• 한국환경과학회지
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• 제8권1호
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• pp.51-59
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• 1999

Chemical composition of atmospheric aerosols was measured at 4 sites in Pusan. All the samples were collected with a high volume air sampler from January to October 1996, to analyze major ions and heavy metals. Dominant ions of aerosols were S $O_4$$^{2-}$ in anion and N $a^{+}$ in cation. Sulfate, nitrate and ammonium ions in aerosols showed high enrichment factor to soil and seawater composition. The concentrations of heavy metals in aerosols was lowest at the site PI near the coast. The lowest concentrations of major ions and heavy metals mainly appeared in August, probably due to scavenging by frequent rains. Especially, the concentrations of total suspended particulate matter(TSP) and heavy metals in aerosols showed good correlations in Pusan. Based on crustal Al, enrichment factors for some metals(Zn, Cu, Pb, Cd) in aerosols were significantly greater than unity, and the order was Cd ＞ Pb ＞ Zn ＞ Cu. This evidence suggests that Cd and Pb are derived predominantly from non-crustal sources.s.

• 동아시아식생활학회지
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• 제22권2호
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• pp.219-223
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• 2012

The purpose of this study was to investigate the body composition, biochemical parameters, and consumption of convenience foods according to leptin receptor polymorphism in university students. A survey was conducted on a total of 418 students - 271 males and 147 females. Based on a self-reporting method, questionnaires were administered for over 20 minutes, and leptin receptor and blood samples were analyzed. The genotype frequencies of leptin receptor polymorphism were Gln/Arg heterozygote (64.8%) and Gln/Gln homozygote (35.2%). Leptin polymormphism showed no significant association with biochemical parameters(ALT, cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol, and hemoglobin) and body composition. GG homozygote was associated with a higher risk of visceral fat obesity compared to those with GA heterozygote (odd ratio 1.758, 95% confidence intervals 0.812~3.803). Leptin polymorphism appeared to be a genetic risk factor for visceral fat obesity. This study suggests that leptin polymorphism has a causative role to body fat distribution in Korean.

• Archives of Pharmacal Research
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• 제10권2호
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• pp.94-99
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• 1987

By using the former equation (8), we modified the equation which can show the dissimilar osmotic behavior of liposome with composition change. The slope of the new equation was presented as the ratio of osmotically active volume (V$_{act}$= ) to the total volume (V$_{totel}$= $_{acl}$+ V$_{dead}$ ; V$_{dead}$ is osmotically inactive volume) of loposomes, we defined is as a Z-value, which can elucidate the dissimilarity of the osmotic activity of multilamellar liposomes with the change of phospholipid composition and the differences of physicochemical properties of liposomes. Z-value was applied for studying the physico-chemical properties of liposomal membrane. The factor that affects on the Z-value was not the lipid concentration of liposome stock dispersion but the lipid composition of liposomal membrane. As the content of dicetylphosphate, the negative charged phospholipid, was increased, the osmotic activity, represented by Z-value, of multilamellar liposome was decreased. Using the hypertonic conditions (shrinking region), Z-value steadily increased and reached a maximum at 10 mole percent cholesterol with increasing the cholesterol content.

• Applied Microscopy
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• 제48권4호
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• pp.117-121
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• 2018

The multiple length scale analysis of previously designed Fe-Mn-Al-C based low-density model alloys reveals the difference in ordered ${\kappa}-carbide$, $(Fe,Mn)_3AlC_x$, between Fe-25Mn-16Al-5.2C (at%) alloy and Fe-3Mn-10Al-1.2C (at%) alloy. For the former alloy composition consisting of fully austenite grains, ${\kappa}-carbide$ showed majorly cuboidal and minorly pancake morphology and its chemical composition was not changed through aging for 24 h and 168 h at $600^{\circ}C$. Meanwhile, for the isothermally annealed ferritic alloy system for 1 hr at 500 and $600^{\circ}C$, the dramatic change in the chemical composition of needle-shape ${\kappa}-carbide$, $(Fe,Mn)_3(Fe,Al)C_x$, was found. Here we address that the compositional fluctuations in the vicinity of the carbides are significantly controlled by abutting phase, either austenite or ferrite. Namely, the cooperative ordering of carbon and Al is an important factor contributing to carbide formation in the high-Mn and high-Al alloyed austenitic steel, while the carbon and Mn for the low-Mn and high Al alloyed ferritic steel.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.197-198
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• 2023

This study was conducted as part of research and development of high-strength grout. Accordingly, dolomite aggregate was used as a filler incorporated into the high-strength grout. Dolomite aggregate has a disadvantage of increasing the viscosity of the grout due to higher generation of fine powder than other aggregates. Accordingly, in this experiment, it was confirmed that the viscosity, flow time, and flow of high-strength grout change according to the volume composition ratio of dolomite aggregate and cement-based material. All experiments were conducted based on the Korean Industrial Standard KS F 4044, and the mixing factor was applied according to the composition ratio of the binder and the filler. In the experiment, the amount of fine powder contained in the dolomite aggregate rather than the silica sand used in the past is grasped, and after mixing with the grout accordingly, the mixture is proceeded to measure the viscosity in an unhardened state. In addition, the flow and flow time of the grout are evaluated according to the viscosity. As a result of the experiment, it was confirmed that the viscosity and flow time decreased and the flow increased as the volume composition ratio of the dolomite aggregate to the cement-based material increased.

