bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of file I/O traces in commercial computing environments
Authors: Ramakrishnan K. K. , Biswas Prabuddha , Karedla Ramakrishna 
Published: January 2007

Improving the performance of the file system is becoming increasingly important to alleviate the effect of I/O bottlenecks in computer systems. To design changes to an existing file system or to architect a new file system it is important to understand current usage patterns. In this paper we analyze file I/O traces of several existing production computer sytems to understand file access behavior.
Our analysis suggests that a relatively small percentage of the files are active. The amount of total data active is also quite small for interactive environments. An average file encounters a relatively small number of file opens while receiving an order of magnitude larger number of reads to it. An average process opens quite a large number of files over a typical prime time period. What is more significant is that the effect of outliers on many of the characteristics we studied is dominant. A relatively small number of processes dominate the activity, and a very small number of files receive most of these operations.
In addition, we provide a comprehensive analysis of the dynamic sharing of files in each of these enviroments, addressing both the simultaneous and sequential sharing aspects, and the activity to these shared files. We observe that although only a third of the active files are sequentially shared, they receive a very large proportion of the total operations. We analyze the traces from a given environment across different lengths of time, such as one hour, three hour and whole work-day intervals and do this for 3 different environments. This gives us an idea of the shortest length of the trace needed to have confidence in the estimation of the parameters.
Cluster-based file replication in large-scale distributed systems
Authors: Sandhu Harjinder S. , Zhou Songnian 
Published: January 2007

The increasing need for data sharing in large-scale distributed systems may place a heavy burden on critical resources such as file servers and networks. Our examination of the workload in one large commercial engineering environment shows that wide-spread sharing of unstable files among tens to hundreds of users is common. Traditional client-based file cacheing techniques are not scalable in such environments.
We propose Frolic, a scheme for cluster-based file replication in large-scale distributed file systems. A cluster is a group of workstations and one or more file servers on a local area network. Large distributed systems may have tens or hundreds of clusters connected by a backbone network. By dynamically creating and maintaining replicas of shared files on the file servers in the clusters using those files, we effectively reduce reliance on central servers supporting such files, as well as reduce the distances between the accessing sites and data. We propose and study algorithms for the two main issues in Frolic, 1) locating a valid file replica, and 2) maintaining consistency among replicas. Our simulation experiments using a statistical workload model based upon measurement data and real workload characteristics show that cluster-based file replication can significantly reduce file access delays and server and backbone network utilizations in large-scale distributed systems over a wide range of workload conditions. The workload characteristics most critical to replication performance are: the size of shared files, the number of clusters that modify a file, and the number of consecutive accesses to files from a particular cluster.
Studying the performance properties of concurrent programs by simulation experiments on synthetic programs
Authors: Candlin Rosemary , Fisk Peter , Phillips Joe , Skilling Neil 
Published: January 2007

We have developed a methodology for constructing performance models of different types of concurrent programs, and hence obtaining estimates of execution times on different multiprocessor machines. A given class of program is characterized in terms of a small set of parameters which summarise the behaviour of the program over time. Synthetic programs with selected sets of parameters can then be generated and their execution simulated on a model of some given parallel machine. By varying the parameters systematically, we can discover which factors most affect performance.
Our approach has been to conduct factorial experiments from which we can obtain quantitative predictions of performance for arbitrary concurrent programs whose parameter values lie within the extreme factor levels, and whose synchronization behaviour conforms to one of a number of common patterns.
Report on the CHI'91 workshop
Authors: Edwards Alistair 
Published: January 2007

This was a two-day workshop, attended by some 13 people. The days were split into sessions following a given theme with 45-minute talks from each of two or three participants followed by an open discussion. An outline of the programme and presentations is as follows:Session 1: Advancing accessibility as an HCI design principle
Alan Newell, Dundee University, Scotland: Extra-ordinary computer-human operation
Rex Hancock, GSA: The Role of the Federal GovernmentSession 2: Accessible design: a framework for current trends and directions
Alistair Edwards, University of York, England: Are 'special needs' really special?
Jackie Ryan, University of Guelph, Canada: An Interface Design Builder
Elliot Cole, University of Pennsylvania: Cognitive prosthetics: application of computer-human interaction to restore function in individuals with brain injuriesSession 3: How to design, implement and evaluate accessible interfaces
Jerome Elkind, Lexia Institute: Models of writing by dyslexics using speech and other output methods
Gary Strong, Drexel University: An evaluation of the PRC Touchtalker with Minspeak: some lessons for speech prosthesis design
Robin Shaw & Anne Loomis, Rhode Island VA: The eye wink control interface and using computers to enhance the abilities of severely handicapped personsSession 4: The changing marketplace: opportunities and obstacles
Saul Greenberg, University of Calgary, Canada: Predictive interfaces: what will they think of next?
Bob Williges, Virginia Tech: Travel alternatives for mobility impaired: the surrogate electronic traveller (SET)
Object-oriented software development with the Demeter Method (abstract)
Authors: Lieberherr Karl 
Published: January 2007

