ppxscal/embedding_network huggingface dataset:
Inventive Tool Use to Comprehend Big Code
Authors: Sukanya Ratanotayanon, Susan Elliott Sim
Venue: IEEE Software (2008)

Software developers often need to understand a large body of unfamiliar code with little or no documentation, no experts to consult, and little time to do it. A post appeared in January 2008 on Slashdot, a technology news Web site, asking for tools and techniques that could help. This article analyzes 301 often passionate and sometimes articulate responses to this query, including the themes and the associated tool recommendations. The most common suggestions were to use a code navigation tool, use a design recovery tool, use a debugger to step through the code, create a runtime trace, use problem-based learning, ask people for help, study the code from top down, and print out all the code. This analysis presents an intriguing snapshot of how software developers in industry go about comprehending big code.
On the robustness of elliptic resolvents computed by means of the technique of hierarchical matrices
Authors: M. Espig, W. Hackbusch
Venue: Applied Numerical Mathematics (2008)

Hierarchical matrices provide a data-sparse way to approximate fully populated matrices. In this paper we exploit robust H-matrix techniques to approximate the resolvents of stiffness matrices as they appear in (finite element or finite difference) discretisations of elliptic partial differential equations.
Santa Claus Meets Hypergraph Matchings
Authors: Arash Asadpour, Uriel Feige, Amin Saberi
Venue: Proceedings of the 11th international workshop, APPROX 2008, and 12th international workshop, RANDOM 2008 on Approximation, Randomization and Combinatorial Optimization: Algorithms and Techniques (2008)

We consider the problem of max-min fair allocation of indivisible goods. Our focus will be on the restricted version of the problem in which there are m items, each of which associated with a non-negative value. There are also n players and each player is only interested in some of the items. The goal is to distribute the items between the players such that the least happy person is as happy as possible, i.e. one wants to maximize the minimum of the sum of the values of the items given to any player. This problem is also known as the Santa Claus problem [3]. Feige [9] proves that the integrality gap of a certain configuration LP, described by Bansal and Sviridenko [3], is bounded from below by some (unspecified) constant. This gives an efficient way to estimate the optimum value of the problem within a constant factor. However, the proof in [9] is nonconstructive: it uses the Lovasz local lemma and does not provide a polynomial time algorithm for finding an allocation. In this paper, we take a different approach to this problem, based upon local search techniques for finding perfect matchings in certain classes of hypergraphs. As a result, we prove that the integrality gap of the configuration LP is bounded by $\frac{1}{5}$. Our proof is nonconstructive in the following sense: it does provide a local search algorithm which finds the corresponding allocation, but this algorithm is not known to converge to a local optimum in a polynomial number of steps.
The Design and Implement of Knowledge Building Classroom Based on Web2.0
Authors: Xinyu Zhang, Zhigang Wang
Venue: Proceedings of the 7th international conference on Advances in Web Based Learning (2008)

With the rapid development of the internet, e-Learning is playing an important role to life-long learning. But the phenomenon that e-Learning is lack of Knowledge Building at large has raised the attention of educational circles. This paper presents an idea that Knowledge Building Classroom based on Web2.0 as a solution to e-Learning. Based on this idea, we design and implement the e-Learning which introduces Knowledge Building Community theory and web 2.0 technologies. By the end of this paper, we take "Laboratory Inquiry" as an example to demonstrate the advantages of Knowledge Building Classroom based on Web2.0.
A Study of Reconstruction Process Load in P2P Storage Systems
Authors: Ghislain Secret, Gil Utard
Venue: Proceedings of the 1st international conference on Data Management in Grid and Peer-to-Peer Systems (2008)

In this paper we present a study of the load generated by the reconstruction process of P2P storage system. This reconstruction process maintains redundancy of data for durability to face peer failures found in P2P architectures. We will show that the cost induced is not negligible and we will show which parameters of the underlying P2P system can reduce it. To our best knowledge it is the first study of this topic.
First principle calculations of dipole-dipole dispersion coefficients for the ground and first &pi; &rarr; &pi;* excited states of some azabenzenes
Authors: Patrick Norman, Auayporn Jiemchooroj, Bo E. Sernelius
Venue: Journal of Computational Methods in Sciences and Engineering (2004)

