• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.460-472
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• 2023

This study was conducted based on the case of an accident (excessive deformation) that occurred during the hydraulic test of a shipboard tank manufactured in accordance with the design regulations. Over-pressure phenomenon was noted as the main cause of accidents in the process of testing tanks without physical damage, which can be found in external factors such as cross-sectional difference between inlet pipe and air pipe and higher water filling rate than the recommended one. The main goal of this paper is to establish a safe water filling rate according to the range of sectional area ratio(SAR) reduced below the regulations for each test situation. The simulation was conducted in accordance with the hydraulic test procedure specified in the Ship Safety Act, and the main situation was divided into two types: filling the tank with water and increasing the water head to the test pressure. The structural safety evaluation of the pressure generated inside the tank and the effect on the structure during the test was reviewed according to the SAR range. Based on the results, guidelines for the optimal filling rate applicable according to SAR during the hydraulic test were presented for the shipboard tanks used in this study.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1047-1065
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• 2023

Multi-detector CT (MDCT) is a highly accurate diagnostic tool that is commonly used to evaluate appendicitis and its complications. The diagnosis of appendicitis based on MDCT findings can be difficult and challenging when the observed findings are inconsistent with the typical features. Atypical appendicitis includes a wide spectrum of features, such as variable positions of the appendix and cecum, complications, and unusual pathological findings of secondary appendicitis that mimic or induce appendicitis. Our pictorial essay describes the diverse spectrum of atypical appendicitis and appendicitis-like conditions in terms of location abnormalities, complications, and uncommon pathologies, including related tumors, reactive appendicitis, appendiceal diverticulitis, and IgG4-related disease. Through this essay, the readers can become more familiar with MDCT findings of atypical appendicitis.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.2
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• pp.141-147
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• 2011

Purpose: Ultrasonography (US) is widely used as a screening test in patients with abdominal pain (AP). We investigated the usefulness of US by a pediatrician in children with AP. Methods: We retrospectively analysed the medical records of children with AP who undertook US from December, 2008 to July, 2010. Results: A total of 628 patients (325 male, 303 female) were enrolled in this study. The mean age of patients was $8.08{\pm}4.61$ years. Duration of AP was acute in 427 and chronic in 201 patients. Localization of AP was diffuse (36.9%), periumbilical (24.4%), epigastric (21.0%), and right lower quadrant (8.1%). On the examination, there were no abnormal findings in 327 patients (52.1%). Abnormal ultrasonographic findings were mesenteric lymphadenitis (27.1%), intestinal mural thickening (10.0%), intussusception (3.0%), appendicitis (2.6%), choledochal cyst (1.6%), and pancreatitis (0.3%). We performed additional imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) in 39 patients who showed obscure findings on the US. In 33 patients (84.6%), the same results were obtained from CT or MRI. Two cases of appendicitis, one case of pancreatitis and one case of Henoch-Sh$\ddot{o}$nlein purpura were diagnosed by the CT examination. However, there were two cases of appendicitis diagnosed by US thathad no evidence of appendicitis on the CT. Diagnostic accuracy of initial US in children with abdominal pain was 99.4%. Conclusion: US by a pediatrician as a screening test in children with AP provides a rapid and accurate diagnostic indication and has non-invasive and radiation-free advantages.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.13 no.1
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• pp.30-35
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• 2010

