data cache locking for higher program predictability Caches have become increasingly important with the widening gap between main memory and processor speeds. However, they are a source of unpredictability due to their characteristics, resulting in programs behaving in a different way than expected.Cache locking mechanisms adapt caches to the needs of real-time systems. Locking the cache is a solution that trades performance for predictability: at a cost of generally lower performance, the time of accessing the memory becomes predictable.This paper combines compile-time cache analysis with data cache locking to estimate the worst-case memory performance (WCMP) in a safe, tight and fast way. In order to get predictable cache behavior, we first lock the cache for those parts of the code where the static analysis fails. To minimize the performance degradation, our method loads the cache, if necessary, with data likely to be accessed.Experimental results show that this scheme is fully predictable, without compromising the performance of the transformed program. When compared to an algorithm that assumes compulsory misses when the state of the cache is unknown, our approach eliminates all overestimation for the set of benchmarks, giving an exact WCMP of the transformed program without any significant decrease in performance.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

data cache analysis
worst-case execution time


computing specified generators of structured matrix inverses The asymptotically fastest known divide-and-conquer methods for inverting dense structured matrices are essentially variations or extensions of the Morf/Bitmead-Anderson algorithm. Most of them must deal with the growth in length of intermediate generators, and this is done by incorporating various generator compression techniques into the algorithms. One exception is an algorithm by Cardinal, which in the particular case of Cauchy-like matrices avoids such growth by focusing on well-specified, already compressed generators of the inverse. In this paper, we extend Cardinal's method to a broader class of structured matrices including those of Vandermonde, Hankel, and Toeplitz types. Besides, some first experimental results illustrate the practical interest of the approach.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

structured linear algebra
matrix inversion


Wireless tracking of cotton modules. Part 1: Automatic message triggering The ability to map profit across a cotton field would enable producers to determine where money is being made or lost on their farms and to implement precise field management practices to facilitate the highest return possible on each portion of a field. Mapping profit requires knowledge of site-specific costs and revenues, including yield and price. Price varies site-specifically because fiber quality varies, so mapping fiber quality is an important component of profit mapping. To map fiber quality, the harvest location of individual cotton bales must be known, and thus a system to track the harvest location of cotton modules must be available. To this end, a wireless module-tracking system was recently developed, but automation of the system is required before it will find practical use on the farm. In Part 1 of this report, research to develop automatic triggering of wireless messages is described. In Part 2, research to enable the system to function with multiple harvesting machines of the same type in the same field a common situation in commercial cotton farming is described along with testing of the entire automated wireless module-tracking system. To automate wireless-message triggering, a sensing and control system was added to a harvester to indicate when the machine is dumping a basket load of cotton so that wireless messages can be automatically sent from the harvester to subsequent field machines. This automated system was incorporated into the existing wireless module-tracking system, field tested, and it ultimately operated as designed, without human intervention. Linking data collected with this system together with cotton classing data enabled the creation of fiber-quality maps.

B O O B O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B I O O O O O B I O O B I O O O O O B O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O

cotton
fiber quality
wireless
profit mapping

fiber-quality mapping
precision agriculture
gps
yield mapping


Optimized caching in systems with heterogeneous client populations ? An important question in providing on-demand access to large widely shared data files, such as popular video files, is how to effectively use regional (proxy) servers that can store some of the data close to the clients. The proxy caching problem is more complex in the context of continuous media files because of the need to consider bandwidth as well as storage constraints at the proxy servers, and because of the bandwidth sharing possibilities provided by recently proposed multicast delivery techniques. This paper develops new highly efficient analytic models for determining optimal proxy cache content in such environments. Specifically, the new models apply to heterogeneous systems in which the proxy servers have different client workloads and server capabilities. Results from the models provide general insights into caching strategies for such systems, and suggest that it may be useful to employ efficient cost models in actual systems to determine what content should be cached in response to the measured client workload.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

heterogenous systems
streaming media
optimization models


Fast multipole boundary element method for electrostatic field computations Purpose - A wide range of micro-electro-mechanical-systems are based on the electrostatic principle, and for their design the computation of the electric capacities is of great importance. The purpose of this paper is to efficiently compute the capacities as a function of all possible positions of the two electrode structures within the transducer by an enhanced boundary element method (BEM). Design/methodology/approach - A Galerkin BEN is developed and the arising algebraic system of equations is efficiently solved by a CG-method with a multilevel preconditioner and an appropriate fast multipole algorithm for the matrix-vector operations within the W-iterations. Findings - It can be demonstrated that the piecewise linear and discontinuous trial functions give an approximation, which is almost as good as the one of the piecewise constant trial functions on the refined mesh, at lower computational costs and at about the same memory requirements. Originality/value - The paper can proof mathematically and demonstrate in practice, that a higher order of convergence is achieved by using piecewise linear, globally discontinuous basis functions instead of piecewise constant basis functions. In addition, an appropriate preconditioner (artificial multilevel boundary element preconditioner, which is based on the Bramble Pasciak Xu like preconditioner) has been developed for the fast iterative solution of the algebraic system of equations.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

electrostatics
galerkin method
mathematics
transducers


Workload-ahead-driven online energy minimization techniques for battery-powered embedded systems with time-constraints This article proposes a new online voltage scaling (VS) technique for battery-powered embedded systems with real-time constraints. The VS technique takes into account the execution times and discharge currents of tasks to further reduce the battery charge consumption when compared to the recently reported slack forwarding technique [Ahmed and Chakrabarti 2004], while maintaining low online complexity of O(1). Furthermore, we investigate the impact of online rescheduling and remapping on the battery charge consumption for tasks with data dependency which has not been explicitly addressed in the literature and propose a novel rescheduling/ remapping technique. Finally, we take leakage power into consideration and extend the proposed online techniques to include adaptive body biasing (ABB) which is used to reduce the leakage power. We demonstrate and compare the efficiency of the presented techniques using seven real-life benchmarks and numerous automatically generated examples.

