ppxscal/embedding_network huggingface dataset:
On models for object lifetime distributions
Authors: Darko Stefanović, Kathryn S. McKinley, J. Eliot B. Moss
Venue: Proceedings of the 2nd international symposium on Memory management (2000)

Analytical models of memory object lifetimes are appealing because having them would enable mathematical analysis or fast simulation of the memory management behavior of programs. In this paper, we investigate models for object lifetimes drawn from programs in object-oriented languages such as Java and Smalltalk. We present certain postulated analytical models and compare them with observed lifetimes for 58 programs. We find that observed lifetime distributions do not match previously proposed object lifetime models, but do agree in salient shape characteristics with the gamma distribution family used in statistical survival analysis for general populations.
Motor Algebra for 3D Kinematics: The Case of the Hand-Eye Calibration
Authors: Eduardo Bayro-Corrochano, Kostas Daniilidis, Gerald Sommer
Venue: Journal of Mathematical Imaging and Vision (2000)

In this paper we apply the Clifford geometric algebra for solving problems of visually guided robotics. In particular, using the algebra of motors we model the 3D rigid motion transformation of points, lines and planes useful for computer vision and robotics. The effectiveness of the Clifford algebra representation is illustrated by the example of the hand-eye calibration. It is shown that the problem of the hand-eye calibration is equivalent to the estimation of motion of lines. The authors developed a new linear algorithm which estimates simultaneously translation and rotation as components of rigid motion.
Letters to the editor: An interpretive input routine for linear programming
Authors: Dennis J. Aigner
Venue: Communications of the ACM (1967)

In this descriptive article an input code is presented which greatly simplifies data input to any linear programming solution routine, for subsequent use either as a predagogical device or for solving rather small LP problems. This latter (limited) use derives not at all from inherent limitations in the code itself, but from an efficiency evaluation: large LP problems would doubtless benefit from an input system more suited for bulk data handling than the input code described. From a user's standpoint, input appears almost exactly as a textbook presentation of the LP problem (limited only by a keypunch's inability to write subscripts, etc.). The input interpreter scans columnwise, thus no fixed format data preparation is required. The user may also, under very general requirements only, liberally use editorial comments throughout the input deck as an aid in identification, e.g., of row constraints. The article includes examples of input, output from a solution routine presently in use, and a skeleton flowchart of the input interpreter.
VHDL modelling and analysis of fault secure systems
Authors: J. Coppens, D. Al-Khalili, C. Rozon
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

This paper presents an analysis process targeted for the verification of fault secure systems during their design phase. This process deals with a realistic set of micro- defects at the device level which are mapped into mutant and saboteur based VHDL fault models in the form of logical and/or performance degradation faults. Automatic defect injection and simulation are performed through a VHDL test bench. Extensive post processing analysis is performed to determine defect coverage, figure of merit for fault secureness, and MTTF.
Closing out a print tape
Authors: Donald P. Moore
Venue: Communications of the ACM (1963)

Some computer operating systems have a bad habit of inserting tape marks into the output stream willy-nilly. This often results in loss of output when a tape is scratched after its first file has been printed. Other operating systems, notably those recently distributed by IBM for use with the 7090, put tape marks on print tapes only on command, so that frequently a print tape is removed from the computer without any tape mark, and extraneous material is printed. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
On Sylow Subgroups of Abelian Affine Difference Sets
Authors: Agnes V. Dizon-Garciano, Yutaka Hiramine
Venue: Designs, Codes and Cryptography (2001)

An n-subset D of a group G of order n^2-1 is called an affine difference set of G relative to a normal subgroup N of G of order n-1 if the list of differences d_1d_2^{-1} ( d_1, d_2 \in D, d_1 \neq d_2) contains each element of G-N exactly once and no element of N. It is a well-known conjecture that if D is an affine difference set in an abelian group G, then for every prime p, the Sylow p-subgroup of G is cyclic. In Arasu and Pott [1], it was shown that the above conjecture is true when p=2. In this paper we give some conditions under which the Sylow p-subgroup of G is cyclic.
On the conversion of decision tables to computer programs
Authors: C. R. Muthukrishnan, V. Rajaraman
Venue: Communications of the ACM (1970)

The use of execution time diagnostics in pinpointing ambiguities in decision tables is discussed. It is pointed out that any attempt at resolving ambiguities at compile time will, in general, be impossible. It is shown that, as a consequence, tree methods of converting decision tables to programs are inadequate in regard to ambiguity detection. Two algorithms for programming decision tables whose merits are simplicity of implementation and detection of ambiguities at execution time are presented. The first algorithm is for limited entry decision tables and clarifies the importance of proper coding of the information in the decision table. The second algorithm programs a mixed entry decision table directly without going through the intermediate step of conversion to a limited entry form, thereby resulting in storage economy. A comparison of the algorithms and others proposed in the literature is made. Some features of a decision table to FORTRAN IV translator for the IBM 7044 developed by the authors are given.
On the formalization of architectural types with process algebras
Authors: Marco Bernardo, Paolo Ciancarini, Lorenzo Donatiello
Venue: Proceedings of the 8th ACM SIGSOFT international symposium on Foundations of software engineering: twenty-first century applications (2000)

