ppxscal/embedding_network huggingface dataset:
On the connectivity of wireless multi-hop networks with arbitrary wireless channel models
Authors: Xiaoyuan Ta, Guoqiang Mao, Brian D. O. Anderson
Venue: IEEE Communications Letters (2009)

Considering a wireless multi-hop network where a total of n nodes are randomly, independently and uniformly distributed in a unit square in R2 and each node has a uniform transmission power, a fundamental problem is to investigate the connectivity of such networks. In this letter, we prove that the probability of having a connected network and the probability of having no isolated node asymptotically converges to the same value as n goes to infinity for an arbitrary wireless channel model satisfying certain intuitively reasonable conditions.
A Novel Non-local Image Inpainting Algorithm: Fractal-Based Image Inpainting
Authors: Yang Xiu-hong, Guo Bao-long
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 02 (2009)

Aiming at overcoming the shortage that the searching scope is limited to the source region of the damaged image, a fractal-based digital image in painting algorithm is presented in this paper. Firstly, the source region of the image to be in painted is partitioned into a set of blocks which form a codebook. Secondly, the best-matched block is chosen in the codebook by means of fast fractal theory. In addition, the proportion of confidence term is increased during computing the priority in order to avoid “false edge” caused by error match and intensify the constraint of searching condition, thus the filling process proceeds by the order of “onion-peel”, meanwhile linear structures can be propagated into the target region. The novel contribution of this paper is to introduce fractal theory into the in painting area and to restore damaged images using the characteristic of self-similarity of the images. Numerical experiments on real and synthetic images are given to illustrate the advantages of the proposed algorithm, and the results compare favorably to those obtained by existing techniques.
Global robust stability and synchronization of networks with Lorenz-type nodes
Authors: Zhisheng Duan, Guanrong Chen
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

This brief addresses in a unified framework both global robust stability and synchronization problems for a class of direded networks with Lorenz-type nodes. When the key parameter in the node equation is modified, it covers the Lorenz, Chen, and Lü types of networks as special cases. Based on an observation about some special nonlinear characteristics of Lorenz-type systems, simple conditions are derived for global stability and synchronization of such networks, where the typical Lipschitz-type condition for nonlinear functions is not needed. By combining the pinning control strategy and a new linear control law, synchronization of a network with different nodes can be achieved. Several examples an given for illustration.
Detecting opinion leaders and trends in online social networks
Authors: Freimut Bodendorf, Carolin Kaiser
Venue: Proceeding of the 2nd ACM workshop on Social web search and mining (2009)

Today, online social networks in the World Wide Web become increasingly interactive and networked. Web 2.0 technologies provide a multitude of platforms, such as blogs, wikis, and forums where for example consumers can disseminate data about products and manufacturers. This data provides an abundance of information on personal experiences and opinions which are extremely relevant for companies and sales organizations. A new approach based on text mining and social network analysis is presented which allows detecting opinion leaders and opinion trends. This allows getting a better understanding of the opinion formation. The overall concept is presented and illustrated by an example.
From e-learning towards u-learning: ICT-enabled ubiquitous learning & training
Authors: G. Graschew, T. A. Roelofs, S. Rakowsky, P. M. Schlag
Venue: Proceedings of the 10th IASTED International Conference on Computers and Advanced Technology in Education (2007)

As the amount of available knowledge increases at a stunning pace and concomitantly its "half-life" shortens dramatically, lifelong learning becomes inevitable for most people. Global networks and the use of computers for educational purposes stimulate and support the development of virtual universities for e-learning. Especially real-time interactive applications can play an important role in tailored and personalised services. However, it takes more than just technology to move from pure e-learning towards the full expansion of ubiquitous access to educational services, anytime and anywhere (u-learning).
Improvement of a Worker's Motion Trace System Using a Terrestrial Magnetism Sensor
Authors: Nobuyoshi Sato, Toshihiro Takahashi, Akira Tajima, Shouichi Odashima, Jun Suzuki, Taiji Ishikawa, Yoshitoshi Murata
Venue: Proceedings of the 2009 International Conference on Network-Based Information Systems (2009)

Guarantee of quality of products is very important for company activities; so many companies consider guaranteeing quality of their products is very important. In guarantee of quality in industrial products, they are not only important that designs, parts and materials but also production process itself. In assembly process, this means that production works is done according with accurate procedure is important. Generally, most assemble processes have steps to confirm results and working quality of former steps. However, there are some cases that it is impossible to confirm quality of former step’s work. For example, in a work to attach and fix a part using some screws, there is certain order to screw some screws to guarantee accuracy to attach the part. However, if the order to screw is not obeyed, this violation cannot be detected by appearance since the screws are enough screws, and the part is fixed. Therefore, we have been developing a worker’s motion trace system by using terrestrial magnetism sensors and acceleration sensors to confirm whether the worker’s motion accords correct assembly procedure. Up to now, our system trace system cannot judge whether worker’s motion is correct or not in 100% accuracy. So we tired to improve a method to judge the worker’s motion. In this paper, we describe this new method based on LOF, and its evaluation.
Decision-directed channel estimation and high I/Q imbalance compensation in OFDM receivers
Authors: Sylvain Traverso, Myriam Ariaudo, Inbar Fijalkow, Jean-Luc Gautier, Christian Lereau
Venue: IEEE Transactions on Communications (2009)