O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O

embedded systems
battery
adaptive body biasing

design
algorithms
dynamic voltage scaling


Imaging Oncogene Expression In 2003, approximately 39,800 women in the US will die from breast cancer. Mammography and physical examination miss up to 40% of early breast cancers. Moreover, if an abnormality is found, an invasive diagnostic procedure must still be performed to determine if the breast contains atypia or cancer, even though approximately 85% of abnormalities are benign. Scintigraphic imaging of gene expression in vivo by noninvasive means could direct physicians to appropriate targets for intervention at the onset of disease and thereby significantly impact patient management. Until now, no method has been available to image specific overexpressed oncogene mRNAs in vivo by scintigraphic imaging. We hypothesize that gamma-emitting Tc-99m-PNA-peptides can be taken up by human ER+ and ER? breast cancer xenografts, hybridize to complementary mRNA targets in those cells, and concentrate sufficiently in tumor tissue to allow noninvasive imaging of oncogene overexpression. To prepare the probes, peptide analogs of insulin-like growth factor 1 (IGF1) were extended from a solid support by Fmoc coupling. Peptide nucleic acid (PNA) dodecamers antisense to CCND1 and MYC mRNAs were then extended from the N-terminus of IGF1, followed by a chelator peptide, using Fmoc coupling for all residues. The cysteine thiols were cyclized on the solid support, either before or after PNA extension. This simplified synthetic approach allows preparation of a variety of multipeptide disulfide-bridged PNA chimeras. A chelating peptide-PNA chimera antisense to MYC mRNA was then labeled efficiently with Tc-99m, yielding a single product. Tissue distribution studies of antisense and mismatch chimeras at 4 h and 24 h after administration displayed modest accumulation in the liver and kidneys, with appreciable levels in tumors. This result enables testing of Tc-99m-peptide-PNA probes to image gene expression in tumors.

B O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B I O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B I O B

antisense
breast cancer
gene expression
imaging
noninvasive
tumors

chelators conjugates hybridization oligonucleotides oncogenes peptides radionucleotides scintigraphy


Improving the effectivity of residual based a posteriori error estimates using a statistical approach For the approximation of differential equations residual based error estimates provide upper bounds (usually gross over estimates) to the true error. In this paper we present a procedure for determining values for the constants in the a posteriori estimates which yield accurate estimates to the true error. Numerical experiments demonstrating the effectiveness of the method are given.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


a survey of state-of-the-art in anonymity metrics Anonymization enables organizations to protect their data and systems from a diverse set of attacks and preserve privacy; however, in the area of anonymized network data, few, if any, are able to precisely quantify how anonymized their information is for any particular dataset. Indeed, recent research indicates that many anonymization techniques leak some information. An ability to confidently measure this information leakage and any changes in anonymity levels plays a crucial role in facilitating the free-flow of cross-organizational network data sharing and promoting wider adoption of anonyimzation techniques. Fortunately, multiple methods of analyzing anonymity exist. Typical approaches use simple quantifications and probabilistic models; however, to the best of our knowledge, only one network data anonymization metric has been proposed. More importantly, no one-stop-shop paper exists that comprehensively surveys this area for other candidate measures; therefore, this paper explores the state-of-the-art of anonymity metrics. The objective is to provide a macro-level view of the systematic analysis of anonymity preservation, degradation, or elimination for data anonymization as well as network communciations anonymization.

O O O O O B B O O O O O O O O O O O O O O O O O B O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O B I O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B B O O O O O O O O O O O O O B O O O O O O O O O O O O O


An Efficient Scalable RNS Architecture for Large Dynamic Ranges This paper proposes an efficient scalable Residue Number System (RNS) architecture supporting moduli sets with an arbitrary number of channels, allowing to achieve larger dynamic range and a higher level of parallelism. The proposed architecture allows the forward and reverse RNS conversion, by reusing the arithmetic channel units. The arithmetic operations supported at the channel level include addition, subtraction, and multiplication with accumulation capability. For the reverse conversion two algorithms are considered, one based on the Chinese Remainder Theorem and the other one on Mixed-Radix-Conversion, leading to implementations optimized for delay and required circuit area. With the proposed architecture a complete and compact RNS platform is achieved . Experimental results suggest gains of 17 % in the delay in the arithmetic operations, with an area reduction of 23 % regarding the RNS state of the art. When compared with a binary system the proposed architecture allows to perform the same computation 20 times faster alongside with only 10 % of the circuit area resources.

O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

residue number system
chinese remainder theorem

computer arithmetic
large dynamic range
mixed radix conversion


Highly metastable amorphous or near-amorphous ternary films (mictamict alloys) Thin ternary films of the generic composition (early transition metal)Si(nitrogen or oxygen) can be synthesized that have an amorphous or near-amorphous structure and are highly resistant to crystallization upon thermal annealing. Common to all of them is the existence of two compounds that form a quasi-binary system. Some known properties of these films are reviewed. Their similarity with amorphous binary metallic alloys is emphasized. Many ternary systems should exist with which such amorphous films can be made. The name mictamict is proposed to identify this general class of materials.

O O O O O B I B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O

amorphous films
mictamict alloys
ternary films


Learning hidden variable networks: The information bottleneck approach A central challenge in learning probabilistic graphical models is dealing with domains that involve hidden variables. The common approach for learning model parameters in such domains is the expectation maximization ( EM) algorithm. This algorithm, however, can easily get trapped in suboptimal local maxima. Learning the model structure is even more challenging. The structural EM algorithm can adapt the structure in the presence of hidden variables, but usually performs poorly without prior knowledge about the cardinality and location of the hidden variables. In this work, we present a general approach for learning Bayesian networks with hidden variables that overcomes these problems. The approach builds on the information bottleneck framework of Tishby et al. (1999). We start by proving formal correspondence between the information bottleneck objective and the standard parametric EM functional. We then use this correspondence to construct a learning algorithm that combines an information-theoretic smoothing term with a continuation procedure. Intuitively, the algorithm bypasses local maxima and achieves superior solutions by following a continuous path from a solution of, an easy and smooth, target function, to a solution of the desired likelihood function. As we show, our algorithmic framework allows learning of the parameters as well as the structure of a network. In addition, it also allows us to introduce new hidden variables during model selection and learn their cardinality. We demonstrate the performance of our procedure on several challenging real-life data sets.

O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O B I O B I O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O

bayesian networks
hidden variables
information bottleneck
continuation


DYNAMIC APPROXIMATE ALL-PAIRS SHORTEST PATHS IN UNDIRECTED GRAPHS We obtain three new dynamic algorithms for the approximate all-pairs shortest paths problem in unweighted undirected graphs: (i) For any fixed epsilon > 0, a decremental algorithm with an expected total running time of (O) over tilde (mn), where m is the number of edges and n is the number of vertices in the initial graph. Each distance query is answered in O(1) worst-case time, and the stretch of the returned distances is at most 1 + epsilon. The algorithm uses (O) over tilde (n(2)) space. (ii) For any fixed integer k >= 1, a decremental algorithm with an expected total running time of (O) over tilde (mn). Each query is answered in O(1) worst-case time, and the stretch of the returned distances is at most 2k - 1. This algorithm, however, uses only O(m + n(1+1/k)) space. It is obtained by dynamizing techniques of Thorup and Zwick. In addition to being more space efficient, this algorithm is also one of the building blocks used to obtain the first algorithm. (iii) For any fixed epsilon, delta > 0 and every t <= m(1/2-delta), a fully dynamic algorithm with an expected amortized update time of (O) over tilde (mn/t) and worst-case query time of O(t). The stretch of the returned distances is at most 1 + epsilon. All algorithms can also be made to work on undirected graphs with small integer edge weights. If the largest edge weight is b, then all bounds on the running times are multiplied by b.

