• Title/Summary/Keyword: Reference temperature

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Estimation of Kinetic Parameters of Nonenzymatic Browning Reaction Using Equivalent Time at Reference Temperarture with Linearly Increasing Temperature Profile (정속가열(定速加熱)조건에서 표준온도상당시간(相當時間)을 이용한 비효소적 갈색화 반응의 동력학 파라미터 추정(推定))

  • Cho, Hyung-Yong;Kwon, Yun-Joong;Kim, In-Kyu;Pyun, Yu-Ruamg
    • Korean Journal of Food Science and Technology
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    • v.25 no.2
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    • pp.178-184
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    • 1993
  • The procedure using equivalent time at reference temperature has been assessed for the estimation of kinetic parameters with experimental data. Kinetic studies of nonenzymatic browning reaction in model and food system were carried out with linearly increasing temperature method. These kinetic parameters, n, $k_{ref}$ and $E_a$ of the systems were evaluated from original data in one step by nonlinear least square regression. The one step procedure yielded efficiently accurate parameter estimation. Computer simulated data with the kinetic models were well consistent with experimental data (average correlation coefficient=0.96).

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An Agrometeorological Reference Index for Projecting Weather-Related Crop Risk under Climate Change Scenario (농작물의 기상재해 발생위험 판정기준 설정 및 지구 온난화에 따른 기준기상위험의 변화 전망)

  • Kim, Dae-jun;Kim, Jin-hee;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.3
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    • pp.162-169
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    • 2016
  • The agrometeorological reference index means 'the agrometeorological damage possibility' or the possibility of the normal year climate condition to damage the crop cultivation in a certain region. It is a reference used to compare the cultivation risk of a crop by region. The global climate warming is expected to increase the winter temperature. At the same time, the frequency of extreme weather events will also increase. Therefore, people pay attention to the potential of low temperature-induced damages (e.g., frost damage and injury) to fruit trees under the future climate condition. However, simple damage projection based on climate conditions does not help the climate change adaptation in the practical aspect because the climate change affects the phenology of fruit trees as well. This study predicted the phenology of the pear, peach, and apple trees by using the climate change scenarios of major regions. Furthermore, low temperature induced agrometeorological reference indices were calculated based on the effects of temperature on each plant growth stage to predict the damage possibility. It was predicted that the breaking rest would delay more in the future while the bud-burst date and flowering date will be earlier. In Daegu, Jeonju, and Mokpo, the breaking rest delayed more as time passed. The bud-burst date and flowering date of Seoul and Incheon regions were later than other regions. Seoul and Incheon showed a similar pattern, while Daegu and Jeonju revealed a similar pattern. Busan and Mokpo also showed a similar pattern. All regions were safe from the frost damage during the dormancy period. However, plants were vulnerable to frost damage between the breaking rest and the bud-burst period. Regions showed different frost damage patterns between the bud-burst period and the flowering period. During the bud-burst and flowering period, the risk level decreased in general, although the risk of some areas tended to increase.

The Most Suitable Reference White Setting for Three-tube Projection HDTV (3관식 프로젝션 HDTV의 기준 백색 설정)

  • 정재영;구병준;권용대;이광순;송규익
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.239-242
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    • 2000
  • The color television signal and color receivers should be balanced for the same value of reference white to achieve colorimetric fidelity and to minimize interference. The NTSC signal is balanced for white at 6774 K and most existing receivers are balanced between 6500 K and 10000 K for many reasons. In this paper, we analyze beam current ratio, lightness, and channel gain ratio according to the color temperature for the three-tube projection HDTV. We also propose the brighter reference white for the three-tube projection HDTV based on the Helmholtz-Kohlrausch effect and the optical resolution of the image. In computer simulation we confirmed the most suitable reference white using the proposed analysis method.

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CMOS on-chip voltage and current reference circuits for low-voltage applications (저전압용 CMOS 온-칩 기준 전압 및 전류 회로)

  • 김민정;이승훈
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.4
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    • pp.1-15
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    • 1997
  • This paper proposes CMOS on-chip voltage and current reference circuits that operate at supply voltages between 2.5V and 5.5V without using a vonventional bandgap voltage structure. The proposed reference circuits based on enhancement-type MOS transistors show low cost, compatibility with other on-chip MOS circuits, low-power consumption, and small-chip size. The prototype was implemented in a 0.6 um n-well single-poly double-metal CMOS process and occupies an active die area of $710 um \times 190 um$. The proposed voltage reference realizes a mean value of 0.97 V with a standard deviation of $\pm0.39 mV$, and a temperature coefficient of $8.2 ppm/^{\circ}C$ over an extended temeprature range from TEX>$-25^{\circ}C$ to $75^{\circ}C$. A measured PSRR (power supply rejection ratio) is about -67 dB at 50kHz.

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Innovative Decision Reference Based Algorithm for Photovoltaic Maximum Power Point Tracking

  • Mehrnami, Siamak;Farhangi, Shahrokh
    • Journal of Power Electronics
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    • v.10 no.5
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    • pp.528-537
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    • 2010
  • A novel decision reference based method for the maximum power point tracking (MPPT) of PV arrays is presented in this paper. The proposed decision reference was derived from a simplified solar cell model. This method solves the problems of conventional MPPT algorithms, such as oscillation of the operating point at the steady state and confusion under rapidly changing insolation. It is shown by simulation and experimental results that the method properly tracks a rapidly changing insolation profile. The signal to noise ratio (SNR) of the new decision reference is also higher than those of conventional P&O and INC methods. An updating subroutine was included in the proposed MPPT algorithm to compensate for temperature and aging effects.

