휴대폰 카메라용 자동초점 구동기의 충격해석

이성민,김봉석,송준호,이수훈,이혜진,이문구,송준엽,이창우 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

Recently, the robustness against daily impact is important according to portablization and downsizing of mobile electronics. Especially, almost parts of cellular phone should undergo drop test when they fall 1.5 m above ground. This test simulates the case when cellular phone slips through user's fingers while he is talking on the phone. This paper studies a drop test of auto focusing (AF) actuator for camera module in cellular phone. This component is composed of voice coil motor (VCM) as an actuator and leaf spring as a guide and suspension. The leaf spring's deformation is essential for the test because its permanent distortion disables the focusing, and then, a high quality photograph cannot be obtained. Up to now the drop test has been carried out after fabricating real AF actuator. We propose a dropt test model which simulates the drop test based on finite element analysis. This model makes us enable investigate the stress acting on the clamping and curved parts of leaf spring. Stress over Von Mises criterion lets the spring deformed permanently, and then AF actuator malfunctioned, It helps us to design and modify AF actuator without manufacturing the real product. And also, it saves the time and cost for the development of new products.

매크로/마이크로 레벨 볼트 결합 구조물에서의 실험적/해석적 방법을 통한 시스템 특성 비교

김봉석,이성민,이문구,이수훈,Jun Ni,송준엽,이창우,하태호 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

As the micro technology and miniaturization of a structure and component in the last couple of decades have been concretely realized, the understanding of structural and dynamic characteristics and prediction of dynamic behavior are indispensable to the miniaturized structures and micro machines. This paper shows the effect of dynamic characteristics in bolt-jointed structures by comparing natural frequencies and mode shapes between macro and micro-scale beams through experimental modal analysis and finite element analysis with a1 8 test models by materials, by size, and by joining condition; that is, SS41 and A16061-T651, micro and macro, and monolithic beam and bolt-jointed beam.

Novel Methylation Biomarker for Non-invasive Diagnostics in Lung Cancer

오태정,( Chang Hun Lee2 ),( Min Ki Lee ),( Yeul Hong Kim ),( Sang Yull Lee ),( Hyo Sung Jeon ),( Shin Yup Lee ),( Seung Soo Yoo ),( Jae Yong Park ),( Sung Whan An ) 대한결핵 및 호흡기학회 2012 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.114 No.-

To identify aberrantly hypermethylated DNA in lung cancer cells we established a genome-wide analysis for hypermethylation sites, namely Methyl DNA Isolation and Amplification (MeDIA) coupled-CpG microarray analysis. In the comprehensive methyaltion profiling analysis between human lung cancer, A549 cells and normal NHBE cells, we observed that several clusters of genes show a significant level of aberrancy in CpG island methylation pattern in cancer cells compared to normal cells. We further identified PCDHGA12 gene as a new marker of non-invasive diagnostics for lung cancer based on followings. 1) Transcription of PCDHGA12 gene is reactivated after treatment of A549 cells with demethylating agent. 2) Bisulfide clonal-sequencing reveals that CpG island of PCDHGA12 shows a distinctive differential methylation between two cell lines. 3) Pyrosequencing-based quantitative methylation assay for such region in tumor and non-tumorous tissues from lung cancer patients shows aberrant hypermethylation in 37 (92%) of the 40 tumor tissues. In clinical validation by pyrosequencingin induced-sputum of lung cancer patients (n=87) and healthy controls (n=51), we observed aberrant hypermethylation incident at significantly elevated level in samples derived from lung cancer patients. According to the optimal threshold calculated by ROC curve analysis, sensitivity and specificity of PCDHGA12 was 86.2% and 82.4%, respectively. PCDHGA12 methylation status could be a potential methylation biomarker alone or combined with others for the screen and the detection of relapse of lung cancer.

