• Journal of Institute of Control, Robotics and Systems
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• v.18 no.11
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• pp.1040-1044
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• 2012

We design a NCS (Networked Control System) where the communication between sensors and controllers takes place over a USN (Ubiquitous Sensor Network). In order to measure time delays between sensors and controllers in real time, we design an algorithm to measure RTT (Round Trip Time) between USN nodes, and implement it into TinyOS of USN. By using the measured time delays, we construct the Smith predictor to compensate the time delays between sensors and controllers in real-time. For the real time experiment, we simulate the dynamic plant model, controller, and USN interface using Real-Time Windows Target provided in MATLAB. The USN interface in the Simulink model consists of serial ports, which connect the plant output and controller with USN nodes. The experiment results show that the time delays between sensors and controllers are precisely measured in real time; the Smith predictor appropriately compensates the time delays; and the stability is achieved in the closed-loop of the NCS.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.378-383
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• 2012

Nowadays, the study is going on develop USN(Ubiquitous Sensor Network) with diffusion of the internet and development of computer network technology. USN sensor nodes equipped with various types of sensors provide sensor information to each individual sensors. To do this there needs standardized data description language for allowing many people to use based on XML in web services environment. In this paper, USN sensor information required for application services in a standardized form to describe the sensor data representation language was designed. USN-based technology utilized in the field, and will be utilized for service activation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4C
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• pp.437-445
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• 2009

Node of USN(Ubiquitous Sensor Network) environments uses radio based communication mechanism for a delivering message. Thus the multiple hop flooding is necessary for considering limited power and communicating unknown node long-range. However if there are many unknown nodes located in users' vision, the flooding of the radio base is insufficient alternative. Thus as a flash may be used to find a key in a darkness, a more direct and short range communication system is required. This study shall resolve such question through 2 different steps. First a Two kind of code method that convert Text message to color code shall be suggested. Second a hardware module, which may deliver various LED(light-emitting diode) color signal, shall be developed. The experiment may take place by fixing the entry angle of light and distance by setting a specific element as a standard mean.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1414-1419
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• 2011

In this paper we study the modeling to quantitatively assess the failure rate of USN system designed for fault-tolerant architecture, aiming at applying the world's best domestic USN technology to safety-critical railways. In order to apply the USN system to the safety-critical field like a train control sector that the failures of controllers may cause severe railway accidents such as train collision and derailment, the quantitative reliability and safety evaluation recommended in IEC 62278 must be preceded. We also develop the evaluation model for overall system failure rate for the distributed network structure, which is the characteristics of USN system. Especially, we allocate reliability targets to component units, and present an availability evaluation plan through the plan on the quantitative achievement of failure rate for sensor nodes, gateways, radio-communication network and servers, along with the failure rate model of the overall system considering network operational features.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.731-735
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• 2005

유비쿼터스 사회를 구현하기 위한 핵심기술로 RFID/USN이 유력하다. 하지만 RFID 기술이 구현되기 전부터 RFID를 사용함으로써 발생하는 RFID 전자파의 유해성 문제가 RFID/USN 확산의 저해 요인으로 대두되고 있다. 본 논문에서는 RFID/USN에서 사용하는 전자파의 특성에 기술하고, 전자파가 인체에 미치는 영향 및 이에 대한 연구 동향에 대하여 분석한다. 또한 세계 각국 및 표준화기구의 전자파 규제 동향에 대하여 분석하고, 이를 기반으로 국내의 전자파 인체 보호 기준을 RFID/USN 전자파 관점에서 분석한다. 최종적으로 RFID/USN 환경에서 전자파에 대한 규제 방안을 제시한다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.53-56
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• 2010

This paper explains a system that is suitable for detecting software error running on multimedia distance control for transportation safety environment. This system consists of an ED, and ES. ED is an agent that detects an error by hooking techniques for multimedia distance education based on IP-USN gateway software stack environment. ES is an agent that is an error sharing system for multimedia distance control based on IP-USN gateway software stack environment. From the perspective of multimedia collaborative environment, an error application becomes another interactive presentation error is shared with participants engaged in a cooperative work.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2754-2759
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• 2011

With information communications and RFID/USN environments merged wire/wireless networks are generalized. In this viewpoint, WAP is used by communication protocol for the data communication in the field of wireless environment. WTLS developed for the secure communications optimize TLS adapted wireless environment in the TCP/IP internet protocol. But WTLS denote WAP security problem, end-to-end problem, and power consumption, etc. Therefore in this paper we proposed WTLS cryptographic algorithm eliminated WTLS disadvantages. Proposed algorithm solved power consumption, calculated complexity, and security problems because it is not unique but hybrid form.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.2
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• pp.101-107
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• 2009

Modern society encounters various accidents due to industrialization and numbers of studies are going on to minimize damage from accidents. For prevention of accidents, it is necessary to design a system that helps making accurate judgment in emergency cases and is able to instantly manage each contingency. Various studies are currently going on contingency information system under ubiquitous environment. However, there have not been sufficient studies on the system that is able to monitor and process multiple contingencies and thus we still have difficulties in coping with multiple contingencies promptly. This study designs a RFID/USN middleware system for multiple contingencies control that receives data from various kinds of sensors and saves data after time marking thus is able to provide conjectured context when requested.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5B
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• pp.816-823
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• 2010

Recently research efforts for ubiquitous technology that includes RFID(Radio Frequency Deification and sensor networks are conducted very actively The architectural framework of the USN sensor network discovery service. The survey of the USN technology is conducted on four technological visions that contain USN system technology USN networking technology and USN middleware along with the service platform, With respect to each technological division domestic and worldwide leading research projects are primarily explored with their technical features and research projects are primarily explored with their technical features and research outputs. Boasted on the result of the survey we establish a USN software model that includes data sensing, sensor data storage sensor data storage sensor data naming and sensor feed name service. This main objective of this model is to provide a reference model for the facilitation of USN application developments.

• International Journal of Contents
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• v.9 no.4
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• pp.22-29
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• 2013

In this paper, we propose a integrated real-time monitoring system for recycling agriculture resourcing based on USN. We design and implement the monitoring system so that we can integrate the quality control of farmyard and liquid manures, barn environment monitoring, and positioning information control into a total management system performing recycling of excrement and manure. Selection of sensors and sensor-node construction and requirements, structure of wire/wireless communication networks, and design of monitoring program are also presented. As a result of operating our system, we can get over various drawbacks of conventional separated system and promote the proper circulation of excrement up to the farmyard. We confirm that these advanced effects arise from the effective management of the total system integrating quality control of farmyard/liquid manure, barn/farmhouse information, and vehicle moving monitoring information etc. Moreover, this monitoring system is able to exchange real-time information throughout communication networks so that we can construct a convenient information environment for agricultural community by converging IT technology with farm and stockbreeding industries. Finally we present some results of processing using our monitoring system. Sensing data and their graphs are processed in real-time, positioning information on the v-world map offers various moving paths of vehicles, and statistical analysis shows all the procedure from excrement occurrence to recycling and resourcing.