ppxscal/embedding_network huggingface dataset:
Virtual 3D camera composition from frame constraints
Authors: William Bares, Scott McDermott, Christina Boudreaux, Somying Thainimit
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

We have designed a graphical interface that enables 3D visual artists or developers of interactive 3D virtual environments to efficiently define sophisticated camera compositions by creating storyboard frames, indicating how a desired shot should appear. These storyboard frames are then automatically encoded into an extensive set of virtual camera constraints that capture the key visual composition elements of the storyboard frame. Visual composition elements include the size and position of a subject in a camera shot. A recursive heuristic constraint solver then searches the space of a given 3D virtual environment to determine camera parameter values which produce a shot closely matching the one in the given storyboard frame. The search method uses given ranges of allowable parameter values expressed by each constraint to reduce the size of the 7 Degree of Freedom search space of possible camera positions, aim direction vectors, and field of view angles. In contrast, some existing methods of automatically positioning cameras in 3D virtual environments rely on pre-defined camera placements that cannot account for unanticipated configurations and movement of objects or use program-like scripts to define constraint-based camera shots. For example, it is more intuitive to directly manipulate an object's size in the frame rather than editing a constraint script to specify that the object should cover 10% of the frame's area.
Entropy increases (or does it?)
Authors: Francis Sullivan
Venue: Computing in Science and Engineering (2001)

At first, there was only one language. All speech was poetry, all science was physics, all invention was engineering, all decoration was art, all reasoning was logic, and all speculation was philosophy. But later, many subtopics arose until at length, knowledge had fragmented into so many mutually incomprehensible sub-subspecialties that it could hardly be called knowledge at all. Information was spread out uniformly. Any fragment was as likely as any other to be in the right place to look. The second law of thermodynamics was at work, and entropy seemed to have increased to its maximum.
Advanced feature extraction for Keyblock-based image retrieval
Authors: Lei Zhu, Aibing Rao, Aidong Zhang
Venue: Proceedings of the 2000 ACM workshops on Multimedia (2000)

Keyblock, which is a new framework we proposed for content-based image retrieval, is a generalization of the text-based information retrieval technology in the image domain. In this framework, keyblocks, which are analogous to keywords in text document retrieval, can be constructed by exploiting the Vector Quantization (VQ) method which has been used for image compression. Then an image can be represented as a code matrix in which the elements are the indices of keyblocks in a codebook. Based on this image representation, information retrieval and database analysis techniques developed in the text domain can be generalized to image retrieval. In this paper, we propose new models named N-block models which are the generalization of the N-gram models in language modeling to extract comprehensive image features. The effort to capture context in a text document motivated the N-gram models. Similarly, the attempt to capture the content in an image motivates us to consider the correlations of keyblocks within an image. By comparing the performance of our approach with conventional techniques using color feature and wavelet texture feature, the experimental results demonstrate the effectiveness of these N-block models.
On the distinct distances determined by a planar point set
Authors: J. Solymosi, Csaba D. Toth
Venue: Proceedings of the seventeenth annual symposium on Computational geometry (2001)

It is shown that every set of $n$ points in the plane has an element f rom which there are at least $cn^{6/7}$ other elements at distinct distances, where $c>0$ is a constant. This improves earlier results of Erd\H os, Moser, Beck, Chung, Szemer\'edi, Trotter, and Sz\'ekely.
An algorithm for reasoning about equality
Authors: Robert E. Shostak
Venue: Communications of the ACM (1978)

A simple technique for reasoning about equalities that is fast and complete for ground formulas with function symbols and equality is presented. A proof of correctness is given as well.
Timing Analysis of Combinational Circuits in Intuitionistic Propositional Logic
Authors: Michael Mendler
Venue: Formal Methods in System Design (2000)

Classical logic has so far been the logic of choice in formal hardware verification. This paper proposes the application of intuitionistic logic to the timing analysis of digital circuits. The intuitionistic setting serves two purposes. The model-theoretic properties are exploited to handle the second-order nature of bounded delays in a purely propositional setting without need to introduce explicit time and temporal operators. The proof-theoretic properties are exploited to extract quantitative timing information and to reintroduce explicit time in a convenient and systematic way.We present a natural Kripke-style semantics for intuitionistic propositional logic, as a special case of a Kripke constraint model for Propositional Lax Logic (Information and Computation, Vol. 137, No. 1, 1&ndash;33, 1997), in which validity is validity up to stabilisation, and implication &sup; comes out as &ldquo;boundedly gives rise to.&rdquo; We show that this semantics is equivalently characterised by a notion of realisability with stabilisation bounds as realisers. Following this second point of view an intensional semantics for proofs is presented which allows us effectively to compute quantitative stabilisation bounds.We discuss the application of the theory to the timing analysis of combinational circuits. To test our ideas we have implemented an experimental prototype tool and run several examples.
STERN: a highly scalable parallel stereo terrain renderer for planetary mission simulations
Authors: Ansel Teng, Scott Whitman, Meemong Lee
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

