• 한국의료질향상학회지
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• 제10권2호
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• pp.216-231
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• 2003

Objectives: To develop a model that predicts a death probability of acute myocardial infarction(AMI) patient, and to evaluate a performance of hospital services using the developed model. Methods: Medical records of 861 AMI patients in 7 general hospitals during 1996 and 1997 were reviewed by two trained nurses. Variables studied were risk factors which were measured in terms of severity measures. A risk model was developed by using the logistic regression, and its performance was evaluated using cross-validation and bootstrap techniques. The statistical prediction capability of the model was assessed by using c-statistic, $R^2$ as well as Hosmer-Lemeshow statistic. The model performance was also evaluated using severity-adjusted mortalities of hospitals. Results: Variables included in the model building are age, sex, ejection fraction, systolic BP, congestive heart failure at admission, cardiac arrest, EKG ischemia, arrhythmia, left anterior descending artery occlusion, verbal response within 48 hours after admission, acute neurological change within 48 hours after admission, and 3 interaction terms. The c statistics and $R^2$ were 0.887 and 0.2676. The Hosmer-Lemeshow statistic was 6.3355 (p-value=0.6067). Among 7 hospitals evaluated by the model, two hospitals showed significantly higher mortality rates, while other two hospitals had significantly lower mortality rates, than the average mortality rate of all hospitals. The remaining hospitals did not show any significant difference. Conclusion: The comparison of the qualities of hospital service using risk-adjusted mortality rates indicated significant difference among them. We therefore conclude that risk-adjusted mortality rate of AMI patients can be used as an indicator for evaluating hospital performance in Korea.

• Current Optics and Photonics
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• 제2권1호
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• pp.59-68
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• 2018

Opto-acoustic systems provide structural and functional information regarding biological tissues. Conventional opto-acoustic systems typically employ continuous or pulsed lasers as transmission sources. Compared to lasers, light emitting diodes (LEDs) are cost-effective and relatively portable excitation sources but are non, coherent. Therefore, in this study, a relatively low cost lens - a type of Ramsden eyepiece - was specially designed to theoretically calculate the illumination and achieve a constant brightness across the pupil of an eye. In order to verify the capability of the developed light-emitting diode-acoustic (LEDA) systems, we carried out experiments on bovine and bigeye tuna eyeball samples, which are of similar size to the human eye, using low frequency (10 MHz) and high frequency (25 MHz) ultrasound transducers. High frequency ultrasound transducers are able to provide higher spatial resolution compared to low frequency ultrasound transducers at the expense of penetration depth. Using the 10 MHz and 25 MHz ultrasound transducers, acceptable echo signals (3.82, 3.94, and 5.84 mV at 10 MHz and 282, 1557, 2356 mV at 25 MHz) from depth greater than 3 cm and 6 cm from the anterior surface of the eye were obtained. We thereby confirmed that the LEDA system using a pulsed LED with the designed Ramsden eyepiece lens, used in conjunction with low and high frequency ultrasound transducers, has the potential to be a cost-effective alternative method, while providing adequate acoustic signals from bovine and bigeye tuna ocular areas.

• 전자공학회논문지 IE
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• 제49권2호
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• pp.52-57
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• 2012

사회발전과 더불어 가전기기의 발전은 누전으로 인한 감전, 화재 등 여러 가지 누전전류의 위험성에 노출되어 있다. 가정 내 배전함에 누전차단기가 설치되어 있지만, 기존의 누전차단기는 배전함에 설치되어 누전시 전원을 차단해주는 기능만을 갖는다. 또한 집안 벽마다 설치된 콘센트에 연결된 가전기기들을 개별적으로 점검하는 일은 쉬운 일이 아니다. 따라서 본 논문에서는 누전차단기회로의 성능 및 회로를 분석하고, ZigBee기반의 센서를 이용하여 가정 내 가전기기들의 누전상태를 모니터링 할 수 있는 방법에 대해 제시하였다. 성능분석 결과, 제안된 ELB 누전전류 제어시스템은 가전기기에 내장된 누전차단기 회로를 응용했기 때문에 각각의 가전기기들의 누전상태를 확인할 수 있어 기존 시스템 보다 누전을 쉽고 편리하게 모니터링 할 수 있을 것이라 기대한다.

• Nuclear Engineering and Technology
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• 제48권3호
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• pp.785-794
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• 2016

