• Asian-Australasian Journal of Animal Sciences
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• v.14 no.8
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• pp.1164-1169
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• 2001

A five-week trial was conducted to evaluate the effect of organic chromium from different sources on growth performance, immune response and serum parameters of weaned pigs. One hundred and eighty Tianjin white pigs weaned at $35{\pm}1$ days of age, were allotted to three treatments with six replicates and10 pigs per pen. Pigs were fed corn-soybean-whey-fishmeal basal diets with either no supplemental Cr, $200{\mu}g/kg$ Cr as chromium picolinate (CrPi), or $200{\mu}g/kg$ Cr as chromium yeast (Cr-yeast). To assess humoral immune response, all pigs were immunized with swine fever virus on day 21 and two pigs from each pen were immunized with pure albumin on day 14. Cell-mediated immunity was measured by determining the double skinfold thickness (DST) of two pigs from each pen before and 24h after stimulation with phytohemagglutinin (PHA) on day 28. The results indicated that: (1) diets with Cr-yeast increased average daily gain (ADG, p<0.05) and tended to increase average daily feed intake (ADFI, p<0.10). Diets with CrPi did not increase ADG and ADFI (p>0.05). (2) Dietary CrPi or Cr-yeast supplementation did not affect blood urea nitrogen, glucose, or cholesterol (p>0.05), but blood urea nitrogen in CrPi and Cr-yeast supplemented groups and blood glucose in the Cr-yeast supplemented group were significantly influenced by sampling days (p<0.05). (3) Serum proteins (TP, ALB, and GLB) were influenced by sampling days (p<0.05), but not by dietary Cr treatment (p>0.10). (4) There were no significant differences among treatments in the titers of albumin antibody and swine fever virus antibody (p>0.05) or DST before and after PHA stimulation (p>0.05), indicating that organic chromium has no significant effect on the immune function of weaning pigs. Therefore, these results agree with other research that the effects of supplemental Cr are variable in weanling pigs.

• Biomedical Science Letters
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• v.8 no.4
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• pp.235-244
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• 2002

This study was carried out to determine the blood and milk progesterone by enzyme-linked immunosorbent assay (ELISA), and milk urea nitrogen (MUN) in cows. MUN and protein concentration were determined using automated infared procedures. The optimum conditions of ELISA system was investigated including the first and second antibody titres, bound percent, and enzyme conjugate and also the factors on MUN and protein concentration by sampling procedures and addition of preservatives. Progesterone antibodies did not react to pregnenlone, testosterone, estrone, estradiol-l7$\beta$, aldosterone, cortisol, corticosterone and 11$\alpha$-dehydroxycortisone (DOC), but reacted with only progesterone. The intra and inter-assay coefficient of variation 4.5%, 6.1~9.4% when used of bovine serum. The morning, MUN concentration (17.6$\pm$2.8 mg/100 ml) in the 13 herds was similar to that of evening MUN concentration of the lactating cows from the same herd. A significant relationship between morning and evening milk samples of upper parameters was found r=0.93. Difference in MUN concentration with sampling procedures and using of preservatives were investigated.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.573-581
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• 2001

The purposes of this study are to estimate mean willingness to pay (WTP) for preventing forest fires by contingent valuation method (CVM), and to calibrate the variables affecting WTP. The forest fire prevention fund was utilized as a payment vehicle to elicit respondents' willingness to pay (WTP). A total of 500 adults who reside in Seoul Metropolitan area were selected by two-stage cluster sampling and conducted the face-to-face interview. The scenario was designed to meet the requirements for double-bounded dichotomous choice CVM. More than half of the respondents (64.6%) have a willing to pay for the fund. The mean WTP was \4,532. Therefore a total WTP for the population was \34,165,758,000. The calibration of Weibull proportional hazard model showed that education level, environmental conservation intention and negative consciousness about the effect of forest fire were independent variables strongly influencing the WTP.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.6
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• pp.65-72
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• 2001

This paper deals with a novel full digital control of the single-phase PWM(Pulse Width Modulation) inviter for UPS(Uninterruptible Power Supp1y). The voltage and current of output filter capacitor as a state variable are the feedback control input. In the proposed scheme a double deadbeat control consisting of minor current control loop and major voltage control loop have been developed In addition, a second order deadbeat currents control which should be exactly equal to its reference in two sampling time without error and overshoot is proposed to remove the influence of the calculation time delay. The load current prediction is achieved to compensate the load disturbance. The simulation and experimental result shows that the proposed system offers an output voltage with THD(Total Harmonic Distortion) less than 5% at a full nonlinear load.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.141-152
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• 2011

The purpose of this study was to investigate the projectile factors and biomechanical characteristics of men's hammer throwing during turning phases. Four national leveled athletes including Korea national record holder participated in this study. After full warm-up, each participant performed 6 trials of hammer throwing with their best. The best recorded trial was selected from each participant and they were analyzed for this study. Three-Dimensional motion analysis using a system of 5 video cameras at a sampling frequency 60Hz was performed for this study. As the number of turns increased, athletes revealed following characteristics. 1) The single and double support time decreased. 2) The rotation foot was closed to axis foot and it revealed greater medio-lateral displacement than that of horizontal one. 3) At the transition point from double support to single support, ball was in front of rotation foot so that not much angular velocity obtained. For the projectile factors, projectile angle did not show differences while projectile height and velocity revealed differences among the participants. It may indicated that each athlete has different fitness and skill level to resist centrifugal force which become larger as the number of turn increased.

