ppxscal/embedding_network huggingface dataset:
Distance-two labellings of Hamming graphs
Authors: Gerard J. Chang, Changhong Lu, Sanming Zhou
Venue: Discrete Applied Mathematics (2009)

Let j>=k>=0 be integers. An @?-L(j,k)-labelling of a graph G=(V,E) is a mapping @f:V->{0,1,2,...,@?} such that |@f(u)-@f(v)|>=j if u,v are adjacent and |@f(u)-@f(v)|>=k if they are distance two apart. Let @l"j","k(G) be the smallest integer @? such that G admits an @?-L(j,k)-labelling. Define @l@?"j","k(G) to be the smallest @? if G admits an @?-L(j,k)-labelling with @f(V)={0,1,2,...,@?} and ~ otherwise. An @?-cyclic L(j,k)-labelling is a mapping @f:V->Z"@? such that |@f(u)-@f(v)|"@?>=j if u,v are adjacent and |@f(u)-@f(v)|"@?>=k if they are distance two apart, where |x|"@?=min{x,@?-x} for x between 0 and @?. Let @s"j","k(G) be the smallest @?-1 of such a labelling, and define @s@?"j","k(G) similarly to @l@?"j","k(G). We determine @l"2","0, @l@?"2","0, @s"2","0 and @s@?"2","0 for all Hamming graphs K"q"""1@?K"q"""2@?...@?K"q"""d (d>=2, q"1>=q"2>=...>=q"d>=2) and give optimal labellings, with the only exception being 2q@?@s@?"2","0(K"q@?K"q)@?2q+1 for q>=4. We also prove the following ''sandwich theorem'': If q"1 is sufficiently large then @l"2","1(G)=@l@?"2","1(G)=@s@?"2","1(G)=@s"2","1(G)=@l"1","1(G)=@l@?"1","1(G)=@s@?"1","1(G)=@s"1","1(G)=q"1q"2-1 for any graph G between K"q"""1@?K"q"""2 and K"q"""1@?K"q"""2@?...@?K"q"""d, and moreover we give a labelling which is optimal for these eight invariants simultaneously.
Distributed Task Synchronization in Wireless Sensor Networks
Authors: Marc Aoun, Julien Catalano, Peter Stok
Venue: Proceedings of the 6th European Conference on Wireless Sensor Networks (2009)

A WSN is envisaged to consist of a large number of nodes, each combining sensing, processing and wireless communication capabilities. The nodes have to cooperate to achieve a global function required by the user. Towards achieving this goal, multiple tasks are performed on all nodes or a subset of nodes in the network. The subject of this paper is the synchronized execution of periodic tasks at different nodes, for example: sensing tasks or a periodic on/off switching of radio transceivers. The method is based on synchronizing timer interrupt occurrences at different nodes to a single reference, leading to tight synchronization of tasks over nodes. Measurements show that task synchronization is achieved on our hardware platform with an average time difference of 5 μs between the starts of temporally related tasks on different nodes.
Fully automatic user interface generation from discourse models
Authors: Jüergen Falb, Sevan Kavaldjian, Roman Popp, David Raneburger, Edin Arnautovic, Hermann Kaindl
Venue: Proceedings of the 13th international conference on Intelligent user interfaces (2009)

Automatic generation of user interfaces (UIs) has made some progress, but it still faces many challenges, especially when starting from high-level models. We developed an approach and a supporting tool for modeling discourses, from which the tool can generate WIMP (window, icon, menu, pointer) UIs automatically. This involves several complex steps, most of which we have been able to implement using model-driven transformations. When given specific target platform specifications, UIs for a variety of devices such as PCs, mobile phones and PDAs can be generated automatically.
Using Elluminate Live to assist distance learning of information assurance capstone seminar
Authors: Keyu Jiang, Xiaohong Yuan, Hongbiao Zeng
Venue: Journal of Computing Sciences in Colleges (2009)

