• E2M - 전기 전자와 첨단 소재
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• 제7권1호
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• pp.32-41
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• 1994

In this study, the TSC spectroscopy has been applied to investigate the influence of structural change due to a process of curing reaction on the electrical properties of epoxy composites cured with acid-anhydride. Five TSC peaks appeared in -160-250[.deg.C]: in the low temperature region below glass transition temperature(T$\_$g/), three relaxation mode peaks due to action of side chains, substitution group or terminal groups have been observed, a peak associated with T$\_$g/, appeared in 110[.deg. C] and p peak due to ionic space charges located in 150[.deg.C]. Each peak was separated into elementary peaks by the partial polarization procedure, and the distribution of activation energy and relaxation time were analized to clearify the origin of each peak. Also, overaboundantly added hardener separated a .betha. peak near 10[.deg. C] into two peaks of .betha.$\_$1/(10.deg. C) and .betha.$\_$2/(20.deg. C) according to increasement of forming field, and the separated hardener was oxidated thermally with increasing surrounding temperatures. The expansion of the free volume need in molecular motion and the reduction of the structural packing density through thermal oxidation process increased TSC between .alpha. peak and .betha. peak and decreased T$\_$g/.

• E2M - 전기 전자와 첨단 소재
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• 제9권4호
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• pp.396-403
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• 1996

In this paper, the (S $r_{0.85}$.C $a_{0.15}$)Ti $O_{3}$ of paraelectric grain boundary layer (GBL) ceramics were fabricated, and the analysis of microstructuye and the thermally stimulated current(TSC) were investigated for understanding effects of GBL's interfacial phenomenon on variations of electrical properties. As a result, the three peaks of .alpha., .alpha. and .betha. were obtained at the temperature of -20 [.deg. C], 20[.deg. C] and 80[.deg. C], respectively. The origins of these peaks are that the .alpha. peak observed at -20[.deg. C] looks like to be ascribed to the ionization excitation from donor level in the grain, and the .alpha.' peak observed at 20[.deg. C] appears to show up by detrap of the trapped carrier of border between the oxidation layer and the grain, and the .betha. peak observed at 80[.deg. C] seems to be resulted from hopping conduction of existing carrier in the trap site of the border between the oxidation and second phase. and second phase.

• 한국운동역학회지
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• 제14권1호
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• pp.1-12
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• 2004

The purpose of this study is to provide training materials for practical use by investigating the kinematical variables of the successful landing by the type of the salto backward such as Tuck, Pike. For this study, the subjects are 4 male national gymnasts using 3-dimensional cinematographic method. Based on the results of this study, the conclusions are drawn as follows. 1. In flight phase, Tuck and Pike show fast extension after completing minimum angle of hip joint passing through the peak. It is very important factor to control body with gaining time before landing while decreasing the velocity of flight rotaion. 2. In Landing phase, the angles of each joint for successful landing are shown as $92deg{\sim}100deg$ for knee angle, $52deg{\sim}57deg$ for hip angle, and $56deg{\sim}70deg$ for shoulder angle. 3. Tuck and Pike dramatically decrease the height of COG, and horizontal/vertical velocity of COG from TD to LD. Also, it is shown that the knee angle, the hip angle and the shoulder angle decrease drastically. On the other hand, the angular velocity of trunk rotation shows negative direction and due to this, the angle of trunk rotation is shown as re-flexion.

• BMB Reports
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• 제38권3호
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• pp.266-274
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• 2005

High temperature requirement A (HtrA) and its homologues constitute the HtrA familiy proteins, a group of heat shock-induced serine proteases. Bacterial HtrA proteins perform crucial functions with regard to protein quality control in the periplasmic space, functioning as both molecular chaperones and proteases. In contrast to other bacterial quality control proteins, including ClpXP, ClpAP, and HslUV, HtrA proteins contain no regulatory components or ATP binding domains. Thus, they are commonly referred to as ATP-independent chaperone proteases. Whereas the function of ATP-dependent chaperone-proteases is regulated by ATP hydrolysis, HtrA exhibits a PDZ domain and a temperature-dependent switch mechanism, which effects the change in its function from molecular chaperone to protease. This mechanism is also related to substrate recognition and the fine control of its function. Structural and biochemical analyses of the three HtrA proteins, DegP, DegQ, and DegS, have provided us with clues as to the functional regulation of HtrA proteins, as well as their roles in protein quality control at atomic scales. The objective of this brief review is to discuss some of the recent studies which have been conducted regarding the structure and function of these HtrA proteins, and to compare their roles in the context of protein quality control.