Architectural styles play an important role in software engineering as they convey codified principles and experience which help the construction of software systems with high levels of efficiency and confidence. We address the problem of formalizing and analyzing architectural styles in an operational setting by introducing the intermediate abstraction of architectural type. We develop the concept of architectural type in a process algebraic framework because of its modeling adequacy and the availability of means, such as Milner's weak bisimulation equivalence, which allow us to reason compositionally and efficiently about the well formedness of architectural types.
Power aware page allocation
Authors: Alvin R. Lebeck, Xiaobo Fan, Heng Zeng, Carla Ellis
Venue: ACM SIGPLAN Notices (2000)

One of the major challenges of post-PC computing is the need to reduce energy consumption, thereby extending the lifetime of the batteries that power these mobile devies. Memory is a particularly important target for efforts to improve energy efficiency. Memory technology is becoming available that offers power management features such as the ability to put individual chips in any one of several different power modes. In this paper we explore the interaction of page placement with static and dynamic hardware policies to exploit these emerging hardware features. In particular, we consider page allocation policies that can be employed by an informed operating system to complement the hardware power management strategies. We perform experiments using two complementary simulation environments: a trace-driven simulator with workload traces that are representative of mobile computing and an execution-driven simulator with a detailed processor/memory model and a more memory-intensive set of benchmarks (SPEC2000). Our results make a compelling case for a cooperative hardware/software approach for exploiting power-aware memory, with down to as little as 45% of the Energy Delay for the best static policy and 1% to 20% of the Energy Delay for a traditional full-power memory.
Exception handling: issues and a proposed notation
Authors: John B. Goodenough
Venue: Communications of the ACM (1975)

This paper defines exception conditions, discusses the requirements exception handling language features must satisfy, and proposes some new language features for dealing with exceptions in an orderly and reliable way. The proposed language features serve to highlight exception handling issues by showing how deficiencies in current approaches can be remedied.
Linear and circular placement by multilevel decomposition and scanning area methods
Authors: Roman Bazylevych, Maryan Rachynsky
Venue: Proceedings of the symposium on Contemporary computing in Ukraine (2000)

The methods of multilevel decomposition and scanning area are employed to place elements on line and circuit. Influences algorithm strategies and parameters on the result quality were determined.
Panel discussion on computer appreciation
Authors: Elliott I. Organick
Venue: Communications of the ACM (1968)

Session 19 of the ACM 20th Anniversary Conference on August 31, 1967, was entitled Education, Design Experiments, and Computer Appreciation. Its second half consisted of a panel discussion on computer appreciation, organized and chaired by Elliot I. Organick. The four panelists were Charles H. Davidson, Bernard A. Galler, Richard W. Hamming, and Alan J. Perlis. After making prepared statements, the panelist were joined in discussion by Andries van Dam and Arthur B. Kahn, who had presented papers in the first half. This is a transcript of the panel discussion, condensed by Dr. Organick and edited him and the panelists. Some remarks referred to papers by van Dam and Kahn or to the discussion during the first half of the session. Pertinent papers are included in the references.
Syntax-directed documentation for PL360
Authors: Harlan D. Mills
Venue: Communications of the ACM (1970)

The language PL360, together with its phrase structure grammar, is used as a concrete basis for illustrating an idea called syntax-directed documentation. This idea is: (1) to use the phrase structure of a program to define the structure of a formal documentation for that program; (2) to use the syntactic types and identifiers in the resulting structure to trigger the automatic formation of questions to the programmer, whose answers will become part of that documentation; and (3) to provide automatic storage and retrieval facilities so that other programmers who want to understand or modify the program can access the resulting documentation, which is cross-indexed in various ways by syntactic types and objects. A small PL360 program, already found in the literature, is worked out as an example.
'TSUPDOOD?: Repackaged problems for you and MMI
Authors: Rebecca G. Bace, Marvin Schaefer
Venue: Proceedings of the 1995 workshop on New security paradigms (1995)

