ppxscal/embedding_network huggingface dataset:
Generalizations of the Statement of Compensator Realizability at the System Input
Authors: V. N. Bukov, V. N. Ryabchenko
Venue: Automation and Remote Control (2003)

Consideration was given to transformation (realizability) of the equivalent compensator at the input of a linear system into a feedback control law. By using the system embedding technology, unique results were obtained for the matrix quotients which enabled one to formulate and prove new assertions which in part contradict the existing results and, in contrast to them, are valid also for the nonregular (degenerate) compensators, as well as for the plants with redundant (dependent) control inputs. Illustrative examples were given.
Observational Equivalence of 3rd-Order Idealized Algol is Decidable
Authors: C.-H. Luke Ong
Venue: Proceedings of the 17th Annual IEEE Symposium on Logic in Computer Science (2002)

We prove that observational equivalence of 3rd-order finitary Idealized Algol (IA) is decidable using Game Semantics. By modelling state explicitly in our games, we show that the denotation of a term M of this fragment of IA (built up from finite base types) is a compactly innocent strategy-with-state i.e. the strategy is generated by a finite view function fM . Given any such fM , we construct a real-time deterministic pushdown automata (DPDA) that recognizes the complete plays of the knowing-strategy denotation of M. Since such plays characterize observational equivalence, and there is an algorithm for deciding whether any two DPDAs recognize the same language, we obtain a procedure for deciding observational equivalence of 3rd-order finitary IA. This algorithmic representation of program meanings, which is compositional, provides a foundation for model-checking a wide range of behavioural properties of IA and other cognate programming languages. Another result concerns 2nd-order IA with recursion: we show that observational equivalence for this fragment is undecidable.
Uniform characterizations of polynomial-query learnabilities
Authors: Yosuke Hayashi, Satoshi Matsumoto, Ayumi Shinohara, Masayuki Takeda
Venue: Theoretical Computer Science (2003)

We consider the exact learning in the query model. We deal with all types of queries introduced by Angluin: membership, equivalence, superset, subset, disjointness and exhaustiveness queries, and their weak (or restricted) versions where no counterexample is returned. For each of all possible combinations of these queries, we uniformly give complete characterizations of boolean concept classes that are learnable using a polynomial number of polynomial-sized queries. Our characterizations show the equivalence between the learnability of a concept class C using queries and the existence of a good query for any subset H of C which is guaranteed to reject a certain fraction of candidate concepts in H regardless of the answer. As a special case for equivalence queries alone, our characterizations directly correspond to the lack of the approximate fingerprint property, which is known to be a sufficient and necessary condition for the learnability using equivalence queries.
Commentary: a New Horizon for Or/Ms
Authors: Arthur M. Geoffrion
Venue: INFORMS Journal on Computing (1998)

The Web creates important OR/MS opportunities, and the Bhargava-Krishnan feature article does an outstanding job of sketching some of them and of explaining the technicalities of how the Web can be used in the service of OR/MS. This commentary discusses briefly two points made in the article, and then calls attention to a new domain for OR/MS applications. This domain arises from a new and potentially large Web clientele for OR/MS that seems to have escaped notice to date: ordinary people. Satisfying this new clientele requires exactly the technologies explained by Bhargava and Krishnan. Doing so would pump new vigor into the field, directly benefit many people who use the Web, and help solve the long-standing public visibility problems of the field.
Optimal Policies for Multi-Echelon Inventory Problems with Batch Ordering
Authors: Fangruo Chen
Venue: Operations Research (2000)

In many production/distribution systems, materials flow from one stage to another in fixed lot sizes. For example, a retailer orders a full truckload from a manufacturer to qualify for a quantity discount; a factory has a material handling system that moves full containers of parts from one production stage to the next. In this paper, we derive optimal policies for multi-stage serial and assembly systems where materials flow in fixed batches. The optimal policies have a simple structure, and their parameters can be easily determined. This research extends the multi-echelon inventory theory in several ways. It generalizes the Clark-Scarf model by allowing batch transfers of inventories. Rosling (1989) shows that assembly systems can be interpreted as serial systems under the assumption that there are no setup costs. We show that the series interpretation still holds when materials flow in fixed batches which satisfy a certain regularity condition. Finally, Veinott (1965) identifies an optimal policy for a single-location inventory system with batch ordering. This paper generalizes his result to multi-echelon settings.
Rijndael FPGA Implementations Utilising Look-Up Tables
Authors: Máire McLoone, John V. McCanny
Venue: Journal of VLSI Signal Processing Systems (2003)

