ppxscal/embedding_network huggingface dataset:
Locking in the multithreaded FreeBSD kernel
Authors: John H. Baldwin
Venue: Proceedings of the BSD Conference 2002 on BSD Conference (2002)

About a year ago, the FreeBSD Project embarked on the ambitious task of multithreading its kernel. The primary goal of this project is to improve performance on multiprocessor (MP) systems by allowing concurrent access to the kernel while not drastically hurting performance on uniprocessor (UP) systems. As a result, the project has been dubbed the SMP next generation project, or SMPng for short. Multithreading a BSD kernel is not just a one-time change; it changes the way that data integrity within the kernel is maintained. Thus, not only does the existing code need to be reworked, but new code must also use these different methods. The purpose of this paper is to aid kernel programmers in using these methods. It is assumed that the audience is familiar with the data integrity methods used in the traditional BSD kernel. The paper will open with a brief overview of these traditional methods. Next, it will describe the synchronization primitives new to the multithreaded FreeBSD kernel including a set of guidelines concerning their use. Finally, the paper will describe the tools provided to assist developers in using these synchronization primitives properly.
Quality-Attribute Based Economic Valuation of Architectural Patterns
Authors: Ipek Ozkaya, Rick Kazman, Mark Klein
Venue: Proceedings of the First International Workshop on The Economics of Software and Computation (2007)

Architectural patterns generate value depending on the utility of the quality attributes that can be achieved from the application of those patterns. However, methods to rigorously evaluate the value-added of patterns do not exist. In this position paper, we make the case that architectural patterns carry economic value in the form of real options, providing designers with the right, but not the obligation, to take subsequent design actions in the future in the face of uncertainty. We summarize our observations in evaluating the relative value of patterns using real option valuation models on a model problem. We draw attention to how such economics-informed approaches can provide better insights for the selection of situated design strategies.
Probabilistic description logic programs
Authors: Thomas Lukasiewicz
Venue: International Journal of Approximate Reasoning (2007)

Towards sophisticated representation and reasoning techniques that allow for probabilistic uncertainty in the Rules, Logic, and Proof layers of the Semantic Web, we present probabilistic description logic programs (or pdl-programs), which are a combination of description logic programs (or dl-programs) under the answer set semantics and the well-founded semantics with Poole's independent choice logic. We show that query processing in such pdl-programs can be reduced to computing all answer sets of dl-programs and solving linear optimization problems, and to computing the well-founded model of dl-programs, respectively. Moreover, we show that the answer set semantics of pdl-programs is a refinement of the well-founded semantics of pdl-programs. Furthermore, we also present an algorithm for query processing in the special case of stratified pdl-programs, which is based on a reduction to computing the canonical model of stratified dl-programs.
Dynamic Perceptual Maps - A Psychophysical Approach to Spatiotemporal Interactions and Plasticity in Body Perception
Authors: Rupert Holzl, Jorg Trojan, Dieter Kleinbohl
Venue: Proceedings of the Second Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (2007)

Tactile illusions like sensory saltation provide a tool to assess the spatiotemporal dynamics of perceptual representations of our body. Brain imaging has been used to analyze the topographical properties of central body representations, but it is unclear how cerebral topography relates to the perceptual domain, and temporal dynamics were not evaluated. Here we show, that psychophysical methods based on spatiotemporal 2D-stimulus arrays can be used to quantify the transformation rules mapping the physical (anatomical) space of the body surface (dynamic tactile maps) via cerebral space (somatosensory maps in SI/SII) into perceptual space. Characteristic spatiotemporal functions are used to parametrize the dynamics of the representational cascade. Combining this technique with brain imaging can be used for dynamic causal modelling of the intermediate steps of the cascade as well as to construct realistic virtual environments based on one's own body as reference space.
Unusual Condition Mining for Risk Management of Hydroelectric Power Plants
Authors: Takashi Onoda, Norihiko Ito, Hironobu Yamasaki
Venue: Proceedings of the Sixth IEEE International Conference on Data Mining - Workshops (2006)

