• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.32-40
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• 2016

IEEE 802.15.4 is the one of the protocols for radio communication in a personal area network. Because of low cost and low power communication for IoT communication, it requires the highest optimization level in the implementation. Recently, the studies of location aware algorithm based on IEEE802.15.4 standard has been achieved. Location estimation is performed basically in equal consideration of reference node information and blind node information. However, an error is not calculated in this algorithm despite the fact that the coordinates of the estimated location of the blind node include an error. In this paper, we enhanced a conventual maximum likelihood estimation using weighted coefficient and implement the hardwired location aware engine for small code size and low power consumption. On the field test using test-beds, the suggested hardware based location awareness method results better accuracy by 10 percents and reduces both calculation and memory access by 30 percents, which improves the systems power consumption.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.530-547
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• 2018

This study examines the importance of location and transportation in the operation of small- and medium-sized hospitals in the rapidly changing clinical environment. Approximately 350 persons were surveyed for approximately 40 days from July-August 2017, and responses were analyzed using SPSS and AMOS Statistical Package for 335 parts excluding 8 parts of 343.The main research results were as follows: First, a hypothesis was adopted that the attractiveness of building materials will positively affect customer satisfaction. Second, the hypothesis that transport infrastructure has a significant impact on customer satisfaction was rejected. Third, the hypothesis that the building appeal will positively affect the site was supported. Fourth, the hypothesis that transport infrastructure will have a significant impact on location marketability was supported. Fifth, the hypothesis that location marketability will significantly impact customer satisfaction was supported. Sixth, the hypothesis that the relationship between the site and customer satisfaction with the relationship between the client and the client is explained is partly attributable to the fact that there is a partial function. The assumption that the relationship between traffic infrastructure and customer satisfaction was confirmed. The hypothesis that the relationship between traffic infrastructure and customer satisfaction was supported. This research focuses on small- and medium-sized hospitals located in Seoul, which does not include the recognition of patients' awareness of the location and transportation of small- and medium-sized hospitals. Moreover, this study has the limitation in analyzing patient satisfaction, rather than the objective data of the financial management performance of the hospital. The results of this study could provide the basis for selecting the future locations of health care facilities.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.422-429
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• 2007

Location awareness is one of the key functionalities to build an U-city. Recently, many of works of the location-aware systems are emerging to commercially apply to on-going large-scale apartment complex based on U-city. As dwellers or cars being attached with active tags are moving in the U-city complex, the active tags periodically broadcast their own identifiers and receivers fixed along the street or in building use those information to calculate location of them. There are several issues to be considered for such an environment. The first is that the number of active tags operating in the same region are large as much as tens of thousands, and the second is that the active tags should be alive without change of batteries more than a year, hence low power consumption is very important. In this paper we propose i) a new architecture for location-aware system considering such issues, ii) technical issues to implement it using active tags, and iii) a mathematical analytic model to investigate overall performance and verify it by comparing with actual experimental results. Through the analysis we can show the theoretical boundary of the lowest packet loss rate and the maximum number of tags with acceptable performance for the systems based on active tags. The results can be applied to practical design of location-based systems of U-City projects.

• Journal of Broadcast Engineering
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• v.23 no.1
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• pp.26-35
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• 2018

The recent development of overlay network technology enables distributed sharing of various types of contents. Although overlay network has great advantages as a huge content repository, it is practically difficult to directly provide such Internet service as streaming of contents. On the other hand, the media server, which is specialized in content services, has excellent service capabilities, but it suffers from the huge contents that are constantly created and requires large expansion of severs and storages, and thus requires much effort for efficient management of the huge repository. Hence, the association of an overlay network of huge storage with a media server of high performance content service will show a great synergy effect. In this paper, a location-aware scheme of constructing overlay networks and associating it with media server is proposed, and then cache-based contents management and service policy are proposed for efficient content service. The performance is analysed for one of the content services, streaming service.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.489-498
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• 2012

Smartphone schedule management applications are widely used in mobile environment with the help of their effective user interface and high user accessibility. Unfortunately, since the applications do not consider frequent context changes like user status or location, they can not support schedule management which reflects the changes. In this paper, we propose an intelligent notification service which gathers context information of users such as location and status, and actively provides appropriate services according to the context information. Based on the notification service, we also present a smartphone application for smart schedule management. Using the GPS sensor of a smartphone, the service can be aware of the status of the user through location and schedule information of the user. Also, according to the changed contexts, it provides proactive notifications to user.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.4
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• pp.117-124
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• 2015

As recent developing computing environments, service is provided without time or place's limitation, and it is constituted dynamically. Above all, in terms of education supporting system, there is need to conceive user's information and provide optimal service as to right with applying context awareness under Ubiquitous computing environment. It should have groundwork based on user location and time. It is requires service providing based on user location under the condition of class to offer appropriate service with the context. In addition, context information providing technology is needed to offer right education support service in the class, where are different context information. Hence, in this research it is suggested education supporting system to provide context-based for instructor. The framework of this system has a foundation within previous work about Multi-agent based Distributed Framework. To examine implementation of context-based education supporting system in Ubiquitous computing environments suggested by this report, arranging system can fit information relates to instructor's location for service applying in the class.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1337-1342
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• 2014