In this paper, we describe STREN, a parallel stereo renderer for fixed-location terrain rendering tasks required for the simulation of planetary exploration missions. The renderer is based on a novel spatial data representation, called the TANPO map. This data representation stores terrain data using a simple and compact structure and provides excellent locality for such rendering applications. Experimental results show that the renderer not only performs very well, but also scales perfectly to different numbers of processors.
Detection of logical errors in decision table programs
Authors: M. Ibramsha, V. Rajaraman
Venue: Communications of the ACM (1978)

In this paper an algorithm to detect logical errors in a limited-entry decision table and in loop-free programs with embedded decision tables is developed. All the conditions in the decision tables are assumed to be inequalities or equalities relating linear expressions. It is also assumed that actions in a decision table are linear in variables which occur in the condition stub of the decision table (or tables) to which control is transferred from the table. The algorithm is based on determining whether a set of linear inequalities has or does not have a solution. The algorithm described in the paper is implemented in Fortran IV.
Comparative analysis of organelle genomes, a biologist's view of computational challenges (abstract only)
Authors: Franz Lang
Venue: Proceedings of the fifth annual international conference on Computational biology (2001)

With genomic data (generated by classical, functional, structural, proteo- and other `omic' approaches) accumulating at a stupendous rate, there is an ever increasing need for the development of new, more efficient and more sensitive computational methods. To highlight aspects of our computational needs, we will present results that emerged from the comparative genome analysis of mitochondria. Having originated from an alpha-proteobacterial endosymbiont, these eukaryotic organelles contain small and extremely variable genomes, and are thus perfect model systems for the much more complex eubacterial and archaeal genomes. We are currently in vestigating mitochondrial DNAs (mtDNAs) in a lineage of unicellular, primitive protistan eukaryotes, the jakobids, with the aim to understand the evolution of mitochondrial genomes, genes and their regulation. Because these organisms are difficult to grow, biochemical approaches aimed at understanding gene regulation are laborious, thus it is possible to capitalize considerably from predictions on genome and gene organization, and regulatory elements. Contrary to approaches in which molecular data (gene order, sequence similarities) are used to infer the phylogenetic relationships among a group of organism, we know their phylogeny and employ this information to identify and model more or less conserved genetic elements and structural RNA genes that are difficult to spot by conventional methods, in a phylogenetic-comparative approach.
Concurrent reading and writing
Authors: Leslie Lamport
Venue: Communications of the ACM (1977)

The problem of sharing data among asynchronous processes is considered. It is assumed that only one process at a time can modify the data, but concurrent reading and writing is permitted. Two general theorems are proved, and some algorithms are presented to illustrate their use. These include a solution to the general problem in which a read is repeated if it might have obtained an incorrect result, and two techniques for transmitting messages between processes. These solutions do not assume any synchronizing mechanism other than data which can be written by one process and read by other processes.
Solutions of systems of polynomial equations by elimination
Authors: Joel Moses
Venue: Communications of the ACM (1966)

The elimination procedure as described by Williams has been coded in LISP and FORMAC and used in solving systems of polynomial equations. It is found that the method is very effective in the case of small systems, where it yields all solutions without the need for initial estimates. The method, by itself, appears inappropriate, however, in the solution of large systems of equations due to the explosive growth in the intermediate equations and the hazards which arise when the coefficients are truncated. A comparison is made with difficulties found in other problems in non-numerical mathematics such as symbolic integration and simplification.
On effectiveness of GC in Java
Authors: Ran Shaham, Elliot K. Kolodner, Mooly Sagiv
Venue: Proceedings of the 2nd international symposium on Memory management (2000)

We study the effectiveness of garbage collection (GC) algorithms by measuring the time difference between the actual collection time of an object and the potential earliest collection time for that object. Our ultimate goal is to use this study in order to develop static analysis techniques that can be used together with GC to allow earlier reclamation of objects. The results may also be used to pinpoint application source code that could be rewritten in a way that would allow more timely GC. Specifically, we compare the objects reachable from the root set to the ones that are actually used again. The idea is that GC could reclaim unused objects even if they are reachable from the root set. Thus, our experiments indicate a kind of upper bound on storage savings that could be achieved. We also try to characterize these objects in order to understand the potential benefits of various static analysis algorithms. The Java Virtual Machine (JVM) was instrumented to measure objects that are reachable, but not used again, and to characterize these objects. Experimental results are shown for the SPECjvm98 benchmark suite. The potential memory savings for these benchmarks range from 23% to 74%.
Some numerical experiments using Newton's method for nonlinear parabolic and elliptic boundary-value problems
Authors: Richard Bellman, Mario L. Juncosa, Robert Kalaba
Venue: Communications of the ACM (1961)

