• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2594-2600
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• 2020

A gamma camera system using radionuclide has a functional imaging technique and is frequently used in the field of nuclear medicine. In the gamma camera, it is extremely important to improve the image quality to ensure accurate detection of diseases. In this study, we designed a blind-deconvolution framework after a noise-reduction algorithm based on a non-local mean, which has been shown to outperform conventional methodologies with regard to the gamma camera system. For this purpose, we performed a simulation using the Monte Carlo method and conducted an experiment. The image performance was evaluated by visual assessment and according to the intensity profile, and a quantitative evaluation using a normalized noise-power spectrum was performed on the acquired image and the blind-deconvolution image after noise reduction. The result indicates an improvement in image performance for gamma camera images when our proposed algorithm is used.

• 품질경영학회지
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• 제13권2호
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• pp.29-36
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• 1985

The problem of selecting the gamma population with the largest mean out of k gamma populations, each of which has the same shape parameter is considered. An elimination type two-stage procedure is proposed which guarantees the same probability requirement using the indifference-zone approach as does the single-stage procedure of Gibbons, Olkin and Sobel (1977). The two-stage procedure has the highly desirable property that the expected total number of observations required by the procedure is always less than that of the corresponding single-stage procedure regardless of the configuration of the population parameters.

• Journal of the Korean Data and Information Science Society
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• 제11권1호
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• pp.57-64
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• 2000

By assuming a Type-I censored sample, we propose the approximate maximum likelihood estimators(AMLE) of the scale and location parameters of the gamma distribution. We compare the proposed estimators with the maximum likelihood estimators(MLE) in the sense of the mean squared errors(MSE) through Monte Carlo method.

• 한국임상수의학회지
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• 제27권6호
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• pp.640-646
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• 2010

네오스포라 감염증은 세포내성 원충성 기생충인 Neospora caninum에 의해 발생하는 질병으로 전세계적으로 발생하고 있으며, 소에서는 번식장해로 인한 막대한 경제적 손실을 유발한다. 본 연구는 4 곳의 각기 다른 목장으로부터 N. caninum에 자연 감염된 양성우와 음성우를 포함한 26두의 임신우를 선정하여 2주 내지 4주 간격으로 혈액을 채취하여 호르몬, 항체가, IFN${\gamma}$ 수준과 유산 혹은 분만과의 상관관계를 조사하였다. 유산하지 않은 Neospora 양성우14두의 S/P 평균값은 분만 전 15주에 최고치를 보였고, 이후 분만 때까지 감소하였다. 유산한 양성우 3두의 유산 시기는 각각 인공 수정 후 20주 (142일), 26주 (185일), 28주 (199일)였으며, 이들의 S/P값은 유산 전 13주부터 유산 때까지 높은 수준을 유지하였다. 유산하지 않은 양성우에서 IFN${\gamma}$ 수준은 개체에 따라 그리고 동일한 개체라도 임신기간이 경과함에 따라 다양하게 나타났으며, 유산한 양성우에서 IFN${\gamma}$ 수준은 계속 높은 상태를 유지하거나 또는 유산시점에 근접하여 급상승하였다. Neospora 음성우 9두의 IFN${\gamma}$ 수준은 양성우보다 낮았지만, 그 양상은 유산하지 않은 양성우와 유사하였다. 유산하지 않은 양성우와 음성우에서 평균적인 progesterone수준은 분만 전 7주부터 뚜렷하게 감소하였다. 유산한 양성우에서는 유산 전 5주와 7주의 평균적인 progesterone 수준은 정상 분만한 음성우나 양성우의 분만전 5주와 7주에 측정된 평균 progesterone 수준보다 낮았다. 유산한 양성우에서 17${\beta}$-estradiol의 평균 수준은 유산 시점에 근접할수록 증가하였지만, 혈청내 총양은 유산하지 않은 양성우와 음성우에서 분만시점에 근접하여 측정한 평균 17${\beta}$-estradiol 수준보다 더 낮았다. 이상의 결과로 미루어 보아 Neospora에 감염된 소에서 17${\beta}$-estradiol과 progesterone 수준의 저하는 IFN${\gamma}$ 산생을 증가시켜, 결국에는 유산을 초래할 수 있다고 생각된다.

