ppxscal/embedding_network huggingface dataset:
A Precise and Automatic Gridding Approach to Noise-Affected and Distorted Microarray Images
Authors: Eleni Zacharia, Dimitris Maroulis
Venue: Proceedings of the 2008 21st IEEE International Symposium on Computer-Based Medical Systems (2008)

In this paper, a precise and fully-automatic approach to the determination of the grid alignment (Gridding) on microarray images is presented. The proposed approach is compared to state-of-the-art software programs and techniques. The conducted experiments demonstrate that it is very effective even when it is applied to noisy or distorted images as well as to images containing spots with various intensities.
Finding Optimal Flows Efficiently
Authors: Mehdi Mhalla, Simon Perdrix
Venue: Proceedings of the 35th international colloquium on Automata, Languages and Programming, Part I (2008)

Among the models of quantum computation, the One-way Quantum Computer [11,12] is one of the most promising proposals of physical realisation [13], and opens new perspectives for parallelisation by taking advantage of quantum entanglement [2]. Since a One-way QC is based on quantum measurement, which is a fundamentally nondeterministic evolution, a sufficient condition of global determinism has been introduced in [4] as the existence of a causal flow in a graph that underlies the computation. A O(n 3)-algorithm has been introduced [6] for finding such a causal flow when the numbers of output and input vertices in the graph are equal, otherwise no polynomial time algorithm was known for deciding whether a graph has a causal flow or not. Our main contribution is to introduce a O(m)-algorithm for finding a causal flow (where m is the number of edges of the graph), if any, whatever the numbers of input and output vertices are. This answers the open question stated by Danos and Kashefi [4] and by de Beaudrap [6]. Moreover, we prove that our algorithm produces a flow of minimal depth.Whereas the existence of a causal flow is a sufficient condition for determinism, it is not a necessary condition. A weaker version of the causal flow, called gflow (generalised flow) has been introduced in [3] and has been proved to be a necessary and sufficient condition for a family of deterministic computations. Moreover the depth of the quantum computation is upper bounded by the depth of the gflow. However the existence of a polynomial time algorithm that finds a gflow has been stated as an open question in [3]. In this paper we answer this positively with a polynomial time algorithm that outputs an optimal gflow of a given graph and thus finds an optimal correction strategy to the nondeterministic evolution due to measurements.
A Semi-blind Complex ICA Algorithm for Extracting a Desired Signal Based on Kurtosis Maximization
Authors: Jun-Yu Chen, Qiu-Hua Lin
Venue: Proceedings of the 5th international symposium on Neural Networks: Advances in Neural Networks, Part II (2008)

Semi-blind independent component analysis (ICA) incorporates some prior information into standard blind ICA, and thus solves some problems of blind ICA as well as provides improved performance. However, semi-blind algorithms thus far have been much focused on the separation of real-valued signals but little on separation of complex-valued signals. We propose in this paper a semi-blind complex ICA algorithm for extracting a complex-valued source of interest within the framework of constrained ICA. Specifically, magnitude information about the desired signal is utilized as inequality constraint to the cost function of kurtosis maximization algorithm, which is an efficient complex ICA algorithm for separating circular and noncircular sources. The simulation results demonstrate that the proposed algorithm can extract a desired complex signal with much improved performance and robustness.
Sobolev norms of holomorphic sections and variations of the density of states
Authors: Duong Phong
Venue:  (2008)

This thesis considers two questions related to the geometry of sections of a holomorphic line bundle over a compact K&auml;hler manifold. First, we derive general L2 Sobolev bounds for holomorphic sections of a power of a holomorphic line bundle over a compact K&auml;hler manifold. We use these bounds to derive a general C0 bound for holomorphic sections. The Sobolev bounds are shown to be sharp by considering the case of n-dimensional complex projective space, however, consideration of the Tian-Yau-Zelditch Theorem shows that, under the more restrictive conditions of that theorem, the C0 bounds can be improved. Second, we examine the evolution of a metric on a holomorphic line bundle within the space of K&auml;hler potentials and derive a general variational formula for the associated density of states function. As an example, we apply this formula to the case in which the metric evolves by the K&auml;hler-Ricci flow.
Fuzzy Extension of Estimations with Randomness: The Perception-Based Approach
Authors: Yuji Yoshida
Venue: Proceedings of the 4th international conference on Modeling Decisions for Artificial Intelligence (2007)

A set of perceived random events is given by a fuzzy random variable, and its estimation is represented by a functional on real random variables. The estimation of the perception regarding random events is obtained, extending the functional to a functional of fuzzy random variables. This paper discusses conditions and various properties of perception-based extension of estimations with randomness, and several examples of the perception-based extension are investigated. The results can be applied other estimations in engineering, economics and so on.
Image Registration by Contour Matching Using Tangent Angle Histogram
Authors: Xiangyu Yu, Lihua Guo
Venue: Proceedings of the 2008 Congress on Image and Signal Processing, Vol. 4 - Volume 04 (2008)

