ppxscal/embedding_network huggingface dataset:
Usage of the contour method in measuring residual stress in welding and peen-welding applications
Authors: Nasri Hassan, Lanteigne Jacques, Champliaud Henri
Venue: Proceedings of the IASTED Asian Conference on Modelling and Simulation (2007)

Residual stresses, which are inherent to many manufacturing processes, may considerably reduce the fatigue properties of mechanical systems. Welding is a process that induces residual stresses due to plastic deformation and phase changes, which take place within the heat-affected zone (HAZ). Mechanical surface treatments are often used to minimize or even reverse the tensile stresses due to welding. In this study the influence of peening on existing welding residual stresses, through all the plate thickness, is shown using the contour method. The contour method, the measurement protocol selected in this paper for estimating residual stresses, allows the assessment of these stresses over a whole cross-section, unlike other common methods which only provide limited local point measurements. This method is based on the relaxation of stresses resulting from EDM cutting. Displacements of the relaxed cross section are measured by a laser beam. The cut surface is treated and approximated through a polynomial surface, which is used to impose displacements on the nodes of a finite element model. The solution to this problem is the normal stress responsible for the released micro-displacements on the plane section cut. This method was applied on 516 carbon steel plates either in the as-welded condition or welded and peened.
Soft-output MMSE V-BLAST detector under ML channel estimation and channel correlation
Authors: Jun Wang, Oliver Yu Wen, Shaoqian Li
Venue: IEEE Communications Letters (2009)

Channel estimation errors have not been taken into account by existing soft-output minimum mean square error (MMSE) vertical Bell Lab Space Time (V-BLAST) detectors. As a result, the system performance will be degraded under practical channel estimation. In this letter, we propose a novel soft-output MMSE V-BLAST detector, which takes the estimation error of maximum likelihood (ML) multiple-input multiple-output (MIMO) channel estimation and receiver spatially correlation into account in the computation of the MMSE filter and log-likelihood ratio (LLR) of each coded bit. When compared with existing MMSE V-BLAST detectors, simulation results show that the proposed novel detector can obtain sizable performance gain.
Ant colony optimization based packet scheduler for peer-to-peer video streaming
Authors: Young H. Jung, Hong-Sik Kim, Yoonsik Choe
Venue: IEEE Communications Letters (2009)

This letter describes a new packet scheduling algorithm for enhancing the quality of distributed peer-to-peer video streaming. The algorithm was designed for when streaming server peers use error recovery such as automatic-repeat-request (ARQ) rather than error protection to avoid overburdening network resources. Ant colony optimization was used for scheduling groups of packets to reflect the channel status and error recovery effect of multiple server peers heuristically. Simulation results show that the proposed algorithm can enhance the quality of distributed video streaming services.
Standby redundancy optimization problems with fuzzy lifetimes
Authors: Ruiqing Zhao, Baoding Liu
Venue: Computers and Industrial Engineering (2005)

Three types of system performances-the expected system lifetime, @a-system lifetime, and system reliability-characterized in the context of credibility are investigated in this paper. Some fuzzy simulations are designed to estimate these system performances. In order to formulate general standby redundancy optimization problems with fuzzy lifetimes, a spectrum of standby redundancy fuzzy programming models are proposed. Fuzzy simulation, neural network, and genetic algorithm are also integrated to produce a hybrid intelligent algorithm for solving those models. Finally, some numerical experiments on multi-stage system and network system are provided.
Developing Curriculum on U-City Education
Authors: Tae-Woong Jung, Jee-Hee Koo
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

Ubiquitous has brought a new paradigm to our society. ‘E’-branded apartments and mobile phones are now catching the public eye with a new brand, the ‘U’ prefix. There are a range of U-City related businesses carried out in diverse fields including R&D, central government, and self-governing bodies. As noted above, U-City is currently the buzz business in many fields but lacks professional manpower. In order to develop U-City as a new growth engine for Korea and export it to overseas, U-City education as well as curriculum development is urgently required. This paper proposed curriculum development methodologies for U-City education and carries a curriculum recommendation.
A synthetic control chart for monitoring process dispersion with sample standard deviation
Authors: H. J. Huang, F. L. Chen
Venue: Computers and Industrial Engineering (2005)

