ppxscal/embedding_network huggingface dataset:
An open-source HyperTransport core
Authors: David Slogsnat, Alexander Giese, Mondrian Nüssle, Ulrich Brüning
Venue: ACM Transactions on Reconfigurable Technology and Systems (TRETS) (2008)

This article presents the design of a generic HyperTransport (HT) core. HyperTransport is a packet-based interconnect technology for low-latency, high-bandwidth point-to-point connections. It is specially optimized to achieve a very low latency. The core has been verified in system using an FPGA. This exhaustive verification and the generic design allow the mapping to both ASICs and FPGAs. The implementation described in this work supports a 16-bit link width, as used by Opteron processors. On a Xilinx Virtex-4 FX60, the core supports a link frequency of 400 MHz DDR and offers a maximum bidirectional bandwidth of 3.2GB/s. The in-system verification has been performed using a custom FPGA board that has been plugged into a HyperTransport extension connector (HTX) of a standard Opteron-based motherboard. HTX slots in Opteron-based motherboards allow very high-bandwidth, low-latency communication, since the HTX device is directly connected to one of the HyperTransport links of the processor. Performance analysis shows a unidirectional payload bandwidth of 1.4GB/s and a read latency of 180 ns. The HT core in combination with the HTX board is an ideal base for prototyping systems and implementing FPGA coprocessors. The HT core is available as open source.
CREATING A RESEARCH AGENDA FOR LOCAL LIBRARIES, ARCHIVES AND MUSEUMS ACROSS EUROPE
Authors: Peter Brophy, Geoff Butters
Venue: The New Review of Information Networking (2007)

A wide-ranging study of innovative local library, museum and archive services across and beyond Europe resulted in the development of a new model of local cultural services from a user perspective. This model is presented here, followed by an analysis of the implications for research and development across these sectors. The work, part of the Cultural Applications: Local Institutions Mediating Electronic Resources (CALIMERA) Action, was funded by the European Commission and involved partners in 42 different countries.
A Simulation Model to Develop QoS Control Strategies for Application Servers
Authors: Daniel F. García, Manuel García, Javier García, Joaquín Entrialgo
Venue: Simulation (2008)

The development of new Quality of Service (QoS) control strategies is essential for improving the global quality of the services provided by application servers operating in business-to-business (B2B) scenarios. Although the development and validation of new QoS control strategies based on prototypes is costly and time-consuming, simulation techniques can noticeably reduce the development effort. A simulation model of the application server and its clients is required. Later, any QoS control strategy can be integrated into the model between the clients and the server. The available models are too simplistic to represent the complex applications currently executed in application servers. This article introduces a new model, which is capable of representing the current applications with a high degree of accuracy. As an application representative of the modern B2B environments, the TPC-App (Transaction Processing Performance Council) benchmark has been modeled.
Clique-circulants and the stable set polytope of fuzzy circular interval graphs
Authors: Gianpaolo Oriolo, Gautier Stauffer
Venue: Mathematical Programming: Series A and B (2008)

In this paper, we give a complete and explicit description of the rank facets of the stable set polytope for a class of claw-free graphs, recently introduced by Chudnovsky and Seymour (Proceedings of the Bristish Combinatorial Conference, 2005), called fuzzy circular interval graphs. The result builds upon the characterization of minimal rank facets for claw-free graphs by Galluccio and Sassano (J. Combinatorial Theory 69:1&#x2013;38, 2005) and upon the introduction of a superclass of circulant graphs that are called clique-circulants. The new class of graphs is invetigated in depth. We characterize which clique-circulants C are facet producing, i.e. are such that $$\sum_{v\in V(C)} x_v\leq\alpha(C)$$ is a facet of STAB(C), thus extending a result of Trotter (Discrete Math. 12:373&#x2013;388, 1975) for circulants. We show that a simple clique family inequality (Oriolo, Discrete Appl. Math. 132(2):185&#x2013;201, 2004) may be associated with each clique-circulant $$C\subseteq G$$, when G is fuzzy circular interval. We show that these inequalities provide all the rank facets of STAB(G), if G is a fuzzy circular interval graph. Moreover we conjecture that, in this case, they also provide all the non-rank facets of STAB(G) and offer evidences for this conjecture.
Modeling and simulating complexity for discrete graphic Markov models: an experimental study
Authors: Elva Díaz, Eunice Ponce de León
Venue: Proceedings of the 5th WSEAS International Conference on Applied Mathematics (2004)