The development of distance learning course of information assurance capstone seminar has fostered a revolution in the manner we communicate between/among teacher and students, and in fair evaluation. This paper describes the limitation of traditional on-line teaching management system and the improvement by introducing Elluminate Live to the teaching of an information assurance capstone seminar through distance learning which demonstrate the students' ability of meeting at least three subcategory level standards of NSTISSI No. 4011 at the performance level.
A Difference Scheme Based on Spline Approximations to Solve the Singularly-perturbed Neumann Problems
Authors: Huan-Wen Liu, Li-Bin Liu
Venue: Proceedings of the 2009 International Conference on Computer Modeling and Simulation (2009)

In this paper, a difference scheme based on the quartic splines for solving the singularly-perturbed two-point boundary-value problem of second-order ordinary differential equations subject to Neumann-type boundary conditions are derived. The accuracy order of the schemes is O(h^4) not only at the interior nodal points but also at the two endpoints, which are better than general center finite difference method. Finally, the numerical results are given to illustrate the efficiency of our methods.
Experiences on enhancing data collection in large networks
Authors: Mohamed Karim Sbai, Chadi Barakat
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2009)

We improve and validate TICP [C. Barakat, M. Malli, N. Nonaka, TICP: Transport Information Collection Protocol, Annals of Telecommunications 61 (1-2) (2006) 167-192], our TCP-friendly reliable transport protocol to collect information from a large number of Internet entities. A collector machine sends probes to a set of information sources that reply by sending back their reports. TICP adapts the sending rate of probes in a way similar to TCP for the purpose of avoiding network congestion and keeps requesting reports until they are well received. In a first part of this work, we add to TICP a mechanism to cluster information sources in order to smooth the variation of network conditions during the collection session and to ensure an efficient handling of congestion at network bottlenecks. Simulations in ns-2 and PlanetLab experiments prove the outperformance of TICP over non-adaptive solutions and the interest of the clustering mechanism in shortening the duration of the collection session and in decreasing the ratio of lost packets. In a second part, we adapt TICP to collect several packets of information from each data source. By the means of simulations, we compare the performance obtained by TICP to that obtained when using parallel short-lived TCP connections. Our main observation is that TICP yields shorter collection sessions due to its inherent multiplexing capability and that it avoids parallel Slow Start phases. Finally, in a last part, we study the impact of delegating collection to some proxy collectors. We explain our method for delegation and we show by simulations that for a judicious choice of proxy collectors, one can decrease considerably the collection session duration.
Surface EMG in advanced hand prosthetics
Authors: Claudio Castellini, Patrick van der Smagt
Venue: Biological Cybernetics (2009)

One of the major problems when dealing with highly dexterous, active hand prostheses is their control by the patient wearing them. With the advances in mechatronics, building prosthetic hands with multiple active degrees of freedom is realisable, but actively controlling the position and especially the exerted force of each finger cannot yet be done naturally. This paper deals with advanced robotic hand control via surface electromyography. Building upon recent results, we show that machine learning, together with a simple downsampling algorithm, can be effectively used to control on-line, in real time, finger position as well as finger force of a highly dexterous robotic hand. The system determines the type of grasp a human subject is willing to use, and the required amount of force involved, with a high degree of accuracy. This represents a remarkable improvement with respect to the state-of-the-art of feed-forward control of dexterous mechanical hands, and opens up a scenario in which amputees will be able to control hand prostheses in a much finer way than it has so far been possible.
Positive Trigonometric Polynomials and Signal Processing Applications
Authors: B. Dumitrescu
Venue:  (2007)

