• The KIPS Transactions:PartD
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• v.12D no.3 s.99
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• pp.395-408
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• 2005

Ubiquitous computing spans a very broad range of technologies and needs very complicated user's requirements. There are many scenarios and technologies involved in ubiquitous computing. We need new software development tools and methodology to meet the requirements. A software product line is one of promising new technology for it. A software product line is a set of software intensive systems that share a common, managed set of features satisfying the specific needs of a particular market segment or mission and that are developed from a common set of core assets. Software architecture-based development is the exploration and maturation of the role of software architecture in the product line life cycle. In this thesis, we identify the foundational concepts underlying software product lines and the essential activities to develop the mobile application systems. So, we define, design, and implement the Mobile Application System Architecture(MASA) that includes the development process for applying into mobile business domain and encompass scoping and gathering requirements for the Product line based on Component Based Development(CBD).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8A
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• pp.791-800
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• 2010

Recently wireless sensor networks as a field of ubiquitous computing technology was in the limelight. To use and collect the necessary information, Sink node mobility is essential. TTDD(Two-Tier Data Dissemination) proposed most common technique associated with Mobile sink node in wireless sensor networks, but issues exist that the use of many control packet falls into the energy efficiency. The technique for solving problems is Cluster-Based Energy-efficient Routing protocol (CBPER). But CBPER does not transmit the data correctly to sink node or source node. In this paper, we propose An Energy-Efficient Routing Protocol based on Static Grid using mobile sink nodes in order to solve the data transmission failure and reduce the energy consumption in Wireless Sensor Networks. We have evaluated it with the NS-2 simulator. Our results show that the proposed protocol saves the energy consumption up to 34% in comparison with CBPER. We also prove that the proposed protocol can transmit more accurate data to the sink de than CBPER.

• Journal of the Korean Institute of Educational Facilities
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• v.15 no.1
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• pp.17-25
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• 2008

As a study on the advancement planning for the telecommunications infrastructure of the educational facilities for the purpose of the proliferation of e-learning, this study was conducted with the intents of preparing for the design guidelines to be considered in the initial stage of an architectural design for applying WLANs(wireless LANs), which play a role as the international standard for next generation of telecommunications, to the educational facilities and of making a proposal for changes of the existing computer rooms according to the appearance of new teaching and learning tools, for example, digital textbooks, and the proliferation of personal information devices. In this study, the design guidelines were made by analyzing the elements to be applied to architecture designs as well as understanding the trend of the cabling, pathways and spaces requirements in the area of telecommunications after examining the relevant international standards, such as ANSI and TIA, etc., in order for applying WLANs to the educational facilities. In addition, a field survey was conducted targeting on the elementary schools in 'C' city in order to suggest a proposal for the improvements of operations and maintenance of the existing computer labs and computers. As the results of analyzing the data from the field study, it was surveyed that the following matters should be urgently improved in order for the schools to be developed as Ubiquitous schools in the future: First, the biggest hold-up is how to maintain the desktop computers well. Second, there are some limitations far the students to use the computers enough due to the lack of the number of computers. Third, the computer education for the students is limited to instructing the students in training themselves only for the functions of each kind of application software.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.758-762
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• 2008

Embedded systems usually utilize Flash Memories with very nice characteristics of non-volatility, low access time, low power and so on. For the multimedia database systems, R-tree is an indexing tree with nice characteristics for multimedia access. MR-tree, which is an upgraded version of R-tree, has shown better performance in searching, inserting and deleting operations than R-tree. Flash memory has sectors and blocks as a unit of read, write and delete operations. Especially, the delete is done on a unit of 512 byte blocks with very large operation time and it is also known that read and write operations on a unit of block matches caching nature of MT-tree. Our research optimizes MR-tree operations in a unit of Flash memory blocks. Such an adjusting leads in better indexing performance in database accesses. With MR-tree on a 512B block units we achieved fast search time of database indexing with low height of MR-tree as well as faster update time of database indexing with the best fit of flash memory blocks. Thus MR-tree with optimized operations shows good characteristics to be a database index schemes on any systems with flash memory.

