ppxscal/embedding_network huggingface dataset:
Hexahedral mesh smoothing using a direct method
Authors: Agustín Menéndez-Díaz, Celestino González-Nicieza, Arturo Ernesto Álvarez-Vigil
Venue: Computers Geosciences (2005)

This paper develops a generalisation of the mesh smoothing direct method proposed by Balendran, to three dimensions by applying its methodology to smoothed hexahedral meshes. A geometric criteria is used where irregular quadrilaterals are converted to regular quadrilaterals on each face of the hexahedron using a local stiffness matrix. This matrix is then converted to a spatial stiffness matrix with reference to absolute coordinates in order to assemble the geometrical stiffness matrix as a global stiffness matrix. The fixing of boundary conditions is analysed and results obtained in a series of hexahedral meshes, used in finite difference method analysis, are illustrated. To evaluate the quality of the obtained results, a degree of uniformity is calculated and a comparative study of the improvement obtained in each zone of the hexahedral mesh is conducted. The proposed method permits the marking out of the portions of mesh in which a Laplacian smoothening fails to improve the mesh quality, therefore, requiring the use of other methods in which inserted mesh points are taken into account.
Delay-line-based analog-to-digital converters
Authors: Guansheng Li, Yahya M. Tousi, Arjang Hassibi, Ehsan Afshari
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

We will introduce a design of analog-to-digital converters (ADCs) based on digital delay lines. Instead of voltage comparators, they convert the input voltage into a digital code by delay lines and are mainly built on digital blocks. This makes it compatible with process scaling. Two structures are proposed, and tradeoffs in the design are discussed. The effects of jitter and mismatch are also studied. We will present two 4-bit, 1-GS/s prototypes in 0.13-µm and 65-nm CMOS processes, which show a small area (0.015 mm2) and small power consumption (< 2.4 mW).
Channel efficiency-based transmission rate control for congestion avoidance in wireless ad hoc networks
Authors: Xinming Zhang, Jun Lv, Xiaojun Han, Dan Keun Sung
Venue: IEEE Communications Letters (2009)

If the transmission rate of transmission control protocol (TCP) does not match that of the medium access control (MAC) protocol in wireless ad hoc networks, it causes network congestion and network performance degradation. This letter proposes a new mechanism to feed back the real channel efficiency of MAC protocol to TCP. Comparing the real channel efficiency in MAC protocol with the virtual channel efficiency in TCP, we can adaptively control the transmission rate in TCP by using the congestion window and the flow of TCP ACKs, in order to alleviate the load of MAC protocol before a congestion event occurs and to enhance the network performance. Simulation results show that the proposed mechanism outperforms 802.11 DCF in terms of throughput and delay.
Optimal resource allocation in the OFDMA downlink with imperfect channel knowledge
Authors: Ian C. Wong, Brian L. Evans
Venue: IEEE Transactions on Communications (2009)

Previous research efforts on OFDMA resource allocation have typically assumed the availability of perfect channel state information (CSI). Unfortunately, this is unrealistic, primarily due to channel estimation errors, and more importantly, channel feedback delay. In this paper, we develop optimal resource allocation algorithms for the OFDMA downlink assuming the availability of only partial (imperfect) CSI. We consider both continuous and discrete ergodic weighted sum rate maximization subject to total power constraints, and average bit error rate constraints for the discrete rate case. We approach these problems using a dual optimization framework, allowing us to solve these problems with O(MK) complexity per symbol for an OFDMA system with K used subcarriers and M active users, while achieving relative optimality gaps of less than 10-5 for continuous rates and less than 10-3 for discrete rates in simulations based on realistic parameters.
An Efficient Method to Hide Information in MPEG Video Sequences
Authors: Peng Zheng, Bo Zhao, Min-zhong Liu
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 02 (2009)

In the paper, we present an efficient algorithm to hide information in MPEG compressed video. In order to utilize the large amount of video streams, and to speed up the process of hiding information, we provide an algorithm that makes use of compressed coefficients to hide information directly. The advantage of the method is that we can make use of DCT coefficients directly without compressing and decompressing. We have experimented with the algorithm, and the result of experiment indicates that the performance of the algorithm is efficient.
Production and delivery scheduling problem with time windows
Authors: J. M. Garcia, S. Lozano
Venue: Computers and Industrial Engineering (2005)

This paper deals with the problem of selecting and scheduling the orders to be processed by a manufacturing plant for immediate delivery to the customer site. Among the constraints to be considered are the limited production capacity, the available number of vehicles and the time windows within which orders must be served. We first describe the problem as it occurs in practice in some industrial environments, and then present an integer programming model that maximizes the profit due to the customer orders to be processed. A tabu search-based solution procedure to solve this problem is developed and tested empirically with randomly generated problems. Comparisons with an exact procedure show that the method finds very good-quality solutions with small computation requirements.
An Introduction and Comparison of Dung's Argumentation Frameworks
Authors: Wei Zhang, Shujuan Ji, Yongquan Liang, Qijia Tian
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 02 (2009)

