• Title/Summary/Keyword: and R&D mechanism

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Influence of Coating Defect Ratio on Tribological Behavior Determined by Electrochemical Techniques (전기화학적 분석을 통해 산출된 코팅 결함율이 트라이볼로지적 특성에 미치는 영향 평가)

  • Lee Young-Ze;Kim Woo-Jung;Ahn Seung-Ho;Kim Ho-Gun;Kim Jung-Gu;Cho Chung-Woo
    • Tribology and Lubricants
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    • v.20 no.6
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    • pp.306-313
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    • 2004
  • Many of the current development in surface modification engineering are focused on multilayered coatings, which have the potential to improve the tribological properties. Four different multilayered coatings were deposited on AISI D2 steel in this study. The prepared samples are designed as $WC-Ti_{0.6}Al_{0.4}N,\;WC-Ti_{0.53}Al_{0.47}N,\;WC-Ti_{0.5}Al_{0.5}N\;and\;WC-Ti_{0.43}Al_{0.57}N$. The multilayered coatings were investigated with respect to coating surface and cross-sectional morphology, roughness, adhesion, hardness, porosity and tribological behaviors. Especially, wear tests of four multilayered coatings were performed by using a ball-on-disc configuration with a linear sliding speed of 0.017 m/sec and a normal load of 5.38 N load. The tests were carried out at room temperature in air by employing AISI 52100 steel ball $(H_R\;=\;66) $ having a diameter of 10 mm. The surface morphology, and topography of the wear scars of samples and balls have been determined by using scanning electron spectroscopy (SEM). Also, wear mechanism was determined by using SEM coupled with energy-dispersive spectroscopy (EDS). Results have showed an improved wear resistance of the $WC-Ti_{1-x}Al_xN$coatings with increasing of Al (aluminum) concentration.

A Study on the Alternative Dispute Resolution in America (미국의 재판외 분쟁해결제도)

  • 김태한
    • Journal of Arbitration Studies
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    • v.13 no.2
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    • pp.181-209
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    • 2004
  • This Study is divided into 5 separate Parts and an Abstract. Part Ⅰ, Ⅱ consist mostly of a collection of problems, current status, motives and the future of ADR. In Pert Ⅲ was described ADR as policies of judicial settlements. We must accept that a diversity of legal culture will always continue to exist. Accordingly we must learn to accommodate those differences of 'culture' around us and to harmonize conflicting laws. This recognition of our reality should in no way be confused with pessimism. In fact if one accepts this perspective of the world ,the study of law seems enriched and becomes academically more challenging. Recently, in the United States, interest in alternative settlement mechanism has increased greatly, which leads me to wonder why such a phenomenon has taken place. In the first place, I'm amazed at the extent to which conciliation or mediation-or the new word, I guess, is alternative dispute resolution, which by now has its own acronym, "A.D.R,"-have gained attention here recently. When 35 years ago, there was virtually no interest in conciliation in this country at the time. What interest there was, was no in the law schools. But looking at the situation now, we have a spate of publications on the subject; we have organizations that are established for no other reason than to promote alternative dispute settlement. We have courses in the law schools. The American Association of Law Schools and the American Bar Association also have active programs. So we have to ask ourselves why. The difference between now and 35 years are striking. On the other hand, I think the interest of the public in ADR has probably been greatly enhanced by the politics of the so-called "poverty programs." I think that many of these assistance programs for the poor-and I do think the "poor" have become a rather expansive political movement beyond simply taking care of the most marginal people of society-have generated money to explore this kind of dispute resolution.

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A Design of Mobile Fitness Recommendation System Based on Data Sharing Mechanism (실시간 이상거래 탐지 기법에 관한 연구)

  • Jang, Ki-Man;Kim, Kyung-Hwan;Choi, Kwang-Nam;Kim, Chang-Su;Jung, Hoe-Kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.763-765
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    • 2015
  • The study is being conducted to ensure the transparency of research and development have identified the problems of the current system and improve the way out. Such a study about the subject that do not follow either outside the institutional system has a disadvantage compared to an unfulfilled. R & D in order to prevent the misuse and fraud enforcement shall detect abnormal transactions that occur from transactions between research institutions and credit card issuers in real time. In this paper, we propose a detection method for real-time transaction over. It is able to detect and respond fraudulent transactions that may occur in a variety of environments by adding the data obtained by the business rules to derive stopped making detection system.