This paper presents single-chip FPGA Rijndael algorithm implementations of the Advanced Encryption Standard (AES) algorithm, Rijndael. In particular, the designs utilise look-up tables to implement the entire Rijndael Round function. A comparison is provided between these designs and similar existing implementations. Hardware implementations of encryption algorithms prove much faster than equivalent software implementations and since there is a need to perform encryption on data in real time, speed is very important. In particular, Field Programmable Gate Arrays (FPGAs) are well suited to encryption implementations due to their flexibility and an architecture, which can be exploited to accommodate typical encryption transformations. In this paper, a Look-Up Table (LUT) methodology is introduced where complex and slow operations are replaced by simple LUTs. A LUT-based fully pipelined Rijndael implementation is described which has a pre-placement performance of 12 Gbits/sec, which is a factor 1.2 times faster than an alternative design in which look-up tables are utilised to implement only one of the Round function transformations, and 6 times faster than other previous single-chip implementations. Iterative Rijndael implementations based on the Look-Up-Table design approach are also discussed and prove faster than typical iterative implementations.
Comments on the evaluation of policy models
Authors: Clive W. J. Granger, Melinda Deutsch
Venue: Essays in econometrics: Spectral analysis, seasonality, nonlinearity, methodology, and forecasting (2001)

This paper examines the evaluation of models claimed to be relevant for policy making purposes. A number of tests are proposed to determine the usefulness of such models in the policy making process. These tests are applied to three empirical examples.
Haptic rendering techniques for the interactive exploration of CFD datasets in virtual environments
Authors: T. van Reimersdahl, F. Bley, T. Kuhlen, C. H. Bischof
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

In pure CFD visualization tools, some flow features are hard to visualize such as the properties of a local flow probe. Haptic rendering techniques offer an intuitive understanding and allow more detailed insights than the visual perception solely. In our application framework ViSTA FlowLib for the interactive visualization and exploration of unsteady flows in virtual environments we implemented haptic rendering techniques as an add-on feature for the commonly used visualization algorithms for scalar and vector fields. We extended the ideas of Pao and Lawrence and developed new promising techniques.
Wireless sensor networks: a new regime for time synchronization
Authors: Jeremy Elson, Kay Römer
Venue: ACM SIGCOMM Computer Communication Review (2003)

Wireless sensor networks (WSNs) consist of large populations of wirelessly connected nodes, capable of computation, communication, and sensing. Sensor nodes cooperate in order to merge individual sensor readings into a high-level sensing result, such as integrating a time series of position measurements into a velocity estimate. The physical time of sensor readings is a key element in this process called data fusion. Hence, time synchronization is a crucial component of WSNs. We argue that time synchronization schemes developed for traditional networks such as NTP [23] are ill-suited for WSNs and suggest more appropriate approaches.
The complexity of XPath query evaluation
Authors: Georg Gottlob, Christoph Koch, Reinhard Pichler
Venue: Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2003)

In this paper, we study the precise complexity of XPath 1.0 query processing. Even though heavily used by its incorporation into a variety of XML-related standards, the precise cost of evaluating an XPath query is not yet wellunderstood. The first polynomial-time algorithm for XPath processing (with respect to combined complexity) was proposed only recently, and even to this day all major XPath engines take time exponential in the size of the input queries. From the standpoint of theory, the precise complexity of XPath query evaluation is open, and it is thus unknown whether the query evaluation problem can be parallelized.In this work, we show that both the data complexity and the query complexity of XPath 1.0 fall into lower (highly parallelizable) complexity classes, but that the combined complexity is PTIME-hard. Subsequently, we study the sources of this hardness and identify a large and practically important fragment of XPath 1.0 for which the combined complexity is LOGCFL-complete and, therefore, in the highly parallelizable complexity class NC2.
Stability of Some Difference Equations with Two Delays
Authors: M. M. Kipnis, R. M. Nigmatulin
Venue: Automation and Remote Control (2003)

In the framework of the general problem for clarifying the stability of the zero solution of the equation x(n) = a1x(n &ndash; m) &ndash; a2x(n &ndash; k) with delays k and m, some partial problems are solved. An appreciable dependence of the stability on the divisibility of one delay by the other is revealed.
Constructing exact octagonal steiner minimal trees
Authors: Chris S. Coulston
Venue: Proceedings of the 13th ACM Great Lakes symposium on VLSI (2003)

