• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.583-592
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• 2005

An important factor influencing the robustness of the Internet is the end-to-end TCP congestion control. However, the congestion control scheme of TCP Reno, the most popular TCP version on the Internet, employs passive congestion indication. It makes the network congestion worse. Brakmo and Peterson proposed a congestion control algorithm, TCP Vegas, by modifying the congestion avoidance scheme of TCP Reno. Many studies indicate that Vegas is able to achieve better throughput and higher stability than Reno. But there are three unfairness problems in Vegas. These problems hinder the spread of Vegas in the current Internet. In this paper, in order to solve these unfairness problems, we propose a new congestion control algorithm called TCP NewVegas. The proposed NewVegas is able to solve these unfairness problems effectively by using the variation of the number of queued packets in a bottleneck router. To evaluate the proposed approach, we compare the performance among NewVegas, Reno and Vegas. Through the simulation, NewVegas is shown to be able to achieve throughput and better fairness than Vegas.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.1286-1287
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• 2007

무선 네트워크에서 TCP Vegas는 다양한 원인으로 발생하는 패킷 손실로 인해 전송률이 떨어진다. 다수의 패킷 손실이 발생하면 TCP Vegas의 혼잡제어 기법은 패킷 손실로 인해 혼잡윈도우가 증가되지 않는다. 본 논문은 TCP Vegas의 혼잡제어 기법을 수정하여 무선 네트워크에서 TCP Vegas의 성능을 향상시킨 wirelessVegas를 제안한다. wirelessVegas는 NS-2를 이용하여 시뮬레이션 한 결과 TCP Vegas 보다 1%의 무선 링크 에러율에서 약 20% 높은 성능을 보인다.

• Journal of Sasang Constitutional Medicine
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• v.19 no.2
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• pp.82-93
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• 2007

1. Objectives Functional medicine is a system which utilizes certain Investigative and treatment methods that are primarily oriented toward the recognition of functional disorder. The 7-zone-diagnostic system(VEGA-DFM722 and ABR-2000, etc) is a diagnostic device which applies pulse signals to predetermined bodily locations. We think that we can discriminate between Soeumin, Soyangin and Taeumin with this system. 2. Methods The subject of our study is no disease men and women who are decided the same constitution both survey of the QSCC II and diagnosis of specialist of the Sasang Constitution. All subject are 76(Soeumin(N=24), Soyangin(N=17), Taeumin(N=35)) cases. We make an analysis of a distinctive feature on the result of the VEGA-DFM722. 3. Results and Conclusions 1) Soeumin or Taeumin women had that the red bar graphs of and 1, 2 and 3 are lower than the red bar graphs of zone 4, 5, 6 and 7 in factor AA on the result of the VEGA-DFM722 with the naked eye. Soyangin or Taeumin men had that the red bar graphs of zone 1,2 and 3 are higher than the red bar graphs of tone 4, 5, 6 and 7 in factor AA on the result of the VEGA-DFM722 with the naked eye. 2) The typical discrimination between Soeumin and Soyangin showed statistical significance(p<0.05) in Factor PF 4(red bar) on the result of VEGA-DFM722.

• Journal of KIISE:Information Networking
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• v.31 no.3
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• pp.269-279
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• 2004

The most important factor influencing the robustness of the Internet Is the end-to-end TCP congestion control. However, the congestion control scheme of TCP Reno, the most popular TCP version on the Internet, employs passive congestion indication. It makes worse the network congestion. Recently, Brakmo and Peterson have proposed a new version of TCP, which is named TCP Vegas, with a fundamentally different congestion control scheme from that of the Reno. Many studies indicate that the Vegas is able to achieve better throughput and higher stability than the Reno. But there are two unfairness problems in Vegas. These problems hinder the spread of the Vegas in current Internet. In this paper, in order to solve these unfairness problems, we propose a new congestion control algorithm called TCP PowerVegas. The existing Vegas depends mainly only on the rtt(round trip time), but the proposed PowerVegas use the new congestion control scheme combined the Information on the rtt with the information on the packet loss. Therefore the PowerVegas performs the congestion control more competitively than the Vegas. Thus, the PowerVegas is able to solve effectively these unfairness problems which the Vegas has experienced. To evaluate the proposed approach, we compare the performance among PowerVegas, Reno and Vegas under same network environment. Using simulation, the PowerVegas is able to achieve better throughput and higher stability than the Reno and is shown to achieve much better fairness than the existing Vegas.