Argumentation is a useful abstract mechanism in artificial intelligence; it has a wide range of applications. P.M. Dung’s abstract argumentation framework (AF) and assumption-based argumentation framework (ABF) are the most famous and fundamental argumentation frameworks. In this paper, we introduce these two frameworks, compare their differences and identify their relationships. These two frameworks and derivation process can instruct the late comers to construct an argument.
A distributed time-driven simulation method for enabling real-time manufacturing shop floor control
Authors: Sohyung Cho
Venue: Computers and Industrial Engineering (2005)

This paper proposes a distributed simulation approach for scheduling discrete-events in manufacturing shop floors. The proposed approach employs a time-driven method to simulate occurrence of discrete-events using distributed entities that replicate physical entities in the manufacturing shop floor. In specific, the proposed approach iteratively controls the timing of discrete-events occurrence using a control theoretic model. In this approach, changing the speed of the simulation clock, termed time-scaling factor, can accelerate or decelerate the simulation speed resulting in simpler synchronizations of discrete-events and faster simulation than standard distributed discrete-event simulations according to the capability of the communication networks. Computational experiments are conducted to test the performance of the proposed system with different values of the time-scaling factor, and the relationship between the system performance and the time-scaling factor is investigated through analysis of the system model. Results obtained from the computational experiments show significant successes in speeding up discrete-event simulations in such a way that the proposed approach can be used for the control of manufacturing shop floors, providing real-time decision supports.
Digital geological mapping with tablet PC and PDA: A comparison
Authors: P. Clegg, L. Bruciatelli, F. Domingos, R. R. Jones, M. De Donatis, R. W. Wilson
Venue: Computers Geosciences (2006)

Both the hardware and software available for digital geological mapping (DGM) have advanced considerably in recent years. Mobile computers have become cheaper, lighter, faster and more power efficient. Global Positioning Systems (GPS) have become cheaper, smaller and more accurate, and software specifically designed for geological mapping has become available. These advances have now reached a stage where it is effective to replace traditional paper-based mapping techniques with those employing DGM methodologies. This paper attempts to assess and evaluate two currently available DGM systems for geological outcrop mapping: one based on a Personal Digital Assistant (PDA) running ESRI ''ArcPad'', and the second based on a Tablet PC running ''Map IT'' software. Evaluation was based on field assessment during mapping of a well-exposed coastal section of deformed Carboniferous and Permian rocks at N. Tynemouth in NE England. Prior to the field assessment, several key criteria were identified as essential attributes of an effective DGM system. These criteria were used as the basis for the assessment and evaluation process. Our findings suggest that the main concerns presented by sceptics opposed to DGM have largely been resolved. In general, DGM systems using a Tablet PC were found to be most suitable for a wide range of geological data collection tasks, including detailed outcrop mapping. In contrast, systems based on a PDA, due to small screen and limited processing power, were best suited for more basic mapping and simple data collection tasks. In addition, PDA-based systems can be particularly advantageous for mapping projects in remote regions, in situations where there is a limited power supply or where total weight of equipment is an important consideration.
Optimum asymmetric constellation design for trellis-coded modulation over Gaussian channels
Authors: Xiaoxin Zhang, Yuping Zhao, Li Zou
Venue: IEEE Communications Letters (2009)

This letter studies the optimization of asymmetric constellations for trellis-coded modulation (TCM). Unlike the conventional criterion of maximizing the free Euclidean distance, the criterion here is to minimize the bit error rate (BER) of TCM systems. The letter presents an easy way to derive the BER upper bound for any TCM codes, and proposes the method for designing optimum asymmetric constellations by minimizing the bound. The given method can be applied to TCM systems with arbitrary state numbers. Numerical results verify that all the codes designed by the proposed method achieve better BER performance than symmetric ones.
NEM-XML: A Fast Non-extractive XML Parsing Algorithm
Authors: Yunsong Zhang, Lei Zhao, Jiwen Yang, Liying Yu
Venue: Proceedings of the 2009 Third International Conference on Multimedia and Ubiquitous Engineering (2009)

XML has become integral to many critical enterprise technologies with its ability to enable data interoperability between applications on different platforms. However, wide adoption of XML is hindered by inefficient parsing methods. In this paper, we present a novel approach for parsing XML in a non-extractive way, encoding node information in 64-bit integers instead of creating node objects during parsing. The testing results show that great improvement has been achieved over present XML parsers, both in terms of memory consumption and parsing performance. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Moment generating function of the generalized α-µ distribution with applications
Authors: Amer M. Magableh, Mustafa M. Matalgah
Venue: IEEE Communications Letters (2009)

