Lead Germanate 단결정의 초음파 감쇠

이수대,채건식,김영국,설정식 慶南大學校 附設 基礎科學硏究所 1989 硏究論文集 Vol.1 No.-

The temperature dependence of the ultrasonic velocity of 10 MHz and the absorption coefficient in the 10-30MHz range by the pulse echo method were determined in lead germanate single crystal. The velocity of longitudinal 10 MHz ultrasound along the c axis changed anomalously at the phase transition point and the jump was approximately 50m/sec. Near Curie point, the relaxation time and the kinetic coefficient of electric polarization from the Landau-Khalatnikov theory were calculated as ?? sec and ??, respectively. At room temperature, the viscosity tensor were measured as, ?? in the MKS units.

알지닌과 특이반응을 일으키는 시약을 이용한 시금치 glycolate 산화효소의 불활성화 연구

이건국, 최정도 忠北大學校 遺傳工學硏究所 1987 遺傳工學硏究 Vol.1 No.1

본문참고

Al/p - Si MIS 형 태양전지의 물성에 관한 연구

이수대,채건식,설정식,김영국,김일홍 慶南大學校 附設 基礎科學硏究所 1989 硏究論文集 Vol.1 No.-

The metal-thin insulating film-semiconductor structure is currently receiving much attention in solar cell studies. In this a MIS solar cell consisting of aluminum on single and poly silicon with an interfacial oxide layer(∼20Å) have been fabricated by vacuum evaporation method and found a good reproducibility. Recent studies show the importance of surface and interfacial oxide thickness. An interfacial of 20∼30Å is optimum and may be achieved by furnace heating to 600℃ in 800cc/min O₂flow. These cells have good rectification with forward and reverse voltage under dark condition. The best Al/p-Si Si solar cell has an open circuit voltage Voc=0.4V, short circuit current density Isc=30mA/㎠, fill factor FF=0.58 and conversion efficiency η=10% for single crystal, and Voc=0.33 V, Isc=30mA/㎠, FF=0.49 and η=5% for poly crystalline silicon substrates for 70mA/㎠ irradiation of AM₂.

알쯔하이머병 환자의 혈소판 아밀로이드 전구단백질 이상

이애영,조은경,김건익,김선국,손은희 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.2

Background:Although Alzheimer's disease (AD) is a progressive neurodegenerative disorder without any truly effective pharmacological treatment at present, early accurate diagnosis is important for the delaying of disease progression and proper management It would be desirable to have a peripheral biological marker to identify patients affected by AD Amyloid β-peptide originates from a larger precursor, the amyloid precursor protein (APP). which can be seen in the platelet of its equivalent to those found in brain. To investigate if there is a correlation between level of platelet APP isoform and AD, we evaluate a cohort of subjects including patients affected by sporadic AD, vascular dementia, and controls Subjects & Methods :Thirty-five patients with sporadic AD diagnosed according to the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Relatec Disorders criteria (NINCDS-ADRDA) and 26 vascular dementia patients diagnosed by the Diagnosis and Statistical Manual of Mental Disorders, Fouth Edition (DSM-Ⅳ) criteria and 12 controls were included Blood sample were drawn from fasting state and collected into 3 mL of 3.8% sodium citrate. Platelets were collected by centrifugation at 500 g for 20 minutes and washed. and the platelet pellet was stored at -80℃ until used APP was assessed by western blot analysis and quantified by densitometry using Image Analyzer Results:In platelets densitometer as well as the result of Western blot was higher compared with those of patients with non-Alzheimer dementia and controls We observed statistically significant reductions in the ratio of 120 kDa to 130 kDa APP to 110 kDa APP (APPr) for patients with probable AD compared with control subjects and patients with vascular dementia APPr levels in AD correlated with the severity of dementia measured by CDR. Accuracy levels measured by Receiver Operating Curve analysis showed that a cut-off level of 0.45 resulted in a sensitivity of 71% and a specificity of 74%, with an area under the curve of 0 793 Conclusion:Platelet APPr allowed to differentiate AD from normal aging and vascular dementia with high sensitivity and specificity These findings suggest that platelet APPr may be a helpful peripheral marker for diagnosis and clinical progression of Alzheimer disease.

