Ubiquitous Sensor Network Research Articles

System Design for a Urban Energy Monitoring and Visualization Environment Using Ubiquitous Sensor Network and Social Sensor Networking

센서 네트워크에 의해 수집되는 다양한 도시 데이터는 도시를 이해하고 분석하는데 있어서 필수적인 수단으로 자리매김하고 있다. 특히 Ubiquitous Sensor Network(USN) 기술들은 u-City 구현에 있어 중추신경망을 제공하였다. 이 연구는 도시 에너지의 사용량에 관한 정보를 USN을 이용하여 수집하고, 이를 도시공간정보와 연계된 직관적 가시화 환경을 통해 제공함으로써 u-City에서 에너지 공급계획을 수립, 모니터링하고, 궁극적으로 실사용자가 능동적으로 에너지를 절약할 수 있도록 도와주는 애플리케이션 구현을 목적으로 한다. 특히 3차원 지리정보환경의 층위에 다층적인 에너지 모니터링 정보를 동적으로 조합하면서 다양한 사용자의 관점에 대응하는 환경을 제시하였다. 또한 도시공간정보에 기반을 둔 논리적 LOD를 제공함으로써 효과적인 실시간 에너지 사용 모니터링 도구를 제공한다. 이를 위하여 관련 선행연구를 분석하여 어플리케이션 구현을 위한 시스템의 개념과 구성을 정의하고 데이터 구조 및 가시화방안을 구체화하였다. 본 논문에서는 특히 시스템 구현에 요구되는 공간정보, E-GIS 데이터, 에너지 사용량센서 데이터를 효과적으로 조합하는 가시화 방법론, 직관적 표현방법, 데이터 구조 및 어플리케이션의 연구결과를 제시하고 Social Sensor Networking을 이용한 모니터링 확장 적용방안에 대해 연구한다.

Intelligent service processing in common USN middleware

The Ubiquitous sensor network (USN) is composed of several heterogeneous sensors with a variety of characteristics. An application based on the sensor network also has various requirements to provide services to users. Therefore it is important to develop the common USN middleware for flexible integration between the sensor networks and applications. Especially, this paper focuses on intelligent service management which is one of the main functions of USN middleware. Several applications in the sensor network environment support not only monitoring services, but also sensor-based context-awareness and intelligent services. In many applications, however, approaches to support intelligent services depend on the application because the standard method has been undefined yet. Therefore this paper proposes a common method for processing intelligent services in USN middleware independent of an application. The proposed method is implemented and evaluated as a component of USN middleware.

USN 기술 기반의 비접촉 식물 생장 측정 시스템 구현

This paper is proposed non-contact plant growth measurement system using infrared sensor based on USN(Ubiquitous Sensor Network) technologies. The proposed system has used noncontact sensors to reduce any potential damage when it measures the growth of the plant. In this system, plant growth parameters such as diameter, cross-sectional area and thickening form are measured in real-time non-contact method. The measured data are transmitted to remote server by using sensor network technologies, stored and analyzed at the server, and the analyzed data are finally provided for users. In this paper, the proposed plant growth measurement system has been designed and implemented using non-contact infrared sensor based measurement methods and devices, and its performances have been verified by actual measurement experiments at the fields.

Dynamic Interpretation Method of XML Configuration Strategy for IP Mode Measurement and Control System

The interoperability among diversified ubiquitous sensor network platforms can be solved well by employing XML technology. According to the requirement that implementing accurately remote XML configuration strategy for spot equipments, a new dynamic interpretation method of XML configuration strategy is proposed. First, an XML-based IP mode measurement & control system is introduced. On the basis of realizing graphical strategy editor, the innovative ways and technologies of some key problems for dynamic interpretation method were especially discussed in this paper, including configuration strategy conversion combining preorder binary tree traversal with stack, XML strategy decomposition based on DOM tree model and dynamical update of XML configuration strategy. Finally, an application example in IP mode ethanol concentration measurement & control system is introduced. Experimental results show that the new method can greatly simplify conversion from measurement & control strategy to microinstructions, which saves system resources and improves greatly the speed of interpretation.

