• Journal of the Korea Society of Computer and Information
• /
• v.16 no.1
• /
• pp.183-189
• /
• 2011

This paper suggests a user based OST(Open Street Traffic) system that solves TPEG's one-way communication problem, UTIS's limited usage and DSRC's small traffic bandwidth. In current commercial TPEG service, only some service providers collect traffic information. Thus, it can't cover traffic status in local lanes And UTIS, which local governments and police supports, requires additional equipments. Currently, only taxi and official vehicles use this system. Therefore, new traffic service by mobile device and user's participation can provide very detail traffic information coupling with previous traffic systems. But in this new system, real-time high volume data can be a problem. So, in this paper, new data storage manager design(TDSM :Traffic Data Storage Manager) is suggested and its performance is measured against commercial DBMS.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.11
• /
• pp.4268-4290
• /
• 2015

Future mobile communications face enormous challenges as traditional voice services are replaced with increasing mobile multimedia and data services. To address the vast data traffic volume and the requirement of user Quality of Experience (QoE) in the next generation mobile networks, it is imperative to develop efficient content distribution technique, aiming at significantly reducing redundant data transmissions and improving content delivery performance. On the other hand, in recent years cloud computing as a promising new content-centric paradigm is exploited to fulfil the multimedia requirements by provisioning data and computing resources on demand. In this paper, we propose a cooperative caching framework which implements State based Content Distribution (SCD) algorithm for future mobile networks. In our proposed framework, cloud service providers deploy a plurality of cloudlets in the network forming a Distributed Cloud Service Network (DCSN), and pre-allocate content services in local cloudlets to avoid redundant content transmissions. We use content popularity and content state which is determined by content requests, editorial updates and new arrivals to formulate a content distribution optimization model. Data contents are deployed in local cloudlets according to the optimal solution to achieve the lowest average content delivery latency. We use simulation experiments to validate the effectiveness of our proposed framework. Numerical results show that the proposed framework can significantly improve content cache hit rate, reduce content delivery latency and outbound traffic volume in comparison with known existing caching strategies.

• Electronics and Telecommunications Trends
• /
• v.4 no.1
• /
• pp.35-43
• /
• 1989

The evolution of telecommunications has raised the profile of many segments of the network that were not previously considered important. Until recently, basic telephony existed with the extension of passive cables without any particular user network interface. In the area of data communications, the introduction of flexible packet switching has allowed the network to evolve in a far more efficient manner. To overcome such separated network problems and business needs of both users and network providers, the integrated narrowband ISDN concept is being developed in most countries for implementation in the public switched telephone network (PSTN). The targets of ISDN, in my opinion, can be explained as follows : To the user, ISDN should provide the services at any time, at any place, through any media. To the business customer using PABX or LAN applications, ISDN should introduce customized services rapidly and also, ISDN should be developed by the modular hardware and software design approach in order for new services to be introduced rapidly and effectively. Software can be also developed by non-expert local staff to cater for adopting new user's service requirements immediately. Finally, ISDN will be able to increase business chances and benefit both users and operating companies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.10 no.1
• /
• pp.11-21
• /
• 1999

Physically, AICPS consists of HSSF(High Speed Switching Fabric) and various types of service interface modules to support services of homogeneous communication networks. Functionally, AICPS consists of UANS(User Access Network Subsystem) to connect users with communication networks, IDNS(Information Delivery Network Subsystem) to connect Information-Providers with information delivery network, and LOMS(Local Operations and Management System to manage AICPS. This paper describes the structures of LOMS, ONAS(Operational Network Access Subsystem), which interfaces between LOMS and HSSF, and describes reliability improvement algorithms and construction methods of nationwide management structure of AICPS.

• International journal of advanced smart convergence
• /
• v.12 no.1
• /
• pp.173-183
• /
• 2023

Recently, local governments that provide mobile-based public delivery app services have been increasing a lot. The purpose of this study is to analyze whether the restaurant self-employed's public delivery app selection attributes and public institutions' perception of support, which are under economic pressure due to the high delivery fee burden of private delivery apps, affect the intention to use public delivery app services. In this study, the degree of perception of each factor was measured using the Likert 5-point scale, and it was verified through statistical analysis using SPSS. The effect of the selection attribute of public delivery apps and the perception of self-employed people in the restaurant industry on the intention to use the service was empirically analyzed, and the hypothesis was verified using regression analysis. As a result of this study, it was confirmed that convenience, economy, and public interest had a significant effect among the factors of public app selection attributes, and educational support had a significant effect on public institution support.

• Journal of Broadcast Engineering
• /
• v.19 no.1
• /
• pp.14-23
• /
• 2014

This paper proposed controlling methods for SDN(Software Defined Network) based multiple radio access technology as the solutions of following two issues which were mainly occurred by explosive increasing of video traffic. The first one is a requirement for traffic off-loading caused by 3rd-party video service providers from the mobile network operator's viewpoint. The other one is a provision of high-speed video contents transmission services with low price. Furthermore, the performance evaluation was also conducted on the real test-bed which is composed of OpenStack cloud and SDN technology such as OpenFlow and Open vSwitch. A virtual machine running on the OpenStack provide a video service and the terminal which is able to use multiple radio access technology supports two 2.4GHz WLANs(Wireless Local Area Network) and three 5GHz WLANs, concurrently. Finally, we can get 820Mbps of the maximum transmission speed by using that five WLAN links for the single service at the same time.

