• Title/Summary/Keyword: static/dynamic balancing

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Effect of Masticating Chewing Gum on the Balance of Stroke Patients

  • Gim, Mina;Choi, Junghyun
    • Journal of International Academy of Physical Therapy Research
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    • v.12 no.2
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    • pp.2370-2374
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    • 2021
  • Background: Masticating is an activity that is free from temporal or spatial constraints, with an advantage that it can be combined easily with other treatment methods. While several studies have reported a positive effect of the intervention of chewing using the jaw on postural stability, only a few studies were conducted on stroke patients. Objectives: To investigated the effects of masticating chewing gum on the static and dynamic balancing of stroke patients. Design: Randomized cross-over study design. Methods: Nineteen stroke patients were randomly assigned to the chewing group or control group. BT4 was used to measure the static and dynamic balancing abilities. Pre-test measurements were taken before mastication of chewing gum, and post-test measurements were taken after 2 days. The stroke patients in the chewing group were guided to sit on a chair and chew gum for 3 min, and their balancing abilities were simultaneously measured. The balancing abilities of the control group patients were measured while they sat at rest without masticating chewing gum. Results: The chewing group showed significant increases in the measures of static balance (i.e., C90 area, trace length, X mean, and Y mean). In the between-group comparison, the measures of static balance were significantly higher in the chewing group than in the control group. Conclusion: These findings suggest that masticating chewing gum enhanced the static balancing ability of stroke patients. Thus, gum chewing should be considered a viable clinical intervention to control posture in stroke patients.

Reaction Wheel Disturbance Reduction Method Using Disturbance Measurement Table

  • Cheon, Dong-Ik;Jang, Eun-Jeong;Oh, Hwa-Suk
    • Journal of Astronomy and Space Sciences
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    • v.28 no.4
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    • pp.311-317
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    • 2011
  • Momentum changing actuators like reaction wheels and control moment gyros are generally used for spacecraft attitude control. This type of actuators produces force and torque disturbances. These disturbances must be reduced since they degrade the quality of spacecraft attitude control. Major disturbances are mainly due to static and dynamic imbalances. This paper gives attention to the reduction of the static and dynamic imbalance. Force/torque measurement system is used to measure the disturbance of the test reaction wheel. An identification method for the location and magnitude of the imbalance is suggested, and the corrections of the imbalance are performed using balancing method. Through balancing, the static and dynamic imbalance is remarkably reduced.

A Packet Distribution Routing for Balancing Energy-Consumption in MANET (MANET의 에너지 분산 소모를 위한 패킷 분산 라우팅)

  • Jin, Dong-Xue;Choi, Yong-Jun;Park, Hee-Joo;Kim, Chong-Gun
    • The KIPS Transactions:PartC
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    • v.15C no.2
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    • pp.79-86
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    • 2008
  • MANET(Mobile Ad hoc Network) is a collection of two or more nodes equipped with wireless communications and constrained by the factor of energy limitation. The running out of energy on some nodes may bring down the performance of network seriously. For solving the problems above, this paper uses completely separated Node-Disjoint multipaths from a source to a destination as many as possible. And, based on average, minimum or variance of energy values on the each multipath, the packets are distributed on paths. Generally, collecting methods for energy information can be classified into two main categories, Static and Dynamic. As the different energy values collected, the packet distribution methods are classified into six criteria, Static-Average, Static-Minimum, Static-Variance, Dynamic-Average, Dynamic-Minimum and Dynamic-Variance respectively. The performance of the packet distribution methods and that of AODV are compared by NS2 simulation.

Load Balancing Policy in Clustered Web Server Using IP Filtering (IP 필터링 방식을 사용하는 클러스터드 웹서버의 부하 분산 정책)

  • 김재천;최상방
    • Proceedings of the IEEK Conference
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    • 2000.06c
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    • pp.105-108
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    • 2000
  • As Internet and WWW grow rapidly, the role of web servers is getting more important, and the number of users in a few popular site is also explosively increasing. Load balancing in clustered web server systems is important task to utilize whole system effectively, so dynamic load balancing is required to overcome the limit of static load balancing. In this paper, we propose two dynamic load balancing schemes, and analyzed load model and Performance improvement and also compare existing load balancing methods and IP filtering method. In case of load balancing with threshold, little extra traffic was required for better performance, but in case of load balancing with load weight, we found that the performance mainly depends on information exchange rate.

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Effects of Fall Experience on the Balancing Ability and Ankle Flexibility in Elderly People

  • Kim, Hong Rae;Go, Jun Hyeok;Shin, Hee Jun
    • Journal of International Academy of Physical Therapy Research
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    • v.9 no.1
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    • pp.1387-1392
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    • 2018
  • The purpose of this study was to investigate the effect of fall injuries on the balancing abilities and ankle flexibility. Fifteen of the voluntary participants had no experience of falling in the last two years (none falling group, NFG) and 15 others experienced at least one (falling group, FG). Static balance (sway length, sway area), dynamic balance (timed up and go (TUG), and functional to reach test (FRT) were measured in each group. In comparison of static balance, sway length was not significantly different between NFG and FG in both eyes open and eyes close, however the sway area of the FG was significantly wider than that of the NFG (p<.05). In dynamic balance comparisons, TUG of FG was significantly longer than that of NFG (p <.05), however FRT and STS were no significant difference between groups. Ankle flexibility was significantly higher in NFG than in FG. This study suggests that the fall prevention program should include methods for improving ankle stability and lower extremity function.

