ppxscal/embedding_network huggingface dataset:
Quality and efficiency in high dimensional nearest neighbor search
Authors: Yufei Tao, Ke Yi, Cheng Sheng, Panos Kalnis
Venue: Proceedings of the 35th SIGMOD international conference on Management of data (2009)

Nearest neighbor (NN) search in high dimensional space is an important problem in many applications. Ideally, a practical solution (i) should be implementable in a relational database, and (ii) its query cost should grow sub-linearly with the dataset size, regardless of the data and query distributions. Despite the bulk of NN literature, no solution fulfills both requirements, except locality sensitive hashing (LSH). The existing LSH implementations are either rigorous or adhoc. Rigorous-LSH ensures good quality of query results, but requires expensive space and query cost. Although adhoc-LSH is more efficient, it abandons quality control, i.e., the neighbor it outputs can be arbitrarily bad. As a result, currently no method is able to ensure both quality and efficiency simultaneously in practice. Motivated by this, we propose a new access method called the locality sensitive B-tree (LSB-tree) that enables fast high-dimensional NN search with excellent quality. The combination of several LSB-trees leads to a structure called the LSB-forest that ensures the same result quality as rigorous-LSH, but reduces its space and query cost dramatically. The LSB-forest also outperforms adhoc-LSH, even though the latter has no quality guarantee. Besides its appealing theoretical properties, the LSB-tree itself also serves as an effective index that consumes linear space, and supports efficient updates. Our extensive experiments confirm that the LSB-tree is faster than (i) the state of the art of exact NN search by two orders of magnitude, and (ii) the best (linear-space) method of approximate retrieval by an order of magnitude, and at the same time, returns neighbors with much better quality.
A Neural Network Model for Solving Nonlinear Optimization Problems with Real-Time Applications
Authors: Alaeddin Malek, Maryam Yashtini
Venue: Proceedings of the 6th International Symposium on Neural Networks: Advances in Neural Networks - Part III (2009)

A new neural network model is proposed for solving nonlinear optimization problems with a general form of linear constraints. Linear constraints, which may include equality, inequality and bound constraints, are considered to cover the need for engineering applications. By employing this new model in image fusion algorithm, an optimal fusion vector is exploited to enhance the quality of fused images efficiently. The stability and convergence analysis of the novel model are proved in details. The simulation examples are used to demonstrate the validity of the proposed model.
A study of oscillation for signal stabilization of nonlinear system
Authors: Onisifor Olaru, Marius-Constantin Popescu, Valentina E. Balas
Venue: Proceedings of the 10th WSEAS international conference on Automation & information (2009)

The phenomena of desynchronization, synchronization, and forced oscillation has been investigation using describing function theory for a two input and two output nonlinear system containing saturation-type nonlinearities and subjected to high-frequency deterministic signal for the purpose of limit cycle quenching. The analytical results have been compared with the results of digital simulation/Matlab-Simulink for a typical example varying the nonlinear element.
The problems of camera measurements in tracking-error fuzzy control of mobile robots
Authors: Sašo Blažič, El-Hadi Guechi, Jimmy Lauber, Michel Dambrine, Gregor Klančar
Venue: WSEAS TRANSACTIONS on SYSTEMS (2009)

This paper deals with Takagi-Sugeno modelling and control of nonholonomic mobile robots in the case when the measurements are given by the camera. The measurements in such case are difficult to deal with: they are given only in discrete time samples, usually they are delayed, a high-level noise is present on the measurements. The nonlinear tracking error-model is solved analytically under the premise of ZOH present at the system input. The nonlinear discrete model is developed. Several discretization issues are discussed and the modelling errors are analysed. The sector nonlinearity approach is used for constructing the Takagi-Sugeno model. The control is designed in the LMI framework. Some performance issues are discussed on the simulation cases.
Evaluation of the student workbook in terms of purpose of use of pictures
Authors: Özden Sahin Izmirli, Isil Kabakçi, Serkan Izmirli
Venue: Proceedings of the international conference on Computational and information science 2009 (2009)

Pictures are frequently used as visuals in education to facilitate learning. Pictures should be used in line with their purposes in order to support learning. Mayer classifies pictures as decorative, representational, organizational and explanative pictures with respect to their purpose of use. Among these, decorative pictures and representational pictures are reported not to serve the instructional purpose, while organizational pictures and explanative pictures are claimed to support the transfer of instructional messages. In the present study, the pictures found in the student workbook of fifth grade elementary school students in the course of Information Technologies were examined in terms of their purpose of use in line with expert views. According to the results obtained at the end of the study, it was concluded that the pictures found in the student workbook does not serve the instructional purpose.
Online Periodic Self-Test Scheduling for Real-Time Processor-Based Systems Dependability Enhancement
Authors: Dimitris Gizopoulos
Venue: IEEE Transactions on Dependable and Secure Computing (2009)

