ppxscal/embedding_network huggingface dataset:
Adaptive MC-CDMA receiver with constrained constant modulus IQRD-RLS algorithm for MAI suppression
Authors: Shiunn-Jang Chern, Chung-Yao Chang
Venue: Signal Processing (2003)

The multicarrier code division multiple access (MC-CDMA) technique is considered to be one of the attractive candidates to achieve high data-rate for future wireless communication systems. In this paper, based on linearly constrained constant modulus (LCCM) least square (LS) criterion, a new robust adaptive constrained filtering algorithm, referred to as the LCCM inverse QRD-RLS (IQRD-RLS) algorithm, is devised for MC-CDMA detector. The proposed robust LCCM IQRD-RLS algorithm can be used to estimate the weights of the combining process to combat the multiple access interference (MAI), effectively, and is more robust to against the imperfect channel estimation error. By this approach we require only the knowledge of code sequences of desired user rather than the code sequences of other users. The superiority of the proposed algorithm for estimating the weights in the combining process is verified by evaluating the performance, in terms of output signal to interference and noise ratio (SINR) and bit error rate (BER). From computer simulation results we showed that it outperformed the conventional techniques, such as the maximum ratio combining (MRC), blind adaptation algorithm, least mean square algorithm with partitioned linear interference canceller structure (PLIC-LMS) and LCCM-gradient based approaches.
Equational reasoning about LOTOS specifications: a rewriting approach
Authors: Rocco De Nicola, Paola Inverardi, Monica Nesi
Venue: Proceedings of the 6th international workshop on Software specification and design (1991)

In this paper we present an equational approach to the verification of concurrent systems specified in the ISO specification language LOTOS. The approach is based on term rewriting techniques. The kind of reasoning and verification strategies which can be performed are illustrated through two examples.
Knowledge Sharing among R and D Scientists
Authors: Prescott C. Ensign, Louis Hébert
Venue: Proceedings of the Proceedings of the 37th Annual Hawaii International Conference on System Sciences (HICSS'04) - Track 8 - Volume 8 (2004)

This study explores the relationship between reputation and knowledge sharing behavior in anenvironment where R&D work is embedded in a social context and may be broken down physically, organizationally, and by area of technology. Scientists in the same firm, though comprising a social community, may work in different locations, may be separated by organizational boundaries (e.g., teams, departments), and work in different scientific disciplines. Findings illuminate attributes of reputation conducive to collaboration. This research examines one scientist's decision to provide or not provide technological knowledge to another scientist in his or her firm. Analysis is based on 213 returned surveys. It was found that the dimensions of reputation, past behavior and expected action, influence the knowledge sharing decision.
Implementing Angelic Nondeterminism
Authors: Orieta Celiku, Joakim von Wright
Venue: Proceedings of the Tenth Asia-Pacific Software Engineering Conference Software Engineering Conference (2003)

This paper extends correctness and refinement reasoningmethods in order to show how angelic nondeterminismcan be systematically transformed into demonic nondeterminismor determinism. This kind of transformation is importantbecause angelic nondeterminism assumes that thechoices will be resolved intelligently by an agent interestedin establishing the postcondition. When angelic nondeterminismis reduced into demonic nondeterminism or determinism,such intelligent choices are no longer necessary.Reducing angelic nondeterminism is generally not a refinement;however, when context is taken into consideration, itcan be a correctness-preserving transformation.
Structurally noise resistant classifier for multi-modal person verification
Authors: Conrad Sanderson, Kuldip K. Paliwal
Venue: Pattern Recognition Letters (2003)

In this letter we propose a piece-wise linear (PL) classifier for use as the decision stage in a two-modal verification system, comprised of a face and a speech expert. The classifier utilizes a fixed decision boundary that has been specifically designed to account for the effects of noisy audio conditions. Experimental results on the VidTIMIT database show that in clean conditions, the proposed classifier is outperformed by a traditional weighted summation decision stage (using both fixed and adaptive weights). Using white Gaussian noise to corrupt the audio data resulted in the PL classifier obtaining better performance than the fixed approach and similar performance to the adaptive approach. Using a more realistic noise type, namely "operations room" noise from the NOISEX-92 corpus, resulted in the PL classifier obtaining better performance than both the fixed and adaptive approaches. The better results in this case stem from the PL classifier not making a direct assumption about the type of noise that causes the mismatch between training and testing conditions (unlike the adaptive approach). Moreover, the PL classifier has the advantage of having a fixed (non-adaptive, thus simpler) structure.
The vlsi implementation and evaluation of area- and energy-efficient streaming media processors
Authors: William J. Dally
Venue:  (2003)

