• 대한전자공학회논문지SD
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• 제41권1호
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• pp.81-90
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• 2004

유한상태기의 상태할당은 이로부터 구현되는 순차회로의 속도, 면적, 테스팅 및 소비전력에 큰 영향을 미친다. 본 논문에서는 상태변수 그룹들 사이에 상호 의존성(dependency)을 최소화하여 테스팅 및 전력소모를 개선하기 위한 m-블록 분할을 이용한 새로운 상태할당 기술을 소개한다. m-블록 분할 알고리즘에 의해 상태도로부터 상태들을 그룹으로 나누어 상태변수의 상호의존성을 줄이고, 상태천이 확률에 의해 결정된 무게인자에 따라 상태간 상태변수의 변화를 최소로하는 코드를 할당하여 상태천이시 스위칭 횟수를 줄인다. 상태변수 의존성을 줄임으로써 순차회로 사이클이 줄어들어서 부분스캔 및 테스트 생성이 용이하게 되고, 상태변수간의 스위칭 횟수를 줄임으로써 소비전력이 줄어들게 든다. 즉, 본 상태할당 기술은 서로 상반 관계에 있는 테스팅과 저전력 문제를 동시에 해결할 수 있는 새로운 기술이다. 벤치마크 회로에 대한 실험결과 기존의 방법보다 고장점검도 및 소비전력이 현저히 개선되었음을 확인하였다.

• Korean Chemical Engineering Research
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• 제52권5호
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• pp.678-687
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• 2014

The catalytic performance of silicon carbide supported nickel catalysts modified with or without second metal (Co, Cu and Zn) for the methanation of CO has been investigated in a fixed-bed reactor using a feed consisting of 25% CO and 75% $H_2$ without any diluent gas. It has been found that the introduction of Co species can clearly improve the catalytic activity of Ni/SiC catalyst, whereas the addition of Cu or Zn can result in a significant decrease in the catalytic activity. The characterizations by means of XRD, TEM, XPS, CO-TPD and $H_2$-TPR indicate that the addition of Co could decrease the particle size of active metal, increase active sites on the surface of methanation catalyst, improve the chemisorption of CO and enhance the reducibility of methanation catalysts. Additionally, the special interaction between Co species and Ni species is likely favorable for the dissociation of adsorbed CO on the surface of catalyst, and this may also contribute to the high activity of 5Co-Ni/SiC catalyst for CO methanation reaction. For 5Cu-Ni/SiC catalyst and 5Zn-Ni/SiC catalyst, Cu and Zn species could cover partial nickel particles and decrease the chemisorption amount of CO. These could be responsible for the low methanation activity. In addition, a 150h stability test under 2 MPa and $300^{\circ}C$ showed that 5Co-Ni/SiC catalyst was very stable for CO methanation reaction.

• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1222-1228
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• 2007

The aim of this experiment was to compare the characterization of fatty acid digestion of Beijing Fatty (BF) and Arbor Acres (AA) chickens. One-day-old male AA and BF chickens were raised in the same house, and fed with the same diet. We first evaluated utilization of dietary fatty acids in chickens by the total collection procedure, and chickens were then killed to compare the abundance of intestinal mRNA expression of liver-fatty acid binding protein (L-FABP) and intestinal-fatty acid binding protein (I-FABP) by Real-time PCR, and also the pH of intestinal mucosa at 3 and 6 weeks of age. Another group of chickens were sampled at 6 weeks of age to compare the total bile acid concentration in serum, and lipase activity in contents of the small intestine. Results showed that compared to AA chickens, BF chickens had higher lipase activity in the content of the small intestine (p<0.05), greater total bile acid content in portal vein blood (p<0.05) at 6 weeks of age, lower intestinal mucosal pH at both 3 weeks (p<0.05) and 6 weeks (p<0.05) of age, and higher abundance of liver-fatty acid binding protein (L-FABP) mRNA expression in intestine tissues at 6 weeks of age (p<0.05), and higher digestibility of fatty acids at both 3 and 6 weeks (p<0.05) of age. There was no difference in I-FABP mRNA expression between AA and BF chickens at either age. Thus, BF chickens had greater fatty acids utilization than AA chickens that was associated with L-FABP, lipase activity, bile acid content and intestinal mucosal pH.

