ppxscal/embedding_network huggingface dataset:
Evaluating design alternatives for reliable communication on high-speed networks
Authors: Raoul A. F. Bhoedjang, Kees Verstoep, Tim Rühl, Henri E. Bal, Rutger F. H. Hofman
Venue: ACM SIGPLAN Notices (2000)

We systematically evaluate the performance of five implementations of a single, user-level communication interface. Each implementation makes different architectural assumptions about the reliability of the network hardware and the capabilities of the network interface. The implementations differ accordingly in their division of protocol tasks between host software, network-interface firmware, and network hardware. Using microbenchmarks, parallel-programming systems, and parallel applications, we assess the performance impact of different protocol decompositions. We show how moving protocol tasks to a relatively slow network interface yields both performance advantages and disadvantages, depending on the characteristics of the application and the underlying parallel-programming system. In particular, we show that a communication system that assumes highly reliable network hardware and that uses network-interface support to process multicast traffic performs best for all applications.
Comparison of several adaptive Newton-Cotes quadrature routines in evaluating definite integrals with peaked integrands
Authors: K. E. Hillstrom
Venue: Communications of the ACM (1970)

This report compares the performance of five different adaptive quadrature schemes, based on Newton-Cotes (2N + 1) point rules (N = 1, 2, 3, 4, 5), in approximating the set of definite integrals &int;1-1 (x2 + p2)-1 dx with relative accuracy &egr;.
Adaptive CFAR PI Processor for Radar Target Detection in Pulse Jamming
Authors: Vera P. Behar, Christo A. Kabakchiev, Lyubka A. Doukovska
Venue: Journal of VLSI Signal Processing Systems (2000)

A new parallel algorithm for signal processing and a parallel systolic architecture of a CFAR processor with adaptive post detection integration (API) are presented in this paper. The processor proposed is used for effective target detection in a single range resolution cell of a radar when echoes from small airborne targets are performed in conditions of pulse jamming. The main property of the algorithm proposed is its ability automatically to determine and censor the unwanted samples corrupted by pulse jamming in both the two-dimensional reference window and the test cell before noise level estimation. In such a way the influence of pulse jamming environment over adaptive thresholding is reduced to minimum. Statistical analysis of the algorithm for target detection shows that the signal-to-noise ratio losses are insignificant even if the power and the frequency of pulse jamming are extremely high. The systolic architecture of the CFAR API is designed. Basic measures of the systolic architecture are the number of processor elements, the computational time and the speed-up needed for real-time implementation.
Computing connected components on parallel computers
Authors: D. S. Hirschberg, A. K. Chandra, D. V. Sarwate
Venue: Communications of the ACM (1979)

We present a parallel algorithm which uses n2 processors to find the connected components of an undirected graph with n vertices in time O(log2n). An O(log2n) time bound also can be achieved using only n&lceil;n/&lceil;log2n&rceil;&rceil; processors. The algorithm can be used to find the transitive closure of a symmetric Boolean matrix. We assume that the processors have access to a common memory. Simultaneous access to the same location is permitted for fetch instructions but not for store instructions.
PetShop: a tool for the formal specification of CORBA systems
Authors: Rémi Bastide
Venue: Addendum to the 2000 proceedings of the conference on Object-oriented programming, systems, languages, and applications (Addendum) (2000)

PetShop is a CASE tool dedicated to the formal behavioral specification of CORBA systems. The tool uses high-level Petri nets as its specification language, and integrates seamlessly in a CORBA distributed environment, allowing for direct interpretation of specification models.
Flexible Transaction Dependencies in Database Systems
Authors: Luigi V. Mancini, Indrajit Ray, Sushil Jajodia, Elisa Bertino
Venue: Distributed and Parallel Databases (2000)

Numerous extended transaction models have been proposed in the literature to overcome the limitations of the traditional transaction model for advanced applications characterized by their long durations, cooperation between activities and access to multiple databases (like CAD/CAM and office automation). However, most of these extended models have been proposed with specific applications in mind and almost always fail to support applications with slightly different requirements.We propose the Multiform Transaction model to overcome this limitation. The multiform transaction model supports a variety of other extended transaction models. A multiform transaction consists of a set of component transactions together with a set of coordinators which specify the transaction completion dependencies among the component transactions. A set of transaction primitives allow the programmer to define custom completion dependencies. We show how a wide range of extended transactions can be implemented as multiform transactions, including sagas, transactional workflows, nested transactions, and contingent transactions. We allow the programmers to define their own primitives&mdash;having very well-defined interfaces&mdash;so that application specific transaction models like distributed multilevel secure transactions can also be supported.
Job and health implications of VDT use: initial results of the Wisconsin-NIOSH study
Authors: Steven L. Sauter, Mark S. Gottlieb, Karen C. Jones, Vernon N. Dodson, Kathryn M. Rohrer
Venue: Communications of the ACM (1983)

