성인의 장중첩증에서 복부전산화단층촬영술의 유용성

김세웅,조영업,고영배,김원곤,김경국,김경래,우제홍,김미영 대한대장항문학회 1998 Annals of Coloproctolgy Vol.14 No.3

컴포넌트 커널 프레임워크를 이용한 커널의 동적 확장성

양순섭,고영웅,유혁 고려대학교 컴퓨터과학기술연구소 2001 JOURNAL OF COMPUTER SCIENCE & ENGINEERING TECHNOLO Vol.3 No.-

기존의 커널 구조는 응용프로그램의 요구에 따라 커널의 기능을 고치거나 새로이 추가하는 것이 커널 자체의 복잡성으로 인하여 어려운 점이 많고 커널 내의 기능성들을 모듈화 함으로써 어려움을 극복하고자 하고 있다. 하지만 응용프로그램이 다양화되고 이러한 응용프로그램들의 요구에 따라 커널 내의 기능성이 변경되거나 추가됨으로써 이러한 모듈화는 깨어지고 있다. 즉 변경되거나 새로이 추가될 기능성을 미리 예측하는 것이 불가능하기 때문에 어떠한 모듈을 접근하는데 있어 고정된 1차원적인 인터페이스만으로는 모듈화를 유지하기가 힘들게 되고 특히 멀티미디어와 같은 새로운 응용프로그램들은 기존의 커널에 많은 새로운 기능들의 추가를 요구하고 있어서 상황은 더욱 악화되고 있다. 본 논문에서는 이러한 커널 복잡도를 낮추고 커널 구조를 보다 유연하게 만들기 위한 방안으로서 코어커널(CoreKernel)과 커널컴포넌트(KernelComponent)들의 집합으로서 커널을 구성하는 컴포넌트 커널 프레임워크(Component Kernel Framework)를 제시하고 이에 기반한 커널의 동적 확장 모델을 설계한다. 제시한 컴포넌트 기반 커널 확장 모델을 검증하고자 현재 개발중인 커널 프로토타입 소개하고 시뮬레이션을 통해 제안된 동적 확장 모델을 검증한다. Traditional kernels like UNIX have lots of difficulties in adding and modifying kernel functionalities due to inherent complexities of kernel architecture. They try to solve these problems through modularization. As there come to be a diversity of application programs and they require modification of existing kernel functionalities and addition of new ones, Modularity of kernel tends to be broken. In other words, because it is difficult to expect which functionality should be modified and what functionality should be newly added, To keep modularity of kernel is almost impossible if the modules are accessed only through fixed one-dimensional interface. This situation is likely to happen as multimedia applications that require new kernel functionalities like real-time scheduling and memory reservation become popular. Trying to decrease kernel complexities and to make kernel more modularized, this paper suggests Kernel Component Framework that construct kernel of Corekernel and a set of KernelComponents and then designs dynamic kernel extension model based on Kernel Component Framework. To verify suggested component-based kernel extension model, we introduce kernel prototype now being developed and simulate dynamic extension model.