Positive and sum-of-squares polynomials have received a special interest in the latest decade, due to their connections with semidefinite programming. Thus, efficient optimization methods can be employed to solve diverse problems involving polynomials. This book gathers the main recent results on positive trigonometric polynomials within a unitary framework; the theoretical results are obtained partly from the general theory of real polynomials, partly from self-sustained developments. The optimization applications cover a field different from that of real polynomials, mainly in signal processing problems: design of 1-D and 2-D FIR or IIR filters, design of orthogonal filterbanks and wavelets, stability of multidimensional discrete-time systems. Positive Trigonometric Polynomials and Signal Processing Applicationshas two parts: theory and applications. The theory of sum-of-squares trigonometric polynomials is presented unitarily based on the concept of Gram matrix (extended to Gram pair or Gram set). The presentation starts by giving the main results for univariate polynomials, which are later extended and generalized for multivariate polynomials. The applications part is organized as a collection of related problems that use systematically the theoretical results. All the problems are brought to a semidefinite programming form, ready to be solved with algorithms freely available, like those from the library SeDuMi.
Exact basic geometric operations on arbitrary angle polygons using only fixed size integer coordinates
Authors: Alexey Lvov, Ulrich Finkler
Venue: Proceedings of the 2008 IEEE/ACM International Conference on Computer-Aided Design (2008)

As the semiconductor technology is scaling down to nanometer regime, accurate layout analysis requires operations with simulated contours of VLSI layouts which are non-rectilinear. The basic operations on non-rectilinear shapes include "intersection", "difference", "union", "find connected components" and "find boundary". Whatever precision one would choose for the representation of vertices of shapes A and B the exact representation of, say, A&cap;B would require an even higher precision. Consequently rounding of intermediate results of a chain of basic operations seems to be inevitable. The presence of rounding errors is unacceptable because the implementation of algorithms for all operations which involve topology, such as "find connected components", " find boundary", etc, becomes impossible or extremely complex We present a complete solution to the following problem: Let a VLSI design or a simulated through a lithography process image of a VLSI design be given by a number of two-dimensional point sets. Each point set consists of polygons with arbitrary (not necessarily 90&deg;) angles and with vertices on an integer grid. Perform any amount of sequential basic operations so that: &bull; The resulting point sets are mathematically exact, that is no rounding errors are allowed. In particular the connectivity of the point sets remains intact, the boundaries remain undistorted and the statements like "A = (A \ B) &cup; (A &cap; B)", "(A \ B) is disjoint with B" and "A &cap; B &sub; A" always hold. &bull; The amount of time and memory per one basic geometric operation on elementary polygons (trapezoids) is constant. For example it would not be an acceptable solution to represent the vertices of the new shapes which appear as a result of the operations of intersection, difference, etc, by unlimited length rational numbers.
An integrated model for evaluating self sustainability of bio-energy settlements: technological, economical and social aspects
Authors: Alessandro Catania A, Roberto Revetria, Francesca Oliva, Lucia Cassettari
Venue: Proceedings of the 40th Conference on Winter Simulation (2008)

The proposed paper present a generalized model based on Monte-Carlo simulation able to support the feasibility study by effectively model the production process, the woods groove and the overall logistics. This model can be applied to quantitatively identify cost and benefits for an integrated biomass energetic district and identify, at the same time, potential and pitfalls that usually reduce the success of an ecologic initiative. A case study implementing the proposed methodology is presented and discussed.
Supporting flexible streaming media protection through privacy-aware secure processors
Authors: Youtao Zhang, Jun Yang, Lan Gao
Venue: Computers and Electrical Engineering (2009)

Due to the explosion of Internet technology in the last decade, there is an increasing demand for secure and effective streaming media protection (SMP) in the new computing environment. Since end users usually have the full control of their machines, pure software based approaches such as user/password validation and group key based content encryption, are not sufficient to defend many attacks, in particular, malicious key sharing. On the other hand, existing hardware-based approaches tend to be too restrictive to adopt. The emerging secure processor designs provide a new direction for hardware assisted streaming media protection (H-SMP). The research in the computer architecture community has shown that secure processors can help to defend various types of attacks such as those with a hijacked and malicious OS. However existing designs focus on securing point-to-point data transfers and face both privacy and performance issues when supporting group-oriented applications, e.g. video on-demand. In this paper, we present privacy-aware secure processor designs for H-SMP against key sharing. We first categorize different protection policies, compare their advantages and disadvantages, and then discuss the novel hardware enhancements including instruction set extensions for supporting these policies. We elaborate the implementation details and present the security and performance analyses.
Umbrella file system: Storage management across heterogeneous devices
Authors: John A. Garrison, A. L. Narasimha Reddy
Venue: ACM Transactions on Storage (TOS) (2009)

