ppxscal/embedding_network huggingface dataset:
Advances in Tangible Interaction and Ubiquitous Virtual Reality
Authors: Dongpyo Hong, Tobias Höllerer, Michael Haller, Haruo Takemura, Adrian David Cheok, Gerard Jounghyun Kim, Mark Billinghurst, Woontack Woo, Eva Hornecker, Robert J. K. Jacob, Caroline Hummels, Brygg Ullmer, Albrecht Schmidt, Elise van den Hoven, Ali Mazalek
Venue: IEEE Pervasive Computing (2008)

The first article reports on context-sensitive augmented-reality research presented at the 2007 International Symposium on Ubiquitous Virtual Reality. This student-organized event explored the use of contextual information, design principles, and effective user evaluation for developing AR applications for ubiquitous computing environments. The second article reports on The International Conference on Tangible and Embedded Interaction, the first conference series worldwide to focus on tangible and embedded interaction. The conference is interdisciplinary, covering the arts, hardware design, software toolkits for prototyping, and user studies and theory development.
The Components and Practice of Information Technology Governance
Authors: Wei Tu, Jinlong Zhang
Venue: Proceedings of the First International Workshop on Knowledge Discovery and Data Mining (2008)

Previous studies primarily focused on the IT decision allocation in Information Technology governance, this paper propose that IT governance is part of corporate governance, it is IT related decision making, motivation and constraint mechanism to work out the asymmetric information problem between shareholders and managers and to maximize IT revenue designed by shareholders-centered stakeholders. IT governance is the combine mechanism of the motivation mechanism, constraint mechanism and decision-making mechanism. This paper also investigate 11 companies around Wuhan ,China, and find IT governance exists and in the initial stage.
Efficient sample sizes in stochastic nonlinear programming
Authors: E. Polak, J. O. Royset
Venue: Journal of Computational and Applied Mathematics (2008)

We consider a class of stochastic nonlinear programs for which an approximation to a locally optimal solution is specified in terms of a fractional reduction of the initial cost error. We show that such an approximate solution can be found by approximately solving a sequence of sample average approximations. The key issue in this approach is the determination of the required sequence of sample average approximations as well as the number of iterations to be carried out on each sample average approximation in this sequence. We show that one can express this requirement as an idealized optimization problem whose cost function is the computing work required to obtain the required error reduction. The specification of this idealized optimization problem requires the exact knowledge of a few problems and algorithm parameters. Since the exact values of these parameters are not known, we use estimates, which can be updated as the computation progresses. We illustrate our approach using two numerical examples from structural engineering design.
Tree-width and functional dependencies in databases
Authors: Isolde Adler
Venue: Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2008)

Conjunctive query (CQ) evaluation on relational databases is NP-complete in general. Several restrictions, like bounded tree-width and bounded hypertree-width, allow polynomial time evaluations.We extend the framework in the presence of functional dependencies. Our exteAnded CQ evaluation problem has a concise equivalent formulation in terms of the homomorphism problem (HOM) for non-relational structures. We introduce the notions of "closure tree-width" and "hyperclosure tree-width" for arbitrary structures, and we prove that HOM (and hence CQ) restricted to bounded (hyper)closure tree-width becomes tractable. There are classes of structures with bounded closure tree-width but unbounded tree-width. Similar statements hold for hyperclosure tree-width and hypertree-width, and for hyperclosure tree-width and closure tree-width. It follows from a result by Gottlob, Miklós, and Schwentick that for fixed k ≥ 2, deciding whether a given structure has hyperclosure tree-width at most k, is NP-complete. We prove an analogous statement for closure tree-width. Nevertheless, for given k we can approximate k-bounded closure tree-width in polynomial time.
The role of market pricing mechanism under imperfect competition
Authors: Hossein Haghighat, Hossein Seifi, Ashkan Rahimi Kian
Venue: Decision Support Systems (2008)

This paper illustrates how a supplier profit may be affected by the market pricing mechanism under imperfect competition. A parameterized Supply Function Equilibrium (SFE) model involving manipulation of the sole intercept is used to represent the strategic behavior of each supplier. Through utilizing a bilevel optimization technique and a Mathematical Program with Equilibrium Constraints (MPECs) approach, market equilibria are calculated and compared under pay-as-bid pricing (PABP) and marginal pricing (MP) mechanisms. For an unconstrained case, analytically it is demonstrated that the optimal bidding strategy and the maximum profit of each supplier, as well as the market clearing price are the same under PABP and MP. The effects of the transmission limits and the supplier capacity constraints are discussed through numerical results.
Applying Unifying Theories Of Programming To Real-Time Programming
Authors: Alvaro E. Arenas, Juan C. Bicarregui
Venue: Journal of Integrated Design Process Science (2006)

