ppxscal/embedding_network huggingface dataset:
A logical framework for history-based access control and reputation systems
Authors: Karl Krukow, Mogens Nielsen, Vladimiro Sassone
Venue: Journal of Computer Security (2008)

Reputation systems are meta systems that record, aggregate and distribute information about principals' behaviour in distributed applications. Similarly, history-based access control systems make decisions based on programs' past security-sensitive actions. While the applications are distinct, the two types of systems are fundamentally making decisions based on information about the past behaviour of an entity. A logical policy-centric framework for such behaviour-based decision-making is presented. In the framework, principals specify policies which state precise requirements on the past behaviour of other principals that must be fulfilled in order for interaction to take place. The framework consists of a formal model of behaviour, based on event structures; a declarative logical language for specifying properties of past behaviour; and efficient dynamic algorithms for checking whether a particular behaviour satisfies a property from the language. It is shown how the framework can be extended in several ways, most notably to encompass parameterized events and quantification over parameters. In an extended application, it is illustrated how the framework can be applied for dynamic history-based access control for safe execution of unknown and untrusted programs.
DepSpace: a byzantine fault-tolerant coordination service
Authors: Alysson Neves Bessani, Eduardo Pelison Alchieri, Miguel Correia, Joni Silva Fraga
Venue: Proceedings of the 3rd ACM SIGOPS/EuroSys European Conference on Computer Systems 2008 (2008)

The tuple space coordination model is one of the most interesting coordination models for open distributed systems due to its space and time decoupling and its synchronization power. Several works have tried to improve the dependability of tuple spaces through the use of replication for fault tolerance and access control for security. However, many practical applications in the Internet require both fault tolerance and security. This paper describes the design and implementation of DepSpace, a Byzantine fault-tolerant coordination service that provides a tuple space abstraction. The service offered by DepSpace is secure, reliable and available as long as less than a third of service replicas are faulty. Moreover, the content-addressable confidentiality scheme developed for DepSpace bridges the gap between Byzantine fault-tolerant replication and confidentiality of replicated data and can be used in other systems that store critical data.
Efficient binary schemes for training heterogeneous sensor and actor networks
Authors: Ferruccio Barsi, Alfredo Navarra, Cristina M. Pinotti, Christian Lavault, Vlady Ravelomanana, Stephan Olariu, Alan A. Bertossi
Venue: Proceeding of the 1st ACM international workshop on Heterogeneous sensor and actor networks (2008)

Sensor networks are expected to evolve into long-lived, autonomous networked systems whose main mission is to provide in-situ users - called actors - with real-time information in support of specific goals supportive of their mission. The network is populated with a heterogeneous set of tiny sensors. The free sensors alternate between sleep and awake periods, under program control in response to computational and communication needs. The periodic sensors alternate between sleep periods and awake periods of predefined lengths, established at the fabrication time. The architectural model of an actor-centric network used in this work comprises in addition to the tiny sensors a set of mobile actors that organize and manage the sensors in their vicinity. We take the view that the sensors deployed are anonymous and unaware of their geographic location. Importantly, the sensors are not, a priori,organized into a network. It is, indeed, the interaction between the actors and the sensor population that organizes the sensors in a disk around each actor into a short-lived, mission-specific, network that exists for the purpose of serving the actor and that will be disbanded when the interaction terminates. The task of setting up this form of actor-centric network involves a training stage where the sensors acquire dynamic coordinates relative to the actor in their vicinity. The main contribution of this work is to propose an energy-efficient training protocol for actor-centric heterogeneous sensor networks. Our protocol outperforms all know training protocols in the number of sleep/awake transitions per sensor needed by the training process. Specifically, in the presence of κ coronas, no sensor will experience more than ⌈log κ⌉ sleep/awake transitions and awake periods.
Evaluating the discrimination of Cu-mineralized rock alteration products from simulated MAPSAR Images in the Curaçá Valley, Brazil
Authors: T. N. Rabelo, W. R. Paradella, A. R. Santos, C. D. Rennó, L. S. Galvão, J. C. Mura, S. S. A. Knust
Venue: International Journal of Remote Sensing (2007)

