ppxscal/embedding_network huggingface dataset:
How laminar frontal cortex and basal ganglia circuits interact to control planned and reactive saccades
Authors: Joshua W. Brown, Daniel Bullock
Venue: Neural Networks (2004)

How does the brain learn to balance between reactive and planned behaviors? The basal ganglia (BG) and frontal cortex together allow animals to learn planned behaviors that acquire rewards when prepotent reactive behaviors are insufficient. This paper proposes a new model, called TELOS, to explain how laminar circuitry of the frontal cortex, exemplified by the frontal eye fields, interacts with the BG, thalamus, superior colliculus, and inferotemporal and parietal cortices to learn and perform reactive and planned eye movements. The model is formulated as fourteen computational hypotheses. These specify how strategy priming and action planning (in cortical layers III, Va and VI) are dissociated from movement execution (in layer Vb), how the BG help to choose among and gate competing plans, and how a visual stimulus may serve either as a movement target or as a discriminative cue to move elsewhere. The direct, indirect and hyperdirect pathways through the BG are shown to enable complex gating functions, including deferred execution of selected plans, and switching among alternative sensory-motor mappings. Notably, the model can learn and gate the use of a What-to-Where transformation that enables spatially invariant object representations to selectively excite spatially coded movement plans. Model simulations show how dopaminergic reward and non-reward signals guide monkeys to learn and perform saccadic eye movements in the fixation, single saccade, overlap, gap, and delay (memory-guided) saccade tasks. Model cell activation dynamics quantitatively simulate seventeen established types of dynamics exhibited by corresponding real cells during performance of these tasks.
Cassandra: Distributed Access Control Policies with Tunable Expressiveness
Venue: Proceedings of the Fifth IEEE International Workshop on Policies for Distributed Systems and Networks (2004)

We study the specification of access control policy inlarge-scale distributed systems. Our work on real-worldpolicies has shown that standard policy idioms such as rolehierarchy or role delegation occur in practice in many subtle variants. A policy specification language should therefore be able to express this variety of features smoothly,rather than add them as specific features in an ad hoc way,as is the case in many existing languages.We present Cassandra, a role-based trust managementsystem with an elegant and readable policy specificationlanguage based on Datalog with constraints. The expressiveness (and computational complexity) of the languagecan be adjusted by choosing an appropriate constraint domain. With just five special predicates, we can easily express a wide range of policies including role hierarchy,role delegation, separation of duties, cascading revocation, automatic credential discovery and trust negotiation. Cassandra has a formal semantics for query evaluation andfor the access control enforcement engine. We use a goal-oriented distributed policy evaluation algorithm that is efficient and guarantees termination. Initial performance results for our prototype implementation have been promising.
From hypercircles to units
Authors: Tomas Recio, J. Rafael Sendra, Carlos Villarino
Venue: Proceedings of the 2004 international symposium on Symbolic and algebraic computation (2004)

This paper deals with a remarkable class of curves (in general r-space) that the two first authors have named "hypercircles" (see [2]). As shown there, such curves appear in the CAD context, when aiming towards finding a parametric representation with simpler coefficients (i.e. without algebraic numbers) for a given parametric curve. In fact, it turns out that the crucial point to solve the simplification problem in general is to solve this same problem for hypercircles [2]. Here we present an algorithm that, for a given parametrization of a hypercircle U, over an algebraic extension, namely, φ(t) ∈ K(α)(t)r, computes the linear fraction over K(α)(t) that generates this hypercircle (and, in particular, a parametrization of the curve over K).
The Kneser&#x2013;Poulsen Conjecture for Spherical Polytopes
Authors: K&#x00e1;roly Bezdek, Robert Connelly
Venue: Discrete Computational Geometry (2004)

