희토류금속 용매추출에 대한 분배계수 예측

강태원,김선욱 울산대학교 1995 공학연구논문집 Vol.26 No.2

희토류금속 용매추출공정의 분배계수를 계산하기 위하여 complex 형성을 감안하는 model을 이용하였다. 실험자료를 회귀분석하여 얻은 parameter를 사용하는 방법과 평형상수에 대한 일반식을 사용한 두가지 방법을 이용하여 단일성분계의 분배계수를 효과적으로 예측할 수 있었다. 또한 이성분계의 경우에 단일성분계에서 구한 parameter로 부터 분배계수의 예측을 시도하였다. A model including complex formation has been utilized to calculate distribution coefficients of rare earth metals in solvent extraction processes. For the single component systems distribution coefficients are predicted effectively by two different methods, which use regressed parameters and generalized correlation of equilibrium constant. Moreover, this methodology also has been tried to predict distribution coefficients of binary systems with paramenters regressed from single component experimental data.

고속 채널환경에 강건한 OFDM 시스템을 위한 채널추정기법

강연석,황태욱,최준철,김영수 경희-다반 ASIC 설계교육센터 2004 경희-다반 ASIC센터 논문집 Vol.5 No.-

본 논문에서는 Orhogonal Frequency Division Multiplexting(OFMB) 시스템의 성능 향상을 위해 파일럿 심볼을 이용한 향상된 채널추정 알고리즘을 제안한다 기존의 LMMSE 알고리즘을 이용한 채널 추정 방법은 파일럿 심볼만을 채널 추정에 이용함으로써 파일럿 간격이 멀어짐에 따라 성능이 현저하게 떨어지는 단점이 있다. 이런 문제를 해결하기 위해 파일럿 사이의 채널을 선 추정하고 이 추정된 값을 다시 파일럿과 함께 이용하여 채널을 추정하는 채널추정기법을 제안하였다. 제안된 추정기법은 도플러 주파수를 36Hz애서 185Hz인 페이딩 채널환경에 적용했다. 기존의 LMMSE 추정기법과 비교했을 때 특히 큰 도플러 주파수애 대해 강건한 특성을 보였다.

CaSO_4 :Mn 열발광선량계의 물리적 특성

강영호,라병욱,최태진,김도성,도시홍 慶北大學校 物理化學硏究所 1986 硏究論文集 Vol.7 No.-

열발광형광체는 방사선계측 및 선량측정에 널리 사용되고 있다. CaSO_4에 Mn을 활성화하여 CaSO_4 : Mn TL 시료를 직접제작하여 이의 열발광특성을 조사하였다. 측정된 CaSO_4 : Mn의 glow-curve 5℃/sec의 가온율에서 peak온도가 126℃였으며, Halperin과 Braner 및 Chen의 이론에 의하여 열발광과정의 차수와 활성화에너지를 결정하였다. 제작된 CaSO_4 : Mn의 TL 강도는 10^-2 ∼ 10^4 Rad의 ^60Co γ선에 대해 선형적인 선량의존성을 보였으며, 100시간에 50% 정도의 fading을 나타내었다. The thermoluminescent phosphors have been widely used in radiation detection and dosimetry. By adding Mn activator to CaSO_4, the CaSO_4 : Mn thermoluminescent phosphor was prepared and its characteristics was investigated. The measured glow-curve of CaSO_4 : Mn phosphor consisted of a single peak around 126℃ at the heating rate of 5℃/sec. The kinetics order of thermoluminescence process and the activation energy of electron trap was determined by analyzing the glow-curves based upon Halperin and Braner, and Chen's theories. The prepared CaSO_4 : Mn phosphor showed the linear dose response within the range of 10^-2 to 10^4 rad of gamma-ray and fading of 50% in 100 hours after irradiation at room temperature.

