|Detection and Prevention of Denial of Service (DoS) Attacks in Mobile Ad Hoc Networks using Reputation-based Incentive Schemes|
Mieso, K Denko
Mobile ad hoc networks (MANETs) are dynamic mobile networks that can be formed in the absence of any pre-existing communication infrastructure. In addition to node mobility, a MANET is characterized by limited resources such as bandwidth, battery power, and storage space. The underlying assumption in MANETs is that the intermediate nodes cooperate in forwarding packets. However, this assumption does not hold in commercial and emerging civilian applications. MANETs are vulnerable to Denial of Service (DoS) due to their salient characteristics. There is a need to provide an incentive mechanism that can provide cooperation among nodes in the network and improve overall network performance by reducing DoS attacks. In this paper, we propose a reputation-based incentive mechanism for detecting and preventing DoS attacks. DoS attacks committed by selfish and malicious nodes were investigated. Our scheme motivates nodes to cooperate and excludes them from the network only if they fail to do so. We evaluated the performance of our scheme using the packet delivery ratio, the routing and communication overhead, and misbehaving node detection in a discrete event-simulation environment. The results indicate that a reputation-based incentive mechanism can significantly reduce the effect of DoS attacks and improve performance in MANETs.
Detection of Defects of BGA by Tomography Imaging
Tetsuhiro SUMIMOTO, Toshinori MARUYAMA, Yoshiharu AZUMA, Sachiko GOTO, Munehiro MONDOU, Noboru FURUKAWA, Saburo OKADA
To improve a cost performance and the reliability of PC boards, an inspection of BGA is required in the surface mount process. Types of defects at BGA solder joints are solder bridges, missing connections, solder voids, open connections and miss-registrations of parts. As we can find mostly solder bridges in these defects, we pick up this to detect solder bridge in a production line. The problems of image analysis for the detection of defects at BGA solder joints are the detection accuracy and image processing time according to a line speed of production. To get design data for the development of the inspection system, which can be used easily in the surface mount process, it is important to develop image analysis techniques based on the X-ray image data. We attempt to detect the characteristics of the defects of BGA based on an image analysis. Using the X-ray penetration equipment, we have captured images of an IC package to search an abnormal BGA. Besides, in order to get information in detail of an abnormal BGA, we tried to capture the tomographic images utilizing the latest imaging techniques.
Development and Evaluation of a Model for Modular Automation in Plant Manufacturing
Uwe Katzke, Katja Fischer, Birgit Vogel-Heuser
The benefit of modular concepts in plant automation is seen ambivalent. On one hand it offers advantages, on the other hand it also sets requirements on the system structure as well as discipline of designer. The main reasons to use modularity in systems design for automation applications in industry are reusability and reduction of complexity, but up to now modular concepts are rare in plant automation. This paper analyses the reasons and proposes measures and solution concepts. An analysis of the work flow and the working results of some companies in several branches show different proposals of modularity. These different proposals in production and process engineering are integrated in one model and represent different perspectives of an integrated system.
Explicit Rate Adjustment (ERA): Responsiveness, Network Utilization Efficiency and Fairness for Layered Multicast
Somnuk PUANGPRONPITAG, Roger Boyle, Surasak Sanguanpong
To provide layered multicast with responsiveness, efficiency in network utilization, scalability and fairness (including inter-protocol fairness, intra-protocol fairness, intra-session fairness and TCP-friendliness) for layered multicast, we propose in this paper a new multicast congestion control, called Explicit Rate Adjustment (ERA). Our protocol uses an algorithm relying on TCP throughput equation and Packet-bunch Probe techniques to detect optimal bandwidth utilization; then adjusts the reception rate accordingly. We have built ERA into a network simulator (ns2) and demonstrate via simulations that the goals are reached.
Formal Methods Unifying Computing Science and Systems Theory
Computing Science and Systems Theory can gain much from unified mathematical models and methodology, in particular formal reasoning ("letting the symbols do the work"). This is achieved by a wide-spectrum formalism.
The language uses just four constructs, yet suffices to synthesize familiar notations (minus the defects) as well as new ones. It supports formal calculation rules convenient for hand calculation and amenable to automation.