Kyushu Electric Power Co.,Inc. collects different sensor data and weather information to maintain the safety of hydroelectric power plants while the plants are running. In this paper, we consider that the abnormal condition sign may be unusual condition. This paper shows results of unusual condition patterns of bearing vibration detected from the collected different sensor data and weather information by using one class support vector machine. The result shows that our approach may be useful for unusual condition patterns detection in bearing vibration and maintaining hydroelectric power plants.
Elliptic curve DSA (ECSDA): an enhanced DSA
Authors: Don B. Johnson, Alfred J. Menezes
Venue: Proceedings of the 7th conference on USENIX Security Symposium - Volume 7 (1998)

The Elliptic Curve Digital Signature Algorithm (ECDSA) is the elliptic curve analogue of the Digital Signature Algorithm (DSA), and is under consideration for standardization by the ANSI X9 committee. Unlike the normal discrete logarithm problem and the integer factorization problem, the elliptic curve discrete logarithm problem has no subexponential-time algorithm. For this reason, the strength-perkey-bit is substantially greater in an algorithm that uses elliptic curves. In this paper, we compare the draft ANSI X9.62 ECDSA to the ANSI X9.30 DSA, the latter of which is identical to FIPS 186 DSS.
Keynote Speech
Authors: Jan Pieter Herweijer
Venue: Proceedings of the 11th European Conference on Software Maintenance and Reengineering (2007)

After his dissertation on dealing with the impact of sea-level changes in the Caribbean, Herweijer lectured for two years in Utrecht before starting his career within General Electric (USA). At General Electric he received his management education while being exposed to various business roles and responsibilities. He joined IBM Global Network Services as manager of Sales Support for Europe, Middle-East, and Africa, followed by operational management in Banking, Insurance, Government, and Education in the Netherlands. During this period he was being schooled for executive management. Akzo (now Akzo Nobel) asked him to be the general manager of their information technology consulting and products business unit and later appointed him as their corporate officer of information systems. After successfully streamlining the European IT operations of Akzo, he became member of the Groepsraad of Getronics, where he was responsible for software and consulting, disaster recovery, and payment systems services. This was later followed by an appointment as board member of Origin International. Thereafter, he was for several years senior vice president for information systems and technology with Royal Ahold.
Which n-Venn Diagrams Can Be Drawn with Convex k-Gons?
Authors: Jeremy Carroll, Frank Ruskey, Mark Weston
Venue: Discrete Computational Geometry (2007)

We establish a new lower bound for the number of sides required for the component curves of simple Venn diagrams made from polygons. Specifically, for any n-Venn diagram of convex k-gons, we prove that k &#x2265; (2n - 2 - n) / (n (n - 2)). In the process we prove that Venn diagrams of seven curves, simple or not, cannot be formed from triangles. We then give an example achieving the new lower bound of a (simple, symmetric) Venn diagram of seven convex quadrilaterals. Previously Grunbaum had constructed a symmetric 7-Venn diagram of non-convex 5-gons ["Venn Diagrams II", Geombinatorics 2:25-31, 1992].
Towards regulatory compliant storage systems
Authors: Randal Burns
Venue:  (2007)

