• Korean Journal of Materials Research
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• v.9 no.10
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• pp.1025-1031
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• 1999

Alloys of TiAl with six different compositions. i. e., Ti-(42, 44)Al-2Nb-4V. Ti-(42, 44)Al-4Nb-2V and Ti -(42, 44)Al-4Nb-2Cr, were manufactured by arc-melting. and their oxidation behavior was studied. Both isothermal and cyclic oxidation tests were performed at 700, 800 and $900^{\circ}C$ in air for 50hr. The oxidation resistance increased in the order of Ti-(42, 44)Al-2Nb-4V, Ti-(42, 44)Al-4Nb-ZV and Ti-(42, 44)Al-4Nb-2Cr. It was found that V was a deleterious element, while Cr was a beneficial element in terms of oxidation resistance. During oxidation, a simultaneous interdiffusion was observed. All the constituent elements in the base alloys diffused outward. whereas oxygen from the atmosphere diffused inward, to form triple oxide layers composed of an outermost $\textrm{TiO}_2$ layer. upper ($\textrm{TiO}_2+\textrm{Al}_2\textrm{O}_3$) mixed layer, and lower $\textrm{TiO}_2$-rich layer.

• Journal of Korea Technology Innovation Society
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• v.15 no.2
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• pp.242-261
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• 2012

Early stages of technology valuation have been often overlooked or under-represented. The early stage technologies are even riskier due to their inadequacy of commercial development and market applicability. More than 95% of patents fail to earn any revenues so that the majority of patents were valueless. Technology transfers from laboratories at universities and research institutes to industrial firms have increased to acquire value from invented technologies. Technology transfer, a process of transferring discoveries and innovations resulted from research to commercial sectors, typically comprises several steps: disclosing the discoveries and innovations, i.e., intellectual property (IP), evaluating the IP's economic prospects, securing a patent, copyright or trademark for the IP, commercializing the technology through licensing, forming a joint venture, or selling. At each of those stages in the research and development of technology, the value of technology would play a very important role of making decision on the movement toward the next step, however, the financial value of technology is not easy to determine due to a great amount of uncertainty in the course of research and development, and commercialization. This paper refers to technology embodied as devices, equipment, software or processes primarily developed at public research institutions such as universities. Sometimes it is also as the result of externally financed projects contracted with industry. Nearly always technology developed at public research entities results in laboratory prototypes. When it is required to define the technology transfer contract terms for the license of the university patrimonial rights to external funding companies or other interested parties, a question arises: what is the monetary value? In this paper, we present a method for technology valuation based on the identification of specific value points related to its development. The final technology value must be within previously defined value limits. This paper consists of the review of issues related to technology transfer and commercialization, the identification of characteristics of technologies in the early stage of technology development, the formulation of framework of methods to value the early stage technologies, and the conclusion and implication of the previous review.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.57-66
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• 1990

The author conducted a dental survey of college girl students and compared with that of college students 20 years and 10 years ago which based on the same criteria. The items of this survey included the prevalence of dental caries, DMFT and the kinds of restored materials. College girl students 2,294 were examined in May 1988, with the recommended criteria and method of W.H.O.. Among them, the data of 2,243 were analyzed and compared with the data of 1968 and 1978. The following results were obtained : 1. The average number of present teeth was $28.86{\pm}1.65$, which does not show much difference when compared to $29.00{\pm}1.94$ of 1968 and $28.97{\pm}1.64$ of 1978. 2. The prevalence of dental caries was 86.22%, which increased in comparison to 83.25% of 1968 and 84.92% of 1978. 3. DMF index was 19.98, which considerably increased in comparison to 14.56 of 1968 and 15.51 of 1978. 4. The number of DMFT was $5.75{\pm}5.04$ per student. Compared to $4.23{\pm}3.88$ of 1968 and $4.49{\pm}3.69$ of 1978, there is a considerable increase. I) The average number of decayed(D) teeth was $1.14{\pm}1.63$, which decreased from $1.16{\pm}1.57$ of 1968 and $2.09{\pm}2.16$ of 1978. II) The average number of missing(M) teeth was $0.23{\pm}0.73$, which also decreased from $0.69{\pm}1.11$ of 1968 and $0.32{\pm}0.79$ of 1978. III) The average number of filled(F) teeth was $4.39{\pm}4.91$, which increased from $2.38{\pm}3.33$ of 1968 and $2.09{\pm}3.17$ of 1978. 5. According to the analysis of filling material, filling baby including amalgam, gold inlay, resin, silicate cement and paladium inlay was 90.5%, which increased in comparison to 72.8% of 1968 and 83.6% of 1978. Among them, amalgam occupied 62.93%, which showed the most increase. On the other hand, crown and bridge was 6.5%, 3.0%, respectively, which showed continuous decrease from 12.1%, 15.1% of 1968 and 8.7%, 7.7% of 1978. Therefore, the prosthodontic treatment reduced due to the decrease of tooth extraction. In contrast, there is continuous increase of conservative treatment which maintaining natural tooth.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.17-26
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• 1987

