• 대한기계학회논문집B
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• 제34권4호
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• pp.429-435
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• 2010

국내를 포함한 전 세계 50여개 원전의 발전사업자는 유동가속부식에 의한 탄소강 배관 감육을 관리하기 위하여 CHECWORKS 프로그램을 이용하고 있다. CHECWORKS 프로그램은 대구경 배관에만 적용 가능한 것으로 알려져 있기 때문에 소구경 배관에 대해서는 현장 배관감육 관리 담당자의 경험과 판단에 따라 배관을 관리하고 있다. 이에 따라 본 논문에서는 국내 원전 소구경 배관 4개 라인그룹에 대하여 CHECWORKS 프로그램과 FLUENT 코드를 이용하여 유동가속부식과 유동 특성을 분석하였다. 그 결과 현장 배관감육 관리 담당자의 기술력에 따라 CHEC- WORKS 프로그램도 소구경 배관 감육 관리에 이용할 수 있는 것으로 나타났다.

• 한국태양에너지학회 논문집
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• 제32권spc3호
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• pp.275-281
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• 2012

Proton Exchange Membrane Fuel Cells (PEMFC) are the most appropriate for energy source of small robot applications. PEMFC has superior in power density and thermodynamic efficiency as compared with the Direct Methaol Fuel Cell (DMFC). Furthermore, PEMFC has lighter weight and smaller size than DMFC which are very important factors as small robot power system. The most significant factor of mobile robots is weight which relates closely with energy consumption and robot operation. This research tried to find optimum specifications in terms of type, number of cell, active area, cooling method, weight, and size. In order to find optimum 500W PEMFC, six options are designed in this paper and studied to reduce total stack weight by applying new materials and design innovations. However, still remaining problems are thermal management, robot space for energy sources, and soon. For a thermal management, design options need to analysis of Computational Fluid Dynamics (CFD) for determining which option has the improved performance and durability.

• 대한두개안면성형외과학회지
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• 제10권2호
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• pp.91-96
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• 2009

Purpose: Frontal sinus fractures are relatively less common than other facial bone fractures. They are commonly concomitant with other facial bone fractures. They can cause severe complications but the optimal treatment of frontal sinus fractures remains controversial. Currently, many principles of treatment were introduced variously. The authors present valid and simplified protocols of treatment for frontal sinus fractures based on fracture pattern, nasofrontal duct injury, and complications. Methods: A retrospective chart review was performed on 36 cases of frontal sinus fractures between January, 2004 and January, 2009. The average age of patients was 33.7 years. Fracture patterns were classified by displacement of anterior and posterior wall, comminution, nasofrontal duct injury. These fractures were classified in 4 groups: I. anterior wall linear fractures; II. anterior wall displaced fractures; III. anterior wall displaced and posterior wall linear fractures; IV. anterior wall and posterior wall displaced fractures. Also, assessment of nasofrontal duct injury was conducted with preoperative coronal section computed tomographic scan and intraoperative findings. Patients were treated with various procedures including open reduction and internal fixation, obliteration, galeal frontalis flap and cranialization. Results: 12 patients are group I (33.3 percent), 14 patient were group II (38.8 percent), group III, IV were 5 each (13.9 percent). Frontal sinus fractures were commonly associated with zygomatic fractures (21.8 percent). 9 patients had nasofrontal duct injury. The complication rate was 25 percent (9 patients), including hypoesthesia, slight forehead irregularity, transient cerebrospinal fluid leakage. Conclusion: The critical element of successful frontal sinus fracture repair is precise diagnosis of the fracture pattern and nasofrontal duct injury. The main goal of management is the restoration of the sinus function and aesthetic preservation.

• 전기화학회지
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• 제14권4호
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• pp.253-260
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• 2011

