• Journal of Acupuncture Research
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• v.23 no.5
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• pp.69-77
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• 2006

Background : Mesenchymal stem cells (MSCs) are present in most of the tissue matrix, taking part in their regeneration when injury or damage occurs. The aim of this study was to investigate the presence of cells with pluripotential characteristics in human subchondral bone and the capacity of these cells to differentiate to osteoblast. Methods : Human subchondral bone were digested with collagenase. Isolated cells were cultured with a-MEM, 15% FBS, 10-8M dexamethasone and 50 ng/mL ascoric acid. Cells from 0 day(isolated cells), 7 day (first subculture) and 14 days (third subculture) were used to carry out phenotypic characterization experiments flowcytometry analysis with 11 monoclonal antibodies) and osteogenic differentiation experiments. Osteogenic differentiation of cells was assessment by quantification of bone extracellular matrix components by following analysis: alkaline phosphatase(ALP) stains to detect ALP activity, RT-PCR and western blot to detect osteocalcin (OCN), osteopontin (OPN) and type I collagen(Col I), and Alizarin red stains to detect calcium deposition. Results : Flowcytometry analyses showed that in our population more than 98% of cells were positive for MSC markers: SH-2(CD105, 99%), CD29 (95%), CD73 (95%). Cells were negative for hematopoietic markers (CD11b, CD34, and CD45). Furthermore, cells showed positive stain to multipotent markers such as CDl17 (c-kit) (15.1%), and CD166 (74.9%), and cell adhesion molecules such as CD54 (78.1%) and CD106 (63.5%). The osteogenic specific marker analyses showed that the culture of these cells for 7 and 14 days stimulates ALP, OCN, OPN and Col I synthesis by RT-PCR and Western blot analysis. Also, after 14 days in the culture of MSCs induces mineralization by Arizarin red stain. Conclusion : In this work, we demonstrated a new and efficient method for osteoblastic differentiation of human subchondral bone stem cells. As MSCs takes part in reparative processes of adult tissues, these cells could play an important role in osteogenesis.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.49-52
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• 2004

본 논문은 연속 밀도 함수를 갖는 HMM별 한국어 연속 음성 인식에 관한 연구이다. 여기서 우리는 밀도 함수가 2개에서 44개까지 갖는 연속 HMM모델에서 가장 효율적인 연속 음성 인식을 위한 방법을 제시한다. 음성 모델은 36개로 구성한 기본음소를 사용한 CI-Model과 3,000개로 구성한 확장음소를 사용한 CD-Model을 사용하였고, 언어 모델은 N-gram을 이용하여 처리하였다. 이 방법을 사용하여 500개의 문장과 6,486 개의 단어에 대하여 화자 독립으로 CI Model에서 최고 $94.4\%$의 단어 인식률과 $64.6\%$의 문장 인식률을 얻었고, CD Model에서는 $98.2\%$의 단어 인식률과 $73.6\%$의 문장인식률을 안정적으로 얻었다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.73-77
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• 2003

Red mud is a waste material formed during the production of alumina when the bauxite ore is subjected to caustic leaching. It is a brick-red colored highly alkaline (pH 10-12) sludge containing mostly oxides of iron, aluminum, titanium, and silica. Red mud, due to its high aluminum, iron, and calcium contents, has been suggested as a cheap adsorbent for removal of toxic metals (e.g., As, Cr, Pb, Cd) as well as for water or wastewater treatment. The basic advantage of red mud is its versatility in application. This study was conducted to evaluate the effect of red mud on stabilization and fixation of heavy metals (such as Pb, Cu, C $r^{6+}$, Cd, Zn) contained in the Al-coating sludge and soil. The results showed that the concentration of heavy metals leached from the treated sludge and soil was low, meeting the regulatory permit level.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.49.2-49.2
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• 2010

We have presented the evolutionary status of four detached double line spectroscopic eclipsing binaries which are CD Tau, CM Lac, HS Hya and ZZ Boo because the component stars of these binary systems still act as a single star. We determined the absolute dimensions of these binary systems using photometric and spectroscopic solutions from analysis of light curves and radial velocity curves. Using the luminosities, effective temperatures and masses we choose evolutionary tracks of these binary systems. Finally we obtained ages and metallicity of the stars. We found that CM Lac and HS Hya are very young stars and their ages are in range of 0.15-1.05 and 0.22-1.14 Gyrs. For CD Tau and ZZ Boo, they are older than the others and their age in range of 1.95-2.95 and 1.48-1.73 Gyrs.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.55
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• pp.73-83
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• 2000

