• Title/Summary/Keyword: Threshold Level

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The immediate effects of 830-nm low-level laser therapy on the myofascial trigger point of the upper trapezius muscle in visual display terminal workers: A randomized, double-blind, clinical trial

  • Lee, Jung-Hoon;Lee, Sun-Min
    • International Journal of Contents
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    • v.7 no.2
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    • pp.59-63
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    • 2011
  • The aim of our study was to evaluate the immediate effects of an 830-nm Aluminium gallium arsenide (GaAlAs) laser, by examining the changes, in pressure-pain threshold (PPT) and tenderness at 3 kg of the myofascial trigger point (MTrP) of the upper trapezius muscle in visual display terminal (VDT) workers in comparison with placebo treatment. Thirty VDT workers (13 males, 17 females) with complaints of upper trapezius muscle were recruited. All participants were given either active GaAlAs laser (830 nm wavelength, 450 mW, 9 J at point) or placebo GaAlAs laser, according to the double-blinded and placebo-controlled trial. Both active and placebo low-level laser therapy (LLLT) treatments showed no significant effect on PPT and tenderness at 3 kg. These results suggest that a higher dosage may be necessary to produce immediate effects when applying LLLT to the MTrP of relatively large muscles such as the upper trapezius muscle.

Minimum Duration Outage of a DS-CDMA Cellular System Due to Cell Traffic Intensity (Cell Traffic Untensity 에 따른 DS-CDMA 셀룰러 시스템의 최소기간 차단율)

  • Kim, Nam-Soo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.4
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    • pp.570-575
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    • 2001
  • The minimum duration outage probability of a cellular system is defined the probability that the received signal level is hold under minimum required threshold duration. This definition is more realistic compared to the outage probability which is the received signal strength level is below predefined threshold level. Especially, in a DS-CDMA cellular system the received signal-to-interference ratio is a function of cell traffic, while the former researches are only considered the minimum duration outage probability independent of the cell traffic. We noticed that the minimum outage probability is rapidly increases as cell traffic increase.

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An Adaptive Multimedia Synchronization Scheme for Media Stream Delivery in Multimedia Communication (멀티미디어 통신에서 미디어스트림 전송을 위한 적응형 멀티미디어 동기화 기법)

  • Lee, Gi-Sung
    • The KIPS Transactions:PartC
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    • v.9C no.6
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    • pp.953-960
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    • 2002
  • Rel-time application programs have constraints which need to be met between media-data. It is client-leading synchronization that is absorbing variable transmission delay time and that is synchronizing by feedback control and palyout control. It is the important factor for playback rate and QoS if the buffer level is normal or not. This paper, The method of maintenance buffer normal state transmits in multimedia server by appling feedback of filtering function. And synchronization method is processing adaptive playout time for smooth presentation without cut-off while media frame is skip. When audio frame which is master media is in upper threshold buffer level we decrease play out time gradually, low threshold buffer level increase it slowly.

Seafloor terrain detection from acoustic images utilizing the fast two-dimensional CMLD-CFAR

  • Wang, Jiaqi;Li, Haisen;Du, Weidong;Xing, Tianyao;Zhou, Tian
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.187-193
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    • 2021
  • In order to solve the problem of false terrains caused by environmental interferences and tunneling effect in the conventional multi-beam seafloor terrain detection, this paper proposed a seafloor topography detection method based on fast two-dimensional (2D) Censored Mean Level Detector-statistics Constant False Alarm Rate (CMLD-CFAR) method. The proposed method uses s cross-sliding window. The target occlusion phenomenon that occurs in multi-target environments can be eliminated by censoring some of the large cells of the reference cells, while the remaining reference cells are used to calculate the local threshold. The conventional 2D CMLD-CFAR methods need to estimate the background clutter power level for every pixel, thus increasing the computational burden significantly. In order to overcome this limitation, the proposed method uses a fast algorithm to select the Regions of Interest (ROI) based on a global threshold, while the rest pixels are distinguished as clutter directly. The proposed method is verified by experiments with real multi-beam data. The results show that the proposed method can effectively solve the problem of false terrain in a multi-beam terrain survey and achieve a high detection accuracy.