A Design of CMOS Subbandgap Reference using Pseudo-Resistors (가상저항을 이용한 CMOS Subbandgap 기준전압회로 설계)

  • Lee, Sang-Ju;Lim, Shin-Il
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.609-611
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    • 2006
  • This paper describes a CMOS sub-bandgap reference using Pseudo-Resistors which can be widely used in flash memory, DRAM, ADC and Power management circuits. Bandgap reference circuit operates weak inversion for reducing power consumption and uses Pseudo-Resistors for reducing the chip area, instead of big resistor. It is implemented in 0.35um Standard 1P4M CMOS process. The temperature coefficient is 5ppm/$^{\circ}C$ from $40^{\circ}C$ to $100^{\circ}C$ and minimum power supply voltage is 1.2V The core area is 1177um${\times}$617um. Total current is below 2.8uA and output voltage is 0.598V at $27^{\circ}C$.

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A Novel Low Voltage Reference Circuit for Low Power OLED Driver ICs (저 소비전력 OLED 구동 IC 응용을 위한 새로운 구조의 Low Voltage Reference 회로 설계에 관한 연구)

  • 김재헌;신홍재;이재선;최성욱;곽계달
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.923-926
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    • 2003
  • This paper presents a novel low voltage reference circuit under the MOS threshold voltage(V$_{th}$) in standard CMOS process. It is based on the weighted difference of the gate-source voltages of an NMOS and a PMOS operating in saturation region. The voltage reference is designed for low power OLED driver ICs. The proposed circuit is designed using 0.35${\mu}{\textrm}{m}$ CMOS technology. The minimum supply voltage is 2V, and the typical temperature coefficient is 99.6ppm/ C.C.

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The Calorie Allowances for Koreans (한국인(韓國人) 칼로리 권장량(勸?量))

  • Kim, D.J.
    • Journal of Nutrition and Health
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    • v.1 no.1
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    • pp.49-51
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    • 1968
  • The Calorie allowances for a reference man (25 years, 60kg, moderate work) and a reference woman (25 years, 52kg, moderate work) were given by the formulae which were recommended by the Food and Agricultural Organization(FAO). E=152 W 0.73 3,000 Calories(man) E=123.4 W 0.73 2,200 Calories (woman) The appropriate adjustments were made for age, body weight (Table 1) and activity (Table 2) of adults other than a 'reference man' and 'reference woman' based on our report of 'Studies of Basal Metabolism and Energy Expenditure of Koreans in Daily Life' supported partly by the U.S. Department of Agriculture. The recommendation of FAO for the calorie requirements for children, the additional allowances for pregnancy, lactation and environmental temperature were adopted.

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Study for the Changes of Annual and Seasonal Mean Temperature Using Adjusted Temperature Data in the Republic of Korea (고품질의 기온자료를 이용한 연.계절평균기온의 변화에 관한 연구)

  • Park, Chang-Yong;Choi, Young-Eun
    • Journal of the Korean Geographical Society
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    • v.46 no.1
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    • pp.20-35
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    • 2011
  • This study suggested the systematic steps for quality control, construction of the climatological reference series and homogeneity test and adjustment of temperature series in the Republic of Korea. It also attempted to evaluate more accurate magnitude of change using adjusted temperature data. All erroneous values produced by quality control were detected by internal inconsistency check. The method selected for homogeneity test in this study well defined fairly correct signals of station relocations. Therefore, this method might be regarded as the appropriate one to test homogeneity of temperature series of the Republic of Korea. The increase of temperature of the Republic of Korea after the adjustment were bigger than before the adjustment of annual and seasonal mean temperature. Adjusted temperature data produced by these steps will enable to evaluate more accurate characteristics and magnitude of climate change.

Reference Electrode at Molten Salt: A Comparative Analysis of Electroceramic Membranes

  • Yoon, Seokjoo;Kang, Dokyu;Sohn, Sungjune;Park, Jaeyeong;Lee, Minho;Choi, Sungyeol
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.2
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    • pp.143-155
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    • 2020
  • A reference electrode is important for controlling electrochemical reactions. Evaluating properties such as the reduction potential of the elements is necessary to optimize the electrochemical processes in pyroprocessing, especially in a multicomponent environment. In molten chloride systems, which are widely used in pyroprocessing, a reference electrode is made by enclosing the silver wire and molten salt solution containing silver chloride into the membranes. However, owing to the high temperature of the molten salt, the choice of the membrane for the reference electrode is limited. In this study, three types of electroceramic, mullite, Pyrex, and quartz, were compared as reference electrode membranes. They are widely used in molten salt electrochemical processes. The potential measurements between the two reference electrode systems showed that the mullite membrane has potential deviations of approximately 50 mV or less at temperatures higher than 650℃, Pyrex at temperatures lower than 500℃, and quartz at temperatures higher than 800℃. Cyclic voltammograms with different membranes showed a significant potential shift when different membranes were utilized. This research demonstrated the uncertainties of potential measurement by a single membrane and the potential shift that occurs because of the use of different membranes.