• Journal of Information Technology Services
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• v.8 no.3
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• pp.171-184
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• 2009

Since the development of the Distributed Hash Tables (DHTs), the distributed lookup services are one of the hot topics in the networking area. The main reason of this popularity is the simplicity of the lookup structure. However, the simple key based search mechanism makes the so called "keyword" based search difficult if not impossible. Thus, the applicability of the DHTs is limited to certain areas. In this paper. we find that DHTs can be used as the ubiquitous sensor network (USN) metadata lookup service across a large number of sensor networks. The popularity of the Ubiquitous Sensor Network has motivated the development of the USN middleware services for the sensor networks. One of the key functionalities of the USN middleware service is the lookup of the USN metadata, by which users get various information about the sensor network such as the type of the sensor networks and/or nodes, the residual of the batteries, the type of the sensor nodes. Traditional distributed hash table based lookup systems are good for one sensor network. However, as the number of sensor network increases, the need to integrate the lookup services of many autonomous sensor networks so that they can provide the users an integrated view of the entire sensor network. In this paper, we provide a hybrid lookup model, in which the autonomous lookup services are combined together and provide seamless services across the boundary of a single lookup services. We show that the hybrid model can provide far better lookup performance than a single lookup system.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.442-444
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• 2005

최근 센서 기술이 발전함에 따라 무선 센서 네트워크 응용에 대한 관심이 크게 증대되고있다. 이와 더불어 무선 센서 네트워크 응용에 적합한 라우팅 프로토콜 개발에 대한 연구가 많이 이루어지고 있다. 그러나 무선센서 네트워크가 내재하고 있는 전원 용량의 제약, 메모리 크기의 제약, 프로세싱 능력의 제약, 통신 거리의 제약 등 다양한 제약사항으로 인하여 응용 특성에 특화된 라우팅 프로토콜 개발이 필요하다. 본 논문에서는 기존 라우팅 프로토콜의 주요 메커니즘을 살펴보고, 이를 바탕으로 무선 센서 네트워크 응용의 특성 밀 요구 사항을 분석하고 프로토콜을 설계하는 우리의 접근 방법을 제시하고자 한다.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.568-572
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• 2007

With the proliferation of advanced wireless network and sensor technologies, smart devices under USN(ubiquitous sensor network) environment are capable of collecting context information such as temperature, humidity, weight, and location about objects at real time. Therefore, applications must be able to analyze collected information and notify useful information to wanted users timely. This service can be realized by implementing an event-based middleware. In the middleware, event messages collected from physical environment will be filtered according to profiles that users define in advance and the result will be sent to the interested users. In this paper, we present XML-based event model, ECA-based profile model, and the architecture of an event-based middleware suitable to USN environment. We will also model and describe them using the examples of logistics area. By implementing the system based on the design above, the middleware enable applications or users to easily access to physical sources. The proposed middleware can also apply to not only logistics area but also other various areas under USN environment such as intelligent traffic control system, national disaster management system and u-medical system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.648-655
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• 2007

Nowadays, to realize ubiquitous computing environment, many research activities have been going on within various kinds of research domains including automatic identification sensor network, home network, telematics and so on. Especially, RFID middleware that supports the aggregation of RFID tag data, control and management, and the integration with legacy systems has recently gained a lot of attention. Meanwhile, EPCglobal defined an ALE(Application Level Events) standard specification, which exists between RFID readers and applications, and substitutes the previous systems called Savant. In the specification internal structures and implementation technologies of ALE are not mentioned and only external interfaces are defined. This approach easies the verification of standard compliance and inter-operability of the layer. In this paper, we present the design of ALE-compliant RFID middleware systems that process RFID tag data efficiently.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1022-1025
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• 2009

USN(Ubiquitous Sensor Network) is a core infrastructure that makes come true the u-life in the ubiquitous society through various services of area such as u-city and u-Health. Therefore, we need to reseach about the domestic standards to establish the core technique of USN. Currently, the status of USN standards is most of technical standard and reseach that are technology for sensor node implementation and a protocol for energy-efficient communication and interlock with existing network. But, Standard and reseach for sensor network, integration management of heterogeneous sensor networks for USN application, sensing data management and USN database structure definition such as application and middleware are weak level. In this paper, we researched for standard development of the domestic sensor network service and relevant standard analysis to configure SWE(Sensor Web Enablement) of OGC(Open Geospatial Consortium) for standarded plattform technoloy in part of the middleware. Also we researched that it's a connection between domestic TTA (Telecommunications Technology Association) standards and SWE Standard. Finally, we researched for standard service plattform architecture on sensor network through analysis on the possibility of applying OGC-based services platform.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2097-2104
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• 2008

