ppxscal/embedding_network huggingface dataset:
Information Technology and Organization Design: Locating Decisions and Information
Authors: Barrie R. Nault
Venue: Management Science (1998)

We study the impact of information technology (IT) on the profitability of individual organization designs and on the relative profitability of different organization designs. We develop models where organization design is defined by the location of investment decision authority. We consider global and local investment when there is an information asymmetry between a central authority and decentralized nodes-decentralized nodes make better local investment decisions because of their local knowledge. We define three separate organization designs: a hierarchy where all investments are made by a central authority, a market where all investments are made by the decentralized nodes, and a mixed mode where global investments are made by a central authority and local investments are made by decentralized nodes. Because of complementarities between global and local investment, we show that there is under investment relative to first-best in all three organization designs. We also find that IT can be used to mitigate that underinvestment, either by bringing information to the decision maker or by redesigning the monitoring and incentive structure. We demonstrate that IT does not necessarily favor decentralized organization designs, and we show how the costs of coordination may resultin the mixed mode being dominated by one or both of the alternative organization designs. Thus, collocation of investment decision rights and information that results in decisions that require coordination might not be optimal when the costs of not synchronizing global and local investment are high.
Robustness of an Elementwise Parallel Finite Element Method for Convection-Diffusion Problems
Authors: W. J. Layton, J. M. Maubach, P. J. Rabier
Venue: SIAM Journal on Scientific Computing (1998)

We consider an elementwise data-parallel finite element procedure, recently proposed by Layton and Rabier [Appl. Math. Lett., 5 (1992), pp. 67--70], [J. Numer. Linear Algebra Appl., 2 (1995), pp. 363--394], applied to singularly perturbed convection-diffusion equations with possibly highly anisotropic diffusion. It is shown that the number of iterations required for the solution of the linear algebraic system is proportional to the inverse of the smallest grid element diameter, uniformly in the diffusion parameter and the degree of anisotropy. This is optimal, since the method can in some cases use only element matrices and load vectors and the algorithm requires only local communication on the physical mesh between adjacent elemental subdomains. Our analysis includes both the usual Galerkin formulation and the streamline upwind finite element formulations. The convergence result holds with conforming elements of any order or elements of arbitrary order from a new family of nonconforming elements.
On the Size of Minimum Super Arrovian Domains
Authors: Samit Dasgupta
Venue: SIAM Journal on Discrete Mathematics (1999)

Arrow's celebrated impossibility theorem states that a sufficiently diverse domain of voter preference profiles cannot be mapped into social orders of the alternatives without violating at least one of three appealing conditions. Following Fishburn and Kelly, we define a set of strict preference profiles to be super Arrovian if Arrow's impossibility theorem holds for this set and each of its strict preference profile supersets. We write $\sigma(m,n)$ for the size of the smallest super Arrovian set for $m$ alternatives and $n$ voters. We show that $\sigma(m,2) = \lceil \frac{2m}{m-2} \rceil$ and $\sigma(3,3)=19.$ We also show that $\sigma(m,n)$ is bounded by a constant for fixed $n$ and bounded on both sides by a constant times $2^n$ for fixed $m.$ In particular, we find that $\lim_{n\rightarrow \infty} \sigma(3,n)/2^n = 3.$ Finally, we answer two questions posed by Fishburn and Kelly on the structure of minimum and minimal super Arrovian sets.
Micro-CT examinations of trabecular bone samples at different resolutions: 14,7 and 2 micron level
Authors: F. Peyrin, M. Salome, P. Cloetens, A. M. Laval-Jeantet, E. Ritman, P. Rüegsegger
Venue: Technology and Health Care (1998)

Tomographic techniques are attractive for the investigation of trabecular bone architecture. Using either conventional X-ray sources or synchrotron sources currently allows the acquisition of 3D images in a wide range of spatial resolution that may be as small as a few micrometers. Since it is technically possible to examine trabecular architecture at different scales, a question is to know what type of information it is possible to get at each scale. For this purpose, a series of ten vertebrae samples from healthy females of different ages (33 to 90) was imaged at various resolutions on three different micro-CT systems (cubic voxel size respectively 14, 6.7 and 1.4 \mum). The comparison of morphometric parameters extracted from the different images is in agreement with simulation results on the influence of spatial resolution on structure parameters. The conclusion is that a 14 \mum voxel size gives a reasonably good parameterisation of trabecular architecture. Besides the synchrotron radiation 2 \mum level images reveal interesting features on the irregularities and rupture of trabecular surface, and on remodeling zones.
Design-Space Exploration for Block-Processing Based TemporalPartitioning of Run-Time Reconfigurable Systems
Authors: Meenakshi Kaul, Ranga Vemuri
Venue: Journal of VLSI Signal Processing Systems (2000)