• 한국콘텐츠학회논문지
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• 제20권10호
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• pp.146-156
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• 2020

본 연구는 팀프로세스와 정서상태유형이 구성원의 조직몰입에 미치는 영향을 검증하는데 그 목적을 두었다. 이를 위해 기업체에서 근무하는 임직원 241명으로부터 유효한 설문을 받았으며, 수집된 설문은 회귀분석을 통해 관계를 분석하였다. 분석 결과, 팀프로세스 요인인 전환과정, 실행과정, 대인과정이 모두 조직몰입에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 그리고, 팀프로세스 요인인 전환과정은 구성원의 정서상태유형 중 긍정활성과 긍정비활성에 유의한 정(+)의 영향을 나타냈고, 대인과정은 긍정활성, 긍정비활성에 유의한 정(+)의 영향을 부정비활성과 부정활성에 유의한 부(-)의 영향을 나타냈다. 또한 팀프로세스와 조직몰입의 관계에서 정서상태유형인 긍정활성이 매개효과를 가지는 것으로 나타났다. 본 연구를 통해 조직 내 인적자원관리의 효율성을 극대화하고 팀의 효과성을 향상시키기 위해서는 팀프로세스의 구축과 관리에 대해 중요성을 제시하였다는 점에서 본 연구의 의의를 찾을 수 있다.

• 동의생리병리학회지
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• 제18권1호
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• pp.206-213
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• 2004

This study was performed to evaluate the anticonvulsant, antioxidant effect of modified formulas Korean traditional medicine Gungchihwadam-Jeon(GCHDJ). The extract of GCHDJ was administered (p.o.) to mice for 14 days in anticonvulsant and antioxidant tests. The pretreatment of GCHDJ extract prohibited the pentylenetrazol(PTZ)-induced convulsion in PTZ-induced convulsion, lowered level of brain r-aminobutyric acid(GABA) was restored by the pretreatment of GCHDJ. Increased level of brain glutamic acid was lowered to normal state by GCHDJ, and increased activity of brain r-aminobutyric acid transaminase(GABA-T) was reduced by GCHDJ. In PTZ-induced convulsion, increased level of brain lipid peroxide was lowered to normal state by the pretreatment of GCHDJ. Increased activity of brain xanthine oxidase(XOD) was lowered to normal state by GCHDJ, and increased activity of brain aldehyde oxidase lowered to normal state by GCHDJ. In PTZ-induced convulsion, increased activities of superoxide dismutase(SOD) and catalase in brain were lowered by the pretreatment of GCHDJ, whereas increased level of glutathione and increased activity of gluthathione peroxidase in brain were not changed significantly. Above results suggest that GCHDJ have anticonvulsant. antioxidant effect. That seems to be strongly related with the levels of GABA, glutamate, lipid peroxide and the activities of GABA-T, XOD, aldehyde oxidase, SOD, catalase in brain tissue. From these results, GCHDJ could be applied to various convulsive disorders.

• 한국산학기술학회논문지
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• 제11권5호
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• pp.1747-1753
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• 2010

본 연구에서는 최대 공비점 압력을 가지는 에탄올과 벤젠 이성분계 혼합물의 기액 상평형 추산을 위하여 상태방정식 모델식과 액체활동도계수 모델식 사이의 비교 연구를 수행하였다. 상태방정식 모델식으로는 Peng-Robinson (PR) 상태방정식을 이용하였으며, Panagiotopoulos 혼합규칙(PRP)을 적용하였다. 한편, 액체 활동도계수 모델식으로는 Renon이 제안한 NRTL 액체 활동도계수 모델식을 이용하였다. PRP 모델식은 2개의 매개변수를 가짐에도 불구하고 3개의 매개변수를 가지는 NRTL 모델식에 비하여 에탄올-벤젠 이성분계에 대해서 저압 영역에서는 유사한 정확성을 고압 영역에서는 좀 더 정확성이 우수함을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1026-1034
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• 2016

