ppxscal/embedding_network huggingface dataset:
CVM -- A Verified Framework for Microkernel Programmers
Authors: Tom In der Rieden, Alexandra Tsyban
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2008)

CVM (communicating virtual machines) is a computational model for concurrent user processes interacting with a generic microkernel-supporting virtual memory-and devices. In this paper, we introduce the computational models needed to define CVM. Furthermore, we describe how CVM can be implemented by means of a concrete kernel, thus providing a trustworthy platform for microkernel programmers. Last but not least, we give an overview on the model formalization and implementation correctness proof, which has been conducted in the interactive theorem prover Isabelle for the most part. An endeavor like this is tedious and of a considerable complexity. Thus, we do not try to present all details, but provide references to publications covering specific aspects.
Microarray subgrid detection: a novel algorithm
Authors: Daniel Morris, Zidong Wang, Xiaohui Liu
Venue: International Journal of Computer Mathematics (2007)

A novel algorithm for detecting microarray subgrids is proposed. The only input to the algorithm is the raw microarray image, which can be of any resolution, and the subgrid detection is performed with no prior assumptions. The algorithm consists of a series of methods of spot shape detection, spot filtering, spot spacing estimation, and subgrid shape detection. It is shown to be able to divide images of varying quality into subgrid regions with no manual interaction. The algorithm is robust against high levels of noise and high percentages of poorly expressed or missing spots. In addition, it is proved to be effective in locating regular groupings of primitives in a set of non-microarray images, suggesting potential application in the general area of image processing.
An accurate conservative level set/ghost fluid method for simulating turbulent atomization
Authors: Olivier Desjardins, Vincent Moureau, Heinz Pitsch
Venue: Journal of Computational Physics (2008)

This paper presents a novel methodology for simulating incompressible two-phase flows by combining an improved version of the conservative level set technique introduced in [E. Olsson, G. Kreiss, A conservative level set method for two phase flow, J. Comput. Phys. 210 (2005) 225-246] with a ghost fluid approach. By employing a hyperbolic tangent level set function that is transported and re-initialized using fully conservative numerical schemes, mass conservation issues that are known to affect level set methods are greatly reduced. In order to improve the accuracy of the conservative level set method, high order numerical schemes are used. The overall robustness of the numerical approach is increased by computing the interface normals from a signed distance function reconstructed from the hyperbolic tangent level set by a fast marching method. The convergence of the curvature calculation is ensured by using a least squares reconstruction. The ghost fluid technique provides a way of handling the interfacial forces and large density jumps associated with two-phase flows with good accuracy, while avoiding artificial spreading of the interface. Since the proposed approach relies on partial differential equations, its implementation is straightforward in all coordinate systems, and it benefits from high parallel efficiency. The robustness and efficiency of the approach is further improved by using implicit schemes for the interface transport and re-initialization equations, as well as for the momentum solver. The performance of the method is assessed through both classical level set transport tests and simple two-phase flow examples including topology changes. It is then applied to simulate turbulent atomization of a liquid Diesel jet at Re=3000. The conservation errors associated with the accurate conservative level set technique are shown to remain small even for this complex case.
Building agent-based hybrid intelligent systems: A case study
Authors: Zili Zhang, Chengqi Zhang
Venue: Web Intelligence and Agent Systems (2007)

Many complex problems (e.g., financial investment planning, foreign exchange trading, data mining from large/multiple databases) require hybrid intelligent systems that integrate many intelligent techniques (e.g., fuzzy logic, neural networks, and genetic algorithms). However, hybrid intelligent systems are difficult to develop because they have a large number of parts or components that have many interactions. On the other hand, agents offer a new and often more appropriate route to the development of complex systems, especially in open and dynamic environments. Thus, this paper discusses the development of an agent-based hybrid intelligent system for financial investment planning, in which a great number of heterogeneous computing techniques/packages are easily integrated into a unifying agent framework. This shows that agent technology can indeed facilitate the development of hybrid intelligent systems.
Teaching operating systems: student assignments and the software engineering perspective
Authors: Vlastimil Babka, Lubomir Bulej, Martin Decky, Viliam Holub, Petr Tuma
Venue: Proceedings of the 2008 international workshop on Software Engineering in east and south europe (2008)

This paper is an experience report outlining a transformation of an operating systems course in a systems oriented master study program. We present the initial and current stages of the transformation and summarize the lessons learned throughout the process. To illustrate the effects of the transformation, we provide feedback gathered from the students who have completed the course during the transformation. We put emphasis on general software engineering experience, which may prove useful in balancing the many issues related to most courses with programming assignments.
Lightweight Shadow Paging for Efficient Memory Isolation in Gandalf VMM
Authors: Megumi Ito, Shuichi Oikawa
Venue: Proceedings of the 2008 11th IEEE Symposium on Object Oriented Real-Time Distributed Computing (2008)

