ppxscal/embedding_network huggingface dataset:
Environmental acquisition: a new inheritance-like abstraction mechanism
Authors: Joseph Gil, David H. Lorenz
Venue: ACM SIGPLAN Notices (1996)

The class of an object is not necessarily the only determiner of its runtime behaviour. Often it is necessary to have an object behave differently depending upon the other objects to which it is connected. However, as it currently stands, object-oriented programming provides no support for this concept, and little recognition of its role in common, practical programming situations. This paper investigates a new programming paradigm, environmental acquisition in the context of object aggregation, in which objects acquire behaviour from their current containers at runtime. The key idea is that the behaviour of a component may depend upon its enclosing composite(s). In particular, we propose a form of feature sharing in which an object "inherits" features from the classes of objects in its environment. By examining the declaration of classes, it is possible to determine which kinds of classes may contain a component, and which components must be contained in a given kind of composite. These relationships are the basis for language constructs that supports acquisition. We develop the theory of acquisition that includes topics such as the kinds of links along which acquisition may occur, and the behaviour of routine (methods) and attribute features under acquisition. The proposed model for acquisition as a hierarchical abstraction mechanism is a strongly typed model that allows static type checking of programs exploiting this mechanism. We compare it to several other mechanisms including inheritance and delegation, and show that it is significantly different than these.
Polynomial-time Membership Comparable Sets
Authors: Mitsunori Ogihara
Venue: SIAM Journal on Computing (1995)

This paper studies a notion called polynomial-time membership comparable sets. For a function $g$, a set $A$ is polynomial-time $g$-membership comparable if there is a polynomial-time computable function $f$ such that for any $x_1, \cdots, x_m$ with $m \geq g(\max\{ |x_1|, \cdots, |x_m| \})$, outputs $b \in \{0,1\}^m$ such that $(A(x_1), \cdots, A(x_m)) \neq b$. The following is a list of major results proven in the paper. 1. Polynomial-time membership comparable sets construct a proper hierarchy according to the bound on the number of arguments. 2. Polynomial-time membership comparable sets have polynomial-size circuits. 3. For any function $f$ and for any constant $c>0$, if a set is $\leq^p_{f(n)-tt}$-reducible to a P-selective set, then the set is polynomial-time $(1+c)\log f(n)$-membership comparable. 4. For any $\cal C$ chosen from $\{ {\rm PSPACE, UP, FewP, NP, C_{=}P, PP, MOD_{2}P, MOD_{3}}, \cdots \}$, if $\cal C \subseteq {\rm P-mc}(c\log n)$ for some $c As a corollary of the last two results, it is shown that if there is some constant $c
Recovering the Position and Orientation of Free-Form Objects from Image Contours Using 3D Distance Maps
Authors: Stéphane Lavallée, Richard Szeliski
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1995)

The accurate matching of 3D anatomical surfaces with sensory data such as 2D X-ray projections is a basic problem in Computer and Robot Assisted Surgery. In model-based vision, this problem can be formulated as the estimation of the spatial pose (position and orientation) of a 3D smooth object from 2D video images. We present a new method for determining the rigid body transformation that describes this match. Our method performs a least squares minimization of the energy necessary to bring the set of the camera-contour projection lines tangent to the surface. To correctly deal with projection lines that penetrate the surface, we consider the minimum signed distance to the surface along each line (i.e., distances inside the object are negative). To quickly and accurately compute distances to the surface, we introduce a precomputed distance map represented using an octree spline whose resolution increases near the surface. This octree structure allows us to quickly find the minimum distance along each line using best-first search. Experimental results for 3D surface to 2D projection matching are presented for both simulated and real data. The combination of our problem formulation in 3D, our computation of line to surface distances with the octree-spline distance map, and our simple minimization technique based on the Levenberg-Marquardt algorithm results in a method that solves the 3D/2D matching problem for arbitrary smooth shapes accurately and quickly.
On the issue of valid time(s) in temporal databases
Authors: Stavros Kokkotos, Efstathios V. Ioannidis, Themis Panayiotopoulos, Constantine D. Spyropoulos
Venue: ACM SIGMOD Record (1995)

Recent research activities in the area of Temporal Databases have revealed some problems related to the definition of time. In this paper we discuss the problem arising from the definition of valid time and the assumptions about valid time, which exist in current Temporal Database approaches. For this problem we propose a solution, while we identify some consistency problems that may appear in Temporal Databases, and which require further investigation.
Model Checking in Practice: The T9000 Virtual Channel Processor
Authors: Geoff Barrett
Venue: IEEE Transactions on Software Engineering (1995)

