• 한국세라믹학회지
• /
• 제49권5호
• /
• pp.404-411
• /
• 2012

The reliability of solid oxide fuel cells (SOFCs) particularly depends on the high quality of solid oxide electrolytes. The application of thinner electrolytes and multi electrolyte layers requires a more reliable characterization method. Most of the investigations on thin film solid electrolytes have been made for the parallel transport along the interface, which is not however directly related to the fuel cell performance of those electrolytes. In this work an array of ion-blocking metallic Ti/Au microelectrodes with about a $160{\mu}m$ diameter was applied on top of an ultrathin ($1{\mu}m$) yttria-stabilized-zirconia/gadolinium-doped-ceria (YSZ/GDC) heterolayer solid electrolyte in a micro-SOFC prepared by PLD as well as an 8-${\mu}m$ thick YSZ layer by screen printing, to study the transport characteristics in the perpendicular direction relevant for fuel cell operation. While the capacitance variation in the electrode area supported the working principle of the measurement technique, other local variations could be related to the quality of the electrolyte layers and deposited electrode points. While the small electrode size and low temperature measurements increaseed the electrolyte resistances enough for the reliable estimation, the impedance spectra appeared to consist of only a large electrode polarization. Modulus representation distinguished two high frequency responses with resistance magnitude differing by orders of magnitude, which can be ascribed to the gadolinium-doped ceria buffer electrolyte layer with a 200 nm thickness and yttria-stabilized zirconia layer of about $1{\mu}m$. The major impedance response was attributed to the resistance due to electron hole conduction in GDC due to the ion-blocking top electrodes with activation energy of 0.7 eV. The respective conductivity values were obtained by model analysis using empirical Havriliak-Negami elements and by temperature adjustments with respect to the conductivity of the YSZ layers.

• 대한예방한의학회지
• /
• 제19권3호
• /
• pp.29-43
• /
• 2015

Objective : The purpose of this study was to identify characteristics of patients' self-perceived health in traditional Korean medical facilities. Method : This research was conducted based on the survey on patients whom have visited traditional Korean medical facilities in 2011 by the Ministry of Health and Welfares and Korean Institute for Health and Social Affairs. Using a sample of 3,931 (1,180 male and 2,751 female) outpatients' self-perceived health based on the data from usage and consumption of Korean Medicine. 'Healthy', 'Fair', and 'Poor Health' were used to measure patients' self-perceived health status. The data was analyzed by frequency, t-test, cross correlation analysis and multiple logistics regression analysis using the SPSS program package. Results : Sex(P<0.001), age(P<0.001), marital status(P<0.001), education(P<0.001), employment status(P<0.001), occupation(P<0.001), health insurance(P<0.001) and income level(P<0.0001) showed statistical significance. Main Treatment Facilities(P<0.001), experience of taking Korean medicine(P=0.032), experience of receiving acupuncture treatment(P<0.001), number of visits(P<0.001), medical expense (P=0.005), and subjective health status after the treatments showed statistical significance for Korean herbal medicine(P=0.038), acupuncture (P=0.001), cupping therapy(P=0.006), oriental physiotherapy(P=0.003), and treatment satisfaction(P<0.001). For subjective health status based on suffering disorders in the past three months, the response of poor health was higher in the group suffering recent illnesses. Statistical significance was seen in hypertension (P=0.002), arthritis(P<0.001), lumbar pain(P<0.001), diabetes mellitus(P=0.001), stroke(P<0.001), hwa-byung (P=0.001), gastric disorders(P=0.021), common cold(P<0.001), ankle sprain(P<0.001), muscular injury(P<0.001), lumbar sprain(p=0.009) and fracture(P=0.03). Also the number of diseases during the past three months showed statistical significance(P<0.001). Statistical significance was also seen in Level of knowledge(P<0.001), route of information(P<0.001), reliability of Korean medicine(P=0.003), insurance coverage(P=0.005), medical costs(P<0.001), and future willingness to use Korean medicine(P<0.001). As a result of the multiple logistics regression analysis, risks of subjective poor health statistically increased in female population, elderlies, medicaid beneficiaries, less educated, higher medical expense, and more disorders during the past three months. Conclusion : Patients' self-perceived health status has significant differences with each variables such as sex, age, marital status, education, health insurance, medical expense, number of diseases.

