• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.5
• /
• pp.906-912
• /
• 2017

In this paper, we studied a design method for a broadband 3-element quasi-Yagi antenna (QYA) for indoor digital television (DTV) reception. The proposed QYA employs a novel balun between a microstrip (MS) line and a coplanar strip (CPS) line feeding the driver dipole. The proposed balun is constructed by connecting the end of MS line to CPS line through a shorting pin, and the CPS and ground reflector are connected through a circular ring-type conductor. An antenna, as an design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV. The antenna fabricated on an FR4 substrate with a size of $270mm{\times}150mm$ showed a good performance such as a frequency band of 470-820 MHz for a voltage standing wave ratio < 2, a gain > 4.0 dBi, and a front-to-back ratio > 8.4 dB over the DTV frequency band.

• Journal of the East Asian Society of Dietary Life
• /
• v.17 no.6
• /
• pp.765-779
• /
• 2007

The objective of this study was to examine Jeonju residents' recognition towards their native local foods. The results indicate that their degree of interest in the native foods was above average. As age and education increased, the degree of interest was also increased. Also, married people showed greater interest as compared to single people (p<$0.05{\sim}0.001$). There were more people who said they preferred native foods than people who said they didn't, where 213 people (41.3%) answered that they preferred the native foods. Of the people who said they like native foods, their main reason was because the native foods taste good. The main reason for the people who said they disliked native foods was that they didn't have many opportunities to try native foods. TV and radio were the first means, among others, from which people learned about native foods. The place where people ate native foods most often was native food restaurants (242 people, 46.95%). A frequency of a native food intake (including home and dining-out) of $1{\sim}2$ times/year was most prominent, with 137 people (26.6%). Also, a cooking frequency of "hardly ever cooks" was most prominent with 163 people (31.6%). The most prominent reason for the low cooking frequency at home was because they didn't know the recipes. Among 5 basic recipe characteristics for native foods (easy preparation of ingredients, simple recipe procedures, quick preparation, reasonable recipe procedures, sanitation), "sanitation" had the highest average score of 3.54, and "simple recipe procedure" had the lowest score of 2.44. To summarize, in order to develop Jeonju native local foods, it is necessary to implement various strategies such as frequently holding events where people can experience their native foods, running a native food training center, advertising through TV and radio, developing easy home recipes, and simplifying recipes.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37C no.12
• /
• pp.1211-1221
• /
• 2012

This paper describes separation distance to protect radiocommunication services from the interference of inductive systems using frequencies below 30 MHz for the co-existence between radiocommunication services and inductive systems. For the analysis, the interference scenario model is proposed between inductive system and radiocommunication services. Then the calculation method of protection distance is suggested by comparing the radiation power of inductive system with the allowable interference level of victim services, radiocommunication services, according to the applied propagation model. Also, the protection distance for protecting radiocommunication services in the 30 MHz below is calculated through the interference analysis from RFID(Radio Frequency IDentification) and PDP(Plasma Display Panel) TV based on the suggested method. The proposed calculation method was adopted as ITU-R recommendation in related with resolution 63 at ITU-R SG(Study Group) 1 meeting in June, 2012. It will be available to use for the protection of radiocommunication services from the interference of wireless power transfer system and power line telecommunication system.

• The Journal of the Korea Contents Association
• /
• v.19 no.9
• /
• pp.135-143
• /
• 2019

Purpose of this study is enhancing usability of online video platform by analyze link-depth and advertisement frequency. In this study, researcher checked market share of video platform which publishing web-drama, and compare their link-depth and advertisement frequency. As a result, access to the latest content has two to three link-depth. So it does not worsen usability. but, if contents doesn't show on main page or search result, it requires more than five to six steps. Image advertisement show up more than twice on every platform. 'Youtube' and 'Naver TV' show up pre-roll video advertisement in video player before offering contents. In this video platform information structure, directory searching needs high link-depth level and advertisement frequency. It will increase user's bounce rate and decrease return visit rate. So researcher suggests prototype using drop-down menu to reduce link-depth and enhance information structure.

• Proceedings of the KIEE Conference
• /
• 2008.10b
• /
• pp.217-218
• /
• 2008

Since the digital TV signal band is very wide ($54{\sim}806MHz$), the VCO used in the frequency synthesizer must also have a wide frequency tuning range. Multiple LC VCOs have been used to cover such wide frequency band. However, the chip area increases due to the increased number of integrated inductors. A general method for achieving both reduced VCO gain(Kvco) and wide frequency band is to use the switched-capacitor bank LC VCO. In this paper, a scheme is proposed to cover the full band using only one VCO. The RF VCO block designed using a 0.18um CMOS process consists of a wideband LC VCO with reduced variation of VCO gain and frequency steps. Buffers, divide-by-2 circuits and control logics the simulation results show that the designed circuit has a phase noise at 100kHz better than -106dBc/Hz throughout the signal band and consumes $9.5{\sim}13mA$ from a 1.8V supply.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.10a
• /
• pp.737-740
• /
• 2003

