PVDF 압전소자 활용 전기 에너지 수집

"이수헌", "여인권", "정재성", "박종대" 배재대학교 자연과학연구소 2015 自然科學論文集 Vol.26 No.1

PVDF(Polyvinylidene Fluoride)를 사용하여 진동에너지를 전기적 에너지로 수집할 수 있는 소형 발전시스템을 개발하였다. 개발된 시스템은 온도, 진동, 압력 등의 데이터를 수집하고 무선으로 전송하는 센서 네트워크의 전원으로 사용될 수 있다. We have developed a small electrical energy harvesting system using PVDF(Polyvinylidene Fluoride) which can convert vibrational energy into electrical energy. The developed system can be used as a power source for sensor network which acquire data such as temperature, vibration, pressure, etc and transmit data to a data center

유동성 복합 레진을 적용한 예방적 레진 수복물의 미세 누출 양상에 관한 비교 연구

박헌정,김종수,김용기 대한소아치과학회 2000 大韓小兒齒科學會誌 Vol.27 No.3

성인에 비해 치료를 견딜 수 있는 시간이 상대적으로 짧은 소아 환자에 있어 시술 시간은 치료 결과의 중요한 변수로 작용하게 된다. 최근 소개된 유동성 복합 레진을 예방적 레진 수복술에 사용하게 될 경우 전색재 도포 과정을 생략할 수 있어 시술 시간의 단축, 편의성 등의 장점이 인정되나 미세누출 등에 관한 연구 결과는 미흡한 실정이다. 본 연구의 목적은 최근 소개된 유동성 복합 레진을 사용한 예방적 레진 수복물과 기존의 복합 레진과 전색재를 사용한 예방적 레진 수복물 간의 미세누출 및 기포발생 정도를 비교하고자 함이었다. 교합면이 건전한 상악 소구치 60개를 대상으로 고속용 1/2 round bur를 이용하여 교합면 열구를 따라 길이3.0 ×폭0.7 ×깊이2.0mm의 Ⅰ급 와동을 형성하고 각 군 당 20개씩 무작위로 시편을 배분하고, 제조자의 지침에 따라 본딩재인 Scotchbond Multipurpose □ (3M dental product, U.S.A.)를 적용하고 유동성 복합 레진 수복군인 Ⅰ,Ⅱ군에는 각각 Revolution □ (Kerr, U.S.A.)과 Arabesk Flow(VOCO, Germany), 대조군인 Ⅲ군(통상적 예방적 레진 수복군)에는 Restorative Z-100 □ (3M dental product, U.S.A.)과 Concise □ (3M dental product, U.S.A.)를 제조자의 지시에 따라 충전, 적용하였다. 3,000회의 열 순환 및 색소 침투 후 시편을 절단하여 컴퓨터에 영상을 입력하고 색소의 침투 길이 및 침투 비율을 계산하고 미세누출 평가 기준을 이용하여 각 시편에 대한 미세누출 정도를 평가하였다. 또한, 각 군별로 특징적으로 나타난 기포의 발생 양상을 별도의 평가기준에 따라 평가하였다. 미세누출은 수복재와 법랑질의 계면부에 국한되어 관찰되었고, 와동 내부까지 침투된 경우는 없었으며, 유동성 복합레진 수복군(Ⅰ, Ⅱ군)이 기존의 예방적 레진 수복군(Ⅲ군)에 비해 낮은 미세 누출 정도를 나타냈다(p〈0.05). 미세누출 결과 외에, 대부분의 충전물 내에서 다양한 형태의 기포가 발견되었으며, Ⅰ, Ⅱ군 표본에서 Ⅲ군에 비해 크기가 큰 기포가 더욱 많이 관찰되었다. The purpose of this study was to compare the microleakage pattern of preventive resin restoration using conventional composite resin and allowable composite resin that recently developed. 60 sound premolar teeth were allocated to three groups. Flowable composite resin was used for the experimental groups(GroupⅠ,Ⅱ) and conventional resin for the control group(Group Ⅲ) . After composite fi11ing and sealant application. all teeth were thermocycled and evaluated for microleakage under light microscope. Additionally, a variety of voids formed inside restorations were also evaluated. Data were analyzed statistically using Kruskal-Wallis test and/or Mann-Whitney U-test. The results of the present study were as fo11ows . 1.Microleakage found in all samples was only limited to the interface o( restoration margin and enamel. 2.The flowable composite resin groups (GroupⅠ, Ⅱ) generally showed less micoleakage than control groups (conventional preventive resin restoration) (p〈0.05) 3.Various types of voids were observed in most specimens. Especially, there was a tendency for more and larger voids to be found in group Ⅰ, Ⅱ than group Ⅲ (p〈0.05).