With the advent of and recent developments in Flash storage, device characteristic diversity is becoming both more prevalent and more distinct. In this article, we describe the Umbrella File System (UmbrellaFS), a stackable file system designed to provide flexibility in matching diversity of file access characteristics to diversity of device characteristics through a user or system administrator specified policy. We present the design and results from a prototype implementation of UmbrellaFS on both Linux 2.4 and 2.6. The results show that UmbrellaFS has little overhead for most file system operations while providing an ability better to utilize the differences in Flash and traditional hard drives. With appropriate use of rules, we have shown improvements of up to 44&percnt; in certain situations.
Performance analysis of accelerated image registration using GPGPU
Authors: Peter Bui, Jay Brockman
Venue: Proceedings of 2nd Workshop on General Purpose Processing on Graphics Processing Units (2009)

This paper presents a performance analysis of an accelerated 2-D rigid image registration implementation that employs the Compute Unified Device Architecture (CUDA) programming environment to take advantage of the parallel processing capabilities of NVIDIA's Tesla C870 GPU. We explain the underlying structure of the GPU implementation and compare its performance and accuracy against a fast CPU-based implementation. Our experimental results demonstrate that our GPU version is capable of up to 90x speedup with bilinear interpolation and 30x speedup with bicubic interpolation while maintaining a high level of accuracy. This compares favorably to recent image registration studies, but it also indicates that our implementation only reaches about 70% of theorectical peak performance. To analyze our results, we utilize profiling data to identify some of the underlying limitations of CUDA that prohibit peak performance. At the end, we emphasize the need to manage memory resources carefully to fully utilize the GPU and obtain maximum speedup.
Design of intelligent power controller for DC&#x2013;DC converters using CMAC neural network
Authors: Chun-Fei Hsu
Venue: Neural Computing and Applications (2009)

DC&#x2013;DC converters are the devices which can convert a certain electrical voltage to another level of electrical voltage. They are very popularly used because of the high efficiency and small size. This paper proposes an intelligent power controller for the DC&#x2013;DC converters via cerebella model articulation controller (CMAC) neural network approach. The proposed intelligent power controller is composed of a CMAC neural controller and a robust controller. The CMAC neural controller uses a CMAC neural network to online mimic an ideal controller, and the robust controller is designed to achieve L 2 tracking performance with desired attenuation level. Finally, a comparison among a PI control, adaptive neural control and the proposed intelligent power control is made. The experimental results are provided to demonstrate the proposed intelligent power controller can cope with the input voltage and load resistance variations to ensure the stability while providing fast transient response and simple computation.
Combining linear programming and principal-agent models: An example from environmental regulation in agriculture
Authors: Davide Viaggi, Fabio Bartolini, Meri Raggi
Venue: Environmental Modelling Software (2009)