특성 인식(Trait Recognition)을 통한 우리나라 은행산업의 건전성 평가

국찬표,이근경,한상일 한국금융연구원 2003 금융연구 Vol.17 No.2

본 논문은 개별은행의 건전성을 평가한 후 일정 은행군의 건전성을 평가할 수 있는 특성인식을 방법론으로 사용하여 우리니라 은행들의 건전성을 평가해 보았다. 표본 내 및 표본 외 자료를 이용한 본 논문의 실증결과에 따르면 특성모형은 미국과 유사하게 우리나라에서도 부실 및 건전은행을 적절히 구별해내며, 로짓 모형보다는 제 1종 및 2종 오류를 적절하게 조절하는 것으로 나왔다. 또한 본 논문에서 분석대상으로 설정한 변수들 가운데 자산건전성을 측정하는 지표인 X_(7)(무수익여신 비율), X_(8)(외화여신/총여신)과 수익성을 나타내는 지표인 X_(9)(순이자소득/총자산), X_(12)(영업이익/총수입), X_(13)(ROA), X_(14)(ROE)등은 은행의 도산가능성을 비교적 정확히 예측하는 변수로 나타났다. 이와 더불어 은행의 유동성을 나타내주는 지표인 X_(15)(유가증권/총자산), X_(16)(주식/총자산), X_(17)(회사채/총자산)등도 은행의 도산가능성을 정확히 예측하는 것으로 나타났으며, 은행의 생산성을 나타내주는 대표적인 지표인 X_(26)(총자산/종업원수), X_(27)(총대출/종업원수), X_(28)(총이익/종업원수)등도 은행의 건전성을 판별하는 데 유효한 변수로 나타났다. 이러한 변수에 대해서 97년 당시의 전체 20개 은행을 분류한 특성(features)을 이용해서 2003년 현재 은행의 건전도를 평가해 보았다. 이 결과 은행의 건전성이 97년보다 크게 개선된 것으로 판단된다. 따라서 외환 위기 이후 금융구조조정의 성과가 일정부분 있었던 것으로 보이며 향후 일정기간 동안 은행위기의 가능성은 낮은 것으로 판단된다. This paper seeks to ascertain the soundness of the Korean banking industry by applying an empirical method calledthe trait recognition model (TRM). We perform an empirical test with 20 banks; 10 failed banks and 10 non-failed banks. The sample is split into (1) an original sample used to build a classification model and (2) a holdout sample reserved for prediction purposes to determine the efficacy of the model. According to the empirical test, TRM identifies non-failed and failed banks relatively well, as it has done in the U.S. TRM also outperforms the logit model in terms of minimizing Type 1 (identifying a failed bank as non-failing) and TypeII( identifying a non-failed bank as failing) errors. The variables related to asset quality, profitability, and productivity predict banking failures relatively well. The variables for bank size, capital adequacy, diversification, and liability are less effective in predicting banking failures. We also evaluate the soundness of those banks that were still in operation at the end of 2002 based on variable bank features in the period of 1996-1997. We find that the soundness of most banks was relatively robust, though several banks still have problems with regard to their asset quality and profitability. Every bank is found to have maintained safe features on the variables related to productivity, which were considered most effective toward determining bank soundness. We believe this is mainly a result of improvements in productivity realized through bank restructuring and M&As.

Mg₂SiO₄ : La, Ho 열형광선량계에서 활성제 농도가 글로우 커브에 미치는 영향 La, Ho TLD on Activation Concentration

김영국,손인호,채건식,노경석,오재근,이은숙 경남대학교 신소재연구소 1996 論文集 Vol.6 No.-

본 연구에서는 Mg₂SiO₄에 활성화 물질로 La, Ho를 첨가하여 열형광체를 제작하였고 불순물의 농도를 1wt.% ∼5 wt.%까지 변화시키면서 열평광강도의 glow curve를 측정하였다. 도한 열형광체의 glow curve를 peak shape법으로 분석해서 TL특성에 대한 포획 매개변수와 활성화 에너지, 발광차수, 선량의존성등을 조사하였으며, 그 물리적 특성을 조사하고 선량계로서 타당성과 실용성을 확인하였다. The Mg₂SiO₄: La, Ho thermoluminescent phospher has been prepared by sintring Mg₂SiO₄after doping the transition elements La and Ho. The heating rate is 10℃/sec at this thermoluminescent phospher are heated. The maximum peaks are found in the measured Mg₂SiO₄: La and Ho. TL glow curve at 229℃ and 345 C when the 1 wt.%-5 wt.%. The glow curve of TLD increased TL intensity and temperature of peak appears to the high temperature when the heating rate is l0℃/sec-25℃/sec. The activation energy of the main peak has been estimated by the peak shape method. The estimated activation energies are 1.77 eV. 1.52 eV respectively. The thermoluminescence process in Mg₂SiO₄: La and Ho are found to the 2nd order when the main peak of the glow curve is analyzed by peak shape method. The dose responses of Mg₂SiO₄: La and Ho TLD are linear up to intensity of X-ray.

