• Title/Summary/Keyword: P-Wave Velocity

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Effects of Rhythm Exercise Training on Body Composition and Arterial Compliance in Elderly Females (리듬운동이 고령여성의 신체조성과 혈관탄성에 미치는 영향)

  • Kim, Daeyeol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.243-250
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    • 2016
  • The body composition and arterial compliance with advanced age increase the risks of cardiovascular diseases, but the elderly can perform rhythm exercise easily, which may positively influence their body composition and arterial compliance. Therefore, this study examined the effects of rhythm exercise training on the body composition and arterial compliance in elderly females. The subjects (n=20) were assigned randomly to either an exercise group (n=10, EX) or non-exercise control group (n=10, CON). The rhythm exercise training for 12 weeks consisted of 3 sessions per week with 60 minutes per session. In addition, the intensity was set to 11-14 of the Borg scale (6-20). The body composition and arterial compliance (pulse wave velocity (PWV)) were measured before and after training. The skeletal muscle mass in the EX was increased significantly (p=0.04) and the right (p=0.002) and left side (p=0.02) of the PWV in the EX were decreased significantly, but the skeletal muscle and both sides of the PWV in the CON were not changed. Elderly females could easily perform rhythm exercise training, which resulted in improvements of the skeletal muscle mass and arterial compliance. Therefore, rhythm exercise training may prevent or delay sarcopenia and reduce the risk of cardiovascular diseases.

P-wave 3d velocity structure using teleseismic earthquakes beneath the Antarctic Peninsula (원격 지진을 이용한 남극 반도 3차원 속도 구조 연구)

  • Park, Yong-Cheol
    • 한국지구물리탐사학회:학술대회논문집
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    • 2010.10a
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    • pp.33-33
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    • 2010
  • 남극 반도 북부에 설치된 임시지진관측소와 세종기지 지진관측소에서 관측된 원격지진을 이용하여 P파의 상부 맨틀 속도 구조 모델링을 하였다. 사용된 자료는 1997년부터 1999년까지 실시된 SEPA (the Seismic Experiment in Patagonia and Antarctica) 연구에 설치된 7대의 임시 광대역 관측소와 IRIS/GSN 영구 관측소인 PMSA, 그리고 칠레 Jubany 기지(JUBA)와 아르헨티나의 Esperanza 기지(ESPZ)에 설치된 광대역 지진관측소에서 관측된 자료를 사용하였다. 모든 관측소가 남극 반도와 남 셔틀랜드 군도에 위치하고 있기 때문에 매우 낮은 신호대 잡음비를 보여주고 있다. 모델링에 사용된 자료는 95개 지진에서 축출한 347개의 P파와 PKP파로 실시되었다. 역산된 상부 맨틀의 속도 구조는 남 셔틀랜드 군도의 북쪽에서 빠르고 브랜스필드 스트레이 지역에서는 느린 속도 구조를 보여주고 있다.

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Field Experiments of Consolidant and Filler for Stone Cultural Heritage: Primary Verification Using Ultrasonic Velocity (석조문화재 적용을 위한 강화제 및 충전제 현장실험 : 초음파 속도를 이용한 일차검증)

  • Song, Chi-Young;Jun, Byung-Kyu;Han, Min-Su;Lee, Jang-Jon;Kim, Sa-Dug
    • Journal of Conservation Science
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    • v.25 no.1
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    • pp.87-100
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    • 2009
  • We carried out the effect verification of conservation treatment focusing on basement rock of alkali granite at the Yukjonbul (two-pairs of Buddha Triads) carved on rock cliff of Samneung valley in Namsan mountain of Gyeongju. The conservation treatments were used to ethylsilicate-type rock consolidant and epoxy-type resin. It is treatment method that the epoxy-type resin have been applied one time into the exfoliation area, after rock consolidation treatment have been worked for three times. As the result of measuring ultrasonic velocity, P-wave velocity of the exfoliation area was relatively increased after applied the conservation treatments. The ultrasonic velocity of all area was increased as 27.8%. This result has been proved with consolidation effects by consolidant and filler for stone cultural heritages. The treatment method should be worked about three time to consolidate sufficiently for rocks.

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Correlating two-dimensional shear wave elastography of acute pancreatitis with Spec cPL in dogs

