• Title/Summary/Keyword: Scat

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Detection of Noise Sources in a Cavitation Tunnel by using Beam-Forming Method (빔형성 기법을 이용한 공동수조 내부의 소음원 탐지)

  • 이정학;서종수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.749-754
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    • 2003
  • In this paper, we introduce the measurement of the underwater noise with 32channel hydrophone array of Samsung CAvitation Tunnel (SCAT) and the detection technique of noise sources by using the beam-forming method. Measurement and way signal Processing under fluid flow are essential works for the underwater acoustics, especially for the detection of noise sources. As the acoustic impedance of the water is relatively high and the tunnel is an enclosed system, we have to consider the interaction between tunnel and water together with the reflection of noise in the beam-forming technique. Also, for a hydrophone array system that is fixed on one side of tunnel wall as done in SCAT is liable to suffer from some limitations in the detection of the noise sources with the array, we discuss these limitations particularly on the frequency range and spacing of noise sources.

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INTERNATIONAL SCATTEROMETER TANDEM MISSIONS AND POTENTIAL SYNERGISM

  • Liu, W. Timothy;Xie, Xiaosu
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.130-133
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    • 2006
  • Three scatterometers will be launched by Europe, India, and China in the next few years and they will fly in tandem with QuikSCAT of the United States. The potential improvement in coverage will open up new operational and research applications.

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Study on Establishment of a Wind Map of the Korean Peninsula (I. Establishment of a Synoptic Wind Map Using Remote-Sensing Data) (한반도 바람지도 구축에 관한 연구 (I. 원격탐사자료에 의한 종관 바람지도 구축))

  • Kim Hyungoo;Choi Jaeou;Lee Hwawoon;Jung Woosik
    • New & Renewable Energy
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    • v.1 no.1 s.1
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    • pp.44-53
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    • 2005
  • To understand general status of the national wind environment and to distinguish potential areas to be developed as a largescale wind farm, a synoptic wind map of the Korean Peninsula is established by processing remote sensing data of the satellite, NASA QuikSCAT which Is deployed for the SeaWinds Project since 1999. According to the validation results obtained by comparing with the measurement data of marine buoys of KMA(Korea Meteorological Administration), the cross-correlation factor Is greatly Improved up to 0.87 by blending the sea-surface dat3 of QuikSCAT with NCEP/NCAR CDAS data. It is found from the established synoptic wind map that the wind speed in winter is prominent temporally and the South Sea shows high energy density up to the wind class 6 spatially. The reason is deduced that the northwest winds through the yellow Sea and the northeast winds through the East Sea derived by the low-pressure developed in Japan are accelerated passing through the Korea Channel and formed high wind energy region in the South Sea; the same trends are confirmed by the statistical analysis of meteorological observation data of KMA.

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Fabrication and Characteristics of a Piezoelectric Valve for MEMS using a Multilayer Ceramic Actuator (적층형 세라믹 엑추에이터를 이용한 MEMS용 압전밸브의 제작 및 특성)

  • 정귀상;김재민;윤석진
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.5
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    • pp.515-520
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    • 2004
  • We report on the development of a Piezoelectric valvc that is designed to have a high reliability for fluid control systems, such as mass flow control, transportation and chemical analysis. The valve was fabricated using a MCA(multilayer ceramic actuator), which has a low consumption power, high resolution and accurate control. The fabricated valve is composed of MCA, a valve actuator die and an seat die. The design of the actuator dic was done by FEM(finite element method) modeling, respectively. And, the valve seat die with 6 trenches was made. and the actuator die, which possible to optimize control to MCA, was fabricated. After Si-wafer direct bonding between the seat die and the actuator die, MCA was also anodic bonded to the scat/actuator die structure. PDMS(poly dimethylsiloxane) sealing pad was fabricated to minimize a leak-rate. It was also bonded to scat die and stainless steel package. The flow rate was 9.13 sccm at a supplied voltage of 100 V with a 50 % duty ratio and non-linearity was 2.24 % FS. From these results, the fabricated MCA valve is suitable for a variety of flow control equipments, a medical bio-system, semiconductor fabrication process, automobile and air transportation industry with low cost, batch recess and mass production.