This paper introduces an approach to verify the correctness of the implementation of real-time languages. We apply the techniques presented in Hoare and He's "Unifying Theories of Programming" to reason about the correctness of compilers and schedulers for real-time languages, using high-level abstractions such as algebraic laws. In the compilation process, the existence of unique fixed-points is exploited to verify the implementation of crucial real-time operators such as asynchronous input, delay and timeout. It is developed an abstract model for scheduling real-time programs into a uniprocessor machine. The applicability of the model is shown by instancing it with two types of schedulers: a round-robin scheduler, employed when the participating parallel processes do not include deadline constraints, and a priority-based scheduler, used when each participating process is periodic and possesses an associated deadline.
Improving Bayesian Network Structure Learning with Mutual Information-Based Node Ordering in the K2 Algorithm
Authors: Xue-Wen Chen, Gopalakrishna Anantha, Xiaotong Lin
Venue: IEEE Transactions on Knowledge and Data Engineering (2008)

Structure learning of Bayesian networks is a well-researched but computationally hard task. We present an algorithm that integrates an information theory-based approach and a scoring function-based approach for learning structures of Bayesian networks. Our algorithm also makes use of basic Bayesian network concepts like d-separation and Markov independence. We show that the proposed algorithm is capable of handling networks with a large number of variables. We present the applicability of the proposed algorithm on four standard network datasets and also compare its performance and computational efficiency with other standard structure learning methods. The experimental results show that our method can efficiently and accurately identify complex network structures from data.
A new method of data transformation for satellite images: I. Methodology and transformation equations for TM images
Authors: Z. Y. Zeng
Venue: International Journal of Remote Sensing (2007)

These two papers deal with a new method of data transformation. By analysing grey level curves (broken lines) of various ground features in image bands of different satellites, we have found that, inherent in 3-or 4-band satellite images (SPOT, IKONOS, Quick Bird, OrbView, FORMOSAT and MSS) there are three basic remote-sensing characteristics as follows: (1) the general radiance level L; (2) the visible-infrared radiation balance B; and (3) the band radiance variation vector (direction and speed) V. However, inherent in 5-or 7-band satellite images (NOAA, TM), besides the above three, there is an extra basic remote-sensing characteristic, i.e. the thermal radiation intensity I. This is denoted by thermal bands, i.e. the TM band 6 or NOAA (AVHRR) bands 4 and 5, which are relatively independent and can be used directly, and hence are unnecessary for information extraction or data transformation. Therefore, the data transformation only lies in extracting the L, B and V from original satellite images. Furthermore, we have also found that there are three basic ground-cover elements on the Earth's surface: i.e. the bare land (in a broad sense), the vegetation and the water body, which, in different proportions, constitute all ground cover. Moreover, there are three basic (primitive) colours on colour image (including colour composite of satellite images): i.e. red, green and blue, which generate all colours on the colour image. Further research has revealed that the three basic remote-sensing characteristics, the three basic ground-cover elements and the three basic colours on the composite can conceptually constitute a three-to-three corresponding regular triangle scheme. Perhaps a good method of data transformation should make the scheme realistic, i.e. make the three 'threes' all correspond to each other. The research presented here has completed this task by regression calculations and selection of specific variables. First, the methodology and transformation equations for TM images are discussed. The transformed L, B and V images have relatively independent and equally distributed information as well as clear and definite physical, mathematical and geographical significance. They can be used effectively for generating high-quality colour composites, on which the red, green, blue, yellow, pink, cyan and other colours of various kinds are all generated and all pure, saturated, equilibrated, meaning-definite and close to the colours of ground features in nature. As a result, interpretations and discriminations of ground features can be easier and conducted not only by experience, but also by logic. The L, B and V images can also be used effectively for classification and digital analysis of ground features. With regard to the transformation equations for SPOT, NOAA, IKONOS, Quick Bird, OrbView, FORMOSAT and MSS images and the method application will be dealt with in the second paper.
The Research on Game Model of Business Incubation Network Trust Problems under Electronic Commerce
Authors: Teng Heqiang, Zhang Daohong, Jiang Renguo
Venue: Proceedings of the First International Workshop on Knowledge Discovery and Data Mining (2008)

Firstly, this paper studies the credit mechanism of business incubation network under E-commerce, on the basis of credit mechanism. We put the method of building incubated enterprises virtual communities and customers virtual communities to increase the B to C e-commerce trust within the business incubation network. Then, on the basis of Game theory analysis the trigger policy of incubated enterprises' dishonesty on the incubation network virtual communities, designing stimulating mechanism and restraint mechanism to ensure enterprise sincere sale on the incubation network virtual communities.
A multi-dimensional approach to the construction and enumeration of Golay complementary sequences
Authors: Frank Fiedler, Jonathan Jedwab, Matthew G. Parker
Venue: Journal of Combinatorial Theory Series A (2008)

