• Title/Summary/Keyword: continuous wave

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A Study on Predominant Periods and Attenuation Characteristics of Ground Motion (지반 탁월주기와 지반 운동특성에 관한 연구)

  • Kim, So-Gu;Cha, Jeong-Sik;Jeong, Hyeong-Sik
    • Geotechnical Engineering
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    • v.11 no.2
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    • pp.139-156
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    • 1995
  • A set of field investigations was performed to estimate accurately the predominant periods of seismic 8round motions and the attenuation characteristics of the seismic ground vibration. Predominant periods of ground motions were estimated from the measurement of the continuous microseismic vibratins of certain periods, inherent in the ground and in the buildings, utilizing the high sensitivity digital velocity seismometer consisting of 3-component geophones and a digital seismograph. Estimated predominant periods of microseismic vibraion of the ground(measured on'the ground surface) and the building (measured on the second floor) were in the range of 0.18~0.235 sec. and 0.26~0.31 sec. respectively. The subsurface structure of the site ground was surveyed by the seismic refraction method utilizing the digital seismicwave probing system. The ground structure was found to be a two-layered system : an upper top soil layer of 7m in thickness with the P-wave velocity of 662m1sec and a lower layer of silty-clayey soils with the P -wave velocity of 2210m1 sec. The attenuation characteristics of the seismic ground vibrations were determined by the amplitude decay measurement method us;ng the Seisgun, which produces strong artificial seismic energy. Measured spatial attenuation coefficients of the ground vibration in vertical(Z) longitudinal(X), transverse(Y) direction were 0.1137, 0.0025, and 0.0290 respectively. Estimated Spartial QP's (inverse of the specific dissipation constant w.r.t. shear waved of X, Y, and Z directions were in the range of 5.913~7.575, 32.371~41.452, 2.794~3.579 re spectively. This indicates that aseimic design of the structures on the site should take stronger consideration regarding the earthquake resistance characteristics of the structures against longitudinal ground motion.

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Characteristics of Erosion Variation at Haeundae Beach due to Multiple Typhoons (복수의 태풍내습에 의한 해운대 해수욕장 침식변화특성)

  • Kang, Tae-Soon;Lee, Jong-Sup;Kim, Jong-Beom;Kim, Jong-Kyu
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.7
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    • pp.920-926
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    • 2019
  • In this study, we analyzed the erosion variation of beach area at Haeundae Beach after coastal improvement project using video monitoring system operated by the Coastal Erosion Monitoring (Ministry of Oceans and Fisheries). Haeundae Beach was well maintained and stabilized following large scale nourishment through coastal improvement project despite of seasonal fluctuations. However, multiple typhoons over the last two years caused beach stabilization patterns and seasonal fluctuations to lost equilibrium, resulting in rapid erosion. In particular, the sandy beach was eroded by typhoon Solic and Kongray in 2018 and failed to recover beach area in winter by seasonal fluctuations. And due to multiple typhoons in 2019, the beach area was reduced 9.5 % (12,607 ㎡) year-on-year. According to analyze the observed wave and beach area data in Haeundae, the tendency of erosion and sedimentation was influenced by seasonal incident wave direction for each section(west, center and east part). Therefore, to identify the causes of decreasing seasonal fluctuation characteristics and continuous erosion, hereafter, more precise monitoring of different factors are needed, such as the crest heights of submerged breakwater and its loss of function, and sand leakage to the outside around submerged breakwater.

Effects of combined exercise on the blood inflammatory factors, DHEA-s and arterial stiffness of elderly women (복합운동이 고령여성의 혈중 염증인자, DHEA-s 및 동맥경직도에 미치는 영향)