O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

transitive closure
strongly connected components


Model Reference Adaptive Control in Fuzzy-Based Context-Aware Middleware Owing to the dynamic characteristics of mobile environments, a mobile application needs to adapt to changing contexts to improve performance and resource utilization. We have developed an adaptive middleware infrastructure that simultaneously satisfies the individual needs of applications while maintaining overall system performance. A Model Reference Adaptive Control mechanism has been implemented in the middleware using control theory and fuzzy-based techniques. With reference to the model reference adaptive control theory, we also present a Self-Adaptive Fuzzy-based Service Adaptation Model (SA-FSAM) by taking historical adaptation information into account, and utilizing a closed-loop control mechanism to fine-tune adaptation decisions. The SA-FSAM and a conventional threshold-based linear-control model have been evaluated using a campus assistant mobile application. With the introduction of self-adaptive elements in the control model, the SA-FSAM shows significant improvements in service adaptation decisions.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O


Second-generation wavelet collocation method for the solution of partial differential equations An adaptive numerical method for solving partial differential equations is developed. The method is based on the whole new class of second-generation wavelets. Wavelet decomposition is used for grid adaptation and interpolation. while a new O (N), hierarchical finite difference scheme, which takes advantage of wavelet multilevel decomposition, is used for derivative calculations. The treatment of nonlinear terms and general boundary conditions is a straightforward task due to the collocation nature of the algorithm. Ln this paper we demonstrate the algorithm for one particular choice of second-generation wavelets, namely lifted interpolating wavelets on an interval with uniform (regular) sampling. The main advantage of using second-generation wavelets is that wavelets can be custom designed for complex domains and irregular sampling. Thus, the strength of the new method is that it can be easily extended to the whole class of second-generation wavelets, leaving the freedom and flexibility to choose the wavelet basis depending on the application. (C) 2000 Academic Press.

O O O O O O O O B I I O O B I O O B I I O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O B O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O

wavelets
partial differential equations
numerical method

lifting scheme
second-generation wavelets
adaptive grid


Operation and maintenance integration to improve safety To improve safety and productivity, this paper presents a methodology that integrates operation and maintenance. This methodology is detailed by developing an activity model, which identifies all the existing operation and maintenance activities and reorganizes them into a consistent arrangement. To illustrate the methodology and the developed model, a prototype system has also been configured. Finally, an exothermic reactor with toxic chemicals is used as a case study to illustrate the use of the methodology. (C) 2000 Elsevier Science Ltd. All rights reserved.

B O B B O O B O O B O O O O O O O O O B O B O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

operation maintenance integration safety


Information management in distributed collaborative systems: The case of collaboration studio This paper presents the Collaboration Studio (CS) system, its argumentation and data-structuring models and gives some insights for dealing with information divergence. The system allows discussions among a group of participants that includes a coordinator. The working mechanisms implemented within CS are perfectly transparent to the user, hiding implementation details, giving an appealing and user-friendly environment, and so users do not have to worry about patterns of data distribution, or the details of distribution management. CS shares characteristics with other collaboration computational tools, such as synchronous and asynchronous support and both group working spaces and a local working space. However, its main purpose differs in that, instead of trying to achieve a single document as the outcome of the joint work of several users, CS aims to achieve a broader objective, which is to register (and to demonstrate) the path used to obtain certain knowledge.

O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

groupware
divergence management
knowledge management


Graphs inducing totally balanced and submodular Chinese postman games A Chinese postman (CP) game is induced by a weighted undirected, connected graph in which the edges are identified as players and a vertex is chosen as post-office location. Granot and Granot (2012) characterized graphs that give rise to CP games that are balanced. This note completes this line of research by characterizing graphs that give rise to CP games that are submodular (totally balanced, respectively).

O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Cancellable biometerics featuring with tokenised random number In this paper we introduce a novel cancellable biometric realisation approach based on the iterated inner products between the tokenised pseudo-random number and the face feature to produce a set of user-specific compact binary code, coined as FaceHash. This approach enables straightforward revocation of FaceHash via token replacement and there is no deterministic way to reveal FaceHash without having both tokenised random number and face feature, thus offers strong protection against biometrics fabrication. In addition, FaceHashing has significant functional advantages over contemporary biometrics like zero error rate and clean separation of the genuine and imposter populations.

O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O

tokenized random number
face recognition


Full Flexible Five-Port Receiver This paper reports the architecture of a five-port receiver without vector base circuit generators in which three antennas provide three phase-shifted copies of the received signal. A 2.4 GHz prototype was implemented for concept proofing and the measurements point to a 6 dB higher sensibility with respect to comparable classic five-port receivers.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

antenna array
radio receivers
high sensitivity receivers


Multi-code multi-carrier CDMA modulation with adaptive bit-loading for VDSL modems This paper presents a new modulation scheme for Very-High Speed Digital Subscriber Lines (VDSL) modem, featuring a Multi-Code Multi-Carrier Code Division Multiple Access (MC2-CDMA) modulation. The system takes advantage from both the CDMA modulation and the Multi-Carrier transmission, and furthermore the channel throughput is increased adopting a multi-code approach. Starting from an overview of this novel scheme, encompassing the transmitter, channel and receiver description, a brief review of the equalization techniques is also considered and a proper bit-loading algorithm is derived to find out the achievable overall channel rate. The aim of this paper, besides introducing this novel scheme, is to demonstrate its suitability for a VDSL environment, where the achievable channel rate represents a real challenge. By means of a further optimisation, a general improvement of the system performance with respect to the standardized Discrete Multi Tone (DMT) modulation is also demonstrated.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

multi-code multi-carrier code division multiple access


designing for a moving target The low cost of change in web service development makes it possible to continually release new and improved versions of the service to users who can respond to changes and offer suggestions, creating a feedback loop cycle. This paper shares experiences building services in agile projects and suggests initially releasing a simple, valuable service to users and starting the feedback loop to evolve the service towards greater value.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

wicked problems
iterative development
evolutionary systems development
user-driven innovation


SECURE QUANTUM CARRIERS FOR QUANTUM STATE SHARING We develop the concept of quantum carrier and show that messages can be uploaded and downloaded from this carrier and while in transit, these messages are hidden from external agents. We explain in detail the working of the quantum carrier for different communication tasks, including quantum key distribution, classical secret and quantum state sharing among a set of n players according to general threshold schemes. The security of the protocol is discussed and it is shown that only the legitimate subsets can retrieve the secret messages, the collaboration of all the parties is needed for the continuous running of the protocol and maintaining the carrier.

