• Journal of The Korean Association of Information Education
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• v.17 no.1
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• pp.1-8
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• 2013

SNS is a social networking service that removes the barrier between cyber spaces and the real world and helps people who have common interests to have a two-way communication, manage their interpersonal relationships and share information. The domestic and international SNS markets have attained a steady growth, and their growth is being more accelerated in recent days. However, studies on SNS have just examined adults, and it's required to research the use of SNS and cyber behaviors via SNS among elementary and middle school students. This study attempted to analyze the relationship of the use of SNS, motivation of using SNS, the use of active SNS functions, SNS-dependent tendency and SNS awareness to cyber behaviors via SNS among elementary and middle school students. As a result, regardless of gender and grade, stealing private information was the most frequent activity and the frequency of 'contacting strangers' activity increased most rapidly with the usage time and grade. SNS dependency turned out to be the most highly correlated with the negative cyber behavior. Moreover, the difference of gender was not significant to the overall negative cyber behavior, whereas that of grade was.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.179-186
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• 2008

Several lines of evidence suggest that osteocytes play a critical role in bone remodeling. Both healthy and apoptotic osteocytes can send signals to other bone surface cells such as osteoblasts, osteoclasts, osteoclast precursors, and bone lining cells through canalicular networks. Osteocytes responding to mechanical strain may also send signals to other cells. To determine the role for osteocytes an mechanical strain in bone remodeling, we examined the effects of fluid flow shear stress on osteoclast precursor cell and osteoblast proliferation and recruitment induced by osteocytes. In addition, the effects of fluid flow shear stress on osteocyte M-CSF, RANKL, and OPG mRNA expression were also examined. MLO-Y4 cells were used as an in vitro model for osteocytes, RAW 264.7 cells and MOCP-5 cells as osteoclast precursors, and 2T3 cells as osteoblasts. MLO-Y4 cells conditioned medium (Y4-CM) was collected after 24h culture. For fluid flow experiments, MLO-Y4 cells were exposed to 2h of pulsatile fluid flow (PFF) at 2, 4, 8, $16{\pm}0.6\;dynes/cm^2$ using the Flexcell $Streamer^{TM}$ system. For proliferation assays, MOCP-5, RAW 264.7, and 2T3 cells were cultured with control media or 10-100% Y4 CM. Cells were cultured for 3d, and then cells were counted. RAW 264.7 and 2T3 cell migration was assayed using transwells with control media or 10-100% Y4-CM. M-CSF, RANKL and OPG in MLO-Y4 mRNA expression was determined by semiquantitative RT-PCR. Y4-CM increased osteoclast precursor proliferation and migration, but decreased 2T3 cell proliferation and migration. CM from MLO-Y4 cells exposed to PFF caused decreased RAW 267.4 cell proliferation and migration and 2T3 migration compared to control Y4-CM. However, Y4-CM from cells exposed to PFF had no effect on 2T3 osteoblastic cell proliferation. PFF decreased RNAKL mRNA and increased OPG mRNA in MLO-Y4 cells compared to control(without PFF). PFF had no effect on M-CSF mRNA expression in MLO-Y4 cells. These results suggest that osteocytes can regulate bone remodeling by communication with osteoclast precursors and osteoblasts and that osteocytes can communicate mechanical signals to other cells.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.511-516
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• 2006

In this raper, we propose the Sequentiel Couleur Avec Memoire or Sequential Color with Memory (SECAM) video encoder system using modified anti-cloche filters and the SECAM video decoder system using a band pass filter (BPF) and an error-free square root. The SECAM encoder requires an anti-cloche filter recommended by International Telecommunication Union-Recommendation (ITU-R) Broadcasting service Television (BT) 470. However, the design of the anti-cloche filter is difficult because the frequency response of the anti-cloche filter is very sharp around rejection-frequency area. So, we convert the filter into a hish pass filter (HPF) by shifting the rejection frequency of 4.286MHz to 0Hz frequency. The design of HPF becomes very easy, compared to that of the anti-cloche filter. The proposed decoder also uses an error-free square root, two differentiators and trigonometric functions to extract color-component information of Db and Dr accurately from frequency modulation (FM) signals in SECAM systems. Also, the BPF in decoder it used for removing color noise in chrominance and dividing CVBS into chrominance and luminance. The proposed systems are experimentally demonstrated with Altera FPGA APEX20KE EP20K1000EBC652-3 device and TV sets.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2307-2314
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• 2015

This paper focuses on the generation algorithm of BeiDou pseudorange correction (PRC) and simulation based performance verification for design of Differential Global Navigation Satellite System (DGNSS) reference station and integrity monitor (RSIM) in order to prepare for recapitalization of DGNSS. First of all, it discusses the International standard on DGNSS RSIM, based on the interface control document (ICD) for BeiDou, estimates the satellite position using satellite clock offset and user receiver clock offset, and the system time offset between Global Positioning System (GPS) and BeiDou. Using the performance verification platform interfaced with GNSS (GPS/BeiDou) simulator, it calculates the BeiDou pseudorange corrections , compares the results of position accuracy with GPS/DGPS. As the test results, this paper verified to meet the performance of position accuracy for DGNSS RSIM operation required on Radio Technical Commission for Maritime Services (RTCM) standard.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.524-527
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• 2008