Tournament‐based congestion control protocol for multimedia streaming in ubiquitous sensor networks

SUMMARYCongestion in the ubiquitous sensor network occurs when traffic load exceeds available capacity at any point in a network. Congestion causes overall channel quality to degrade and loss rates to rise, leads to buffer drops and increases latencies. Therefore, congestion and latency have effects on energy efficiency, memory size, buffer size, and throughput. This paper proposes a new method, called TCCP (Tournament‐based Congestion Control Protocol), to minimize congestion in the ubiquitous sensor network. In this paper, the winner is the stream with the highest importance level in the competition of ubiquitous sensor network. In general, there are a lot of congestion and delay in the continuous streaming of multimedia streams with lower importance level. The proposed method consists of three parts: tournament decision, best‐fit control strategy and service differentiation. The final winner in the tournament controls congestion effectively, minimizes packet loss due to congestion, decreases energy consumption, and improves QoS. The simulation result shows that the proposed method is more effective and has better performance compared with those of CCF (congestion control and fairness), PCCP (priority based congestion control protocol), and CODA (congestion detection and avoidance). Copyright © 2010 John Wiley & Sons, Ltd.

Automated Construction of Node Software Using Attributes in a Ubiquitous Sensor Network Environment

In sensor networks, nodes must often operate in a demanding environment facing restrictions such as restricted computing resources, unreliable wireless communication and power shortages. Such factors make the development of ubiquitous sensor network (USN) applications challenging. To help developers construct a large amount of node software for sensor network applications easily and rapidly, this paper proposes an approach to the automated construction of node software for USN applications using attributes. In the proposed technique, application construction proceeds by first developing a model for the sensor network and then designing node software by setting the values of the predefined attributes. After that, the sensor network model and the design of node software are verified. The final source codes of the node software are automatically generated from the sensor network model. We illustrate the efficiency of the proposed technique by using a gas/light monitoring application through a case study of a Gas and Light Monitoring System based on the Nano-Qplus operating system. We evaluate the technique using a quantitative metric—the memory size of execution code for node software. Using the proposed approach, developers are able to easily construct sensor network applications and rapidly generate a large number of node softwares at a time in a ubiquitous sensor network environment.

A development of next generation intelligent construction liftcar toolkit for vertical material movement management

High-rise construction sites, especially those situated in spatially-constrained urban areas, have difficulties in timely delivery of materials. IT-driven management techniques can be further benefited from state-of-the-art devices such as Radio Frequency Identification (RFID) tags and Ubiquitous Sensor Networks (USN), which have resulted in notable achievements in automated logistics management at the construction sites. Based on those achievements, this research develops USN hardware toolkits for hoists, which aims to automate the vertical material delivery by sensing the material information and routing it automatically to the right place. The gathered information from the sensors can also be used for monitoring the overall status. To support the system, a hoist-mountable intelligent toolkit was developed. Its feasibility test was conducted by applying the implemented system to a test bed and then analyzing efficiency of the system and the toolkit.

USN 융합기술을 활용한 자전거 시설물의 안전향상에 관한 연구

This research aims to enhance the security and safety of bicycle facilities by utilizing convergence technology of ubiquitous sensor network in the transportation system. To achieve the aim, U-bike system has developed by utilizing sensor network technology, and the serviceability and safety function of public facilities in the system have enhanced. This research also presents a plan for the construction of U-bike using ubiquitous sensor network and safety infrastructure of facilities by analyzing bicycle traffic reports and characteristics of service through studying the literature on the security of bicycles and the safety of facilities on bicycle lanes. The result of this research will contribute to the enhancement of safety function of bicycle lanes and facilities around National 4 major rivers bicycle lanes in the future.

