pinecone/core-2020-05-10-deduplication huggingface dataset:
Testing real-time systems using TINA

The paper presents a technique for model-based black-box conformance testing of real-time systems using the Time Petri Net Analyzer TINA. Such test suites are derived from a prioritized time Petri net composed of two concurrent sub-nets specifying respectively the expected behaviour of the system under test and its environment.We describe how the toolbox TINA has been extended to support automatic generation of time-optimal test suites. The result is optimal in the sense that the set of test cases in the test suite have the shortest possible accumulated time to be executed. Input/output conformance serves as the notion of implementation correctness, essentially timed trace inclusion taking environment assumptions into account. Test cases selection is based either on using manually formulated test purposes or automatically from various coverage criteria specifying structural criteria of the model to be fulfilled by the test suite. We discuss how test purposes and coverage criterion are specified in the linear temporal logic SE-LTL, derive test sequences, and assign verdicts
Search for More Declarativity

Good tree search algorithms are a key requirement for inference
engines of rule languages. As Prolog exemplifies, inference engines
based on traditional uninformed search methods with their well-known
deficiencies are prone to compromise declarativity, the primary concern
of rule languages. The paper presents a new family of uninformed search
algorithms that combine the advantages of the traditional ones while
avoiding their shortcomings. Moreover, the paper introduces a formal
framework based on partial orderings, which allows precise and elegant
analysis of such algorithms.
Iterative Refinement of Reverse-Engineered Models by Model-Based Testing

This paper presents an iterative technique to accurately reverse engineer models of the behaviour of software systems. A he novelty of the approach is the fact that it uses model-based testing to refine the hypothesised model. The process call in principle be entirely automated, and only requires a very small amount of manually generated information to begin with. We have implemented the technique for use in the development of Erlang systems and describe both the methodology as well as our implementation.Peer-reviewedPost-print2nd World Congress on Formal Methods/16th International Symposium on Formal Methods (FM 2009), Eindhoven, Netherlands, 2-6 November 200
A Metric Encoding for Bounded Model Checking (extended version)

In Bounded Model Checking both the system model and the checked property are
translated into a Boolean formula to be analyzed by a SAT-solver. We introduce
a new encoding technique which is particularly optimized for managing
quantitative future and past metric temporal operators, typically found in
properties of hard real time systems. The encoding is simple and intuitive in
principle, but it is made more complex by the presence, typical of the Bounded
Model Checking technique, of backward and forward loops used to represent an
ultimately periodic infinite domain by a finite structure. We report and
comment on the new encoding technique and on an extensive set of experiments
carried out to assess its feasibility and effectiveness
An Optimal Self-Stabilizing Firing Squad

Consider a fully connected network where up to $t$ processes may crash, and
all processes start in an arbitrary memory state. The self-stabilizing firing
squad problem consists of eventually guaranteeing simultaneous response to an
external input. This is modeled by requiring that the non-crashed processes
"fire" simultaneously if some correct process received an external "GO" input,
and that they only fire as a response to some process receiving such an input.
This paper presents FireAlg, the first self-stabilizing firing squad algorithm.
  The FireAlg algorithm is optimal in two respects: (a) Once the algorithm is
in a safe state, it fires in response to a GO input as fast as any other
algorithm does, and (b) Starting from an arbitrary state, it converges to a
safe state as fast as any other algorithm does.Comment: Shorter version to appear in SSS0
Separation of Circulating Tokens

Self-stabilizing distributed control is often modeled by token abstractions.
A system with a single token may implement mutual exclusion; a system with
multiple tokens may ensure that immediate neighbors do not simultaneously enjoy
a privilege. For a cyber-physical system, tokens may represent physical objects
whose movement is controlled. The problem studied in this paper is to ensure
that a synchronous system with m circulating tokens has at least d distance
between tokens. This problem is first considered in a ring where d is given
whilst m and the ring size n are unknown. The protocol solving this problem can
be uniform, with all processes running the same program, or it can be
non-uniform, with some processes acting only as token relays. The protocol for
this first problem is simple, and can be expressed with Petri net formalism. A
second problem is to maximize d when m is given, and n is unknown. For the
second problem, the paper presents a non-uniform protocol with a single
corrective process.Comment: 22 pages, 7 figures, epsf and pstricks in LaTe
CLON: overlay networks and gossip protocols for cloud environments

Although epidemic or gossip-based multicast is a robust and scalable approach to reliable data dissemination, its inherent redundancy results in high resource consumption on both links and nodes. This problem is aggravated in settings that have costlier or resource constrained links as happens in Cloud Computing infrastructures composed by several interconnected data centers across the globe.