The basic framework has two main elements. First, a functional predicate calculus makes formal logic practical for engineers, allowing them to calculate with predicates and quantifiers as easily as with derivatives and integrals. Second, concrete generic functionals support smooth transition between pointwise and point-free formulations, facilitating calculation with functionals and exploiting formal commonalities between CS and Systems Theory.
Elaborating a few small but representative examples shows how formal calculational reasoning about diverse topics such as mathematical analysis, program semantics, transform methods, systems properties (causality, LTI), data types and automata provides a unified methodology.
Hierarchical Patterns: A Way to Organize (Analysis) Patterns
The paper addresses the issue of categorization and generalization in software patterns. It focuses on the realm of analysis (conceptual) patterns in which the problem is more noticeable when compared to design patterns. The paper introduces hierarchical analysis patterns as a means for categorization and balancing generality and real-world usefulness. A three level hierarchy of analysis patterns is presented. It is documented using real-world examples. Finally, there is a rational that hierarchization might be useful for other kinds of software patterns as well.
Influence of Combination of Criteria for Extraction of Features on the Classification of Biological Signals
Ángel GUTIÉRREZ, Alfredo SOMOLINOS
Expert doctors use the shape of the principal components of the Brain Stem Auditory Evoked Potential (BSAEP) signal to diagnose patients with multiple sclerosis. The diagnosis involves the estimation of the effects of the disease on the form of the waveform components of BSAEPs. Since these components are localized in time and frequency a packet wavelet decomposition of the signal is used to compress it. The information obtained by the packed wavelet can be use to feed artificial neural networks (ANN) with Radial Basis Functions for the same purpose of obtaining a diagnosis. Due to the paucity of data, the signals must be preprocessed. From the hundreds or thousands of wavelet coefficients, only eight are selected using different criteria. Those are used to train an artificial neural network with radial basis functions. We have found that if we combine some of the selection criteria to differentiate sick and healthy people, only one combination of criteria provided better results that using each criterion alone, and other combinations worked better only with some wavelet bases.
Integrating UML, the Q-model and a Multi-Agent Approach in Process Specifications and Behavioural Models of Organisations
Efficient estimation and representation of an organisation’s behaviour requires specification of business processes and modelling of actors’ behaviour. Therefore the existing classical approaches that concentrate only on planned processes are not suitable and an approach that integrates process specifications with behavioural models of actors should be used instead. The present research indicates that a suitable approach should be based on interactive computing. This paper examines the integration of UML diagrams for process specifications, the Q-model specifications for modelling timing criteria of existing and planned processes and a multi-agent approach for simulating non-deterministic behaviour of human actors in an organisation. The corresponding original methodology is introduced and some of its applications as case studies are reviewed.
|Intelligent Virtual Reality and its Impact on Spatial Skills and Academic Achievements|
Esther Zaretsky, Varda Bar
It is known that the training of intelligent virtual reality, through the use of computer games, can improve spatial skills especially visualization and enhances academic achievements. Through an experiment of using Tetris software, two objectives were achieved: developing spatial as well as intelligence skills and enhancing academic achievements, focusing on mathematics. This study followed studies dealing with the impact on putting the learner into action in 3d space software. During teaching a transition from 2d to 3d spatial perception and operation occurred. A positive transfer from 3d virtual reality rotation training to structural induction skills, by means of mental imaging, was also achieved. At the same time the motivation for learning was enhanced, without using extrinsic reinforcements. The duration of concentration while using the intelligent software increased gradually up to 60 minutes.
ITIL Based Service Level Management if SLAs Cover Security
Current level of information technology creates new perspectives for more IT service oriented market. Quality of these services requires slightly different approach then was applied for products including software. No IT services are delivered and supported in risk free environment. Risks would be considered consistently with IT services quality gaps from Service Level Management (SLM) perspective. SLM is one of ITIL modules that are widely used within the IT service industry. We identified some weaknesses in how SLM is developed in ITIL environment if service level agreement (SLA) has cover Security.
We argue that in such cases Architecture modeling and risk assessment approach let us effectively control analytical effort that relates to risks identification and understanding. Risk driven countermeasures designed in a next step (Risk treatment) have significant impact to the SLM especially from responsibility perspective.
To demonstrate SLM’s importance in real practice we analyze SLA synthesize process in CCI (Cyber Critical Infrastructure) environment.
