ppxscal/embedding_network huggingface dataset:
Program development by stepwise refinement
Authors: Niklaus Wirth
Venue: Communications of the ACM (1983)

The creative activity of programming&mdash;to be distinguished from coding&mdash;is usually taught by examples serving to exhibit certain techniques. It is here considered as a sequence of design decisions concerning the decomposition of tasks into subtasks and of data into data structures. The process of successive refinement of specifications is illustrated by a short but nontrivial example, from which a number of conclusions are drawn regarding the art and the instruction of programming.
CyPhone&mdash;bringing augmented reality to next generation mobile phones
Authors: Tino Pyssysalo, Tapio Repo, Tuukka Turunen, Teemu Lankila, Juha Röning
Venue: Proceedings of DARE 2000 on Designing augmented reality environments (2000)

We describe a prototype implementation of a future mobile phone called CyPhone. In addition to voice calls, it has been designed to support context-specific and multi-user multimedia services in an augmented reality manner. Context-awareness has been implemented with GPS-based navigation techniques and a registration algorithm, capable of detecting a predefined 3-D model or a landmark in the environment. A new adaptive transport protocol has been developed to support real-time packet-switched data transfer between concurrent users of mobile augmented reality applications. The prototype itself is based on PC/104+ architecture. As a case example we describe an augmented reality-based personal navigation service.
Practical error coefficients in the integration of periodic analytic functions by the trapezoidal rule
Authors: Philip Rabinowitz
Venue: Communications of the ACM (1968)

Theoretical and practical values of error coefficients useful in bounding the error in integrating periodic analytic functions with the trapezoidal rule are tabulated for various ranges of the parameters.
Improving Memory Traffic by Assembly-Level Exploitation of Reuses for Vector Registers
Authors: Chih-Yung Chang, Tzung-Shi Chen, Jang-Ping Sheu
Venue: The Journal of Supercomputing (2000)

In this paper, we propose a compilation scheme to analyze and exploit the implicit reuses of vector register data. According to the reuse analysis, we present a translation strategy that translates the vectorized loops into assembly vector codes with exploitation of vector reuses. Experimental results show that our compilation technique can improve the execution time and traffic between shared memory and vector registers. Techniques discussed here are simple, systematic, and easy to be implemented in the conventional vector compilers or translators to enhance the data locality of vector registers.
A terminal-oriented communication system
Authors: Paul G. Heckel, Butler W. Lampson
Venue: Communications of the ACM (1977)

This paper describes a system for full-duplex communication between a time-shared computer and its terminals. The system consists of a communications computer directly connected to the time-shared system, a number of small remote computers to which the terminals are attached, and connecting medium speed telephone lines. It can service a large number of terminals of various types. The overall system design is presented along with the algorithms used to solve three specific problems: local echoing, error detection and correction on the telephone lines, and multiplexing of character output.
Reconstructing occlusal surfaces of teeth using a genetic algorithm with simulated annealing type selection
Authors: Vladimir Savchenko, Lothar Schmitt
Venue: Proceedings of the sixth ACM symposium on Solid modeling and applications (2001)

In this paper, we present an application of numerical optimization for surface reconstruction (more precisely: reconstruction of missing parts of a real geometric object represented by volume data) by employing a specially designed genetic algorithm to solve a problem concerning computer-aided design in dentistry. Using a space mapping technique the surface of a given model tooth is fitted by a shape transformation to extrapolate (or reconstruct) the remaining surface of a patient's tooth with occurring damage such as a &ldquo;drill hole.&rdquo; Thereby, the genetic algorithm minimizes the error of the approximation by optimizing a set of control points that determine the coefficients for spline functions, which in turn define a space transformation. The fitness function to be minimized by the genetic algorithm is the error between the transformed occlusal surface of the model tooth and the remaining occlusal surface of the damaged (drilled) tooth. The algorithm, that is used, is based upon a proposal by Mahfoud and Goldberg. It uses a simulated-annealing type selection scheme, which is applied sequentially (pair-wise, or one-by-one) to the members in the parent generation and their respective offspring generated by mutation-crossover. We outline a proof of convergence for this algorithm. The algorithm is parallel in regard to computing the fitness-values of creatures.
A generalized polyphase merge algorithm
Authors: Samuel W. Reynolds
Venue: Communications of the ACM (1961)

