ppxscal/embedding_network huggingface dataset:
Novel Strategies for the Optimal Registration of Biomedical Images
Authors: Jorge Larrey-Ruiz, Juan Morales-Sánchez, Rafael Verdú-Monedero
Venue: Proceedings of the 2nd international work-conference on Nature Inspired Problem-Solving Methods in Knowledge Engineering: Interplay Between Natural and Artificial Computation, Part II (2007)

This paper is intended to address three of the most common problems arising in the field of non-rigid biomedical image registration. Firstly, a regularization term based on fractional-order derivatives is proposed. It can be seen as a generalization of the bio-inspired diffusion and curvature smoothing terms but, since it incorporates features of both regularizers, with this approach it is possible to obtain better registration results from a variational point of view. Next, a frequency-domain formulation for the image registration problem is presented. It provides efficient and stable implementations for the considered registration techniques. Finally, a two-step method is proposed for obtaining the optimal values of the registration parameters, because in the literature there is no agreement about which are the optimal values for these parameters, leading the authors to arbitrarily fix them. The resulting registration scheme, after the incorporation of these three strategies, is tested on two biomedical imaging scenarios.
Strongly Equivalent Temporal Logic Programs
Authors: Felicidad Aguado, Pedro Cabalar, Gilberto Pérez, Concepción Vidal
Venue: Proceedings of the 11th European conference on Logics in Artificial Intelligence (2008)

This paper analyses the idea of strong equivalence for transition systems represented as logic programs under the Answer Set Programming (ASP) paradigm. To check strong equivalence, we use a linear temporal extension of Equilibrium Logic (a logical characterisation of ASP) and its monotonic basis, the intermediate logic of Here-and-There (HT). Trivially, equivalence in this temporal extension of HT provides a sufficient condition for temporal strong equivalence and, as we show in the paper, it can be transformed into a provability test into the standard Linear Temporal Logic (LTL), something that can be automatically checked using any of the LTL available provers. The paper shows an example of the potential utility of this method by detecting some redundant rules in a simple actions reasoning scenario.
Preserving temporal behaviour of legacy real-time software across static binary translation
Authors: Thomas Heinz
Venue: Proceedings of the 1st workshop on Isolation and integration in embedded systems (2008)

In contrast to the shorter and shorter life cycles of electronic components, some embedded systems like automotive ECUs need to be supplied for decades. Thus, an embedded system may be subject to several hardware redesigns during its life cycle which may cause tremendous software porting and redevelopment efforts. Static binary translation has the potential to significantly cut these redevelopment costs by automating the software retargeting process. While static binary translation has been successfully applied to non-real-time software, there is hardly any work in the real-time field. Besides preserving the functional software behaviour, static binary translation of real-time software requires that its temporal behaviour at the machine code level is preserved to a certain extent. Traditionally, this is achieved by maintaining the source machine time (number of CPU clock cycles elapsed on the original machine since its activation) on the target machine. However, this does not scale for processors with pipelines or caches. The contribution of this paper is a scalable approach to preserve the temporal behaviour of the original software on the target machine by statically generated temporal barriers. It reduces the runtime overhead of the traditional approach and provides a safe upper bound of the maximum temporal displacement, i.e. the time that the execution of any program point on the target is at most ahead or behind its execution on the source machine.
Stochastic optimal control of ultradiffusion processes with application to dynamic portfolio management
Authors: Michael D. Marcozzi
Venue: Journal of Computational and Applied Mathematics (2008)

We consider theoretical and approximation aspects of the stochastic optimal control of ultradiffusion processes in the context of a prototype model for the selling price of a European call option. Within a continuous-time framework, the dynamic management of a portfolio of assets is effected through continuous or point control, activation costs, and phase delay. The performance index is derived from the unique weak variational solution to the ultraparabolic Hamilton-Jacobi equation; the value function is the optimal realization of the performance index relative to all feasible portfolios. An approximation procedure based upon a temporal box scheme/finite element method is analyzed; numerical examples are presented in order to demonstrate the viability of the approach.
Experimental Evaluation of EAP Performance in Roaming Scenarios
Authors: Saber Zrelli, Yoichi Shinoda
Venue: Proceedings of the 3rd Asian conference on Internet Engineering: Sustainable Internet (2007)

