This paper introduces a Quaternion-based rotational representation of low power, low resource, commercial-of-the-shelf (COTS) IMU sensors, offering high accuracy, reliability and real time performance. A critical aspect of this work is the distributed implementation of the proposed solution that facilitates its integration with IoT platforms utilizing the MQTT communication protocol while efficiently applying a modified Madgwick's filter implementation to extract the sensor's orientation and rotation. Based on the proposed solution, sensor orientation outperforms conventional implementations based on previously widely applied methods like Euler Angles and effectively tackles important shortcomings such as a sluggish response and issues like Gimbal Lock. Comprehensive, experimental evaluation reveals that the proposed solution yields state-of-the-art accuracy, while being deployed on a typical, low-cost COTS sensor while delay measurements indicate a highly reliable and time constrained performance adequate for a wide range of real life scenarios.

This work presents the concept and methodology as well as the architecture and physical implementation of an integrated node for smart-city applications. The presented integrated node lies on active RFID technology whereas the use case illustrated, with results from a small-scale verification of the presented node, refers to common-type waste-bins. The sensing units deployed for the use case are ultrasonic sensors that provide ranging information which is translated to fill-level estimations; however the use of a versatile active RFID tag within the node is able to afford multiple sensors for a variety of smart-city applications. The most important benefits of the presented node are power minimization, utilization of low-cost components and accurate fill-level estimation with a tiny data-load fingerprint, regarding the specific use case on waste-bins, whereas the node has to be deployed on public means of transportation or similar standard route vehicles within an urban or suburban context.

Modbus/TCP is a network protocol for industrial communications encapsulated in TCP/IP network packets. There is an increasing need to test existing Modbus protocol implementations for security vulnerabilities, as devices become accessible even from the Internet. Fuzz testing can be used to discover implementation bugs in a fast and economical way. We present the design and implementation of MTF, a Modbus/TCP Fuzzer. The MTF incorporates a reconnaissance phase in the testing procedure so as to assist mapping the capabilities of the tested device and to adjust the attack vectors towards a more guided and informed testing rather than plain random testing. The MTF was used to test eight implementations of the Modbus protocol and revealed bugs and vulnerabilities that crash the execution, effectively resulting in denial of service attacks using only a few network packets.

In the age of automation the need for indoor navigation has become quite important for a rising number of applications. In this work a strapdown INS (SINS) in terms of Inertial Navigation System is discussed. INS is an electronic device, containing an Inertial Measurement Unit (IMU), implementing a Dead Reckoning (DR) algorithm. This algorithm estimates position, velocity and orientation utilizing readings from motion sensors. The logic behind DR algorithm is to continually adding detected changes from the sensors to its previously calculated results. This is the main reason why INS is limited to measure relative position and orientation. Thus the accuracy of the propagated position depends heavily on the quality of the initial conditions. In addition, if absolute position or orientation updates are obtained by another sensor source at a high rate, the INS can be used to deliver high precision positions. In this paper, an INS fused with the new Bluetooth v4.0 technology is described.

A fuzzy rule-based and energy-efficient method for estimating the free size of parking places in smart cities is proposed. In particular, the estimation is the output value of a fuzzy inference system (FIS) which was implemented on each wireless sensor mote (WSM) of a wireless sensor network (WSN) placed in the ground below the parking places and it was observed that it requires 8.9 Kbytes and 5 Kbytes of flash program memory and RAM respectively. Moreover, the fuzzy rules were formulated by using real numerical data obtained from the WSN. Next, the well known network simulator 2 (NS-2) was used for acquiring simulation results concerning the energy consumption of the battery of the WSMs. In order to model the error of the output value of the FIS and the energy consumption of the battery, a data fitting problem was solved and the cubic polynomial was fitted to the real and simulation data. As a result, a real-valued cost function was formed which was minimized to get the optimal values for the distance between the WSMs and the sampling period based on which the output of the FIS should be re-computed.

It is increasingly regarded that data local caching in WSN can benefit the resource conservation and performance. A critical challenge is that cached data comprise only a small percentage of the data that a WSN node may require, thus leading to the replacement of data items. Consequently, replacement policy comprises critical factors in order to maximize performance benefits. Equally important in WSN is the interplay of such policies, application and network characteristics. Therefore, this paper aims to experimentally evaluate prominent replacement policies performance with respect to critical application and network parameters. An already presented cache model is developed and appropriately extended in the context of the prominent WSN TelosB platform. Valuable insights are provided concerning the behavior of considered policies in typical WSN scenarios and important trade-offs are revealed.