Plant regeneration from callus of Iris odaesanensis Y. N. Lee native to Korea via organogenesis

Bae, Kee-Hwa,Yoo, Kyoung-Hwa,Lee, Mi-Hyun,Jeong, Jae-Hun,Choi, Yong-Eui,Yoon, Eui-Soo The Korean Society of Plant Biotechnology 2013 식물생명공학회지 Vol.40 No.3

Iris odaesanensis Y. N. Lee. is an important endangered and native plant belonging to the family Iridaceae in Korea. This study describes a method for rapid micropropagation of this species via from leaf, rhizome and root explants derived calli. Leaf, rhizome and root explants were cultured on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D) for callus induction. Rhizome explants yielded calli at a frequency of 72% when cultured at 1.0 mg/l 2,4-D. Calli were maintained at 1.0 mg/l 2,4-D. These calli were transferred to MS medium supplemented with 0, 0.5, 1.0, and 2.0 mg/l 2,4-D in combination with 0, 0.5, 1.0, and 3.0 mg/l BA for adventitious shoot induction. The highest number of adventitious shoot (228.9 per petri-dish) were formed at 1.0 mg/l 2,4-D and 1.0 mg/l BA. WPM medium was the best to convert calli into plantlets, where up to 98.2% of calli were regenerated into plantlets. This in vitro propagation protocol should be useful for conservation of this endangered plant.

관동맥질환에서 저밀도 지단백 입자 크기의 분포

임효영,김인숙,승기배,강동헌,전두수,장기육,박준철,이수영,홍순조,최규보 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.8

한국의 기수련이 심장박동간격변화에 미치는 영향

이명수,허화정,김병기,류훈,정현택 한국정신과학학회 1998 韓國精神科學學會誌 Vol.2 No.2

심장박동간격은 최근 교감신경과 부교감신경의 안정을 알아보는 척도로 쓰이고 있다. 본 연구는 4~12개월 천도선법 기수련을 행한 20대의 20명의 기수련자와 동일 연령층의 20명의 일반인을 대상으로 하여 1시간 동안 천도선법을 수행하게 하여 전, 참선, 후의 심장박동을 생리 기록계로 측정을 하여 빠른 퓨리에 변환 (FFT)을 통하여 심장박동간격을 조사하였다. 그 결과 자율신경제의 안정척도인 저주파수 적분 값과 고주파수 적분 값의 비(LF/HF)가 수련전과 수련 중에서 천도선법 기수련생들의 값이 일반인과 비교하여 통계적으로 유의한 차이가 났으며 (p<0. 01) 특히 두 그룹 모두 HF 의 값이 유의하게 변화하는 것을 보았을 때 천도선법 기수련이 부교감신경의 활동을 조절하여 자율신경계를 안정화 시킨다는 것을 보여주었다. The effects of ChunDoSunBup (CDSB) Qi-training on the power spectrum of heart rate variability were studied in 20 healthy subjects and 20 CDSB Qi-trainee (subjects with CDSB Qi-training for 4-12 months) Continuous ECG signals were recorded during 1) 10 min of rest in sitting position, 2) 1 hour of CDSB Qi-training , 3) 10 min of post-training. Fast Fourier transformation was used to determine the power spectrum of heart rate variability While CDSB Qi-training, there were significant decrease in the ratio of low to high frequency power spectrum. And value of pre and mild-training in CDSB Qi-trainees were lower than that of control subjects There was a significant changes in high frequency power of both group, but net in low frequency These results suggest that CDSB Qi-training may stabilize autonomic nervous system by modulate parasympathetic nervous system.

