• KSBB Journal
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• v.11 no.6
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• pp.712-717
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• 1996

Cellulase was modified with synthetic copolymers of polyoxyethylene derivative and maleic acid anhydride. The saccharification characteristics and enzymatic reaction kinetic mechanism of modified and native cellulases were observed. In modification reaction of cellulase, degree of modification(DM) increased, as mass ratio of copolymers to enzyme increased. Maximum DM was 55% at mass ratio of 4 and remained activity was 75%. In saccharification experiment modified enzyme had maintained higher stability than native enzyme over all the reaction and the final conversion yield of modified enzyme was greater than that of native enzyme. Numerical simulation based on the reaction mechanism considering enzymatic deactivation was performed. Modified enzyme had kept higher free enzyme concentration over all the reaction than that of native enzyme. Comparing calculation values with experimental data, calculation values were in accordance with experimental data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6A
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• pp.885-892
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• 2000

A multi-used detector(MUD) using a radial basis function(RBF) network is proposed in a multicarrier-code division multiple access (MC-CDMA) system. In the proposed scheme, a RBF network is connected to the frequency domain in order to effectively utilize the frequency diversity. Simulations have been performed over the frequency selective and multipath fading channel. From these simulations, the proposed receiver is verified to be used for making the performance improvement in combating near-far effects and increasing the number of active users. The system capacity is increaed about 1.8 times at a BER of $10^{-3}$ under a single cell when the proposed scheme is compared with MUD using a parallel interference canceller(PIC).

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.79-82
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• 2012

기존의 서버 전원 모드 제어에는 서버를 Off할 때 정적 종료 방식을 사용하는 관계로 서버가 사용자 요청을 모두 처리하는 최적의 종료 시간을 찾는데 시간이 많이 걸리는 단점을 가진다. 이 시간이 짧게 되면 사용자 QoS를 보장할 수 없고, 반대로 이 시간이 길게 되면 전력 절감을 기대할 수 없다. 본 논문에서는 정적 종료 방식의 단점을 극복하는 동적 종료 방식을 제안한다. 제안된 방식은 최적의 종료 시간을 찾을 필요 없이 각 서버가 사용자의 요청을 모두 처리하였을 때 자동적으로 서버를 Off한다. 제안된 방법은 최적의 시간을 자동적으로 찾아내기 때문에 사용자 QoS를 보장하고, 전력을 절감한다. 실험은 30대의 PC 클러스터를 이용하여 수행되었고, 실험을 통하여 제안하는 동적 종료 방법이 기존의 정적 종료 방법에 비해 운영자의 수고 없이 자동적으로 전력 절감 및 사용자 QoS에 기여함을 확인하였다.

• Journal of Korean Society of societal Security
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• v.1 no.1
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• pp.81-87
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• 2008

The cigarette holds more than 10 percents of the entire fire accidents despite the number of smokers rapidly decreases every year. The purpose of this study is to examine the ignition characteristics of cigarette by experimentation. This study analyzed the cases of fires inferred that they were caused by cigarette in Incheon during 2006. As the representative ignition materials, corrugated board, gasoline, lacquer thinner, tarpaulin, flexible PVC sheet, and poly ethylene were tested. In this experimentation, the corrugated board was ignited by cigarette. However gasoline, lacquer thinner, tarpaulin, flexible PVC sheet, and poly ethylene were seldom ignited. Meanwhile most fire investigators have argued that oils and tents were ignited by cigarette, but this study experimentally proved that such an argument might be ungrounded.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.429-435
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• 1994

The effect of methionine (Met) supplementation on glutathione peroxidase(GSHPx) activity in young and 14 month-old rat and mice was investigated. GSHPx activity was more enhanced by methionine supplementation in young rats when selenium (Se) was given as selenite than given in the form of selenomethione (Se-Met). However, GSHPx activity was not influenced by Met supplementation in the old rats. When diets were low in Se, the biopotency of ht eenzyme by Met was facilitated. No significant differences in GSHPx activity was observed with Met supplement in growing mice when Met was given 0.3% and 0.8% iin the diet at high levels of Se (2 ppm). The peak GSHPx in liver and kidney occurred at day 18, thereafter it decreased. Particularly, the liver GSHPx at day 18 increased 4.2 times than that at day 4 by 0.5% Met supplementation, while the unsupplemented group remained only 2.5 times increase. It is considered that in some tissues Met requirement may be met by Se-Met when rats were fed a diet suboptimal in Met. In addition, at lower levels of Se the utilization of Se is more enhanced by Met than at higher levels of dietary Se. Therefore, GSHPx activity may be influenced greatly by Met status along with dietary Se.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.808-813
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• 2002

