ppxscal/embedding_network huggingface dataset:
Photochemical hole burning in free-base porphyrin and chlorin in n-alkane matrices
Authors: S. Völker, R. M. Macfarlane
Venue: IBM Journal of Research and Development (1979)

In inhomogeneously broadened lines, selective photochemistry with narrow band lasers leads to photochemical hole burning. We describe this phenomenon with particular reference to free-base porphyrin (H2P) and chlorin molecules in nalkane matrices at low temperatures. It is shown that hole burning, which is permanent at low temperatures, can be used to study homogeneous optical dephasing processes as a function of temperature, to measure fast vibronic relaxation, and to assign complex vibronic spectra. Some of the parameters that are important to the potential use of photochemical hole burning for information storage in inhomogeneously broadened lines are measured and discussed.
Image Similarity: From Syntax to Weak Semantics Using Multimodal Features with Application to Multimedia Retrieval
Authors: Jukka Perkiö, Antti Tuominen, Petri Myllymäki
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

Measuring image similarity is an important task for various multimedia applications. Similarity can be defined at two levels: at the syntactic (lower, context-free) level and at the semantic (higher, contextual) level. As long as one deals with the syntactic level, defining and measuring similarity is a relatively straightforward task, but as soon as one starts dealing with the semantic similarity, the task becomes very difficult. We examine the use of very simple syntactic image features combined with other multimodal features to derive a similarity measure that captures the weak semantics of an image. We test and further use this similarity measure to do video retrieval.
Optimal channel detection for nonbinary coded partial response channels
Authors: Wu Chang, J. R. Cruz
Venue: IEEE Transactions on Communications (2009)

We derive a recursive algorithm to compute the joint maximum a posteriori probabilities of p consecutive bits on partial response channels. This channel detector is optimal for nonbinary soft-iterative decoding with multiple channel iterations. It is validated on a nonbinary low-density parity-check coded perpendicular magnetic recording channel.
A Novel Deblocking Filter Algorithm in H.264 for Real Time Implementation
Authors: Yuan Li, Ning Han, Chen Chen
Venue: Proceedings of the 2009 Third International Conference on Multimedia and Ubiquitous Engineering (2009)

Due to the limitation of computing complexity, it is difficult to apply the H.264 deblocking filter to low-end terminals. Although some technologies to optimize it have been proposed, the complexity is still high for real time implementation. Considering that deblocking filter is applied to all of the vertical and horizontal edges of 4x4 blocks but only some of them actually need to be filtered , in this paper, based on previous encoding or decoding information, we propose a novel deblocking filter algorithm to reduce complexity of exist algorithms by skipping quantities of needless edges. The experimental results show that our proposed algorithm has better performance in subjective video quality and time efficiency compared to JM 10.2 algorithm.
The Realization of Information Hiding in BMP Images
Authors: Yuhua Qin
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 02 (2009)

This paper introduces a method of hiding information in a 24-bit BMP image. The key technique of encryption is to convert the hidden messages into a bit stream, and fills it in the certain position of the BMP file. The size of the cover image file is not changed after data embedding and the color variations of each byte of the image are changed at most 1/256, which will not detected by human eyes and raise suspicion by the eavesdropper. This crypto system can be used to hide and encrypt messages sent between two communicating parties so that an attacker will not know the existence of the messages and not be able to decode them. It also shows the combination of steganography and the cryptography which improves the overall goal of protecting or concealing information from unintended recipients and has higher security.
View usability and safety for the answering of top-k queries via materialized views
Authors: Eftychia Baikousi, Panos Vassiliadis
Venue: Proceeding of the ACM twelfth international workshop on Data warehousing and OLAP (2009)

In this paper, we investigate the problem of answering top-k queries via materialized views. We provide theoretical guarantees for the adequacy of a view to answer a top-k query, along with algorithmic techniques to compute the query via a view when this is possible. We explore the problem of answering a query via a combination of more than one view and show that it is impossible to improve our theoretical guarantees for the answering of a query via a combination of views. Finally, we experimentally assess our approach for its effectiveness and efficiency.
Parallel Collision Detection Algorithm Based on Decomposing a Polyhedron into Tetrahedrons
Authors: Xiong Yumei, Chen Yiming
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 01 (2009)

Despite significant progress that has been made in developing efficient collision detection algorithms for convex polyhedrons, limited and slow progress has been reported in developing collision detection algorithm for nonconvex polyhedron. To narrow this gap we present a parallel collision detection algorithm. The algorithm consist of two stages. The first stage involves decomposing nonconvex polyhedron into terahedrons. The second stage involves detecting the collision to tetrahedrons in parallel. In the first stage, the decomposing methode’s theoretic provement and its implementation was given. In the second stage, we detailed described the parallel algorithm. Compared with the other algorithms, research result shows that the parallel algorithm greatly improve the collision detection speed with high accuracy.
A blind CFO estimator based on smoothing power spectrum for OFDM systems
Authors: Lu Wu, Xian-Da Zhang, Pei-Sheng Li, Yong-Tao Su
Venue: IEEE Transactions on Communications (2009)