Bio-inspired Load Balancing Routing for Delay-Guaranteed Services in Ever-Changing Networks

  • Kim, Young-Min;Kim, Hak Suh;Jung, Boo-Geum;Park, Hea-Sook;Park, Hong-Shik
    • ETRI Journal
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    • v.35 no.3
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    • pp.414-424
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    • 2013
  • We consider a new load balancing routing for delay-guaranteed services in the network in which the traffic is dynamic and network topologies frequently change. For such an ever-changing network, we propose a new online load balancing routing called AntLBR, which exploits the ant colony optimization method. Generally, to achieve load balancing, researchers have tried to calculate the traffic split ratio by solving a complicated linear programming (LP) problem under the static network environment. In contrast, the proposed AntLBR does not make any attempt to solve this complicated LP problem. So as to achieve load balancing, AntLBR simply forwards incoming flows by referring to the amount of pheromone trails. Simulation results indicate that the AntLBR algorithm achieves a more load-balanced network under the changing network environment than techniques used in previous research while guaranteeing the requirements of delay-guaranteed services.

An Efficient Dynamic Load balancing Strategy for Tree-structured Computations (트리구조의 계산을 위한 효율적인 동적 부하분산 전략)

  • Hwang, In-Jae;Hong, Dong-Kweon
    • The KIPS Transactions:PartA
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    • v.8A no.4
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    • pp.455-460
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    • 2001
  • For some applications, the computational structure changes dynamically during the program execution. When this happens, static partitioning and allocation of tasks are not enough to achieve high performance in parallel computers. In this paper, we propose a dynamic load balancing algorithm efficiently distributes the computation with dynamically growing tree structure to processors. We present an implementation technique for the algorithm on mesh architectures, and analyze its complexity. We also demonstrate through experiments how our algorithm provides good quality solutions.

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A Dynamic QoS Adjustment Enabled and Load-balancing-aware Service Composition Method for Multiple Requests

  • Wu, Xiaozhu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.3
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    • pp.891-910
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    • 2021
  • Previous QoS-aware service composition methods mainly focus on how to generate composite service with the optimal QoS efficiently for a single request. However, in the real application scenarios, there are multiple service requests and multiple service providers. It is more important to compose services with suboptimal QoS and maintain the load balance between services. To solve this problem, in this paper, we propose a service composition method, named as dynamically change and balancing composition method (DCBC). It assumes that the QoS of service is not static, and the services can adjust the value of QoS to gain more opportunities to be selected for composition. The method mainly includes two steps, which are the preprocessing step and the service selection step. In the preprocessing step, a backward global best QoS calculation is performed which regarding the static and dynamic QoS respectively; then guided by the global QoS, the feasible services can be selected efficiently in the service selection step. The experiments show that the DCBC method can not only improve the overall quality of composite services but also guarantee the fulfill ratio of requests and the load balance of services.

A Dynamic Load Balancing Scheme based on Host Load Information in a Wireless Internet Proxy Server Cluster (무선 인터넷 프록시 서버 클러스터에서 호스트 부하 정보에 기반한 동적 부하 분산 방안)

  • Kwak Hu-Keun;Chung Kyu-Sik
    • Journal of KIISE:Information Networking
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    • v.33 no.3
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    • pp.231-246
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    • 2006
  • A server load balancer is used to accept and distribute client requests to one of servers in a wireless internet proxy server cluster. LVS(Linux Virtual Server), a software based server load balancer, can support several load balancing algorithms where client requests are distributed to servers in a round robin way, in a hashing-based way or in a way to assign first to the server with the least number of its concurrent connections to LVS. An improved load balancing algorithm to consider server performance was proposed where they check upper and lower limits of concurrent connection numbers to be allowed within each maximum server performance in advance and apply the static limits to load balancing. However, they do not apply run-time server load information dynamically to load balancing. In this paper, we propose a dynamic load balancing scheme where the load balancer keeps each server CPU load information at run time and assigns a new client request first to the server with the lowest load. Using a cluster consisting of 16 PCs, we performed experiments with static content(image and HTML). Compared to the existing schemes, experimental results show performance improvement in the cases of client requests requiring CPU-intensive processing and a cluster consisting of servers with difference performance.

A Study on the Effect of Trunk Stabilization Program on Body Balance, Lung Capacity, Muscular Activity of Healthy Adults (체간 안정화운동이 정상성인의 균형, 폐활량, 근활성도에 미치는 영향)

  • Nam, Hyoungchun;Jo, Yoonjin;Kang, Byeongjoo;Kim, Seulbi;An, Wookjoo;Lee, Hwajoo;Jeong, Sujin
    • Journal of The Korean Society of Integrative Medicine
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    • v.3 no.4
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    • pp.43-51
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    • 2015
  • Purpose : This study examines the effect of trunk stabilization program on the body balance, lung capacity, and muscular activity of the rectus abdominis and external oblique of healthy adults. Method : A survey was conducted for 20 students of K University located in the city of Y in Gyeongsangbuk-do Province of Korea. The trunk stabilization program consisted of a hollowing exercise, curl-up, bridging exercise, and birddog exercise. This was performed 14 times in total (7 times a week for two weeks). For analysis, good balance was used to measure both static and dynamic balancing ability. A peak flow meter was used to measure the maximum expiratory flow, and MP150 was used to measure muscular activity of the rectus abdominis and external oblique. Result : After the trunk stabilization program, the participants showed a difference in score and time taken to achieve static and dynamic balance, and muscular activity of the rectus abdominis and external oblique at a statistically significant level (p<0.05). However, no significant difference was observed in the left-to-right distance and front-to-back distance in a dynamic balance, and the lung capacity (p>0.05). Conclusion : The results showed that the trunk stabilization program was effective in enhancing both static and dynamic balancing ability and muscular activity. It also increased the lung capacity although the change was not at a statistically significant level.