• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 1부
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• pp.278-281
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• 2012

본 연구는 고주파를 발생시키는 고주파기기를 이용한 조류배양시스템에 관한 것으로, 미세조류 배양시 고주파 파형을 이용하는 것이다. 미세조류 배양을 위한 생물반응기에 200KHz~400KHz 고주파 파형이 나오도록 설계되었으며, Osillograph상에서 impedence가 최소가 되는 특정 지점에서 공명을 일으킬 때, 전기적 저항은 최소가 되며, 이상적인 고주파 파형 발생으로 생물반응기내의 미세조류의 Survival과 Growth에 직접적인 영향을 미치는 것을 확인하였다. 본 연구의 고주파 파형을 이용한 조류배양 시스템 개발은 자외선 흡수능을 높이는 조류배양에 활용될 수 있을 뿐만 아니라, 미세조류세포 내의 다양한 신호전달에 관련된 특정 피토케미칼, 펩타이드, 단백질 대사 연구에 유용하게 활용될 수 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.144-144
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• 1999

최근 국내 반도체 기술의 비약적인 발전으로 전자 기기 전반에 소형화, 고주파화, 고기능화 등이 진행되는데 반해, 반도체 소자등에 전원을 공급하거나 회로 전체를 운용하는 전기 신호를 변조.증폭시키는데 반해, 반도체 소자등에 전원을 공급하거나 회로 전체를 운용하는 전기신호를 변조.증폭시키는 인덕터, 트랜스 포머와 같은 수동 자기 소자는 아직도 3차원 벌크 형태로 사용되고 있다. 일본을 중심으로 각국에서는 자기 소자의 박막.소형화에 대한 다각도의 연구가 진행되었으나 국내서는 아직 미미한 실정이다. 따라서 고집적 전원 공급 장치나 지능 센서 등에 반도체와 자기 소자의 사용 주파수 대역과 크기가 통합된 반도체-자성체 IC(semiconductor-magnetic integrated circuit)의 필요성이 절실히 요구되고 있다. 현재 사용중인 벌크형 인덕터나, 트랜스 포머의 경우 10NHz이상의 고주파 대역에는 응용되지 못하고 있다. 이는 적용된 자성체가 페라이트(ferrite)로서 초투자율은 크지만 고주파대역에서의 공진 현상에 의해 저투자율을 나타내고, 포화 자속밀도가 낮기 때문이다. 이러한 페라이트 자성체의 대체품으로 주목받고 있는 것이 Fe, Co계 고비저항 자성마이다. 그러나 Co는 낮은 포화자속밀도를 나타내기 때문에 이러한 조건을 충족시키는 자성막으로 Fe계 미세 결정막을 사용하였다. 본 연구에서는 선택적 전기 도금법(selective electroplating method)과 LIGA like process를 이용하여 공시형 인덕터(air core inductor)의 라이브러리(library)를 구축한 뒤, 고주파 대역에서의 우수한 연자기 특성을 가지는 Ti/FeTaN막을 적용한 자기 박막 인덕터(magnetic thin film inductor)를 제작하여 비교.분석하였다. 제조된 인덕터의 특성 추정은 impedence analyzer를 이용하여 주파수에 따른 저항(resistance), 인덕턴스(inductance)를 측정, 계산한 성능지수(quality factor)로서 인덕터의 성능을 평가하였다. 제조된 박막 인덕터의 코일 형상은 5턴의 double rectangular spiral 구조였으며, 적용된 자성막의 유효 투자율9effective permeability)은 1500, 자성막, 절연막 그리고 코일의 두께는 각각 2$\mu\textrm{m}$, 1$\mu\textrm{m}$, 20$\mu\textrm{m}$이며 코일의 폭은 100$\mu\textrm{m}$, 코일간의 간격은 100$\mu\textrm{m}$였다. 제조된 박막 인덕터는 5MHz에서 1.0$\mu$H의 인덕턴스를 나타내었으며 dc current dervability는 100mA까지 유지되었다.

• 대한한방소아과학회지
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• 제25권1호
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• pp.82-89
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• 2011

Objectives: This study was designed to regulate the percentile of body fat percentage by Bioelectrical Impedence Analysis (BIA) in order to detect overweight and obesity in preschool children. Methods 1301 three to six year old children's height, weight, and body fat percentage using BIA was measured. Results: The percent of the boys with 85th percentiles of the body fat percentage were 22.3%(3years), 23.4%(3.5years), 23.9%(4years), 24.8%(4.5years), 22.8%(5years), 24.6%(5.5years) and 23.8%(6years). The percent of the girls with 95th percentiles of the body fat percentage were 24.9%(3years), 27.5%(3.5years), 27.3%(4years), 28.6%(4.5years), 28.1%(5years), 33.3%(5.5years) and 32.7%(6years). For the girls, the percent of girls with 85th percentiles of body fat percentage were 23.3%(3years), 24.4%(3.5years), 23.6%(4years), 23.7%(4.5years), 24.7%(5years), 26.0%(5.5years) and 28.1%(6years). And the 95th percentiles of the body fat percentage were 28.6%(3years), 27.3%(3.5years), 25.4%(4years), 28.0%(4.5years), 31.7%(5years), 33.5%(5.5years) and 36.4%(6years). Conclusions: The 85th percentiles of body fat percentage to classify as overweight and the 95th percentiles of body fat percentage to classify as obesity were accord with the Body Mass Index (BMI) criteria by the Korean pediatrics society in 2007.