• 전자공학회논문지
• /
• 제50권8호
• /
• pp.128-135
• /
• 2013

본 논문에서는 고전압 공정기술을 이용하여 고속 디밍제어가 가능한 고출력-LED 드라이버를 설계하였다. 제안하는 고출력-LED 드라이버는 디밍신호를 통해서 LED에 필요한 전류량을 예측하고, 예측된 전류의 일부분을 인덕터 전류로 피드백시키는 방법을 사용하여서, LED 전류 상승시간이 최소화되도록 설계하였다. 기존 고출력-LED 드라이버의 최소 LED 전류 상승시간은 $3{\mu}s$로 제한된 반면 제안하는 고출력-LED 드라이버의 최소 LED전류 상승시간은 1/10 정도로 감소되었다. 설계된 LED 드라이버는 $0.35{\mu}m$ 60V BCDMOS 2-poly 4-metal 공정으로 제작되었으며 측정 결과 입력전압 12V, 9개의 백색 LED, 353mA LED전류, 1KHz 디밍주파수에서 LED전류 상승시간과 전력전달효율은 각각 240ns, 93.7%로 측정되었다.

• 지역사회간호학회지
• /
• 제11권1호
• /
• pp.231-244
• /
• 2000

Parish nursing is a community health nursing role developed in 1983 by Lutheran Chaplain Granger Westberg. An increasing emphasis on holistic care, personal responsibility for a healthy lifestyle, and changes in healthcare delivery systems have undoubtedly facilitated the establishment of an innovative nursing role in the community. Parish nurses are functioning in a variety of church congregations of various denominations. The parish nurse is a educator, a personal health counselor, a coordinator of volunteers. The parish nurses helps people relate to the complexed medical care system and assists people to integrate faith and health. The purpose of this study is to investigate what the korean parishioners want in parish nursing and what type of role expectation from parish nurse. The subjects were 1138 parishioners of 23 churches of various denominations in nationwide Korea. Data were collected by self-reported question naires from Feb 4 to June 25. 1999. The data were analyzed by using percentage. frequency. $x^2-test$. multiple Response set with SPSS program. The results are as follows: 1. Desired parish nursing contents by parish nurses are: psychological counselling(23.4%) out of private counselling. stress management(21.1 %) out of private health education. Emergency care(14.1%) out of group health education. Blood Pressure check-ups (19.0%) out of Health check ups. home visiting(44.9%) out of patient visiting method. B T. pulse, respiration and blood pressure check(15.0%) in Care to serve in home visiting. spiritual preparation to accept the death(41.7%) in hospice care, advices to choice of medical treatment using guide(50.1%) in introducing and guiding of health care facilities, pray(21.7%) in spiritual care' faith support. 2. Desired Health Teaching Content According to Period of Clients by Parish Nurse are: Vaccination(22.5%) in infant and toddler health management. sexual education(25.3%) in adolescent health management. prenatal care (29.5%) in pregnant health management. osteoporosis prevention and management (22.4%) in Middle aged health management. dementia prevention and management(25.5%) in elderly health management. 3. The expectant role from parish nurse is spiritual care faith support(14.1%). patient visiting care(13.2%), hospice care(12.9%), private counseling(12.8%), health check ups (11.1 %), volunteer organization and training out of believer(11.0%), private health education (9.3%), group health education (8.3%). 4. In Necessity of Performing Parish Nursing according to Region, Most(over 95%) responded that nursing program is needed. so there is no significance between regions. In Performing Parish Nursing in their church, Most(92.2%) responded they want to perform program. 5. In case of performing parish nursing, 52% out of the subjects responded they want to participated in parish nursing volunteer's activity, for example. to be in active to be a companion to chat(42.1%), necessity support (25.3%), donation support(25.0%), exercise support(18.2%), vehicles support (9.9%). As a result. in holistic care and spiritual care, the need of parish nursing and the role expectation from parish nurse are very high among korean believers. Therefore, I suggest parish nursing centering around Taegu and Kyungbuk province should be extended to nationwide. For extending parish nursing program. more active advertisement and research is needed. After performing parish nursing program through out the country, further comparative research between regions should be practiced and Korean parish nursing program will be developed and activated.

• Journal of Korean Neurosurgical Society
• /
• 제29권2호
• /
• pp.240-248
• /
• 2000

Objective : Spontaneous intracranial hypotension is a rarely reported syndrome of spontaneous postural headache associated with low CSF pressure and has rarely been demonstrated radiographically or surgically. But recently, it is being recognized with increasing frequency. The purpose of this study was to characterize clinical and imaging features, etiologic factors, and outcome in the spontaneous intracranial hypotension. Patients and Methods : We reviewed our experience with documented cases of spontaneous intracranial hypotension in 5 consecutive patients with orthostatic headaches from April 1998 to April 1999. Results : The mean age was 41 years(from 35 to 49 years). All patients had postural headaches, which were completely alleviated by recumbency position. Nausea, neck pain, horizontal diplopia, photophobia, and blurred vision were noted in some of the patients. Brain MRI showed diffuse pachymeningeal gadolinium enhancement, subdural collections of fluid, and descent of the brain. The opening pressure from lumbar puncture was $4cmH_2O$ or less in three of five patients whereas the opening pressure was within normal range in two patients. All patients underwent radioisotope cisternography and computerized tomographic myelography. On radioisotope cisternography, CSF leakage was suspected at the level of cervical area(1 patient), upper thoracic area(2 patients), mid-thoracic area(1 patient). Computed tomography myelography revealed extraarachnoid accumulation of contrast media(compatible finding with CSF leakage) at the level of cervical or thoracic area. In all patients, the symptoms resolved in response to supportive measures or epidural blood patch(1 patient). Conclusion : Spontaneous spinal CSF leakage is increasingly recognized as a cause of spinal postural headache. Most CSF leaks are located at the cervicothoracic junction or in the thoracic spine and can be demonstrated by variable diagnostic method. The condition is usually self-limiting and its prognosis is typically good.