Demands are increasing for consolidating multiple OSes on a single multi-core CPU rather than using multiple sets of an OS and a CPU. A VMM enables multiple guest OSes to run concurrently on one CPU while providing separate security domains. We have developed Gandalf, a lightweight VMM targeting embedded systems with multi-core CPUs. This paper focuses on the shadow paging mechanism of Gandalf, which enables physical memory isolation among guest OSes by separating guest page tables from CPUs, because shadow paging significantly affects VMM overheads and is a key to make a VMM lightweight. We designed and implemented two models of shadow paging, single shadow model and multiple shadow model. The measurement results show that they are realized lightweight.
Word level multi-script identification
Authors: Peeta Basa Pati, A. G. Ramakrishnan
Venue: Pattern Recognition Letters (2008)

We report an algorithm to identify the script of each word in a document image. We start with a bi-script scenario which is later extended to tri-script and then to eleven-script scenarios. A database of 20,000 words of different font styles and sizes has been collected and used for each script. Effectiveness of Gabor and discrete cosine transform (DCT) features has been independently evaluated using nearest neighbor, linear discriminant and support vector machines (SVM) classifiers. The combination of Gabor features with nearest neighbor or SVM classifier shows promising results; i.e., over 98% for bi-script and tri-script cases and above 89% for the eleven-script scenario.
Image denoising with an optimal threshold and neighbouring window
Authors: Zhou Dengwen, Cheng Wengang
Venue: Pattern Recognition Letters (2008)

NeighShrink is an efficient image denoising algorithm based on the decimated wavelet transform (DWT). Its disadvantage is to use a suboptimal universal threshold and identical neighbouring window size in all wavelet subbands. In this paper, an improved method is given, which can determine an optimal threshold and neighbouring window size for every subband by the Stein's unbiased risk estimate (SURE). Its denoising performance is considerably superior to NeighShrink and also outperforms SURE-LET, which is an up-to-date denoising algorithm based on the SURE. It is well known that increasing the redundancy of wavelet transforms can significantly improve the denoising performances. The proposed method is also extended to the redundant dual-tree complex wavelet transform (DT-CWT). Experiments demonstrate that the proposed method on the DT-CWT achieves better results than some of the best denoising algorithms published currently.
Detecting IEEE 802.11 MAC layer misbehavior in ad hoc networks: Robust strategies against individual and colluding attackers
Authors: S. Radosavac, Alvaro A. Cárdenas, John S. Baras, George V. Moustakides
Venue: Journal of Computer Security (2007)

Selfish behavior at the Medium Access (MAC) Layer can have devastating side effects on the performance of wireless networks, with effects similar to those of Denial of Service (DoS) attacks. In this paper we consider the problem of detection and prevention of node misbehavior at the MAC layer, focusing on the back-off manipulation by selfish nodes. We first propose an algorithm that ensures honest behavior of non-colluding participants. Furthermore, we analyze the problem of colluding selfish nodes, casting the problem within a minimax robust detection framework and providing an optimal detection rule for the worst-case attack scenarios. Finally, we evaluate the performance of single and colluding attackers in terms of detection delay. Although our approach is general and can be used with any probabilistic distributed MAC protocol, we focus our analysis on the IEEE 802.11 MAC.
Uniform approximation by discrete least squares polynomials
Authors: Jean-Paul Calvi, Norman Levenberg
Venue: Journal of Approximation Theory (2008)

We study uniform approximation of differentiable or analytic functions of one or several variables on a compact set K by a sequence of discrete least squares polynomials. In particular, if K satisfies a Markov inequality and we use point evaluations on standard discretization grids with the number of points growing polynomially in the degree, these polynomials provide nearly optimal approximants. For analytic functions, similar results may be achieved on more general K by allowing the number of points to grow at a slightly larger rate.
Expanding Trace Buffer Observation Window for In-System Silicon Debug through Selective Capture
Authors: Joon-Sung Yang, Nur A. Touba
Venue: Proceedings of the 26th IEEE VLSI Test Symposium (2008)