Legislators have begun to recognize the importance of how electronically stored data should be maintained and secured. Similarly, the courts have begun to differentiate electronic data from their paper analogs. Examples of some sweeping electronic record management legislation include: the Health Insurance Portability and Accountability Act (HIPAA) of 1996, the Gramm-Leach-Bliley Act (GLBA) of 1999, and the more recent Federal Information Security Management Act (FISMA) and Sarbanes-Oxley Act (SOX) of 2002. Altogether, there exist over 4,000 acts and regulations that govern digital storage, all with a varying range of requirements for maintaining electronic records. Many current storage solutions fail to meet the new demands legislation placed on storage systems. Systems must now provide confidentiality through encrypted storage and data transmission. Some legislation requires an auditable trail of changes made to electronic records that are accessible in real-time. This implies versioning files and providing a means of quickly retrieving versions from any point in time. Other legislation sets limits on the amount of time an organization may be liable for maintaining their electronic data, but for those data that go out of scope, permanently deleting data from magnetic media can be challenging. Because electronic data is dynamic, and therefore easily malleable on disk, new methods for authentication and non-repudiation need to be developed to ensure a binding of an individual to an auditable trail of data changes. Further, these systems must be robust against both external and internal attacks. A data loss or compromise due to negligence may result in an organization falling out of compliance and susceptible to litigation. We present three technical contributions to the field of regulatory compliant storage. The first is an open-source versioning file system designed to be a platform for developing regulatory compliant storage technologies. We then introduce algorithms and an architecture for the secure deletion of individual versions of a file. Lastly, we construct an audit trail model for a versioning file system so that the changes made to data, and the order in which they occurred, may be verifiable.
Performance evaluation of RAID6 systems
Authors: Yan Li, Tim Courtney, Roland N. Ibbett, Nigel Topham
Venue: Proceedings of the 5th USENIX conference on File and Storage Technologies (2007)

The aim of this on-going work is to study the performance of RAID6 protected storage systems under a Storage Performance Council-1 (SPC-1) benchmark based workload [3]. With the scale of modern storage systems becoming increasingly large, the probability of having double disk failure in a protection group is much higher than before. As a result, there is an increasing demand for products protected against double disk failure. Although a number of double disk failure protection algorithms have been proposed, RAID6 has not been used extensively in practice due to its poor small write performance. In addition, there have been few publications about its performance under real world workloads. Given the trend of using RAID6 protection, it is important to understand the performance of RAID6 under real-world workloads. This work will study the performance of P+Q-like RAID6 algorithm as an exemplar (other RAID6 algorithms deploying two redundant disks in a protection group include Row-Diagonal Parity (RDP) [2] and EVENODD [1]) under an SPC-1 benchmark based workload using simulation. A discrete-event driven simulation model called SIMRAID has been developed to model the storage sub-system. SIMRAID contains a benchmark workload generator, a detailed RAID controller coupled with cache model, a transport-level Fibre-Channel model and disk model. The accuracy of SIMRAID has been verified through simulation of a system for which there are published SPC-1 benchmark results. This simulation shows a maximum inaccuracy of 5%. We use the maximum Business Scale Unit (BSU) value for which the average response time does not exceed 30ms as the performance metric.
Signaled receiver processing
Authors: José Brustoloni, Eran Gabber, Abraham Silberschatz, Amit Singh
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (2000)

Protocol processing of received packets in BSD Unix is interrupt-driven and may cause scheduling anomalies that are unacceptable in systems that provide quality of service (QoS) guarantees. We propose an alternative mechanism, Signaled Receiver Processing (SRP), that generates a signal to the receiving process when a packet arrives. The default action of this signal is to perform protocol processing asynchronously. However, a receiving process may catch, block, or ignore the signal and defer protocol processing until a subsequent receive call. In any case, protocol processing occurs in the context of the receiving process and is correctly charged. Therefore, SRP allows the system to enforce and honor QoS guarantees. SRP offers several advantages over Lazy Receiver Processing (LRP), a previous solution to BSD's scheduling anomalies: SRP is easily portable to systems that support neither kernel threads nor Resource Containers (e.g., FreeBSD); gives applications control over the scheduling of protocol processing; uses a demultiplexing strategy that is appropriate for both hosts and gateways; and easily enables real-time or proportional-share scheduling.
A Formal Model for Compensable Transactions
Authors: Jing Li, Huibiao Zhu, Geguang Pu, Jifeng He
Venue: Proceedings of the 12th IEEE International Conference on Engineering Complex Computer Systems (2007)