Online periodic self-testing is a cost-effective technique to ensure correct operation of microprocessor-based systems in the field and improve their dependability in the presence of failures caused by components aging/wearout. Effective online self-test tasks in embedded systems should have limited resource requirements: memory, execution time, and power consumption, while at the same time, they should guarantee the highest possible self-test quality levels. These requirements are not always easy to satisfy in real-time embedded systems with hard task deadlines. In this paper, we investigate the maximization of the effective self-test utilization and present solutions for the scheduling of online self-test tasks in hard real-time systems. The primary goal is to guarantee high self-test quality without affecting the deadline requirements of normal hard real-time tasks. We show that with appropriate selection of the periodicity of the self-test tasks, these goals can be met.
You asked for IT!: phrasing questions for computer science assessment
Authors: Vreda Pieterse, Cecilia M. du Toit
Venue: Proceedings of the 2009 Annual Conference of the Southern African Computer Lecturers' Association (2009)

The formulation of questions is central to the design of good assessment practices. In reality, however, lecturers, seriously pressed for time, often neglect to pay the necessary consideration to the student's reception of the question. Students' failure to sufficiently grasp the essence of a question is often informally cited as a reason for inadequate performance in a test. In this study we attempted to extrapolate aspects that may cause computer science students to misunderstand the instructions and scientific inquiry with the result that they fail to address the very issues that the lecturer wishes to assess. The theoretical underpinning includes the application of seminal instructional frameworks such as Bloom's Taxonomy of Educational Objectives and its revision by Krahtwohl as well the SOLO taxonomy by Biggs and Collis [1]. The main objective of this research is to answer the question: Why do students consistently fail to accurately and fully comprehend set questions? Misconception and failure can be avoided if we can answer the following: &bull; How to identify the essence of the specialist knowledge and insight that need to be assessed? &bull; How to suitably elicit the answer that we seek? &bull; How to aid the students' conceptualisation of the gist of the matter? &bull; How to phrase the question in a suitably unambiguous, explicit, relevant and comprehensible manner? This study comprised an electronic survey hosted on a web server. A number of closed groups of educators interested in computer science and information technology was invited via e-mail to participate. The respondents to the questionnaire were asked to reflect on the rigour and relevance of two set questions. In a second level of inquiry the respondents were asked to provide examples of problematic question formulation. In addition they were requested to explicate their student's failure to answer these questions satisfactorily. The rich data that was gathered during the survey was analysed in a two-tiered coding procedure that involved scrutiny of responses in a qualitative, interpretive model. After thematic synthesis, the results provided findings that include the following: &bull; the importance of clarity of expression &bull; insufficient reading comprehension, especially of second language speakers &bull; the facilitation of conceptualisation through graphic representation. After identification of possible causes of misconception of questions we aim to compile a set of guidelines to address problems related to miscomprehension of set questions, that can serve as a tool for computer science educators to improve their assessment skills and ultimately the performance of their students.
A new approach in wavelet based speech compression
Authors: Jalal Karam
Venue: Proceedings of the 10th WSEAS international conference on Mathematical methods, computational techniques and intelligent systems (2008)

This paper introduces via reflective properties of perfect reconstruction filter banks a mother wavelet related to the Daubechies orthogonal family. The construction of this wavelet is detailed, its properties are derived and its effectivness in compressing speech signals is tested. Compression parameters are computed for speech frames at level 5 Discrete Wavelet Transform (DWT) representation of the signals. Results are obtained and compared for Global threshold and level dependent threshold techniques. Comparisons with Signal to Noise Ratios, Peak Signal to Noise Ratios and Normalized Root Mean Square Error are also recorded.
Speed adaptive probabilistic flooding in cooperative emergency warning
Authors: Yiannos Mylonas, Marios Lestas, Andreas Pitsillides
Venue: Proceedings of the 4th Annual International Conference on Wireless Internet (2008)

Vehicular Ad Hoc Networks (VANETs) are emerging as the preferred network design for intelligent transportation systems and are envisioned to be useful in road safety and commercial applications. A significant issue in VANETs is the design of an effective broadcast scheme which can facilitate the fast and reliable dissemination of critical safety messages to neighbouring vehicles in case of an unexpected event, such as a traffic accident. Towards this goal, we propose a novel Speed Adaptive Probabilistic Flooding algorithm (SAPF). Its decision to rebroadcast a message is based on a probability, evaluated using the speed of the vehicle. The algorithm enjoys a number of benefits relative to other approaches: it is simple to implement and does not introduce additional communication burden as it requires local information only, it does not rely on the existence of a positioning system which may not always be available and above all, mitigates the effect of the broadcast storm problem, typical when utilizing blind flooding. Our results indicate that the proposed algorithm outperforms blind flooding, especially in cases of heavy congestion. The SAPF algorithm achieves high reachability and unlike blind flooding, it also maintains low latency as the density of vehicles in the road network increases.
A SPICE-Like 2T-FLOTOX Core-Cell Model for Defect Injection and Faulty Behavior Prediction in eFlash
Authors: O. Ginez, J. -M. Daga, P. Girard, C. Landrault, S. Pravossoudovitch, A. Virazel
Venue: Journal of Electronic Testing: Theory and Applications (2009)

