• Title/Summary/Keyword: FDL

Search Result 21, Processing Time 0.028 seconds

A Study on the Loss Probability and Dimensioning of Multi-Stage Fiber Delay Line Buffer (다단 광 지연 버퍼의 손실률과 크기에 관한 연구)

  • 김홍경;이성창
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.40 no.10
    • /
    • pp.95-102
    • /
    • 2003
  • The buffering is a promising solution to resolve the contention problem in optical network. we study the packet loss probability and the dimensioning of optical buffer using a Fiber Delay Line for variable length packet. In this paper, we study the relation between the granularity and the loss of FDL buffer in Single-Stage FDL buffer and propose the Single-Bundle Multi-Stage FDL buffer. The Multi-Stage FDL buffer is too early yet to apply to the current backbone network, considering the current technology in view of costs. but we assume that the above restriction will be resolved in these days. The appropriate number of delay and pass line for a dimensioning is based on a amount of occupied time by packets. Once more another multi-stage FDL buffer is proposed, Split-Bundle multi-stage FDL buffer. The Split-Bundle ms-FDL buffer is more feasible for a FDL buffer structure, considering not only a size of switching matrix but also a bulk of switching element. its feasibility will be demonstrated from a loss probability.

The Tendinous Slip of the Flexor Digitorum Longus for the Great Toe: An Anatomic Variation (엄지발가락으로 가는 긴발가락굽힘근 힘줄: 해부학적 변이 연구)

  • Lee, Ju-Young;Hur, Mi-Sun
    • Anatomy & Biological Anthropology
    • /
    • v.30 no.2
    • /
    • pp.61-65
    • /
    • 2017
  • This report describes a variation of the tendinous slip of the flexor digitorum longus (FDL) for the great toe. In addition, compositions of the long flexor tendons for all five toes were examined. The tendons of the FDL in the foot were investigated in 66 specimens of embalmed Korean adult cadavers. The tendons of the flexor hallucis longus (FHL) and the FDL with the lumbrical muscles were cut at the calcaneus and the metatarsophalangeal joints and were removed en bloc specifically to observe the FDL and the FHL tendons of the great toe. The tendinous slip of the FDL for the great toe was found bilaterally in the foot of a 52-year-old male. Its prevalence was two of 66 specimens (3.0%). The tendinous slip of the FDL for the great toe passed forward the great toe, and it constituted the superficial portion of the long flexor tendon for the great toe. The tendon of the FHL passed forward to constitute the deep portion of the long flexor tendon for the great toe. Thus, both the tendinous slip of the FDL and the tendon of the FHL composed the long flexor tendon for the great toe. The tendinous slip of the FDL and the tendon of the FHL for the great toe were similar in thickness; thus, each tendinous slip of the FDL and the tendon of the FHL were approximately one-half of the long flexor tendon for the great toe in thickness. The present study demonstrated an anatomical variation of the interconnection between the FHL and the FDL tendons, which will be useful for various surgeries and biomechanical research.

Hop-by-Hop Priority Increasing Scheme for Improving End-to-end Throughput in Multi-Hop OBS Networks (다중 홉 광 버스트 교환망에서 종단간 수율 향상을 위한 홉 단위 우선 순위 증가 기법)

  • 김병철;조유제
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.40 no.10
    • /
    • pp.35-42
    • /
    • 2003
  • In this paper, we classified the wavelength reservation mechanisms of optical burst switching (OBS), and investigated the path length priority effect of the offset time/delayed reservation (OT/DR)-based scheme like the just-enough-time (JET) protocol. And, we showed that the fiber delay line (FDL)-based scheme can avoid the path length priority effect in multiple hop network environments. Also, we proposed a novel FDL/DR with hop-by-hop priority increasing (HPI) scheme which can improve the end-to-end throughput by increasing the priority of bursts hop-by-hop using the input FDLs at each node. The simulation results showed that the proposed FDL/DR with HPI scheme could avoid the path length priority effect and enhance the end-to-end throughput in multiple hop network environments.

Performance Enhancement for Vertical Handover in Heterogeneous Wireless Networks Using Freeze DeadLine (이기종 무선망 환경에서 Freeze DeadLine 기법을 통한 수직 핸드오버의 성능개선)

  • Jeong, Hyeon-Jin;Choi, Seung-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.39B no.8
    • /
    • pp.499-509
    • /
    • 2014
  • In this paper, we propose that a FDL(Freeze DeadLine) Algorithm to solve handover problems in heterogeneous wireless networks. Many previous studies concentrated on low level layer to solve handover problems. In this paper, however, we concentrate on high level handover problems such as network layer and transport layer. We analyze handover's problems of transport layer in Heterogeneous wireless network, propose the FLD algorithm for better performance than others studies. The Proposed method is analyzed by theoretical frames and we verify that the propose method using the NS-2(Network Simulation - 2).