Using a generalization of Newton's method, a non-linear parabolic equation of the form ut - uxx = g(u), and a non-linear elliptic equation uxx + uyy = eu, are solved numerically. Comparison of these results with results obtained using the Picard iteration procedure show that in many cases the quasilinearization method offers substantial advantages in both time and accuracy.
Algorithmic modifications to the Jacobi-Davidson parallel eigensolver to dynamically balance external CPU and memory load
Authors: Richard Tran Mills, Andreas Stathopoulos, Evgenia Smirni
Venue: Proceedings of the 15th international conference on Supercomputing (2001)

Clusters of workstations (COWs) and SMPs have become popular and cost effective means of solving scientific problems. Because such environments may be heterogenous and/or time shared, dynamic load balancing is central to achieving high performance. Our thesis is that new levels of sophistication are required in parallel algorithm design and in the interaction of the algorithms with the runtime system. To support this thesis, we illustrate a novel approach for application-level balancing of external CPU and memory load on parallel iterative methods that employ some form of local preconditioning on each node. There are two key ideas. First, because all nodes need not perform their portion of the preconditioning phase to the same accuracy, the code can achieve perfect loadbalance, dynamically adapting to external CPU load, if we stop the preconditioning phase on all processors after a fixed amount of time. Second, if the program detects memory thrashing on a node, it recedes its preconditioning phase from that node, hopefully speeding the completion of competing jobs hence the relinquishing of their resources. We have implemented our load balancing approach in a state-of-the-art, coarse grain parallel Jacobi-Davidson eigensolver. Experimental results show that the new method adapts its algorithm based on runtime system information, without compromising the overall convergence behavior. We demonstrate the effectiveness of the new algorithm in a COW environment under (a) variable CPU load and (b) variable memory availability caused by competing applications.
The editing of picture segmentations using local analysis of graphs
Authors: Steven L. Tanimoto, Theodosios Pavlidis
Venue: Communications of the ACM (1977)

A major problem in picture processing is the elimination of the large number of spurious regions that result from an initial segmentation by region growing techniques. Such regions have been eliminated either on the basis of semantic information or on the basis of size and contrast. A scheme is presented which performs eliminations on the basis of local properties of the region adjacency graph. The scheme is based on definitions of graph properties which are satisfied when a spurious region is present; then editing is equivalent to fast graph operations. A number of examples are shown.
Towards a real-time distributed systems annex in Ada
Authors: José Javier Guitiérrez García, Michael González Harbour
Venue: ACM SIGAda Ada Letters (2001)

In this paper we address the problem of combining two issues that are standardized separately in two Ada 95 annexes: Real-Time Systems (Annex D) and Distributed Systems (Annex E). With these annexes it is possible to build applications with real-time requirements, or alternatively distributed applications; but real-time distributed applications are not directly supported. In this paper we propose extensions to the Distributed Systems Annex that would provide support for developing distributed real-time applications in Ada. The paper proposes an interface for assigning priorities to the messages in the interconnection networks, and also to the tasks executing remote operations, in a way that avoids priority inversions. It also addresses the issues of configuration of the RPC handler tasks and non blocking asynchronous remote procedure calls.
Preconditioned Lanczos Methods for the Minimum Eigenvalue of a Symmetric Positive Definite Toeplitz Matrix
Authors: Michael K. Ng
Venue: SIAM Journal on Scientific Computing (1999)

In this paper, we apply the preconditioned Lanczos (PL) method to compute the minimum eigenvalue of a symmetric positive definite Toeplitz matrix. The sine transform-based preconditioner is used to speed up the convergence rate of the PL method. The resulting method involves only Toeplitz and sine transform matrix-vector multiplications and hence can be computed efficiently by fast transform algorithms. We show that if the symmetric Toeplitz matrix is generated by a positive $2 \pi$-periodic even continuous function, then the PL method will converge sufficiently fast. Numerical results including Toeplitz and non-Toeplitz matrices are reported to illustrate the effectiveness of the method.
Semi-numerical determination of irreducible branches of a reduced space curve
Authors: André Galligo, David Rupprecht
Venue: Proceedings of the 2001 international symposium on Symbolic and algebraic computation (2001)

In this paper, we propose a semi-numerical algorithm for computing all irreducible branches of a curve in C3 defined by polynomials with rational coefficients. It is based on some properties appearing after a generic change of coordinate. Using numerical computation, Galois group action and rational approximation, it provides an efficient probabilistic algorithm for medium degrees. Our method generalizes our study on absolute factorization of polynomials ([2, 6]).
Power Efficient Folding of Pipelined LMS Adaptive Filters with Applications to Wireline Digital Communications
Authors: Ahmed F. Shalash, Keshab K. Parhi
Venue: Journal of VLSI Signal Processing Systems (2000)

