bluuebunny/crossref_metadata_2025_split huggingface dataset:
Writing Larch interface language specifications
Authors: Wing Jeannette M. 
Published: October 2002

Current research in specifications is emphasizing the practical use of formal specifications in program design. One way to encourage their use in practice is to provide specification languages that are accessible to both designers and programmers. With this goal in mind, the Larch family of formal specification languages has evolved to support a two-tiered approach to writing specifications. This approach separates the specification of state transformations and programming language dependencies from the specification of underlying abstractions. Thus, each member of the Larch family has a subset derived from a programming language and another subset independent of any programming languages. We call the former interface languages, and the latter the Larch Shared Language.
This paper focuses on Larch interface language specifications. Through examples, we illustrate some salient features of Larch/CLU, a Larch interface language for the programming language CLU. We give an example of writing an interface specification following the two-tiered approach and discuss in detail issues involved in writing interface specifications and their interaction with their Shared Language components.
The geometry of semaphore programs
Authors: Carson Scott D. , Reynolds Paul F. 
Published: October 2002

Synchronization errors in concurrent programs are notoriously difficult to find and correct. Deadlock, partial deadlock, and unsafeness are conditions that constitute such errors.
A model of concurrent semaphore programs based on multidimensional, solid geometry is presented. While previously reported geometric models are restricted to two-process mutual exclusion problems, the model described here applies to a broader class of synchronization problems. The model is shown to be exact for systems composed of an arbitrary, yet fixed number of concurrent processes, each consisting of a straight line sequence of arbitrarily ordered semaphore operations.
Time from Newton to Einstein to Friedman
Authors: Rindler Wolfgang 
Published: October 2002

AbstractThis article traces in as untechnical a way as possible the metamorphoses that Newton's absolute time has undergone at the hands of Einstein, only to come round almost full-circle in present-day Friedmannian cosmology. The recurring theme is that of moments being slices through the spacetime of history, and how these slices are affected by gravity.
Intentionality and the Experience of Time
Authors: Modell Arnold 
Published: October 2002

AbstractThis paper explores the experience of time from the perspective of a concept of intentionality derived from Thomas Aquinas. As action directed at some future goal is determined by memorial categories, intentionality contains within it reference to past and future time. Meaning is achieved through action into the world and in turn the self is altered by that action. As the world is essentially an unlabeled place, we organize experience by means of memorial categories. Memorial categories serve as relatively stable templates, modified by the recontextualization that follows from novel experiences. Thus, the sense of the permanence of the past, that gives time its direction, is a construction of our brain. The now moment of experience is not emotionally neutral; our relation between past and future time is mediated by means of feeling rhythmic synchrony, keeping in time with the other provides the earliest medium for emotional bonding.
A Holocene Paleoclimatic and Environmental Record from Stoneman Lake, Arizona
Authors: Hasbargen Jim 
Published: October 2002

AbstractStoneman Lake, Coconino County, Arizona, occupies a 600,000-yr-old caldera on the southern edge of the Colorado Plateau. Changes in fossil diatom floras, pollen profiles, macrofossil remains, and geological characteristics of a sediment core show changing aquatic and terrestrial environments over the past 9000 yr. Cool temperatures and greater effective precipitation than at present are indicated during the early Holocene, prior to 8500 yr B.P. A warmer and drier period followed (8000 and 2000 yr B.P.) during which time a marsh-like environment developed within the caldera, and xeric pleat communities were established along the southern Colorado Plateau. Modern plant communities have existed in this region for the past 6000 yr, although lake conditions have fluctuated.
Determinants of time‐series properties of earnings and cash flows
Authors: Ismail Badr , Choi Kwan 
Published: October 2002

AbstractThis paper examines the relative ability of some economic factors in explaining systematic differences in the time‐series properties of earnings vs. cash flows. The factors used are: firm size, inventory level, capital intensity, degree of competition, and product type (durable‐ nondurable). The results confirm that these factors explain firms' cash flow properties better than earnings properties. Specifically, tests of the differences in the coefficients of variation and autocorrelation coefficients of the earnings series suggest size and product‐type effect. Cash flows, in contrast, indicate an effect with respect to all variables. These findings contribute to our understanding of how the structural forms of the processes generating earnings and cash flows are fundamentally different. The strength of the relationship between economic factors and cash flow properties is potentially relevant to some research efforts directed at cash flow prediction.
Wealth effects of reserve requirement reductions in the 1990s on depository institutions
Authors: Bartunek Kenneth S. , Madura Jeff 
Published: October 2002