This study investigated the effects of different kinds of dietary fibers, cellulose, psyllium husk, pectin and the Psyllium husk Plus Pectin, on the lipid concentration and hernobiochemical enzyme activity in male Sprague-Dawley rats. The experimental groups were divided into four groups : the cellulose group, the psyllium husk group, the pectin group and the psyllium husk Plus Pectin group. Dietary fiber was supplemented at 10% (w/w) levels in the diet. Body weight gain, food intake and relative tissue seight were not significantly different among the dietary groups. Concentrations of triglyceride and phospholipid of serum in the psyllium husk and the pectin groups were significantly lower than those of the cellulose and the psyllium husk plus pectin groups. Concentration of total cholesterol of serum in the psyllium husk plus pectin group was lower than other dietary groups. However, concentrations of triglyceride and phospholipid of liver in the psyllium husk and the pectin groups were significantly higher than those of the cellulose and the psyllium husk plus pectin groups. The hemobiochemical Parameters, total protein, albumin, glutamic pyruvic transaminase, glutamic oxaloacetic transaminase, alkaline phosphatase, lactate dehydrogenase and blood urea nitrogen in serum of the psyllium husk group were lower than other dietary groups. These results showed that dietary psyllium husk could have lowering effects on serum triglyceride concentration without any side effect of hemobiochemical enzyme activity in rats.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.15
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• pp.99-113
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• 1974

This experiment was carried out to find reasonable semi. hot seedbed system for early transplanting of "Tongil"rice cultivar. The quality of the young rice-plants, yield, and the occurrence of the reddish dry leaves were not significant differences between the seedbed with polyethylene tunnel and that of Rat covering. The per cent of healthy seedling of the soil preparation with the dry soil plowing was increased than that of the water soil plowing. The stability of the seedling cultivation of the thin layer straw mulching seedbed beneath the polyethylene film was higher than that of the common flat seedbed system.ed system.

• Journal of The Korean Association For Science Education
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• v.35 no.1
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• pp.27-35
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• 2015

General education is changed by accepting the change in education environment to digital generation, emphasis about student-centered education, and change of teacher's role. E-learning has taken center stage as an effective learning environment but the problems are drawn for the absence of interaction that is important in learning. In this study, on the basis of questionnaire results about learning using website, we operated blended-learning where students come and go in cyberspace and physical space to set up the lesson environment for emphasizing interaction. We selected a control group (N=40) and an experimental group (N=40) from second grade students in a middle school for this research. General instructor-led lessons were implemented in the control group and blended-learning lessons to emphasize interaction between teacher and students were implemented in the experimental group. The experiments were applied to eight class-hours in 'characteristics of matter' unit. We implemented Test of Science Related Attitude (TOSRA) to the students before and after the lessons and administered questionnaire for checking attitude changes and perception in students. The results of the test show that the experimental group students were more encouraged and became more confident and curious about scientific learning than the control group students. The analysis of the interview and results of TOSRA show that blended-learning provided guidance and feedback by the teacher to the experimental group students more than the control group students. Blended-learning is suggested as a learning-method that is helpful in improving scientific attitude in students because it enables them to express their experiences without limit of time-space and promote interaction between teacher and students.

• Journal of Gifted/Talented Education
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• v.19 no.3
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• pp.457-476
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• 2009

The research aimed to investigate characteristics of middle school students in a biology class as science gifted education in terms of self-regulated learning abilities, personality traits and learning preferences. The twenty subject in the study responded to questionnaires of a self-regulated learning ability instrument, a personality trait tool, and a learning preference survey in March, 2009. It was found that the research subjects showed higher levels of cognitive strategies, meta-cognition, and motivation than those students in a previous study(Jung et. al., 2004), while environment was opposite. The level of cognitive strategies was significantly correlated with meta-cognition(r=.610, p=.004) and motivation (r=.538, p=.014) and meta-cognition with environment(r=.717, p=.000). Those students who showed highest levels of self-regulated learning ability displayed various personality traits. One male student with the highest level of self-regulated learning ability showed a personality of hardworking, tender-minded, and conscientious traits and wanted to be a medical doctor. The female student with the second highest level of self-regulated learning ability presented a personality as creative, abstract and divergent thinker and she showed a strong aspiration to be a world-famous biologist with breakthrough contribution. The five students with highest levels of self-regulated learning ability showed a common preference in science learning: they dislike memory-oriented and theory-centered lecture with note-taking from teacher's writings on chalkboard; they prefer science learning with inquiry-oriented laboratory work, discussion among students as well as teachers. However, reasons to prefer discussion were diverse as one student wants to listen other students' opinions while the other student want to present his opinion to other students. The most favorable science teachers appeared to be who ask questions frequently, increase student interests, behave friendly with students, and is a active person. In conclusion, science teaching for the gifted should employ individualized teaching strategies appropriate for individual personality and preferred learning styles as well as meeting with individual interests in science themes.

• KSBB Journal
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• v.15 no.1
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• pp.14-21
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• 2000

In this study, algae cultivation using the photobioreactor has been applied to remove the nitrogen and phosphorus compounds in the wastewater of the livestock industry. The optimal ratio of nitrate and ortho-phosphate concentration was found for the enhancement of removal efficiency. To achieve the high density culture of algae, the photobioreactor consisted of optical fibers wes developed to get the sufficient light intensity. The light could be illuminated uniformly from light source to the entire reactor by the optical fibers. The structured kinetic model was proposed to describe the growth rate, consumption rate of nitrates and ortho-phosphates in algae culture. The self-organizing fuzzy logic controller incorporated with genetic algorithm was constructed to control the semi-continuous wastewater treatment system. The proposed fuzzy logic controller was applied to maintain the nitrated concentration at the given set-point with the control of wastewater feeding rate. The experimental results showed that the self-organizing fuzzy logic controller could keep the nitrate concentration and enhance algae growth.