• International Journal of Korean Welding Society
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• 제3권1호
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• pp.23-28
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• 2003

The effect of the welding speeds on the weld bead shape, microstructure, and mechanical properties in type 304 austenitic stainless steels was investigated by microscopic test, Erichsen test and tensile test. In this study welds were produced using autogeneous Direct Current Straight Polarity (DCSP) and pulsed current GTA welding. This study shows the ferrite content, ductility, tensile strength and elongation of high speed welds are decreased with increasing welding speed. The high speed welds exhibits satisfactory tensile strength, though the ductility is not good as that of the base metal.

• 핵의학기술
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• 제17권2호
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• pp.101-106
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• 2013

Purpose: As UBC IRMA is being tested, patients out of the reference value are reacting within the value again a few days later the urine collection tested, which causes the reliability of the test to decrease as a result. In this study, we can assume that the physiological changes in the factors would affect the results. The purpose of the study is to find out whether hematuria and proteinuria in the sample as well as the interval time (3 hours or more recommended) have affected the results. As a result, we could discover the changes in factors and increase the reliability of the test. Materials and Methods: 468 people (female: 249, male: 219) who came for the check-up were presented herein for medical examination from 2013.3.15 to 2013.1.2. Some people out of 468 who have reacted onto the reference value were divided into group low titer zone, ow-middle titer zone, and middle-high titer zone and tested for hematuria and proteinuria. During that period, 48 outpatients were asked to fill in a questionnaire regarding the urination interval time. The reagents used were (IDL Biotech AB, Sweden) and UBC IRMA. Results: Of the patients that are formed in the reference value of ($0.1-34.0{\mu}g/L$) turn out to be 52.7 years average age in their low concentration, ($mean{\pm}SD$) of the value of $0.10{\pm}0.02{\mu}g/L$. Among 80 people (50.8%, female: 49.2%), 16 patients (20%) have shown reaction to microscopic hematuria and 10 patients (12.5%) responded to proteinuria. In the average low concentration under 52.5 years of average age, 43 people (53%) have shown reaction to microscopic hematuria and 21 people (26.3%) are proteinuric patients out of 80 patients (male: 50.8%, female: 51.3%). In the middle high concentration of $11.8{\pm}4.82{\mu}g/L$ under the average age 51.7 years, 35 patients (53%) have responded to the microscopic hematuria and proteinuric patients are 26 people (39.3%) out of 66 people (men: 44%, women: 56%). In addition, in the concentration of $51.7{\pm}43.5{\mu}g/L$, some patients who get out of the reference value are observed as the average age of 52.0. 11 patients (78.6%) out of 14 (male: 35.7%, female: 64.3%) react to the microscopic hematuria. There show 6 people (42.8%) who turn out to be as proteinuric patients. As for the interval time, $1.67{\pm}3.71{\mu}g/L$ was the average value among 48 patients (female: 45.8%, male: 54.2%). Conclusion: We cannot see if proteinuria and hematuria directly affect abnormal results of inspection of 8,18 cytokeratin; however, we can find out that they statistically have an influence on highly generating UBC among several mechanisms. Also, although urination interval time was various every 15 minutes, we it does not affect these results.

• Elastomers and Composites
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• 제29권3호
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• pp.213-225
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• 1994

The Purpose of this dissertation is to study the preparation technique and physical properties of expanded rubber. The respective samples of NR, NBR and the standard compounds of EPDM rubber were prepared by mixing plasticizer DOP and LCR in various ratio. And their vulcanization characteristics, physical properties and foaming states were studied. Vulcanization characteristics were investigated using cure curve that had been obtained from Oscillating Disk Rheometer study, and the microscopic photographs of foaming states were obtained using electron microscope. The vulcanization characteristics of the samples, DOP 30phr and LCR 30phr, were found to be suitable. The tests, like hardness test and resilience, tensile test on the physical properties of each sample showed that plasticizing efficiencies of DOP and LCR were almost the same. Oil resistance test exhibited DOP was better than LCR and compression set test showed LCR was excellent plasticizer. The foaming states of NR, EPDM compounds were uniform, but those of NBR compounds were not uniform. Consequently vulcanization characteristics, physical properties and foaming states of all the samples satisfied the SAE requirements.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2488-2493
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• 2007

A gap conductance is very important factor which can affect nuclear fuel temperature. Especially, in case of an annular fuel, a gap conductance effect can lead an unexpected heat split phenomena which is caused by a large difference of an inner and outer gap conductance. The gap conductance mechanism is very complicated behavior due to the its strong dependency on microscopic factors such as a contact surface roughness, local contact pressure and local temperature. In this paper, for the decision of test temperature and pressure range, a procedure and calculation results of in-reactor fuel temperature and pressure analysis are summarized which can be applied to test equipment design and determination of test matrix. Based upon analysis results, it is concluded that the minimum and maximum test temperature are $300^{\circ}C$ and $530^{\circ}C$ respectively, and the maximum pellet/cladding interfacial contact pressure should be observed up to 45MPa.