The Argonne National Laboratory of the United States and the Kharkov Institute of Physics and Technology of the Ukraine have been collaborating on the design, development and construction of a neutron source facility at Kharkov Institute of Physics and Technology utilizing an electron-accelerator-driven subcritical assembly. The electron beam power is 100 kW using 100-MeV electrons. The facility was designed to perform basic and applied nuclear research, produce medical isotopes, and train nuclear specialists. The biological shield of the accelerator building was designed to reduce the biological dose to less than 5.0e-03 mSv/h during operation. The main source of the biological dose for the accelerator building is the photons and neutrons generated from different interactions of leaked electrons from the electron gun and the accelerator sections with the surrounding components and materials. The Monte Carlo N-particle extended code (MCNPX) was used for the shielding calculations because of its capability to perform electron-, photon-, and neutron-coupled transport simulations. The photon dose was tallied using the MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is very small, ~0.01 neutron for 100-MeV electron and even smaller for lower-energy electrons. This causes difficulties for the Monte Carlo analyses and consumes tremendous computation resources for tallying the neutron dose outside the shield boundary with an acceptable accuracy. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were utilized for this study. The generated neutrons were banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron dose. The weight windows variance reduction technique was also utilized for both neutron and photon dose calculations. Two shielding materials, heavy concrete and ordinary concrete, were considered for the shield design. The main goal is to maintain the total dose outside the shield boundary less than 5.0e-03 mSv/h during operation. The shield configuration and parameters of the accelerator building were determined and are presented in this paper.

• 지역사회간호학회지
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• 제15권2호
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• pp.308-322
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• 2004

Purpose: 'The purpose of the present study was to understand students' experiences from their standpoint, to identify relevant variables and to examine into their relations by analyzing and describing what phenomenon 'nursing students' visiting ambulatory bathing service' is, what are the reasons for the phenomenon, and what interactions are in the phenomenon. Method: The subjects were thirteen students. Data were collected through in-depth interviews and analyzed by Strauss and Corbin's analysis method. Result: With regard to ambulatory bathing service, participants responded 'lack of education', 'inexperienced personal relations' and 'disappointment with recipients families'. They recognized 'burden' and 'compassion'. The intensity of generated 'burden' and 'compassion' was determined by volunteering persons, the degree of health care service, recipients' response and interaction of climate. When 'burden' and 'compassion' were generated, participants selected their own coping strategies. Strategies in the situation of 'burden' and 'compassion' were significantly influenced by 'burden' and 'compassion' and structural situation - 'mutual relation structure,' 'volunteers' capability,' 'the degree of volunteering guidance,' 'community participation,' 'recipients' environment,' 'information sharing,' 'special vehicle equipment' and 'economical burden.' Strategies include' service training,' 'receiving volunteering training,' 'preliminary service preparation,' 'volunteering.' 'connection to local medical center,' 'intention,' 'information sharing,' 'passive response to recipients' appreciation' and 'the understanding of publicity'. The results of selected 'burden' and 'compassion' are described with 'worthiness' and 'cohesion' as follows. Conclusion: This study is significantly meaningful in that it examined bathing service welfare in its initial stage. There are not much outcome from previous studies. However. it is meaningful that this study intended to develop theories on the nature of experiences and the relations among concepts derived from the visiting ambulatory bathing service process of nursing students. Professors who taught social volunteering in universities understood the experience of nursing students who did the visiting ambulatory bathing service. Consequently, professors will provide an effective instruction to enable these students to carry out visiting ambulatory bathing services efficiently in order to meet demands when they conduct the services. For the volunteering service activity in major-related fields among college students' social volunteering activities, they recognized the necessity of systematic education and preparation.

• 한국보건간호학회지
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• 제17권1호
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• pp.47-57
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• 2003

The purpose of this study was to investigate health status and health promoting behaviors of female elderly, and their needs for health-related services in an urban-rural combined city. The data were collected from the subjects registered in senior welfare center and senior citizens' clubs. A total of 119 women were participated in the survey. The results of the study are as follows; 1. The subjects perceived their health status relatively unhealthy. Their health promotion behavior score was 10.82 (range 0-17), and more than $60\%$ of them performed well in smoking and drinking control, regular meal. taking breakfast, and maintaining good relationship with others. 2. The most needed service was health screening followed by health risk assessment, disease diagnosis and treatment. 3. The most demanded education was on dementia prevention, followed by exercise, balanced diet, and maintenance of memorial and mental capability. 4. As the health interest and the health responsibility increased, the need for health service increased as well. Likewise, the health education needs increased as the health interest, health responsibility, and health promotion behavior increased. The results show that the health promotion programs for female elderly need to be focused, primarily, on health screening, health risk assessment, medical services for disease diagnosis and treatment, and health consulting and education. And health consulting and education programs should be designed to promote health interest and health responsibility of female elderly, change positively their attitude to aging, and include education on dementia prevention, exercise and nutrition management. Recommendations are discussed.

• 전자공학회논문지
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• 제53권5호
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• pp.163-167
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• 2016

본 논문은 밀리미터파 라디오미터를 이용한 의료응용의 한 분야인 인체 내부의 밝기온도 측정에 관한 연구이다. 밀리미터파 대역 중에서 Ka - band의 주파수 영역에서 동작하는 렌즈, 직접 검출 수신기, 캘리브레이션 소스 등을 설계 제작하여 라디오미터 시스템을 구성하였다. 밀리미터파 렌즈 초점에 수신안테나를 스캔하는 방식을 통하여 미약한 신호를 수신하였으며, 렌즈 수차를 감소시키기 위해 광선 추적 방법을 사용하여 비구면 렌즈를 설계 하였다. 직접 검출 수신기는 Dicke 타입 수신기 형태로 설계되었으며, 제작된 수신기의 잡음지수는 3.3 dB, 온도감도는 0.1 K으로 측정되었다. 라디오미터의 수신기 교정은 밀리미터파 대역에서 사용가능한 새로운 형태의 블랙바디(Black body)를 제작하여 물체의 등가 잡음온도와 출력전압의 관계를 도출하였다. 제작된 시스템을 이용하여 1.7 m 거리에서 인체의 상반신을 측정하여 약 $38^{\circ}$[C]의 밝기온도를 측정하였다. 적외선 영상과 라디오미터 영상의 비교를 통해 상반신의 밝기온도 영상을 통하여 밀리미터파 라디오미터의 의료응용 가능성을 제시하였다.

