• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.9
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• pp.1005-1014
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• 2007

In this paper, The four types SRA(Sequential Rotated Array) antennas has been analyzed. Those are consisted of a 4-elements SRA, a 8-elements SRA, the $2{\times}2$ planer array SRA and the triple (4+8+4)-elements SRA. These LHCP SRA antennas are used a probe feeding multi-layer truncated microstrip antenna whose center frequency is 11.85 CHz. The cooperated feeding circuits are designed for feeding to each elements with equal amplitude and regular phase. Comparing with the each simulation results and experiment results of this 4-type SRA antennas, the triple (4+8+4)-elements SRA showed the most electrical characteristics in the degree of integration, high gain and low cross polarization.

• YAKHAK HOEJI
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• v.52 no.5
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• pp.323-330
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• 2008

This study was conducted to investigate the actual conditions of vitamin supplement usage, the importance of their agents for health management, and the distribution of basic data for their correct consumption. For a period of one month 2003, the study was conducted based on questionnaires to the parents of students in both a middle school and a high school, and the personnel of K Company at random. The material used the survey sheets by setting up the previous investigation. The collected data analyzed the frequency and percentage of the following items: General demographic characteristics of consumers; the supplements taking; the reasons for taking them; the kinds of supplements taken; the media used for distributing data on their use; the potential use in the future, etc. According to the survey, the number of people who were taking supplements was higher than the number of people who weren’t taking them. Multi-vitamins were mostly consumed. The rate of supplements consume was high in people of a higher income bracket, had the time to exercise and to enjoy physical recreation. Most of the consumers who were taking the supplements said they did it to maintain their health and to recover from the fatigue. Those who weren’t taking them said they had enough vitamins from eating the appropriate food, and they were also concerned about the effectiveness of taking the supplements. The majority of useful information or advice for purchasing vitamins came from doctors, medical experts, relatives, and various media sources such as TV, newspapers, and magazines.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.441-449
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• 2007

In video coding, motion estimation is a process to estimate the pixel of the current frame from the reference frame, which affects directly the predictive quality and the encoding time. This paper is related to AHHS(Adaptive Hierarchical Hexagon Search) using spatio-temporal motion activity for fast motion estimation. The proposed method defines the spatio-temporal motion activity of the current macroblock using the motion vectors of its spatio-temporally adjacent macroblocks, and then conventional AHS(Adaptive Hexagon Search) is performed if the spatio-temporal motion activity is lower, otherwise, hierarchical hexagon search is performed on a multi-layered hierarchical space constructed by multiple sub-images with low frequency in wavelet transform. In the paper, based on computer simulation results for multiple video sequences with different motion characteristics, the performance of the proposed method was analysed and assessed in terms of the predictive quality and the computational time. Experimental results indicate that the proposed method is both suitable for (quasi-) stationary and large motion searches. The proposed method could keep the merit of the adaptive hexagon search capable of fast estimating motion vectors and also adaptively reduce the local minima occurred in the video sequences with higher spatio-temporal motion activity.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.33-33
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• 2016

Mycotoxins are toxic secondary metabolites produced by fungi. They can be present in where agricultural-based commodities are contaminated with toxigenic fungi. These mycotoxins cause various toxicoses in human and livestock when consumed. Small grains including corn, barley, rice or wheat are frequently contaminated with mycotoxins due to infection mainly by toxigenic Fusarium species and/or under environment favorable to fungal growth. One of the most well-known Fusarium toxin groups in cereals is trichothecenes consisting of many toxic compounds. Deoxynivalenol (DON), nivalenol (NIV), T-2 toxin, and various derivatives belong to this group. Zearalenone and fumonisin (FB) are also frequently produced by many species of the same genus. In order to monitor Korean cereals for contamination with Fusarium and other mycotoxigenic fungal species as well, barley, corn, maize, rice grains, and soybean were collected from fields at harvest or during storage for several years. The fungal colonies outgrown from the grain samples were identified based on morphological and molecular characteristics. Trichothecene chemotypes of Fusarium species or presence of FB biosynthetic gene were determined using respective diagnostic PCR to predict possible toxin production. Heavy grain contamination with fungi was detected in barley, rice and wheat. Predominant fungal genus of barley and wheat was Alternaria (up to 90%) while that of rice was Fusarium (~40%). Epicoccum also appeared frequently in barley, rice and wheat. While frequency of Fusarium species in barley and wheat was less than 20%, the genus mainly consisted of Fusarium graminearum species complex (FGSC) which known to be head blight pathogen and mycotoxin producer. Fusarium composition of rice was more diverse as FGSC, Fusarium incarnatum-equiseti species complex (FIESC), and Fusarium fujikuroi species complex (FFSC) appeared all at considerable frequencies. Prevalent fungal species of corn was FFSC (~50%), followed by FGSC (<30%). Most of FFSC isolates of corn tested appeared to be FB producer. In corn, Fusarium graminearum and DON chemotype dominate within FGSC, which was different from other cereals. Soybeans were contaminated with fungi less than other crops and Cercospora, Cladosporium, Alternaria, Fusarium etc. were detected at low frequencies (up to 14%). Other toxigenic species such as Aspergillus and Penicillium were irregularly detected at very low frequencies. Multi-year survey of small grains revealed dominant fungal species of Korea (barley, rice and wheat) is Fusarium asiaticum having NIV chemotype.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.1
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• pp.357-377
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• 2020