AbstractReserves banks hold against deposits do not earn interest and hence, represent an implicit tax on deposits. Thus, adjustments to reserve requirements might be expected to influence the value of depository institutions because they would affect the present value of future implicit taxes on the institutions. This paper measures the share price response of banks to two unique reserve requirement adjustments in the early 1990s. The results indicate that not all of the benefit from the reduction in the implicit tax resulting from the lowering of reserve requirements was passed on to depositors and borrowers. The larger banks tended to experience strong favorable valuation effects.
Participation rates of dividend reinvestment plans: Differences between utility and nonutility firms
Authors: Todd Janet M. , Domian Dale L. 
Published: October 2002

AbstractThis paper examines survey data to study features of dividend reinvestment plans and their relationship to participation rates. Differences between utility and nonutility firms are examined. Discount features and new issue shares are found to be used more often by the utility group, while both groups allow cash contributions along with the dividend reinvestment. Discount features and high returns are correlated with higher participation rates. There is also some preliminary evidence that participation rates by large blockholders may increase trading volume.
Default probability on corporate bonds: A contingent claims model
Authors: Trussel John 
Published: October 2002

AbstractThe purpose of this paper is to develop and test a model of the probability of default on corporate bonds that is based upon the tenets of the contingent claims literature. Equity is considered a call option on the firm's assets, with the exercise price being the face value of the firm's debt. Using this framework, a model is developed with the probability of default as a function of five variables‐firm value, face value of the debt, time to maturity of the debt, instantaneous return and standard deviation of firm value. The model is found to be statistically significant, explains approximately 54 percent of the variation in the bond ratings, and correctly classifies, 68 percent and 66 percent of the bonds in an initial and holdout sample, respectively, according to their agency ratings. The model is also found to provide a reasonable estimate of the probability of default.
Studies on the biological effects of ozone: 11. Release of factors from human endothelial cells
Authors: Valacchi Giuseppe , Bocci Velio 
Published: October 2002

Background: Empirical observations have shown that ozonated autohemotherapy markedly improves the symptoms of chronic limb ischemia (muscular pain at rest, intermittent claudication, etc ) in atherosclerotic patients, but mechanisms of action remain unclear.Aims: Human endothelial cells (HUVECs) are known to release nitrogen monoxide (NO) and we investigated the biological effects of human ozonated serum on HUVECs in culture.Methods: We assessed the relevance of peroxidation, the release of NO as nitrite and of three classical cytokines.Results: The treatment of HUVECs with ozonated serum yields a dose dependent increase of thiobarbituric acid reactive substances (TBARS) and of hydrogen peroxide (H2O2) and a decrease of protein thiol groups (PTG). Concomitantly, in comparison to either the control or the oxygenated sample, there is a significant and steady increase of nitric oxide (NO) production; this is markedly enhanced by the addition of L‐arginine (20 μM) and inhibited in the presence of the NO inhibitor, L‐NAME (20 mM). The main mediator of ozone action is H2O2 as it has been shown either after its direct measurement or by the addition of 20, 40 and 100 μM. Moreover, during 24 hours incubation we have investigated the production of endothelin 1 (ET‐1), E‐selectin and Interleukin 8 (IL‐8) and it appears that ozonation enhances IL‐8, inhibits E‐selectin and hardly modifies ET‐1 production.Conclusions: It appears that reinfusion of ozonated blood, by enhancing release of NO, may induce vasodilation in ischemic areas and reduce hypoxia.
Prescribing to drug misusers in practice—often effective, but rarely straightforward
Authors: Seivewright Nicholas , Iqbal Muhammad Z. 
Published: October 2002

AbstractMany reviews describe the effectiveness of methadone treatment in reducing illicit drug use and associated behaviours among opiate misusers. The strongest evidence includes social outcomes such as reduced debt and crime, and relates overwhelmingly to maintenance rather than detoxification treatment. Drug clinics are often dominated by individuals unable to withdraw fully from methadone, while the “harm reduction” model accepts some ongoing drug use, with attendant risks. Security measures are necessary to avoid abuse of treatments, but these may be undermined by the agenda of “partnerships with patients” in decision‐making. Buprenorphine appears both safer and less addictive than methadone, and lofexidine is effective as a non‐substitute detoxification method. Naltrexone can clearly reduce relapse rates, provided consumption is assured, while for individuals unable to detoxify or avoid euphoriant opiates, morphine and diamorphine are sometimes used. In non‐opiate misuse, clinical studies of a wide range of medications have produced relatively few positive findings.
Leiomyosarcoma of the Oropharynx and Neurogenic Tumors in a Young Patient With Turner′s Syndrome
Authors: De Chiara Annarosaria , Apice Gaetano , Silvestro Giustino , Losito Simona , Botti Gerardo , Ionna Francesco , De Rosa Vincenzo , Borghese Annamaria , Ninfo Vito 
Published: October 2002

