The service-oriented environment offers the opportunity to create new applications, by combining existing applications offered as services, in order to react to the business' increasing pressure of quickly deliver...
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The service-oriented environment offers the opportunity to create new applications, by combining existing applications offered as services, in order to react to the business' increasing pressure of quickly delivering new applications. With a large number of web services offering the same functionality, choosing the web services that meet best the client's quality of service (QoS) requirements is a very important task. We introduce a QoS-aware end to end web service composition approach that handles all the stages from the web service discovery step, to the actual binding of the services. This approach uses our method of expressing nonfunctional preferences, which requires minimal effort on the part of the clients, but offers great flexibility in managing trade-offs. We define a QoS preferences ontology and use it in our semantic web service selection to choose an initial candidate list of services for every task in the orchestration model. Then, one concrete service is chosen from each candidate list and is boand to the corresponding task. This step involves computing and comparing the aggregated QoS of the resulting composite services. The selection is performed using a genetic algorithm.
Information Security Assurance implies ensuring the integrity, confidentiality and availability of critical assets for an organization. The large amount of events to monitor in a fluid system in terms of topology and ...
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Information Security Assurance implies ensuring the integrity, confidentiality and availability of critical assets for an organization. The large amount of events to monitor in a fluid system in terms of topology and variety of new hardware or software, overwhelms monitoring controls. Furthermore, the multi-facets of cyber threats today makes it difficult even for security experts to handle and keep up-to-date. Hence, automatic "intelligent" tools are needed to address these issues. In this paper, we describe a `work in progress' contribution on intelligent based approach to mitigating security threats. The main contribution of this work is an anomaly based IDS model with active response that combines artificial immune systems and swarm intelligence with the SVM classifier. Test results for the NSL-KDD dataset prove the proposed approach can outperform the standard classifier in terms of attack detection rate and false alarm rate, while reducing the number of features in the dataset.
A router exploiting the active queue management can drop arriving packets even if its buffer is not full. This is meant to notify the TCP senders to reduce their sending rates. One type of the active queue management ...
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A router exploiting the active queue management can drop arriving packets even if its buffer is not full. This is meant to notify the TCP senders to reduce their sending rates. One type of the active queue management is based on dropping arriving packets with probability that is a function of the queue size observed upon packet arrival. Although the queuing models of algorithms of this type have been developed, they present some numerical difficulties that have to be overcome in order to be practically usable, e.g. they require inverting large matrices. In this paper we compare several inversion methods with respect to their applicability in the parameterization of the dropping mechanism of the active queue management. In addition to their implementations on a CPU, we also check their performance when implemented on a graphics processor unit.
Large scale, cyber-infrastructure systems include a large base of heterogeneous data sources, geographically distributed. Cloud storage services can be an ideal candidate for storing all these data. However, it is dif...
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Large scale, cyber-infrastructure systems include a large base of heterogeneous data sources, geographically distributed. Cloud storage services can be an ideal candidate for storing all these data. However, it is difficult to find the optimal solution in order to select a set of storage providers, with respect to different multiple objectives of this type of systems, such as cost optimization, budget constraints, Quality of Service (QoS), load balancing etc. In this paper, we study the multi-objective optimization problem for storage service selection with budget constraints. We start from a real world case scenario and build our mathematical model for the optimization problem. Then we propose a linear programming technique to find a near optimal solution for the service selection problem.
Current concerns about data privacy have lead to increased focus on data anonymization methods. Differential privacy is a new mechanism that offers formal guarantees about anonymization strength. The main challenge wh...
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Current concerns about data privacy have lead to increased focus on data anonymization methods. Differential privacy is a new mechanism that offers formal guarantees about anonymization strength. The main challenge when using differential privacy consists in the difficulty in designing correct algorithms when operating on complex data types. One such data type is sequential data, which is used to model many actions like location or browsing history. We propose a new differential privacy algorithm for short sequence counting called Recursive Budget Allocation (RBA). We show that RBA leads to lower relative errors than current state of the art techniques. In addition, it can also be used to improve relative errors for generic differential privacy algorithms which operate on data trees.
This paper presents a thorough analysis of the behavior of a bio-inspired model to care for casualties in a disaster. The model was proposed by the authors in a previous paper and a simulation based on it was performe...
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This paper presents a thorough analysis of the behavior of a bio-inspired model to care for casualties in a disaster. The model was proposed by the authors in a previous paper and a simulation based on it was performed and evaluated. Here, we analyze the evolution of the system and the impact that various model parameters can have over it. Once the behavior is well understood, we can then focus our research on certain groups of parameter adjustments so that with a minimum implementation cost to achieve a maximum benefit in terms of saved lives.
The paper deals with a mathematical model of switched reluctance motor, with stator of on induction motor. The parameters of this model were determined experimentally. The motor winding were supplied from different fr...
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The paper deals with a mathematical model of switched reluctance motor, with stator of on induction motor. The parameters of this model were determined experimentally. The motor winding were supplied from different frequencies AC voltage source. Based on the measurements of current and voltage equivalent resistance and inductance of motor windings as a function of frequency were determined using the least squares method. The measurements for different rotation angle of the rotor were carried out. The measured resistance value was significantly higher than the value of the winding resistance because of “iron losses”. The losses are modeled as the losses of a single turn wound on the rotor core, representing the eddy currents circuit. The losses are dependent on the angle of the rotor rotation relative to the stator. Based on the relationship between the equivalent inductance and resistance of the motor measured and specified of the model, the parameters were determined.
The continuous fermentation processes involving yeast Saccharomyces cerevisiae or bacterium Zymomonas mobilis often exhibit oscillatory behavior. Because, the oscillatory mode of operation may lead to higher or lower ...
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The continuous fermentation processes involving yeast Saccharomyces cerevisiae or bacterium Zymomonas mobilis often exhibit oscillatory behavior. Because, the oscillatory mode of operation may lead to higher or lower average ethanol concentrations, hence, there is a natural need to control this behavior. The idea presented in this paper is based on the use of a mixture of two substrates that are continuously fed into the reactor chamber and the continuous fermentation process is described by an unstructured mathematical model with a product inhibition on cell growth. The relative contribution of both substrates will be treated as a new control variable. Moreover, it is assumed that the microorganisms exhibit diauxic growth and that the occurrence of the oscillatory behavior is related to a time delay in the response of cells to changes in the environment. From the bifurcation analysis of the system, it is shown that an appropriate ratio of both substrates to the mixture allows for induction and elimination of the oscillatory behavior.
Medical centres are obliged to store past medical records, including the results of quality assurance (QA) tests of the medical equipment, which is especially useful in checking reproducibility of medical devices and ...
Medical centres are obliged to store past medical records, including the results of quality assurance (QA) tests of the medical equipment, which is especially useful in checking reproducibility of medical devices and procedures. Analysis of multivariate time series is an important part of quality control of NMR data. In this work we proposean anomaly detection tool based on Reiteration of Hankel Singular Value Decomposition method. The presented method was compared with external software and authors obtained comparable results.
Using the coefficients matrices we obtained upper and lower exact boundaries of mobility of Lyapunov, Perron, upper and lower Bohl exponents for linear difference systems under small perturbations of the coefficients ...
Using the coefficients matrices we obtained upper and lower exact boundaries of mobility of Lyapunov, Perron, upper and lower Bohl exponents for linear difference systems under small perturbations of the coefficients matrices.
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