Determination of Significance Threshold for Detecting QTL in Pigs (돼지의 QTL 검색을 위한 유의적 임계수준(Threshold) 결정)

  • Lee, H.K.;Jeon, G.J.
    • Journal of Animal Science and Technology
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    • v.44 no.1
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    • pp.31-38
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    • 2002
  • Interval mapping using microsatellite markers was employed to detect quantitative trait loci (QTL) in the experimental cross between Berkshire and Yorkshire pigs. In order to derive critical values (CV) for test statistics for declaring significance of QTL, permutation test (PT) of Churchill and Doerge method(1994) and the analytical method(LK) of Lander and Kruglyak(1995) were used by each trait and chromosome. 525 $F_2$ progeny phenotypes of five traits(carcass weight, loin eye area, marbling score, cholesterol content, last back fat thickness) and genotypes of 125 markers covering the genome were used. Data were analyzed by line cross regression interval mapping with an F-test every by 1cM. PT CV were based on 10,000 permutations. CV at genome-wise test were 10.5 for LK and ranged from 8.1 to 8.3 for PT, depending on the trait. CV, differed substantially between methods, led to different numbers of quantitative trait loci (QTL) to be detected. PT results in the least stringent CV compared at the same % level.

Noise-Induced Hearing Disturbance of Textile Weavers by Individual Pure Tone Threshold Determination Test in Taegu City (대구시내(大邱市內) 일부(一部) 방직공장(紡織工場)의 기직공(機織工)에 대(對)한 개별청력검사(個別聽力檢査) 보고(報告))

  • Park, Hong-Chin
    • Journal of Preventive Medicine and Public Health
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    • v.7 no.1
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    • pp.177-183
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    • 1974
  • It is generally recognized that the environmental noise of the various working places thought to be the cause of hearing disturbance. This survey was carried out to evaluate the prevalence of noise-induced occupational bearing loss among the weavers of 39 textile industries in Taegu, Korea. For this survey, 432 male workers and 2,023 female workers were examined their hearing acuity by Individual pure tone threshold determination test(air conduction), from November, 1972, to January, 1973. Main findings were as follows : 1. The mean of noise intensity of the 54 weaving rooms was, in over all, $95.6{\pm}4.2dB\;(A),\;95.9{\pm}4.0dB\;(B)\;and\;96.2{\pm}3.9dB\;(C)$. 2. The mean hearing threshold levels by service years in the 4,000 Hz were intensively increased from 1st to 3rd year and slightly decreased. than that of 3rd year, from after 3rd to 5th year, after 5th year that increased slightly. 3. The mean hearing threshold levels by frequencies were highest in the 4,000 Hz(male: $25.0{\pm}11.3dB$, female: $22.0{\pm}10.2dB$) and followed by 6,000, 8,000 and 3,000 Hz. 4. The mean hearing threshold level of the 6,000 Hz (male: 17.0 dB. female: 17.9dB) was higher than that of 4,000Hz (male: 16.4 dB, female: 17.1dB) in tile 1st service year. 5. The mean hearing loss of examinees was $16.2{\pm}8.0dB$ in male and $15.4{\pm}7.8dB$ in female.

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A1lowing Anonymity in Fair Threshold Decryption (익명성을 제공하는 공평한 그룹 복호화 기법)

  • Kim, Jin-Il;Seo, Jung-Joo;Hong, Jeong-Dae;Park, Kun-Soo
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.6
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    • pp.348-353
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    • 2010
  • A threshold decryption scheme is a multi-party public key cryptosystem that allows any sufficiently large subset of participants to decrypt a ciphertext, but disallows the decryption otherwise. When performing a threshold decryption, a third party is often involved to guarantee fairness among the participants. To maintain the security of the protocol as high as possible, it is desirable to lower the level of trust and the amount of information given to the third party. In this paper, we present a threshold decryption scheme which allows the anonymity of the participants as well as the fairness by employing a semi-trusted third party (STTP) which follows the protocol properly with the exception that it keeps a record of all its intermediate computations. Our solution preserves the security and fairness of the previous scheme and reveals no information about the identities of the participants and the plaintext even though an attacker is allowed to access the storage of the STTP.

