ppxscal/embedding_network huggingface dataset:
A mass storage system for supercomputers based on Unix
Authors: J. Richards, T. Kummell, D. G. Zarlengo
Venue: Proceedings of the 1988 ACM/IEEE conference on Supercomputing (1988)

This paper presents the design, implementation and utilization of a large Mass Storage Subsystem (MSS) at the Numerical Aerodynamics Simulation (NAS) at NASA-Ames Research Center. The MSS supports a large networked, multi-vendor Unix-based supercomputing facility. The MSS at Ames Research Center provides all processors on the Numerical Aerodynamics System Processing Network (NPSN), from workstations to supercomputers, the ability to store large amounts of data in a highly accessible, long-term repository. The MSS uses Unix System V and is capable of storing hundreds of thousands of files ranging from a few bytes to 2 Gigabytes in size. This utilization of Unix, to mask the underlying MVS system, reduces the training requirements for the end user and allows the use of existing Unix networking solutions such as RCP, REMSH, and TCP/IP with locally developed performance enhancements. The systems are currently networked via the NSC HYPERchannel and Ethernet. To assure data integrity and to accommodate spanned volume files the IBM MVS Operating System was implemented so that it is transparent to the Unix user. Since the MSS was released for production at NAS in June of 1987, experience with the system has led to design improvements and enhancements which have resulted in more than an order of magnitude in performance improvement. The current production system is capable of data transfer rates in excess of 6,900 Kilobits per second end-to-end from the Cray 2 supercomputer disk to the MSS DASD. Future improvements include parallel data transmission across multiple NSC HYPERchannel adapters and data-striping on the Amdahl 6380 double density disk drives. Initial performance tests have demonstrated a further increase to 17,800 Kilobits per second when these improvements are placed into production. This article is based upon a less extensive paper presented at the IEEE Symposium on Mass Storage Systems, October 1988 [1].
A paediatric management information system in APL
Authors: C. M. Sykes
Venue: Conference proceedings on APL as a tool of thought (1989)

Many British hospitals contain 'special care baby units' designed for the careful and skilled nursing required to keep prematurely born babies alive. With the aid of much electronic monitoring equipment, the environment is carefully maintained to maximise the babies' survival chances. Nevertheless, most of the information recorded on the baby's progress is transitory and only temporarily available. Consequently there is no facility for the paediatrician to review his/her actions and validate the decisions made.This paper describes a continuing project in conjunction with Morriston Hospital, Swansea to provide the required paediatric information system to allow the paediatrician to reflect on decisions made and consequent behaviour of the child.
Implementing the results of a manufacturing simulation in a semiconductor line
Authors: D. J. Miller
Venue: Proceedings of the 21st conference on Winter simulation (1989)

Semiconductor manufacturing is an extremely complex process. The requirements for ultraclean environments and intricate production capabilities result in capital intensive facilities and equipment. Wafer fabrication involves hundreds of individual tools performing multiple processes to produce an array of sophisticated end products. Worldwide competitive realities produce ongoing pressures to reduce the time and cost of both development and manufacturing activities. Simulation provides a practical and powerful method for analyzing and optimizing such a complex environment.This paper presents an overview of a modeling and simulation effort designed to quantify turnaround time improvement opportunities in a leading-edge semiconductor development line. Product turnaround time is a key determinant of success in semiconductor manufacturing due to its contribution in critical areas including contamination, yield-learning, and process control.The focus of the simulation project was the analysis of line loading levels and their impact on turnaround time. The results of the project led to policy changes and significantly improved turnaround time performance. The paper presents an overview of the line modeled, a discussion of the line characteristics incorporated in the model, and the simulation results. The changes implemented in the line are discussed, and the resultant improvements described.
Operating system support for adaptive distributed real-time systems in DRAGON SLAYER
Authors: H. F. Wedde, G. S. Alijani, W. G. Brown, S. Chen, G. Kang
Venue: ACM SIGOPS Operating Systems Review (1989)

We analyze current and future needs in building adaptive real-time systems, and then formulate a series of design requirements for their hardware/interconnection, operating system, and application levels from which we derive a plea for a layered and integrated system design. We report on the novel distributed operating system DRAGON SLAYER which provides highly reliable and adaptive kernel services for real-time applications. It supports the novel file system MELODY which, in order to both meet real-time constraints and provide for high availability in a hazardous environment, allows for replicating, relocating, or deleting of file copies. Such copies may also assume a different status regarding the recency, reliability, and consistency of their information: They may be public or private. Status changes as well as file replication, deletion, or relocation are analyzed and managed by local file assigners, based on cost and time delay criteria and - for public copies - on cooperation with all file assigners responsible for the other public copies of a given file. A distributed implementation of our integrated system design model is currently being completed in our labs in order to serve as a distributed real-time testbed. For systems modeled according to our design requirements all relevant parameters could be checked and fine-tuned according to the environmental situation for the tested system.- We also report on a sensitivity study that shows how promptly the MELODY file system reacts to changing environmental situations (changing request patterns). Our findings are discussed, future work is outlined.
Interoperability of multiple autonomous databases
Authors: Witold Litwin, Leo Mark, Nick Roussopoulos
Venue: ACM Computing Surveys (CSUR) (1990)