In this letter, we consider the α-µ channel fading model and we evaluate the moment generating function (MGF) for the probability density function characterizing this new channel model. The derived MGF expression is used in evaluating the bit error rate for different coherent modulation techniques over this generalized fading channel. We also derive an expression for the outage probability for this channel model. All the derived expressions are in closed forms and general that can reduce to the well known fading channel distributions in the literature such as Rayleigh, Nakagami-m, and Weibull model as special cases.
A New Spatial Index Structure for GIS Data
Authors: Xiaoqian Wu, Chuanqin Zang
Venue: Proceedings of the 2009 Third International Conference on Multimedia and Ubiquitous Engineering (2009)

With the development of information technology, spatial data plays an increasingly important part in both people’s daily life and industrial manufacture. The demand of spatial data processing and retrieving is challenging traditional database technology. The emergence of spatial database has greatly raised the efficiency of spatial data handling. As the key component of spatial database, spatial index technology got a booming development in the past few years; kinds of new index structure is being developed, improved, and eliminated. This article pays attention to the spatial index structure; we first give a survey on the mesh index structure, present the classical R-tree index structure and its variations, then according to the nature of GIS data, we develop a new spatial index structure for GIS data composing the advantage of mesh index and R-tree index, and verify its high efficiency experimentally.
A compact diplexer using square open loop with stepped impedance resonators
Authors: Jessada Konpang
Venue: Proceedings of the 4th international conference on Radio and wireless symposium (2009)

In this paper, a compact diplexer using a square open loop with stepped impedance resonators is proposed to develop the microstrip square open loop resonators bandpass filter. The filter is based upon a square open loop resonator consisting of two identical patches which is attached to the inner corner of the square open loop for size reduction. The compact miniaturized two poles square open loop resonators are used to design filters and a diplexer for IMT-2000 bands application. A prototype diplexer is designed at 1950 MHz and 2140 MHz. The diplexer channels are 3.07% and 2.8% fractional bandwidth. The measured insertion losses are about 3.0 dB for the two channels with better than 45 dB isolation. It is very useful for applications in the IMT- 2000 mobile communication systems.
Beyond the stars: exploiting free-text user reviews to improve the accuracy of movie recommendations
Authors: Niklas Jakob, Stefan Hagen Weber, Mark Christoph Müller, Iryna Gurevych
Venue: Proceeding of the 1st international CIKM workshop on Topic-sentiment analysis for mass opinion (2009)

In this paper we show that the extraction of opinions from free-text reviews can improve the accuracy of movie recommendations. We present three approaches to extract movie aspects as opinion targets and use them as features for the collaborative filtering. Each of these approaches requires different amounts of manual interaction. We collected a data set of reviews with corresponding ordinal (star) ratings of several thousand movies to evaluate the different features for the collaborative filtering. We employ a state-of-the-art collaborative filtering engine for the recommendations during our evaluation and compare the performance with and without using the features representing user preferences mined from the free-text reviews provided by the users. The opinion mining based features perform significantly better than the baseline, which is based on star ratings and genre information only.
Improved Speaker Identification Algorithm Based on Discriminative Weighted Method
Authors: Shaomei Li, Yunfei Guo, Lixiong Liu
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

How to decrease false acceptance rate is an ever-lasting target in speaker identification system. This paper proposes a new method based on the thought of discriminative weighting, which is realized by previously distributing a discriminative weighted value vector between each two speakers. The improved algorithm means to calculate discriminative weighted values based on the difference between each two speakers, which are formed into a discriminative weighted vector to discriminate the similarity of test speech from these two speakers. In the identification process, test speech will be measured between each two speakers one by one, and the final result will be derived from syncretizing these results. Effect of the improved algorithm was proved by experimental results. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Valley Landscape Reconstruction Based on VRGIS - A Case Study in Juntang Lake Valley
Authors: Dunli Liu, Jianghua Zheng, Zhihui Liu, Yuan Zhao
Venue: Proceedings of the 2009 Third International Conference on Multimedia and Ubiquitous Engineering (2009)