  • Cho, Hyun;Yang, Seungwhwa;Suh, Gukhyun;Choi, Jihye
    • Journal of Veterinary Science
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    • v.23 no.5
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    • pp.79.1-79.11
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    • 2022
  • Background: Pancreatitis is a common disease in which 37% of dogs had evidence of acute or chronic pancreatitis at necropsy. Although biopsy is still the gold standard to diagnose acute pancreatitis, clinical data including ultrasonographic findings and measurement of canine serum pancreatic lipase immunoreactivity (cPLI) are used in routine. However, it may be insufficient in the diagnostic approach to acute pancreatitis. Objectives: To evaluate the clinical diagnostic feasibility of two-dimensional shear wave elastography (2D SWE) on canine acute pancreatitis for enhanced diagnostic confidence. Methods: 2D SWE was used to assess pancreatic stiffness and determine the correlation between pancreatic shear wave velocity (SWV) and Spec cPL concentration in 31 dogs with healthy pancreas and 10 dogs with acute pancreatitis. Results: The pancreatic SWV was significantly higher in the acute pancreatitis group (2.67 ± 0.20 m/s) than in the healthy pancreas group (2.30 ± 0.26 m/s; p < 0.05). The moderate positive correlation was found between the pancreatic SWV and Spec cPL concentration (95% confidence interval, 0.214-0.693; r = 0.489; p < 0.05). Conclusions: These results indicated that 2D SWE was feasible for assessing pancreatic stiffness in acute pancreatitis, and that pancreatic SWV using 2D SWE correlated with Spec cPL concentration. SWE could provide a quantitative measure of pancreatic stiffness, which can increase the accuracy of diagnosing acute pancreatitis in dogs. The 2D SWE can be used as a complementary imaging modality for diagnosing acute pancreatitis in dogs.

Changes on Physical Property of Ilmenite due to Microorganism (미생물에 의한 티탄철석의 물리적 특성 변화)

  • Park, Young Ho;Kang, Dae Wan;Kang, Seong-Seung
    • Tunnel and Underground Space
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    • v.22 no.5
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    • pp.321-329
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    • 2012
  • Laboratory tests for measuring absorption, porosity, P-wave velocity and uniaxial compressive strength (UCS) were performed to examine weathering characteristics of ilmenite by microorganism. Physical property changes were quantitatively estimated with comparing culture period on the condition of abiotic oxidation without microorganism and biooxidation with microorganism. As a result, the measured pH during 45 days was distributed in the range from 3.82 to 4.26, on the other hand, biooxidation showed the range from 2.20 to 2.57. The measured absorption according to microorganism and culture period represented 0.052% at final stage in the case of abiotic oxidation and 0.073% in the case of biooxidation. Porosity showed 0.206% at final stage in the case of abiotic oxidation and 0.281% in the case of biooxidation. In general, the values by biooxidation showed higher than that by abiotic oxidation. Change range of P-wave velocity with culture period showed that the measured value as 1410 m/s at final stage in the case of biooxidation was lower than 1886 m/s of that in the case of abiotic oxidation. The UCS was decreased with increasing culture period in all specimens and represented 241.1 MPa at final stage in the case of abiotic oxidation and 140.0 MPa in the case of bioxidation. In conclusion, it implies that influence of physical property on ilmenite by biooxidation related with microorganism was larger than that by abiotic oxidation.

A Study on Mechanical Properties of Strand/Particle Composites (II) - Measuring of Young's Moduli and Estimating of Anisotropy Using an Ultrasonic Method - (스트랜드/파티클 복합체의 기계적 성질에 관한 연구(II) - 탄성률 측정 및 초음파법에 의한 이방성의 예측 -)

  • Kim, Yu-Jung
    • Journal of the Korean Wood Science and Technology
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    • v.29 no.1
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    • pp.22-30
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    • 2001
  • Composites with various layer constructions involving the ratio of S/P were produced from wood strands(S) and particles(P) (Cryptomeria japonica D.Don) to measure various Young's moduli and anisotropy by ultrasonics. As a result, static Young's moduli of composites were almost same as dynamic Young's moduli obtained from natural frequency. However, these were smaller than those evaluated from ultrasonic wave propagation velocity. The differences between propagation velocity of the parallel(${\parallel}$) and perpendicular(${\bot}$) in-plane direction resulted in a tendency of anisotropy. The tendency of anisotropy was larger in three-layer constructions than in seven-layer constructions. The differences of strand surface layers showed larger values than those of particle surface layers. Also, composites with higher weight ratio of strand had a tendency to propagate rapidly in each direction. In contrast to these results, the propagation velocity in the thickness direction had a tendency to propagate rapidly in composites with particle surface layers and the lower weight ratio of strand.

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Flow Control by Piezoceramic Actuator in a flat plate (평판에서 압전 세라믹 액추에이터에 의한 유동제어)

  • Kim, Dong-Ha;Han, Jong-Seob;Chang, Jo-Won;Kim, Hak-Bong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.11
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    • pp.1080-1088
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    • 2009
  • An actuator using piezoceramic material was designed in order to perform a flow control for flat plate flow. Boundary layer measurements were carried out to explore the flow disturbances by the designed actuator that was activated at low excitation frequency(15Hz). The mean velocity and fluctuation in the boundary layers were measured at $x/{\delta}^*=31.9$ downstream from the actuator tip by a one-dimensional hot-wire probe(55P14). Results reveal that low- and high-velocity regions were observed in the vicinity of the actuator center and in the outer area of the actuator respectively, and the formation of counter-rotating streamwise vortices was predicted. The fluctuations were persistently found in the outer part of the actuator and an inflection point in the spanwise gradient of the streamwise velocity was observed. Boundary layer instability was amplified at both the actuator excitation frequency and the T-S wave frequency when the actuator was excited at low frequency.