가정환경·스트레스원·스트레스 수준의 상호관련성에 관한 연구

이종헌,전은정 대구효성가톨릭대학교 응용과학연구소 1997 응용과학연구논문집 Vol.6 No.1

The measure of adolescent family environment used here come from well-known sources; that is, sex, age, religion, economy level, mother's occupation, mother's age, birth order, family number. The stress measure is a 45-item standard stress questionnaire discussed in detail else where. The items fall into 7 areas; pysical and psychological stability, other sex friends relationship, self-satisfaction, personal relationship, family relationship, school grade, and headache. The subjects of this study were randomly selected 534 Middle school and High school students who lived in Hayang-up Kyong san-shi Kyongbuk and they interviewed in 1 to 31 May, 1996. The purpose of this study is to investigate the relationships between the stress level of adolescent and family environment and stress factor. The data were analyzed by the statistical methods taking advantage of SAS and LISREL. The result of this study as follows; 1. Through the correlation analysis, correlation coefficients among all sub-categories and stress level were statistically significant at the P〈0.01. 2. Through the path analysis, this study found that physical and psychological stability other sex friends relationship, self-satisfaction, personal relationship, family relationship, school grade, and headache, age, religion, economy level, and mother's occupation, mother's age, family number had influences on stress level. 3. The goodness of fit of the path model may be judged by means of five measures. ◁표 삽입▷(원문을 참조하세요)

강우시 채수빈도가 논 오염부하량 산정에 미치는 영향

한국헌,김진호,이종식,이정택,조재영,윤광식 한국환경농학회 2005 한국환경농학회지 Vol.24 No.1

한정된 수질자료를 이용 오염부하 산정시 집중적으로 많은 샘플을 채취한 경우에 비해 어느 정도 차이를 갖는지를 규명하는 것은 모니터링에 따른 오염부하량 산정결과의 신뢰 범위 파악뿐만 아니라 경제적인 수질 샘플 채수빈도 수립에 곡 필요한 것으로 사료된다. 그 결과를 요약하면 다음과 같다. 논에서의 강우-유출시 채수 빈도가 오염부하 산정에 미치는 영향을 파악하기 위해 9개의 강우사상에 대해 2시간 간격으로 연속 수질샘플을 실시하여 분석한 결과 전체적으로 강우-유출과정 중 T-N, T-P, SS 농도는 시간별로 증·감변동을 하였으나 유량과의 상관성은 나타나지 않았다. 수질샘플 횟수에 의한 영향은 강우-유출과정 중 5회 정도 샘플을 실시하면 많은 수의 샘플을 채수한 경우에 비해 T-N ±15.2%, T-P는 -20.0~26.2%, SS는 -28.6~35.7% 범위안에서 오염부하를 추정할 수 있는 것으로 나타났으며, 차이범위가 ±10% 내에 들어가기 위한 샘플수는 일주기 조사시 T-N, T-P의 경우는 6회, SS의 경우는 단기유출시는 4회 정도 실시하면 되고, 장기 유출시에는 11회 정도 실시하면 되는 것으로 조사되었다. 유량-유하부하량 관계식으로 ±10%내의 차이를 보일 샘플횟수는 T-N의 경우는 6회 이상, T-P와 SS는 9회 이상 정도 실시하면 되는 것으로 조사되었다. In order to examine effects of sampling frequency during rainfall-runoff process from paddy field on the estimation of pollution load, EMCs of several water sampling frequencies were examined. Water quality samples were conducted by every two hours interval for each event. It was found that difference of load estimation between five times sampling and two hours consecutive sampling during rainfall-runoff showed 15.2~-15.2% for T-N, 20.0~-26.2% for T-P, 28.6~-35.7% for the SS, respectively. In the same way, the effects of number of sampling data on estimation of pollution load using runoff-mass load(L-Q) method were investigated. L-Q equation made of five times sampling data provided 10% differences in estimation of mass loads of T-N, T-P, and SS when compared to those by L-Q equation using entire two hours consecutive sampling data during runoff process.