Some factors in manufacturing such as faulty raw material, unskilled/careless operators, and loosening of machine settings may lead to a change in process dispersion without necessarily influencing the level of the process mean. This paper proposes a synthetic control chart for monitoring the changes in the standard deviation of a normally distributed process. The synthetic chart is a combination of the sample standard deviation (S) chart and the conforming run length (CRL) chart. The S chart can be regarded as a special case of the synthetic chart. The operation, design, and performance of this chart are described. Average run length comparisons between other procedures and the synthetic chart are presented. It indicates that the synthetic chart is a good alternative for monitoring process dispersion. The variable sampling interval (VSI) schemes as an enhancement to the synthetic chart are discussed to further improve the chart performance. An example is presented to illustrate the application of synthetic chart and its VSI scheme.
An analysis of information diffusion in the blog world
Authors: Yong-Suk Kwon, Sang-Wook Kim, Sunju Park
Venue: Proceeding of the 1st ACM international workshop on Complex networks meet information & knowledge management (2009)

In the blog world, bloggers produce information, establish relationships with other bloggers in order to exchange information, and form a blog network, an online social network. In social network theory, information diffusion is said to occur through the relationships of the social network's constituents. Contrary to the social network theory, however, when the history of information diffusion that occurs in the actual blog world is examined, a majority of information spreads between the constituents without any established relationship. Moreover the phenomenon of explosive information diffusion is also observed. Using the real-world blog data, this paper reveals that these two phenomena are related to each other and examines the causes that induce explosive information diffusion.
Adaptive terminal to base station assignment in BFWA systems
Authors: Balázs Héder, László Csurgai-Horváth, János Bitó
Venue: IEEE Communications Letters (2009)

In point-multipoint systems the signal to interference plus noise ratio highly depends on the assignment of terminal stations (TS) to base stations (BS). The Broadband Fixed Wireless Access (BFWA) systems operate at high carrier frequencies. In this frequency range wave propagation is highly influenced by precipitation. Applying site diversity can mitigate rain attenuation effects. Present contribution provides a special site diversity method adopting genetic algorithm to adaptively optimize TS-BS assignments from point of view of the interference in BFWA service area. Rain events are generated with a Markov modeled simulation of the rain cell translations.
Single-inductor-multiple-output switching DC-DC converters
Authors: Dongwon Kwon, Gabriel A. Rincón-Mora
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

Emerging feature dense portable microelectronic devices pose several challenges, including demanding multiple supply voltages from a single miniaturized power-efficient platform. Unfortunately, the power inductors used in magnetic-based switching converters (which are power efficient) are bulky and difficult to integrate. As a result, single-inductor-multiple-output (SIMO) solutions enjoy popularity, but not without design challenges. This brief describes, illustrates, and evaluates how SIMO dc-dc converters operate, transfer energy, and control (through negative feedback) each of their outputs.
F-TPR: fine two-phase IP routing scheme over shortest paths for hose model
Authors: Eiji Oki, Ayako Iwaki
Venue: IEEE Communications Letters (2009)

This letter proposes an IP-based finely-distributed routing scheme based on two-phase routing (TPR) over shortest paths for the hose model. It is called the fine-TPR (F-TPR) scheme. Compared to the original TPR, F-TPR distributes traffic from a source node to intermediate nodes more finely, where the distribution ratio is determined for each source-destination pair. To determine an optimum set of the distribution ratios, we successfully formulate our problem as a quadratic constraint programming (QCP) formulation that can be solved by using a mathematical programming solver. Numerical results show that F-TPR greatly outperforms TPR and its performance approaches that provided by the sophisticated traffic engineering (TE) scheme of Multi-Protocol Label Switching (MPLS-TE).
Multiple indicator cokriging with application to optimal sampling for environmental monitoring
Authors: Eulogio Pardo-Igúzquiza, Peter A. Dowd
Venue: Computers Geosciences (2005)

