• Title/Summary/Keyword: wave duration

Search Result 269, Processing Time 0.026 seconds

Search for broadband extended gravitational-wave emission bursts in LIGO S6 in 350-2000 Hz by GPU acceleration

  • van Putten, Maurice H.P.M.
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.42 no.1
    • /
    • pp.37.3-37.3
    • /
    • 2017
  • We present a novel GPU accelerated search algorithm for broadband extended gravitational-wave emission (BEGE) with better than real-time analyis of H1-L1 LIGO S6 data. It performs matched filtering with over 8 million one-second duration chirps. Parseval's Theorem is used to predict the standard deviation ${\sigma}$ of filter output, taking advantage of near-Gaussian LIGO (H1,L1)-data in the high frequency range of 350-2000 Hz. A multiple of ${\sigma}$ serves as a threshold to filter output back to the central processing unit. This algorithm attains 80% efficiency, normalized to the Fast Fourier Transform (FFT). We apply it to a blind, all-sky search for BEGE in LIGO data, such as may be produced by long gamma-ray bursts and superluminous supernovae. We report on mysterious features, that are excluded by exact simultaneous occurrance. Our results are consistent with no events within a radius of about 20 Mpc.

  • PDF

The Diagnosis and Treatment of Plantar Fasciitis (족저 근막염의 진단과 치료)

  • Eun, Il-Soo
    • Journal of Korean Foot and Ankle Society
    • /
    • v.20 no.3
    • /
    • pp.93-99
    • /
    • 2016
  • Plantar fasciitis is the most common cause of heel pain. The diagnosis of plantar fasciitis is primarily based on the presentation of symptoms and physical examination. Patients usually complain of heel pain at the medial calcaneal tubercle when taking their first step in the morning or when walking after resting. Diagnostic imaging is rarely required for the initial diagnosis of plantar fasciitis; however, it can be used for differential diagnosis. Conservative treatments, such as stretching, rest, ice massage, oral analgesics, foot orthotics, use of night splint, and corticosteroid injection, may be effective. The majority of patients report improvement with conservative treatments, and those who show no response from conservative treatments for a duration of six months or longer can consider extracorporeal shock wave therapy or surgery.

Sleep and Pain (수면과 통증)

  • Lee, Jin-Seong;Jeong, Do-Un
    • Sleep Medicine and Psychophysiology
    • /
    • v.19 no.2
    • /
    • pp.63-67
    • /
    • 2012
  • The reciprocal interaction between sleep and pain has been reported by numerous studies. Patients with acute or chronic pain often complain of difficulty falling asleep, frequent awakenings, shorter sleep duration, unrefreshing sleep, and poor sleep quality in general. According to the majority of the experimental human studies, sleep deprivation may produce hyperalgesic changes. The selective disruption of slow wave sleep has shown this effect more consistently, while results after selective REM sleep deprivation remain unclear. Patients with chronic pain have a marked alteration of sleep structure and continuity, such as frequent sleep-stage shifts, increased nocturnal awakenings, decreased slow wave sleep (SWS), decreased rapid eye movement (REM) sleep, and alpha-delta sleep. Many analgesic medications can alter sleep architecture in a manner similar to the effects of acute and chronic pain, suppressing SWS and REM sleep.

Effects of RF pulsing and axial magnetic field onionized magnetron sputtering

  • Joo. Junghoon
    • Journal of Korean Vacuum Science & Technology
    • /
    • v.2 no.2
    • /
    • pp.133-138
    • /
    • 1998
  • To enhance the ionization level of I-PVD and reduce the coil voltage two approaches were tried and as a diagnostic, optical emission spectroscopy and impedance analysis of the plasma was done with a range of Ar pressures and RF power along with XRD analysis of deposited Ag films. RF sputtering power was pulsed with various on/off time scales to recover the ICP quenched by sputtered metals. This in average enhances the ionization of the sputtered atoms with 10 ms/10 ms and 100 ms/100ms pulse on/off time duration and gives higher (200) preferred orientation over (111) in deposited Ag films. Secondly, Small axial B field about 8G remarkably reduced RF coil sputtering and showed scaled relationship between RF power and magnetic field strength for optimal process condition. From OES of Ar0 and Ar+, wave-like dispersion structure appeared and reduced the coil voltage about 20% at very weak field strength of 8G. This should be studied further to have nay relation with low mode helicon wave launching.

