bluuebunny/crossref_metadata_2025_split huggingface dataset:
Co-synthesis of pipelined structures and instruction reordering constraints for instruction set processors
Authors: Huang Ing-Jer 
Published: July 2002

This paper presents a hardware/software co-synthesis approach to pipelined ISP (instruction set processor) design. The approach synthesizes the pipeline structure from a given instruction set architecture (behavioral) specification. In addition, it generates a set of reordering constraints that guides the compiler back-end (reorderer) to properly schedule instructions so that possible pipeline hazards are avoided and throughput is improved.
Co-synthesis takes place while resolving pipeline hazards, which can be attributed to interin-struction dependencies (IIDs). An extended taxonomy of IIDs have been proposed for the systematic analysis of pipeline hazards. Hardware/software methods are developed to resolve IIDs. Algorithms based on taxonomy and resolutions are constructed and integrated into the pipeline synthesis process to explore hardware and software design space. Application benchmarks are used to evaluate possible designs and guide the design decision. The power of the co-synthesis tool PIPER is demonstrated through pipeline synthesis of one illustrative example and two ISPs, including an industrial one (TDY-43). In comparison with other related approaches, our approach achieves higher throughput and provides a systematic way to explore the hardware/software trade-off.
FastSlim
Authors: Jin Wei , Sun Xiaobai , Chase Jeffrey S. 
Published: July 2002

Trace-driven simulation is a valuable tool for evaluating I/O systems. This article presents a new algorithm, called FASTSLIM, that reduces the size of I/O traces and improves simulation performance without compromising simulation accuracy.
FASTSLIM is more general than existing trace reduction algorithms in two ways. First, it is prefetch-safe: traces reduced by FASTSLIM yield provably exact simulations of I/O systems that use prefetching, a key technique for improving I/O performance. Second, FASTSLIM is compatible with a wide range of replacement policies, including common practical approximations to LRU. FASTSLIM-reduced traces are safe for simulations of storage hierarchies and systems with parallel disks.
This article gives a formal treatment of prefetching and replacement issues for trace reduction, introduces the FASTSLIM algorithm, proves that FASTSLIM and variants are safe for a broad range of I/O caching and prefetching systems, and presents empirical results comparing FASTSLIM to competing trace reduction algorithms.
Language Policies and Language Rights
Authors: Paulston Christina Bratt 
Published: July 2002

This review is an overview of the newly developing field of language rights. It distinguishes between (a) historical/descriptive studies where language rights are treated as the resultant variable with no attempt to predict consequences, and (b) exhortatory and ideologically based studies in which language rights are considered a causal variable. An attempt at definitions follows, set within the field of language planning. Principal concerns, such as territoriality versus personality principles and individual versus collective rights, are discussed.The review ends with an argument to consider language rights as emic rights, which is to say culture-language-context–specific rights, rather than to consider linguistic human rights from a universal rights perspective which overstates issues and masks rights to as also being rights against. We need a careful exploration of the nature of language rights and their consequences.
The Carbon Budget in Soils
Authors: Amundson Ronald 
Published: July 2002

▪ Abstract  The global soil C reservoir, ∼1500 Gt of C (1 Gt = 1012kg of C), is dynamic on decadal time scales and is sensitive to climate and human disturbance. At present, as a result of land use, soil C is a source of atmospheric CO2in the tropics and possibly part of a sink in northern latitudes. Here I review the processes responsible for maintaining the global soil C reservoir and what is known about how it responds to direct and indirect human perturbations.“I am fire and air; my other elements I give to baser life”     —William Shakespeare, Antony and Cleopatra
GEOTHERMAL ENERGY FROM THE EARTH: Its Potential Impact as an Environmentally Sustainable Resource
Authors: Mock John E. , Tester Jefferson W. , Wright P. Michael 
Published: July 2002