  • Ha, Soo-Min;Kim, Jung-Sook;Kim, Ji-Hyeon;Kim, Do-Yeon
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1096-1107
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    • 2018
  • The purpose of this study was to investigate the effects of combined exercise on blood inflammatory factors, DHEA-s and arterial stiffness in elderly women. The subjects were 42 elderly females volunteers, aged 70 to 85 years, composed of the combined exercise group (n=21) and control group (n=21). The 60 minute combined exercise program(aquarobics 1 time/week, strength exercise 2 times/week) was performed 3 times per week for 12 weeks, and the intensity was progressively increased every 4 weeks(1-4 weeks: RPE 12 to 13, 5-8 weeks: RPE 13 to 14, 9-12weeks: RPE 14 to 15). The test data were analyzed by two-way repeated measures ANOVA, paired t-test, independent t-test and the alpha level of .05 was set for all tests of significance. As a result, the combined exercise for 12 weeks reduced the inflammatory response of elderly women, and DHEA-s was found to have a positive effect on aging hormone. The arterial stiffness decreased the central arterial blood pressure (systolic and diastolic), prevented the increase of the pulse pressure and the wave increase index, and decreased the pulse wave velocity. These results suggest that regular and continuous combined exercise may be recommended for the healthy aging and longevity of elderly women by inducing anti-inflammation effect and improving the aging hormonal function and the vascular health.

The Effects for Brain stress by SUKI Alternative Therapy (SUKI 대체의학에 의한 뇌스트레스 감소 효과 연구)

  • Park, Young-Sik;Hong, Seong-Gyun
    • Journal of Convergence for Information Technology
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    • v.9 no.3
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    • pp.104-111
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    • 2019
  • The purpose of this study is to know the change of brain wave with stress by SUKI pressure alternative therapy. The experiment group was 12 students(male 6/female 6) with complained upper trapezius pain. Calculated the brain wave before and after stimulate the upper trapezius trigger point by SUKI and the stimulate time was 3min each persons(FP2, F3, F4, FP1, T3, T4, P3, P4). the experimet periods was 5times in a weeks with EEG(QEEG-S). The Date collecting used by Telescan(LXE5209). All the data was analyzed with SPSS 22.0 for window program. To compare the differences before and after the point pressure method, a corresponding sample of t-test was performed, and the statistical significance level was p<.05. The results was followed. The points of Fp2, F3, F4(*p<0.049, *p<0.042, *p<0.019) of EEG was showed a significant differences but Fp1, T3, T4, P3, P4 points did not showed. The SUKI alternative medicine techniques had a reduced effects for the some kind of brain stress. It is need to continuous research in the future.

Effects of Interference Signals on the Performance of EFTS (간섭신호가 EFTS의 성능에 미치는 영향)

  • Kang, Sanggee
    • Journal of Satellite, Information and Communications
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    • v.9 no.3
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    • pp.1-4
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    • 2014
  • A radio communication system has interference caused by other radio transmitters operated in co-channel or adjacent channels. Therefore technical specifications are made by considering and investigating the effects of interference between the new system and present systems when the new system will be started to serve in the near future. FTS is used for preventing an abnormal mission and guaranteeing public protection. Recently the next generation FTS's are researched to reinforce the security and to increase the operating capability of simultaneous use. EFTS known as one of the next generation FTS's is suitable for such purposes. In this paper the effects of interference signals on the performance of EFTS are investigated. Noncoherent DPSK and noncoherent CPFSK are considered for the modulation method of EFTS and a FMCW and a pulse RADAR considered as a interferer. The power of FMCW is 20.3dB lower than the power of EFTS and the power of pulse RADAR is 19.1dB lower than that of EFTS. Simulation results show that FMCW interferer reduce $E_b/N_o$ of about 1dB and $E_b/N_o$ of EFTS deteriorates about 0.5dB due to interference signals generated from pulse RADAR.

Effects of Electroacupuncture on Parameters Related to Obesity in Adults with Abdominal Obesity:Three arm Randomized Single Blind Pilot Study (전침이 복부비만 성인의 비만관련 지표에 미치는 영향-무작위배정 단일 맹검 예비연구-)