Different from traditional transactions, a compensable transaction relies on compensations to amend partial execution whenever an error occurs. The compensation is preserved on successful completion of its forward transaction for possibly later use. In this paper, we pay attention to the compositional structure of compensable transactions. Except for sequential and parallel compositions, other useful compositional constructs, such as speculative choice, exception handling, alternative forwarding and programmable compensation, are also investigated. All these constructs are not only devised to describe distinct business flow but also used to enhance the capability for dealing with errors. t-calculus is such a transactional language that involves a variety of primitives for composing compensable transactions in a wise way. We present a clear operational semantics for this language and the corresponding concept of bisimulation is defined, which is used to derive equational laws for compensable transactions.
Distributed Resource Selection in Grid Using Decision Theory
Authors: Lilian Noronha Nassif, Jose Marcos Nogueira, Flavio Vinicius de Andrade
Venue: Proceedings of the Seventh IEEE International Symposium on Cluster Computing and the Grid (2007)

Grid technology allows resource sharing among several entities, but selecting the best resource to run a specific job remains one of its main problems. The challenges for the best resource selection involve analysis of several factors such as prediction time to run a job, access restriction to resources, and cost to use resources. This paper presents a resource selection model using decision theory for combining these influential factors in the resource selection process. The model is based on a multi-attribute utility function that maximizes the user preference. This model forms part of a multi-agent system deploying distributed and parallel processing for job execution prediction, access policy verification, and resource selection models. All models of this paper were verified through experiments using real machines. They have presented appropriate functional behaviors and positive performance results.
2007 Special Issue: An experimental unification of reservoir computing methods
Authors: D. Verstraeten, B. Schrauwen, M. D'Haene, D. Stroobandt
Venue: Neural Networks (2007)

Three different uses of a recurrent neural network (RNN) as a reservoir that is not trained but instead read out by a simple external classification layer have been described in the literature: Liquid State Machines (LSMs), Echo State Networks (ESNs) and the Backpropagation Decorrelation (BPDC) learning rule. Individual descriptions of these techniques exist, but a overview is still lacking. Here, we present a series of experimental results that compares all three implementations, and draw conclusions about the relation between a broad range of reservoir parameters and network dynamics, memory, node complexity and performance on a variety of benchmark tests with different characteristics. Next, we introduce a new measure for the reservoir dynamics based on Lyapunov exponents. Unlike previous measures in the literature, this measure is dependent on the dynamics of the reservoir in response to the inputs, and in the cases we tried, it indicates an optimal value for the global scaling of the weight matrix, irrespective of the standard measures. We also describe the Reservoir Computing Toolbox that was used for these experiments, which implements all the types of Reservoir Computing and allows the easy simulation of a wide range of reservoir topologies for a number of benchmarks.
Speech enhancement for robust speech communication
Authors: V. John Mathews
Venue:  (2006)

With more and more wide usage of speech communication systems, making such systems robust to background environment becomes important. Speech enhancement systems are front-end processing elements to provide enhanced speech for use in other applications. In this dissertation, a subband speech enhancement system is explored. Subband speech enhancement systems are composed of two parts---signal representation and signal estimation.For signal representation, traditional methods use short-time Fourier transform (STFT). STFT-based methods analyze the signal with fixed time-frequency resolution once the analysis window is selected. However, speech signals are nonstationary in general. It is believed that multiresolution analysis/synthesis methods can better represent the nonstationarity of speech signals. Discrete wavelet/wavelet packet transform is a popular multiresolution representation method that has recently been explored in speech enhancement systems. Though multiresolution analysis of speech signals matches some aspects of human perception, the practical realization of a perceptually-tuned speech enhancement system using wavelet/wavelet packet transform has not yet been successful. This is due to the trade-offs between aliasing cancelation and low delay inherent in the transform. In this dissertation, I present a method for directly designing a multiresolution filter bank that has an independent subband aliasing cancelation property and at the same time achieves low delay.For signal estimation, the independent Gaussian signal assumption is commonly used for the multiresolution signal components. Recent research results have shown that independent Gaussian might not be an appropriate assumption to make. This dissertation presents a time-varying nonlinear and non-Gaussian model for the subband sequences for signal estimation. This model results in an estimation problem that does not have any analytic solution. Particle filtering was developed for fullband speech enhancement systems as a numerical solution to nonlinear/non-Gaussian estimation problems that has no analytic solution. The use of particle filtering is extended to subband domain and for colored noise cases in this dissertation.The presented subband speech enhancement outperforms its competitors and can be applied in real-time applications that have low-delay requirements.
Unifying Reasoning and Search to Web Scale
Authors: Dieter Fensel, Frank van Harmelen
Venue: IEEE Internet Computing (2007)