L-band images simulating MAPSAR satellite sensor data were used to identify Cu-mineralized rock alteration products in the Curaçá Valley, Brazil. The area is characterized by a semi-arid terrain, with residual soils and xerophytic vegetation. The mineralizations are mainly associated with pyroxenites but are also found in norites, gabbro-norites, and anorthosites. These mafic-ultramafic rocks produce characteristic Vertisols. A quantitative analysis for the rock discrimination was based on JM distances derived from training samples (amplitude values of L-HH, L-VV, and L-HV). The investigation showed the possibility of the discrimination of ore-bearing intrusives from the host rocks, with the exception of amphibolite. Variations in the surface moisture affected the SAR responses, prior to the data acquisition, and caused the higher returns created by wet Vertisols, favouring the discrimination of the rock alteration products.
A nonlinear transversal fuzzy filter with online clustering
Authors: Zhengrong Li, Meng Joo Er
Venue: Proceedings of the 2nd WSEAS International Conference on Electronics, Control and Signal Processing (2003)

In this paper, a nonlinear transversal fuzzy filter with online clustering is proposed. It is based on radial-basis-function networks (RBFN) and implements the TSK fuzzy systems functionally. The proposed filter has the following features: (1) Hierarchical structure self-construction. The fuzzy rules, i.e., the RBF neurons are generated automatically in training process. (2) Online clustering. Instead of selecting the centers and widths of membership functions arbitrarily, an online clustering method is applied to ensure the reasonable representation of input terms of an input variable. It not only ensures the proper feature representation, but also optimizes the structure of the filter by reducing the number of fuzzy rules. (3) All free parameters in the premise and consequence parts are online determined by a hybrid sequential algorithm without repeated computation to make real-time applications possible. Using a proposed hybrid learning algorithm, low computation load and less memory requirements are achieved. Simulation results show that the proposed filter can obtain better or same accuracy with lower system resource requirements compared with other similar approaches.
Resource Usage Policy Specification for Managing Application Resources
Authors: Prem Uppuluri, Ajay Gupta
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

Specification and enforcement of resource usage policies of applications is an important problem in different areas of Computer Science such as in Grid Computing and execution of mobile code on language-based virtual machines such as JVM. In this paper we survey existing approaches to resource management; identify some of the key requirements of a language to specify resource usage policies and propose a new language to enforce resource usage policies. We give examples on how the language can be used to specify different types of resource usage policies.
The effect of tourniquet release timing on perioperative blood loss in simultaneous bilateral cemented total knee arthroplasty: A prospective randomized study
Authors: Fritz Thorey, Christina Stukenborg-Colsman, Henning Windhagen, Carl Joachim Wirth
Venue: Technology and Health Care (2008)

Today the use of pneumatic tourniquet is commonly accepted in total knee arthroplasty (TKA) to reduce perioperative blood loss. There are a few prospective randomised and nonrandomised studies that compare the effect of tourniquet release timing in cementless or cemented unilateral TKA. However, many of these studies show an inadequate reporting and methodology. This randomized prospective study was designed to investigate the efficiency of tourniquet release timing in preventing perioperative blood loss in a simultaneous bilateral TKA study design. To our knowledge, this is the first study of its kind, in which the effect of tourniquet release timing on perioperative blood loss was investigated in simultaneous bilateral cemented TKA to compare both techniques intraindividually. In 20 patients (40 knees) one knee was operated with tourniquet release and hemostasis before wound closure, and the other knee with tourniquet release after wound closure and pressure dressing. We found no significant difference in total blood loss between both techniques (p=0.930), but a significant difference in operating time (p=0.035). There were no postoperative complications at a follow-up of 6 month. Other studies report an increase the blood loss in early tourniquet release and an increase the risk of early postoperative complications in deflation of tourniquet after wound closure. In this study we found no significant difference in perioperative blood loss and no increase of postoperative complications. Therefore, we recommend a tourniquet release after wound closure to reduce the duration of TKA procedure and to avoid possible risks of extended anaesthesia.
Power optimization in fault-tolerant topology control algorithms for wireless multi-hop networks
Authors: Mohammad Taghi Hajiaghayi, Nicole Immorlica, Vahab S. Mirrokni
Venue: IEEE/ACM Transactions on Networking (TON) (2007)

