• Proceedings of the Korean Society of Computer Information Conference
• /
• 2012.07a
• /
• pp.203-206
• /
• 2012

The System of communication with wireless devices is experiencing a huge growth. While traditional communication paradigms deal with fixed networks, mobility raises a new set of questions, techniques, and solutions. In order to realize service mobility, there is a need of protocol that can support mobility while nodes are communicating without any disruption of their connection status. This paper proposes a handover authentication protocol for mobility support. Careful considerations must be taken in priority to security issues since many unreliable public and private resources; both networks and devices are involved. The protocol is based on public key cryptography with Diffie-Hellman algorithm which provides security against both leakage-resilience of private keys on untrustworthy devices and forward secrecy.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.9
• /
• pp.1681-1688
• /
• 2009

This paper proposes a new fault restoration method which adopts the recloser as top agent to release the problems of the data concentration and fault processing delay of the existing DAS(distribution Automation System) under the ubiquitous distribution system. In proposed method, top agent collects the data based on the multi-casting communication with the tie switches of the interconnection point, and then selects a closed switch(tie switch) to transfer the sound outage load to other feeders based on the heuristic search strategy step by step until the load transfer work is finished. Here, a new heuristic rule is developed which can guarantee the relational load balancing and line loss from the collected voltage data. Finally, the several faults are simulated for typical multi-section and multi-interconnection distribution system to prove the effectiveness of the proposed strategy, in particular, for each simulation cases, the load balancing index and line loss index of the obtained solution from the proposed method is compared with those of all of feasible solutions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.10
• /
• pp.59-65
• /
• 2007

Recently, ubiquitous sensor network(USN) techniques have been applied to electric power facility management. This paper dealt with the designed and fabricated ubiquitous sensors which monitor transformers and lightning arresters installed in overhead distribution systems. The sensors consist of a 8-[bit] microprocessor unit, a wireless communication nodule specified in IEEE 802.15.4, and associated electronics. A Rogowski coil was fabricated to measure load of transformer and surge current without saturation having good linearity up to 1000[A]. A zero-phase current transformer with a high relative permeability of $10^5$ at 180[Hz] was used to detect small leakage current of $50[{\mu}A]{\sim}1[mA]$ flowing lightning arrester, and the frequency bandwidth of the module is ranges from 12[Hz] to 1.24[kHz] at -3[dB].

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.8
• /
• pp.1587-1592
• /
• 2009

RFID is Playing a central role in ubiquitous technology according with the advent of the ubiquitous era, and the development of an RFID reader is also emerging as an important technical development field. In this paper, we developed a hardware system which is able to make use of the 13.56MHz RFID infrastructure being used as a transportation card, a credit card, and so on as well as the 125KHz RFID infrastructure being used in security company, and which is applicable to a location identification, an entrance and exit control, and security control over the TCP/IP communication. The existing local RFID methods have some problems which bottlenecks such as administrative problems, technical problems, and so force frequently occur because a casual server is placed and operated in a company. Hence, in this paper we developed an RFID multi reader which is connected to a central administrable server over the TCP/IP in order to solve these problems, and we make it be possible to keep an security control and be easy to install, transfer and administrate RFID infrastructures.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.6
• /
• pp.201-210
• /
• 2009

Studies on human-centered services are approaching their highest peak with the emergence of a new concept of the network environment, a ubiquitous environment. Among these ubiquitous service technologies, services related to health care are very closely related to the current social environment. In this paper, With social aging and changes in ubiquitous IT environment, studies on health care, which is among the essential application services and which has been defined as a key application technology, and studies related to it have been conducted. In addition, healthcare services, which are essentially applicable to the ubiquitous environment, were suggested by analyzing existing healthcare studies and drawing from them the requirements for such. This paper proposes management protocol for serious case except from health care research. This system is constructed database using RFID, it has location information. It provides procedures to consistently monitor the status of patients and process the outcome in real-time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.925-928
• /
• 2007

Abilities of sensing and communication are vested in private things of actual space, therefore, Ubiquitous Computing which is offered various services with human approach will be common in the future society. For the realization of this Ubiquitous Service requires some technique such as situations of environment and recognition of locations by the Sensor Network, then sensor data have to be transferred to an application service after processes. However, there are some hindrances for communication between an application service and sensor data, these are that accessibility of data usefulness and problems of Platform and protocol in each sensors. In this paper, suggest a reference model that is independent from platform and implementation language, for USN application service with using standardized protocol.