Efficient scheme of verifying integrity of application binaries in embedded operating systems

Currently, embedded systems have been widely used for ubiquitous computing environments including digital setup boxes, mobile phones, and USN (Ubiquitous Sensor Networks). The significance of security has been growing as it must be necessarily embedded in all these systems. Up until now, many researchers have made efforts to verify the integrity of applied binaries downloaded in embedded systems. The research of problem solving is organized into hardware methods and software-like methods. In this research, the basic approach to solving problems from the software perspective was employed. From the software perspective, unlike in the existing papers (Seshadri et al., Proc. the IEEE symposium on security and privacy, 2004; Seshadri et al., Proc. the symposium on operating systems principals, 2005) based on the standardized model (TTAS.KO-11.0054. http://www.tta.or.kr 2006) publicized in Korea, there is no extra verifier and conduct for the verification function in the target system. Contrary to the previous schemes (Jung et al. http://ettrends.etri.re.kr/PDFData/23-1_001_011.pdf , 2008; Lee et al., LNCS, vol. 4808, pp. 346---355, 2007), verification results are stored in 1 validation check bit, instead of storing signature value for application binary files in the i-node structure for the purpose of reducing run-time execution overhead. Consequently, the proposed scheme is more efficient because it dramatically reduces overhead in storage space, and when it comes to computing, it performs one hash algorithm for initial execution and thereafter compares 1 validation check bit only, instead of signature and hash algorithms for every application binary. Furthermore, in cases where there are frequent changes in the i-node structure or file data depending on the scheme application, the scheme can provide far more effective verification performance compared to the previous schemes.

Low power micro-gas sensors using mixed SnO 2 nanoparticles and MWCNTs to detect NO 2, NH 3, and xylene gases for ubiquitous sensor network applications

Using mixed SnO 2 nanoparticles with 1 wt.% MWCNTs sensing materials, NO 2, NH 3, and xylene gas sensors were fabricated on micro-platforms. A micro-platform consists of micro-sensing electrode and micro-heater on 2 μm thick SiN x membrane. The fabricated gas sensors were characterized to NO 2, NH 3, and xylene gases, respectively, as a function of concentration at 300 °C and temperature from 180 °C to 380 °C at constant concentration. The measured highest sensitivities for the NO 2, NH 3, and xylene were 1.06 at 1.2 ppm and 220 °C, 0.19 at 60 ppm, and 220 °C, and 0.15 at 3.6 ppm and 220 °C, respectively. So, it was found that 220 °C was the optimum temperature to have the best sensitivities. From these results, mixed SnO 2 nanoparticles with 1 wt.% MWCNTs showed good sensitivity and selectivity at low power operation below 30 mW. Fabricated micro-gas sensors could be used for ubiquitous sensor network applications to monitor environmental pollutants in the air.

VBLM: High-Accuracy Localization Method with Verification Mechanism for Unstable-Signal Sensor Networks

Wireless sensor networks have received a lot of attention in recent years due to their wide spectrum of applications. Localization a technique used in ubiquitous sensor networks. Most localization techniques apply RSSI-based ranging techniques to compute the location of the object in a wireless sensor network. However, a wireless sensor network is a fading-signal environment that has noise, which causes RSSI to become unstable and leads to abrupt distance estimates. In this paper, we propose the Verification-Based Localization Method (VBLM) to alleviate the effect of unstable signals to provide high-accuracy location estimates in wireless sensor environments. VBLM filters noisy signals in the localization process. The sensor node uses a neighboring beacon to help verify the quality of received signal under acceptable communication cost. Noisy signals can thus be removed to decrease localization error. A set of experiments was conducted in an outdoor environment. The experimental results show that VBLM reduces the localization error in unstable signal sensor networks better than is possible with other localization methods.

유비쿼터스 센서 네트워크 기반 환경 모니터링 시스템에 관한 연구

유비쿼터스 센서 네트워크는 부착된 태그와 센서로부터 사물 및 환경 정보를 감지, 저장, 가공, 전달하여 인간 생활에 폭넓게 활용되며, 환경오염에 대해서도 사람이 직접 측정 및 모니터링 하기 힘든 지역에 설치되어 활용되고 있다. 기존 네트워크에 비해 초소형, 저전력, 저비용으로 쉽게 구성 가능하기 때문에 꾸준히 연구되어지고 있으며 환경과 IT의 전략적 융합을 통한 그린 IT의 네트워크 접목 또한 중요한 연구 분야로 조명되고 있다. 본 논문에서는 네트워크 기반하에 실내 공기질 관리 센싱 메커니즘 구성도를 구현하고 환경요소를 측정하여 향후 환경 모니터링 시스템의 활용방안을 제안한다. USN(Ubiquitous Sensor Network) is the network that widely applies for life of human being. It works out to sense, storage, process, deliver every kind of appliances and environmental information from the stucktags and sensors. And it is possible to utilize to measure and monitor about the place of environmental pollution which is difficult for human to install. It's studied constantly since it be able to compose easily more subminiature, low-power, low-cost than previous one. And also it spotlights an important field of study, graft the green IT and IT of which the environment and IT unite stragically onto the Network. This study realize a IAQM(Indoor Air Quility Management) sensing mechanism composition under the network and suggest the application of Environment monitoring system outlook to measure an Environment element.