Media applications such as image processing, signal processing, and graphics require tens to hundreds of billions of arithmetic operations per second of sustained performance for real-time application rates, yet also have tight power constraints in many systems. For this reason, these applications often use special-purpose (fixed-function) processors, such as graphics processors in desk-top systems. These processors provide several orders of magnitude higher performance efficiency (performance per unit area and performance per unit power) than conventional programmable processors. In this dissertation, we present the VLSI implementation and evaluation of stream processors, which reduce this performance efficiency gap while retaining full programmability. Imagine is the first implementation of a stream processor. It contains 48 32-bit arithmetic units supporting floating-point and integer data-types organized into eight SIMD arithmetic clusters. Imagine executes applications stream programs consisting of a sequence of computation kernels operating on streams of data records. The prototype Imagine processor is a 21-million transistor chip, implemented in a 0.15 micron CMOS process. At 232 MHz, a peak performance of 9.3 GFLOPS is achieved while dissipating 6.4 Watts with a die size measuring 16 mm on a side. Furthermore, we extend these experimental results from Imagine to stream processors designed in more area- and energy-efficient custom design methodologies and to future VLSI technologies where thousands of arithmetic units on a single chip will be feasible. Two techniques for increasing the number of arithmetic units in a stream processor are presented: intracluster and intercluster scaling. These scaling techniques are shown to provide high performance efficiencies to tens of ALUs per cluster and to hundreds of arithmetic clusters, demonstrating the viability of stream processing for many years to come.
Workflow analysis with communication norms
Authors: Hans Weigand, Aldo de Moor
Venue: Data Knowledge Engineering (2003)

The language/action perspective (LAP) as orginally introduced by Winograd and Flores has inspired several tools and information system design methodologies. The goal of this article is to make the communication norms underlying various LAP workflow loop models (DEMO, ActionWorkflow) explicit and to contrast them with the auditing norms of internal control. It appears that the communicative action paradigm embedded in DEMO and the customer satisfaction orientation of ActionWorkflow lead to norms which resemble the ones required by internal control, but there are some important differences. For that reason, we propose an extended workflow loop model that distinguishes between customer relations and agency relations. Whereas current LAP approaches do not take agency relations explicitly into account, the extended workflow loop model allows us to analyze the effects of delegation on communicative processes. A framework is offered for the normative analysis of workflows based on a number of formalized communication norms.
Supporting activity-centric collaboration through peer-to-peer shared objects
Authors: Werner Geyer, Jürgen Vogel, Li-Te Cheng, Michael Muller
Venue: Proceedings of the 2003 international ACM SIGGROUP conference on Supporting group work (2003)

We describe a new collaborative technology that is mid-way between the informality of email and the formality of shared workspaces. Email and other ad hoc collaboration systems are typically lightweight and flexible, but build up an unmanageable clutter of copied objects. At the other extreme, shared workspaces provide formal, structured collaboration, but are too heavyweight for users to set up. To bridge this gap between the ad hoc and formal, this paper introduces the notion of "object-centric sharing", where users collaborate in a lightweight manner but aggregate and organize different types of shared artifacts into semi-structured activities with dynamic membership, hierarchical object relationships, as well as real-time and asynchronous collaboration. We present a working prototype implemented with a replicated peer-to-peer architecture, which we describe in detail, and demonstrate its performance in synchronous and asynchronous modes.
Time Explicit Schemes and Spatial Finite Differences Splittings
Authors: Jean-Paul Chehab, Bruno Costa
Venue: Journal of Scientific Computing (2004)

In this article, we conjugate time marching schemes with Finite Differences splittings into low and high modes in order to build fully explicit methods with enhanced temporal stability for the numerical solutions of PDEs. The main idea is to apply explicit schemes with less restrictive stability conditions to the linear term of the high modes equation, in order that the allowed time step for the temporal integration is only determined by the low modes. These conjugated schemes were developed in &lsqb;10&rsqb; for the spectral case and here we adapt them to the Finite Differences splittings provided by Incremental Unknowns, which steems from the Inertial Manifolds theory. We illustrate their improved capabilities with numerical solutions of Burgers equations, with uniform and nonuniform meshes, in dimensions one and two, when using modified Forward&ndash;Euler and Adams&ndash;Bashforth schemes. The resulting schemes use time steps of the same order of those used by semi-implicit schemes with comparable accuracy and reduced computational costs.
Towards a more piece-ful world
Authors: Peri Tarr
Venue: Proceedings of the 2nd international conference on Generative programming and component engineering (2003)