Recently, digital and the Internet are widespread out of the world, and multimedia processing technology and the development of information and communication technology in education using the Internet as the demand is rapidly increasing. Also, we tan easily use informations with less restrictions of time and space. however, several kinds of audio, media to integrate multimedia data, such as the proliferation of demands for representation. Therefore, in 1998, W3C presented an international standard, SMIL in order to solve multimedia object representation and synchronization problems. By using SMIL, various multimedia elements can be integrated as a multimedia document with proper view in a spate and time. Using this SMIL document, we can create new internet radio broadcasting service that delivers not noly audio data but also various text, image and video. In this paper, with the system, teachers can easily create multimedia courseware and living broadcast their torture on network, students can receive audio-video information of the teacher, screen displays of the teachers computer. Moreover students can communicate with teacher simultaneously by text editor windows. Students can also order courseware after class.

• Journal of Distribution Science
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• v.12 no.12
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• pp.75-82
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• 2014

Purpose - Due to the rapidly changing environment, the needs of information distribution are emphasized more than ever before. As information changes to cater to diversity, professionalism, and detailed segmentation, this information is produced exponentially. Many researchers working in intelligence agencies are feeling the need to establish a comprehensive information management and information distribution system in a systematic and more effective manner. Mobile marketing is based on communication when consumers can access information using GPS systems whatever their location may be when they are on a trip. Until recently, Korean companies have been struggling to perform well in the larger mobile tourism information service (MTIS) for Chinese tourists, which is regarded as a blue ocean area. The principal dimensions of the characteristics of a mobile tourism information service were analyzed, and the influence on perceived value and satisfaction was identified. Moreover, the relationship among the variable satisfaction and using intentions was empirically analyzed. Research design, data, and methodology - This study examined the structural relationship among mobile tourism information features, perceived value, satisfaction, and behavioral intentions. It is based on analyzed data from questionnaires involving advanced research. A questionnaire survey targeting Chinese students using a mobile tourism information service in Korea was conducted. A total of 230 questionnaires were circulated, and 221 questionnaires were used for empirical analysis, excluding invalid data. The data were analyzed with structural equation modeling with SPSS 21.0 statistic package reliability analysis, factor analysis, and regression analysis were implemented, and the effects of the mobile tourism information service features on perceived value, satisfaction, and using intentions were presented. Results - First, mobile tourism information service features have a direct positive effect on the practical value, and do not affect the hedonic value. Second, perceived value has a statistically positive effect on satisfaction. Third, perceived value has a positive effect on behavioral intentions. Fourth, satisfaction has a direct positive effect on behavioral intentions. Conclusion - MTIS (mobile tourism information service) involves personal, social, and technical characteristics. We have analyzed the effects of mobile tourism information service on perceived value, and on satisfaction and using intentions. First, the study shows that the characteristics of mobile tourism information service and perceived value in relation to mobile tourism information service usage are important for marketing in the Chinese market. Moreover, after using a mobile tourism information service, the effect on practical value is more than on hedonic value. We could not analyze the program for tourism information service extensively, and used only questionnaires from Chinese students in Korea. In the future, there should be research on the programs for a tourism information service. We expect to study the MTIS program in greater detail, and to improve the quality and reputation of MTIS through the analysis of its program. We hope that this research will allow an evaluation of the relationship between Korea and China regarding MTIS.

• Journal of Distribution Science
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• v.12 no.12
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• pp.119-130
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• 2014

Purpose - Franchise industries are significant both socially and economically. However, with increasing interest, there are manifold problems. It is necessary to seek measures for mature operation constantly despite unprepared franchisors, negative perceptions of the media and society toward franchise, and rapid changes in business start-up trends and propensity to consume that make business start-ups difficult. The paper aims to explain the effects of relational commitment and performance on the franchisor's management characteristics and justice in the food service franchise system. Research design, data, and methodology - This is an exploratory survey examining franchising in Korea. Based on a literature synthesis, we extract five constructs: managerial characteristics, support, fairness, trust, and satisfaction. We hypothesize that these factors influence the trust, satisfaction, and performance of franchisees. To examine these hypotheses empirically, we conducted a survey on the database of the Franchising Council of Korea. The study employs data from May to September 2014. In total, 135 completed questionnaires were received, of which 128 were usable. The data was analyzed with SPSS/PC 22.0. First, to test unidimensionality and nomological validity of the measures of each construct, we employed a scale refinement procedure. The result of a reliability test with Cronbach's α and factor analysis warranted unidimensionality of the measures for each construct. In addition, nomological validity of the measures was warranted from the result of the correlation and regression analysis. By analyzing the data, we can confirm most hypotheses. Results - Frist, franchisor characteristics have a positive effect on trust and satisfaction. Second, franchisor fairness has an effect on trust and satisfaction. Third, franchisor support has an effect on satisfaction. Further, the franchisee trust has an effect on satisfaction. Fourth, the satisfaction of a franchisee with a franchisor affects the performance of a franchisee. Finally, there is a possibility that not only franchisee performance but also increasing the credibility and improving the image of the franchisor through communication between franchisor and franchisee can improve franchisees' performance and satisfaction by motivating the franchisee for sustainable growth. Franchisers should endeavor for franchisees to obtain stable revenue with continuous and practical support. They should recognize that they can expand their business by supporting their franchisees. Franchisors should not only instantly respond to franchisees' troubles with interactive communications but also raise the ability of supervisors for better support. Franchisors should share their visions and goals with their franchisees and provide systematic and continuous support based on trust and clear company management. Franchisees should understand franchisors' position as well as participate in establishing the basic franchise system. Contributions - The paper contributes to understanding franchising in Korea. It offers insights and assistance to franchisors hoping to start franchises. This paper explores measurement issues related to franchisee performance by estimating its determinant factors (managerial characteristics, support, fairness, trust, and satisfaction). This study provides franchisors and practitioners planning to extend their franchising business with some practical knowledge.

