• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.6-16
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• 2008

An instable wireless channel condition causes more packet losses and retransmissions due to interference, fading, station mobility, and so on. Therefore video streaming service over a wireless networks is a challenging task because of the changes in the wireless channel conditions and time-constraints characteristics of the video streaming services. To provide efficient video streaming over a wireless networks, QoS-enhanced MAC protocol, IEEE 802.11e, is standardized recently. Tn this paper, we propose a new network-adaptive H.264 video streaming mechanism in the IEEE 802.11e wireless networks. To improve the quality of video streaming services, video stream has to adapt to the changes in the wireless channel conditions. The wireless channel conditions are estimated by the packet loss probability and informed to the application layer by the cross-layering. According to the wireless channel information, the video streaming application filters out the low-priority data. This adaptation mechanism efficiently uses system resources because it drops the low-priority data in advance. Therefore, our cross-layer design can provide improved video streaming services to the end-user. Through the implementation and performance evaluation, we prove that the proposed mechanism improves the QoS of the video streaming by providing the smoothed playback.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.437-441
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• 2006

Wireless sensor network consists of sensor nodes which are disseminated closely to each other to collect informations for the various requests of a sensor application applied for sensing phenomenons in real world. Each sensor node delivers sensing informations to an end user by conducting cooperative works such as processing and communicating between sensor nodes. In general, the power supply of a sensor node is depends on a battery so that the power consumption of a sensor node decides the entire life time of a sensor network. To resolve the problem, optimal routing algorithm can be used for prolong the entire life time of a sensor network based on the information on the energy level of each sensor node. In this paper, different from the existing Directed Diffusion and SPTN method, we presents a data dissemination protocol based on lower-power consumption that effectively maximizes the whole life time of a sensor network using the informations on the energy level of a sensor node and shortest-path hops. With the proposed method, a data transfer path is established using the informations on the energy levels and hops, and the collected sensing information from neighboring nodes in the event-occurring area is merged with others and delivered to users through the shortest path.

• KIISE Transactions on Computing Practices
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• v.21 no.7
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• pp.506-511
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• 2015

IOV is a technology that supports one or more virtual desktops, and can share a single physical device. In general, the virtual desktop uses the virtual IO devices which are provided by virtualization SW, using SW emulation technology. Virtual desktops that use the IO devices based on SW emulation have a problem in which service quality and performance are declining. Also, they cannot support the high-end application operations such as 3D-based CAD and game applications. In this paper, we propose a physical network separation system using Virtual Desktop Service based on HW direct assignments to overcome these problems. The proposed system provides independent desktops that are used to access the intranet or internet using server virtualization technology in a physical desktop computer for the user. In addition, this system can also support a network separation without network performance degradation caused by inspection of the network packet for logical network separations and additional installations of the desktop for physical network separations.

• Nuclear Engineering and Technology
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• v.39 no.1
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• pp.31-42
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• 2007

Energy supply is increasingly showing up as a major issue for electricity supply, transportation, settlement, and process heat industrial supply including hydrogen production. Nuclear power is part of the solution. For electricity supply, as exemplified in Finland and France, the EPR brings an immediate answer; HTR could bring another solution in some specific cases. For other supply, mostly heat, the HTR brings a solution inaccessible to conventional nuclear power plants for very high or even high temperature. As fossil fuels costs increase and efforts to avoid generation of Greenhouse gases are implemented, a market for nuclear generated process heat will be developed. Following active developments in the 80's, HTR have been put on the back burner up to 5 years ago. Light water reactors are widely dominating the nuclear production field today. However, interest in the HTR technology was renewed in the past few years. Several commercial projects are actively promoted, most of them aiming at electricity production. ANTARES is today AREVA's response to the cogeneration market. It distinguishes itself from other concepts with its indirect cycle design powering a combined cycle power plant. Several reasons support this design choice, one of the most important of which is the design flexibility to adapt readily to combined heat and power applications. From the start, AREVA made the choice of such flexibility with the belief that the HTR market is not so much in competition with LWR in the sole electricity market but in the specific added value market of cogeneration and process heat. In view of the volatility of the costs of fossil fuels, AREVA's choice brings to the large industrial heat applications the fuel cost predictability of nuclear fuel with the efficiency of a high temperature heat source tree of Greenhouse gases emissions. The ANTARES module produces 600 MWth which can be split into the required process heat, the remaining power drives an adapted prorated electric plant. Depending on the process heat temperature and power needs, up to 80% of the nuclear heat is converted into useful power. An important feature of the design is the standardization of the heat source, as independent as possible of the process heat application. This should expedite licensing. The essential conditions for success include: ${\bullet}$ Timely adapted licensing process and regulations, codes and standards for such application and design ${\bullet}$ An industry oriented R&D program to meet the technological challenges making the best use of the international collaboration. Gen IV could be the vector ${\bullet}$ Identification of an end user(or a consortium of) willing to fund a FOAK

• Journal of Korea Multimedia Society
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• v.12 no.8
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• pp.1142-1154
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• 2009

The brand new type of mobile terminal services are kept being introduced in accordance with the development of mobile communication technology. Among many kinds of mobile application services, the PoC application standard which is using instant messaging service and group calls method with the existing walkie-talkie technology has been finished as the version 1.0 after tremendously active discussion and is being continued to be confirmed as 2.0 and 2.1. The PoC Box, which is discussed for replacing the PoC client and intermediate object as a voice messaging box, is currently being introduced and the biggest issues for PoC Box technology topics include the part of saved informations' processing and effective multimedia contents' transmission in the PoC Box system. In this research, we propose that the PaC client could effectively transmit the media to the end-user by specifying the playback location or range, focusing on the contents and the methods of dynamic controlling for saved media in PoC Box. This paper deals with the way of dynamic controlling method using the RTSP which is appropriate for PoC Box and the effective method for generation, expression, processing of various multimedia contents including audio and video objects.