Deduction of TWCs and Internal Wavelengths Needed for a Design of Asynchronous OPS System with Shared or Output FDL Buffer (공유형 혹은 아웃풋 광 지연 선로 버퍼를 갖는 비동기 광패킷 스위칭 시스템 설계를 위해 필요한 가변 파장 변환기 및 내부 파장 개수의 도출)

  • Lim, Huhnkuk
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.39B no.2
    • /
    • pp.86-94
    • /
    • 2014
  • Optical packet switching (OPS) is being considered as one of the switching technologies for a future optical internet. For contention resolution in an optical packet switching (OPS) system, the wavelength dimension is generally used in combination with a fiber delay line (FDL) buffer. In this article, we propose a method to reduce the number of tunable wavelength converters (TWCs) by sharing TWCs for a cost-effective design of an asynchronous OPS system with a shared or an output FDL buffer. Asynchronous and variable-length packets are considered in the OPS system design. To investigate the number of TWCs needed for the OPS system, an algorithm is proposed, which searches for an available TWC and an unused internal wavelength, as well as an outgoing channel. This algorithm is applied to an OPS system with a shared or an output FDL buffer. Also, the number of internal wavelengths (i.e., the conversion range of the TWC) needed for an asynchronous OPS system is presented for cost reduction of the OPS system.

Influence of the Knee Angles on the Electromyographic Activites and Fatigue of the Ankle Muscles in Healthy Subjects (무릎관절 각도가 발목 근육의 근전도 활동에 미치는 영향)

  • Yu, Gyeong-Seok;Kim, Taek-Yean
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
    • /
    • v.12 no.1
    • /
    • pp.16-26
    • /
    • 2006
  • The purpose of this study was to investigate the influence of the various knee angles and ground state on the muscular activities and fatigue of the ankle muscles by integrated electromyograms (iEMG) and median frequency of tibialis anterior (TA), peroneus longus (PL), flexor digitorum longus (FDL) and gastrocnemius (GC). Ten healthy male subjects were participated into stable and balance ball sessions at four angles of knee joint. The surface electromyograms (sEMG) were recorded from the TA, PL, FDL and GC on stable and balance ball with full weight bearing at four knee angles of $0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$. The time serial data of the surface electromyographic signals were transformed into integrated and frequency serial data by fast fourier transformation. On the stable ground, the iEMG signals of the TA, PL, FDL and GC were significantly higher at $45^{\circ}$ and $30^{\circ}$ of knee angles than $0^{\circ}$ and $15^{\circ}$ of knee flexion (p<0.05). On the balance ball, the iEMG of the TA, PL, FDL and GC were significantly higher at $45^{\circ}$ and $30^{\circ}$ of knee angles than $0^{\circ}$ and $15^{\circ}$ of knee flexion (p<0.05). The median frequency of the TA, PL, FDL and GC were significantly lower at $45^{\circ}$ and $30^{\circ}$ of knee angles than $0^{\circ}$ and $15^{\circ}$ of knee on the stable ground (p<0.05). On the balance ball, also the median frequency of the TA, PL, FDL and GC were significantly lower at $45^{\circ}$ and $30^{\circ}$ of knee angles than $0^{\circ}$ and $15^{\circ}$ of knee flexion (p<0.05). The iEMG of the TA, PL, FDL and GC were significantly higher on the balance ball at $0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ of knee angles compared with stable ground. The median frequency of the TA, PL, FDL and GC were significantly lower on the balance ball at $0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ of knee angles compared with stable ground. These results indicate that the ground conditions and angles of the knee joint involved to muscular activities and fatigue of ankles muscles, may performed at first on stable ground and then balance ball in order to $0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ of knee flexion.

  • PDF

Implementation of Network for AutomationUusing Fieldbus (필드버스를 이용한 자동화 네트워크의 구현)

  • 이석원;장석호;남부희
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1996.10b
    • /
    • pp.1420-1423
    • /
    • 1996
  • This paper presents the implementation of network for automation using fieldbus. The RS-485 and twisted pair are used in layer 1 and medium, respectively. We implement FDL(Fieldbus Datalink Layer) using C-language and use token-bus network. The network consists of polling system and token passing system. The amount of transmitted data frames is evaluated with various transmission speeds that affect the system stability.

  • PDF

Research on the Improvement of Convergence Characteristics of the Fast Decoupled Load Flow (고속분할법의 수렴특성 개선에 관한 연구)

  • Lee, In-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.25 no.5
    • /
    • pp.403-408
    • /
    • 2012
  • In this paper, we propose useful load flow algorithms called FEDL (fast enhanced decoupled load flow). The proposed load flow method can improve the convergence characteristics particularly when the P-Q coupling becomes significant and the power system operating states deviate from the conditions required for stable convergence of the FDL by reflecting in part the effects of the off-diagonal terms in the Jacobian. In our test with IEEE AEP-30 bus system and RTS-96 73-bus system, it converge even when the fast decoupled load flow (FDL) and its variations keeping load flow matrices constant experience convergence problems. Test results show promising performances of the proposed algorithms in their convergence characteristics both in number of iterations and overall convergence speeds.

Experimental Performance Evaluation of Profibus-FDL and Implementation of Profibus Master Board (Profibus Master FDL 보드 구현과 파라미터 변경에 따른 성능평가)

  • Park, Jong-Min;Hong, Seung-Ho
    • Proceedings of the KIEE Conference
    • /
    • 2002.11c
    • /
    • pp.434-438
    • /
    • 2002
  • Profibus is a open industrial communication system for a wide range of applications in manufacturing and process automation. In this study presented in this article, implementation of Profibus master board is implemented. Using an experimental model, this study investigates the relationship between network parameter in the Profibus data link layer and the network performance. Base on the results, this study suggests some factors that should be considered when a Profibus-based automation system is designed and implemented.

  • PDF