In this paper the problem studied is how the complexity of the model structure affects the performance of an algorithm constructed to simulate random samples from the model structure S of a discrete graphic Markov model. A definition of the complexity of the structure S of a discrete Markov model is given proportional to the sum of the number of edges of the maximal cliques, minus the number of edges that are in the intersections of the maximal cliques. The constructed algorithm is a hybrid consisting of a modified IPF and a Gibbs-Sampler. The model structure of the family is encoded as a list of strings, each string correspond to a maximal clique GM of the graph of the model. This graph represents the conditional independence restrictions defining the structure of the model. As results, the departure model fits each sample generated by the modified IPF algorithm the performance of the Gibbs-Sampler algorithm depends on the complexity of the model: the percent of Gibbs-Sampler samples not significant different from the corresponding probability distributions of departure decreases with the growing complexity of the models and is the least with dense models, this means that the performance of the Gibbs-Sampler depends on the complexity of the models.
On the Loebl&ndash;Koml&oacute;s&ndash;S&oacute;s conjecture
Authors: Cristina Bazgan, Hao Li, Mariusz Woźniak
Venue: Journal of Graph Theory (2000)

The Loebl&ndash;Koml&oacute;s&ndash;S&oacute;s conjecture says that any graph G on n vertices with at least half of vertices of degree at least k contains each tree of size k. We prove that the conjecture is true for paths as well as for large values of k(k&thinsp;&ge;&thinsp;n&thinsp;-&thinsp;3). &copy; 2000 John Wiley & Sons, Inc. J Graph Theory 34: 269&ndash;276, 2000
Digital libraries and engines of search: new information systems in the context of the digital preservation
Authors: Ricardo Campos
Venue: Proceedings of the 2007 Euro American conference on Telematics and information systems (2007)

The first's library projects occur some years ago with digitization, but just in 1996, the first's web archive initiatives start occurring. Such, was based in the Internet growth and in its increasing use, items that revealed to be an opportunity to transform and readapt the traditional library services. In this context, search engines play a fundamental role of support to the new paradigm of knowledge, by capturing, storing and providing access to the resources, allowing the existence of a digital library in each computer with internet access. In this article we analyze the ways of developing a digital library, taking higher attention to the web harvesting technique, and presenting digital libraries capabilities and limitations. Then we fully summarize relevant projects and initiatives, to finally study the role of search engines in what concerns to, digital preservation, access and information diffusion.
Coexistence of IEEE 802.11b and bluetooth: an integrated performance analysis
Authors: Min Song, Sachin Shetty, Deepthi Gopalpet
Venue: Mobile Networks and Applications (2007)

IEEE 802.11b wireless networks and Bluetooth networks provide complimentary services using the same unlicensed radio frequency band. As the benefits of utilizing these services become increasingly apparent, the likelihood of mutual interference also increases. The well-known frequency hopping algorithm and adaptive frequency hopping algorithm do not fully consider the interference level of the operating environment. In this paper an algorithm called interference-aware adaptive frequency hopping (IAFH) is presented and implemented on Bluetooth devices to mitigate the interference between IEEE 802.11b and Bluetooth wireless networks. An analytical model of IAFH is developed to evaluate the performance of 802.11b stations and Bluetooth devices in a mutual interference environment. The analysis comprises the collision probability, packet error rate, and throughput performance for both IEEE 802.11b and Bluetooth wireless networks. Simulation results confirm that 802.11b station and IAFH-enabled Bluetooth devices experience lower packet error rates and better throughput as compared to the frequency hopping and adaptive frequency hopping algorithms.
A syntactic recognizer for Arabic characters
Authors: John Cowell, Fiaz Hussain
Venue: Machine Graphics Vision International Journal (2007)

Commercial OCR systems for high quality Latin characters are widely available. However, the recognition of Arabic characters, particularly those of poor quality, is still an important research area. This paper gives details of two recognition systems for isolated Arabic characters based on the extraction of critical features. The limitations of this approach and its successful extension to a syntactic recognition system are discussed. The syntactic system uses a new web grammar, in which the critical features are nodes and a set of operators describes the spatial relationships between them. The approach used is insensitive to variations in the size and orientation of the characters and even the relative lengths of strokes. The described system has been implemented and the theoretical behaviour of this approach is supported by the experimental results.
The Role of Standardization in Future Autonomic Communication Systems
Authors: John Strassner, Joel Fleck, David Lewis, Manish Parashar, Willie Donnelly
Venue: Proceedings of the Fifth IEEE Workshop on Engineering of Autonomic and Autonomous Systems (2008)

This paper examines the potential problems of interoperability in the development and widespread future deployment of autonomic communication systems. It draws on experiences from previous standardization efforts in the communications domain and outlines the new challenges faced in building industrial strength networks that are self-configuring, self-healing, self optimizing, self-protecting, and most importantly, self-governing. It then outlines the work-program being undertaken by the Autonomic Communication Forum and introduces the other papers in this session that present details of these challenges and directions being pursued.
From writing and analysis to the repository: taking the scholars' perspective on scholarly archiving
Authors: Catherine C. Marshall
Venue: Proceedings of the 8th ACM/IEEE-CS joint conference on Digital libraries (2008)