One of the major obstacles to the integration of formal methods in the design of industrial products is the height and gradient of the learning curve. Anything which can alleviate this problem is of enormous benefit. Automatic model checking and visual specification styles provide a gentle introduction to the concept of refinement. This paper presents a case study of the design of the T9000 virtual channel processor as an illustration of the use of some nonstandard CSP operators and a visual specification style. The development which is shown here has been implemented in a single model checking tool which is currently being integrated into the INMOS CAD system.
Equidistribution in All Dimensions of Worst-Case Point Sets forthe Traveling Salesman Problem
Authors: Timothy Law Snyder, J. Michael Steele
Venue: SIAM Journal on Discrete Mathematics (1995)

Given a set $S$ of $n$ points in the unit square $[0,1]^d$, an optimal traveling salesman tour of $S$ is a tour of $S$ that is of minimum length. A worst-case point set for the traveling salesman problem in the unit square is a point set $S^{(n)}$ whose optimal traveling salesman tour achieves the maximum possible length among all point sets $S\subset [0,1]^d$, where $|S|=n$. An open problem is to determine the structure of $S^{(n)}$. We show that for any rectangular parallelepiped $R$ contained in $[0,1]^d$, the number of points in $S^{(n)}\cap R$ is asymptotic to $n$ times the volume of $R$. Analogous results are proved for the minimum spanning tree, minimum-weight matching, and rectilinear Steiner minimum tree. These equidistribution theorems are the first results concerning the structure of worst-case point sets like $S^{(n)}$.
Board-level multi-terminal net routing for FPGA-based logic emulation
Authors: Wai-Kei Mak, D. F. Wong
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

We consider a board-level routing problem applicable to FPGA-based logic emulation systems such as the Realizer System [3] and the Enterprise Emulation System [5] manufactured by Quickturn Systems. Optimal algorithms have been proposed for the case where all nets are two-terminal nets [10,11]. In this paper, we show how multi-terminal nets can be handled by decomposition into two-terminal nets. We show that the multi-terminal net decomposition problem can be modelled as a bounded-degree hypergraph-to-graph transformation problem where hyperedges are transformed to spanning trees. A network flow-based algorithm that solves both problems is proposed. It determines if there is a feasible decomposition and gives one whenever such a decomposition exists.
An equational object-oriented data model and its data-parallel query language
Authors: Susumu Nishimura, Atsushi Ohori, Keishi Tajima
Venue: ACM SIGPLAN Notices (1996)

This paper presents an equational formulation of an object-oriented data model. In this model, a database is represented as a system of equations over a set of oid's, and a database query is a transformation of a system of equations into another system of equations. During the query processing, our model maintains an equivalence relation over oid's that relates oid's corresponding to the same "real-world entity." By this mechanism, the model achieves a declarative set-based query language and views for objects with identity. Moreover, the query primitives are designed so that queries including object traversal can be evaluated in a data-parallel fashion.
Evaluation of Polynomials Using the Structure of the Coefficients
Authors: Jurg Ganz
Venue: SIAM Journal on Computing (1995)

A new algorithm to evaluate polynomials that exploits the structure of their coefficients is proposed. This algorithm is an extension of one due to Savage with the advantage that it is not restricted to coefficients from a set whose cardinality is small compared to the degree of the polynomial. The new algorithm is shown to be asymptotically optimum for evaluating arbitrary functions in finite fields and for evaluating polynomials with real coefficients in a binary fixed-point representation. To illustrate that it is nonasymptotically useful as well, the new algorithm is shown to reduce the time for syndrome calculation for binary Bose-Chaudhuri-Hocquenghem (BCH) codes of practical interest.
Specification and Analysis of System Architecture Using Rapide
Authors: David C. Luckham, John J. Kenney, Larry M. Augustin, James Vera, Doug Bryan, Walter Mann
Venue: IEEE Transactions on Software Engineering (1995)

Rapide is an event-based, concurrent, object-oriented language specifically designed for prototyping system architectures. Two principle design goals are 1) to provide constructs for defining executable prototypes of architectures and 2) to adopt an execution model in which the concurrency, synchronization, dataflow, and timing properties of a prototype are explicitly represented. This paper describes the partially ordered event set (poset) execution model and outlines with examples some of the event-based features for defining communication architectures and relationships between architectures. Various features of Rapide are illustrated by excerpts from a prototype of the X/Open distributed transaction processing reference architecture.
A popular new course
Authors: Scott Badman
Venue: 3C ON-LINE (1996)