Database systems were a solution to the problem of shared access to heterogeneous files created by multiple autonomous applications in a centralized environment. To make data usage easier, the files were replaced by a globally integrated database. To a large extent, the idea was successful, and many databases are now accessible through local and long-haul networks. Unavoidably, users now need shared access to multiple autonomous databases. The question is what the corresponding methodology should be. Should one reapply the database approach to create globally integrated distributed database systems or should a new approach be introduced? We argue for a new approach to solving such data management system problems, called multidatabase or federated systems. These systems make databases interoperable, that is, usable without a globally integrated schema. They preserve the autonomy of each database yet support shared access. Systems of this type will be of major importance in the future. This paper first discusses why this is the case. Then, it presents methodologies for their design. It further shows that major commerical relational database systems are evolving toward multidatabase systems. The paper discusses their capabilities and limitations, presents and discusses a set of prototypes, and, finally, presents some current research issues.
A specialized data management system for parallel execution of particle physics codes
Authors: Jean L. Bell
Venue: Proceedings of the 1988 ACM SIGMOD international conference on Management of data (1988)

The specialized data management system described in this paper was motivated by the need for much more efficient data management than a standard database management system could provide for particle physics codes in shared memory multiprocessor environments. The special characteristics of data and access patterns in particle physics codes need to be fully exploited in order to effect efficient data management. The data management system allows parameteric user control over system features not usually available to them, especially details of physical design and retrieval such as horizontal clustering, asynchronous I/O, and automatic distribution across processors. In the past, each physics code has constructed the equivalent of a primitive data management system from scratch. The system described in this paper is a generic system that can now be interfaced with a variety of physics codes.
Models for the Combined Logical and Physical Design of Databases
Authors: Rajiv M. Dewan, Bezalel Gavish
Venue: IEEE Transactions on Computers (1989)

Given the set of intended transactions, the authors model the problem of choosing the most efficient decomposition of the universal set of attributes. Unlike other models which neglect the logical structure developed in database theory, the model developed incorporates it as part of a mathematical program. This provides a comprehensive and an integrated formulation for the combined logical and physical database design problem. The integrated problem and its epsilon -approximation schemes are shown to be NP-complete. An example shows the benefit of such an approach over more conventional ones.
Singularity Theory and Phantom Edges in Scale Space
Authors: J. J. Clark
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

The process of detecting edges in a one-dimensional signal by finding the zeros of the second derivative of the signal can be interpreted as the process of detecting the critical points of a general class of contrast functions that are applied to the signal. It is shown that the second derivative of the contrast function at the critical point is related to the classification of the associated edge as being phantom or authentic. The contrast of authentic edges decreases with filter scale, while the contrast of phantom edges are shown to increase with scale. As the filter scale increases, an authentic edge must either turn into a phantom edge or join with a phantom edge and vanish. The points in the scale space at which these events occur are seen to be singular points of the contrast function. Using ideas from singularity, or catastrophy theory, the scale map contours near these singular points are found to be either vertical or parabolic.
Varieties of computer graphics courses in computer science
Authors: Steve Cunningham, Judith R. Brown, Robert P. Burton, Mark Ohlson
Venue: ACM SIGCSE Bulletin (1988)

The increased importance of graphics in computer systems has made computer graphics a more visible and important part of computer science education. This graphics education can take any of several forms. This panel describes four of these: the graphics service course for non-majors, the graphics systems course, the graphics concepts and algorithms course, and advanced or graduate courses in graphics. This panel is based on part of a workshop presented at SIGGRAPH '87.
On the Identification of Covert Storage Channels in Secure Systems
Authors: Chii-Ren Tsai, Virgil D. Gligor, C. S. Shandersekaran
Venue: IEEE Transactions on Software Engineering (1990)