O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Importance Sampling for Turbo Codes over Slow Rayleigh Fading Channels This study shows a fast simulation method of turbo codes over slow Rayleigh fading channels. The reduction of the simulation time is achieved by applying importance sampling (IS). The conventional IS method of turbo codes over Rayleigh fading channels focuses only on modification of additive white Gaussian noise (AWGN) sequences. The proposed IS method biases not only AWGNs but also channel gains of the Rayleigh fading channels. The computer runtime of the proposed method is about 1/5 of that of the conventional IS method on the evaluation of a frame error rate of 10(-6). When we compare with the Monte Carlo simulation method, the proposed method needs only 1/100 simulation runtime under the condition of the same accuracy of the estimator.

B I O B I O O B I O O O O O B I O O B I O O B I O O O O O O O O O O O B I O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

turbo codes
importance sampling
fast simulation
rayleigh fading


a statistical performance simulation methodology for vlsi circuits A statistical performance simulation (SPS) methodology for VLSI circuits is presented. Traditional methods of worst-case corner analysis lack accuracy and Monte-Carlo simulations cannot be applied to VLSI circuits because of their complexity. SPS methodology is accurate because no statistical information about the device parameter variation is lost. It achieves efficiency by analyzing the smaller circuit blocks and generating the performance distribution for the entire circuit. Circuit evaluation at any specified performance level is possible.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

custom sizing
timing optimazation
migration


Division of labour and sharing of knowledge for synchronous collaborative information retrieval Synchronous collaborative information retrieval (SCIR) is concerned with supporting two or more users who search together at the same time in order to satisfy a shared information need. SCIR systems represent a paradigmatic shift in the way we view information retrieval, moving from an individual to a group process and as such the development of novel IR techniques is needed to support this. In this article we present what we believe are two key concepts for the development of effective SCIR namely division of labour (DoL) and sharing of knowledge (SoK). Together these concepts enable coordinated SCIR such that redundancy across group members is reduced whilst enabling each group member to benefit from the discoveries of their collaborators. In this article we outline techniques from state-of-the-art SCIR systems which support these two concepts, primarily through the provision of awareness widgets. We then outline some of our own work into system-mediated techniques for division of labour and sharing of knowledge in SCIR. Finally we conclude with a discussion on some possible future trends for these two coordination techniques.

O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

collaborative information retrieval
collaborative search


Shape characterization of subdivision surfaces - Case studies For subdivision surfaces, it is important to characterize local shape near flat spots and points where the surface is not twice continuously differentiable. Applying general principles derived in [Computer Aided Geometric Design, doi:10.1016/j.cagd.2004.04.006, in press], this paper characterizes shape near such points for the subdivision schemes devised by Catmull and Clark and by Loop. For generic input data, both schemes fail to converge to the hyperbolic or elliptic limit shape suggested by the geometry of the input mesh: the limit shape is a function of the valence of the extraordinary point rather than the mesh geometry. We characterize the meshes for which the schemes behave as expected and indicate modifications of the schemes that prevent convergence to the wrong shape. We also introduce a type of chart that, for a specific scheme, can help a designer to detect early when a mesh will lead to undesirable curvature behavior. (C) 2004 Elsevier B.V. All rights reserved.

B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O


An enthalpy-based finite element method for nonlinear heat problems involving phase change Within the framework of the finite element method, we present in this paper an efficient algorithm for solving nonlinear heat problems involving phase change. In particular, two problems are considered in this work: the stationary convectiondiffusion problem, and the classical transient heat problem. The mathematical models used to solve these problems are based upon enthalpy formulations. The algorithmic design is based on a Newton-type iterative procedure for the stationary problem, and for the transient one, a combination with classical finite difference schemes in time is performed. The proposed phase change algorithmic treatment is applicable for both the situations in which the latent heat takes place over a temperature range or at fixed temperature. Hence, for this latter situation, a regularization over a narrow temperature range is not necessary. The numerical implementation is discussed in detail where we include also the other possible nonlinearities, namely, the temperature dependence of the thermal conductivity and the radiation-type boundary conditions. Finally, a set of representative numerical simulations to illustrate the effectiveness of the proposed method is given.

O O B I I O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

stationary convectiondiffusion
finite element method

enthalpy formulation
mushy phase change
isothermal phase change
transient heat problems


Design and analysis of three-dimensional OCDMA code families A new code design algorithm for application in three-dimensional (3D) optical code division multiple access (OCDMA) for asynchronous optical fiber communication is proposed 3D refers to space-wavelength-time codes. The performance analysis of the proposed algorithm in 3D multiple pulses per plane (MPP) codes is shown. This design ensures a maximum cross-correlation of '1' between any two codes. The performance metrics that have been investigated are the bit error rate due to multiple access interference (MAI) for different values of the number of simultaneous users and, cardinality for different values of temporal length (C) 2009 Elsevier B.V. All rights reserved.

O O O O O B B I O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


global delay optimization using structural choices This paper presents a fast global method for delay optimization after technology mapping. Timing analysis is used to identify timing-critical areas in the mapped network where new structures are synthesized to favor late-arriving signals. Unlike previous methods that make incremental local changes to the mapped network, the proposed method records many alternative structures and defers the final decision to the technology mapper. Experimental results for networks mapped into 6-input look-up tables (6-LUTs) show that the delay is, on average, improved 14\% using a realistic delay library for LUTs with variable-pin delays and wire-delay estimation. The area penalty after the delay optimization is about 2\% and can be eliminated by area-oriented resynthesis. When the algorithm is compared with DAOmap, the experimental results show 27\% logic level reduction while the area is increased by only 1\%. The algorithm is also fast and applicable to very large networks. The runtime of the proposed algorithm is 16x and 3x faster than DAOmap for large industrial and academic designs, respectively.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

fpga
technology mpping
boolean satisfiability
windowing
interpolation
logic optimization


From experiments to hydrodynamic traffic flow models: II - Sensitivity analysis This paper deals with a parameter sensitivity analysis for a class of traffic flow macroscopic models obtained by mass conservation equation linked to a phenomenological model suitable to relate the local mass velocity to the density of vehicles. The analysis allows to focus how the result of simulations is modified by variations of the parameters. A suitable functional is introduced to give a measure of this sensitivitv. (c) 2005 Elsevier Ltd. All rights reserved.

