• 오토저널
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• 제7권4호
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• pp.49-56
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• 1985

This study consists of instrumenting and running tests on variable compression engines and measuring the following combustion characterics: (a)flame speed, (b) emission and (c)performance parameter such as power and economy. The results were as follows: 1) The phase separation diagram of substitute fuels were obtained from phase separation experiment. 2) The flame propagation speed of substitute fuels were higher than gasoline and increased with increasing methanol weight percent of substitute fuels. 3) BEMP of substitute fuels was slightly less than that of gasoline but in the range of small weight percent, BEMP was compatible to gasoline. 4) Concentration of NOx decreased significantly with delaying spark advancing time. Also, it decreased for rich equivalence ratio but increased with high compression ratio. In general, NOx concentration was much lower than that of gasoline. 5) Concentration of HC and CO increased for rich equivalence ratio. Also it was lower than that of gasoline.

• Nutritional Sciences
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• 제6권2호
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• pp.94-99
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• 2003

The purpose of this study was to investigate in vivo lipid peroxidation in rats under conditions of streptozotocin-induced oxidative stress and the antioxidant effects of probucol. In vivo lipid peroxidation was observed by measuring low molecular weight aldehydes and related carbonyl compounds in rat urine. Three groups of male Wistar rats weighing 165-190 g were used: normal (N), streptozotocin-induced oxidative stress (OS) and oxidative stress plus probucol treatment (P). following streptozotocin treatment of the rats, a variety of secondary lipid peroxidation products were increased. The levels of butanal, hexanal, hex-2-enal, kept-2-enal, octanal, non-2-enal, deca-2,4-dienal, 4-hydroxyhex-2-enal, 4-hydroxyno n-2-enal, malondi aldehyde(MDA), and unknown carbonyl compounds were significantly increased in the oxidative stress group compared to the control group. Treatment with probucol resulted in significant decreases in buoal, hexanal, hex-2-enal, octanal, deca-2,4-dienal, 4-hydroxyhex-2-enal, MDA and unknown carbonyl compounds. Hept-2-enal, hepta-2,4-dienal and non-2-enal appeared to have a tendency to decrease due to pobucol treatment.

• 한국자기학회지
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• 제4권2호
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• pp.168-172
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• 1994

박막의 자왜와 그 측정에 연관되는 기판과 박막의 영율 및 자장 중에서 자성체의 영율이 변화하는 ${\Delta}\;E$ 효과 등을 하나의 장치로 측정하는 방법을 연구하였다. 박막이 중착된 기판을 전 극위에 나란하게 외팔보가 되게 지지하면, 전기용량이 형성되고, 그 용량은 시료자체의 무게, 인가된 자장 및 전기장에 의한 굴곡으로 미소변화하며 그것을 미소용량 브리지로 검출하여 역학적 계산으로 박막과 기판의 영율과 자왜 및 ${\Delta}\;E$ 효과를 측정항여 그 결과에 대하여 고찰하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.731-734
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• 2005

Crushed sand is blended in order to investigate the quality changes and characteristics of concrete with variation of blend ratio of crushed sand (50, 60, 70, 80, 90, $100\%$). Slump and air content were measured to investigate properties of fresh concrete, and unit weight, compressive strength and modulus of elasticity in age of 7, 28, 60, 90, 180 days were measured to investigate properties of hardened concrete. Compressive strength, unit weight and modulus of elasticity were increased as time goes by and they are expected to keep on increasing in long-term age as well. As a result of measuring compressive strength and modulus of elasticity in age of 7, 28, 60, 90, 180days, compressive strength was highest when it is $70\%$ of blended ratio.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 연구회 합동 학술발표회 논문집
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• pp.60-63
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• 1998

The widely used power supply (Switched Mode Power Supply : SMPS) as a source in order to stabilize direct current for electronics or communication systems has merits, when it is compared to the existing source for stability, such as high efficiency, small size, light weight by means of switching process of the semiconductor device which controls the flow of power. However, due to existence of inductors and capacitors used for charging energy, the source part in electronic or communication systems hasn't reached the speed, that is supposed to get, for achieving smaller size and lighter weight. In order to get smallness in size, it is necessary to increase switching frequency. And that makes devices for measuring energy smaller. Nevertheless, the rise switching frequency brings increases in switching loss, inductor loss, and power loss. Also, the occurrence of surge and noise caused by high frequency switching is getting higher. The resonant converter has been considered as one of methods that give solutions for the problems of SMPS and that method have been paid attention as a source technology in electronics and communication.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.16-20
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• 2003