Changes in computer usage have significantly changed the so-called computer security, network security and information security problems. The changes are largely due to the rapid proliferation and interconnection of computers and the associated distribution of software. Of concern is the uncontrolled nature of this activity: systems and workstations are often interconnected without notice being given to all of the affected parties. The result has been increased user-perception of the breaches in &ldquo;security&rdquo;, especially in the form of computer takeover, data destruction, or service denial by virus, worm or trapdoor. It is expected that consciouness of these problems, and of confidentiality comprosmises, will increases in the coming months. It is posited that a principal cause of the problem is willful promiscuity and a pronounced lack of mutual suspicion. The separation kernel concept is revisited as a potential practical means of improving security protections consistent with preserving the use of legacy systems and of commercial products.
Temperature effect on delay for low voltage applications
Authors: J. M. Daga, E. Ottaviano, D. Auvergne
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

This paper presents one of the first analysis of the temperature dependence of CMOS integrated circuit delay at low voltage. Based on a low voltage extended Sakurai's a-power current law, a detail analysis of the temperature and voltage sensitivity of CMOS structure delay is given. Coupling effects between temperature and voltage are clearly demonstrated. Specific derating factors are defined for the low voltage range (1-3VT0). Experimental validations are obtained on specific ring oscillators integrated on a 0.7mm process by comparing the temperature and voltage evolution of the measured oscillation period to the calculated ones. A low temperature sensitivity operating region has been clearly identified and appears in excellent agreement with the expected calculated values.
Geometric permutations of high dimensional spheres
Authors: Yingping Huang, Jinhui Xu, Danny Z. Chen
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

We prove the maximum number of geometric permutations, induced by line transversals to a set of n pairwise disjoint congruent spheres in Rd with d &gne; 3, is no more than 4 when n is sufficiently large, achieving the best known upper bound for this problem. We also prove the maximum number of geometric permutations of a set of n noncongruent spheres of bounded radius ratio in Rd, d &gne; 3, is at most 2[&radic;2M]+1, where M is the ratio or the largest radius and the smallest radius. Our result settles a conjecture in combinatorial geometry.
Bistro: a framework for building scalable wide-area Upload applications
Authors: Samrat Bhattacharjee, William C. Cheng, Cheng-Fu Chou, Leana Golubchik, Samir Khuller
Venue: ACM SIGMETRICS Performance Evaluation Review (2000)

Hot spots are a major obstacle to achieving scalability in the Internet. At the application layer, hot spots are usually caused by either (a) high demand for some data or (b) high demand for a certain service. This high demand for data or services, is typically the result of a real-life event involving availability of new data or approaching deadlines; therefore, relief of these hot spots may improve quality of life. At the application layer, hot spot problems have traditionally been dealt with using some combination of (1) increasing capacity; (2) spreading the load over time, space, or both; and (3) changing the workload.We note that the classes of solutions stated above have been studied mostly in the context of applications using the following types of communication (a) one-to-many, (b) many-to-many, and (c) one-to-one. However, to the best of our knowledge there is no existing work on making applications using many-to-one communication scalable and efficient (existing solutions, such as web based submissions, simply use many independent one-to-one transfers). This corresponds to an important class of applications, whose examples include the various upload applications such as submission of income tax forms, conference paper submission, proposal submission through the NSF FastLane system, homework and project submissions in distance education, voting in digital democracy applications, voting in interactive television, and many more. Consequently, the main focus of this paper is scalable infrastructure design for relief of hot spots in wide-area upload applications.The main contributions of this paper are as follows. We state (a) a new problem, specifically, the many-to-one communication, or upload, problem as well as (b) the (currently) fundamental obstacles to building scalable wide-area upload applications. We also propose a general framework, which we term the Bistro system, for a class of solutions to the upload problem. In addition, we suggest a number of open research problems, within this framework, throughout the paper.
Building a World-Wide virtual machine based on web and HPCC technologies
Authors: Kivanc Dincer, Geoffrey C. Fox
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

In today's high performance computing arena, there is a strong trend toward building virtual computers from heterogeneous resources on a network. In this paper we describe our experiences in building a world-wide virtual machine (WWVM) based on emerging Web and existing HPCC technologies. We have constructed a Web-based parallel/distributed programming environment on top of this machine demonstrating MPI and PVM message-passing programs and High Performance Fortran programs. Alternatively, the WWVM can be configured as a metacomputer for the solution of metaproblems.
A Protocol for Deadlock-Free Dynamic Reconfiguration in High-Speed Local Area Networks
Authors: Rafael Casado, Aurelio Bermúdez, Francisco J. Quiles, José L. Sánchez, José Duato
Venue: IEEE Transactions on Parallel and Distributed Systems (2001)