The embedded Flash technology can be subject to complex defects creating functional faults. In this paper, we describe the different steps in the electrical modeling of 2T-FLOTOX core-cells for a good understanding of failure mechanisms. At first, we present a first order electrical model of 2T-FLOTOX core-cells which is characterized and compared with silicon data measurements based on the ATMEL 0.15 µm eFlash technology. Next, we propose a study of resistive defect injections in eFlash memories to show the interest of the proposed simulation model. At the end of the paper, a table summarizes the functional fault models for different resistive defect configurations and experimental set-ups. According to these first results and with additional analysis on actual defects presented in [3] we are then able to enhance existing test solutions for eFlash testing.
Probabilistic Ranking Support Vector Machine
Authors: Nguyen Thi Thuy, Ngo Anh Vien, Nguyen Hoang Viet, Taechoong Chung
Venue: Proceedings of the 6th International Symposium on Neural Networks: Advances in Neural Networks - Part II (2009)

Recently, Support Vector Machines (SVMs) have been applied very effectively in learning ranking functions (or preference functions).They intend to learn ranking functions with the principles of the large margin and the kernel trick. However, the output of a ranking function is a score function which is not a calibrated posterior probability to enable post-processing. One approach to deal with this problem is to apply a generalized linear model with a link function and solve it by calculating the maximum likelihood estimate. But, if the link function is nonlinear, maximizing the likelihood will face with difficulties. Instead, we propose a new approach which train an SVM for a ranking function, then map the SVM outputs into a probabilistic sigmoid function whose parameters are trained by using cross-validation. This method will be tested on three data-mining datasets and compared to the results obtained by standard SVMs.
Parametric and nonparametric evolutionary computing with a content-based feature selection approach for parallel categorization
Authors: Wei Song, Shi Tong Wang, Cheng Hua Li
Venue: Expert Systems with Applications: An International Journal (2009)

This paper proposes two modified evolutionary computing methods for genetic algorithms (GAs) and proves an effective content-based feature selection approach to improve clustering performance. The conventional GAs suffer from the problem of slow learning and are prone to be trapped into a local minimum due to a high dimensional exploration space. In this paper, we propose a parametric and a nonparametric evolutionary algorithms to properly adjust the operators of GA. In the parametric approach, several fuzzy control parameters are artificially defined to adaptively optimize the GA behaviors. By contrast, they are automatically adjusted by GA itself in the nonparametric approach. Moreover, a content-based feature selection (CFS) approach is demonstrated to create a robust semantic space and reduce the number of dimension which accelerates the speed of evolutionary computing. We take advantage of a parallel computing technology to improve the efficiency of clustering. The experimental results show that our methods enhance the performance of the standard GA and are more efficient than those implemented on a single processor. The CFS approach not only reduces the document dimension, but also indirectly advances clustering efficiency.
Quantum Information and the PCP Theorem
Authors: Ran Raz
Venue: Algorithmica (2009)

Our main result is that the membership x&#x2208;SAT (for x of length n) can be proved by a logarithmic-size quantum state |&#x03a8;&#x232a;, together with a polynomial-size classical proof consisting of blocks of length polylog(n) bits each, such that after measuring the state |&#x03a8;&#x232a; the verifier only needs to read one block of the classical proof. This shows that if a short quantum witness is available then a (classical) PCP with only one query is possible. Our second result is that the class QIP/qpoly contains all languages. That is, for any language L (even non-recursive), the membership x&#x2208;L (for x of length n) can be proved by a polynomial-size quantum interactive proof, where the verifier is a polynomial-size quantum circuit with working space initiated with some quantum state |&#x03a8; L,n &#x232a; (depending only on L and n). Moreover, the interactive proof that we give is of only one round, and the messages communicated are classical. The advice |&#x03a8; L,n &#x232a; given to the verifier can also be replaced by a classical probabilistic advice, as long as this advice is kept as a secret from the prover. Our result can hence be interpreted as: the class IP/rpoly contains all languages. For the proof of the second result, we introduce the quantum low-degree-extension of a string of bits. The main result requires an additional machinery of quantum low-degree-test.
Another Simple Recurrent Neural Network for Quadratic and Linear Programming
Authors: Xiaolin Hu, Bo Zhang
Venue: Proceedings of the 6th International Symposium on Neural Networks: Advances in Neural Networks - Part III (2009)

