• Journal of Korean Neurosurgical Society
• /
• v.67 no.5
• /
• pp.568-577
• /
• 2024

Objective : Post-stroke shoulder pain (PSSP) is a common complication that limits the range of motion (ROM) of the shoulder, the patient's rehabilitation and in turn, affects the patients' quality of life (QoL). Several treatment modalities such as sling, positioning, strapping, functional electrical stimulation, and nerve block have been suggested in literatures, however none of the treatments had long-term effects for PSSP. In this study, the authors evaluated clinical efficacy of pulsed radiofrequency (PRF) neuromodulation on the suprascapular nerve for PSSP, and suggested it as a potential treatment with long-term effect. Methods : This retrospective case series was conducted at a single center, a private practice institution. From 2013 to 2021, 13 patients with PSSP underwent PRF neuromodulation of the suprascapular nerve. The primary outcome measure was the Visual analog scale (VAS) score. The secondary outcome measurements included the shoulder ROM, Disability assessment scale (DAS), modified Ashworth scale, modified Rankin scale (mRS), and EuroQol-5 dimension-3L questionnaire (EQ-5D-3L) scores. These parameters were evaluated before PRF modulation, immediately after PRF modulation, and every 3 months until the final follow-up visit. Results : Six men and seven women were enrolled, and all patients were followed-up for a minimum of 12 months. The mean VAS score was 7.07 points before PRF neuromodulation and 2.38 points immediately post-procedure. Shoulder ROM for abduction and flexion, DAS for pain, mRS, and EQ-5D-3L demonstrated marked improvement. No complications were reported. Conclusion : PRF neuromodulation of the suprascapular nerve is an effective modality in patients with PSSP, and has long-term effect of pain relief, improvement of QoL.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.3
• /
• pp.1336-1356
• /
• 2017

The spectrum scarcity crisis has resulted in a shortage of resources for many emerging wireless services, and research on dynamic spectrum management has been used to solve this problem. Game theory can allocate resources to users in an economic way through market competition. In this paper, we propose a bidding game-based spectrum allocation mechanism in cognitive radio network. In our framework, primary networks provide heterogeneous wireless service and different numbers of channels, while secondary users have diverse bandwidth demands for transmission. Considering the features of traffic and QoS demands, we design a weighted interference graph-based grouping algorithm to divide users into several groups and construct the non-interference user-set in the first step. In the second step, we propose the dynamic bidding game-based spectrum allocation strategy; we analyze both buyer's and seller's revenue and determine the best allocation strategy. We also prove that our mechanism can achieve balanced pricing schema in competition. Theoretical and simulation results show that our strategy provides a feasible solution to improve spectrum utilization, can maximize overall utility and guarantee users' individual rationality.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.4
• /
• pp.772-776
• /
• 2005

To support abruptly increasing data traffic in these days, network management is needed. And also to maintain the steady infra, there is MPLS need which can support traffic engineering. It's necessary that MPLS doesn't only manage network to support recently booming data traffic, but has capacity to support traffic engineering to keep static infrastructure. Traffic engineering, method that a large-scale user shifts traffic to the beforehand designated routes that pass through specific nodes on network, is operation that is mapping traffic flow to the physical network topology. In this paper, we supplement the defect of the traditional RSVP traffic engineering and to construct far more steady infra, we suggest the way of its development of ERSVP signaling protocol.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.105-108
• /
• 2005

To support abruptly increasing data traffic in these days. network management is needed. And also to maintain the steady infra, there is MPLS need which can support traffic engineering. It's necessary that MPLS doesn't only manage network to support recently booming data traffic, but has capacity to support traffic engineering to keep static infrastructure. Traffic engineering, method that a large-scale user shifts traffic to the beforehand designated routes that pass through specific nodes on network, is operation that is mapping traffic flow to the physical network topology. In this paper, we supplement the defect of the traditional RSVP traffic engineering and to construct far more steady infra, we suggest the way of its development of ERSVP signaling protocol.