Image registration is a fundamental task in image processing. In this paper, a novel contour-based image registration approach is proposed for images with affine distortion. In the proposed algorithm, the normalized histogram formed by the tangent angle of the contour is constituted. The peak in the circular correlation result of these two histograms indicates the rotational difference between images. Other affine parameters are determined using the ratio of length of contour and the position translation of centroids, thus the coarse registration result is determined. After refinement, the final registration result is acquired. The contour matching algorithm proposed in the paper can be used for both open and closed contour. Experimental results demonstrated that this approach is an effective way to register images automatically.
Geometric and topological approaches to semantic text retrieval
Authors: Chung-Ping Kwong
Venue:  (2007)

With the vast amount of textual information available today, the task of designing effective and efficient retrieval methods becomes more important and complex. The Basic Vector Space Model (BVSM) is well known in information retrieval. Unfortunately, it can not retrieve all relevant documents since it is based on literal term matching. The Generalized Vector Space Model (GVSM) and the Latent Semantic Indexing (LSI) are two famous semantic retrieval methods, in which some underlying latent semantic structures in the dataset are assumed. However, their assumptions about where the semantic structure locates are a bit strong. Moreover, the performance of LSI can be very different for various datasets and the questions of what characteristics of a dataset and why these characteristics contribute to this difference have not been fully understood. The present thesis focuses on providing answers to these two questions. In the first part of this thesis, we present a new understanding of the latent semantic space of a dataset from the dual perspective, which relaxes the above assumed conditions and leads naturally to a unified kernel function for a class of vector space models. New semantic analysis methods based on the unified kernel function are developed, which combine the advantages of LSI and GVSM. We also show that the new methods possess the stable property on the rank choice, i.e., even if the selected rank is quite far away from the optimal one, the retrieval performance will not degrade much. The experimental results of our methods on the standard test sets are promising. In the second part of this thesis, we propose that the mathematical structure of simplexes can be attached to a term-document matrix in the vector-space model (VSM) for information retrieval. The Q-analysis devised by R. H. Atkin may then be applied to effect an analysis of the topological structure of the simplexes and their corresponding dataset. Experimental results of this analysis reveal that there is a correlation between the effectiveness of LSI and the topological structure of the dataset. By using the information obtained from the topological analysis, we develop a new query expansion method. Experimental results show that our method can enhance the performance of VSM for datasets over which LSI is not effective. Finally, the notion of homology is introduced to the topological analysis of datasets and its possible relation to word sense disambiguation is studied through a simple example.
Transnational Support to Visually Impaired in Scientific University Courses
Authors: Cristian Bernareggi, Barbara Hengstberger, Valeria Brigatti
Venue: Proceedings of the 11th international conference on Computers Helping People with Special Needs (2008)

Blind and visually impaired students seldom choose to attend university technical or scientific courses. The major problems concern access to scientific documentation, to scientific software and getting advantage of attending lessons. Many solutions exist, but they are often available or known at national level. This paper introduces the @science thematic network, which aims at collecting and documenting pratices and experiences at transnational level to facilitate blind and visually impaired students to go through scientific studies at university.
A multiple case study investigating the interaction between manufacturing and development organizations in automotive software engineering
Authors: Joakim Pernstål, Ana Magazinovic, Peter Öhman
Venue: Proceedings of the Second ACM-IEEE international symposium on Empirical software engineering and measurement (2008)

As most future automotive innovations will be realized with software, the automotive industry is facing a transition from mechanical to software engineering. To achieve successful product launches, this is also true for manufacturing engineering. This paper presents an empirical study of the interaction between the organizations for product development and manufacturing, specifically focusing on automotive software engineering. It is presented as a multiple case study with a qualitative approach where data were collected from documents and in interviews with practioners at two Swedish automotive companies. To obtain validity of the results, multiple information sources were triangulated in within-case analysis and cross-case analysis. It can be concluded that there are challenges in the research area since 18 issues emerged from the data. Furthermore, a majority of the findings were supported by data sources from both cases, which indicates a possibility to generalize the results to the automotive domain.
An efficient low-complexity joint multi-user power control and partial crosstalk cancellation in xDSL systems
Authors: M. Measoumi, M. A. Masnadi-Shirazi
Venue: Proceedings of the 7th WSEAS International Conference on Instrumentation, Measurement, Circuits and Systems (2008)

