FCAW 십자형 용접재의 피로거동에 관한 연구

李龍福,吳炳德 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

The influence of weld size(l/t) and specimen geometry(a/w) on fatique life and fatique crack growth rate of flux cored arc welded(FCAW) cruciform joints, containing lack of penetration(LOP) defects, has been studied experimentally. It was found that fatique life of the weld joint increases with the larger weld size(l/t) and the smaller specimen geometry(a/w) and exhibits significant variations in low stress region. the crack growth rates are relatively higher with the smaller weld size(l/t) for a constant stress intensity factor range(AK), and are faster with the larger stress intensity factor range. The longer weld leg length appears to be beneficial for the fatigue life in an allowable range of weldment size.

용접방법에 따른 하중전달 십자형 필렛 용접부의 피로특성

이용복,오병덕 한국공작기계학회 2003 한국생산제조학회지 Vol.12 No.1

In this study, endurance limit and fatigue behavior of load carrying fillet welded cruciform joints depending on commonly used welding methods such as SMAW, SAW, MIG and FCAW are investigated. In respect of endurance limit, SMAW specimen showes highest result, and then MIG, SAW, FCAW in descending order. However, SMAW specimen showes lowest crack growth rate and it followed by MIG, FCAW, SAW. By these results, it is needed to use SMAW or MiG welding methods for welding structures with small welding capacity and SAW or FCAW methods for large welding structures with respect to economic benefits and operation efficiency of welding. It was also shown fatigue crack growth rate was more influenced by the strenght of welding materials than the endurance limit of welding materials.

2차 전지의 방전에 의한 수소-공기 혼합가스의 점화에 관한 연구

이춘하,권병덕,오종용 한국안전학회 2004 한국안전학회지 Vol.19 No.3

This papers describes on the experimental consideration for the intrinsically-safe explosion-proof capability of rechargeable battery's body about main item, rechargeable battery and cellular phone battery which is selling in domestic that IEC(Intemational Electrotechnical Commission) recommend the measurement of ignition limit by short circuit of rechargeable battery and temperature increase test to use a explosion grade Group ΠC type of explosion-proof type apparatus test an object of hydrogen gas. Because of that, there are many different results for existence or nonexistence for ignition by different company and different types. It is concluded that the maximum of self temperature increasing by spark circuit of rechargeable battery is 180℃ in case of Nickel-Hydrogen, and 110C in case of Nickel-Cadmium. The reaction of cellular battery for external temperature have following processes. It is confirmed that the temperature of reaction is rise slantly as the ambient temperature rising, then exterior shape of one is swell up and change when the temperature of ambient reach to about 130~140℃, and when reach to about 160℃ the battery is blown up. Therefore, it is considered that have to be in considering selection of rechargeable battery using in itself due to different ignition limits of various rechargeable battery when the portable electric containing rechargeable battery are designed, produced and used, the characteristics and the proper safety factors of devices.

위절제술 환자의 표준진료지침 개발 및 적용 효과

김은희,김철규,이순교,김순덕,이혜옥,권정순,이경미,이민미,심순미,유용만,신종식,강은희,이상일,김병식,오성태,육정환,박수길 한국의료QA학회 2003 한국의료질향상학회지 Vol.10 No.2

Background : Gastric cancer is the most common malignant tumor in Korea. surgical operation is one of the major treatment modalities for gastric cancer patients. Therefore, gastrectomy is one of the most common procedures in General Surgery. There were variation in length of hospital stay and medical treatment for gastrectomy between three surgeons at Asan Medical Center. Clinical pathways have received considerable attention as a tool for recucing the medical practice variation, increasing the efficiency of care process, and improving the quality of care. The aim of this study was to evaluate the effect of a clinical pathway for gastrectomy in gastric cancer patients. Methods : The clinical pathway for gastrectomy was developed and implemented by a multidisciplinary group in Asan Medical Center. A computerized clinical pathway program was developed and revised after a pilot test. A total of 145 patients underwent gastrectomy by three surgeons at Asan Medical Center. We compared the length of hospital stay, patient satisfaction, and unplanned readmission rate between the pre-pathway group(n=67) and the post-pathway group(n=78). We also investigated the degree of satisfaction among the physicians and nurses who were main end-users of the clinical pathway. Results : The clinical pathway was applied to all target patients. The average length of hospital stay was shortened from 12.7days to 10.6days(p<0.01). The degree of patient satisfaction with the care process changed from 90.3% to 89.2% after the implementation of the clinical pathway, but the difference was of satistically significant(p=0.761). Unplanned readmission rate was 2.9% in the pre-pathway group. More than 90% of physicians and nurses answered that the clinical pathway had been a useful tool in their medical practice. Conclusions : The findings of the study demonstrated that implementation of the clinical pathway for gastrectomy produced substantial reduction in the length of hospital stay while improving the quality of patient outcomes. The computerized clinical pathway program can be used as one of the powerful patient management tools for reducing the practice variations and increasing the efficiency of care process in Korea hospital settings.

