ppxscal/embedding_network huggingface dataset:
Extending Tabletops to Support Flexible Collaborative Interactions
Authors: Yvonne Rogers, Youn-Kyung Lim, William R. Hazlewood
Venue: Proceedings of the First IEEE International Workshop on Horizontal Interactive Human-Computer Systems (2006)

Tabletops have been used to support a range of colocated activities, from games to image sorting. However, their limited display space and resolution can restrict the kinds of collaborative interactions that take place. Our research is concerned with how to extend the tabletop by integrating it with other spaces and artifacts in the physical world. Our goal is to design workspaces that support a wider range of collaborative tasks, determining which are well suited to the tabletop and which are better performed using physical representations and spaces. We describe a physicaldigital space that we built for this purpose and then a study that compared how groups collaborate on a design task when using this versus solely the tabletop. The findings showed that extending the tabletop into a physical space enabled groups to collaborate more easily and flexibly.
Multilevel Risk Management System for Project-Oriented Field
Authors: Artem Aleshin
Venue: Proceedings of the 18th International Conference on Systems Engineering (2005)

This article is devoted to the matters of risk management in a project-oriented field. Multilevel risk management system is considered. Risk management process is connected with the improvement of the enterprise's activity.
Latent Process Model for Manifold Learning
Authors: Gang Wang, Weifeng Su, Xiangye Xiao, Lochovsky Frederick
Venue: Proceedings of the 17th IEEE International Conference on Tools with Artificial Intelligence (2005)

In this paper, we propose a novel stochastic framework for unsupervised manifold learning. The latent variables are introduced, and the latent processes are assumed to characterize the pairwise relations of points over a high dimensional and a low dimensional space. The elements in the embedding space are obtained by minimizing the divergence between the latent processes over the two spaces. Different priors of the latent variables, such as Gaussian and multinominal, are examined. The Kullback-Leibler divergence and the Bhattachartyya distance are investigated. The latent process model incorporates some existing embedding methods and gives a clear view on the properties of each method. The embedding ability of this latent process model is illustrated on a collection of bitmaps of handwritten digits and on a set of synthetic data.
Defining and Evaluating Greynets (Sparse Darknets)
Authors: Warren Harrop, Grenville Armitage
Venue: Proceedings of the The IEEE Conference on Local Computer Networks 30th Anniversary (2005)

Darknets are increasingly being proposed as a means by which network administrators can monitor for anomalous, externally sourced traffic. Current darknet designs require large, contiguous blocks of unused IP addresses - not always feasible for enterprise network operators. In this paper we introduce, define and evaluate the concept of a Greynet - a region of IP address space that is sparsely populated with 'darknet' addresses interspersed with active (or 'lit') IP addresses. We use raw traffic traces collected within a university network to evaluate how sparseness affects a greynet's effectiveness and hence show that enterprise operators can achieve useful levels of network scan detection, with only small numbers of 'dark' IP addresses making up their greynets.
A Low Leakage and SNM Free SRAM Cell Design in Deep Sub Micron CMOS Technology
Authors: Sanjeev K. Jain, Pankaj Agarwal
Venue: Proceedings of the 19th International Conference on VLSI Design held jointly with 5th International Conference on Embedded Systems Design (2006)

As the IC process technology scales, the oxide thickness and operating voltage continues to decrease. The gate oxide thickness in recent and future IC process technology has approached the limit when direct tunneling causes gate leakage in both on state and off state of MOSFET transistor operation modes. Also, lower operating voltage will lower the stability of SRAM cell resulting in lower value of static noise margin. In this paper, a novel read '0' static noise margin (SNM) free eight transistors (8T) SRAM cell is proposed that reduces gate leakage power in the zero state, taking into consideration the fact that in ordinary program most of the bits stored in caches are zeros for both the data and instruction streams. Compared to conventional six transistors (6T) SRAM cell, new 8T SRAM cell reduces total leakage by 50.2% in the zero state at low temperature, where gate leakage is dominant. High V_T transistors in 8T SRAM cell can be used to further reduce both gate and sub threshold leakage. This new high V_T 8T SRAM cell reduces total leakage by 60% in zero state at highest temperature. The 8T SRAM cell is SNM free in read operation for the case when cell stores logic '0'. Interestingly, new cell improves SNM by 2.2 times as compared to conventional 6T SRAM cell in read operation and standby mode for the case when cell stores logic '1'.
An object-oriented program development environment for the first programming course
Authors: Michael Kölling, John Rosenberg
Venue: Proceedings of the twenty-seventh SIGCSE technical symposium on Computer science education (1996)