관동맥우회술 후 발생한 급성 장간막경색 1예

문용화,김지현,강웅철,박병은,고영국,최동훈,유경종 대한내과학회 2004 대한내과학회지 Vol.66 No.3

관동맥우회술을 포함한 심장수술 후에 생기는 급성 장간막경색은 매우 드물지만 치명적인 합병증으로 발생률은 비교적 낮으나 사망률은 매우 높게 보고 되고 있다. 본 증례에서는 55세 여자 환자가 관동맥우회술을 시행받고 수술 후 1일째에 발생한 복부통증에 대해서 장간막경색증을 의심하지 못하고 수술과 연관된 비특이적 증상으로 판단하였으나 그 후 환자의 증상이 악화되면서 상장간막동맥 혈전 색전증에 의한 광범위한 급성 장괴사로 판명되었다. 관독맥우회술 후 상장간막 동맥에 생긴 혈전색전증에 의해 발생한 급성 장간막경색의 증례는 국내에 보고된 바 없고 본 증례를 통해 교육적인 경험을 하였기에 저자들은 문헌고찰과 함께 보고하는 바이다. 심폐우회술을 요하는 심장수술을 받은 환자 중 특히 급성 장간막허혈의 위험인자를 가지고 있는 환자에 대해서는 급성 장간막허혈이 생길 수 있다는 세심한 관찰이 진단이 늦어지지 않게 하는 방법이며 장간막허혈이 의심되면 즉시 적극적인 진단 및 치료적인 접근을 시도해야 하겠다. Acute mesenteric ischemia leading to massive bowel infarction following cardiac surgery particularly coronary artery bypass graft (CABG), is reported to be a very rare but serious life-threatening complication. In this case, a 55-year-old female underwent CABG and complained of abdominal pain on the first postoperative day, which was thought to be nonspecifically related to the operation wound, In the further hospital course, the patient was found to have extensive acute mesenteric infarction due to thromboembolism of superior mesenteric artery. This is a valuable educational case, since only high index of suspicion does not delay making a diagnosis especially in the patients with risk factors of acute mesenteric ischemia after cardiac surgery requiring cardiopulmonary bypass. On suspicion of acute mesenteric ischemia, an aggressive diagnostic and therapeutic approach should be performed immediately.(Korean J Med 66:317-320, 2004)

Stride Static Chunking Algorithm for Deduplication System

KO, Young-Woong,JUNG, Ho-Min,LEE, Wan-Yeon,KIM, Min-Ja,YOO, Chuck 'Institute of Electronics, Information and Communi 2013 IEICE transactions on information and systems Vol.96e.d No.7

LC : Noninvasive Fibrosis Panels Predict 5-year Outcomes of Chronic Hepatitis B; Preliminary Study

( Young Baek Kim ),( Jeong Han Kim ),( Hong Seok Choi ),( Yong Hwang ),( Yong Hoon Choi ),( Jun Jae Kim ),( Seo Jung Woong ),( Soon Young Ko ),( Won Hyeok Choe ),( So Young Kwon ) 대한간학회 2013 춘·추계 학술대회 (KASL) Vol.2013 No.1

Background: In patients with chronic liver disease, level of fi- brosis predicts liver-related complication and survival. Previous report (Gastroenterology 2011;140:1970-1979) showed noninvasive tests for fibrosis predict 5-year survival of patients with chronic hepatitis C. We aimed to evaluated abilities of noninvasive tests for fibrosis to predict overall survival with a 5-year period in chronic hepatitis B (CHB) patients. Methods: The medical records of CHB patients visited Konkuk University Medical Center in year 2005. APRI and FIB-4 were calculated as previously described elsewhere. Kaplan- Meier survival analysis and log rank test were used to analyze correlation of these tests and patient`s survival. Results: Total 218 patients were included for analysis and of these, 26 patients were deceased within 5 year follow up period. Male patients were 138 (63.3%) and mean age was 47.7 years. HBeAg positive patients were 135 (61.9%) and underlying cirrhotic patients were 91 (41.7%). Mean value of APRI was 1.7 and that of FIB-4 was 3.8. If cut-off level of APRI was set as 0.72, P-value was 0.0086 and hazard ratio was 2.7603 (95% CI, 1.2433-6.1279). If cut-off level of FIB-4 was set as 2.32, p-value was 0.0007 and hazard ratio was 3.6904 (95% CI, 1.6380- 8.3147) Conclusions: Noninvasive test for liver fibrosis, such as APRI and FIB-4 can help prediction of 5 year survival of CHB patients. Large scale cohort analysis is warranted.