Patient: A case of Turner′s syndrome developing a leiomyosarcoma of the oropharynx and metachronous neurogenic
tumors (mediastinal ‘ganglioneuroblastoma intermixed’, subcutaneous neurilemoma) is described.Discussion: To our knowledge, this case is the second reported leiomyosarcoma in a patient with Turner′s syndrome. Also
the site of involvement (palate and oropharynx) is particularly unusual for the already rare leiomyosarcomas in the young age.
Molecular Characterization of a Chromosomal Rearrangement Involved in the Adaptive Evolution of Yeast Strains
Authors: Pérez-Ortı́n José E. , Querol Amparo , Puig Sergi , Barrio Eladio 
Published: October 2002

Wine yeast strains show a high level of chromosome length polymorphism. This polymorphism is mainly generated by illegitimate recombination mediated by Ty transposons or subtelomeric repeated sequences. We have found, however, that the SSU1-R allele, which confers sulfite resistance to yeast cells, is the product of a reciprocal translocation between chromosomes VIII and XVI due to unequal crossing-over mediated by microhomology between very short sequences on the 5′ upstream regions of the SSU1 andECM34 genes. We also show that this translocation is only present in wine yeast strains, suggesting that the use for millennia of sulfite as a preservative in wine production could have favored its selection. This is the first time that a gross chromosomal rearrangement is shown to be involved in the adaptive evolution ofSaccharomyces cerevisiae.[The sequence data from this study have been submitted to EMBL under accession nos. AF239757,AF239758, and AJ458340–AJ458367. The following individual kindly provided reagents, samples, or unpublished information as indicated in the paper: N. Goto-Yamamoto.]
Metalevel building blocks for modular systems
Authors: Jagannathan Suresh 
Published: October 2002

The formal definition of any namespace device found in a programming language can be given in terms of transformations on a semantic environment. It is worthwhile, therefore, to consider the implications of incorporating environments as bona fide data objects in a programming system.
In this article, we propose a treatment of environments and the mechanism by which they are reified and manipulated, that addresses these concerns. The language described below (Rascal) permits environments to be reified into data structures, and data structures to be reflected into environments, but gives users great flexibility to constrain the extent and scope of these processes. We argue that the techniques and operators developed define a cohesive basis for building large-scale modular systems using reflective programming techniques.
Static analysis of upper and lower bounds on dependences and parallelism
Authors: Pugh William , Wonnacott David 
Published: October 2002

Existing compilers often fail to parallelize sequential code, even when a program can be manually transformed into parallel form by a sequence of well-understood transformations (as in the case for many of the Perfect Club Benchmark programs). These failures can occur for several reasons: the code transformations implemented in the compiler may not be sufficient to produce parallel code, the compiler may not find the proper sequence of transformations, or the compiler may not be able to prove that one of the necessary transformations is legal.
When a compiler fails to extract sufficient parallelism from a program, the programmer may try to extract additional parallelism. Unfortunately, the programmer is typically left to search for parallelism without significant assistance. The compiler generally does not give feedback about which parts of the program might contain additional parallelism, or about the types of transformations that might be needed to realize this parallelism. Standard program transformations and dependence abstractions cannot be used to provide this feedback.
In this paper, we propose a two-step approach to the search for parallelism in sequential programs. In the first step, we construct several sets of constraints that describe, for each statement, which iterations of that statement can be executed concurrently. By constructing constraints that correspond to different assumptions about which dependences might be eliminated through additional analysis, transformations, and user assertions, we can determine whether we can expose parallelism by eliminating dependences. In the second step of our search for parallelism, we examine these constraint sets to identify the kinds of transformations needed to exploit scalable parallelism. Our tests will identify conditional parallelism and parallelism that can be exposed by combinations of transformations that reorder the iteration space (such as loop interchange and loop peeling).
This approach lets us distinguish inherently sequential code from code that contains unexploited parallelism. It also produces information about the kinds of transformations needed to parallelize the code, without worrying about the order of application of the transformations. Furthermore, when our dependence test is inexact we can identify which unresolved dependences inhibit parallelism by comparing the effects of assuming dependence or independence. We are currently exploring the use of this information in programmer-assisted parallelization.
Optimal evaluation of array expressions on massively parallel machines
Authors: Chatterjee Siddhartha , Gilbert John R. , Schreiber Robert , Teng Shang-Hua 
Published: October 2002