The Demeter Method is a formal method that lifts object-oriented software development to a higher level of abstraction by using a graphical specification language for describing object-oriented programs. Executable programs are automatically generated by a CASE tool (the Demeter System/C++) from the graphical high-level descriptions. Unlike other specification languages, the Demeter Method allows you to keep the binding of methods to classes flexible under changing class structures. The higher level of abstraction leads to shorter and more reusable programs than by programming directly in one of todays object-oriented languages such as C++, Smalltalk, Eiffel or CLOS.
Because the Demeter Method is regularly taught at NU both at the graduate and undergraduate level with the 10 week quarter system, it has become, by nnecessity, very easy to learn.
This tutorial is for professionals who want to learn powerful, formally defined high-level concepts that describe the programming task in terms of data-model-based graphs and their subgraphs.
Testing object-oriented software (abstract)
Authors: Berard Edward 
Published: January 2007

Testing of object-oriented software is just as important as testing non-object-oriented software, but the process is fundamentally different because of such factors as information hiding, encapsulation, and inheritance. This tutorial teaches you the terms and concepts of testing software in general, and object-oriented software in particular; how to apply a number of different testing techniques to object-oriented software; how to construct test cases; and an appreciation of what is involved in planning a successful software testing effort. The testing techniques that are covered include both white-box testing such as basis path testing and coverage testing, and black-box testing techniques such as equivalence class partitioning and boundary value analysis.
This course is designed for those with experience in object-oriented software engineering who would like to follow a more rigorous approach to testing.
Teaching “object think” with multi-sensory engagement (abstract)
Authors: Coad Peter 
Published: January 2007

This is a tutorial about how to teach the big picture of objects, especially in an industrial environment where time is short. It is based on the whole brain theory and multi-sensory engagement. The tutorial shows over twenty specific techniques for teaching using multi-sensory engagement, many of these unified into The Object Game, which lets those new to objects see and manipulate them. The tutorial describes a set of specific techniques for leading someone into more effective object think, and compares and contrasts whole-brain multi-sensory engagement with other "object think" techniques, such as graphics, languages, and CRC cards.
This tutorial is designed for those trying to teach object-oriented development who have been frustrated by the inability of some people to reach effective object think. It will also be of interest to those planning to teach object-oriented programming, or if you are responsible for selecting such a course.
Object-oriented communication server for banking applications (abstract)
Authors: Cartiant Ion 
Published: January 2007

In France, there is a generalized file transfer method used for customer-bank information exchange, on X25 networks and on telephone switched lines (BSC 2780/3780 like protocol). It is used by (almost) all France-based banks, and thousands of customers.
RONDO is an 00 file server, supporting these protocols. It was developed in BORLAND C++, with TURBO VISION graphics library. Without the included files, the overall code lines, as reported by the project manager, are 22,000. The server works fine on a 386 based PC, DOS 5.0. RONDOs capabilities are:
The demonstrations purposes are:
Through graphic objects, this technology brings a spectacular new comfort to DOS users with less overhead than in graphical environments. For developers it provides reusable objects and simple building logic.
Selecting the checkpoint interval in time warp simulation
Authors: Lin Yi-Bing , Preiss Bruno R. , Loucks Wayne M. , Lazowska Edward D. 
Published: January 2007

In Time Warp parallel simulation, the state of each process must be saved (checkpointed) regularly in case a rollback is necessary. Although most existing Time Warp implementations checkpoint after every state transition, this is not necessary, and the checkpoint interval is in reality a tuning parameter of the simulation.
Lin and Lazowska[6] proposed a model to derive the optimal checkpoint interval by assuming that the rollback behavior of Time Warp is not affected by the frequency of checkpointing. An experimental study conducted by Preiss et al.[10] indicates that the behavior of rollback is affected by the frequency of checkpointing in general, and that the Lin-Lazowska model may not reflect the real situations in general.
This paper extends the Lin-Lazowska model to include the effect of the checkpoint interval on the rollback behavior. The relationship among the checkpoint interval, the rollback behavior, and the overhead associated with state saving and restoration is described. A checkpoint interval selection algorithm which quickly determines the optimal checkpoint interval during the execution of Time Warp simulation is proposed. Empirical results indicate that the algorithm converges quickly and always selects the optimal checkpoint interval.
Stochastic performance models of parallel task systems (extended abstract)
Authors: Tayyab Athar B. , Kuhl Jon G. 
Published: January 2007