• 열처리공학회지
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• 제11권4호
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• pp.324-332
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• 1998

The grain growth characteristics of dual-phase (${\alpha}+{\gamma}$) containing high Cr-steel have investigate using ${\alpha}$-, ${\gamma}$-single phases and (${\alpha}+{\gamma}$)dual-phase of 12%Cr Steel. The heat treatment has performed at $1000-1200^{\circ}C$ for 1-100hr. The results are as follows : 1) The grain growth rate in (${\alpha}+{\gamma}$) dual phase was substantially slower than that of single grain. 2) The relation between mean grain radius $\bar{{\gamma}}$ and annealing time t is, in general, described as following equation : $$(\bar{{\gamma}})^n-(\bar{{\gamma}_o})^n=K_n{\cdot}t{\cdots}{\cdots}(1)$$ i) In the case of single phase of high Cr steel, Eq.(1) is described as $(\bar{{\gamma}})^2-(\bar{{\gamma}_o})^2=K_2{\cdot}t$ and the grain growth is controlled by boundary migration. ii) In dual phase, the grain growth needs diffusion of alloying elements because the chemical composition of ${\alpha}$- and ${\gamma}$- phases differs from each other. When the volume fraction of ${\alpha}$-, ${\gamma}$-phase was almost equal and ${\gamma}$-phase in the case of 80 and $90%{\gamma}$. Eq.(1) is described as $(\bar{{\gamma}})^3-(\bar{{\gamma}_o})^3=K_3{\cdot}t$ because the grain growth is controlled by volume diffusion iii) In the case of ${\gamma}$-rich phase (80 and $90%{\gamma}$), the grain growth of minor phase (10 and $20%{\alpha}$) is described as $(\bar{{\gamma}})^4-(\bar{{\gamma}_o})^4=K_4{\cdot}t$ because the boundary diffusion is predominent rather than volume diffusion.

• 한국도로학회논문집
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• 제6권3호
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• pp.55-64
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• 2004

최대건조단위중량은 노상토 재료 특성으로서 매우 중요한 인자이다. 최대건조단위중량을 예측하는 기존의 모델들은 많은 변수를 포함하고 있어 다소 복잡해 보인다 본 논문에서는 사질토의 최대건조단위중량을 예측할 수 있는 간편한 식을 제안하였다. 이를 위해 36개 시료를 체분석하여 입도분포를 구하고, 다짐시험 한 후 그 결과를 회귀 분석하였다. 제안식은 변수로 노상토의 기하평균과 기하표준편차 또는 입도분포계수를 포함한다. 제안식의 검증을 위해 전국16개 지역의 채취 시료에 대한 최대건조단위중량의 실측치와 예측치를 비교한 결과 잘 맞는 것으로 밝혀졌다.

• Wind and Structures
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• 제31권4호
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• pp.299-309
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• 2020

In this study, wind data such as speeds, loads and potential of Muğla which is located in the southwest of Turkey were statistically analyzed. The wind data which consists of hourly wind speed between 2010 and 2013 years, was measured at the 10-meters height in four different ground stations (Datça, Fethiye, Marmaris, Köyceğiz). These stations are operated by The Turkish State Meteorological Service (T.S.M.S). Furthermore, wind data was analyzed by using Log-Normal and Gamma distributions, since these distributions fit better than Weibull, Normal, Exponential and Logistic distributions. Root Mean Squared Error (RMSE) and the coefficients of the goodness of fit (R²) were also determined by using statistical analysis. According to the results, extreme wind speed in the research area was 33 m/s at the Datça station. The effective wind load at this speed is 0.68 kN/㎡. The highest mean power densities for Datça, Fethiye, Marmaris and Köyceğiz were found to be 46.2, 1.6, 6.5 and 2.2 W/㎡, respectively. Also, although Log-normal distribution exhibited a good performance i.e., lower AD (Anderson - Darling statistic (AD) values) values, Gamma distribution was found more suitable in the estimation of wind speed and power of the region.

• Journal of Korean Neurosurgical Society
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• 제30권11호
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• pp.1308-1313
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• 2001

Object : The goals of radiosurgery include preservation of neurological function and prevention of tumor growth. We document the results of gamma-knife radio-surgery for vestibular schwannoma. Method & Object : Eighty-two patients underwent stereotactic radiosurgery for an vestibular schwannoma from October, 1994 to December, 2000. Sixty-five of these patients were followed up for radiological and clinical evaluation. As pregamma-knife modality, surgical resection were done in 23 patients,and V-P shunt in 2 patients. Initial symptoms were headache(n=45), dizziness(n=16), tinnitus(n=17). While normal facial function(House-Brackmann grade 1) was present in 48 patients(73.8%), other patients showed grade 2 function in 8, grade 3 function in 7,and grade 4 function in 2. The Gardner/Robertson scale was used to code hearing function. Male to female ratio was 1:3. Mean tumor volume was $7.98cm^3$. Mean dose delivered to the tumor margin was 14.2Gy,and mean maximal dose was 28.3Gy. Results : Mean follow-up duration of 19.9 months. Thirty-five showed decrease(53.8%) in size, 19 patients(29.2%) stationary, 3(4.6%) initial decrease follow up increase, 5(7.6%) initial increase follow up decrease,and 59 patients (90.8%) were well controlled. Two patients experienced transient facial neuropathy, one transient trigeminal neuropathy, and one transient hearing deterioration. After gamma-knife radiosurgery, ventriculoperitoneal shunt was done in 4 patients. Conclusions : Gamma-knife radiosurgery can be used to treat postoperative residual tumors as well as in patients with concomitant medical problems in patients with preserved hearing function. Gamma-knife radiosurgery is safe and effective method to treat small, medium sized(less than 3cm in extracanalicular diameter), intracanalicular vestibular schwannoma, associated with low rate of cranial neuropathy.