• Journal of Digital Convergence
• /
• v.12 no.10
• /
• pp.317-327
• /
• 2014

To improve the efficiency of wireless channel, IEEE 802.11ac uses the DL MU-MIMO MAC scheme through which an AP transmits multiple frames to different mobile nodes simultaneously. IEEE 802.11ac DL MU-MIMO MAC needs a new step, called as TXOP sharing, between legacy IEEE 802.11n DL SU-MIMO's two operations, the obtaining an EDCA TXOP and the transmitting multiple frames for EDCA TXOP. In the TXOP sharing operation, both wireless channel destinations and frames transmitted for its TXOP period should are determined. So this paper deals with the TXOP sharing for improving IEEE 802.11ac MAC performance. However, the EDCA priority based method mentioned by IEEE 802.11ac standard document not fair among the buffers and the frames of buffers, and occurs in high_loss rate and high_delay about specific buffers. In this paper, we propose a new scheme of the TXOP sharing with sequencing p-AC, s-AC in similar properties, and all S-AC. This method provides a differentiated service without damage of EDCA characteristics.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.6
• /
• pp.1099-1104
• /
• 2020

In order to provide various types of application services based on the Internet, it is ideal to guarantee the quality of service(QoS) for each flow. However, realizing these ideas is not an easy task.. It is effective to classify multiple flows having the same or similar service quality requirements into same group, and to provide service quality for each group. The queue management mechanism in the router plays a very important role in order to efficiently transmit data and to support differentiated quality of service for each service. In order to efficiently support various multimedia services, an intelligent and adaptive queue management mechanism is required. This paper proposes an intelligent queue management mechanism based on deep reinforcement learning that decides whether to deliver packets for each group based on the traffic information of each flow group flowing in for a certain period of time and the current network state information.

• Journal of the Korea Society of Computer and Information
• /
• v.24 no.11
• /
• pp.11-19
• /
• 2019

Recently, hybrid CDN/P2P video streaming architecture is specially designed and deployed to achieve the scalability of P2P networks and the desired low delay and high throughput of CDNs. In this paper, we propose a cooperative video streaming and active node buffer management technique in hybrid CDN/P2P architecture. The key idea of this streaming strategy is to minimize network latency such as jitter and packet loss and to maximize the QoS(quality of service) by effectively and efficiently utilizing the information sharing of file location in CDN's proxy server which is an end node located close to a user and P2P network. Through simulation, we show that the proposed cooperative video streaming and active node buffer management technique based on CDN and P2P network improves the performance of realtime video streaming compared to previous methods.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2008.11a
• /
• pp.1332-1335
• /
• 2008

In order to various service types of real time and non-real time traffic with varying requirements are transmitted over the IEEE 802.16 standard is expected to provide quality of service(QoS) researchers have explored to provide a queue management scheme with differentiated loss guarantees for the future Internet. The sides of a packet drop rate, an each class to differential drop probability on achieving a low delay and high traffic intensity. Improved a queue management scheme to be enhanced to offer a drop probability is desired necessarily. This paper considers multiple random early detection with differential drop probability which is a slightly modified version of the Multiple-RED(Random Early Detection) model, to get the performance of the best suited, we analyzes its main control parameters (max_th, min_th, max_p) for achieving the proportional loss differentiation (PLD) model, and gives their setting guidance from the analytic approach. we propose Dynamic-multiple queue management scheme based on differential drop probability, called Dynamic-VQSDDP(Variable Queue State Differential Drop Probability)T, is proposed to overcome M-RED's shortcoming as well as supports static max_p parameter setting values for relative and each class proportional loss differentiation. M-RED is static according to the situation of the network traffic, Network environment is very dynamic situation. Therefore max_p parameter values needs to modify too to the constantly and dynamic. The verification of the guidance is shown with figuring out loss probability using a proposed algorithm under dynamic offered load and is also selection problem of optimal values of parameters for high traffic intensity and show that Dynamic-VQSDDP has the better performance in terms of packet drop rate. We also demonstrated using an ns-2 network simulation.