SFN (Single Frequency Network) and OCR (On Channel Repeater) are often considered for the efficiency of frequency allotment in digital TV. In this paper, we discuss the performance and evaluate some coverage criterions for SFN and OCR. Also, we propose MATLAB simulator for coverage planning and estimation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.69-71
• /
• 2014

MLCCs are used broadly in electronic industry like smart phone and TV. Although they are fabricated in small size and have high capacitance, there are acoustic noise problems to reduce comfort of user. Acoustic noise results from linear piezoelectricity and nonlinear electrostriction of $BaTiO_3$ in MLCC and there are some researches on MLCC vibration under AC electric field. When only AC electric field without DC bias is applied to MLCC, fundamental frequency response is affected by piezoelectricity and second-harmonic frequency response shows electrostrictive vibration. In this study we get vibration shape of MLCC under AC electric field for each frequency and analysis on the mechanism of MLCC vibration affected by piezoelectricity and electrostriction.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.11
• /
• pp.779-789
• /
• 2014

Cognitive radio (CR) technology based on geo-location database access approach and/or wideband spectrum sensing approach is absolutely vital in order to recognize available frequency bands in white spaces (WSs), and efficiently utilize shared spectrums. This paper presents a new structure for the TVWS database access protocol implementation based on Internet Engineering Task Force (IETF) Protocol to Access WS database (PAWS). A wideband compressive spectrum sensing (WCSS) scheme using a modulated wideband converter is also proposed for the TVWS utilization. The developed database access protocol technology which is adopted in both the TV band device (TVBD) and the TVWS database operates well in the TV frequency bands. The proposed WCSS shows a stable performance in false alarm probability irrespective of noise variance estimation error as well as provides signal detection probabilities greater than 95%. This paper also investigates Federal Communications Commision (FCC) regulatory requirements of TVWS database as well as European Telecommunications Standards Institute (ETSI) policy related to TVWS database. A standardized protocol to achieve interoperability among multiple TVBDs and TVWS databases, which is currently prepared in the IETF, is discussed.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.45 no.4
• /
• pp.50-58
• /
• 2008

In this paper, we propose a color transient improvement (CTI) algorithm based on image fusion to improve the color transient in the television(TV) receiver or in the MPEG decoder. Video image signals are composed of one luminance and two chrominance components, and the chrominance signals have been more band-limited than the luminance signals since the human eyes usually cannot perceive changes in chrominance over small areas. However, nowadays, as the advanced media like high-definition TV(HDTV) is developed, the blurring of color is perceived visually and affects the image quality. The proposed CTI method improves the transient of chrominance signals by exploiting the high-frequency information of the luminance signal. The high-frequency component extracted from the luminance signal is modified by spatially adaptive weights and added to the input chrominance signals. The spatially adaptive weight is estimated to minimize the ${\iota}_2-norm$ of the error between the original and the estimated chrominance signals in a local window. Experimental results with various test images show that the proposed algorithm produces steep and natural color edge transition and the proposed method outperforms conventional algorithms in terms of both visual and numerical criteria.

• Journal of the Korean Dietetic Association
• /
• v.11 no.1
• /
• pp.51-66
• /
• 2005

The purpose of this study was to do the quantitative analysis about food and nutrition informations in TV program by monitoring newscastings, health-related food and nutrition information programs, dramas for family, education programs for children, and seniors’ information programs in major TV broadcasting companies (KBS, MBC, SBS, EBS). In this study, number of cases about the health-related food and nutrition informations and the length of program were analyzed. Also, they were compared and analyzed by the year. Monitoring staff, who had majored in food and nutrition and completed the monitoring training, monitored programs and analysis the quantity of food and nutrition informations in each program from 2002 to 2003. Results of quantitative analysis for this study are as follows; There were total number of 15,226 cases. Among them, the total number of health-related information was 5,623 cases(36.9%), and the total number of food-related information was 3,848 cases (25.3%). The ratio of total food and nutrition information to total health-related informations was 86.2%. In news programs from 2002 to 2003, the total number of health-related information to total cases decreased to 16.1% from 17.9%. The ratio of total food and nutrition information to total cases decreased to 3.6% from 6.6%. The frequency of the health-related informations was mostly served in the newscastings was highest, in both October 2002, and September 2003. In health information programs from 2002 to 2003, the ratio of food and nutrition information to total cases increased to 57.4% from 32.4%. In dramas from 2002 to 2003 , the ratio of broadcasting time of food-related scenes to total cases decreased to 17.2% from 20.8%. In education programs for children the ratio of food and nutrition information to total cases was 8.2% in 2002. In information programs for seniors the ratio of food and nutrition information was to total cases 26.2% in 2002. As the result of this study, the rate of health-related information in TV program and the rate of food and nutrition information were changing. And the rate of nutrition information in health information programs are increased. To give sound informations to the public, monitoring should be established and managed continuously.