구간 분할 제어를 이용한 형상기억합금 와이어의 온도제어에 관한 연구

정상화,김주환,김태호,서호진,박진완 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.1

The key technology of robot is the design of the actuator. Particularly breakthroughs of power-to-weight ratio or energy-density III actuator technology have significant impacts upon the design and the control of robotic systems. To realize the anthropomorphic motion, artificial muscles such as shape memory alloy(SMA) and electro active polymer(EAP) are used. These actuators have the higher energy density than the electromechanical actuators such as the electric motor. The EAP has the property of good elasticity, but it is difficult to get the required power. The SMA has the good power density and simple structure, but the control scheme of the actuator is difficult. In this paper, temperature control of SMA wire using segment control is studied. The SMA wire is segmented by thermo-electric module(TEM). To supply constant currents in TEMs, MOSFET is used. Hysteresis in one segment of SMA wire is evaluated. The force and displacement of SMA wire are measured according to the number of segment. The program to control the temperature of TEM is developed by using LabVIEW software.

고온초전도체의 탄성상수

정기주,권태송 公州大學校 基礎科學硏究所 2003 自然科學硏究 Vol.10 No.-

고온초전도체 La_(2-x)Sr_(x)CuO_(4)의 탄성상수의 온도 의존성을 설명할 수 있는 미시적인 model을 제시하고, 온도가 내려감에 따라 탄성상수 c_(66)만이 감소하는 현상은 페르미 준위 E_(F) 근처에 존재하는 이중으로 축퇴된 itinerant p-band 때문에 발생함을 밝혔다. A microscopic model is presented to explain the temperature dependence of the elastic constants of La_(2-x)Sr_(x)CuO_(4). It is shown that the elastic softening of c_(66) originates from the doubly degenerate itinerant p-band near E_(F).

P3-F계 세제의 살균력 측정

정명주,손태문,박형숙 慶星大學校 1998 論文集 Vol.19 No.2

The microbial activity of P3-luboklar FC,FC-A,FC-A(XT)DX and DXB was compared by DGHM Germ Carrier Test method. The following results were obtained. 1. FC,KB and KC has shown to be effective against all strains within 10 minutes. 2. FC-A was effective against E. coli, immediately, and kill could be achieved against Pseudomonas aeruginosa and Staphylococcus aureus within 4 minutes and 16 minutes, respectively. 3. DXB was effective against all strains within 10 minutes with the exeption of B. subtilis. 4. FC-A(XT) was the most effective against B. subtilis.

성견 치은에서 90% Phenol을 이용한 멜라닌 색소의 제거에 관한 연구

정태술,김영준,이영규,정현주 전남대학교 치의학연구소 2001 구강과학 Vol.13 No.4

In this present study, the healing process and the recurrence of pigmentation were evaluated clinically and histologically in accordance with the extent and the range of pigmentation after phenol was applied to remove melanin pigmentation in gingiva. Six mongrel dogs were used. The melanin pigmentation in canine gingiva were classified into slight, moderate, and severe according to the extent of pigmentation and divided into local and diffuse types according to the range. Following general and local anesthesia, 90% phenol was applied to the pigmented gingiva of the subjects with small cotton balls until the surface was etched to be whitish and was neutralized with small cotton balls soaked by 95% alcohol. The contralateral pigmented gingiva to the one treated with phenol, was treated by surgical deepithelialization. At1, 3, and 8 weeks, the treated gingiva was examined clinically and evaluated histologically following H-E stain, and HMB 45 stain for melanocyte after biopsy. In the phenol treated sites, epithelium and connective tissue healed normally and there was no pigmentation at 1 week. At 3 weeks of healing, melanin repigmentation was observed in the severe local type and moderate to severe diffuse type. In the surgically deepithelialized sites, healing was delayed, compared to phenol treated sites and the infiltration of the inflammatory cells and congestion in connective tissue was shown at 1 week. At 3 weeks, healing was completed and there was a partial melanin repigmentation. At 8 weeks of healing, the extent and the range of repigmentation were increased in both group according to the extent or range priot to depigmentation procedure. These results suggest that the removal of melanin pigmentation with 90% phenol application result in normal healing process of gingiva. However, in the severe local type and moderate to severe diffuse type, sites treated with phenol showed repigmentation at 3 week, which was earlier than surgical deepithelialized sites. Therefore it is required to select appropriate method according to initial condition of pigmentation.

Electropulsing Treatment on Enhancement of Electrical Conductivity of Screen-Printed Ag Wire

Ju‑Won Park,Howook Choi,Hwangsun Kim,Simoon Sung,Hye‑Jin Jeong,Il Kim,Jaeseok Gong,Sung‑Tae Hong,Heung Nam Han 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

The effect of high electric current density on the sintering of Ag wires manufactured by screen printing is evaluated throughelectrical resistivity analysis and microstructure observation. Different forms (continuous and pulsed) of electric currentwith different current densities are applied to the specimens. Conventional heat treatment is also performed as a controlgroup to examine the athermal effect of electropulsing treatment. Compared to the conventional heat treatment, the resistivityis reduced more under the electropulsing treatment with continuous current for the same temperature and treatment time.Also, the process time of electropulsing treatment can be reduced by applying a pulse form of high density current insteadof continuous current without losing the benefit of enhanced reduction of resistivity. The microstructural observationsobtained from high angle annular dark field scanning transmission electron microscope and a digital precession instrumentclearly show that necking connecting the crystals is formed more firmly under electric current. In addition, the temperaturechange of Ag wire and substrate is calculated according to the change of the resistivity when the electric current is appliedto confirm the reliability.