• Journal of Chest Surgery
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• v.26 no.11
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• pp.827-832
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• 1993

From Jan 1982 through Dec.1991, thirty-three DeVega`s tricuspid annuloplasties were performed in association with mitral and combined mitral and aortic valve disease. Preoperatively,all of the patients were in NYHA functional class III or IV.There were one early death and 4 patients died during follow up period of 18 to 138 months [ mean follow up : 67.3 months ]. Nine patients required reoperation because of biological mitral valve failure at 4.7 to 11 years after tricuspid annuloplasty[TAP]. Among these patients,2 cases needed for reoperation of TAP due to loosening of suture material. Twenty four [86%] of the survivors were in NYHA functional class I or II after TAP.The actuarial survival rate for the TAP was 74% at 138 months. Rt atrial pressure of 9 reoperation cases were significantly decreased [P<0.05] compared with initial Rt.atrial pressure [ Mean period; 93.6 months].Doppler echocardiographic studies for tricuspid regurgitation were performed in 15 cases after TAP [Mean period: 42.3 months].These results showed significantly reduced [P<0.01] tricuspid annulus diameter and tricuspid regurgitation distance [ P<0.05 ].Our surgical experience that the DeVega`s TAP is a simple,safe,effective procedure and resulted in good hemodynamic improvement with moderate to severe functional tricuspid regurgitation.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.211-213
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• 2002

TCP Vegas는 TCP Reno에 비해 효율성과 안전성 측면에서 보다 나은 성능을 보이고 있으나, 두 버전이 같이 사용되는 경우 충분한 성능을 발휘하지 못하여 공정성에 문제점을 드러내고 있다. 본 논문에서는 TCP Vegas의 알고리즘에서 사용하는 상수 요소인 $\alpha$, $\beta$ 값의 변화에 의해 TCP Reno 버전과의 공정성이 향상되는 사실을 시뮬레이션을 통해 확인하였으며, 이에 따른 향후 연구과제를 제시하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.11a
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• pp.149-152
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• 2000

This paper addresses the wavelet fuzzy modeling using Virus-Evolutionary Genetic Algorithm (VEGA). We build a fuzzy system model which is equivalent to the wavelet transform after identifying the coefficients of wavelet transform. We can obtain an accurate system model with a small number of coefficients due to the energy compaction property of the wavelet transform. It thus means that we can construct a fuzzy system model with a small number of rules. In order to identify the wide-ranged coefficients of the wavelet transform, VEGA is adopted, which has prominent ability to avoid premature local convergence that is suitable to complex optimization problems. We demonstrate the superiority of our proposed fuzzy system modeling method over the previous results by modeling nonlinear function.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.290-292
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• 2007

인터넷의 안정성에 가장 큰 영향을 미치는 요소는 종단간에 이루어지는 TCP 혼잡제어이다. 현재 TCP Vegas가 효율성과 안정성 측면에서 TCP Reno보다 우수함에도 불구하고, TCP Vegas와 TCP Reno를 혼용하여 사용하는 경우 충분한 성능을 발휘하지 못하는 경우와 또한 RTT가 서로 다른 TCP Vegas간에 존재하는 공정성 문제가 있다. 본 논문에서는 이러한 불공정성 문제에 대해 TCP Vegas의 알고리즘의 주요 파라미터인 $\alpha$, $\beta$, $\gamma$�璲だ� 변화에 따라 TCP Reno와의 공정성 향상과 RTT가 서로 다른 TCP Vegas끼리의 공정성 문제를 분석하였다.

• Journal of Acupuncture Research
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• v.23 no.3
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• pp.231-239
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• 2006

Functional medicine is a system which utilizes certain investigative and treatment methods that are primarily oriented toward the recognition of functional disorder. Functional disorders take place on an energetic plane. This plane is not capturable using our regular investigatory techniques, such as X -ray. ultrasound, computer tomography and laboratory analyses. The 7-zone-diagnostic system(VEGA-DFM 722 and ABR-2000, etc) is a diagnostic device Which applies pulse signals to predetermined bodily locations. Applying alternating positive and negative stress to tissues with positive and negative pulses first manifests itself as negative and positive wave forms. The skin has many functions as an organ. It is the organism's interlace with the outsider world. Hence, the manner in which the skin reacts to external stimuli reflects the current state of the organism(as meridian systems). This system make a diagnosis of functional disorder or some typical organic diseases include stress of the mind or the body, and the energetic situation, reserves. We are known a disorder or disease throw the result chart. This result chart contain disorder flow wave forms and some valuable diagnostic hints (letters ; S, OM, RA, etc). In spite of this 7-zone-diagnostic system that is applied plentifully in the clinical application, there is not a statistics which is suitable. Therefor we must carry out many various research in the future.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.5
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• pp.432-441
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• 2000

This paper deals with the fuzzy modeling for the complex and uncertain nonlinear systems, in which conventional and mathematical models may fail to give satisfactory results. Genetic algorithm has been used to identifY parameters and structure of fuzzy model because it has the ability to search optimal solution somewhat globally. The genetic algorithm, however, has a problem, which optimization process can be premature convergence in the case of lack of genetic divergence of population. Virus- evolutionary genetic algorithm(VEGA) could be a strategy against this local convergence. Therefore, we use VEGA for fuzzy modeling. In this method, local information is exchanged in population so that population can sustain genetic divergence. finally, to prove the theoretical hypothesis, we provide numerical examples to evaluate the feasibility and generality of fuzzy modeling using VEGA.