• E2M - 전기 전자와 첨단 소재
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• 제10권2호
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• pp.97-104
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• 1997

In this paper, in order to investigate the behavior of charged particles on (Sr.Ca)TiO$_{3}$ ceramics with paraelectric properties, the characteristics of electrical conduction and thermally stimulated current was measured respectively. As a result, the conduction mechanism is divided into three regions having different mechanism as the current increased. The region I below 200[V/Cm] shows the ohmic conduction. The region B between 200[V/cm] and 2000[V/cm] can be explained by the Poole-Frenkel emission theory, and the region III above 2000[V/cm] is dominated by the tunneling effect. The three peaks of TSC were obtained at the temperature of -20[.deg. C], 20[.deg. C] and 80[.deg. C], respectively. The origins of these peaks are that the .alpha. peak observed at -20[.deg. C] looks like to be ascribed to the ionization excitation from donor level in the grain, and the .alpha.' peak observed at 20 [.deg. C] appears to show up by hopping conduction of the trapped carrier of border between the oxidation layer and the grain, and the .betha. peak observed at 80[.deg. C] seems to be resulted from hopping conduction of existing carrier in the trap site of the border between the oxidation and second phase.

• 미생물학회지
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• 제14권1호
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• pp.39-47
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• 1976

This experiment was designed to study the effects of temperature on the peroxidase isoenzymes of a mesophilic microorganism, Escherichia coli (grown within biokinetic zone). Optimum temperature for the growth of E. coli was $37{\circ}C.$ Three different temperatures, 20, 30 and $40{\circ}C,$ were selected. And the isoenzyme patterns of peroxidase of E. coli, growth respectively at each temperature, were analysed by disc electrophoresis. The sample of 20.deg.C showed 4 bands, that of 30.deg.C, 5 bands and that of 40.deg.C, 6 bands. Two dark bands (higher molecular weight, 56,000 and 54,000) and two light bands (lower molecular weight, 11,500 and 10,000) were constant at all samples. But two intermediate bands (M.W.44,000 and 34,000) were variable ; at $20{\circ}C,$ no banding pattern, one band 9M.W. 34,000) only at $30{\circ}C,$ and at $40{\circ}C$ two bands were appeared. And the shifts of growth temperatures between 30.deg.C and 40.deg.C showed the alteration of the isoenzyme patterns ; the isoenzyme patterns of the smaple of tmeperature shift from $30{\circ}C$ to $40{\circ}C$ were same as that of 40.deg.C and vice versa.

• 한국멀티미디어학회논문지
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• 제24권9호
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• pp.1299-1310
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• 2021

Under the background of the rapid development of digital educational games, we have to evidently research the elements of the achievement system of children's DEG (Digital Educational Game), and analyze the relations between the elements and make a profound study on the achievement system and its components on the impact of player's attitude. Compared with the existing research, the research contents and methods are innovative and reliable. The results show that players have a positive attitude towards the DEG achievement system, DEG achievement system has important value and role for educational games. Which is made of five elements: symbol, reward, logic, social interaction, and knowledge. The five elements interact with each other and have a positive impact on players' attitudes. DEG achievement system with five elements will bring players a positive experience. These findings provide a detailed study of the components of the achievement system. With all of these, we can explain the role and relationship of the components, and provide new ideas and empirical evidence for the design and development of children's educational game achievement system. The above findings provide a detailed description of the components of the DEG achievement system, explain the role and value of each component, and the relationships and patterns among the components, it provides a new perspective and empirical evidence for the design and development of the children's system DEG results.

