• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.1
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• pp.84-92
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• 1989

The purpose of this paper is to demonstrate the effect of a FH spread spectrum communication interference in TV channels and frequency compatibility in 30-88 MHz frequency band. To calculate this interferece, the strength of electric field of TV signals is derived as a function of distance between TV transmitter and receiver. An interference model is established based upon thefield strength by using the relation between the transmitted power of FH spread spectrum communications and the distance between the TV image signals, which makes TV screen a cceptble, Simultaneous transmission of FH sprea spectrum signals and TV signals is shown to be feasible, as far as the interference level is lower than the TV image signal level by 23.5dBm. As a result of frequency analysis and experiment, the FH spread spectrum communication can be used together with TV channels.

• IE interfaces
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• v.13 no.4
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• pp.694-702
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• 2000

For the graceful transition from the analog to digital TV systems, a systematic frequency assignment scheme must be incorporated into the transition planning procedure. In this study, we have studied the frequency assignment methodology for the efficient management of the limited spectrum resources. By applying the graph-theoretic approach, this study developed a new solution method for additional frequency assignment problem whose objective is to assign available frequencies for newly generated requirements (digital TV stations) with minimum reassignment of the preassigned frequencies to LPTV stations while meeting the interference-related constraints. The proposed algorithm can be effectively applied not only to the current digital TV introduction phase but also to the development phase with some further development. This study can be utilized as the basis for the future study on frequency assignments that aims at graceful transition from analog TV to digital TV.

• Korean Journal of Community Nutrition
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• v.18 no.5
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• pp.429-441
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• 2013

This study was conducted to examine the interrelations among snack preference, purchasing behavior and intake of fifth and sixth grade students in elementary schools in Gyeongnam province. Frequency of snack intake was the highest in those who reported 'once a day' (45.6%) snack habit. Longer-time television viewers also showed higher frequency of snack intake than shorter-time viewers. Thirty-three percent of students purchased snacks by themselves and the frequency of snack purchasing had a significant positive relationship with TV watching time (p < 0.01). The main reason, place and time of eating snacks were 'hunger' (79.2%), their home environment (50.9%) and 'after school hours' (89.7%). The favorite snack was 'ice cream' and, this snack habit was significantly different by gender of the child (p < 0.01) and TV watching time (p < 0.01). 'Milk and dairy products' scored highest (3.47) in snack intake frequency among longer-time TV viewers (> 2hr) compared to shorter-time TV viewers and this difference was statistically significant (p < 0.001). The snack preference score was correlated positively (r = 0.454) with the intake frequency for snack and its explanation power ($R^2$) was 20.5%. With regard to snack purchase behaviors, the scores of 'checking the expiration date' and 'comparing the price with similar products' were high (in what group?). Female students (p < 0.001) and shorter-time TV viewers (< 2hr) (p < 0.01) had a more reasonable purchasing behavior. The total score of preference was significantly higher (p < 0.05) in shorter-timeTV viewers (< 2hr). In the correlation between snack purchasing behaviors and intake frequency, attractiveness (r = 0.208, p < 0.001) and preference (r = 0.330, p < 0.001) showed significant positive correlations. The result of regression analysis, preference only was selected ($R^2$= 0.108).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.613-623
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• 2000

Digital TV tuner for 8-VSB modulation was developed with satisfying the requirements of ATSC. The double frequency conversion and the active tracking filter in the front-end were used to reduce interference of the adjacent channels and multi-channels, which suppress If beat and image band. However, it was impossible to get frequency mapping between tracking filter and first VCO(Voltage Controlled Oscillator) in the double conversion digital TV tuner differing from conventional NTSC tuner. This paper, therefore, suggests the available structure and a new method for automatic frequency selection by obtaining the mapping of frequency characteristic over tracking voltage and the combined hardware which compose of Micro-controller, EEPROM, D/A(Digital-to-Analog Converter), OP amp and switch driver to solve above problems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.17-22
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• 2018

