• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.153-156
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• 2004

An electric power efficiency of electrodeless fluorescent lamp has big relative property of gas in lamp, gas pressure, lamp formation, ingredients of magnetic substance and shape and action frequency etc. We used magnetic substance that open self examination material of electrodeless fluorescent lamp antenna. Ferrite that is used in this experiment was Mn-Zn type. We have examined resistance kind, impedance, Q-factor's frequency characteristic by ferrite. Impedance, resistance and capacitance did not show difference in start frequency 2.65 [MHz] but there was difference quantity. We could know Q-factor's difference according to material, and Q-factor's is important part of antenna design.

• Journal of the Korean Institute of Navigation
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• v.20 no.4
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• pp.129-137
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• 1996

In this paper, we simulated a radiation pattern directivity of microstrip patch antenna for 9[GHz] using the computer. It is analyzed and compared the directivity of field characteristics at two different aspects. One is that of 1-dimension and 2-dimension array, the other is that of a linear and planar array antenna. We tried the constants for the simulation of teflon substrate, dielectric constant ${\varepsilon}r=2.50$, ground plane conductor thickness t=0.03556, substrate height h=0.72188, dielectric loss degree $tan{\delta}$=0.00085, characteristics impedence of line $Zo=50({\Omega})$. The major advantage of microstrip patch antenna is that the arrangement of antenna is associated with the directivity and effectiveness. We have been studied the difference of the radiation pattern of antenna with wave variety through computer simulation.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.809-811
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• 1993

The load impedance of power lines generally varies with time, areas, and season. Also, the harmonic noises by the power electrical equipments are scattered through the power lines. The received signal level varies with the environment and is not able to detect the PLC(Power Line Carrier) signal. For this reason, it is requried for the signal transmitter to hold the received signal level uniform independently with the variation of the load impedence. In this paper, the power lines are modeled simply and a method keeping the received signal level uniform is suggested through the analysis of the signal transmission characteritics of the PLC coupler using tank circuit.

• Research in Community and Public Health Nursing
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• v.9 no.2
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• pp.458-466
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• 1998

The purpose of this study is to investigate the differences in body fat distribution between obese boys and girls in high school and the relationship between the precent of body fat and the Broca Index. The survey of data was conducted from November 3rd to the 11th in 1997. The data were analyzed by the use of a mean, standard deviation and a Pearson's correlation coefficient. Measurements of the percentage of body fat and lean body mass were made by a Bioelectrical Impedence while height, weigh and the Broca index were measured by a fatness measuring system. First, measurements of height, weight and the Broca index were made by a fatness measuring system on 1,125 1st year students and 1,076 2nd year students. The result of measurements, 216 obese boys and 100 obese girls appeared to have above 10% of the Broca index. The result of this study can be summarized as follows: 1) Obese boys and girls were grouped by the level of the Broca index as follows: boys, 110-less than 120 60.0%, 120-less than 130 20.8%, 130-less than 140 11.1%, above 140 7.4%. ; girls, 110-less than 120 44.4%, 120-less than 130 32.0%, 130-less than 140 13.0%, above 140 11.0%. 2) Obese boys and girls were grouped by level of the percentage of body fat by Bioelectrical Impedence as follows: boys, less than 20% 5%, 20%-less than 25% 34.7%, above 25% 33.8% ; girls. less than 25% 15.0%, 25%-less than 30% 43.0%, above 30% 42.0%. 3) In obese boys the Broca index score appeared to be positively related to body weight(r = .741, p<.001), the percent of body fat(r=.604, p<.001), lean body mass(r=.375, p<.001), body fluid(r=.445, p<.001l). On the other hand the percent of body fat was not a significant correlation of lean body mass (r= -.074), body fluid(r= -.073). 4) In obese girls, the Broca index score appeared to be positively related to body weight(r= .693, p<.001), the percent of body fat(r=.645, p<.001), lean body mass(r=.531, p<.001), body fluid(r=.532, p<.01), and the percent of body weight score appeared to be positively related to lean body mass(r=.206, p<.01), body fluid(r=.207, p<.01).

• Journal of Preventive Medicine and Public Health
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• v.43 no.6
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• pp.479-485
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• 2010

Objectives: The Korean Genome and Epidemiology Study (KoGES), a multicenter-based multi-cohort study, has collected information on body composition using two different bioelectrical impedence analysis (BIA) machines. The aim of the study was to evaluate the possibility of whether the test values measured from different BIA machines can be integrated through statistical adjustment algorithm under excellent inter-rater reliability. Methods: We selected two centers to measure inter-rater reliability of the two BIA machines. We set up the two machines side by side and measured subjects' body compositions between October and December 2007. Duplicated test values of 848 subjects were collected. Pearson and intra-class correlation coefficients for inter-rater reliability were estimated using results from the two machines. To detect the feasibility for data integration, we constructed statistical compensation models using linear regression models with residual analysis and R-square values. Results: All correlation coefficients indicated excellent reliability except mineral mass. However, models using only duplicated body composition values for data integration were not feasible due to relatively low $R^2$ values of 0.8 for mineral mass and target weight. To integrate body composition data, models adjusted for four empirical variables that were age, sex, weight and height were most ideal (all $R^2$ > 0.9). Conclusions: The test values measured with the two BIA machines in the KoGES have excellent reliability for the nine body composition values. Based on reliability, values can be integrated through algorithmic statistical adjustment using regression equations that includes age, sex, weight, and height.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1083-1091
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• 2016