  • Chung, Jie-Youn;Kim, Jong-In;Lee, Sang-Hoon;Kang, Sung-Keel
    • Journal of Acupuncture Research
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    • v.27 no.6
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    • pp.43-57
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    • 2010
  • Objectives : To investigate the effects of electroacupuncture on parameters related to obesity in adults with abdominal obesity. Methods : A three arm randomized single blind pilot study was conducted from Jan 4 to March 25, 2010 in Kyung Hee Oriental Medical Hospital. The subjects were 39 adults with abdominal obesity and were randomly divided by computer generated random table into 3 groups; EA(electroacupuncture), sham EA(sham electroacupuncture) and waitlist groups. Acupuncture points located at abdomen($CV_{12}$, $CV_6$, $ST_{25}$, $SP_{15}$, $SP_{14}$) and extremities($LI_4$, $LI_{11}$, $ST_{36}$, $ST_{44}$) were inserted by disposable stainless steel needles and were stimulated 30 minutes with 24Hz, 0.27~1.3mA(tolerable strength), asymmetric biphasic continuous pulse wave form by STN-111 Stratek device in EA group. Two treatment sessions per week for 5 weeks(10 sessions in total) were done in EA and sham EA groups. The primary outcome measurement was WC(waist circumference), and the secondary outcome measurements included WHR(waist hip ratio), ASF(thickness of abdominal subcutaneous fat), and inbody measurements of BW(body weight), BMI(body mass index), BFR(body fat ratio) and VFA(visceral fat area), and also scores of BULIT-R(bulimia test revised), KoQoL(Korean obesity of QoL) and BSQ(body shape questionnaire). Results : All of 39 subjects were included in ITT(intention-to-treat) analysis. There were significant reductions in WC, WHR and ASF after 5-week electroacupuncture treatments and the percentage reductions were significantly greater than sham EA or waitlist group. There were no significant differences between groups in percentage reductions of other parameters(BW, BMI, BFR, VFA, BULIT-R, KoQoL and BSQ). But, there were continuous reductions in BW, BMI, BFR and VFA at 3 weeks after the end of treatment and there was significant reduction in BW compared with the baseline value in EA group. No seriously adverse effects were reported during the period. Conclusions : Electroacupuncture was more effective than sham electroacupuncture or no intervention on the reduction of WC, WHR and ASF in adults with abdominal obesity.

Various Factors Influencing Thoracic Duct Lymph Flow in the Dogs (임파유통에 영향을 주는 인자에 관한 실험적 연구)

  • Kim, Ki-Whan;Earm, Yung-E
    • The Korean Journal of Physiology
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    • v.9 no.1
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    • pp.45-56
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    • 1975
  • Various factors influencing the lymph flow from thoracic duct were investigated in an attempt to evaluate their contributing degree and the mechanisms. Sixteen mongrel dogs weighing between 10 and 16 kg were anesthetized and polyethylene catheters were inserted into the thoracic duct and femoral veins. Arterial blood pressure, heart rate, central venous pressure, lymph pressure and lymph flow were measured under various conditions. Electrical stimulation of left sciatic nerve, stepwise increase of central venous pressure, manual application of rhythmical depressions onto abdomen, injection of hypertonic saline solution and histamine infusion were employed. Measurement of cental venous pressure was performed through the recording catheter inserted into abdominal inferior vena cava. Changes in central venous pressure were made by an air-ballooning catheter located higher than the tip of the recording catheter in the inferior vena cava. Lymph flow from thoracic duct was measured directly with a graduated centrifuge tube allowing the lymph to flow freely outward through the inserted cannula. The average side pressure of thoracic lymph was $1.1\;cmH_2O$ and lymph flow was 0.40 ml/min or 1.9 ml/kg-hr. Hemodynamic parameters including lymph flow were measure immediately before and after (or during) applying a condition. Stimulation of left sciatic nerve with a square wave (5/sec, 2 msec, 10V) caused the lymph flow to increase 1.4 times. The pattern of lymph flow from thoracic duct was not continuous throughout the respiratory cycle, but was continuous only during Inspiration. Slow and deep respiration appeared to increase the lymph flow than a rapid and shallow respiration. Relationship between central venous pressure and the lymph flow revealed a relatively direct proportionality; Regression equation was Lymph Flow (ml/kg-hr)=0.09 CVP$(cmH_2O)$+0.55, r=0.67. Manual depressions onto the abdomen in accordance with the respiratory cycle caused the lymph flow to increase most remarkably, e.g,. 5.5 times. The application of manual depressions showed a fluctuation of central venous pressure superimposed on the respiratory fluctuation. Hypertonic saline solution (2% NaCl) administered Intravenously by the amount of 10 m1/kg increased the lymph flow 4.6 times. The injection also increased arterial blood pressure, especially systolic Pressure, and the central venous pressure. Slow intravenous infusion of histamine with a rate of 14-32 ${\mu}g/min$ resulted in a remarkable increase in the lymph flow (4.7 times), in spite of much decrease in the blood pressure and a slight decrease in the central venous pressure.