• The KIPS Transactions:PartD
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• v.10D no.2
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• pp.247-260
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• 2003

To share and standardize information, especially in the database environments, MDR (Metadata Registry) can be used to integrate various heterogeneous databases within a particular domain. But due to the discrepancies of data element representation between organizations, global information integration is not so easy. And users who are searching integrated information on the Web have limitation to obtain schema information for the underlying source databases. To solve those problems, in this paper, we present a 3-layered Information Integration System (LI2S) based on MDRs and Ontology. The purpose of proposed architecture is to define information integration model, which combine both of the nature of MDRs standard specification and functionality of ontology for the concept and relation. Adopting agent technology to the proposed model plays a key role to support the hierarchical and independent information integration architecture. Ontology is used as for a role of semantic network from which it extracts concept from the user query and the establishment of relationship between MDRs for the data element. (MDR and Knowledge Base are used as for the solution of discrepancies of data element representation between MDRs. Based on this architectural concept, LI2S was designed and implemented.

• Journal of vocational education research
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• v.37 no.3
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• pp.65-83
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• 2018

In this study, we want to analyze the aspect that required in the classroom for the operation of NCS-based curriculum, the interest of specialized subject teachers on implementable teaching and learning methods. As a result, the overall interest in teaching-learning method of specialized subject teachers was similar to that of non-user patterns among four types of interest patterns. In other words, specialized subject teachers want to know more about teaching-learning method for applying NCS-based curriculum, but we are only aware of the general facts at present, and it seems that there is low interest in actual operation. In addition, there was no statistically significant difference in the degree of interest in the teaching-learning method according to general variables(gender, related training experience, career, and curriculum group) of the specialized subject teachers. The specialized subject teachers are not well aware of the influence of the teaching-learning method according to the introduction of NCS-based curriculum, and to that end, there was little interest in collaboration with colleagues.

• Journal of the Korean Society for Library and Information Science
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• v.53 no.1
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• pp.5-31
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• 2019

In this study, in order to foster human resources equipped with expertise in libraries and spatial organization that contributes to the development of libraries, planning, design, and construction, the self-designed library space planning major was developed and the education goal, human resources award, and major capabilities were presented. To this end, the relevant literature analysis, expert opinion collection, and consumer survey were conducted, and the results are as follows. First, the person-in-person awards required for library space planning were identified as space planning personnel, design thinking personnel, and creative working people. Second, the person-specific majors were derived with the ability to analyze the library environment, ability to express spatial concepts, ability to analyze user needs, ability to coordinate interests, ability to understand spatial design, ability to understand spatial design, and ability to apply practical applications. Based on the plan, subjects should be developed that can fulfill the educational goals of the future library space planning major, human resources award, and human resources status, and operation plans should be designed so that the library space planning major can adapt students without fail due to its own design-based major.

• The Journal of Society for e-Business Studies
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• v.24 no.2
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• pp.199-216
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• 2019

The public SW market is 3 trillion won, which is less than 10% of the total SW market. However, due to the nature of the domestic market, it is an important market with a relatively large impact on small and medium-sized software companies. In this market, government is operating the Public SW Project Demand Forecasting System in order to support the marketing activities of small and medium sized SW companies and establish a fair market order. The current system has limitations such as lack of user convenience, insufficient analysis capability and less business connection. This study was conducted to identify the problems of these systems and to propose a new system for improving the convenience of users and expanding the information utilization of SMEs. To this end, we analyzed the requirements of each stakeholder. We proposed the 2-phased forecasting cycle, the management cycle, and the system life cycle of public SW projects and created a unified identifier (UID) so that the information of those projects can be identified and linked among them. As a result, an integrated reference model of project information management based on system life cycle was developed, which can explain the demand forecasting and project information, and the improved processes was also designed to implement them. Through the result of this study, it is expected that integrated management of public SW projects will be possible.

• The Journal of Sustainable Design and Educational Environment Research
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• v.18 no.1
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• pp.1-16
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• 2019

The purpose of this study is to diagnose the problems of an elementary school care classroom in terms of facilities and physical environment and to suggest an improvement plan for building safer and more pleasant facilities and environment in further proceeding the policies of a whole-day care classroom. To this end, we analyzed the main contents of the domestic policies for elementary school care classes and the related spatial standards amongst the management plans of provincial education offices nationwide. In addition, we analyzed the relevant care facility standards of advanced countries such as the U.S., Australia, and Singapore and diagnosed the physical environmental level of Korean care classes in comparison to the international standards. Afterwards, we conducted a case study of elementary school care classes in order to examine the key issues with the environment of care classes, the causes of these issues and the user recognition and demand. The key results of this research are as follows. First, it is necessary to elaborate and refine the guidelines on elementary school care classrooms. Second, in order to provide high-quality elementary care services, it is important to have a combined classroom that can be operated at the level equivalent to or similar to a dedicated care classroom. Third, it is necessary to regularly check the facilities and environment of the elementary school care classroom.