본 연구에서는 10개의 배터리로 구성된 모듈에 대한 열관리 전산모사를 수행하였다. 배터리의 구조를 단순화 하였고, 전기저항 등가식을 이용한 열전도 이론을 사용하였다. 2.6 mm의 좁은 배터리 사이의 간격에 대한 격자의 신뢰도 검증 실험을 진행하였고, 그 결과 배터리 사이에 최소 3개 이상 나누어진 격자의 형태가 필요하였다. 크게 모듈의 후면에서 공기가 유입되는 형태, 모듈의 상부에서 공기가 유입되는 형태 그리고 모듈의 하부에 공기가 유입되는 형태로 나누어 팬과 공기흡입구의 위치에 따른 모듈의 효과적인 냉각방법을 모색하였다. 배터리의 성능에 영향을 미치는 모듈의 최고온도와 배터리간의 온도 차이를 비교하였고, 공기의 유속을 비교하여 유체의 거동을 확인하였다. 모듈의 하부에서 공기가 유입되는 경우, $40.27^{\circ}C$로 가장 낮은 최고온도를 보였고, 모듈의 상부에서 공기가 유입되는 경우에 $0.73^{\circ}C$로 가장 적은 온도편차를 보였다.

• Journal of Korean Neurosurgical Society
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• 제58권4호
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• pp.334-340
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• 2015

Objective : Pineal parenchymal tumors (PPTs) in adults are rare, and knowledge regarding their optimal management and treatment outcome is limited. Herein, we present the clinical results of our series of PPTs other than pineoblastomas managed by stereotactic radiosurgery (SRS) at upfront setting. Methods : Between 1997 and 2014, nine consecutive adult patients with the diagnosis of PPTs, either pineocytoma or pineal parenchymal tumor of intermediate differentiation, were treated with SRS. There were 6 men and 3 women. The median age was 39 years (range, 31-53 years). All of the patients presented with symptoms of hydrocephalus. Endoscopic third ventriculostomy and biopsy was done for initial management. After histologic diagnosis, patients were treated with Gamma Knife with the mean dose of 13.3 Gy (n=3) or fractionated Cyberknife with 32 Gy (n=6). Results : After a mean follow-up of 78.6 months (range, 14-223 months), all patients were alive and all of their tumors were locally controlled except for one instance of cerebrospinal fluid seeding metastasis. On magnetic resonance images, tumor size decreased in all patients, resulting in complete response in 3 patients and partial response in 6. One patient had experienced temporary memory impairment after SRS, which improved spontaneously. Conclusion : SRS is effective and safe for PPTs in adults and can be considered as a useful alternative to surgical resection at upfront setting.

• Journal of Chest Surgery
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• 제44권4호
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• pp.279-284
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• 2011

Background: The aim of this study is to investigate the clinical characteristics and management of intrathoracic bronchogenic cysts. Materials and Methods: Twenty-four (n=24) patients with intrathoracic bronchogenic cysts were treated surgically between August 1990 and December 2009 at our institution. Patients were divided into two groups by bronchogenic cyst location: mediastinal or intrapulmonary. Symptoms at diagnosis, radiologic findings, locations, surgical methods, pathological findings, and surgical outcomes were investigated retrospectively from consecutive patient medical records. Results: There were 12 females (50.0%). The mean age was 26.8 (range, 5 to 64) years. The mean follow-up period was 27.3 (range, 1 to 121) months. There were 15 (62.5%) mediastinal and 9 (37.5%) intrapulmonary bronchogenic cysts. Symptoms occurred in 8 patients with mediastinal bronchogenic cysts (53.3%) and 5 patients with intrapulmonary bronchogenic cysts (55.6%) (p=1.000). On computed tomography (CT), 7 patients (46.7%) showed homogenous solid masses in mediastinal bronchogenic cysts and five (55.6%) patients exhibited heterogeneous cystic masses with air-fluid levels in intrapulmonary bronchogenic cystic masses. Open thoracotomy was performed in 17 (70.8%) patients, and video-assisted thoracic surgery was performed in 7 (29.2%) patients. On pathological findings, there were 16 (66.7%) complicated cysts, and in 13 symptomatic patients, 11 (84.6%) patients had complicated cysts. There was no operative death in this study. During the follow-up period, no recurrence was detected. Conclusion: Intrathoracic bronchogenic cysts have a wide variety of clinical characteristics and radiologic findings. Even though some patients do not experience symptoms and signs caused by bronchogenic cysts, serious symptoms and complications may develop with the passage of time.