A practical method for the identification of covert storage channels is presented and its application to the source code of the Secure Xenix kernel is illustrated. The method is based on the identification of all visible/alterable kernel variables by using information-flow analysis of language code. The method also requires that, after the sharing relationships among the kernel primitives and the visible/alterable variables are determined, the nondiscretionary access rules implemented by each primitive be applied to identify the potential storage channels. The method can be generalized to other implementation languages, and has the following advantages: it helps discover all potential storage channels is kernel code, thereby helping determine whether the nondiscretionary access rules are implemented correctly; it helps avoid discovery of false flow violations and their unnecessary analysis; and it helps identify the kernel locations where audit code and time-delay variables need to be placed for covert-channel handling.
The Cost of Data Flow Testing: An Empirical Study
Authors: Elaine J. Weyuker
Venue: IEEE Transactions on Software Engineering (1990)

A family of test data adequacy criteria employing data-flow information was previously proposed, and a theoretical complexity analysis was performed. The author describes an empirical study to determine the actual cost of using these criteria. The aim is to establish the practical usefulness of these criteria in testing software and provide a basis for predicting the amount of testing needed for a given program. The first goal of the study is to confirm the belief that the family of software testing criteria considered is practical to use. An attempt is made to show that even as the program size increases, the amount of testing, expressed in terms of the number of test cases sufficient to satisfy a given criterion, remains modest. Several ways of evaluating this hypothesis are explored. The second goal is to provide the prospective user of these criteria with a way of predicting the number of test cases that will be needed to satisfy a given criterion for a given program. This provides testers with a basis for selecting the most comprehensive criterion that they can expect to satisfy. Several plausible bases for such a prediction are considered.
Compiling C* programs for a hypercube multicomputer
Authors: Michael J. Quinn, Philip J. Hatcher, Karen C. Jourdenais
Venue: Proceedings of the ACM/SIGPLAN conference on Parallel programming: experience with applications, languages and systems (1988)

A data parallel language such as C* has a number of advantages over conventional hypercube programming languages. The algorithm design process is simpler, because (1) message passing is invisible, (2) race conditions are nonexistent, and (3) the data can be put into a one-to-one correspondence with the virtual processors. Since data are mapped to virtual processors, rather than physical processors, it is easier to move algorithms implemented on one size hypercube to a larger or smaller system. We outline the design of a C* compiler for a hypercube multicomputer. Our design goals are to minimize the amount of time spent synchronizing, limit the number of interprocessor communications, and make each physical processor's emulation of a set of virtual processors as efficient as possible. We have hand translated three benchmark programs and compared their performance with that of ordinary C programs. All three programs&mdash;matrix multiplication, LU decomposition, and hyperquicksort&mdash;achieve reasonable speedup on a commercial hypercube, even when solving problems of modest size. On a 64-processor NCUBE/7, the C* matrix multiplication program achieves a speedup of 27 when multiplying two 64 &times; 64 matrices, the hyperquicksort program achieves a speedup of 10 when sorting 16,384 integers, and LU decomposition attains a speedup of 7 when decomposing a 256 &times; 256 system of linear equations. We believe the degradation in machine performance resulting from the use of a data parallel language will be more than compensated for by the increase in programmer productivity.
Multiprocessor architectures are converging
Authors: E. P. DeBenedicits
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications: Architecture, software, computer systems, and general issues - Volume 1 (1988)

Hypercubes are one of several architectures trying to eliminate the Von Neumann Bottleneck without drastically changing the appearance of computers. Examining these projects reveals that certain common approaches have been successful for all the projects even though they were independently motivated. This paper examines these approaches, which are named modular and protocol programming. To show the completeness of these methods, the paper shows how to build a system that could be used like a conventional computer but runs faster due to its transparent use of parallelism.
FFTs in external of hierarchical memory
Authors: D. H. Bailey
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

Conventional algorithms for computing large one-dimensional fast Fourier transforms (FFTs), even those algorithms recently developed for vector and parallel computers, are largely unsuitable for systems with external or hierarchical memory. The principal reason for this is the fact that most FFT algorithms require at least m complete passes through the data set to compute a 2m-point FFT. This paper describes some advanced techniques for computing an ordered FFT on a computer with external or hierarchical memory. These algorithms (1) require as few as two passes through the external data set, (2) employ strictly unit stride, long vector transfers between main memory and external storage, (3) require only a modest amount of scratch space in main memory, and (4) are well suited for vector and parallel computation. Performance figures are included for implementations of some of these algorithms on Cray supercomputers. Of interest is the fact that a main memory version outperforms the current Cray library FFT routines on the Cray-2, the Cray X-MP, and the Cray Y-MP systems. Using all eight processors on the Cray Y-MP, this main memory routine runs at nearly two gigaflops.
Including Scalars in a Programming Language Based on the Relational Algebra
Authors: T. H. Merrett, N. Laliberte
Venue: IEEE Transactions on Software Engineering (1989)

