ppxscal/embedding_network huggingface dataset:
Semantically-Aided Data-Aware Service Workflow Composition
Authors: Ondrej Habala, Marek Paralič, Viera Rozinajová, Peter Bartalos
Venue: Proceedings of the 35th Conference on Current Trends in Theory and Practice of Computer Science (2009)

Composition of workflows of computational tasks, grid jobs, or even web services is not a new topic. Many papers and research projects have tackled this problem in the past, in recent years also using semantic description of resources. Most of the proposed or developed solutions deal only with the composition of the functional part of the workflow, the data necessary to actually execute it is considered secondary. The system, design of which we describe in this paper, tries to overcome this gap, and create workflows with the input data of the workflow actions already included. Our design is based on an existing solution from the project K-Wf Grid. The workflow is modeled as a Petri net, which allows for easy incorporation of data into the process. It utilizes semantic description of resources by means of ontologies, and operates on a SOA-based grid composed of web services. It is being developed in the context of a project called SEMCO-WS.
Stack-based parallel recursion on graphics processors
Authors: Ke Yang, Bingsheng He, Qiong Luo, Pedro V. Sander, Jiaoying Shi
Venue: ACM SIGPLAN Notices (2009)

Recent research has shown promising results on using graphics processing units (GPUs) to accelerate general-purpose computation. However, today's GPUs do not support recursive functions. As a result, for inherently recursive algorithms such as tree traversal, GPU programmers need to explicitly use stacks to emulate the recursion. Parallelizing such stack-based implementation on the GPU increases the programming difficulty; moreover, it is unclear how to improve the efficiency of such parallel implementations. As a first step to address both ease of programming and efficiency issues, we propose three parallel stack implementation alternatives that differ in the granularity of stack sharing. Taking tree traversals as an example, we study the performance tradeoffs between these alternatives and analyze their behaviors in various situations. Our results could be useful to both GPU programmers and GPU compiler writers.
Exploring the design space of reliable multicast protocols for wireless mesh networks
Authors: Dimitrios Koutsonikolas, Y. Charlie Hu
Venue: Ad Hoc Networks (2009)

Many important applications in wireless mesh networks require reliable multicast communication, i.e., with 100% packet delivery ratio (PDR). Previously, numerous multicast protocols based on automatic repeat request (ARQ) have been proposed to improve the packet delivery ratio. However, these ARQ-based protocols can lead to excessive control overhead and drastically reduced throughput. In this paper, we present a comprehensive exploration of the design space for developing high-throughput, reliable multicast protocols that achieve 100% PDR. Motivated by the fact that 802.11 MAC layer broadcast, which is used by most wireless multicast protocols, offers no reliability, we first examine if better hop-by-hop reliability provided by unicasting the packets at the MAC layer can help to achieve end-to-end multicast reliability. We then turn to end-to-end solutions at the transport layer. Previously, forward error correction (FEC) techniques have been proved effective for providing reliable multicast in the Internet, by avoiding the control packet implosion and scalability problems of ARQ-based protocols. In this paper, we examine if FEC techniques can be equally effective to support reliable multicast in wireless mesh networks. We integrate four representative reliable schemes (one ARQ, one FEC, and two hybrid) originally developed for the Internet with a representative multicast protocol ODMRP and evaluate their performance. Our experimental results via extensive simulations offer an in-depth understanding of the various choices in the design space. First, compared to broadcast-based unreliable ODMRP, using unicast for per-hop transmission only offers a very small improvement in reliability under low load, but fails to improve the reliability under high load due to the significantly increased capacity requirement which leads to congestion and packet drop. Second, at the transport layer, the use of pure FEC can significantly improve the reliability, increasing PDR up to 100% in many cases, but can be inefficient in terms of the number of redundant packets transmitted. In contrast, a carefully designed ARQ-FEC hybrid protocol, such as RMDP, can also offer 100% reliability while improving the efficiency by up to 38% compared to a pure FEC scheme. To our best knowledge, this is the first in-depth study of high-throughput, reliable multicast protocols that provide 100% PDR for wireless mesh networks.
A process variation tolerant, high-speed and low-power current mode signaling scheme for on-chip interconnects
Authors: Marshnil Vipin Dave, Maryam Shojaei Baghini, Dinesh Kumar Sharma
Venue: Proceedings of the 19th ACM Great Lakes symposium on VLSI (2009)

