ppxscal/embedding_network huggingface dataset:
Networking strategy at traveler's insurance
Authors: Linda Jean Camp, Marvin Sirbu
Venue: Proceedings of the 1993 conference on Computer personnel research (1993)

The focus of this case study is The Travelers Companies' communications network. Change in the corporate arena comes more slowly than in the academic world. Economics force companies to change their networks; change is not usually sought. This study identifies the business and technology drivers that have forced technological change at The Travelers. The case study includes a history of The Travelers' network for perspective on this information - intensive company. Telecommunications and data processing have changed the nature of the insurance business. Following is a summary of how economics demanded and technology enabled change.
On the orthogonality of assignments and procedures in Algol
Authors: Stephen Weeks, Matthias Felleisen
Venue: Proceedings of the 20th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1993)

According to folklore, Algol is an &ldquo;orthogonal&rdquo; extension of a simple imperative programming language with a call-by-name functional language. The former contains assignments, branching constructs, and compound statements; the latter is based on the typed &lgr;-calculus. In an attempt to formalize the claim of &ldquo;orthogonality&rdquo;, we define a simple version of Algol and an extended &lgr;-calculus. The calculus includes the full &bgr;-rule and rules for the reduction of assignment statements and commands. It has the usual properties, e.g., it satisfies a Church-Rosser and Strong Normalization Theorem. In support of the claim that the imperative and functional components are orthogonal to each other, we show that the proofs of these theorems are combinations of separate Church-Rosser and Strong Normalization theorems for each sublanguage. An acclaimed consequence of Algol's orthogonal design is the idea that the evaluation of a program has two distinct phases. The first phase corresponds to an unrolling of the program according to the usual &bgr; and fixpoint reductions, which provide the formal counterpart to Algol's famous copy rule. The result of this phase is essentially an imperative program. The second phase executes the output of the first phase in the imperative fashion of a stack machine. Given our calculus, we can prove a Postponement Theorem and can thus formalize this phase separation.
Versatile visual programming environment for scientific applications
Authors: F. M. Rijnders, H. J. W. Spoelder, E. P. M. Corten, A. H. Ullings, F. C. A. Groen
Venue: ACM SIGSMALL/PC Notes (1992)

We report on a visual programming environment designed to make and execute programs using already existing procedures written in some third generation language. The utilization of a client/server model combined with the dataflow principle makes this visual programming environment capable of networkwide operations. This feature can be used to elegantly incorporate dedicated hardware like data-acquisition devices and/or number crunchers into one visual program. The combination of these features offers interesting possibilities in the field of e.g. parallel processing and data-acquisition combined with number crunching thus making this tool very apt for the physics community.
MOB forms: a class of multilevel block algorithms for dense linear algebra operations
Authors: Juan J. Navarro, Toni Juan, Tomás Lang
Venue: Proceedings of the 8th international conference on Supercomputing (1994)

Multilevel block algorithms exploit the data locality in linear algebra operations when executed in machines with several levels in the memory hierarchy. It is shown that the family we call Multilevel Orthogonal Block (MOB) algorithms is optimal and easy to design and that using the multilevel approach produces significant performance improvements. The effect of interference in the cache, of the TLB misses, and of page faults are also considered. The multilevel block algorithms are evaluated analytically for an ideal memory system with M cache levels without interferences. Moreover, experimental results of the MOB forms in some present high performance workstations are presented.
The definition of dependence distance
Authors: Michael Wolfe
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1994)

Several definitions of dependence distance can be found in the literature. A single coherent definition is the vector distance between the iteration vectors of two iterations involved in a dependence relation. Different ways to associate iteration vectors with iterations can give different dependence distances to the same program, and have different advantages.
An intelligent business forecasting system
Authors: H. C. Harrison, Gong Qizhong
Venue: Proceedings of the 1993 ACM conference on Computer science (1993)

The main objective of this paper is to explore the possibility of the integration of expert systems technology with a forecasting decision support system. A prototype of an intelligent business forecasting system, called IBFS, has been developed by the authors. Like general DSS, IBFS has a relational database, a model base that contains most of the forecasting models provided in the many commercial forecasting packages, and a user interface. The main feature of IBFS is that a rule-based expert system is integrated to assist the user in selecting appropriate models based on the user's requirements and data patterns. The system also assists in performing, graphing, evaluation, combining and monitoring the models in a systematic fashion.
On being responsible (abstract)
Authors: N. R. Jennings
Venue: ACM SIGOIS Bulletin (1992)

