by applying the developed marine ICS RF repeater into marine IoT network including monitoring system of fishing gear automatic identification.