• Journal of KIISE:Software and Applications
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• v.36 no.3
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• pp.200-207
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• 2009

U-Healthcare is more efficient as a solving method for health problems rather than visiting the hospital. Recently, systems have been studied to offer appropriate service to user, which gather and analyze biological signals of a user and context information around the user from a variety of sensors. The existing systems for U-Healthcare are based on domain specific service so it is difficult to expand and link to other systems. Also, they lack services focusing on the specific quality of the user, because they offer a general service which targets a lot of users. To address this problem, we expand an extensibility of system using the context-awareness agent based on multi-agents. Also, we provide the suitable services which match with the context information of user to each user using the modeling toolkit JaUCE based on GUI. We design and implement U-Silvercare service to demonstrate the effectiveness of the proposed context-awareness agent and modeling toolkit.

• The KIPS Transactions:PartC
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• v.14C no.7
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• pp.589-596
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• 2007

Although flooding has the disadvantages like a transmission of duplicated packets and a packet collision, it has been used frequently to find a path between a source and a sink node in a wireless ad hoc network. Clustering is one of the techniques that have been proposed to overcome those disadvantages. In this paper, we propose a new flooding mechanism in ad hoc networks using cluster formation based on the link density which means the number of neighbors within a node's radio reach. To reduce traffic overhead in the cluster is to make the number of non-flooding nodes as large as possible. Therefore, a node with the most links in a cluster will be elected as cluster header. This method will reduce the network traffic overhead with a reliable network performance. Simulation results using NS2 show that cluster formation based on the link density can reduce redundant flooding without loss of network performance.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.9-14
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• 2020

With the distribution modernization policy advanced by the government and consumers preference toward it, the so called "modern market" has undergone rapid growth. Conversely, traditional market is losing popularity with consumers as a result of inadequate modern structures, small market size, convoluted relationships, inefficient operation and disordered transactions, among others. Therefore, this study seeks to utilize ubiquitous computing, that is, the upgrade of context aware information to 6W1H and promote the market through the interface with Smartphone and provide advanced information through the augmented reality technology. For the construction of context-aware system using user context, the results may significantly differ according to how reference rules are applied to and implemented on knowledge base. In light of above, through the use of RFID technology and 6W1H context awareness, we seek to promote traditional markets.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.181-186
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• 2017

Child crimes such as child abduction and lost children(MIA) have long been pointed out as social problems. However, there are few ways to solve these problems. According to MIA statistics, about 3,000 babies are lost each year. This paper presents a study on prevention of lost children ratio using mobile LBS in order to reduce the incidence of lost children ratio in dense space. First, we input the personal information of the child and the contact information of the parent. Second, we use the Google Maps API to get the location (parent's location, child's location) information. Third, the personal information of the child and the parent is indicated in the obtained location information. In future research, based on SNS, we will carry out research on sending child location information and parent location information via SMS. It is expected that the prevention system of lost child using LBS and SNS will make a great contribution to reduce the lost children ratio in the ubiquitous society.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.297-306
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• 2007

Bar-code based airway logistics systems have many problems like freight loss and data management error due to semiskilled air-cargo process and individual information system. To solve these problems, this paper analyzed how to process an air-cargo practically and designed and implemented the RFID-based airway logistics system. This system has an information service system which manages data from RFID systems in realtime and provides a communication interface for data sharing. And, this system precesses data queries from capture applications and access applications to provide various services to users such as the freight track and trace service. Also, this system includes a H/H reader agent to integrate existing bar-cord systems. It allows us to realize automation and information-oriented air-cargo process and achieve improvement of air-cargo services with reduction of freight loss and management error.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.4
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• pp.43-51
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• 2010

In this paper, we studied line coding technology tendency for high speed data communication at LED-ID (Identification) communication system in indoor environment. A LED-ID technology is a communication using visible ray (RGB) that come out in LED device. It is energy curtailment effect and possible in ubiquitous network service applications. The LED-ID system has the above advantages about that the communication throughout the whole room is enabled by high power lighting and lighting equipment with white colored LED which are easy to install and have good outward appearance. Therefore, the transmission by light waves is more suitable for wireless networks than by radio waves. We compared with the NRZ, AMI, 4B5B, HDB3, 8B10B line coding for efficient in error detection and serves data transmission of high speed.