The goal of this work is therefore to improve the efficiency of gossip-based reliable multicast by reducing the load imposed on those constrained links. In detail, the proposed clon protocol combines an overlay that gives preference to local links and a dissemination strategy that takes into account locality. Extensive experimental evaluation using a very large number of simulated nodes shows that this results in a reduction of traffic in constrained links by an order of magnitude, while at the same time preserving the resilience properties that make gossip-based protocols so attractive.HP Labs Innovation Research Award, project DC2MS (IRA/CW118736
Automatic Selection of Object Recognition Methods using Reinforcement Learning

Studies in Computational Intelligence. Springer. Volume 262, Dedicated to the Memory of Professor Ryszard S.MichalskiSelecting which algorithms should be used by a mobile robot computer vision system is a decision that is usually made a priori by the system developer, based on past experience and intuition, not systematically taking into account information that can be found in the images and in the visual process itself to learn which algorithm should be used, in execution time. This paper presents a method that uses\ud
Reinforcement Learning to decide which algorithm should be used to recognize objects\ud
seen by a mobile robot in an indoor environment, based on simple attributes\ud
extracted on-line from the images, such as mean intensity and intensity deviation.\ud
Two state-of-the-art object recognition algorithms can be selected: the constellation\ud
method proposed by Lowe together with its interest point detector and descriptor,\ud
the Scale-Invariant Feature Transform and Nist´er and Stew´enius Vocabulary Tree\ud
approach. A set of empirical evaluations was conducted using a image database acquired\ud
with a mobile robot in an indoor environment, and results obtained shows\ud
that the approach adopted here is very promising.This work has been partially funded by the FI grant and the BE grant from the AGAUR, the 2005-SGR-00093 project, supported by the Generalitat de Catalunya, the MIDCBR project grant TIN 2006-15140-C03-01 and FEDER funds. Reinaldo Bianchi is supported by CNPq grant 201591/2007-3.Peer reviewe
Monte-Carlo tree search in poker using expected reward distributions

acceptance rate = 25%We investigate the use of Monte-Carlo Tree Search (MCTS) within the field of computer Poker, more specifically No-Limit Texas Hold'em.  The hidden information in Poker results in so called miximax game trees where opponent decision nodes have to be modeled as chance nodes.  The probability distribution in these nodes is modeled by an opponent model that predicts the actions of the opponents.  
We propose a modification of the standard MCTS selection and backpropagation strategies that explicitly model and exploit the uncertainty of sampled expected values. The new strategies are evaluated as a part of a complete Poker bot that is, to the best of our knowledge, the first exploiting no-limit Texas Hold'em bot that can play at a reasonable level in games of more than two players.status: publishe
Improving adaptive bagging methods for evolving data streams

We propose two new improvements for bagging methods on evolving data streams. Recently, two new variants of Bagging were proposed: ADWIN Bagging and Adaptive-Size Hoeffding Tree (ASHT) Bagging. ASHT Bagging uses trees of different sizes, and ADWIN Bagging uses ADWIN as a change detector to decide when to discard underperforming ensemble members. We improve ADWIN Bagging using Hoeffding Adaptive Trees, trees that can adaptively learn from data streams that change over time. To speed up the time for adapting to change of Adaptive-Size Hoeffding Tree (ASHT) Bagging, we add an error change detector for each classifier. We test our improvements by performing an evaluation study on synthetic and real-world datasets comprising up to ten million examples
Conditional density estimation with class probability estimators

Many regression schemes deliver a point estimate only, but often it is useful or even essential to quantify the uncertainty inherent in a prediction. If a conditional density estimate is available, then prediction intervals can be derived from it. In this paper we compare three techniques for computing conditional density estimates using a class probability estimator, where this estimator is applied to the discretized target variable and used to derive instance weights for an underlying univariate density estimator; this yields a conditional density estimate. The three density estimators we compare are: a histogram estimator that has been used previously in this context, a normal density estimator, and a kernel estimator. In our experiments, the latter two deliver better performance, both in terms of cross-validated log-likelihood and in terms of quality of the resulting prediction intervals. The empirical coverage of the intervals is close to the desired confidence level in most cases. We also include results for point estimation, as well as a comparison to Gaussian process regression and nonparametric quantile estimation
A Simulation Model Articulation of the REA Ontology

This paper demonstrates how the REA enterprise ontology can be used to construct simulation models for business processes, value chains and collaboration spaces in supply chains. These models support various high-level and operational management simulation applications, e.g. the analysis of enterprise sustainability and day-to-day planning. First, the basic constructs of the REA ontology and the ExSpect modelling language for simulation are introduced. Second, collaboration space, value chain and business process models and their conceptual dependencies are shown, using the ExSpect language. Third, an exhibit demonstrates the use of value chain models in predicting the financial performance of an enterprise
On the use of i* for architecting hybrid systems: a method and an evaluation report

