• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.1 s.343
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• pp.103-110
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• 2006

Internet engineering task force (IETF) has proposed hierarchical mobile IPv6 (HMIPv6) in order to reduce a frequent location registration of a mobile node in mobile IPv6 (MIPv6). All traffics toward a mobile node must be transmitted through a MAP in HMIPv6. This brings unnecessary packet latency because of the increased processing cost of packet at the MAP. At this point the processing cost of packet at the MAP is influenced by the packet arrival rate for a mobile node and the number of mobile nodes in MAP domain. In this paper, we propose that MIPv6 and HMIPv6 are adaptively selected to minimize signaling coast of network as complementing weak point of MIPv6 and HMIPv6. After suppose that the packet arrival rate for a mobile node is fixed ,with this in mind, we find the optimal number of mobile nodes compared the total cost of HMIPv6 with the total cost of MIPv6. And if Mobile Nodes that the MAP is able to manage is full in MAP domain, a mobile node entering MAP domain is provided connection by MIPv6 instead of HMIPv6. In the conclusion, the proposed method of this paper shows that the weak points of MIPv6 and HMIPv6 are removed by adaptive selecting each other.

• Journal of the Korean Vacuum Society
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• v.17 no.2
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• pp.160-164
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• 2008

The Characterization of $MgB_2$ Thin Film by Slow Positron Annihilation Spectroscopy Enhance signal-to-noise ratio, slow positron coincidence Doppler Broadening method has been applied to study of characteristics of $MgB_2$ superconductor film, which were performed at 30 K and 50 K sample temperature near Tc of it. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S, defined as the ratio between the amount of counts in a central portion of the spectrum and the total counts of whole spectrum. The S-parameter values were increased then decreased while the positron implantation energies were increasing, that indicated the diffusion into the samples. The S-parameters of the anisotropic 1 ${\mu}m$ $MgB_2$ thin film which were implanted by positrons at 10 keV are 0.567 at 30 K and 0.570 at 50 K. It is believed that the positrons annihilate with normal-electrons instead of super-electrons in the $MgB_2$ superconductor.

• Korean Journal of Community Nutrition
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• v.23 no.4
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• pp.318-332
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• 2018

Objectives: The purpose of this study was to investigate the behavioral modification of obese adults who underwent nutritional and physical activity education. Twenty obese females, aged 20-60 years old, with BMIs (Body Mass Index) >30 or body fat (%) >40 were subjected to this study. Methods: The physical activity education program consisted of doing exercise in a gymnasium together or home exercise. Dietary attitudes and dietary intakes were assessed using weight control, physical activity, and eating habits. The nutrition-exercise educational period was 12 weeks. Results: After the study period, there was significant improvement in physical activity and eating habits score. Furthermore, there was a significant increase in the dietary intakes of fiber, iron, potassium, vitamin A, vitamin $B_6$, and niacin. Blood pressure, blood glucose, and total cholesterol levels showed a tendency to decrease, but there was no significant difference. BMI, fat mass, abdominal circumference, and visceral fat levels were significantly reduced while muscle mass significantly increased. Conclusions: This study suggests that behavioral modification by nutrition and physical activity education with feedback has positive effects on dietary intake and anthropometric biomarkers in obese adults. Therefore, lifestyle interventions of this kind could be recommended as a method for obesity management.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.767-775
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• 2008

Uncoupling protein-1 (UCP-1) plays a major role in thermogenesis at brown adipose tissues and has been implicated in the pathogenesis of obesity and metabolic disorders. The purpose of this study was to estimate the effects of A-3826G polymorphism in 117 Korean prepubertal children aged 8-11 years olds. Anthropometry by bioelectrical impedance analysis method, plasma lipid profiles by auto-biochemical analyzer and UCP-1 genotyping by PCR-RFLP were done. The frequencies of UCP-1 genotypes were AA; 17.7%, AG; 57.8%, GG; 26.6%. The frequencies of each G allele (55.5%) was similar to Japanese's (49%) and higher than Caucacian's (25%). No correlation UCP-1 polymorphism and BMI (kg/$m^2$) or the degree of obesity described by the relative percentiles of the standard weight according to height in prepubertal children. However, plasma total- and LDL-cholesterol were significantly increased in G allele when sex, age and weight were adjusted. Our results suggested that G allele of UCP-1 gene was stronger risk factors in hyperLDLcholesterolemia than A allele. This impact might be progressed as the precaution against the revalence of obesity based-metabolic disease.