In ad hoc wireless networks, it is crucial to minimize power consumption while maintaining key network properties. This work studies power assignments of wireless devices that minimize power while maintaining k-fault tolerance. Specifically, we require all links established by this power setting be symmetric and form a k-vertex connected subgraph of the network graph. This problem is known to be NP-hard. We show current heuristic approaches can use arbitrarily more power than the optimal solution. Hence, we seek approximation algorithms for this problem. We present three approximation algorithms. The first algorithm gives an O(kα)-approximation where α is the best approximation factor for the related problem in wired networks (the best α so far is O(log k).) With a more careful analysis, we show our second (slightly more complicated) algorithm is an O(k)-approximation. Our third algorithm assumes that the edge lengths of the network graph form a metric. In this case, we present simple and practical distributed algorithms for the cases of 2- and 3-connectivity with constant approximation factors. We generalize this algorithm to obtain an O(k2c+2)-approximation for general k-connectivity (2≤c≤4 is the power attenuation exponent). Finally, we show that these approximation algorithms compare favorably with existing heuristics. We note that all algorithms presented in this paper can be used to minimize power while maintaining k-edge connectivity with guaranteed approximation factors. Recently, different set of authors used the notion of k-connectivity and the results of this paper to deal with the fault-tolerance issues for static wireless network settings.
Primal-dual stability in continuous linear optimization
Authors: Miguel A. Goberna, Maxim I. Todorov
Venue: Mathematical Programming: Series A and B (2008)

Any linear (ordinary or semi-infinite) optimization problem, and also its dual problem, can be classified as either inconsistent or bounded or unbounded, giving rise to nine duality states, three of them being precluded by the weak duality theorem. The remaining six duality states are possible in linear semi-infinite programming whereas two of them are precluded in linear programming as a consequence of the existence theorem and the non-homogeneous Farkas Lemma. This paper characterizes the linear programs and the continuous linear semi-infinite programs whose duality state is preserved by sufficiently small perturbations of all the data. Moreover, it shows that almost all linear programs satisfy this stability property.
The Traveling Salesman Problem: A Computational Study (Princeton Series in Applied Mathematics)
Authors: David L. Applegate, Robert E. Bixby, Vasek Chvatal, William J. Cook
Venue:  (2007)

This book presents the latest findings on one of the most intensely investigated subjects in computational mathematics--the traveling salesman problem. It sounds simple enough: given a set of cities and the cost of travel between each pair of them, the problem challenges you to find the cheapest route by which to visit all the cities and return home to where you began. Though seemingly modest, this exercise has inspired studies by mathematicians, chemists, and physicists. Teachers use it in the classroom. It has practical applications in genetics, telecommunications, and neuroscience.The authors of this book are the same pioneers who for nearly two decades have led the investigation into the traveling salesman problem. They have derived solutions to almost eighty-six thousand cities, yet a general solution to the problem has yet to be discovered. Here they describe the method and computer code they used to solve a broad range of large-scale problems, and along the way they demonstrate the interplay of applied mathematics with increasingly powerful computing platforms. They also give the fascinating history of the problem--how it developed, and why it continues to intrigue us.
An evaluation of airborne laser scan data for coalmine subsidence mapping
Authors: D. R. Palamara, M. Nicholson, P. Flentje, E. Baafi, G. M. Brassington
Venue: International Journal of Remote Sensing (2007)