The purpose of this study was to investigate factors affecting the adolescent's health literacy. First, we examined whether information literacy affects adolescents' understanding of health information, and then analyzed how demographic statistics and various other characteristics of adolescents affect health literacy. Data was collected through a survey of 277 middle and high school students. The results of analysis of Multi-regression showed that information literacy was found to have a positive impact on adolescent's health literacy. In addition, factors such as gender, grade level, academic performance, health concern, and frequency of use of digital devices were statistically significant in their affect on adolescent's health literacy. The results of this study can be used as basic data to improve adolescent' comprehension of health information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5A
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• pp.479-486
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• 2008

In this paper, an efficient training symbol design with m-sequence is proposed for the MIMO-OFDM based next generation wireless transmission system which supports gigabits per second data rate. In the traditional blute force method, the preamble design is based on the case by case comparison with the system requirements. This paper discusses a training symbol design methodology for the MIMO-OFDM system based on the m-sequence which has been widely used in the spread spectrum communication areas due to its good correlation characteristics. Also the step-by-step design and performance verification method within the limited search space is discussed. The proposed method targets the design of the training symbol which satisfies system requirements for the packet based MIMO-OFDM wireless communication system including automatic gain control(AGC), timing synchronization, frequency and sampling offset estimation, and MIMO channel estimation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.1
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• pp.40-46
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• 2002

In this paper we design and fabricate the Skeleton slot antenna which operates dually in GSM 900 and 1800 bands. Its simulation results are also compared with the measured ones. The original Skeleton slot antennas had the problems of unsatisfactory VSWR characteristics and considerably changing horizontal radiation patterns at high frequencies, but the proposed design improves these problems using multi-path feeding network and folding structure. The size of the radiator is 154 $\times$ 106(mm), and its height is 33(mm), and the reflector of 190$\times$190(mm) is used. The material of the radiator and reflector is 1mm-thick aluminum. Using NTC process reduces the mass production cost significantly. The measured return losses are 13.7 % at 900 MHz band and 16.4 % at 1800 MHz band, respectively. The horizontal radiation beam width is stable within $\pm$ 1$^{\circ}$ at both frequency bands.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.292-297
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• 2003

A diode-pumped single-mode Nd:YV $O_4$ green laser was developed. Frequency doubling of the laser was achieved by using an intracavity KTP generated green beam (532 nm). By comparing the diode laser spectrum with absorption spectrum of the Nd:YV $O_4$ crystal, we found optimal operating temperature of the diode laser. From output power measured for various mirror curvatures and cavity lengths, we found the optimal matching of TE $M_{00}$ mode with the pump beam gives the best efficiency. When the pump power was 1.9 W, 80 ㎽ of TE $M_{00}$ mode green beam was obtained. We tried to get a single longitudinal mode lasing as the fluctuation of the laser power was caused by the shift of longitudinal modes and the beating between the modes. We tested the intracavity etalon method and birefringent filter method for single mode operation. The etalon method resulted in the best single mode output power of 60 ㎽. The power fluctuation of the single-mode laser was reduced to 1/10 of that of the multi-mode laser.

• The Korean Journal of Food And Nutrition
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• v.34 no.4
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• pp.372-380
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• 2021

In this study, data from the 7th (2016~2018) and 8th (2019) Korea National Health and Nutrition Examination Surveys were used, which included 5,325 subjects. Health behavior, dietary and nutrient intake status, physical measurement and biochemical characteristics, and risk factors for elderly related chronic diseases were classified and analyzed according to the changing composition of single households and other households in the current society. As a result, the ratio of current smokers and drinkers in young adult single households, walking less than 30 minutes per day, subjective health status was poor, breakfast rate less than three times per week, eating out frequency more than once a day, lipid intake ratio to total calories, saturation fatty acid intake were significantly higher. In addition, waist circumference, and diastolic blood pressure were significantly higher. However, dietary fiber intake level was significantly lower. The results for hypertension, which is the representative chronic disease that causes old age-related chronic diseases, were significantly higher in single households (ORs=1.400 (95% CI: 1.095, 1.791), p=0.007). Although young adults may not have showed particularly serious health problems yet, education is believed as important to recognize and prevent age-related disease risk factors.

• Smart Structures and Systems
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• v.23 no.6
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• pp.641-651
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• 2019

The stochastic stability control of the parameter-excited vibration of an inclined stay cable with multiple modes coupling under random and periodic combined support disturbances is studied by using the direct eigenvalue analysis approach based on the response moment stability, Floquet theorem, Fourier series and matrix eigenvalue analysis. The differential equation with time-varying parameters for the transverse vibration of the inclined cable with control under random and deterministic support disturbances is derived and converted into the randomly and deterministically parameter-excited multi-degree-of-freedom vibration equations. As the stochastic stability of the parameter-excited vibration is mainly determined by the characteristics of perturbation moment, the differential equation with only deterministic parameters for the perturbation second moment is derived based on the $It{\hat{o}}$ stochastic differential rule. The stochastically and deterministically parameter-excited vibration stability is then determined by the deterministic parameter-varying response moment stability. Based on the Floquet theorem, expanding the periodic parameters of the perturbation moment equation and the periodic component of the characteristic perturbation moment expression into the Fourier series yields the eigenvalue equation which determines the perturbation moment behavior. Thus the stochastic stability of the parameter-excited cable vibration under the random and periodic combined support disturbances is determined directly by the matrix eigenvalues. The direct eigenvalue analysis approach is applicable to the stochastic stability of the control cable with multiple modes coupling under various periodic and/or random support disturbances. Numerical results illustrate that the multiple cable modes need to be considered for the stochastic stability of the parameter-excited cable vibration under the random and periodic support disturbances, and the increase of the control damping rather than control stiffness can greatly enhance the stochastic stability of the parameter-excited cable vibration including the frequency width increase of the periodic disturbance and the critical value increase of the random disturbance amplitude.