• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.12
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• pp.45-51
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• 2011

This paper presents a wideband low-noise amplifier (LNA) covering 800MHz~5.8GHz for various wireless communication standards by utilizing in a 0.13um CMOS technology. Particularly, the LNA consists of two stages to improve the low-noise characteristics, that is, a cascode input stage and an output buffer with noise cancellation technique. Also, a feedback resistor is exploited to help achieve wideband impedance matching and wide bandwidth. Measure results demonstrate the bandwidth of 811MHz~5.8GHz, the maximum gain of 11.7dB within the bandwidth, the noise figure of 2.58~5.11dB. The chip occupies the area of $0.7{\times}0.9mm^2$, including pads. DC measurements reveal the power consumption of 12mW from a single 1.2V supply.

• Journal of Community Nutrition
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• v.4 no.1
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• pp.3-11
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• 2002

The purpose of this study is to evaluate the iron nutritional status by investigating dietary intake and analyzing the hematological iron status indices including serum transferrin receptor (sTfR) in 8 to 28 month old infants md young children taking supplementary foods. The nutrient intake of 60 healthy infants and young children from 8 to 24 months of age was investigated by means of a 24-hour recall method, and the subjects were divided into 2 groups (8- 12 months and 13-28 months) according to age. Venous blood samples from these groups were collected and measured for the following : hemoglobin(Hb), hematocrit(Hct) , mean corpuscular volume (MCV), mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration (MCHC), serum ferritin, serum iron, total iron binding capacity (TIBC), and sTfR. Anemia is defined as hemoglobin < 11g /dl , serum ferritin level < 10ng1m1 for iron deficiency , serum transferring receptor(sTfR) > 4.5mg / 1 for iron deficient erythropoiesis. Total daily calorie intake was 934.6 ${\pm}$ 284.5kcal (98.32% of RDA) on average. Average daily iron intake in infants aged 8 to 12 months was 8.92 ${\pm}$ 3.32mg. The mean daily iron intake in infants aged 13 to 28 months was 7.15 ${\pm}$ 3.35mg (90% of Recommended Dietary Allowance, RDA). Mean values for Hb, Hct sew ferritin and sTfR were 12.10 ${\pm}$ 0.77g141,36.02 ${\pm}$ 2.31%,20.91 ${\pm}$ 11.58ng/m1 and 3.78 ${\pm}$ 1.47mg /1, respectively. In the young children from 13 to 28 months of age, the prevalence of anemia was 5.6%. The prevalence of iron deficiency was 9.5% in those from 8 to 12 months of age, and 27.8% in those from 13 to 28 months of age. The prevalence of iron deficient erythropoiesis was 16.7% in infants aged 8 to 12 months and 44.4% in those aged 13 to 28 months. The prevalence of both serum ferritin level < 10ng/m1 sTfR > 4.5mg/1 was 22% in the young children aged 13 to 28 months. The measureand ment of sTfR may be a promising new tool in diagnosis of iron deficiency in early childhood when the iron deficiency is prevalent. It seems appropriate to emphasize nutritional education and evaluation to promote the iron nutritional status of infants and young children.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.1-11
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• 2015

Purpose : Evaluating absorbed dose related to 2D and 3D imaging confirmation devices Materials and Methods : According to the radiographic projection conditions, absorbed doses are measured that 3 glass dosimeters attached to the centers of 0', 90', 180' and 270' in the head, thorax and abdomen each with Rando phantom are used in field size $26.6{\times}20$, $15{\times}15$. In the same way, absorbed doses are measured for width 16cm and 10cm of CBCT each. OBI(version 1.5) system and calibrated glass dosimeters are used for the measurement. Results : AP projection for 2D imaging check, In $0^{\circ}$ degree absorbed doses measured in the head were $1.44{\pm}0.26mGy$ with the field size $26.6{\times}20$, $1.17{\pm}0.02mGy$ with the field size $15{\times}15$. With the same method, absorbed doses in the thorax were $3.08{\pm}0.86mGy$ to $0.57{\pm}0.02mGy$ by reducing field size. In the abdomen, absorbed dose were reduced $8.19{\pm}0.54mGy$ to $4.19{\pm}0.09mGy$. Finally according to the field size, absorbed doses has decreased by average 5~12%. With Lateral projection, absorbed doses showed average 5~8% decrease. CBCT for 3D imaging check, CBDI in the head were $4.39{\pm}0.11mGy$ to $3.99{\pm}0.13mGy$ by reducing the width 16cm to 10cm. In the same way in thorax the absorbed dose were reduced $34.88{\pm}0.93(10.48{\pm}0.09)mGy$ to $31.01{\pm}0.3(9.30{\pm}0.09)mGy$ and $35.99{\pm}1.86mGy$ to $32.27{\pm}1.35mGy$ in the abdomen. With variation of width 16cm and 10cm, they showed 8~11% decrease. Conclusion : By means of reducing 2D field size, absorbed dose were decreased average 5~12% in 3D width size 8~11%. So that it is necessary for radiation therapists to recognize systematical management for absorbed dose for Imaging confirmation. and also for frequent CBCT, it is considered whether or not prescribed dose for RT refer to imaging dose.