• Journal of Korea Spatial Information System Society
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• v.7 no.3 s.15
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• pp.93-106
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• 2005

Recently, the web map services with standard interfaces have been developed to a high degree for the purpose of sharing of spatial data through the web. Among the various kinds of works related, the specification for the web map service released by Open Geospatial Consortium (OGC) is the most prominent, and is nearly adopted as international standard (ISO/DIS 19128) in developing the web map servers. The web map server of OGC, however, provides the insufficient capabilities for mobile applications. Unlike the wired applications, the mobile applications would require the map server to minimize of size of data transferred, because the size of data is very important factor in communication cost and the response time of map clients. And the mobile applications require different quality of map according to the screen size of mobile devices. The mobile application, also require some application specific queries. In this paper, We have Proposed the interfaces for mobile web map services (M-WMS) which fully comply with the standard interfaces proposed in OGC. And we have designed and implemented the web map server for mobile map services. This paper has contributed to construction and practical use of the web map servers in mobile applications, such as LBS and telematics.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.129-139
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• 2009

The transportation network is a critical infrastructure in the event of natural and human caused disasters such as rainfall, snowfall, and terror and so on. Particularly, the transportation network in an urban area where a large number of population live is subject to be negatively affected from such events. Therefore, efficient traffic operation plans are required to assist rapid evacuation and effective detour of vehicles on the network as soon as possible. Recently, ubiquitous communication and sensor network technology is very useful to improve data collection and connection related emergency information. In this study, we develop a specific algorithm to provide evacuation route and detour information only for vehicles under emergency situations. Our algorithm is based on shortest path search technique and dynamic traffic assignment. We perform the case study to evaluate model performance applying hypothetical scenarios involved terror. Results show that the model successfully describe effective path for each vehicle under emergency situation.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.553-567
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• 2007

Migrant Worker are rapidly increasing in Korea since 1990. They are nowadays main sources of laborer groups engaging in medium-sized factories. The purpose of this study is to provide the basic information to establish proper oral health policy. Dental caries and periodontal disese are the most common disease that occur in the mouth. Periodontal disease is the most common disease in humans and the biggest reason for the loss of the teeth in the adult population. The CPITIN has been developed jontly by the international Dental Federation and the World Health Organization. CPITN is now an established index of level, of periodontal condition in populations for which specific intervention might be considered. This study was conducted to obtain the information regarding to CPITN of migrant workers located in Daegu, Questionaire survey was carried out for 289 workers from July 9 to August 8, 2006. Total survey was 289, 224 males and 65 females. The result was as follows: First, The number of nationality was 14. The first majority was China as 31.8% Among 14 nationalities were Cambodia 18.0%, Vietnam 12.8%, Sri Lanka 12.1%, Indonesia 7.3%, Nepal 4.2%, the other 13.8%, those who are aged from 20 to 29 were 43.9%, and salary from 1,000,000 won to 1,490,000 won 51.2%.(as for their residence, those who resided) over 3 years were 42.6% and not insured reached 68.5%. Second, more than 93.4% of the subjects need periodontal treatment, only 4.9% of non-smoker was health periodontal states, four times frequency of tooth brushing per a day was 16.7%. Third, 28.7% of migrant workers had experienced visit of dental clinic, and 22.9% had received treatment of decayed tooth. Fourth, It is difficult for them 65.1% of them to visit dental clinic in korea, the First was a communication problem and the second was time. Fifth, Most of them didn't have a oral health education but 85.1% of them said that they wish they attend oral health education. We conclude that the situation of migrant workers was very bad considering their working conditions, circumstances, and health condition. According to this study, more than 93.4% of the people need periodontal treatment. Besides they didn't have accurate knowledge about prevention of periodontal disease. Therefor our considering these facts, the policy of dental health by government should be established for migrant workers.