Joint responsibility is a mental and behavioural state which captures and formalizes many of the intuitive underpinnings of collaborative problem solving. It defines the pre-conditions which must hold before such activity can commence, how individuals should behave (in their own problem solving and towards others) once such problem solving has begun and minimum conditions which group participants must satisfy.
Finitely representable databases (extended abstract)
Authors: Stéphane Grumbach, Jianwen Su
Venue: Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1994)

We study classes of infinite but finitely representable databases based on constraints, motivated by new database applications such as geographical databases. The mathematical framework is based on classical decidable first-order theories. We investigate the theory of finitely representable models and prove that it differs strongly from both classical model theory and finite model theory. In particular, we show that most of the well known theorems of either one fail (compactness, completeness, locality, 0/1 laws, etc.). An immediate consequence is the lack of tools to consider the definability of queries in the relational calculus over finitely representable databases. We illustrate this very challenging problem through some classical examples.
Branch prediction for free
Authors: Thomas Ball, James R. Larus
Venue: Proceedings of the ACM SIGPLAN 1993 conference on Programming language design and implementation (1993)

Many compilers rely on branch prediction to improve program performance by identifying frequently executed regions and by aiding in scheduling instructions.Profile-based predictors require a time-consuming and inconvenient compile-profile-compile cycle in order to make predictions. We present a program-based branch predictor that performs well for a large and diverse set of programs written in C and Fortran. In addition to using natural loop analysis to predict branches that control the iteration of loops, we focus on heuristics for predicting non-loop branches, which dominate the dynamic branch count of many programs. The heuristics are simple and require little program analysis, yet they are effective in terms of coverage and miss rate. Although program-based prediction does not equal the accuracy of profile-based prediction, we believe it reaches a sufficiently high level to be useful. Additional type and semantic information available to a compiler would enhance our heuristics.
A process-dependent partitioning strategy for cache memories
Authors: Yannick Deville
Venue: ACM SIGARCH Computer Architecture News (1993)

This paper presents a method for partitioning cache memories which contain both instruction and data blocks. This partitioning scheme limits the total number of instruction blocks, while no conditions are set on the total number of data blocks. The partitioning is reconfigured by changing the maximum allowed number of instruction blocks, called a &ldquo;threshold&rdquo;. A method for choosing this threshold is provided, based on the observation that its optimum value depends on the executable code of the processes considered but almost not on its input data. Trace-driven simulations show that, when medium cache sizes are considered, the proposed structure often yields a much lower miss ratio than the corresponding classical mixed cache (typically 20% to 40% and 50% to 80% lower, respectively if the caches have 4 and 16 ways).
Object migration
Authors: Alberto O. Mendelzon, Tova Milo, Emmanuel Waller
Venue: Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1994)

We study a mechanism that supports the migration of objects from one class of an OODB to another, thereby enabling us to model the same object playing different roles throughout its lifetime. Object migration may introduce typing conflicts due to the different typing constraints imposed by the classes. We present a coercion-like adaptation process that automatically resolves these conflicts. The process combines re-classification of objects and modification of attributes. We study the computational complexity of the problem, and show that the adaptation process can be performed efficiently in databases with covariant schemas.
Consistency and orderability: semantics-based correctness criteria for databases
Authors: Divyakant Agrawal, Amr El Abbadi, Ambuj K. Singh
Venue: ACM Transactions on Database Systems (TODS) (1993)

The semantics of objects and transactions in database systems are investigated. User-defined predicates called consistency assertions are used to specify user programs. Three new correctness criteria are proposed. The first correctness criterion consistency is based solely on the users' specifications and admit nonserializable executions that are acceptable to the users. Integrity constraints of the database are maintained through consistency assertions. The second correctness criterion orderability is a generalization of view serializability and represents a weak notion of equivalence to a serial schedule. Finally, the third correctness criterion strong order-ability is introduced as a generalization of conflict serializability. Unlike consistency, the notions of orderability allow users to operate an isolation as maintenance of the integrity constrainst now becomes the responsibility of the database system.
High assurance discretionary access control for object bases
Authors: Elisa Bertino, Pierangela Samarati, Sushil Jajodia
Venue: Proceedings of the 1st ACM conference on Computer and communications security (1993)

Discretionary access control, based on checking access requests against users' authorizations, does not provide any way of restricting the usage of information once it has been &ldquo;legally&rdquo; accessed. This makes discretionary systems vulnerable to Trojan Horses maliciously leaking information. Therefore the need arises for providing additional controls limiting the indiscriminate flow of information in the system. This paper proposes a message filter complementing discretionary authorization control in object-oriented systems to limit the vulnerability of authorization systems to Trojan Horses. The encapsulation property of the object-oriented data model, which requires that access to objects be possible only through defined methods, makes information flow in such systems have a very concrete and natural embodiment in the form of messages and their replies. As a result, information information flow can be controlled by mediating the transmission of messages exchanged between objects. The message filter intercepts every message exchanged between objects to ensure that information is not leaked to objects accessible by users not allowed for it.
A Sorting Classification of Parallel Rendering
Authors: Steven Molnar, Michael Cox, David Ellsworth, Henry Fuchs
Venue: IEEE Computer Graphics and Applications (1994)