Carrier frequency offset (CFO) estimation is a critical problem in orthogonal frequency-division multiplexing (OFDM) systems. This letter proposes a blind CFO estimator based on smoothing the signal power spectrum. A closed-form CFO estimate is also presented, which greatly reduces the computational complexity of the proposed method. Analysis and simulation results show that the proposed estimator is very effective for OFDM systems.
An Agent-Based Migration Transparency and Fault Tolerance in Computational Grid
Authors: Srimathi Chandrasekaran, Eunmi Choi, Venkat Viswanadh
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

A Grid is a large-scale, geographically distributed hardware and software infrastructure for flexible, secure, and coordinated sharing of vast amounts of heterogeneous resources within large, dynamic and distributed communities of users belonging to virtual organizations, to enable solving of complex scientific problems. From the perspective of one computer, such network partitioning may appear as a failure to other computers. These types of failures may lead to major impact on whole application which is executing on Grid for many days. Thus, failures in the grid computing environment can be solved to some extent by performing migration of application through node agents. As executing applications in nodes have contiguous service features, it becomes important to handle and mask fault and migrate the current job to another grid node without stopping the on-going processes. In this paper, we use agents to provide communication between grid nodes and handle failure tolerant techniques on grid. The agent is dynamically reallocated to Grid nodes though a transparent migration mechanism, as a way to provide fault tolerance in computational grids
Performance bounds for unequal error protecting turbo codes
Authors: Mehmet Aydinlik, Masoud Salehi
Venue: IEEE Transactions on Communications (2009)

In many communications systems, data can be divided into different importance levels. For these systems, unequal error protection (UEP) techniques are used to guarantee lower BER for the more important classes. In particular, if the precise characteristics of the channel are not known, UEP can be used to recover the more important classes even in poor receiving conditions. In this paper, we derive bounds on the performance of unequal error protecting turbo codes. These bounds serve as an important tool in predicting the performance of these codes. In order to derive the bounds, we introduce the notion of UEP-uniform interleaver which is a random interleaver that does not change the order of classes in the turbo code frame. We also present a method to derive the weight enumerating function for UEP turbo codes.
Mitigating error propagation of MMSE-DFE by joint parameter optimization
Authors: Rujiang Wang, Gilles Y. Delisle
Venue: IEEE Transactions on Communications (2009)

A joint optimization of the decision feedback equalizer (DFE) filter weights and an erasure slicer is proposed in this letter. The feedback weights of the DFE are constrained with an accurate mean square error (MSE) model as the criterion. An erasure slicer is adopted to further decrease error propagation. Two consecutive 1-D optimizations are shown as good as that of a single 2-D optimization. Simulation results verify the performance improvements of the proposed scheme.
Bilateral exchange of soft-information for iterative reliability-based decoding with adaptive belief propagation
Authors: Chung-Hsuan Wang, Yu-Min Hsieh, Hsin-Chuan Kuo
Venue: IEEE Communications Letters (2009)

For linear block codes without a sparse graph representation, there exists an iterative decoding algorithm which combines the traditional reliability-based decoding (RBD) with adaptive belief propagation (ABP) to achieve a good trade-off between the error performance and decoding complexity. However, in the original design of the iterative scheme, only a one-way flow of soft-information from the ABP-part to the RBD-part is available, hence limiting the performance of iterative processing. In this study, several low-complexity schemes are presented for the RBD-part to produce desirable soft-outputs such that decoded results can be bilaterally exchanged between both of the RBD and ABP parts. Simulation results also verify the superiority of the proposed idea over the conventional design.
Power minimization of central Wishart MIMO block-fading channels
Authors: Jia Chen, Kai-Kit Wong
Venue: IEEE Transactions on Communications (2009)

In this correspondence, a central Wishart multiple-input multiple-output (MIMO) K-block fading channel with an information outage probability constraint is studied. Under this block-limited channel condition, we aim to minimize the transmit power required for attaining a given outage probability based on the statistical channel information at the transmitter (SCIT). Using Gaussian approximation to express the probability density function (pdf) of the instantaneous mutual information and by deriving analytically the mean and variance of the mutual information of the MIMO channel, the optimal power allocation can be obtained numerically by a simple one-dimensional sampling method such as DIviding RECTange (DIRECT).
IMS Based PoC Service Deployment
Authors: Jae-Hyung Cho, Jae-Oh Lee
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