Purpose: Infectious ileocecitis is an infection confined to the ileocecal area and one of the most common causes of pediatric abdominal pain. This study was performed to demonstrate the clinical features of infectious ileocecitis in children. Methods: The medical records and radiologic findings of 37 patients with ileocecitis diagnosed by ultrasonography and/or computed tomography, who were admitted to Pusan National University Hospital from January 2004 and July 2008, were reviewed retrospectively. Viral gastroenteritis and secondary ileocecitis were excluded. Results: The mean age of the patients was 4.8${\pm}$3.4 years. One-half of the patients were preschool children. The chief complaint was abdominal pain (75.7%), diarrhea (10.8%), and vomiting (8.1%). Accompanying symptoms were fever (56.8%), vomiting (21.6%), and diarrhea (16.2%). The mean duration of abdominal pain, fever, diarrhea, and vomiting was 3.8${\pm}$2.1, 3.0${\pm}$1.9, 3.4${\pm}$1.9, and 2.4${\pm}$2.3 days, respectively. The frequency of diarrhea and vomiting was 5.8${\pm}$2.2 and 4.0${\pm}$2.8 per day, respectively. Diagnosis was made by abdominal ultrasonography in 22 patients (59.5%), abdominal CT in 2 patients (5.4%), and both modalities in 13 patients (35.1%). Besides the radiologic finding of thickening of the bowel wall, mesenteric lymphadenitis (59.5%), ascites (5.4%), and both mesenteric lymphadenitis and ascites (16.2%) were revealed. The mean duration of illness was 7.5${\pm}$5.0 days. There were no specific laboratory findings, and culture studies with stool or blood were negative. All of the patients recovered completely without specific treatment. Conclusion: Infectious ileocecitis has acute appendicitis-mimicking symptoms, but is self-limited within a few days, thus unnecessary treatment and work-up is avoided. However, distinguishing infectious ileocecitis from appendicitis, inflammatory bowel disease, and mesenteric lymphadenitis is important.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.11 no.2
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• pp.127-131
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• 2006

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2005.10a
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• pp.154-158
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• 2005

• 대한예방의학회:학술대회논문집
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• 2005.10a
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• pp.366-366
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• 2005

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.277-283
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• 1996

원자력 발전소의 일차계통 부분충수운전시 잔열제거 계통 입구에서 자유수면 와동으로 인해 계통에 공기가 흡입될 수 있으며 이로 인해 계통이 상실되거나 계기에 오차가 유발되어 많은 안전상의 문제를 야기할 수 있다. 이러한 문제들을 해결할 수 있도록 흡입구의 구조를 개선하기 위해 다양한 구조에 대해 실험을 수행한 결과 깔때기 모양과 우회유로를 설치한 경우. 그리고 기존 T자형에 와동 방지판을 부착하는 것이 매우 효과적임이 밝혀졌다. 하지만 깔때기 모양이나 우회유로의 경우는 배관구조의 변경이 필요하여 따라서 기존 발전소나 신설 발전소에 적용시 문제점이 많으므로 필요시 붙이고 불필요하면 제거가능한 탈착식인 다공 와동 방지판을 최종적으로 선정하였다. 이 경우에 대하여 1/4 축소 실험장치로 실험한 결과 운전유량 영역에서 와동의 발생으로 인한 공기흡입과 펌프의 정지를 획기적으로 줄여주는 것으로 밝혀졌다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.309-314
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• 2003

표고버섯은 특이한 향과 육질, 약효성분 때문에 오래 전부터 식용으로 애용된 임산물이다. 표고버섯은 원래 한국, 중국, 일본에서만 자생하던 극동지역 특산물로서 미국, 유럽 등지에서는 발견되지 않았으나, 현재는 전 세계에서 광범위하게 인공재배 되고 있다. 표고버섯에 포함되어있는 수용성 다당류인 렌티난(lentinan)은 종양세포인 Sarcoma-180의 생장을 저해하는 항암효과가 있는 것으로 알려져 있다(최 등 1995). 또한 여러 종류의 유리 아미노산이 들어 있고 열량이 낮은 반면, 비타민과 식이섬유 등이 풍부한 영양식품이다(황 1983). 그러나 버섯은 함수율이 높고 조직이 연약하여 저장하기 어렵고, 부패되기 쉽기 때문에 수확 후 단시일 내에 생버섯으로 판매하거나, 통조림 또는 건조가공하고 있지만, 후자가 일반적이다(하 등 2001). (중략)

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1277-1281
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• 2007

A Nano-tip as a cold field emitter for inducing a field emission current has manufactured in many ways. In the paper, the electrochemical etching method is used. Thus, in order to optimize the final shape as the field emitter, the reliable fabrication system for electrochemical etching was constructed. In addition, the effective parameters such as applied voltage, submerged length, meniscus height, electrolyte concentration and environmental condition(vibration, humidity, cut-off time) have investigated in detail. By controlling the parameters, reliable tungsten tip for field emitter was fabricated. And the fabricated tungsten tip was evaluated optically. Finally, the very sharp apex of the tungsten tip was observed with scanning electron microscope.