데스크탑 밀링머신의 고속 스핀들 설계 해석

장성현,황현영,정우영,홍정표,최영휴 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

During a decade, there are many researches on microfactory which is the miniature, flexible, and efficient manufacturing system for the micro/meso scale machining device. Moreover many micro machine tool has developed in Japan, U.S., Europe, and Korea. Already we are developing a desktop milling machine with 380×450×450 ㎣ machine size for microfactory or BT (Bio technology) factory. In this study, we carried out the design analysis of a high speed spindle system for our desktop milling machine by using ADROS, which is our own developed S/W for dynamic design analysis of rotor systems. As the result, we obtained some analyzed dynamic characteristics of a spindle system, such as natural frequency, whirl frequency, critical speed, and harmonic response.

노인의 팔 굽힘/폄 저항 운동 시 하중 증가에 따른 근육의 활성도 및 기여도 분석

김현동(Hyun Dong Kim),황성재(Sungjae Hwang),손종상(Jongsang Son),김한성(Han Sung Kim),김영호(Young Ho Kim) 대한인간공학회 2009 大韓人間工學會誌 Vol.28 No.4

The purpose of this study was to assess activation and contribution of muscles of the elderly according to increased loading during the arm flexion extension resistance exercise. Surface electromyographic signals were acquired from biceps brachii, triceps brachii, deltoid posterior, pectoralis major and latissimmus dorsi to determine the difference of the activation of specific muscles between the elderly and young. Five elderly and five young males with no musculoskeletal disease volunteered for the study. Electromyographic activities in the muscles were measured during resistance exercise and normalized to the maximum EMG activity recorded in the maximal voluntary static contraction (MVC). Against the increased loading during arm flexion/extension resistance exercises, the young uses muscles evenly but the elderly uses one specific muscle frequently. Contribution of triceps brachii during extension and deltoid posterior during flexion was principal in the elderly.

Increased 11β-hydroxysteroid dehydrogenase type 1 contributes to barrier dysfunction in aged skin

( Beom Jun Kim ),( Noo Ri Lee ),( Chung Hyeok Lee ),( Young Bin Lee ),( Solam Lee ),( Hyun Jee Hwang ),( Eunjung Kim ),( Eung Ho Choi ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.2

Background: 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts inactive cortisone into cortisol, an active form, and is expressed by several tissues including the skin. Excessive active glucocorticoid (GC) deteriorates skin barrier function. Objectives: To find out if 11β-HSD1 affects on the barrier function in aged skin. Methods: We have performed human and in vivo studies. We measured cortisol in stratum corneum (SC) and oral epithelium of the elderly and young. Hairless mice were used for 11β-HSD1 immunohistochemistry staining of skin and measuring skin barrier function and serum cytokines. 11β-HSD1 knock-out (KO) mice and its wild-type were used for measuring lipid synthesis related enzyme. Results: Cortisol levels were elevated in SC and oral epithelium of the elderly rather than young. The 11β -HSD1 expression was increased in immunohistochemistry stain of aged mice skin. Aged mice showed decreased transepidermal water loss (TEWL) and SC hydration, and increased SC integrity than young. Serum inflammatory cytokines including interleukin-1α, -4, -10, -31 and tumor necrosis factor-α were increased in aged mice than young. The expressions of lipid synthesis related enzymes in epidermis were elevated in KO mice and topical 11β -HSD1 inhibitor applied mice. Conclusion: 11β-HSD1 expression is elevated in aged skin. It increases active GC and then deteriorates skin barrier function.

