ppxscal/embedding_network huggingface dataset:
Feasibility Analysis of Real-Time Periodic Tasks with Offsets
Authors: Rodolfo Pellizzoni, Giuseppe Lipari
Venue: Real-Time Systems (2005)

The problem of feasibility analysis of asynchronous periodic task sets, where tasks can have an initial offset, is known to be co-NP-complete in the strong sense. A sufficient pseudo-polynomial test has been proposed by Baruah, Howell and Rosier, which consists in analyzing the feasibility of the corresponding synchronous task set (i.e. all offsets are set equal to 0). If the test gives a positive result, then the original asynchronous task set is feasible; else, no definitive answer can be given. In many cases, this sufficient test is too pessimistic, i.e. it gives no response for many feasible task sets.In this paper, we present a new sufficient pseudo-polynomial test for asynchronous periodic task sets. Our test reduces the pessimism by explicitely considering the offsets in deriving a small set of critical arrival patterns. We show, trough a set of extensive simulations, that our test outperforms the previous sufficient test.
SSIML: designing structure and application integration of 3D scenes
Authors: Arnd Vitzthum, Andreas Pleuß
Venue: Proceedings of the tenth international conference on 3D Web technology (2005)

The integration of 3D scenes into complex software systems can be a great challenge. The results of different developer groups working on a project with different tools have to be composed into a single software product. This is an expensive and error prone task because of the lack of specialized concepts and tools. A visual and tool supported modelling language called SSIML (Scene Structure and Integration Modelling Language) is introduced allowing to design 3D scene integration. Since SSIML is a UML extension it can be integrated in common UML tools. The SSIML models form a contract between the different developer groups. Based on the models main parts of the implementation code are generated automatically to ensure consistency.
Information markets vs. opinion pools: an empirical comparison
Authors: Yiling Chen, Chao-Hsien Chu, Tracy Mullen, David M. Pennock
Venue: Proceedings of the 6th ACM conference on Electronic commerce (2005)

In this paper, we examine the relative forecast accuracy of information markets versus expert aggregation. We leverage a unique data source of almost 2000 people's subjective probability judgments on 2003 US National Football League games and compare with the "market probabilities" given by two different information markets on exactly the same events. We combine assessments of multiple experts via linear and logarithmic aggregation functions to form pooled predictions. Prices in information markets are used to derive market predictions. Our results show that, at the same time point ahead of the game, information markets provide as accurate predictions as pooled expert assessments. In screening pooled expert predictions, we find that arithmetic average is a robust and efficient pooling function; weighting expert assessments according to their past performance does not improve accuracy of pooled predictions; and logarithmic aggregation functions offer bolder predictions than linear aggregation functions. The results provide insights into the predictive performance of information markets, and the relative merits of selecting among various opinion pooling methods.
A framework for fusion methods and rendering techniques of multimodal volume data: Research Articles
Authors: Maria Ferre, Anna Puig, Dani Tost
Venue: Computer Animation and Virtual Worlds (2004)

Many different direct volume rendering methods have been developed to visualize 3D scalar fields on uniform rectilinear grids. However, little work has been done on rendering simultaneously various properties of the same 3D region measured with different registration devices or at different instants of time. The demand for this type of visualization is rapidly increasing in scientific applications such as medicine in which the visual integration of multiple modalities allows a better comprehension of the anatomy and a perception of its relationships with activity. This paper presents different strategies of direct multimodal volume rendering (DMVR). It is restricted to voxel models with a known 3D rigid alignment transformation. The paper evaluates at which steps of the rendering pipeline the data fusion must be realized in order to accomplish the desired visual integration and to provide fast re-renders when some fusion parameters are modified. In addition, it analyses how existing monomodal visualization algorithms can be extended to multiple datasets and it compares their efficiency and their computational cost. Copyright &copy; 2004 John Wiley & Sons, Ltd.
Lower bounds on systolic gossip
Authors: Michele Flammini, Stéphane Pérennès
Venue: Information and Computation (2005)