Current mode signaling(CMS) scheme is one of the promising alternatives to voltage mode buffer insertion scheme for high-speed low-power data transmission over long on-chip interconnects. In this paper we present a CMS scheme with dynamic overdriving driver (DOD) whose performance is robust against intra-die and inter-die process variations. We show that throughput of the CMS scheme proposed in [1] degrades by 33% in the presence of intra-die process variations whereas that of the scheme in [2] degrades by 36% in the worst case process corner. Simulation results show that throughput of the proposed CMS scheme degrades by only 9.5% in presence of intra-die process variations and 22% in the worst case process corner. In this process corner, logic speed itself degrades by 23% and hence 22% of throughput degradation of the proposed signaling scheme is not a major concern. In the typical process corner, the proposed CMS scheme shows 14% and 19% improvement in delay and power, respectively over CMS scheme proposed in [1].
Implementation of PCCD-OFDM-ASK Robust Data Transmission over GSM Speech Channel
Authors: Zdenko Mezgec Amor Chowdhury Bojan Kotnik, Rajko Svečko
Venue: Informatica (2009)

This paper presents a novel data modulation scheme PCCD-OFDM-ASK: the phase continuous context dependent orthogonal frequency division multiplexing amplitude shift keying. The proposed modulation is successfully applied in the mobile payment system. It is used to transmit the digital data over the speech channel of the mobile communication system GSM, as well as CDMA. The main key points of the proposed modulation schemes are: precise signal synchronization between the modulator and demodulator, signal energy independent operation, on line adaptation of frequency characteristics of the transmission channel, and controlled frequency bandwidth thus enabling non-overlapped full duplex communication over the GSM's voice channel.
Policy-Aware Visualization of Internet Dynamics
Authors: Luca Cittadini, Tiziana Refice, Alessio Campisano, Giuseppe Battista, Claudio Sasso
Venue: Graph Drawing: 16th International Symposium, GD 2008, Heraklion, Crete, Greece, September 21-24, 2008. Revised Papers (2009)

The Internet can be represented as a graph of Autonomous Systems (ASes). Each AS dynamically selects the (AS-)paths to reach destinations on the Internet, according to inter-AS customer-provider relationships. Such relationships define a hierarchy of all the ASes.
An Infrastructure for Application Level Multicast in Publish/Subscribe System
Authors: Peng Hu, Yuan'an Liu, Lidong Zhai, Xiaolei Ma, Ming Yang
Venue: Proceedings of the 2009 WRI International Conference on Communications and Mobile Computing - Volume 03 (2009)

The Application level multicast is an important technique for indirect communication model. However, there are few works to integrate them together. An Infrastructure for Application Level Multicast Routing in Publish/Subscribe system (IALMRS) is proposed in this paper. We realize a multicast routing protocol for such Publish/Subscribe systems based on IALMRS. From the tests for this multicast routing protocol in publish/subscribe system, IALMPS has a good performance in time delay.
Role of lanthanum in the gate stack: Co-sputtered TaLaN metal gates on Hf-based dielectrics
Authors: Brian Coss, Hyun-Chul Kim, Francisco S. Aguirre-Tostado, Robert M. Wallace, Jiyoung Kim
Venue: Microelectronic Engineering (2009)