Wireless Sensor Networks (WSNs) have limited power capabilities, whereas they serve applications which usually require specific packets, i.e. High Priority Packets (HPP), to be delivered before a deadline. Hence, it is essential to reduce the energy consumption and to have real-time behavior. To achieve this goal we propose a hybrid technique which explores the benefits of data aggregation without data size reduction in combination with prioritized queues. The energy consumption is reduced by appending data from incoming packets with already buffered Low Priority Packets (LPP). The real-time behavior is achieved by directly forwarding the HPP to the next node. Our study explores the impact of the proposed hybrid technique in several all-to-one data flow scenarios with various traffic loads, wait time intervals and percentage of HPP. Our results show gain up to 23,3% in packet loss and 36,6% in energy consumption compared with the direct forwarding of packets.

Wireless Sensors Networks (WSNs) emphasize the necessity of accurate event detection in realistic environments, while health monitoring comprise one of their most pronounced applications. Although respective fuzzy logic systems have been proposed based on vital and environmental sensors, there is a significant lack of investigation on the reliability of such systems when applied in error prone wireless environments. Therefore, this paper aims to address this need by porting an adequate fuzzy inference system (FIS) to a WSN simulation framework. The considered FIS has been validated in previous work and is implemented in a TelosB emulated mote, which evaluates the health status of a monitored person. Such implementation allows the thorough performance evaluation of the FIS under a wide range of communication conditions. Respective results and comparative evaluation against Matlab environment reveal strong dependencies to critical WSN network parameters.

Wireless Sensor and Actor Networks emphasize the necessity for cooperative communication between actors as well as sensors in order to achieve ubiquitous monitoring and efficient interaction in realistic physical environments and appropriate acting on them. This collaboration aims to assure appropriate decision making related to specific event detection, appropriate classification as well as selection of the optimal actor able to react to the event. Therefore this paper aims to propose a suitable architecture providing a data fusion model necessary for the first goal as well as a task assignment method comprising an essential component for energy efficient communication between the actors so as to allocate the acting tasks.

The Wireless Sensor Networks (WSNs) have limited power and communication capabilities, combined with the requirement for long network lifetime. To increase it, methods to reduce energy consumption are highly required. To achieve this goal, we study a data aggregation technique without size reduction, i.e. data merge. It is a generic technique, since it is also usable in applications with heterogeneous data and requirements for high accuracy. This study presents the impact of the data merge technique on WSNs applications executed under various realistic data flow scenarios, traffic loads and wait time intervals. Our results show significant reductions in both packet loss and radio energy consumption.

A modular architecture for power constrained embedded devices which leverages an agent based middleware in order to impose intelligence over critical infrastructures which require real time actions is always desirable in the case of Wireless Sensor Networks. The main objective of such architecture is the integration of a Wireless Sensor Network with the internet. This objective indicates the need of Ipv6 ready devices as well as the utilization of newly emerged standards such as the 6lowpan which forms an abstraction layer between the Medium Access control and the IP layers.

Aim of this research is to propose an accurate model of measuring business excellence by applying the theory of System Dynamics. This theory defines the interaction of system variables giving the opportunity of a reliable and fair score as well as objective decision-making with regard to the areas that are susceptible of continuous improvement. This paper utilises the principles of the System Dynamics in order to propose a new method for measuring business excellence and thus contributing to a thorough evaluation of an enterprise which implements a Business Excellence Model. The proposed business excellence system is adopted and applied as the Hellenic National Quality Award scheme. The study only adopts empirical data from the application of the proposed business excellence system due to the early stages of implementation in the market. Future research may use more data to better tune the proposed method. Based on the more accurate analytical results achieved by the proposed model, the Hellenic national authority of managing the Hellenic scheme of business excellence might use the proposed model for measuring business excellence and to drive continuous improvement and competitiveness according to its strategy.

