• Journal of Ship and Ocean Technology
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• 제9권4호
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• pp.1-10
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• 2005

The effect of buoyancy orientation on turbulent channel flow has been investigated using DNS (direct numerical simulation). Grashof number is kept at 9.6 $\times 10^{5}$ while changing the orientation of the buoyancy vector to be parallel or perpendicular to the channel walls. Four study cases can be distinguished during this research namely; streamwise, wall-normal unstable stratification, wall-normal stable stratification and spanwise oriented buoyancy. The driving mean pressure gradient used in all cases is adjusted to keep mass flow rate constant while friction Reynolds number is around 150. At this Grashof number, the skin friction shows decrement in the unstable and stable stratification and increment in the other two cases. Analyses of the changes of flow structure for the four cases are presented highlighting on the mean quantities and second order statistics.

• Kyungpook Mathematical Journal
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• 제56권4호
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• pp.1135-1140
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• 2016

Let A be an abelian variety over a global field K. We know [6, 7] that, in many cases, the average number of n-torsion points of A over various residue fields of K, takes the minimal possible value. In this article, we study several defect cases by calculating the number of Galois orbits.

• Journal of Preventive Medicine and Public Health
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• 제53권3호
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• pp.168-170
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• 2020

On December 31, 2019, the Chinese government officially announced that the country had some cases of pneumonia with an unknown cause. By February 8, 2020, there were 24 confirmed cases in Korea, and the number of cases has steadily increased since then. On March 9, 2020, the cumulative number of confirmed cases in Korea was 7382, with 51 deaths. This study examines the characteristics of the coronavirus disease 2019 (COVID-19) outbreak from the perspective of the large-scale number of confirmed COVID-19 cases and deaths. This study is significant in that it emphasizes the precautionary principle in preventing and managing infectious diseases, and makes suggestions for urgently needed public health policies.

• 한국도서관정보학회지
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• 제39권1호
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• pp.119-138
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• 2008

이 연구는 4년제 국공립대학도서관을 대상으로 1992$\sim$2006년까지 이루어진 상호대차의 양적 규모와 관련요소 간의 상관 및 미치는 영향력의 정도와 양적 규모의 영향요인을 구명한 것이다. 이 연구의 결과는 다음과 같다. 대학도서관의 상호대차 관련 요소들은 상호대차의 접수 및 의뢰건수에 공히 정(+)의 방향으로 대부분 높은 상관관계를 유지하고 있고, 단순회귀분석 결과 유의적인 영향을 미치고 있으며, 이들의 설명력도 대체로 높게 나타났다. 그리고 이를 바탕으로 추출한 양적 규모의 영향요인으로는 중다회귀분석 결과 접수건수는 '대학원 학생수', 의뢰건수는 '대출책수'와 '학부학생수'로 나타났다.

• 치과방사선
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• 제16권1호
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• pp.93-102
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• 1986

The author examined fifty cases of sialolithiasis diagnosed in the Dept. of Oral Radiology in SNUH by conventional radiography and sialography, and analyzed patient's age, sex, location, radio density, numbers, shapes, and relation with ducts and parenchymas. 1. The results of this study were as follows: 1. The average age of patients was 38.6 years in submandibular sialolithiasis, and 39.2 years in parotid sialolithiasis. 2. There was slightly higher incidence in males (58.0%) than in females (42.0%). 3. Salivary stones were found to be much more in the submandibular gland and duct (82.0%) than in the parotid gland and duct (18.0%). 4. Of 62 submandibular salivary stones, 33 (53.2%) occurred in the main duct, 25 (40.3%) occurred in the hilum, and 4 (6.5%) occurred in the parenchyma. Of 18 parotid salivary stones, 9(50.0%) occurred in the main duct, 5(27.8%) occurred in the parenchyma, and 4(22.2%) occurred in the hilum. 5. Of the submandibular salivary stones, the number of radiopaque type was 45 (75.8%), and the number of radiolucent type was 17 (24.2%). Of the parotid salivary stones, the number of radiopaque type was 12 (66.7%), and the number of radiolucent type was 6(33.3%). 6. The single type was 30 cases (73.2%) in submandibular gland, 6 cases (66.7%) in parotid gland, and the multiple type was 11 cases (26.8%) in submandibular gland, and 3 cases (33.3%) in parotid gland. 7. Round shape was 35 cases (43.8%), ovoid shape was 22 cases (27.5%), irregular shape was 17 cases (21.3%), and cylindrical shape was 6 cases (7.5%).

