• Journal of Community Nutrition
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• v.5 no.3
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• pp.132-140
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• 2003

The objective of this study was to investigate the effect of soymilk and exercise on bone mineral density (BMD) in underweight college women of 19-22 years of age, who had lower bone mass. The BMD of the lumbar spine and femoral neck was measured for 52 underweight college women. Among them, 33 subjects, whose t-score value was below -1, were selected. Questionnaire survey, anthropometrical measurements, dietary recall, analysis of BMD, fasting serum osteocalcin and urinary deoxypyridinoline (DPD) were conducted before and after the 10 week study. The 33 subjects were divided into 2 groups： soymilk group (n=19), and soymilk ＋ exercise group (n=14). The soymilk group was given 400$m\ell$ soymilk containing 60mg of isoflavones on a daily basis and the soymilk ＋ exercise group exercised three times a week with a daily intake of 400$m\ell$ soymilk for 10 weeks. The average ages of the soymilk group and the soymilk ＋ exercise group were 21.1 years and 20.4 years, respectively and, there were no significant differences between the soymilk group and the soymilk ＋ exercise group in the areas of height, weight or Body Mass Index (BMI). At the baseline, the mean daily energy intake of the soymilk group and the soymilk ＋ exercise group was 1,597.9kcal (79.43％ of RDA) and 1,704.2kcal (85.2％ of RDA), respectively. The mean calcium intake of the soymilk group (408.3mg) was not significantly different from that of the soymilk ＋ exercise group (389.4mg). Despite the 400$m\ell$ soymilk supplementation, there were no significant changes of nutrient intake in either group after treatment. However, there were significant increases in BMD's of lumbar spine and femoral neck in both groups. There were some increases in the serum osteocalcin level and decreases in the urinary deoxypyridinoline level as well. BMD change of the soymilk group was not significantly different from that of the soymilk ＋ exercise group. In conclusion, supplementary intake of soymilk (containing 60mg of isoflavones) resulted in a significant increase in the BMD's of the lumbar spine and femoral neck in underweight college women with low bone mass. However, exercise did not result in any significant changes in the BMD's, implying the necessity for more intensive and specific long-term physical training for any substantial changes. Further investigation is necessary to determine the exercise that most strongly affects BMD.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.9-17
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• 2010

Recently, there has been much interest in orthogonal frequency division multiplexing (OFDM) for next generation wireless wideband communication systems. OFDM is a special case of multicarrier transmission, where a single data stream is transmitted over a number of lower-rate subcarriers. One of the main reasons to use OFDM is to increase robustness against frequency-selective fading or narrowband interference. However, in the radio systems it is also important to distortion introduced by high power amplifiers (HPA's) such as solid state power amplifier (SSPA) considered in this paper. Since the signal amplitude of the OFDM system is Rayleigh-distributed, the performance of the OFDM system is significantly degraded by the nonlinearity of the HPA in the OFDM transmitter. In this paper, we propose a canonical piecewise-linear (PWL) model based digital predistorter to prevent signal distortion and spectral re-growth due to the high peak-to-average power ratio (PAPR) of OFDM signal and the nonlinearity of HPA's. Computer simulation on an OFDM system under additive white Gaussian noise (AWGN) channels with QPSK, 16-QAM and 64-QAM modulation schemes and modulator/demodulator implemented with 1024-point FFT/IFFT, demonstrate that the proposed predistorter achieves significant performance improvement by effectively compensating for the nonlinearity introduced by the SSPA.