DChord: An Efficient and Robust Peer to Peer Lookup System

Dynamic Hash Tables (DHTs) are distributed systems that maintain key-value pairs and provide efficient lookup services. Traditional DHTs usually rely on a random ID distribution of the keys to achieve such efficiency. Uniformly random hash functions are typically used to create uniformly random ID distributions from non-random key distributions. However, there are many cases where such random hash functions cannot be applied. For example, those systems that provide range queries over the keys cannot apply random hash functions on the keys, otherwise, the range query is very difficult to support. In this paper, we present a new lookup system called DChord, which does not depend on the randomness assumption to achieve its performance. To show the performance of the proposed system, we provide mathematical analysis and extensive simulation results in a highly non-random USN (Ubiquitous Sensor Network) metadata identifier space. To be specific, we show that DChord has high regularity in terms of in-degree and out-degree distributions. Thus, the system is robust against random node failures. We also show that query processing load is well balanced among nodes and the lookup speed is deterministic in such a way that the number of nodes to visit for a query is at most log2(N).

유비쿼터스 센서네트워크를 위한 압전효과 기반의 무구속 휴대용 풍력 전원 장치

본 논문은 풍력에 의해 구동되는 압전효과 기반의 무구속 휴대용 전원 장치를 제안한다. 기계적 에너지를 효율적으로 변환하는 메커니즘의 한가지로 기계적 에너지를 전기적 에너지로 변환하는 압전효과를 이용하는 방법이 있다. 압전효과는 주기적으로 변하는 응력을 필요로 하지만, 자연 바람은 거의 일정한 속도를 보이거나, 변화하더라도 매우 느리고 불규칙적인 주파수를 갖기 때문에, 효과적으로 전기적 에너지를 얻어내기 힘들다. 본 연구에서는 바람을 프로펠러에 통과시켜, 손쉽게 주기적으로 변하는 응력을 만들어내고, 이를 압전외팔보에 전달하여 효율적으로 에너지를 변환하였다. 본 연구결과는 유비쿼터스 센서네트워크 시스템에 대한 에너지 공급의 실질적인 해결책이 되리라고 기대된다.

USN응용과 범용목적에 적용가능한 센서 신호처리기

In sensor signal conditioning and processing, offset and drift characteristics of an operational amplifier are an important factor when the amplifier is used for a precise sensor signal amplifier. In order to use it in high accuracy, an expensive trimming or a complex compensation circuit is required. This paper presents the improved sensor signal conditioning and processing device for ubiquitous sensor network(USN) application or general purpose by developing a hardware of the circuit for reducing the offset voltage and drift characteristics, and a software for its control and sensor signal processing. We realize better offset voltage and drift characteristics of the signal conditioning circuit using low cost operational amplifiers. The experimental results show that this technique is effective in improving the performance of the sensor signal processing device.

Design and Implementation of Ubiquitous Sensor Network System for Monitoring the Bio-information and Emergency of the Elderly in Silver Town

An ubiquitous sensor network (USN) system to monitor the bio information and the emergency of the elderly in the silver town is presented. The USN system consists of the sensor node platforms based on MCU of Atmage128L and RF Chip of CC2420 satisfying IEEE 802.15.4, which includes the bios sensor module such as the electrocardiogram (ECG) sensor and the temperature sensor. Additionally, when an emergency of the elderly is occurred in the silver town, the routing algorithm suitable to find and inform the location of the elderly is proposed, and the proposed routing algorithm is applied to the USN. To collect and manage the ECG data at the PC connected to the sink node, LabView software is used. The bio information and the emergency of the elderly can also be monitored at the client PC by TCP/IP networks in the USN system.

