ppxscal/embedding_network huggingface dataset:
Simulation of human gait using computed torque control
Authors: Nilgün Fescioğlu Ünver, S. Turgut Tümer
Venue: Technology and Health Care (2000)

This paper presents a method for the mathematical modeling of both the single and double support phases of the human gait. The governing equations are obtained by considering the linkage model to be in a floating state and the foot-ground interaction is imposed in the form of geometric constraints. Two stages for the single support phase and one stage for the double support phase are considered, each described by a different foot-ground constraint. Feedback controller functioning according to the computed torque control method is used to achieve the normal gait described by the hip and ankle trajectories. Weighted least square optimization is used to solve the redundancy of control torques during the double support phase. The geometric simulation indicates that the imposed trajectories can be realized by the proposed model with some deviations in joint motions. The control strategy is tested by artificially perturbing the trajectories. The corrective actions are able to resume the desired pattern within half cycle, but with control torque magnitudes considerably away from reasonable limits. This is attributed to the insufficiency of the planar kinematic model and the assumption that the joint torques are unbounded.
Measured performance of an Ethernet local network
Authors: John F. Shoch, Jon A. Hupp
Venue: Communications of the ACM (1980)

The Ethernet communications network is a broadcast, multiaccess system for local computer networking, using the techniques of carrier sense and collision detection. Recently we have measured the actual performance and error characteristics of an existing Ethernet installation which provides communications services to over 120 directly connected hosts. This paper is a report on some of those measurements&mdash;characterizing &ldquo;typical&rdquo; traffic characteristics in this environment and demonstrating that the system works very well. About 300 million bytes traverse the network daily; under normal load, latency and error rates are extremely low and there are very few collisions. Under extremely heavy load&mdash;artificially generated&mdash;the system shows stable behavior, and channel utilization approaches 98 percent, as predicted.
Fully reflexive intensional type analysis
Authors: Valery Trifonov, Bratin Saha, Zhong Shao
Venue: Proceedings of the fifth ACM SIGPLAN international conference on Functional programming (2000)

Compilers for polymorphic languages can use runtime type inspection to support advanced implementation techniques such as tagless garbage collection, polymorphic marshalling, and flattened data structures. Intensional type analysis is a type-theoretic framework for expressing and certifying such type-analyzing computations. Unfortunately, existing approaches to intensional analysis do not work well on types with universal, existential, or fixpoint quantifiers. This makes it impossible to code applications such as garbage collection, persistence, or marshalling which must be able to examine the type of any runtime value.We present a typed intermediate language that supports fully reflexive intensional type analysis. By fully reflexive, we mean that type-analyzing operations are applicable to the type of any runtime value in the language. In particular, we provide both type-level and term-level constructs for analyzing quantified types. Our system supports structural induction on quantified types yet type checking remains decidable. We show how to use reflexive type analysis to support type-safe marshalling and how to generate certified type-analyzing object code.
Real-Time Tracking of Moving Persons by Exploiting Spatio-Temporal Image Slices
Authors: Yann Ricquebourg, Patrick Bouthemy
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

This paper addresses the problem of analyzing human motion in an image sequence. This is of particular importance for video-surveillance applications. We have developed an original and efficient approach to track the apparent contours of a moving articulated structure, avoiding the use of 3D models. This method exploits spatio-temporal $XT$-slices from the image sequence volume $XYT$, where typical trajectory patterns can be associated with articulated motion such as human walking. We reconstruct these trajectories online by introducing an appropriate predictive model while correctly handling occlusion periods. This paradigm can lead to a simple trajectory recognition scheme. Experiments with real-world images depicting human walk or gesture are reported, and obtained results validate the proposed approach.
The essential guide to computing
Authors: E. Garrison Walters
Venue:  (2000)

The complete, easy-to-understand guide to IT-now and in the future! Computers, networks, and pervasive computing Hardware, operating systems, and software How networks work: LANs, WANs, and the Internet E-business, the Web, and securityThe guide for ANYONE who needs to understand the key technologies driving today's economy and high tech industries!You can't afford not to understand the information revolution that's sweeping the world-but who's got time for all the acronyms and hype most technology books give you? The Essential Guide to Computing demystifies the digital society we live in with an intelligent, thorough, and up-to-date explanation of computer, networking, and Internet technologies. It's perfect for smart professionals who want to get up to speed, but don't have computer science or engineering degrees! You'll find up-to-the-minute coverage on all of today's hottest technologies including: The evolution of computing: from the room-sized "monoliths" of the 1950s to today's global Internet Preview of the next revolution: "pervasive computing" Computer hardware: microprocessors, memory, storage, I/O, displays, and architecture Windows, Macintosh, UNIX/Linux, DOS, NetWare, Palm: what operating systems do, and how they compare Programming languages: from machine language to advanced object-oriented technologies Key software applications: databases, spreadsheets, word processing, voice recognition, and beyond Microsoft and the software industry: where they stand, where they're headed How networks work: LANs, WANs, packet switching, hardware, media, and more The Internet, e-commerce, and security Enterprise applications: data warehousing, Web-centered development, and groupwareWhether you're a consumer, investor, marketer, or executive, this is your start-to-finish briefing on the information technologies that have changed the world-and the coming technologies that will transform it yet again!
Matrix reduction&mdash;an efficient method
Authors: H. C. Johnston, C. A. R. Hoare
Venue: Communications of the ACM (1975)