We investigate the problem of evaluating Fortran 90-style array expressions on massively parallel distributed-memory machines. On such a machine, an elementwise operation can be performed in constant time for arrays whose corresponding elements are in the same processor. If the arrays are not aligned in this manner, the cost of aligning them is part of the cost of evaluating the expression tree. The choice of where to perform the operation then affects this cost.
We describe the communication cost of the parallel machine theoretically as a metric space; we model the alignment problem as that of finding a minimum-cost embedding of the expression tree into this space. We present algorithms based on dynamic programming that solve the embedding problem optimally for several communication cost metrics: multidimensional grids and rings, hypercubes, fat-trees, and the discrete metric. We also extend our approach to handle operations that change the shape of the arrays.
Language support for the specification and development of composite systems
Authors: Feather Martin S. 
Published: October 2002

When a complex system is to be realized as a combination of interacting components, development of those components should commence from a specification of the behavior required of the composite system. A separate specification should be used to describe the decomposition of that system into components. The first phase of implementation from a specification in this style is the derivation of the individual component behaviors implied by these specifications.
The virtues of this approach to specification are expounded, and specification language features that are supportive of it are presented. It is shown how these are incorporated in the specification language Gist, which our group has developed. These issues are illustrated in a development of a controller for elevators serving passengers in a multistory building.
A Language for Array and Vector Processors
Authors: Perrott R. H. 
Published: October 2002

The scientific community has consistently demanded from computing machines an increase in the number of instructions executed per second. The latest increase has been achieved by duplication of arithmetic units for an array processor and the pipelining of functional units for vector processors. The high level programming languages for such machines have not benefited from the advances which have been made in programming language design and implementation techniques.
A high level language is described in this paper which is appropriate for both array and vector processors and is defined without reference to the hardware of either type of machine. The syntax enables the parallel nature of a problem to be expressed in a form which can be readily exploited by these machines. This is achieved by using the data declarations to indicate the maximum extent of parallel processing and then to manipulate this, or a lesser extent, in the course of program execution. It was found to be possible to modify many of the structured programming and data structuring concepts for this type of parallel environment and to maintain the benefits of compile time and run time checking. Several special constructs and operators are also defined.
The language offers to the large scale scientific computing community many of the advances which have been made in software engineering techniques while it exploits the architectural advances which have been made.
Global Context Recovery: A New Strategy for Syntactic Error Recovery by Table-Drive Parsers
Authors: Pai Ajit B. , Kieburtz Richard B. 
Published: October 2002

Described is a method for syntactic error recovery that is compatible with deterministic parsing methods and that is able to recover from many errors more quickly than do other schemes because it performs global context recovery. The method relies on fiducial symbols, which are typically reserved key words of a language, to provide mileposts for error recovery. The method has been applied to LL(1) parsers, for which a detailed algorithm is given, and informally proved correct. The algorithm will always recover and return control to the parser if the text being analyzed satisfies only minimal requirements: that it contains one or more occurrences of fiducial symbols following the point at which an error is detected. Tables needed for error recovery have been automatically generated, along with parsing tables, by a parser constructor for the LL(1) grammars.
A theoretical characterization of fiducial symbols is given, and the utility of this characterization in practice is discussed. It has been applied to a grammar for the programming language Pascal to aid in selection of a set of fiducial symbols. The error recovery scheme has been tested on a set of student-written Pascal program texts and is compared with other error recovery strategies.
Design of a Machine-Independent Optimizing System for Emulator Development
Authors: Ma Perng-Ti , Lewis T. G. 
Published: October 2002

Methods are described to translate a certain machine-independent intermediate language (IML) to efficient microprograms for a class of horizontal microprogrammable machines. The IML is compiled directly from a high-level microprogramming language used to implement a virtual instruction set processor as a microprogram.
The primary objective of the IML-to-host machine interface design is to facilitate language portability. Transportability is accomplished by use of a field description model and a macro expansion table which describe the host machine to the translator system.
Register allocation scheme and control flow analysis are employed to allocate the symbolic variables of the IML to the general-purpose registers of the host machine. A set of 5-tuple microoperations (function, input, output, field, phase) is obtained with the aid of the field description model. Then a compaction algorithm is used to detect the parallelism of microoperations and to generate suboptimal code for a horizontal microprogrammable machine. The study concludes with a description of the effects of the above methods upon the quality of microcode produced for a specific commercial computer.