Tourism presents quite an important industry that needs to evolve so that it confronts with the changes occurring on a global scale. In order for this to be possible a different approach should be followed regarding the provision of an integrated tourist product combining all the different characteristics of a tourist destination. Clustering of both tourist enterprises and other local enterprises affecting the overall tourist product could play an important role towards this direction. This paper presents such an approach leading to inter-enterprise integration through suitable semantics.

Wireless Sensor Networks (WSNs) is a novel and promising technology used in commercial applications to monitor data that would be difficult or expensive to monitor using wired sensors. However, pure WSNs are still insufficient for many industrial applications where the reliability and high computational power of wired networks is needed. Hybrid networks can provide solutions to such applications, combining the advantages of both types of networks.This paper presents the evaluation of a hybrid network using TinyOS-based systems and traditional Ethernet. To the best of our knowledge, it is the first attempt of implementing a hybrid network using the novel research area of TinyOS systems.

As networks become more and more complicated and applications more and more demanding, a very common network topology for state-of-the-art multimedia applications supporting emerging user - centric frameworks is a heterogeneous wired/wireless architecture. A network architecture solution for indoor/outdoor heterogeneous networking applications, to support both multimedia and sensor applications suitable for such frameworks is proposed in this paper. Furthermore, an integrated DRM system architecture is proposed for the protection of intellectual property, characterized by its interoperability aspect.

The manufacturing environment is characterized by a high degree of heterogeneity. The seamless integration of MES and Shop-Floor layers poses a significant challenge. Industrial manufacturing ontologies provide the necessary semantics for such and integration. A gap nevertheless exists between the industrial ontology semantics and the behaviour and activity model utilized by a multi-agent system that implements the MES layer. Work presented in this paper presents a way to close this gap through the enforcement of a sound methodology utilizing an appropriate meta-ontology. The applicability of the methodology is evaluated against a Multi-Agent System paradigm modeled according to the GAIA methodology.

Ad hoc wireless networks are power constrained since nodes operate with limited battery energy. Thus, energy consumption is crucial in the design of new ad hoc routing protocols. To design such protocols, we have to look away from the traditional minimum hop routing schemes. This paper presents an energy-aware routing mechanism to balance the energy consumption among the nodes of the network. The mechanism was based on the AODV protocol using a realistic energy consumption model which takes into account the battery of a node and the transmission energy. The results show that the modified AODV protocol reduces the energy consumption of the nodes by routing packets to their destination using energy-optimal routes. The outcome is the improvement of network survivability by maintaining the network connectivity without affecting negatively the others parameters of the protocol.

This paper presents an ad-hoc sensor network especially developed for a disaster relief application that provides the rescue teams with a quickly deployable, cost-effective, and reliable tool to collect information about the presence of people in a collapsed building space and the state of the ruins. The hardware/software architecture of the wireless sensor nodes is developed for a low-cost design implementation. Energy efficiency is another objective of this paper, achieved by the combination of a low-power-mode algorithm and a power-aware routing strategy. A selected set of simulation studies indicate a reduction in energy consumption and a significant increase in node lifetime whereas network performance is not affected significantly. Finally, a lightweight management architecture is presented to facilitate autonomous management of ad-hoc sensor networks

This paper aims to study and analyze lost packet tendencies for ad hoc wireless networks. Lost packets greatly influence all performance aspects of such a network. Moreover, lost or drop packets are directly involved in many active research fields concerning ad hoc network nowadays. Accordingly, investigating the various kinds of packets dropped more frequently in conjunction with critical network parameters, can result in very usefully conclusions. These conclusions can give new insights in designing new protocols and more importantly in cross-layer designs in order to enhance the performance of the whole network.

Collaborative B2B e-commerce provides enterprises with the necessary level of flexibility and efficiency to retain competitiveness under the increasingly turbulent business environment. Widely accepted XML-based frameworks like RosettaNet may be utilized to provide generic inter-enterprise B2B infrastructure. This paper presents an innovative approach towards utilizing RosettaNet in combination with Web services, ontologies and workflow management systems for the enforcement of the continuous replenishment planning process.

This paper describes the ERMIS system, specially designed to support the fleet and personnel scheduling and management issues, as well as to support various business collaboration issues for a helicopter taxi company. The implemented system offers a Web-based interface for the flying and stationary personnel and a software application running on a PDA with GSM and GPS capabilities for the pilots. The information flow and the business processes of the ERMIS system are based on XML Web services which makes the system open and interoperable with other company-owned information systems.