• Journal of Life Science
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• v.18 no.9
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• pp.1299-1304
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• 2008

The purpose of this study was to develop a exercise program adopted from Jazz dance and to analyze the effect of the Jazz dance program on the Body composition, Blood components and Bone metabolism and also to study the supplement effects of Iron with Jazz dance. The Jazz dance program was composed of warming-up (10 min), Jazz dance (40 min) and cooling-down (10 min) parts. The 21 adult women between 25 and 35 year were divided into three groups; Jazz dance + iron intake group (7), Jazz dance group (7) and control group (7). The Jazz dance program was applied three times a week and 80 mg intake per day were given. The results were as follows. The body weight and lean body mass were decreased in the Jazz dance + iron intake group. The body fat mass were increased in the Jazz dance + iron intake group. The lean body mass were decreased in the Jazz dance group. The RBC, WBC, Hb were increased in the Jazz dance+iron intake group. The MCV were decreased in the Jazz dance+iron intake group. The WBC, MCHC were increased in the Jazz dance group. The MCHC were decreased in the Jazz dance group. The Deoxypyridinoline, Osteocalcin were decreased in the Jazz dance+iron intake group and the Jazz dance group.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.53-61
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• 2014

In this paper, we present the design, fabrication and measurement of high efficiency GaN HEMT power amplifier using harmonic matching technique. In order to achieve high efficiency, harmonic load-pull simulation is performed, that is, the optimum load impedances are determined at $2^{nd}$ and $3^{rd}$ harmonic frequencies as well as at the fundamental. Then, the output matching circuit is designed based on harmonic load-pull simulation. The measurement of the fabricated power amplifier shows the linear gain of 20 dB and $P_{1dB}$(1 dB gain compression point) of 33.7 dBm at 1.85 GHz. The maximum power added efficiency(PAE) of 80.9 % is achieved at the output power of 38.6 dBm, which belongs to best efficiency performance among the reported high efficiency power amplifiers. For W-CDMA input signal, the power amplifier shows a PAE of 27.8 % at the average output power of 28.4 dBm, where an ACLR (Adjacent Channel Leakage Ratio) is measured to be -38.8 dBc. Digital predistortion using polynomial fitting was implemented to linearize the power amplifiers, which allowed about 6.2 dB improvement of an ACLR performance.

• Korean Journal of Clinical Pharmacy
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• v.21 no.4
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• pp.297-304
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• 2011

배경: 골다공증은 골대사의 불균형으로 인해 골 흡수가 골 형성보다 많아져 골밀도가 감소함으로서 발생한다. 골다공증의 이상적인 치료목표는 골형성을 증가시키거나 골소실을 방지하여 골량을 현 상태로 유지하는 것이다. 따라서 향후 발생되는 골소실을 에방하는 것이 골다공증의 원칙적이고 효과적인 치료방법이 될 것이다. 본 연구에서는 흑효모 중 $Aureobasidium$ $pullulans$으로부터 유래한 폴리칸(베타-글루칸)이 중년여성의 골대사에 미치는 영향을 규명하고자 하였다. 연구방법: 골대사에 대한 폴리칸의 효과를 규명하기 위해 12주간의 무작위배정, 이중눈가림, 플라세보 대조 임상연구를 수행하였다. 총 60명(폴리칸 투여군30명, 플라세보 투여군 30명)의 중년 여성 피험자가 등록되어 이 중 총 58명의 피험자가 최종적으로 12주간의 임상연구를 종료하였다. 결 과: 폴리칸(150 mg/d) 투여 12주 후, 폴리칸 투여군은 요 중 Deoxypyridinoline (DPD) 농도가 유의적인 감소를 보였다($P$=0.014). 혈청 중 Osteocalcin(OSC) 농도는 두 군 모두에서 유의적으로 증가하였으며, bone-specific alkaline posphatase (bALP) 와 collagen type 1 cross-linked C-telopeptide (CTx)는 유의적 변화가 보이지 않았다. 폴리칸은 골밀도(BMD)와 혈청 부갑상선 호르몬(iPTH)에 대해 유의적인 변화를 보이지 않았으나, 24시간 요 중 Ca 배설량은 폴리칸 투여군에서 유의하게 감소되었다($P$=0.028). 또한 폴리칸 투여군에서 고밀도지단백 콜레스테롤(HDL-cholesterol) 농도의 증가 경향 및 중성지방(triglyceride)의 유의적인 감소가 보였다. 임상연구 기간 중에 발생한 이상반응은 두 군간에 유의적인 차이를 보이지 않았다. 결 론: 본 연구에서는 폴리칸이 골대사 및 지질에 대해 일부 개선효과가 있음을 보여주었다. 그러나, 골다공증 예방 측면에서 보다 장기적인 임상연구와 피험자 수를 확대하여 골대사 및 지질대사에 대한 폴리칸의 예방적 효과를 규명할 필요가 있을것으로 사료된다.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.46-53
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• 2003