청소년 정신장애에 관한 정신의학적 연구

이길홍,김헌수,나철,민병근 중앙대부설한국의과학연구소 1983 한국의과학 Vol.15 No.2

학생청소년의 문제행동과 가정의 심리풍토 특성과의 관계에 관한 상관분석

이길홍,김헌수,민병근 大韓神經精神醫學會 1982 신경정신의학 Vol.21 No.4

The purpose of the study was aimed to examine the relationship between the adolescent problem behaviors and their family climate among high school students in Korea, and to collect baseline data for the establishment of effective measures to prevent delinquent acting-out. In order to achieve these aims, sampling were made by three stage clustered random sampling method, and questionnaires were finally supplied to a total 1620 high school student. These data were statistically analysed by simple correlation coefficient and stepwise multiple regression analysis in order to reveal the relationship between 8 types of factor structures of male & female problem behaviors created through factor analysis of 57 problem behaviors, and 5 categories of psychological climate of family. The collected data were analysed by CDC-174 Computer of KIST, using SPSS program, and their results of the study were presented below; 1. The principal factor structures of problem behaviors among adolescent school boys and girls were classified as follows : The socialized nonaggressive, neurotic withdrawal, overt impulsive sexual, adult modelling, socialized latent sexual, school-norm avoidant, narcissistic sexual, and under-socialized latent aggressive behaviors. Among them, the socialized non-aggressive behavior and the narcissistic sexual behavior were predominantly observed in the male students, on the other hand, the socialized latent aggressive behavior and the socialized non-aggressive behavior were more common in females. From these results, we proposed that studies on causation of problem behavior and measures for guidance should be applied differently by their sex categories. 2. The defective psychological climate of family tended to affect their children's problem behaviors, and their degree of influence was more influential in male students than female students. The family stability, family member's satisfaction with home, and parent-child relation showed more significant correlation with their children's problem behavior comparing with parental child rearing practices. 3. The psychological instability of family tended to be positive correlation with their children's problem behavior. The familial tenseness, coldness, disharmony, uncooperativeness, and parental marital discord revealed significant correlation with their children's socialized latent aggressive behavior and neurotic withdrawal behavior. 4. The family member's dissatisfaction with home tended to bear significant relationships with their children's problem behavior, that is, their children's neurotic flighting behaviors including the socialized non-aggressive, neurotic withdrawal, and school-norm avoidant behavior. 5. The disharmonious parent-child relationships were positively correlated with their children's problem behavior. Particularly, parental rejection of children's opinions, children's rejection of parental opinions, alienated parent-child relationship, lesser degree of devotion, and paternal loss of affection were significantly correlated with their children's problem behaviors such as son's neurotic withdrawal behavior and daughter's socialized non-aggressive behavior. 6. The defective parental child rearing practices tended to affect their children's problem behavior. Particularly, parental mistrust to their children, parent-centered approach, authoritative approach, punishment oriented system, rigid discipline, and parental closed-mindedness were significantly correlated with their son's narcissistic sexual behavior & neurotic withdrawal behavior or daughter's school norm avoidant & undersocialized latent aggressive behavior. 7. In comparison of both parent in the degree of influence on their children's problem behavior, it was revealed that father's was more influential than mother's. Particularly, the parental child rearing practices showed more significant correlations with their son's problem behaviors comparing with their daughter's behaviors, and showed higher correlations with their same-sex children than their opposite sex children. 8. Among 7 types of parental child rearing practices, parental mistrust toward their children was most important factor. These mistrust attitude toward their children showed higher correlations with neurotic flighting types of behavior than antisocial fighting types of behavior.

근로청소년의 산업재해와 음주양상과의 상호관계에 관한 산업정신의학적 연구

이길홍,김헌수,이규항,민병근 중앙대부설한국의과학연구소 1983 한국의과학 Vol.15 No.1

가상공간의 가공 공정과 상태 구현에 관한 연구

이수훈,김봉석,홍민성,김종민,JUN NI,박상호,송준엽,이창우,하태호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

This paper presents virtual machining system in order to realize turning process in virtual space. A reliable virtual turning process simulation was developed based on the surface shaping system which is capable of considering geometric model, thermal error model, and vibration model. Accuracy of surface shape resulting from proposed machining simulator was verified experimentally. This paper also developed the watchdog agent that continuously assessed, diagnosed, and predicted performance of products and machines in machining. The Watchdog agent extracted feature signal using time-frequency analysis among various signals from multi-sensor and evaluated machining condition using performance confidence value.