개선된 Bridgman법으로 성장한 Bi₂Sr₂CaCu₂O_(8+δ) 單結晶의 초전도성

채건식,손인호,설정식,이수대,김영국,전동성,오재근,강성욱 경남대학교 환경문제연구소 1995 환경연구 Vol.17 No.-

The Bi₂Sr₂CaCu₂O_(8)+_(δ) single crystals are grown from the melt using a stoichiometric starting composition fer the cautions. The size and thickness of the Bi₂Sr₂CaCu₂O_(8)+_(δ) crystals depends on the cooling rate. The lower the cooling rate, the bigger and thicker the Bi₂Sr₂CaCu₂O_(8)+_(δ) crystals become. Bi₂Sr₂CaCu₂O_(8)+_(δ) X-ray diffraction(XRD) measurements of the single crystals were carried out using the radiation source of Cu Kα . In these Patterns only the (0,0,2n) diffraction appeared. The result indicated that the cleared surface of the single crystal was of the a-b face, and that the single crystal had a single phase without any undergrowth with 7K and 85K phases. In addition, although the figure is not shown, XRD patterns from (006) to (00□) were observed in the range of 2θ=0 to 60 degrees. The characterization of as-grown single crystals have been analyzed by Laue X-ray backsdattering along the c-axis and X-ray precession experiments. The result of magnetic moment vs Tc in 10 Gauss for a crystals were measurements indicated that the samples have a superconducting transition temperature of 85K.

상부위장관 출혈의 임상적 고찰

장금석,이승일,박삼규,조건국,장정수 조선의대 1984 The Medical Journal of Chosun University Vol.9 No.1

Mg₂SiO₄: Tb, Nd, Dy 열형광선량계에서 활성제 농도가 Glow Curve에 미치는 영향

노경석,채근식,오재근,김영국,이은숙,설정식,손인호 慶南大學校 附設 基礎科學硏究所 1996 硏究論文集 Vol.8 No.-

The Mg₂SiO₄: Tb, Nd, Dy thermoluminescent phospher has been prepared by sintering Mg₂SiO₄after doping the transition elements Tb, Nd and Dy. The heating rate is 10℃/sec at this thermoluminescent phospher are heated. From the results of this study, the following conclusions were obtained. The maximum peaks are found in the measured Mg₂SiO₄: Tb, Nd, Dy, and TL glow curve at 289℃, 252℃ and 220℃ when the 1wt.% ∼ 5wt.%. Glow curve of TLD increased TL intensity and temperature of peak appears to the high temperature when the heating rate is 10℃/sec∼25℃/sec. The activation energy of the main peak has been estimated by the peak shape method. The estimated activation energies are 1.26 eV, 0.53 eV and 0.80 eV respectively. The thermoluminiscence process in Mg₂SiO₄: Tb, Nd, Dy are found to the 2nd order when the main peak of the glow curve is analyzed by peak shape method. The Mg₂SiO₄: Tb thermoluminescent phosphor is the most sensitive to X-rays among the other materials. The dose responses of Mg₂SiO₄: Tb, Dy TLD are linear up to intensity of X-ray.

투명전극을 이용한 태양전지의 제작 및 특성에 관한 연구

전철원,채건식,이수대,김영국 경남대학교 환경문제연구소 1987 환경연구 Vol.9 No.-

Highly conductive and transparent thin films of ITO are fabricated by spray Pylosis method. The parameters of these thin films are as follows : resistivity ρ=1.5x10^(-3) Ωㆍ??, transmission 90% over visible and IR region. The Parameters of SnO_(2) : F thin films are follows : resistivity ρ=1.8x10^(-3)Ωㆍ??, trans-mission 80% over visible ant IR region. ITO thin films have simple cubic structure with lattice constant α=10.2Å and polycrystalline with (400) and (222). SnO_(2): F thin films have tetragonal system with lattice constant α=4.8Å and polycrystalline with (110), (200), (211) and (310). Under AMI sunlight simulator, the Parameters for ITO/n-Si heterojunction solar cells are open-circuit voltage Voc =0.42 V, short-circuit current Isc =34mA, fill factor FF=0.67 and conversion efficiency η=10%. Under AMI sunlight simulator, the parameters for SnO_(2): F/n -Si heterojunction solar cells are open-circuit voltage Voc =0.36V, short-circuit current Isc =28mA fill factor FF=0.55 and conversion efficiency η=6%.