Event-driven Systems Research Articles

Traffic Management in Wireless Sensor Network Based on Modified Neural Networks

Wireless Sensor Networks (WSNs) are event-driven network systems consist of many sensors node which aredensely deployed and wirelessly interconnected that allow retrieving of monitoring data. In Wireless sensor network,whenever an event is detected, the data related to the event need to be sent to the sink node (data collection node). Sink nodeis the bottleneck of network there may be chance for congestion due to heavy data traffic. Due to congestion, it leads to dataloss; it may be important data also. To achieve this objective, soft computing based on Neural Networks (NNs) CongestionController approach is proposed. The NN is activated using wavelet activation function that is used to control the traffic ofthe WSN. The proposed approach which is called as Modified Neural Network Wavelet Congestion Control (MNNWCC), hasthree main activities: the first one is detecting the congestion as congestion level indications; the second one is estimated thetraffic rate that the upstream traffic rate is adjusted to avoid congestion in next time, the last activates of the proposedapproach is improved the Quality of Services (QoS), by enhancement the Packet Loss Ratio (PLR), Throughput (TP), BufferUtilization (BU) and Network Energy (NE) . The simulation results show that the proposed approach can avoid the networkcongestion and improve the QoS of network.

On asynchronous eventful session semantics

Event-driven programming is one of the major paradigms in concurrent and communication-based programming, where events are typically detected as the arrival of messages on asynchronous channels. Unfortunately, the flexibility and performance of traditional event-driven programming come at the cost of more complex programs: low-level APIs and the obfuscation of event-driven control flow make programs difficult to read, write and verify.This paper introduces a π-calculus with session types that modelsevent-driven session programming(called ESP) and studies its behavioural theory. The main characteristics of the ESP model are asynchronous, order-preserving message passing, non-blocking detection of event/message arrivals and dynamic inspection of session types. Session types offer formal safety guarantees, such as communication and event handling safety, and programmatic benefits that overcome problems with existing event-driven programming languages and techniques. The new typed bisimulation theory developed for the ESP model is distinct from standard synchronous or asynchronous bisimulation, capturing the semantic nature of eventful session-based processes. The bisimilarity coincides with reduction-closed barbed congruence.We demonstrate the features and benefits of ESP and the behavioural theory through two key use cases. First, we examine an encoding and the semantic behaviour of the event selector, a central component of general event-driven systems, providing core results for verifying type-safe event-driven applications. Second, we examine the Lauer–Needham duality, building on the selector encoding and bisimulation theory to prove that a systematic transformation from multithreaded to event-driven session processes is type- and semantics-preserving.

A Benchmarking Tool for Wireless Sensor Network Embedded Operating Systems

The emergence of the technology of Wireless Sensor Networks (WSNs) has lead to many changes in current and traditional computational techniques in order to adapt to their harsh and scarce requirements. A WSN consists of sensor nodes with wireless communication abilities that allow them to form a network. New system architectures have emerged to overcome sensor network limitations. Each architecture follows one of the two traditional design concepts, event-driven or thread-driven design. Although event-driven systems were assumed to generally perform better for embedded systems, tests have shown that event-driven systems tend to save more energy and space, while the thread-driven systems provide more concurrency and predictability, hence creating a tradeoff depending on the requirements of the application at hand. Performance analyzers are often used to accurately measure the performance of a certain system when such a tradeoff is evident. Performance analyzers can also locate deficiencies in a certain system for future improvements. The ever increasing complexity of applications executed by WSNs and the evolving nature of the underlying Embedded Operating Systems (EOSs) has led to the need for an accurate evaluation technique to guide practitioners in the field. This paper presents a novel approach towards providing a benchmarking and performance evaluation tool for comparing and analyzing the performance of WSN EOSs.

Event-driven observer-based output feedback control for linear systems

This paper concerns the problem of event-driven observer-based output feedback control of linear systems. Contrary to normal sampled-data control systems, where the controller is updated periodically, in event-driven systems, it is updated only when an “event” happens, and a typical event is defined as some error signals exceeding a given threshold. Both continuous- and discrete-time event detector cases are considered. It is shown that even with the significantly reduced sampling frequency, the global uniform ultimate boundedness of the event-driven closed-loop systems can also be guaranteed. A numerical example is finally used to illustrate the effectiveness and advantages of the proposed approaches.