This paper reports the results of a qualitative field study of the scholarly writing, collaboration, information management, and long-term archiving practices of researchers in five related subdisciplines. The study focuses on the kinds of artifacts the researchers create in the process of writing a paper, how they exchange and store materials over the short term, how they handle references and bibliographic resources, and the strategies they use to guarantee the long term safety of their scholarly materials. The findings reveal: (1) the adoption of a new CIM infrastructure relies crucially on whether it compares favorably to email along six critical dimensions; (2) personal scholarly archives should be maintained as a side-effect of collaboration and the role of ancillary material such as datasets remains to be worked out; and (3) it is vital to consider agency when we talk about depositing new types of scholarly materials into disciplinary repositories.
Robust l∞-stability of systems with repeated perturbations: a case study
Authors: Patrick Cadotte, Hannah Michalska, Benoit Boulet
Venue: Proceedings of the 9th WSEAS International Conference on Systems (2005)

The paper presents a pair of necessary and sufficient conditions for robust l∞-stability of discrete-time systems with structured, repeated, linear time-varying, induced l∞-norm bounded perturbations. The quality of these conditions is confirmed employing a realistic example involving an electronic circuit with repeated operational-amplifiers, persistent noise disturbances, and peak-to-peak gain performance objectives.
Uniform direct product theorems: simplified, optimized, and derandomized
Authors: Russell Impagliazzo, Ragesh Jaiswal, Valentine Kabanets, Avi Wigderson
Venue: Proceedings of the 40th annual ACM symposium on Theory of computing (2008)

The classical Direct-Product Theorem for circuits says that if a Boolean function f: {0,1}n -> {0,1} is somewhat hard to compute on average by small circuits, then the corresponding k-wise direct product function fk(x1,...,xk)=(f(x1),...,f(xk)) (where each xi -> {0,1}n) is significantly harder to compute on average by slightly smaller circuits. We prove a fully uniform version of the Direct-Product Theorem with information-theoretically optimal parameters, up to constant factors. Namely, we show that for given k and ε, there is an efficient randomized algorithm A with the following property. Given a circuit C that computes fk on at least ε fraction of inputs, the algorithm A outputs with probability at least 3/4 a list of O(1/ε) circuits such that at least one of the circuits on the list computes f on more than 1-δ fraction of inputs, for δ = O((log 1/ε)/k). Moreover, each output circuit is an AC0 circuit (of size poly(n,k,log 1/δ,1/ε)), with oracle access to the circuit C. Using the Goldreich-Levin decoding algorithm [5], we also get a fully uniform version of Yao's XOR Lemma [18] with optimal parameters, up to constant factors. Our results simplify and improve those in [10]. Our main result may be viewed as an efficient approximate, local, list-decoding algorithm for direct-product codes (encoding a function by its values on all k-tuples) with optimal parameters. We generalize it to a family of "derandomized" direct-product codes, which we call intersection codes, where the encoding provides values of the function only on a subfamily of k-tuples. The quality of the decoding algorithm is then determined by sampling properties of the sets in this family and their intersections. As a direct consequence of this generalization we obtain the first derandomized direct product result in the uniform setting, allowing hardness amplification with only constant (as opposed to a factor of k) increase in the input length. Finally, this general setting naturally allows the decoding of concatenated codes, which further yields nearly optimal derandomized amplification.
Representing short-term observations of moving objects by a simple visual language
Authors: Björn Gottfried
Venue: Journal of Visual Languages and Computing (2008)

In a variety of dynamical systems, formations of motion patterns occur. Observing colonies of animals, for instance, for the scientist it is not only of interest which kinds of formations these animals show, but also how they altogether move around. In order to analyse motion patterns for the purpose of making predictions, to describe the behaviour of systems, or to index databases of moving objects, methods are required for dealing with them. This becomes increasingly important since a number of technologies have been devised which allow objects precisely to get traced. However, the indeterminacy of spatial information in real world environments also requires techniques to approximate reasoning, for example, in order to compensate for small and unimportant distinctions which are due to noisy measurements. As a consequence, precise as well as coarse motion patterns have to be dealt with. A set of 16 atomic motion patterns is proposed. On the one hand, a relation algebra is defined on them. On the other hand, these 16 relations form the basis of a visual language using which motion patterns can easily be dealt with in a diagrammatic way. The relations are coarse but crisp and they allow imprecise knowledge about motion patterns to be dealt with, while their diagrammatic realisation also allow precise patterns to get handled. While almost all approaches consider motion patterns along arbitrary time intervals, this paper in particular focuses on short-term motion patterns as we permanently observe them in our everyday life. The bottom line of the current work, however, is yet more general. While it has been widely argued that it makes sense to use both sentential and diagrammatic representations in order to represent different things in the same system adequately (and hence differently), we argue that it makes even sense to represent the same things differently in order to grasp different aspects of one and the same object of interest from different viewpoints. We demonstrate this by providing both a sentential and a diagrammatic representation for the purpose of grasping different aspects of motion patterns. It shows that both representations complement each other.
Range bounding with Taylor models for global optimization
Authors: Kyoko Makino, Martin Berz
Venue: Proceedings of the 5th WSEAS/IASME International Conference on Systems Theory and Scientific Computation (2005)