Gossiping is an extensively investigated information dissemination process in which each processor has a distinct item of information and has to collect all the items possessed by the other processors. In this paper, we provide an innovative and general lower bound technique relying on the novel notion of delay digraph of a gossiping protocol and on the use of matrix norm methods. Such a technique is very powerful and allows the determination of new and significantly improved lower bounds in many cases. In fact, we derive the first general lower bound on the gossiping time of systolic protocols, i.e., constituted by a periodic repetition of simple communication steps. In particular, given any network of n processors and any systolic period s, in the directed and the undirected half-duplex cases every s-systolic gossip protocol takes at least log(n)/log(1/λ) - O(log log(n)) time steps, where λ is the unique solution between 0 and 1 of λ ċ √P[s/2]λ ċ √P[s/2]λ = 1, with Pi(λ) = 1 + λ2 +...+ λ2i-2 for any integer i > 0. We then provide improved lower bounds in the directed and half-duplex cases for many well-known network topologies, such as Butterfly, de Bruijn and Kautz graphs. All the results are extended also to the full-duplex case. Our technique is very general, as for s → ∞ it allows the determination of improved results even for non-systolic protocols. In fact, for general networks, as a simple corollary it yields a lower bound only an O(log log(n)) additive factor far from the general one independently proved in [Proc. 1st ACM Symposium on Parallel Algorithms and Architectures (SPAA), 1989, p. 318; Topics in Combinatorics and Graph Theory (1990) 451; SIAM Journal on Computing 21(1) (1992) 111; Discrete Applied Mathematics 42 (1993) 75] for all graphs and any (non-systolic) gossip protocol. Moreover, for specific networks, it significantly improves with respect to the previously known results, even in the full-duplex case. Correspondingly, better lower bounds on the gossiping time of non-systolic protocols are determined in the directed, half-duplex and full-duplex cases for Butterfly, de Bruijn and Kautz graphs. Even if in this paper we give only a limited number of examples, our technique has wide applicability and gives a general framework that often allows to get improved lower bounds on the gossiping time of systolic and non-systolic protocols in the directed, half-duplex and full-duplex cases.
Reducing Encoder Bit-Rate Variation in MPEG Video
Authors: Albert Mo Cheng, Rajat Agarwal
Venue: Journal of VLSI Signal Processing Systems (2005)

A shortcoming of current video transmission using the MPEG standard is that its encoder produces a variable bit rate (VBR). Due to this, the encoder output has to be buffered and released over the network at a constant rate. This buffering of the encoder output introduces an additional delay between the encoding and decoding phases of the video transmission. To remedy this problem, we present a strategy to distribute the load produced by the encoder as evenly as possible, i.e., try to have a constant bit rate (CBR). This is done by treating the slices in each frame separately while compressing them and then mixing the different kinds of slices that are sent over the network. The resulting load variation is much more uniform, reducing the buffering delay and making future bandwidth requirement estimates more accurate.
Geometric texture synthesis by example
Authors: Pravin Bhat, Stephen Ingram, Greg Turk
Venue: Proceedings of the 2004 Eurographics/ACM SIGGRAPH symposium on Geometry processing (2004)

Patterns on real-world objects are often due to variations in geometry across the surface. Height fields and other common parametric methods cannot synthesize many forms of geometric surface texture such as thorns, scales, and bark. We present an example-based technique for synthesizing a variety of geometric textures on a model's surface. The applied textures can be from models specifically created for this purpose, or may be drawn from user-specified regions of an example model. We extend existing neighborhood-based texture synthesis algorithms to operate on volumetric models. Similar to image analogies [11], given a training pair of unfiltered and filtered source models and an unfiltered destination model (all volumetric grids), we synthesize a filtered fourth model that exhibits the desired geometric texture. The user defines vector fields to specify the direction of texture anisotropy on the source and destination models. The vector field defines a coordinate frame on the destination object's surface that is used to sample the voxel density values in the neighborhood near a given voxel, which then gives a feature vector that is matched to the neighborhoods in the source model. Destination voxels are visited in an order that is dictated by the vector field. We show geometric synthesis results on a variety of models using textures such as pits, grooves, thru-holes and thorns.
A Master-Slave Adaptive Load-Distribution Processor Model on PCA
Authors: Toshiyuki Ito, Junji Kitamichi, Kenichi Kuroda, Yuichi Okuyama
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 3 - Volume 04 (2005)

In this paper, we propose a new load-distribution processor model that adapts hardware resources optimally and autonomously to target applications on dynamical reconfiguration devices. In the procedure of load-distribution, the processor detects the load of task-processing by itself and changes the kinds and number of resources optimally. We adopt the master-slave model, which consists of a management unit (master) and two or more processing units (slaves). The former detects overload and distributes tasks and the latter execute task-processing. One of the features of this model is that it is possible to change the number of processing units without reconfiguring the management unit's structure. Moreover, in order to use this load-distribution system efficiently, we propose a reordering unit that buffers data from processing units and outputs rearranged data. In this paper, we describe the requirements and organization of a management unit and processing units. Next, we implement the proposed model on real chips of PCA, a dynamical reconfiguration device, and measure the overheads of processing and reconfiguration. Finally, we evaluate the proposed model based on the experimental results. From the experiments, we show that our proposed model can reduce a designer's efforts to estimate the amount of hardware resources according to applications in advance.
Dynamic Pricing and the Direct-to-Customer Model in the Automotive Industry
Authors: Stephan Biller, Lap Mui Chan, David Simchi-Levi, Julie Swann
Venue: Electronic Commerce Research (2005)

