• Journal of dental hygiene science
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• v.17 no.4
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• pp.315-322
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• 2017

The aim of this study was to explore the association between daily toothbrushing frequency and health risk behaviors of school-going adolescents in poor urban areas of Peru. A cross-sectional survey was conducted among 959 school-going adolescents 11~19 years of age in poor urban areas of Peru in 2014. Health risk behaviors we assessed in the study were smoking; drinking; consuming sugar-sweetened soft drinks (more than one cup); leisure time activities including watching television, playing games, and using the Internet; and never or rarely handwashing with soap. Daily toothbrushing frequency was divided into two groups (once and twice daily). For statistical analyses, the chi-square test and hierarchical logistic regression were used at 5% level of significance. Of the total respondents, 63 (14.3%) were boys and 53 (10.3%) were girls and 116 (12.1%) engaged in toothbrushing (${\leq}1$ times daily). According to the adjusted logistic regression analysis for socio-demographic characteristics, two behaviors (leisure time use activities, including watching television, playing games, and using the Internet (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.20~4.35), and never or rarely hand washing with soap (OR, 4.09; CI, 2.48~6.75) were statistically associated with toothbrushing frequency (${\leq}1$ times daily). We found two health risk behaviors (leisure time activities, including watching television, playing games, and using the Internet, and never or rarely handwashing with soap) associated with toothbrushing frequency among adolescents in the study area. Thus, oral health promotion programs should consider these health risk behaviors associated with toothbrushing frequency.

• Journal of Information Technology Applications and Management
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• v.21 no.4_spc
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• pp.449-462
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• 2014

As mobile traffic is growing, the demand for spectrum is increasing but the deficiency of spectrum becomes serious as the supply is restricted essentially. For resolving the issue, spectrum sharing system is discussed from the technical and regulatory point of view, where multiple radio users occupy same frequency. In this paper, the policies and adoptions of spectrum sharing system in some countries are analyzed with a focus on TV white space and licensed shared access, which are based on unlicensed and licensed spectrum usage respectively. Some legal and regulatory plans to adopt and activate spectrum sharing in the Radio Waves Act system of Korea are proposed as well.

• Wind and Structures
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• v.12 no.5
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• pp.401-412
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• 2009

A method is applied for the estimation of structural damage of tall slender structures using natural frequency and displacements measurements by GPS. The relationship between the variation in the global stiffness matrix (or in the stiffness of each finite element) and the change in the natural frequencies of the structure is given. In engineering practice the number of frequencies which can be derived by GPS measurement of long-period structures will be equal to one, two or three first natural frequencies. This allows us in initial studies to detect damage with frequency changes based on forward methods in which the measured frequencies are compared with the predicted analytical data. This idea, of health monitoring from possible changes to natural frequencies, or from a statement of excessive displacements is applied to the Stuttgart TV Tower.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.398-400
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• 2013

2012년 말 아날로그 TV의 종료와 함께 기존의 아날로그 TV에서 사용하고 있는 채널들이 유휴 대역으로 존재한다. 현재 비교적 많은 유휴 상태로 있는 대역을 효율적으로 사용하기 위한 논의가 지속적으로 진행 중이다. 본 논문에서는 차세대 방송서비스를 위한 주파수 재분배 방법에 대해서 분석하였다. 차세대 방송 서비스는 역호환성(Backward Compatibility)이 보장되어야 한다고 가정하고, 현재 구성 되어있는 다중 주파수 망(MFN : Multi Frequency Network)의 한계와 이를 극복할 수 있는 방법에 대해서 기술하였다. 단일 주파수 망(SFN : Single Frequency Network)의 구성이 가능 한 경우, 현재 서비스 중인 HDTV 방송 서비스와 차후 제공할 수 있는 차세대 방송 서비스를 동시에 제공할 수 있도록 주파수 분배 안을 제시하였다.

• Journal of the Korean institute of surface engineering
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• v.45 no.1
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• pp.43-52
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• 2012

Recently, it has been developed for Eco-environment, Super light, Multi-functional nano materials. As needed mobile parts in Smart phone or TV, computer, information communication for high pass signal, multi-function, Magnetic thin film materials have been developed. As last, magnetic powder, sintered and sputtering parts were thick and low purity than electroplating layer, low pass signal and noise were resulted, vibrated TV screen. Because chemical complex temperature was high and ununiform surface layer, it has been very difficult for data pass in High Frequency (GHz) area. Large capacity data pass is used to GHz. Above GHz, signal pass velocity is dependent on Skin Effect of surface layer. If surface layer is thick or ununiform, attachment is poor, low pass signal and cross talk, noise are produced and leaked. It has been reported technical trend of Electrochemically plating and Surface treatment of Metal, Polymer, Ceramic etc. by dispersion/complex for Multi functional nano-magnetic material in this paper.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.2
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• pp.119-124
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• 2010

In this paper, microstrip antenna for Digital TV from 406 to 806 MHz has been designed and fabricated. In order to broaden the bandwidth of the antenna and improve of frequency properties, slot size, radius for capacitance controls were changed. DTV antenna was designed using HFSS simulation program and fabricated by FR4 substrate of dielectric constant 4.4.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.79-84
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• 2014