This paper considers the class of parallel computations represented by directed, acyclic task graphs. These include parallel loops, multiphase algorithms, partitioning and merging algorithms, as well as any arbitrary parallel computation that can be structured by a task graph. The paper reviews the current state of the art in stochastic bound models of parallel programs and presents new stochastic bound performance models that predict the expected execution time of parallel programs on a given shared-memory multiprocessor system; and provide qualitative and quantitative description of the relationships between the structure of parallel programs, computation and synchronization behavior of the program, and architectural features of the underlying multiprocessor system.
The models use a new formulation based on stochastic bound analysis and are solvable for a number of distribution functions. They are applicable to shared-memory multiprocessors with significantly different architectural and synchronization performance characteristics. The accuracy of the models is validated via several measurements on two different shared-memory multiprocessor systems, the Alliant FX/2800 and the Encore Multimax. The results show the models to be quite accurate, even when some of the modeling assumptions are violated. The maximum error of prediction ranges from about 10% to under 1%.
An object-oriented APL2
Authors: Selby David A. 
Published: January 2007

Object oriented programming has become an important and accepted part of the computer software industry. Nearly every new operating system that has recently arrived or is scheduled to arrive soon is object oriented in nature. If APL2 is to continue to be a mainstream computational environment, it is very important that it becomes object oriented.
Finding a way that APL2 may sit comfortably in these new operating systems is important. Unfortunately, in both implementation and current programming teaching philosophy, existing APL2 does not easily offer the end user the ability to adopt this new approach. This paper proposes some small changes to the basic APL2 language definition which will permit objects to be defined and used. It also suggests some major changes to the end user's programming methodology.
A microarchitecture description language for retargeting firmware tools
Authors: Nixon J. F. , Schach S. R. , Winner R. I. 
Published: January 2007

ARCHI is a microarchitecture description language designed to serve as the underlying language for a retargetable firmware development environment. ARCHI provides a hierarchical, procedural description at the register transfer level of the target microarchitecture. This description can then be utilized by a meta-environment to generate an instantiation of the firmware development environment for a specific target microarchitecture.
ARCHI has been successfully used to generate debugging simulators for the vertical Perkin-Elmer 3220, and the horizontal VAX-11/780. It is shown that if a microarchitecture description language is powerful enough to retarget a debugging simulator then it can be used to retarget almost every tool in a firmware development meta-environment, and that ARCHI accordingly satisfies its design objectives.
An efficient retargetable microcode generator
Authors: Balakrishnan M. , Bhatt P. C P , Madan B. B. 
Published: January 2007

This paper presents a microcode generator, which accepts a source program (algorithm) and a target description (microarchitecture) as input and generates microcode to implement the algorithm on the defined microarchitecture. The target description is similar to the outputs produced by datapath synthesis phase in hardware design packages. Thus, it can be incorporated to synthesise a microprogrammed control.
The microcode generator is based on an algorithm which preserves retargetability without sacrificing on design time. This is achieved by implementing the generator in two phases: in the first phase, a set of 'feasible' register transfer operations (called base-set) is generated from the microarchitecture description. In the second phase, translation is carried out by simply searching and matching the source program statements with the base-set.
A dynamic very high-level debugger for low-level microprograms
Authors: Wahl N. J. , Schach S. R. , Winner R. I. 
Published: January 2007

Microcode debuggers may be classified according to the following three criteria: static or dynamic output, the level of debugging, and the type of debugging facilities provided. A very high level interactive debugger that supports dynamic debugging of microcode written for the Perkin-Elmer 3220 is described in this paper.
The system allows the user to debug microcode at a very high level because the microarchitecture of the machine can be displayed in the format conceived by the user. The display is dynamic in that the user sees the flow of data as it occurs during the execution of microinstructions. The system supports the usual debugging facilities including setting breakpoints, executing in step or continuous modes, executing in trace mode, examining and changing the contents of memory locations and registers, and restarting the microprogram at an earlier location. But, these facilities are greatly enhanced because the output of the debugger is graphical and dynamic.
Early bankruptcy detection using neural networks
Authors: Rudorfer Gottfried 
Published: January 2007

In 1993, Austria had the highest number of bankruptcies since 1945. The total liabilities came to approximately US$3 billion.
Powerful tools for the early detection of company risks are very important to avoid high economic losses. Artificial neural networks (ANN) are suitable for many tasks in pattern recognition and machine learning. In this paper we present an ANN for early detection of company failures using balance sheet ratios. The neural network has been successfully tested with real data of Austrian private limited companies. The research activities included the design of an APL application with a graphical user interface to find out the relevant input data and tune the ANN.
The developed APL workspace takes advantage of modern windowing features running on IBM compatible computers.
A notation for manipulating arrays of operations
Authors: Landaeta David J. 
Published: January 2007

