Backward validation of communicating complex state machines in web services environments

Communicating Finite State Machines (CFSM) lack the high level syntactic and structural abstractions of Communicating Complex State Machines (CCSM), such as nesting and encapsulation, to model highly complex protocols that are likely to arise in web services environments. The incorporation of these features in a protocol specification model would require the design of a new validation technique to efficiently check for protocol errors, such as deadlocks and non-reachable transitions. A reachability graph is used to represent the execution states of the protocol and to verify their consistency. In this paper, we propose a new validation technique for protocols modeled with complex FSM, called RLRA (Reverse Leaping Reachability Analysis), which enables the detection of all deadlock errors. It is a backtracking approach, which first identifies an initial set of suspected states, those possibly containing deadlocks, then refines this set to those likely to cause deadlock, and finally backtracks through the graph while checking for errors until the root state of the protocol is reached. Leap graphs are employed to prune the number of execution states examined, and thereby mitigate the combinatorial explosion of the state space. Extensive tests and comparisons were performed, which show the effectiveness of our technique.     

Facility location with double-peaked preferences

We study the problem of locating a single facility on a real line based on the reports of self-interested agents, when agents have double-peaked preferences, with the peaks being on opposite sides of their locations. We observe that double-peaked preferences capture real-life scenarios and thus complement the well-studied notion of single-peaked preferences. As a motivating example, assume that the government plans to build a primary school along a street; an agent with single-peaked preferences would prefer having the school built exactly next to her house. However, while that would make it very easy for her children to go to school, it would also introduce several problems, such as noise or parking congestion in the morning. A 5-min walking distance would be sufficiently far for such problems to no longer be much of a factor and at the same time sufficiently close for the school to be easily accessible by the children on foot. There are two positions (symmetrically) in each direction and those would be the agent’s two peaks of her double-peaked preference. Motivated by natural scenarios like the one described above, we mainly focus on the case where peaks are equidistant from the agents’ locations and discuss how our results extend to more general settings. We show that most of the results for single-peaked preferences do not directly apply to this setting, which makes the problem more challenging. As our main contribution, we present a simple truthful-in-expectation mechanism that achieves an approximation ratio of \(1+b/c\) for both the social and the maximum cost, where b is the distance of the agent from the peak and c is the minimum cost of an agent. For the latter case, we provide a 3 / 2 lower bound on the approximation ratio of any truthful-in-expectation mechanism. We also study deterministic mechanisms under some natural conditions, proving lower bounds and approximation guarantees. We prove that among a large class of reasonable strategyproof mechanisms, there is no deterministic mechanism that outperforms our truthful-in-expectation mechanism. In order to obtain this result, we first characterize mechanisms for two agents that satisfy two simple properties; we use the same characterization to prove that no mechanism in this class can be group-strategyproof.     

Extraction and fractionation of wheat flour proteins

With the aid of a 1.5% sodium dodecyl sulphate solution (SDS) the proteins of two Dutch wheat flours were separated into an SDS-soluble and an SDS-insoluble fraction. The SDS-soluble fraction was fractionated with the aid of ethanol precipitation and gel filtration chromatography into albumins, globulins, gliadins, glutenins II and III, and glutelins I, II, III and IV. The SDS-insoluble proteinaceous material was separated into glutenins I and glycoproteins. The protein fractions were identified with the aid of SDS-polyacrylamide gel electrophoresis and amino acid analysis. The glutenins I and II consist of A, B and C subunits. Their molecular weights ranged from about 600 000 to 10 million. The glutenins III consist only of B and C subunits and their molecular weights ranged from 300 000 to 600 000. A hypothesis explains how the glutenins III are the precursors for glutenins I and II and how they contribute to gluten's structure. The glutelins I consist of α β and γ subunits and their molecular weights ranged from about 600 000 to several millions. The glutelins II consist also of α β and γ subunits with a molecular weight of about 300 000 to 600 000, while the molecular weights of the glutelins III and IV ranged from 10 000 to 200 000. All glutelins are insoluble in 70 % aqueous ethanol and 5 M urea, but soluble in SDS and 0.1M NaOH. Only the glutelins III and IV are soluble in 0.1M HAc. The globulins consist of a heterogeneous fraction of components, their molecular weights arranged from 98 000 to 10 000. The gliadins form a heterogeneous but homologous group of polypeptides with an average molecular weight of 35 000. The albumins consist of components with molecular weights lower than 15 000.     

Exact Knowledge Hiding through Database Extension

In this paper, we propose a novel, exact border-based approach that provides an optimal solution for the hiding of sensitive frequent itemsets by (i) minimally extending the original database by a synthetically generated database part - the database extension, (ii) formulating the creation of the database extension as a constraint satisfaction problem, (iii) mapping the constraint satisfaction problem to an equivalent binary integer programming problem, (iv) exploiting underutilized synthetic transactions to proportionally increase the support of non-sensitive itemsets, (v) minimally relaxing the constraint satisfaction problem to provide an approximate solution close to the optimal one when an ideal solution does not exist, and (vi) by using a partitioning in the universe of the items to increase the efficiency of the proposed hiding algorithm. Extending the original database for sensitive itemset hiding is proved to provide optimal solutions to an extended set of hiding problems compared to previous approaches and to provide solutions of higher quality. Moreover, the application of binary integer programming enables the simultaneous hiding of the sensitive itemsets and thus allows for the identification of globally optimal solutions.     