Up to the present, ISO 9000 series have contributed which construction of quality management system and improvement of quality competition. Therefore many enterprises have taken an increasing interest in ISO 9000 series and the number certification of it is on the increase every year. In these processes, the side effect has come out. It is of no use to competitive power of enterprise. Because they made an effort for certification without preparation for a short period or there was no continuous system control. In this paper, We review the weakness of existing ISO 9000 series, which have soon ahead of revision. In addition, We propose the considering items or contents in revision for enterprise competition power.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.73-74
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• 2006

New iridium complexes that have carbonyl group were synthesized and demonstrated various red light emission in organic light-emitting diodes (OLEDs). The maximum luminance of $57000{\sim}15300\;cd/m^2$ at 15 V and the luminance efficiency of 22.8~5.6 cd/A at $20\;mA/cm^2$ were achieved respectively. The peak wavelength of the electroluminescence were at 570~604 nm and the device also showed a stable color chromaticity with various voltages.

• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.1-7
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• 1999

This study was performed to investigate the contents of the heavy metals such as cadmium(Cd), copper(Cu), iron(Fe), lead(Pb) and zinc(Zn) in meat and meat products. For this experiment, each 20 samples of beef and pork were collected at slaughterhouse in Seoul areas and 45 samples of meat products(ham, sausage, processed meat and seasoned meat) were purchased from commercial food markets. The contents of the heavy metals was determined by atomic absorption spectrophotometry from Jan. to Nov. In 1998. The results obtained were summarized as follows ; 1. In Korean native beef, mean values of the heavy metals(mg/kg) were Pb : 0.14$\pm$0.10, Cd : 0.07$\pm$0.02, Cu : 1.73$\pm$0.95, Zn : 42.82$\pm$8.17 and Fe : 67.43$\pm$24.18, respectively. 2. In imported beef, mean values of the heavy metals(mg/kg) were Pb : 0.03$\pm$0.08, Cd : 0.06$\pm$0.02, Cu : 1.41$\pm$0.62, Zn : 42.93$\pm$4.95 and Fe : 40.06$\pm$12.77, respectively. 3. In pork, mean values of the heavy metals(mg/kg) were Pb : not detected, Cd : 0.09$\pm$0.02, Cu : 1.08$\pm$0.23, Zn : 19.49$\pm$6.02 and Fe : 30.21$\pm$10.51, respectively. 4. In ham, mean values of the heavy metals(mg/kg) were Pb : trace, Cd : trace, Cu . 1.19$\pm$0.46, Zn : 13.58$\pm$4.99 and Fe : 31.43$\pm$11.74, respectively. 5. In sausage, mean values of the heavy metals(mg/kg) were Pb : 0.15$\pm$0.34, Cd : 0.08$\pm$0.05, Cu : 1.15$\pm$0.46, Zn : 13.70$\pm$7.13 and Fe . 27.28$\pm$15.05, respectively. 6. In processed meat, mean values of the heavy metals(mg/kg) were Pb : 0.08$\pm$0.13, Cd : 0.09$\pm$0.04, Cu : 1.28$\pm$0.60, Zn : 14.72$\pm$7.09 and Fe : 24.04$\pm$10.33, respectively. 7 In seasoned meat, mean values of the heavy metals(mg/kg) were Pb : 1.05$\pm$2.21, Cd : 0.13$\pm$0.03, Cu : 1.06$\pm$0.16, Zn : 17.53$\pm$8.72 and Fe : 26.76$\pm$9.02, respectively.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.161-167
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• 2015