Over the last ten years there has been a major shift in programming language design from procedural languages to object-oriented languages. Most universities have adopted an object-oriented language for their first programming course. However, far less consideration has been given to the program development environment. In this paper we argue that the environment is possibly more important than the language and existing environments fail to fully support the object-oriented paradigm. We describe a new program development environment and show how it has been specifically designed to support object-oriented design and programming.
Analysis of the early workload on the Cornell Theory Center IBM SP2
Authors: Steven Hotovy, David Schneider, Timothy O'Donnell
Venue: ACM SIGMETRICS Performance Evaluation Review (1996)

Parallel computers have matured to the point where they are capable of running a significant production workload. Characterizing this workload, however, is far more complicated than for the single-processor case. Besides the varying number of processors that may be invoked, the nodes themselves may provide differing computational resources (memory size, for example). In addition, the batch schedulers may introduce further categories of service which must be considered in the analysis.The Cornell Theory Center (CTC) put a 512-node IBM SP2 system into production in early 1995. Extended traces of batch jobs began to be collected in mid-1995 when the usage base became sufficiently large. This paper offers an analysis of this early batch workload.
The merge/purge problem for large databases
Authors: Mauricio A. Hernández, Salvatore J. Stolfo
Venue: Proceedings of the 1995 ACM SIGMOD international conference on Management of data (1995)

Many commercial organizations routinely gather large numbers of databases for various marketing and business analysis functions. The task is to correlate information from different databases by identifying distinct individuals that appear in a number of different databases typically in an inconsistent and often incorrect fashion. The problem we study here is the task of merging data from multiple sources in as efficient manner as possible, while maximizing the accuracy of the result. We call this the merge/purge problem. In this paper we detail the sorted neighborhood method that is used by some to solve merge/purge and present experimental results that demonstrates this approach may work well in practice but at great expense. An alternative method based upon clustering is also presented with a comparative evaluation to the sorted neighborhood method. We show a means of improving the accuracy of the results based upon a multi-pass approach that succeeds by computing the Transitive Closure over the results of independent runs considering alternative primary key attributes in each pass.
Backtracking without trailing in CLP ( RLin )
Authors: Pascal Van Hentenryck, Viswanath Ramachandran
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1995)

Existing CLP languages support backtracking by generalizing traditional Prolog implementations: modifications to the constraint system are trailed and restored on backtracking. Although simple and efficient, trailing may be very demanding in memory space, since the constraint system may potentially be saved at each choice point.This article proposes a new implementation scheme for backtracking in CLP languages over linear (rational or real) arithmetic. The new scheme, called semantic backtracking, does not use trailing but rather exploits the semantics of the constraints to undo the effect of newly added constraints. Semantic backtracking reduces the space complexity compared to implementations based on trailing by making it essentially independent of the number of choice points. In addition, semantic backtracking introduces negligible space and time overhead on deterministic programs. The price for this improvement is an increase in backtracking time, although constraint-solving time may actually decrease. The scheme has been implemented as part of a complete CLP system CLP (RLin) and compared analytically and experimentally with optimized trailing implementations. Experimental results on small and real-life problems indicate that semantic backtracking produces significant reduction in memory space, while keeping the time overhead reasonably small.
Skewed associativity enhances performance predictability
Authors: François Bodin, André Seznec
Venue: Proceedings of the 22nd annual international symposium on Computer architecture (1995)

Performance tuning becomes harder as computer technology advances. One of the factors is the increasing complexity of memory hierarchies. Most modern machines now use at least one level of cache memory. To reduce execution stalls, cache misses must be very low. Software techniques used to improve locality have been developped for numerical codes, such as loop blocking and copying. Unfortunately, the behavior of direct mapped and set associative caches is still erratic when large numerical data is accessed. Execution time can vary drasticly for the same loop kernel depending on uncontrolled factors such as array leading size. The only software method available to improve execution time stability is the copying of frequently used data, which is costly in execution time. Users are not usually cache organisation experts. They are not aware of such phenomena, and have no control over it.In this paper, we show that the recently proposed four-way skewed associative cache yields very stable execution times and good average miss ratios on blocked algorithms. As a result, execution time is faster and much more predictable than with conventional caches. As a result of its better comportment, it is possible to use larger blocks sizes with blocked algorithms, which will furthermore reduces blocking overhead costs.
Soft issues and hard problems in software development (panel)
Authors: Paul S. R. Chisholm, Larry Constantine
Venue: Proceedings of the 11th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (1996)

The key to making object technology work isn't technology. So what is it? This panel will cover a lot of the "soft" issues about dealing with people and teams. It's partly about managing software development, and mostly about doing it.
On Computing Algebraic Functions using Logarithms andExponentials
Authors: Dima Grigoriev, Michael Singer, Andrew Yao
Venue: SIAM Journal on Computing (1995)

