• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1118-1122
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• 2005

수중보는 하천, 하수관 또는 인공수로에 건기시 유지수량을 확보할 목적으로 설치되며 제한 범위 이상의 물이 유입되는 경우 원활한 치수를 위하여 이를 자동적으로 방출시키도록 자동으로 수문을 개폐시키는 장치가 필요하다. 보통 10년 주기 내외의 평균 강우량에 맞추어서 그 용량이 결정되어야 경제성을 확보할 수 있게 된다. 그러나 10년 주기의 평균 강우량을 초과하는 강우가 발생할 경우에 유입되는 전체 수량을 유입시키면 해당 기기에 상당한 손상을 입히게 된다. 또한 재현기간을 너무 길게 잡을 경우, 해당 수처리의 설치비용이 과다하게 되고, 경제성이 낮아질 수 밖에 없다. 따라서 수처리를 위한 장치의 규모는 적정한 재현기간에 맞추어 설계하고, 재현기간을 초과하여 강우가 발생할 경우 강우 유입을 우회시킬 필요가 있게 된다. 이와 같이 수량을 우회 또는 통과시킬 목적으로 초과유량을 방출할 수 있는 완충회전수문 실험 모형을 제작하여 여러 차례의 실험을 토대로 한계수심 및 충격량을 이론적으로 산정하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1906-1914
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• 2012

In this paper, relative service differentiation in JET based optical burst-switched networks with deflection routing is presented. It differs from conventional schemes in that it tries to make the loss rate of high class bursts as low as possible while maintaining the desired proportional ratio between the high class bursts and low class bursts. Strategies applied to it are dynamic wavelength allocation and the preemption which are combined to deflection routing. With dynamic wavelength allocation, the number of wavelengths allocated to high class bursts are dynamically changed. Preemption which gives more preference to high class bursts is also applied to decrease its loss rate. To lower the loss rate, deflection routing is applied for any kind of traffic. With those strategies, the suggested scheme shows desired properties that the loss rate of high class traffic is as lowered as possible. A queueing model for the scheme is developed to approximate loss ratio and the numerical results show that the proposed scheme provisions relative service differentiation.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.68-71
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• 2006

We operated on a 41-year-old man using venous bypass shunt for superior vena cava (SVC) syndrome caused by mediastinal fibrosis. The patient had substantially high venous pressure and high risk of postoperative neurologic deficits. The collateral veins were deemed to be interrupted during the surgical reconstruction of SVC. Treatment included resection of the obstructed SVC and innominate vein and reconstruction with an autologous pericardial tube graft. During the operation, venous drainage from upper body was maintained with an extraluminal bypass shunt. The shunt was effective at prompt relief of venous hypertension, eliminating the time constraints, and preventing the postoperative complications.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.3
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• pp.17-28
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• 2006

The appearance of variant malicious codes using obfuscation techniques is accelerating the spread of malicious codes around the detection by a vaccine. n a system does not patch detection patterns for vulnerabilities and worms to the vaccine, it can be infected by the worms and malicious codes can be spreaded rapidly to other systems and networks in a few minute. Moreover, It is limited to the conventional pattern based detection and treatment for variants or new malicious codes. In this paper, we propose a method of behavior based detection by the static analysis, the dynamic analysis and the dynamic monitoring to detect a malicious code using obfuscation techniques with the PE compression. Also we show that dynamic monitoring can detect worms with the PE compression which accesses to important resources such as a registry, a cpu, a memory and files with the proposed method for similarity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2301-2308
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• 2013

These days, Rehabilitation psychology analysis system is being used by world wide web in everyday's life. And on the other hand, we are facing spam messages' problems. To block these spam message, we are using filtering or pricing systems. But these solutions are raising other problems such as impediment in reception or availability caused by false positive or payment resistance. To solve these problems, we propose an Indirect Model on Message Control System(IMMCS) which controls an unsolicited message and prevents an useful message from discarding. We design and implement the IMMCS to enhance the usefulness and the availability. Being tested the IMMCS to verify the usability and the efficiency, it gave us a very successful result.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.2
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• pp.348-354
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• 2005

These days, Electronic mail is being used in everyday's life. And on the other hand, we are facing spam mails' problems. Spam mails are widely used by means of marketing in e-Commerce. To block these spam mails, we are using filtering or pricing systems. But these solutions are raising other problems such as impediment in reception or availability caused by false positive or payment resistance. To solve these problems, we propose an Indirect Model on Electronic Mail Control System(IMEMCS) which controls an unsolicited electronic mail and prevents an useful electronic mail from discarding. We design and implement the IMEMCS to enhance the usefulness and the availability. Being tested the IMEMCS to verify the usability and the efficiency, it gave us a very successful result.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.365-368
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• 2002