• 한국멀티미디어학회논문지
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• 제13권1호
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• pp.143-152
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• 2010

생활수준의 향상과 더불어 의료 기술의 발달로 우리나라도 2018년에는 노인인구가 전체의 14%이상이 고령화 사회로 진입할 것으로 예상되고 있으며, 실버세대가 생산과 소비의 주체로서 경제적으로 차지하는 비율도 증가할 것이다. 실버세대들은 신체적 노화로 지각능력, 학습능력, 운동능력이 상대적으로 낮으므로, 신체적?정신적 기능 유지, 여가 시간 활용과 함께 기능성 운동을 지속적으로 제공할 수 있는 게임 콘텐츠 개발의 중요성이 강조되고 있다. 본 논문에서는 실버세대의 여가 활용과 건강을 유지할 수 있는 하체 운동 효과를 갖는 게임 콘텐츠를 개발하기 위한 방법을 제안한다. 제안 방법은 실버세대의 인지능력, 신체 활동 능력에 맞는 기능적 디자인 요소와 개별적인 특성에 따른 맞춤형 게임 진행 방법, 그리고 실버세대들이 사용하기 쉬운 체감형 인터페이스를 통해 실버세대에게 게임으로서의 재미와 함께 지속적인 신체 활동에 도움이 될 수 있을 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.631-637
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• 2013

Luteolin is a naturally occurring flavonoid present in many plants with diverse applications in pharmacology. Despite several studies elucidating its significant anti-cancer activity against various cancer cells, the mechanism of action in skin cancer is not well addressed. Hence, we investigated the effects of luteolin in HaCaT (human immortalized keratinocytes) and A375 (human melanoma) cells. The radical scavenging abilities of luteolin were determined spectrophotometrically, prior to a cytotoxic study (XTT assay). Inhibitory effects were assessed by colony formation assay. Further, the capability of luteolin to induce cell cycle arrest and apoptosis were demonstrated by flow cytometry and cellular DNA fragmentation ELISA, respectively. The results revealed that luteolin possesses considerable cytotoxicity against both HaCaT and A375 cells with $IC_{50}$ values of 37.1 ${\mu}M$ and 115.1 ${\mu}M$, respectively. Luteolin also inhibited colony formation and induced apoptosis in a dose and time-dependent manner by disturbing cellular integrity as evident from morphological evaluation by Wright-Giemsa staining. Accumulation of cells in G2/M (0.83-8.14%) phase for HaCaT cells and G0/G1 (60.4-72.6%) phase for A375 cells after 24 h treatment indicated cell cycle arresting potential of this flavonoid. These data suggest that luteolin inhibits cell proliferation and promotes cell cycle arrest and apoptosis in skin cancer cells with possible involvement of programmed cell death, providing a substantial basis for it to be developed into a potent chemopreventive template for skin cancer.

• 대한의용생체공학회:의공학회지
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• 제20권3호
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• pp.307-314
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• 1999

M-wave 는 신경전도 연구에 있어서 후기반응 현상 중 직접적인 반응으로, 반응 후 일정시간내에 정보가 존재하는 단발 반응의 특성을 가지고 있다. 이러한 M-wave 는 신경계통의 질환을 진단하기 위한 유용한 요소이며, 따라서 M-wave 의 형태 및 시간에 관한 정보가 간단히 표현될 수 있다면 신경질환 연구에 많은 도움이 될 것이다. 따라서 본 연구에서는 Ar 모델링 방법이 이러한 M-wave 의 정보 압축에 있어서 효과적임을 증명하였다. 이로 인해 먼저 실제로 측정된 M-wave 신호에서 Ar 파라메터를 추정하였으며, 추정된 파라메터를 가지고 근사화한 곡선과 최근의 M-wave의 정보압축에 관한 연구인 Hermite 변환을 이용한 방법에 따른 근사화 곡선을 비교하였다. 제안된 방법의 구체적인 검증을 위해 실신호와 근사화 곡선의 정규화 평균자승오차(NMSE)를 구하여 비교하였다. 결론적으로 M-wave 의 정보를 압축하는데 있어 Hermite 변환은 30개의 파라메터가 필요한 반면, 본 연구에서 제시한 AR 모델링방법은 3개의 파라메터만 가지고도 효과적으로 M-wave 의 특징을 압축할 수 있음을 보였다.