• Journal of Astronomy and Space Sciences
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• v.16 no.1
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• pp.11-20
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• 1999

In this paper all the photoelectric times of minimum for the triple star SW Lyn have been analyzed in terms of light-time effect due to the third-body and secular period decreases induced by mass transfer process. The light-time orbit determined recently by Ogloza et al.(1998) were modified and improved. And it is found that the orbital period of SW Lyn have been decreasing secularly. The third-body revolves around the mass center of triple stars every $5^y.77$ in a highly eccentric elliptical orbit(e=0.61). The third-body with a minimum mass of $1.13M_{odot}$ may be a binary or a white dwarf. The rate of secular period-decrease were obtained as ${Delta}P/P=-12.45{ imes}10^{-11}$, implying the mass-transfer from the massive primary star to the secondary. The mass losing rate from the primary were calculated as about $1.24{ imes}10^{-8}M_{odot}/y$. It is noticed that the mass-transfer in SW Lyn system is opposite in direction to that deduced from it's Roche geometry by previous investigators.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.77-82
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• 2020

In order to analyze the positive rate of hepatitis B surface antibody by age before and after hepatitis B vaccination, 13,855 serum specimens who were referred for the hepatitis B surface antibody test at the General Hospital of Jeju Hospital were examined by CMIA method. The positive rate of HBs Ab was 5,176 (37.36%). The positive rate according to gender was 40.13% for female and 34.77% for male. The age group with the highest HBs Ab average was in their 40's (399.86 mIU/mL), while the lowest age group was in the 90's (211.50 mIU/mL). It is remarkable that the age group with the highest HBs Ab positive rate is in the 30's, and that teenagers (age group of 10-20 years) had the lowest positive rate. Especially 15, 18, 19 years old was statistically significant. Consideration should be given to determining the titer of vaccination and to clarify the timing of vaccination.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.800-806
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• 2013

The purpose of this study was to evaluate the marginal fitnesses on the effect of span length of bridge and the marginal gaps within the clinically allowed range. The samples were fabricated with zirconia core using CAD/CAM system. The test groups were divided by four groups, single crown, 2-units bridge, 3-units bridge and 4-units bridge and 10 zirconia cores per each group. The results of mean marginal gaps were $42.95{\pm}6.93{\mu}m$ in the single crown, $43.53{\pm}5.27{\mu}m$ in 2-unit, $53.43{\pm}13.38{\mu}m$ in 3-unit, and $50.85{\pm}8.25{\mu}m$ in 4-unit on each. The marginal gap of mesial and distal surfaces were statistically significant differences between single, 2-unit group and 3-unit, 4-unit group (p<.05) and this results was effected by the span length. The buccal and lingual surfaces were no statistically significant differences within all groups(p>.05). From this results the span length of the zirconia core may have influence on marginal fitness and the marginal gaps were within the clinically allowed range.

• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.43-53
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• 2008

This study was conducted to simulate storm hydrographs on a small forested watershed using TOPMODEL, which is a distributed hydrological model. The Myeongseong watershed, which is 58.3 ha in size, was selected to monitor rainfall and runoff data. The Monte Carlo simulation was also used to calibrate parameters of TOPMODEL. Six rainfall-runoff pairs collected at the watershed in the year 1997 were used for parameter calibration, and eight rainfall-runoff pairs collected during the period of $1998\sim1999$ were used for validation effort. The errors of runoff volume ranged from -2.74% to 1.81%, and an average value of model efficiency in terms of runoff volume was 0.92 for the calibration period. The average value of observed peak discharge was $0.324m^3\;s^{-1}$ for six rainfall-runoff pairs, while the prediction value was $0.295m^3\;s^{-1}$. The simulation errors of peak discharge varied according to rainfall characteristics and antecedent condition, within ranges of -27.65% to -1.13%. The model efficiency for the validation period was 0.92. For the validation period, observed peak discharges have an average value of $0.087m^3\;s^{-1}$ and average value of simulated peak discharge was $0.090m^3\;s^{-1}$. Observed and simulated values of time to peak for the calibration period were 18.3 hrs and 11.0 hrs, respectively, and 16.6 hrs and 13.5 hrs, respectively, for the validation period.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.742-750
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• 2018

In this paper, in order to enable zero-layer FTP cell using only 5V MOS devices on the basis of $0.13{\mu}m$ BCD process, the tunnel oxide thickness is used as the gate oxide thickness of $125{\AA}$ of the 5V MOS device at 82A. The HDNW layer, which is the default in the BCD process, is used. Thus, the proposed zero layer FTP cell does not require the addition of tunnel oxide and DNW mask. Also, from the viewpoint of memory IP design, a single memory structure which is used only for trimming analog circuit of PMIC chip is used instead of the dual memory structure dividing into designer memory area and user memory area. The start-up circuit of the BGR (Bandgap Reference Voltage) generator circuit is designed to operate in the voltage range of 1.8V to 5.5V. On the other hand, when the 64-bit FTP memory IP is powered on, the internal read signal is designed to maintain the initial read data at 00H. The layout size of the 64-bit FTP IP designed using the $0.13-{\mu}m$ Magnachip process .is $485.21{\mu}m{\times}440.665{\mu}m$($=0.214mm^2$).

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.147-151
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• 2019

In chest and abdomen CT scans, the radiation exposure doses by scattering lines were measured at the eyeball and thyroid. Radiation exposure was investigated by using shielding devices. The chest and abdomen CT scan protocols used in the real examination were applied to measure and compare radiation doses before and after the use of shielding devices at the eyeball and the thyroid. The radiaton doses were measured with OSLD dosimeters. Barium, tungsten sheets, goggles and neck shields were used to protect the scattered X-ray. The chest CT scans showed respectively 3.01 mSv and 6.21 mSv at the eyeball and the thyroid by the scattered X-ray. The abdomen CT scans showed 0.55 mSv and 3.22 mSv for the eyeball and the thyroid respectively. Barium and tungsten sheets had 11% to 13% protection rates at the eyeball and the thyroid for chest CT scan, and 34% to 49% reduction in radiation dose for the abdomen CT scan. Because of the significant radiation dose, which causes cataracts and thyroid cancer by the repeated and continuous radiation exposure, for the chest and the abdomen CT scans, it is required to use shielding devices to reduce radiation dose for examinations.

• KSBB Journal
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• v.10 no.2
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• pp.183-190
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• 1995

The effects of enzymatic pretreatments on the bleaching of kraft pulp were studied. The kappa number of pulp samples which represents the lignin content of pulp decreased by 25.2% by the pretreatments with xylanase(EC 3.2.1.8, Pulpzyme HB) while it decreased by 13.7% without enzyme pretreatments after the extraction of the pretreated pulp samples in 1N NaOH. To enhance the effects of enzymatic pretreatment on the bleaching of kraft pulp, phenols were used as radical carriers with the simultaneous use of peroxidase(EC 1.11.1.7, Novozyme 502), $H_2O_2$, and xylanase. Guaiacol (1mM) was most effective by decreasing the kappa number by 29.6% when a low initial concentration of $H_2O_2$ (0.1mM) was used. The use of either a higher initial concentration of $H_2O_2$ or phenols lacking electron donating substituents such as phenol and p-chloyophenol, however, decreased the efficiency of enzymatic pretreatment indicating that the production rate and the stability of phenolic radicals are important parameters.