The complex polarization propagator method has been applied to the calculation of dipole-dipole dispersion coefficients (also known as $C_6$ coefficients) of pyridine, pyrazine, and s-tetrazine. These calculations refer to the electronic ground states as well as the first excited states of &pi; &rarr; &pi;* character. It is argued that accurate ground state dispersion coefficients are obtained with density functional theory using the B3LYP exchange-correlation functional. The proposed values for the $C_6$ coefficients of pyridine, pyrazine, and s-tetrazine in their ground states are 1543 a.u., 1398 a.u., and 1014 a.u., respectively. Multi-configurational complete active space calculations are performed on these compounds in their respective &pi; &rarr; &pi;* excited state. The isotropic averages of the frequency-dependent polarizabilities are smaller in the excited states, but the effective frequencies - defined in the London - van der Waals dispersion relation - are on the other hand larger.
Modeling of information system correlated events time dependencies
Authors: Jacques Saraydaryan, Véronique Legrand, Stéphane Ubéda
Venue: Proceedings of the 8th international conference on New technologies in distributed systems (2008)

Many works have been carried out in events correlation and intrusion detection. Although they use different methods or correlation approaches, they all highlight the importance of time in their modeling process. In this paper, we suggest a new time consideration for our previous works Bayesian behavior intrusion detection. Using a probabilistic approach, we introduce time consideration in the profile of user/system interactions. This enriched profile will integrate all time dependencies among correlated alerts. Some works provide attack graphs scenarios where time dependencies are explicitly defined. In our case, they are learnt during a training period.
A new parallel algorithm for lagrange interpolation on a hypercube
Authors: C. P. Katti, R. Kumari
Venue: Computers Mathematics with Applications (2006)

We present a new parallel algorithm for computing N point lagrange interpolation on an n-dimensional hypercube with total number of nodes p = 2^n. Initially, we consider the case when N = p. The algorithm is extended to the case when only p (p fixed) processors are available, p
KCT-Based Group Key Management Scheme in Clustered Wireless Sensor Networks
Authors: Huifang Chen, Hiroshi Mineno, Yoshitsugu Obashi, Tomohiro Kokogawa, Tadanori Mizuno
Venue: Proceedings of the 3rd international conference on Embedded Software and Systems (2007)

Confidentiality, integrity, and authentication services are critical to preventing an adversary from compromising the security of a Wireless Sensor Network (WSN). An essential component of any key-based security solution is managing the encryption keys to providing this protection. Hence, we propose a novel group key management scheme based on the key-chain tree mechanism for the clustered WSNs in this paper. In this scheme, the functions of key management are decoupled and distributed among multiple network elements of the clustered WSNs for providing compromise/failure resistance. This scheme also supports rekeying to enhance network security and survivability against the node capture. Analysis results show that the scheme does provide a secure encryption of the messages even if the revoked sensor nodes collude with each other or the cluster head is compromised.
Finding Most Likely Solutions
Authors: Osamu Watanabe, Mikael Onsjö
Venue: Proceedings of the 3rd conference on Computability in Europe: Computation and Logic in the Real World (2007)

As one simple type of statistical inference problems we consider Most Likely Solution problem, a task of finding a most likely solution (MLS in short) for a given problem instance under some given probability model. Although many MLS problems are NP-hard, we propose, for these problems, to study their average-case complexity under their assumed probabality models. We show three examples of MLS problems, and explain that "message passing algorithms" (e.g., belief propagation) work reasonably well for these problems. Some of the technical results of this paper are from the author's recent joint work with his colleagues [WST, WY06, OW06] .
An Algebraic Approach for Proving Data Correctness in Arithmetic Data Paths
Authors: Oliver Wienand, Markus Wedler, Dominik Stoffel, Wolfgang Kunz, Gert-Martin Greuel
Venue: Proceedings of the 20th international conference on Computer Aided Verification (2008)