The paper develops a methodology whereby a Principal-Agent model is combined with Linear Programming in order to deal with the design of environmental regulation in agriculture. Linear Programming is intended here mainly as a tool to estimate an agent's cost/profit function for the purpose of the Principal-Agent model. Two variants of the methodology are considered. First, agents' profit functions are estimated through the interpolation of the results of the parametrisation of the Linear Programming model. In the second option, relevant corner points of the discontinuous profit function generated by the parametrisation of the Linear Programming models are identified. These relevant corner points are then fed into a discrete-action Principal-Agent model. An exploratory application is provided, using a case study related to the purchase of environmental services from agriculture. The results show that Linear Programming may represent a useful way to estimate cost/profit functions to feed Principal-Agent models as long as it allows to incorporate more information from the point of view of how decision making is carried out, particularly when the underlying agent's cost/profit function is generated by a bundle of different production activities. However, the choice of the specific procedure should be cautiously evaluated in order to fit the actual properties of the underlying production process. Also, particular attention should be placed on the manner in which constraints and technical coefficients affect the result of the downstream model.
Convergent Compilation Applied to Loop Unrolling
Authors: Nicholas Nethercote, Doug Burger, Kathryn S. Mckinley
Venue: Transactions on High-Performance Embedded Architectures and Compilers I (2007)

Well-engineered compilers use a carefully selected set of optimizations, heuristic optimization policies, and a phase ordering. Designing a single optimization heuristic that works well with other optimization phases is a challenging task. Although compiler designers evaluate heuristics and phase orderings before deployment, compilers typically do not statically evaluate nor refine the quality of their optimization decisions during a specific compilation.This paper identifies a class of optimizations for which the compiler can statically evaluate the effectiveness of its heuristics and phase interactions. When necessary, it then modifies and reapplies its optimization policies. We call this approach convergent compilation, since it iterates to converge on high quality code. This model incurs additional compilation time to avoid some of the difficulties of predicting phase interactions and perfecting heuristicsThis work was motivated by the TRIPS architecture which has resource constraints that have conflicting phase order requirements. For example, each atomic execution unit (a TRIPS block) has a maximum number of instructions (128) and a fixed minimum execution time cost. Loop unrolling and other optimizations thus seek to maximize the number of mostly full blocks. Because unrolling enables many downstream optimizations, it needs to occur well before code generation, but this position makes it impossible to accurately predict the final number of instructions. After the compiler generates code, it knows the exact instruction count and consequently if it unrolled too much or too little or just right. If necessary, convergent unrolling then goes back and adjusts the unroll amount accordingly and reapplies subsequent optimization phases. We implement convergent unrolling which automatically matches the best hand unrolled version for a set of microbenchmarks on the TRIPS architectural simulator.Convergent compilation can help solve other phase ordering and heuristic tuning compilation challenges. It is particularly well suited for resource constraints that the compiler can statically evaluate such as register usage, instruction level parallelism, and code size. More importantly, these resource constraints are key performance indicators in embedded, VLIW, and partitioned hardware and indicate that convergent compilation should be broadly applicable.
On systematic methods to remove redundant monitors from liveness-enforcing net supervisors
Authors: ZhiWu Li, HeSuan Hu
Venue: Computers and Industrial Engineering (2009)

Petri nets based deadlock prevention for flexible manufacturing systems has received much attention over the past decade, primarily due to the seminal work of Ezpeleta et al. in 1995. A Petri net based deadlock prevention mechanism is usually implemented by adding monitors or control places to a plant Petri net model such that liveness can be enforced. The significance of this methodology lies in that both a plant model and its supervisor are in a same formalism-Petri nets. Due to the inherent complexity of Petri nets, in theory, the number of additional monitors that have to been added to achieve liveness-enforcement purpose for an uncontrolled plant model is exponential with respect to the size of the model. This paper first proposes a systematic method to minimize the number of additional monitors in a liveness-enforcing Petri net supervisor such that the resultant net system has the same permissive behavior while liveness can still be preserved. Furthermore, for the liveness-enforcing Petri net supervisors of flexible manufacturing systems, which have some particular property, an algorithm is developed such that more permissive liveness-enforcing Petri net supervisors can be obtained after liveness-restrictive monitor removal. Compared with the existing techniques of eliminating redundant monitors in the literature, the complete state enumeration of a supervisor is avoided, which implies the high computational efficiency of the methods in this paper. Flexible manufacturing examples are used to demonstrate the proposed approaches.