Octagonal Steiner Minimal Trees (OSMTs) are used in the global routing phase of pervasive octagonal VLSI layout. The OSMT problem seeks a minimal length spanning structure using edges composed of line segments having one of four equally spaced orientations. The concept of a canonical form is introduced providing a strong framework for the structure and characteristics of OSMTs. An exact algorithm and a variety of pruning techniques are introduced. Random and OR Library instances are solved and compared against rectilinear and Euclidean SMTs. These experiments demonstrate the utility of pervasive octagonal routing, showing that octagonal SMTs are consistently 10% smaller than rectilinear SMTs.
Jazz Improvisation and Organizing: Once More from the Top
Authors: Michael H. Zack
Venue: Organization Science (2000)

This is a response to the special issue ofOrganization Science on Jazz Improvisation and Organizing (Vol. 9, No. 5, 1998). It is a call to unpack the jazz metaphor by extending the notion of jazz, and thereby the value of the metaphor, beyond the limited definition described in the issue. In that issue, jazz was described as a process of improvising within a highly constrained structure and set of rules. Other genres of jazz, however, have gone beyond those constraints. Jazz improvisation has occurred within forms, with forms, and beyond forms. Perhaps organizational improvisation may as well.
Spatial inhomogenity due to Turing bifurcation in a system of Gierer-Meinhardt type
Authors: Sándor Kovács
Venue: The Korean Journal of Computational Applied Mathematics (2003)

This paper treats the conditions for the existence and stability properties of stationary solutions of reaction-diffusion equations of Gierer-Meinhardt type, subject to Neumann boundary data. The domains in which diffusion takes place are of three types: a regular hexagon, a rectangle and an isosceles rectangular triangle. Considering one of the relevant features of the domains as a bifurcation parameter it will be shown that at a certain critical value a diffusion driven instability occurs and Turing bifurcation takes place: a pattern emerges.
Conditional tests for elliptical symmetry
Authors: Li-Xing Zhu, Georg Neuhaus
Venue: Journal of Multivariate Analysis (2003)

In this paper, we suggest the conditional test procedures for testing elliptical symmetry of multivariate distribution. The conditional tests are exactly valid if the symmetric center and the shape matrix are given and are asymptotically valid if they are unknowns to be estimated. The equivalence, in the large sample sense, between the conditional tests and their unconditional counterparts is established The power behavior of the tests under global as well as local alternatives is investigated theoretically. A small simulation study is performed.
Region proximity in metric spaces and its use for approximate similarity search
Authors: Giuseppe Amato, Fausto Rabitti, Pasquale Savino, Pavel Zezula
Venue: ACM Transactions on Information Systems (TOIS) (2003)

Similarity search structures for metric data typically bound object partitions by ball regions. Since regions can overlap, a relevant issue is to estimate the proximity of regions in order to predict the number of objects in the regions' intersection. This paper analyzes the problem using a probabilistic approach and provides a solution that effectively computes the proximity through realistic heuristics that only require small amounts of auxiliary data. An extensive simulation to validate the technique is provided. An application is developed to demonstrate how the proximity measure can be successfully applied to the approximate similarity search. Search speedup is achieved by ignoring data regions whose proximity to the query region is smaller than a user-defined threshold. This idea is implemented in a metric tree environment for the similarity range and "nearest neighbors" queries. Several measures of efficiency and effectiveness are applied to evaluate proposed approximate search algorithms on real-life data sets. An analytical model is developed to relate proximity parameters and the quality of search. Improvements of two orders of magnitude are achieved for moderately approximated search results. We demonstrate that the precision of proximity measures can significantly influence the quality of approximated algorithms.
Inductive verification of smart card protocols
Authors: Giampaolo Bella
Venue: Journal of Computer Security (2003)

An existing approach based on induction and theorem proving is tailored to the verification of security protocols that make use of smart cards. Smart cards are modelled operationally, hence only their functionalities, rather than their implementative technicalities, are of interest. The spy can steal certain smart cards, and clone others while learning their stored secrets. In terms of generality, the approach scales up to protocols that assume secure or insecure means between agents and smart cards, as well as to smart cards being PIN-operated or PIN-less. In terms of extensibility, new, application-dependent smart card functionalities can be easily included.The approach is demonstrated on the key distribution protocol designed by Shoup and Rubin [30], and the assumptions are studied that are necessary on the smart cards for the protocol goals to be met. It is found that, if the data buses of the smart cards are unreliable as to produce outputs in an unspecified order, then the protocol does not confirm to the peers its goals of confidentiality, authentication, and key distribution because of lack of explicitness. A simple fix is introduced and proved.
Update propagation strategies to improve freshness in lazy master replicated databases
Authors: Esther Pacitti, Eric Simon
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2000)