This paper proposes a new approach for proving arithmetic correctness of data paths in System-on-Chip modules. It complements existing techniques which are, for reasons of complexity, restricted to verifying only the control behavior. The circuit is modeled at the arithmetic bit level (ABL) so that our approach is well adapted to current industrial design styles for high performance data paths. Normalization at the ABL is combined with the techniques of computer algebra. We compute normal forms with respect to Gröbner bases over rings ¿/$\left\langle{2^n}\right\rangle$. Our approach proves tractable for industrial data path designs where standard property checking techniques fail.
Letters: Two-dimensional direct and weighted linear discriminant analysis for face recognition
Authors: Ruicong Zhi, Qiuqi Ruan
Venue: Neurocomputing (2008)

In this paper, a novel algorithm for feature extraction-two-dimensional direct and weighted linear discriminant analysis (2D-DWLDA)-is proposed. The improvement of 2D-DWLDA algorithm over traditional linear discriminant analysis (LDA) and 2D-LDA methods benefits mostly from three aspects: (1) 2D-DWLDA is based on 2D image matrices rather than 1D vectors, so the scatter matrices can be constructed directly using the image matrices, and calculated accurately; (2) by introducing weighting function, the overlap of the neighboring classes is weaken; (3) direct LDA method is utilized so that the extracted features have more discriminant power. Finally, we performed a series of experiments on three face databases: ORL, CAS-PEAL and Yale database, the recognition accuracies are higher using 2D-DWLDA than 2D-LDA and LDA.
Curriculum Model Checking: Declarative Representation and Verification of Properties
Authors: Matteo Baldoni, Elisa Marengo
Venue: Proceedings of the 2nd European conference on Technology Enhanced Learning: Creating New Learning Experiences on a Global Scale (2007)

When a curriculum is proposed, it is important to verify at least three aspects: that the curriculum allows the achievement of the user's learning goals, that the curriculum is compliant w.r.t. the course design goals, specified by the institution that offers it, and that the sequence of courses that defines the curriculum does not have competency gaps. In this work, we present a constrained-based representation for specifying the goals of "course design" and introduce a design graphical language, grounded into Linear Time Logic.
Generalized Ordering-Search for Learning Directed Probabilistic Logical Models
Authors: Jan Ramon, Tom Croonenborghs, Daan Fierens, Hendrik Blockeel, Maurice Bruynooghe
Venue: Inductive Logic Programming: 16th International Conference, ILP 2006, Santiago de Compostela, Spain, August 24-27, 2006, Revised Selected Papers (2007)

Recently, there has been an increasing interest in directed probabilistic logical models and a variety of languages for describing such models has been proposed. Although many authors provide high-level arguments to show that in principle models in their language can be learned from data, most of the proposed learning algorithms have not yet been studied in detail. We introduce an algorithm, generalized ordering-search, to learn both structure and conditional probability distributions (CPDs) of directed probabilistic logical models. The algorithm upgrades the ordering-search algorithm for Bayesian networks. We use relational probability trees as a representation for the CPDs. We present experiments on blocks world domains, a gene domain and the Cora dataset.
Applications of artificial neural networks in mobile robots navigation
Authors: V. Tiponut, A. Gacsady, I. Gavrilut
Venue: Proceedings of the 9th WSEAS International Conference on International Conference on Automation and Information (2008)

In the present paper, it will be reported original results concerning the application of Artificial Neural Networks (ANN) and in particular Cellular Neural Networks (CNN) in mobile robot control. In the first part of the paper, a complete solution, using ANN, for obstacles detection and robot navigation in unstructured environment is presented. The rest of the paper is entirely devoted to applications implemented using CNN. Different methods for path finding to the target and trajectory planning, for a single robot and mobile robot collectivities, are analyzed and the obtained results are reported.
Studies on maximal hyperclique pattern analysis and wireless networks approximate algorithm design
Authors: Weili Wu
Venue:  (2008)