To develop the rehabilitation measures for rockily denuded forest lands which are widely distributed in Seoul metropolitan area, erosional characteristics of denudation should, first of all, be evaluated and analysed. As a fundamental study for developing such technical measures, the rockily denuded lands were classified into 6 types according to denudation features of the mountain land, and also movements of stone debris-and-sand on rock-exposed hillslopes were measured and analysed. The 6 basic types of denudation features include a) natural rock-outcrop-exposed land, b) stone debris-and-sand scattered land, c) stone debris-and-sand deposited land, d) coarse sand producing bare land susceptible to weathering and erosion, e) dwarfed pine growing land, and f) torrential valley susceptible to the debris slides. In the stone debris-and-sand scattered hillslopes (type b), average amount of moved-down debris reached to about 3.9 ton/ha/yr due to surface washing and slidings. In the particle size distribution of the moved-down debris, it amounts to about 25% of 10-25mm, about 15% of 5-10mm, about 24% of 2-5mm, and about 36% of less than 2mm in diameter class, respectively. The detailed experimental studies should be accomplished further more about the denudation processes including weathering, erosion and debris slides on rock-exposed hillslopes.

• Journal of Acupuncture Research
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• v.22 no.1
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• pp.41-60
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• 2005

Objective : The purpose of the present study was to evaluate the effect of acupuncture therapy on the premenstrual syndrome. Methods : Volunteers of twenty subjects were employed using DRSP questionnaire. Subjects were divided into two groups including active-acupuncture treatment group, placebo acupuncture treatment group. In the control group, subjects were needled at $SI_5$, $ST_{40}$ points and in the acupuncture group, subjects were stimulated at two basic points, $SP_6$ and $CV_6$, and several points were inserted additionally depending the symptoms including $LR_2$, $LR_3$, $SP_10$, $LI_4$, and $ST_3$. A total of 13 acupuncture sessions were performed for each patient depending on the individual menstruation cycle over 8 weeks. Concentration of blood progesterone was examined and Digital Infrared Thermal Imaging (DITI) was taken before and after acupuncture treatment.

• 전자공학회논문지 IE
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• v.47 no.3
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• pp.19-25
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• 2010

We developed a RFID terminal to voice guide the blind who have difficulties in reaching out to the pharmaceutical information. In this work, we used RFID technology to instruct the pharmaceutical information to the blind. The voice guidance reader was made to read the RFID tag attached to the drugs and announced the pharmaceutical information matching to the tag specific ID. We had the reader to obtain the pharmaceutical information from the ezDrug site operated by Korea Food & Drug Association. The voice guidance reader was fabricated as necklace type for the easy carry, and we added mp3 player as dual uses. ARM series Cortex M3 chip was used for the reader's core chip and low power MFRC523 chipset of NXP was used to construct RFID circuit. MFRC523 chip uses low power to meet the mobile application. We used VS1003B MP3 Decoder IC to make the voice generation circuit and CC2500 chipset for the wireless communication to the pharmaceutical information server. We also developed the system that can support ISO 14443A type and ISO 14443B type so that the system can be used to extend to various RFID protocols. Utilization of this system can conveniently convey the pharmaceutical information to the blind and reduce the drug abuse.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.185-192
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• 1999