O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

hydrodynamics
conservation equations
parameter identification


Pairwise comparisons of means under realistic nonnormality, unequal variances, outliers and equal sample sizes A Monte Carlo simulation evaluated six pairwise multiple comparison procedures for controlling Type I error rates, any-pair power, and all-pairs power. Realistic conditions of nonnormality were based on a previous survey, and the effects of outliers were investigated. Variance ratios varied from 1:1 to 8:1. Evaluated procedures included Tukey's honestly significant difference (HSD) preceded by an F-test, the Hayter-Fisher, the Games-Howell procedure tested at 0.9, the Peritz with F-tests, the Peritz with Brown-Forsythe tests, and the Peritz with Alexander-Govern tests. Peritz with Brown-Forsythe procedure shows the greatest robustness in Type I error control. Any-pair power is generally best with the Hayter-Fisher, whereas all-pairs power is best with the Peritz F-test procedure. Even though the Hayter-Fisher shows only slightly lower all-pair power rates than the Peritz, it is still much easier to perform.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

multiple hypothesis testing
all pairwise comparisons
anova
tukey test


A practical evaluation of sequential estimation for vision metrology1 Parameter estimation in photogrammetry is generally accomplished by means of a simultaneous least-squares adjustment in which all observational data must be at hand prior to solution. It follows that, despite the rapid turnaround provided by digital imagery and current measurement technology, the simultaneous adjustment cannot offer an indication of quality until acquisition and measurement are complete. On-line quality control of single-sensor vision metrology (VM) can be implemented effectively through on-line triangulation (OLT) with sequential estimation. In combination with established network design principles, sequential estimation can have a significant positive influence on economy and productivity in the industrial environment. While enhancing the efficiency of the triangulation procedure, the risks of collecting either insufficient or surplus imagery are also diminished. Furthermore, localised weaknesses within the overall network can be isolated and corrected. Sequential estimation is applicable to a variety of VM tasks. Here, in addition to quality control for single-sensor VM, the calibration of real-time, multi-sensor systems is addressed. This paper presents an overview of sequential estimation for VM consisting of a description of the general sequential problem followed by the necessary mathematical derivations. Significant implementational aspects are discussed and evaluations of practical testing are given. Promising experimental results clearly demonstrate that OLT can be an effective and valuable tool in industrial VM.

O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

givens transformations
on-line
real-time
recursive least-squares


A Robust Spectral Method for Solving Hestons Model In this paper, we consider the Hestons volatility model (Heston in Rev. Financ. Stud. 6: 327343, 1993]. We simulate this model using a combination of the spectral collocation method and the Laplace transforms method. To approximate the two dimensional PDE, we construct a grid which is the tensor product of the two grids, each of which is based on the Chebyshev points in the two spacial directions. The resulting semi-discrete problem is then solved by applying the Laplace transform method based on Talbots idea of deformation of the contour integral (Talbot in IMA J. Appl. Math. 23(1): 97120, 1979).

O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O

hestons volatility model
laplace transform


Coplanar waveguide gyroelectric circulator A three-port coplanar waveguide semiconductor circulator is analyzed. A theoretical 60-GHz N-type indium antimonide design at an operating temperature of 77 K is presented with a 20-dB isolation bandwidth of approximately 25%. A six-port microstrip ferrite circulator is also designed to provide a validity check using the ANSOFT(TM), High Frequency Structure Simulator. (C) 2002 Wiley Periodicals, Inc.

B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

semiconductor devices
indium compounds
millimeter wave circulators
computer-aided analysis


Impact of ATM cell delay on multimedia applications The impact of ATM cell delays on multimedia application performance is studied through measurements using a broadband network analyser. A method is developed to measure the ATM cell delays of an application using the analyser. It is found that the cell delay distribution becomes continuous as the traffic load on a connection becomes lighter. The effect of background traffic on cell delay for a reference connection is studied. Though the cell delay of the reference connection is unaffected by the presence of background traffic, the cell-delay auto-correlation is found to decrease. A gamma distribution is used to approximate the cell delay distribution. The measurement results closely match the delay prediction using the approximation. In a network with multiple ATM switches, the gamma distribution only slightly overestimates the delay. The frame level statistics and the cell delay performance of a video conferencing application based on motion JPEG are measured. Using the gamma cell delay distribution, the frame loss of an MPEG-I video source is predicted and compared against the measured values based on MPEG-I traces. (C) 2000 Elsevier Science B.V. All rights reserved.

O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

traffic modelling
asynchronous transfer mode
qos


Using virtual pheromones and cameras for dispersing a team of multiple miniature robots To safely and efficiently guide personnel of search and rescue operations in disaster areas, swift gathering of relevant information such as the locations of victims, must occur. Using the concept of 'repellent virtual pheromones' inspired by insect colony coordination behaviors, miniature robots can be quickly dispersed to survey a disaster site. Assisted by visual servoing, dispersion of the miniature robots can quickly cover an area. An external observer such as another robot or an overhead camera is brought into the control loop to provide each miniature robot estimations of the positions of all of the other near-by robots in the robotic team. These miniature robots can then move away from the other near-by robots on the team, resulting in the robot collective becoming swiftly distributed through the local area. The technique has been simulated with differing pheromone persistence levels and implemented using the miniature Scout robots, developed by the Center for Distributed Robotics at the University of Minnesota, which are well-suited to surveillance and reconnaissance missions.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O


temporal vision-guided energy minimization for portable displays This paper presents a novel backlight driving technique for liquid crystal displays. By scaling the intensity, frequency, and duty cycle of the backlight, this technique not only increases the perceived brightness but also prolongs the service time of rechargeable batteries. The increased brightness comes from a perceptual effect of temporal vision - a brief flash appears brighter than a steady light of the same intensity, called Brcke brightness enhancement effect. The prolonged service time comes from the relaxation phenomenon - a lithium-ion battery lasts longer by pulsed discharge. Combining these two effects, a great amount of service time can be obtained at the cost of flickering. We performed visual experiments to parameterize the Brcke effect and derived an optimization algorithm accordingly. To demonstrate the potential energy savings of this technique, we profiled the power consumption of an Apple iPod and fabricated an LED driving module. Based on experimental data, 75\% of energy consumption can be saved and the service time can be extended to 300\%.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

backlight management
tft-lcd
power minimization


a model transformation approach for verifying multi-agent systems using spin In our previous work, we developed a nested Petri net framework for modeling multi-agent systems. In this paper, we present a method to analyze the nested Petri net model using model checking. Our method systematically translates a nested Petri net model into a PROMELA program in SPIN.

O B I O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B


The tail-recursive SECD machine One method for producing verified implementations of programming languages is to formally derive them from abstract machines. Tail-recursive abstract machines provide efficient support for iterative processes via the ordinary procedure call mechanism. This document argues that the use of tail-recursive abstract machines incurs only a small increase in theorem-proving burden when compared with what is required when using ordinary abstract machines. The position is supported by comparing correctness proofs performed using the Boyer-Moore theorem prover. A by-product of this effort is a syntactic criterion based on tail contexts for identifying which procedure calls must be implemented as tail calls. The concept of tail contexts was used in the latest Scheme Report, the only language specification known to the author that defines the requirement that its implementations must be tail recursive.