The paper describes an efficient method for reduction of the binary matrices which arise in some school time-tabling problems. It is a development of that described by John Lions. It has been generalized and adapted to fit into the complete timetabling process; to use a more compact data representation and more efficient processing techniques; to take fuller advantage of possible available previous knowledge about the matrix. And it is designed as a structured program, which can readily be coded by the reader in the high level or low level programming language of his choice. Practical tests of the method have shown it to be a good basis for a realistic timetabling algorithm.
FRIDGE: a fixed-point design and simulation environment
Authors: H. Keding, M. Willems, M. Coors, H. Meyr
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

Digital systems, especially those for mobile applications are sensitive to power consumption, chip size and costs. Therefore they are realized using fixed-point architectures, either dedicated HW or programmable DSPs. On the other hand, system design starts from a floating-point description. These requirements have been the motivation for FRIDGE (Fixed-point pRogrammIng DesiGn Environment), a design environment for the specification, evaluation and implementation of fixed-point systems. FRIDGE offers a seamless design flow from a floating- point description to a fixed-point implementation. Within this paper we focus on two core capabilities of FRIDGE: (1) the concept of an interactive, automated transformation of floating-point programs written in ANSI-C into fixed-point specifications, based on an interpolative approach. The design time reductions that can be achieved make FRIDGE a key component for an efficient HW/SW-CoDesign. (2) a fast fixed-point simulation that performs comprehensive compile-time analyses, reducing simulation time by one order of magnitude compared to existing approaches.
An extensible editor for a small machine with disk storage
Authors: Arthur J. Benjamin
Venue: Communications of the ACM (1972)

A design philosophy for developing a sophisticated utility program is illustrated by the actual design and implementation of a text editor. A versatile data structure is employed so that only a small number of programmed subroutines are necessary for all types of data manipulation. Such a data structure is described, and its merits are illustrated by the ease with which powerful extensions can be implemented in terms of a few basic editing functions.
General time-varying systems error sensitivities program
Authors: R. D. Wilkins
Venue: Communications of the ACM (1966)

The evaluation, by the propagation of variance technique, of the sensitivity of time-varying systems to initial condition and parameter errors, involves the determination of several system-dependent partial derivative matrices. This requirement has led to separate programs for each system under investigation. A new program, through utilization of the Wengert differentiation technique, automatically determines the required matrices from specific system equations supplied in subroutine from at execution time, eliminating the need for individualized programs, and presaging the further development of extremely general computer programs.
The implementation of a BASIC system in a multiprogramming environment
Authors: Helen V. Braden, William A. Wulf
Venue: Communications of the ACM (1968)

A mechanical procedure is derived for determining whether a given context-free phrase structure grammar is a simple precedence grammar. This procedure consists of elementary operations on suitably defined Boolean matrices. Application of the procedure to operator grammars is also given.
A note on a relevance estimate and its improvement
Authors: Robert R. Korfhage
Venue: Communications of the ACM (1968)

In this paper the effect of iterating the improvement procedure is examined. It is shown that applications of the improvement factor beyond the first time are ineffectual, and that the factor is but a scale factor.
On the complexity of join predicates
Authors: Jin-Yi Cai, Venkatesan T. Chakaravarthy, Raghav Kaushik, Jeffrey F. Naughton
Venue: Proceedings of the twentieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2001)

We consider the complexity of join problems, focusing on equijoins, spatial-overlap joins, and set-containment joins. We use a graph pebbling model to characterize these joins combinatorially, by the length of their optimal pebbling strategies and computationally, by the complexity of discovering these strategies. Our results show that equijoins are the easiest of all joins, with optimal pebbling strategies that meet the lower bound over all join problems and that can be found in linear time. By contrast, spatial-overlap and set-containment joins are the hardest joins, with instances where optimal pebbling strategies reach the upper bound over all join problems and with the problem of discovering optimal pebbling strategies being NP-complete. For set-containment joins, we show that discovering the optimal pebbling is also MAX-SNP-Complete. As a consequence, we show that unless NP = P, there is a constant &isin;o, such that this problem cannot be approximated within a factor of 1 + &isin;&Ogr; in polynomial time. Our results shed some light on the difficulty the applied community has had in finding &ldquo;good&rdquo; algorithms for spatial-overlap and set-containment joins.
Real-Time CORBA
Authors: Victor Fay-Wolfe, Lisa C. DiPippo, Gregory Copper, Russell Johnston, Peter Kortmann, Bhavani Thuraisingham
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