Taylor models provide enclosures of functional dependencies by a polynomial and an interval remainder bound that scales with a high power of the domain width, allowing a far-reaching suppression of the dependency problem. For the application to range bounding, one observes that the resulting polynomials are more well-behaved than the original function; in fact, merely naively evaluating them in interval arithmetic leads to a quadratic range bounder that is frequently noticeably superior to other second order methods. However, the particular polynomial form allows the use of other techniques. We review the linear dominated bounder (LDB) and the quadratic fast bounder (QFB). LDB often allows an exact bounding of the polynomial part if the function is monotonic. If it does not succeed to provide an optimal bound, it still often provides a reduction of the domain simultaneously in all variables. Near interior minimizers, where the quadratic part of the local Taylor model is positive semidefinite, QFB minimizes the quadratic contribution to the lower bound of the function, avoiding the infamous cluster effect for validated global optimization tasks. Some examples of the performance of the bounders for unconstrained global optimization problems are given, beginning with various common toy problems of the community, and also including a rather challenging Lennard-Jones problem.
Adaptive S-method for SAR/ISAR imaging
Authors: LJubiša Stankovic, Thayananthan Thayaparan, Vesna Popovic, Igor Djurovic, Miloš Dakovic
Venue: EURASIP Journal on Advances in Signal Processing (2008)

We propose the adaptive S-method-based technique for imaging of SAR and ISAR targets. This approach can be applied in the 1D and 2D modes. It is a postprocessing technique, since the first stage is the standard radar imaging with the 2D Fourier transform. In addition, selection of the adaptive parameter in this technique is efficient and can be performed based on simple rules in real time. The proposed technique produces highly concentrated (focused) radar image without interferences commonly associated with time-frequency representations and without defocusing target images that are already focused in the 2D Fourier domain.
A probabilistic framework for representing and simulating uncertain environmental variables
Authors: G. B. M. Heuvelink, J. D. Brown, E. E. van Loon
Venue: International Journal of Geographical Information Science (2007)

Understanding the limitations of environmental data is important for managing environmental systems effectively and for encouraging the responsible use of uncertain data. Explicit assessment of the uncertainties associated with environmental data, and their storage in a database, are therefore important. This paper presents a statistical framework for representing and simulating uncertain environmental variables. In general terms, an uncertain variable is completely specified by its probability distribution function (pdf). Pdfs are developed for objects with uncertain locations ('positional uncertainty') and uncertain attribute values ('attribute uncertainty'). Objects comprising multiple space-time locations are separated into 'rigid objects', where positional uncertainty cannot alter the internal geometry of the object, and 'deformable' objects, where positional uncertainty can vary between locations in one object. Statistical dependence is allowed between uncertainties in multiple locations in one object. The uncertainties associated with attribute values are also modelled with pdfs. The type and complexity of these pdfs depend upon the measurement scale and the space-time variability of the uncertain attribute. The framework is illustrated with examples. A prototype software tool for assessing uncertainties in environmental data, storing them within a database, and for generating realizations for use in Monte Carlo studies is also presented.
Learning to divide and conquer: applying the L* algorithm to automate assume-guarantee reasoning
Authors: Corina S. Păsăreanu, Dimitra Giannakopoulou, Mihaela Gheorghiu Bobaru, Jamieson M. Cobleigh, Howard Barringer
Venue: Formal Methods in System Design (2008)

Assume-guarantee reasoning enables a "divide-and-conquer" approach to the verification of large systems that checks system components separately while using assumptions about each component's environment. Developing appropriate assumptions used to be a difficult and manual process. Over the past five years, we have developed a framework for performing assume-guarantee verification of systems in an incremental and fully automated fashion. The framework uses an off-the-shelf learning algorithm to compute the assumptions. The assumptions are initially approximate and become more precise by means of counterexamples obtained by model checking components separately. The framework supports different assume-guarantee rules, both symmetric and asymmetric. Moreover, we have recently introduced alphabet refinement, which extends the assumption learning process to also infer assumption alphabets. This refinement technique starts with assumption alphabets that are a subset of the minimal interface between a component and its environment, and adds actions to it as necessary until a given property is shown to hold or to be violated in the system. We have applied the learning framework to a number of case studies that show that compositional verification by learning assumptions can be significantly more scalable than non-compositional verification.