• The Korean Journal of Pain
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• 제9권1호
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• pp.63-68
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• 1996

Background; Epidural analgesia for controlling labor pain has recently gained world-wide popularity. However, many patients scheduled for continuous epidural analgesia voice concern over harmful effects to their fetus and other possible complications such as hemodynamic changes, back pain and neurologic sequelae etc. The aim of this study was to evaluate the hemodynamic changes with and without epidural block as a measure to determine the safety of epidural analgesia during labor and delivery. Methods: Twenty healthy subjects were divided equally into two groups(Group 1 without epidural block, and Group 2 with epidural block) and serial hemodynamic measurements were taken in all subjects with transcutaneous impedence cardiography. The epidural catheter was inserted at the level of $L_{3,4}$ in Group 2 and analgesia was maintained using 0.25% bupivacaine mixed with fentanyl. Results: Cardiac output increased slightly with cervical dilatation in both groups, but no significant differences were found between the two groups. Similarly, no significant differences were found in blood pressures between the two groups. Stroke volume and end-diastolic volume indices were slightly decreased in group 1 and slightly increased in group 2. However, there were no significant differences between the two groups. The ejection fraction was nearly constant and ranging 56~59%. Conclusion: We concluded epidural analgesia for labor and delivery is a safe technique for the parturients since results indicated no significant differences in hemodynamic changes, as compared to the control group.

• 대한지역사회영양학회지
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• 제5권3호
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• pp.484-492
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• 2000

In an attempt to figure out the relationship between zinc status and taste acuity of old and young women, dietary zinc intake, urinary zinc excretion, and taste acuity were determined for 118 women. Zinc intake was measured by 2-day food records and food frequency method. Urinary zinc excretion was measured from urine samples collected for twenty four hours. Body fat, lean body mass (LBM), and total body water were measured by bio-impedence. Average dietary zinc intake by food record was 4.15$\pm$1.33mg (=35% if Korean RDA) for the old women and 5.41$\pm$2.76mg (=25% of RDA) for young women. When zinc intake was measured by a frequency method, the average intakes of the old and young women were 3.5$\pm$1.7mg 4.5$\pm$1.9mg, respectively. It appears that dietary zinc intake of young women was significantly higher than that of the old women. Average urinary zinc excretion of the subjects was 0.27$\pm$0.16mg in the elderly and 0.24$\pm$0.13mg in young women, which indicated a marginal zinc status. However, zinc status was not significantly different between old and young women. Correlation analysis indicated that zinc intake and urinary zinc excretion were positively related to BMI and LBM in young women. The old women (m=49) showed significantly higher taste detection thresholds than young subjects (n=47) for both sweet and salty tastes. Recognition thresholds for sodium chloride and sucrose were not significantly different between old and young women. The lower the taste thresholds for salty taste, the higher the average dietary zinc intake. However, taste perception concentration was not related to the urinary zinc excretion level.

• 한방비만학회지
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• 제4권1호
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• pp.95-123
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• 2004

Objects: This study was aimed to find out correlation between life style and cardiopulmonary function and body fat. Methods: We divided two groups by the score of behavior modification therapy questionnaire. Westudied tendency of change of cardiopulmonary function and body fat for medication of Mahuang capsule by ergogenic aids and placebo with circuit training. We got the results for Exercise stress test and Segmental Bioelectrical Impedence Analysis. Results: 1. High Score Group in Behavior Modification Therapy Questionnaire significantly(p<.05) showed elevation of Lean Body Mass, Body Fat, Waist Circumference and not significantly elevation of Body Weight, But Basal Metabolic Rate was declined. Low Score Group in Behavior Modification Therapy Questionnaire significantly(p<.05) showed elevation of Waist Circumference and not significantly elevation of Body Weight and Body Fat, Lean Body Mass but decline of Basal Metabolic Rate, Waist to Hip Ratio 2. High Score Group in Behavior Modification Therapy Questionnaire significantly(p<.05) showed elevation of $VO_{2max}$ and not significantly elevation of the rest. Low Score Group in Behavior Modification Therapy Questionnaire significantly(p<.05) showed elevation of rest Heart Rate, Diastolic Blood Pressure, and not significantly elevation of the rest except for METs Conclusion: High score group in Behavior Modification Therapy Questionnaire showed significantly elevation of body composition, but had no relationship with Cardiopulmonary function

• 대한지역사회영양학회지
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• 제7권4호
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• pp.539-547
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• 2002