Scalars, arrays, and records, together with associated operations and syntax, have been introduced as special cases of relations into the relational programming system, relix. This permits all of these data types, as well as relations, to be stored persistently. The requirement in most languages that array elements and record fields can be assigned to leads in this case to the general implementation of QT-selectors as l-expressions, with, in particular, systematic interpretations of assignment to projections and selections of relations. The authors discuss the principles and the implementation of this extension to the relational algebra. They take advantage of the very specialized syntax of array access to build a tuned access method, using B-trees and Z-order. The performance results show the advantage of this implementation over the slower implementation required for general QT-selectors.
Definition of the DISC concurrent language
Authors: G. Iannello, A. Mazzeo, G. Ventre
Venue: ACM SIGPLAN Notices (1989)

Although commercial distributed computers are now available, developing software for these systems is still a hard task. This prevents the users from getting full advantage out of the use of distributed computers. Among the techiniques proposed to make it easier to program the new architectures, concurrent languages have proved to be an effective approach both in system programming and in application development.The concurrent programming language DISC has been designed to promote software engineering techniques in the development of distributed programs. The language extends C with CSP-based concurrent mechanisms and it is especially suited for system programming of loosely coupled distributed architectures. A simple programming environment, running under UNIX System V operating system, allows the user to develop programs in a modular fashion. A first implementation of DISC has been developed on a network of UNIX machines. DISC programs are portable on a wide class of distributed computers, because of both the choice of UNIX as the host environment and the substantial independence of the language run time support from the hardware.In this article we report the definition of DISC and an example to show informally the practical use of the language.
Safe run-time overloading
Authors: Francois Rouaix
Venue: Proceedings of the 17th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1989)

We present a functional language featuring a form of dynamic overloading akin to message passing in object oriented languages. We give a dynamic semantics describing a non-deterministic evaluation, as well as a type discipline (static semantics) supporting type inference. The type system ensures that a well-typed program has a correct execution, unique up to a semantic equivalence relation, and allows this execution to proceed deterministically, while resolving overloading at run-time.
Using Inspections to Investigate Program Correctness
Authors: Robert N. Britcher
Venue: Computer (1988)

An approach to inspections is proposed that would emphasize the search for correctness. It would hold up to scrutiny to not only what is on the page, but also the thought behind the representation. Inspectors would investigate how the program developed, looking for evidence of disciplined methods in its construction, adequate consideration of the error domain, and the program's ability to withstand years of use and inevitable change. An example inspection is given that uses a program developed according to IBM's design methods. The inspection presents the arguments as a series of questions that the inspectors would ask the author and themselves.
The ADABTPL type system
Authors: Leo Fegaras, Tim Sheard, David Stemple
Venue: Proceedings of the second international workshop on Database programming languages (1989)

ADABTPL (Abstract DAtaBase Type Programming Language, pronounced abaptable) is a high level programming language based on finite sets and total functions. It has the purpose of bringing polymorphic, axiomatic types to bear on the problem of specifying database systems. It contains a type definition language for specifying the types of database objects and transaction inputs along with a transaction specification language. In this paper we present the features of the type system.
A critiquing model of flexible constraint evaluation for a scheduler's workbench
Authors: Michael Prietula, Peng Si Ow, Brian Huguenard, Steve Vicinanza
Venue: Proceedings of the 1st international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1988)

Scheduling complex tasks is a difficult and ill-structured problem. Totally automated solutions to certain scheduling problems have certainly been achieved; however, other types of scheduling tasks do not yield easily to traditional solution methods. The latter tasks often involve both quantitative and qualitative constraints as well as changing preferences and subjective judgement. Consequently, it is sometimes impossible to take the human element out of the loop. Faced with similar problems, research in medical artificial intelligence has yielded a model of advising, called critiquing, which can be made to be comprehensible to, and consistent with, the decisionmaker's methods. In this paper we describe a project which incorporates a version of the critiquing model within a hybrid artificial intelligence/analytical-based scheduler's workbench, called MRL.
A field study of the software design process for large systems
Authors: Bill Curtis, Herb Krasner, Neil Iscoe
Venue: Communications of the ACM (1988)

The problems of designing large software systems were studied through interviewing personnel from 17 large projects. A layered behavioral model is used to analyze how three of these problems&mdash;the thin spread of application domain knowledge, fluctuating and conflicting requirements, and communication bottlenecks and breakdowns&mdash;affected software productivity and quality through their impact on cognitive, social, and organizational processes.