Sr·페라이트 플라스틱자석의 제조에 관한 연구

문현욱,최희태,서강수,신용진 明知大學校 産業技術硏究所 1995 産業技術硏究所論文集 Vol.14 No.-

In this paper, we mention he fabrication of Sr ferrite plastic magnet. In order to compose Sr ferrite, first, a little CaO, SiO₂, Na₂SiO₃, and Al₂O₃ are added to SrO5.9Fe₂O₃. Then, the composition is calcinated at 1225℃ under N₂ enviroment for 1 hourwith addition of PVA 5wt% solution. The carbon coating method increase grinding effect on powder fabrication. To fabricate anisotropic Sr ferrite plastic magnet, 80-89wt% of Sr ferrite and polyamide6 are kneaded and then 0-12kOe of magnetic field is applied. On magnet fabrication, an optimal condition of injection mold is obtained under the injection temperature 270℃, the injection pressure 120㎏/㎠, the magnetic field 8kOe and magnetic field applied time 8sec. As the result of experiments, we obtain (BH)max = 2.09MGOe property on anisotropic plastic magnet which is fabricated by using injection mold method in magnetic field.

슬관절 등속성 운동시 근골격 모델의 검증:실험 및 모의실험 연구 : 실험 및 모의실험 연구 An Experimental and Simulatio study

배태수,강성재,최경주,김신기,유재욱,진미령,문무성 대한정형외과연구학회 2003 대한정형외과연구학회지 Vol.6 No.2

플라스틱 기어의 피로수명 평가 및 수명 예측

정태형,강성규,하영욱 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

Through the fatigue test of plastic gears using polyacetal polymer, this research aims at providing basic data for not only specifying operation conditions of plastic gears, but also designing dimensions of plastic gears with giving fatigue life and the estimated equation of fatigue life of plastic gears. That is, from the fatigue life curves, the estimated equation of fatigue life of plastic gears is taken out. For the estimated equation of fatigue life of plastic gears, this research provides two test methods; one is preserving non-limited temperature of tooth flank, the other is preserving limited temperature of tooth flank. As results, how the temperature of tooth flank affects the fatigue life is shown. In addition, based on the endurance limit, the essential factors of the unit load and K-factor are determined, which are needed in the design of gear by bending strength and surface durability.

우리나라 主要 樹木園 및 植物園의 植物保有實態 分析에 關한 硏究

金泰旭,田承勳,姜基縞 서울大學校農業生命科學大學附屬樹木園 1991 서울大學校 樹木園 硏究報告 Vol.- No.11

우리나라 樹木園(植物園)들의 植物保有 實態를 把握하기 위하여 韓國植物園 聯合會 總監集을 대상으로 분석, 고찰한 결과 현재 우리나라에 수집되어 있는 식물의 전체 分類群 數는 225科 1,428屬 9,481種類로 나타났으며 이중 국내 自生樹種과 外國原産 導入種의 경우는 각각 166科 683屬 2,001種類와 193科 1,052屬 7,480種類로 파악되어 자생식물의 수집이 극히 저조한 것으로 나타났다. 樹木園別 수집현황으로는 천리포樹木園이 4,479種類로 가장 많고 광릉樹木園이 2,719種類, 여미지植物園이 1,614종류, 서울대공원이 931종류, 서울대 관악樹木園이 740종류 등을 각각 보유하고 있는 것으로 나타났다. 樹木園別 식물수집의 特色은 多樣한 植物資源의 수집보다는 관상적 가치가 높은 수종 중심의 劃一的 計劃에 의한 수집으로 분석되었다. 따라서 장차 식물자원의 綜合的인 利用 및 硏究등에 필요한 수종과 특히 自生樹種에 대한 集中的인 蒐集이 이루어져야 할 것으로 판단되었다. This study was carried out to figure out the current status of plant holdings of arboreta (botanical gardens) in Korea and to establish the sound basis for plant resource management by means of analyzing "A Comprehensive Bibliography of Botanical Gardens" (Korean Association of botanical Gardens, 1991). The total number of taxa, which consist of 225 families and 1,428 genera, was 9,481 kinds. Those taxa include 4,793 species, 735 varieties, and 3,953 infraspecific taxa, respectively. And the total plant holdings were classified into 2,001 kinds of plants native to Korea and 7,480 kinds of plants introduced. Species holdings of major arboreta were 4,497 kinds at the Chollipo Arboretum, 2,719 kinds at the Kwangneung Arboretum, 1,614 kinds at the Cheju Fantasy Garden, 931 kinds at the Seoul Grand Park, and 740 kinds at the Kwanak Arboretum of Seoul National University. The present collection priorities for those arboreta were mostly confined to specific families and genera, and also showing increasing trends of introducing more exotic species rather than native ones.