Design and Application of Task Scheduling Module Based on Priority Table Query in Wireless Sensor Network Node

Event-driven systems and thread-driven systems are two major design philosophies of operating system in wireless sensor networks. Systems based on multi-threaded are more timeliness than the event-driven systems, which can meet the requirements of time-critical tasks by means of task preemption, while systems based on event-driven are more energy efficient.The article introduces a task scheduling module in event-driven system. The module takes a kind of priority table query method to choose the most important task with highest priority to schedule.It is seen that the module is suitable wireless sensor network.

Vector-Matrix Multiply and Winner-Take-All as an Analog Classifier

The vector-matrix multiply and winner-take-all structure is presented as a general-purpose, low-power, compact, programmable classifier architecture that is capable of greater computation than a one-layer neural network, and equivalent to a two-layer perceptron. The classifier generates event outputs and is suitable for integration with event-driven systems. The main sources of mismatch, temperature dependence, and methods for compensation are discussed. We present measured data from simple linear and nonlinear classifier structures on a 0.35-μm chip and analyze the power and computing efficiency for scaled structures.

プロセスの順序性に着目した事象駆動型システムの確率的故障診断

This paper presents a fault diagnose method for event-driven systems based on probabilistic inference, Timed Markov Model (TMM). The TMM is one of semi-Markov process models wherein state transition probabilities depend on stay time at a state. The TMM requires numerous amount of learning data to establish a diagnosis system, and it is difficult to collect enough learning data in a large and complex system. This paper focuses on a diagnosis strategy based on sequential order of processes in the event-driven system, and the method can diagnose the fault even if the amount of learning data is not rich. Finally, the usefulness of the proposed strategy is verified through some experimental results of an automatic transfer line.

An Architecture to Implement Event-Driven Web Monitoring Systems

Traditional monitoring systems are based on C/S mode because desktop software still has inherent advantages though desktop software is replaced by web applications rapidly in many fields. Meanwhile, traditional monitoring systems use relational database as data source, however, relational database lacks the ability to process influx of queries per second. In this paper, we will do an in-depth research to design an architecture to implement event-driven web monitoring systems. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.3466

AODA: an Autonomic and Ontology-Driven Architecture for service-oriented and event-driven systems

The large diversity and heterogeneity of collaborating objects and services in modern networking environments such as personal, vehicular or home networks makes difficult the efficient configuration, deployment and management of composite dynamic systems without a major participation of human actors. This paper proposes an autonomic architecture based on decision models built on ontologies and aimed at self-configuring and self-adapting information networks. Our work follows a top-down approach based on well-known and accepted standards. A detailed structure composite diagram is illustrated to describe AODA modules and show how they interact together. Our proposition had been implemented as an ecosystem-wide ontology aimed at characterising the properties of services and events related to consumers and producers entities participating in the information network. We propose a smart metering use case to compute the overload generated by our solution in handling a large number of objects.

On the asynchronous information embedding for event-driven systems in molecular communications

Molecular communications is emerging as a promising paradigm for nanoscale communications in nanotechnology. Though still at an early stage, research efforts have been devoted and various molecular communication systems have been proposed. However, each proposed system possesses a specific structure to achieve communications in its own way. To our best knowledge, no unified system description exists so far. In this paper, we propose an abstract system structure called an event-driven system; a significant group of molecular communication systems can be classified into such an abstract form. We define event-driven systems and further show that, for these systems, there is a signaling scheme called asynchronous information embedding which carries additional information while at the same time keeping the original communication mechanisms uninfluenced. Instead of investigating asynchronous information embedding in full generality, we consider synchronous type-based systems as a demonstrative example which still captures most of the features. For such type-based systems, we develop an approximation method for obtaining the channel capacity as a general performance measure. Numerical results are provided to show the capacity gain of asynchronous information embedding.