다차원 색인 구조에서의 질의처리에 관한 연구

吳廉德,金炳坤 충주대학교 산업대학원 1999 大學院論文輯 Vol.1 No.-

Because multimedia data contain high dimensional property,it is important to construct indexing structure to express data's own nature efficiently. And based on this indexing structure,fast query processing strategy to retrieve multimedia data is needed. In this paper, first we illustrate several high dimensional indexing methods and many kind of high­dimensional queries. Next, in terms of nearest neighbor query, the most frequently used high dimensional query,we describe query processing strategy for efficient and fast query processing and propose new direction for further research.

멀티미디어 데이터의 빠른 처리를 위한 주기억 데이터베이스 시스템

吳廉德,金炳坤 충주대학교 산업대학원 1999 大學院論文輯 Vol.1 No.-

Indexing strategy to save and retrieve multimedia data efficiently and main memory database technology to handle data fast are important part of processing multimedia data. In main memory database, all or a major portion of the database is placed in main memory. This concept is very important to process multimedia data fast. In this paper, we illustrate this two field and propose connection concept of the two field.

Effect of High-Dose Tamoxifen on Malignant Gliomas

Oh, Yeon Chul,Kim, Jung Hoon,Lee, Jung Kyo,Kim, Chang Jin,Kwon, Yang,Rhim, Seung Chul,Kwun, Byung Duck,Whang, C. Jin 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.9

배양된 신경교종에서 tomoxifen은 핵산의 합성 및 세포의 증식을 억제할 수 있음을 in vitro study상 알 수 있다. 이러한 성장 억제는 tamoxifen의 항에스트로겐 특성에 의존하지 않고, protein kinase C라는 효소의 억제를 통해서 이루어지는 듯 하다. 저자들은 1991년 2월부터 1993년 1월까지 본원 신경외과에 입원하여 수술 후 부가적 치료로써 고용량 tamoxifen을 병행한 28명의 악성 신경교종환자들에서 고용량 tamoxifen의 부가적 치료 효과 및 그 부작용을 알아보기 위하여 본 임상실험을 시행하였다. 고용량 tamoxifen의 부가적 치료효과는 통계학적으로 유의하게 증가된 생존기간 및 생존율로 정의하였다. Tamoxifen 치료군의 경우 처음에는 약제의 부작용을 알아보기 위하여 표준 항에 스트로겐 용량인 20㎎을 하루에 2회 경구 투여하였으며, 특별한 문제가 없으면 1달 이상에 걸쳐 매주 용량을 증가하여 100㎎을 하루 2회 경구 투여하였다. Tamoxifen 사용 후 역형성 성상세포종과 다형성 교아세포종간의 생존기간 및 생존율을 비교하여 보았을 때 역형성 성상세포종에서 다형성 교아세포종보다 중간 생존율이 약간 높았으나 통계학적 유의한 차이는 없었다. 또한 치료 방법(방사선 단독 치료군, 방사선 치료와 ACNU 화학요법을 병행한 치료군, 그리고 방사선 치료와 tamoxifen을 병행은 치료군)에 따른 생존기간 및 생존율을 비교하여 보았을 때, tamoxifen 치료군에서 다른 치료군들보다 생존기간 및 생존율이 약간 높았으나 역시 통계학적 의미는 없었다. 고용량 tamoxifen으로 치료하였던 대부분의 환자들에서 심한 부작용은 관찰할 수 없었다. Tamoxifen 용량을 증가시키는 동안 5명의 환자에서 식욕부진 증상이 발생하였으며, 다른 합병증들로서 무월경, 오심/구토, 그리고 변비 등을 관찰할 수 있었으나 혈액학적 변화는 관찰할 수 없었다 저자들은 고용량 tamoxifen을 악성 신경교종 환자에서 비교적 안전하게 사용할 수 있다고 생각한다. 본 임상실험 결과는 만족스럽지 못했으나 저자들은 제한된 본 연구결과로 악성 신경교종 환자들에서 고용량 tamoxifen의 치료 효과를 단정할 수 없다고 생각하며, 따라서 이 약제에 대한 보다 광범위한 연구가 이루어져야만 한다고 생각한다. In vitro studies have shown that the nonsteroidal antiestrogen tamoxifen can suppress deoxyribonucleic acid(DNA) synthesis and cell proliferation in cultured human gliomas. This frowth suppression is independent on its antiestrogenic properties. Tamoxifen may act through the inhibition of the enzyme protein kinase C(PKC), which transduces mitogenic signals from the cell surface to the nucleus. In order to evaluate the therapeutic response and side effect of high-dose tamoxifen, we performed a clinical study of 28 patients with malignant gliomas who were treated with high-dose tamoxifen in our hospital between Febrary 1991 and January 1993. An effect was defined as a statistically improved survival times/rates. In patients who were assigned to receive high-dose tamoxifen, it was first administered at standard antiestrogen doses(20㎎ orally bid/day) to observe for any side effect and if tolerated, the dose was increased weekly to achieve target doses(100㎎ orally bid/day) over a 1 month period. We compared the survival times/rates between anaplastic astrocytomas and glioblastoma multiformes. Although the median survival time was slightly longer in anaplastic astrocytomas and glioblastoma multiformes, there was no statistical difference of survival curves between two groups at the p=0.05 level. We also exmamined the survival times/rates of malignant gliomas according to treatment modalities(radiotherapy along, radiotherapy plus ACNU, and radiotherapy plus tamoxifen). Although the survival rate and time were slightly higher in radiotherapy plus tamoxifen group than those of another treatment groups, we could not find the statistical significance of survival curves between three treatment groups(p>0.05)). High-dose oral tamoxifen appeared to be well tolerated in most patients. Five patients developed anorexia following dose escalation of tamoxifen. Another complications were amenorrhea, nausea/vomiting, and constipation. There were no changes in hematological studies that could be attributed to tamoxifen. We think that high-dose tamoxifen can be administered safely to malignant glioma patients. Our results were not impressive. We conclude that the definition of the true efficacy of high-dose tamoxifen in patients harboring malignant gliomas is not possible from this limited study, and a further large scale, randomized trial of this agent is necessary.