• The Journal of Korean Society for School & Community Health Education
• /
• v.16 no.1
• /
• pp.93-105
• /
• 2015

Objectives: This study is for understanding the perceived job training of the public health promotion program officials and analysis the educational needs in order to serve as the basis for the development of the future educational programs. Methods: To this end, we have developed a survey based on references and consultations with experts. We had explained the purpose and the intent of the survey to nationwide public health directors in advance and an online questionnaire was conducted for health promotion program and service providing personnel; the results from a total of 763 survey respondents were used in the final analysis. Collected data were analyzed through SPSS Win 21.0. Results: The results shows that the tasks of public health promotion personnel are 'business practices,' 'planning and evaluation related work' and so on in order of importance while the duties of service providing personnel are 'counseling,' 'education' and so on. One of the factors affecting field applications of education is 'awareness of the connection between education and career development' which accounts for 33% of explanatory power; the selected six other factors constitute 41.7%. Necessary educational contents for public officials are 'public health service planning,' 'report writing skills' and 'project evaluation methods.' On the other hand, for service providers, the contents are 'counseling methods,' 'development of educational materials,' 'monitoring health status' and so on. Conclusions: In order for trained service personnel to accord with the changed health promotion environment and the demand of local residents, Public Health Promotion officials should increase educational opportunities based on the competencies for each job, provide continuous learning opportunities and information even after the training, and finally, create a system that can link to career development.

• Journal of Korea Society of Industrial Information Systems
• /
• v.18 no.2
• /
• pp.71-83
• /
• 2013

Because of rapid advance of wireless Internet-related technology and fast diffusion of Smart phone, a variety of mobile applications through domestic and foreign app stores have been made and used. Under the recognition of current trend, both central government and local government have developed and provided public mobile app in order to accomplish the mobile e-government. However, public mobile app is not popular in spite of vast investment for its development and service. This study investigated current issues and problems of public mobile app in public service, management, and technology aspects. To do so, this study categorized the interested people of public mobile app into users, providers, and developers, and conducted deep interviews to them. Based on the interview results, the study suggested the following recommendations for the activating tools of public mobile app: providing user-customized information, fruitfulness of public information management, maintenance of management system for public mobile app service, user-friendly promotion appropriate in mobile environment, public mobile app development based on e-government standard framework, etc.. This study may provide the researchers with the successive study guidelines in mobile e-government and public mobile app fields. Also, the study may help the practitioners to make effective decisions on polices and strategies for mobile e-government of local government.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.1
• /
• pp.171-174
• /
• 2006

A large number of service providers in countries all over the world have established GNSS reference station networks in the last years and are using network software today to provide a correction stream to the user as a routine service. In current GNSS network processing, all the geometric related information such as ionospheric free carrier phase ambiguities from all stations and satellites, tropospheric effects, orbit errors, receiver and satellite clock errors are estimated in one centralized Kalman filter. Although this approach provides an optimal solution to the estimation problem, however, the processing time increases cubically with the number of reference stations in the network. Until now one single Personal Computer with Pentium 3.06 GHz CPU can only process data from a network consisting of no more than 50 stations in real time. In order to process data for larger networks in real time and to lower the computational load, a federated filter approach can be considered. The main benefit of this approach is that each local filter runs with reduced number of states and the computation time for the whole system increases only linearly with the number of local sensors, thus significantly reduces the computational load compared to the centralized filter approach. This paper presents the technical aspect and performance analysis of the federated filter approach. Test results show that for a network of 100 reference stations, with the centralized approach, the network processing including ionospheric modeling and network ambiguity fixing needs approximately 60 hours to process 24 hours network data in a 3.06 GHz computer, which means it is impossible to run this network in real time. With the federated filter approach, only less than 1 hour is needed, 66 times faster than the centralized filter approach. The availability and reliability of network processing remain at the same high level.

• Korean Journal of Social Welfare Studies
• /
• v.40 no.3
• /
• pp.5-40
• /
• 2009

As of June 2008, the government's expansion policy for the long-term care service infrastructure has achieved an outstanding 96.4% occupancy rate of facilities across the country. Despite such achievement, practical issues including the physical lack of facilities, disproportional regional spread and decline in government accountability have raised concerns about the effectiveness of the policy's implementation. This study was aimed at defining the implementation procedure of expansion policy for long-term care service infrastructure, analyzing variables that affect it, examining the problems revealed in implementation procedure, and suggesting improved plan on that policy. Research methods were to review literatures on infrastructure expansion policy, to conduct case studies on K province, C city and 4(2 corporations and 2 privately owned) facilities in C city for studying practical implementation procedure on a local government level, and to use Alexander(1985)'s framework for analyzing variables of policy implementation. As a result of this study, policy variables including the clarity and adequacy of policy goal, nature of service providers, task and responsibility between government authorities, and implementation variables such as propensity toward budget allocation, financial restraint, swift utilization of budgets and the streamlining of involved procedures and inter-agency relations stood out as the main factors affecting policy implementation. In adddition, this study suggested several improvement measures such as accounting facilities need based on real local demand and supporting to private participation and so on.