NiTi-형상기억합금 차동식 액츄에이터의 동특성연구

정상화,김현욱,장우양,김경석,차경래,나윤철 朝鮮大學校 機械技術硏究所 2001 機械技術硏究 Vol.4 No.2

최근 전 세계적으로 초소형 정밀 기계 기술에 관한 연구 및 개발이 활발하게 이루어지면서 형상기억합금(Shape Memory Alloy : SMA)을 이용한 초소형 액츄에이터(Micro Actuator)에 관한 관심이 증대되고 있다. 형상기억합금을 액츄에이터에 응용하기 위해서는 동적 특성의 분석이 필수적이지만 지금까지의 연구에서는 형상기억합금의 물질 및 재료적 특성은 많이 보고되고 있으나 동적 특성에 대한 연구는 매우 부족한 실정이다. 본 논문에서는 비저항(resistivity)이 큰 NiTi합금 와이어(wire)를 이용하여 나선형 스프링(helical spring)을 제작하여 디지털 힘 측정기(Digital force gauge)와 적외선 온도센서(Infrared themometer) 그리고 레이저 변위 센서(Laser displacement sensor)를 이용하여 이 NiTi 스프링의 힘의 크기와 반응속도, 온도와 변위를 측정하여 형상기억합금의 동적 특성을 분석하였다. 또한 형상기억합금을 이용하여 차동식 액츄에이터를 제작하여 그 동적 성능을 실험하였다. In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance.

정신분열병에서 TAP2 유전자의 다형성

송정민,전태연,이경욱,배치운,표철우 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.3

한국판 섬망 평가 척도-98(K-DRS-98)의 표준화 연구

임경옥,김수영,이양현,이선우,김정란 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.6

Objective : This study was conducted to develop and to validate the Korean version of Delirium Rating Scale-Revised-98(K-DRS-98), which is a scale for diagnosing delirium and evaluating its severity. Method : After developing the K-DRS-98, 102 patients were rated by it among 4 diagnostic groups, such as delirium (N=25), dementia (N=27), schizophrenia (N=25) and others (N=25). To test for reliability, K-DRS-98 was independently administered by two psychiatrist. To test for validity, Korean version of Mini-Mental State Examination (MMSE-K) and Clinical Global Impression (CGI) were administered simultaneously. Statistical analysis was done with SPSS window version 12 package and statistical significance was p<0.05. Result : Intemal consistencies (Cronbach α) of two raters were 0.867 and 0.858, respectively. Inter-rater reliability (κ) was 0.893 for severity items of K-DRS-98 and κ value of diagnosis items was 0.969. In Delirium group, Pearson correlation Coefficients (r) of K-DRS-98 were -0.682 for MMSE-K and 0.667 for CGI. In comparison Delirium group with Others, ANOVA post hoc multiple comparison LSD was statistically significant (p<0.001). The cutoff score to diagnosis of delirium can be recommended 16 for seventy items and 21.5 for total score, respectively. Conclusion : The K-DRS-98 was showed good reliability and validity for the assessment of delirium. The K-DRS-98 is an easy and useful tool for diagnosing delirium and assessing its severity.

열공형과 비열공형 피질하 혈관성 치매에서 위험인자의 차이에 관한 비교 연구

배희준,정지향,유경호,나덕렬,김상윤,최경규,양동원,손의주,이상도,김재우,박경원,김응규,이재홍,박미영,한일우,함동석,최문성,하충건,최성혜,이애영,이병철,한설희 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.2

Backgrounds and Objectives: Vascular dementia is a group of dementing disoders arising from various stroke syndrome. Among these. subcortical ischemic vascular dementia (SIVD) is regarded as a relatively distinct clinical entity. However, MRI patterns of SIVD are not homogenous. In some patients, lacunes are dominant, and in others, subcortical white matter changes are. This study was designed to compare risk factor profiles between SIVD with and without multiple lacunes. Methods: We divided 47 subjects (22 males, mean age. 68 years) recruited from VADAPET (Multicenter Trial For Evaluation Of The Changes In the PET Images Of Subcortical Vascular Dementia Patient) study into two groups one with more than 5 lacunes in deep gray matter (lacune group) and the other with 5 or less(non-lacune group) Clinical characteristics and laboratory findings of two groups were compared. Results: Nineteen of 47 patients (40%) belonged to the lacune group. The lacune and non-lacune groups d d not differ in the following variables: age, hypertension, diabetes mellitus, hyperlipidemia heart disease, history of stroke or TIA, history of trauma or major surgery, family history of hypertension stroke, or dementia, age at diagnosis of dementia, body mass index, white blood cell count, ESR, CRP, fibrinogen, hemoglobin A1C, total cholesterol. LDL cholesterol creatinine, proteinuria, glucosuria, and microhematuria. However, male sex, smoking alcohol. hemoglobin, and HDL cholesterol were possibly associated more with lacune group SIVD than with non-lacune group (p<0 1) Multivariate analyses revealed that smoking, hemoglobin, and HDL cholesterol were independent predictors of SIVD with multiple lacunes Conclusion: Our study suggests that SIVD with multiple lacunes may be significantly different in smoking habits hemoglobin, and HDL cholesterol from SIVD without multiple lacunes.