We describe a classification scheme that we believe provides a more structured framework for reasoning about parallel rendering. The scheme is based on where the sort from object coordinates to screen coordinates occurs, which we believe is fundamental whenever both geometry processing and rasterization are performed in parallel. This classification scheme supports the analysis of computational and communication costs, and encompasses the bulk of current and proposed highly parallel renderers - both hardware and software. We begin by reviewing the standard feed-forward rendering pipeline, showing how different ways of parallelizing it lead to three classes of rendering algorithms. Next, we consider each of these classes in detail, analyzing their aggregate processing and communication costs, possible variations, and constraints they may impose on rendering applications. Finally, we use these analyses to compare the classes and identify when each is likely to be preferable.
Phased-mission system analysis using Boolean algebraic methods
Authors: Arun K. Somani, Kishor S. Trivedi
Venue: Proceedings of the 1994 ACM SIGMETRICS conference on Measurement and modeling of computer systems (1994)

Most reliability analysis techniques and tools assume that a system is used for a mission consisting of a single phase. However, multiple phases are natural in many missions. The failure rates of components, system configuration, and success criteria may vary from phase to phase. In addition, the duration of a phase may be deterministic or random. Recently, several researchers have addressed the problem of reliability analysis of such systems using a variety of methods. We describe a new technique for phased-mission system reliability analysis based on Boolean algebraic methods. Our technique is computationally efficient and is applicable to a large class of systems for which the failure criterion in each phase can be expressed as a fault tree (or an equivalent representation). Our technique avoids state space explosion that commonly plague Markov chain-based analysis. We develop a phase algebra to account for the effects of variable configurations and success criteria from phase to phase. Our technique yields exact (as opposed to approximate) results. We demonstrate the use of our technique by means of an example and present numerical results to show the effects of mission phases on the system reliability.
A formal definition of priority in CSP
Authors: C. J. Fidge
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1993)

The process models of Ada and occam are formally based on the CSP process algebra. However, for fine-tuning real-time performance, they include &ldquo;prioritized&rdquo; constructs that have no counterparts in CSP. These constructs therefore lack any formal definition, a situation that leaves room for misunderstandings. We extend CSP with a formal definition of the notion of priority. The definition is then used to assess the transputer implementation of priority in occam and the definition of priority in Ada.
Relative serializability (extended abstract): an approach for relaxing the atomicity of transactions
Authors: D. Agrawal, J. L. Bruno, A. El Abbadi, V. Krishnaswamy
Venue: Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1994)

In the presence of semantic information, serializability is too strong a correctness criterion and unnecessarily restricts concurrency. We use the semantic information of a transaction to provide different atomicity views of the transaction to other transactions. The proposed approach improves concurrency and allows interleavings among transactions which are non-serializable, but which nonetheless preserve the consistency of the database and are acceptable to other users. We develop a graph-based tool whose acyclicity is both a necessary and sufficient condition for the correctness of an execution. Our theory encompasses earlier proposals that incorporate semantic information of transactions. Furthermore it is the first approach that provides an efficient graph based tool for recognizing correct schedules without imposing any restrictions on the application domain. Our approach is widely applicable to many advanced database applications such as systems with long-lived transactions and collaborative environments.
Counting networks
Authors: James Aspnes, Maurice Herlihy, Nir Shavit
Venue: Journal of the ACM (JACM) (1994)

Many fundamental multi-processor coordination problems can be expressed as counting problems: Processes must cooperate to assign successive values from a given range, such as addresses in memory or destinations on an interconnection network. Conventional solutions to these problems perform poorly because of synchronization bottlenecks and high memory contention.Motivated by observations on the behavior of sorting networks, we offer a new approach to solving such problems, by introducing counting networks, a new class of networks that can be used to count. We give two counting network constructions, one of depth log n(1 &plus; log n)/2 using n log (1 &plus; log n)/4 &ldquo;gates,&rdquo; and a second of depth log2 n using n log2 n/2 gates. These networks avoid the sequential bottlenecks inherent to earlier solutions and substantially lower the memory contention.Finally, to show that counting networks are not merely mathematical creatures, we provide experimental evidence that they outperform conventional synchronization techniques under a variety of circumstances.
Information technology alignment or &ldquo;fit&rdquo; in highly turbulent environments: the concept of flexibility
Authors: Kathleen Knoll, Sirkka L. Jarvenpaa
Venue: Proceedings of the 1994 computer personnel research conference on Reinventing IS : managing information technology in changing organizations: managing information technology in changing organizations (1994)