The Internet is changing the automotive industry as the traditional manufacturer and dealer structure faces increased threats from third party e-tailers. Dynamic pricing together with the Direct-to-Customer business model can be used by manufacturers to respond to these challenges. Indeed, by coordinating production and inventory decisions with dynamic pricing, the automotive industry can increase profits and improve supply chain performance. To illustrate these benefits, we discuss a strategy that incorporates pricing, production scheduling, and inventory control under production capacity limits in a multi-period horizon. We show that under concave revenue curves, a greedy algorithm provides the optimal solution, and we describe extensions to the model such as multiple products sharing production capacity. Using computational analysis, we quantify the profit potential and sales variability due to dynamic pricing, and we suggest that it is possible to achieve significant benefit with few price changes.
Key trends in the information and communication technologies
Authors: Kiril Boyanov, Dimitar Todorov
Venue: Proceedings of the 5th international conference on Computer systems and technologies (2004)

The paper describes the key trends in Information and Communications Technologies. It begins with the current status of ICT market and continues with the trends discussion of semiconductor, Information storage, telecommunications and Software technologies. The attention is paid on driving forces of ICT evolution and on some of existing limiting factors.
On simplex-based piecewise-linear approximations of non-linear mappings: Research Articles
Authors: Janne Roos
Venue: International Journal of Circuit Theory and Applications (2005)

Simplex-based piecewise-linear (PWL) approximations of non-linear mappings are needed when the robust PWL analysis is used to directly solve non-linear equations. This paper proposes a straightforward technique for transforming the well-known approximations into another form. This new form is computationally more efficient, since it preserves the sparse structure of the original Jacobian matrix. Furthermore, this new form of PWL approximation explicitly relates the simplex-based PWL analysis to the conventional formulation of the Katzenelson algorithm. The proposed transform technique is also extended to treat groupwise-separable mappings and, finally, non-separable but sparse mappings that arise in real-life simulation of large electronic circuits. In this paper, all these (transformed) simplex-based PWL approximations are compared in terms of their generality and efficiency. The computational efficiency of the PWL approximation that utilizes sparsity is validated with realistic simulations. Copyright &copy; 2005 John Wiley & Sons, Ltd.
A note on the number of matchings and independent sets in trees
Authors: Miranca Fischermann, Lutz Volkmann, Dieter Rautenbach
Venue: Discrete Applied Mathematics (2005)

We prove best-possible upper and lower bounds on the number of matchings in a tree in terms of the number of independent sets and the number of 2-independent sets.
Expressive audio-visual speech: Research Articles
Authors: Elisabetta Bevacqua, Catherine Pelachaud
Venue: Computer Animation and Virtual Worlds (2004)

We aim at the realization of an Embodied Conversational Agent able to interact naturally and emotionally with user. In particular, the agent should behave expressively. Specifying for a given emotion, its corresponding facial expression will not produce the sensation of expressivity. To do so, one needs to specify parameters such as intensity, tension, movement property. Moreover, emotion affects also lip shapes during speech. Simply adding the facial expression of emotion to the lip shape does not produce lip readable movement. In this paper we present a model based on real data from a speaker on which was applied passive markers. The real data covers natural speech as well as emotional speech. We present an algorithm that determines the appropriate viseme and applies coarticulation and correlation rules to consider the vocalic and the consonantal contexts as well as muscular phenomena such as lip compression and lip stretching. Expressive qualifiers are then used to modulate the expressivity of lip movement. Our model of lip movement is applied on a 3D facial model compliant with MPEG-4 standard. Copyright &copy; 2004 John Wiley & Sons, Ltd.
A statistical framework for efficient monitoring of end-to-end network properties
Authors: David Chua, Eric D. Kolaczyk, Mark Crovella
Venue: Proceedings of the 2005 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (2005)