Hardware Implementation of the Pattern Recognize Processor based on DNA Computing technique

Byung-Soo Kim,Joo-Kyung Kim,Oh Hyuk Kwon,Seung Kon Hwang,Jae-Yeon Song,Byoung-Tak Zhang,Chong Ho Lee,Jaehyun Park,Duck-Jin Chung 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

In this paper, a Pattern Recognize Processor based on DNA Computing technique is proposed in order to provide the massive parallelism and reduce the recognition time. The proposed hardware architecture performs simple DNA-computing operations by using the simple memory access technology and classifies the input pattern as molecular evolutionary learning model. The proposed hardware architecture compares 1000 patterns at once and hardware recognition time is 8 × 10? times faster than the software recognition time without accuracy loss. ModelSim and ISE simulation is applied for the proposed hardware design verification using the Xilinx Virtex-4LX100 FPGA.

Reclosing Operating Characteristics of a Flux-Coupling Type SFCL in the Three-Phase Power System of a Single Line-to-Ground Fault

Byung-Ik Jung,Hyo-Sang Choi,Hyoung-Min Park,Yong-Sun Cho,Kyoung-Hun Ha,Soo-Geun Choi,Geum-Gon Oh,Duck-Gu Kim,Sung-Pil Ko 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

초저체온마취하에서 시행한 Fallot 사징후(四徵候)근치술

오흥근,윤덕미,조범구,장병철 대한마취과학회 1980 Korean Journal of Anesthesiology Vol.13 No.2

Early correction of congenital cardiac defects has been facilitated by the use of deep hypothermia and cardiorespiratory arrest. Simple deep hypothermia has a number of advantages for infant open heart surgery, such as a quiet heart and bloodless operative field, reduced blood requirement, elimination of pulmonary and coagulation problems following cardiopulmonary bypass, elimination of cannulation, simple anesthetic technique, no neccessity of complicated facilities, and stable postoperative course. Deep ether anesthesia is the ideal agent for induction of deep hypothermia by surface cooling, especially when combined with ganglionic blocking agents in large quantities to elimiminate some of the undesirable effects of ether, thus improving and maintaining good peripheral perfusion. We have performed a total correction of TOF on March, 1979. Anesthesia was induced with intravenous thiopental and succinylcholine for intubation and maintained by a tight closed circuit system with ether. As soon as routine EKG, direct intra-arterial pressure, esophageal and rectal temperature monitoring devices were installed, slow intravenous administration of triflupromazine was followed by surface cooling. Surface cooling was done by the technique of covering the child with bags of crushed ice after placing the infant on an icewater blanket. After cooling, the intracardiac procedure was performed under circulatory occlusion and cardiac arrest, following cardioplegic infusion, for 45 minutes. After the intracardiac procedure, cardiac resuscitation and rewarming were accomplished by cardiopulmonary bypass technique. The patient recovered satisfactorlly and was discharged on POD14 without any complication.