A probabilistic solution to the problem of spatial interpolation of a variable at an unsampled location consists of estimating the local cumulative distribution function (cdf) of the variable at that location from values measured at neighbouring locations. As this distribution is conditional to the data available at neighbouring locations it incorporates the uncertainty of the value of the variable at the unsampled location. Geostatistics provides a non-parametric solution to such problems via the various forms of indicator kriging. In a least squares sense indicator cokriging is theoretically the best estimator but in practice its use has been inhibited by problems such as an increased number of violations of order relations constraints when compared with simpler forms of indicator kriging. In this paper, we describe a methodology and an accompanying computer program for estimating a vector of indicators by simple indicator cokriging, i.e. simultaneous estimation of the cdf for K different thresholds, {F(u,z"k),k=1,...,K}, by solving a unique cokriging system for each location at which an estimate is required. This approach produces a variance-covariance matrix of the estimated vector of indicators which is used to fit a model to the estimated local cdf by logistic regression. This model is used to correct any violations of order relations and automatically ensures that all order relations are satisfied, i.e. the estimated cumulative distribution function, F@^(u,z"k), is such that:F@^(u,z"k)@?[0,1],@?z"k,andF@^(u,z"k)=
Throughput analysis considering coupling effect in IEEE 802.11 networks with hidden stations
Authors: Taejoon Kim, Jong-Tae Lim
Venue: IEEE Communications Letters (2009)

This letter investigates the throughput performance of the IEEE 802.11 networks with hidden stations. Note that the decoupling approximation of the Bianchi's Markov chain model is valid for the IEEE 802.11 networks with a large number of the hidden stations. Hence, we propose a new analytic model to accommodate the effect of the hidden stations and estimate the network throughput based on the analytic model.
Optimisation-based scheduling: A discrete manufacturing case study
Authors: Michael C. Georgiadis, Aaron A. Levis, Panagiotis Tsiakis, Ioannis Sanidiotis, Constantinos C. Pantelides, Lazaros G. Papageorgiou
Venue: Computers and Industrial Engineering (2005)

This work presents the development and implementation of a production scheduling system for an electrical appliance manufacturer. Based on recent advances in optimisation-based scheduling approaches, two different software architectures based on two different scheduling formulations, namely the RTN and the STN, are proposed to integrate information available in the different production units and stages with formal algorithmic tools. Optimization results indicate that significant economic benefits can be achieved (e.g. minimization of total operating costs) while ensuring full customer satisfaction as opposed to normal practices followed in the company relying on human expertise. The work indicates that it is possible to solve real-life manufacturing problems using optimization-based approaches but the integration of information in a timely fashion seems to be a major factor in successfully implementing the system and fully realizing its benefits.
Capacity region of multiuser shared channel with time-varying transmission power
Authors: Hanbyul Seo, Daeyoung Park, Byeong Gi Lee
Venue: IEEE Transactions on Communications (2009)

In this paper, we investigate the capacity region of a multiuser shared channel with time-varying transmission power, whose typical examples are the Forward Packet Data Channel (F-PDCH) of IS-2000 1xEV-DV system and the High Speed Downlink Shared Channel (HS-DSCH) in 3GPP High Speed Downlink Packet Access (HSDPA) system. The concavity of the throughput yields the property that additional power contributes more to a weaker user having a lower channel gain than to a stronger user. Noting this property, we consider a power-balanced policy which tries to balance the received SNR of each user by serving a weaker user with higher transmission power. Then, we establish the equivalence of the power-balanced policy and the Pareto optimal policy which yields a throughput vector at the boundary of the capacity region. This enables to characterize the capacity region explicitly, and also renders an easy means to maximize the total throughput while meeting each user's requirement.
Anticipative Inquiry Scheme for Efficient RFID Tag Identification
Authors: Ching-Hsien Hsu, Bo-Yu Chen, Chao-Tung Yang
Venue: Proceedings of the 2009 Third International Conference on Multimedia and Ubiquitous Engineering (2009)