The purpose of this study was to investigate whether the health status as determined by a self-assessment checklist was related to the nutritional status of elderly Korean women. We interviewed 59 female subjects living in the Daegu area aged over 55 years. Information on their dietary intake on two consecutive days was collected by the 24-hour Recall Method. Their body compositions were measured using a Bio-electrical Impedence Fatness Analyzer. Their zinc status was evaluated according to their dietary zinc intake and urinary zinc excretion in urine samples collected for 24 hours. Their heath status was determined by a NSI Checklist. While 50.9% of the total subjects belonged to a moderate nutritional risk group,23.7% of the subjects were at a high nutritional risk. It appeared that only 25.4% of the subjects were evaluated as being healthy. Therefore, the overall nutritional health status of the elderly females belonged to the moderate nutritional risk group. Except for vitamin C, the average daily nutrient intake of the subjects was below the level of the recommended dietary allowances (RDA) for Koreans. The lower the nutritional health score, the better was their dietary intake of energy (p<.05), protein (p<.001), and zinc (p<.01). A positive relationship between their nutritional health score and body fat ratio was also observed (p<.05). Therefore, we suggest that the NSI Checklist could be used as a practical screening tool at the beginning of nutritional surveillance of the elderly in the community.

• 한국전기전자재료학회논문지
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• 제15권9호
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• pp.783-787
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• 2002

In recent year, B $i_{4-}$x L $a_{x}$ $Ti_3$ $O_{12(BLT)}$ is one of promising substitute materials for the ferroelectric random access memory(FRAM) applications. But the systematic composition is still insufficient, so this experiment was carried out in ceramic ambient sintering process which has the very excellent ferroelectric property. Samples were prepared by a bulk and the purpose which was estimated with a suitability of thin films applications. The density of B $i_{3.75}$ L $a_{0.25}$ $Ti_3$ $O_{12}$ was high and the XRD pattern showed that the intensity of main peak (117) was increased at the argon ambient sintering. Controlling the quantity of oxygen, crystallization showed a thin, long plate like type, and we obtained the excellent dielectric and polarization properties at the argon atmosphere sintering. Also this sintering process was effective at the bulk sample. Argon ambient sintered sample produced higher permittivity of 154, the remanent polarization(2Pr) of 6.8 uC/$\textrm{cm}^2$ compared with that sintered in air and oxygen ambient. And this sintering process showed a possibility which could be applied to thin films process..

• 대한기계학회논문집A
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• 제34권11호
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• pp.1613-1622
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• 2010

본 연구는 고진공 환경중 초음파 리니어 스테이지의 나노미터 위치제어를 기술하고 있다. 고진공 환경 중 초정밀 위치 제어 시스템에 응용하기 위해 3 차 종진동 모드와 6 차 횡진동 모드를 가지는 BLT를 개발 했다. 안정적인 고출력을 위해 BLT 는 하나의 공진 주파수로 두 개의 모드 진동을 발생 시켜야 한다. 하나의 공진 주파수를 이용 하기 위해 어드미턴스를 변화시켜 각 모드의 공진 주파수를 일치시켜 조건이 다른 대기 환경에서 안정적인 고출력을 얻을 수 있었다. 기압 변화에 따라 구동 특성이 달라지는 시스템을 제어하기 위해 마찰력 변화에 따른 비선형 특성을 보상한 NCTF 제어를 사용했다. 설계된 제어기를 이용해 고진공 환경에서 시스템을 나노미터 정도로 제어하는 결과를 얻을 수 있었다.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1978년도 제12차 학술대회연제 순서 및 초록
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• pp.8.2-8
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• 1978

언어는 청각을 통해서 발달하는 것으로서 난청이 있어서 듣지 못하는 경우 그 사람의 언어발달은 정지되어 농아자가 되는 경우가 많다. 따라서 언어발달에 미치는 영향 때문에 유아난청의 조기진단 및 치료는 대단히 중요하다고 하겠다. 이에 저자를은 유아난청의 원인을 조사함으로써 유아난청의 예방 및 치료에 도움을 주고자 1977년 1월부터 8월까지 8개월 동안에 본원 외래 난청실로 내방한 만5세 이하의 난청아 185명을 대상으로 하여 자세한 병력과 상세한 임상적 검사 및 Impedance audiometer(Madsen ZO 70)에 의한 청역검사를 실시하고 그 원인에 대한 통계적 고찰을 시도하여 다음과 같은 결과를 얻었다. 1. 유아난청 중 감각신경성난청의 가장 흔한 원인은 유아자신의 감염(123례중, 44례, 35.8%)이었으며 임신중의 모체의 상태(37례 30.1%), 분만시 외상 혹은 두부외상(18례, 14.7%)의 순이었다. 2. 유아난청 중 부음성난청의 가장 흔한 원인은 급성 혹은 만성중이질환이었으며(62례중 32례, 51.6%), 다음으로는 잦은 상기도감염(19례, 30.6%), 아데노이드 증식증(7례, 11.3%)의 순이었다. 3. 유아난청은 외인성원인이 185례중 179례(96.8%), 내인성원인이 6례(3.2%)로 대부분이 외인성 원인이었다.