• 한국정보시스템학회지:정보시스템연구
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• 제11권1호
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• pp.51-74
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• 2002

The purpose of this study is to empirically investigate critical success factors for effective implementation of web-based distance learning system. First of all, four critical success factors are theoretically derived from reviewing previous research. They are: (1) learner-related factor including the variables such as teaming ability, learning attitude, and attending motivation, (2) environmental factor including the variables of physical and mental support for learners, (3) instructional design factor represented by one variable, the degree of appropriateness of learning contents, and (4) the factor concerning the level of self-directed learning readiness embracing the variables such as curiosity for learning, openness towards challenge of learning and affection for learning. Subsequently, the relationships between these four critical success factors and the degree of learning satisfaction are empirically investigated. The data for empirical analysis of the research are collected from 1,020 respondents who have already passed the web-based distance learning courses which have been implemented in Information and Communication Officials Training Institute. Out of 1,020 responded questionnaires, 875 data were available for statistical analyses. The main results of this study are as follows. Firstly, the most important factor for successful implementation of the web-based distance learning system is shown to be the instructional design factor, and in the next place, the self-directed learning readiness factor, the environmental factor and the learner-related one in sequence. Secondly, additional analysis of the variables included in the instructional design factor shows that availability of practical information and knowledge is the most influencing variable, and next, interesting composition of contents, reasonable learning amount, optimal level of instruction, and understandable explanation are significantly important in the descending order. Lastly, among learning motivators, strong intention of acquiring business knowledges and skills is found to be the most important satisfier in the web-based distance learning. The theoretical contribution of this study is to derive a comprehensive model of critical success factors for implementing the web-based distance learning system. And, the practical implication of this study is to propose efficient and effective guidelines for developing and operating the web-based distance learning system in the various kinds of organizations.

• 벤처창업연구
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• 제4권4호
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• pp.1-25
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• 2009

정부는 '국가 연구개발 사업 등의 성과평가 및 성과관리에 관한 법률'을 제정하여 국가연구개발 사업성과의 효율성과 생산성을 제고하기 위하여 노력하고 있다. 본 연구는 범정부적인 차원에서 수행하고 있는 국가 연구개발 사업 평가시스템 중 특정평가에 대하여 메타평가방법을 통한 효율성을 분석하기 위한 평가모형 및 지표를 개발한 결과이다. 국가 연구개발 사업 평가시스템의 효율성 분석을 위한 베타평가 모형은 평가 상황 요소, 평가자원요소, 평가수행요소, 평가결과요소, 평가활용요소 등 5개 구성요소로 구분하여 평가지표를 개발하였다. 아울러 평가항목을 선정하기 위하여 분석한 평가구성요소 및 평가지표에 대한 신뢰성 검증결과 Cronbach' $\alpha$ 계수가 0.933으로서 평가지표체계는 큰 무리가 없는 것으로 나타났다. 그리고 평가구성요소 및 평가지표별 가중치 산정은 계층분석기법을 사용하여 분석하였다. 분석결과 조사자의 전체 일관성 지수는 0.1 미만으로 나타나 조사자의 일관성이 있는 것으로 분석되었다.

• 산업융합연구
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• 제21권3호
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• pp.171-179
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• 2023

본 연구는 중년여성 18명을 대상으로 저항성 운동군 A그룹 6명(1RM 40-60%), 유산소 운동군 B그룹 6명(VO2max 60-70%), 유연성 운동군 C그룹(10~60 sec/sets) 6명으로 무선 배정하여 12주간 주 3회(월, 수, 금) 1일 50~60분의 운동 형태에 따른 신체구성과 염증인자, 혈관내피 성장인자에 미치는 영향을 알아보기 위하여 비교·분석한 결과, 첫째, 염증인자의 변화에서는 CRP 및 IL-6의 시기의 주효과에서는 유의한 차이(p<.05)가 나타났다. 둘째, 혈관내피 성장인자의 변화에서는 VEGF의 시기의 주효과 및 시기×그룹의 상호작용에서는 유의한 차이(p<.05)가 나타났다. 본 연구의 결과를 토대로 운동 형태에 따른 염증인자와 혈관내피 성장인자에 관한 다양한 각도의 연구와 개선을 위한 기초 자료로 활용되기를 기대한다.

• 한국식품영양학회지
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• 제24권4호
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• pp.489-495
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• 2011

These studies were conducted to investigate the effects an herbal extract composition(MHE) containing $Hovenia$ $dulcis$ T., $Artemisa$ $capillaris$ T., $Pueraria$ $thunbergiana$ B., $Polygonatum$ $falcatum$ A., $Agastache$ $rugosa$ O., $Silybum$ $marianum$ L. and $Glycyrrhiza$ $uralensis$ F. in alcohol administered mice. Prophylactic administration of different doses of MHE(20~100 mg/kg) had beneficial actions toward alcohol degradation in acute alcohol treated mice. In addition, intraperitoneal administration of the MHE showed anti-inflammatory effects in inhibition tests of vascular permeability produced by acetic acid. MHE also reduced the concentrations of nitric oxide(NO) and tumor necrosis factor(TNF)-${\alpha}$ in macrophages that were activated by LPS. These results demonstrate that MHE possesses the potential to stimulate alcohol degradation and inhibit inflammatory effects in mice.

• Journal of Microbiology and Biotechnology
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• 제28권1호
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• pp.175-179
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• 2018

In a preliminary study, Lactobacillus plantarum C29 was found to suppress 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in mice. Therefore, to understand whether an anti-colitic probiotic C29 could attenuate memory impairment, we examined the effects of C29 on TNBS-induced memory impairment in mice. Orally administered Lactobacillus plantarum C29 attenuated TNBS-induced memory impairment in mice in the Y-maze, noble object, and passive avoidance task tests. C29 treatment increased TNBS-suppressed hippocampal brain-derived neurotrophic factor expression and inhibited TNBS-induced hippocampal NF-${\kappa}B$ activation and blood LPS levels. Moreover, C29 restored the TNBS-disturbed gut microbiota composition. These findings suggest that C29 can alleviate memory impairment presumably by restoring the gut microbiota composition.