We argue that a Golay complementary sequence is naturally viewed as a projection of a multi-dimensional Golay array. We present a three-stage process for constructing and enumerating Golay array and sequence pairs:1.construct suitable Golay array pairs from lower-dimensional Golay array pairs; 2.apply transformations to these Golay array pairs to generate a larger set of Golay array pairs; and 3.take projections of the resulting Golay array pairs to lower dimensions. This process greatly simplifies previous approaches, by separating the construction of Golay arrays from the enumeration of all possible projections of these arrays to lower dimensions. We use this process to construct and enumerate all 2^h-phase Golay sequences of length 2^m obtainable under any known method, including all 4-phase Golay sequences obtainable from the length 16 examples given in 2005 by Li and Chu [Y. Li, W.B. Chu, More Golay sequences, IEEE Trans. Inform. Theory 51 (2005) 1141-1145].
Performances comparison of pulse-pair and 2-step prediction algorithms for the doppler spectrum estimation
Authors: Mohand Lagha, Messaoud Bensebti
Venue: Multidimensional Systems and Signal Processing (2008)

In this work we use real data provided by terminal pulse Doppler radar (WSR-88D) echoes to estimate the windshear hazards disastrous for the aircraft takeoffs and landings. Briefly two different methods are used to estimate the received Doppler moments. The second central moment which is the variance of the wind speed is called width or shear. A first method is in the time domain and also called pulse-pair, while the second is in the frequency domain. The main aim of this study is a performances comparison of results provided by the two mentioned methods and assumes that the power spectrums of the received signals are approached with the Gaussian shape.
Establishing a Consistent Curriculum in a Distributed Campus Environment: Lessons Learned while Moving Towards Accreditation
Authors: Janet L. Kourik, Peter Maher
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

We report on efforts to communicate and ensure a consistent curriculum in a distributed university setting for a school of business and technology. The school’s programs and courses are delivered via 100+ physical campuses throughout the world. Many programs, including the largest, are also delivered via on-line distance learning. The paper examines issues and requirements about what information to communicate for each course and describes a system for communicating curriculum information in this diverse educational environment. The contribution of the new curriculum system in assessment and accreditation are discussed. Findings and recommendations are presented.
On the relative value of local scheduling versus routing in parallel server systems
Authors: Rong Wu, Douglas G. Down
Venue: Proceedings of the 13th International Conference on Parallel and Distributed Systems - Volume 01 (2007)

We consider a system with a dispatcher and several identical servers in parallel. Task processing times are known upon arrival. We first study the impact of the local scheduling policy at a server. To this end, we study random routing followed by a priority scheme at each server. Our numerical results show that the performance (mean waiting time) of such a policy could be significantly better than the best known suggested policies that use FCFS at each server. We then propose to use multi-layered round robin routing, which is shown to further improve system performance. Our analysis involves a combination of comparing analytic models, heavy traffic asymptotic and numerical work.
Evaluating the use of a audio-video mobile phone for web magazine reporters
Authors: Seamus Hickey, Carolina Rosa, Minna Isomursu
Venue: Proceedings of the 4th international conference on mobile technology, applications, and systems and the 1st international symposium on Computer human interaction in mobile technology (2007)

This paper describes the usability issues encountered by Web reporters in the production of video reports using mobile Smartphones. It examines their ability to use the Smartphone to capture video and editing tools used to alter the video content before publication on the web. The purpose was to understand the usefulness of the technology, whether the devices are usable, useful, add value, improve the reporters work routines. The study was carried out as a case study with participants from two web magazines. The study showed that the video quality, the distraction of operating the phones and support structure were negative aspects, while the reporters saw value in the audio recording capability, usefulness of the phone and the ability to catch breaking news activities. The reporters also wanted accessories like microphones to enhance usability.
Terracost: Computing least-cost-path surfaces for massive grid terrains
Authors: Thomas Hazel, Laura Toma, Jan Vahrenhold, Rajiv Wickremesinghe
Venue: Journal of Experimental Algorithmics (JEA) (2008)

This paper addresses the problem of computing least-cost-path surfaces for massive grid terrains. Consider a grid terrain T and let C be a cost grid for T such that every point in C stores a value that represents the cost of traversing the corresponding point in T. Given C and a set of sources S &isin; T, a least-cost-path grid &Delta; for T is a grid such that every point in &Delta; represents the distance to the source in S that can be reached with minimal cost. We present a scalable approach to computing least-cost-path grids. Our algorithm, terracost, is derived from our previous work on I/O-efficient shortest paths on grids and uses O(sort(n)) I/Os, where sort(n) is the complexity of sorting n items of data in the I/O-model of Aggarwal and Vitter. We present the design, the analysis, and an experimental study of terracost. An added benefit of the algorithm underlying terracost is that it naturally lends itself to parallelization. We have implemented terracost in a distributed environment using our cluster management tool and report on experiments that show that it obtains speedup near-linear with the size of the cluster. To the best of our knowledge, this is the first experimental evaluation of a multiple-source least-cost-path algorithm in the external memory setting.
DEDiscover: A Computation and Simulation Tool for HIV Viral Fitness Research
Authors: Hulin Wu, Ongyu Miao, Gregory R. Warnes, Canglin Wu, Alain LeBlanc, Carrie Dykes, Lisa M. Demeter
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 01 (2008)

