• The Journal of Korean Institute of Communications and Information Sciences
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• 제35권12B호
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• pp.1199-1210
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• 2010

In recent years opportunistic computing has gained popularity in Ad-hoc network research area and it is highly required to research for actual services and related requirements. In this paper we summarized a virtual opportunistic service that is named "Children Care System" and proposed an Ad-hoc communication node (uMobile) that is connected with cellular phone and a sensor node (uClo) which is embedding into clothes. uMobile can support cellular phone communication and Ad-hoc communication and uClo can be embedded into clothes and recognize the user status using multiple sensors. In this paper we implemented the location awareness and user status awareness services using uMobile and uClo. We also tested them in indoor situation and showed the result. We expect that our research can play a significant role to inspire another various opportunistic computing services.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제34권10B호
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• pp.973-980
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• 2009

Many studies which have been done for efficient installation and management of wireless sensor networks (WSN) include energy savings, key managements and sensor deployments. Sensor deployment problem is one of the most important and fundamental issues among them in that the topic is directly related with the system cost and performance. In this paper, we suggest a sensor deployment scheme that reduces the system cost of WSN while satisfying the fundamental system requirements of connectivity between sensor nodes and sensing coverage. Using graphical information system(GIS) which contains region-dependent information related with connectivity condition, the initial positions of sensors in the procedure simulated annealing (SA) are determined. The GIS information helps in reducing system cost reduction not only at the initial deployment of SA but also at the final deployment of SA which is shown by computer simulations.

• Journal of Digital Contents Society
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• 제12권1호
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• pp.95-105
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• 2011

It has become commonplace to use web-based business process systems in a variety of fields, and electronic litigation is not an exception. In electronic procedures where court records are at the core of the system, the electronic document architecture should be designed in a way that electronic documents are safely circulated and utilized on the web with a consideration of the authentication of records, particularity of cases and document security such as prevention of forgery or falsification. Based on a study of electronic formats suitable for court records, the Extensible Markup Language (XMP) for management of special case information and security requirements for circulation of electronic documents, this paper suggests an adequate architecture for electronic documents designed for electronic litigation involving constitutional matters and looks into cases where such architectures are applied. The studies in this paper will serve as a useful reference for those planning to realize web-based business process that enables exchanges of electronic documents.

• Journal of the Korean Society of Marine Environment & Safety
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• 제19권1호
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• pp.45-51
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• 2013

In order to facilitate the private maritime security system with high quality guard services, the status of private security companies and the security instructor system which has been operated in land side, are analyzed. Through screening the spectrums of private maritime security and analyzing the status of maritime security guard, the characteristics and expertise of maritime guard service, and it's system need are elicited. we propose the system of marine civil guard officer who will play a major role in private maritime security domain, and design the job requirements, the subjects of qualification test and the education program to enhance his professionalism and practicality. Moreover, the enactment of a provision on marine guard company in Marine guard law will be the platform to develop a private maritime security industry and to strengthen international competitiveness through supervising and piloting private guard service at sea by Korea coast guard.

• Smart Structures and Systems
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• 제6권3호
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• pp.225-238
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• 2010

We report on the development of a new technology for the fabrication of Micro-Electro-Mechanical-System (MEMS) strain sensors to realize a novel type of crackmeter for health monitoring of ageing civil infrastructures. The fabrication of micromachined silicon MEMS sensors based on a Silicon On Insulator (SOI) technology, designed according to a Double Ended Tuning Fork (DETF) geometry is presented, using a novel process which includes a gap narrowing procedure suitable to fabricate sensors with low motional resistance. In order to employ these sensors for crack monitoring, techniques suited for bonding the MEMS sensors on a steel surface ensuring good strain transfer from steel to silicon and a packaging technique for the bonded sensors are proposed, conceived for realizing a low-power crackmeter for ageing infrastructure monitoring. Moreover, the design of a possible crackmeter geometry suited for detection of crack contraction and expansion with a resolution of $10{\mu}m$ and very low power consumption requirements (potentially suitable for wireless operation) is presented. In these sensors, the small crackmeter range for the first field use is related to long-term observation on existing cracks in underground tunnel test sections.