USN 응용 서비스를 위한 서비스 아키텍처의 설계 및 구현

USN(Ubiquitous Sensor Network) environment that provides the service measured from sensors in real-time the information is delivered to application service. However, domestic service, application service provider environment between providers and users, most of the research are on the service platform architecture, and process the information detected by sensors between the providers of standard services platform architecture, which is a very weak level. In this paper, we proposed new service architecture though analysis of the OGC SWE(Sensor Web Enablement) with standards and research analysis of domestic standards. And we designed and implemented to each component of provider side.

Self-Adapting Event Configuration in Ubiquitous Wireless Sensor Networks

Wireless Sensor Networks are the key-enabler for low cost ubiquitous applications in the area of homeland security, health-care, and environmental monitoring. A necessary prerequisite is reliable and efficient event detection in spite of sudden failures and environmental changes. Due to the fact that the sensors need to be low cost, they have only scarce resources leading to a certain level of failures of sensor nodes or sensing devices attached to the nodes. Available fault tolerant solutions are mainly customized approaches that revealed several shortcomings, particularly in adaptability and energy efficiency. The authors present a complete event detection concept including all necessary steps from formal event definition to autonomous device configuration. It features an event definition language that allows defining complex events as well as enhance the reliability by tailor-made voting schemes and application constraints. Based on that, this paper introduces a novel approach for self-adapting on-node and in-network processing, called Event Decision Tree (EDT). EDT autonomously adapts to available resources and environmental conditions, even though it requires to (re-)organize collaboration between neighboring nodes for evaluation. The authors’ approach achieves fine-grained event-related fault tolerance with configurable adaptation rate while enhancing maintainability and energy efficiency.

유비쿼터스 센서 네트워크를 위한 효율적인 시간 동기화 프로토콜 연구

유비쿼터스 센서 네트워크 환경은 다양한 이기종의 센서와 센서들 상호간의 통신을 통해 데이터를 수집하고 제공하여 물리공간의 지능화된 환경을 제공한다. 이러한 상태감지를 위한 센서노드들은 싱크노드와 센서노드로 구성되는데 이기종 센서 노드들간의 시간동기화를 고려하지 않고 전체 센서네트워크의 시간 동기화가 불가능 하게 된다는 문제점이 발생한다. 이러한 이기종 센서노드들간의 시간동기화 문제를 해결하기 위해서 본 논문에서는 싱크노드 아래의 센서노드들 중 싱크노드와 클럭소스가 같은 센서노드를 시간동기 마스터로 설정하고, 싱크노드와 다른 클럭소스를 가지는 센서노드를 마스터 아래에 속하는 시간동기 슬레이브로 설정하여 시간동기 마스터가 동작을 개시 할 때에만 시간동기 슬레이브 노드들이 동작하도록 하는 마스터 슬레이브 시간동기화 기법을 제안한다. 제안하는 마스터-슬레이브 토폴로지 기반 시간 동기화 기법은 센서의 설치가 용이하지 않은 USN환경에서 최대 슬립타임을 유지함으로써 센서의 전력소모를 최소화 할 수 있다. 【The sensor networks can be used attractively for various application areas. Time synchronization is important for any Ubiquitous Sensor Networks (USN) systems. USN makes extensive use of synchronized time in many contexts for data fusion. However existing time synchronization protocols are available only for homogeneous sensor nodes of USN. It needs to be extended or redesigned in order to apply to the USN with heterogeneous sensor nodes. Because heterogeneous sensor nodes have different clock sources with the SinkNode of USN, it is impossible to be synchronized global time. In addition, energy efficiency is one of the most significant factors to influence the design of sensor networks, as sensor nodes are limited in power, computational capacity, and memory. In this paper, we propose specific time synchronization based on master-slave topology for the global time synchronization of USN with heterogeneous sensor nodes. The time synchronization master nodes are always able to be synchronized with the SinkNode. Then time synchronization master nodes enable time synchronization slave nodes to be synchronized sleep periods. The proposed master-slave time synchronization for heterogeneous sensor nodes of USN is also helpful for power saving by maintaining maximum sleep time.】

OGC 기반의 센서 네트워크 서비스 분석 연구

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.