평양 남정리 53호분 출토 토제칠기의 보존 및 제작기법 연구 : 토제칠이배, 토제칠반, 토제칠안

황현성,임수경,김희진,이태진,고민정,윤은영 국립중앙박물관 2013 고고학지 Vol.19 No.-

본고는 일제 강점기 조사 미등록 유물 정리사업의 일환으로 수행한 평양 남정리 53호분 출토 토제칠이배, 토제칠반, 토제칠안에 관한 연구이다. 남정리 출토 유물은 소지가 목심이 아닌 토제라는 것과 칠이배와 칠반을 얹은 칠안이 함께 출토되었다는 점에서 주목할 만하다. 토제칠이배 및 칠반 그리고 칠안의 보존처리를 통해 이들의 형태와 문양 등에 대해 알 수 있었다. 또한 칠기에 사용된 붉은색 안료의 성분을 분석하여 안료의 주성분이 진사(HgS)였음을 확인하였다. 이번 연구에서 기존에 잘 알려지지 않았던 한반도 내 위치한 낙랑의 토제칠기에 관해 살펴볼 수 있었으며 이러한 제작방법이 한나라 고유의 문화인지 아니면 재지세력이 한나라의 영향을 받아 현지화한 문화의 산물인지에 대해 생각해 볼 수 있는 기회라 생각된다. This research paper examines the lacquered pottery cup, plate and table unearthed from Tomb No. 53 at Namjeong-ri in Pyongyang, which were under conservation treatment as a part of the Project of Unregistered Artefacts Uncovered in the Japanese Colonial Era. It is very rare to have a lacquered pottery cup and plate, lying on a lacquered pottery table, as a set of grave goods. In particular, they are not wooden but pottery items. Through conservation treatment for lacquered pottery cup, plate and table, it was possible to find out their shapes and decoration patterns. The resulting analysis of the red pigment used indicates that cinnabar (HgS) is the main element. This research is significant because it examines lacquered pottery wares produced in Lelang, which has rarely been conducted. Further research will need to prove whether their production techniques were in the unique Chinese Han style or were produced by indigenous craftsmen who adopted the Chinese Han technique.

간호대학생이 지각하는 임상실습지도자의 교수효율성과 임상실습만족도의 관계

황현아,김희진,김예지,이규희,이영롱,박성희,손수빈 이화여자대학교 간호과학대학 2012 이화간호학회지 Vol.- No.46

Purpose: The purpose of this study was to investigate the relationship between teaching effectiveness and clinical practice satisfaction among nursing students. Method: The subjects of this study were 107 junior and senior nursing students in E university. Data were collected using self-reported questionnaire including general and practicum related characteristics, teaching effectiveness of clinical instructors and clinical practice satisfaction from September 12 to September 21, 2011. Collected data were analyzed by SPSS 19 program using t-test, ANOVA with Scheffe test, and Pearson`s correlation coefficients. Result: The mean score of teaching effectiveness was 3.35(±.51), and mean of clinical practice satisfaction was 3.19±.47. There were significant differences of teaching effectiveness of clinical instrutor by satisfaction of overall clinical practicum(F=8.332, p<.001), satisfaction of practice hour(F=3.230, p=.044), and satisfaction of major(F=9.883, p<.001). There were significant differences of clinical practice satisfaction by grade(t=2.274, p=.025), motive of choosing nursing science as a major(F=3.329, p=.007), satisfaction of overall clinical practicum(F=17.437, p<.001), satisfaction of practice hours(F=9.925, p<.001), and satisfaction of nursing major(F=12.748, p<.001). Relationship between teaching effectiveness of clinical instructor and clinical practice satisfaction showed positive correlation(r=.704, p<.001). Conclusion: In this study, teaching effectiveness of clinical instructor was related with clinical practice satisfaction. Therefore, we should consider improving teaching effectiveness of clinical instructor to improve clinical practice satisfaction.

Ethyoene Oxide 폭로 근로자의 말초 임파구 자매염색분체 교환에 관한 연구

황천현,박종태,장성훈,김대성,이원진,김청식,김영환 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.4

Operators of hospital sterilizers who use ethylene oxide(EtO) were studied to determine the exposure of EtO level and the frequency of sister chromatid exchanges(SCEs) from June 12 to July 20, 1997. To evaluate SCEs in the peripheral blood cells, we selected 22 workers at the central supply room of 4 university hospitals and 22 unexposed workers at the same hospitals according to match sex, age, and smoking habit and also did questionnaires. The mean air concentrations(8-hr TWA) of EtO at 4 university hospitals were less than 1 ppm. The SCE frequencies in exposed workers to EtO and controls were normally distributed. The SCE frequencies in exposed workers to EtO and controls were 6.42±0.63, 5.86±0.69, respectively and their differences were statistically significant(p=0.0093). But there were no statistically significant differences in smoking, alcohol intake, coffee drinking. Especially smokers who exposed to EtO were increased SCE statistically significant than the exposed group who did not smoke.