Nurse Scheduling Problem Using Backtracking

Ko, Young-Woong,Kim, Dong-Hoi,Uhmn, Saangyong,Kim, Jin American Scientific Publishers 2017 Advanced Science Letters Vol.23 No.4

Rate-based Page Fault Handling Mechanism for Soft Real-time Task

Ko, Young Woong,Yoo, Chuck 고려대학교 컴퓨터과학기술연구소 2003 JOURNAL OF COMPUTER SCIENCE & ENGINEERING TECHNOLO Vol.5 No.-

In virtual memory system, whenever a new task is dynamically launched, it suffers from transient overload that caused by excessive page fault handing. As transient overload state occurred, the QoS of multimedia application may be degraded because the deadine miss ratio is increased. In this paper, we suggest new methodology that supports soft real-time task efficiently. To improve real-time characteristics in memory management, we present efficient memory management techniques called Rate-based Page Fault Handling mechanism. With these mechanism, we can support soft real-time characteristics in memory constraint situation. A significant feature of the mechanism is resource reservation for kenel activity and page fault dispersion based on per process limit. We implement the memory management mechanism on Linux kernel and present the experiment results with Berkeley MPEG-1 video decoder. Experiment result shows that our mechanism could achieve 10%-20% reduction in deadline miss ratio and 50%-60% reduction in average delay.

Metabolic characterization of imatinib-resistant BCR-ABL T315I chronic myeloid leukemia cells indicates down-regulation of glycolytic pathway and low ROS production

Ko, Byung Woong,Han, Jeongsu,Heo, Jun Young,Jang, Yunseon,Kim, Soo Jeong,Kim, Jungim,Lee, Min Joung,Ryu, Min Jeong,Song, Ik Chan,Jo, Young Suk,Kweon, Gi Ryang Informa UK (Informa Healthcare) 2016 Leukemia & lymphoma Vol.57 No.9

<P>Long-term imatinib treatment induces drug-resistant chronic myeloid leukemia (CML) cells harboring T315I gate keeper mutation of breakpoint cluster region (BCR)-ABL oncogenic kinase. However, although cell proliferation is coupled with cellular energy status in CML carcinogenesis, the metabolic characteristics of T315I-mutant CML cells have never been investigated. Here, we analyzed cell proliferation activities and metabolic phenotypes, including cell proliferation, oxygen consumption, lactate production, and redox state in the KBM5 (imatinib-sensitive) and KBM5-T315I (imatinib-resistant) CML cell lines. Interestingly, KBM5-T315I cells showed decreased cell proliferation, lactate production, fatty acid synthesis, ROS production, and down regulation of mRNA expression related to ROS scavengers, such as SOD2, catalase, GCLm, and GPx1. Taken together, our data demonstrate that the lower growth ability of KBM5-T315I CML cells might be related to the decreased expression of glycolysis-related genes and ROS levels, and this will be used to identify therapeutic targets for imatinib resistance in CML.</P>

An Improvement Technique for Simulated Annealing and Its Appli-cation to Nurse Scheduling Problem

Young-Woong Ko,DongHoi Kim,Minyeong Jeong,Wooram Jeon,Saangyong Uhmn,Jin Kim 보안공학연구지원센터 2013 International Journal of Software Engineering and Vol.7 No.4

Application-controlled Multimedia Scheduling

Ko, Young Woong,Yoo, Chuck 고려대학교 컴퓨터과학기술연구소 2002 JOURNAL OF COMPUTER SCIENCE & ENGINEERING TECHNOLO Vol.4 No.-

Real-time scheduling algorithms such as Rate Monotonic and Earliest Deadline First are a basis for many multimedia scheduling algorithms. However, real-time scheduling mechanisms have drawbacks to multimedia applications. One of them is that multimedia application such as digital video has a large variation in execution time, which makes real-time scheduling algorithms very inefficient in terms of resource utilization. To improve the resource utilization, this paper introduces an application-controlled approach. A task passes scheduling information to the scheduler so that the scheduler dynamically changes the priority of the task. In addition, an advantage of our approach is that multimedia tasks are scheduled based on priority only. Therefore, multimedia tasks do not penalize time-sharing tasks. We implement the new scheduler on Linux kernel and present the experiment results with Berkeley MPEG-1 video decoder.