In the current study, a total of 135 enterococci strains from different sources were screened for the presence of the enterocin-encoding genes entA, entP, entB, entL50A, and entL50B. The enterocin genes were present at different frequencies, with entA occurring the most frequently, followed by entP and entB; entL50A and L50B were not detected. The occurrence of single enterocin genes was higher than the occurrence of multiple enterocin gene combinations. The 80 isolates that harbor at least one enterocin-encoding gene (denoted "Gene⁺ strains") were screened for antimicrobial activity. A total of 82.5% of the Gene⁺ strains inhibited at least one of the indicator strains, and the isolates harboring multiple enterocin-encoding genes inhibited a larger number of indicator strains than isolates harboring a single gene. The indicator strains that exhibited growth inhibition included Listeria innocua strain CLIP 12612 (ATCC BAA-680), Listeria monocytogenes strain CDC 4555, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, S. aureus ATCC 29213, S. aureus ATCC 6538, Salmonella enteritidis ATCC 13076, Salmonella typhimurium strain UK-1 (ATCC 68169), and Escherichia coli BAC 49LT ETEC. Inhibition due to either bacteriophage lysis or cytolysin activity was excluded. The growth inhibition of antilisterial Gene⁺ strains was further tested under different culture conditions. Among the culture media formulations, the MRS agar medium supplemented with 2% (w/v) yeast extract was the best solidified medium for enterocin production. Our findings extend the current knowledge of enterocin-producing enterococci, which may have potential applications as biopreservatives in the food industry due to their capability of controlling food spoilage pathogens.

• 보건교육건강증진학회지
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• 제24권3호
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• pp.21-34
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• 2007

Objectives: This study aims to examined whether physical activity prevent the negative effect of psychological stress on cardiovascular reactivity by reducing stress induced sympathetic output and preventing norepinephrine depletion negative psych-affective responses. It is assumed that physical activity reduces the magnitude of cardiovascular responses and psychological responses to stress which threaten individuals' physical and mental health. The result of investigating the effect of physical activity on reducing negative physiological and psychological responses would suggest useful information health for practitioners who want to prevent stress-induced diseases, especially coronary heart disease. Methods: participants of this study were 30 students (10 males & 20 females), whose mean age was 21.30 (SD=2.29). Fifteen students (5 males & 10 females) were assigned for in each group, treatment and control groups. They were interviewed and given a survey that included a consent form, demographics sheet and psychological tests, such as State-Trait Anger Expression Inventory and State-Trait Anxiety Inventory. Before the application of psychological stress, participants in treatment group were going through with a course of physical exercise, running on treadmill 15minutes, while participants in control group were not physically active. After exercise, there was 15 minutes resting period before applying cognitive stress. During the experiment, all participants performed challenging cognitive tasks for 20minutes in situations that were designed to experience learned helplessness and measured their cardiovascular reactivity including blood pressure and heart rate every 5 minutes, until 10 minutes after finishing the application of psychological stress(recovering state). In the end of experiment, they were given some psychological test again. Results: Heart rates of exercise group were significantly higher than non-exercise group, especially, five minute after applying cognitive stress and at the end of recovery, in other word 10 minutes after stressful event. Systolic blood pressures of exercise group were lower than those of non-exercise group during the stressful event, but this differences in borderline level of significance. state anger level of exercise group decreased even experiencing stress, while those of non-exercise group increase. And state anxiety level of exercise group decreased in borderline level of significance. Conclusion: This study reiterate health benefits of physical activity and suggest that regular moderate exercise may regulate cardiovascular reactivity and psycho-affective responses from stress by reducing stress induced sympathetic output.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1996년도 춘계학술대회논문집
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• pp.259-263
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• 1996

Psychological action is physiological response of outernal stimulus. Physiological response is accompanied b physiological signals which are EEG, EMG, GSR, ECG, BP, and tec. Physiological signals are recently studied for determination of human phychological state. Psychological activity causes electric potential of brain. Physiological signal is considered as measurement of human psychological state. Aditory sensibility which is one of the sense of human may determine differences between positive and negative feeling. EEG and GSR variation with auditory quality of stimulus can be define human negative and positive mental state. This study is to characterize parameters which can determine negative and positive psycholigical state of human.

• BMB Reports
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• 제45권8호
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• pp.452-457
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• 2012

Diketoreductase (DKR) from Acinetobacter baylyi contains two tryptophan residues at positions 149 and 222. Trp-149 and Trp-222 are located along the entry path of substrate into active site and at the dimer interface of DKR, respectively. Single and double substitutions of these positions were generated to probe the roles of tryptophan residues. After replacing Trp with Ala and Phe, biochemical and biophysical characteristics of the mutants were thoroughly investigated. Enzyme activity and substrate binding affinity of W149A and W149F were remarkably decreased, suggesting that Trp-149 regulates the position of substrate at the binding site. Meanwhile, enzyme activity of W222F was increased by 1.7-fold while W222A was completely inactive. In addition to lower thermostability of Trp-222 mutants, molecular modeling of the mutants revealed that Trp-222 is vital to protein folding and dimerization of the enzyme.