• Title/Summary/Keyword: dB difference

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A Comparision of a Direct and Three Indirect Methods of Measuring Blood Pressure (직접혈압측정치와 3가지 간접혈압측정치의 비교)

  • Lee Myung-Hwa;Park Hyo-Kyung;Shon Soo-Kyung
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.5 no.1
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    • pp.95-106
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    • 1998
  • The purpose of this study was to compare direct and three indirect blood pressure measurements in adults and to compare among three indirect blood pressure measurements in adults. One direct(intraarterial) and three indirect(using a mecury sphygmomanometer, a aneroid type sphygmomanometer and an automatic auscultatory device) methods of blood pressure measurement were compared in adult patients who had an arterial line. The subjects for this study consisted of 29 patients in K medical center, B medical center, B hospital and M hospital in Pusan. The data was collected from October 1, 1992 to June 30, 1993. The collected data was analysed with the SPSS program, frequency, percentage, mean, S.D., t-test, ANOVA. The results of this study were as follows : 1) There was a significant difference in the systolic BP when using the direct and three indirect measurements(P<0.05). 2) There was no overall significant difference in the diastolic BP when using the direct and three indirect measurements. 3) There was no significant difference in the SBP and DBP among the three indirect measurements.

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Experimental Study on Boiling Heat Transfer of the Tubes with Sintered Metal Surface for Freon-11 (냉매의 소결금속관 표면에서의 비등 열전달에 관한 실험적 연구)

  • Park C. J.;Mun B. S.;seo J. Y.
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.10 no.3
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    • pp.220-227
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    • 1981
  • The purpose of this paper is to investigate the potential ability of sintered metal tube to promote heat transfer. In the experiment for Freon - 11, the boiling heat transfer on the sintered metal tube of bronze element is investigated and compared with that of the bronze tube (bare tube) atmospheric pressure. The experimental results are obtained as follows : 1) For sintered metal tubes of bronze element with particle diameters which ranges from $79({\mu})\;to\;461({\mu})$ and bare tube, boiling characteristic curves are expressed as : a) Sintered metal tube $$q{\propto}{\Delta}T^{1.05\~1.373}$$ b) Brae tube $$q{\propto}{\Delta}T^{3.096}$$ 2) Compared with that of the bare tube at low temperature difference$({\Delta}T_{sat})$, boiling heat transfer coefficient of the sintered bronze tube are relatively high. 3) There is tendency that curves of boiling heat transfer coefficients of sintered ·bronze tube and bare tube approach each other at rather high temperature difference. It is due to the increasing rate of the former heat transfer coefficient along with temperature difference is smaller than that of the latter. 4) Referring to particle diameter, optimum condition, i. e. , maximum heat transfer coefficient is found to be at approximately 2 mm thickness of sintered layer with $D_p=150({\mu})$.

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Effects of wearing disposable diaper with the endothermic agent on thermal responses of infant (흡열제가 첨가된 일회용 기저귀의 착용이 유아의 온열생리적 반응에 미치는 영향)

  • 성유진;이수원
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.4
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    • pp.499-509
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    • 1999
  • This study was carried out to investigate the effects of wearing disposable diaper with the endothermic agent on thermoregulatory response of infant. Five healthy female infants aged about 5 months were taken as a subject of this experiment. Experimental diapers were six kinds of disposable diaper constructed of nonwoven tissue, fluff pulp, super absorbent polymer, back sheet film, leg elastic, and 0g urea(A) 1g urea(B) , 2g urea(C), 3g urea (D), 4g urea(E) 5g, urea(F) respectively. Urea(98% or over purity) was used as an endothermic agent. Experiment was proceeded while infants were sleeping at 27.5$\pm$0.5$^{\circ}C$, 50$\pm$5% R.H, 0.04m/sec. Each disposable diaper's properties was tested. During the experiment rectal temperature skin temperature of 9 areas temperature inside the disposable diapers were measured, the results were as follows : 1) There was not significant difference among the diapers in absorption capacity retention capacity and rewet(p=0.05). The absorption under load was showed to A, B,

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A Wafer Level Packaged Limiting Amplifier for 10Gbps Optical Transmission System