Magnitudes and correlates of stress were investigated among 248 office workplace VDT users and 85 nonuser counterparts using field survey and objective physical measurement techniques. Other than a tenuous indication of increased eyestrain and reduced psychological disturbances among users, the two groups were largely undifferentiated on job-attitudinal, affective, and somatic manifestations of stress. However, aspects of working conditions were judged less favorably by VDT users. Stress mechanisms were much the same for both groups, involving psychosocial as well as physical environmental job attributes. For VDT users, the chair and workstation configuration were particularly important predictors of musculo-skeletal disturbances, as were corrective eyewear use and ambient lighting for visuo-ocular disturbances.
Defense data network security architecture
Authors: Robert W. Shirey
Venue: ACM SIGCOMM Computer Communication Review (1990)

The Department of Defense (DOD) is changing the security structure of the Defense Data Network. Existing classified backbones are merging to form a single segment. DISNET, that uses a new host - to - host encryption system. When completed, DISNET will carry classified data of all security levels, while MILNET continues to carry unclassified traffic. MILNET is being strengthened by link encryption devices on trunk and access lines. Subscriber computers and network elements in both DISNET and MILNET will have to satisfy at least Class C2 (Controlled Access Protection) of the DOD Trusted Computer System Evaluation Criteria. There are no similar plans for the Internet.
From Few to Many: Illumination Cone Models for Face Recognition under Variable Lighting and Pose
Authors: Athinodoros S. Georghiades, Peter N. Belhumeur, David J. Kriegman
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2001)

We present a generative appearance-based method for recognizing human faces under variation in lighting and viewpoint. Our method exploits the fact that the set of images of an object in fixed pose, but under all possible illumination conditions, is a convex cone in the space of images. Using a small number of training images of each face taken with different lighting directions, the shape and albedo of the face can be reconstructed. In turn, this reconstruction serves as a generative model that can be used to render¿or synthesize¿images of the face under novel poses and illumination conditions. The pose space is then sampled and, for each pose, the corresponding illumination cone is approximated by a low-dimensional linear subspace whose basis vectors are estimated using the generative model. Our recognition algorithm assigns to a test image the identity of the closest approximated illumination cone (based on Euclidean distance within the image space). We test our face recognition method on 4,050 images from the Yale Face Database B; these images contain 405 viewing conditions (9 poses $\times$ 45 illumination conditions) for 10 individuals. The method performs almost without error, except on the most extreme lighting directions, and significantly outperforms popular recognition methods that do not use a generative model.
A controlled experiment in program testing and code walkthroughs/inspections
Authors: Glenford J. Myers
Venue: Communications of the ACM (1978)

This paper describes an experiment in program testing, employing 59 highly experienced data processing professionals using seven methods to test a small PL/I program. The results show that the popular code walkthrough/inspection method was as effective as other computer-based methods in finding errors and that the most effective methods (in terms of errors found and cost) employed pairs of subjects who tested the program independently and then pooled their findings. The study also shows that there is a tremendous amount of variability among subjects and that the ability to detect certain types of errors varies from method to method.
A Cost Model for Selecting Checkpoint Positions in Time Warp Parallel Simulation
Authors: Francesco Quaglia
Venue: IEEE Transactions on Parallel and Distributed Systems (2001)

Recent papers have shown that the performance of Time Warp simulators can be improved by appropriately selecting the positions of checkpoints, instead of taking them on a periodic basis. In this paper, we present a checkpointing technique in which the selection of the positions of checkpoints is based on a checkpointing-recovery cost model. Given the current state $S$, the model determines the convenience of recording $S$ as a checkpoint before the next event is executed. This is done by taking into account the position of the last taken checkpoint, the granularity (i.e., the execution time) of intermediate events, and using an estimate of the probability that $S$ will have to be restored due to rollback in the future of the execution. A synthetic benchmark in different configurations is used for evaluating and comparing this approach to classical periodic techniques. As a testing environment we used a cluster of PCs connected through a Myrinet switch coupled with a fast communication layer specifically designed to exploit the potential of this type of switch. The obtained results point out that our solution allows faster execution and, in some cases, exhibits the additional advantage that less memory is required for recording state vectors. This possibly contributes to further performance improvements when memory is a critical resource for the specific application. A performance study for the case of a cellular phone system simulation is finally reported to demonstrate the effectiveness of this solution for a real world application.
Adaptive precision setting for cached approximate values
Authors: Chris Olston, Boon Thau Loo, Jennifer Widom
Venue: ACM SIGMOD Record (2001)