▪ Abstract  Geothermal energy technology is reviewed in terms of its current impact and future potential as an energy source. In general, the geothermal energy resource base is large and well distributed globally. Geothermal systems have a number of positive social characteristics (they are simple, safe, and adaptable systems with modular 1–50 MW [thermal (t) or electric (e)] plants capable of providing continuous baseload, load following, or peaking capacity) and benign environmental attributes (negligible emissions of CO2, SOx, NOx, and particulates, and modest land and water use). Because these features are compatible with sustainable growth of global energy supplies in both developed and developing countries, geothermal energy is an attractive option to replace fossil and fissile fuels. In 1997, about 7,000 MWe of base-load generating capacity and over 15,000 MWt of heating capacity from high-grade geothermal resources are in commercial use worldwide. A key question is whether these levels can grow to a point where geothermal energy is more universally available and thus have a significant impact on global energy supplies in the twenty-first century. Such an achievement will require the economic development of low-grade resources.The current status of commercial and emerging technologies for electric power production and direct heat use is reviewed for the major geothermal resources including hydrothermal, geopressured, hot dry rock, and magma. Typically, high-temperature resources (>150°C) provide base-load generating capacity while lower-temperature resources provide energy for geothermally assisted heat pumps and for direct use in domestic, agricultural, and aquacultural heating applications. Critical development issues relating to resource quality and distribution, drilling costs, and reservoir productivity are discussed in the context of their economic impact on production costs. Advanced drilling and improved heat mining methods are suggested as approaches to increase the worldwide use of geothermal energy by reducing field development costs. With these improvements, lower-grade resources can compete in growing global energy markets that are currently controlled by abundant and low-cost fossil fuels.
Queries on the Human Use of the Earth
Authors: Kates Robert W. 
Published: July 2002

[Figure: see text] ▪ Abstract  The central question of my scientific work has been, what is and ought to be the human use of the earth? It has been pursued collectively, with mentor, colleagues, students, and friends as a set of research questions related to hazards, hunger, and sustainable development. Regarding hazard, I tried to understand why people persist in occupying areas subject to natural and technological hazards and how adaptation made this possible. An extended stay in Africa to research both environment and development led to new queries. Why does hunger persist amid a world of plenty, and what can be done to end it? Can there be a transition to sustainability that over the next two generations would meet human needs and reduce hunger and poverty while maintaining the essential life support systems of the planet? All three themes and the research methods used to pursue them come together in an emerging sustainability science.
Ventricular Fibrillation: Mechanisms of Initiation and Maintenance
Authors: Jalife José 
Published: July 2002

▪ Abstract  Ventricular fibrillation (VF) is the major immediate cause of sudden cardiac death. Traditionally, VF has been defined as turbulent cardiac electrical activity, which implies a large amount of irregularity in the electrical waves that underlie ventricular excitation. During VF, the heart rate is too high (> 550 excitations/minute) to allow adequate pumping of blood. In the electrocardiogram (ECG), ventricular complexes that are ever-changing in frequency, contour, and amplitude characterize VF. This article reviews prevailing theories for the initiation and maintenance of VF, as well as its spatio-temporal organization. Particular attention is given to recent experiments and computer simulations suggesting that VF may be explained in terms of highly periodic three-dimensional rotors that activate the ventricles at exceedingly high frequency. Such rotors may show at least two different behaviors: (a) At one extreme, they may drift throughout the heart at high speeds producing beat-to-beat changes in the activation sequence. (b) At the other extreme, rotors may be relatively stationary, activating the ventricles at such high frequencies that the wave fronts emanating from them breakup at varying distances, resulting in complex spatio-temporal patterns of fibrillatory conduction. In either case, the recorded ECG patterns are indistinguishable from VF. The data discussed have paved the way for a better understanding of the mechanisms of VF in the normal, as well as the diseased, human heart. When the heart is diseased, its work is imperfectly performed: the vessels proceeding from the heart become inactive, so that you cannot feel them … If the heart trembles, has little power and sinks, the disease is advancing and death is near. Ebers Papyrus ∼3500 BC
A Twin MRI Study of Size Variations in the Human Brain
Authors: Pennington Bruce F. , Filipek Pauline A. , Lefly Dianne , Chhabildas Nomita , Kennedy David N. , Simon Jack H. , Filley Christopher M. , Galaburda Albert , DeFries John C. 
Published: July 2002