Remedy of Mixed Initiative Conflicts in Model-based System Engineering

SPACE is a technique for model-driven engineering of reactive dis- tributed systems. One of the strengths of its tool-set Arctis is that the system en- gineer can formally analyze the models for design errors such that these can be corrected early in the development process. In this paper, we go a step further and introduce a technique that refines the fault detection and, in addition, offers a highly automatic mechanism to remedy the errors. For that, we combine model checking, the already existing analysis method of Arctis, with graph transformation. Using graph rewriting rules, we can analyze the state space graph of a system for the exact reason of an error as well as remove the erroneous parts of a model by changing the model description. We exemplify the approach by envisaging the detection and rem- edy of mixed initiatives, a quite common cause for faulty behavior in event-driven systems that often is overlooked in system development.

Modular Supervisory Control and Hierarchical Supervisory Control of Fuzzy Discrete-Event Systems

This paper establishes modular and hierarchical supervisory control theories of Fuzzy Discrete-Event Systems (FDES). It aims to resolve the horizontal and vertical complexities present in large-scale event-driven systems, which are affected by uncertainties in their event and state representations. The modular supervisory control architecture composed of a set of noncommunicating local supervisors, in which one supervisor is assigned for each module having its own sensing and acting capabilities. The notion of separability for languages in FDES is introduced and the property of a language specification of FDES, termed as separably-controllable-observability, is proposed to determine the existence of modular supervisors to the control problem. The hierarchical supervisory control architecture consists of multilevel supervisors assigned to detailed low-level and abstract high-level models of the plant. The notion of output-control-consistency is introduced for languages in FDES. Then, the property called strictly-output-control-consistency is defined for FDES in order to maintain the hierarchical consistency between low-level and high-level FDES modules. The property of H-fuzzy observability is introduced to ensure the hierarchical consistency under the partial observation of low-level FDES. Finally, using the established hierarchical supervisory control theory of FDES, a behavior-based mobile robot navigation example is discussed.

Performance modeling and analysis of message-oriented event-driven systems

Message-oriented event-driven systems are becoming increasingly ubiquitous in many industry domains including telecommunications, transportation and supply chain management. Applications in these areas typically have stringent requirements for performance and scalability. To guarantee adequate quality-of-service, systems must be subjected to a rigorous performance and scalability analysis before they are put into production. In this paper, we present a comprehensive modeling methodology for message-oriented event-driven systems in the context of a case study of a representative application in the supply chain management domain. The methodology, which is based on queueing Petri nets, provides a basis for performance analysis and capacity planning. We study a deployment of the SPECjms2007 standard benchmark on a leading commercial middleware platform. A detailed system model is built in a step-by-step fashion and then used to predict the system performance under various workload and configuration scenarios. After the case study, we present a set of generic performance modeling patterns that can be used as building blocks when modeling message-oriented event-driven systems. The results demonstrate the effectiveness, practicality and accuracy of the proposed modeling and prediction approach.

Reformulation and assessment of the inventory approach to urban growth boundaries

Based on the theoretical framework, in this article we demonstrate how Decision Network can be used to formulate the inventory approach to urban growth boundaries (UGBs) as an application of the planning tool to a general case. In particular, in the inventory approach expansions of UGBs are considered as decision situations, land consumptions as problems, and order sizes of UGBs as solutions. We compare the time- and event-driven systems of the inventory control problem based on the decision network framework. The former in the framework is considered as making single, independent decisions in time, whereas the latter as making multiple, linked decisions in time. Our numerical example shows that the event-driven system is more effective than the time-driven system in that the former incurs less total cost than the former in the UGBs context. The implication is that making multiple, linked decisions, as manifested by Decision Network, would yield more benefits, such as lowering the total cost, to the planner than making these decisions independently.

1A1-F03 事象駆動系の分散型故障診断法におけるBayesian Networkの構築法 : KL情報量を用いたアークの重要度評価手法(生産システム・生産機器メカトロニクス)

This paper presents decentralized fault diagnosis strategy of event-driven systems based on probabilistic inference together with a method to construct the structure of the inference network, Bayesian network (BN). The structure of BN is essential since the computational burden and the fault diagnosis performance greatly depend on it. In this paper, we particularly focus on a construction methodology of BN structure based on evaluation of the arcs via Kullback-Leibler divergence of the conditional probabilities.