  • PDF

Critical Free Surface Flows in a Sloshing Tank

  • Scolan, Y.M
    • Journal of Advanced Research in Ocean Engineering
    • /
    • v.4 no.4
    • /
    • pp.163-173
    • /
    • 2018
  • There are many issues in fluid structure interactions when dealing with the free surface flows in a sloshing tank. For example the problem of how yielding a highly nonlinear wave with a simple forced motion over a short duration is of concern here. Nonlinear waves are generated in a rectangular tank which is forced horizontally; its motion consists of a single cycle of oscillation. One of the objectives is to end up with a shape of the free surface yielding a wide range of critical flows by tuning few parameters. The configuration that is studied here concerns a plunging breaker accompanied with a critical jet where great kinematics are simulated. The numerical simulations are performed with a twodimensional code which solves the fully nonlinear free surface boundary conditions in Potential Theory.

The Effects of Pain and Range of Motion by Continuous Wave Ultrasound and Pulsed Wave Ultrasound on Patient with Temporomandibular Joint Disability (측두하악관절장애 환자에서 연속초음파와 맥동초음파 적용이 통증과 관절가동범위에 미치는 효과)

  • Moon, Hyun-Ju;Seo, Hyun-Kyu;Gong, Won-Tae
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
    • /
    • v.13 no.2
    • /
    • pp.1-11
    • /
    • 2007
  • Purpose: The purpose of this study was to determine the effect of continuous wave ultrasound and pulsed wave ultrasound that influence changes in pain and range of motion when applied to patients with temporomandibular joint disability. Methods: The subjects of the study were 40 selected patients who had been diagnosed with temporomandibular joint movement restriction and had endured pain for more than two weeks. These patients had visited K orthopedic surgery in Deagu measured from October 1, 2004 to March 31, 2005. The subjects were divided into two groups with 20 patients each. The one group was applied to continuous wave ultrasound and the other group was applied to pulsed wave ultrasound at a dosage of 1.5 W/$cm^2$ for a duration of 5 minutes and eight times for two weeks. The pain perception degree were measured by using Visual Analogue Scale(VAS) and the range of motion was measured by using a rule for each group. Results: The results obtained were as follows The change in the pain perception degree were statistically significant in both group(p<0.05) ; however, the continuous wave ultrasound group showed more difference in the average decrease in the pain perception degree than did the pulsed wave ultrasound group. Both groups showed significant results regarding changed in the range of motion(p<0.05) ; Comparing the difference in the average of the range of motion between the two groups, came back from normal the range of motion of temporomandibular joint at the both groups. Conclusion : Based on the results of this study, we found that both groups showed decreased pain and increased the range of motion, but the continuous wave ultrasound method had a higher therapy effect pain and the range of motion than the pulsed wave ultrasound method to patients with temporomandibular joint disability. With such finding, we expect that according to ultrasound therapy applicant method can be helped usable accurately to patients with variety symptoms temporomandibular joint disability.

  • PDF

Numerical Analysis of Synchronous Edge Wave Known as the Driving Mechanism of Beach Cusp (Beach Cusp 생성기작으로 기능하는 Synchronous Edge Wave 수치해석)

  • Lee, Hyung Jae;Cho, Yong Jun
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.31 no.6
    • /
    • pp.409-422
    • /
    • 2019
  • In this study, we carried out the 3D numerical simulation to investigate the hydraulic characteristics of Synchronous Edge wave known as the driving mechanism of beach cusp using the Tool Box called the ihFoam that has its roots on the OpenFoam. As a wave driver, RANS (Reynolds Averaged Navier-Stokes equation) and mass conservation equation are used. In doing so, we materialized short-crested waves known as the prerequisite for the formation of Synchronous Edge waves by generating two obliquely colliding Cnoidal waves. Numerical results show that as can be expected, flow velocity along the cross section where waves are focused are simulated to be much faster than the one along the cross section where waves are diverged. It is also shown that along the cross section where waves are focused, up-rush is moving much faster than its associated back-wash, but a duration period of up-rush is shortened, which complies the typical characteristics of nonlinear waves. On the other hand, due to the water-merging effect triggered by the redirected flow toward wave-diverging area at the pinacle of run-up, along the cross section where waves are diverged, offshore-ward velocity is larger than shore-ward velocity at the vicinity of shore-line, while at the very middle of shoaling process, the asymmetry of flow velocity leaned toward the shore is noticeably weakened. Considering that these flow characteristics can be found without exception in Synchronous Edge waves, the numerical simulation can be regarded to be successfully implemented. In doing so, new insight about how the boundary layer streaming occur are also developed.