Direct-conversion architectures suffer from the mismatch between the In-phase (I) and the Quadrature-phase (Q) branches, commonly called I/Q imbalance. Even low I/Q imbalances imply poor performance of Orthogonal Frequency Division Multiplexing (OFDM) systems. In this paper, we propose a new algorithm that uses both training and data symbols in a decision-directed fashion to jointly estimate the channel and compensate for high receiver I/Q imbalance. Simulation results show that our method can compensate for high I/Q imbalance values and also estimate a frequency selective channel.
Regularization Methods for Semidefinite Programming
Authors: Jérôme Malick, Janez Povh, Franz Rendl
Venue: SIAM Journal on Optimization (2009)

We introduce a new class of algorithms for solving linear semidefinite programming (SDP) problems. Our approach is based on classical tools from convex optimization such as quadratic regularization and augmented Lagrangian techniques. We study the theoretical properties and we show that practical implementations behave very well on some instances of SDP having a large number of constraints. We also show that the &ldquo;boundary point method&rdquo; from Povh, Rendl, and Wiegele [Computing, 78 (2006), pp. 277-286] is an instance of this class.
Memory-efficient and high-throughput decoding of quasi-cyclic LDPC codes
Authors: Yongmei Dai, Zhiyuan Yan, Ning Chen
Venue: IEEE Transactions on Communications (2009)

We propose turbo-sum-product (TSP) and shuffled-sum-product (SSP) decoding algorithms for quasi-cyclic low-density parity-check codes, which not only achieve faster convergence and better error performance than the sum-product algorithm, but also require less memory in partly parallel decoder architectures. Compared with the turbo decoding algorithm, our TSP algorithm saves the same amount of memory and may achieve a higher decoding throughput. The convergence behaviors of our TSP and SSP algorithms are also compared with those of the SP, turbo, and shuffled algorithms by their extrinsic information transfer (EXIT) charts.
Computer-supported example-based learning: When instructional explanations reduce self-explanations
Authors: Silke Schworm, Alexander Renkl
Venue: Computers Education (2006)

We investigated whether the findings from worked-out example research on the effects of self-explanation prompts and on instructional explanations can be generalized to other example types - in this case: solved example problems. Whereas worked-out examples consist of a problem formulation, solution steps, and the final solution, solved example problems merely provide the problem formulation and the solution. We employed a first module of a computer-based environment for student teachers presenting solved example problems from which they learned how to select and to design worked-out examples for high school students. The participants (47 student teachers for German low- and medium-track schools and 33 student teachers for high-track schools) were randomly assigned to the cells of our 2x2 design (with vs. without self-explanation prompts; with vs. without instructional explanations). The effects of the different program versions on objective and subjective learning outcomes, on the perceived helpfulness of the program, and on the learning time were analyzed. As learning process data, the written and spoken self-explanations were assessed. The following main results were obtained: Particularly self-explanation prompts had favorable effects on learning outcomes, whereas instructional explanations can reduce the student teacher's self-explanation activities and thereby the learning outcomes. Whereas ''objectively'' the most favorable learning outcomes were obtained when only self-explanation prompts were employed, the student teachers perceived their learning outcome best when only instructional explanations were provided. It can be concluded that the status of self-explanation prompts and of instructional explanations is comparable irrespective of the example type presented for learning.
A simple bit error probability analysis for square QAM in Rayleigh fading with channel estimation
Authors: Hua Fu, Pooi Yuen Kam
Venue: IEEE Transactions on Communications (2009)

A new approach is presented for analyzing the bit error probability (BEP) of square, multilevel, quadrature amplitude modulation over a nonselective Rayleigh fading channel, with imperfect channel estimation employing pilot-symbol-assisted-modulation. It is much simpler and more powerful than those in the literature, and the average BEP is obtained by calculating the BEP for each individual bit. The results are given in simple, exact, closed-form expressions that do not require any numerical integration. These expressions show explicitly the behavior of the BEP as a function of various system parameters. Three channel estimation schemes are investigated. It is shown that existing channel estimation schemes using sinc interpolation and Gaussian interpolation can be improved.
A Novel Approach Using SVR Ensembles for Minor Prototypes Prediction of Seawater Corrosion Rate
Authors: Wang Ling, Fu Dong-Mei
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 02 (2009)