납노출지표와 적혈구내 protein kinase C 활성도의 연관성

황규윤,황보영,안현철,김용배,리갑수,이성수,안규동,이병국 大韓産業醫學會 2001 대한직업환경의학회지 Vol.13 No.4

목적 : Protein kinase C는 칼슘-인지질 의존형인산화 효소로 'H VJ'tfO에서 납에 의하여 활성화되지만, 납에 노출된 인체내에서 그 영향을 평가한 경우는 얼다. 본 연구의 목적은 납에 직업적으로 노출되는 근로자를 대상으로 납 노출이 적혈구막의 단백질내에서 PKC 활성에 의한 인산화 수준에 영향을 주는지 알아보고자 하였다. 방법 : 1998년부터 국내 납 근로자를 대상으로 납에 의한 건강 영향조사가 4년간의 코호트 연구로 실행하였다. 1차년도에 630명의 납 근로자와 135명의대조군이 조사되었고 이들중 본 연구에서는 직업적노출이 되는 사업장에 근무하는 212명의 근로자를대상하였다. 156명의 남자와 56명의 여자 근로자를 대상으로 인구학적, 과거병력, 직업력 등을 구조화된 설문과 면접으로 조사되었고 납 노출 평가는 혈중 납농도 및 ZPP, 경골중 납농도를 측정하였다. PKC의 활성도는 적혈구막 단백질내 PKC 의존형인산화 수준으로 평가하였다. 적혈구막 단백질인spectrin과 band 4.9의 후인산화수준을 측정하여각 납 노출지표(혈중 납, ZPP, 경골중 납. 노출기간)와의 관련성은 다중회귀분석을 이용하였다. 결과 : 조사대상자의 평균(SD) 연령은39.1(10.0)세, 근무기간은 8.1(6.5)년 이었으며, 경골중 납농도는 범위가 0.8에서 290.8 trg Pb/gbone mineral로 평근(SD) 34.4(35.2) rig Pb/gbone mineral이었다. 적혈구막 단백질의 후인산화수준은 개인간 변이가 매우 컸으며, spectrin은 평균(SD) 540 7(304.1), band 4.9 SfkDa는198.6(78.2), 48 kDa는 247.7(83.3) PSL이었다.경골중 납농도와 노출 기간은 이들 후인산화 수준과역상관성을 보였으나(p(0.05), 혈중 납 농도와 ZPP는 상관성이 없었다(p)0.05). 가능성 있는 혼란변수를 통제한 상태에서도 경골중 납 농도와 노출기간은 이들 후인산화수준과 유의한 회귀계수를 나타내었다. 결론 : 만성적 납 노출에 의하여 적혈구내 PKC활성도는 영향을 받아 증가되어있는 것으로 평가되어 적혈구막 단백질의 인산화수준은 납의 노출지표로 이용될 수 있을 것이다. 납의 신경독성은 부분적으로 PKC의 활성도왁 관련되어 있을 기전을 배제하기 어렵기 때문에 PfC 활성도와 신경행동학적 기능과의 관련성 평가가 진행되어야 할 것이다. Objectives : Protein kinase C(PKC) , a calcium and phospholipid dependent enzyme, is activated by lead in vitro at picomolar concentrations. However, the effect of lead on PKC has never been studied in a human population. The purpose of the study was to evaluate whether lead exposure was associated with PKC mediated-phosphorylation in erythrocytes among lead workers. Methods : Two hundred and twelve lead workers were studied. To determine the levels of phosphorylation ir vivo, an in vivo back phosphorylation technique was used by adding PKC and γ-32P to preparations of erythrocyte membranes. We measured back phosphorylations of erythrocyte membrane proteins, spectrin, and 52 kDa and 48 kDa, as an indirect measure of PKC activation if vivo. Results : The mean(SD) age and exposure duration was 39.1(10.0) years and 8.1(6.5) years, respectively. Tibial lead ranged from 0.8 to 290.8 μg Pb/g bone mineral with a mean (SD) of 34.4(35.2) μg Pb/g bone mineral. The means(SD) of back phosphorylation levels of the three proteins were 540.7(304.1), 198.6(78.2), and 247.7(83.3) photostimulated luminescence units (PSL), respectively, by phosphoimager. After adjustment for potential confounding factors, tibial lead and exposure duration were significantly and inversely associated with back phosphorylation levels. One unit of increase in tibial lead (1 μg Pb/g bone mineral) is associated with a decline in spectrin, band 4.9 52 kDa, and band 4.9 48 kDa back phosphorylation levels by 1.4(p〈0.05), 0.34(p〈0.05), and 0.47(p〈0.01), respectively However, there were no associations between the back phosphorylation levels and either blood lead or ZPP levels. Conclusions : These findings suggest that the PKC activity in erythrocytes is increased by chronic lead exposure and that erythrocyte membrane protein phosphorylation may be a biomarker of lead exposure.