Trace buffers are commonly used to capture data during in-system silicon debug. This paper exploits the fact that it is not necessary to capture error-free data in the trace buffer since that information is obtainable from simulation. The trace buffer need only capture data during clock cycles in which errors are present. A three pass methodology is proposed. During the first pass, the rough error rate is measured, in the second pass, a set of suspect clock cycles where errors may be present is determined, and then in the third pass, the trace buffer captures only during the suspect clock cycles. In this manner, the effective observation window of the trace buffer can be expanded significantly, by up to orders of magnitude. This greatly increases the effectiveness of a given size trace buffer and can rapidly speed up the debug process. The suspect clock cycles are determined through a two dimensional (2-D) compaction technique using a combination of multiple-input signature register (MISR) signatures and cycling register signatures. By intersecting the signatures, the proposed 2-D compaction technique generates a small set of remaining suspect clock cycles for which the trace buffer needs to capture data. Experimental results indicate very significant increases in the effective observation window for a trace buffer can be obtained.
Novel features in languages of the epsilon model management platform
Authors: Dimitrios S. Kolovos, Richard F. Paige, Fiona A.C. Polack
Venue: Proceedings of the 2008 international workshop on Models in software engineering (2008)

We present a set of novel features that we have recently incorporated to model management languages of the Epsilon platform. We provide a detailed discussion on the usefulness of each feature and present motivating scenarios that highlight the benefits they deliver to programmatic model management.
Agile rrocess myths
Authors: Elke Hochmüller, Roland T. Mittermeir
Venue: Proceedings of the 2008 international workshop on Scrutinizing agile practices or shoot-out at the agile corral (2008)

Based on the introduction of some more or less common myths concerning expected benefits of agile practices, this paper features some challenging topics in agile software development. These topics still need thorough discussion when characterizing agile practices and are particularly relevant for deciding on the applicability of agile practices for a particular project.
A behavioral pattern adapted to individual for providing ubiquitous service in intelligent space
Authors: Hiroyuki Yamahara, Hideyuki Takada, Hiromitsu Shimakawa
Venue: Proceedings of the 5th WSEAS International Conference on Computational Intelligence, Man-Machine Systems and Cybernetics (2006)

We aim to provide ubiquitous services proactively in a ubiquitous environment according to user intention. User behavior must be precisely recognized for providing appropriate services for individual user. This paper proposes a user behavior detection method with a personalized behavioral pattern in an intelligent space which identify objects a user touches. They are adapted to individual user. The proposed method focuses on some special scenes in which user's mode significantly changes, such as a scene of going out. In such scenes, user can be provided services most effectively. The method can detect user behavior precisely with a behavioral pattern created by focusing on discrete order of objects a user touches. It separates the order check from a probabilistic model. Because a behavioral pattern can be adapted to individual user in a short time, the method can start providing services to user early. Experiments have proved that our method detects more than 90% of user behavior correctly with a behavioral pattern which is created in a practical short time with less than 10 sample behavior logs.
Integration of panchromatic and SAR features into multispectral SPOT images using the 'à trous' wavelet decomposition
Authors: Y. Chibani
Venue: International Journal of Remote Sensing (2007)

A method is described for integrating panchromatic (P) and synthetic aperture radar (SAR) features into multispectral (XS) images using conjointly the modified Brovey transform (MBT) and the 'à trous' wavelet decomposition (ATDW). The MBT is based on the local modulation of each multispectral image by the ratio of the new and initial intensity components to produce new multispectral images directly. The ATWD allows extraction of features from P and SAR images, which are combined through a feature selection rule to integrate into the initial intensity component. For evaluating the effect of each feature selection on new XS images, experimental results are conducted on SPOT (XS, P) and Radarsat (SAR) images using both visual inspection and many refined statistical measures.
SRec: an animation system of recursion for algorithm courses
Authors: J. Ángel Velázquez-Iturbide, Antonio Pérez-Carrasco, Jaime Urquiza-Fuentes
Venue: Proceedings of the 13th annual conference on Innovation and technology in computer science education (2008)

In this paper we describe SRec, a system to animate recursion in Java programs. It is intended to assist in algorithm courses to better understand and analyze algorithm behavior. We make several contributions. Firstly, SRec exhibits a comprehensive set of animation and educational features. It provides three complem- entary, coordinated views of recursion: traces, the execution stack and activation trees. SRec allows the user constructing and modifying animations without effort. The animation can be played flexibly, both forward and backwards. It also provides facilities to integrate animations into courses. Secondly, the paper describes the educational features of the system and its use in algorithm courses. Thirdly, the system has been fully evaluated with respect to usability (using formative and summative methods) and has been compared to other systems reported in the literature. The results of both evaluations are highly positive.
Re-ranking search results using document-passage graphs
Authors: Michael Bendersky, Oren Kurland
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