지방간에서 발생한 폐 지방색전증의 병리학적 및 임상적 의의에 대한 연구

권태정,강현욱 大韓法醫學會 2001 대한법의학회지 Vol.25 No.1

Fat embolism is the presence of fat globules in the peripheral circutation and in the lung, brain, kidney, pearl, and so on -not in the fine emulsion of a metabolic lipemia but in globules large enough to obstruct arterioles and capillaries. The fat droplets can deride from fractures of long bone due to disruption of the fatty marrow from extensive bruising of the soft tissue, and from fat tissue in burns. Fat embolism has also been reported in patients suffering from various diseases including alcoholism, fatty liver, diabetes mellitus and pancreatitis. We investigated 19 autopsies with fatty liver of varying degrees to establish a correlation between fatty change of limier and pulmonary fat embolism. Among 19 cases, 3 cases with moderate to severe fatty change of elver, and 1 case with submassive hepatic necrosis and mild fatty change showed Grade II pulmonary fat embolism. In histologic section with Sudan III stain, the arteries and capillaries of lung were occupied and distended by round, oval, or staghorn fat globules. The alveoli may contain edema fluid and blood Although the pulmonary fat embolism occuring in the presented cases didn't cause death on its own, one should be aware that a life-threatening mobilization of fat into the lungs and ever into the systemic circulation is possible In fatty fiver and submassive hepatic necrosis.

소음 해석을 이용한 소형 모터 구조물의 최적 설계

조성욱,강태진 중앙대학교 미래신기술연구소 2001 미래신기술연구소 논문집 Vol.10 No.1

In the operation of industrial motors, one of the significant problems is noise. To consider the effect of noise at design stages, we have to perform an optimum design for the minimization of noise level, using numerical analysis method with basic values. We need to know the vibration features and choose proper ways of acoustic analysis in order to control the noise radiating from motor structure. Also we need to find an appropriate optimum design procedure in order to minimize noise. Particulary, it is important to define design variables which does not affect the operating quality and is sensitive to noise level, proper constraint conditions should also be established. Finally all of this procedures must be done in a package with numerical mithods. In this study, we investigated optimum design procedure for motor structure using commercial vibration and acoustic analysis packages(ANSYS & SYSNOISE).

BOX-Wilson 실험계획법에 의한 인산알루미늄의 최적합성조건에 관한 연구

신화우,강태욱,안세민 원광대학교 식품약품안전성연구소 1992 食品藥品安全性硏究 Vol.5 No.-

Aluminum phosphate is used as an antacid in pharmacy as the gel or dried gel, must meet specified neutralization rate and acid consuming capacity criteria. This nonadsorbable antacid has been used in place of aluminum hydroxide gel where loss of phosphate may be a problem to the patient. Since aluminum phosphate gel is regenerated in the intestine, endogenous phosphate is spared. The acid-consuming ability of aluminum phosphate is based on the release of phosphate anion : AlPO_4 ?? Al^3+ + PO^3-, PO^3-_4 + H_3O^+ ?? HPO^2-_4 + H_2O, HPO^2-_4 + H_3O^- ?? H_2PO_4 + H_2O. Aluminum phosphate gel was synthesized by reacting aluminum chloride as a soluble aluminum salt to sodium phosphate in this study ; AlCl_3 + NaPO_4 → AlPO_4↓ + 3NaCl. The optimum synthesis conditions based on the yield of product were investigated by applying Box-Wilson experimental design. It was found that optimal synthesis conditions were as follows ; Reaction temperature;90∼98℃, Concentration of two reactants;15.3∼15.5%, Concentration ratio of two reactants, [Na_3PO_4]/[AlCl_3];1.48∼1.49, reaction time;10minutes, drying temperature of product;60∼70℃.