The reconfiguration capability of modern FPGA devices can be utilized to execute an application by partitioning it into multiple segments such that each segment is executed one after the other on the device. This division of an application into multiple reconfigurable segments is called temporal partitioning. We present an automated temporal partitioning technique for acyclic behavior level task graphs. To be effective, any behavior-level partitioning method should ensure that each temporal partition meets the underlying resource constraints. For this, a knowledge of the implementation cost of each task on the hardware should be known. Since multiple implementations of a task that differ in area and delay are possible, we perform design-space exploration to choose the best implementation of a task from among the available implementations.To overcome the high reconfiguration overhead of the current day FPGA devices, we propose integration of the temporal partitioning and design space exploration methodology with block-processing. Block-processing is used to process multiple blocks of data on each temporal partition so as to amortize the reconfiguration time. We focus on applications that can be represented as task graphs that have to be executed many times over a large set of input data. We have integrated block-processing in the temporal partitioning framework so that it also influences the design point selection for each task. However, this does not exclude usage of our system for designs for which block-processing is not possible. For both block-processing and non block-processing designs our algorithm selects the best possible design point to minimize the execution time of the design.We present an ILP-based methodology for the integrated temporal partitioning, design space exploration and block-processing technique that is solved to optimality for small sized design problems and in an iterative constraint satisfaction approach for large sized design problems. We demonstrate with extensive experimental results for the Discrete Cosine Transform (DCT) and random graphs the validity of our approach.
Computing Complex Polynomial Chebyshev Approximants on the Unit Circle by the Real Remez Algorithm
Authors: B. Le Bailly, J. P. Thiran
Venue: SIAM Journal on Numerical Analysis (1999)

In recent decades, several generalizations of the real Remez algorithm to the complex domain have been proposed. For example, a recent paper by Tseng, [SIAM J. Numer. Anal., 33 (1996), pp. 2017--2049] presents a generalized multiple exchange method for solving Chebyshev approximation problems by polynomials on the unit circle. His method is particularly efficient when the number of extremal points characterizing the optimal solution is close to its lower bound n+1. (n-1 is the degree of the polynomial approximant.) Under the same assumptions, the aim of this paper is to show that the complex problem can be solved by considering a real polynomial Chebyshev approximation. Hence, we apply the real Remez algorithm and we illustrate the efficiency of this approach by various numerical experiments, e.g., in digital filter design.
Combining observations of intentional and unintentional behaviors for human-computer interaction
Authors: Yoshinori Kuno, Tomoyuki Ishiyama, Satoru Nakanishi, Yoshiaki Shirai
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

Human interfaces are usually designed to respond only to intentional human behaviors. However, humans show unintentional behaviors as well. They can convey useful information to realize user-friendly human interfaces. This paper presents how to combine observations of both types of behaviors by taking two human- machine systems: a gesture-based interface and an intelligent wheelchair. In the first system, intentional hand gestures are chosen using unintentional behaviors. In the second system, near unintentional behaviors following intentional behaviors can be used to control the wheelchair motion. Experimental systems working in real time have been developed. Operational experiments prove our approach promising.
The multiple container packing problem: a genetic algorithm approach with weighted codings
Authors: Günther R. Raidl
Venue: ACM SIGAPP Applied Computing Review (1999)

This paper presents a genetic algorithm (GA) approach to the problem of choosing C disjoint subsets of n items to be packed into distinct containers, such that the total value of the selected items is maximized, without exceeding the capacity of each of the containers. This so-called multiple container packing problem (MCPP) has applications in naval as well as financial management. It is a hard combinatorial optimization problem comprising similarities to the knapsack problem and the bin packing problem.A novel technique for encoding MCPP solutions is used within the GA: The genotype is a vector of numerical weights associated with the items of the problem. The corresponding phenotype is obtained by temporarily modifying the original problem according to these weights and applying a greedy decoding heuristic for the MCPP to the new problem. This solution is then evaluated using the original problem data again. Two different techniques for biasing the original problem and four decoding heuristics are discussed. They were tested in a weight-coded steady-state GA on a variety of MCPP instances. One biasing technique and one decoding heuristic turned out to be clearly more effective than the others, and the GA using them found solutions of significantly higher quality than direct-encoded and order-based GAs from a previous work.
The application of JavaCC to develop a C/C++ preprocessor
Authors: Giancarlo Succi, Raymond W. Wong
Venue: ACM SIGAPP Applied Computing Review (1999)