Network service providers and customers are often concerned with aggregate performance measures that span multiple network paths. Unfortunately, forming such network-wide measures can be difficult, due to the issues of scale involved. As a result, it is of interest to explore the feasibility of methods that dramatically reduce the number of paths measured in such situations while maintaining acceptable accuracy.In previous work [4] we have proposed a statistical framework for efficiently addressing this problem. The key to our method lies in the observation and exploitation of the fact that network paths show significant redundancy (sharing of common links).We now make three contributions in [3]: (1) we generalize the framework to make it more immediately applicable to network measurements encountered in practice; (2) we demonstrate that the observed path redundancy upon which our method is based is robust to variation in key network conditions and characteristics, including the presence of link failures; and (3) we show how the framework may be applied to address three practical problems of interest to network providers and customers, using data from an operating network.
S-WFMS: A Service-Based Workflow Management System in Grid Environment
Authors: Mingkui Yang, Hongbing Liang, Bin Xu
Venue: Proceedings of the 19th International Conference on Advanced Information Networking and Applications - Volume 1 (2005)

Grid computing is becoming a mainstream technology for large-scale distributed resource sharing and system integration. In grid environment, everything can be regarded as a grid service. Workflow technology has grown to be an important method to manage processes and resource. Building a distributed workflow management system (WFMS) based on grid services brings many attractive characteristics such as great efficiency, higher fault tolerant ability, good load balancing and reliability etc. This paper presents the architecture of s-WFMS, a service-based workflow management system in grid environment. In s-WFMS, most functional components of a WFMS are abstracted and evolved to high-level grid services. A feasible implementation method of the architecture is also presented.
Resource usage analysis
Authors: Atsushi Igarashi, Naoki Kobayashi
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (2005)

It is an important criterion of program correctness that a program accesses resources in a valid manner. For example, a memory region that has been allocated should eventually be deallocated, and after the deallocation, the region should no longer be accessed. A file that has been opened should be eventually closed. So far, most of the methods to analyze this kind of property have been proposed in rather specific contexts (like studies of memory management and verification of usage of lock primitives), and it was not clear what the essence of those methods was or how methods proposed for individual problems are related. To remedy this situation, we formalize a general problem of analyzing resource usage as a resource usage analysis problem, and propose a type-based method as a solution to the problem.
Motion prediction for caching and prefetching in mouse-driven DVE navigation
Authors: Addison Chan, Rynson W. H. Lau, Beatrice Ng
Venue: ACM Transactions on Internet Technology (TOIT) (2005)

A distributed virtual environment (DVE) allows geographically separated users to participate in a shared virtual environment via connected networks. However, when the users are connected by the Internet, bandwidth limitation and network latency may seriously affect the performance and the interactivity of the system. This explains why there are very few DVE applications for the Internet. To address these shortcomings, caching and prefetching techniques are usually employed. Unfortunately, the effectiveness of these techniques depends largely on the accuracy of the prediction method used. Although there are a few methods proposed for predicting 3D motion, most of them are primarily designed for predicting the motion of specific objects by assuming certain object motion behaviors. We notice that in desktop DVE applications, such as virtual walkthrough and network gaming, the 2D mouse is still the most popular device used for navigation input. Through studying the motion behavior of a mouse during 3D navigation, we have developed a hybrid motion model for predicting the mouse motion during such navigation---a linear model for prediction at low-velocity motion and an elliptic model for prediction at high-velocity motion. The predicted mouse motion velocity is then mapped to the 3D environment for predicting the user's 3D motion. We describe how this prediction method can be integrated into the caching and prefetching mechanisms of our DVE prototype. We also demonstrate the effectiveness of the method and the resulting caching and prefetching mechanisms through extensive experiments.
Tile-based design of a serial memory in QCA
Authors: V. Vankamamidi, M. Ottavi, F. Lombardi
Venue: Proceedings of the 15th ACM Great Lakes symposium on VLSI (2005)

Quantum-dot Cellula Automata (QCA) has been widely advocated as a new device architecture fo nano technology. QCA systems require extremely low power together with the potential for high density and regularity. These features make QCA an attractive technology for manufacturing memories in which the paradigm of memory-in-motion can be fully exploited. This paper proposes a novel serial memory architecture for QCA implementation. This architecture is based on utilizing new building blocks (referred to as tiles) in the storage and input/output circuitry of the memory. The QCA paradigm of memory-in-motion is accomplished using a novel arrangement in the storage loop and timing/clocking; a three-zone memory tile is proposed by which information is moved across a concatenation of tiles by utilizing a two-level clocking mechanism. Clocking zones are shared between memory cells and the length of the QCA line in a clocking zone is independent of word size. This results in a substantial eduction in clocking zones compared with previous serial memories.