The First Crustal Refraction Survey in the Korean Peninsula

  • Jung Mo Lee;Wooil Moon;Chang-Eob Baag;Heeok Jung;Ki Young Kim;Bong Gon Jo;Woohan Kim;Sung Kyun Kim
    • Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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    • 2003.05a
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    • pp.15-15
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    • 2003
  • The first crustal refraction survey in the Korean Peninsula was carried out over the survey line connecting Seosan-Yeongdong-Kyeongiu on Dec. 15, 2002. The total length of the survey line was about 300 Km and 198 portable seismometers were deployed with approximately 1.5-km interval. The survey line itself was geologically important since it was almost normal to the so-called Sino-Korean structural trend. Two shots, one at Seosan (west end point) and the other at Yeongdong (mid-point), were exploded. They were 100-m deep drill well explosions. The Seosan shot consisted of a ton emulsion type explosive, while Youngdong consisted of 500 kg one. Both shots generated signals with good S/N ratios to the farthest receivers. Seismic signals were recorded by 195 receivers out of 198 ones. Although the originally planned Kyeongju shot (east end point) could not be exploded due to public discontent, the experiment was evaluated very successful. First breaks in all recorded traces were picked up and two preliminary analyses were carried out. The one is conventional flat layer analysis and the other was refraction tomographic analysis. The one resulted in average 32-km thick two-layer crust and the underlying mantle with 8.05-km/s P-velocity. The top crust layer with 3.86 kw/s P-velocity was 2.5-km thick and the lower crust layer with 6.0l km/s P-velocity was 29.5-km thick. The other resulted in a velocity cross-section. The confidence level of the velocity cross-section could not be evaluated at this time because only two shot were exploded. Detailed analyses such as surface wave dispersion are on going. Continuing crustal scale refraction surveys are planned in Korea.

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Analysis of Seismic Velocity Change and AVO Response Depending on Saturation of Kerogen and GOR in Shale Reservoirs (셰일 저류층에서 케로젠, GOR 변화에 따른 속도 변화 및 AVO 반응 분석)

  • Choi, Junhwan;Lee, Jaewook;Byun, Joongmoo;Kim, Bona;Kim, Soyoung
    • Geophysics and Geophysical Exploration
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    • v.19 no.1
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    • pp.29-36
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    • 2016
  • Recently, the studies about rock physics model (RPM) in shale reservoir are widely performed. In shale reservoir, the degree of the maturity can be estimated by kerogen and GOR (Gas-Oil Ratio). The researches on the rock physics model of shale reservoir with the amount of kerogen have been actively carried out but not with GOR. Thus, in this study, we analyzed the changes in seismic velocity and density, and AVO (Amplitude Variation with Offset) response depending on changes in GOR and the amount of kerogen. Since the shale consists of plate-like particles, it has vertical transverse isotropy (VTI). Therefore we estimated the seismic velocity and density by using Backus averaging method and analyzed AVO responses based on these estimated properties. The results of analysis showed that the changes in the velocity with the GOR variation are small but the velocity changes with the variation in kerogen amount are relatively larger. In case, GOR 180 (Litre/Litre) which is boundary between heavy oil and light oil, when volume fraction of kerogen increased from 5% to 35%, the P-wave velocity normal to the layering increased 51%. That is, it helps estimating maturity of kerogen through the velocity. Meanwhile, when rates of oil-gas mixture are large, the effect of GOR variation on the velocity change became larger. In case volume fraction of kerogen is 5%, the P-wave velocity normal to the layering was estimated $1.46km/s^2$ in heavy oil (GOR 40) but $1.36km/s^2$ in light oil (GOR 300). The AVO responses analysis showed class 4 regardless of the GOR and amount of kerogen because variation of poisson's ratio is small. Therefore, shale reservoir has possibility to have class 4.

Formation Identification using Anisotropic Parameters from Sonic and Density Logs (음파검층과 밀도검층 자료에서 산출된 이방성 변수를 이용한 지층 구분)

  • Jang, Seonghyung;Kim, Tae Youn;Hwang, Seho
    • The Journal of Engineering Geology
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    • v.27 no.3
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    • pp.323-330
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    • 2017
  • For the formation identification, surface geological survey, drill core analysis, core description and well log analysis are widely used. Among them well log analysis is a popular method with drill core analysis, since it measures continuously physical properties at in-situ. In this study we calculated Thomsen anisotropic parameters (${\varepsilon},\;{\delta},\;{\eta}$) after applying Backus averaging method to the P wave velocity, S wave velocity, and density logs. The well log data application of Blackfoot, Canada, shows the formation could be divided by 12 layers. This shows that Thomsen anisotropic parameters for identifying formation using anisotropic parameters is useful if there is no natural gamma log that is widely used for the formation identification.