As the preliminary works for the preparation of exfoliated nanocomposites by reactive extrusion (REX) the modified anionic polymerization proceeded in a flask using an $\varepsilon$-caprolactam, catalyst, initiator, and clay. Polymerization methods were classified with a variation of the clay adding time. Intercalations mechanism of clay layers was investigated by measuring the WAXD peaks of clay with polymerization. In the preparation of nanocomposites, the molecular weight of nylon 6 was affected by the clay content. From the mechanical property measurement, improved properties were obtained in comparison to the neat nylon 6, and these properties were also affected by the molecular weight.

• Biomolecules & Therapeutics
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• 제1권1호
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• pp.44-49
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• 1993

cis-Dichlorodiammineplatinum(cisplatin) is one of the most effective antitumor agents currently available for cancer therapy. However, its clinical use has been limited by its severe side effects, especially nephrotoxicity. So, to evaluate the effects of 2(3)-tert-butyl-4-hydroxyanisole(BHA) on cisplatin nephrotoxicity in rats, both compounds were given intraperitoneally. Remarkable protective effects of BHA against nephrotoxicity of cisplatin were observed when BHA was administered to rats 1hr after cisplatin injection. On the other hand pretreatment with BHA 1hr prior to cisplatin did not reduce weight loss, blood urea nitrogen and creatinine levels. Hepatotoxicity induced by combination treatment of cisplatin and BHA was evaluated by measuring serum glutamic pyruvate transaminase and serum glutamic oxalate transaminase. Combination treatment did not affect the levels of SGPT and sGOT except 1hr pretreatment. The present results indicate that BHA may provide protection against cisplatin nephrotoxicity, when it is given 1hr after cisplatin.

• 대한기계학회논문집B
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• 제22권12호
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• pp.1647-1656
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• 1998

The drag reduction is the phenomenon that occurs only when the shear stress from the wall of pipe is beyond the critical point. The drag reduction increase as the molecular weight, concentration of the polymer and Reynolds number increase, but it is limited by Virk's maximum drag reduction asymptote. Because of the strong shear force for the polymer on the turbulent flow, the molecular weight and the drag reduction do not decrease. Such mechanical degradation of the polymer occurs in all polymer solvent systems. This paper is to identify and develop high performance polymer additives for fluid transportations with the benefits of turbulent drag reduction. In addition, drag reduction in vertical flow by measuring the pressure drop and local void fraction on vertical-up flow of close system is evaluated.

• 한국멀티미디어학회논문지
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• 제21권9호
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• pp.1035-1043
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• 2018

There is a case where the core content of another person's work is decorated as though it is his own thoughts by changing own thoughts without showing the source. Plagiarism test of copykiller free service used in plagiarism check is performed by comparing plagiarism more than 6th word. However, it is not enough to judge it as a plagiarism with a six - word match if it is replaced with a similar word. Therefore, in this paper, we construct word clusters by using DBSCAN algorithm, find synonyms, convert the words in the clusters into representative synonyms, and construct L-R tables through L-R parsing. We then propose a method for determining the similarity of documents by applying weights to the thesaurus and weights for each paragraph of the thesis.

• 한국염색가공학회지
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• 제11권1호
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• pp.48-60
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• 1999

In this paper, a new regenerated celluosic fiber, "Tencel" was treated with cellulase enzyme. Also Tencel fabrics were pretreated with NaOH and dyed with various reactive dyes, and subsequently finished with DMDHEU. $\Delta{E}^*_{ab}$ value was calculated by measuring color difference before and after wet abrasion test to rubbing. The fibrillation propensity was estimated on Tencel by means of weight loss, $\Delta{E}^*_{ab}$ value, and SEM observation. Weight loss of NaOH pretreated Tencel fabric is more lower than that of original fabric. The cellulase treatment decreased tensile strength but improved wet abrasion strength, wrinkle recovery, and bending properties. Tendency of fibrillation for Tencel fabric was reduced by NaOH-pretreatment, dyeing with multifunctional reactive dyes, and afterfinishing by DMDHEU.by DMDHEU.