A hyperclique pattern is a new type of association pattern that contains items which are highly affiliated with each other. Specifically, the presence of an item in one transaction strongly implies the presence of every other item that belongs to the same hyperclique pattern. In this dissertation, we present an algorithm for mining maximal hyperclique patterns, which specifies a more compact representation of hyperclique patterns and are desirable for many applications, such as pattern-based clustering. Our algorithm exploits key advantages of both the Depth First Search (DFS) strategy and the Breadth First Search (BFS) strategy. Indeed, we adapt the equivalence pruning method, one of the most efficient pruning methods of the DFS strategy, into the process of the BFS strategy. Our experimental results show that the performance of our algorithm can be orders of magnitude faster than standard maximal frequent pattern mining algorithms, particularly at low levels of support. With the development of biology, microarray technology has been used to analyze relations between genes, cells and the other biological samples. Obviously, the microarray profiles are data sets containing quantitative attributes, where the relation values are not binary values. If we partition quantitative attributes into Boolean attributes there is potential information loss due to partitioning. Here, we design a new normalization scheme for such kind of dataset with quantitative attributes. Additionally, we adapt the algorithm structures of three popular association pattern mining algorithms and add a critical clique pruning technique for the hyperclique patterns in the normalized datasets. Mobile ad hoc networks are the next generation in communication networks. Devices can enter or leave the network anytime, devices can be mobile, and no centralized control points or base stations are necessary. This flexibility makes mobile ad hoc networks very interesting for the consumer and military market, but also makes them more complex than many existing wireless networks (such as GSM). Minimum-Weight Connected Dominating Set (MWCDS) problem is to select a vertex subset with minimum weight for a given unit disk graph, such that each vertex of the graph is contained in this subset or has a neighbor in this subset. Besides, the subgraph induced by this vertex subset is connected. It will be beneficial if we can get minimum weighted connected dominating set in the wireless network. We presents a (10 + &egr;)-approximation algorithm to compute MWCDS in unit disk graphs.
One Digital Signature Scheme in Semimodule over Semiring
Authors: Eligijus Sakalauskas
Venue: Informatica (2005)

A modernization of signature scheme published in (Sakalauskas, 2004) is presented. This scheme differs from the prototype by its structure and uses a more general algebraic systems. It has a higher security and shorter key length and is also more computationally effective. The introduced new algebraic structures, semiring and semimodule, are mutually compatible algebraic systems. The semiring is a set of operators acting in a semimodule as endomorphisms. There is postulated that action operation has a one-way function (OWF) property. The compatibility of both algebraic structures' means that the action operation has right and left distributivity property with respect to the additive operation defined in semimodule and semiring. Two other essential OWFs are defined. The latter are based on known constructions and have a greater complexity than other recognized hard problems such as conjugator search problem in noncommutative groups, for example.
Kernel k-Means Clustering Applied to Vector Space Embeddings of Graphs
Authors: Kaspar Riesen, Horst Bunke
Venue: Proceedings of the 3rd IAPR workshop on Artificial Neural Networks in Pattern Recognition (2008)

In the present paper a novel approach to clustering objects given in terms of graphs is introduced. The proposed method is based on an embedding procedure that maps graphs to an n-dimensional real vector space. The basic idea is to view the edit distance of an input graph g to a number of prototype graphs as a vectorial description of g. Based on the embedded graphs, kernel k-means clustering is applied. In several experiments conducted on different graph data sets we demonstrate the robustness and flexibility of our novel graph clustering approach and compare it with a standard clustering procedure directly applied in the domain of graphs.
Stability analysis of uncertain genetic sum regulatory networks
Authors: G. Chesi, Y. S. Hung
Venue: Automatica (Journal of IFAC) (2008)