Caching approximate values instead of exact values presents an opportunity for performance gains in exchange for decreased precision. To maximize the performance improvement, cached approximations must be of appropriate precision: approximations that are too precise easily become invalid, requiring frequent refreshing, while overly imprecise approximations are likely to be useless to applications, which must then bypass the cache. We present a parameterized algorithm for adjusting the precision of cached approximations adaptively to achieve the best performance as data values, precision requirements, or workload vary. We consider interval approximations to numeric values but our ideas can be extended to other kinds of data and approximations. Our algorithm strictly generalizes previous adaptive caching algorithms for exact copies: we can set parameters to require that all approximations be exact, in which case our algorithm dynamically chooses whether or not to cache each data value. We have implemented our algorithm and tested it on synthetic and real-world data. A number of experimental results are reported, showing the effectiveness of our algorithm at maximizing performance, and also showing that in the special case of exact caching our algorithm performs as well as previous algorithms. In cases where bounded imprecision is acceptable, our algorithm easily outperforms previous algorithms for exact caching.
Power-Aware Design Synthesis Techniques for Distributed Real-Time Systems
Authors: Dong-In Kang, Stephen Crago, Jinwoo Suh
Venue: Proceedings of the 2001 ACM SIGPLAN workshop on Optimization of middleware and distributed systems (2001)

This paper presents an end-to-end synthesis technique for low-power distributed real-time system design. This technique synthesizes supply voltages of resources to optimize system-level power consumption while satisfying end-to-end hard real-time latency bounds. A system is modeled as a set of distributed task chains (or pipelines). Each task chain is given its own end-to-end constraints. Task chains may share resources. Our approach searches the space of the trade-off between end-to-end latency and supply voltages of resources to minimize system-level power consumption. A power optimization algorithm is proposed for simple distributed real-time systems that do not have any resource sharing between task chains, and its optimality is shown. For more general systems, a heuristic based on the same techniques is proposed.
Remark 2 on algorithm 300 [S22]
Authors: H. Vos
Venue: Communications of the ACM (1973)

The procedure Coulomb can be used very well to generate the Coulomb wave functions FL and GL and their derivatives, needed in elastic scattering calculations in nuclear physics. When the procedure is used many times for many values of rho and eta, it is not only very useful but also necessary to have in each instance an indication about the accuracy of the results. It is obvious to use the Wronskian relations FL&prime;GL - FLGL&prime; &equiv; 1 for the purpose of checking the results, as Fr&ouml;berg [1] states after formula (3.4). However, one has to be very careful in using these relations. The most significant check is given later on, but first it is shown what can go wrong.
Location dependent query processing
Authors: Ayse Y. Seydim, Margaret H. Dunham, Vijay Kumar
Venue: Proceedings of the 2nd ACM international workshop on Data engineering for wireless and mobile access (2001)

The advances in wireless and mobile computing allow a mobile user to perform a wide range of aplications once limited to non-mobile hard wired computing environments. As the geographical position of a mobile user is becoming more trackable, users need to pull data which are related to their location, perhaps seeking information about unfamiliar places or local lifestyle data. In these requests, a location attribute has to be identified in order to provide more efficient access to location dependent data, whose value is determined by the location to which it is related. Local yellow pages, local events, and weather information are some of the examples of these data. In this paper, we give a formalization of location relatedness in queries. We differentiate location dependence and location awareness and provide thorough examples to support our approach.
Multiplex: unifying conventional and speculative thread-level parallelism on a chip multiprocessor
Authors: Chong-Liang Ooi, Seon Wook Kim, Il Park, Rudolf Eigenmann, Babak Falsafi, T. N. Vijaykumar
Venue: Proceedings of the 15th international conference on Supercomputing (2001)

Recent proposals for Chip Multiprocessors (CMPs) advocate speculative, or implicit, threading in which the hardware employs prediction to peel off instruction sequences (i.e., implicit threads) from the sequential execution stream and speculatively executes them in parallel on multiple processor cores. These proposals augment a conventional multiprocessor, which employs explicit threading, with the ability to handle implicit threads. Current proposals focus on only implicitly-threaded code sections. This paper identifies, for the first time, the issues in combining explicit and implicit threading. We present the Multiplex architecture to combine the two threading models. Multiplex exploits the similarities between implicit and explicit threading, and provides a unified support for the two threading models without additional hardware. Multiplex groups a subset of protocol states in an implicitly-threaded CMP to provide a write-invalidate protocol for explicit threads. Using a fully-integrated compiler infrastructure for automatic generation of Multiplex code, this paper presents a detailed performance analysis for entire benchmarks, instead of just implicitly-threaded sections, as done in previous papers. We show that neither threading models alone performs consistently better than the other across the benchmarks. A CMP with four dual-issue CPUs achieves a speedup of 1.48 and 2.17 over one dual-issue CPU, using implicit-only and explicit-only threading, respectively. Multiplex matches or outperforms the better of the two threading models for every benchmark, and a four-CPU Multiplex achieves a speedup of 2.63. Our detailed analysis indicates that the dominant overheads in an implicitly-threaded CMP are speculation state overflow due to limited L1 cache capacity, and load imbalance and data dependences in fine-grain threads.
Control flow and data structure documentation: two experiments
Authors: Ben Shneiderman
Venue: Communications of the ACM (1982)