• 한국가스학회지
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• 제4권2호
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• pp.37-45
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• 2000

지하에 매설되어 있는 도시가스배관은 부식성 없는 유체이기 때문에 화학플랜트배관보다는 상대적으로 안전하다. 그러나, 도시가스는 일반적으로 도심지역에 공급됨으로 공급지역의 여러 간섭시설물과 환경에 의한 부식과 시설물의 굴착공사로 야기되는 제 3자 사고등으로 큰 사고를 야기할 수 있다. 특히 지하매설된 배관이므로, 배관의 손상여부를 파악하고 검사하는 것이 상당히 난해하다. 따라서, 본 고에서는 지하매설배관의 위험성 개념을 도입하여, 위험지역 배관을 선정하여 관리하는 것으로 접근하였다. 여기서 위험성은 부식요인, 설계 및 시공요인, 유지관리요인으로 파악하여 나타내었고, 배관의 정성적인 위험성을 점수로 표현하여, 정량적인 숫자로 표현하였다. 또한 Key 인자 개념과 비용에 대한 손상보완대책 개념을 프로그램에 도입하여, 신뢰성과 안전경영에 도움이 되리라 생각된다. 본 위험성 평가 프로그램은 비쥬얼 베이직을 사용하여 개발하였고, GIS와 연계하였다.

• Clinical and Experimental Pediatrics
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• 제58권4호
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• pp.154-157
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• 2015

Plastibell is one of the three most common devices used for neonatal circumcision in the United States, with a complication rate as low as 1.8%. The Plastibell circumcision device is commonly used under local anesthesia for religious circumcision in male neonates, because of cosmetic reasons and ease of use. Occasionally, instead of falling off, the device may get buried under the skin along the shaft of the penis, thereby obstructing the normal flow of urine. Furthermore, the foreskin of neonates is highly vascularized, and hence, hemorrhage and infection are possible when the skin is cut. Necrosis of penile skin, followed by urethral obstruction and renal failure, is a serious surgical mishap requiring immediate corrective surgery and medical attention. We report a case of fulminant urosepsis, acute renal failure, and pyelonephritis in a 4-day-old male neonate secondary to impaction of a Plastibell circumcision device. Immediate medical management was initiated with fluid resuscitation and mechanical ventilation; thereby correcting life threatening complications. Pediatricians and Emergency Department physicians should be cognizant of the complications from Plastibell circumcision device in order to institute appropriate and timely management in neonates.

• Journal of Korean Neurosurgical Society
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• 제41권4호
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• pp.236-240
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• 2007

Objective : The aim of this study is to analyze on the external ventricular drainage [EVD] related ventriculitis, especially on their risk factors, management, and prevention. Methods : From January 2003 to December 2005, a total of 174 EVD catheters were placed in 112 patients at our institution. Of these patients, EVD-related ventriculitis were developed in 15 cases. Clinical variables such as age, sex, prior clinical diagnosis, placement of EVD insertion, duration of EVD, total numbers of EVD per person, and outcome were analyzed in theses cases to verify the risk factors, causative agents and outcomes. Results : Fifteen cases of EVD related ventriculitis were noted presenting infection incidence of 13.39 % per patient and 8.62% per procedure. Of these, five patients died from sepsis, seven patients were recovered from infection but neurological complications remained and three patients were recovered without any complications. Microbes were obtained from cerebrospinal fluid only in six patients. Acinetobactoer baumanii was the most common pathogen in our study [4 cases]. Among the various risk factors, only the prior clinical diagnosis showed the statistical significance. Patients who underwent decompressive craniectomy after severe brain trauma showed unfavorable outcome because of possible contaminative environment compared with other cases. Conclusion : EVD is considered as a safe procedure with good control of intracranial pressure if meticulous care is provided for EVD procedure and maintenance. With regards to risk factors and prevention, the higher incidence and unfavorable outcome was seen especially in patients with severe head trauma. Thus, special attention is required in these clinical settings.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.159-164
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• 2001

An extensive range of pumping facilities are employed in the regional water supply system in metropolitan areas, and optimization and the systematic combination of the pump facilities have direct bearing on the stability and economy of the water supply system concerned. These systems must be able to guarantee stability, efficiency and offer high reliability. Preparation of metropolitan area regional water supply system construction project must include a basic plan which takes into account the suitability of pumping facilities to be used, the environment in which facilities will be installed, man-power requirements and basic operational and management policies. This paper contains over-all analysis of the management of metropolitan area regional water supply systems and highlights the cause of Inefficiency and energy waste and puts forward a remedial plan of action. In addition, pump/motor specification programs were developed using Visual Basic to assist selection of the same.