• 한국임상수의학회지
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• 제14권1호
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• pp.1-5
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• 1997

This experiment was performed to investigate the leptospiral antibody in dairy cattle with serological test in three areas of Kangwondo from February to June, 1995. Twelve different living antigen's (S icterohemorrhagiae, Lpomona, L hardjo, L australis, L canicola, L autumnalis, L grippotyphosa, L tarassovi, L pyroenes, L bataviae, L hebdomadis and L ballum) of Leptospira interrogans were used for the serological test in dairy cattle. The blood samples of 130 cattle were examinde by microscopic agglutination test. Among the serum samples of the dairy cattle, 5 heads of the dairy cattle (3.8%) were positive. Among the positive samples of 5 heads, 3 heads of dairy cattle (2.3%) showed the antibody of L canicola, 2 heads of dairy cattle (1.5%) showed the antibody of L icterohaemorrhagiae. Positive rate by age was 0% ($\leq $2year), 4.6% (3~4year) and 6.6% ($\geq $5year).

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.67-70
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• 2000

This study was performed to investigate the material behavior of hybrid thermoplastic composites contained glass fiber and calcium carbonate. The composite was prepared with each combination ratio of calcium carbonate, and the content of glass fiber was fixed with 10% by weight. In order to investigate the material behavior for various combination ratio, tension test, flexural test, and impact test were performed. Microscopic observation were conducted to examine the fractured surface of specimen for tension test. And the material behavior of the hybrid thermoplastic composite immersed in salt water with definite time was investigated.

• Archives of Pharmacal Research
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• 제28권9호
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• pp.1079-1085
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• 2005

The purpose of this study was to investigate the safety of chitosan oligosaccharide and the effects of chitosan oligosaccharide on mercury induced genotoxicity in mice using the micronuclei and chromosome aberration. The micronuclei test was performed by microscopic examination $(\times1,000,\;stained\;using\;a\;May-Grunwald\;solution)$ after administering 0.01, 0.1, and $1\%(10\;mg/mL)$ chitosan oligosaccharide for 7, 60, and 180 days ad libitum in mice. Total micronuclei of 1,000 polychromatic erythrocytes were recorded for each group. There was no difference between the untreated and experimental groups. The intake periods and concentrations of chitosan oligosaccharide did not affect the occurrence of micronuclei in bone marrow cells (P>0.05). The chromosomal aberration test was performed by microscopic examination $({\times}1,000,\;stained\;using\;a\;4\%\;Giemsa\;solution)$ after administering the same concentration of chitosan oligosaccharide to mice, in $F_1,\;F_2,\;F_3$ generations and parents. The frequency of chromosomal aberrations was defined as [Ydr=(D+R)/total number of counted lymphocytes]. Similar to the micronuclei test, there was no difference between the untreated and treated groups. These results showed that the intake periods and concentrations of chitosan oligosaccharide did not affect chromosomal aberrations in bone marrow cells (P>0.05). To investigate the effect of chitosan oligosaccharide on mercury-induced chromosome aberration, mice in each condition were supplied with $^{203}HgCl_2$ and chitosan oligosaccharide ad libitum. Chitosan oligosaccharide significantly inhibited $^{203}HgCl_2-induced$ chromosome aberration in mice. Based on the results of this study, it may be concluded that the chitosan oligosaccharide is a nontoxic material that could be used as a suppressor of heavy metal-induced genotoxicity.