Viral fitness is one of the most important areas in HIV virology research. Modeling viral fitness poses significant computational challenges which must be solved in order to appropriately design and analyze experimental data. To facilitate the HIV viral fitness research, we have designed a computation and simulation tool, DEDiscover, to deal with both simulation and estimation problems for ordinary and delay differential equation models. In this paper, we describe the design and features of DEDiscover and demonstrate how it may be used to analyze the results of an HIV viral fitness experiment.
A dynamically-allocated virtual channel architecture with congestion awareness for on-chip routers
Authors: Mingche Lai, Zhiying Wang, Lei Gao, Hongyi Lu, Kui Dai
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

In this paper, the dynamically-allocated virtual channels (VCs) architecture with congestion awareness is introduced. All the buffers are shared among VCs whose structure varies with traffic condition. In low rate, this structure extends VC depth for continual transfers to reduce packet latencies. In high rate, it dispenses many VCs and avoids congestion situations to improve the throughput. We modify the VC controller and VC allocation modules, while designing simple congestion avoidance logic. The experiment shows that the proposed routers outperform conventional ones under different traffic patterns. They provide 8.3% throughput increase and 19.6% latency decrease while saving 27.4% of area and 28.6% of power.
Improving fairness among TCP flows by stateless buffer control with early drop maximum
Authors: Hsu-Sheng Tsai, Wei Kuang Lai
Venue: Information Sciences: an International Journal (2008)

Transmission control protocol (TCP) has been recognized as the most important transport-layer protocol for the Internet. It is distinguished by its reliable transmission, flow control, and congestion control. However, the issue of fair bandwidth-sharing among competing flows was not properly addressed in TCP. As web-based applications and interactive applications grow more popular, the number of short-lived flows conveyed on the Internet continues to rise. With conventional TCP, short-lived flows will be unable to obtain a fair share of available bandwidth. As a result, short-lived flows will suffer from longer delays and a lower service rate. It is essential for the Internet to come up with an effective solution to this problem in order to accommodate the new traffic patterns. With a more equitable sharing of bottleneck bandwidth as its goal, a stateless queue management scheme featuring early drop maximum (EDM) is developed and presented in this article. The fundamental idea is to drop packets from those flows having more than an equal share of bandwidth. The congestion window size of a TCP sender is carried in the options field on each packet. The proposed scheme will be exercised on routers and make its decision on packet dropping according to the congestion windows. In case of link congestion, the queued packet with the largest congestion window will be dropped from the queue. This will lower the sending rate of its sender and release part of the occupied bandwidth for the use of other competing flows. By so doing, the entire system will approach an equilibrium point with a rapid and fair distribution of bandwidth. As a stateless approach, the proposed scheme inherits numerous advantages in implementation and scalability. Extensive simulations were conducted to verify the feasibility and the effectiveness of the proposed approach. As revealed in the simulation results, the proposed scheme outperforms existing stateless techniques, including Drop-Tail and Random Early Drop, in many respects, such as a fairer sharing of available bandwidth and a shorter response time for short-lived flows.
A modified Newton--Lavrentiev regularization for nonlinear ill-posed Hammerstein-type operator equations
Authors: Santhosh George, M. Thamban Nair
Venue: Journal of Complexity (2008)

Recently, a new iterative method, called Newton-Lavrentiev regularization (NLR) method, was considered by George (2006) for regularizing a nonlinear ill-posed Hammerstein-type operator equation in Hilbert spaces. In this paper we introduce a modified form of the NLR method and derive order optimal error bounds by choosing the regularization parameter according to the adaptive scheme considered by Pereverzev and Schock (2005).
Digraph measures: Kelly decompositions, games, and orderings
Authors: Paul Hunter, Stephan Kreutzer
Venue: Theoretical Computer Science (2008)

We consider various well-known, equivalent complexity measures for graphs such as elimination orderings, k-trees and cops and robber games and study their natural translations to digraphs. We show that on digraphs the translations of these measures are also equivalent and induce a natural connectivity measure. We introduce a decomposition for digraphs and an associated width, Kelly-width, which is equivalent to the aforementioned measure. We demonstrate its usefulness by exhibiting potential applications including polynomial-time algorithms for NP-complete problems on graphs of bounded Kelly-width, and complexity analysis of asymmetric matrix factorization. Finally, we compare the new width to other known decompositions of digraphs.