The idea for our new Microcomputer Hardware and Systems course came from a student named Carmella who is majoring in Computer Information Systems (CIS) at Jamestown Community College. She showed one of the other computing faculty members a description of a course titled Microcomputer Operations offered at a small college about a hundred miles away. She wondered why no college in this area offered such a course. This course covered microcomputer setup and configuration, networks, DOS, Windows, software installation, and board replacement repairs. When a faculty member from the technology area heard about the course he said it would fit well into some proposed changes he was developing for the Computer Technology (CT) degree program. Collectively we realized we had the potential to serve three different constituencies: CIS majors, CT majors, and non-matriculated adults. Since the subject matter fit well with my earlier experience as an electronics technician, I volunteered to develop the course.
Experiences with network simulation
Authors: Lawrence S. Brakmo, Larry L. Peterson
Venue: Proceedings of the 1996 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1996)

Simulation is a critical tool in developing, testing, and evaluating network protocols and architectures. This paper describes x-Sim, a network simulator based on the x-kernel, that is able to fully simulate the topologies and traffic patterns of large scale networks. It also illustrates the capabilities and usefulness of the simulator with case studies. Finally, based on our experiences using x-Sim, we identify a set of principles (guidelines) for network simulation, and present concrete examples that quantify the value of these principles, along with the cost of ignoring them.
Implementation aspects of an object-oriented DBMS
Authors: Asuman Dogac, Mehmet Altinel, Cetin Ozkan, Ilker Durusoy
Venue: ACM SIGMOD Record (1995)

This paper describes the design and implementation of an OODBMS, namely the METU Object-Oriented DBMS (MOOD). MOOD [Dog 94b] is developed on the Exodus Storage Manager (ESM) [ESM 92] and therefore some of the kernel functions like storage management, concurrency control, backup and recovery of data were readily available through ESM. In addition ESM has a client-server architecture and each MOOD process is a client application in ESM. The kernel functions provided by MOOD are the optimization and interpretation of SQL statements, dynamic linking of functions, and catalog management. SQL statements are interpreted whereas functions (which have been previously compiled with C++) within SQL statements are dynamically linked and executed. A query optimizer is implemented by using the Volcano Query Optimizer Generator. A graphical user interface, namely Mood-View [Arp 93a, Arp 93b], is developed using Motif. MoodView displays both the schema information and the query results graphically. Additionally it is possible to update the database schema and to traverse the references in query results graphically.The system is coded in GNU C++ on Sun Sparc 2 workstations. MOOD has a SQL-like object-oriented query language, namely MOODSQL [Ozk 93b, Dog 94c]. MOOD type system is derived from C++, thus eliminating the impedance mismatch between MOOD and C++. The users can also access the MOOD Kernel from their application programs written in C++. For this purpose MOOD Kernel defines a class named UserRequest that contains a method for the execution of MOODSQL statements. The MOOD source code is available both for anonymous ftp users from ftp.cs.wisc.edu and for the WWW users from the site http://www.srdc.metu.edu.tr along with its related documents.In MOOD, each object is given a unique Object Identifier (OID) at object creation time by the ESM which is the disk start address of the object returned by the ESM. Object encapsulation is considered in two parts, method encapsulation and attribute encapsulation. These encapsulation properties are similar to the public and private declarations of C++.Methods can be defined in C++ by users to manipulate user defined classes and after compilation, they are dynamically linked and executed during the interpretation of SQL statements. This late binding facility is essential since database environments enforce run-time modification of schema and objects. With our approach, the interpretation of functions are avoided thus increasing the efficiency of the system. Dynamic linking primitives are implemented by the use of the shared object facility of SunOS [Sun 90]. Overloading is realized by making use of the signature concept of C++.
Inductive Policy: The Pragmatics of Bias Selection
Authors: Foster John Provost, Bruce G. Buchanan
Venue: Machine Learning (1995)

This paper extends the currently accepted model of inductive bias by identifying six categories of bias and separates inductive bias from the policy for its selection (the inductive policy). We analyze existing &ldquo;bias selection&rdquo; systems, examining the similarities and differences in their inductive policies, and identify three techniques useful for building inductive policies. We then present a framework for representing and automatically selecting a wide variety of biases and describe experiments with an instantiation of the framework addressing various pragmatic tradeoffs of time, space, accuracy, and the cost of errors. The experiments show that a common framework can be used to implement policies for a variety of different types of bias selection, such as parameter selection, term selection, and example selection, using similar techniques. The experiments also show that different tradeoffs can be made by the implementation of different policies&semi; for example, from the same data different rule sets can be learned based on different tradeoffs of accuracy versus the cost of erroneous predictions.
Residual Bounds on Approximate Solutions for the Unitary Eigenproblem
Authors: Ji-guang Sun
Venue: SIAM Journal on Matrix Analysis and Applications (1996)

