• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1007-1014
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• 2015

Plectasin, the first defensin extracted from a fungus (the saprophytic ascomycete Pseudoplectania nigrella), is attractive as a prospective antimicrobial agent. The purpose of this study was to establish a bacterium-based production system and evaluate the antimicrobial activity of the resulting plectasin. A gene encoding plectasin, with the codon preference of Escherichia coli, was optimized based on its amino acid sequence, synthesized using genesplicing with overlap extension PCR, and inserted into the expression vector pGEX-4T-1. The fusion protein was expressed in the soluble fraction of E. coli and purified using glutathione Stransferase affinity chromatography. Plectasin was cleaved from the fusion protein with thrombin and purified by ultrafiltration. The purified plectasin showed strong, concentrationdependent antimicrobial activity against gram-positive bacteria, including antibiotic-resistant bacteria, especially penicillin-resistant Enterococcus faecium. This antimicrobial activity was equal to chemically synthesized plectasin and was maintained over a wide range of pH and temperatures. This soluble recombinant expression system in E. coli is effective for producing plectasin at a relatively lower cost, and higher purity and efficiency than prior systems, and might provide a foundation for developing a large-scale production system. Overall, plectasin shows potential as a novel, high-performance, and safe antibiotic for the treatment of refractory diseases caused by drug-resistant bacterial strains.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.9_10
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• pp.466-475
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• 2008

Owing to the improved wireless communication technologies, it is possible to provide streaming service of multimedia with PDAs and mobile phones in addition to desktop PCs. Since mobile client devices have low computing power and low network bandwidth due to wireless network, the transcoding technology to adapt media for mobile client devices considering their characteristics is necessary. Transcoding servers transcode the source media to the target media within corresponding grades and provide QoS in real-time. In particular, an effective load balancing policy for transcoding servers is inevitable to support QoS for large scale mobile users. In this paper, the transcoding load estimation algorithm is proposed for load balance on the distributed transcoding environments. The proposed algorithm estimates transcoding time from transcoding server information, movie information and target transcoding bit-rate. The estimated transcoding time is proved based on experiments.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.3
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• pp.277-286
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• 2000

Switch-based network is suitable for the environment of demanding high performance network. Traditional shared-medium Local Area Networks(LANs) do not provide sufficient throughput and latency. Specially, communication performance is more important with multimedia application. In these environments, switch-based network results in high performance. A kind of switch-based network provides higher bandwidth and low latency. Thus high-speed switch is essential to build switch-based LANs. An effective switch design is the most important factor of the switch-based network performance, and is required for the multicast message processing. In the previous cut-through switching technique, switch element reconfiguration has the capability of multicasting and deadlock-free. However, it has problems of low throughput as well as large scale of switch. Therfore, effective multicating can be implemented by using divided hardware unicast and multicast. The objective of this thesis is to suggest switch configuration with these features.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.573-580
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• 2020

Hydrogen emerged as a sustainable transport energy source. To increase hydrogen utilization, hydrogen refueling stations must be available in many places. However, this requires large-scale financial investment. This paper proposed a methodology for selecting the optimal location to maximize the use of hydrogen charging stations. The location of gas stations and natural gas charging stations, which are competing energy sources, was first considered, and the expected charging demand of hydrogen cars was calculated by further reflecting data such as population, number of registered vehicles, etc. Using k-medoids clustering, one of the machine learning techniques, the optimal location of hydrogen charging stations to meet demand was calculated. The applicability of the proposed method was illustrated in a numerical case of Seoul. Data-based methods, such as this methodology, could contribute to constructing efficient hydrogen economic systems by increasing the speed of hydrogen distribution in the future.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.133-144
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• 1998

International capital movement has made progress at global liberalization of finance and foreign exchange, international monetary norm changing into floating exchange rate system, easiness of collection of information and trade at improvement of information communication technology from early of 1970's. Results of empirical test for relation between foreign exchange rate or various determination factors of foreign exchange rate and interest rate are followed by next sentences. First, according to relation between foreign exchange rate and interest rate, correlation for each of variables after OECD entrance is increased. But, long-term & short-term interest rate is affected by Hanbo & Kia's bankruptcy, continuous large scale corporates bankruptcy and crisis of foreign exchange. Therefore, financial instability is occured. If portfolio investment fund has been inflow as it is mollified by continuous shortage of foreign exchange and fall of country's credit rating, it is expected to have positive effect for long-term & short-term interest rate from appreciation of won against dollar. Second, results from relation between determination factor of foreign exchange rate and interest rate are followed by next sentences. If surplus of current account and goods account is continued, yield of corporate bond is to be stable. But, margin of surplus is expected to diminish after second quarter 98, and difference between external and domestic interest (after adjusting foreign exchange rate) is to be diminished. And if net inflows of foreign investor's fund (stock and bond) is diminished, it is to have negative effect for yield of corporate bond. According to foreign investor's investment movement of previous years, hedge fund were stayed at least during two years in Mexico. It means that sudden capital outflow is not to be happened at Korea. But if external factors from depreciation of yen and China's renminbi are instable, interest rate is expected to increase from capital's outflows. Third, if it is to decrease instability of foreign exchange rate from increase in surplus of future current account, credit rating's upwardness, stability of yen and renminbi, foreign exchange rate is expected to be stable. It is expected to have continuous stability from short-term interest rate to long-term interest rate in this empirical test.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.1
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• pp.1-10
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• 2018