The commonly available software metrics-extraction tools for C/C++ depend on commercial preprocessors to preprocess the source file before being input into the analyzers. The following paper introduces a Java compiler generator called JavaCC and the application of the generator to develop a Java-based preprocessor for C/C++. Some technical features to the development of preprocessor are also mentioned, such as (1) handling of rescanning in preprocessing with LL(k) parsers, (2) managing conditional compiling with the state-based features of the lexical analyzer in JavaCC, and (3) resolving macro replacement and expansion with parsers.
Evaluating course Web sites and student performance
Authors: Jesse M. Heines
Venue: Proceedings of the 4th annual SIGCSE/SIGCUE ITiCSE conference on Innovation and technology in computer science education (1999)

Erwin Boschmann [1] listed four major issues pertaining to "the infusion of technology in higher education" in a recent posting on The Technology Source. His third issue is ,that "there is little existing research on learning." This paper addresses that issue by analyzing a course web site now in its fifth semester of operation and focusing squarely on its effect on student learning. It discusses research methods for evaluating the web site's effect on student performance and statistical methods for identifying performance trends. Data on multiple undergraduate courses is presented, comparing student performance before and after the web site was introduced.
Approximate Jacobian Matrices for Nonsmooth Continuous Maps and C1-Optimization
Authors: V. Jeyakumar, D. T. Luc
Venue: SIAM Journal on Control and Optimization (1998)

The notion of approximate Jacobian matrices is introduced for a continuous vector-valued map. It is shown, for instance, that the Clarke generalized Jacobian is an approximate Jacobian for a locally Lipschitz map. The approach is based on the idea of convexificators of real-valued functions. Mean value conditions for continuous vector-valued maps and Taylor's expansions for continuously Gâteaux differentiable functions (i.e., C1-functions) are presented in terms of approximate Jacobians and approximate Hessians, respectively. Second-order necessary and sufficient conditions for optimality and convexity of C1-functions are also given.
Instrumental interaction: an interaction model for designing post-WIMP user interfaces
Authors: Michel Beaudouin-Lafon
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2000)

This article introduces a new interaction model called Instrumental Interaction that extends and generalizes the principles of direct manipulation. It covers existing interaction styles, including traditional WIMP interfaces, as well as new interaction styles such as two-handed input and augmented reality. It defines a design space for new interaction techniques and a set of properties for comparing them. Instrumental Interaction describes graphical user interfaces in terms of domain objects and interaction instruments. Interaction between users and domain objects is mediated by interaction instruments, similar to the tools and instruments we use in the real world to interact with physical objects. The article presents the model, applies it to describe and compare a number of interaction techniques, and shows how it was used to create a new interface for searching and replacing text.
Logjam: a tangible multi-person interface for video logging
Authors: Jonathan Cohen, Meg Withgott, Philippe Piernot
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

This paper describes the evolution, implementation, and use of logjam, a system for video logging. The system features a game-board that senses the location and identities of pieces placed upon it. The board is the interface that enables a group of people to log video footage together. We report on some of the surprising physical and social dynamics that we have observed in multi-person logging sessions using the system.
Automatic test bench generation for simulation-based validation
Authors: M. Lajolo, L. Lavagno, M. Rebaudengo, M. Sonza Reorda, M. Violante
Venue: Proceedings of the eighth international workshop on Hardware/software codesign (2000)

In current design practice synthesis tools play a key role, letting designers to concentrate on the specification of the system being designed by carrying out repetitive tasks such as architecture synthesis and technology mapping. However, in the new design flow, validation still remains a challenge: while new technologies based on formal verification are only marginally accepted for large designs, standard techniques based on simulation are beginning to fall behind the increased system complexity. This paper proposes an approach to simulation-based validation, in which an evolutionary algorithm computes useful input sequences to be included in the test bench. The feasibility of the proposed approach is assessed with a preliminary implementation of the proposed algorithm.
Value prediction in VLIW machines
Authors: Tarun Nakra, Rajiv Gupta, Mary Lou Soffa
Venue: ACM SIGARCH Computer Architecture News (1999)