• 한국응용과학기술학회지
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• 제35권4호
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• pp.1145-1155
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• 2018

본 연구는 비만여대생을 대상으로 섭식제한(DG), 유산소운동(EG), 섭식제한과 유산소운동(DEG) 그룹으로 나누어 체중, 비만의 개선, 혈중지질성분 및 대사성위험요인에 미치는 영향을 분석하였다. 실험은 8주간 주 5회 실시하였으며, DG는 1일 에너지 섭취열량을 300kcal를 제한하였고, EG는 런닝머신을 이용하여 300kcal를 소비시켰으며, DEG는 각각 150kcal를 제한과 소비시켰다. 결과, 신체조성의 경우 DG에서는 체중(p<.011), BMI(p<.008)가 감소하였고, EG와 DEG에서는 체중(p<.044, p<.017), 체지방량(p<.047, p<.018), BMI(p<.03, p<.008), 체지방률(p<.036, p<.015), WHR(p<.049, p<.027)이 유의하게 감소하였다. 혈중지질성분은 DG에서 HDL-C(p<.028), EG에서 TG(p<.038), DEG에서는 TC(p<.014), LDL-C(p<.007)에서 유의하게 감소하였다. 대사성위험요인은 DG에서 HOMA-IR(p<.035), leptin(p<.007), EG에서 FBG(p<.043), leptin(p<.003), DEG에서 FBG(p<.014), insulin(p<.005), HOMA-IR(p<.005), leptin(p<.016), resistin(p<.040)에서 유의한 차이가 나타났다. 따라서 본 연구의 결과로부터 비만여대생들이 섭식제한, 유산소운동의 단독처치보다 섭식제한과 유산소운동을 병행하는 것이 신체조성, 혈중지질성분, 대사성위험요인의 개선에 가장 효과가 있을 것으로 판단된다.

• 대한기계학회논문집
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• 제14권1호
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• pp.197-206
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• 1990

본 연구에서는 수평등온평면의 가장자리에 주위물의 온도와 동일한 수평등온 평판을 부착한 모델을 사용하여 수평평면 선단의 하부에서 유체가 상부로 유입되는 것 을 방지함으로서 특별한 가정없이 단열평판의 선단에서의 경계조건을 직접 구할 수 있 었다.그리고 기존 밀도식의 복잡성과 신뢰도를 개선한 Gebhart등의 밀도식을 사용 하여 수치해석결과의 신뢰도를 증진하였다. 유한착분법을 사용하여 수평등온평면 주 위에서 일어나는 자연대류에 대한 기배방정식을 수치계산하여 주위물의 온도변화가 유 선분포, 온도분포, 국소열전달계수 및 평균 Nusselt수에 미치는 영향을 구명하였고, 상향 및 하향 수평등온면 주위에서 일어나는 자연대류의 유동형태와 열전달 특성을 비 교 검토하였다.

• Journal of Microbiology and Biotechnology
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• 제25권11호
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• pp.1856-1862
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• 2015

In order to improve the stability of endoglucanase under thermal and acidic conditions, the endoglucanase gene was fused to the N-terminus of the Saccharomyces cerevisiae pir gene, encoding the cell wall protein PIR. The fusion gene was transformed into Pichia pastoris GS115 for expression. A resulting strain with high expression and high activity was identified by examining resistance to Geneticin 418, Congo red staining, and quantitative analysis of enzyme activity. SDS-PAGE analysis revealed that the endoglucanase was successfully displayed on the yeast cell surface. The displayed endoglucanase (DEG) showed maximum activity towards sodium carboxyl methyl cellulose at approximately 275 IU/g cell dry weight. DEG exhibited greater than 60% residual activity in the pH range 2.5-8.5, higher than free endoglucanase (FEG), which had 40% residual activity at the same pH range. The highest tolerated temperature for DEG was 70℃, much higher than that of FEG, which was approximately 50℃. Moreover, DEG showed 91.1% activity at 65℃ for 120 min, while FEG only kept 77.8% residual activity over the same period. The half-life of DEG was 270 min at 65℃, compared with only 150 min for FEG. DEG could be used repeatedly at least three times. These results suggest that the DEG has broad applications as a yeast whole-cell biocatalyst, due to its novel properties of high catalytic efficiency, acid-thermal stabilities, and reusability.