• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.491-494
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• 2001

IP 망에서 Qos(Quality of Service)를 보장하기 위하여 요구되는 것이 수락 제어이다. 기존의 수락 제어 메커니즘은 크게 RSVP(Resource Reservation Protocol) 시그널링 방법과 MBAC(Measurement Based Admission Control)로 분류된다. 첫번째 방법의 경우 코어 망에서 각 플로우마다 상태를 유지해야 하는 확장성 문제때문에 적용이 쉽지 않고, 두 번째 방법의 경우 긴 경로를 가진 플로우의 경우 짧은 경로를 가진 플로우에 비해 블록킹 확률이 높아지는 문제점이 있다. 본 논문에서는 IP 코어 망에서 사용자의 QoS 요구사항과 서로 다른 경로상의 플로우간 블록킹 확률의 공평성을 위한 TPED MBAC(Two-Phase Edge-to-Edge Distributed Measurement Based Admission Control) 메커니즘을 제안한다. 이 MBAC 메커니즘은 수락 제어를 Quantitative Provisioning 단계와 Qualitative Provisioning 단계로 나누어 수행하며 프로빙 패킷 전송을 위해 홉 카운터에 기반 한 WRR(Weighted Round-Robin) 스케쥴링을 적용함으로써 각 플로우간의 블록킹 확률의 공평성을 제어할 수 있는 메커니즘이다.

• Journal of KIISE:Information Networking
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• v.29 no.6
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• pp.595-612
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• 2002

One of the most important issues in guaranteeing the high degree of QoS on mobile computing is how to reduce hand-off drops caused by lack of available bandwidth in a new cell. Each cell can request bandwidth reservation to its adjacent cells for hand-off calls. This reserved bandwidth can be used only for hand-offs, not for new calls. It is also important to determine how much of bandwidth should be reserved for hand-off calls because reserving too much would increase the probability of a new call being blocked. Therefore, it is essential to develop a new mechanism to provide QoS guarantee on a mobile computing environment by reserving an appropriate amount of bandwidth and call admission control. In this paper. bandwidth reservation and call admission control mechanisms are proposed to guarantee a consistent QoS for multimedia traffics on a mobile computing environment. For an appropriate bandwidth reservation, we propose an adaptive bandwidth reservation mechanism based on an MPP and a 2-tier cell structure. The former is used to predict a next move of the client while the latter to apply our mechanism only to the client with a high hand-off probability. We also propose a call admission control that performs call admission test only on PNC(Predicted Next Cell) of a client and its current cell. In order to minimize a waste of bandwidth caused by an erroneous prediction of client's location, we utilize a common pool and QoS adaptation scheme. In order evaluate the performance of our call admission control mechanism, we measure the metrics such as the blocking probability of new calls, dropping probability of hand-off calls, and bandwidth utilization. The simulation results show that the performance of our mechanism is superior to that of the existing mechanisms such as NR-CAT2, FR-CAT2, and AR-CAT2.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.749-751
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• 1999

We acquired operating data in an existing steam turbine power plant using analog control system to investigate operation characteristics. We analyzed a load control logic to develop a digital turbine control system. The load control logic is constituted of load target, load reference, loading rate, load limit and admission mode transfer of valve. The result of this paper is utilized to implement a digital turbine control system.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.180-180
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• 1998

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.555-555
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.426-426
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• 2004

• Sleep Medicine and Psychophysiology
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• v.4 no.1
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• pp.77-88
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• 1997

The purpose of this study was to investigate the prevalence, primary causes, and management of insomnia newly admitted patients in a university hospital. Subjects consisted of 168 adult patients (95 men and 73 women, 88 medical and 94 surgical patients) newly admitted to Gyeongsang National University Hospital from September 7 through September 27, 1996. Sleep patterns of all subjects in the usual nights before admission(UN), the previous night to admission(PN), the night on admission(ON), and the 5th night after admission(5N) were investigated using the Korean version of the St. Mary's Hospital Sleep Questionaire. In addition, all insomnia patients and their doctors and nurses in charge were interviewed by psychiatric residents. Additionally, their medical records were reviewed. Prevalence of insomnia were 22.6% in the UN, 42.9% in PN, 51.8% in ON, and 43.5% in 5N. The prevalence of insomnia was significantly increased immediately before and after admission. There were no significant differences in the prevalence of insomnia by age and sex. The most ammon primary causes of insomnia were somatic symptoms and psychological factors in PN, somatic symptoms and noise in ON and 5n. Only 17 (10.1%) of insomnia patients took medicstions for insomnia control(analgesics in 15, hypnotics in 2). These results shorred that the prevalence of insomnia was significantly increased on hospitalization due to somatic symptoms, environmental factors, and psychological factors, but nearly none were adequately managed.

• Physical Therapy Korea
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• v.15 no.2
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• pp.1-10
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• 2008

This study compared the effect of therapeutic exercise with conservative treatment in women with chronic neck pain. Subjects were allocated to control, neck isometric exercise, and cervical stabilization exercise groups consisting of 29, 32, and 31 patients, respectively. The conservative treatment for the control group consisted of hot packs, ultrasound, interferential current therapy, and intermittent cervical traction. The neck isometric exercise group performed a neck isometric exercise and the cervical stabilization exercise group performed a cervical stabilization exercise. To compare the three groups, the levels of perceived pain, neck disability, and psychological depression were assessed on admission, at discharge, and one month after discharge. On admission and at discharge, the pain and neck disability scores did not differ significantly among the groups. However, one month after discharge, both the neck isometric and cervical stabilization exercise groups had significantly improved perceived pain levels as compared to control (p<.05). The improvement in the degree of neck disability was most significant in the cervical stabilization exercise group (p<.05). On comparing the changes in the variables at the three assessments for each group, there was a significant difference between the control and cervical stabilization exercise groups (p<.05). The findings indicate that therapeutic exercises, especially cervical stabilization exercises, are more effective for improving pain and neck disability than conservative treatment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1421-1425
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• 1999

A restoration scheme is presented when a failure occurs at nodes or links on the ATM network. Each node on the network contains the same topology information for resources on the network by Exchanging NSE(Network State Element) which has the network state information through RCC(Routing Control Channel). We also propose a new establishing algorithm that set up a new alternate path reflecting the state of the network changed dynamically at the source node. In the result of applying our scheme, the rates of restoration can be improved and the number of messages decreased so that fast recovering could be possible by reducing traffics on the network by lowering the rates of the call-setup failure at the stage of CAC(Connection Admission Control).

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.115-118
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• 2000

In order to control the flow of traffics in ATM networks and optimize the usage of network resources, an efficient control mechanism is necessary to cope with congestion and prevent the degradation of network performance caused by congestion. To effectively control traffic in UNI(User Network Interface) stage, we proposed algorithm of integrated model using on-line teaming neural network for CAC(Call Admission Control) and UPC(Usage Parameter Control). Simulation results will show that the proposed adaptive algorithm uses of network resources efficiently and satisfies QoS for the various kinds of traffics.