Abstract
Although it is well known that there is considerable variation among individuals in the size of the human brain, the etiology of less extreme individual differences in brain size is largely unknown. We present here data from the first large twin sample (N=132 individuals) in which the size of brain structures has been measured. As part of an ongoing project examining the brain correlates of reading disability (RD), whole brain morphometric analyses of structural magnetic response image (MRI) scans were performed on a sample of adolescent twins. Specifically, there were 25 monozygotic (MZ) and 23 dizygotic (DZ) pairs in which at least one member of each pair had RD and 9 MZ and 9 DZ pairs in which neither member had RD. We first factor-analyzed volume data for 13 individual brain structures, comprising all of the neocortex and most of the subcortex. This analysis yielded two factors (“cortical” and “subcortical”) that accounted for 64% of the variance. We next tested whether genetic and environmental influences on brain size variations varied for these two factors or by hemisphere. We computed intraclass correlations within MZ and DZ pairs in each sample for the cortical and subcortical factor scores, for left and right neocortex, and for the total cerebral volume. All five MZ correlations were substantial (r's=.78 to .98) and significant in both samples, as well as being larger than the corresponding DZ correlations, (r's=0.32 to 0.65) in both samples. The MZ-DZ difference was significant for 3 variables in the RD sample and for one variable in the smaller control sample. These results indicate significant genetic influences on these variables. The magnitude of genetic influence did not vary markedly either for the 2 factors or the 2 hemispheres. There was also a positive correlation between brain size and full-scale IQ, consistent with the results of earlier studies. The total cerebral volume was moderately correlated (r=.42, p&lt;.01, two-tailed) with full-scale IQ in the RD sample; there was a similar trend in the smaller control sample (r=.31, p&lt;.07, two-tailed). Corrections of similar magnitude were found between the subcortical factor and full-scale IQ, whereas the results for the cortical factor (r=.16 and .13) were smaller and not significant. In sum, these results provide evidence for the heritability of individual differences in brain size which do not vary markedly by hemisphere or for neocortex relative to subcortex. Since there are also correlations between brain size and full-scale IQ in this sample, it is possible that genetic influences on brain size partly contribute to individual differences in IQ.
IV. Neuroanatomy of Williams Syndrome: A High-Resolution MRI Study
Authors: Reiss Allan L. , Eliez Stephan , Schmitt J. Eric , Straus Erica , Lai Zona , Jones Wendy , Bellugi Ursula 
Published: July 2002

AbstractWilliams syndrome (WMS), a genetic condition resulting from a contiguous deletion on the long arm of chromosome 7, is associated with a relatively consistent profile of neurocognitive and neurobehavioral features. The distinctiveness and regularity of the profile of learning and behavioral characteristics in this genetic condition suggests that underlying neurobiological correlates may be identifiable. In this initial study, we report findings derived from a high-resolution neuroimaging study of 14 young adult subjects with WMS and an individually matched normal control group. Compared to controls, subjects with WMS were noted to have decreased overall brain and cerebral volumes, relative preservation of cerebellar and superior temporal gyrus (STG) volumes, and disproportionate volume reduction of the brainstem. Analyses also suggested that the pattern of cerebral lobe proportions in WMS may be altered compared to normal controls with a greater ratio of frontal to posterior (parietal+occipital) tissue. Assessment of tissue composition indicated that, relative to controls, individuals with WMS have relative preservation of cerebral gray matter volume and disproportionate reduction in cerebral white matter volume. However, within the cerebral gray matter tissue compartment, the right occipital lobe was noted to have excess volume loss. Combined with our growing knowledge of the function of genes in the commonly deleted region for WMS, more detailed information regarding the structure and function of the WMS brain will provide a unique opportunity for elucidating meaningful correlations amongst genetic, neurobiological, and neurobehavioral factors in humans.
The Fusiform “Face Area” is Part of a Network that Processes Faces at the Individual Level
Authors: Gauthier Isabel , Tarr Michael J. , Moylan Jill , Skudlarski Pawel , Gore John C. , Anderson Adam W. 
Published: July 2002