The purpose of this research is to demonstrate the possibility of valley landscape reconstruction by VRGIS technology, to design and realize the dynamic observation and changing simulation. The work takes Juntang lake valley as a case. The Delaunay triangulation is constructed by Successive Interpolation Algorithm in order to establish the TIN model. The rainy and snowy scenes are simulated by Particle System and the function of the model is designed by OpenGL technology, at the same time the VRGIS component is devised by COM anamnesis. The result indicates that 3D reconstructed Juntang lake valley landscape can be used for better representing analyzing the dynamic geographical phenomenon by the functions such as roaming, ranging, virtual flying, submerging analysis, rainy and snowy simulating, display controlling of features. The conclusion is that valley landscape can be well reconstructed by VRGIS technology, which is important to realize real-time emersion, query analysis, and variational forecast with valley landscape.
Bottleneck zone analysis in energy-constrained wireless sensor networks
Authors: Qinghua Wang, Tingting Zhang
Venue: IEEE Communications Letters (2009)

In a typical sensor network, nodes around the sink consume more energy than those further away. It is not unusual that limited energy resources available at the nodes around the sink become the bottleneck which confines the performance of the whole network. In this letter, we firstly present our considered bottleneck zone in a general sensor network scenario. Then, the effect of the bottleneck zone on network performance is investigated by deducing performance bounds imposed by the energy resources available inside the bottleneck zone. In this letter, both the performance bound in terms of network lifetime and the performance bound in terms of information collection are explored. Finally, the ways by which network deployment variables may affect the performance bounds are analyzed.
Computer-Based Copyright Control System in Social Network and an Ordinal Measure Based on Gray Scale Value
Authors: Longfei Ma, Dengpan Ye, Shiguo Lian, Lina Wang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

In social network, more and more video websites were appeared around the world, and everyone can upload or download the media freely. Therefore, it brings some content security problems, such as piracy, sensitive contents' disclosure and so on. This paper proposes a system to detect the media which is prepare to be uploaded. First we should initialize a Media Feature Database (MFD) which contains numerous Media Features (MF) of the certificated media contents. When a media is preparing to be uploaded, our system will check the media's feature to make sure that whether this media's feature has already existed in the MFD. If conflict accrued, the system will prevent the uploading. Else, the uploading will be allowed and the MFD will be updated when the uploading finished. Based on this system, this paper proposes a method of the MF's extraction- ordinal measure based on gray scale value. The experiment shows that this method is robust and efficient.
Design solutions for sample-and-hold circuits in CMOS nanometer technologies
Authors: Francesco Centurelli, Pietro Monsurrò, Salvatore Pennisi, Giuseppe Scotti, Alessandro Trifiletti
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

Solutions for the design of low-voltage sample-and-hold (S/H) circuits in CMOS nanometer technologies are presented. As a design example, a 0.8-V supply S/H is designed and simulated using a 130-nm CMOS process. It dissipates 0.5 mW at dc and provides almost a rail-to-rail signal swing. When clocked at 40 MS/s and with a 1.4-VPP differential input signal, the simulated spurious-free dynamic range, signal-to-noise ratio, and total harmonic distortion are 57, 67, and -56 dB (9 equivalent bits), respectively, with low sensitivity to supply, temperature, process, and mismatch variations. The proposed solution employs a three-stage low-voltage amplifier without a tail current source in the differential pair and a switch topology, which combines clock voltage doubling and dummy switches.
Design of the Classified File Management and Control System
Authors: Yanmei Lv, Jiangsheng Sun, Gefang Wang
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 01 (2009)

The classified file management control state at present was analyzed at first in the paper. Then, according to improve the security and the management capability of the inside network information, the classified file management and control system was designed, which consists of three modules: the management control platform, the electronic file examine and approve system, and the classified moving flash disk. The functions of each module were designed in detail. Through the design, the system was given the functions, which are collectively storage, unified management and monitoring control in the whole course for the classified file, so as to achieve the aim of prevention in advance, trail afterwards under the classified file use course, and control the channel of revealing the classified information from the mobile medium effectively.
A computer model for volcanic ash fallout and assessment of subsequent hazard
Authors: G. Macedonio, A. Costa, A. Longo
Venue: Computers Geosciences (2005)

hazmap is a fortran code for the solution of the equations of diffusion, transport and sedimentation of small particles, in order to model the dispersion of ash generated by a convective column. The model was developed simplifying the advection-diffusion-sedimentation equation for volcanic ash transport in the atmosphere from three to two dimensions and using a semi-analytical computational method to greatly reduce the required computer time and memory. hazmap can be used either to simulate the mass distribution of the deposit if a wind profile is given (''deposit mode''), or to define the probability of a given accumulation of mass on the ground if a statistical set of wind profiles is provided (''probability mode''). The model needs the definition of the physical system (spatial distribution of the point sources, total erupted mass, settling velocity distribution, wind velocity profile, atmospheric turbulent diffusion coefficients), and of a computational grid. The output values of mass accumulation on the ground or the probability of mass accumulation are computed on a regular grid, suitable for further analysis.