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Radioprotective Potential of Panax ginseng: Current Status and Future Prospectives (고려인삼의 방사선 방어효과에 대한 연구현황과 전망)

  • Nam, Ki-Yeul;Park, Jong-Dae;Choi, Jae-Eul
    • Korean Journal of Medicinal Crop Science
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    • v.19 no.4
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    • pp.287-299
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    • 2011
  • Pharmacological effects of Panax ginseng have been demonstrated in cardiovascular system, endocrine secretion and immune system, together with antitumor, anti-stress and anti-oxidant activities. Modern scientific data show protective effect of ginseng against bone marrow cell death, increased survival rate of experimental animals, recovery of hematopoietic injury, immunopotentiation, reduction of damaged intestinal epithelial cells, inhibition of mutagenesis and effective protection against testicular damages, caused by radiation exposure. And also, ginseng acts in indirect fashion to protect radical processes by inhibition of initiation of free radical processes and thus reduces the radiation damages. The research has made much progress, but still insufficient to fully uncover the action mechanism of ginseng components on the molecule level. This review provides the usefulness of natural product, showing no toxic effects, as an radioprotective agent. Furthermore, the further clinical trials on radioprotection of ginseng need to be highly done to clarify its scientific application. The effective components of ginseng has been known as ginsenosides. Considering that each of these ginsenosides has pharmacological effect, it seems likely that non-saponin components might have radioprotective effects superior to those of ginsenosides, suggesting its active ingredients to be non-saponin series. These results also show that the combined effects of saponin and non-saponin components play an important role in the radioprotective effects of ginseng.

Heat Treatment Deformation Analysis of Bearing Considering Phase Transformation (상변태를 고려한 베어링의 열처리 변형 해석)

  • S.P. Lee;S.J. Lee;T.B. Kim;K.T. Cho
    • Journal of the Korean Society for Heat Treatment
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    • v.36 no.6
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    • pp.351-358
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    • 2023
  • Bearings are mechanical components that support loads and transmit rotation. The inner and outer rings come into contact with the rotating mechanism, requiring a very high level of hardness. To meet this requirement, heat treatment is commonly performed. The heat treatment process inherently involves thermal deformation. Particularly in the case of large bearings, significant deformation relative to the bearing's shape can occur, making accurate deformation prediction during heat treatment essential. However, predicting deformation in heat treatment is challenging due to the simultaneous consideration of phase transformation, heat transfer, and bearing deformation. In this study, an analysis of heat treatment-induced deformation in bearings was conducted, taking phase transformation into account. The thermal and mechanical properties were calculated based on the chemical composition of the bearing material. This information was then used to perform a deformation-heat transfer-phase transformation analysis. To validate the reliability of the analysis, experiments were conducted under the same conditions. When comparing the analysis and experimental results, differences in deformation were observed. These differences were attributed to variations in phase transformation conditions between the analysis and experiments. Consequently, it is anticipated that supplementing these results will enable the prediction of deformation while considering phase transformation conditions in bearings.

Experimental Study of Endostar Injection Concomitant with Cryoablation on Lung Adenocarcinoma A549 Xenografts

  • Ma, Chun-Hua;Jiang, Rong;Li, Jin-Duo;Wang, Bin;Sun, Li-Wei;Lv, Yuan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6697-6701
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    • 2013
  • Objective: To explore the inhibiting effect and mechanism of Endostar injection concomitant with cryoablation on lung adenocarcinoma A549 xenografts in nude mice. Materials and Methods: A total of 24 nude mice with subcutaneous xenografts of the A549 cell line were established and divided into 4 groups when the maximal diameters of tumors became 1 cm: control group, Endostar group, cryoablation group and combination group (Endostar concomitant with cryoablation). The nude mice were sacrificed after 21-days treatment, tumour tissues were removed to measure their volume, in situ test of TdT-mediated dUTP nick end labeling (TUNEL) was adopted to determine the cellular apoptosis around freezing injury zones, and immunohistochemical SP test was applied for the detection of micro-vessel density (MVD) and vascular endothelial growth factor (VEGF) expression levels. Results: At 21-days after treatment, the growth velocities of control group, Endostar group, cryoablation group and combination group were $236.7{\pm}51.2%$, $220.0{\pm}30.6%$, $159.5{\pm}29.3%$ and $103.3{\pm}25.5%$ (P<0.01), while cellular apoptosis rates of tumors were $21.7{\pm}2.34%$, ($22.17{\pm}1.47$)%, $38.3{\pm}1.37%$ and $49.2{\pm}1.72%$, (P<0.01), respectively, according to the immunohistochemical test. MVD and VEGF expression levels in the combination group were both lower than in other groups (P<0.01), also being positively related (r=0.925, P<0.01). Conclusions: Endostar can significantly improve the inhibitory effects of cryoablation on xenografts of lung adenocarcinoma A549, and the mechanism is probably associated with its function as an inhibitor of tumour neo-angiogenesis through down-regulating VEGF expression.

Study on the Compact MR fluid Brake for the Training and Sporting Equipment for Leg Rehabilitation (하지 재활운동치료 기구에 적용하기 위한 소형 MR 유체 브레이크에 관한 연구)

  • Park, Woo-Cheul;Lee, Hyun-Chang;Kim, Il-Gyoum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.7
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    • pp.2878-2885
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    • 2012
  • In this study, the training and sporting equipment for leg rehabilitation featuring the MR fluids is proposed. The compact MR fluid brake is designed and manufactured to apply to the rehabilitation training and sporting mechanism. The resistance characteristic of the MR fluid brake is controllable by varying the magnetic field around the fluid. Under consideration of spatial limitation, design parameters which are related with the magnetic strength are determined to maximize to a torque using finite element method. The FE analysis is performed using a commercial code, ANSYS Workbench. The proposed brake device is manufactured, and its field-dependant torque is experimentally evaluated. When the electric current is supplied, the torque of the MR fluid brake is increased and the response is very fast. Depending on the strength of the current supply, torques of the MR fluid brake also increase similar to Bingham property of MR fluid.