A novel approach based on support vector regression is proposed to establish a model for prediction of the corrosion rate of the steel. Under different seawater environment, the dataset can be identified into natural subgroups by clustering algorithm, but, in the real world the minor prototypes may be within a small, dense region located at a relatively large distance from any of the major cluster centers, which degrades the prediction performance. In this paper, we present SVR ensembles to address the minor prototypes problem and the combination strategy of hierarchical SVR is investigated. Our experiment results show that the generalization ability of SVR ensembles model consistently surpasses that of SVR by applying the test samples, and indicate that SVR ensembles may be a promising and practical methodology to monitor the seawater corrosion rate of steel.
Orthogonal decode and forward relaying with improved spectral efficiency
Authors: K. V. Srinivas, K. Giridhar, R. D. Koilpillai
Venue: IEEE Communications Letters (2009)

Cooperative relay communications can significantly improve the reliability of data transmission over wireless fading channels by implementing spatial diversity in a distributed fashion. Orthogonal decode and forward (ODF) relaying achieves maximum diversity provided by the source-destination and relay-destination channels, but suffers from low spectral efficiency. We propose a novel ODF protocol having higher spectral efficiency without sacrificing the diversity gain. We analyze the symbol error probability of the proposed protocol and also present simulation results.
Enhancing potential field data using filters based on the local phase
Authors: G. R. J. Cooper, D. R. Cowan
Venue: Computers Geosciences (2006)

Measures of the local phase of potential fields can be a useful aid to their interpretation. There are several variations in use, such as the tilt angle, tilt derivative and the Theta map. This paper compares the results of these filters, and introduces some new phase-based filters which show improved performance as edge detectors in different ways. The filters are demonstrated on synthetic gravity data and on magnetic data from Australia. Source code in Matlab format is available from the server at: www.iamg.org.
Real-Time Realistic Rendering of Tissue Surface with Mucous Layer
Authors: Aimin Hao, Feng Song, Shuai Li, Xuemei Liu, Xuping Xu
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 01 (2009)

This paper deals with the rendering issues of producing a realistic surgery simulation in real-time. In general, the visual fidelity of the simulator determines the degree of realism experienced by users. On top of the tissue, there is a mucous layer which is wet and semi-transparent. It significantly influences the surface appearance by reflecting and scattering incoming light rays. This paper describes a novel method to rendering such organs. It decomposes the incoming light into two parts, which include surface specular reflectance and subsurface scattering. First it uses bump mapping to disturb the surface normal in order to rendering the specular highlight. Then it uses an image-space algorithm to calculating the subsurface scattering contribution.
The use of textural analysis to locate features in geophysical data
Authors: G. R. J. Cooper, D. R. Cowan
Venue: Computers Geosciences (2005)

Textural analysis is a powerful tool, but it is rarely applied to geophysical potential field data because the results are often noisy and ambiguous. New texture filters (based on grey-level co-occurrence matrices (GLCMs)) have been specifically designed for gravity and magnetic data, and are useful for the detection of subtle monopolar and dipolar geophysical anomalies. The method uses two GLCM kernels simultaneously; in the first kernel the GLCM vectors are oriented along the contour lines of the feature to be located, and in the second the vectors are oriented in the 'uphill' direction, i.e. orthogonal to those of the first kernel. The ratio of the GLCM texture amplitudes from the two kernels then yields a maximum when the kernel is centred over an example of the feature within the data. The method has general application and is not limited to potential fields. It works with any type of target, as long as an example is available. Applications to both synthetic data and real data (from South Africa and Australia) are demonstrated.
User authentication scheme with privacy-preservation for multi-server environment
Authors: Ren-Chiun Wang, Wen-Shenq Juang, Chin-Laung Lei
Venue: IEEE Communications Letters (2009)

New user authentication schemes for multiple-servers environment were proposed by Liao-Wang and Tsai. In their schemes, application servers do not need to maintain a verification table and this admired merit is not addressed by previous scholarship. Besides, the privacy of users is also addressed in Liao-Wang's scheme. In this article, we show that their schemes are not secure against the server spoofing and the impersonation attacks. Then we propose a robust user authentication scheme to withstand these attacks and keep the same merits.
A new spatial path persistency model for TOA-based indoor geolocation
Authors: Ferit Ozan Akgul, Kaveh Pahlavan
Venue: IEEE Communications Letters (2009)

Analysis of the persistency and birth/death of multipath components of the channel impulse response is essential for performance evaluation of indoor geolocation algorithms using indirect paths for ranging. The use of indirect paths via multipath diversity is particularly important for situations where the direct path gets blocked. In this letter, we propose a statistical model for the spatial behavior of the persistency of multipath components as a mobile moves inside a building. Based on empirical data from a measurement calibrated ray tracing algorithm we show that the persistency in a typical building is modeled by log-logistic distribution rather than commonly assumed exponential distribution and path birth can be modeled as a Poisson distribution.
Achieving near-capacity at low SNR on a multiple-antenna multiple-user channel
Authors: Chau Yuen, Bertrand M. Hochwald
Venue: IEEE Transactions on Communications (2009)