We envision a world in which we can develop, synthesize, adapt, integrate, and evolve software based on high-quality, perpetually flexible pieces. New pieces may be produced by generation, adaptation of existing pieces, or integration of pieces, and this process of "pieceware" engineering continues-statically or dynamically-until a piece with the desired capabilities and properties is synthesized. The pieces themselves may comprise fragments of requirements, models, architectures, patterns, designs, code, tests, and/or any other relevant software artifacts. Many technologies are critical to achieving pieceware engineering; some have been developed in this community and elsewhere, and others are still required.Despite the progress in this field, we have encountered two major problems along the way towards realizing the pieceware vision. First, what paradigms, technologies, and methodologies are required to enable full-lifecycle pieceware engineering? Second, how do we provide the necessary tool support?Our inability to address the second problem has seriously compromised our ability to address the first. The development of tools to realize different pieceware engineering approaches represents a huge investment of time and effort. This is largely because each one must be built from scratch or from low-level abstractions. Consequently, the tools themselves represent isolated point solutions, and rarely have any ability to interoperate or be integrated. This has impeded the development and validation of full-lifecycle pieceware engineering paradigms, technologies, and methodologies.The Concern Manipulation Environment (CME) represents the first effort to define an open, extensible set of components and abstractions to promote the rapid development and integration of tools that support pieceware engineering. The initial focus is on tools for aspect-oriented software development (AOSD), an emerging technology area that is key to pieceware engineering. This talk describes the pieceware engineering vision, the major issues to be addressed, and the technologies required to achieve it. It then discusses how the CME helps to address many of these issues-illustrated by the use of the CME to enable the evolution of a real-world system-and how it can be leveraged by researchers and developers to produce, experiment with, validate, and integrate new pieceware techologies and paradigms. Finally, we identify some of the key challenges remaining to achieve the vision of pieceware engineering.
An effective decision method for semidefinite polynomials
Authors: Zeng Guangxing, Zeng Xiaoning
Venue: Journal of Symbolic Computation (2004)

The purpose of this paper is to present an effective method of deciding the semidefiniteness of multivariate polynomials with coefficients in a computable ordered field, which admits an effective method of finding an isolating set for every non-zero univariate polynomial. Based on this method, the decision of the semidefiniteness of a multivariate polynomial may be reduced to testing some resulted polynomials in fewer variables, of which the total degrees and the term numbers do not exceed those of the given polynomial. With the aid of the computer algebra system Maple, our method is used to solve several examples.
Isothermal and natural convection flows in fractal cavities
Authors: Erwin Doescher, Haroldo F. de Campos Velho, Fernando M. Ramos
Venue: Applied Numerical Mathematics (2003)

In the present work the dynamics of a fluid flow in a fractal domain is analyzed. This domain is a cavity in which the edges are pre-fractals of the Koch square curve. Simulations were carried out considering the pre-fractals of levels 0 (square cavity), 1 and 2. The isothermal regime and the natural convection simulation were performed on a structured staggered grid using a finite volume method. For the level-0 fractal, the numerical code reproduces the results found in the literature. For non-isothermal flow some oscillations were detected at the kinetic energy for Re > 4000, but they are not verified for the standard cavity under the same conditions. Some oscillations were also already observed, but for a deep cavity (aspect ratio equal 2) and for Re > 5000.
Power modeling and reduction of VLIW processors
Authors: Weiping Liao, Lei He
Venue: Compilers and operating systems for low power (2003)

In this chapter, we first present a cycle-accurate power simulator based on the IMPACT toolset. This simulator allows a designer to evaluate both VLIW compiler and micro-architecture innovations for power reduction. Using this simulator, we then develop and compare the following techniques with a bounded performance loss of 1% compared to the case without any dynamic throttling: (i) clock ramping with hardware-based prescan (CRHP), and (ii) clock ramping with compiler-based prediction (CRCP). Experiments using SPEC2000 floating point benchmarks show that the power consumed by floating point units can be reduced by up to 31% and 37%, in CRHP and CRCP respectively.
Experiences in developing a typical web/database application
Authors: J.-P. Rosen
Venue: Proceedings of the 2003 annual ACM SIGAda international conference on Ada: the engineering of correct and reliable software for real-time & distributed systems using ada and related technologies (2003)

This paper describes Gesem, an application developed internally by Adalog for managing the registration to its training sessions. The application features a Web interface that uses AWS, an interface to the MySQL DBMS (over ODBC), and a local interface that uses GTK. The project explored various solutions, and identified a number of design patterns that made the development of new functionalities very straightforward. The experience gained in this project can be reused for any development in a similar environment.
Views for light-weight Web ontologies
Authors: Raphael Volz, Daniel Oberle, Rudi Studer
Venue: Proceedings of the 2003 ACM symposium on Applied computing (2003)