The architectural definition of hybrid software systems is a challenging problem that demands to reconcile stakeholders’ strategic needs and components marketplace, whilst defining an appropriate set of services. We have defined a method called DHARMA based on the i* framework. The goal\ud
of this paper is to present an experience report about the use of i* in large-scale\ud
projects. We provide two different viewpoints: the viewpoint of the stakeholder\ud
and the viewpoint of the modeller. Apart from general lessons learned, we also provide some insights about the use of i* in the specific context of architecting\ud
hybrid systems using DHARMA.Peer ReviewedPostprint (author’s final draft
EMon : embodied monitorization

Serie : Lecture Notes in Computer Science, vol. 5859The amount of seniors in need of constant care is rapidly rising: an
evident consequence of population ageing. There are already some
monitorization environments which aim to monitor these persons while they
remain at home. This, however, although better than delocalizing the elder to
some kind of institution, may not still be the ideal solution, as it forces them to
stay inside the home more than they wished, as going out means lack of
accompaniment and a consequent sensation of fear. In this paper we propose
EMon: a monitorization device small enough to be worn by its users, although
powerful enough to provide the higher level monitorization systems with vital
information about the user and the environment around him. We hope to allow
the representation of an intelligent environment to move with its users, instead
of being static, mandatorily associated to a single physical location. The first
prototype of EMon, as presented in this paper, provides environmental data as
well as GPS coordinates and pictures that are useful to describe the context of
its user
Sensor field: a computational model

We introduce a formal model of computation for networks of tiny artifacts, the static synchronous sensor field model (SSSF) which\ud
considers that the devices communicate through a fixed communication graph and interact with the environment through input/output data streams. We analyze the performance of SSSFs solving two sensing problems the Average Monitoring and the Alerting problems. For constant memory SSSFs we show that the set of recognized languages is contained in DSPACE(n + m) where n is the number of nodes of the communication graph and m its number of edges. Finally we explore the capabilities of SSSFs having sensing and additional non-sensing constant memory devices.Peer ReviewedPostprint (published version
On the design of forgiving biometric security systems

This is a conference paper, the original publication is available at www.springerlink.com, further information can be obtained from http://dx.doi.org/10.1007/978-3-642-05437-2_1This work aims to highlight the fundamental issue surrounding biometric security\ud
systems: it's all very nice until a biometric is forged, but what do we do after that? Granted,\ud
biometric systems are by physical nature supposedly much harder to forge than other factors\ud
of authentication since biometrics on a human body are by right unique to the particular human\ud
person. Yet it is also due to this physical nature that makes it much more catastrophic\ud
when a forgery does occur, because it implies that this uniqueness has been forged as well,\ud
threatening the human individuality; and since crime has by convention relied on identifying\ud
suspects by biometric characteristics, loss of this biometric uniqueness has devastating consequences\ud
on the freedom and basic human rights of the victimized individual. This uniqueness\ud
forgery implication also raises the motivation on the adversary to forge since a successful\ud
forgery leads to much more impersonation situations when biometric systems are used i.e.\ud
physical presence at crime scenes, identi cation and access to security systems and premises,\ud
access to  nancial accounts and hence the ability to use the victim's  nances. Depending on\ud
the gains, a desperate highly motivated adversary may even resort to directly obtaining the\ud
victim's biometric parts by force e.g. severing the parts from the victim's body; this poses\ud
a risk and threat not just to the individual's uniqueness claim but also to personal safety\ud
and well being. One may then wonder if it is worth putting one's assets, property and safety\ud
into the hands of biometrics based systems when the consequences of biometric forgery far\ud
outweigh the consequences of system compromises when no biometrics are used
Engineering social reality with inheritance relations

In systems based on organisational specifications a reoccurring problem remains to be solved in the disparity between the level of abstractness of the organisational concepts and the concepts used in the implementation. Organisational specifications (deliberately) abstract from general practice, which creates a need to relate the abstract concepts used in the specification to concrete ones used in the practice. The prevailing solution for this problem is the use of counts-as statements.\ud
However, current implementations of counts-as view the relations expressed\ud
in this notion as static ontological classifications, which presents problems in dynamic environments where the meaning of abstract concepts can change over time. This limitation has already been solved in\ud
complex formal theoretical investigations, but the results of that study are far too complex to make a practical implementation. This paper investigates the limitations of current implementations of counts-as, and\ud
proposes a more flexible implementation based on the use of inheritance relations.Peer ReviewedPostprint (published version
Polynomial kernels for 3-leaf power graph modification problems