We examine the characteristics of TaLaN metal gates in direct contact with HfO"2 dielectric, in particular focusing on the effect of La in the gate stack for NMOS applications. Effective work functions (EWF) and vacuum work functions (WF) are measured as a function of lanthanum content in TaLaN without any intentional heating using X-ray photoelectron spectroscopy, U-V photoelectron spectroscopy, and electrical C-V measurements. We find that the addition of lanthanum to tantalum nitride lowered both the EWF and the WF of the metal gate by ~0.2eV and ~0.9eV, respectively. Furthermore, XPS indicates that lanthanum in TaLaN at the interface with HfO"2 is primarily bonded to nitrogen rather than oxygen and not reacting with the dielectric.
Recovery domains: an organizing principle for recoverable operating systems
Authors: Andrew Lenharth, Vikram S. Adve, Samuel T. King
Venue: ACM SIGPLAN Notices (2009)

We describe a strategy for enabling existing commodity operating systems to recover from unexpected run-time errors in nearly any part of the kernel, including core kernel components. Our approach is dynamic and request-oriented; it isolates the effects of a fault to the requests that caused the fault rather than to static kernel components. This approach is based on a notion of "recovery domains," an organizing principle to enable rollback of state affected by a request in a multithreaded system with minimal impact on other requests or threads. We have applied this approach on v2.4.22 and v2.6.27 of the Linux kernel and it required 132 lines of changed or new code: the other changes are all performed by a simple instrumentation pass of a compiler. Our experiments show that the approach is able to recover from otherwise fatal faults with minimal collateral impact during a recovery event.
Stabilization of the fuzzy control systems, with application at the second order systems
Authors: Constantin Volosencu
Venue: Proceedings of the 8th conference on Simulation, modelling and optimization (2008)

The paper presents a method to assure stability of the fuzzy control systems of the second order processes, based on a compensation of the input-output characteristic of the fuzzy blocks used in the PI fuzzy controllers. For this purpose is acting at the correction of the fuzzy control law by the action in parallel of a crisp block. Stability analysis of the control systems of the second order systems with fuzzy controllers is framed in the field of non-linear systems. The paper presents the way to prove the absolute stability in such a situation. The correction principle is theoretically substantiated and methodologically structured with application at the fuzzy control of the second order processes.
ARQ performance in SNA networks
Authors: Martin A. Reed, Terence D. Smetanka
Venue: Proceedings of the May 19-22, 1980, national computer conference (1980)

In order to examine various data link control (DLC) procedures, one must first have a basic understanding of the overall network. The network depicted will be one implementing the IBM Systems Network Architecture (SNA). The fundamental communication system within SNA is referred to as the Transmission Subsystem. The Transmission Subsystem includes three types of elements. The first element, Data Link Control (DLC), transfers packets (or SNA Basic Transmission Units) across noisy transmission mediums. The protocol used here is that of SDLC (Synchronous Data Link Control). The second element, referred to as Path Control (PC), routes packets either to an end user in the node or to the proper DLC element for transmission back through the network. Path Control also blocks incoming messages and deblocks outgoing messages (i.e., SNA segmenting). Transmission Control (TC) helps manage SNA session (i.e., connection) initiation and termination, provides sequence number manipulation, controls pacing, and performs many other functions on behalf of the end user. Pacing is a means of controlling the rate at which TC sends and receives normal data flow requests.
Collaborative authentication in unattended WSNs
Authors: Roberto Di Pietro, Claudio Soriente, Angelo Spognardi, Gene Tsudik
Venue: Proceedings of the second ACM conference on Wireless network security (2009)

An unattended wireless sensor network (UWSN) might collect valuable data representing an attractive target for the adversary. Since a sink visits the network infrequently, unattended sensors cannot immediately off-load data to some safe external entity. With sufficient time between sink visits, a powerful mobile adversary can easily compromise sensor-collected data. In this paper, we propose two schemes (CoMAC and ExCo) that leverage sensor co-operation to achieve data authentication. These schemes use standard (and inexpensive) symmetric cryptographic primitives coupled with key evolution and few messages exchange. We provide security analysis for proposed schemes and assess their effectiveness via simulations. We show that proposed schemes cope well with real WSN issues, such as message loss and sensor failure. We also compare the two schemes with respect to robustness and overhead, which allows network designers to carefully select the right scheme and tune appropriate system parameters.
Effects of psychostimulants on alertness and spatial bias in healthy participants
Authors: Chris Dodds, Ulrich Müller, Tom Manly
Venue: Journal of Cognitive Neuroscience (2009)