If a finite set of balls of radius &#x03c0;/2 (hemispheres) in the unit sphere Sn is rearranged so that the distance between each pair of centers does not decrease, then the (spherical) volume of the intersection does not increase, and the (spherical) volume of the union does not decrease. This result is a spherical analog to a conjecture by Kneser (1954) and Poulsen (1955) in the case when the radii are all equal to &#x03c0;/2.
The overlap problem in content-oriented XML retrieval evaluation
Authors: Gabriella Kazai, Mounia Lalmas, Arjen P. de Vries
Venue: Proceedings of the 27th annual international ACM SIGIR conference on Research and development in information retrieval (2004)

Within the INitiative for the Evaluation of XML Retrieval(INEX) a number of metrics to evaluate the effectiveness of content-oriented XML retrieval approaches were developed. Although these metrics provide a solution towards addressing the problem of overlapping result elements, they do not consider the problem of overlapping reference components within the recall-base, thus leading to skewed effectiveness scores. We propose alternative metrics that aim to provide a solution to both overlap issues.
Embeddings of partial Steiner triple systems
Authors: Darryn Bryant
Venue: Journal of Combinatorial Theory Series A (2004)

Any partial Steiner triple system of order u can be embedded in a Steiner triple system of order v if v ≡ 1, 3 (mod 6) and v ≥ 3u - 2.
More About 4-Isosceles Planar Sets
Authors: Changqing Xu, Ren Ding
Venue: Discrete Computational Geometry (2004)

A finite planar set is k-isosceles for k &#x2265; 3 if every k-point subset of the set contains a point equidistant from the other two. In [1] Fishburn obtains several important results about isosceles planar sets and poses a series of conjectures and open questions. We disprove Conjecture 1 in [1] and provide another 34 nonsimilar 4-isosceles 8-point planar sets which answer one of the open questions in [1] negatively.
SITO High Output Impedance Transadmittance Filter Using FTFNs
Authors: N. A. Shah, S. Z. Iqbal, B. Parveen
Venue: Analog Integrated Circuits and Signal Processing (2004)

FTFN based single input and three outputs transadmittance filter topology supporting simultaneously three filtering signals LP, BP, and HP without any passive component matching conditions is presented. The filter uses three PFTFNs and five passive components and realizes all current signals at high impedances, lending feature of cascadibility to the circuit. The circuit enjoys low sensitivity figures. PSPICE simulation results confirming the theoretical calculations are included.
A Constraints Programming Approach to Communication Scheduling on SoPC Architectures
Authors: Christophe Wolinski, Krzysztof Kuchcinski, Maya Gokhale
Venue: Proceedings of the Digital System Design, EUROMICRO Systems (2004)

This paper presents a novel method to obtain an optimized static schedule of CSP-like communications between a collection of concurrent hardware processes implemented on "System on a Programmable Chip" (SoPC). The hardware processes are the applications tailored "cells" in the Processor-Coupled Polymorphous Fabric ([Polymorphous fabric-based systems: Model, tools, applications], [Anew polymorphous computing fabric]) implemented on the Altera Excalibur Arm SoPC platform. In our global approach, a static communications schedule is adopted to reduce hardware overhead due to inter-cells message transfer synchronization and to speed-up application execution. The scheduling problem is defined and solved using constraints programming approach. This approach makes it possible to obtain optimal communication schedules in a number of real cases. It makes also possible to easily generate pipelined schedules that improve significantly performance of the final implementation. Our method is illustrated with a Fabric-based implementation of the K-means clustering algorithm. An optimal communication scheduled is achieved for this application.
An Improved Randomized On-Line Algorithm for a Weighted Interval Selection Problem
Authors: Hiroyuki Miyazawa, Thomas Erlebach
Venue: Journal of Scheduling (2004)

