• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2B
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• pp.130-142
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• 2009

In this paper, we propose a self-adaptation framework that selects a TCP variant adapted to current end-to-end path among available TCP variants. There is no single version of TCP that is suitable to all network environments since the causes for performance degradation are different one another according to characteristics of network environments. Thus, determining that which TCP variants should be selected in order to get best performance is very important. To enable adaptation through such determination, we integrate the existing network estimation schemes and some TCP variants into our framework then make light-weight performance knowledge database for TCP selection. Through implementing and evaluating the proposed framework we show that our solution can help TCP get high and stable performance on the various types of network environments by pure end-to-end.

• Korean Journal of Agricultural Science
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• v.28 no.2
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• pp.147-161
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• 2001

Efficiency and competitive power in agribusiness management has became important issue due to the rapid changes in farming environment under new WTO agreement. To increase competitive power, small-sized petty farm should be restructured to be specialized large-scaled farming system. Trust farming corporation(TFC) has been introduced to increase farm productivity and competitive power through large scale farming system and refined management skills. Eventually, TFCs are expected to revitalize rural economy. TFCs are increasing in numbers, but they are unsatisfactory in quality often with insolvent operations. The typical problems with TFCs are internal conflicts among members, lack of management abilities and incentives, inefficiency in machinery use, and insolvent operations. The self effort by members and legal-institutional assistance can alleviate the negative factors against the rational for cooperative management and sustain TFCs. This study identifies the management problems of TFCs. To provide the methods for increasing management efficiency, improving rational management skills, and hence to help revitalizing the rural economy with competitive power, 20 TFCs in Nonsan County is surveyed. The major findings are as follows; 1) According to the survey result of 20 trust farming corporations, investments on the accumulation of knowledges and information, accounting management, machinery management are required due to the present lack of management/accounting ability. There also exist problems associated with revenue sources, labor uses, and public recognition. To increase management efficiency under current situation, corporations should import active business plans with expanding farming execution and off-farm season business. 2) Based on the result of corporations' business analysis, more than 50% of the corporations were not able to provide profit dividends to the members. It suggests that trust farming corporations need appropriate and stable revenue sources to sustain business. It is also required that corporations should reduce their excessive expenditure on fixed assets. 3) Theoretical amounts of consignment fees for tillage operation, planting, and harvesting were found to be 338,874 won, 216,596 won, and 332,318 won, respectively. Although actual levels of fee are 110%~120% of these theoretical levels of consignment fee, corporations' expected fee levels could not be acheived because of competency of consignment market.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.5
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• pp.429-437
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• 2008

In this study the progressive collapse potential of braced frames were investigated using the nonlinear static and dynamic analyses. All of nine different brace types were considered along with a special moment-resisting frame for comparison. According to the pushdown analysis results, most braced frames designed per current design codes satisfied the design guidelines for progressive collapse initiated by loss of a first story mid-column; however most model structures showed brittle failure mode. This was caused by buckling of columns after compressive braces buckled. Among the braced frames considered, the inverted- V type braced frames showed superior ductile behavior during progressive collapse. The nonlinear dynamic analysis results showed that all the braced frame model structures remained in stable condition after sudden removal of a column, and their deflections were less than that of the moment-resisting frame.

• Journal of Digital Contents Society
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• v.14 no.1
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• pp.65-72
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• 2013

Current and future parallel computing model has been suggested for running and solving large-scale application problems such as climate, bio, cryptology, and astronomy, etc. Parallel computing is a form of computation in which many calculations are carried out simultaneously. And we are able to shorten the execution time of the program, as well as can extend the scale of the problem that can be solved. In this paper, we perform the actual cryptographic algorithms through parallel processing and evaluate its efficiency. Length of the key, which is stable criterion of cryptographic algorithm, judged according to the amount of complete enumeration computation. So we present a detailed procedure of DES key search cryptographic algorithms for executing of enumeration computation in parallel processing environment. And then, we did the simulation through applying to clustering system. As a result, we can measure the safety and solidity of cryptographic algorithm.

• Journal of Digital Convergence
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• v.8 no.2
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• pp.13-28
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• 2010

Korean service industry has been rapidly growing so far and economic trends in korea is shifting to service economy. However Information Communication Technology (ICT) investment and use in service sector are still relatively low in comparison with US. Keeping the current state of the service industry in mind, this paper is to review the potential productivity growth of service industry empirically by analyzing the effect of ICT on total factor productivity after investing the ICT using outlook of Korean service industry. The results show that service sectors, with more using ICT, show high productivity growth and stable TFP change during the financial period. Sectors with lower using ICT are more sensitive to changes in the business environment when compare to sectors with highly using ICT. Concerning the period of 1997-1999, the TFP growth of most of sectors slowed down and turned to recovery immediately afterwards, 2000-2002.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.37.1-37.7
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• 2018

Background: Fibrous dysplasia (FD) is characterized by the replacement of normal bone by abnormal fibro-osseous connective tissue and typically treated with surgical contouring of the dysplastic bone. When dysplastic lesions involve occlusion, not only is surgical debulking needed, orthognathic surgery for correction of dentofacial deformity is mandatory. However, the long-term stability of osteotomized, dysplastic bone segments is a major concern because of insufficient screw-to-bone engagement during surgery and the risk of FD lesion re-growth. Case presentation: This case report reviewed two patients with non-syndromic FD that presented with maxillary occlusal canting and facial asymmetry. Le Fort I osteotomy with recontouring of the dysplastic zygomaticomaxillary region had been performed. The stability of osseous segments were favorable. However, dysplastic, newly formed bone covered the previous plate fixation site and mild bony expansion was observed, which did not influence the facial profile. Including the current cases, 15 cases of orthognathic surgery for FD with dentition have been reported in the literature. Conclusion: The results showed that osteotomy did not appear to significantly reduce the long-term stability of the initial fixation insufficiency of the screw to the dysplastic bone. However, based on our results and those of the others, long-term follow-up and monitoring are needed, even in cases where the osteotomized segment shows stable results.