유연구조물의 잔류진동제어를 위한 시간지연기법 연구

황재혁,조현권,이혜진,박영창,박진호 한국 항공대학교 항공산업기술연구소 2001 航空宇宙産業技術硏究所 硏究誌 Vol.11 No.-

본 논문에서는 유연한 부착물을 갖는 우주구조물의 회전 시 발생할 수 있는 잔류진동을 최소화하고 또한 그 응용 범위가 넓은 입력설계 방법과 등가화 된 시간 지연기법을 다루었다. 먼저 Singh과 Vadali가 제안한 제어기를 이용하여 하나의 모드에 대한 시간 지연 제어기를 설계하고 입력설계 방법과 등가화 됨을 보였다. 그리고 실제 모델에 대한 적용과 해석을 위하여 우주구조물에서 많이 사용되는 유연구조물의 운동방정식을 유도하고 해석하였고, 실험을 통하여 입력 설계 방법과 시간 지연 기법을 이용한 잔류 진동 제어에 대한 성능이 우수함을 확인할 수 있었다. In this paper, the time-delay control (TDC) design methods for command signals to minimize the induced residual vibration followed by the maneuvers of the flexible structures has been studied. The equivalence between the time-delay control and the input shaping control has been shown and TDC is applied to control the residual vibration of the flexible structure in this study. It has been shown by a series of simulation and experiments that TDC is very effective to suppress the residual vibration of flexible structure induced by its maneuvers.

부산시 사회지역특성에 관한 연구

황영우,윤철현 동아대학교 건설기술연구소 1997 硏究報告 Vol.21 No.2

Social Area Analysis is valuable method to understand urban land use pattern by there residents. The result of this study using factor and cluster analyses is similar to the our common understanding on Pusan situations. Puasn can be divided 9 homogeneous regions through this study. The types of Pusan land use pattern cannot be fitted to Concentric Zone Theory, Sector Theory and Multiple Nuclei Theory like western cities. But the social determinants - invasion and succession, concentration and deconcentration, centralized decentralization system- were discovered partly in Pusan. The economic and public determinants have to be considered with complexity for the much deeper understanding on Pusan land use pattern.

C_3 및 C_7위치에 치환된 새로운 세파로스포린 化合物의 合成과 抗菌活性(Ⅰ)

황화영,하재천,김영수,고옥현,강형룡 조선대학교 약학연구소 1994 藥學硏究誌 Vol.16 No.1

The synthesis and antimicrobial activity of cephalosporin having (Z)-2-(2-aminothiazol-4-yl)-2-trityloxyiminoacetamido group and 5-(2-chlorophenyl)-4-phenyl-4H-1, 2, 4-triazol-3-thiomethyl group on the C_3 and C_7 position of the cephem ring, respectively are descrived. This compound was tested for antimicrobial activity in vitro against Candida albicans ATCC 10231, Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 6538P, Mycobacterium phlei IIP-IPH, Escherichia coli KCTC 1039, Escherichia coli ESS, Klebisiella pneumoniae KCTC 1560, Salmonella typhymurium TV-119, Pseudomonas aeruginosa IFO 13130. The antimicrobial activity of synthetic compound was better as compare with cefotaxime and cefazoline against Micrococcus luteus ATCC 9341 & Escherichia coli KCTC ESS.