The k-generalized Fibonacci numbers are defined as in [1]. A polyphase merge (merging an equal number of sequences from k tapes onto a single unused tape) using k+1 tapes is defined in terms of linear combinations of these numbers. A method is described to output sequences onto k of k+1 tapes after the internal sorting of elements to form sequences. This method will permit a polyphase merge of sequences of sorted elements provided that enough sequences are generated internally to place the proper numbers of sequences on each of the k tapes. For each value of k, there is a set of permissible numbers that can represent the total number of sequences generated during the original output process. If one of these numbers is met exactly and if there is a specific distribution of sequences on the k tapes, then a polyphase merge may proceed. If these conditions are not met, an algorithm is necessary to adjust the numbers of sequences to permit a polyphase merge. This paper describes such an algorithm.
Optimistic simulation of parallel message-passing applications
Authors: Thomas Phan, Rajive Bagrodia
Venue: Proceedings of the fifteenth workshop on Parallel and distributed simulation (2001)

Optimistic techniques can improve the performance of discrete-event simulations, but one area where optimistic simulators have been unable to show performance improvement is in the simulation of parallel programs. Unfortunately parallel program simulation using direct execution is difficult: the use of direct execution implies that the memory and computation requirements of the simulator are at least as large as that of the target application, which restricts the target systems and application problem sizes that can be studied. Memory usage is especially important for optimistic simulators due to the need for periodic state-saving and rollback. In our research we addressed this problem and have implemented a simulation library running a Time-Warp-based optimistic engine that uses direct execution to simulate and predict the performance of parallel MPI programs while attaining good simulation speedup. For programs with data sets too large to be directly executed with our optimistic simulator, we reduced the memory and computational needs of these programs by utilizing a static task graph and code-slicing methodology; an approach which also exhibited good performance speedup.
The quality of managerial training in telecommunications: a comparison of the marketing and information systems managers' viewpoints
Authors: Karen Ketler, John R. Willems
Venue: Proceedings of the 2001 ACM SIGCPR conference on Computer personnel research (2001)

This paper compares the results of two studies - the first study targeted the marketing manager while the information systems (IS) managers were the focus of the second study. Both studies questioned the respondents about the quality of their training in thirty telecommunications issues. What was most surprising was the total dissatisfaction with the training in telecommunications voiced by both the marketing and IS managers. The marketing managers did not rate their training on even one issue as average or above. Only one issue, Local Area Networks (LAN), was rated as average or above average in the quality of their training by the IS managers. Training in the currently used applications was rated the highest while training in the advanced or emerging applications was rated the lowest. When these applications are used innovatively, an organization can capture a strategic advantage. Self-study, organizational programs, educational institutions and professional agencies were the primary sources of the training. Training programs provided by professional agencies were rated the highest in quality while the organizational in-house programs were rated the weakest.
Least squares fitting of planes to surfaces using dynamic programming
Authors: Brian Gluss
Venue: Communications of the ACM (1963)

Dynamic programming has recently been used by Stone, by Bellman and by Gluss to determine the closest fit of broken line segments to a curve in an interval under the constraint that the number of segments is fixed. In the present paper successive models are developed to extend the method to the fitting of broken plane segments to surfaces z = g(x, y) defined over certain types of subareas of the (x, y)-space. The first model considers a rectangular area, with the constraint that the plane segments are defined over a grid in the (x, y)-space. It is then shown how this model may be incorporated into an algorithm that provides successive approximations to optimal fits for any type of closed area. Finally, applications are briefly described.
An Analog-Digital Merged Neural Circuit Using Pulse Width Modulation Technique
Authors: Takashi Morie, Jun Funakoshi, Makoto Nagata, Atsushi Iwata
Venue: Analog Integrated Circuits and Signal Processing (2000)

This paper presents a neural circuit using PWM technique based on an analog-digital merged circuit architecture. Some new PWM circuit techniques are proposed. A bipolar-weighted summation circuit is described which attains 8-bit precision in SPICE simulation at 5 V supply voltage by compensating parasitic capacitance effects. A high performance differential-type latch comparator which can discriminate 1 mV difference at 100 MHz in SPICE simulation is also described. Next, we present a prototype chip fabricated using a 0.6 &mu;m CMOS process. The measurement results demonstrate that the overall precision in the weighted summation and the sigmoidal transformation is 5 bits. A neural network has been constructed using the prototype chips, and the experimental results for realizing the XOR function have successfully verified the basic neural operation.
Secure Electronic Payments Based on Mobile Agents
Authors: Artur Romão, Miguel Mira Da Silva, Alberto Silva
Venue: Distributed and Parallel Databases (2000)