The accurate mapping of coalmine subsidence is necessary for the continued management of potential subsidence impacts. The use of airborne laser scan (ALS) data for subsidence mapping provides an alternative method to traditional ground-based approaches that affords increased accessibility and complete spatial coverage. This paper evaluates the suitability and potential of ALS data for subsidence mapping, primarily through the examination of two pre-mining surveys in a rugged, densely vegetated study site. Data quality, in terms of mean point spacing and coverage, is evaluated, along with the impact of interpolation methods, resolution and terrain. It was assumed that minimal surface height changes occurred between the two pre-mining surfaces. Therefore any height changes between digital elevation models of the two ALS surveys were interpreted as errors associated with the use of ALS data for subsidence mapping. A mean absolute error of 0.23 m was observed, though this error may be exaggerated by the presence of a systematic 0.15 m offset between the two surveys. Very large (several metres) errors occur in areas of steep or dynamic terrain, such as along cliff lines and watercourses. Despite these errors, preliminary subsidence mapping, performed using a third, post-mining dataset, clearly demonstrates the potential benefits of ALS data for subsidence mapping, as well as some potential limitations and the need for further careful assessment and validation concerning data errors.
Towards a Security Cockpit
Authors: Nguyen Pham, Loic Baud, Patrick Bellot, Michel Riguidel
Venue: Proceedings of the 2008 International Conference on Information Security and Assurance (isa 2008) (2008)

Building systems that are guaranteed to be secure or to remain secure over time is still an unachievable goal. The need for a security cockpit that helps to determine security assurance level of a system in a near real time manner is therefore vital in order to maintain and improve overall security. This paper discusses different steps in the whole security assurance assessment process in order to build such cockpit. To test and evaluate the applicability of our approach, we introduce then a system capable of assessing the security assurance level of a network system. Currently, this assessment system focuses on the availability aspect of the security.
Multivariate stochastic fuzzy forecasting models
Authors: Tahseen Ahmed Jilani, Syed Muhammad Aqil Burney
Venue: Expert Systems with Applications: An International Journal (2008)

In this paper, we have presented two new multivariate fuzzy time series forecasting methods. These methods assume m-factors with one main factor of interest. Stochastic fuzzy dependence of order k is assumed to define general methods of multivariate fuzzy time series forecasting and control. These new methods are applied for forecasting total number of car road accidents casualties in Belgium using four secondary factors. Practically, in most of the situations, actuaries are interested in analysis of the patterns of casualties in road accidents. Such type of analysis supports in deciding approximate risk classification and forecasting for each area of a city. This directly affects the underwriting process and adjustment of insurance premium, based on risk intensity for each area. National Institute of Statistics, Belgium provides risk intensity based classification of each city. Thus, this work provides support in deciding the appropriate risk associated with an insured in a particular area.
Reversible Network Iterative Construct Method Based on the Cascade Operation
Authors: Zhijin Guan, Xiaolin Qin, Xinchun Cui
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

This paper presents an algorithm of iterative construct reversible network by cascade operation. The cascade operation was implemented with Boolean permutation. We proposed two important decision condition of Boolean permutation, and changed to choose balance function of suffice Boolean permutation condition for the problem of construct reversible network. The result of algorithm analysis show that it is can be implemented fleetly.
SCCR digital learning system for scientific conceptual change and scientific reasoning
Authors: Hsiao-Ching She, Chin-Quen Lee
Venue: Computers Education (2008)