The IP Multimedia Subsystem (IMS) has brought us feasibilities by separating control functions from bearer and services. Multi-Access technology enables us connecting the IMS Core by kinds of network such as wireless, wire-line network and Internet. By IMS Service Delivery Platform (SDP) richness of services have been developed and deployed into realization through its common protocols and interfaces. Push-to-talk over Cellular (PoC) as the outstanding half-duplex Voice over IP (VoIP) application service enables traditional walkie-talkie service over mobile network.. In this paper we will focus on the advantage of PoC service and PoC architecture firstly, and then describes the session flows of PoC service and its simple simulation. At last we make some conclusions.
Research of Velocity Control Based on Genetic Algorithm Training RBF Neural Network
Authors: Min Ke, Ji Ying
Venue: Proceedings of the 2009 Second International Symposium on Knowledge Acquisition and Modeling - Volume 02 (2009)

Ram velocity tracking control is an important process in injection molding control. Due to the nonlinearity of the injection system and the fluctuation of the system parameters during the process, traditional PID controller can't satisfy the requirement of precision injection. A method of utilizing RBF neural network to adjust PID control parameters is presented, which conquers the deficiency of traditional PID controller. Genetic algorithm is used to optimize the centers and widths of hidden layer and the weights between hidden layer and output layer of RBF neural network. Gradient descent method is used to adjust the PID controller parameters. Simulations are provided to evaluate the performance of the proposed injection velocity control system.
A capture-aware access control method for enhanced RFID anti-collision performance
Authors: Woo Jin Shin, Jeong Geun Kim
Venue: IEEE Communications Letters (2009)

This letter presents a novel anti-collision algorithm for Radio Frequency Identification (RFID) systems that drastically improve throughput performance via an intelligent access control for capture inducement. In order to induce the capture, our protocol attempts to divide tags into multiple groups depending on received signal strength, and allow only a selected pair of groups to join the contention process, in which the outcome of contention is more likely to lead to capture due to a significant difference in their signal strengths. Numerical results show that our proposed algorithm significantly outperforms the existing approaches in terms of throughput.
Cooperative spectrum sensing based on the limiting eigenvalue ratio distribution in Wishart matrices
Authors: Federico Penna, Roberto Garello, Maurizio A. Spirito
Venue: IEEE Communications Letters (2009)

Recent advances in random matrix theory have spurred the adoption of eigenvalue-based detection techniques for cooperative spectrum sensing in cognitive radio. These techniques use the ratio between the largest and the smallest eigenvalues of the received signal covariance matrix to infer the presence or absence of the primary signal. The results derived so far are based on asymptotical assumptions, due to the difficulties in characterizing the exact eigenvalues ratio distribution. By exploiting a recent result on the limiting distribution of the smallest eigenvalue in complex Wishart matrices, in this paper we derive an expression for the limiting eigenvalue ratio distribution, which turns out to be much more accurate than the previous approximations also in the non-asymptotical region. This result is then applied to calculate the decision sensing threshold as a function of a target probability of false alarm. Numerical simulations show that the proposed detection rule provides a substantial improvement compared to the other eigenvalue-based algorithms.
Discovering functional dependencies for multidimensional design
Authors: Oscar Romero, Diego Calvanese, Alberto Abelló, Mariano Rodríguez-Muro
Venue: Proceeding of the ACM twelfth international workshop on Data warehousing and OLAP (2009)

Nowadays, it is widely accepted that the data warehouse design task should be largely automated. Furthermore, the data warehouse conceptual schema must be structured according to the multidimensional model and as a consequence, the most common way to automatically look for subjects and dimensions of analysis is by discovering functional dependencies (as dimensions functionally depend on the fact) over the data sources. Most advanced methods for automating the design of the data warehouse carry out this process from relational OLTP systems, assuming that a RDBMS is the most common kind of data source we may find, and taking as starting point a relational schema. In contrast, in our approach we propose to rely instead on a conceptual representation of the domain of interest formalized through a domain ontology expressed in the DL-Lite Description Logic. We propose an algorithm to discover functional dependencies from the domain ontology that exploits the inference capabilities of DL-Lite, thus fully taking into account the semantics of the domain. We also provide an evaluation of our approach in a real-world scenario.
A low-leakage open-loop frequency synthesizer allowing small-area on-chip loop filter
Authors: Fredrik Jonsson, Håkan Olsson
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