• 한국산학기술학회논문지
• /
• 제21권2호
• /
• pp.19-24
• /
• 2020

화석 연료의 고갈로 인해 신재생 에너지에 관한 관심이 증가하고 있다. 특히, 예측가능성이 높고 이용 가능한 양이 풍부한 파력에너지 (Wave Power Energy)에 관한 연구가 활발히 진행되고 있다. 본 연구에 사용된 동축 가속형 파력 발전장치 (Coaxial Accelerator Type Wave Power Generator)는 양방향 선형 운동을 회전력으로 변환함으로써 발전 효율을 향상시킬 수 있도록 설계되었다. 본 연구에서는 해양공학수조에서 파를 생성 한 후, 파주기 및 파고에 따른 케이스 실험을 수행하였다. 실험 연구의 결과는 주파수 응답과 관련된 이론적인 방법을 통해 검증하였으며, 전반적인 경향이 일치하는 것을 확인하였다. 본 연구의 결과는 제작 전 설계 단계에서 파력 발전기의 전력을 예측하고 파력에너지의 효율을 개선하기 위한 매개 변수를 연구하는데 유용할 것으로 예상된다. 또한 제조업체는 본 연구의 결과를 통해 파력 발전기의 파력 에너지 효율을 예측하여 시행착오방지를 통해 개발 시간과 비용을 절감할 수 있을 것으로 기대할 수 있다.

• 인터넷정보학회논문지
• /
• 제14권4호
• /
• pp.25-33
• /
• 2013

RFID 시스템에서는 다중 태그가 동일한 주파수로 동시에 리더의 요청에 응답하기 때문에 발생하는 태그 충돌을 중재하는 절차가 필수적이다. 이 절차를 충돌 방지 알고리즘이라 하며 RFID 시스템에서 가장 핵심적인 기술이다. 본 논문에서는 다중 태그의 고속 식별을 위한 4-BPSA(4-Bit Pattern Slot Allocation) 알고리즘을 제안한다. 제안한 알고리즘은 슬롯을 사용하는 트리 기반의 알고리즘으로서 4비트 패턴에 따른 슬롯 할당 기법을 이용하여 정확한 예측을 통해 빠르고 효율적으로 태그를 식별한다. 알고리즘에 대한 수학적 성능 분석을 통해 worst-case에서 4-BPSA의 시간 복잡도가 O(n)이며 기존의 알고리즘에 비해 성능이 개선되었음을 보인다. 또한 MATLAB을 이용한 시뮬레이션 실험을 통한 알고리즘의 성능 평가 결과에 의거해 4-BPSA 알고리즘이 태그당 평균 0.7회의 질의를 수행하며 태그의 개수와 상관없이 안정적인 성능을 보이는 것을 검증하였다.

• Journal of Preventive Medicine and Public Health
• /
• 제21권2호
• /
• pp.431-441
• /
• 1988

The purpose of this study was to compare the difference of two survey methods for health services research. Data were collected by means of two types of household survey conducted from March 11 to September 19, 1985. A probability sample of 30,613 persons was taken from 180 Enumerated Districts designated by the Economic Planning Board. The sample was divided into two groups systematically. One group was surveyed by the self-administered questionnaire and the other group was interviewed. Response rates were 81.4% and 90.6% respectively. The data were analysed by the ratio of the results of the self-administered survey to those of the interview survey. No difference was observed in sex, age, residence, or occupation between the two groups. However the respondents' characteristics were statistically different between the two groups. The major findings of this study are as follows : 1. The morbidity rate was 142.5 per 1,000 persons during the two week period by the self-administered questionnaire survey and 74.3 per 1,000 persons with the interview survey method. The ratio of the morbidity rate by the self-administered questionnaire to that by the interview was 1.92, and the difference between the two rates were due to the personal characteristics. 2. The out-patient utilization rate was 10.2 visits per person per year by the self-administered questionnaire survey and 5.4 by the interview survey, and the ratio was 1.89; the admission rate was 3.2 times per 100 persons per year by the self-administered questionnaire survey and 1.9 times by the interview survey, and the ratio was 1.68. Differences due to the sociodemographic characteristics were greater in the out-patient utilization rates than in the adimssion rates. 3. Percentages of effective medical care demand were 90.2% in the self-administered survey and 92.3% in the interview survey; the ratio was 0.98 which was less than that of the morbidity rate and medical care utilization. But, differences of effective medical care demand occurred in persons with no occupation, and aged or low educated respondents. 4. Respiratory illness had the highest frequency in the two survey methods. But there was a slight difference between the two survey methods in morbidity composition. 5. It was concluded that data collected by the interview survey were inclined to be underestimated and this problem can be corrected by a modified self-administered survey.