O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

tail recursion
tail call
cek machine
verified implementation
boyer-moore theorem prover


Penta- and heteropentadienyl ligands coordinated to beryllium In this work we have performed a systematic study of new organometallic complexes containing penta-and heteropentadienyl (CH2CHCHCHX, X=CH2, O, NH, S) ligands coordinated to beryllium. Calculated complexes were studied using the density functional theory (PBE) in combination with the 6-311++G(3d,2p) basis set. The coordination number on the beryllium atom varies according to the type of ligand. Pentadienyl ligand shows hapticities eta(1) and eta(5), while heteropentadienyl ligands display eta(1) and eta(2) hapticities. A Wiberg bond indices study was performed in order to get information about their bond orders.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

berylliumcomplexes
dft
heterodienyl ligands
organometallic chemistry


Local coarsening of simplicial finite element meshes generated by bisections A simple criterion that allows the efficient local coarsening of simplicial finite element meshes generated by bisections is devised and analyzed. Under a mild condition on the initial triangulation the proposed criterion allows to gradually reverse the entire refinement without employing its history explicitly. Numerical experiments underline the efficiency of the resulting algorithm.

O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Case study: Network intrusion investigation lessons in forensic preparation Investigations of network security breaches are both complex and costly. Even a moderate amount of forensic preparation in an organization can mitigate the impact of a major incident and can enable the organization to obtain restitution. A case study of an intrusion is outlined in which the victim organization worked with law enforcement agencies to apprehend the perpetrator. This case study contains examples of challenges that can arise during this type of investigation, and discusses practical steps that an organization can take to prepare for a major incident. The overlapping roles of System Administrators, Incident Handlers, and Forensic Examiners in a network intrusion are explored, with an emphasis on the need for collaboration and proper evidence handling. This case study also shows how effective case management and methodical reconstruction of events can help create a more complete picture of the crime and help establish links between computer intruders and their illegal activities.

O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

forensic readiness
incident response
incident handling
network forensics
computer intrusion
rootkit
forensic computing
tracking intruders
attribution


Data analysis by positive decision trees Decision trees are used as a convenient means to explain given positive examples and negative examples, which is a form of data mining and knowledge discovery. Standard methods such as ID3 may provide non-monotonic decision trees in the sense that data with larger values in all attributes are sometimes classified into a class with a smaller output value. (In the case of binary data, this is equivalent to saying that the discriminant Boolean function that the decision tree represents is not positive.) A motivation of this study comes from an observation that real world data are often positive, and in such cases it is natural to build decision trees which represent positive (i.e., monotone) discriminant functions. For this, we propose how to modify the existing procedures such as ID3, so that the resulting decision tree represents a positive discriminant function. In this procedure, we add some new data to recover the positivity of data. which the original data had but was lost in the process of decomposing data sets by such methods as ID3. To compare the performance of our method with existing methods, we test (1) positive data, which are randomly generated from a hidden positive Boolean function after adding dummy attributes, and (2) breast cancer data as an example of the real-world data. The experimental results on (1) tell that, although the sizes of positive decision trees are relatively larger than those without positivity assumption, positive decision trees exhibit higher accuracy and tend to choose correct attributes, on which the hidden positive Boolean function is defined. For the breast cancer data set, we also observe a similar tendency; i.e., positive decision trees are larger but give higher accuracy.

O O O O B I B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O B O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O

mid
extensions
positive functions
quasi-positive functions
knowledge discovery and data analysis


energy optimization in wireless medical systems using physiological behavior Wearable sensing systems are becoming widely used for a variety of applications, including sports, entertainment, and military. These systems have recently enabled a variety of medical monitoring and diagnostic applications in Wireless Health. The need for multiple sensors and constant monitoring lead these systems to be power hungry and expensive, with short operating lifetimes. In this paper, we introduce a novel methodology that takes advantage of the influence of human behavior on signal properties and reduces those three metrics from the data size point of view. This, in turn, directly influences the wireless communication and local processing power consumption. We exploit intrinsic space and temporal correlations between sensor data while considering both user and system behavior. Our goal is to select a small subset of sensors to accurately capture and/or predict all possible signals of a fully instrumented wearable sensing system. Our approach leverages novel modeling, partitioning, and behavioral optimization, which consists of signal characterization, segmentation and time shifting, mutual signal prediction, and subset sensor selection. We demonstrate the effectiveness of the technique on an insole instrumented with 99 pressure sensors placed in each shoe, which cover the bottom of the entire foot, resulting in energy reduction of 56\% to 96\% for error rates of 5\% to 17.5\%.

B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

behavioral sensing
wearable medical systems


Cooperative recurrent modular neural networks for constrained optimization: a survey of models and applications Constrained optimization problems arise in a wide variety of scientific and engineering applications. Since several single recurrent neural networks when applied to solve constrained optimization problems for real-time engineering applications have shown some limitations, cooperative recurrent neural network approaches have been developed to overcome drawbacks of these single recurrent neural networks. This paper surveys in details work on cooperative recurrent neural networks for solving constrained optimization problems and their engineering applications, and points out their standing models from viewpoint of both convergence to the optimal solution and model complexity. We provide examples and comparisons to shown advantages of these models in the given applications.

O O O O O O O O O O O O O O B I I O O O O O O O O B I O O O B I I O O O O B I I O O B I O O O O O O O O O O O O O O O O O O B I I O O O O O O O O B I I O O B I I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

recurrent neural networks
constrained optimization problems
engineering applications


Instance-specific accelerators for minimum covering This paper presents the acceleration of minimum-cost covering problems by instance-specific hardware. First, we formulate the minimum-cost covering problem and discuss a branch & bound algorithm to solve it. Then we describe instance-specific hardware architectures that implement branch & bound in 3-valued logic and use reduction techniques similar to those found in software solvers. We further present prototypical accelerator implementations and a corresponding design tool flow. Our experiments reveal significant raw speedups up to five orders of magnitude for a set of smaller unate covering problems. Provided that hardware compilation times can be reduced, we conclude that instance-specific acceleration of hard minimum-cost covering problems will lead to substantial overall speedups.