• East Asian Journal of Business Economics (EAJBE)
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• v.5 no.4
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• pp.1-19
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• 2017

Purpose - The current study attempts to enhance competitiveness by improving Chinese restaurant chefs' work environment and analyzes its effect on work environment and burnout. Also, this study analyzes to see if there is moderation role of enthusiasm between work environment and burnout. Based on analyzation, the present study aims to suggest more effective measure of human resource management by reducing burnout and turnover through providing chefs with more stable and consistent work environment and through their enthusiasm. Research design, data, methodology - Surveys were distributed to chefs working in Chinese restaurant in Seoul and Kyunggi region. Total of 500 surveys were distributed between September 1, 2017 and September 20, 2017 (about 20 days), and 417 surveys were returned to be used in the analysis. Results - As a result of testing effect of chefs' work environment on burnout (1) welfare environment, personal environment, and institution environment had significant effect on loss of accomplishment. (2) welfare, personal, and institution environment had significant effect on deindividuation. (3) welfare environment and institution had significant effect on emotional deprivation while personal environment did not. Second, as a result of analysis on moderation role of obsessive enthusiasm between Chinese restaurant chefs' work environment and burnout (1) as a result of interaction between work environment and loss of accomplishment, personal environment had significant effect while welfare environment and institution environment did not. (2) As a result of interaction between work environment and deindividuation, welfare, personal, and institution environment did not have significant effect. (3) As a result of interaction between work environment and emotional deprivation, institution environment had significant effect while personal environment and welfare environment did not. Conclusions - There is manpower shortage due to poor work environment of Chinese restaurant. Studies that are not limited to work environment are needed to more efficiently utilize human resources.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.6
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• pp.31-38
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• 2009

To improve the image quality and lower the power consumption of the mobile applications, it is the one of the best candidate to control the backlight unit of the LCD module with ambient light. Ambient light sensor and readout circuit were integrated in LCD panel for the mobile applications, and we designed them with LTPS TFT. We proposed noble start-up correction in order to correct the variation of the photo sensors in each panel. We used time-to-digital method for converting photo current to digital data. To effectively merge time-to-digital method with start-up correction, we proposed noble dual slope correction method. The entire readout circuit was designed and estimated with LTPS TFT process. The readout circuit has very simple and stable structure and timing, so it is suitable for LTPS TFT process. The readout circuit can correct the variation of the photo sensors without an additional equipment, and it outputs the 4-levels digital data per decade for input luminance that has a dynamic range of 60dB. The readout rate is 100 times/sec, and the linearity error for digital conversion is less than 18%.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.223-229
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• 2014

The acoustic cleaning system is widely used to remove foreign materials in factories, such as thermal power plants and incinerators. However, the acoustic cleaning systems tend to be clogged by foreign materials. In this paper, we develop a wireless sensor network for the sound wave detection in order to monitor proper operations in the acoustic cleaning systems. We observe that the developed wireless sensor network for the wave detection shows a stable operation in various industrial environments of wide temperature ranges. We also develop a data gathering device, which displays the current status of the sound generator and several values detected from the wireless sensor.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2413-2418
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• 2013

Forensic and legal medicine require reliable data to indicate excessive alcohol consumption. Ethanol is oxidatively metabolized to acetate by alcohol dehydrogenase and non-oxidatively metabolized to ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanol, or fatty acid ethyl esters (FAEE). Oxidative metabolism is too rapid to provide biomarkers for the detection of ethanol ingestion. However, the non-oxidative metabolite EtG is a useful biomarker because it is stable, non-volatile, water soluble, highly sensitive, and is detected in body fluid, hair, and tissues. EtG analysis methods such as mass spectroscopy, chromatography, or enzyme-linked immunosorbent assay techniques are currently in use. We suggest that nuclear magnetic resonance (NMR) spectroscopy could be used to monitor ethanol intake. As with current conventional methods, NMR spectroscopy doesn't require complicated pretreatments or sample separation. This method has the advantages of short acquisition time, simple sample preparation, reproducibility, and accuracy. In addition, all proton-containing compounds can be detected. In this study, we performed $^1H$ NMR analyses of urine to monitor the ethanol and EtG. Urinary samples were collected over time from 5 male volunteers. We confirmed that ethanol and EtG signals could be detected with NMR spectroscopy. Ethanol signals increased immediately upon alcohol intake, but decreased sharply over time. In contrast, EtG signal increased and reached a maximum about 9 h later, after which the EtG signal decreased gradually and remained detectable after 20-25 h. Based on these results, we suggest that $^1H$ NMR spectroscopy may be used to identify ethanol non-oxidative metabolites without the need for sample pretreatment.