• Journal of Astronomy and Space Sciences
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• v.28 no.1
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• pp.55-62
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• 2011

The precise orbit determination (POD) of low earth orbiter (LEO) has complied with its required positioning accuracy by the double-differencing of observations between International GNSS Service (IGS) and LEO to eliminate the common clock error of the global positioning system (GPS) satellites and receiver. Using this method, we also have achieved the 1 m positioning accuracy of Korea Multi-Purpose Satellite (KOMPSAT)-2. However double-differencing POD has huge load of processing the global network of lots of ground stations because LEO turns around the Earth with rapid velocity. And both the centimeter accuracy and the near real time (NRT) processing have been needed in the LEO POD applications--atmospheric sounding or urgent image processing--as well as the surveying. An alternative to differential GPS for high accuracy NRT POD is precise point positioning (PPP) to use measurements from one satellite receiver only, to replace the broadcast navigation message with precise post processed values from IGS, and to have phase measurements of dual frequency GPS receiver. PPP can obtain positioning accuracy comparable to that of differential positioning. KOMPSAT-5 has a precise dual frequency GPS flight receiver (integrated GPS and occultation receiver, IGOR) to satisfy the accuracy requirements of 20 cm positioning accuracy for highly precise synthetic aperture radar image processing and to collect GPS radio occultation measurements for atmospheric sounding. In this paper we obtained about 3-5 cm positioning accuracies using the real GPS data of the Gravity Recover and Climate Experiment (GRACE) satellites loaded the Blackjack receiver, a predecessor of IGOR. And it is important to reduce the latency of orbit determination processing in the NRT POD. This latency is determined as the volume of GPS measurements. Thus changing the sampling intervals, we show their latency to able to reduce without the precision degradation as the assessment of their precision.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.1
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• pp.43-48
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• 2009

We constructed a simple wavelength readout system for a tunable fiber laser which was used for a fiber Bragg grating sensor array system. A quadrature sampling method was used to demodulate wavelength variations of the tunable laser which consisted of a SOA(semi-conductor optical amplifier) and a fiber-optic Fabry-Perot filter. Internal triggers, which have a 90 degree phase period, have been generated by using a double-pass Mach-Zehnder interferometer. From Lissajous plots with quadrature sampled data, a mean phase error of ${\sim}2.51$ mrad was obtained. From the wavelength readout experiments, an accurate and fast linear wavelength demodulation has been confirmed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.11
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• pp.35-42
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• 2004

A CMOS folding ADC with transistor differential pair folding circuit for low power consumption and high speed operation is presented in this paper. This paper explains the theory of transistor differential pair folding technique and many advantages compared with conventional folding and interpolation circuits. A ADC based on transistor differential pair folding circuit uses 16 fine comparators and 32 interpolation resistors. So it is possible to achieve low power consumption, high speed operation and small chip size. Design technology is based on fully standard 0.25${\mu}{\textrm}{m}$ double poly 2 metal n-well CMOS process. A power consumption is 45mW at 2.5V applied voltage and 250MHz sampling frequency. The INL and DNL are within $\pm$0.15LSB and $\pm$0.15LSB respectively. The SNDR is approximately 50dB at 10MHz input frequency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1442-1447
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• 2004

In this paper, a 6-Bit CMOS Folding and Interpolating AD Converter is presented. The converter is considered to be useful as an integrated part of a VLSI circuit handling both analog and digital signals as in the case of HDD or LAN applications. A built-in analog circuit for VLSI of a high-speed data communication requires a small chip area, low power consumption, and fast data processing. The proposed folding and interpolating AD Converter uses a very small number of comparators and interpolation resistors, which is achieved by cascading a couple of folders working in different principles. This reduced number of parts is a big advantage for a built-in AD converter design. The design is based on 0.25m double-poly 2 metal n-well CMOS process. In the simulation, with the applied 2.5V and a sampling frequency of 500MHz, the measurements are as follows: power consumption of 27mw, INL and DNL of $\pm$0.1LSB, $\pm$0.15LSB each, SNDR of 42dB with an input signal of 10MHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.826-832
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• 2004

A CMOS 8 bit folding and interpolating ADC for an embedded system inside VLSI is presented in this paper. This folding ADC uses the 2 stage architecture for improving of nonlinearity. repeating the folding and interpolating twice. At a proposed structure, a transistor differential pair operates on the second folder. A ADC with 2 stage architecture reduces the number of comparators and resisters. So it is possible to provide small chip size, low power consumption and high operating speed. The design technology is based on fully standard 0.25m double-Poly 2 metal n-well CMOS Process. The simulated Power consumption is 45mW with an applied voltage of 2.5V and sampling frequency of 250MHz. The INL and DNL are within <ㅆㄸㅌ>$\pm$0.2LSB, respectively. The SNDR is approximately 45dB for input frequency of 10MHz.