Operating System Design in Future Wireless Sensor Networks

Traditional operating systems do not take into consideration the limitations in space and energy of wireless sensor networks. Thus, contemporary architectural demands in terms of power, heat, size and cost will not be satisfactorily met by such uniprocessing design. Also, the transition to multithreaded, multi-core designs places a greater responsibility on programmers and software for improving performance which is becoming increasingly important as sensor nodes are migrating towards dual processor designs. By analyzing and summarizing the activity of a system, one could locate sections of code that have a potential to generate enhanced performance. First, this paper studies the differences between different operating system designs introducing a thread-driven scheduling algorithm which focuses on the value of preemption to overcome the energy tradeoff brought by event-driven systems. We then devise efficient techniques that will enable us to locate sections in OS code that could behave more efficiently when parallelized, especially in terms of energy consumption. Finally, we provide simulation results that will validate our proposed techniques.

Interaction protocol mediation in web service composition

This article presents a mediation framework supporting the integration of web services in orchestrated and choreographed services and the conciliation of interaction protocol mismatches. Our framework supports a loosely-coupled interaction among web services, based on the publish and subscribe pattern. Moreover, it manages web services as event-driven systems, in order to enable them to perform their operations in context-dependent way. By decoupling the web service interaction, our framework addresses several interaction protocol mismatches, ranging from differences in the signatures of the messages, to the order and number of the messages to be exchanged, including cross-protocol mismatches involving more than two peers.

Environment generation for validating event-driven software using model checking

Event-driven systems maintain an ongoing dialog with their environment. Examples include: distributed programs, where each process reacts to received messages by performing computation and sending messages to peers; graphical user interfaces (GUI), where the interface software and the underlying application react to user inputs and web-based applications, where presentation, business logic and storage tier functionality react to user inputs and response from other web-based services. Such applications are difficult to test because the set of possible interaction sequences between the system and its environment can be very large and governed by complex constraints. The exhaustive nature of software model checking techniques offers hope for effectively validating such systems, however, they only work for closed systems. Previously, the authors developed the Bandera Environment Generator, which given an open system, called a unit under analysis, closes it with a model of its environment. The authors' previous work on environment generation has focused on developing broadly applicable mechanisms for modelling environment behaviour. The generality of this approach often makes it difficult to produce environment models that enable precise and efficient system analysis. The authors' experience shows that by exploiting information about the application domain, generated environments can be made both more precise and more efficient for model checking. This study presents the concept of domain-specific environment generation, details techniques for customising environment generation for the domain of event-driven software, and assesses those techniques on the domains of GUI and web-based applications.

An Identification Technique for Timed Event Systems

Compared to time-driven systems, few tools are available for identification of timed event-driven systems. Here we address the identification problem for those systems that require not only proper ordering, but also correct timing, of input and output events for their complete description. First we review well-known results from computational learning theory, noting their roots in classical systems theory and interpreting their relevance to the identification problem. Next, as a prerequisite to identification, we introduce a simple formalism for timed deterministic event-based system behavior that is also well-adapted to identification. Then we present the main result of the paper, an algorithm that under appropriate conditions computes an automaton whose behavior reliably imitates a given timed event system. Simulation results illustrate best-case and worst-case identification conditions.

Decentralized Diagnosis of Event-Driven Systems for Safely Reacting to Failures

We introduce the notion of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">safe-codiagnosability</i> , extending the notion of safe-diagnosability (Paoli and Lafortune, 2005) to the decentralized setting. For a system, a certain subbehavior is deemed safe (captured via a safety specification), and a further subbehavior is deemed nonfaulty (captured via a nonfault specification). Safe-codiagnosability requires that when the system executes a trace that is faulty, there exists at least one diagnoser that can detect this within bounded delay and also before the safety specification is violated. The above notion of safe-codiagnosability may also be viewed as an extension of the notion of codiagnosability (Qiu and Kumar, 2006), where the latter did not have any safety requirement. We show that safe-codiagnosability is equivalent to codiagnosability together with ldquozero-delay codiagnosabilityrdquo of ldquoboundary safe tracesrdquo. (A safe trace is a boundary safe trace if there exists a single-event extension that is unsafe.) We give an algorithm of polynomial complexity for verifying safe-codiagnosability. For a safe-codiagnosable system, the same methods as those proposed in (Qiu and Kumar, 2006) can be applied for offline synthesis of individual diagnosers, as well as for online diagnosis using them.