O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

reconfigurable computing
instance-specific acceleration


Example-driven meta-model development The intensive use of models in model-driven engineering (MDE) raises the need to develop meta-models with different aims, such as the construction of textual and visual modelling languages and the specification of source and target ends of model-to-model transformations. While domain experts have the knowledge about the concepts of the domain, they usually lack the skills to build meta-models. Moreover, meta-models typically need to be tailored according to their future usage and specific implementation platform, which demands knowledge available only to engineers with great expertise in specific MDE platforms. These issues hinder a wider adoption of MDE both by domain experts and software engineers. In order to alleviate this situation, we propose an interactive, iterative approach to meta-model construction, enabling the specification of example model fragments by domain experts, with the possibility of using informal drawing tools like Dia or yED. These fragments can be annotated with hints about the intention or needs for certain elements. A meta-model is then automatically induced, which can be refactored in an interactive way, and then compiled into an implementation meta-model using profiles and patterns for different platforms and purposes. Our approach includes the use of a virtual assistant, which provides suggestions for improving the meta-model based on well-known refactorings, and a validation mode, enabling the validation of the meta-model by means of examples.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

meta-modelling
domain-specific modelling languages
interactive meta-modelling
meta-model induction
example-driven modelling
meta-model design exploration
meta-model validation


Projection Reconstruction Magnetic Particle Imaging We acquire the first experimental 3-D tomographic images with magnetic particle imaging (MPI) using projection reconstruction methodology, which is similar to algorithms employed in X-ray computed tomography. The primary advantage of projection reconstruction methods is an order of magnitude increase in signal-to-noise ratio (SNR) due to averaging. We first derive the point spread function, resolution, number of projections required, and the SNR gain in projection reconstruction MPI. We then design and construct the first scanner capable of gathering the necessary data for nonaliased projection reconstruction and experimentally verify our mathematical predictions. We demonstrate that filtered backprojection in MPI is experimentally feasible and illustrate the SNR and resolution improvements with projection reconstruction. Finally, we show that MPI is capable of producing three dimensional imaging volumes in both phantoms and postmortem mice.

B I O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O

filtered backprojection
projection reconstruction

biomedical imaging
field free line (ffl)
image reconstruction
magnetic particle imaging (mpi)
magnetic particles


Pathwidth and layered drawings of trees An h-layer drawing of a graph G is a planar drawing of Gin which each vertex is placed on one of h parallel lines and each edge is drawn as a straight line between its end-vertices. In such a drawing, we say that an edge is proper if its endpoints lie on adjacent layers, flat if they lie on the same layer and long otherwise. Thus, a proper h-layer drawing contains only proper edges, a short h-layer drawing contains no long edges, an upright h-layer drawing contains no flat edges, and an unconstrained h-layer drawing contains any type of edge. In this paper, we derive upper and lower bounds on the number of layers required by proper, short, upright, and unconstrained layered drawings of trees. We prove that these bounds are optimal with respect to the pathwidth of the tree being drawn. Finally, we give linear-time algorithms for obtaining layered drawings that match these upper bounds.

B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O


Sensor fault diagnosis with a probabilistic decision process In this paper a probabilistic approach to sensor fault diagnosis is presented. The proposed method is applicable to systems whose dynamic can be approximated with only few active states, especially in process control where we usually have a relatively slow dynamics. Unlike most existing probabilistic approaches to fault diagnosis, which are based on Bayesian Belief Networks, in this approach the probabilistic model is directly extracted from a parity equation. The relevant parity equation can be found using a model of the system or through principal component analysis of data measured from the system. In addition, a sensor detectability index is introduced that specifies the level of detectability of sensor faults in a set of analytically redundant sensors. This index depends only on the internal relationships of the variables of the system and noise level. The method is tested on a model of the Tennessee Eastman process and the result shows a fast and reliable prediction of fault in the detectable sensors.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

fault diganosis
sensor error recovery
process monitoring


Arm load magnitude affects selective shoulder muscle activation For isometric tasks, shoulder muscle forces are assumed to scale linearly with the external arm load magnitude, i.e., muscle force ratios are constant. Inverse dynamic modeling generally predicts such linear scaling behavior, with a critical role for the arbitrary load sharing criteria, i.e., the cost function. We tested the linearity of the relation between external load magnitude exerted on the humerus and shoulder muscle activation. Six isometric force levels ranging from 17 to 100% of maximal arm force were exerted in 24 directions in a plane perpendicular to the longitudinal axis of the humerus. The direction of maximum muscle activation, the experimentally observed so called Principal Action (PA), was determined for each force magnitude in 12 healthy subjects. This experiment was also simulated with the Delft Shoulder and Elbow Model (DSEM) using two cost functions: (1) minimizing muscle stress and (2) a compound, energy related cost function. PA, both experimental (PAexp) and simulated (PAsim), was expected not to change with arm forces magnitudes. PAexp of the mm. trapezius pars descendens, deltoideus pars medialis and teres major changed substantially as a function of external force magnitude, indicating external load dependency of shoulder muscle activation. In DSEM simulations, using the stress cost function, small non-linearities in the muscle forceexternal load dependency were observed, originating from gravitational forces working on clavicular and scapular bone masses. More pronounced non-linearities were introduced by using the compound energy related cost function, but no similarity was observed between PAexp and PAsim.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Fast Pareto set generation for nonlinear optimal control problems with multiple objectives Many practical engineering problems involve the determination of optimal control trajectories for given multiple and conflicting objectives. These conflicting objectives typically give rise to a set of Pareto optimal solutions. To enhance real-time decision making efficient approaches are required for determining the Pareto set in a fast and accurate way. Hereto, the current paper integrates efficient multiple objective scalarisation strategies (e.g., Normal Boundary Intersection and Normalised Normal Constraint) with fast deterministic approaches for dynamic optimisation (e.g., Single and Multiple Shooting). All techniques have been implemented as an easy-to-use add-on module of the automatic control and dynamic optimisation toolkit ACADO (both freely available at http://www.acadotoolkit.org). Several algorithmic synergies (e.g., hot-start initialisation strategies) are exploited for an additional speed-up. The features of ACADO Multi-Objective are discussed and its use is illustrated on different multiple objective optimal control problems arising in several engineering disciplines.

O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O

optimal control
normalised normal constraint
normal boundary intersection

multiobjective optimization
dynamic optimization


Simple random number generation A wide variety of random number generators is discussed based on truncating functional outcomes and considering the fractional remainders as random digits in the interval, ]0,1[. These generators do not require seeding in the traditional sense, moreover offer an infinite number of outcomes, apparently without periodicity. These generators are trivial in their software implementation. Those that are based on logarithms perform best in tests of randomness. When applied for spatial simulation, though, quality of the random number generator seems unimportant to the outcome.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O


Adaptive rule weights in neuro-fuzzy systems Neuro-fuzzy systems have recently gained a lot of interest in research and application. They are approaches that use learning techniques derived from neural networks to learn fuzzy systems from data. A very simple ad hoc approach to apply a learning algorithm to a fuzzy system is to use adaptive rule weights. In this paper, we argue that rule weights have a negative effect oil the linguistic interpretation of a fuzzy system, and thus remove one of the key advantages for applying fuzzy systems. We show how rule weights can be equivalently replaced by modifying the fuzzy sets of a fuzzy system. If this is done, the actual effects that rule weights have pit a fuzzy rule base become visible. We demonstrate at a simple example the problems of using rule weights. We suggest that neuro-fuzzy learning should be better implemented by algorithms that modify the fuzzy sets directly without using rule weights.

