• Title/Summary/Keyword: Timing recovery

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Fourth-Power-Law Timing Recovery for Minimum-Bandwidth Systems (최소대역폭 시스템을 위한 4승법 동기복구)

  • 박문태;김대영;강창구
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.15 no.6
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    • pp.485-493
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    • 1990
  • Timing recovery for recently proposed nonlinear minimum-bandwidth systems is of concern since most conventional methods fail for these systems. As a method to surmount this retiming difficulty, this paper proposes the fourth-power-law method. The feasibility of the proposed method for minimum-bandwidth systems is shown through a rigorous analysis. Furthermore, extensive computer simulations are used to determine the best configurational strategy for various filters around the fourth-power nonlinear process. It is found that no intermediate filtering is necessary in general and even the pre-filtering can be omitted for systems having symmetric power spectral densities.

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Research of Synchronization Schemes for Uplink Cable Modem System (상향 링크 케이블 모뎀 시스템을 위한 동기 방법)

  • Kim, Young-Je;Oh, Wang-Rok;Kim, Whan-Woo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.2
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    • pp.6-12
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    • 2008
  • In uplink cable modem link operated in time-division multiple access mode, it is crucial to employ a suitable preamble pattern enabling frame detection, coarse timing/carrier recovery. Preamble pattern based on the constant envelope zero autocorrelation sequence is proposed for the uplink cable modem compliant to the data over cable service interface specification. Frame detection, coarse/fine timing and carrier recovery algorithms suitable for the proposed preamble pattern are also proposed. We check up the performances using numerical results.

New M-ary Differential-Frequency Shift Keying Modulation Enhancing Acoustic Modem's Synchronization For Ubiquitous Communication (Ubiquitous 통신을 위한 Acoustic 모뎀의 동기부 성능을 개선하는 새로운 M진 상태천이 주파수 쉬프트 키잉 변조 기법)

  • Kim, En-Ki;Kim, Young-Ju;Lee, In-Sung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.1 s.343
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    • pp.25-32
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    • 2006
  • We propose a new M-ary state-transition FSK modulator technique for enhancing demodulator's symbol timing recovery which can be applied to acoustic MODEM. In the previous technique, the demodulator's symbol timing performance can degrade when the sequences of same symbols are transmitted. This proposed method, because the transmission symbol changes in every single symbol period, increases the synchronization performance dramatically and has a simple MODEM and frame structure. On the one hand, we improve modulation-derived synchronization(MDS) which is M-ary FSK's symbol timing recovery scheme, then analyze it. Finally the proposed method is analyzed from the viewpoint of frequency efficiency, which proves this method is appropriate for acoustic MODEM.

The Importance of Early Surgical Decompression for Acute Traumatic Spinal Cord Injury

  • Lee, Dong-Yeong;Park, Young-Jin;Song, Sang-Youn;Hwang, Sun-Chul;Kim, Kun-Tae;Kim, Dong-Hee
    • Clinics in Orthopedic Surgery
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    • v.10 no.4
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    • pp.448-454
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    • 2018
  • Background: Traumatic spinal cord injury (SCI) is a tragic event that has a major impact on individuals and society as well as the healthcare system. The purpose of this study was to investigate the strength of association between surgical treatment timing and neurological improvement. Methods: Fifty-six patients with neurological impairment due to traumatic SCI were included in this study. From January 2013 to June 2017, all their medical records were reviewed. Initially, to identify the factors affecting the recovery of neurological deficit after an acute SCI, we performed univariate logistic regression analyses for various variables. Then, we performed a multivariate logistic regression analysis for variables that showed a p-value of < 0.2 in the univariate analyses. The Hosmer-Lemeshow test was used to determine the goodness of fit for the multivariate logistic regression model. Results: In the univariate analysis on the strength of associations between various factors and neurological improvement, the following factors had a p-value of < 0.2: surgical timing (early, < 8 hours; late, 8-24 hours; p = 0.033), completeness of SCI (complete/incomplete; p = 0.033), and smoking (p = 0.095). In the multivariate analysis, only two variables were significant: surgical timing (odds ratio [OR], 0.128; p = 0.004) and completeness of SCI (OR, 9.611; p = 0.009). Conclusions: Early surgical decompression within 8 hours after traumatic SCI appeared to improve neurological recovery. Furthermore, incomplete SCI was more closely related to favorable neurological improvement than complete SCI. Therefore, we recommend early decompression as an effective treatment for traumatic SCI.