In this paper, a new two-step algorithm is introduced for power efficient implementation of the folding algorithm transformation of the LMS adaptive FIR filters. The first step handles the scheduling within the folding sets to reduce the switching activity using a greedy algorithm solution for the traveling sales person (TSP) NP-hard problem. The greedy algorithm gives a sub-optimal solution of the TSP problem with low implementation cost. For a typical word-length, and for large folding factors, the projected reduction in switching activity can be as large as 50%. HEAT tool was used to simulate the effect of this reduction using a typical Baugh-Wooley multiplier and the reduction in power consumption for a wireline equalization implementation was found to lie between 25% and 60%. The new algorithm is based on a simple breadth-first search approach and can be easily performed for one time only when the filter is geared to the steady-state mode. The second step involves optimal pipelining of the folded hardware elements for minimum power. The tradeoff between the number of pipelining levels and the power consumption is evaluated. To compensate for the LMS degradation due to pipelining, a 1-pole IIR compensator is introduced in the error loop for relaxed LMS. The IIR based relaxation outperforms the relaxed lookahead pipelining by 2-3 dB of output error. Another feature of the IIR relaxation is the &ldquo;smoothing&rdquo; nature of the filter, thus reducing the effective switching activities on the multiplier input. The combined effect of the two techniques can lead to power savings up to 65% compared to a normal folded structure. Simulations for the combined techniques are carried out for the digital subscriber loop channel and significant savings in power are demonstrated.
Optimal implementation of the weakest failure detector for solving consensus (brief announcement)
Authors: Mikel Larrea, Antonio Fernández, Sergio Arévalo
Venue: Proceedings of the nineteenth annual ACM symposium on Principles of distributed computing (2000)

Unreliable failure detectors were introduced by Chandra and Toueg [2] as a mechanism that provides (possibly incorrect) information about process failures. They showed how unreliable failure detectors can be used to solve the Consensus problem in asynchronous systems. They also showed in [1] that one of the classes of failure detectors they defined, namely Eventually Strong (&diam;S), is the weakest class allowing to solve Consensus1.This brief announcement presents a new algorithm implementing &diam;S. Due to space limitation, the reader is referred to [4] for an in-depth presentation of the algorithm (system model, correctness proof, and performance analysis). Here, we present the general idea of the algorithm and compare it with other algorithms implementing unreliable failure detectors.The algorithm works as follows. We have n processes, p1, &hellip;, pn. Initially, process p1 starts sending messages periodically to the rest of processes. The rest of processes initially trust p1, and wait for its messages. If a process does not receive a message within some timeout period from its trusted process, then it suspects its trusted process and takes the next process as its new trusted process. If a process trusts itself, then it starts sending messages periodically to its successors. Otherwise, it just waits for periodical messages from its trusted process. If, at some point, a process receives a message from a process pi such that pi precedes its trusted process, then it will trust pi again, increasing the value of its timeout period with respect to pi. With this algorithm, eventually all the correct processes will permanently trust the same correct process. This provides the eventual weak accuracy property required by &diam;S. By simply suspecting the rest of processes, we obtain the strong completeness property required by &diam;S. Our algorithm compares favorably with the algorithms proposed in [2] and [3] in terms of the number and size of the messages periodically sent and the total amount of information periodically exchanged. Since algorithms implementing failure detectors need not necessarily be periodic, we propose a new and (we believe) more adequate performance measure, which we call eventual monitoring degree. Informally, this measure counts the number of pairs of correct processes that will infinitely often communicate. We show that the proposed algorithm is optimal with respect to this measure. Table 1 summarizes the comparison, where C denotes the number of correct processes and LFA denotes the proposed algorithm.
Automation of etching-pattern layout
Authors: Itaru Aramaki, Tomokazu Kawabata, Kazuhiko Arimoto
Venue: Communications of the ACM (1971)

HELP (Heuristic Etching-Pattern Layout Program) is an application program developed to computerize the tedious and error-prone although vitally important wiring design of printed circuit boards. HELP helps automate a design stage one step closer to production than logical design. It can be used to design wiring patterns of two-layer circuit boards on which ICs in dual-in-line packages as well as discrete components such as transistors and resistors have been placed. HELP employs two methods of wiring. One is the heuristic method, which simulates human approaches to wiring design, and the other is the theoretically interesting but time-consuming method of maze-running, based on the Lee's algorithm. HELP performs more than 90 percent of required wiring by the heuristic method. The maze-running method finds an optimal path with respect to a performance function for each point-to-point, and point-to-line connection. It can bring the number of successful wiring connections very close to 100 percent.