• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.322-326
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• 2008

In this paper, we have studied the images which have been reconstructed by using combination of images acquired by the variation of operating frequency. When inner images have been reconstructed, they have been superposed by the surface state effect. In this case, the images of the phase object can be enhanced by the contrast of inner images. There is a kind of specimen, one is a reference block having 1/4T, 1/2T, 3/4T side drilled holes as main run piping material of the steam generator in nuclear power plants. It has been shown that the two results of defect shapes have better than before in this processing and phase contrast grow about twice. And we have constructed the acoustic microscope by using a quadrature detector that enables to acquire the amplitude and phase of the reflected signal simultaneously. Further more we have studied the reconstruction method of the amplitude and phase images, the enhancement method of the defect images' contrast.

• 대한화학회지
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• 제15권5호
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• pp.256-265
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• 1971

An ESR study has been made on free radicals produced in frozen aqueous solutions (ices) of glycine, DL-${\alpha}$-alanine, DL-serine, L-cysteine, DL-leucine and DL-isoleucine by gamma-irradiation at dry ice temperature. All free radicals induced were decayed concomitant to the successive annealing but the radical species which is believed to be dominant seems to be stable even near the melting point of the ice. These dominant species were found to be identical to those resulted from direct action of radiation in the solid at room temperature. Small but significant changes in the spectra of glycine and DL-${\alpha}$-alanine were observed by varying the microwave power. These results seem to support the view that the spectra obtained were composite consisting of more than two different resonances having different power saturation characteristics. The relative contribution of unidentified resonances to the composite spectra was greater for solutions of low concentration. These resonances are assumed to be induced by indirect effects, mainly hydrogen abstraction by radiation produced hydroxyl radicals and also C-N bond cleavage by hydrated electrons.

• 한국도서관정보학회지
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• 제43권3호
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• pp.239-263
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• 2012

학교도서관이 상황이 열악하다보니 학교도서관의 운영이나 독서교육과 관련하여 지역의 공공도서관에 도움을 청하는 학교가 적지 않다. 그러나 공공도서관이 처한 여러 가지 현안을 해결해 나가는 데에도 벅찬 실정에서 학교도서관 지원에 관한 업무까지 해나가야 한다는 사실에 공공도서관에서는 적지 않은 부담을 느끼고 있다. 이러한 상황에서 부산시에서는 지역대표도서관인 부산시립시민도서관과 대학의 문헌정보학과, 그리고 지역교육청이 공동으로 참여하여 '학교도서관을 활용한 독서 멘토링 활동'을 시범적으로 전개해 보았다. 이 연구는 지난 7개월 간의 경험을 토대로 학교도서관의 독서교육을 활성화하기 위한 방안으로서 독서 멘토링 활동의 효과에 대해 고찰하는데 목적을 두고 있다.

• 한국IT서비스학회지
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• 제11권sup호
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• pp.177-189
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• 2012

We developed the ocean disaster detection system(OD2S) which copes with the occurrences of ocean disasters (e. g. the red and green tide, the oil spill, the typhoon, and the sea ice) by converging and integrating the ocean color remote sensing using the satellite and the information technology exploiting the mass data processing and the pattern recognitions. This system which is based on the cosine similarity detects the ocean disasters in real time. The existing ocean color sensors which are operated in the polar orbit platforms cannot conduct the real time observation of ocean environments because they support the low temporal resolutions of one observation a day. However, geostationary ocean color imager(GOCI), the first geostationary ocean color sensor in the world, produces the ocean color images(e. g. the chlorophyll, the colored dissolved organic matter(CDOM), and the total suspended solid(TSS)), with high temporal resolutions of hourly intervals up to eight observations a day. The evaluation demonstrated that the OD2S can detect the excessive concentration of chlorophyll, CDOM, and TSS. Based on these results, it is expected that OD2S detects the ocean disasters in real time.

• 자원환경지질
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• 제33권5호
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• pp.353-365
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• 2000

After their first appearance on Earth, bacteria have exerted significant influence on geochemical behavior of elements. Numerous evidence of their control on geochemistry through geologic history has been observed in a variety of natural environments. They have mediated weathering rate, formation of secondary minerals, redox transformation of metals and metalloids, and thus global cycling of elements. Such ability of bacteria receives so considerable attention from microbiologists, mineralogists, geologists, soil scientists, limnologists, oceanographers, and atmospheric scientists as well as geochemists that a new and interdisciplinary field of research called 'geomicrobiology' is currently expanding. Some recent subjects of geomicrobiology which are studied extensively are as follows: 1) Functional groups distributed on bacterial cell walls adsorb dissolved cations onto cell surfaces by electrostatic surface complexation, which is followed by hydrous mineral formation. 2) Dissimilatory metal reducing bacteria conserve energy to support growth by oxidation of organic matter coupled to reduction of some oxidized metals and/or metalloids. They can be effectively used in remediating environments contaminated with U, As, Se, and Cr. 3) Bacteria increase the rate of mineral dissolution by excreting proton and ligands such as organic acids into aqueous system. 4) Thorough investigation on the effects of biofilm on geochemical processes is needed, because most bacteria are adsorbed on solid substrates and form biofilms in natural settings.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2001년도 Bulletin of The 5th Asian Design Conference International Symposium on Design Science
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• pp.27.1-27
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• 2001