Much has been written on the-possibility of incorporating arrays of functions and arrays of operators into APL. Various methods have been proposed for creating and restructuring such arrays. This paper proposes the introduction of arrays of operations in general into APL2. Vector notation is extended, as suggested by Brown and Benkard, to allow easy creation of vectors of operations. A new object, called an ELEVATOR, is introduced in order to create operations for manipulating arrays of operations. The semantics of the jot is extended, as per Benkard, to provide a means of extracting structural information from operation arrays.
An analysis of the meaning behind the new notation is undertaken. Definitions are given which not only satisfy the notational requirements but also provide insights into the nature of structural operations on function arrays. The information retained in an empty function array is explained, and the relationship between the primitive ENCLOSE function and the EACH operator becomes clear.
APL2 and AI: a study of search
Authors: Eusebi Ed , Brown James A. 
Published: January 2007

The APL2 language and its environment offers a number of features which make it an effective vehicle for AI research and for the development of knowledge-based systems. In the language, general arrays can easily model various knowledge representations; it is easy to model parallel behavior; there are various ways to implement deductive reasoning: and there are some interesting features that support a functional style of programming. In the environment, editors, interactive graphics, and debugging tools provide excellent human interfaces; Fortran, REXX, and Assembler routines may transparently replace APL2 functions; relational tables which are subsets of APL2 arrays may be retrieved dynamically; and user-to-user shared variable processing can be used to model parallel behavior.
In this paper, we will demonstrate the usage of APL2 for AI problems by presenting concise functional programs for searching a database of rules and facts. Various simple enhancements are shown which extend the scope of the programs to and/or, heuristic, bi-directional, and parallel search.
Human computer interaction in the year 2000
Authors: Thomas J. , Brown J. S. , Buxton W. , Curtis B. , Landauer T. 
Published: January 2007

Much of the work in the field of computer human interaction consists of finding out what is wrong with existing interfaces or which of several existing alternatives is better. Over the next few decades, the possibilities for computer human interaction will explode. This will be due to: 1) continued decrease in the costs of processing and memory, 2) new technologies being invented and existing technologies (e.g., handwriting recognition, speech synthesis) being extended, 3) new applications and 4) new ideas about how people can interact with computers.
While changes along these lines are bound to occur, we need not take the view that investigators in human-computer interaction are to be passive observers of some uncontrolled and uncontrollable evolution. Indeed, we can help steer this process by visions of what the future of human computer interaction could and should be like.
Artificial intelligence development aids (AIDA)
Authors: Sullivan Gary , Fordyce Kenneth 
Published: January 2007

AIDA is a suite of APL based functions, and an approach, to assist in the development of modules to perform artificial intelligence (AI) tasks within a computer based information system (CBIS) or decision support system (DSS). The AIDA functions provide four basic capabilities:
This paper will describe some of the functions in AIDA, and briefly describe some of the systems developed with the help of AIDA. This should help demonstrate that APL is an excellent language for development of expert systems.
N-dimensional geometry using APL2
Authors: Haspel Charles , Vasquez Alphonse Thomas 
Published: January 2007

We describe a computational investigation of the geometry of fundamental domains and units in totally real algebraic number fields. Our approach requires the finding of convex hulls and fundamental domains in n-dimensional space and their display and manipulation. APL2 [API] and graphics are used for this purpose and appear to be essential for any practical pursuit of this approach.
This paper presents a definition of the problem and an example solution including drawings of a fundamental domain in 4-space and portions of the APL2 code for finding n-dimensional convex hull boundaries and picking fundamental domains. The overall approach has been to generalize to n dimensions the techniques of [HV1] and [HV2], which attacked the same problem in three dimensions.
An APL based relational data management language using SYSTEM R as data server
Authors: Antonacci F. , Dell'Orco P. 
Published: January 2007

This report describes a system for accessing System R, via AQL, a query language based on APL, developed by IBM Italy Scientific Centers. System R and AQL reside in two different Virtual Machines: the DB Machine and the User Machine, respectively. The two Machines communicate through VMCF, an inter-machine communication facility in VM/370 environment.
Queries formulated in AQL are shipped to System R, translated into SQL (the native query language of System R) and the results brought back to the User Machine.
The major advantage of this architecture is easiness of implementation and separability between the two environments. From the user's standpoint, this approach combines a friendly and flexible query language with a powerful data manager.