Increasing demand for realistic media and improvement of transmission and device techniques accelerate ultra-high definition(UHD) service realization. In Korea, the cable TV broadcasting companies are planning to commercialize in Apr. 2014. For the terrestrial TV broadcasting service, technical issues are considered for the specification of UHD broadcasting system. However, the frequency bands and the system bandwidth for the terrestrial UHD broadcasting system have not been decided. In this paper, we propose required spectrum bandwidth for the next-generation terrestrial broadcasting service considering source coding, error correcting codes and modulation techniques. Also, we propose frequency management plan for terrestrial UHD broadcasting system in which we divide all parts of the country into 9 frequency zones and allocate 4 frequency band to each frequency zone considering single frequency network (SFN).

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.294-301
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• 2011

The current study examined the influence of current TV health programs on old people's practice of health behaviors through analyzing their recognition, watching behaviors and satisfaction. The study conducted 293 old people living in Pohang City, North Gyeongsang Province from March 17, 2008 to March 28, 2008. The results of this study were as follows: 86.3% of the respondents has watching experience of TV health programs in a month while there was a meaningful difference in frequency of watching by education, obesity and a clinical history. The degree of health behavior practice, 62.1% answered high while 17.7% said low. Factors that influence the degree of health behavior practice were sex, interest in health and experience of watching. In addition, men practiced 1.78 times more than women, those with more interest in health practiced 3.3 times of those with no interest, and those with watching experience presented 6.1 times higher practice degree than those with no experience. It was found that old people's recognition for TV health programs was positive, and the more frequently they watch the programs, the higher their practice of health behaviors was. In addition, old people's popularity rate of TV health programs means that they have a lot of opportunities to be exposed to information provided in health programs. Accordingly, it is thought that TV health programs should try to provide correct health information that can meet old people's needs.

• Research in Community and Public Health Nursing
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• v.12 no.2
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• pp.513-531
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• 2001

Television news programs are becoming significant source of health information. This study aims at investigating the current state of health coverage of the prime time news program in Korea. Data were collected from KBS 9 0'clock news in the period of thirteen months. from December 1. 1998. to November 1. 1999. The data were analyzed using content analysis method. and the reliability degree was 99.7% according to the Holsti's inter-coder reliability test. The current research classified 489 health related news items into 49 sub-categories and five health categories through content analysis. Some of the basic results of this study are as follows. 1. The frequency according to health category, health maintenance promotion(57.3%) topped followed by disease prevention(23.2%), disease treatment(14.9%), life ethics(4.0%), and growth development(0.6%). 2. According to human developmental age. for the most part(80.1 %) is applicable to the entire range of human developmental age. 3. Health maintennance promotion category take top of health category by the rate of 57.3% and contain 20 sub-categories. 4. News items in the life ethics category, which had six sub-categories. occupied only four percent of the total health related news. News in the growth development category included two sub categories and occupied 0.6% of the total news items. 5. In disease prevention and disease treatment category, infectious disease(33.2%) showed the highest percentage according to the WHO's international disease classification system. Disease prevention occupied 23.2% and contained eleven sub-categories while disease treatment occupied 14.9% and included ten sub-categories. Television news coverage on health showed a wide variety of selection in terms that they are reporting various issues. This study, however, found that some news items were confusing and failing in presenting scientific evidences. It is suggested that the television coverage on health could be beneficial to most of viewers in receiving important health information and guidelines, only if they are utilizing their own sound discretion in consuming those news.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.96-107
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• 2011

Recently, studies of 3D HDTV broadcasting technology have been processed actively. Korea is making efforts to modify Advanced Television Systems Committee (ATSC) 8-Vestigial Side Band (8-VSB) systems for terrestrial 3D HDTV broadcasting services. We intend to adopt a new frame structure to use PN (Pseudo-Noise) sequence as frame header, and VSB modulation. PN sequence is used to recover carrier freqeuncy offset, carrier phase error. In this paper, we will describe this system as the modified ATSC systems. The receiver of the modified ATSC system should be able to estimate and recover carrier frequency offset exactly. A existing ATSC systems inserts pilot to recover carrier frequency offset, on the other hand the modified ATSC systems use PN sequence to recovery carrier frequency offset without the use of pilot. In this paper, we introduce carrier frequency recovery (CFR) scheme for the modified ATSC systems. The proposed CFR scheme is composed of coarse CFR scheme using Fitz algorithm and fine CFR scheme using a simple PN sequence correlation algorithm. And, the symbol information of QAM modulated signal is contained in both In-phase (I)channel and Quadrature-phase (Q)channel. However the symbol information of VSB modulated signal is contained in I channel, and Q channel is just Hilbert transform of I channel. For the reason, VSB modulated symbols can not have fixed phase like QAM modulated symbols, and VSB modulated symbols is more sensitive to carrier frequency offset. Therefore we perform phase correction of received PN sequence to improve performance.