Two experiments were carried out to assess the utility of external documentation aids such as macro flowcharts, pseudocode, data structure diagrams, and data structure descriptions. A 223 line Pascal program which manipulates four arrays was used. The program interactively handles commands that allow the user to manage five lists of items. A comprehension test was given to participants along with varying kinds of external documentation. The results indicate that for this program the data structure information was more helpful than the control flow information, independently of whether textual or graphic formats were used.
An analytic model of the HASP execution task monitor
Authors: J. C. Strauss
Venue: Communications of the ACM (1974)

The HASP Execution Task Monitor periodically rearranges the OS/360 dispatching chain to give tasks preemptive execution priority in inverse order to that of their cpu utilization history. The effect is to keep the I/O bound tasks active and to prevent cpu bound tasks from locking out other tasks. This paper develops a simple model of the Execution Task Monitor and employs it to study the effectiveness of the monitor in improving system performance. A modified strategy for monitor control is investigated for the case of task execution in a memory heirarchy of varying speeds.
Optimal paths in graphs with stochastic or multidimensional weights
Authors: Ronald Prescott Loui
Venue: Communications of the ACM (1983)

This paper explores computationally tractable formulations of stochastic and multidimensional optimal path problems, each as an extension of the shortest path problem. A single formulation encompassing both problems is considered, in which a utility function defines preference among candidate paths. The result is the ability to state explicit conditions for exact solutions using standard methods, and the applicability of well-understood approximation techniques.
A data-parallel implementation of O(N) hierarchical N-body methods
Authors: Yu Hu, S. Lennart Johnsson
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

The O(N) hierarchical N-body algorithms and Massively Parallel Processors allow particle systems of 100 million particles or more to be simulated in acceptable time. We present a data-parallel implementation of Anderson's method and demonstrate both efficiency and scalability of the implementation on the Connection Machine CM-5/5E systems. The communication time for large particle systems amounts to about 10-25%, and the overall efficiency is about 35%. The evaluation of the potential field of a system of 100 million particles takes 3 minutes and 15 minutes on a 256 node CM-5E, giving expected four and seven digits of accuracy, respectively. The speed of the code scales linearly with the number of processors and number of particles.
Incremental clustering for profile maintenance in information gathering web agents
Authors: Gabriel L. Somlo, Adele E. Howe
Venue: Proceedings of the fifth international conference on Autonomous agents (2001)

User profiles are the central component of most personalized Web information agents. They consist of a set of models representing the various topics of interest to the user. Often the agent learns the user's preferences from examples of documents deemed relevant to the user. The topic of the document can either be supplied by the user (active modeling), or it must be guessed by the agent (passive modeling), which is more convenient but is expected to diminish the agent's accuracy. We present an empirical study assessing the trade-offs in passive versus active document classification. We compare a manual profile maintenance technique in which the user supplies the document topic, and two incremental clustering methods (greedy and the doubling algorithm) for automated maintenance of the user profile components. The study is performed using our SurfAgent, a testbed information gathering Web agent. Our evaluation methodology exploits the strong parallel between Web information agents and text filtering; we use text filtering benchmarks from the information retrieval community (TREC disk \#5) to simulate user behavior and thus speed up data collection, exert additional experimental control and improve the objectivity of our results.
Meaningful Alignments
Authors: Agnès Desolneux, Lionel Moisan, Jean-Michel Morel
Venue: International Journal of Computer Vision (2000)

We propose a method for detecting geometric structures in an image, without any a priori information. Roughly speaking, we say that an observed geometric event is &ldquo;meaningful&rdquo; if the expectation of its occurences would be very small in a random image. We discuss the apories of this definition, solve several of them by introducing &ldquo;maximal meaningful events&rdquo; and analyzing their structure. This methodology is applied to the detection of alignments in images.
Data directed input-output in FORTRAN
Authors: A. Hassitt
Venue: Communications of the ACM (1967)

A statement which is similar to the NAMELIST statement of FORTRAN IV has been incorporated in the FORTRAN 63 compiler. The FORTRAN 63 implementation allows a greater flexibility and simplicity than the FORTRAN IV feature. The Hollerith names, the location, the made and the dimensions of a variable can be discovered by means of standard FORTRAN statements. Methods of using this information are illustrated in relation to general purpose data directed input and output routines; some other uses such as matrix manipulation are discussed.
The legal protection of computer software
Authors: Robert L. Graham
Venue: Communications of the ACM (1984)

As new as the technology itself, a sometimes confusing array of legal protections are now available to safeguard the huge investment of time and money that goes into the development of sophisticated commercial software.