One of the challenges in designing modern RFID systems is that when more than one tag exists in an RFID environment, it may occurs collisions so that the whole system becomes inefficient and increases the time for identifying RFID Tags. In order to simultaneously recognize several tags within a reader interrogation zone, an anti-collision algorithm should be applied. In this paper, we present an Anticipative Inquiry Scheme (AIS), which is an enhanced technique based on the query tree protocol, for efficient tag identification. The main idea of the Anticipative Inquiry Scheme is to limit number of collisions on different level of a query tree. When number of collisions reaches a predefined acceptable ratio, it reveals that density in RF field is too high. To avoid sending unnecessary inquiries, the prefix matching will be jumped to next level, alleviating the collision problems. We have implemented the Anticipative Inquiry Scheme along with query tree protocol. The experimental results show that the method of setting frequency bound indeed improves the identification efficiency in high density and randomly deployed RFID systems.
TCP transmission rate control mechanism based on channel utilization and contention ratio in ad hoc networks
Authors: Xinming Zhang, Nana Li, Wenbo Zhu, Dan Keun Sung
Venue: IEEE Communications Letters (2009)

In ad hoc networks, both contention and congestion can severely affect the performance of TCP. In our work, we first show that the over-injection of conventional TCP window mechanism results in severe contentions, and medium contentions cause network congestion. Furthermore, introducing two metrics, channel utilization (CU) and contention ratio (CR), we characterize the network status. Then, based on these two metrics, we propose a new TCP transmission rate control mechanism based on Channel utilization and Contention ratio (TCPCC). In this mechanism, each node collects the information about the network busy status and determines the CU and CR accordingly. The CU and CR values fed back through ACK are ultimately determined by the bottleneck node along the flow. The TCP sender controls its transmission rate based on the feedback information. Simulation results show that the proposed TCPCC mechanism significantly outperforms the conventional TCP mechanism and the TCP contention control mechanism in terms of throughput and end-to-end delay.
Research on Vector-Control System of PMSM Based on Internal Model Control of Current Loop
Authors: Jun Liu, Meng-zhi Huang, Yang Wang
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 01 (2009)

The current regulation based on the internal model control is applied to vector control of PMSM. It avoids the adjustment of two PI-parameters; moreover the IMC structure improves the characteristic of the current loop. Generally, the flux of PMSM is changing with the load current (torque). Simulation results under flux saturation considered and not considered show that the current internal model controller can provide good performance with matched model and unmatched model. And the system has good features of the robustness to disturbances, and parameter variations. Satisfactory performance can be achieved.
Fast algorithm for updating the discriminant vectors of dual-space LDA
Authors: Wenming Zheng, Xiaoou Tang
Venue: IEEE Transactions on Information Forensics and Security (2009)

Dual-space linear discriminant analysis (DSLDA) is a popular method for discriminant analysis. The basic idea of the DSLDA method is to divide the whole data space into two complementary subspaces, i.e., the range space of the within-class scatter matrix and its complementary space, and then solve the discriminant vectors in each subspace. Hence, the DSLDA method can take full advantage of the discriminant information of the training samples. However, from the computational point of view, the original DSLDA method may not be suitable for online training problems because of its heavy computational cost. To this end, we modify the original DSLDA method and then propose a data order independent incremental algorithm to accurately update the discriminant vectors of the DSLDA method when new samples are inserted into the training data set. We conduct experiments on the AR face database to confirm the better performance of the proposed algorithms in terms of the recognition accuracy and computational efficiency.
Building intersubjectivity at a distance during the collaborative writing of fairytales
Authors: M. Beatrice Ligorio, Alessandra Talamo, Clotilde Pontecorvo
Venue: Computers Education (2005)