• Journal of Preventive Medicine and Public Health
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• 제53권3호
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• pp.158-163
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• 2020

Objectives: In the current early phase of the coronavirus disease 2019 (COVID-19) outbreak, Bali needs to prepare to face the escalation of cases, with a particular focus on the readiness of healthcare services. We simulated the future trajectory of the epidemic under current conditions, projected the impact of policy interventions, and analyzed the implications for healthcare capacity. Methods: Our study was based on the first month of publicly accessible data on new confirmed daily cases. A susceptible, exposed, infected, recovered (SEIR) model for COVID-19 was employed to compare the current dynamics of the disease with those predicted under various scenarios. Results: The fitted model for the cumulative number of confirmed cases in Bali indicated an effective reproduction number of 1.4. Interventions have decreased the possible maximum number of cases from 71 125 on day 86 to 22 340 on day 119, and have prolonged the doubling time from about 9 days to 21 days. This corresponds to an approximately 30% reduction in transmissions from cases of mild infections. There will be 2780 available hospital beds, and at the peak (on day 132), the number of severe cases is estimated to be roughly 6105. Of these cases, 1831 will need intensive care unit (ICU) beds, whereas the number of currently available ICU beds is roughly 446. Conclusions: The healthcare system in Bali is in danger of collapse; thus, serious efforts are needed to improve COVID-19 interventions and to prepare the healthcare system in Bali to the greatest extent possible.

• Journal of Chest Surgery
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• 제27권6호
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• pp.460-471
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• 1994

Between Feb. 1990 and Aug. 1993, 180 cases of the open heart surgery were performed under cardiopulmonary bypass in the Department of Thoracic & Cardiovascular surgery, Gil General Hospital. There were 83 cases with congenital heart diseases [CHD] and 97 cases with acquired heart diseases [AHD]. The CHD consisted of 78 acyanotic[mortality: 3.8 %] and 5 cyanotic cases with heart anomaly[mortality:l case]. The AHD were 97 cases, which contained 53 valvular, 27 ischemic heart diseases, 10 aortic diseases, 5 cases with myxoma, 1 case with post-infarct VSD, and 1 case with removal of infected pacing wire in right ventricle. In the 53 valvular heart diseases, there were 45 cases with valve replacement[MVR 27, AVR 9,MVR + AVR 9] and 8 cases with valvuloplasty. The number of the implanted prosthetic valves were 53. In MVR, 25 St. Jude, 6 Sorin, 3 Carpentier-Edward and 2 Intact medical valves were used. In aortic position, 13 St. Jude, 3 Sorin and 1 Intact medical valves were applied. The operative mortality was 5.6 % [3/53]. The annuloplasty applying artificial ring was performed in 17 patients[4 cases associated with MVR] and the number of the implanted ring was 19, which included 14 Duran ring[10 mitral, 4 tricuspid] and 5 Carpentier ring [3 mitral, 22 tricuspid]. In the 27 ischemic heart diseases, there were 9 cases with left main coronary artery lesions, 7 one vessel, 5 two vessels, and 6 three vessels. Average number of anastomosis was 2.8 per patient. The operative mortality was 14.3 % [4/27]. Among the 10 patients with aortic diseases, 7 cases were aortic dissection[type A: 5, type B: 2] and 3 cases were descending thoracic aortic aneurysm. The operative morality occurred in 3 cases. The overall mortality and the operative mortality of congenital and acquired heart disease was 7.8 %, 4.8% and 10.4%, respectively.

