• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.2
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• pp.154-173
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• 2010

Database outsourcing is unavoidable in the near future. In the scenario of data stream outsourcing, the data owner continuously publishes the latest data and associated authentication information through a service provider. Clients may register queries to the service provider and verify the result's correctness, utilizing the additional authentication information. Research on On-line Stream Analytics (OLSA) is motivated by extending the data cube technology for higher multi-level abstraction on the low-level-abstracted data streams. Existing work on OLSA fails to consider the issue of database outsourcing, while previous work on stream authentication does not support OLSA. To close this gap and solve the problem of OLSA query authentication while outsourcing data streams, we propose MDAHRB and MDAHB, two multi-dimensional authentication approaches. They are based on the general data model for OLSA, the stream cube. First, we improve the data structure of the H-tree, which is used to store the stream cube. Then, we design and implement two authentication schemes based on the improved H-trees, the HRB- and HB-trees, in accordance with the main stream query authentication framework for database outsourcing. Along with a cost models analysis, consistent with state-of-the-art cost metrics, an experimental evaluation is performed on a real data set. It exhibits that both MDAHRB and MDAHB are feasible for authenticating OLSA queries, while MDAHRB is more scalable.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3751-3774
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• 2014

With the rapid development of wireless communication, the confliction between the scarce frequency resources and the low spectral efficiency caused by the stationary spectrum sharing strategies seriously restricts the evolution of the future mobile communication. For this purpose, cognitive radio (CR) emerges as one of the most promising inventions which can overcome the spectrum shortage. As the key technology and main objective of CR, spectrum sharing can make full use of the limited spectrum, alleviate the scarcity of frequency resources and improve the system utilities, playing thereby an important role in improving the system performance of cognitive radio networks (CRNs). In this survey, the spectrum sharing in CRNs is discussed in terms of the sharing process, mainstream sharing technologies and spectrum sharing models. In particular, comparisons of different spectrum sharing strategies are concluded, as well as that of different spectrum sensing schemes in sharing procedure. Moreover, some application examples of the spectrum sharing in CRNs, such as smart grid, public safety, cellular network and medical body area networks are also introduced. In addition, our previous related works are presented and the open research issues in the field of spectrum sharing are stated as well.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.2171-2185
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• 2014

From the perspectives of regulation and convergence, several debates on the industrial definition of smart TV service in the Korean broadcasting and communications market are currently in progress. The most heated controversy mainly depends on whether smart TV is controlled under broadcasting regulations or under communications regulations. This Korean- specific problem is summarized in regulation fairness or asymmetric regulations between smart TV and IPTV operators. Although both operators utilize very similar technology and share the same business model, the regulations for only smart TV operators are unfettered. This would be an intrinsic cause that prohibits fair competition in the new converging market. Currently we confront the matter of asymmetric regulations between smart TV and others including IPTV or ISP. The purpose of this study, thus, is to provide the strategic, regulatory guidance and theoretical definitions on smart TV service, as one of converging services, based on a qualitative approach through subjectivity methodology. The study identifies three issues net neutrality, regulation fairness and new media and new market and proposes desirable promotion plans regarding those issues. The study draws lessons learned through a Korean smart TV case and provides directions to strategic-policy studies for future emergent converging services.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.2152-2170
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• 2014

With advances in smart and ICT(information and communication technology) technologies, our life style has been changing dramatically. Now everybody can enjoy the benefits of such technologies in every aspect of his/her daily life. Currently more and more people are trying to have smart devices such as smart phones and tablet PCs so that smart devices become the bare necessities. New smart technologies have created a new concept called smart learning in education area. As educational smart contents become popular, we need quality standards for the contents. Those standards are essential for evaluating the smart contents and suggesting guidance for future smart contents production. Although there are some standards for the existing e-learning environments, to our best knowledge, there are no standards for educational smart contents in the literature. The purpose of this paper is to develop quality standards for educational smart contents. The proposed quality standards are based on the existing quality standards in e-learning environments and include some characteristics of smart learning. For development of quality standards, wide experts group from academy and industry are selected and surveyed. Their responses are analyzed based on thorough statistical analysis so that final quality standards for educational smart contents are developed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3966-3991
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• 2018