Let $A$ be an $n \times n$ unitary matrix, and let the columns of an $n \times l \, (l
Security risks in computer-communication systems
Authors: Peter Neumann
Venue: ACM SIGSAC Review (1996)

This section provides a few highlights from the Risks-Forum Digest (comp.risks) (risks-request@csl.sri.com) relating to security and privacy. Pointers '(R i j)' to items in the on-line Risks Forum denote RISKS vol i number j. The RISKS archives are available on ftp.sri.com, cd risks. Please send RISKS-related items to risks@CSL.sri.com. Read RISKS as a newsgroup (comp.risks), or subscribe via the automated listserv at risks-request@CSL.sri.com. Peter G. Neumann, SRI International EL-243, 333 Ravenswood Ave., Menlo Park CA 94025-3493 (1-415-859-2375; neumann@csl.sri.com).
After Action Review System development trends
Authors: Gerald Vasend
Venue: Proceedings of the 27th conference on Winter simulation (1995)

We present an evaluation of current developments and directions in the After Action Review System (AARS). First, a common After Action Review (AAR) domain architecture is described that will form the basis for future AARS requirements and technologies. Next, a brief status of constructive, live and virtual AAR legacy systems is presented to illustrate current technology. Current limitations such as lack of standardized simulation interfaces and access to internal simulation data are discussed. Then we describe AARS driving factors, which include requirements and technology. Next, we associate AARS driving factors with technologies that will be required by future AARSs. In conclusion, we describe challenges to be met by future AARSs and the need to account for AARS requirements in developing simulation interface protocols.
Building reusable simulators using hierarchical event graphs
Authors: Lee W. Schruben
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Hierarchical event graphs are an easy way to build special purpose simulators. At the lowest level, event graphs are created to represent particular components of the system being simulated; steps in a process flow, or hyper-events. These low-level graphs can then be viewed as different classes of vertices that make up the next higher level graph. A special purpose simulation toolkit is thus developed. Three very different types of hierarchical event-graph simulation toolkits are discussed in this article: a Petri net simulator that is used to teach the activity-scanning approach to simulation modeling; SIMAN and GPSS network simulators that are used to teach process interaction modeling and introduce these languages; and an industrial process simulator called QUALPLAN that is used for planning quality inspection systems.
An inter-reference gap model for temporal locality in program behavior
Authors: Vidyadhar Phalke, Bhaskarpillai Gopinath
Venue: Proceedings of the 1995 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems (1995)

The property of locality in program behavior has been studied and modelled extensively because of its application to memory design, code optimization, multiprogramming etc. We propose a k order Markov chain based scheme to model the sequence of time intervals between successive references to the same address in memory during program execution. Each unique address in a program is modelled separately. To validate our model, which we call the Inter-Reference Gap (IRG) model, we show substantial improvements in three different areas where it is applied. (1) We improve upon the miss ratio for the Least Recently Used (LRU) memory replacement algorithm by up to 37%. (2) We achieve up to 22% space-time product improvement over the Working Set (WS) algorithm for dynamic memory management. (3) A new trace compression technique is proposed which compresses up to 2.5% with zero error in WS simulations and up to 3.7% error in the LRU simulations. All these results are obtained experimentally, via trace driven simulations over a wide range of cache traces, page reference traces, object traces and database traces.
An appreciation of Laurence Rosenberg
Authors: Gary M. Olson
Venue: Communications of the ACM (1995)

It takes many different kinds of contributions to create a viable research community, and many dedicated people have made major contributions in the past decade to make things like the NSF Digital Libraries initiative happen. I'd like to take a few moments to honor one such individual who left our community when he died this past spring following a brave fight with cancer. Laurence Rosenberg affected many of our lives and careers through his activities and his vision as a program manager and a deputy director in the Division of Information, Robotics, and Intelligent Systems at the National Science Foundation.
Adjoint equations and random walks for illumination computation
Authors: S. N. Pattanaik, S. P. Mudur
Venue: ACM Transactions on Graphics (TOG) (1995)

In this paper we introduce the potential equation that along with the rendering equation forms an adjoint system of equations and provides a mathematical frame work for all known approaches to illumination computation based on geometric optics. The potential equation is more natural for illumination computations that simulate light propagation starting from the light sources, such as progressive radiosity and particle tracing. Using the mathematical handles provided by this framework and the random-walk solution model, we present a number of importance sampling schemes for improving the computation of flux estimation. Of particular significance is the use of approximately computed potential for directing a majority of the random walks through regions of importance in the environment, thus reducing the variance in the estimates of luminous flux in these regions. Finally, results from a simple implementation are presented to demonstrate the high-efficiency improvements made possible by the use of these techniques.