Researchers have developed reasoning methods for rather small, closed, trustworthy, consistent, and static domains, but Web-scalereasoning remains elusive. The authors seek to merge semantic reasoning and search in something new that reflects proper unificationwithout adding bizarre syntax to programming languages or nonscalable logic to superficially align Web principles and reasoning.
Diner based Channel Access Protocol for Nano-Machines
Authors: Adeel Ghayur
Venue: Proceedings of the First International Conference on Quantum, Nano, and Micro Technologies (2007)

Diner based Access Channel (DAC) Protocol is a Dynamic Channel Allocation Protocol. This protocol has been developed specifically for networking nano-machines, however, it can be utilized for any Mobile Ad hoc Network (MANET). The operation of the protocol is based on the way a diner operates. This paper presents the DAC protocol for any MANET describes its concept, algorithm and working, and also discusses its application areas.
Teaching introductory graphics with web assistance
Authors: J. A. Vila
Venue: Proceedings of the Frontiers in Education Conference, 2001. 31st Annual - Volume 02 (2001)

The introduction of high speed computers with excellent graphic rendering capabilities and software that takes advantage of those capabilities have precipitated a change in the philosophy of teaching introductory courses in graphics. Studies of introductory computer graphics courses have indicated that algorithms, such as line and circle drawing and polygon fills, and the study of data structures to support graphics are common topics taught in introductory courses. A cursory review of available software tools for teaching computer graphics topics indicates that there is a lack of web-based visualizations of commonly taught computer graphics algorithms. The purpose of this paper is to describe a web-based tutorial that has been used to supplement an introductory computer graphics course.
Performance Evaluation of SIPv6 Transitioning
Authors: Thomas Hoeher, Martin Petraschek, Slobodanka Tomic, Michael Hirschbichler
Venue: Proceedings of the International Multi-Conference on Computing in the Global Information Technology (2007)

Due to the continuous massive growth of the global Internet, available IPv4 network addresses will run out within the next years. The solution to this problem is the IPv6 protocol with its vast address space. During the transition period from IPv4 to IPv6, both protocols will coexist, which makes it necessary to have transition techniques in place to maintain interoperability. These transition techniques have an inevitable impact on network performance. To quantify this impact, we set up a testbed to measure the performance penalties introduced by four transition techniques. In general, measurements of the transition performance can be carried out on different layers. The decision to pick the Session Initiation Protocol (SIP) as application layer protocol is based on the fact that Voice over IP may be one of the major drivers for IPv6. This paper presents measurement results and conclusions for transition and native scenarios that we gained in performance studies.
CARA: A Cultural-Reasoning Architecture
Authors: V. S. Subrahmanian, Massimiliano Albanese, Maria Vanina Martinez, Dana Nau, Diego Reforgiato, Gerardo I. Simari, Amy Sliva, Octavian Udrea, Jonathan Wilkenfeld
Venue: IEEE Intelligent Systems (2007)

The Cognitive Architecture for Reasoning about Adversaries supports methods to gather data about different cultural groups and learn the intensity of those groups' opinions on various topics. It also lets users build and extract models of those groups' behavior and continuously refine those models through shared multiperson learning experiences. Researchers have applied the architecture to develop cultural-reasoning applications for example, a game that teaches soldiers about cultural norms in an Afghan village.