• The Korea Journal of Herbology
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• v.33 no.2
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• pp.59-67
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• 2018

Objective : Plantago asiatica L. has been used for many years in Korea, China, and Japan for the treatment of many diseases such as anti-inflammatory, anti-asthma and diuretic. But the anti-obesity effect of Plantaginis asiaticae Folium has not been studied yet. Thus, this study aimed to demonstrate the anti-obesity efficacy of Plantaginis asiaticae Folium water extract (PAF) in high fat diet-induced obesity animal model. Method : Male, five-weeks old C57BL/6 mice were divided into 5 groups; ND (normal diet + 0.9% saline), HFD (high-fat diet + 0.9% saline), PC (high-fat diet + Garcinia cambogia 500 mg/kg), PAF 100, 300 (high-fat diet + PAF 100, 300 mg/kg. Treatments were performed daily for 6 weeks per os. We evaluated the changes of body weight, white adipose tissues weight, hepatic and fecal lipids level, pancreatic lipase activity and lipid profiles in plasma. Result : Body weights, adipose tissue weights and FER were significantly lower in mice fed the high-fat diet with PAF treatment than in mice fed the high-fat diet alone. In plasma, TG, TC, LDL-C, ATS and ALT levels significantly decreased in PAF groups compared with HFD group. Also, hepatic triglyceride (TG) levels decreased and fecal TG increased in PAF groups compared to HFD group. In addition, the activity of pancreatic lipase was decreased in the PAF groups compared to that of HFD group. Conclusion: These results suggest PAF extract is effective in preventing and improvement obesity, so it might be a potential and safe material for anti-obesity agent of weight control or functional supplements.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.330-338
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• 1997

This study investigated the method to adjust acquisition time(a) and injection dose (i) to make the best basal and subtraction images in consecutive SPECT. Image quality was assumed to be mainly affected by signal to noise ratio(S/N). Basal image was subtracted from the second image consecutively acquired at the same position. We calculated S/N ratio in basal SPECT images($S_1/N_1$) and subtraction SPECT images(Ss/Ns) to find a(time) and i(dose) to maximize S/N of both images at the same time. From phantom images, we drew the relation of image counts and a(time) and i(dose) in our system using fanbeam-high-resolution collimated triple head SPECT. Noise by imaging process depended on Poisson distribution. We took maximum tolerable duration of consecutive acquisition as 30 minutes and maximum injectible dose as 1,850MBq(50 mCi)(sum of two injections) per study. Counts of second-acquired image($S_2$), counts($S_s$) and noise($N_s$) of subtraction SPECT were as follows. $C_1$ was the coefficient of measurement with our system. $$S_2=S_1{\cdot}(\frac{30-a}{a})+background{\cdot}(1-\frac{30-a}{a})+C_1{\cdot}(30-a){\cdot}{\epsilon}{\cdot}(50-i)$$ $$Ss=S_2-\{S_1{\cdot}(\frac{30-a}{a})+background{\cdot}(1-\frac{(30-a)}{a})\}$$ $$Ns={\sqrt{N_2^2+N_1^2{\cdot}\frac{(30-a)^2}{a^2}}={\sqrt{S_2+S_1{\cdot}\frac{(30-a)^2}{a^2}}$$ In case of rest/acetazolamide study, effect(${\epsilon}$) of acetazolamide to increase global brain uptake of Tc-99m-HMPAO could be 1.5 or less. Varying ${\epsilon}$ from 1 to 1.5, a(time) and i(dose) pair to maximize both $S_1/N_l$ and Ss/Ns was determined. 15 mCi/17 min and 35mCi/13min was the best a(time) and i(dose) pair for rest/acetazolamide study(when ${\epsilon}$ were 1.2) and came to be used for our clinical routine after this study. We developed simple method to maximize S/N ratios of basal and subtraction SPECT from consecutive acquisition. This method could be applied to ECD/HMPAO and brain activation studies as well as rest/acetazolamide studies.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.33-37
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• 2010