The present study was performed to investigate the efficacy and safety of laser assisted hatching (AH) on mouse embryos. Non-contact $1.48{\mu}m$ diode laser system used to create a precise hole on zona pellucida. 2-cell embryos were collected from the mice (ICR) that had the coitus vaginal plug confirmed at 48 hours after hCG injection. Collected 2-cell embryos were cultured in the HTF medium supplemented with 0.4% BSA. For experiments, embryos at 8-cell stage were used after 18-22 hours in culture. After assisted hatching, the embryos were further cultured in HTF medium containing 0.1% PVP (anti-hatching system) for 3 days. For evaluate efficiency of laser on mouse embryo hatching, the effect of AH methods (acidic tyrode, pronase and laser), the number of artificial holes (1, 2 and 3 hole) and the irradiation time of laser (2, 4, 6, 8 and 10 ms) were examined. Hatching rates of laser AH group (95.2%) was significantly higher than that of control group (50.8%), but there was no differences among the laser (95.2%), acidic tyrode (100%) and pronase (98.5%) groups. Hatching rates of the number of zona pellucida opening by laser, there were no differences among the 1 hole (87.5%),2 hole (92.1%) and 3 hole (85.9%) groups. Developmental and hatching rates of embryos according to laser irradiation time were similar in the treatment groups. Therefore, these results suggest that laser AH using non-contact $1.48{\mu}m$ diode laser is a simple and accurate and effective procedure for AH. Based on these results, laser AH could be use safely for human ART program.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1753-1764
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• 2014

Numerical flow simulation models in the riverine environments have been widely utilized for analyzing flow dynamics in various degrees in researches and practical applications. However, most of the simulated results have been validated based on the data from indoor experimental models or very limited in-situ measurements. Therefore, it has been required to more accurately validate the performance of the numerical models in terms of the detailed field observations. In particular, it was also hard to validate the performances of the existing numerical models in the real meandered river channels that encompass more sophisticated flow and geometric structures. Recently, advancements of the modern flow measuring instrumentations such as acoustic Doppler current profilers (ADCPs) enabled us to efficiently acquire the detailed flow field in the broad range of river channels, thus that it became to be possible to accurately validate any numerical models with the field observations. In this study, based on the detailed flow measurements in a actual meandered river channel using ADCP, we validated FaSTMECH model in iRIC in terms of water surface elevation, which is relatively new but began to get highlighted in the research areas. As the validation site, a meandering channel in River Experiment Center of KICT was chosen, which has 6.5 m of width, 0.38m of flow depth, 1.54 m3/s of flow discharge, 0.61 m/s of mean flow velocity, and 1.2 of sinuosity. As results, whereas the FaSTMECH precisely simulated water surface elevation, simulated velocity field in the bend did not match well with ADCP dataset.

• Korean Journal of Clinical Pharmacy
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• v.21 no.4
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• pp.297-304
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• 2011