This study reports an adaptive digital learning project, scientific concept construction and reconstruction (SCCR), that was developed based on the theories of Dual Situated Learning Model (DSLM) and scientific reasoning. In addition, the authors investigated the effects of an SCCR related to a ''combustion'' topic for sixth grade students conceptual change and scientific reasoning. An experimental research design including the Combustion Achievement Test (CAT), Scientific Reasoning Test (SRT) and Combustion Dependent Reasoning Test (CDRT) was applied for both experimental and conventional group students before, directly after, and after the sixth week of the research as pre-, post- and retention-test. Results indicated that the experimental group students significantly outperformed the conventional group students on both post- and retention- of CAT and CDRT scores. In addition, experimental group students performed better than conventional group students on the post-SRT scores. The success rate of conceptual change ranged from 70% to 100% for experimental group students for most web-based dual situated learning events. The nature of the scientific reasoning used by experimental group students mainly either made progression (PG) or maintain-correct (MTC) across most events from before to after web-based dual situated learning events. All of these results support the claim that students' conceptual change their scientific reasoning ability can be promoted through an SCCR digital learning program.
Modeling the Plasticity in Motor Cortex
Authors: Dong-Mei Hao, Ming-Ai Li, Ying Li
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 01 (2008)

To study the mechanism of motor deficiency, therapy and rehabilitation following stroke, motor cortex network was represented as a directed graph and implemented as a dynamical system. Complexity was used to express the extent to which a system is both functionally segregated and functionally integrated. Motor cortex network was optimized by pattern search to investigate the change of connection under normal, stroke and rehabilitation state. The simulation results show that motor areas have strong connections in normal state. The connections between motor areas decrease greatly, but connections with other areas and self-connections increase in stroke. Stimulation acting on specified areas help to strengthen motor areas connections and weaken other connections to evolve the system to normal state. It indicates the model can reflect the plasticity of motor cortex qualitatively.
A highly efficient implementation of a backpropagation learning algorithm using matrix ISA
Authors: Mostafa I. Soliman, Samir A. Mohamed
Venue: Journal of Parallel and Distributed Computing (2008)

BackPropagation (BP) is the most famous learning algorithm for Artificial Neural Networks (ANN). BP has received intensive research efforts to exploit its parallelism in order to reduce the training time for complex problems. A modified version of BP based on matrix-matrix multiplication was proposed for parallel processing. In this paper, we present the implementation of Matrix BackPropagation (MBP) using scalar, vector, and matrix Instruction Set Architectures (ISAs). Besides this, we show that the performance of the MBP is improved by switching from scalar ISA to vector ISA. It is further improved by switching from vector ISA to matrix ISA. On a practical application, speech recognition, the speedup of training a neural network using unrolling scalar ISA over scalar ISA is 1.83. On eight parallel lanes, the speedups of using vector, unrolling vector, and matrix ISAs are respectively 10.33, 11.88, and 15.36, where the maximum theoretical speedup is 16. The results obtained show that the use of matrix ISA gives a performance close to optimal, because of reusing the loaded data, decreasing the loop overhead, and overlapping the memory operations with arithmetic operations.
WavePipe: parallel transient simulation of analog and digital circuits on multi-core shared-memory machines
Authors: Wei Dong, Peng Li, Xiaoji Ye
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

While the emergence of multi-core shared-memory machines offers a promising computing solution to ever complex chip design problems, new parallel CAD methodologies must be developed to gain the full benefit of these increasingly parallel computing systems. We present a parallel transient simulation methodology and its multi-threaded implementation for general analog and digital ICs. Our new approach, Waveform Pipelining (abbreviated as WavePipe), exploits coarsegrained application-level parallelism by simultaneously computing circuit solutions at multiple adjacent time points in a way resembling hardware pipelining. There are two embodiments in WavePipe: backward and forward pipelining schemes. While the former creates independent computing tasks that contribute to a larger future time step by moving backwards in time, the latter performs predictive computing along the forward direction of the time axis. Unlike existing relaxation methods, WavePipe facilitates parallel circuit simulation without jeopardying convergence and accuracy. As a coarse-grained parallel approach, WavePipe not only requires low parallel programming effort, more importantly, it creates new avenues to fully utilize increasingly parallel hardware by going beyond conventional finer grained parallel device model evaluation and matrix solutions.