Let $\rho$ be a set of algebraic expressions constructed with radicals and arithmetic operations, and which generate the splitting field $F$ of some polynomial. Let $N_{\beta}(\rho)$ be the minimum total number of root-takings and exponentiations used in any straightline program for computing the functions in $\rho$ by taking roots, exponentials, logarithms, and performing arithmetic operations. In this paper it is proved that $N_{\beta}(\rho) = \nu(G)$, where $\nu(G)$ is the minimum length of any cyclic Jordan--Holder tower for the Galois group $G$ of $F$. This generalizes a result of Ja'Ja' [Proceedings of the 22nd IEEE Symposium on Foundations of Computer Science, 1981, pp.\ 95--100], and shows that the inclusion of certain new primitives, such as taking exponentials and logarithms, does not improve the cost of computing such expressions as compared with programs that use only root-takings.
Schensted Algorithms for Dual Graded Graphs
Authors: Sergey Fomin
Venue: Journal of Algebraic Combinatorics: An International Journal (1995)

This paper is a sequel to &lsqb;3&rsqb;. We keep the notation and terminology and extend the numbering of sections, propositions, and formulae of &lsqb;3&rsqb;.The main result of this paper is a generalization of the Robinson-Schensted correspondence to the class of dual graded graphs introduced in &lsqb;3&rsqb;, This class extends the class of Y-graphs, or differential posets &lsqb;22&rsqb;, for which a generalized Schensted correspondence was constructed earlier in &lsqb;2&rsqb;.The main construction leads to unified bijective proofs of various identities related to path counting, including those obtained in &lsqb;3&rsqb;. It is also applied to permutation enumeration, including rook placements on Ferrers boards and enumeration of involutions.As particular cases of the general construction, we re-derive the classical algorithm of Robinson, Schensted, and Knuth &lsqb;19, 12&rsqb;, the Sagan-Stanley &lsqb;18&rsqb;, Sagan-Worley &lsqb;16, 29&rsqb; and Haiman's &lsqb;11&rsqb; algorithms and the author's algorithm for the Young-Fibonacci graph &lsqb;2&rsqb;. Some new applications are suggested.The rim hook correspondence of Stanton and White &lsqb;23&rsqb; and Viennot's bijection &lsqb;28&rsqb; are also special cases of the general construction of this paper.In &lsqb;5&rsqb;, the results of this paper and the previous paper &lsqb;3&rsqb; were presented in a form of extended abstract.
Discovering the way programmers think about new programming environments
Authors: Joseph Dumas, Paige Parsons
Venue: Communications of the ACM (1995)

An interesting usability study of a prototype development environment for the Dylan programming language is presented here. This study's purpose is to determine just how close the prototype is to developers. New approaches to source code organization and to the relationship between the environment and the application being developed are introduced. An asessment of how effectively the prototype conveys these innovations to Dylan developers is also given, followed by some proposed improvements.
MultiSIX: how it improves interoperability in a multi-vendor network
Authors: Scott Scudamore
Venue: ACM SIGSAC Review (1995)

The purpose of this paper is to describe how MultiSIX, Digital's Trusted Network Architecture, improves interoperability within multi-vendor trusted networking environments. I will describe the Interoperability Challenges, the basic facets of the MultiSIX Architecture, the main points of the DNSIX 3.0, and how this together improves interoperability.
Hypervisor-based fault tolerance
Authors: Thomas C. Bressoud, Fred B. Schneider
Venue: ACM Transactions on Computer Systems (TOCS) (1996)

Protocols to implement a fault-tolerant computing system are described. These protocols augment the hypervisor of a virtual-machine manager and coordinate a primary virtual machine with its backup. No modifications to the hardware, operating system, or application programs are required. A prototype system was constructed for HP's PA-RISC instruction-set architecture. Even though the prototype was not carefully tuned, it ran programs about a factor of 2 slower than a bare machine would.
Analysis of an importance sampling estimator for tandem queues
Authors: Paul Glasserman, Shing-Gang Kou
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (1995)

We analyze the performance of an importance sampling estimator for a rare-event probability in tandem Jackson networks. The rare event we consider corresponds to the network population reaching K before returning to &oslash;, starting from &oslash;, with K large. The estimator we study is based on interchanging the arrival rate and the smallest service rate and is therefore a generalization of the asymptotically optimal estimator for an M/M/1 queue. We examine its asymptotic performance for large K, showing that in certain parameter regions the estimator has an asymptotic efficiency property, but that in other regions it does not. The setting we consider is perhaps the simplest case of a rare-event simulation problem in which boundaries on the state space play a significant role.
The influence of caches on the performance of heaps
Authors: Anthony LaMarca, Richard Ladner
Venue: Journal of Experimental Algorithmics (JEA) (1996)