Converging evidence from neuropsychological and neuroimaging studies suggests that the ability to maintain an alert, ready-to-respond state is mediated by a network of right-hemisphere frontal and parietal cortical areas. This right lateralization may help to explain why visuospatial hemineglect, a cluster of deficits in detecting and responding to contralesional stimuli, is more common and persistent after right-hemisphere lesions. Indeed, it has been hypothesized that this asymmetry reflects a direct, functional link between alertness and spatial attention. In the present study, we investigated whether a pharmacologically induced increase in alertness would influence lateral bias in healthy people. Eighteen healthy participants were each given placebo or the psychostimulant drugs methylphenidate 40 mg or modafinil 400 mg on separate days and completed an hour-long version of the spatially sensitive landmark task. For those participants who demonstrated the expected alerting effect of modafinil, there was a significant Condition by Time interaction, consistent with the effects of the drug resisting time-on-task rightward drifts in spatial bias in the placebo condition. In contrast, no effect of methylphenidate on spatial bias was observed. These results suggest that spatial bias may be modulated by a psychostimulant-induced increase in alertness, supporting the hypothesis of a direct, functional link between right-hemisphere systems controlling alertness and visuospatial attention.
Web hypermedia content management system effort estimation model
Authors: Naveen Aggarwal, Nupur Prakash, Sanjeev Sofat
Venue: ACM SIGSOFT Software Engineering Notes (2009)

This study aims at creation of a well defined estimation model which can be used to estimate the effort required for designing and developing the web hypermedia content management systems. The data from the different content management system projects are studied and the linear regression approach is used to finalize the model. This model also provides guidelines to calculate phase wise distribution of effort. The model is designed to help project manager to estimate effort at the very early stage of requirement analysis. A set of questionnaire is used to estimate the complexity of the project, which has to be filled after completing the initial requirement analysis. Final effort is estimated using the project size and the different adjustment factors. For better calculation of these adjustments factors, these are categorized into three categories based on their characteristics such as Production and General system characteristics. This model is proposed to be used differently for the different types of projects. These projects are categorized based on their size and total/build effort ratio. The size of the project is estimated by using the modified object point analysis approach. The estimated effort is further phase wise distributed for better scheduling of the project. Another questionnaire is used to refine the model and it has to be filled by the project managers after completing the project. The proposed model is validated by studying twelve completed projects taken from industry and seventy different projects completed by the students. The proposed model shows a great improvement as compared to the earlier models used in effort estimation of CMS projects.
Mapping of large magnitude discontinuous sea ice motion
Authors: M. Thomas, C. Kambhamettu, C. A. Geiger
Venue: SIGSPATIAL Special (2009)

In this work, we attempt to extend the body of knowledge on sea ice motion tracking in two specific directions. The first direction is the development of a computationally efficient, high resolution motion tracking system with a resolution of 400m, which is an order of magnitude greater than the currently available standard data products (3--5km). Validation of this method using GPS measurements shows an average error that is less than 0.06cm/s. The second direction is the development of objective analysis technique to handle motion at close proximity to discontinuities. The goal of this second direction is to identify and track discontinuous features such as cracks, leads, ridges and other material damage zones. These developments allow motion to be estimated at a high resolution in a robust manner (validated against various noise models). With the observed changes in global climate, sparked by variations in the sea ice thickness and extent, our long term goal is to use this system to merge the "temporally rich" GPS measurements with the "spatially rich" measurements from satellite images.
Model Predictive Control --- Numerical Methods for the Invariant Sets Approximation
Authors: H. Benlaoukli, S. Olaru
Venue: Numerical Analysis and Its Applications: 4th International Conference, NAA 2008, Lozenetz, Bulgaria, June 16-20, 2008. Revised Selected Papers (2009)