• Journal of Korean Society for Geospatial Information Science
• /
• v.14 no.3 s.37
• /
• pp.39-46
• /
• 2006

This study is aimed at the development of ubiquitous based road disaster management system. The fundamental technologies used for developing this system are classified into three modules - wireless internet communication module, mobile module and server module. These fundamental technologies can be used not only for developing road disaster management system but also for developing various mobile or ubiquitous systems. With this system, workers can download many DB (Digital map, Attribute information etc.) from server to the field in realtime. The accuracy and objectivity of the DB could be improved with these informations collected at fields because these data can be used as basic data for road disaster information collection. Because in the web based server module - Web based Road Disaster Management System (URDMS) - field disaster information was showed link up with exist DB on road by absolute coordinate, the decision making with all of the field information was made and it sent to a field staff in realtime. The problems of current road disaster management rule ran be solved by this URDMS.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.3
• /
• pp.145-152
• /
• 2010

With the recent development of the ubiquitous computing technology, there are increasing interest and research in technologies such as sensors and RFID related to information recognition and location positioning in various ubiquitous fields. Especially, RTLS(Real-Time Locating Services) dealing with spatio-temporal data is emerging as a promising technology. For these reasons, the ISO/IEC published the RTLS standard specification for compatibility and interoperability in RTLS. Therefore, in this paper, we designed and implemented Spatio-temporal Query Processing Systems for efficiently managing and searching the incoming Spatio-temporal data stream of moving objects. Spatio-temporal Query Processing Systems's spatio-temporal middleware maintains interoperability among heterogeneous devices and guarantees data integrity in query processing through real time processing of unceasing spatio-temporal data streams and two way synchronization of spatio-temporal DBMSs. Web Server uses the SOAP(Simple Object Access Protocol) message between client and server for interoperability and translates client's SOAP message into CQL(Continuous Query Language) of the spatio-temporal middleware. Finally, this thesis proved the utility of the system by applying the spatio-temporal Query Processing Systems to a real-time Locating Services.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.12
• /
• pp.2769-2774
• /
• 2013

The key of USN(Ubiquitous Sensor Network) technology is low power wireless communication technology and proper resource allocation technology for efficient routing. The distinguished resource allocation method is needed for efficient routing in sensor network. To solve this problems, we propose an algorithm that can be adopted in USN with making up for weak points of PQ and WRR in this paper. The proposed algorithm produces the control discipline by the fuzzy theory to dynamically assign the weight of WRR scheduler with checking the Queue status of each class in sensor network. From simulation results, the proposed algorithm improves the packet loss rate of the EF class traffic to 6.5% by comparison with WRR scheduling method and that of the AF4 class traffic to 45% by comparison with PQ scheduling method.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.6
• /
• pp.1182-1189
• /
• 2007

As ubiquitous environment rapidly emerges due to the development of network and information communication technology, ubiquitous computing is being noticed as a technology that will take the lead in information technology industry of the future. To the end, the data recognized from each sensors, collected and processed need be transferred to applied service so that they may be used as data for providing sum to users. However, in reality as the definitions of metadata and platform for each sensor are not clear, approach from applied service for data use is difficult and there are limitations in transferring sensor measurement data of the applied service because of the difference of platform and protocol. In this paper, we designed sensor service technology language that expresses sensor and measurement data and describes the service though sensor data service. Also the researcher implemented a sensor data processing system that transfers sensor data to the applied service by using web service. The thesis will apply a reference model for standardization to guarantee mutual compatibility in exchanging sensor data through the system.