Abstract
According to modular models of cortical organization, many areas of the extrastriate cortex are dedicated to object categories. These models often assume an early processing stage for the detection of category membership. Can functional imaging isolate areas responsible for detection of members of a category, such as faces or letters? We consider whether responses in three different areas (two selective for faces and one selective for letters) support category detection. Activity in these areas habituates to the repeated presentation of one exemplar more than to the presentation of different exemplars of the same category, but only for the category for which the area is selective. Thus, these areas appear to play computational roles more complex than detection, processing stimuli at the individual level. Drawing from prior work, we suggest that face-selective areas may be involved in the perception of faces at the individual level, whereas letter-selective regions may be tuning themselves to font information in order to recognize letters more efficiently.
A Limit to the Speed of Processing in Ultra-Rapid Visual Categorization of Novel Natural Scenes
Authors: Fabre-Thorpe Michèle , Delorme Arnaud , Marlot Catherine , Thorpe Simon 
Published: July 2002

Abstract
The processing required to decide whether a briefly flashed natural scene contains an animal can be achieved in 150 msec (Thorpe, Fize, & Marlot, 1996). Here we report that extensive training with a subset of photographs over a 3-week period failed to increase the speed of the processing underlying such Rapid Visual Categorizations: Completely novel scenes could be categorized just as fast as highly familiar ones. Such data imply that the visual system processes new stimuli at a speed and with a number of stages that cannot be compressed. This rapid processing mode was seen with a wide range of visual complex images, challenging the idea that short reaction times can only be seen with simple visual stimuli and implying that highly automatic feed-forward mechanisms underlie a far greater proportion of the sophisticated image analysis needed for everyday vision than is generally assumed.
On “Natural” Learning and Pruning in Multilayered Perceptrons
Authors: Heskes Tom 
Published: July 2002

Several studies have shown that natural gradient descent for on-line learning is much more efficient than standard gradient descent. In this article, we derive natural gradients in a slightly different manner and discuss implications for batch-mode learning and pruning, linking them to existing algorithms such as Levenberg-Marquardt optimization and optimal brain surgeon. The Fisher matrix plays an important role in all these algorithms. The second half of the article discusses a layered approximation of the Fisher matrix specific to multilayered perceptrons. Using this approximation rather than the exact Fisher matrix, we arrive at much faster “natural” learning algorithms and more robust pruning procedures.
Correctness of Belief Propagation in Gaussian Graphical Models of Arbitrary Topology
Authors: Weiss Yair , Freeman William T. 
Published: July 2002

Graphical models, such as Bayesian networks and Markov random fields, represent statistical dependencies of variables by a graph. Local “belief propagation” rules of the sort proposed by Pearl (1988) are guaranteed to converge to the correct posterior probabilities in singly connected graphs. Recently, good performance has been obtained by using these same rules on graphs with loops, a method we refer to as loopy belief propagation. Perhaps the most dramatic instance is the near Shannon-limit performance of “Turbo codes,” whose decoding algorithm is equivalent to loopy propagation. Except for the case of graphs with a single loop, there has been little theoretical understanding of loopy propagation. Here we analyze belief propagation in networks with arbitrary topologies when the nodes in the graph describe jointly gaussian random variables. We give an analytical formula relating the true posterior probabilities with those calculated using loopy propagation. We give sufficient conditions for convergence and show that when belief propagation converges, it gives the correct posterior means for all graph topologies, not just networks with a single loop. These results motivate using the powerful belief propagation algorithm in a broader class of networks and help clarify the empirical performance results.
Concentration Tuning Mediated by Spare Receptor Capacity in Olfactory Sensory Neurons: A Theoretical Study
Authors: Cleland Thomas A. , Linster Christiane 
Published: July 2002