• Imaging Science in Dentistry
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• 제43권2호
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• pp.99-104
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• 2013

Purpose: This study was performed to investigate the clinical usefulness of teleradiology in general dental practice. Materials and Methods: Two hundred and seventy five cases were submitted for inquiry to the case presentation board of the website of The Korean Academy of Oral and Maxillofacial Radiology for a 5 year periods. The diagnosis results of those cases were analyzed according to the disease classification, the correlation with the patient's chief complaint, the necessity of additional examinations or treatments, the image modalities, and the number of dentists inquiring. Results: Differential diagnoses of normal anatomic structures were the most frequently submitted cases, covering 15.6% of all cases. Among 275 cases, 164 cases required no additional treatments or examinations. Panoramic radiographs were the most frequently submitted images, accounting for 248 inquiries. The 275 cases were submitted by 96 dentists. Fifty-two dentists wrote one inquiry, and 44 inquired 2 or more times. The average inquiry number of the latter group was 5.0 cases. Conclusion: A teleradiology system in general dental practice could be helpful in the differential diagnosis of common lesions and reduce unnecessary costs.

• Journal of Nutrition and Health
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• 제38권2호
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• pp.161-172
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• 2005

Children regard newspapers and magazines as the important source of information. Because informations about diet in the newspaper and magazines are regarded as good, it is necessary to find out whether informations provided to children are correct. Thus, this study shows the present situation of informations on diet by monitoring 3 newspapers (Kids. Chosun, Kids. Donga, Kids. Hankook) and 2 magazines (Earinee - Dongsan, Sae-But) for children. This study focused on the quantitative and the qualitative analysis for articles and advertisements. For the quantity, rate and number were calculated. For the quality, the accuracy was analyzed. Result of this study were as follow; Analyzed the number of articles and advertisements on diet, there are 2 times more number of advertisements (339 cases) than that of articles (180 cases) in the newspaper. There are slightly more number of advertisements (24 cases) than that of articles (18 cases) in the magazine. Most of advertisements are about processed foods and children' favorite foods. Especially, the advertisement of processed foods are ranked first by the quantity with 245 cases (75%) in the newspaper. In the magazine, 10 cases (42%) are about processed foods. About source of advertisements on diet informations in the newspaper, there are 300 cases (86.7%) without evidence based data and 34 cases (9.8%) of interview with entertainers, from the total 346 cases. In the magazine, there are high rate of cases without evidence based data and interview with entertainers. For the evaluation of the information about diet in the newspaper, there are 148 cases (19.7%) with no clear guidance and position, some cases with advertisements for specific products and etc. Discordance between subjects and contents, and emphasis of specified field or some parts are found from the total 750 cases. About the accuracy of contents, from the total 180 cases in the newspaper, 99 cases (55%) are inappropriate and 19 cases (10.6%) are appropriate. In magazines from the total 18 cases, 7 cases (38.9%) are inappropriate and 11 cases (61.1 %) are appropriate. With these results, we can conclude that informations about diet in newspapers and magazine for children needs improvement. Therefore, for newspapers and magazines contents should be reported scienifically by inspecting contents and by taking professional advice, in order to spread the accurate information about diet. Also, there are need to manage the systematic monitoring, for children. (Korean J Nutrition 38(2): 161～172, 2005)

• 품질경영학회지
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• 제48권3호
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• pp.493-510
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• 2020

Purpose: As of July 31, there were 14,336 confirmed cases of COVID-19 in South Korea, including 301 deaths. Since the daily confirmed number of cases hit 909 on February 29, the spread of the disease had gradually decreased due to the active implementation of preventive control interventions, and the daily confirmed number had finally recorded a single digit on April 19. Since May, however, the disease has re-emerged and retaining after June. In order to eradicate the disease, it is necessary to suggest suitable forward preventive strategies by predicting future infectivity of the disease based on the cases so far. Therefore, in this study, we aim to evaluate the transmission potential of the disease in early phases by estimating basic reproduction number and assess the preventive control measures through effective reproduction number. Methods: We used publicly available cases and deaths data regarding COVID-19 in South Korea as of July 31. Using ensemble model integrated stochastic linear birth model and deterministic linear growth model, the basic reproduction number and the effective reproduction number were estimated. Results: Estimated basic reproduction number is 3.1 (95% CI: 3.0-3.2). Effective reproduction number was the highest with 7 on February 15, decreased as of April 20. Since then, the value is gradually increased to more than unity. Conclusion: Preventive policy such as wearing a mask and physical distancing campaigns in the early phase of the outbreak was fairly implemented. However, the infection potential increased due to weakening government policy on May 6. Our results suggest that it seems necessary to implement a stronger policy than the current level.