A new recurrent neural network is proposed for solving quadratic and linear programming problems, which is derived from two salient existing neural networks. One of the predecessors has lower structural complexity but were not shown to be capable of solving degenerate QP problems including LP problems while the other does not have this limitation but has higer structural complexity. The proposed model inherits the merits of both models and thus serves as a competitive alternative for solving QP and LP problems. Numerical simulations are provided to demonstrate the performance of the model and validate the theoretical results.
A Novel Model for Recognition of Compounding Nouns in English and Chinese
Authors: Lishu Li, Jiawei Chen, Qinghua Chen, Fukang Fang
Venue: Proceedings of the 6th International Symposium on Neural Networks: Advances in Neural Networks - Part III (2009)

Compounds are very common in many kinds of language. Most of the research in this field is from the view of morphology, while artificial neural network is seldom concerned. Based on Hopfield model, we create a novel neural network to simulate the recognition process of compounds in English and Chinese. Our model is composed of two layers: abstraction layer and recognition layer. The first layer can extract the common features of the training samples and represent it as a new attractor, which can be transferred into the next layer. This step imitates morpheme abstraction of compounds. Recognition layer is constructed as an improved Hopfield network, in which two existing attractors can merge into a new one. This step reflects the cognition of a new compound when all the morphemes are memorized. One specific example `raincoat' is demonstrated, and the results provide strong evidence to our model.
An architectural co-synthesis algorithm for energy-aware Network-on-Chip design
Authors: Yi-Jung Chen, Chia-Lin Yang, Yen-Sheng Chang
Venue: Journal of Systems Architecture: the EUROMICRO Journal (2009)

Network-on-Chip (NoC) has been proposed to overcome the complex on-chip communication problem of System-on-Chip (SoC) design in deep sub-micron. A complete NoC design contains exploration on both hardware and software architectures. The hardware architecture includes the selection of Processing Elements (PEs) with multiple types and their topology. The software architecture contains allocating tasks to PEs, scheduling of tasks and their communications. To find the best hardware design for the target tasks, both hardware and software architectures need to be considered simultaneously. Previous works on NoC design have concentrated on solving only one or two design parameters at a time. In this paper, we propose a hardware-software co-synthesis algorithm for a heterogeneous NoC architecture. The design goal is to minimize energy consumption while meeting the real-time requirements commonly seen in embedded applications. The proposed algorithm is based on Simulated-Annealing (SA). To compare the solution quality and efficiency of the proposed algorithm, we also implement the branch-and-bound and iterative algorithm to solve the hardware-software co-synthesis problem of a heterogeneous NoC. With the given synthetic task sets, the experimental results show that the proposed SA-based algorithm achieves near-optimal solution in a reasonable time, while the branch-and-bound algorithm takes a very long time to find the optimal solution, and the iterative algorithm fails to achieve good solution quality. When applying the co-synthesis algorithms to a real-world application with PE library that has little variation in PE performance and energy consumption, the iterative algorithm achieves solution quality comparable to that of the proposed SA-based algorithm.
Generic screen representations for future-proof systems, is it possible?
Authors: Helma van der Linden, Tony Austin, Jan Talmon
Venue: Computer Methods and Programs in Biomedicine (2009)

Background: Future-proof EHR systems must be capable of interpreting information structures for medical concepts that were not available at the build-time of the system. The two-model approach of CEN 13606/openEHR using archetypes achieves this by separating generic clinical knowledge from domain-related knowledge. The presentation of this information can either itself be generic, or require design time awareness of the domain knowledge being employed. Objective: To develop a Graphical User Interface (GUI) that would be capable of displaying previously unencountered clinical data structures in a meaningful way. Methods: Through ''reasoning by analogy'' we defined an approach for the representation and implementation of ''presentational knowledge''. A proof-of-concept implementation was built to validate its implementability and to test for unanticipated issues. Results: A two-model approach to specifying and generating a screen representation for archetype-based information, inspired by the two-model approach of archetypes, was developed. There is a separation between software-related display knowledge and domain-related display knowledge and the toolkit is designed with the reuse of components in mind. Conclusions: The approach leads to a flexible GUI that can adapt not only to information structures that had not been predefined within the receiving system, but also to novel ways of displaying the information. We also found that, ideally, the openEHR Archetype Definition Language should receive minor adjustments to allow for generic binding.
A mixed digital / physical snapshot of early internet / web usage in New Zealand
Authors: Sally Jo Cunningham, Jillene Bydder
Venue: Proceedings of the 9th ACM/IEEE-CS joint conference on Digital libraries (2009)

We are in the early stages of developing a unique physical and digital record of New Zealand's early experience of the Internet.