소아기 뇌졸중 후 발생한 간질에 대한 임상적 관찰

박현주,정경중,김근모,김병주,우영종,이정길,김재휴 대한간질학회 1998 대한간질학회지 Vol.2 No.1

뇌실내출혈로 인한 급성 수두증에서 관찰된 해리증후군

김광기,이경민,이정주,오종배,안태범,정상욱,남현우,박성호 대한신경과학회 1999 대한신경과학회지 Vol.17 No.5

CMP 공정의 재현성 확보를 위한 공정제어 범위의 결정

서용진,정소영,김철복,박성우,이경진,김기욱,박창준 대불대학교 2002 大佛大學校大學院 硏究論文集 Vol.- No.1

To achieve the ULSI goals of higher density and greater performance, STI(shallow trench isolation)-CMP(chemical mechanical polishing) process has been attracted. Recently, the direct STI-CMP process without the conventional complex reverse moat etch process has established by using slurry additive with the high selectivity between SiO2 and Si3N4 films for the purpose of process simplification and in-situ EPD(end point detection). However, STI-CMP process has various defects such as nitride residue, torn oxide and demage of silicon active region. Also, it was difficult to assure the suitable process margin in the STI-CMP process. To solve these problems, in this paper, we discussed to determine the control limit of process, which can entirely remove the oxide on nitride film from the most area of high density as reducing the damage of dense moat area and minimizing dishing effect in the large field area. We, also, evaluated the wafer-to-wafer thickness variation and the day-by-day reproducibility of STI-CMP process after repeatable tests.

Thioacetamide에 의한 BALB/c 마우스 간의 시간별 약물대사효소 억제 양상 : A Time-Course Study

이정운,고우석,김갑호,배연경,하현정,한상섭,천영진,정태천 영남대학교 약품개발연구소 2001 영남대학교 약품개발연구소 연구업적집 Vol.11 No.-

Thioacetamide is a potent hepatotoxicant which requires metabolic activation by cytochrome P450s (P450s) for toxicity. In the present study, the elevation kinetic of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities by thioacetamide treatment was investigated in male BALB/c mice. Inaddition, the inhibitory effects of thioacetamide on liver microsomal P450 enzymes were further investigated. Thioacetamide at 100 mg/kg/ was treated intraperitoneally for 6, 12, 24, 36, 48 and 72 hr. The blood was collected at the designated time for assaying the serum enzyme activities. To determine the P450 isozyme-specific activities. ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), and benzyloxyresorufin O-debenzylase (BROD) activities were determined for P450 1A1, 1A2 and 2B1, respectively, in liver microsomal fractions. The activities of ALT and AST were started to be elevated 6 hr after thioacetamide treatment andreached the maximun at 36 hr after the treatment. The elevated activities were dramatically recovered at 72 hr. The microscopic exmination of the liver specimen also showed a similar profile of hepatotoxicity. All P450-associated enzyme activities were time-dependently inhibited by the treatiment with thioacetamide. The maximum inhibition of P450 enzymes was observed 36 hr after the treatment. Because the inhibition of P450 enzymes by thioacetamide was time-dependent, our present results suggest that thioacetamide might inhibit P450 enzymes in mechanism-based inactivation.

양극성 장애 1형에서 종양괴사인자 베타 유전자 다형성

전태연,이경욱,배치운,김원,우영섭,채정호,박원명 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.6

Objectives : Bipolar disorder is known to have a high genetic predisposition. Recently, the main focus of etiologic studies in bipolar disorder has been concentrated on molecular genetic approach including gene polymorphism analysis. The present study was conducted to investigate whether TNFB polymorphism is associated with bipolar I disorder in the Korean population. Methods : 89 bipolar I disorder patients diagnosed by DSM-IV criteria were assigned as the patient group and 202 normal population, matched on age and sex from Catholic hemopoietic stem cell bank (Seoul, Korea), were enrolled as the control group in this study. Genotyping was performed by a polymerase chain reaction-restriction fragment length polymorphism method. All data was analyzed by x² test. Results : There were no significant differences in frequency of TNFB*1/1,TNFB*1/2 and TNFB*2/2 between bipolar I disorder patient group and normal control group. The frequency of TNFB*1 was not statistically different between bipolar I disorder patient group and normal control group. Conclusion : The difference of frequency in TNFB*1/TNFB*2 gene between the bipolar I disorder gropup and the normal contro1 could not be verified. The present result suggested that the gene polymorphism of TNFB may not play a significant role in susceptibility to bipolar I disorder. Studies with a larger number of subjects from different ethnic backgrounds, considring clinical phenotype and controlling various factors, should be launched to further determine the role of TNFB in bipolar I disorder.

HSS STI-CMP적용을 위한이중 패드의 최적화

서용진,박성우,김철복,정소용,이경진,김기욱,박창준 대불대학교 2002 大佛大學校大學院 硏究論文集 Vol.- No.1

As the device geometry shrinks to the deep submicron region, chemical mechanical polishing(CMP) planarization become a more essential technique of advanced ULSI process. Also, CMP process was required for the global planarization of inter-metal dielectric(IMD), inter-level dielectric(ILD) layers and interconnections with free-defect. Especially, the complete global planarization of IMD, ILD and interconnections can be achieved only with the CMP process. However, as the IMD and ILD layer gets thinner, several problems were found in the CMP process. It does have various problems such as dishing effect, torn oxide defects and nitride residues in oxide. So, it leads to severe circuit failure, which affects yield. In this paper, we studied the characteristics of polishing pad, which can apply STI-CMP process for global planarization of multilevel interconnection structure. Also, we investigated the effects of different sets of polishing pad, such as soft and hard pad. As an experimental result, hard pad showed center-fast type, and soft pad showed edge-fast type. Totally, the defect level has shown little difference, however, the counts of scratch was defected less than 2 on JR111 pad. Through the above result, we can select optimum polishing pad, so we can expect the improvement of throughput and device yield.