  • Ju, Chul-Won;Min, Byoung-Gue;Kim, Seong-Il;Lee, Kyung-Ho;Lee, Jong-Min;Kang, Young-Il
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.4 no.3
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    • pp.189-195
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    • 2004
  • A 10 Gb/s limiting amplifier IC with the emitter area of $1.5{\times}10{\mu}m^2$ for optical transmission system was designed and fabricated with a AIGaAs/GaAs HBTs technology. In this stud)', we evaluated fine pitch bump using WL-CSP (Wafer Level-Chip Scale Packaging) instead of conventional wire bonding for interconnection. For this we developed WL-CSP process and formed fine pitch solder bump with the $40{\mu}m$ diameter and $100{\mu}m$ pitch on bonding pad. To study the effect of WL-CSP, electrical performance was measured and analyzed in wafer and package module using WL-CSP. In a package module, clear and wide eye diagram openings were observed and the riselfall times were about 100ps, and the output" oltage swing was limited to $600mV_{p-p}$ with input voltage ranging from 50 to 500m V. The Small signal gains in wafer and package module were 15.56dB and 14.99dB respectively. It was found that the difference of small signal gain in wafer and package module was less then 0.57dB up to 10GHz and the characteristics of return loss was improved by 5dB in package module. This is due to the short interconnection length by WL-CSP. So, WL-CSP process can be used for millimeter wave GaAs MMIC with the fine pitch pad.

Propagation Loss Variability due to Hourly Variations of Underwater Sound Speed profiles in the Korea Strait (대한해협에서 수중음속 구조의 단기변화에 의한 전파손실의 변화정도)

  • Na, Youn-Nam;Shim, Tae-Bo;Kim , Seong-Il
    • The Journal of the Acoustical Society of Korea
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    • v.14 no.1E
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    • pp.5-13
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    • 1995
  • In order to estimate the variability of the wave propagation loss (PL) du e to hourly variations of the sound speed profiles (SSPs), we conducted oceanographic measurements every hour for 39 hours in October 1993 in the Korea Strait. Currents and meteorological data were measured simultaneously to examine the causes of the temporal variations of temperatures. During the experiment, the temporal variations of temperatures in the surface layer highly depend on the water mass transport from adjacent seas. The PL for low frequency (75-300 Hz) is calculated using the parabolic equation scheme and averaged over the whole water depth. The hourly variation of the SSP may cause a PL difference of up to 10 dB over a 30-50 km range. The variability of PL, represented by standard deviation for the 39 SSPs, is as large as 3 dB over a 50 km range.

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Study on the Acceptance Level for Damage due to Underwater Noise from the Case Study of Field Measurement at Marphysa sanguinea Farm (바위갯지렁이 양식장 인접지역 계측 사례를 포함한 수중소음 피해인정기준에서 배경소음과의 차에 대한 문제점)

  • Choi, Tae-Hong;Kim, Jae-Woong;Ko, Chin-Surk
    • Explosives and Blasting
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    • v.35 no.1
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    • pp.34-42
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    • 2017
  • It is very difficult to clearly define the damages caused by blasting-induced noise and vibration, because the damages depend on, besides the level of noise and vibration, the response of the object, environmental conditions, subjective feeling, and mental condition. Especially, it is more difficult when the fish is concerned, because that experimental approach is not easy and that we lack of the reasonable criterion for the acceptance level of noise and vibration. In Korea, the acceptance level for damage due to underwater noise is 140 dB re $1{\mu}Pa$, and the difference from the underwater background sound level is defined as more than 20 dB re $1{\mu}Pa$. It is however, appropriate for continuous noise not for transient sound. The authors compared the relationship between vibration velocity and underwater noise measured from the test blasting around Marphysa sanguinea farm. This paper presents the measurement results and suggestions the acceptance level for damage due to underwater noise from explosive blasting.

Omnidirectional Circularly Polarized Antenna Using Zeroth-Order Resonance (영차 공진을 이용한 전방향성 원형 편파 안테나)

  • Park, Byung-Chul;Lee, Jeong-Hae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.8
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    • pp.806-812
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    • 2009
  • In this paper, the omnidirectional circularly polarized(CP) antenna using arc-shaped mushroom structure with curved branch is proposed. To obtain a vertical polarization and an omnidirectional radiation pattern, the CP antenna uses zeroth-order resonance(ZOR) mode of composite right and left handed(CRLH) transmission line. The horizontal polarization is achieved by the curved branches. Also, the spacing between curved branch and arc-shaped mushroom structure gives the $90^{\circ}$ phase difference between vortical and horizontal polarization. The proposed antenna, therefore, has an omnidirectional CP radiation pattern In the azimuthal plane. The electrical size of the proposed antenna is reduced by 38%, compared with that of the previously presented omnidirectional CP antenna. In addition, the CP antenna is simply designed without $90^{\circ}$ phase shifter and dual feed line. The proposed antenna uses a Bazooka balun for good impedance matching and radiation pattern. To improve 3 dB axial ratio in XY plane, the designed antenna is optimized. After optimization, the measured 3 dB axial ratio in XY plane is observed in $86{\sim}282^{\circ}$.