A graph G=(V,E) is a 3-leaf power iff there exists a tree T whose leaves are
V and such that (u,v) is an edge iff u and v are at distance at most 3 in T.
The 3-leaf power graph edge modification problems, i.e. edition (also known as
the closest 3-leaf power), completion and edge-deletion, are FTP when
parameterized by the size of the edge set modification. However polynomial
kernel was known for none of these three problems. For each of them, we provide
cubic kernels that can be computed in linear time for each of these problems.
We thereby answer an open problem first mentioned by Dom, Guo, Huffner and
Niedermeier (2005).Comment: Submitte
On the maximal number of cubic subwords in a string

We investigate the problem of the maximum number of cubic subwords (of the
form $www$) in a given word. We also consider square subwords (of the form
$ww$). The problem of the maximum number of squares in a word is not well
understood. Several new results related to this problem are produced in the
paper. We consider two simple problems related to the maximum number of
subwords which are squares or which are highly repetitive; then we provide a
nontrivial estimation for the number of cubes. We show that the maximum number
of squares $xx$ such that $x$ is not a primitive word (nonprimitive squares) in
a word of length $n$ is exactly $\lfloor \frac{n}{2}\rfloor - 1$, and the
maximum number of subwords of the form $x^k$, for $k\ge 3$, is exactly $n-2$.
In particular, the maximum number of cubes in a word is not greater than $n-2$
either. Using very technical properties of occurrences of cubes, we improve
this bound significantly. We show that the maximum number of cubes in a word of
length $n$ is between $(1/2)n$ and $(4/5)n$. (In particular, we improve the
lower bound from the conference version of the paper.)Comment: 14 page
Towards self-adaptation for dependable service oriented systems

Increasingly complex information systems operating in dynamic environments ask for management policies able to deal intelligently and autonomously with problems and tasks. An attempt to deal with these aspects can be found in the Service-Oriented Architecture (SOA) paradigm that foresees the creation of business applications from independently developed services, where services and applications build up complex dependencies. Therefore the dependability of SOA systems strongly depends on their ability to self-manage and adapt themselves to cope with changes in the operating conditions and to meet the required dependability with a minimum of resources. In this paper we propose a model-based approach to the realization of self-adaptable SOA systems, aimed at the fulfillment of dependability requirements. Specifically, we provide a methodology driving the system adaptation and we discuss the architectural issues related to its implementation. To bring this approach to fruition, we developed a prototype tool and we show the results that can be achieved with a simple example
Filter banks for hyperspectral pixel classification of satellite images

Satellite hyperspectral  imaging deals with heterogenous images containing different texture areas. Filter banks are frequently used to characterize textures in the image performing pixel classification. This filters are designed using
Different scales and orientations in order to cover all areas in the frequential domain. This work is aimed at studying the influence of the different scales used in the analysis, comparing texture analysis theory with hyperspectral imaging necessities. To pursue this, Gabor filters over complex planes and opponent features are taken into account and also compared in the feature extraction proces
Color image registration under illumination changes

The estimation of parametric global motion has had a significant attention
during the last two decades, but despite the great efforts invested, there
are still open issues. One of the most important ones is related to the ability to recover
large deformation between images in the presence of illumination changes
while kipping accurate estimates. Illumination changes in color images are another
important open issue. In this paper, a Generalized least squared-based motion
estimator is used in combination with color image model to allow accurate
estimates of global motion between two color images under the presence of large
geometric transformation and illumination changes. Experiments using challenging
images have been performed showing that the presented technique is feasible
and provides accurate estimates of the motion and illumination parameter
Towards an Iterative Algorithm for the Optimal Boundary Coverage of a 3D Environment

This paper presents a new optimal algorithm for locating a set of sensors in 3D able to see the boundaries of a polyhedral environment. Our approach is iterative and is based on a lower bound on the sensors' number and on a restriction of the original problem requiring each face to be observed in its entirety by at least one sensor. The lower bound allows evaluating the quality of the solution obtained at each step, and halting the algorithm if the solution is satisfactory. The algorithm asymptotically converges to the optimal solution of the unrestricted problem if the faces are subdivided into smaller part
Dealing with inaccurate face detection for automatic gender recognition with partially occluded faces

Gender recognition problem has not been extensively studied in situations where the face cannot be accurately detected and it also can be partially occluded. In this contribution, a comparison of several
characterisation methods of the face is presented and they are evaluated in four different experiments that simulate the previous scenario. Two of the characterization techniques are based on histograms, LBP and local contrast values, and the other one is a new kind of features, called Ranking Labels, that provide spatial information. Experiments have proved Ranking Labels description is the most reliable in inaccurate situation