• 한국운동역학회지
• /
• 제25권3호
• /
• pp.323-333
• /
• 2015

Objective : The purpose of this study was to investigate the changes of gait patterns and muscle activations with increased loads during stair walking. Also, it can be used as descriptive data about continuous stair walking in a real life setting. Method : Twelve sedentary young male adults(Age: $27.0{\pm}1.8yrs$, Weight: $65.8{\pm}9.9kg$) without any lower extremity injuries participated in this study. Participants performed stair walking up 7 floors and their ascending and descending motion on each floor was analyzed. A wireless electromyography(EMG) were attached on the Rectus Femoris(RF), Biceps Femoris(BF), Gastrocnemius(GN), Tibialis Anterior(TA) muscle to calculate integrated EMG(iEMG), median frequency(MDF) and co-contraction index(CI). Chest and left heel accelerometer signal were recorded by wireless accelerometer and those were used to calculate approximate entropy(ApEn) for analyzing gait pattern. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was LSD. Results : During ascending stairs, there were a statistically significant difference in Walking time between 1-2nd and other floors(p=.000), GN iEMG between 2-3th and 6-7th(p=.043) floor, TA MDF between 1-2nd and 5-6th(p=.030), 6-7th(p=.015) floor and TA/GN CI between 2-3th and 6-7th(p=.038) floor and ApEn between 1-2nd and 6-7th(x: p=.003, y: p=.005, z: p=.006) floor. During descending stairs, there were a statistically significant difference in TA iEMG between the 6-5th and 3-2nd(p=.026) floor, and for the ApEn between the 1-2nd and 6-7th(x: p=.037, y: p=.000, z: p=.000) floor. Conclusion : Subjects showed more regular pattern and muscle activation response caused by regularity during ascending stairs. Regularity during the first part of stair-descending could be a sign of adaptation; however, complexity during the second part could be a strategy to decrease the impact.

• 한국학교ㆍ지역보건교육학회지
• /
• 제1권2호
• /
• pp.87-104
• /
• 2000

The purpose of this study was to obtain the basic data as a improvement method through the fact-revealing concerning the drinking water management of school and utilization of student. The problems of the research are as follows: First, to investigate status of management of drinking water by area and school. Second, to investigate student's utilization of drinking water by area and school. 1,400 students was selected at 45 elementary and middle-high schools located in Kang-won province, and this study was constituted of two questionnaires(for school's questionnaire and student's questionnaire). The results was analyse through the frequency analysis, $x^2$-test on the basis of the above research problem by SPSS program. The findings of this research are as follows; 1) The Management of School Drinking Water First, the source of school drinking water was mostly piped water. Inspection of water quality has been fulfilled under four times a year, in the other hands, from the result inspection, the schools which was given inadequate determination was 22.2%. Second, reservoir cleaning and hygiene inspection failed far short of the regulations. Especially, reservoir cleaning was managed by exterior consignment industry not low-level officials. Third, school water drinking was the most supplied through the type of water purifier. Water purifier has been distributed to city-located and middle-high school highly, factually the water from water purifier was served with water cup. Fourth, the selection standard of water drinking manager showed slightly differently by school, accordingly there need to develope integrated system with the respective to its effective systematic management. Fifth, water cup was mostly treated by only water clear, which is to vindicate the problems concerning hygiene management. 2) Utilization of school student on Drinking Water First, Disbelief on drinking water of school student was very high. Especially, proportion of middle-high school student's disbelief of drinking water was higher than elementary school student, also girls higher than boys. Many of student have heard to don't drink water from around people. And there were showed meaningful differences by area and school. Second, It was showed many student recognize had to utilize water purifier, boiled water. However, they have still drunken the tap water or portable water from their home. Third, Many of student showed negative response with the respective to the management conditions of drinking water in classroom, There were showed meaningful differences by area and school. From the fact-revealing of water cup management, Students mostly answered to 'only water clear' and the answer of 'None use' or 'With personal cup' was higher. Fourth, In bad experience of Drinking Water, student mostly answered to 'occasionally' and there were showed meaningful differences by school. student's disease experience with school drinking water was few and there were showed meaningful differences by area and gender.