A frequency synthesizer targeting low-power packet-based frequency-shift-keying (FSK) applications using open-loop modulation of the oscillator is presented. Unlike conventional implementations, the proposed synthesizer is open both when transmitting and receiving data. It is, therefore, possible to use a wide loop-filter bandwidth without violating the noise or spurious requirements. A wideband loop-filter can be implemented using small component values, allowing an on-chip loop filter. To handle the frequency drift associated with open-loop implementations, a low-leakage charge pump is proposed. The synthesizer is implemented using a 0.18-µm CMOS process. The total power consumption is 9 mW, and the circuit area including the voltage-controlled oscillator (VCO) inductors and on-chip loop-filter is 0.32 mm2. The measured frequency drift indicates a leakage current of below 2 fA.
A multi-mode resource-constrained scheduling problem in the context of port operations
Authors: Luciano Lessa Lorenzoni, Hannu Ahonen, Arlindo Gomes de Alvarenga
Venue: Computers and Industrial Engineering (2006)

We discuss a problem of attending ships within agreed time limits at a port under the condition of the first come first served order. In addition, we indicate the use of the developed tool to support decisions at a strategic level with the objective of improving the attendance of the ships. The tool is based on a mathematical model of a multi-mode resource-constrained scheduling problem and on an extension of a differential evolution algorithm. We illustrate the implementation by computational tests with data generated on the basis of the characteristics of a real port environment.
Curvature analysis applied to the Cantarell structure, southern Gulf of Mexico: implications for hydrocarbon exploration
Authors: J. J. Mandujano, R. V. Khachaturov, G. Tolson, J. Duncan Keppie
Venue: Computers Geosciences (2005)

The middle Miocene Cantarell structure is host to the largest hydrocarbon field in Mexico. It has been variously interpreted as a fold-and-thrust or a dextral transpressional structure and the hydrocarbons are generally located in fold culminations adjacent to major faults. The host rocks are predominantly latest Cretaceous-earliest Paleogene breccias, but also include early middle Miocene sedimentary rocks. Primary factors favourable for hydrocarbon traps include porosity and permeability of the rocks, which may be augmented by subsequent fracturing. Such fracturing generally correlates with the intensity of deformation, one measure of which is curvature of fold structures, where curvature can be expressed as the inverse of the radius of an inscribed circle. We have derived a mathematical algorithm to calculate the greatest local curvature of a contoured surface in any of four directions at 45^o to one another. Applying this algorithm to the structure contour map at the top of the Cretaceous-Paleocene breccia in the Cantarell structure shows that the highest curvatures occur adjacent to faults and associated folds, and greater values coincide with the largest hydrocarbon fields.
One-class support vector machines-an application in machine fault detection and classification
Authors: Hyun Joon Shin, Dong-Hwan Eom, Sung-Shick Kim
Venue: Computers and Industrial Engineering (2005)

Fast incipient machine fault diagnosis is becoming one of the key requirements for economical and optimal process operation management. Artificial neural networks have been used to detect machine faults for a number of years and shown to be highly successful in this application area. This paper presents a novel test technique for machine fault detection and classification in electro-mechanical machinery from vibration measurements using one-class support vector machines (SVMs). In order to evaluate one-class SVMs, this paper examines the performance of the proposed method by comparing it with that of multilayer perception, one of the artificial neural network techniques, based on real benchmarking data.
Similarity coefficient methods applied to the cell formation problem: a comparative investigation
Authors: Yong Yin, Kazuhiko Yasuda
Venue: Computers and Industrial Engineering (2005)

Although many similarity coefficients have been proposed, very few comparative studies have been done to evaluate the performance of various similarity coefficients. In this paper, we compare the performance of 20 well-known similarity coefficients. Two hundred and fourteen numerical cell formation problems, which are selected from the literature or generated deliberately, are used for the comparative study. Nine performance measures are used for evaluating the goodness of cell formation solutions. Two characteristics, discriminability and stability of the similarity coefficients are tested under different data conditions. From the results, three similarity coefficients are found to be more discriminable. Jaccard is found to be the most stable similarity coefficient. Four similarity coefficients are not recommendable due to their poor performances.
Reading and writing facilitating ICT use in school science
Authors: Jari Lavonen, Kalle Juuti, Veijo Meisalo
Venue: Proceedings of the 10th IASTED International Conference on Computers and Advanced Technology in Education (2007)

Activities for science teaching and learning focusing on reading and writing as processes and the use of modern Information and Communication Technologies (ICT) in learning have been designed using the design-based research approach. Based on our theoretical problem analysis reading and writing activities should support collaborative, constructive, reflective and contextual learning. The data in our empirical problem analysis included answers of 14 science teachers about their experience of developed 21 activities in real classroom situations. Our qualitative content analysis indicated that the developed activities facilitated learning and discouraged the use of copy-paste techniques. They especially made learning constructive and collaborative. These activities serve as examples of how science teachers can guide their students to read and write and use ICT in a manner that leads efficiently to learning.