• The Magazine of the IEIE
• /
• v.25 no.6
• /
• pp.69-78
• /
• 1998

프레임 릴레이망을 백본으로 한 LAN과 LAN접속으로 형성되는 기업통신망이 현재 활발히 전개되면서 인터넷을 통한 광고, 전자거래가 중요한 서비스로 진행되고 있다. 국내의 프레임 릴레이 서비스 현황을 살펴보면 KT, 데이콤, 일부기업등에서 프레임 릴레이 교환기를 수입하여 주고객인 기업에 서비스를 제공하고 있다. 이들은 사용자 요구에 의해 주로 LAN과 LAN에 접속된 라우터 등의 종단 시스템간 PVC(영구가상회선: Permanant Virtual Circuit)접속을 통하여 다양한 서비스를 제공하면서 독자적인 기업통신체계를 구축하고 있는 실정이다. 이와같이 사용자 요구로 PVC등록시 프레임 릴레이망과 LAN을 연결하는 링크의 QoS(서비스 질: Quality of Service), 트래픽 파라메터는 수동적으로 설정된다. 현재 국내에서는 프레임 릴레이 교환기 개발은 전무하고 단지 그들을 수입하여 운용하는 수준이며 향후 ATM(비동기 전달모드: Asynchronous Transfer Mode)망의 중요 서비스 연동이 될 프레임 릴레이 기술은 심도있게 연구되고 있다. 향후 고속통신을 제공하는 백본망은 기존의 프레임 릴레이망과 ATM망이 공존할 추세이며 점진적으로 프레임 릴레이망은 사라질 것이다. 이때 ATM 망이 기존의 프레임 릴레이망을 백본으로 한 기업통신망 수용시 원할한 서비스 제공을 위해서는 프레임 릴레이망을 백본으로 채택한 기존의 기업통신망을 ATM망에서 수용시 야기되는 문제점의 제시와 이의 해결은 매우 중요하다고 생각된다. FR/ATM(Frame Relay/ATM)연동시 기업통신망 입장에서는 PVC뿐만 아니라 SVC(교환가상회선: Switched Virtual Circuit)호처리가 수용되어야 한다. 이와같이 PVC와 SVC 수용으로 기업통신망은 통신망의 구성 및 관리가 복잡, 다양해지며, 또 그 기업은 관련된 다양하고 수많은 고객과 접속될 수 있어야 한다. 이때 ATM망을 백본으로 한 공중망이 관련 기업의 사설 정보를 관리하도록 한다는 것은 그 서비스의 이용자에게 보안문제를 제기함은 물론 서비스 이용자가 자신의 망에서 동작하는 여러 서비스를 고객 스스로가 관리하는 것이 바람직하다. CNN(고객망관리 : Customer Network Management)은 이러한 고객에 의한 통신망, 공중망에 대한 부분적 관리 및 서비스에 대한 관리가 이루어 질수 있도록 수행하는 기능이다. 본 논문에서는 ATM망이나 프레임 릴레이망과 ATM 망이 공존시 기업통신망관점에서 야기되는 문제점의 제시와 이의 해결 방안을 살펴보았다. 우선 FR/ATM 연동에서 PVC설정뿐만 아니라 SVC 설정 방법의 연구, 이때 고려된 QoS,트래픽 처리과정을 살펴보았다. 또한 망관리 입장에서 기업통신망 관리자와 ATM망 관리자와의 온-라인 서비스를 제공하기 위해서는 변화된 통신망 차원서의 확장된 Managed Object(MO)를 근간으로한 체계적인 CNN-NMS(CNM-Network management System)연동을 살펴본후 결론에서는 추후 계속연구 및 조사 되어야 할 항목을 기업통신망 입장에서 서술하여 보았다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37B no.9
• /
• pp.849-858
• /
• 2012

We proposed a scheme to accurately detect elephant flows. Along the ever increasing traffic trend, certain flows occupy the network heavily in terms of time and network bandwidth. These flows are called elephant flows. Elephant flows raises complicated issues to manage for Internet traffics and services. One of the methods to identify elephant flows is the Landmark LRU cache scheme, which improved the previous method of Least Recently Used scheme. We proposed a cache update algorithm, to further improve the existing Landmark LRU. The proposed scheme improves the accuracy to detect elephant flow while maintaining efficiency of Landmark LRU. We verified our algorithm by simulating on Sangmyung University's wireless real network traces and evaluated the improvement.