This paper deals with the computational issues encountered in the construction of invariant sets for LTI (Linear Time Invariant) systems subject to linear constraints. Three algorithms to compute or approximate the invariant set are presented. Two of theme are based on expansive and contractive strategy, while the third one uses the transition graph over the partition of the closed loop piecewise affine system.
Paradigms of Denotational Mathematics for Cognitive Informatics and Cognitive Computing
Authors: Yingxu Wang
Venue: Fundamenta Informaticae (2009)

The abstract, rigorous, and expressive needs in cognitive informatics, intelligence science, software science, and knowledge science lead to new forms of mathematics collectively known as denotational mathematics. Denotational mathematics is a category of expressive mathematical structures that deals with high level mathematical entities beyond numbers and sets, such as abstract objects, complex relations, behavioral information, concepts, knowledge, processes, and systems. Denotational mathematics is usually in the form of abstract algebra that is a branch of mathematics in which a system of abstract notations is adopted to denote relations of abstract mathematical entities and their algebraic operations based on given axioms and laws. Four paradigms of denotational mathematics, known as concept algebra, system algebra, Real-Time Process Algebra (RTPA), and Visual Semantic Algebra (VSA), are introduced in this paper. Applications of denotational mathematics in cognitive informatics and computational intelligence are elaborated. Denotational mathematics is widely applicable to model and manipulate complex architectures and behaviors of both humans and intelligent systems, as well as long chains of inference processes.
A new system of generalized nonlinear quasi-variational-like inclusions with A-monotone operators in Banach spaces
Authors: Hai Rong Feng, Xie Ping Ding
Venue: Journal of Computational and Applied Mathematics (2009)

In this paper, we study some properties of A-monotone operator in Banach space, give the notion of proximal mapping associated with the A-monotone operator and show its Lipschitz continuity. We also consider a new system of generalized nonlinear quasi-variational-like inclusions with A-monotone operators in Banach spaces and constructed a new iterative algorithm for solving the system of generalized nonlinear quasi-variational-like inclusions in Banach spaces. Under suitable assumptions, we prove the convergence of the iterative sequences generated by the algorithm.
Fitting multidimensional data using gradient penalties and the sparse grid combination technique
Authors: Jochen Garcke, Markus Hegland
Venue: Computing (2009)

Sparse grids, combined with gradient penalties provide an attractive tool for regularised least squares fitting. It has earlier been found that the combination technique, which builds a sparse grid function using a linear combination of approximations on partial grids, is here not as effective as it is in the case of elliptic partial differential equations. We argue that this is due to the irregular and random data distribution, as well as the proportion of the number of data to the grid resolution. These effects are investigated both in theory and experiments. As part of this investigation we also show how overfitting arises when the mesh size goes to zero. We conclude with a study of modified &#x201c;optimal&#x201d; combination coefficients who prevent the amplification of the sampling noise present while using the original combination coefficients.
Extending Symmetry Reduction by Exploiting System Architecture
Authors: Richard Trefler, Thomas Wahl
Venue: Proceedings of the 10th International Conference on Verification, Model Checking, and Abstract Interpretation (2008)

Symmetry reduction is a technique to alleviate state explosion in model checking by replacing a model of replicated processes with a bisimilar quotient model. The size of the quotient depends strongly on the set of applicable symmetries, which in many practical cases allows only polynomial reduction. We introduce architectural symmetry, a concept that exploits architectural system features to compensate for a lack of symmetry in the system model. We show that the standard symmetry quotient of an architecturally symmetric and well-architected model preserves arbitrary Boolean combinations and nestings of reachability properties. This quotient can be exponentially smaller than the model, even in cases where traditional symmetry reduction is nearly ineffective. Our technique thus extends the benefits of symmetry reduction to systems that are in fact not symmetric. Finally, we generalize our results to all architecturally symmetric models, including those that are not well-architected. We illustrate our method through examples and experimental data.