Perfect crosstalk cancellation techniques have been proposed to mitigate the effect of crosstalk. However, the online complexity of these crosstalk cancellation techniques grows with the square of the number of lines in the binder. Fortunately, most of the crosstalk originates from a limited number of lines on a limited number of tones. As a result, a fraction of the complexity of perfect crosstalk cancellation suffices to cancel most of the crosstalk. This is known as partial crosstalk cancellation. Because the crosstalk profile changes over time, there is additional requirement that partial crosstalk cancellation provide a very low pre-processing complexity. Also, a much lower online complexity can be obtained if the multi-user power control and partial crosstalk cancellation problems are solved jointly. Currently, this joint problem is formulated as a constrained optimization problem and solved by employing Lagrange dual decomposition method. However, it suffers from per-tone exhaustive search because of non-convexity of its per-tone problem. This paper presents a solution for the joint multi-user power control and partial crosstalk cancellation problem with significantly lower pre-processing complexity than the currently proposed algorithms. The problem is considered as a mixed binary-non-convex problem. Then it is reformulated as a mixed binary-convex problem via a successive convex relaxation. Finally it is solved by an efficient branch and bound method. The complexity analysis of our algorithm shows that it provide much lower pre-processing complexity than currently proposed algorithms, allowing it to work efficiently in time-varying crosstalk environment. Moreover, the analytical and simulation results demonstrate that our algorithm is close to the optimal solution from the crosstalk cancellation point of view.
Image Tagging Using PageRank over Bipartite Graphs
Authors: Christian Bauckhage
Venue: Proceedings of the 30th DAGM symposium on Pattern Recognition (2008)

We consider the problem of automatic image tagging for online services and explore a prototype-based approach that applies ideas from manifold ranking. Since algorithms for ranking on graphs or manifolds often lack a way of dealing with out of sample data, they are of limited use for pattern recognition. In this paper, we therefore propose to consider diffusion processes over bipartite graphs which allow for a dual treatment of objects and features. As with Google's PageRank, this leads to Markov processes over the prototypes. In contrast to related methods, our model provides a Bayesian interpretation of the transition matrix and enables the ranking and consequently the classification of unknown entities. By design, the method is tailored to histogram features and we apply it to histogram-based color image analysis. Experiments with images downloaded from flickr.com illustrate object localization in realistic scenes.
Joint routing and playout buffering of IP telephony flows in MANETs
Authors: Fabrizio Boi, Luigi Atzori
Venue: Mobile Networks and Applications (2008)

The low-cost of packet-based networking technologies with respect to traditional circuit-switched ones and the reliability of the current (wired) IP networks have brought to a considerable employment of the VoIP (Voice over IP) technologies in the voice services market. This success is expected to happen also in mobile ad hoc networks (MANETs), which may offer a good platform for the fast deployment of VoIP mobile networks. However, efforts must be made to improve performance before MANETs can be used for this purpose. One of the main limitations is related to the highly variability of the network topology and channel behavior, which heavily influences the service quality due to route losses and significant delay variations. In this paper, we propose a strategy where these impairments are jointly addressed. The source is responsible for jointly selecting the transmission paths and adjusting the playout delay, with an adaptive inter-talkspurt approach. These tasks are accomplished on the basis of historical data on network connectivity and transmission delays, and are driven by a quality-based approach. The collection of statistics of the network status relies on the QOLSR routing algorithm, whereas the voice quality is measured by means of the ITU-T E-Model.
Non-uniform Optimal Subband Beamforming: An Evaluation on Real Acoustic Measurements
Authors: S. Nordholm, S. Y. Low, I. Claesson, K. F. C. Yiu
Venue: Proceedings of the 2008 Congress on Image and Signal Processing, Vol. 5 - Volume 05 (2008)

This paper presents an evaluation of a subband beamforming scheme for speech enhancement and acoustic echo suppression applications, such as hands-free telephony, internet telephony and video conferencing. The aim of the paper is to study the impact of the different types of subband filter banks on the speech enhancement performance. Results show that the octave band filter banks provide an effective means to give an overall efficient processing by using a fewer free filter parameters while providing a similar performance in terms of Signal to Noise Interference Ratio(SNIR) as compared to the uniform case. Whilst the critical band filter bank uses the most subbands, it provides the best performance both objectively and subjectively. This study provides insight to the design of filter bank for future hardware implementations.
Computer-Aided Assessment of Drug-Induced Lung Disease Plausibility
Authors: Brigitte Séroussi, Jacques Bouaud, Hugette Lioté, Charles Mayaud
Venue: Proceedings of the 11th conference on Artificial Intelligence in Medicine (2007)