We analyze the sensitivity of the capacity of a multi-antenna multi-user system to the number of users being served. We show analytically that, for a given desired sum-rate, the extra power needed to serve a subset of the users at low SNR (signal-to-noise ratio) can be very small, and is generally much smaller than the extra power needed to serve the same subset at high SNR. The advantages of serving only subsets of the users are many: multi-user algorithms have lower complexity, reduced channel-state information requirements, and, often, better performance. We provide guidelines on how many users to serve to get near-capacity performance with low complexity. For example, we show how in an eight-antenna eight-user system we can serve only four users and still be approximately 2 dB from capacity at very low SNR.
An Efficient Certificate-Based Signature Scheme without Pairings
Authors: Jianhong Zhang, Hua Chen, Qin Geng
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 02 (2009)

Certificate-based cryptography solves certificate revocation problem and eliminate third-party queries in the traditional PKI and avoid key escrow in the ID-based cryptography. It is a better alternative for the traditional public key system. In this paper, we proposed an efficient certificate based signature scheme based on Schnorr signature and zero-knowledge proof technique. Our proposed scheme doesn't use pairing operator which is the most expensive computation. Then we show that our proposed scheme is proven to be against two forgeable attacks in the random oracles model, and the security is related to that of Schnorr signature.
A Game Theory Analysis on TD-SCDMA Standard: The Role of Government in Integrated Innovation of China
Authors: Zhang Jihong
Venue: Proceedings of the 2009 Second International Symposium on Knowledge Acquisition and Modeling - Volume 01 (2009)

This paper analyzes the competition among the three technology standards in the Chinese 3G market with a three-player game model. Based on our basic assumptions, we build and solve our game models under different market conditions: one is with government subsidy to TD-SCDMA and the other is without such subsidy. Furthermore, we conduct a comparative analysis of the Nash equilibrium under these two market conditions. Our analysis shows that the commercialization and success of the TD-SCDMA technology standard in the Chinese 3G market depends on not only the R&D of the relevant firms but also the government subsidy, and that the stronger the government subsidy the more competitive this standard will be.
Fingerprint verification using spectral minutiae representations
Authors: Haiyun Xu, Raymond N. J. Veldhuis, Asker M. Bazen, Tom A. M. Kevenaar, Ton A. H. M. Akkermans, Berk Gokberk
Venue: IEEE Transactions on Information Forensics and Security (2009)

Most fingerprint recognition systems are based on the use of a minutiae set, which is an unordered collection of minutiae locations and orientations suffering from various deformations such as translation, rotation, and scaling. The spectral minutiae representation introduced in this paper is a novel method to represent a minutiae set as a fixed-length feature vector, which is invariant to translation, and in which rotation and scaling become translations, so that they can be easily compensated for. These characteristics enable the combination of fingerprint recognition systems with template protection schemes that require a fixed-length feature vector. This paper introduces the concept of algorithms for two representation methods: the location-based spectral minutiae representation and the orientation-based spectral minutiae representation. Both algorithms are evaluated using two correlation-based spectral minutiae matching algorithms. We present the performance of our algorithms on three fingerprint databases. We also show how the performance can be improved by using a fusion scheme and singular points.
Production Scheduling of Agile Manufacturing Based on Multi-agents
Authors: Ming Xu
Venue: Proceedings of the 2009 Second International Symposium on Knowledge Acquisition and Modeling - Volume 02 (2009)

In the analysis of agile manufacturing environment and the characteristics of the production scheduling control method. This paper utilizes Multi-Agents technology to production scheduling system and builds a rapid response and intelligence agile manufacturing system. This paper utilizes Multi-Agents' ability to achieve the task decomposition. Then this paper makes use of consultation and multi-attributes decision mechanism of contract net to solve the scheduling problem in task allocation and coordination of agile manufacturing. The experimental result shows that the system is effective and efficient.
The Number of Passengers Forecast in Emergency Situation of Airport Based on Time Series Analysis
Authors: Bing Li, Xiaochen Ding, Wen Han, Long Cheng, Mengying Yu
Venue: Proceedings of the 2009 Second International Symposium on Knowledge Acquisition and Modeling - Volume 02 (2009)

The number of delayed passengers forecast is a key factor to improve the efficiency of airport facility in emergency situation. But it is rarely considered to make a forecast beforehand based on a scientific method preparing for dealing with this kind of event in the future. Aiming at this problem, this paper proposed a forecasting method based on time series analysis. The method provides a relatively all-around approach for airport to better response to emergency.