Performance Analysis of Error and Congestion Control Algorithm in Transport Layer Mobility Support Approach (트랜스포트 계층 이동성 지원 방안에서의 오류 및 혼잡제어 알고리즘 성능분석)

  • Jang, Moon-Jeong;Lee, Mee-Jeong
    • The KIPS Transactions:PartC
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    • v.12C no.5 s.101
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    • pp.733-740
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    • 2005
  • In this paper, we propose an approach to transport layer mobility support leveraging the SCTP extension dubbed dynamic address reconfiguration in IPv6 networks. Timing issues related to the end-to-end address management, and a novel error recovery mechanism associated with a handover are discussed. The proposed error recovery mechanism is analyzed and compared to that of the plain SCTP to show that it reduces the handover latency and error recovery time.

Design of Synchronization Algorithms for Burst QPSK Receiver (버스트 QPSK 수신기의 동기 알고리즘 설계)

  • 남옥우;김재형
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.7
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    • pp.1219-1225
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    • 2001
  • In this Paper we describe the design of synchronization algorithms for burst QPSK receiver, which are applicable to BWLL uplink. The demodulator consists of digital down converter, matched filter and synchronization circuits. For symbol timing recovery we ufo Gardner algorithm. And we use forth power method and decision directed method for carrier frequency recovery and phase recovery, respectively. For the sake of performance analysis, we compare simulation results with the board implemented by FPGA which is APEX20KE series chip for Alter. The performance results show it works quite well up to the condition that a frequency offset equal to 4.7% of symbol rate.

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Pre-sleep casein protein ingestion: new paradigm in post-exercise recovery nutrition

  • Kim, Jooyoung
    • Korean Journal of Exercise Nutrition
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    • v.24 no.2
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    • pp.6-10
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    • 2020
  • [Purpose] Milk is a commonly ingested post-exercise recovery protein source. Casein protein, found in milk, is characterized by its slow digestion and absorption. Recently, several studies have been conducted with a focus on how pre-sleep casein protein intake could affect post-exercise recovery but our knowledge of the subject remains limited. This review aimed at presenting and discussing how pre-sleep casein protein ingestion affects post-exercise recovery and the details of its potential effector mechanisms. [Methods] We systematically reviewed the topics of 1) casein nutritional characteristics, 2) pre-sleep casein protein effects on post-exercise recovery, and 3) potential effector mechanisms of pre-sleep casein protein on post-exercise recovery, based on the currently available published studies on pre-sleep casein protein ingestion. [Results] Studies have shown that pre-sleep casein protein ingestion (timing: 30 minutes before sleep, amount of casein protein ingested: 40-48 g) could help post-exercise recovery and positively affect acute protein metabolism and exercise performance. In addition, studies have suggested that repeated pre-sleep casein protein ingestion for post-exercise recovery over a long period might also result in chronic effects that optimize intramuscular physiological adaptation (muscle strength and muscle hypertrophy). The potential mechanisms of pre-sleep casein protein ingestion that contribute to these effects include the following: 1) significantly increasing plasma amino acid availability during sleep, thereby increasing protein synthesis, inhibiting protein breakdown, and achieving a positive protein balance; and 2) weakening exercise-induced muscle damage or inflammatory responses, causing reduced muscle soreness. Future studies should focus on completely elucidating these potential mechanisms. [Conclusion] In conclusion, post-exercise ingestion of at least 40 g of casein protein, approximately 30 minutes before sleep and after a bout of resistance exercise in the evening, might be an effective nutritional intervention to facilitate muscle recovery.