The current study investigated the effect of Korean safflower (Carthamus tinctorius L.) seed powder and its water and ethanol extracts on bone metabolism during recovery from rib-fracture induced by surgical operation in rats. 10-week-old male Sprague-Dawley rats weighing about 320 g were divided into 9 groups after arrival: 10d control (AIN 76 semi-purified diet), 10d safflower seed powder (10d SS-powder), 10d safflower seed ethanol extract (10d SS-EtOH), 10d safflower seed water extract (10d SS-$H_2O$), 20d control (AIN-76 semi-purified diet), 20d safflower heed powder (20d SS-powder), 20d safflower seed ethanol extract (20d SS-EtOH), 20d safflower seed water extract (20d SS-$H_2O$), and 20d sham-operation (20d sham), The dietary level for all the supplements was 5% based on the raw material weight. The rats were fed the experimental diets for 10 days before the rib fracture operation and for a further 10 or 20 days after the operation. A number 9 rib was fractured surgically and a sham-operation also performed. The rats were then sacrificed on the l0th or 20th day after the operation. The body weight initially decreased after the operation in all the rib-fractured groups, then gradually recovered. The concentrations of plasma osteocalcin were higher in the control group than in all the safflower-supplemented groups 10 and 20 days after the rib-fracture (p < 0.05). The bone-specific ALP (alkaline phosphatase) activity was significantly higher in the SS-EtOH group than in the other groups 20 days after the rib-fracture (p < 0.05). The level of urinary DPD (deoxypridinoline) was significantly higher in the SS-EtOH and SS-$H_2O$ groups than in the other groups 10 days after the rib-fracture. When comparing the PTH (parathyroid hormone) and calcitonin levels, the SS-$H_2O$ group exhibited the highest PTH level among the groups 10 and 20 days after the rib-fracture. Thus, it was concluded that the bone turnover during the fracture-healing period was more rapid in the rats supplemented with safflower seed powder or its fractions than in the control rats. Furthermore, the SS-$H_2O$ fraction was identified as the most effective in stimulating bone remodeling, as bone resorption and bone formation were both significantly increased during fracture healing when compared to the control group.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.44-51
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• 2008

Purpose: We performed this study to evaluate reliability on interpretation of three phase bone scintigraphy (TPBS) in patients with post-traumatic complex regional pain syndrome (PT-CRPS). Methods: Based on International Association for the Study of Pain guideline in 1994, 34 patients with PT-CRPS were selected for this study. Two nuclear medicine physicians evaluated identical TPBS according to the uptake pattern, extent and intensity of the lesion, and their agreements (kappa values) were analysed. The final diagnosis based on arbitrary criteria of each physician were compared with those obtained by the criteria for PT-CRPS established in this study, which are hyperactivity on all phases (criteria 1), hyperactivity of whole joints on delayed phase (criteria 2), and hyperactivity of either whole or FDGal joints on delayed phase (criteria 3). Results: Intra-observer agreements were good for uptake pattern, intensity, and extent on TPBS. Inter-observer agreements were also good, except extent on blood pool phase (0.55). The inter-observer agreements on final diagnosis improved when criteria 1-3 were applied (0.77-0.88), compared to when physician's own criteria were used (0.63). Those also improved from 0.29 to 0.47-0.82 for acute stage, and from 0.37 to 1.0 for chronic stage. The sensitivities of chronic stage were relatively lower to those of acute stage. Conclusions: Inter-observer's variations in diagnosis of the patients with PT-CRPS using TPBS were observed. These results were attributed to different criteria set by observers. In order to improve agreement on interpretation of TPBS, common positive criteria should be established, especially considering uptake pattern and clinical stages.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1560-1567
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• 2008