• 대한미생물학회지
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• 제12권1호
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• pp.33-49
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• 1977

These studies were carried out to detect the presence of mycotoxin fungi and detoxification of toxins in various kinds of grain and foodstuffs in Korea. The experiments were divided into three parts: mycologic, toxicologic and electron microscopic study. The resuIts were summarized as follows: 1. From the 210 various, samples(local grains, 150 samples; rice-cakes, 50 samples; meju, 10 samples), 1,205 colonies or fungi were isolated. In 1,127 of 1,205 colonies, it was possible to identify 21 genera. Among the identified strains, the predominant genera were Aspergillus sp.(28.5%), Penicillium sp.(27.1%) and Mucor sp.(7.8%). 2. In cytotoxicity test on HeLa cells, 25 strains showed severe toxic effects among the 240 strains of experiments. 3. In histopathologic test on mice, 21 strains showed severe toxic effect to mouse liver cells among the 240 tested strains. 4. In electron microscopic studies of HeLa cells and mouse liver cells from animal which had been treated with crude toxin, the liver cells showed the cytoplasmic change: dillatation or vacuolization of endoplasmic reticulum, swelling of mitochondria and disappearance of mitochondrial cristae, increased number of lipid and glycogen particles. Nucleus and nucelar envelope alterations, were also noted. 5. In the detoxification study with ultraviolet irradiation, 90% of the toxic substances were denatured by the ultraviolet light irradiation for 24 hours. 6. As a mass screening, the cytotoxicity test of HeLa cells and histopathologic study of mice liver cells treated with culture filtrates, employed and feasible to detect mycotoxin producing fungi.

• 한국ITS학회 논문지
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• 제4권2호
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• pp.53-66
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• 2005

미시적 시뮬레이션 모델은 차량과 차량, 차량과 교통제어와의 개별차량 상호작용을 분석할 수 있어 교통공학 분야에 광범위하게 사용되고 있다. 미시 교통 시뮬레이션 모형을 이용하여 교통시스템을 분석 및 평가할 때 많은 고려요소가 있다. 이 요소들은 현장의 분석 대상지, 시뮬레이션 소프트웨어, 분석 시간, 평가 척도, 패러미터, OD 자료, 랜덤 넘버 등을 포함한다. 이러한 요소들이 미시적 시뮬레이션 결과에 어떠한 영향을 미치는지 평가하기 위해 CORSIM과 TRANSIMS 결과를 토대로 민감도 분석이 실시되었다. 휴스톤에 위치한 I-10과 US290, 샌안토니오에 위치한 I-37 고속도로가 분석에 이용되었다. 오전 첨두, 오후 첨두, 비첨두 시간이 분석되었고, 세 개의 OD 자료가 이용되었다. 분석결과 모델의 패러메터와 OD 자료가 가장 큰 영향을 주었다. 또한 분석대상지와 분석 시간에 따라 민감도가 달라졌다

• 대한교통학회지
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• 제19권6호
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• pp.143-160
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• 2001

본 연구에서는 국내 일부지역에 운영중인 첨단신호제어시스템(COSMOS)의 효율성을 평가할 수 있는 미시적(microscopic), 모의실험기(simulator)의 원형(prototype)을 개발하였다. 이 모의실험기의 개발은 원형적인 형성을 목표로 차량의 이동방식과 모듈적용체계 그리고 첨단신호알고리즘 중 독립교차로 실시간제어의 기능을 개발모형의 범위로 하였으며 구체적인 개발 사항은 다음과 같다. 첫째로, 기본적인 차량진행 외에 부가적인 첨단신호기능을 수행하기 위해서 검지기 체계를 통한 자료수집 및 지역제어기 그리고 센터시스템의 알고리즘의 수행이 필요하므로, 미시적 시뮬레이터의 가장 큰 문제점인 연산속도의 문제는 더욱 대두된다. 따라서 이러한 점을 개선할 수 있도록 소프트웨어적인 측면에서 차량의 이동방식을 공간중심방식으로 구성하여 진행시킬 것과 링크별로 각 수행모듈을 합리적으로 적용하도록 제안하였다. 그리고 차량추종 및 차로변경의 모형의 적용을 포함한 링크의 이원화 적용 제안이 타당한지를 평가하기 위하여 NETSIM모형과 비교를 실시하였다. 둘째로, 이러한 모의실험기의 구조를 기초로 개별차량의 검지자료 수집과 매 주기마다 주기 및 녹색시간을 결정하는 독립교차로 실시간 제어 알고리즘의 구현으로 첨단신호제어의 전략을 평가할 수 있는 가능성을 제시하였다. 마지막으로 독자적인 모의실험기로 발전할 수 있도록 Animation 기능과 다양한 효과척도를 산출하여 종합적인 연구를 수행하였다.