Recently, interest in the development of alternative water resources has been increasing rapidly due to environmental pollution and depletion of water resources. In particular, seawater desalination has been attracting the most attention as alternative water resources. As seawater desalination consumes a large amount of energy due to high operating pressure, many researches have been conducted to improve energy efficiency such as energy recovery device (ERD). Consequently, this study aims to compare the energy efficiency of RO process according to ERD of isobaric type which is applied in scientific control pilot plant process of each $100m^3/day$ scale based on actual RO product water. As a result, it was confirmed that efficiency, mixing rate, and permeate conductivity were different depending on the size of the apparatus even though the same principle of the ERD was applied. It is believed that this is caused by the difference in cross-sectional area of the contacted portion for pressure transfer inside the ERD. Therefore, further study is needed to confirm the optimum conditions what is applicable to the actual process considering the correlation with other factors as well as the factors obtained from the previous experiments.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.5
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• pp.55-66
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• 2010

As people's living standards and expectations for life increase, by applying advanced technology in the city, to enhance the convenience and safety needs are being expanded gradually. Accordingly, so the future of the city to see a viable alternative to that the ubiquitous city fused information communication technologies, large-scale projects conducted at the national level. Sectoral Disaster Prevention is ready for sure how much the lack of response capabilities in the field for checking solution has been suggested for The National Emergency Management Agency. These results present a Sectoral Disaster Prevention response capabilities somewhat different in were identified. Through these are proposed policy recommendations about Sectoral Disaster Prevention and insufficient areas of step response capabilities and building fire protection system approach combines ubiquitous technology in the new paradigm rather than traditional disaster management, greet era of ubiquitous.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.245-251
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• 2009

Without pesticide applications, mass-trapping by sex pheromone was successful to control Spodoptera litura (Fabricius) in a large scale tomato glasshouse (10,000 $m^2$) at a low cost of 60 won/$m^2$. Pheromone traps were placed both inside and outside of the glasshouse. Inside the glasshouse traps were installed in a regular space, one trap per 500 $m^2$, to catch the moths that were present in the glasshouse, and traps were also set outside of the glasshouse, at intervals of ca. 20 m, to prevent the moths from invading the glasshouse. In the experiment, more than 400 S. litura were captured per trap.

• Journal of Digital Contents Society
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• v.18 no.7
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• pp.1419-1425
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• 2017

The ultimate goal of legal knowledge search is to obtain optimal legal information based on laws and precedent. Text mining research is actively being undertaken to meet the needs of efficient retrieval from large scale data. A typical method is to use a word embedding algorithm based on Neural Net. This paper demonstrates how to search relevant information, applying Korean law information to word embedding. First, we extracts reference laws from precedents in order and takes reference laws as input of Law2Vec. The model learns a law by predicting its surrounding context law. The algorithm then moves over each law in the corpus and repeats the training step. After the training finished, we could infer the relationship between the laws via the embedding method. The search performance was evaluated based on precision and the recall rate which are computed from how closely the results are associated to the search terms. The test result proved that what this paper proposes is much more useful compared to existing systems utilizing only keyword search when it comes to extracting related laws.

• Korean Journal of Occupational Health Nursing
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• v.9 no.2
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• pp.86-93
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• 2000

This study was conducted to find out the degree of tiredness, accumulated tendencies of fatigues in accordance with 3 types of circadian rhythms and 3 types of perceived fatigue signs such as physical, psychological and neurosensory aspects in before and after work at night. Samples were chosen from the 217 intensive care units nurses working in 13 general hospitals which had 3 shift rotating systems, Data were collected from November to December in 1999. Two hundreds seventeen respondents were classified by 3 circadian types such as 59 morning, 110 middle and 48 evening. Circadian type was measured by the circadian type scale which was designed by ${\ddot{O}}stberg$ and Home (1976). in order to estimate the level of tiredness, the investigator used the fatigue checklist designed by the Labor and Health Institute of Japan(1970). Analysis was done by frequency a percentages, ${\chi}^2$ test and repeated measures ANOVA test. The result of this study were as follow: 1. In the general characteristics of the subjects circadian types, moderate type had the large proportion at 50.7% and morning type had 27.2% and evening type had 22.1%. 2. According to the 3 types of fatigue signs, the highest general tendency was 'General weakness' and 'Feeling of headsore' for physically perceived sign, 'Drowsiness' for psychological sign, and 'Uncomfortableness in sight seeing' for neurosensory sign. 3. The most frequently complained fatigue were observed in physical symptoms among physical, mental, and neurosensual symptoms. The percentage of complained was higher after night work than before the work started. 4. There was not any statistical significant difference between the circadian type and the degree of physical, mental, neurosensory fatigue. 5. There was not any statistical significant difference in regarding to each date of night shift except difference between 1st and 2nd days of fatigue perceived physically. Therefore, the study concluded that the fatigue perceived by night shift nurses might be related with shift working condition rather than circadian types.