Due to the lack of visualization services and organic combinations between public and private buildings data, the usability of the basic map has remained low. To address this issue, this paper reports on a solution that organically combines public and private data while providing visualization services to general users. For this purpose, factors that can affect building prices first were examined in order to define the related data attributes. To extract the relevant data attributes, this paper presents a method of acquiring public information data and real estate-related information, as provided by private real estate portal sites. The paper also proposes a pretreatment process required for intelligent machine learning. This report goes on to suggest an intelligent machine learning algorithm that predicts buildings' value pricing and future value by using big data regarding buildings' spatial information, as acquired from a database containing building value attributes. The algorithm's availability was tested by establishing a prototype targeting pilot areas, including Suwon, Anyang, and Gunpo in South Korea. Finally, a prototype visualization solution was developed in order to allow general users to effectively use buildings' value ranking and value pricing, as predicted by intelligent machine learning.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.4057-4071
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• 2018

The software centered world following the fourth industrial revolution is rapidly approaching us. Countries around the world attach importance to software's ability as one of the key elements for training future human resources. In order to train software centered human resources, each university has designated Software Education as an essential curriculum for not only major but also non-majors. In the past Software Education was an education for a major, but recent Software Education was changed to the essential education that is necessary for all living in the software centered world. In the past the curriculum was focused on software development and implementation-oriented education, but recent curriculum emphasizes sequential arranging and thinking of problem solving. In order to reflect trends in recent Software Education in detail, we integrate Software Education with major concept of Computational Thinking. In this paper, we analyzed the effect of the main concept of Computational Thinking on Software Education for non-majored learners who received Software Education based on Computational Thinking (here refers to learners who major in humanities, social sciences and arts). In addition, research models of satisfaction, self-efficacy, and occupational change was established as the elements of Software Education, and it was found that there was a relation between Computational Thinking and Software Education.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2003.09a
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• pp.189-201
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• 2003

Grid is a new Information Technology (IT) concept of "super Internet" for high-performance computing: worldwide collections of high-end resources - such as supercomputers, storage, advanced instruments and immerse environments. The Grid is expected to bring together geographically and organizationally dispersed computational resources, such as CPUs, storage systems, communication systems, real-time data sources and instruments, and human collaborators. The term "the Grid" was coined in the mid l990s to denote a proposed distributed computing infrastructure for advanced science and engineering. The term computational Grids refers to infrastructures aimed at allowing users to access and/or aggregate potentially large numbers of powerful and sophisticated resources. More formally, Grids are defined as infrastructure allowing flexible, secure, and coordinated resource sharing among dynamic collections of individuals, institutions and resources referred to as virtual Organizations. GRID is an emerging IT as a kind of next generation Internet technology which will fit very well with Agrometeorological services in the future. I believe that it would contribute to the resource sharing in AgroMeteorology by providing super computing power, virtual storage, and efficient data exchanges, especially for developing countries that are suffering from the lack of resources for their agmet services at national level. Thus, the establishment of CAgM-GRID based on existing RAMINSII is proposed as a part of FWIS of WMO.part of FWIS of WMO.

• Journal of Internet Computing and Services
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• v.2 no.4
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• pp.25-32
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• 2001

The CAD tools for ASIC design, which are already developed or will be developed in the future, have their own functions and different working environments in many cases. Therefore, it would be more effective in achieving the final design goal, if we have a system called CAD framework in which these CAD tools are systematically integrated. In this paper, we introduce same novel techniques for integrating systematically such the CAD tools, which are usually developed under UNIX shell environments, into the CAD framework with the standard graphics interface such as X-windows. Some meta languages and script file formats are developed for flexible specification of the system MENU hierarchy and the data dependencies among executable programs. We integrated two existing CAD tools into our CAD framework using the techniques and find out the integrated protype system is working well under the new system environments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.93-99
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• 2016

In this paper, higher order coupler using small size waveguide which applicable for mobile Ku-band multimode monopulse satellite tracking antenna system, has been designed, implemented and tested. Proposed higher order mode coupler adopts a coaxial structure for low profile characteristic considering installation property to mobile satellite terminal system. In addition, by using proposed coupler, extracted tracking error signal pattern has measured and confirmed that required tracking accuracy is satisfied in desired frequency band. In the future, proposed coupler could utilize for multimode monopulse satellite tracking system for high tracking accuracy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.115-122
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• 2012

In this paper, we demonstrate that indoor wireless optical communication is possible with lighting LEDs without a photo diode or a solar cell. A LED is used for both light emitting and light signal detection. This scheme is very useful because transmission is possible without any additional communication systems. In experiments, wireless optical communication will be carried out at a higher signal frequency of 5MHz using a lighting LEDs with both light emitting and light detection characteristics in the future.