Short-duration Electron Precipitation Studied by Test Particle Simulation

  • Lee, Jaejin;Kim, Kyung-Chan;Lee, Jong-Gil
    • Journal of Astronomy and Space Sciences
    • /
    • v.32 no.4
    • /
    • pp.317-325
    • /
    • 2015
  • Energy spectra of electron microbursts from 170 keV to 340 keV have been measured by the solid-state detectors aboard the low-altitude (680 km) polar-orbiting Korean STSAT-1 (Science and Technology SATellite). These measurements have revealed two important characteristics unique to the microbursts: (1) They are produced by a fast-loss cone-filling process in which the interaction time for pitch-angle scattering is less than 50 ms and (2) The e-folding energy of the perpendicular component is larger than that of the parallel component, and the loss cone is not completely filled by electrons. To understand how wave-particle interactions could generate microbursts, we performed a test particle simulation and investigated how the waves scattered electron pitch angles within the timescale required for microburst precipitation. The application of rising-frequency whistler-mode waves to electrons of different energies moving in a dipole magnetic field showed that chorus magnetic wave fields, rather than electric fields, were the main cause of microburst events, which implied that microbursts could be produced by a quasi-adiabatic process. In addition, the simulation results showed that high-energy electrons could resonate with chorus waves at high magnetic latitudes where the loss cone was larger, which might explain the decreased e-folding energy of precipitated microbursts compared to that of trapped electrons.

Partial Discharge Detection for the Power Cables using AC and Oscillating wave Voltage (전력케이블에서 교류전압과 진동파 전압을 이용한 부분방전 측정)

  • Kim, Jeong-Tae;Kim, Nam-Jun;Lee, Jeon-Seon;Gu, Ja-Yun
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.48 no.4
    • /
    • pp.247-252
    • /
    • 1999
  • In this paper, in order to investigate availability of the OW-PD measurement method which has been proposed as an alternative of AC-PD measurement method to an after laying test and/or diagnosis for the power cable system, partial discharges owing to the needle-type defect integrated into the cable have been measured using AC and OW(Oscillating Wave) voltages. In the AC-PD measurement, the magnitude, phase and pulse number of partial discharges have been changed with the duration of voltage application, which can be analyzed through the relation with the process of the electrical tree initiation and propagation. In addition, the characteristics of partial discharges using OW voltage are appeared to be similar to those in case of AC-PD measurement and to be different with the shapes of electrical tree. From these results, it is concluded that the OW-PD measurement method is available to the tests for the cable system.

  • PDF

Electron Microburst Energy Dispersion Calculated by Test Particle Simulation

  • Lee, Jae-Jin;Kim, Yeon-Han;Park, Young-Deuk
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.36 no.2
    • /
    • pp.94.2-94.2
    • /
    • 2011
  • Electron microbursts, energetic electron precipitation having duration less than 1 sec, have been thought to be generated by chorus wave and electron interactions. While the coincidence of chorus and microburst occurrence supports the wave-particle interaction theory, more crucial evidences have not been observed to explain the origin of microbursts. We propose the measurement of energy dispersion of microbursts could be an evidence supporting wave-particle theory. During chorus waves propagate along magnetic field, the resonance condition should be satisfied at different magnetic latitude for different energy electrons. If we observed electron microbursts at low altitude, the arrival time of different energy electrons should make unique dispersion structures. In order to observe such energy dispersion, we need a detector having fast time resolution and wide energy range. Our study is motivated from defining the time resolution and energy range of the detectors required to measure microburst energy dispersions. We performed test particles simulation to investigate how electrons interact with simple coherent waves like chorus waves. We compute a large number of electron's trajectories and successfully produce energy dispersion structures expected when microbursts are observed with 10 msec time resolution detectors at the altitude of 600 km. These results provide useful information in designing electron detectors for the future mission.

  • PDF