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A Practical Algorithm to Simulate Erosion of On-Shore Zone (실용적 해안선 후퇴 반영 알고리즘)

  • Kim, Hyoseob;Lee, Jungsu;Jin, Jae-Youll;Jang, Changhwan
    • Journal of Wetlands Research
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    • v.15 no.3
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    • pp.423-430
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    • 2013
  • An algorithm to allow shoreline movement during numerical experiment on sediment transport, deposition or resuspension for general coastal morphology is proposed here. The bed slope near shoreline, i.e. mean sea level, is influenced by bed material, tidal current, waves, and wave-induced current, but has been reported to remain within a stable range. Its annual variation is not large, either. The algorithm is adjusting the bathymetry, if the largest bed slope within shoreline band exceeds a given bed slope due to continuous erosion at zones below the shoreline. This algorithm automatically describes retreat of shoreline caused by erosion, when used within a numerical system. The algorithm was tested to a situation which includes a continuous dredging at a point, and showed satisfactory development of concentric circle contours. Next, the algorithm was tested to another situation which includes sinking of eroded part of bed plate, and produced satisfactory results, too. Finally, the algorithm was tested to a movable-bed laboratory experimental conditions. The shoreline movement behind detached breakwater was reasonably reproduced with this algorithm.

A Study on the Types and Determinants of Longitudinal Changes in the Economic Preparations for the aging Among People with Physical Disabilities: Using Latent Class Growth Model (지체장애인의 경제적 노후준비에 대한 종단적 변화유형과 결정요인에 관한 연구 : 잠재계층성장분석을 활용하여)

  • Lee, Gye Seung;Kim, Dong Ha
    • Korean Journal of Social Welfare Studies
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    • v.48 no.4
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    • pp.157-185
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    • 2017
  • This study aimed to explore the trajectories of economic preparations for the aging among people with physical disabilities and to identify the determinants according to the Andersen model. For this study, data were drawn from Panel Survey of Employment for the Disabled (PSED). A total of 1,847 samples were used from the second to the eighth wave. Latent class growth model was conducted to explore the longitudinal change classes for the disabled, and the multinominal logistic regression analysis was conducted to examine the influence of the determinants. As a result, four classes were identified: preparation decrease group, continuous non-preparation group, preparation increase group, and continuous preparation group. Each group was found to be associated deferentially with education level, family income, socioeconomic status, employment, home ownership, national basic livelihood security recipient status, and ADL. These findings proposed the practical and political implications for the strategies concerned with facilitating the economic preparations for the aging among the disabled.

The Effects of c-Fos Expression on Ultrasound Treatment in Sciatic Nerve Crush Damaged Rats (초음파 치료가 좌골신경 압좌 손상된 흰쥐의 c-Fos 발현에 미치는 영향)

  • Kim, Dong-Dae
    • Journal of Korean Physical Therapy Science
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    • v.14 no.1_4
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    • pp.11-23
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    • 2007
  • This study was performed to evaluate the effects of low-intensity ultrasound application to the peripheral nerve injury animal model on enhancement of nerve regeneration and functional recovery. Using aseptic microsurgical techniques, the sciatic nerve of adult male Sprague-Dawley rats was crushed at the outside of right mid-thigh for 30 seconds with fine forceps. Beginning just after surgery, various continuous-wave ultrasound treatments with intensities of 0.2 W/$cm^2$, 0.5 W /$cm^2$ and 1.0 W /$cm^2$ operated at 1 MHz or sham treatment were applied to the opposite inside of the crush site for 1 minute every other day with a transducer moving speed of 2cm/sec. For evaluation of the progress of sciatic nerve regeneration, c-Fos expression in the lumbar spinal cord (L4-5) dorsal horn was investigated. c-fos expression was markedly increased at 1hour after sciatic nerve crush injury, then gradually decreased thereafter. The c-fos expressions were significantly decreased (p<0.05) in all the experimental groups in comparison with the control group until 3days post-crush, and the degrees of decrease were higher in 0.5 W/$cm^2$ and 1 W/$cm^2$ intensity ultrasound application groups. It is suggested that low-intensity ultrasound application to an animal model of sciatic crush injury may suppress pain transmission and promote nerve regeneration, and which may result in delayed progress of muscle atrophy and accelerated progress of muscle recovery and eventually may result in accelerated and improved foot function recovery.

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