This paper presents a survey of results in developing Real-Time CORBA, a standard for real-time management of distributed objects. This paper includes background on two areas that have been combined to realize Real-Time CORBA: the CORBA standards that have been produced by the international Object Management Group; and techniques for distributed real-time computing that have been produced in the research community. The survey describes major RT CORBA research efforts, commercial development efforts, and standardization efforts by the Object Management Group.
Storage organization in programming systems
Authors: Jane G. Jodeit
Venue: Communications of the ACM (1968)

The system of program and data representation that has been in use on the Rice University computer for five years is described. Each logical entity in storage occupies a block of consecutive memory locations. Each block is labeled by a codeword and may contain a program, a data vector, or codewords which in turn label blocks to form arrays. This storage arrangement is discussed with its realized advantages in programming systems: simplicity of programmed addressing, flexibility of data structures, efficiency of memory utilization, variability of system composition during execution, means of linkage between programs and from programs to data, and basis for storage protection. The application of labeled blocks may be extended to areas of time-sharing and multi-media storage control. On the basis of experience at Rice, some ideas on such extensions are presented.
Automatic data structure choice in a language of very high level
Authors: J. T. Schwartz
Venue: Communications of the ACM (1975)

SETL is a set-theoretically oriented language of very high level whose repertoire of semantic objects includes finite sets, ordered n-tuples, and sets of ordered n-tuples usable as mappings. This paper describes the structure of an optimizer for this language. Among other methods of interest, the optimizer uses techniques which allow relations of inclusion and membership to be established, the domains and ranges of (tabulated) mappings to be estimated from above and below, and the single-valuedness of (tabulated) mappings to be proved. Once facts of this kind have been established, automatic choice of data structures becomes possible. The methods employed are based upon, and extend, known techniques of data flow analysis.
A fast procedure for generating exponential random variables
Authors: M. D. MacLaren, G. Marsaglia, T. A. Bray
Venue: Communications of the ACM (1964)

A very fast method for generating exponential random variables in a digital computer is outlined.
Character manipulation in 1620 FORTRAN II
Authors: Jesse H. Poore,  Jr.
Venue: Communications of the ACM (1962)

The suggested method of manipulating alphabetic characters in FORTRAN which appeared in this section of the August, 1962, issue of the Communications of the ACM has been incorporated into the IBM 1620 FORTRAN II system.
Fixed point approximations for TCP behavior in an AQM network
Authors: Tian Bu, Don Towsley
Venue: Proceedings of the 2001 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (2001)

In this paper, we explore the use of fixed point methods to evaluate the performance of a large population of TCP flows traversing a network of routers implementing active queue management (AQM) such as RED (random early detection). Both AQM routers that drop and that mark packets are considered along with infinite and finite duration TCP flows. In the case of finite duration flows, we restrict ourselves to networks containing one congested router. In all cases, we formulate a fixed point problem with the router average queue lengths as unknowns. Once these are obtained, other metrics such as router loss probability, TCP flow throughput, TCP flow end-to-end loss rates, average round trip time, and average session duration are easily obtained. Comparison with simulation for a variety of scenarios shows that the model is accurate in its predictions (mean errors less than 5%). Last, we establish monotonicity properties exhibited by the solution for a single congested router that explains several interesting observations, such as TCP SACK suffers higher loss than TCP Reno.
Architecture of the IBM system/370
Authors: Richard P. Case, Andris Padegs
Venue: Communications of the ACM (1978)

This paper discusses the design considerations for the architectural extensions that distinguish System/370 from System/360. It comments on some experiences with the original objectives for System/360 and on the efforts to achieve them, and it describes the reasons and objectives for extending the architecture. It covers virtual storage, program control, data-manipulation instructions, timing facilities, multiprocessing, debugging and monitoring, error handling, and input/output operations. A final section tabulates some of the important parameters of the various IBM machines which implement the architecture.
Optimum data base reorganization points
Authors: Ben Shneiderman
Venue: Communications of the ACM (1973)

In certain data base organization schemes the cost per access may increase due to structural inefficiencies caused by update. By reorganizing the data base the cost per access may be reduced. However, the high cost of a reorganization prohibits frequent reorganizations. This paper examines strategies for selecting the optimum reorganization points.
Selective families, superimposed codes, and broadcasting on unknown radio networks
Authors: Andrea E. F. Clementi, Angelo Monti, Riccardo Silvestri
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