The Extensible Authentication protocol (EAP), is the main component of the standard AAA (Authentication Authorization and Accounting) framework for network access control. AAA frameworks support cross-domain authentication that enables a certain access network to authenticate a roaming client that belongs to a remote network. The cross-domain authentication requires message exchange between the AAA server of the visited network and the AAA server of the client's home network. Because these inter-domain exchanges occur over the Internet, they are subject to degradations such as packet loss and network delays thus increasing the overall authentication time. When the client changes of access point, the same authentication procedure takes place again, disrupting the user traffic at each hand-off.In this paper, we examine the performance of inter-domain EAP authentication in terms of authentication delay using an emulated environment. Moreover, in an effort to understand the performance of Inter-domain authentication over the Internet, we model the authentication time using mathematical approach and we define basis of future research items focusing on the estimation of inter-domain EAP authentication delays.
Geometric calibration of multi-projector systems on general display-surfaces
Authors: Brent Seales, Christopher Jaynes
Venue:  (2008)

Multi-projector systems provide scalability for low-cost, high-resolution display needed for many applications including data visualization, telepresence, and ambient or immersive displays. But geometric calibration of the systems is a great challenge, and for many display configurations, existing camera-based techniques are unsatisfactory. A simple, non-parametric robust technique exists for single-camera calibration, but it doesn't scale to high-resolution displays. Scalability can be gained with a parametric model, but general approaches have tended to compromise robustness or accuracy. Special-purpose models have improved the situation, but at the cost of flexibility. We describe a hybrid calibration framework that combines the robustness of non-parametric calibration with the scalability of parametric calibration. Each parametric calibration technique has a hybrid cousin. The parametric model is fit just as before, but it is not directly used by the rendering algorithm. Instead, the rendering algorithm resembles a non-parametric renderer&ndash;it corrects the rendered output using an interpolated lookup table of correspondences between projector framebuffers and a common space. But the space isn't the camera's image; rather it consists of the screen points reconstructed according to the parametric model. By structuring the correspondences and lookup table in a particular way, we are able to ensure that parametric model-fitting error does not hurt the calibration's registration accuracy. We achieve accurate calibration with a general parametric model. Projectors are not modelled, and their radial distortion is corrected implicitly. Multiple cameras are supported. The calibration supports headtracked immersive rendering. A number of related and ancillary research contributions are described in this dissertation, including an analysis of resolution loss in two-pass rendering, together with a technique for preventing the loss by dividing the display surface into clusters based on surface normal. Also techniques are described which improve the reliability of the structure from motion estimation needed for calibration. Other contributions include work in precision feature localization and uncertainty estimation, and a technique for calibrating radial distortion using any number of cameras and without knowledge or assumptions about scene structure. We believe that this work provides key contributions towards robust, hassle-free strong geometric calibration of wide-area, heterogeneous multi-projector environments. Keywords: Projector-Camera Systems, Camera Calibration, Feature Matching, Multi-View Geometry, 3D Reconstruction .
Even more patterns for secure operating systems
Authors: Eduardo B. Fernandez, Tami Sorgente, Maria M. Larrondo-Petrie
Venue: Proceedings of the 2006 conference on Pattern languages of programs (2006)

An operating system (OS) interacts with the hardware and supports the execution of all the applications. As a result, its security is very critical. Many of the reported attacks to Internetbased systems have occurred through the OS (kernel and utilities). The security of individual execution time actions such as process creation, memory protection, and the general architecture of the OS are very important and we have previously presented patterns for these functions. We present here patterns for the representation of processes and threads, emphasizing their security aspects. Another pattern considers the selection of virtual address space structure. We finally present a pattern to control the power of administrators, a common source of security problems.
An Algorithm to Improve the Performance of Watermarking Systems
Authors: Duan-quan Xu, Guang-xi Zhu
Venue: Proceedings of the 2008 Congress on Image and Signal Processing, Vol. 5 - Volume 05 (2008)

Random permutation and sharpening are basic methods of image processing. In some digital image watermarking schemes, if original image is pre-processed with random permutation before embedding and the watermarked image is pre-processed with sharpening before detecting, the performance of watermarking systems can be improved, that means the images can seem better, or the veracity rate of detection is higher. In this article, this method is validated in Barni’s semi-blind watermarking system. The method is suitable for some semi-blind or blind watermarking systems, whether in spatial domain or in other transform domain.
Finite Automata, Palindromes, Powers, and Patterns
Authors: Terry Anderson, Narad Rampersad, Nicolae Santean, Jeffrey Shallit
Venue: Language and Automata Theory and Applications: Second International Conference, LATA 2008, Tarragona, Spain, March 13-19, 2008. Revised Papers (2008)

Given a language L and a nondeterministic finite automaton M, we consider whether we can determine efficiently (in the size of M) if M accepts at least one word in L, or infinitely many words. Given that M accepts at least one word in L, we consider how long the shortest word can be. The languages L that we examine include the palindromes, the non-palindromes, the k-powers, the non-k-powers, the powers, the non-powers (also called primitive words), and words matching a general pattern.
A Slicing-Based Coherence Measure for Clusters of DTI Integral Curves
Authors: Çağatay Demiralp, Gregory Shakhnarovich, Song Zhang, David H. Laidlaw
Venue: Proceedings of the 11th international conference on Medical Image Computing and Computer-Assisted Intervention - Part I (2008)