Purpose: In the early stage of using PET/CT, it was used to damper revision but recently shows that CT with MDCT is commonly used and works well for an anatomical diagnosis. This hospital makes the accuracy and convenience more higher in the diagnosis and evaluate of coronary heart disease through concurrently running myocardial perfusion SPECT examination, myocardial PET examination with FDG, and CT coronary artery CT angiography(coronary CTA) used PET/CT with 64-slice. This report shows protocol and image based on results from about 400 coronary heart disease examinations since having 64 channels PET/CT in July 2007. Materials and Methods: An Equipment for this examination is 64-slice CT and Discovery VCT (DVCT) that is consisted of PET with BGO ($Bi_4Ge_3O_{12}$) scintillation crystal by GE health care. First myocardial perfusion SPECT with pharmacologic stress test to reduce waiting time of a patient and get a quick diagnosis and evaluation, and right after it, myocardial FDG PET examination and coronary CTA run without a break. One-stop evaluation protocol of ischemic heart disease is as follows. 1)Myocardial perfusion SPECT with pharmacologic stress: A patient is injected with $^{99m}Tc$-MIBI 10 mCi and does not have any fatty food for myocardial PET examination and drink natural water with ursodeoxcholic acid 100 mg and we get SPECT image in an hour. 2)Myocardial FDG PET: To reduce blood fatty content and to increase uptake of FDG, we used creative oral glucose load using insulin and Acipimox to according to blood acid content. A patient is injected with $^{18}F$-FDG 5 mCi for reduction of his radiation exposure and we get a gated image an hour later and get delay image when we need. 3) Coronary CTA: The most important point is to control heart rate and to get cooperation of patient's breath. In order to reduce a heart rate of him or her below 65 beats, let him or her take beta blocker 50 mg ~ 200 mg after a consultation with a doctor about it and have breath-practices then have the examination. Right before the examination, we spray isosorbide dinitrate 3 to 5 times to lower tension of bessel wall and to extension a blood wall of a patient. It makes to get better the shape of an anatomy. At filming, a patient is injected CT contrast with high pressure and have enough practices before the examination in order to have no problem. For reduction of his radiation exposure, we have to do ECG-triggered X-ray tube modulation exposure. Results: We evaluate coronary artery stenosis through coronary CTA and study correlation (culprit vessel check) of a decline between stenosis and perfusion from the myocardial perfusion SPECT with pharmacologic stress, coronary CTA, and can check viability of infarction or hibernating myocardium by FDG PET. Conclusion: The examination makes us to set up a direction of remedy (drug treatment, PCI, CABG) because we can estimate of effect from remedy, lesion site and severity. In addition, we have an advantage that it takes just 3 hours and one-stop in that all of process of examinations run in succession and at the same time. Therefore it shows that the method is useful in one stop evaluation of ischemic heart disease.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.8
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• pp.15-26
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• 2011

In this paper, we present a new beamforming scheme for a downlink of multiuser multiple-input multipleoutput (MIMO) communication systems. Recently, a block-diagonalization (BD) algorithm has been proposed for the multiuser MIMO downlink where both a base station and each user have multiple antennas. However, the BD algorithm is not efficient when the number of supported streams per user is smaller than that of receive antennas. Since the BD method utilizes the space based on the channel matrix without considering the receive combining, the degree of freedom for beamforming cannot be fully exploited at the transmitter. In this paper, we optimize the receive beamforming vector under a zero forcing (ZF) constraint, where all inter-user interference is driven to zero. We propose an efficient algorithm to find the optimum receive vector by an iterative procedure. The proposed algorithm requires two phase values feedforward information for the receive combining vector. Also, we present another algorithm which needs only one phase value by using a decomposition of the complex general unitary matrix. Simulation results show that the proposed beamforming scheme outperforms the conventional BD algorithm in terms of error probability and obtains the diversity enhancement by utilizing the degree of freedom at the base station.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.1
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• pp.19-27
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• 2007

Combined method of extraction chromatography and liquid scintillation analysis was established for determinating $^{55}Fe\;and\;^{63}Ni$ radioactivity in solid samples. Activated concrete wastes generated from dismantling KRR-2 were analysed. The sequential separation including precipitation and extraction chromatography resulted in the above 90% chemical recoveries of Fe. Above 62% recoveries of Ni were obtained by this procedure exception to 43.6 and 46.5% recoveries. The seperation and counting procedure was also confirmed with spiked samples of known quantity. The measured and spiked quantity were agreed with the 3.7% and 0.7% variations in the $^{55}Fe\;and\;^{63}Ni$ experiments, respectively. The radioactivities of $^{55}Fe$ in the dismantled concretes are shown from below MDA to maximum 362 Bq/g. The radioactivities of $^{63}Ni$ in all concrete samples are below MDA. The $^{63}Ni$ doesn't exist in dismantled concretes from KRR-2. The radioactivity of $^{55}Fe$ is decreased rapidly as the sampling depth is increased from the concrete surface.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.29-35
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• 2010

The cooperative transmission between sectors in next generation communications standards, e.g., 3GPP LTE-Advanced and IEEE 802.16m, has become an important research issue. Hence methods to decide the optimal antenna tilting angle in cooperative transmission between sectors are needed. This paper proposes methods to decide the optimal antenna tilting angle in cases of non-cooperative and cooperative transmissions between sectors. The proposed methods use an objective function that maximizes the cell average log rate or the cell average rate for users distributed uniformly within the radius of the sector. Also, the objective function which maximizes the cell average rate determined by adaptive modulation and coding (AMC) used in actual cellular systems is considered. When the cell average rate becomes the objective function, the system rate efficiency increases significantly for both cooperative and non-cooperative transmission. When the cell average log rate and the AMC rate become the objective functions, an optimal antenna tilting decision method which effectively increases the efficiency of cell boundary users is discussed.