B형 만성 활동성 간염 환자에서 Prednisolone 단기이탈 및 Alpha Interferon 병합요법의 효과

이종선,김병호,성자원,허승식,이기천,정현용,이헌영,김영건 충남대학교 의과대학 지역사회의학연구소 1991 충남의대잡지 Vol.18 No.2

To evaluate the safety and efficacy of Pd withdrawal followed by recombinant alpha- Interferon 2b therapy. Nine patients were given a single daily subcutaneous injection of ^α-Interferon at a dose of 3 x 10 exp(6) units/day for first weeks and thrice weekly for next 15 weeks (maintenance) after pd tappered over 6 weeks. To evaluate the efficacy of therapy, we measured serum aminotransferase activities monthly during and after therapy, and also measured serm HBsAg, HBeAg and DNA probe before and after therapy. To evaluate the safety of therapy, all patients checked peripheral blood WBC, Hemoglobin, Platelet, BUN and Creatinine. The results were as follows : 1. In control group, the normalization of s-AST & ALT level, negative seroconversion of DNA probe & HBeAg were observed in 1/12(8%) & 7/10(17%), 0/10(0%) & 0/12(0%) at 6 months later, and maintained response in 1/11(9%) & 1/11(9%), 2/9(22%) & 2/11(18%) until 1 years later. 2. In treatment group, Serum AST and ALT returned to normal in 8/9 & 8/9 cases (89%) after 1 montns Tx. (mean serum AST : 33±8, ALT : 34±12 IU/ml) and maintained to normal response in 5/9(56%) & 6/9 cases(67%)after 6 months Tx. (mean s-AST : 55±43, ALT : 66±84 IU/ml), 3/9(33%) & 4/9 cases(44%) after 1 years Tx. It was statistically significant reponse except s-AST of after 1 years Tx. 3. In treatment group, s- HBeAg returned to normal in 3/9 cases(33%) after 1 months Tx., and maintained to normal response in 1/7 & 1/4 cases among follow up patients in after 6 & 12 months Tx. Serm DNA probe level were observed significantly negative seroconversion in 8/9 cases(89%) after 1 months Tx. (p<0.003), and maintained to negative response in 2/6 & 1/3 cases after 6 & 12 months Tx. 4. Serum AST, ALT, HBeAg and DNA probe were not significantly correlated with therapeutic response in relation to histologic diagnosis. 5. Fever and myalgia were noted in 9(100%) & 6(67%) cases. Headache, mild hair loss, anorexia, nausea, facial flushing & diarrhea were noted in few cases. Peripheral WBC(3cases) & platelet counts(3cases) were decreased transiently. This study shows that Pd withdrawal followed by recombinant alpha Interferon 2b therapy may be safe and effective in decrease the level of s-DNA probe, transaminase activity, loss of HBeAg and less adverse effect of clinical and hematologic examinations in patients with CAH type B. But it was necessary for study with large number of patients, more prolonged follow up duration and more strict control study.

급성심근경색증의 조기진단에 있어서 Myoglobin의 진단적 의의

이정헌,김종근,정병천,서강석,박정배,조용근,류재근,전재은,채성철,박의현 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: Exact and early diagnosis of acute myocardial infarction (AMI) is essential for the subsequent routine management of this frequent cardiovascular disease. Currently, AMI has been diagnosed using the combination of the history, electrocardiogram(ECG), and biochemical markers of myocardial necrosis. At present, many biochemical markers are used to diagnose AMI. In this study, the predictive values of serum myoglobin and creatine kinase-MB(CK-MB) were compared in the emergency department. Methods: Fifty-four consecutive patients who presented within 12 hours from onset of chest pain of presumed cardiac origin were enrolled into the study. Patients with trauma or renal failure were excluded. The serial serum myoglobin and CK-MB levels were obtained prospectively at admission and 2, 4, 6, 12, 24 and 48 hours after admission. We compare the levels of serum myoglobin and CK-MB within 2, 4, 6, 8, 10, 12, 24, and 48 hours after symptom onset respectively. And we compare the sensitivity, specificity, positive predictive value, and negative predictive value of myoglobin and CK-MB. Results: using World Health Organization criteria, 28 AMI patients were identified. Mean time from symptom onset to presentation was 4.1±1.3 hours. The predictive values of serum myoglobin were better than those of CK-MB within 6 hours after symptom onset. But, 6 hours after symptom onset, the predictive values of CK-MB were better than those of serum myoglobin. The false positive cases of serum myoglobin were 3-one was lung cancer with pleural effusion and the others were unstable angina. The false positive cases of CK-MB were 6-one case was viral myocarditis and the ohters were unstable angina. Conclusion: To compare the serum myoglobin and CK-MB in the diagnosis of AMI, serum myoglobin had better predictive values than CK-MB within 6 hours after symptom onset and useful in the early diagnosis of AMI. But, 6 hours after symptom onset, CK-MB had better predictive values than serum myoglobin and useful in following up.