The Semantic Web aims at easy integration and usage of content by building on a semi-structured data model where data semantics are explicitly specified through ontologies. However, ontologies and thereby ontology-based applications themselves suffer from heterogeneity. Therefore a new level of data independence is required to allow the customization of information, e.g. towards the needs of other agents, which can be achieved by exploiting database view principles. This paper addresses this issue and presents a new view mechanism for the data models underlying the Semantic Web, RDF and RDFS.
Homoeroticism and electroacoustic music: absence and personal voice
Authors: Barry Truax
Venue: Organised Sound (2003)

The absence of gay themes and homoeroticism in electroacoustic music is discussed within the context of issues of gender and music that have been raised in the last decade. The author's emerging body of work that deals with these issues suggests possible uses of voice, text, video and music theatre within an electroacoustic language to portray sexuality and desire.
On internet interconnection agreements and yield management of information goods
Authors: Pavan Kumar Gundepudi
Venue:  (2003)

Part I: On Internet interconnection agreements. Public peering points, where Internet backbone networks inter-connect primarily, are congested. Consequently, bilateral private agreements for increased interconnection capacity between networks have become common. In essay 1, we model two networks serving different regions and evaluate benefits from private interconnection over public-peering connection. We find the benefits are unevenly distributed and that smaller networks gain more. Further, this disparity grows as public points get more congested. This makes larger networks less willing to peer with others. In essay 2, we model two networks competing in some common region and hosting different proportions of content. We show that for a low overlap, they favor private interconnection with high interconnection capacity. For a high overlap, on the other hand, they reject private interconnection, preferring low interconnection capacity. In between, the network with more content prefers low capacity whereas the other network favors high capacity. Part II: On yield management of information goods. We evaluate strategy of a seller who offers an information good through spot buying, forward buying at reduced price, or a combination of the two. In essay 3, we model consumer reaction. We establish that consumers preferring forward buying have relatively high expectation and low uncertainty in their reservation prices for the good at the time of advance purchase, while those preferring spot buying have relatively low expectation and high uncertainty. Further, consumers' expected surplus from a mixed offering is at least as high as from a pure offering of either spot buying only or forward buying only. In essay 4, we analyze the firm's problem when it is either a price taker or a price setter. When the firm is a price taker, the choice is whether to offer the good for only forward buying, only spot buying, or a combination of the two. We show that when the spot price and the forward discount are moderate in value, the seller chooses the combination strategy. When the firm is a price setter, the choice is how to price the two offerings. We show the firm can increase its revenue with the combination strategy.
Eliminating Redundancies in SAT Search Trees
Authors: Richard Ostrowski, Bertrand Mazure, Lakhdar Saïs, Éric Grégoire
Venue: Proceedings of the 15th IEEE International Conference on Tools with Artificial Intelligence (2003)

Conflict analysis is a powerful paradigm of backtrack search algorithms, in particular for solving satisfiability problems arising from practical applications. Accordingly, most recent Boolean satisfiability solvers implement forms of conflict analysis, at least to some extent. In this paper, a branching criterion initially introduced by Purdom is revisited and extended. Contrary to the author's a priori analysis, it is shown very efficient from a practical point of view in that it allows search trees in SAT solving to be pruned in a significant way while obeying an interesting time and space trade-off. More precisely, we show that redundancies during the search process can be avoided without adding new constraints explicitly. Moreover, the technique can be used not only to prune branches in the search tree, but also to derive implied literals. Extensive experimental results illustrate the feasibility and practical interest of this approach.
An Efficient Algorithm for OSPF Subnet Aggregation
Authors: Aman Shaikh, Dongmei Wang, Guangzhi Li, Jennifer Yates, Charles Kalmanek
Venue: Proceedings of the 11th IEEE International Conference on Network Protocols (2003)

Multiple addresses within an OSPF area can be aggregated and advertised together to other areas. This process is known as address aggregation and is used to reduce router computational overheads and memory requirements and to reduce the network bandwidth consumed by OSPF messages. The downside of address aggregation is that it leads to information loss and consequently sub-optimal (non-shortest path) routing of data packets. The resulting difference (path selection error) between the length of the actual forwarding path and the shortest path varies between different sources and destinations. This paper proves that the path selection error from any source to any destination can be bounded using only parameters describing the destination area. Based on this, the paper presents an efficient algorithm that generates the minimum number of aggregates subject to a maximum allowed path selection error. A major operational benefit of our algorithm is that network administrators can select aggregates for an area based solely on the topology of the area without worryingabout remaining areas of the OSPF network. The other benefit is that the algorithm enables trade-offs between the number of aggregates and the bound on the path selection error. The paper also evaluates the algorithm's performance on random topologies. Our results show that in some cases, the algorithm is capable of reducing the number of aggregates by as much as 50% with only a relatively small introduction of maximum path selection error.