Effective and efficient classification on a search-engine model

Traditional document classification frameworks, which apply the learned classifier to each document in a corpus one by one, are infeasible for extremely large document corpora, like the Web or large corporate intranets. We consider the classification problem on a corpus that has been processed primarily for the purpose of searching, and thus our access to documents is solely through the inverted index of a large scale search engine. Our main goal is to build the “best” short query that characterizes a document class using operators normally available within search engines. We show that surprisingly good classification accuracy can be achieved on average over multiple classes by queries with as few as 10 terms. As part of our study, we enhance some of the feature-selection techniques that are found in the literature by forcing the inclusion of terms that are negatively correlated with the target class and by making use of term correlations; we show that both of those techniques can offer significant advantages. Moreover, we show that optimizing the efficiency of query execution by careful selection of terms can further reduce the query costs. More precisely, we show that on our set-up the best 10-term query can achieve 93% of the accuracy of the best SVM classifier (14,000 terms), and if we are willing to tolerate a reduction to 89% of the best SVM, we can build a 10-term query that can be executed more than twice as fast as the best 10-term query.     

Internet of things for healthcare monitoring applications based on RFID clustering scheme

Wireless Networks - COVID-19 surprised the whole world by its quick and sudden spread. Coronavirus pushes all community sectors: government, industry, academia, and nonprofit organizations to take...     

Optical S-ALOHA/CDMA systems for multirate applications: architecture, performance evaluation, and system stability

In this paper, a new multirate optical network based on a hybrid slotted-ALOHA (S-ALOHA)/overlapped code division multiple access (O-CDMA) system is proposed as an effective way of integrating multiclass traffic. The key issue in this proposal is to exploit the potential of the optical O-CDMA using fiber Bragg gratings when jointly used with the S-ALOHA protocol in a link layer. The newly proposed system is modeled using a general Markov chain from which both the system throughput and the average packet delay are derived. The system stability passing through a general finite user model is also envisaged. The system is then compared to the classical S-ALOHA/variable processing gain (VPG) CDMA system. Numerical results show that the proposed system outperforms the latter one, especially at high transmission rates. In addition, stability measures demonstrate that the overlapped system tends to be more stable than the VPG system.     

Stress relaxation behavior and low cycle fatigue behavior of bulk SAC 305

Bulk Sn_96.5Ag₃Cu_0.5 samples were mechanically tested to investigate the effect of temperature, frequency and applied stress on the low cycle fatigue and stress relaxation behavior and the corresponding microstructure. Samples were tested under a variety of parameters including applied stresses between 8 and 80 MPa, temperatures of 25, 50, 100 and 150 °C and frequencies of 1, 0.1 and 0.01 Hz, respectively. Samples used for the stress relaxation behavior exhibited plastic behavior with increased softening behavior with increased stress levels, increased temperature and lower frequencies. Bayesian analysis revealed that stress relaxation behavior could be expressed in general by the following expression: ?σ = AN ^B In the previous expression, Bayesian analysis showed that the testing frequency has an exponential dependency while the temperature has a power law dependency on the parameters A and b. The results of the low cycle fatigue study showed that life decreased with increased applied stress, decreased frequency and increased temperature. Bayesian analysis revealed that the low cycle fatigue behavior could be described by the following expression: ?σ = G(logN) ^m . Additionally, Bayesian analysis showed that the testing frequency and temperature both have a power law dependency on the parameters G and m.     

Band depth analysis of CHRIS/PROBA data for the study of a Mediterranean natural ecosystem. Correlations with leaf optical properties and ecophysiological parameters

The absorption feature approach was used in CHRIS multiangular hyperspectral data in order to investigate its potential for ecosystem remote sensing. For that purpose, CHRIS images in mode 1 were acquired throughout a two-year period for a Mediterranean ecosystem dominated by the semi-deciduous shrub Phlomis fruticosa. During each acquisition, coincident in situ Leaf spectra and ecophysiological measurements (Leaf Area Index, leaf pigment content and leaf water potential) were conducted. After data preprocessing, absorption feature information was calculated for both CHRIS and Leaf spectra for the whole spectrum. Three common characteristic absorption features within the spectral areas 450-550 nm, 550-750 nm and 900-1000 nm were detected. Each spectral area was then examined separately and four characteristic parameters were calculated that described the pattern, magnitude and position of the maximum absorption. Correlations between CHRIS and Leaf spectra for each date and viewing angle (VA) were then conducted. All correlations, either on full continuum removed spectra or on spectral areas, showed high coefficients of determination, especially (i) in higher observation angles (VA + 55), (ii) during the wet season and (iii) in strong absorptions such as the “red absorption”. Subsequently, correlations between CHRIS and Leaf absorption parameters of selected spectral areas with field-measured ecophysiological parameters were examined. Ecophysiological parameters proved to be highly correlated to CHRIS and Leaf absorption parameters in magnitude and/or pattern of the absorption feature and less in wavelength of the maximum absorption. CHRIS VAs +/− 36 showed the highest correlations although the type of relation, linear or nonlinear, was not conclusive. Finally, a first comparison between narrowband spectral indices and absorption features in correlations with ecophysiological parameters showed that both methods provide significant and comparable results, with oblique angles showing best performance. However, ecophysiological parameters are generally better predicted linearly by narrowband spectral indices issued from CHRIS, with most significant differences appearing on pigments absorbing mainly within 450-550 nm.