• Title/Summary/Keyword: Range of variation

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Ultrasonic Velocity and Absorption Measurements in Egg White

  • Kim, Jeong-Koo;Bae, Jong-Rim
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.3E
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    • pp.126-131
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    • 2002
  • Ultrasonic measurements are made in egg white to study the properties of the solution of the natural protein. The high-Q ultrasonic resonator method is used to get the ultrasonic absorption spectra over the range 0.2-10 ㎒ at 20℃. It is proportional to the 1.25th power of the frequency. The gelation process caused by heat is studied from the change in the velocity and the absorption. at 3 ㎒ using the pulse echo overlap technique over the range of 10-80℃. The absorption decreases with increasing temperature up to 60℃ where it turns up sharply and rapidly increases thereafter. The strong absorption in the gel region is described by the interaction between the solution and the network structure made of protein. Very slow variation in time elapse is observed after the temperature is quickly raised. It would be a real-time observation of the network building process and the characteristic time for the process is shown to be 400 min. A hysteresis phenomenon with respect to the temperature is observed. This phenomenon is associated with the memorizing effect of the network structure of protein of the gel.

Measurement of noise characteristics of an image sensor (화상센서의 잡음 특성 측정)

  • Lee, Tae-Kyoung;Hahn, Jae-Won
    • Transactions of the Society of Information Storage Systems
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    • v.5 no.2
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    • pp.89-95
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    • 2009
  • We setup the system to measure the noise characteristics of the 5M complementary metal-oxide semiconductor (CMOS) image sensor by generic measurement indicator of Standard mobile imaging architecture (SMIA) which is one of internal standard of mobile imaging architecture. To evaluate the effect of environment and setting parameters, such as temperature and integration time, we measure the variation of the dark signal, dynamic range and fixed pattern noise of image sensor. We also detect the number of defective pixels and cluster defects defined as adjacent single defect pixels at 5M CMOS image sensor. Then, we find the existence of some cluster defects in experiment, which are not expected in calculation.

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Electrical Breakdown Properties of Insulating Oils for oil-immersed transformer (유입변압기용 절연유의 절연파괴특성)

  • 이인성;신현택;이종필;이수원;홍진웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.605-608
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    • 2001
  • With the intention of investigating the breakdown properties of oil-immersed transformer oils in temperature range of 20∼100[$^{\circ}C$], we are made researches AC breakdown in the gap of 500∼2,500[$\mu\textrm{m}$]. The classification for the physical properties of oil for oil-immersed transformer by FTH and $^1$H-NMR experiments was confirmed to type of mineral oils. As the dependance of breakdown properties due to electrode gap length variation, breakdown voltage was found increasing according to the increase of gap, while dielectric strength was decreasing. As a result the characteristics for AC breakdown, It goes to prove that the breakdown voltage was increased to 90[$^{\circ}C$] but decreased over 90[$^{\circ}C$] in the temperature range. Also, breakdown voltage was found increasing in the increase of gap and the rising of temperature according to Weibull distribution.

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A Method for Identifying Source Regions of Asian Dust Using the Long-range Transport Model and Satellite Images

  • Goto, Takeshi;Kawaguchi, Kazuo;Kusaka, Takashi
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.738-740
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    • 2003
  • A method for identifying the released region and time of Asian dust using the long-range inverse transport model that traces the wind field in the backward direction from positions where Asian dust was observed is described. Initial conditions for the inverse transport simulation were obtained from the time variation of the density distribution of the suspended particulate matter (SPM) in the air measured at various places in Japan. Based on a concentration of trajectories of the air mass computed by the inverse transport model, the source region of Asian dust clouds observed at meteorological stations in Japan on March 17 to 18, 2002 was estimated. As a result, it was found that dust particles were released at about 6h on March 15 in the neighborhood of Inner Mongolian Autonomous Region.

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A study on color planning appropriate for residential space (주거공간의 색채 계획에 대한 공간별 비교분석에 관한 연구)

  • Ha, Mi-Kyeong;Shin, Sun-Joo
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2007.11a
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    • pp.79-83
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    • 2007
  • The demand for residential space is encompassing diverse ranges to keep pace with the times. Due to the Increase in wealth, people today want more functional and physical well being as well as giving more weight to the emotional aspect in spatial planning. This study paid special attention on the psychological effect of color--especially difference of warm/cold temperature--and the individual variation on favorable colors. 1. For a communal space (e.g. living rooms), subjects showed high preference of YR range of colors and warm colors. 2. For an individual space (e.g. bedrooms), subjects showed high preference of GY range of colors and neutral colors. 3. For a sanitary space (e.g. bathrooms), subjects showed high preference of PB and B ranges of colors, and cold colors. 4. For all of the above spaces, subjects showed high preference of warm colors.