The SET protocol for secure electronic payments, in particular its purchasing phase, is intended for users connected to the Internet during the entire transaction. This requirement cannot be easily met in high communication costs and/or low bandwidth settings, typically found in mobile computing environments.In this paper we describe SET/A, a system that works according to the SET rules for purchasing operations without forcing the user to be connected during the entire transaction. This is achieved by sending an agent to the merchant's server carrying all the data necessary to order and pay the goods (products, services or information). The paper shows that this can be achieved safely and efficiently, providing an alternative way for Internet payments using the SET protocol. We give our first impressions on SET/A usage by describing a prototype implementation based on a mobile agent system called AgentSpace, as well as a detailed example of what we consider a realistic application of the system.
Automating camera management for lecture room environments
Authors: Qiong Liu, Yong Rui, Anoop Gupta, J. J. Cadiz
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2001)

Given rapid improvements in network infrastructure and streaming-media technologies, a large number of corporations and universities are recording lectures and making them available online for anytime, anywhere access. However, producing high-quality lecture videos is still labor intensive and expensive. Fortunately, recent technology advances are making it feasible to build automated camera management systems to capture lectures. In this paper we report on our design, implementation and study of such a system. Compared to previous work-which has tended to be technology centric-we started with interviews with professional video producers and used their knowledge and expertise to create video production rules. We then targeted technology components that allowed us to implement a substantial portion of these rules, including the design of a virtual video director. The system's performance was compared to that of a human operator via a user study. Results suggest that our system's quality in close to that of a human-controlled system. In fact most remote audience members could not tell if the video was produced by a computer or a person.
Implementation of mode changes with the Ravenscar profile
Authors: Alejandro Alonso, Juan Antonio de la Puente
Venue: ACM SIGAda Ada Letters (2001)

The use of concurrency in the development of safety-critical systems has not been recommended for a long time. Recently, a safe Ada tasking subset has been defined, known as the Ravenscar Profile. The imposed restrictions invalidated most of the proposed implementations for dealing with mode changes.In this paper, it is described an implementation approach for mode changes, that is compliant with the Ravenscar Profile. It relies on the decoupling between jobs and tasks and on centralizing tasks activations in a system manager. The proposed ideas have been tested with the ORK, which is a kernel integrated with the GNAT compiler for developing and executing applications that follow the Ravenscar Profile.
Indirect threaded code
Authors: Robert B. K. Dewar
Venue: Communications of the ACM (1975)

An efficient arrangement for interpretive code is described. It is related to Bell's notion of threaded code but requires less space and is more amenable to machine independent implementations.
Developing mixed reality boundaries
Authors: Boriana Koleva, Holger Schnädelbach, Steve Benford, Chris Greenhalgh
Venue: Proceedings of DARE 2000 on Designing augmented reality environments (2000)

Our work in the field of mixed reality has been concerned with the development of the mixed reality boundary approach. In contrast to other approaches that focus on superimposing the virtual and the physical environment, the spaces on either side of the boundary are adjacent but remain distinct. In this position statement we describe the development of mixed reality boundaries, including the basic idea, the properties that can be associated with them and demonstrators. We also discuss our latest work on a particular type of boundary that establishes the illusion that virtual and physical worlds are joined together and that users can physically cross from one to the other.
The effects of a simulated cellular phone conversation on search for traffic signs in an elderly sample
Authors: Charles T. Scialfa, Lisa McPhee, Geoffrey Ho
Venue: Proceedings of the 2000 symposium on Eye tracking research & applications (2000)

The effects of clutter and a simulated cellular telephone conversation on search for traffic signs were investigated using eye movement and reaction time measures. One-half of an elderly sample searched for traffic signs while simultaneously listening to a story, followed by 15 &ldquo;yes or no&rdquo; questions. This simulated cellular phone conversation had detrimental effects on reaction time, fixation number and fixation duration. Performance decrements observed might be an indication of the demands cellular telephones have on a driver's processing resources. In addition, these methods could be used to further investigate the safety implementation of using a cellular telephone while driving.
Computational materials science and industrial R&D: accelerating progress
Authors: Sharon C. Glotzer, James A. Warren
Venue: Computing in Science and Engineering (2001)

Computational materials research has made major advances over the past decade in accelerating the design, processing, and property optimization of technologically important materials. Materials simulation is still in its infancy, however, as the nature of materials problems are so complex. Fortunately, as computational power has grown, so too has our ability to attack increasingly challenging materials problems and pose increasingly difficult questions. To fully capitalize on these advances and accelerate the integration of computational materials science into day-to-day R D, we must work to strengthen the infrastructure for computational materials research and identify, develop, and focus the resources and talents of the computational materials science research community.
Query clustering using content words and user feedback
Authors: Ji-Rong Wen, Jian-Yun Nie, Hong-Jiang Zhang
Venue: Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (2001)