사춘기 여학생의 初潮와 體格요인간의 相關에 관한 연구

이종헌,전은정 대구효성가톨릭대학교 응용과학연구소 1998 응용과학연구논문집 Vol.6 No.2

The purpose of this study was to find the relationship between menarche and physique factor. The subjects of this study were randomly selected 275 Junior High school students who lived in Taegu and divided into four groups according to menarche. And height, weight, chest grith, relative body weight, relative chest grith, Rohrer's index, Koup's index, Vervaeck's index were used for the physique factor. The results were as follws, 1. It was shown that menarche of adolescent junior students was 12.8 years old. 2. It was shown that the growth condition of physique factor - height, weight, chest grith, relative body weight, Koup's index, Vervaeck's index - from 7 to 15 years old girls who had an earlier menarche group was superior to later menarche group (P<0.05). 3. It was shown that the growth condition of physique factor - relative chest grith, Rohrer's index - from 13 to 15 years old girls who had an earlier menarche group was superior to later menarche group (P<0.05). 4. At the 12 years old, the growth condition difference of physique factor who had an menarche group aged 12 is likely to bigger than menarche group aged 15. And, at the 12~13 years old, growth velocity of physique factor is most fast.

사춘기 여학생의 신체발육형태에 관한 고찰

이종헌,전은정 대구효성가톨릭대학교 응용과학연구소 1998 응용과학연구논문집 Vol.6 No.2

The purpose of this study was to find the patterns of height and weight growth were in terms of growth distance, growth velocity, and adolescent growth spurt by PHV age and PWV age. For the study, 275 randomly sampled girl students in Taegu were served as subject. The results were as follws, 1. It was found that the growth distance of height from 7 to 14 years old girls who had an earlier PHV age was superior to later PHV age(P<0.01), and PHV age 9 and 10 showed maturity type. It was found that the growth distance of weight from 7 to 15 years old girls who had an earlier PWV age(P<0.01), and PWV age 9, 10 and 11 showed maturity type. 2. At the age of 15 years old, mean value of height is 158.7 cm in PHV age 9 and is 160.1cm in PHV age 12, and mean value of weight is 53.5kg in PWV age 9 and 48.9kg in PWV age 13. Therefore, growth patterns of earlier PHV age group and Later PWV age group is likely to smaller than later PHV age group and earlier PWV age group. 3. It was found that the patterns of height and weight growth velocity curve showed a one-phase pattern. 4. It was found that the earlier occurance of PHV age and PWV age is related to the amount of adolescent growth spurt.

만성활동성간염과 간경변에서의 고-Alpha Fetoprotein 혈증의 의의(Ⅰ)

이현영,이종선,정현용,이복희 충남대학교 의과대학 지역사회의학연구소 1990 충남의대잡지 Vol.17 No.2

Ten patients with chronic liver disease, whose serum levels of AFP were markedly increased, were detected from Jan. 1985 to Sep. 1990. The clinical and laboratory findings were examined and the results were as follows. 1. The objective patients were 4 males and 6 females, and their mean age was 40.2 years old. Five cases were chronic active hepatitis-B, and the other 5 cases were liver cirrhosis. 2. At the time of first examination, the mean level of serum AFP was 499ng/ml and this initial level of AFP declined to 10.4ng/ml after 5.1 monthes. 3. Initially the mean levels of serum AST, ALT and ALP were 271.7, 299.1 and 177.1 IU/L, and after 5.1 monthes these levels were changed to 61.0, 53.6 and 72.1 IU/L.

중·고등학생의 스트레스에 관한 연구

이종헌,전은정 대구효성가톨릭대학교 응용과학연구소 1997 응용과학연구논문집 Vol.6 No.1

In modern society, stress is so widely experimenced that it seems to apply to every life situation. Stress means that the person is responding to stressors in a characteristic way. A stessor is anything that requires you to cope with or adapt to a situation. Physical stessors include all environmental stimuli. Psychosocial stessors include life-changing events, both desirable and undersirable. Among the most common kinds of stressor experienced by Middle school and High school students are those that involve pressure to achieve. On top of the demands of school are needs for parental approval and students' own high standards. Meeting these demands can lead to the satisfaction of achievement, but sometimes these demands arouse anxiety that can cause mental and physical harm. Accordingly, to effective stress management for Middle school and High school students, we need to recognize stress and to identify its source. In this study, the number of subjects were 534 Middle school and High school students who lived in Hayang-up Kyongsan-shi Kyongbuk and they were interviewed in 1 to 31 May, 1996. The data were analyzed by the statistical methods taking advantage of SAS. The result of this study as follows, 1. According to the stress questionnaire, high risk stress states were 13.3%, mild stress states were 62.2% and healthy states were 24.5%. 2. In reliability analysis, Cronbach ∝ coefficient is 0.87. Factor analysis reveals 7 principle factors that mostly explain 45 items. The first factor is physical and psychological stability, the second factor is the other sex friends relationship, the third is self-satisfaction, the forth is personal relationship, the fifth is family relationship, the sixth is school grade, the last is headache. 3. Among the family environmental characteristic variable, the sex, age, religion economy level, mother's occupation, mother's age, family number have turned out to be significant on the level of stress(P〈0.05).