We present a slicing-based coherence measure for clusters of DTI integral curves. For a given cluster, we probe samples from the cluster by slicing it with a plane at regularly spaced locations parametrized by curve arc lengths. Then we compute a stability measure based on the spatial relations between the projections of the curve points in individual slices and their change across the slices. We demonstrate its use in refining agglomerative hierarchical clustering results of DTI curves that correspond to neural pathways. Expert evaluation shows that refinement based on our measure can lead to improvement of clustering that is not possible directly by using standard methods.
Phylogenetic networks: simulation, characterization, and reconstruction
Authors: Bernard M. Moret
Venue:  (2007)

Phylogenetic trees are topological depictions of evolutionary histories that involve birth and death events. This tree model inherently assumes that active lineages evolve independently from all others. However, interspecific events such as hybridization and lateral gene transfer are known to occur, resulting in an intermingling of DNA information. In essence, this creates a bridge between two previously independent lineages. By definition, these processes are fundamentally dependent on other contemporary species and lead to a more complex history, which is often referred to as a phylogenetic network. Although tree topology software is abundant and mature, algorithms and applications that permit and address issues specific to phylogenetic networks are less common and still in their infancy. The primary contributions of this work include modelling phylogenetic networks and algorithms for their reconstruction and characterization. This involved the development of three new applications: NET GEN for simulating source topologies, NETR ECONSTRUCT for inferring histories, and NETM EASURE for quantitatively comparing and categorizing network features. Phylogenetic networks are created by extending the traditional birth-death model to include hybridizations. This approach is unique in that the DNA sequences are evolved in conjunction with the topology, thereby permitting the outcome of hybrid events to be influenced by genetics. By utilizing the sequence information from NETGEN's final active lineages, a proposed history containing a single-diploid-hybrid event is inferred. This reconstruction process segments the species into sets for which subtrees are created and then merged to form the final topology. Finally, hybrid events in a topology can be quantitatively characterized with three new measures and two networks can be compared using the existing tripartition method. Our results show that tripartition scores for this reconstruction model improve when the number of current day species increases and the branch lengths of the topology shorten. Additionally, topologies containing a single ancient hybridization event (one occurring early in time) result in reconstructions more analogous to their source histories as compared to those with a hybrid event having occurred more recently. This work supports the ongoing effort of phylogenetic reconstruction in fields such as pharmacology, genetics, and systematics.
The CASPA Tool: Causality-Based Abstraction for Security Protocol Analysis
Authors: Michael Backes, Stefan Lorenz, Matteo Maffei, Kim Pecina
Venue: Proceedings of the 20th international conference on Computer Aided Verification (2008)

CASPA constitutes a push-button tool for automatically proving secrecy and authenticity properties of cryptographic protocols. The tool is grounded on a novel technique for causality-based abstraction of protocol executions that allows establishing proofs of security for an unbounded number of concurrent protocol executions in an automated manner. We demonstrate the expressiveness and efficiency of the tool by drawing a comparison with T4ASP, the static analyzer for secrecy properties offered by the AVISPA tool. CASPA is capable of coping with a substantially larger set of protocols, and excels in performance.
An Approach Towards the Integration of Adaptive Business Intelligent and Constraint Programming
Authors: José Miguel Rubio, Broderick Crawford
Venue: Proceedings of the 2008 International Symposiums on Information Processing (2008)

Adaptive Business Intelligence is the discipline that combines prediction, optimization and adaptability into a system answering two important questions: What would probably happen in the future? and What is the better decision now? To build such system, first of all we must understand methods and techniques that provide prediction, optimization and adaptability. Hundreds of authors have already investigated about business intelligence, data mining and prediction methods and optimization techniques. However, none of them has explained how to combine these concepts into a system that is able to predict, optimize and adapt. In this article we propose a working framework, which allows incorporate constraint programming as adaptive business intelligence, in the development of adaptive business intelligence software.
Fifteen Years of Formal Property Verification in Intel
Authors: Limor Fix
Venue: 25 Years of Model Checking: History, Achievements, Perspectives (2008)

Model checking technologies have been applied to hardware verification in the last 15 years. Pioneering work has been conducted in Intel since 1990 using model checking technologies to build industrial hardware verification systems. This paper reviews the evolution and the success of these systems in Intel and in particular it summarizes the many challenges and learning that have resulted from changing how hardware validation is performed in Intel to include formal property verification. The paper ends with a discussion on how the learning from hardware verification can be used to accelerate the industrial deployment of model-checking technologies for software verification.
T(O)RMC: A Tool for (ω)-Regular Model Checking
Authors: Axel Legay
Venue: Proceedings of the 20th international conference on Computer Aided Verification (2008)