Analysis of the Relation between Spatial Resolution of Initial Data and Satellite Data Assimilation for the Evaluation of Wind Resources in the Korean Peninsula (한반도 풍력자원 평가를 위한 초기 공간해상도와 위성자료 동화의 관계 분석)

  • Lee, Soon-Hwan;Lee, Hwa-Woon;Kim, Dong-Hyuk;Kim, Hyeon-Gu
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.6
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    • pp.653-665
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    • 2007
  • Several numerical experiments were carried out to clarify the influence of satellite data assimilation with various spatial resolution on mesoscale meteorological wind and temperature field. Satellite data used in this study is QuikSCAT launched on ADEOS II. QuikSCAT data is reasonable and faithful sea wind data, which have been verified through many observational studies. And numerical model in the study is MM5 developed by NCAR. Difference of wind pattern with and without satellite data assimilation appeared clearly, especially wind speed dramatically reduced on East Sea, when satellite data assimilation worked. And sea breeze is stronger in numerical experiments with RDAPS and satellite data assimilation than that with CDAS and data assimilation. This caused the lower estimated surface temperature in CDAS used cases. Therefore the influence of satellite data assimilation acts differently according to initial data quality. And it is necessary to make attention careful to handle the initial data for numerical simulations.

Establishment of a Wind Map of the Korean Peninsula I. Evaluation of Offshore Wind Resources Using Remote-Sensing Data (한반도 바람지도 구축에 관한 연구 I. 원격탐사자료를 이용한 해상풍력자원 평가)

  • Kim Hyun-Goo;Lee H.W;Jung W.S
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.1
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    • pp.63-72
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    • 2005
  • In order to understand regional wind characteristics and to estimate offshore wind resources, a wind map of the Korean Peninsula was established using remote-sensing data from the satellite, U.S. NASA Quik SCAT which has been deployed for the Sea Winds Project since 1999. According to the linear regression result between the wind map data and in-situ marine-buoy data, the correlation factor was greatly improved up to 0.87 by blending the remote-sensing data of Quik SCAT with U.S. NCEP/NCAR CDAS reanalysis data to eliminate precipitation interference and to increase temporal resolution. It is found from the established wind map that the wind speed in winter is prominent temporally and the South Sea shows spatially high energy density over the wind class 6. The reason is deduced that the north-west winds through the Yellow Sea and the north-east winds through the East Sea derived by the low pressure developed in Japan are accelerated passing through the Korea Channel and formed high wind energy region in the South Sea; the same trends are confirmed from the statistical analysis of the meteorological observation data of KMA.

Effects of dietary n-6:n-3 polyunsaturated fatty acid ratio on growth performance, blood indexes, tissue fatty acid composition and the expression of peroxisome proliferator-activated receptor gamma signaling related genes in finishing pigs

