• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.598-603
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• 2006

Background: High thoracic epidural anesthesia allows awake coronary artery bypass grafting, avoiding the drawbacks of mechanical ventilation and general anesthesia. Materian and Method: From April, 2005 to September, 2005, 12 patients were underwent awake coronary artery bypass grafting using high thoracic epidural anesthesia. There were 1 female and 11 male patients, with a mean age of $66{\pm}6$ years. Off pump coronary artery. bypass grafting was performed through a median sternotomy using arterial grafts. Result: There were no mortality. Pneumothorax was developed during surgery in 8 patients. Five patients required secondary intubation because of pneumothorax (n=3), bowel herniation (n=1), and hemothorax after chest tube insertion (n=1). Postoperative coronary angiography was performed before discharge in all patients and all the grafts were patent. Conclusion: Our intial experience demonstrated the feasibility of awake off-pump coronary artery bypass grafting. Further study is required to define the indications, advantages and limitations of this strategy.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.7
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• pp.435-440
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• 2016

Effects of the increase rate of Reynold number on near-wall turbulent structures are investigated by performing direct numerical simulations of transient turbulent channel flows. The simulations were started with the fully-developed turbulent channel flow at $Re_{\tau}=180$, then temporal accelerations were applied. During the acceleration, the Reynolds number, based on the channel width and the bulk mean velocity, increased almost linearly from 5600 to 13600. To elucidate the effects of flow acceleration rates on near-wall turbulence, a wide range of durations for acceleration were selected. Various turbulent statistics and instantaneous flow fields revealed that the rapid increase of flow rate invoked bypass-transition like phenomena in the transient flow. By contrast, the flow evolved progressively and the bypass transition did not clearly occur during mild flow acceleration. The present study suggests that the transition to the new turbulent regime in transient channel flow is mainly affected by the flow acceleration rate, not by the ratio of the final and initial Reynolds numbers.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.270-272
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• 2017

스마트폰 애플리케이션의 종류가 다양해지고 사용 빈도수가 높아지는 만큼 정보보안에 대한 중요성도 나날이 증가하고 있다. 최근 기업, 금융기관들은 스마트폰 애플리케이션 서비스에서 사용자와 서버 간 통신 시 MITM공격에 대비하기 위해 SSL Pinning 기술을 사용하고 있는데 본 연구에서는 이를 우회할 수 있는 방법을 소개하고 시연하며, 이에 대한 대응방안을 소개한다.

• KIISE Transactions on Computing Practices
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• v.20 no.12
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• pp.694-699
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• 2014

In mobile ad-hoc networks (MANET), the network topology and neighboring nodes change frequently, since MANET is composed of nodes that have mobility without a fixed network infrastructure. The AODV routing protocol is advantageous for MANET, but AODV has a delay in the transmission of data packets because AODV can not transmit data during route recovery. This paper proposes solving the above problem of AODV by using a bypass generation mechanism for data transmission during route recovery. For further improvement, additional mechanisms that coordinate the reception threshold of a hello packet are proposed in order to improve the accuracy of the information obtained from the neighboring nodes when the bypass is generated due to a link failure and the immediacy of the route recovery. Simulation results show that the proposed technique improves the performance in terms of the delay in transmission compared to traditional AODV.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.72-75
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• 2006

In a 40 year-old man who has complained of epigastric pain and dyspnea for 10 days including melena for 1 month, abdominal ultrasonography and computerized tomography revealed a large, solid mass in the right kidney and thrombus of inferior vena cava (IVC) that extended to the cavoatrial junction. Renal cell carcinoma was performed by percutaneous needle biopsy. IVC thromboembolectomy was performed using centrifugal pump driven venovenous bypass without cardiac arrest and cardiopulmonary bypass (CPB).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.15-23
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• 2021

In most hacking attacks, hackers intrudes inside for a long period of time and attempts to communicate with the outside using a circumvent connection to achieve purpose. research in response to advanced and intelligent cyber threats has been mainly conducted with signature-based detection and blocking methods, but recently it has been extended to threat hunting methods. attacks from organized hacking groups are advanced persistent attacks over a long period of time, and bypass remote attacks account for the majority. however, even in the intrusion detection system using intelligent recognition technology, it only shows detection performance of the existing intrusion status. therefore, countermeasures against targeted bypass rwjqthrwkemote attacks still have limitations with existing detection methods and threat hunting methods. in this paper, to overcome theses limitations, we propose a model that can detect the targeted circumvent connection remote attack threat of an organized hacking group. this model designed a threat hunting process model that applied the method of verifying the origin IP of the remote circumvent connection, and verified the effectiveness by implementing the proposed method in actual defense information system environment.

• Journal of the Korea Society of Computer and Information
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• v.14 no.12
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• pp.181-190
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• 2009

DBMS access that used high speed internet web service through WAS is increasing. Need application of DB security technology for 3-Tier about DBMS by unspecified majority and access about roundabout way connection and competence control. If do roundabout way connection to DBMS through WAS, DBMS server stores WAS's information that is user who do not store roundabout way connection user's IP information, and connects to verge system. To DBMS in this investigation roundabout way connection through WAS do curie information that know chasing station security thanks recording and Forensic data study. Store session about user and query information that do login through web constructing MetaDB in communication route, and to DBMS server log storing done query information time stamp query because do comparison mapping actuality user discriminate. Apply making Rule after Pattern analysis receiving log by elevation method of security authoritativeness, and develop Module and keep in the data storing place through collection and compression of information. Kept information can minimize false positives of station chase through control of analysis and policy base administration module that utilize intelligence style DBMS security client.

• Journal of Digital Policy
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• v.2 no.4
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• pp.33-39
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• 2023

With a continuous occurrence of right-turn traffic accidents at intersections, there is an increasing demand for measures to address these incidents. In response, a technology has been developed to detect the presence of pedestrians through object detection in CCTV footage at right-turn areas and display warning messages on the screen to alert drivers. The YOLO (You Only Look Once) model, a type of object detection model, was employed to assess the performance of object detection. An algorithm was also devised to address misidentification issues and generate warning messages when pedestrians are detected. The accuracy of recognizing pedestrians or objects and outputting warning messages was measured at approximately 82%, suggesting a potential contribution to preventing right-turn accidents

• 전기의세계
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• v.39 no.4
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• pp.30-31
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• 1990

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.101-113
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• 2008

VMS are installed in many Korean highways in oder to give drivers informations such as travel time to destination, congestion and Incident situation. However, some guidelines for install VMS are restricted in only geometric factors although human factors considering driver behavior are very important to affect the VMS installation. Therefore, this paper are focusing on developing and verifying the discriminant model for VMS installation considering human factors. As a result, following outputs are obtained ; (1) developing the discriminant model using human factors of driving simulation experiments in oder to predict driver reading VMS messages safely detour highway. (2) proving that driving experiences in highway, personal driving history, vehicle speed orderly affects VMS installation (3) verifying predictability of developed model by comparing the real values with predicted values. (4) suggesting that VMS should be installed off 3.2Km from the I.C. of rural highway.