• Title/Summary/Keyword: Link capacity

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The Effect of Exhalation Breathing Exercise on Respiratory Synergist Muscle Activity and Pulmonary Functions in Patients with Forward Head Posture

  • Kang, Jeong-Il;Jeong, Dae-Keun
    • The Journal of Korean Physical Therapy
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    • v.28 no.2
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    • pp.149-154
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    • 2016
  • Purpose: The aim of this study is to suggest an intervention method for clinical use in the future by analyzing the effect of breathing exercise on activity of sternocleidomastoid muscle and scalenus anterior muscle, which are respiratory synergist muscles, and pulmonary functions in patients with forward head posture. Methods: Prior to the experiment, 12 patients (experimental group) performed feedback exhalation exercise along with conventional deep neck exercise, and 11 subjects (control group) performed feedback deep neck exercise along with conventional deep neck exercise. The intervention programs were performed for 40 minutes once a day (three times a week for four weeks). Results: Before intervention, %RMS was measured for surface electromyography (sEMG), and FVC, FEV1, and FEV1/FVC were measured using a spirometer. After four weeks, these items were re-measured under the same condition and analyzed. In within-group comparison of the experimental group, activity of sternocleidomastoid muscle and scalenus anterior muscle showed a significant decrease (p<0.05)(p<0.001), and forced vital capacity (FVC) showed a significant increase (p<0.05). In within-group comparison of the control group, activity of sternocleidomastoid muscle and scalenus anterior muscle showed a significant decrease (p<0.05), and in between-group comparison, there were significant differences in activity of sternocleidomastoid muscle and FVC (p<0.05). Conclusion: Long-term forward head posture restrains exercise performance of the neck and leads to exercise avoidance of the neck during daily activities, thus restraint factors might be created even while breathing. To cut off this link, a constant effort is required and diversified research on the correlation between neck functions and breathing should be conducted.

Efficient Stream Distributions Algorithm for Heterogeneous Multimedia Multicast (이질형 멀티미디어 멀티캐스트를 위한 효과적인 스트림 분배 알고리즘)

    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.6B
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    • pp.1098-1107
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    • 1999
  • In multimedia applications, a source usually generates multiple streams. By heterogeneous multimedia multicast, we mean a recipient can receive some of them, not necessarily all of them. A recipient bids for what it wants to receive and the source gains the same amount when a connection is established. The problem of distributing streams for heterogeneous multicast to maximize the source's gain, can be solved using a 0-1 integer programming, hewn as NP-complete. In this paper, we propose efficient stream distribution algorithms in two different types of multicast models. The first restricted model assumes that the capacity for a link in the multicast tree is grater than or equal to the capacities of its descendant links. In the second unrestricted model, we drop out the restriction in the restricted model. Proposed algorithms have better time and space complexities compared with any existing one. In addition, distributed implementations are straightforward, which is very useful for large networks.

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Performance Evaluation of a Survivable Ship Backbone Network Exploiting k-Shortest Disjoint Paths (k-최단 분리 경로 배정을 적용한 장애 복구형 선박 백본 네트워크의 성능 평가)

  • Tak, Sung-Woo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.4
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    • pp.701-712
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    • 2012
  • The concept of $k$-shortest disjoint paths is considered important because the establishment of primary and backup forwarding paths exploiting shorter distance and faster propagation time is a dominant consideration for the design of a survivable backbone network. Therefore, we need to evaluate how well the concept of $k$-shortest disjoint paths is exploited for the design of a survivable ship backbone network considering the international standard related to ship backbone networks, the IEC61162-410 standard specifying how to manage redundant message transmissions among ship devices. Performance evaluations are conducted in terms of following objective goals: link capacity, hop and distance of primary and backup paths, even distribution of traffic flows, restoration time of backup forwarding paths, and physical network topology connectivity.

QoS Analysis of 3GPP Service based on PBMN and DiffServ (PBNM과 DiffServ 적용한 3GPP 서비스의 QoS 해석)

  • Song, Bok-Sob;Kim, Jeong-Ho
    • The Journal of the Korea Contents Association
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    • v.11 no.12
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    • pp.570-577
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    • 2011
  • In this paper, Policy-based QoS in 3GPP service network management techniques are not applied to the DiffServ technology is applied to the first interpretation. The next PBNM and DiffServ associated technologies by applying QoS performance improvement is verified. In this case that PBNM and DiffServ technology is applied, the amount of voice traffic reduced about 1 msec while best-effort traffic occurs 75 percent of the output link capacity. Also, video traffic which is the same as data traffic showed a decreased $0\sim10^{-4}$ packet loss rate than the case that DiffServ technology is applied. We apply the appropriate policy PBNM and DiffServ QoS mechanisms of the existing set of policies is not affected, just by using the appropriate 3GPP Service QoS level to suit the network operation, management can do that was found. This analytical method based on the University of California at Berkeley through NS-2 DiffServ technology into existing systems and next-generation networks mandated PBNM and DiffServ technology is applied to performance evaluation for the case.