BACKGROUND: For the heavy metal cotamination sites, it is very important to estimate the human bioavailability quotients for heavy metals in paddy soils released from mine tailings, which is a major source of contamination in Korea, and to assess the human health risks of heavy metals. METHODS AND RESULTS: This experiment was carried out to investigate the human bioavailability quotient of the heavy metals in paddy soils below part of the closed metalliferous mine. For estimating the human bioavailability quotients for heavy metals, 30 paddy soils below part of the closed mine were collected, and analyzed for Cd, Cu, Pb, Zn, and As using simple bioavailability extraction test(SBET). The quantities of Cd, Cu, Pb, Zn and As extracted from paddy soils below part of the mine by using the SBET analysis were 28.1, 17.3, 34.1, 14.6 and 2.3% respectively. Specially, the maximum values of Cd, Pb and Zn were 73.3, 81.5 and 58.1% of human bioavailability quotient, respectively, and varied considerably among the sampling sites. The human bioavailability quotient of Cd, Cu, Pb and Zn in soils near the closed mine showed significant positive correlation among soil pH value, O.M. and Ex. Ca. contents, while it correlated negatively between soil Ex. K and Ex. Mg contents in paddy soils. Also, its of Cd, Cu, Pb and Zn in paddy soils showed significant positive correlation with 0.1M HCl extractable and total contents, while in soils, it correlated negatively with As content in soil near the closed mine. CONCLUSION: The results of the simple bioavailability extraction test (SBET) indicate that regular ingestion of soils by the local population could be closed a potential health threat due to long-term heavy metals exposure in these mine areas.

• Radiation Oncology Journal
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• v.14 no.1
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• pp.53-59
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• 1996

Purpose : Radiation-induced alteration in the immune function is well known phenomenon in cancer patients. Our purpose is to evaluate the extent of immune suppression immediately after mediastinal or pelvic irradiation, which include significant volume of active bone marrow in adults. Materials and Methods'48 cancer patients with mediastinal(N=29) and pelvic irradiation(N=19) were the basis of this analysis. Age ranged from 36 to 76 and mean and median value was 57 years, respectively Sex ratio was 1.3(M: F=27/21). The immunological parameters were the complete blood cell(CBC) with differential cell(D/C) count, T cell subset(CD3, CD4, CD8 CDl9), NK cell test(CDl6, CD56), and serum immunoglobulin(IgG, IgA, IgM) level. Results : The mean value of white blood cell(WBC) was reduced from 7017 to 4470 after irradiation(p=0.0000). In the differential count, the number of lymphocyte, neutrophil, and basophil was markedly reduced with statistical significance(p<0.01) and the number of monocyte was not changed and, on the contrary, that of eosinophil was increased by irradiation. In the lymphocyte subpopulation analysis, the number of all subpopulations, CD3(T cell), CD4(helper T cell), CD8(suppressor T cell), CDl6(NK cell), CDl9(B, cell) was reduced with statistical significance. The mean ratio of CD4 to CD8 in all patients was 1.09 initially and reduced to 0.99 after radiotherapy(p=0.34) , but the proportional percentage of all subpopulations was not changed except CD19(B cell) after irradiation. In the immunoglobulin study, initial values of Ig G, Ig A, and Ig M were relatively above the normal range and the only Ig M was statistically significantly reduced after radiotherapy(p=0.02). Conclusion : Mediastinal and pelvic irradiation resulted in remarkable suppression of lymphocyte count in contrast to the relatively good preservation of other components of white blood cells. But the further study on the functional changes of lymphocyte after radiotherapy may be necessary to conclude the effects of the radiation on the immunity of the cancer Patients.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.641-647
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• 2014

In this study, sludge waste which has a difficulty in treating it was used to manufacture a fiber type of biosorbent. To solve the problems such as the release of organic pollutants and the difficulty in separating solid from treated water, entrapment method using Ca-alginate was used to immobilize sludge waste. Considering ease of manufacture as well as improvement of adsorptive ability, the biosorbent was manufactured in the form of fiber type. Optimum immobilization condition for minimizing the amount of alginate used and maximizing the performance of biosorbent was determined to be 10 g/L alginate concentration, 40 g/L sludge concentration, and 0.3-0.4 mm fiber diameter. The maximum Cd(II) uptake of the biosorbent was 60.73 mg/g. Pseudo-second-order kinetic model and Langmuir isotherm model adequately described the dynamic and equilibrium behaviors of Cd(II) biosorption onto the biosorbent, respectively. In conclusion, sludge waste generated from wastewater treatment process is a cheap raw material for the manufacture of biosorbent which can be used to remove toxic heavy metals from industrial wastewaters efficiently.