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Investigation on field emission properties of diamond-like carbon thin film by variation of laser processing parameters (레이저 공정변수 변화에 따른 다이아몬드상 카본박막의 전계방출 특성분석)

  • Shim, Kyung-Suk;Lee, Sang-Yeol
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1511-1513
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    • 1999
  • In order to investigate the properties of diamond-like carbon(DLC) thin films depending on the deposition parameters, DLC thin films were systematically fabricated by pulsed laser deposition (PLD), DLC thin films have been shown advantageous field emission properties due to a negative electron affinity (NEA) and a low work function. At the atomic level. DLC is referred to the group of carbon materials with strong chemical bonding composition of $sp^2$ and $sp^3$ arrangements of atoms incorporated with an amorphous structure. The experiment was performed at substrate temperature in the range of room temperature to $600^{\circ}C$. The laser energy densiy was used to be in the range of $6J/cm^2$ to $20J/cm^2$, SEM, Raman, PL, XPS and field emission characteristics were used to investigate the DLC thin films.

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Variation of Carbonization Pattern and Crystal Structure of Polyvinyl Chloride Wire Under the Thermal Stresses (열 스트레스에 의한 비닐절연전선의 탄화 패턴 및 결정 구조의 변화)

  • Choi, Chung-Seog;Kim, Hyang-Kon
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.3
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    • pp.332-337
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    • 2008
  • We analyzed carbonization pattern and crystal structure of polyvinyl chloride wire by thermal stress. Copper that is oxidized at normal temperature is a reddish brown. If under the thermal stress range of 500 to 700 [$^{\circ}C$], carbonization and exfoliation occurrence. Section structure of electric wire is same as arrangement of particle in metallograph analysis. But, as thermal stress increases, size of particle is enlarged. Electric wire displays elongation structure in SEM image analysis and elongation structure collapses when receive thermal stress at 300 [$^{\circ}C$]. In EDX analysis, we get the spectra of CuL, CuK, OK, and ClK. FT-IR analysis was shown new spectra with in range of $1,440{\sim}1,430\;[cm^{-1}]$, 1,340 [$cm^{-1}$], 1,240 [$cm^{-1}$].

pH Effect on the Aerobic Biodegradation of Nitrophenolic Compound in SBR (니트로페놀화합물의 호기성생물분해시 pH 영향에 관한 연구)

  • Jo, Kwan-Hyung
    • Journal of Environmental Science International
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    • v.16 no.7
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    • pp.779-784
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    • 2007
  • Dinitrophenol is preventing cells from making energy for growth and it has been suggested that pH may be important in mitigating effects of uncouplers. The effect of pH on toxicity of dinitrophenol at high concentration was investigated, over a pH range of 5.7 to 8.7. DNP inhibition was found to be strongly dependent on mixed liquor pH. The DNP degradation rate was highest in the pH range of 7.0 to 7.8; at pH 6.0 degradation of 0.41 mM dinitrophenol was significantly inhibited; at pH <5.7, dinitrophenol degradation was completely inhibited after approximately 25% of the dinitrophenol was degraded. However no significant effect of pH variation was seen on glucose uptake by the activated sludge mixed culture.

A Study on Dielectric Properties of Printed Circuit Board(PCB) Materials with Variation of Frequency and Temperature (온도 및 주파수 변화에 따른 프린트 배선기판의 유전특성 연구)

  • 박종성;김종헌;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.135-138
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    • 1998
  • This paper presents the results of measured permittivity of PCB sheet material in the frequency range of 0.1[GHz] - 2[GHz] and temperature range of $25[^{\circ}C]$ - $85[^{\circ}C]$. Microstrip lines with different physical length are implemented to measure the attenuation and phase shift of the signals though these lines. The loss factor of these materials could be obtained with the dielectric constant and the attenuation of the microstrip lines.

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Impoved Performance of Sensorless Induction Motor Drive in Low Speed Range Using Variable Link Voltage (가변 링크전압에 의한 센서리스 유도전동기의 저속운전 성능개선)

  • 김상균;권영안
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.53 no.2
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    • pp.90-98
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    • 2004
  • Variable-speed drives are being continually innovated. Recently, sensorless induction motor drives have been much studied due to several advantages. Most sensorless algorithms are based on the mathematical modeling of motors, and all the information is obtained from the monitored voltages and currents. Therefore, the accuracy of such variables largely affects the performance of a sensorless induction motor drive. However, the output voltage of the SVPWM-VSI which is widely used in a sensorless induction motor drive has a considerable error, especially in a low speed range. This paper proposes a variation of the dc link voltage as a high-performance strategy for overcoming the above problem. The proposed strategy leads to an improved resolution of the output voltage of the SVPWM-VSI in a sensorless induction motor drive. Simulation and experiment have been performed for the verification of the proposed strategy.