  • Chen, Jing;Cui, Hongze;Liu, Xianjun;Li, Jiantao;Zheng, Jiaxing;Li, Xin;Wang, Liyan
    • Animal Bioscience
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    • v.35 no.5
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    • pp.730-739
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    • 2022
  • Objective: This study investigated the effects of dietary n-6:n-3 polyunsaturated fatty acid (PUFA) ratio on growth performance, blood indexes, tissue fatty acid composition and the gene expression in finishing pigs. Methods: Seventy-two crossbred ([Duroc×Landrace]×Yorkshire) barrows (68.5±1.8 kg) were fed one of four isoenergetic and isonitrogenous diets with n-6:n-3 PUFA ratios of 2:1, 3:1, 5:1, and 8:1. Results: Average daily gain, average daily feed intake and gain-to-feed ratio had quadratic responses but the measurements were increased and then decreased (quadratic, p<0.05). The concentrations of serum triglyceride, total cholesterol and interleukin 6 were linearly increased (p<0.05) with increasing of dietary n-6:n-3 PUFA ratio, while that of high-density lipoprotein cholesterol tended to decrease (p = 0.062), and high-density lipoprotein cholesterol:low-density lipoprotein cholesterol ratio and leptin concentration were linearly decreased (p<0.05). The concentration of serum adiponectin had a quadratic response but the measurement was decreased and then increased (quadratic, p<0.05). The proportion of C18:3n-3 was linearly decreased (p<0.05) in the longissimus thoracis (LT) and subcutaneous adipose tissue (SCAT) as dietary n-6:n-3 PUFA ratio increasing, while the proportion of C18:2n-6 and n-6:n-3 PUFA ratio were linearly increased (p<0.05). In addition, the expression levels of peroxisome proliferator-activated receptor gamma (PPARγ) and lipoprotein lipase in the LT and SCAT, and adipocyte fatty acid binding protein and hormone-sensitive lipase (HSL) in the SCAT had quadratic responses but the measurements were increased and then decreased (quadratic, p<0.05). The expression of HSL in the LT was linearly decreased (p<0.05) with increasing of dietary n-6:n-3 PUFA ratio. Conclusion: Dietary n-6:n-3 PUFA ratio could regulate lipid and fatty acid metabolism in blood and tissue. Reducing dietary n-6:n-3 PUFA ratio (3:1) could appropriately suppress expression of related genes in PPARγ signaling, and result in improved growth performance and n-3 PUFA deposition in muscle and adipose tissue in finishing pigs.

A study on the Cochlear View Radiography in Multichannel Cochlear Implantees

  • Kweon Dae Cheol;Kim Seong Lyong;Chung Kyung Mo;Kim Hae Seong;Lee Yong Woo
    • Journal of The Korean Radiological Technologist Association
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    • v.25 no.1
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    • pp.20-20
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    • 1999
  • Purpose : Cochlear implant poses a contraindication to the magnetic resonance imaging (MRI) process, because MRI generates artifacts, inducing an electrical current and causing device magnetization. CT is relatively expensive and the metal electrodes scat

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The study of train ticket allocation methods (열차좌석배분방식에 대한 연구)

  • Hong, Soon-Heum;Kim, Gil-Sang
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.531-533
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    • 1995
  • This paper describes the effect of the train ticket allocation methods. Two types of the allocation method, 'proportional to the distance between two stations' and proportional to ticket-demand', are compared. From the result of calculation, the letter case shows better characteristics than the former case especially on the scat occupation ratio and the regional equality or allocation.

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Clinical Study on Constitutional Herbal Tea for Treating Chronic Fatigue

  • Park, Soo-Jung;Bae, Young-Chun;Choi, Na-Rae;Ryu, Seung-Yeob;Kwon, Young-Mi;Joo, Jong-Cheon
    • Journal of Pharmacopuncture
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    • v.17 no.4
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    • pp.55-60
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    • 2014
  • Objectives: This study was designed to evaluate the efficacy and the safety of constitutional herbal tea for treating chronic fatigue with no diagnosed cause, which is called Mibyeong in Korea. Methods: Males and females with ages between 40 and 59 years who had complained of fatigue for 1 month consistently or for 6 months intermittently without a definite cause were recruited. At the same time, a Chalder fatigue scale (CFS) score of 19 was essential for participation in this study. Sixty five subjects completed the entire process, including blood tests and tests with medical devices. Five assessments of health status were accomplished over 8 weeks by using the CFS and the visual analogue scale (VAS). To ensure that the constitutional herbal tea was being safely used, we conducted and analyzed renal function and liver function tests. For the diagnosis of the Sasang constitution, the Sasang Constitutional Analysis Tool (SCAT) was used, and a specialist in Sasang constitutional medicine made the final diagnosis based on the SCAT result. Constitutional herbal tea was served four weeks after the first visit. The subjects took the constitutional herbal tea twice a day for one month. Results: The results are as follows: The CFS and the VAS scores were significantly improved for the subjects in the constitutional herbal tea. No abnormalities were found on the blood tests to evaluate safety after taking the constitutional herbal tea. The improvements in the CFS and the VAS scores due to the constitutional herbal tea had no significant differences according to the Sasang constitution. Conclusion: Constitutional herbal tea may be used to reduce fatigue and improve health and has no adverse effect on either the kidney or the liver.