Background: Coronary artery bypass grafting(CABG) imposes large amount of medical costs, which are greatly affected by the surgical approach, quality of perioperative care and associated co-morbidities. Recently, off-pump CABG(OPCAB) has been introduced and performed with increasing frequency. To evaluate the efficacy of OPCAB in view of financial impact, we analyzed the costs and medical resources of OPCAB and compared with conventional CABG. Material and Method: From January 1998 to July 1999, 184 patients underwent CABG operation; 111 patients with OPCAB(group I) and 73 patients with conventional CABG(group II). We prospectively collected clinical data including risk factors and retrospectively reviewed the hospital resources. Result: Preoperative parameters including risk factors, postoperative mortality, morbidity and length of hospital stay were not different between the two groups, Duration of stay in the intensive care unit(ICU) (51.3 vs 128.3 hours, p<0.01) and ventilator, support time(14.9 vs 56.2 hours, p<0.01) were significantly shorter in the OPCAB group. Total hospital coats were 17,220,000 add 21,250,000(Korean Won) in group I and II, respectively(p<0.01). There were significant differences in operation fee, costs for operative materials, transfusion and diagnostic radiology between two groups. In group I, all the resources except diagnostic radiology were significantly decreased compared with group II. Conclusion: OPCAB has a beneficial effect on hospital charge and resource utilization. Shorter duration of the ICU stay and ventilatory support time may reduce the total hospital costs.

• Journal of Chest Surgery
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• v.38 no.2 s.247
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• pp.146-151
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• 2005

Background: Preoperative elevated serum creatinine values are associated with increased risk for both morbidity and mortality in patients undergoing on-pump coronary artery bypass surgery (CABG). We investigated the postoperative changes of renal function and proper management in the patients. Material and Method: Among 74 consecutive patients who underwent isolated on-pump CABG, 17 patients with increased serum creatinine level $(creatinine\;\geqq\;1.5\;mg/dL)$ within preoperative one week wereincluded in the study. Seven patients showed pre­operative serum creatinine level of 2.0 mg/dL or higher, and 3 of them had been undergoing hemodialysis. Preoperative hemodialysis was performed in the 3 patients due to end-stage renal failure (ESRD) the day before the operation. We started peritoneal dialysis immediately after the cardiopulmonary bypass in patients with ESRD or postoperative acute renal failure if it was necessary to remove intravascular volume and lower serum creatinine level. Result In most of the patients with CABG, postoperative serum creatinine level increased and recovered to the preoperative level at the discharge. In 2 of the 4 patients with serum creatinine level of 2.0 mg/dL or higher and 3 patients with ESRD, intravascular volume, serum creatinine level and serum electrolyte were controlled with peritoneal dialysis. Conclusion: Postoperative serum creatinine level increased transiently in most of CABG patients, and intravascular volume and serum creatinine level were controlled by peritoneal dialysis only in the patients with acute renal failure postoperatively and those depending on hemodialysis.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.1
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• pp.84-93
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• 2004

Recently, domain-specific demands with respect to practical applications and analysis scheme using spatial thematic information are increasing. Accordingly, in this study, GIS-based application program is implemented to perform spatial analysis in transportation geography with base road layer data. Using this program, quantitative estimation of circuity and accessibility, which can be extracted from nodes composed of the graph-typed network structure, in a arbitrary analysis zone or administrative boundary zone is possible. Circuity is a concept to represent the difference extent between actual nodes and fully connected nodes in the analysis zone. While, accessibility can be used to find out extent of accessibility or connectivity between all nodes contained in the analysis zone, judging from inter-connecting status of the whole nodes. In put data of this program, which was implemented in AVX executable extension using AvenueTM of ArcView, is not transportation database information based on transportation data model, but layer data, directly obtaining from digital map sets. It is thought that computation of circuity and accessibility can be used as kinds of spatial analysis functions for GIS applications in the transportation field.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.11
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• pp.297-304
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• 2021

Commercial obfuscation tools (protectors) aim to create difficulties in analyzing the operation process of software by applying obfuscation techniques and Anti-reversing techniques that delay and interrupt the analysis of programs in software reverse engineering process. In particular, in case of virtualization detection and anti-debugging functions, the analysis tool exits the normal execution flow and terminates the program. In this paper, we analyze Anti-reversing techniques of executables with Debugger Detection and Viralization Tools Detection options through VMProtect 3.5.0, one of the commercial obfuscation tools (protector), and address bypass methods using Pin. In addition, we predicted the location of the applied obfuscation technique by finding out a specific program termination routine through API analysis since there is a problem that the program is terminated by the Anti-VM technology and the Anti-DBI technology and drew up the algorithm flowchart for bypassing the Anti-reversing techniques. Considering compatibility problems and changes in techniques from differences in versions of the software used in experiment, it was confirmed that the bypass was successful by writing the pin automation bypass code in the latest version of the software (VMProtect, Windows, Pin) and conducting the experiment. By improving the proposed analysis method, it is possible to analyze the Anti-reversing method of the obfuscation tool for which the method is not presented so far and find a bypass method.