High-speed local area networks (LANs) consist of a set of switches interconnected by point-to-point links, and hosts linked to those switches through a network interface card. High-speed LANs may change their topology due to switches being turned on/off, hot expansion, link remapping, and component failures. In these cases, a distributed reconfiguration protocol analyzes the topology, computes the new routing tables, and downloads them to the corresponding switches. Unfortunately, in most cases, user traffic is stopped during the reconfiguration process to avoid deadlock. These strategies are called static reconfiguration techniques. Although network reconfigurations are not frequent, static reconfiguration such as this may take hundreds of milliseconds to execute, thus degrading system availability significantly. Several distributed real-time applications have strict communication requirements. Distributed multimedia applications have similar, although less strict, quality of service (QoS) requirements [3], [4]. Both stopping packet transmission and discarding packets due to the reconfiguration process prevent the system from satisfying the above requirements. Therefore, in order to support hard real-time and distributed multimedia applications over a high-speed LAN, we need to avoid stopping user traffic and discarding packets when the topology changes. In this paper, we propose a new deadlock-free distributed reconfiguration protocol that is able to asynchronously update routing tables without stopping user traffic. This protocol is valid for any topology, including regular as well as irregular topologies. It is also valid for packet switching as well as for cut-through switching techniques and does not rely on the existence of virtual channels to work. Simulation results show that the behavior of our protocol is significantly better than for other protocols based on stopping user traffic.
Bin Packing with Discrete Item Sizes, Part I: Perfect Packing Theorems and the Average Case Behavior of Optimal Packings
Authors: E. G. Coffman,  Jr., C. Courcoubetis, M. R. Garey, D. S. Johnson, P. W. Shor, R. R. Weber, M. Yannakakis
Venue: SIAM Journal on Discrete Mathematics (2000)

We consider the one-dimensional bin packing problem with unit-capacity bins and item sizes chosen according to the discrete uniform distribution U{j,k}, $1 k,2/k,. . .,j/k} has probability 1/j of being chosen. Note that for fixed j,k as $m\rightarrow\infty$ the discrete distributions U{mj,mk} approach the continuous distribution U(0,j/k], where the item sizes are chosen uniformly from the interval (0,j/k]. We show that average-case behavior can differ substantially between the two types of distributions. In particular, for all j,k with j<k-1, there exist on-line algorithms that have constant expected wasted space under U{j,k}, whereas no on-line algorithm has even o(n1/2) expected waste under U(0,u] for any $0 < u \leq 1$. Our U{j,k} result is an application of a general theorem of Courcoubetis and Weber [C. Courcoubetis and R. R. Weber, Probab. Engrg. Inform. Sci., 4 (1990), pp. 447--460] that covers all discrete distributions. Under each such distribution, the optimal expected waste for a random list of n items must be either $\Theta (n)$, $\Theta (n^{1/2} )$, or O(1), depending on whether certain "perfect" packings exist. The perfect packing theorem needed for the U{j,k} distributions is an intriguing result of independent combinatorial interest, and its proof is a cornerstone of the paper.
The nucleus of a multiprogramming system
Authors: Per Brinch Hansen
Venue: Communications of the ACM (1970)

This paper describes the philosophy and structure of a multi-programming system that can be extended with a hierarchy of operating systems to suit diverse requirements of program scheduling and resource allocation. The system nucleus simulates an environment in which program execution and input/output are handled uniformly as parallel, cooperating processes. A fundamental set of primitives allows the dynamic creation and control of a hierarchy of processes as well as the communication among them.
On Parsing and Compiling Arithmetic Expressions on Vector Computers
Authors: Charles N. Fischer
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1980)

The problem of parsing and compiling arithmetic expressions on vector computers is considered. Methods are developed which allow encodings of one or more arithmetic expressions to be transformed directly into encodings of their corresponding derivation trees. The algorithm which performs this transformation is compact, efficient, and able to make extensive use of concurrent vector operations. Routines which concurrently transverse encoded derivation trees in a top-down or bottom-up manner are presented. These routines can be used to structure efficient, compact, and highly concurrent algorithms which complete the process of compiling arithmetic expressions.
Matchmaking among minimal agents without a facilitator
Authors: Elth Ogston, Stamatis Vassiliadis
Venue: Proceedings of the fifth international conference on Autonomous agents (2001)

Multi-Agent Systems are a promising way of dealing with large complex problems. However, it is not yet clear just how much complexity or pre-existing structure individual agents must have to allow them to work together effectively. In this paper, we ask to what extent agents with minimal resources, local communication and without a directory service can solve a consumer-provider matchmaking problem. We are interested in finding a solution that is massively scalable and can be used with resource poor agents in an open system. We create a model involving random search and a grouping procedure. Through simulation of this model, we show that peer-to-peer communication in a environment with multiple copies of randomly distributed like clients and providers is sufficient for most agents to discover the service consumers or providers they need to complete tasks. We simulate systems with between 500 and 32,000 agents, between 10 and 2000 categories of services, and with three to six services required by each agent. We show that, for instance, in a system with 80 service categories and 2000 agents, each requiring three random services between 93\% and 97\% of possible matches are discovered. Such a system can work with at least 90 different service categories and tens of thousands of agents.