• Nuclear Engineering and Technology
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• 제36권4호
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• pp.357-363
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• 2004

A prototype long pulse ion source was developed, and the beam extraction experiments of the ion source were carried out at the Neutral Beam Test Stand (NBTS) of the Korea Superconducting Tokamak Advanced Research (KSTAR). The ion source consists of a magnetic bucket plasma generator, with multi-pole cusp fields, and a set of tetrode accelerators with circular apertures. Design requirements for the ion source were a 120kV/65A deuterium beam and a 300 s pulse length. Arc discharges of the plasma generator were controlled by using the emission-limited mode, in turn controlled by the applied heating voltage of the cathode filaments. Stable and efficient arc plasmas with a maximum arc power of 100 kW were produced using the constant power mode operation of an arc power supply. A maximum ion density of $8.3{\times}10^{11}\;cm^{-3}$ was obtained by using electrostatic probes, and an optimum arc efficiency of 0.46 A/kW was estimated. The accelerating and decelerating voltages were applied repeatedly, using the re-triggering mode operation of the high voltage switches during a beam pulse, when beam disruptions occurred. The decelerating voltage was always applied prior to the accelerating voltage, to suppress effectively the back-streaming electrons produced at the time of an initial beam formation, by the pre-programmed fast-switch control system. A maximum beam power of 0.9 MW (i.e. $70\;kV{\times}12.5\;A$) with hydrogen was measured for a pulse duration of 0.8 s. Optimum beam perveance, deduced from the ratio of the gradient grid current to the total beam current, was $0.7\;{\mu}perv$. Stable beams for a long pulse duration of $5{\sim}10\;s$ were tested at low accelerating voltages.

• Journal of Service Research and Studies
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• 제2권2호
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• pp.45-51
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• 2012

U-healthcare is real-time monitoring of personal biometric information using by portable devices, home network and information and communication technology based healthcare systems, and fused together automatically to overcome the constraints of time and space are connected with hospitals and doctors. As u-healthcare gives health service in anytime and anywhere, it becomes to be a new type of medical services in patients management and disease prevention. In this paper, recent changes in prevention-oriented care is analyzed in becoming early response for Healthcare Information System by requirements analysis for technology development trend. According to the healthcare system, PACS, OCS, EMR and emergency medical system, U-healthcare is presenting the design of a patient-centered integrated client system. As the relationship between the meaning of the terms is used in the ontology, information models in the system is providing a common vocabulary with various levels of formality. In this paper, we propose an ontology-based system for patient-centered services, including the concept of clustering to clustering the data to define the relationship between these ontologies for more systematic data.

• Journal of the Korea Society for Simulation
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• 제17권4호
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• pp.89-97
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• 2008

In wireless personal area networks (WPANs), the successful design of channel time allocation algorithm is a key factor in guaranteeing the various quality of service (QoS) requirements for the stringent real-time constraints of multimedia services. In this paper we propose a channel time allocation algorithm for achieving a high quality transmission and high channel error tolerance of MPEG stream in the IEEE 802.15.3 high-rate wireless PANs. Our algorithm exploits the characteristics of MPEG stream. When a new MPEG stream arrives, a DEV models it by the traffic envelope and delivers the traffic envelope to the piconet coordinator (PNC) along with the channel time request. The PNC performs channel time allocation according to the envelope. Performance of the proposed scheme is investigated by simulation and analysis. Our results show that compared to conventional scheme, the proposed scheme is very effective and provides a good performance under typical channel error conditions.

• Journal of Digital Convergence
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• 제12권11호
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• pp.133-139
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• 2014

This study has designed the system that can manage the amount of exercise required for health management, viewing the health management courses which are currently being operated, register the desire courses and verifying the registered schedules and monthly health performances at a glance by using a mobile application. The advantage of health club management system is automatically transmits the daily exercise information to the server without a separate sensor through a simple QR scanning using a smart phone. Since the overall operating requirements of services and various facilities of health club is transmitted as the data to the remote server through a smart phone, users of various levels including workers, students, housewives, etc can easily access and use the health club management system using the WiFi, LTE, 3G, etc.

• Journal of Digital Convergence
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• 제11권3호
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• pp.175-180
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• 2013

To compete global marketplace, many firms are adopting product families to increase variety, satisfy customer requirements, shorten lead-times and reduce costs. The key to a successful product family is the platform from which it is derived. When designing product families, it is important to resolve the tradeoff between product commonality and distinctiveness. To measure the commonality within a product family, it is necessary to develop the commonality index. It utilizes different parameters such as the number of common components, their cost, their manufacturing processes and so on. This paper present a new product family assessment index using the benchmarking method and considering environmental performance called green product family index(GPFI). Through the comparison analysis between some previous developed commonality indices and GPFI, we verify the suitability and effectiveness. Eventually, the proposed a new green product family assessment index can be helpful to design and develop the environmentally conscious product families.