배경: 골다공증은 골대사의 불균형으로 인해 골 흡수가 골 형성보다 많아져 골밀도가 감소함으로서 발생한다. 골다공증의 이상적인 치료목표는 골형성을 증가시키거나 골소실을 방지하여 골량을 현 상태로 유지하는 것이다. 따라서 향후 발생되는 골소실을 에방하는 것이 골다공증의 원칙적이고 효과적인 치료방법이 될 것이다. 본 연구에서는 흑효모 중 $Aureobasidium$ $pullulans$으로부터 유래한 폴리칸(베타-글루칸)이 중년여성의 골대사에 미치는 영향을 규명하고자 하였다. 연구방법: 골대사에 대한 폴리칸의 효과를 규명하기 위해 12주간의 무작위배정, 이중눈가림, 플라세보 대조 임상연구를 수행하였다. 총 60명(폴리칸 투여군30명, 플라세보 투여군 30명)의 중년 여성 피험자가 등록되어 이 중 총 58명의 피험자가 최종적으로 12주간의 임상연구를 종료하였다. 결 과: 폴리칸(150 mg/d) 투여 12주 후, 폴리칸 투여군은 요 중 Deoxypyridinoline (DPD) 농도가 유의적인 감소를 보였다($P$=0.014). 혈청 중 Osteocalcin(OSC) 농도는 두 군 모두에서 유의적으로 증가하였으며, bone-specific alkaline posphatase (bALP) 와 collagen type 1 cross-linked C-telopeptide (CTx)는 유의적 변화가 보이지 않았다. 폴리칸은 골밀도(BMD)와 혈청 부갑상선 호르몬(iPTH)에 대해 유의적인 변화를 보이지 않았으나, 24시간 요 중 Ca 배설량은 폴리칸 투여군에서 유의하게 감소되었다($P$=0.028). 또한 폴리칸 투여군에서 고밀도지단백 콜레스테롤(HDL-cholesterol) 농도의 증가 경향 및 중성지방(triglyceride)의 유의적인 감소가 보였다. 임상연구 기간 중에 발생한 이상반응은 두 군간에 유의적인 차이를 보이지 않았다. 결 론: 본 연구에서는 폴리칸이 골대사 및 지질에 대해 일부 개선효과가 있음을 보여주었다. 그러나, 골다공증 예방 측면에서 보다 장기적인 임상연구와 피험자 수를 확대하여 골대사 및 지질대사에 대한 폴리칸의 예방적 효과를 규명할 필요가 있을것으로 사료된다.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.429-447
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• 1996

Transforming growth factor $-{\beta}$ is one of the polypeptide growth factors that mediate the activity of mesenchymal cells and regulate wound healing process via cell proliferation, migration and extracellular matrix formation. The purposes of this study is to evaluate the effects of transforming growth factor $-{\beta}$ on the protein synthetic activity of human periodontal ligament cells and human gingival fibroblasts. The cells which were prepared were primary cultured gingival fibroblasts and periodontal ligament cells from humans, and the fourth or sixth subpassage were used in the experiments. Cells were seeded and at a confluent state, 0, 0.5, I, 2.5, 5, 10 ng/ml $TGF-{\beta}$ and $2{\mu]Ci/ml\;[^3H]$ proline were added to the cells and cultured for 24 hours. Then, 1 and 5 ng/ml concentrations were selected and added to confluent cells and cultured for 24 and 48 hours. They were labeled with $2{\mu}Ci/ml\;[^3H]$ proline for 24 hours and a collagen assay was done by the Peterkofsky and Diegelman method. The results were presented as the mean disintegration per minute (dpm) per well and S.D. of four determinations, The results were as follows. : The total protein, collagen and noncollagenous protein synthesis in periodontal ligament cells and gingival fibroblasts were increased dose- dependently by transforming growth factor-p to 2.5-5 ng/ml concentration and decreased at 10 ng/ml concentration. The percent of collagen was slightly changed according to the concentration of transforming growth factor-po The effect of transforming growth $factor-{\beta}$ was not specific for collagen synthesis since it increased the total, noncollagenous and collagenous protein, simultaneously. In the comparison of protein synthetic activity between the human periodontal ligament cells and human gingival fibroblasts, the human gingival fibroblasts had higher activities than the human periodontal ligament cells at all times and concentrations of $TGF-{\beta}$. In the comparison of protein synthetic activity between the 24 hour effect and the 48 hour effect of $TGF-{\beta}$, the 48 hour cultured cells' synthetic activity decreased more than the 24 hour cultured cells at human periodontal ligament cells and human gingival fibroblasts. In conclusion, $TGF-{\beta}$ has important roles in the stimulation of protein synthesis in human periodontal ligament cells and human gingival fibroblasts. Thus, it may be useful for clinical application in periodontal regenerative procedures.