Given a set of weighted intervals, the objective of the weighted interval selection problem (WISP) is to select a maximum-weight subset such that the selected intervals are pairwise disjoint. We consider on-line algorithms that process the intervals in order of non-decreasing left endpoints. Preemption is allowed, but rejections are irrevocable. This problem has natural applications in various scheduling problems. We study the class of monotone instances of WISP, i.e., we require that the order of right endpoints of the given intervals coincides with that of the left endpoints. This class includes the case where all intervals have the same length. For monotone instances of WISP, the best possible competitive ratio for deterministic on-line algorithms is known to be 1/4. It has long been an open question whether there exists a randomized algorithm with better competitive ratio. In this paper, we present a new randomized algorithm and prove that it achieves a better competitive ratio 1/3 for the special case of monotone WISP where the sequence of weights of the arriving intervals is non-decreasing. Thus we provide the first result towards a solution of the long-standing open question. Furthermore, we show that no randomized algorithm achieves a competitive ratio strictly larger than 4/5. This is the first non-trivial upper bound for randomized algorithms for monotone WISP.
Interactive Focus+Context Visualization with Linked 2D/3D Scatterplots
Authors: Harald Piringer, Robert Kosara, Helwig Hauser
Venue: Proceedings of the Second International Conference on Coordinated & Multiple Views in Exploratory Visualization (2004)

Scatterplots in 2D and 3D are very useful tools, but also suffer from a number of problems. Overplotting hides the true number of points that are displayed, and showing point clouds in 3D is problematic both in terms of perception and interaction. We propose a combination of 2D and 3D scatterplots, together with some extensions to overcome these problems. By linking 2D and 3D views, it is possible to interact in 2D and get feedback in 3D. That feedback is also enhanced by depth cues (color and point size) such that the user gets a better depth impression. Histograms in 2D and 3D show additional information about point densities and additional context can be displayed. An example application demonstrates the usefulness of the technique.
Fast computation in adaptive tree approximation
Authors: Peter Binev, Ronald DeVore
Venue: Numerische Mathematik (2004)

Adaptive methods of approximation arise in many settings including numerical methods for PDEs and image processing. They can usually be described by a tree which records the adaptive decisions. This paper is concerned with the fast computation of near optimal trees based on n adaptive decisions. The best tree based on n adaptive decisions could be found by examining all such possibilities. However, this is exponential in n and could be numerically prohibitive. The main result of this paper is to show that it is possible to find near optimal trees using computations linear in n.
Virtual design and testing of protective packaging buffers
Authors: S. W. Lye, S. G. Lee, B. H. Chew
Venue: Computers in Industry (2004)

Manufactured products are commonly encased in moulded protective packaging buffers to protect them from damage due to impact shock during handling and transportation. The materials used to fabricate these buffers are well-known and cost-effective but not friendly to the environment. New bio-degradable materials such as paper pulp and starch have emerged as formidable alternatives, but little is known about how to design buffers from them.This paper describes a novel intelligent methodology for the virtual modeling, testing and design of protective packaging buffers. The methodology employs the use of genetic algorithms, finite element model and design routines developed to determine the optimal buffer design. Based on an ANSYSTM finite element model of the buffer, simulated drop tests were performed. The magnitudes of the largest reaction forces for the simulated drop tests as encountered by the model are computed and translated into the highest G value that the buffer can sustain without damage to the product. From the results, a more superior set of buffer designs is then derived with each passing generation.Validation tests were conducted on six different buffer configurations designed to protect six common consumer electrical appliances. The simulated G values were found to differ by a maximum of 11.8% from empirical results. The industrial norm of 10% deviation between empirical and simulated values can easily be realized when further refinements are made to the basic finite element model of the buffer. The findings validate the new methodology in buffer design in particular for new packaging materials where there are only a limited number of explicit or heuristic design rules.
IP-Block Based Integration of Very High Performance WLAN Modem
Authors: Jussi Roivainen, Jukka Rautio
Venue: Proceedings of the Digital System Design, EUROMICRO Systems (2004)