This study was designed to evaluate the effect of green tea products (GTP) on bone metabolism marker in ovariectomized (OVX) rats fed high cholesterol diet. Forty Sprague-Dawley female rats, 10 weeks of age ($279{\pm}2g$), were divided into 4 groups and fed on the experimental diets for 6 weeks: sham operated control (Sham-C) and OVX-control (OVX-C) groups treated high cholesterol diet. OVX-GTP 5% (OVX-G5) and OVX-GTP 20% (OVX-G20) groups were treated with high cholesterol diet containing 5% GTP and 20% GTP, respectively. Food efficient ratio was significantly (p<0.05) lower in OVX-G20 than in the other OVX groups. Bone mineral density of femur was not significantly different among the experimental groups in the order of Sham-C>OVX-G5 and OVX-G20>OVX-C. Alkaline phosphatase activities on serum was lower in the GTP supplement groups than in the OVX-C. Estradiol levels of serum were higher in the GTP supplement groups than in the OVX-C. Osteocalcin levels of serum was the lowest in the OVX-G20. Deoxypyridinoline crosslink values of urine, indicator of bone absorption, was the lowest in the OVX-G20 group. The GTP supplemented groups had a lower bone resorption ratio than in the OVX-C group. From the above results, these findings suggest the possibility of using GTP as a functional food materials related to bone metabolism in menopause.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.105-110
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• 2010

Purpose: Three phase bone scan was considered sensitive in Patients with Reflex Symphathetic Dystrophy Syndrome (RSDS). Generally, three phase bone scan in the RSDS patients shows increased uptake of one side extremity joint. But three phase bone scan has been performed with flow, blood pool and delayed scan. We performed blood pool half body scan in order to investigate its usefulness. Materials and Methods: From October 2007 to September 2009, three phase bone scan (flow, blood pool, half body blood pool, delayed) was performed after injection of 750 MBq of $^{99m}Tc$-DPD in diagnosed patients with RSDS (M:F=8:7, R:L=9:6). For quantitative analysis, we obtained the count ratios of bilateral hands by drawing a region of interest (ROI) in the three phase images and compared with the count ratios of shoulders in half body blood pool and delayed images. Results: In flow images, right/left ratios were $1.09{\pm}0.53$. In blood pool images, right/left ratios were $1.13{\pm}0.47$ (hand), $1.08{\pm}0.26$ (shoulder). In delayed images, right/left ratios were $1.24{\pm}0.75$ (hand), $1.11{\pm}0.31$ (shoulder). As a result, Log of right/left counts of the others and that of shoulder blood pool image were correlated well with statistical significance (Spearman's R, p<0.005 SPSS for windows ver.12.0). Conclusion: Half body blood pool scan may be helpful in the diagnosis of patients with RSDS. Moreover, Half body blood pool scan reduced false negative and false positive rates. In order to improve agreement on interpretation of RSDS, Blood pool half body scan should be established as common criteria.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.880-886
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• 2007

We have proposed a new "hybrid" envelope elimination and restoration(EER) transmitter architecture using an efficiency optimized power amplifier(PA) and modified bias modulator. The efficiency of the PA at the average drain voltage is very important for the overall transmitter efficiency because the PA operates mostly at the average power region of the modulation signal. Accordingly, the efficiency of the PA has been optimized at the region. Besides, the bias modulator has been accompanied with the emitter follower for the minimization of memory effect. A saturation amplifier, class $F^{-1}$ is built using a 5-W PEP LDMOSFET for forward-link single-carrier wideband code-division multiple-access(WCDMA) at 1-GHz. For the interlock experiment, the bias modulator has been built with the efficiency of 64.16% and peak output voltage of 31.8 V. The transmitter with the proposed PA and bias modulator has been achieved an efficiency of 44.19%, an improvement of 8.11%. Besides, the output power is enhanced to 32.33 dBm due to the class F operation and the PAE is 38.28% with ACLRs of -35.9 dBc at 5-MHz offset. These results show that the proposed architecture is a very good candidate for the linear and efficient high power transmitter.