The performance of VLIW architectures is dependent on the capability of the compiler to detect and exploit instruction-level parallelism during instruction scheduling. To exploit the detected parallelism, instructions are reordered to reduce the length of the code schedule and minimize the cycle count for execution. Code reordering is limited by the dependencies among instructions arising from both control flow and data flow. In this paper, we present the design of a VLIW architecture that uses value prediction to remove data dependencies and improve the instruction schedule. Our architecture consists of two execution engines, one for executing the original VLIW code, and the other for executing compensation code after a misprediction. Any code executed due to mispredictions is executed in parallel with the VLIW instructions. The instruction set and hardware of a traditional VLIW machine are modified accordingly to support this type of concurrent execution. The efficacy of the proposed architecture is demonstrated by implementing the prediction model in the Trimaran compiler infrastructure and studying the speedups that result due to the parallel execution of compensation code.
Effects of Chemical Reaction on Two-Dimensional Turbulence
Authors: F. A. Jaberi, S. James
Venue: Journal of Scientific Computing (1999)

Direct numerical simulations of compressible two-dimensional homogeneous turbulent reacting flows are conducted to investigate the interactions between turbulence and chemical reaction. Both isothermal and exothermic nonpremixed reactions are considered. In isothermal reacting simulations, the turbulence is not affected by the reaction and is characterized by the large scale coherent vortices and vorticity-gradient sheet structures. The spatial structures of the density and temperature fields are similar to that of vorticity. However, mixing and reaction occur in the layer like (lamellar) structures which are mainly formed in the hyperbolic flow regions, where the vorticily-gradient sheets are present and the turbulent stretching dominates the circulation. Analysis of the simulations with exothermic reactions indicates that the heat of reaction has significant influence on thc spatial and the compositional structure of velocity, scalar and thermodynamic variables. The fluctuations of the density, the temperature, the pressure and the dilatation are substantially increased due to nonuniform heat release. The heat of reaction also modifies the small scale solenoidal velocity field. At early times, when the reaction is significant, the magnitude of the vorticity (enstrophy) is enhanced by the baroclinic vorticity generation. At late times, when the reaction is almost completed, the molecular dissipation is dominant and the magnitude of vorticity decays continuously. Examination of the energy transfer among the rotational and the compressive components of the kinetic energy and the internal energy indicates that the energy of reaction is transfered to the compressive component of the kinetic energy by the pressure-dilatation correlations. The turbulent advection then transfer the energy from the compressive component of the kinetic energy to its rotational component.
Document Image Coding for Processing and Retrieval
Authors: Omid E. Kia, David S. Doermann
Venue: Journal of VLSI Signal Processing Systems (1998)

Document images belong to a unique class of images where the information is embedded in the language represented by a series of symbols on the page rather than in the visual objects themselves. Since these symbols tend to appear repeatedly, a domain-specific image coding strategy can be designed to facilitate enhanced compression and retrieval. In this paper we describe a coding methodology that not only exploits component-level redundancy to reduce code length but also supports efficient data access. The approach identifies and organizes symbol patterns which appear repeatedly. Similar components are represented by a single prototype stored in a library and the location of each component instance is coded along with the residual between it and its prototype. A representation is built which provides a natural information index allowing access to individual components. Compression results are competitive and compressed-domain access is superior to competing methods. Applications to network-related problems have been considered, and show promising results.
Towards applicable ballistic walking
Authors: R. Q. Van der Linde
Venue: Technology and Health Care (1999)

Ballistic walking has been a topic of research in biomechanics and robotics several times. The main advantages of this approach are colon; self-organizing properties, minimal energetic expenditure, and natural movement. This would make ballistic walking a perfect physical principle for application in rehabilitation, and robotics. However a typical shortcoming of this approach is that it does not explicitly involve actuation (e.g., muscles or motors). In this work ballistic walking is extended with variable intrinsic system parameters, which can be used as an energy input and for disturbance control. With a limit cycle approach walking cycles can be synthesized and cycle controllers can be designed. Experiments with a bipedal robot and simulations illustrate the route towards more robust, and applicable ballistic walking.