In the IP-block based design the problems of Integration work have not been discussed as thoroughly as IP-block development, system development or physical designing problems. The complexity of controlling is the major design challenge, especially in communication devices where the network sets parameters for control. In this paper, we present the FAR (Flexible, Adaptive, Reconfigurable) demonstrator integration for FPGA platform, the integration problems and lessons learned. The challenges in the integration work are identified, including complexity, interface style diversity and control requirements. The incremental integration approach was found effective strategy to manage and solve the challenges. Dividing the work is required to manage complexity but effective co-operation with designers is a necessity for preventing new artificial interfaces.
Using probabilistic reasoning to automate software tuning
Authors: David G. Sullivan, Margo I. Seltzer, Avi Pfeffer
Venue: Proceedings of the joint international conference on Measurement and modeling of computer systems (2004)

Manually tuning the parameters or "knobs" of a complex software system is an extremely difficult task. Ideally, the process of software tuning should be automated, allowing software systems to reconfigure themselves as needed in response to changing conditions. We present a methodology that uses a probabilistic, graphical model known as an influence diagram as the foundation of an effective, automated approach to software tuning. We have used our methodology to simultaneously tune four knobs from the Berkeley DB embedded database system, and our results show that an influence diagram can effectively generalize from training data for this domain.
Policy Transformation Techniques in Policy-based Systems Management
Venue: Proceedings of the Fifth IEEE International Workshop on Policies for Distributed Systems and Networks (2004)

Policy based systems management provides ameans for administrators, end-users and applicationdevelopers to manage and dynamically change thebehavior of computing systems. One advantage ofpolicy-based management is that it simplifies andautomates the administration of IT environments. Asignificant part of the simplification is obtained byallowing the system administrator to specify only theobjectives or goals that are to be met, rather thanhaving to specify detailed configuration parameters foreach of the different devices in the system. It may notbe obvious to the administrator how the goals can beachieved without having to know the internals of thesystem. This knowledge thus needs to be captured inthe policy driven actions. The existing algorithms formapping policy objectives to specific configurationdetails tend to be specific to each policy discipline.This makes the policy-based approach harder todeploy for new disciplines. In this paper, we addressdifferent types of policy transformations and proposemethods, which are not discipline specific for mappingobjectives to system configurations.
Asynchronous Circuits Sensitivity to Fault Injection
Authors: Y. Monnet, M. Renaudin, R. Leveugle
Venue: Proceedings of the International On-Line Testing Symposium, 10th IEEE (2004)

This paper presents an analysis of the faultssensitivity of Quasi Delay Insensitive (QDI)asynchronous circuits. Faults considered in this workcan be either natural or intentional. However, faultinjection attacks which consist in causing anintentional temporary dysfunction of a circuit byinjecting faults in its combinational or sequential partsare of prime interest. This failure enables hackers toaccess protected memory areas or secret informationlike cryptographic keys. This work focuses onanalysing the sensitivity of asynchronous circuits tofault injection. A circuit fault-sensitivity criterion isdefined, which enables to point out weak parts of thecircuits in order to specify hardening strategies.
Versatile bondpad report process for non-planar compound semiconductor devices
Authors: Sophie Garidel, Jean-Pierre Vilcot, Mohammed Zaknoune, Pascal Tilmant
Venue: Microelectronic Engineering (2004)

We present a versatile bondpad report process that can be used either for high relief compound semiconductor devices or interconnection schemes. It is based on the use of two different polymers (photoresists) and one electroplating step.
A Sequence of Unique Quaternary Griesmer Codes
Authors: Harold N. Ward
Venue: Designs, Codes and Cryptography (2004)

This paper establishes that there is no [98,5,72]_{4} code. Such a code would meet the Griesmer bound and the weights of its codewords would all be divisible by 4. The proof of nonexistence uses the uniqueness of codes with parameters [n,4,n - 5]4,14 &le; n &le; 17. The uniqueness of these codes for n &ge; 15 had been established geometrically by others; but it is rederived here, along with that of the [14,4,9]4 code, by exploiting the Hermitian form obtained when the weight function is read modulo 2.
Bypassing the embedding: algorithms for low dimensional metrics
Authors: Kunal Talwar
Venue: Proceedings of the thirty-sixth annual ACM symposium on Theory of computing (2004)

