• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.892-905
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• 2018

In smart home environment, certificate based signature technology is being studied by communication with Internet of Things(IoT) device. However, block - chain technology has attracted much attention because of the problems such as single - point error and management overhead of the trust server. Among them, Keyless Signature Infrastructure(KSI) provides integrity by configuring user authentication and global timestamp of distributed server into block chain by using hash-based one-time key. In this paper, we provide confidentiality by applying group key and key management based on multi - solution chain. In addition, we propose a smart home environment that can reduce the storage space by using Extended Merkle Tree and secure and efficient KSI-based authentication and communication with enhanced security strength.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.6
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• pp.678-684
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• 2005

In this Paper telemetering system for home automation is Proposed and implemented. Proposed and developed systems are composed with a home server and a few clients which send metering data of gas electric power water and home security to home server using power line communication. Management computer located in office of apartment complex collects all kinds of measured home data from each home server with multi drop communication by UDP Protocol A simple ASK method is used for power line communication Collected data from each home can be used for issuing the bill of each house and web service. The experiments were carried out under laboratory environment using various kinds of electric home appliances to ascertain the performance.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.1033-1040
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• 2014

Recently, the concept of mobile content service has changed from providing unilaterally contents for single-device to providing same contents for multi-device. This service should be able to provide diverse contents for multi-devices without platform and specification of multi-device. In this study, we propose a bridge technique of heterogeneous smart platform supporting social immersive game. It is possible to access social immersive game by using a multi-platform bridge. To achieve this, we explain techniques of device connection and data transmission between heterogeneous devices using server-client structure and UPnP. It provides an immersive game environment for multi-user, which is able to play in a public place using big screen.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.214-220
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• 2009

Recent advanced technologies enable multiple users to share the virtual environment and work together as they are collocated. Additional sensory information such as haptic could improve the cooperation. In this paper, we propose a server-client architecture with multi-rate haptic control to support a tangible cooperation. Using our approach, the system is able to maintain a consistent simulation state across multiple users as well as to provide a highfidelity stable haptic interaction. To verify our approach, we have developed an experimental application and tested the cooperation among multiple users. The results confirm that our system is able to provide coherency among clients as well as haptic transparency.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.795-800
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• 2008

The paper presents research for the established experiment environment of multi vehicle robot, localization algorithm that is based on vehicle control, and path tracking. The established experiment environment consists of ultrasonic positioning system, vehicle robot, server and wireless module. Ultrasonic positioning system measures positioning for using ultrasonic sensor and generates many errors because of the influence of environment such as a reflection of wall. For a solution of this fact, localization algorithm is proposed to determine a location using vehicle kinematics and selection of a reliable location data. And path tracking algorithm is proposed to apply localization algorithm and LOS, finally, that algorithms are verified via simulation and experimental

• Journal of Korea Multimedia Society
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• v.8 no.3
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• pp.355-361
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• 2005

This paper proposed a system collecting image information by agents in multi-threaded environment and then retrieving them with content based image retrieval. This system uses multi threads to retrieve web information effectively, then improves efficiency of CPU cycles to reduce latency time, which is the time requesting queries, executing communication processing 4hat the retrieval agents perform and filtering the retrieval results. Also, the agents for image retrieval use Java language, which is platform independent, to be suitable for distributed environment. Using JDBC to save the retrieved images, the agents are connected to database. The images themselves are stored in distributed agents' databases, and only the image indexes are stored in an index server so that the efficiency of storage and retrieval time can be improved.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.1
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• pp.80-85
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• 2007

As home network system begins serving in earnest, the recent fruits of research in home service robot show that the new epoch that human and intelligent robots are living, communicating and interacting together at home, may come true in the near future. In the other hand, it is generally known that the multiagent system, performing distributed process together with other different devices in a home network system, is better than single robot or single home server for adapting themselves to home environment and completing their mission because the characteristic of home environment is 'open'. Therefore, in this paper we suggest the framework model to define agents, which is needed lot the home with a home network system, and the communication protocol architecture between agents. For this, we focus our attention on an agent comprising the set of many agent instances rather than the single intelligent or ability of a robot or home server, and also suggest the way of adaptation for agent systems to their environments and interaction with human in the manner of cooperation and negotiation among agents or agent instances in each agent.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.885-892
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• 2013

In the model Utilizing the TCP / IP socket communication to transmit and receive data, if the size of data is small and if data-transmission aren't frequently requested, the importance of communication speed between a server and a client isn't emphasized. But nowadays, it has emerged for large amounts of data transfer requests and frequent data transfer request. This paper propose the TCP/IP communication model that can be improved the data transfer rate in multi-core environment by changing the receiving structure of the client to receive large amounts of data and the transmission structure of the server to send large amounts of data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4B
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• pp.424-434
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• 2004

Ubiquitous network consists of various devices using several heterogeneous protocols and requires seamless communication between devices. This paper proposes a new hierarchical event service and multiple event server architecture to implement the service under ubiquitous environment. The proposed event service classifies devices by logical and physical location to abstract the idiosyncrasy of used protocols, and reduces network load. Due to the design consideration, the proposed architecture removes transfer of duplicated event data effectively. As a result, we can guarantee the reliable event delivery. The prototype multiple event server architecture was implemented according to the proposed idea and evaluated its performance under a home network test bed.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.457-467
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• 2004

The efficiency of algorithms managing data caches has a major impact on the performance of systems that utilize client-side data caching. In these systems, two versions of data can be maintained without an additional space overhead of the server by exploiting the replication of data in the server's buffer and clients' caches. In this paper, we present a new cache consistency algorithm employing versions: Two Versions-Callback Locking (2V-CBL). Our experimental results indicate that 2V-CBL provides good performance, particularly outperforms a leading cache consistency algorithm, Asynchronous Avoidance-based Gache Consistency, when some clients run only read-only transactions.