An Available Bandwidth Measurement Scheme for Efficient Streaming Service (효율적인 스트리밍 서비스를 위한 가용대역폭 측정 기법)

  • Lee, Hee-Sang;Lee, Sun-Hun;Chung, Kwang-Sue
    • Journal of KIISE:Information Networking
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    • v.34 no.2
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    • pp.100-109
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    • 2007
  • Streaming protocol with the Available Bandwidth measurement scheme has problems that are to measure a Available Bandwidth uncorrectly and slowly. In this basis, in order to overcome limitations of the previous streaming protocols, we propose the NABO that is a New Available Bandwidth measurement scheme used by OWD(One-Way Delay). Proposed NABO(New Available Bandwidth measurement based on OWD) measures the constant transmission delay occurred by bottleneck link capacity and the variable delay. Competing traffic contribute to the variable delay. Through the measurement of the constant transmission delay and the competing traffic, a NABO can measure the Available Bandwidth correctly and fast in network. The simulation result proves that the proposed NABO has a performance that satisfies both accuracy viewpoint and measurement speed viewpoint.

언어적 측면에서 고찰한 도서관의 커뮤니케이션에 관한 연구 -의미전달을 중심으로-

  • 손연옥
    • Journal of Korean Library and Information Science Society
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    • v.8
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    • pp.69-96
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    • 1981
  • We all know that we can not keep a proper social life without language. Yet language is so much a part of our environment that we hardly realize it is there. The purpose of this study is to provide an understanding of the linguistical aspect of communication process in order to carry out a successful human relations in the operation of libraries. Human development rests upon man's capacity to digest large quantities of knowledge and it is language which allows facts to be communicated, stored, and disseminated. An attempt was made in this study to illustrate the elementary meaning-of-words aspect of communication. In order to share the most commonly agreed meanings in interpersonal communication, a careful study of semantic noises is important. In a constant struggle to meet client needs, staff and administrators, librarian must understand communication dialogues, their messages and be able to read all level of meanings. In order to perform a successful function of the librarian, to act as a link-man or communicator and to cope with its ever growing information, it is suggested that the deep understanding of the following linguistical aspect of communication elements is essential. 1. Characteristics of Language: (1) Words have different meanings to different people. (2) Words vary in the degree of abstraction. (3) Language is incomplete by its nature. (4) Language reflects not only the personality of the individual but also the culture of man's society. 2. Noises in transmitting meanings: (1) Mechanical or Technical noises. (2) Semantic Noises (3) Noises caused by the psychological factors a. attention b. perception, sensation, cognition and perceptual field. 3. Linguistic Stratum Languages differ considerably in vocabulary by the physical and cultural environment setting as well as situation of individual living. There are seven different language stratum which reflects different region, sex, age, profession, special social stratum, academic and tabooed words.

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ATM Network Survivability Enhancement Scheme using Disjoint VP Groups (분리 VP 그룹을 이용한 ATM 망 생존도 향상 방안)

  • Lee, Gil-Heung;Choe, Yong-Hun;Park, Won-Seo;Lee, Jae-Yong;Lee, Sang-Bae
    • Journal of KIISE:Computer Systems and Theory
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    • v.26 no.8
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    • pp.949-956
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    • 1999
  • 이 논문에서는 ATM (Asynchronous Transfer Mode) 방식의 초고속망의 장애 발생 시 이용자 연결의 QoS (Quality of Service)를 고려하여 복구할 수 있게 하는 보호 망 설계 방안을 제시한다. 제시한 설계 방안에 기초한 비용과 복구 특성을 분석과 모의 실험을 통해 알아본다. 제안하는 망에서의 복구는 분리 VP 그룹 (Disjoint Virtual Path Group, DVPG) 을 사용하는 상태 독립적 (State- independent) 방식으로 복구된다. ATM 망의 운용 및 보호 VP 할당과 용량 배정 문제를 정의하고 이를 바탕으로 최소의 비용을 갖는 VP 망을 설계한다. 망의 고장 시 기존 노드간의 VP 연결은 미리 할당된 링크 또는 노드 분리 보호 VP 경로를 따라 간단한 복구 알고리즘에 의해 빠르게 복구된다. QoS의 고려는 추가 비용을 필요로 하지만 정확한 이용자 연결의 복구를 실현하며, 분리 VP 그룹의 적용은 비용을 상승시키지만, 빠른 복구와 복수의 고장에 대처할 수 있는 방안이 된다.Abstract A cost evaluation of protection scheme for VP-based ATM network is presented here and its related characteristics are evaluated. The proposed and evaluated scheme is a state-independent restoration scheme using a disjoint path group. For fast and simple restoration of failed connections, link disjoint or node disjoint VP groups (DVPG) were utilized in this paper. A VP assignment and capacity planning problem is formulated. When failure occurs, the failed working VPs are switched to the protection VPs of disjoint path groups with a simple restoration scheme. And, cost evaluation and restoration characteristics are presented. The consideration of multiple QoS (Quality of Service) levels and disjoint path group protection scheme require additional network cost but acquire fit and fast restoration.