The need for interoperability is prominent in the industrial enterprise environment. Different applications and systems that cover the overall range of the industrial infrastructure from the field to the enterprise level need to interoperate. This quest is driven by the enterprise need for greater flexibility and for the wider possible integration of the enterprise systems. This paper presents a distributed system architecture that utilizes dominant state-of-the-art standard technologies, such as workflows, ontologies, and web services, in order to address the above quest in an efficient way.

This paper aims to study and analyze the real time performance of dominant routing protocols for ad hoc wireless networks under power consumption constraints. It is evaluated the influence of the power consumption to the whole system performance (throughput, delay, network lifetime, channel fairness etc.) under various data flow patterns. The results of this study can be very useful for cross-layer design targeted to the improvement of the whole system performance of the ad hoc wireless networks.

This paper proposes a middleware architecture that serves as a framework for the management of industrial processes in an industrial grid environment. The proposed system is based on agents making possible the effective distribution of intelligence, thus fortifying the survivability of the industrial network, while a central point of monitoring and control allows agent monitoring. By the term `agent' we denote a piece of software which overviews a well-defined part of an industrial process, abides to rules, accepts inputs, issues reports and easily adapts to environmental changes. Utilizing key technologies like Web services, workflow allocation and ontologies, a scalable and highly adaptable architecture is achieved

Collaborative e-commerce provides an increased level of flexibility and dynamicity and generates an entrepreneurial competitive edge. Widely accepted implementation frameworks like RosettaNet may be utilized to provide generic inter-enterprise B2B infrastructure. This paper presents an innovative approach towards utilizing RosettaNet in combination with Web services and ontologies for the enforcement of the continuous replenishment planning model

Ad hoc networks are characterized by dynamic topology caused by node mobility, multihop wireless connectivity and channel non-deterministic behavior (interference, multipath, hidden and exposed node problem make the wireless channel very difficult to predict). The behavior of ad hoc networks must be analyzed in detail as a result of the pairing of the selected MAC and routing protocols. We focus our studies in the routing layer while closely observing the developments in MAC layer. We present and examine analytical simulation results for the routing protocols DSR, TORA and ZRP especially focusing in ZRP and the impact of some of its most important attributes to network performance, using the well known network simulator OPNET 10.0.PL2

In this work the characteristics of the radio channel of a typical industrial environment are examined in detail by means of experimental measurements. The channel impulse response is measured at several representative positions. These measurements are then used to calculate important propagation parameters like attenuation, rms delay spread and coherence bandwidth. Furthermore, directional antennas are used to investigate the effect of directional transmission in propagation parameters. Finally, the performance of direct sequence spread spectrum (DSSS) radio transmission (in the 2.4 GHz band) is evaluated for omnidirectional and directional reception by means of bit error rate (BER) measurements at the same characterized positions

In this paper, the architecture and the operation of a cut-through forwarding device to be used in broadcasting, hybrid wired/wireless fieldbus systems are described. Analytical models of the delay overhead introduced due to frame forwarding are presented. It is shown that the usage of cut-through forwarding devices relaxes the bit-rate requirements in the radio segments, while it drastically improves the inherent advantages and reduces the drawbacks of hybrid transmission media architectures which are based on a single MAC domain.

The benefits of wireless extensions in industrial networks are well recognized as long as the integration of the wireless and fieldbus domains will be capable to offer the realtime and dependability quality of the current wired industrial networking solutions. This paper presents a study, from a performance point of view, for the possible integration of the most popular 3G and WLAN radio technologies with fieldbus technologies. A brief examination of a number of dominant wireless protocols against the basic wireless fieldbus requirements is presented. For the case study, Profibus is used, on which, the basic message cycle performance is calculated for each of the UNITS, 802.11b and HIPERLAN protocols, under different integration approaches.

The adaptive reservation protocol, referred to as ATP-2, uses two frequency separated subchannels, the request and information subchannels, for the request and information packets. The nature of the accessing algorithms for these two subchannels characterizes the overall ATP-2 protocol quality. Extended ATP-2 performance results are presented and a comparison is made between the ATP-2 and some other well-known multiple-access protocols.>