Within the context of the verification of infinite-state systems, "(&omega;)-Regular model checking" is the name of a family of techniques in which states are represented by words, sets of states by finite automata on these objects, and transitions by finite automata operating on pairs of state encodings, i.e. finite-state transducers. If the states are encoded by finite words, then sets of (pairs of) states can be represented by finite-word automata. This setting can be used to represent various classes of infinite-state systems, [17], including parametric systems, FIFO-queue systems, and systems manipulating integer variables (those defined in Presburger arithmetic). When the states are encoded by infinite words, sets of (pairs of) states are represented by deterministic weak B&uuml;chi automata. This setting is mainly used to represent systems involving both integer and real variables [4,6], such as linear hybrid systems with a constant derivative.
Generalization of the Selective-ID Security Model for HIBS Protocols
Authors: Jin Li, Xiaofeng Chen, Fangguo Zhang, Yanming Wang
Venue: Computational Intelligence and Security: International Conference, CIS 2006, Guangzhou, China, November 3-6, 2006, Revised Selected Papers (2007)

At PKC 2006, Chatterjee and Sarkar gave a generalization of the selective-ID security model for hierarchical identity-based encryption (HIBE). Corresponding to HIBE, in this paper, a generalization of the selective-ID security model for hierarchical identity-based signature (HIBS) is first proposed. They yield a complete generalization of the selective-ID security model for hierarchical identity-based cryptosystem. We introduce two security models which allow the adversary to commit to a set of identities and in the forgery phase choose any of the previously committed identities. Two constructions of HIBS are presented which can be proved to be secure in the two models. Furthermore, one of the HIBS schemes supports an unbounded number of levels.
Connections in Networks: Hardness of Feasibility Versus Optimality
Authors: Jon Conrad, Carla P. Gomes, Willem-Jan Hoeve, Ashish Sabharwal, Jordan Suter
Venue: Proceedings of the 4th international conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems (2007)

We study the complexity of combinatorial problems that consist of competing infeasibility and optimization components. In particular, we investigate the complexity of the connection subgraph problem, which occurs, e.g., in resource environment economics and social networks. We present results on its worst-case hardness and approximability. We then provide a typical-case analysis by means of a detailed computational study. First, we identify an easy-hard-easy pattern, coinciding with the feasibility phase transition of the problem. Second, our experimental results reveal an interesting interplay between feasibility and optimization. They surprisingly show that proving optimality of the solution of the feasible instances can be substantially easier than proving infeasibility of the infeasible instances in a computationally hard region of the problem space. We also observe an intriguing easy-hard-easy profile for the optimization component itself.
On the performance benefits of sharing and privatizing second and third-level cache memories in homogeneous multi-core architectures
Authors: Fadi N. Sibai
Venue: Microprocessors Microsystems (2008)

The benefits and deficiencies of shared and private caches have been identified by researchers. The performance impact of privatizing or sharing caches on homogeneous multi-core architectures is less understood. This paper investigates the performance impact of cache sharing on a homogeneous same-ISA 16-core processor with private first-level (L1) caches by considering 3 cache models which vary the sharing property of second-level (L2) and third-level (L3) cache banks. It is observed that across many scenarios, the cache privatization's average memory access time improved as the L1 cache miss rate increased and/or the cross-partition interconnect latencies increased. Under uniform memory address distribution, and when the L3 cache miss rate is close to 0, privatizing both L2s and L3s performs best among the 3 cache models. Furthermore, we mathematically demonstrate that when the interconnect's bridge latency is below 264 cycles, privatizing L2 caches beats privatizing both L2 and L3 caches, while the reverse is true for large bridge latencies representing high-traffic and heavy workload applications. For large interconnect delays, the private L2 and L3 model is best. For low to moderate interconnect latencies, and when the L3 miss rate is not close to 0, sharing both L2 and L3 banks among all cores performs best followed by privatizing L2s, while privatizing both L2s and L3s ranks last. Under worst case address distributions, cache privatizing benefits generally increase, and with large bridge latencies, privatizing L2 and L3 banks outperforms the other cache models. This reveals that as application workloads become heavier with time, resulting in large cache miss rates and long bridge and interconnect delays, privatizing L2 and L3 caches may prove beneficial. Under less stressful workloads, sharing both L2 and L3 caches have the upper hand. This study confirms the desired configurability and flexibility of the cache memory's sharing degree based on the running workload.