Many distributed database applications need to replicate data to improve data availability and query response time. The two-phase commit protocol guarantees mutual consistency of replicated data but does not provide good performance. Lazy replication has been used as an alternative solution in several types of applications such as on-line financial transactions and telecommunication systems. In this case, mutual consistency is relaxed and the concept of freshness is used to measure the deviation between replica copies. In this paper, we propose two update propagation strategies that improve freshness. Both of them use immediate propagation: updates to a primary copy are propagated towards a slave node as soon as they are detected at the master node without waiting for the commitment of the update transaction. Our performance study shows that our strategies can improve data freshness by up to five times compared with the deferred approach.
Disjoint cocircuits in matroids with large rank
Authors: James F. Geelen, A. M. H. Gerards, Geoff Whittle
Venue: Journal of Combinatorial Theory Series B (2003)

We prove that, for any positive integers n, k and q, there exists an integer R such that, if M is a matroid with no M(Kn)- or U2,q+2-minor, then either M has a collection of k disjoint cocircuits or M has rank at most R. Applied to the class of cographic matroids, this result implies the edge-disjoint version of the Erdös-Pósa Theorem.
Reducing the time complexity of the derandomized evolution strategy with covariance matrix adaptation (CMA-ES)
Authors: Nikolaus Hansen, Sibylle D. Müller, Petros Koumoutsakos
Venue: Evolutionary Computation (2003)

This paper presents a novel evolutionary optimization strategy based on the derandomized evolution strategy with covariance matrix adaptation (CMA-ES). This new approach is intended to reduce the number of generations required for convergence to the optimum. Reducing the number of generations, i.e., the time complexity of the algorithm, is important if a large population size is desired: (1) to reduce the effect of noise; (2) to improve global search properties; and (3) to implement the algorithm on (highly) parallel machines. Our method results in a highly parallel algorithm which scales favorably with large numbers of processors. This is accomplished by efficiently incorporating the available information from a large population, thus significantly reducing the number of generations needed to adapt the covariance matrix. The original version of the CMA-ES was designed to reliably adapt the covariance matrix in small populations but it cannot exploit large populations efficiently. Our modifications scale up the efficiency to population sizes of up to 10n, where n is the problem dimension. This method has been applied to a large number of test problems, demonstrating that in many cases the CMA-ES can be advanced from quadratic to linear time complexity.
Investigating the effects of downsizing on software professionals' self-efficacy and its consequences on software development quality
Authors: Ananth Chiravuri, Paul Ambrose
Venue: Proceedings of the 2003 SIGMIS conference on Computer personnel research: Freedom in Philadelphia--leveraging differences and diversity in the IT workforce (2003)

This study primarily examines the effects of downsizing on the self-efficacy of software professionals. We argue that downsizing results in a realignment of social networks, thereby affecting the self-efficacy and the outcome expectations of a software professional, which in turn affects software development quality. We synthesize relevant literature from self-efficacy, outcome expectations, downsizing and software quality research streams and develop a conceptual model linking these variables of interest.
Modified Kadomtsev-Petviashvili (MKP) equation and electromagnetic soliton
Authors: V. Veerakumar, M. Daniel
Venue: Mathematics and Computers in Simulation (2003)

We study the propagation of electromagnetic wave (EMW) in an isotropic charge-free infinite ferromagnetic thin film by solving the associated coupled Maxwell and Landau-Lifshitz (LL) equations in (2 + 1) dimensions using a reductive perturbation method. The dynamical equations reduce to the modified Kadomtsev-Petviashvili-II (MKP-II) equation which admits line and lump solitons in addition to breathers. The results show that the magnetisation of the medium is excited in the form of solitons and also the magnetic field component of the propagating EMW is modulated in the form of solitons.
Contextual Confidence and Active Trust Development in the Chinese Business Environment
Authors: John Child, Guido Möllering
Venue: Organization Science (2003)

This paper contributes to the conceptual and empirical understanding of organizational trust. It confirms the importance of "contextual confidence" in institutions for building trust. Moreover, it extends models of trust production to include the effects of purposive action by the truster over and above the contextual prediction of trust emphasized in previous research. Accordingly, "active trust development" is conceptualized as a strategy to strengthen the basis for trust. Empirical evidence is drawn from a survey of 615 Hong Kong firms that manage operations in mainland China.Confidence in China's institutional context was found to have a strong positive association with trust in the local staff working within that context. Active trust development was validated as a means of enhancing trust, though its effect on trust was not as strong as that of perceived institutional effectiveness.Active trust development initiatives are particularly valuable in an environment such as contemporary China, where the institutional foundations for trust remain underdeveloped. The positive correlation of trust with organizational performance provides an incentive for managers to explore these initiatives. At the same time, government and other bodies in China and elsewhere, which are in a position to create and promote effective institutions, are encouraged to intensify their efforts in that direction.