CITIS 지원 기술정보관리 시스템의 설계

정석찬,한태창,서범수,조장혁,주경준 한국경영과학회 1998 한국경영과학회 학술대회논문집 Vol.- No.1

CITIS(Contractor Integrated Technical Information Service) is a contractor's developed service to provide electronic access and/or delivery of contractually required information. CITIS satisfies one of the major CALS objectives to furnish a single-entry point for authorized access to contractor-generated Contract Data Requirement List(CDRL) data. A critical requirement for the practical implementation of the CITIS concept is the ability to access multiple existing heterogeneous databases in a fashion transparent to the CITIS user. In this paper, we will propose a prototype system model for CITIS, and discuss the system architecture of proposed CITIS system as a global information management system for distributed and heterogeneous local information systems. Furthermore, we will discuss about the required server module and using-scenario of proposed CITIS system.

해양미생물로부터 카로테노이드 색소의 생산을 위한 최적조건

정영기,박정욱,주우홍,류병호,정명주,김태수 동의대학교 기초과학연구소 2000 基礎科學硏究論文集 Vol.10 No.1

The optimal medium composition for the production of carotenoid pigment from Haloarcular sp. EH-1 as a dietary for fishes were 1.0% sucrose, 1.0% yeast extract, 25% sodium chloride, 0.3% sodium citrate, 0.2% potassium chloride, 2.0% magnesium sulphate, 0.002% ferric sulphate(pH7.0). The incubation temperate, aeration rate and agitation speed were 40℃, 100ml medium/500ml vol. shaking flask, and 180 rpm/min. The carotenoid pigment production was highest after 5 days of incubation with the light.

우울증 관련 평가도구의 개관

조현주,채정호,전태연 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.2

Objective : Since a lot of assessment tools for depression have been developed and used, it is difficult to choose the proper and optimal instruments for the purpose of their usage, In order to maximize the effectiveness of assessment for depression, this paper reviewed the characteristics and specific features of currently using tools. Method : The domestically and internationally using assessment tools for depression were reviewed and classified by litera-hire search and clinical experience. Results : Methods of assessment, selecting guides and characteristics of assessment tools for depression were presented. Conclusion : This paper would provide helpful guidelines for selecting the assessment tools. We suggest that it is needed to develop the assessment tools for depression that reflects Korean specific culture and custom.

소유역에 대한 제 유출해석 모형의 비교에 관한 연구

강주복,정연태,강인식,김태희 부산대학교 1995 生産技術硏究所論文集 Vol.48 No.-

It is difficult to make an exact estimate of the peak discharge, the runoff depth of flood, and establish the proper measurement for the flood protection since the water stage or discharge has been rarely measured at medium or small river basin in Korea. Therefore, Runoff analyses were perfomed using the storage function method, the discrete, linear, input-output model and linear reservoir model, respectively. Various parameters for the study areas were determined. The calculated hydrographs by three methods showed good agreement with observed flood hydrographs. The capabilities of regenerating flood hydrographs were evaluated based on rainfall from the storage function parameters, the Ø-index method, and the constant percentage method. The storage function parameters provided better effective rainfall for regenerating flood hydrographs than any others considered in the study. 우리나라의 중소하천 유역 중 대부분은 수위나 유량 관측을 행하지 않은 미계측 유역으로 방치되어 있는 상태이므로, 홍수시 정확한 유출량의 추정, 홍수피해 경감을 위한 적절한 대책 수립 및 수공구조물의 건설에 필요한 계획홍수량의 산정 등이 극히 어려운 실정이다. 따라서 본 연구에서는 수영강유역을 대상으로 기존의 유출해석 모형 중 저류함수법, 선형 이산화 입력-출력 모형 및 선형저수지 모형을 채택하여 유출해석을 실시하고, 대상유역에 대한 각종 매개변수를 산정한다. 유출결과로부터 세가지 방법에 의한 계산수문곡선은 실측수문곡선과 잘 일치하였다. 또한 저류함수법 매개변수를 이용한 방법과 Ø-index법 및 일정비손실법 등의 유효강우량 산정방법에 따라 수문곡선의 재현능력을 평가하였다. 본 연구에서는 저류함수법 매개변수를 이용한 방법이 가장 양호한 재현결과를 나타내었다.

Bovine teeth에 대한 수 종 상아질 접착제의 미세인장결합강도

송은주,김재문,김신,정태성 대한소아치과학회 2007 大韓小兒齒科學會誌 Vol.34 No.3