• 보건교육건강증진학회지
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• 제16권1호
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• pp.149-166
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• 1999

Self-care and the performance of their own role might be important for the prevention of complications and improvement of quality of life in hemodialysis patients with chronic renal failure(CRF). To improve well-being and quality of life for the patients, the author estimated the level of self-care and associating factors through a questionnaire. The information was composed of the knowledge for hemodialysis and renal disease, the level of self-care, health belief, supports from the family, disease-related stresses, personal characteristics, medical history, relationships with medical personnel, etc. The data was gathered from 126 hemodialysis patients who were undergoing hemodialysis in one university hospital and five hospitals in Kyungsangnam-Do area from December 1997 to January 1998, and was analyzed by PC SAS program(version 6.12) with the level of significance($\alpha$=0.05). The mean age of subjects was 47.0$\pm$13.5years with no significant difference in gender distribution. The mean duration of hemodialysis was 39.0 months, and their frequencies of hemodialysis were more than three times per week(77.0%). Only 21.4% had the specific education on hemodialysis and CRF. In the level which was expressed as the score out of 100, the mean of knowledge was 90.7$\pm$9.1 and the mean of self-care was 73.9$\pm$12.7, that means, they only partially carried their knowledge into practice. They showed a significant correlation between knowledge and health belief($\gamma$=0.282); self-care and health belief($\gamma$=0.357), family supports and knowledge($\gamma$=0.221), self-care($\gamma$=0.402), health belief($\gamma$=0.431); and health belief and stress($\gamma$=-0.361). Age, religion, marrital status, education, and relationships with medical personnel showed positive correlations, and smoking showed negative correlation with self-care. In the multiple regression with the level of self-care as dependent variable, and each of the characeristics as independent variables, supports from the family($\beta$=6.615=0.158), the experience of disease specific education($\beta$=4.959), relationships with medical personnel($\beta$=6.615), current smoking($\beta$=-6.986), and current drinking ($\beta$=-7.095) were detected as significant factors. The value of R-square was 34%. In summary, to promote the level self-care and to improve the well beings and Quality of life for the hemodialysis patients, it would be emphasized that they terminate smoking and drinking, and it would be recommended that the education programs and supports from the family be strengthened. And, because there was a considerable difference between the level of knowledge and self-care, it would also be emphasized to propose the education programs which focused on execution. In addition to that, there is a need to improve relationships between the patients and medical personnel through positive changes in the attitudes of the medical personnel.

• Journal of Preventive Medicine and Public Health
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• 제31권4호
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• pp.728-739
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• 1998

To improve wellness and quality of life by recognizing the health efforts of stress, the author estimated the relationships between stress, subjective symptoms and clinical diagnosis through a questionnaire and a battery of specified laboratory tests; electrocardiography, blood pressure, cholesterol, aspartate aminotransferase(AST), alanine aminotransferase(ALT), gamma glutamyl transferase$(\gamma-GTP)$, fasting blood sugar, gastro-endoscopy or UGI, abdominal sonography, etc. The data was gathered from 337 clients who were undergoing multiphasic screening program at a University Hospital from January to March 1998. The mean age of subjects was $46.5{\pm}11.2$ years and the mean of body mass index was $24.0{\pm}3.7kg/m^2$. The mean vol of stress was $18.5{\pm}6.0$ expressed as the score out of 40. By general characteristics and lift style among male, mean level of stress was significantly higher in case of lower socioeconomic status, habitual drug use, longer daily working time(>10 hours), no regular exercise, drinkers, irregular meal, skip-ping breakfast(p<0.05). In case of female, that was significantly higher in case of lower education, lowe. socioeconomic status, longer daily working time(>10 hours), no regular exercise, drinkers, smokers, irregular meal, skipping breakfast(p<0.05). Significant correlations were observed between stress and subjective symptoms in all kinds of organ system (p<0.01). Correlation coefficients of stress among male were relatively high with neuro-psychiatric symptom$(\gamma=0.476)$ and cardio-vascular symptom$(\gamma=0.361)$ in order, and correlation coefficients of stress among female was highest with neuro-psychiatric symptom$(\gamma=0.371)$. The prevalence of the diagnosis through the battery of laboratory tests was high in upper gastrointestinal disorders and hypercholesterolemia in order in both sex group. Among male the mean score of stress was significantly high in ulcerative peptic disorder of upper gastrointestine and hepatopathy in order (p<0.05) . Among female that was significantly high in diabetes mellitus. In summary, it is likely that there are associations between stress, subjective symptoms and clinical diagnosis. To promote wellness and quality of life it would be of value that periodic stress evaluation program and stress management including apropriate control of smoking and drinking, regular exercise and meal.