Threshold Crossing Rate, Phase Distribution and Group Properties of Nonlinear Random Waves of finite Bandwidth (유한한 Bandwidth를 갖는 비선형 불규칙 파열에서의 Threshold Crossing Rate, 위상분포와 파군특성)

  • Jo, Yong-Jun
    • Journal of Korea Water Resources Association
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    • v.30 no.3
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    • pp.225-233
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    • 1997
  • The nonlinear effects on the statistical properties of wave groups in terms of the average nomber of waves in a group and the mean number of waves in a high run is studied in this paper utilizing the complex envelope and total phase function, random variable transformation technique and perturbation method. It tures out that the phase distribution is modified significantly by nonlinearities and it show systematic excess of values near the mean phase and the corresponding symmetrical deficiency on both sides away from the mean. for the case of threshold crossing rate, it turns out that threshold crossing rate reaches its maxima just below the mean water level rather than zero and considerable amount of probability mass is shifted toward the larger values of water surface elevation as nonlinearity is getting profound. Furthermore, the mean waves in a high run associated with nonlinear wave are shown to have larger values than the linear counterpart. Similar trend can also be found in the average number of waves in a group.

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Threshold Condition for the Propagation of Short Fatigue Crack (炭素鋼 微小疲勞크랙 전파의 不限界條件)

  • 김민건
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.3
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    • pp.505-512
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    • 1988
  • Since the propagation of a short fatigue crack is directly related to the large crack which causes the fracture of bulk specimen, the detailed study on the propagation of the short crack is essential to prevent the fatigue fracture. However, a number of recent studies have demonstrated that the short crack can grow at a low applied stress level which are predicted from the threshold condition of large crack. In present study, the threshold condition for the propagation of short fatigue crack is examined with respect to the microstructure and cyclic loading history. Specimens employed in this study were decarburized eutectoid steels which have various decarburized ferrite volume fraction. Rotating bending fatigue test was carried out on these specimens with the special emphasis on the '||'&'||'quot;critical non-propagating crack length.'||'&'||'quot; It is found that the reduction of the endurance limit of their particular microstructures can be due to the increase of the length of critical non-propagating crack, and the quantitative relationship between the threshold stress .DELTA. .sigma. $_{th}$ and the critical non-propagating crack length Lc can be written as .DELTA. .sigma. $_{th}$, Lc=C where m, C is constant. Further experiments were carried out on the effect of pearlitic structure and cyclic loading history on the length of critical non-propagating crack. It is shown that the length of critical non-propagating crack is closely related to both pearlite interlamellar spacing and cyclic loading history.ory. cyclic loading history.

A Back-Pressure Algorithm for Lifetime Extension of the Wireless Sensor Networks with Multi-Level Energy Thresholds (센서네트워크 수명 연장을 위한 에너지 임계값 기반 다단계 Back-Pressure 알고리즘)

  • Jeong, Dae-In
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.12B
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    • pp.1083-1096
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    • 2008
  • This paper proposes an energy-aware path management scheme, so-called the TBP(Threshold based Back-Pressure) algorithm, which is designed for lifetime extension of the energy-constrained wireless sensor networks. With the goal of fair energy consumptions, we extensively utilize the available paths between the source and the sink nodes. The traffic distribution feature of the TBP algorithm operates in two scales; the local and the whole routing area. The threshold and the back-pressure signal are introduced for implementing those operations. It is noticeable that the TBP algorithm maintains the scalability by defining both the threshold and the back-pressure signal to have their meanings locally confined to one hop only. Throughout several experiments, we observe that the TBP algorithm enhances the network-wide energy distribution. which implies the extension of the network lifetime. Additionally, both the delay and the throughput outcomes show remarkable improvements. This shows that the energy-aware path control scheme holds the effects of the congestion control.