Selective families, a weaker variant of superimposed codes [KS64, F92, 197, CR96], have been recently used to design Deterministic Distributed Broadcast (DDB) protocols for unknown radio networks (a radio network is said to be unknown when the nodes know nothing about the network but their own label) [CGGPR00, CGOR00]. We first provide a general almost tight lower bound on the size of selective families. Then, by reverting the selective families - DDB protocols connection, we exploit our lower bound to construct a family of &ldquo;hard&rdquo; radio networks (i.e. directed graphs). These networks yield an &OHgr;(n log D) lower bound on the completion time of DDB protocols that is superlinear (in the size n of the network) even for very small maximum eccentricity D of the network, while all the previous lower bounds (e.g. &OHgr;(D log n) [CGGPR00]) are superlinear only when D is almost linear. On the other hand, the previous upper bounds are all superlinear in n independently of the eccentricity D and the maximum in-degree d of the network. We introduce a broadcast technique that exploits selective families in a new way. Then, by combining selective families of almost optimal size with our new broadcast technique, we obtain an &Ogr;(Dd log3 n) upper bound that we prove to be almost optimal when d = &Ogr;(n/D). This exponentially improves over the best known upper bound [CGR00) when D, d = &Ogr;(polylogn). Furthermore, by comparing our deterministic upper bound with the best known randomized one [BGI87] we obtain a new, rather surprising insight into the real gap between deterministic and randomized protocols. It turns out that this gap is exponential (as discovered in [BGI87]), but only when the network has large maximum in-degree (i.e. d = &OHgr;(na), for some constant a > O). We then look at the multibroadcast problem on unknown radio networks. A similar connection to that between selective families and (single) broadcast also holds between superimposed codes and multibroadcast. We in fact combine a variant of our (single) broadcast technique with superimposed codes of almost optimal size available in literature [EFF85, HS87, I97, CHI99]. This yields a multibroadcast protocol having completion time &Ogr;(Dd2 log3 n). Finally, in order to determine the limits of our multibroadcast technique, we generalize (and improve) the best known lower bound [CR96] on the size of superimposed codes.
A syntactic algorithm for peak detection in waveforms with applications to cardiography
Authors: Steven L. Horowitz
Venue: Communications of the ACM (1975)

Peaks in a digitized waveform are detected by an algorithm incorporating piecewise linear approximation and tabular parsing techniques. Several parameters serve to identify the waveform context enabling accurate measurement of peak amplitude, duration, and shape. The algorithm is of sufficient speed to allow on-line real-time processing. An example of its application is demonstrated on an electrocardiogram.
Supply-Chain Analysis at Volkswagen of America
Authors: Nejat Karabakal, Ali Günal, Warren Ritchie
Venue: Interfaces (2000)

In 1995, Volkswagen of America began a review of its vehicle-distribution system looking for opportunities to improve customer responsiveness and simultaneously reduce system costs. An analytical tool was required to evaluate alternative designs in terms of cost and customer service level, both of which are functions of probabilistic and dynamic elements. These elements include inventory policies, demand seasonality and volume, customer-choice patterns, and transportation delays. By using an innovative combination of simulation and discrete optimization models, we addressed the problem of analyzing a large number of alternatives efficiently. Our analysis indicated opportunities for significant savings in estimated annual transportation costs, and it provided insights on how to implement the proposed system.
Hierarchical dummy fill for process uniformity
Authors: Yu Chen, Andrew B. Kahng, Gabriel Robins, Alexander Zelikovsky
Venue: Proceedings of the 2001 Asia and South Pacific Design Automation Conference (2001)

To improve manufacturability and performance predictability, we seek to make a layout uniform with respect to prescribed density criteria, by inserting "fill" geometries into the layout. Previous approaches for at layout density control are not scalable due to the necessity of solving very large linear programs, the large data volume of the solution, and the impact of hierarchy-breaking on verification. In this paper, we give the first methods for hierarchical layout density control for process uniformity. Our approach trades off naturally between runtime, solution quality, and output data volume. We also allow generation of compressed GDSII of fill geometries. Our experiments show that this hybrid hierarchical filling approach saves data volume and is scalable, while yielding solution quality that is competitive with existing Monte-Carlo and linear programming based approaches.
The use of FORTRAN in subroutines with COBOL main programs
Authors: Zalman A. Shavell
Venue: Communications of the ACM (1965)

By using the proper COBOL coding techniques and accounting for differences in storage allocation and library routines between the two languages, it is possible to write FORTRAN IV subroutines that may be called from COBOL main programs. Such a technique enables the programmer to take advantage of the most useful properties of each language while minimizing their respective disadvantages.