This paper addresses the problem of establishing robust stability of uncertain genetic networks with sum regulatory functions. Specifically, we first consider uncertain genetic networks where the regulation occurs at the transcriptional level, and we derive a sufficient condition for robust stability by introducing a bounding set of the uncertain nonlinearity. We hence show that this condition can be formulated as a convex optimization through polynomial Lyapunov functions and polynomial descriptions of the bounding set by exploiting the square matricial representation (SMR) of polynomials which allows to establish whether a polynomial is a sum of squares (SOS) via a linear matrix inequality (LMI). Then, we propose a method for computing a family of bounding sets by means of convex optimizations. It is worthwhile to remark that these results are derived in spite of the fact that the variable equilibrium point cannot be computed as being the solution of a system of parameter-dependent nonlinear equations, and is hence unknown. Lastly, the proposed approach is extended to models where the regulation occurs at different levels and both mRNA and protein dynamics are nonlinear.
On Synchronous and Asynchronous Interaction in Distributed Systems
Authors: Rob Glabbeek, Ursula Goltz, Jens-Wolfhard Schicke
Venue: Proceedings of the 33rd international symposium on Mathematical Foundations of Computer Science (2008)

When considering distributed systems, it is a central issue how to deal with interactions between components. In this paper, we investigate the paradigms of synchronous and asynchronous interaction in the context of distributed systems. We investigate to what extent or under which conditions synchronous interaction is a valid concept for specification and implementation of such systems. We choose Petri nets as our system model and consider different notions of distribution by associating locations to elements of nets. First, we investigate the concept of simultaneity which is inherent in the semantics of Petri nets when transitions have multiple input places. We assume that tokens may only be taken instantaneously by transitions on the same location. We exhibit a hierarchy of `asynchronous' Petri net classes by different assumptions on possible distributions. Alternatively, we assume that the synchronisations specified in a Petri net are crucial system properties. Hence transitions and their preplaces may no longer placed on separate locations. We then answer the question which systems may be implemented in a distributed way without restricting concurrency, assuming that locations are inherently sequential. It turns out that in both settings we find semi-structural properties of Petri nets describing exactly the problematic situations for interactions in distributed systems.
Shape sensitivity of constructively represented geometric models
Authors: Jiaqin Chen, Michael Freytag, Vadim Shapiro
Venue: Computer Aided Geometric Design (2008)

Most solid models are archived using boundary representations, but they are created, edited, and optimized using high level constructive methods that rely on parameterized Boolean set operations and feature-based techniques. Downstream applications often require optimization of integral-valued performance measures over such models that include volume, mass, and energy properties, as well as more general distributed fields (stress, temperature, etc.). A key computational utility in all such applications is the computation of the sensitivity of the performance measure with respect to the parameters in the solid's construction history. We show that for a class of performance measures defined as domain integrals, the sensitivity with respect to a parameter requires integration over a subset of the solid's boundaries that is affected by that parameter. In contrast to earlier methods, the proposed approach for computing sensitivities does not require solid's boundary to remain homeomorphic, and may be used with most types of constructive representations, including CSG and feature-based representations, where the defining Boolean expression may not be known. The simplicity and effectiveness of the proposed technique are illustrated on several common shape optimization problems.
Collaboration Model for Ship Design
Authors: Marina Z. Solesvik
Venue: Proceedings of the 5th international conference on Cooperative Design, Visualization, and Engineering (2008)

The paper presents a model for inter-organizational and interdisciplinary collaboration in ship design. Two case studies illustrate the application of this model in ship design practice. Case studies also demonstrate usage of two computer-based collaboration tools employed by a large design firm and a small one.
The absent participant: more patterns for group awareness
Authors: Till Schümmer, Stephan Lukosch
Venue: Proceedings of the 2006 conference on Pattern languages of programs (2006)

The awareness of group members is one crucial aspect in computer-mediated interaction. This paper presents a set of patterns that support groups in which one or more group members are currently away from the group. The patterns help the group to stay aware of the missing user and the user to keep up to date of what happens in the group. The patterns are part of a larger pattern collection for computer-mediated interaction.