The doubling dimension of a metric is the smallest k such that any ball of radius 2r can be covered using 2k balls of radius r. This concept for abstract metrics has been proposed as a natural analog to the dimension of a Euclidean space. If we could embed metrics with low doubling dimension into low dimensional Euclidean spaces, they would inherit several algorithmic and structural properties of the Euclidean spaces. Unfortunately however, such a restriction on dimension does not suffice to guarantee embeddibility in a normed space.In this paper we explore the option of bypassing the embedding. In particular we show the following for low dimensional metrics: Quasi-polynomial time (1+ε)-approximation algorithm for various optimization problems such as TSP, k-median and facility location. (1+ε)-approximate distance labeling scheme with optimal label length. (1+ε)-stretch polylogarithmic storage routing scheme.
A resource-allocation queueing fairness measure
Authors: David Raz, Hanoch Levy, Benjamin Avi-Itzhak
Venue: Proceedings of the joint international conference on Measurement and modeling of computer systems (2004)

Fairness is a major issue in the operation of queues, perhaps it is the reason why queues were formed in the first place. Recent studies show that the fairness of a queueing system is important to customers not less than the actual delay they experience. Despite this observation little research has been conducted to study fairness in queues, and no commonly agreed upon measure of queue fairness exists. Two recent research exceptions are Avi-Itzhak and Levy [1], where a fairness measure is proposed, and Wierman and Harchol-Balter [18] (this conference, 2003), where a criterion is proposed for classifying service policies as fair or unfair; the criterion focuses on customer service requirement and deals with fairness with respect to service times.In this work we recognize that the inherent behavior of a queueing system is governed by two major factors: Job seniority (arrival times) and job service requirement (service time). Thus, it is desired that a queueing fairness measure would account for both. To this end we propose a Resource Allocation Queueing Fairness Measure, (RAQFM), that accounts for both relative job seniority and relative service time. The measure allows accounting for individual job discrimination as well as system unfairness. The system measure forms a full scale that can be used to evaluate the level of unfairness under various queueing disciplines. We present several basic properties of the measure. We derive the individual measure as well as the system measure for an M/M/1 queue under five fundamental service policies: Processor Sharing (PS), First Come First Served (FCFS), Non-Preemptive Last Come First Served (NP-LCFS), Preemptive Last Come First Served (P-LCFS), and Random Order of Service (ROS). The results of RAQFM are then compared to those of Wierman and Harchol-Balter [18], and the quite intriguing observed differences are discussed.
Covering arrays for efficient fault characterization in complex configuration spaces
Authors: Cemal Yilmaz, Myra B. Cohen, Adam Porter
Venue: ACM SIGSOFT Software Engineering Notes (2004)

Testing systems with large configurations spaces that change often is a challenging problem. The cost and complexity of QA explodes because often there isn't just one system, but a multitude of related systems. Bugs may appear in certain configurations, but not in others.The Skoll system and process has been developed to test these types of systems through distributed, continuous quality assurance, leveraging user resources around-the-world, around-the-clock. It has been shown to be effective in automatically characterizing configurations in which failures manifest. The derived information helps developers quickly narrow down the cause of failures which then improves turn around time for fixes. However, this method does not scale well. It requires one to exhaustively test each configuration in the configuration space.In this paper we examine an alternative approach. The idea is to systematically sample the configuration space, test only the selected configurations, and conduct fault characterization on the resulting data. The sampling approach we use is based on calculating a mathematical object called a covering array. We empirically assess the effect of using covering array derived test schedules on the resulting fault characterizations and provide guidelines to practitioners for their use.