Drug-induced lung disease (DILD), often suspected in pneumology, is still a diagnostic challenge because of the ever increasing number of pneumotoxic drugs and the large diversity of observed clinical patterns. As a result, DILD can only be evoked as a plausible diagnosis after the exclusion of all other possible causes. PneumoDoc is a computer-based decision support that formalises the evaluation process of the drug-imputability of a lung disease. The knowledge base has been structured as a two-level decision tree. Patient-specific chronological and semiological criteria are first examined leading to the assessment of a qualitative intrinsic DILD plausibility score. Then literature-based data including the frequency of DILD with a given drug and the frequency of the observed clinical situation among the clinical patterns reported with the same drug are evaluated to compute a qualitative extrinsic DILD plausibility score. Based on a simple multimodal qualitative model, extrinsic and intrinsic scores are combined to yield an overall DILD plausibility score.
Balancing Cognitive and Motivational Scaffolding in Tutorial Dialogue
Authors: Kristy Elizabeth Boyer, Robert Phillips, Michael Wallis, Mladen Vouk, James Lester
Venue: Proceedings of the 9th international conference on Intelligent Tutoring Systems (2008)

A key challenge in the design of tutorial dialogue systems is identifying tutorial strategies that can effectively balance the tradeoffs between cognitive and affective student outcomes. This balance is problematic because the precise nature of the interdependence between cognitive and affective strategies is not well understood. Furthermore, previous studies suggest that some cognitive and motivational goals are at odds with one another because a tutorial strategy designed to maximize one may negatively impact the other. This paper reports on a tutorial dialogue study that investigates motivational strategies and cognitive feedback. It was found that the choice of corrective tutorial strategy makes a significant difference in the outcomes of both student learning gains and self-efficacy gains.
Extensions of maximum concurrent flow to identify hierarchical community structure and hubs in networks
Authors: David W. Matula
Venue:  (2008)

This research has lead to the development of three new tools for social network analysis that are extensions of the maximum concurrent flow problem. One is the Maximum Concurrent Flow (MCF) cut algorithm that identifies the hierarchical community structure of a network by iteratively solving the maximum concurrent flow problem for the least-dense component. A second is a new measure of accuracy for comparing two partitionings of a network. It is based upon the inter-community and intra-community classification of edges rather than the problematic vertex counting that has been universally employed for this purpose. The third tool is a new, canonical centrality measure based upon the hierarchical maximum concurrent flow problem that is more stable than the currently-used betweenness centrality measure and is useful in identifying hub-type vertices within networks that conduct higher-levels of flow between other vertices. The new centrality measure can be a tool to improve research that involves social network analysis and other fields involved with the analysis of network flows. The proposed &ldquo;flowthrough&rdquo; centrality measure overcomes the problem of overstating or understating the roles that significant actors play in social networks.Rigorous experiments have found this measure to be more stable than the traditional betweenness centrality measurement used in social network analysis when knowledge of the network topology is incomplete or in transition. Perturbations do not alter the flowthrough centrality values of vertices based upon all realized flow as much as they do betweenness centrality values based upon geodesics only. It is canonical in that it is determined from a natural and standardized flow applicable to all networks.The major benefits of this study are the development of more reliable tools for the identification of the hierarchical community structure of networks, a new measure of accuracy for comparing partitionings of networks, a new and more stable flowthrough centrality measurement that can identify hub vertices, and the evidence for that reliability.
Speed-Up Theorems in Type-2 Computation
Authors: Chung-Chih Li
Venue: Proceedings of the 3rd conference on Computability in Europe: Computation and Logic in the Real World (2007)

A classic result known as the speed-up theorem in machine-independent complexity theory shows that there exist some computable functions that do not have best programs for them [2][3]. In this paper we lift this result into type-2 computation under the notion of our type-2 complexity theory depicted in [15][13][14]. While the speed-up phenomenon is essentially inherited from type-1 computation, we cannot directly apply the original proof to our type-2 speed-up theorem because the oracle queries can interfere the speed of the programs and hence the cancellation strategy used in the original proof is no longer correct at type-2. We also argue that a type-2 analog of the operator speed-up theorem [16] does not hold, which suggests that this curious phenomenon disappears in higher-typed computation beyond type-2.
Optimizing Conjunctive Queries over Trees Using Schema Information
Authors: Henrik Björklund, Wim Martens, Thomas Schwentick
Venue: Proceedings of the 33rd international symposium on Mathematical Foundations of Computer Science (2008)

We study the containment, satisfiability, and validity problems for conjunctive queries over trees with respect to a schema. We show that conjunctive query containment and validity are 2EXPTIME-complete w.r.t. a schema (DTD or Relax NG). Furthermore, we show that satisfiability for conjunctive queries w.r.t. a schema can be decided in NP. The problem is NP-hard already for queries using only one kind of axis. Finally, we consider conjunctive queries that can test for equalities and inequalities of data values. Here, satisfiability and validity are decidable, but containment is undecidable, even without schema information. On the other hand, containment w.r.t. a schema becomes decidable again if the "larger" query is not allowed to use both equalities and inequalities.