This paper introduces intersubjectivity as a concept playing a crucial role in collaborative tasks, even when performed between partners at a distance. Two 5th grade classes from two European countries (Italy and Greece), collaborated in writing fairytales inspired by philosophically relevant issues. The software supporting the task is an asynchronous virtual environment. Videos recorded in the Italian class and materials posted on the platform were analyzed using qualitative approaches and discourse analysis. The case-study discussed shows how the construction of intersubjectivity at a distance is a complex process involving many aspects. The main results highlight how participants: (a) use the narrative structure as a pre-requisite to build an intersubjective space where partners' representation plays an important role; (b) exploit to a high degree the intellectual reasoning needed to accomplish the task in a truly collaborative way; (b) attain a fine tuning of reflective and metacognitive skills fostering a genuine interdependency during the task. Within this process, computer mediation amplifies the partners' ''presence'' all through the creative writing process, expanding [Bruner, J., 2002. Making stories: law, literature, life. Farrar Straus & Giroux] definition of writing as an activity where the ''audience'' plays a fundamental role as a ''co-author''.
A method for identifying a minimal set of test conditions in 2k experimental design
Authors: H. -S. Jacob Tsao, Irene Wibowo
Venue: Computers and Industrial Engineering (2005)

A primary task of the analysis of a 2^k factorial design is to estimate the 2^k unknown effects/interactions. When some of these interactions are known to be zero or negligible, a full 2^k factorial design may no longer be necessary. In general, when only M effects/interactions are non-zero, only M test conditions are required for the estimation. Both fractional factorial design and Taguchi's method typically require 2^n test conditions, n=2,3,4,..., and hence do not take full advantage of this fact. We first demonstrate that when there are M non-zero effects/interactions in a 2^k model, not every set of M test conditions out of the 2^k test conditions would suffice for estimating the M unknowns. We then propose an algorithm to find a set of M test conditions that suffices. The proposed algorithm can be used to identify all such minimal sets of test conditions. In this paper, we report two such minimal sets for all possible scenarios of interest for 2^3 and 2^4 designs. If the assumed zero interactions are indeed zero, confounding is not an issue. Moreover, such assumptions can be double-checked via ANOVA.
Spherical Mapping Based Motion Recovery for Panoramic Cameras
Authors: Yanli Li, Zhong Zhou, Wei Wu
Venue: Proceedings of the 2009 Third International Conference on Multimedia and Ubiquitous Engineering (2009)

Although motion recovery for limited field-of-view (FOV) cameras has been studied for decades under the pin-hole projection, few attentions have been paid on omni-directional cameras. Omni-directional cameras are usually constituted complicatedly, especially some are made of several limited FOV cameras, and thus motion recovery for omni-directional cameras is more different. In this paper, an algorithm is presented to estimate motion of the omni-directional camera under the spherical projection. Unlike motion recovery algorithms for traditional limited FOV cameras, in which the intrinsic matrix plays an important part, this algorithm only estimates extrinsic matrices without the influence of intrinsic matrix. So it is more efficient and robust. To reduce computation, a method is also presented to select key frames using the translation offset of neighboring frames and remove some mismatched feature points. The experiments verify the efficiency of the algorithm and the visual result is demonstrated through a simulation experiment.
Existence and Stability of Periodic Solution for Impulsive Hopfield Neural Networks
Authors: Yanling Li, Anping Liu, Li Xiao
Venue: Proceedings of the 2009 Second International Symposium on Computational Intelligence and Design - Volume 02 (2009)

As an useful tool to study practical problems of biology, engineering and image processing, the cellular neural networks (CNNs) has caused more and more attention. Some interesting results about the existence of periodic solution for cellular neural networks have been obtained. In this paper, by means of iterative analysis, the existence of periodic solution and the uniform stability of the equilibrium point of Hopfield neural networks with impulsive effects are considered.