Query clustering is crucial for automatically discovering frequently asked queries (FAQs) or most popular topics on a question-answering search engine. Due to the short length of queries, the traditional approaches based on keywords are not suitable for query clustering. This paper describes our attempt to cluster similar queries according to their contents as well as the document click information in the user logs.
Precision averaging for real-time analysis
Authors: Mark J. Cloutier, Matthew J. Friedman
Venue: Communications of the ACM (1983)

An analysis of the computation of the arithmetic mean using only single-precision fixed-point arithmetic is presented. This is done to ease the timing constraints common to many on-line applications. Others have introduced several averaging algorithms in floating-point arithmetic for use in inferential statistics. In this paper, these algorithms are evaluated with respect to their feasibility as fixed-point methods in the context of real-time analysis. Modifications of these algorithms are presented, and previously unpublished ones are introduced in the interest of avoiding overflow (necessary) and minimizing truncation errors (highly desirable). All algorithms presented are tested for speed and accuracy on several sets of data, including their own &ldquo;worst case.&rdquo; The applicability of each algorithm is discussed with respect to some of the basic functions that real-time programs must perform.
Analysis of locking policies in database management systems
Authors: D. Potier, Ph. Leblanc
Venue: Communications of the ACM (1980)

Consistency control has to be enforced in database management systems (DBMS) where several transactions may concurrently access the database. This control is usually achieved by dividing the database into locking units or granules, and by specifying a locking policy which ensures integrity of the information. However, a drawback of integrity enforcement through locking policies is the degradation of the global system performance. This is mainly due to the restriction imposed by the locking policies to the access of transactions to the database, and to the overheads involved with the management of locks. A framework for the quantitative analysis of the impact of these factors on the performance of DBMS is presented in this paper. In a first step, the main factors which determine the behavior of these systems are pointed out and analyzed independently. The results hereby obtained are aggregated in a second step to yield a global performance evaluation. Throughout this hierarchical modeling approach various analytical techniques are used and the results are illustrated by numerical examples. The paper concludes by pointing out the final results' sensitivity to some basic assumptions concerning transaction behavior and the need for more experimental studies in this area.
RC(L) interconnect sizing with second order considerations via posynomial programming
Authors: Tao Lin, Lawrence T. Pileggi
Venue: Proceedings of the 2001 international symposium on Physical design (2001)

There has been substantial work on interconnect sizing algorithms for delay and area optimization in terms of the Elmore delay. Recently, however, signal integrity issues have become of equal or greater importance than delay and area for deep submicron designs. Modeling signal integrity requires more than the Elmore delay approximation, especially when interconnect inductance effects are considered. This paper studies a new interconnect sizing formulaðtion with signal attenuation and transition time constraints that capðtures the same global optimality as the Elmore delay based approaches. With the signal attenuation (or the signal transition time) modeled by the second order central moment of the circuit response, we formulate a provably posynomial optimization probðlem for RC trees such that the well studied algorithms for geometric programming can be applied with guaranteed convergence to a gloðbal minima. For RCL cases we demonstrate that this formulation remains convex and posynomial under reasonable conditions. Suffiðcient conditions are given in terms of the technology parameters and termination conditions.
Formal specification of CORBA services: experience and lessons learned
Authors: Rémi Bastide, Philippe Palanque, Ousmane Sy, David Navarre
Venue: Proceedings of the 15th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (2000)

CORBA is now established as one of the main contenders in object-oriented middleware. Beyond the definition of this standard for distributed object systems, the Object Management Group (OMG) has specified several object services (Common Object Services, COS) that should foster the interoperability of distributed applications. Based on experiment, the goal of this paper is to show that the OMG's style of specification of the CORBA services is not suited to guarantee that implementers will produce interoperable and substitutable implementations. To illustrate our point, we give an account of an experiment based upon the formal specification of one COS, namely the CORBA Event Service. This formal specification highlights several ambiguities and under-specifications in the OMG document. We then test several commercial and public domain implementations of the CORBA Event Service, in order to assess how the implementers have dealt with these under-specifications. We show that the choices made by the implementers lead to incompatible implementations. We finally suggest a solution to overcome the problem of specification of object services, which satisfies the views of both implementers and users. Specifically, we suggest that the specification of such services be made using a formal description technique, and that implementers be provided with test cases derived from the formal specification.