Review of Injection-Locked Oscillators

  • Choo, Min-Seong;Jeong, Deog-Kyoon
    • Journal of Semiconductor Engineering
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    • v.1 no.1
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    • pp.1-12
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    • 2020
  • Handling precise timing in high-speed transceivers has always been a primary design target to achieve better performance. Many different approaches have been tried, and one of those is utilizing the beneficial nature of injection locking. Though the phenomenon was not intended for building integrated circuits at first, its coupling effect between neighboring oscillators has been utilized deliberately. Consequently, the dynamics of the injection-locked oscillator (ILO) have been explored, starting from R. Adler. As many aspects of the ILO were revealed, further studies followed to utilize the technique in practice, suggesting alternatives to the conventional frequency syntheses, which tend to be complicated and expensive. In this review, the historical analysis techniques from R. Adler are studied for better comprehension with proper notation of the variables, resulting in numerical results. In addition, how the timing jitter or phase noise in the ILO is attenuated from noise sources is presented in contrast to the clock generators based on the phase-locked loop (PLL). Although the ILO is very promising with higher cost effectiveness and better noise immunity than other schemes, unless correctly controlled or tuned, the promises above might not be realized. In order to present the favorable conditions, several strategies have been explored in diverse applications like frequency multiplication, data recovery, frequency division, clock distribution, etc. This paper reviews those research results for clock multiplication and data recovery in detail with their advantages and disadvantages they are referring to. Through this review, the readers will hopefully grasp the overall insight of the ILO, as well as its practical issues, in order to incorporate it on silicon successfully.

Design of the Upstream Cable Modem for Symmetric Multimedia Services over HFC Networks (HFC망 기반 대칭형 멀티미디어 서비스를 위한 상향 채널 케이블 모뎀 설계)

  • Cho, Byung Hak
    • Journal of Broadcast Engineering
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    • v.10 no.3
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    • pp.401-412
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    • 2005
  • We propose and design the algorithms of symbol timing recovery, carrier recovery, and equalization for the receiver of S-DMT cable modem, which supports more channels and better symmetric mutimedia services over HFC network. We evaluate the performance of the concatenated entire receiving system of 16QAM, 64QAM in the mixed noise channel of AWGN, ISI and impulse. The result of evaluation shows those algorithms work correctly and designed S-DMT receiver has good performance. We also verify the designed system has excellent immunity against impulse noise channel of practical Cable TV networks by the result of simulation with the parameters of impulse internal $\varepsilon$ and noise power $\gamma^{k}$.

Influence of Kinesio Taping of Patient with Foot Drop following CVA (편마비 환자의 족하수에 운동성 테이핑 적용이 보행능력에 미치는 영향)

  • Jung, Sam-Hee;Kong, Se-Jin;Yoon, Jung-Gyu
    • Journal of Korean Physical Therapy Science
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    • v.7 no.2
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    • pp.607-613
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    • 2000
  • Objective: This study is designed to examine how an application of a kinesio taping to the foot drop of a hemiplegic patient affects the functional recovery of a gait. Method: The patient was a man with left hemiplegia of about 11 months' duration. a single subject design (ABAB design) was used to investigate the timing difference at a stance phase between an unaffected side and an affected side in the gait ability of the hemiplegic patient by using the kinesio taping. The study was divided into four phase: an initial base-line, an experimental, a second base-line, and second experimental phase. Result: The timing difference at a stance phase between an unaffected side and an affected side in the gait was decreased in the case of the affected side by following the result of applying the kinesio taping to a lower extremity. Conclusion: The kinesio taping applied to the foot drop of a hemiplegic patient affects the improvement of the gait ability.

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