A Prediction Search Algorithm in Video Coding by using Neighboring-Block Motion Vectors (비디오 코딩을 위한 인접블록 움직임 벡터를 이용한 예측 탐색 알고리즘)

  • Kwak, Sung-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.8
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    • pp.3697-3705
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    • 2011
  • There is the temporal correlation of the video sequence between the motion vector of current block and the motion vector of previous block. In this paper, we propose a new prediction search algorithm for block matching using the temporal and spatial correlation of the video sequence and local statistics of neighboring motion vectors. The proposed ANBA(Adaptive Neighboring-Block Search Algorithm) determines the location of a better starting point for the search of an exact motion vector using the point of the smallest SAD(Sum of Absolute Difference) value by the predicted motion vectors of neighboring blocks around the same block of the previous frame and the current frame and use a previous motion vector. Simulation results show that PSNR(Peak-to-Signal Noise Ratio) values are improved up to the 1.06dB as depend on the video sequences and improved about 0.01~0.64dB over MVFAST and PMVFAST.

In situ acoustic characteristics of the large jellyfish Nemopilema nomurai in the East China Sea (동중국해에서 노무라입깃해파리의 in situ 음향산란특성)

  • Yoon, Eun-A;Hwang, Doo-Jin;Shin, Hyeong-Ho;Gwa, Du-Seong;Cha, Cheol-Pyo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.3
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    • pp.256-268
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    • 2012
  • The Nemopilema nomurai is a large jellyfish attaining a weight of 200 kg and bell diameter of 2 m when fully grown. To prevent damage to this species, this study determined the acoustic characteristics of N. nomurai using frequencies 38 and 120 kHz. The CPUE of N. nomurai and the averaged SV of 38 and 120 kHz had a lower (+) correlation coefficient and relationship at 120 kHz (R=0.51) than at 38 kHz (R=0.15) was significant. In addition, the averaged SV at 120 kHz was higher than at 38 kHz. The ${\Delta}MVBS_{120-38}$ in section catches ${\geq}97.8%$ wet mass of N. nomurai was -2.2 to 5.6 dB. The ${\Delta}TS_{120-38}$ in situ TS was extracted in sections catches of only N. nomurai by FMT. It was found that the averaged in situ ${\Delta}TS_{120-38}$ were at 0.6 and 0.1 dB. Furthermore, it results showed a close relationship between the bell diameter and TS of N. nomurai. The dominance of smaller N. nomurai (11.0~20.0 cm bell diameter in the air) corresponded to a similar proportion of low TS values (-69.0~-65.0 dB). A small number of larger N. nomurai (25.0~38.0 cm bell diameter in the air) were collected, in which TS values were the highest (-62.0~-58.0 dB).

The Influence of the Aspect Ratio on the Natural Frequency of the Composite Laminated Plates (복합적층판의 고유진동수에 대한 형상비의 영향)

  • Han, Bong-Koo;Suck, Ju-Won
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.1 no.2
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    • pp.14-19
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    • 2010
  • Theories for advanced composite structures are too difficult for such design engineers for construction and some simple but accurate enough methods are necessary. The senior author has reported that some laminate orientations have decreasing values of $D_{16}$, $B_{16}$, $D_{26}$ and $B_{26}$ stiffnesses as the ply number increases. For such plates, the fiber orientations given above behave as specially orthotropic plates and simple formulas developed by the senior author. Most of the bridge and building slabs on girders have large aspect ratios. For such cases further simplification is possible by neglecting the effect of the longitudinal moment terms(Mx) on the relevant partial differential equations of equilibrium. In this paper. the influence of the aspect ratio on the natural frequency of the composite laminated plates is studied and it is concluded that the method used is sufficiently accurate for engineering purposes.

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