Ubiquitous services are high duality and differentiated services which are provided for users by recognizing the context of users and environmental conditions actively. In this case, context-aware middleware is one of the most important technologies required to implement the ubiquitous services. In this paper, we propose a method for providing ubiquitous services in a specific user space effectively and monitoring human bio-signal sensors. That is, the design and implementation of intelligent home service middleware and monitoring human bio-signal sensor based on context awareness is discussed here. Context information from various sensors is gathered, and suitable services are inferred and provided to users by the middleware system. In our approach, user services can be modelled easily by using facts and rules, and the system can be extended easily to support various ubiquitous services other than intelligent home services also. The system can be integrated with external applications and legacy systems effectively by using various protocols such as RMI, socket and HTTP, XML and Zigbee etc. We have designed and evaluated various facts and rules for intelligent home services in real environments. Functionality evaluation with the system shows that ubiquitous services can be provided to users effectively in a home environment.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.9-18
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• 2009

This paper proposes a Ubiquitous Henhouse Monitoring System (UHMS) that can not only monitor henhouse's conditions and raising environments, but also control the henhouse remotely by using sensor network technology. The system consists of three layers. The physical layer connects sensors with facilities. The middleware layer processes and manages data collected from the physical layer. And the application layer provides the user with the user requested services. The system provides a real-time monitoring service, a facility controlling service, an expert service, a consumer safety service, and a mobile message service via interacting with components of each layer. Finally, a henhouse model is defined and the relevant system components and the application GUIs are implemented.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.85-86
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• 2008

다수 이기종 센서 네트워크로부터 수집한 대량의 센싱 데이터를 통합 처리/저장/관리/검색하고, 이로부터 실시간 이벤트정보 및 적합한 서비스를 제공하며, 다수 이기종 센서 네트워크 기반 USN 서비스의 효율적 개발을 지원하는 USN 미들웨어 플랫폼에 대한 개념모델 및 아키텍쳐, 기능 및 표준화 동향을 설명한다.

• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.137-147
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• 2013

The RFID(Radio Frequency Identification) and the WSN(Wireless Sensor Network) have technical similarities and mutual effects, they have been recognized to be studied separately, and sufficient studies have not been conducted on the technical integration of the RFID and the WSN. Therefore, EPC global which realized the issue proposed the EPC(Electronic Produce Code) Sensor Network to efficiently integrate and interoperate the RFID and WSN technologies based on the international standard EPC global network. The proposed EPC Sensor Network technology uses the Complex Event Processing method in the middleware to integrate data occurring through the RFID and the WSN in a single environment and to interoperate the events based on the EPC global network. However, as the EPC Sensor Network technology continuously performs its operation even in the case that the minimum conditions are not to be met to find complex events in the middleware, its operation cost rises. Therefore, to address the problems of the existing system, we defined the minimum conditions of the complex events to detect unnecessary complex events in the middleware, and proposed an algorithm that can extract complex events only when the minimum conditions are to be met. To examine the minimum conditions, a index and a query index are used to extract complex events. To evaluate the performance of the proposed methods, In the case of the method of extracting complex events based on a bitmap index, we used the existing extraction method and NS2 simulation to evaluate its performance and thus to show its good performance in terms of the number of operation and the processing time for the complex events.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.774-780
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• 2010

USN(Ubiquitous Sensor Network) is a core infrastructure that u-life use to enable the realization in the ubiquitous society through various services of area such as u-city, u-Health. Therefore, we need a research for domestic standards to establish USN technique. Currently, status of USN standards is most standard and research that it is a technology for sensor node implementation and a protocol for energy-efficient communication and interlock with existing network. But, Standard and research for sensor network and integration management of heterogeneous sensor networks for USN application and sensing data management and USN database structure definition such as application and middleware is weak level. In this paper, we researched for standard development of domestic a sensor network and the relevant standard analysis to configure SWE(Sensor Web Enablement) of OGC(Open Geospatial Consortium) for standarded plattform technology. Also we researched that it's a connection between domestic ITA(Telecommunications Technology Association) standards and SWE Standard.