The olfactory system is capable of detecting odorants at very low concentrations. Physiological experiments have demonstrated odorant sensitivities down to the picomolar range in preparations from the sensory epithelium. However, the contemporary model for olfactory signal transduction provides that odorants bind to olfactory receptors with relatively low specificity and consequently low affinity, making this detection of low-concentration odorants theoretically difficult to understand. We employ a computational model to demonstrate how olfactory sensory neuron (OSN) sensitivity can be tuned by modulation of receptor-effector coupling and/or by other mechanisms regulating spare receptor capacity, thus resolving this conundrum.The EC10–90intensity tuning ranges (ITRs) of whole olfactory glomeruli and postsynaptic mitral cells are considerably broader than the commensurate ITRs of individual OSNs. These data are difficult to reconcile with certain contemporary hypotheses that convergent OSNs in mammals exhibit a homogeneous population of olfactory receptors and identical tuning for odor stimuli. We show that heterogeneity in spare receptor capacities within a convergent OSN population can increase the ITR (EC10–90) of a convergent population of OSNs regardless of the presence or absence of a diversity of receptor expression within the population.The modulation of receptor-effector coupling has been observed in OSNs; other mechanisms for cellular regulation of spare receptor capacity are also highly plausible (e.g., quantitative regulation of the relative expression levels of receptor and effector proteins). We present a model illustrating that these processes can underlie both how OSNs come to exhibit high sensitivity to odorant stimuli without necessitating increased ligand-receptor binding affinities or specificities and how a population of convergent OSNs could exhibit a broader concentration sensitivity than its individual constituent neurons, even given a population expressing identical odorant receptors. The regulation of spare receptor capacity may play an important role in the olfactory system's ability to reliably detect low odor concentrations, discriminate odor intensities, and segregate this intensity information from representations of odor quality.
JUDGING WITH GOD'S LAW ON EARTH: JUDICIAL POWERS OF THE QĀDĪ AL-JAMĀ'A OF CORDOBA IN THE FIFTH/ELEVENTH CENTURY
Authors: Müller Christian 
Published: July 2002

AbstractCourt cases from al-Ahkām al-kubrā, a fatwā collection compiled by the Andalusian qādī Ibn Sahl (d. 486/1093), form the basis for this inquiry into the judicial authority of the qādī al-jamā'a. The article, which deals with both institutional and legal aspects of the office, demonstrates that adherence to procedural law during court procedure and consideration of the jurisconsults' legal opinions were required to produce a judgment that was binding but potentially reversible. The possible influence of Mālikī fiqh on the range of qādī jurisdiction in Cordoba is tested on a sample of fifty cases that originated in the period between 456/1064 and 464/1072. These cases are noteworthy for their reliability as source material and because they were handled not only by the qādī al-jamā'a but also by other judicial magistrates.
THE ADMINISTRATION OF THE IRON INDUSTRY IN ELEVENTH-CENTURY CHINA
Authors: Wagner Donald 
Published: July 2002

AbstractRobert Hartwell's research in the early 1960's into the iron industry of Song China (960-1279) showed, using a variety of evidence, that the applications of iron expanded greatly in the early Song. He then calculated from tax data the annual iron production of China in the 11th century. This article argues that, while Hartwell's qualitative conclusions hold, his specific calculation of annual production is flawed: no reliable calculation is possible based on presently available sources. Les recherches de Robert Hartwell au début des années 1960 sur l'industrie du fer en Chine à l'époque Song (960-1279) ont montré, en exploitant un large éventail de faits évidents, que les demandes en fer ont fort augmenté dans la première période de l'époque Song. Il avait alors calculé, d'après les données tirées des registres d'imposition, la production annuelle de ce minerai en Chine au XIème siècle. Cet article relève que, si les conclusions qualitatives de Hartwell paraissent correctes, son évaluation de la production annuelle s'avère infondée: aucun calcul fiable ne peut être effectué en exploitant les données actuellement disponibles.