We present a novel passage-based approach to re-ranking documents in an initially retrieved list so as to improve precision at top ranks. While most work on passage-based document retrieval ranks a document based on the query similarity of its constituent passages, our approach leverages information about the centrality of the document passages with respect to the initial document list. Passage centrality is induced over a bipartite document-passage graph, wherein edge weights represent document-passage similarities. Empirical evaluation shows that our approach yields effective re-ranking performance. Furthermore, the performance is superior to that of previously proposed passage-based document ranking methods.
Dynamic networks are as fast as static networks
Authors: B. Awerbuch, M. Sipser
Venue: Proceedings of the 29th Annual Symposium on Foundations of Computer Science (1988)

An efficient simulation is given to show that dynamic networks are as fast as static ones up to a constant multiplicative factor. That is, any task can be performed in a dynamic asynchronous network essentially as fast as in a static synchronous network. The simulation protocol is based on an approach in which locality is perceived as the key to fast adaptation to changes in network topology. The heart of the simulation is a technique called a dynamic synchronizer, which achieves 'local' simulation of a global 'clock' in a dynamic asynchronous network. Using this result, improved solutions to a number of well-known problems on dynamic networks are obtained. It can also be used to improve the solution to certain static network problems.
Orchestration of network instruments: a way to de-emphasize the partition between incremental change and innovation?
Authors: Trond Haga
Venue: AI Society (2008)

Incremental change and innovation are often regarded as two separate concepts, with some interconnections. Based on two practical cases that emphasize respectively incremental change and innovation, the article discusses whether a division between these concepts can be maintained. Action research is seen as having a central role, offering an integral working method in industrial networks.
Experimental Demonstration of a Hybrid Privacy-Preserving Recommender System
Authors: Esma Aimeur, Gilles Brassard, Jose M. Fernandez, Flavien Serge Mani Onana, Zbigniew Rakowski
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

Recommender systems enable merchants to assist customers in finding products that best satisfy their needs. Unfortunately, current recommender systems suffer from various privacy-protection vulnerabilities. We report on the first experimental realization of a theoretical framework called ALAMBIC, which we had previously put forth to protect the privacy of customers and the commercial interests of merchants. Our system is a hybrid recommender that combines content-based, demographic and collaborative filtering techniques. The originality of our approach is to split customer data between the merchant and a semi-trusted third party, so that neither can derive sensitive information from their share alone. Therefore, the system can only be subverted by a coalition between these two parties. Experimental results confirm that the performance and user-friendliness of the application need not suffer from the adoption of such privacy-protection solutions. Furthermore, user testing of our prototype show that users react positively to the privacy model proposed.
ReMo: An Energy Efficient Reprogramming Protocol for Mobile Sensor Networks
Authors: Pradip De, Yonghe Liu, Sajal K. Das
Venue: Proceedings of the 2008 Sixth Annual IEEE International Conference on Pervasive Computing and Communications (2008)

Existing code update protocols for reprogramming nodes in a sensornetwork are either unsuitable or inefficient when used in a mobile environment. The prohibitive factor of uncertainty about a node's location due to their continuous movement coupled with the obvious constraint of a node's limited resources, pose daunting challengesto the design of an effective code dissemination protocol for mobilesensor networks. In this paper, we propose \emph{ReMo}, an energy efficient, multihop reprogramming protocol for mobile sensor networks.Without making any assumptions on the location of nodes, ReMo uses the LQI and RSSI measurements of received packets to estimate link qualities and relative distances with neighbors in order to select the best node for code exchange. The protocol is based on a probabilisticbroadcast paradigm with the mobile nodes smoothly modifying their advertisement transmission rates based on the dynamic changes in network density, thereby saving valuable energy. Contrary to previous protocols, ReMo downloads pages regardless of their order, thus, exploiting the mobility of the nodes and facilitating a fast transfer of the code. Our simulation results show significant improvement in reprogramming time and number of message transmissions over other existing protocols under different settings of network mobility.
On the realization of 2-D orthogonal state-space systems
Authors: Robert T. Wirski
Venue: Signal Processing (2008)

The problem of Roesser model realization is considered in this paper. Sample-by-sample scheduling techniques are discussed, which utilize index mapping functions, resulting in column-by-column, row-by-row, and diagonal-by-diagonal implementations. It is shown that the diagonal-by-diagonal implementation requires specific approach, and can be realized using a novel switched delay structure. An adopted technique is presented for the realization of memoryless block of orthogonal 2-D state-space equations, which leads to a structure consisting of Givens rotations, possibly a -1 multiplier, and unit delays. Processing time and concurrency issues of such approach are briefly discussed.