Most information technology (IT) &ldquo;fit&rdquo; literature has taken a structural contingency approach to studying the alignment of IT to organizational characteristics. The research has focused on internal fit, and assumed placid and stable environments. External fit is likely to be more important than internal fit for firms operating in highly dynamic environments. The concept of flexibility is introduced as a form of alignment in turbulent environments. Our definition of flexibility (based on work in IT, manufacturing, strategic management, and living systems theory) identifies three types of flexibility: flexibility in functionality, in use, and in modification. Twenty dimensions of IT flexibility help illustrate some possible measures. We conclude by discussing what our dimensions reveal about flexibility in the client/server domain.
Imaging Cerebral Function
Authors: Phoebe G. Spetsieris, Vijay Dhawan, Shugo Takikawa, Donald Margouleff, David Eidelberg
Venue: IEEE Computer Graphics and Applications (1993)

The Scan Analysis and Visualization Processor (Scan/VP), a flexible, portable, Unix-based software package for visualizing and analyzing positron emission tomography (PET) images in a clinical-research setting, is described. PET systems are compared to computerized tomography (CT) and magnetic resonance imaging (MRI) systems. The imaging and software aspects of Scan/VP, and procedures devoted specifically to functional PET imaging, including mathematical modeling, image registration, regional thresholding, and derivation of regional covariation patterns, are discussed. Basic surface display, animation, and stereo techniques for visualizing variations in metabolic topology and underlying disease patterns are also discussed.
Register allocation with instruction scheduling
Authors: Shlomit S. Pinter
Venue: ACM SIGPLAN Notices (1993)

We present a new framework in which considerations of both register allocation and instruction scheduling can be applied uniformly and simultaneously. In this framework an optimal coloring of a graph, called the parallel interference graph, provides an optimal register allocation and preserves the property that no false dependences are introduced, thus all the options for parallelism are kept for the scheduler to handle. For this framework we provide heuristics for trading off parallel scheduling with register spilling.
What are virtual environments?
Authors: Stephen R. Ellis
Venue: IEEE Computer Graphics and Applications (1994)

Virtual environment displays arose from vehicle simulation and teleoperations technology of the 1960s. They are interactive, head-referenced computer displays that give users the illusion of displacement to another location. Different terms have been applied to the illusion. Some, like the oxymoronic "artificial reality" and "virtual reality", suggest much higher performance than current technology can generally provide. Others, like "cyberspace" are puzzling neologisms. Expressions like "virtual worlds" and "virtual environment" seem preferable because they are linguistically conservative, relating to well-established terms like virtual image. In fact, we can define virtual environments as interactive, virtual image displays enhanced by special processing and by nonvisual display modalities, such as auditory and haptic, to convince users that they are immersed in a synthetic space. Why are these displays useful? Who uses them? How are they developed? The article addresses these and other questions related to this emerging technology.
Reports of the workshop on interdisciplinary theory for CSCW design
Authors: William Hunt
Venue: ACM SIGCHI Bulletin (1993)

This report describes the Workshop on Interdisciplinary Theory for CSCW Design which took place on 31 October 1992 during the first day of the ACM 1992 Conference on Computer-Supported Cooperative Work.
A decomposition-based simulated annealing technique for data clustering
Authors: Kien A. Hua, S. D. Lang, Wen K. Lee
Venue: Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1994)

It has been demonstrated that simulated annealing provides high-quality results for the data clustering problem. However, existing simulated annealing schemes are memory-based algorithms; they are not suited for solving large problems such as data clustering which typically are too big to fit in the memory space in its entirety. Various buffer replacement policies, assuming either temporal or spatial locality, are not useful in this case since simulated annealing is based on a randomized search process. Poor locality of references will cause the memory to thrash because too many replacements are required. This phenomenon will incur excessive disk accesses and force the machine to run at the speed of the I/O subsystem. In this paper, we formulate the data clustering problem as a graph partition problem (GPP), and propose a decomposition-based approach to address the issue of excessive disk accesses during annealing. We apply the statistical sampling technique to randomly select subgraphs of the GPP into memory for annealing. Both the analytical and experimental studies indicate that the decomposition-based approach can dramatically reduce the costly disk I/O activities while obtaining excellent optimized results.