This research uses public transportation card data to analyze the inter-regional transfer times, transfer frequencies, and transfer resistance that passengers experience during transit amongst the metropolitan public transportation modes. Currently, mode transfers between bus and rail are recorded up to five times during one transit movement by Trip Chain, facilitating greater comprehension of intermodal movements. However, lack of information on what arises during these transfers poses a problem in that it leads to an underestimation of transfer resistances on the Trip Chain. As such, a path choice model that reflects passenger movements during transit activities is created, which attains explanatory power on transfer resistance through its inclusion of transfer times and frequencies. The methodology adopted in this research is to first conceptualize the idea of metropolitan public transportation transfer, and in the case that mode transfers include the city-rail, to newly conceptualize the idea of transfer resistance using transportation card data. Also, the city-rail path choice model within the Trip Chain is constructed, with transfer time and frequency used to reevaluate transfer resistance. Further, in order to align bus and city-rail station administrative level small-zone coordinates to state and regional level mid-zone coordinates, the big node methdod is utilized. Finally, case studies on trip chains using at least one transfer onto the city-rail is used to determine the validity of the results obtained.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.267-274
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• 1997

To select potential inhibitors of platelet aggregation from large numbers of crude plant extracts, the modified thin smear method for the anti-platelet aggregating activity using platelet rich plasma was further modified by direct observation under a light microscope without staining the smear. The activities determined by the method were coincided with those by the electrical impedence method using whole blood, when ADP or collagen was employed as the aggregating agent. Among 130 varieties of edible and herbal plants which collected from markets or experimental farms of agricultural research institutes, those showed the anti-platelet aggregating activities were selected by testing the crude methanol extracts: Aster scaber, Aster tataricus, Ligularia stenocephala, Platycodon glaucum Allium victorialis, Allium oderum, Moros bombycis, Portulaco oleracea, Aamthopanax sessiliflorus and Rosa davurica. However, some of them activated the platelet aggregation under the same assay conditions: Pimpinella brachycarpa, Hosta plantaginea, Capsella bursapastoris, Fagopyrm esculentum, Prunus mume, Rubus coreanus and Limaria japonica. In addition, those revealed the antioxidant activities were selected by measuring the abilities to scavenge superoxide anion radicals: Pteridium aquilinum, Aster scaber, Ligularia fischeri, Chrysanthemum zawadskii, Artemisia capipparis, Cirsium setidens, Commelina communis and Capsella bursapastoris among edible plants.

• Proceedings of the KOSOMBE Conference
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• v.1991 no.05
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• pp.89-93
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• 1991

The purpose of this reserch is to design the blood cell counting instrument which can measure the number of RBC(Red Blood Cell) and WBC(White Blood Cell) including many other blood component. The proposed method uses the electrical impedence method and the new discrimination method wi th DSP chip and software algorithm. The system consist of control unit, blood cell discrimination unit, hemoglobin spectrometer, post detect ion processor unit, and IBM-PC interface unit. In this paper, the discrimination system has been implemented using digital signal processor, which result in the reduction of system hardware and cost. The system is helpful in providing necessary clinical test for screen test and quality control of hematology.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.163.2-163.2
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• 2010

In this work, nano-flake shaped nickel oxide (NiO) films were synthesized by chemical bath deposition technique for electrochemical capacitors. The deposition was carried out for 1 and 2 h at room temperature using nickel foam as the substrate and the current collector. The structure and morphology of prepared NiO film were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). And, electrochemical properties were characterized by cyclic voltammetry, galvanostatic charge-discharge, and AC impedence measurement. It was found that the NiO film was constructed by many interconnected NiO nano-flakes which arranged vertically to the substrate, forming a net-like structure with large pores. The open macropores may facilitate the electrolyte penetration and ion migration, resulted in the utilization of nickel oxide due to the increased surface area for electrochemical reactions. Furthermore, it was found that the deposition onto nickel foam as substrate and curent collector led to decrease of the ion transfer resistance so that its specific capacitance of a NiO film had high value than NiO nano flake powder.

• Journal of the Korean Chemical Society
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• v.58 no.5
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• pp.437-444
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• 2014

The electrochemical corrosion and passivation of Co-RDE in borate buffer solution was studied by Potentiodynamic and electrochemical impedance spectroscopy. The mechanisms of both the active dissolution and passivation of cobalt and the hydrogen evolution in reduction reaction were hypothetically established while utilizing the Tafel slope, the rotation speed of Co-RDE, impedance data and the pH dependence of corrosion potential. Based on the EIS data, an equivalent circuit was suggested. In addition, the electrochemical parameters for specific anodic dissolution regions were carefully measured. An induction loop in Nyquist plot measured at the open-circuit potential was observed in the low frequency, and this could be attributed to the adsorption-desorption behavior in the corrosion process.