A Transfer Rate-Based Congestion Control Algorithm for ABR Service in ATM Networks (ATM 망에서 ABR 서비스를 위한 전송률 기반 폭주 제어 알고리즘)

  • Cho, Sung-Goo;Cho, Sung-Hyun;Oh, Yoon-Tak;Park, Sung-Han
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.9
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    • pp.28-34
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    • 1998
  • In ATM networks CBR data traffic is sent in constant bit rate, and VBR data traffic in variable bit rate. Therefore unused bandwidth at network capacity may exist. To avoid waste of network resourcesm, ABR traffic utilizes the unused bandwidth to the utmost after CBR and VBR data traffic being first served. In this paper, a transfer rate-based congestion control algorithm is proposed for efficient ABR service in ATM networks. In the proposed algorithm the ATM switch first calculates bandwidth according to variable cell transfer rate in an ABR source. records this value in ER field in a RM cell, and then transmits a RM Cell to an ABR source. In this way the proposed algorithm dynamically allocates bandwidth to each ABR source, and the switch also can rapidly adapt to a change of a transfer rate of an source. The performance simulation of the proposed algorithm has batter performance in terms of source condition and link utilization.

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Legal Approach to the Concept of 'Sustainability' in Sustainable Development (지속적 개발의 '지속성' 개념에 관한 법학적 접근)

  • Seo, Won-Sang
    • Journal of Environmental Policy
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    • v.3 no.2
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    • pp.59-87
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    • 2004
  • In its Declaration of Principles, the United Nations Conference on Environment and Development recommends that, "to achieve sustainable development and a higher quality of life for all people, states should reduce and eliminate unsustainable patterns of production and consumption...." This notion of sustainability lies at the core of many "commons" problems, where the central issue is to enable "individuals to sustain long-term, productive use of natural resource systems". In other worlds, a common definition of "sustainability" captures the idea of aligning human consumption with the capacity of ecological systems to supply, over a long period of time, such natural resources as air, soil, or water on which production depends. The concept of sustainability raises all sorts of political, social, and economic questions about the distribution of environmental protection. For sustainable community development to be addressed, these questions must be raised. In order to convince different citizenry of the necessity of sustainability, these questions must also be answered. This is where questions of equity, justice, and fairness arise. Sustainability and equity require that we deal with nature as an undivided whole, with no part being unsustainable. Sustainability and social policy also requires that we deal with the human population as an undivided whole. We simply cannot move people around the planet to either perpetuate past practices of earth exploitation or to implement sustainable planning. Everyone must work with the people inhabiting sensitive ecological areas, especially areas of regeneration. In the sustainable global community, we are as strong as our weakest link, or our most toxic community. This is the undeniable driving force for the infusion of equity into the sustainable development debate.

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A Study on Delayed ACK Scheme for TCP Traffic in Ad-hoc Network (Ad-hoc 네트워크에서 지연 ACK를 이용한 TCP성능 향상에 관한 연구)

  • Park Kwang-Chae;Na Dong-Geon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.9
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    • pp.1654-1662
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    • 2006
  • An ad hoc network is multi-hop network composed of radio links. and the transmission quality of a radio link is more unstable than that of a wired circuit. Packet loss thus occurs frequently in an ad hoc network, and the consequent connection failure results in a severe deterioration of TCP performance. TCP performance also deteriorates because of the collision of data packets and ACK packets in the radio channel. In this paper we study to improve the performance of the Mobile Ad-hoc network by using Delayed ACK algorithm with our proposed ODA(Ordering-Delayed ACK) method. The proposed ODA algorithm increases the number of the data packets orderly at the receiver side which is going to be applied for the Mobile Ad-hoc network. We accomplished a computer simulation using NS-2. From the simulation results, we find the proposed ODA algorithm obviously enlarge the channel capacity and improve the network performance at the situation of multi-hop of ad-hoc network than the existing Delayed ACK algorithm.