An Investigation on Surgical Parameters for the Treatment of Intervertebral Disc during Electrothermal Therapy (디스크의 전기열치료시 수술변수에 관한 연구)

  • Jin E.D.;Choi J.S.;Tack G.R.;Lee B.S.;Lee B.Y.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.513-514
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    • 2006
  • Recently intradiscal electrothermal therapy is introduced, which is a new and minimally invasive technique fer the treatment of discogenic low back pain. This procedure involves the percutaneous threading of a flexible catheter into the disc under fluoroscopic guidance. The catheter, composed of thermal resistive coil, heats the posterior annulus of the disc, causing contraction of collagen fibers and destruction of afferent nociceptors. This study tries to investigate the effects of the important factors of this procedure such as heat source temperature and heat applying time on the temperature distribution within the intervertebral disc. This study utilized both computer simulation and the experiment for the verification of finite element analysis. FE analysis was carried out with ANSYS v7.0 (ANSYS Inc, USA) using 10,980 number of brick element and 12,551 number of node. The functional spinal units of 5 month old swine were used for the experiment and the temperature was monitored using 10 channel temperature measurement device MV200. Through this study, it was able to analyze the temperature range of inner intervertebral disc by two mechanisms which are known to alleviate pain clinically. The results showed that when the heat source temperature was kept up 80 degree for 1,020 seconds, the temperature of inner annulus reached at 45 degree up to the distance of 15.6mm from heat source, which explains coagulation of inner annulus by heat. When the same heat source was used, the temperature of inner nucleus reached at 60 degree up to the distance of 9mm from heat source, which explains contraction of inner nucleus by heat.

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Molecular dynamics study of redeposition effect by Ar ion bombardments on Au, Pd(001) (Ar이온 충돌에 의한 Au, Pd(001) 표면에서 재증착 효과의 분자동역학 연구)

  • Kim, S.P.;Kim, S.J.;Kim, D.Y.;Chung, Y.C.;Lee, K.R.
    • Journal of the Korean Vacuum Society
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    • v.17 no.2
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    • pp.81-89
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    • 2008
  • Atomic behavior during ion beam sputtering was investigated by using classical molecular dynamics simulation. When Ar ion bombards on Au and Pd(001) surface with various incidence energies and angles, some atoms which gained substantial energy by impacting Ar ion were sputtered out and, simultaneously, others were landed on the surface as if surface atoms were redeposited. It was observed that the redeposited atoms are five times for Au and three times for Pd as many as sputtered atoms irrespective of both incidence energy and angle. From sequential ion bombarding calculations, contrary to the conventional concepts which have described the mechanism of surface pattern formation based only on the erosion theory, the redeposition atoms were turned out to play a significant role in forming the surface patterns.

Light-regulated Translation of Chloroplast Reaction Center Protein D1 mRNA in Chlamydomonas reinhardtii

  • Kim, Jungmook
    • Proceedings of the Botanical Society of Korea Conference
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    • 1999.07a
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    • pp.57-62
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    • 1999
  • Light-regulated translation of chloroplast mRNAs requires nuclear-encoded trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. A set of four proteins (60, 55, 47, and 38 kDa) that bind to the 5'-UTR of the psbA mRNA had been identified in C. reinhardtii. 47 kDa protein (RB47) was found to encode a chloroplast poly (A)-binding protein (cPABP) that specifically binds to the 5'-UTR of the psbA mRNA, and essential for translation of this mRNA, cDNA encoding 60 kDa protein (RB60) was isolated, and the amino acid sequence of the encoded protein was highly homologous to plants and mammalian protein disulfide isomerases (PDI), normally found in the endoplasmic reticulum (ER). Immunoblot analysis of C. reinhardtii proteins showed that anti-PDI recognized a distinct protein of 56 kDa in whole cell extract, whereas anti-rRB60 detected a 60 kDa protein. The ER-PDI was not retained on heparin-agarose resin whereas RB60 was retained. In vitro translation products of the RB60 cDNA can be transported into C. reinhardtii chloroplast in vitro. Immunoblot analysis of isolated pea chloroplasts indicated that higher plant also possess a RB60 homolog. In vitro RNA-binding studies showed that RB60 modulates the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP using redox potential or ADP-dependent phosphorylation. Site-directed mutagenesis of -CGHC- catalytic site in thioredoxin-like domain of RB60 is an unique PDI located in the chloroplast of C. reinhardtii, and suggest that the chloroplast PDI may have evolved to utilize the redox-regulated thioredoxin like domain as a mechanism for regulating the light-activated translation of the psbA mRNA.

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