Increasingly important user based service on the smart media era, and increasing awareness about the user experience. In this study, by considering these realities, what impact location based constructs on smartphone environment, continuous intention to use you want to identification. Thus, this study conducted of preference the influencing factors for location based constructs. First steps, based constructs known empirical studies were categorized information, entertainment, safe&emergency, navigation&tracking and advertising& commerce. Second Steps, the categorized factors were analyzed preference relationship between constructs using AHP(analytic hierarchy process) technique. Questionnaire survey was conducted to those who employees S Telecom in Busan city and Gyeongnam province during 2000. 4. 15 and 2014. 4. 30. The result of the analysis might be summarized that the navigation(0.133) has the highest preference ran in the constructs. Based on these findings, several theoretical and practical implications were suggested and discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.171-174
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• 2014

Increasingly important user based service on the smart media era, and increasing awareness about the user experience. In this study, by considering these realities, what impact location based constructs on smartphone environment, continuous intention to use you want to identification. Thus, this study conducted of preference the influencing factors for location based constructs. First steps, based constructs known empirical studies were categorized information, entertainment, safe&emergency, navigation&tracking and advertising& commerce. Second Steps, the categorized factors were analyzed preference relationship between constructs using AHP(analytic hierarchy process) technique. Questionnaire survey was conducted to those who employees S Telecom in Busan city and Gyeongnam province during 2000. 4. 15 and 2014. 4. 30. The result of the analysis might be summarized that the navigation(0.133) has the highest preference ran in the constructs. Based on these findings, several theoretical and practical implications were suggested and discussed.

• Journal of Korean society of Dental Hygiene
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• v.1 no.2
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• pp.227-242
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• 2001

The purpose of this study was 10 examine whether or not the dental- health education experiences of elementary school teachers have any influence on their oral-health awareness and attitude. The subjects in this study were 414 selected teachers from Seoul and North Cholla province. The instrument used by Lee Heung-su was modified into self- reporting questionnaire, and the schools where the subjects were working were visited to conduct a survey for 28 days from September 15 to October 13, 2000. For data analysis, SPSS was employed, and chi-squre, t-test and ANOVA were implemented. The findings of this study could be listed as below: 1. 184(44.4%) out of the techers investigated had ever been educated in dental health, and 230 teachers(55.6%) hadn't. 47% replied they hadn't received oral-health education for the lack of education opportunities. 2. In regard to dental-health awareness and attitude. the presence or absence of dental-health education experiences didn't make any difference to their daily toothbrushing frequency(p>0.05). The use of fluorine was significantly different between the groups(p<0.01), as 42.9% of the teachers with dental-health education experiences and 63.9% of the others with no such a experience didn't use that, 45.7% of the former group and 29.1 % of the latter accurately knew how to brush teeth, and the difference between the two was significant (p<0.01). 3. Concerning student-related dental-health awareness and attitude, the dental-health education experiences make 45.7% of the educated group and 31.7% of the uneducated group agreed to the strong need for oral examination, and the gap between the two was significant(p<0.01). 90.8% of the former group gave counsel to students on dental health, and 77.2% of the latter didn't. The gap between the two was significant as well (p<0.01). 77.2% of the educated group and 41.3% of the uneducated group offered frequent dental-health education, and the difference between the two was significant (p<0.01). 4. Their awareness of the fluorine-based toothbrushing project differed significantly by region(p<0.05), as the teachers from North Cholla province recognized it better than those from Seoul. The female teachers provided more education regarding that project, and those who were older or had more teaching experiences were more aggressive in instructing that project(p<0.01). And the married teachers took more forward attitude than the unmarried (p<0.01). By school location, the teachers from Seoul showed more active attitude than those from North Cholla province(p<0.01), and the gap between the two was significant. As to cooperation, those who were older or had more teaching experience were more cooperative, and the married teachers joined forces better than the unmarried. The gap was significant (p<0.01). 5. Concerning the awareness and attitude of the fluorine-based toothbrushing project, the educated teachers took more aggressive attitude, and the difference between the two was significant(p<0.01). The above-mentioned findings suggested that the dental-health awareness and attitude of the elementary school teachers were under a lot of influence of their oral-health education experiences, and there is a need to develop and carry out education programs for teacher.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.8
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• pp.648-659
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• 2018

In this study, both the altitude error due to the refraction and the range error due to the delay in the ionosphere with respect to the frequency are extracted according to the radar elevation to analyze the effect of atmosphere on the space surveillance radar. To achieve this, the radio refractivity profile is modeled using the measured data from domestic weather stations. Then, the altitude-error due to the refraction is extracted using the ray tracing method, and the range error in the ionosphere is extracted according to the frequency. Further, considerations for radar design with respect to the radar error characteristics are discussed based on the abroad space surveillance radar and proposed domestic space surveillance radar. This analysis of the error characteristics is expected to be utilized for the determination of radar location, range of steering, and frequency in the space surveillance radar design.