As memory access times grow larger relative to processor cycle times, the cache performance of algorithms has an increasingly large impact on overall performance. Unfortunately, most commonly used algorithms were not designed with cache performance in mind. This paper investigates the cache performance of implicit heaps. We present optimizations which significantly reduce the cache misses that heaps incur and improve their overall performance. We present an analytical model called collective analysis that allows cache performance to be predicted as a function of both cache configuration and algorithm configuration. As part of our investigation, we perform an approximate analysis of the cache performance of both traditional heaps and our improved heaps in our model. In addition empirical data is given for five architectures to show the impact our optimizations have on overall performance. We also revisit a priority queue study originally performed by Jones [25]. Due to the increases in cache miss penalties, the relative performance results we obtain on today's machines differ greatly from the machines of only ten years ago. We compare the performance of implicit heaps, skew heaps and splay trees and discuss the difference between our results and Jones's.
Measuring user involvement: a diffusion of innovation perspective
Authors: Leon A. Kappelman
Venue: ACM SIGMIS Database (1995)

User involvement is a need-based motivational attitude toward information systems and their development. As such, it has important implications for the successful creation and deployment of information systems in organizations. This paper reports on the development and validation of an instrument to determine if the distinction between a user's involvement in the process of information system diffusion can be measured independently of that user's involvement with the information system innovation itself. Utilizing previously-validated instruments from consumer behavior research, these two object-based categories of user involvement were operationalized.A longitudinal field study was conducted of users in a large financial institution during the implementation phase, in particular the later activities of the adaptation stage, of the information system diffusion process. During adaptation, the information system product becomes available for use in the organization. Late adaptation stage activities include hardware installation, system conversion, and training. The instruments were pre-tested and assessed as to their content validity, internal consistency, convergent validity, unidimensionality, temporal stability, discriminant validity, predictive validity, and factorial validity. The evidence indicates that the measurement scales are reliable and valid. The primary question of scale independence was examined by discriminant validity. The empirical evidence supports the theoretical distinction between user process involvement and user system involvement. The implications of these findings to research and practice are discussed.
Implementing deletion in B+-trees
Authors: Jan Jannink
Venue: ACM SIGMOD Record (1995)

This paper describes algorithms for key deletion in B+-trees. There are published algorithms and pseudocode for searching and inserting keys, but deletion, due to its greater complexity and perceived lesser importance, is glossed over completely or left as an exercise to the reader. To remedy this situation, we provide a well documented flowchart, algorithm, and pseudo-code for deletion, their relation to search and insertion algorithms, and a reference to a freely available, complete B+-tree library written in the C programming language.
Automated consistency checking of requirements specifications
Authors: Constance L. Heitmeyer, Ralph D. Jeffords, Bruce G. Labaw
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1996)

This article describes a formal analysis technique, called consistency checking, for automatic detection of errors, such as type errors, nondeterminism, missing cases, and circular definitions, in requirements specifications. The technique is designed to analyze requirements specifications expressed in the SCR (Software Cost Reduction) tabular notation. As background, the SCR approach to specifying requirements is reviewed. To provide a formal semantics for the SCR notation and a foundation for consistency checking, a formal requirements model is introduced; the model represents a software system as a finite-state automation which produces externally visible outputs in response to changes in monitored environmental quantities. Results of two experiments are presented which evaluated the utility and scalability of our technique for consistency checking in real-world avionics application. The role of consistency checking during the requirements phase of software development is discussed.
Intersecting solids on a massively parallel processor
Authors: Michael Karasick, David Strip
Venue: ACM Transactions on Graphics (TOG) (1995)

Solid modeling underlies many technologies that are key to modern manufacturing. These range from CAD systems to robot simulators, from finite-element analysis to integrated circuit process modeling. The accuracy, and hence the utility, of these models is often constrained by the amount of computer time required to perform the desired operations. In this paper we present, in detail, an efficient algorithm for parallel intersections of solids using the Connection Machine, a massively parallel SIMD processor. We describe the data structure for representing the solid models and detail the intersection algorithm, giving special attention to implementation issues. We provide performance results, comparing the parallel algorithm to a serial intersection algorithm.
A pruned and bootstrapped American option simulator
Authors: Mark Broadie, Paul Glasserman
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The pricing of American options on multiple assets or with path-dependent payoffs is an important but computationally challenging problem. In earlier work, we introduced simulation estimators for this problem which, though biased, are consistent and asymptotically unbiased. In this paper, we introduce enhancements to reduce bias. One enhancement exploits more easily computed European option prices; another uses bootstrapping for bias estimation.
Auction allocation of computing resources
Authors: Ross A. Gagliano, Martin D. Fraser, Mark E. Schaefer
Venue: Communications of the ACM (1995)

Standard methods for allocating computing resources normally employ schedulers and either queue or priority schemes. Alternative methods utilizing marketlike processes are being investigated, with direct applicability to evolving distributed systems. In this article, we present results of simulations of an auction allocation is which computing tasks are provided sufficient intelligence to acquire resources by offering, bidding, and exchanging them for funds.