The purpose of rhis research is proposing rhe sysrem which does information supporr as for a truck driver, and verifying the validity. First, it investigated by visiting the Transporr Company and interview for the present situation and the opinion on computerization from the operation administrator and truck drivers. Consequently, the problem of computerization could be found out to the present system. Next, the present system was considered. As for present machine system, human's "Choosing a function", srarts processing. Then this system is called "Function-Oriented-System". And three problems were extracted from this sysrem. As a solution of those problems, the Purpose-Oriented-System was proposed. In order to attain user's purpose, Agent that situation is perceived and works a function autonomously assumed that this system was inherent. 3D-Sceanrio-Expression was proposed as the description method of rhe task process. It consists of "Machine and Functional-Item axis", "Time axis", and "Situation-Item axis". And, the task execution process of Function-Oriented-System and Purpose-Oriented-System was compared using 3D-Sceanrio-Expression supposing the scene of truck business. As a resulr, rhe following two things could be found out. (1) The concepr of Purpose-Oriented-System that Agent is inherent is effective as siruarion correspondence machine. (2) A solid scenario can express the interaction rhar cannor be seen, in the relarion of rhe conventional Human and Machine.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.766-772
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• 2002

The plasmid, pJHKJ4, containing the endoxylanase gene, was introduced into Bacillus subtilis DB 104. The recombinant cells produced 587 unit/ml of endoxylanase at 33 h. The endoxylanase was immobilized covalently on the surface of silica fur effective xylan hydrolysis. The activities of the immobilized and free endoxylanases were optimal at pH 6.5 and 10 mM $MnSO_4$. The optimal temperature of the immobilized endoxylanase was $60^{\circ}C$, whereas that of the free endoxylanase was $65^{\circ}C$. Under these optimal conditions, the activity of the immobilized endoxylanase was 1.7 times higher than that of the fee endoxylanase. From microscope photographs, the immobilized endoxylanase was found to be bounded and evenly distributed on the surface of silica, a nonporous solid support. The enzyme kinetics between the immobilized and free endoxylanases was estimated to be uncompetitive, when plotting double-reciprocal plots against xylan concentrations and endoxylanase activities. These results suggest that the higher activity of the immobilized endoxylanase may be due to increased formation of enzyme-substrate complex, because of the easy accessibility of the immobilized enzyme to the polysaccharide-xylan as a high molecular weight substrate.

• Tribology and Lubricants
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• 제28권6호
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• pp.278-282
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• 2012

Various bearings such as deep-groove ball bearings, angular-contact ball bearings, and roller bearings are used to support the load and to lubricate between the shaft and the housing. The bearings of potential rolling systems in a turbo pump are the deep-groove ball bearings as comparing with the bearings with rolling elements such as cylindrical rollers, tapered cylindrical rollers, and needle rollers. The deep-groove ball bearings consist of rolling elements, an inner raceway, an outer raceway and a retainer that maintain separation and help to lubricate the rolling element that is rotating in the raceways. In the case of water-lubricated ball bearings, however, fluid friction between the ball and raceways is affected by the entry direction of flow, rotation speed, and flow rate. In addition, this friction is the key factor affecting the bearing life cycles and reliability. In this paper, the characteristics of flow conditions corresponding to a deep-groove ball bearing are investigated numerically, with particular focus on the friction distribution on the rolling element, in order to extend the analysis to the area that experiences solid friction. A simple analysis model of fluid flow inside the water-lubricated ball bearing is analyzed with CFD, and the flow characteristics at high rotation speeds are presented.

• 한국임상수의학회지
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• 제18권4호
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• pp.358-362
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• 2001

Brain dead (BD) patients remain the largest source of solid organs for transplantation. BD has shown to decrease graft function and survival in rodent models. The aim of this study was to evaluate how brain death affects graft viability in the donor and kidney tolerance to cold preservation as assessed by survival in a canine transplantation. 13 Beagle dogs were used for the study. Brain death was induced by the sudden inflation of a subdural balloon catheter with continuous monitoring of arterial blood pressure and eletroencephalographic activity (n=3). Sixteen hours after conformation of brain death, kidney graft were retrieved (n=6). Non-BD donors served as controls (n=4). All kidneys were flushed with University of Wisconsin (UW) solution and preserved for 24 hours at 4$^{\circ}C$ before transplantation. Recipient survival rates, serum creatinine level were analyzed. Brain death induced the well-known Cushing reaction with a severe increase in blood pressure and tachycardia. Thereafter, cardiac function returned progressively to baseline within 8 hours and remained stable until the end of the experiment. All of dogs in both group transplanted were survived until 7 days (100%), and the kidneys showed functional early rejection at 8.3$\pm$0.5 days and 8.5$\pm$0.5 days after transplantation, in BD and allograft group, respectively. BD kidneys were functionally similar to control kidneys for 7 days after transplantated. Brain death has no deleterious effect on preservation injury and survival of dog kidney transplantation, although it induces changes in hemodynamic parameters. This study reveals that kidneys from BD donors do not exhibit more ischemia reperfusion injury, and support good early function and survival.

• 분석과학
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• 제28권1호
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• pp.17-25
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• 2015

A rapid, sensitive and specific method was developed and validated using electrospray ionization (ESI) tandem mass spectrometry (LC-MS/MS) for determination of misoprostol acid in human plasma. Misoprostol $acid-d_5$ was used as in internal standard (IS). The analyte and IS were extracted by simple one step solid phase extraction (SPE). Linearity in plasma was obtained over the concentration range 10~3000 pg/mL and lower limit of quantification (LLOQ) was identifiable and reproducible at 10 pg/mL. The intra- and inter-day precision values were below 9% and the accuracy was ranged from 93.81% to 102.02% at all four quality control samples. The method was has been successfully applied for routine assay to support pharmacokinetic study of misoprostol acid in human plasma after an oral administration of 0.4 mg misoprostol.