This study suggests that 'Will not we use more smartphones while watching TV commercials? Then, will the TV advertising effect decrease due to the distributed concentration?". As a result of the preliminary study, it was confirmed that about 63% of users watching TV commercials use smartphones together. In this study, we propose the possibility of a new mobile advertising service by experimenting and analyzing the effect of high frequency technology based TV advertising linked mobile advertising service. Experimental results show that the response rate of the same content is improved about 9 times as compared with that of the general mobile advertisement when the advertisement of the same content is provided by the TV advertisement interlocking type. It can be confirmed that it is quite effective to provide the same content advertisement to the customers who are in front of the TV at the time of sending the TV advertisement. Therefore, it is expected that various services based on high frequency technology will be activated as a new advertising service that will preserve the effect of TV commercials in the future.

• The Journal of the Korea Contents Association
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• v.7 no.10
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• pp.135-145
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• 2007

Hana TV, representative TV portal, has the similar function of internet portal media. This study will focus on the practical use of Hana TV which is increasing rapidly its subscribers. Monthly connecting rate by subscriber, frequency of program request will be analysed. For this research, the data, documents of Hana TV and its home page were taken. According to the analyse, the subscribers of Hana TV prefer to watch free TV's programs and hope to watch more free TV's library.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.5 s.164
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• pp.705-716
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• 2007

The purpose of this study was to examine the relationship structure in TV home shopping focusing on purchasing frequency and gender. Subjects for this study were 300 customers who had purchased fashion products in TV home shopping. For date analysis, factor analysis, t-test, correlation analysis and path analysis were used. As the result, when comparing groups by the purchasing frequency, the group which had higher purchase experiences had significant relationship between trust and commitment than other group of lower purchase experiences. There were statistically significant differences in 'service', 'benefits', 'influence', 'security' variables between purchasing frequency groups. Also when comparing groups by the gender, both men and women had 'relationship maintenance intention' in CRM. However, women had the effects from 'trust' to 'commitment', while men had not effects. However, there were statistically significant differences in 'service', 'information', 'reputation', 'influence' variables between men and women. Based on these results, TV home shopping fashion marketing strategies would be suggested.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.302-312
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• 2000

Digital TV tuner for 8-VSB modulation was developed with satisfying the requirements of ATSC. Double frequency conversion and active tracking filter was used in order to suppress IF beat and image band, which results in reducing the interference between adjacent channels and multi-channels. The implemented digital TV tuner has excellent performance such as the wide dynamic range, good flatness in passing band, and low phase noise. The developed tuner is available to handle the digital and analogue television signal at the same time.

• Journal of electromagnetic engineering and science
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• v.1 no.2
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• pp.131-138
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• 2001

The DTV (Digital TV) tuner for an 8-VSB (Vestigial Side-Band) modulation was developed to meet the requirements of the ATSC (Advanced Television Systems Committee). The double frequency conversion and the active tracking filter in the front-end were used to cancel interferences between adjacent channels and multi-channels by suppressing the IF beat and the Image frequency. However, It was impossible to get frequency mapping between the tracking filter and the first VCO (Voltage Controlled Oscillator) in the existing DTV tuner structure which differs from the NTSC (National Television Systems Committee) tuner. This paper, therefore, suggests an assailable structure and a new method for the automatic frequency selection by mapping the frequency characteristics over the tracking voltage and the combined HW which is composed of a Micro-controller, an EEPROM (Electrically Erasable Programmable Read Only Memory), a DAC (Digital-to-Analog Converter), an OP amplifier, and a switch driver.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.21-27
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• 2014

The broadcasting of the analog TV was terminated in 2012 and was converted into the broadcasting of the digital TV, so methods for arrival of DAB(Digital Audio Broadcasting) are planned recently. Thus, with digitization of analog broadcasting and appearance of new service, it takes effort to improve efficiency of broadcasting frequency. T-DMB which came in 2005 uses existing analog TV band and its channel is allocated inefficiently in order to avoid interference between mutual services. However, the foundation which can afresh reorganize T-DMB channel is building up because the broadcasting of the analog TV was terminated. So, this paper proposes the method for national SFN composition of T-DMB considering existing local broadcasting in order to provide better service to users as well as improve efficiency of broadcasting frequency.