Organizational Knowledge Creation Aspectof ETS-VIII Spacecraft Development
Organizational knowledge creation (OKC) is increasingly essential in technology development of large-scale systems on information, communication, computer, and cybernetics. It is because innovation always emerges where those disciplines meet interactively to form interdisciplinary area, embedding full of tacit knowledge. This fact motivates us to investigate how to maximize dynamics of knowledge creation in organizational members at daily tasks for innovation in science and technology. The case study of ETS-8 Spacecraft Development is given here to examine the aspect of OKC.
Portable Rule Extraction Method for Neural Network Decisions Reasoning
Darius PLIKYNAS, Leonas SIMANAUSKAS, Ausra Rasteniene
Neural network (NN) methods are sometimes useless in practical applications, because they are not properly tailored to the particular market’s needs. We focus thereinafter specifically on financial market applications. NNs have not gained full acceptance here yet. One of the main reasons is the “Black Box” problem (lack of the NN decisions explanatory power). There are though some NN decisions rule extraction methods like decompositional, pedagogical or eclectic, but they suffer from low portability of the rule extraction technique across various neural net architectures, high level of granularity, algorithmic sophistication of the rule extraction technique etc. The authors propose to eliminate some known drawbacks using an innovative extension of the pedagogical approach. The idea is exposed by the use of a widespread MLP neural net (as a common tool in the financial problems’ domain) and SOM (input data space clusterization). The feedback of both nets’ performance is related and targeted through the iteration cycle by achievement of the best matching between the decision space fragments and input data space clusters. Three sets of rules are generated algorithmically or by fuzzy membership functions. Empirical validation of the common financial benchmark problems is conducted with an appropriately prepared software solution.
Reinforcement Learning for a New Piano Mover
Yuko Ishiwaka, Tomohiro Yoshida, Yukinori Kakazu
We attempt to achieve corporative behavior of autonomous decentralized agents constructed via Q-Learning, which is a type of reinforcement learning. As such, in the present paper, we examine the piano mover’s problem. We propose a multi-agent architecture that has a training agent, learning agents and intermediate agent. Learning agents are heterogeneous and can communicate with each other. The movement of an object with three kinds of agent depends on the composition of the actions of the learning agents. By learning its own shape through the learning agents, avoidance of obstacles by the object is expected. We simulate the proposed method in a two-dimensional continuous world. Results obtained in the present investigation reveal the effectiveness of the proposed method.
Self-Organized Synchronization Phenomena in Spatiotemporal Coupled Oscillator Model for Emergent Systems
The author proposes a spatiotemporal coupled Lorenz model with an excitatory-excitatory connection or an excitatory-inhibitory connection, which consists of three temporal coupling coefficients c1,2,3 and three spatial coupling coefficients d1,2,3. This model is an emergent device that has synchronized three nonlinear oscillators.
In this study, the author discovers that self-organized various phase transition phenomena appear in this model in changing the values of
c1,2,3 and d1,2,3 in the case of using the excitatory-inhibitory connection. Proposed model also concerns the neural population model
for autonomous agent.
Software aspects of qualification in the SafeAir II Project
Philippe Baufreton, Cyrille Rosay
The SafeAir II project is a European Commission project that contributed to “Dependability in Services and Technologies”. It implements a comprehensive open environment that help keeping the validation effort needed to achieve the present safety level of the embedded software systems within reasonable costs despite their increasing size and complexity.
The paper describes the Software aspects of qualification in the Project.
Spectral Subtraction Approach for Interference Reduction of MIMO Channel Wireless Systems
Tomohiro Ono, Takahiro Baba, Shigeo Wada
In this paper, a generalized spectral subtraction approach for reducing additive impulsive noise, narrowband signals, white Gaussian noise and DS-CDMA interferences in MIMO channel DS-CDMA wireless communication systems is investigated. The interference noise reduction or suppression is essential problem in wireless mobile communication systems to improve the quality of communication. The spectrum subtraction scheme is applied to the interference noise reduction problems for noisy MIMO channel systems. The interferences in space and time domain signals can effectively be suppressed by selecting threshold values, and the computational load with the FFT is not large. Further, the fading effects of channel are compensated by spectral modification with the spectral subtraction process. In the simulations, the effectiveness of the proposed methods for the MIMO channel DS-CDMA is shown to compare with the conventional MIMO channel DS-CDMA.