O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O B O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O

neural network
neuro-fuzzy system
rule weight


An exploratory study to understand the critical factors affecting the decision to adopt cloud computing in Taiwan hospital To investigate the factors to adopt cloud computing in Taiwan hospitals industry. To integrate the TOE framework and HOT-fit model for the study. A significant difference exist in CIO innovativeness, data security, compatibility. Important dimensions are technology and then human, organization, and environment.

O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O


evaluation of different complexity measures for signal detection in genome sequences Analyzing large amounts of data is one of the most challenging problem in modern molecular biology. In this work, different complexity measures and methods are applied to identify the signals in the whole genome of the three prokaryotic organisms. In addition to previous complexity measures, new measures are introduced for representing Open Reading Frames (ORF). We apply classification algorithms to determine which complexity measures can lead to better predictive performance in discriminating genes from pseudo-genes in ORFs. Also, we investigate whether positions and lengths of windows in ORFs have significant impact on distinguishing between genes and pseudo-genes. Different classification algorithms are applied for classifying ORFs into genes and pseudo-genes.

O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Microfluidic etching driven by capillary forces for rapid prototyping of gold structures Soft lithographic methods based on poly(dimethylsiloxane) (PDMS) for pattern transfer are established alternatives to conventional lithographic methods. For applications in the biological sciences functionalized and structured noble metal surfaces are required. In order to allow for rapid prototyping of such gold structures a method is needed that does not change the surface chemistry. This can be achieved by a microfluidic system on a gold substrate that is filled with an etchant. From theoretical considerations simple thumb rules for the geometric and chemical design of such a microfluidic system were established. For experimental testing a microfluidic system was realized by contacting a structured PDMS stamp with a substrate consisting of a 50-nm-thick gold layer on a glass object slide. The etchant was applied to the entrance of the capillary and the acid was drawn into the fluidic system by capillary forces. Taking advantage of a PDMS stamp structured with wetting and non-wetting regions no additional self-assembled monolayer was needed for masking.

B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Probabilistic versus possibilistic risk assessment models for optimal service level agreements in grid computing We present a probabilistic and a possibilistic model for assessing the risk of a service level agreement for a computing task in a cluster/grid environment. These models can also be applied to cloud computing. Using the predictive probabilistic approach we develop a framework for resource management in grid computing, and by introducing an upper limit for the number of failures we approximate the probability that a particular computing task is successful. In the predictive possibility model we estimate the possibility distribution of the future number of node failures by a fuzzy nonparametric regression technique. Then the resource provider can use the probabilistic or the possibilistic model to getalternative risk assessments.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

grid and cloud computing
service level agreement (sla)
predictive probabilities
predictive possibilities


A gradient method for the monotone fused least absolute shrinkage and selection operator We propose the monotone fused least absolute shrinkage and selection operator (LASSO) model and develop a continuous algorithm for it. The LASSO model is a special case of the fused LASSO model. The LASSO technique improves prediction accuracy and reduces the number of predictors, while the fused LASSO procedure also encourages flatness of the regression predictors. The monotone fused LASSO model describes regression with monotonic constraints better than the fused LASSO model. We adapt Nesterov's fast gradient methods to the monotone fused LASSO model, we give closed-form solutions for each iteration and prove the boundedness of the optimal solution set, and we provide convergence results. Numerical examples are provided and discussed. Our approach can easily be adapted to related problems, such as the monotone regression and the fused LASSO model.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O B O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O


Human capital externality and chaotic equilibrium dynamics This study develops a two-period overlapping generations model in which adults undertake educational investment decisions oil behalf of young agents. In addition to educational investment, we argue that the accumulation of human capital is also dependent upon the externality from average human capital within the economy. In a departure from the previous literature in this area, we assume that there is a reduction in the overall productivity of human capital accumulation brought about by human capital externality, and show that complicated dynamics will emerge under this circumstance. In addition to displaying the chaotic dynamics in the sense of Li and Yorke, we also verify the existence of Devaney's chaos and Smale's chaos.

O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O B O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O

chaotic dynamics
externality
human capital accumulation


Statistical Functional Yield Estimation and Enhancement of CNFET-Based VLSI Circuits Carbon nanotube field effect transistors (CNFETs) show great promise as extensions to silicon CMOS. However, imperfections, which are mainly related to carbon nanotubes (CNTs) growth process, result in metallic and nonuniform CNTs leading to significant functional yield reduction. This paper presents a comprehensive technique for statistical functional yield estimation and enhancement of CNFET-based VLSI circuits. Based on experimental data extracted from aligned CNTs, we propose a compact statistical model to estimate the failure probability of a CNFET. Using the proposed failure model, we show that enhancing the CNT synthesis process alone cannot achieve acceptable functional yield for upcoming CNFET-based VLSI circuits. We propose a technique which is based on replacing each transistor by series-parallel transistor structures to reduce the failure probability of CNFETs in the presence of metallic and nonuniform CNTs. The technique is adapted to use single directional independence, which is inherent in aligned CNTs, to enhance the functional yield as validated by theoretical analysis and simulation results. Tradeoffs between failure probability reduction and design overheads such as area and current drive are explored. As demonstrated by extensive simulation results, the proposed technique achieves 80% functional yield in CNFET technology at the cost of 7.5X area and 34% current drive overheads if the CNT density and the fraction of semiconducting CNTs are improved to 200 CNTs per mu m and 99.99%, respectively.

B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

failure probability
statistical functional yield

carbon nanotube field effect transistor (cnfet)


Experimental investigation of an IR-UWB positioning system with comparators Impulse Radio (IR)-Ultra Wideband (UWB) enables accurate ranging due to very short duration pulses. Therefore, UWB may provide accurate positioning capability. In order to relax the complexity in circuit implementation, UWB system with low resolution analog digital converters (ADCs) has been investigated. In this paper, the accuracy of UWB positioning with comparators is investigated through experiment. The accuracy of positioning,kith comparators is compared to that with 8 [bit] ADCs, and effectiveness of the system with the comparators is confirmed within the area of 1.8 x 1.8 [m].

O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A New Replica Placement Algorithm for Improving the Performance in CDNs With the advent of services and applications over the Internet, speed and reliability have become critical issues for clients, and the Internet currently is not well suited for the purpose of the emerging new service delivery contemplated by today's applications. In response to these challenges, commercial Content Distribution Network (CDN) deploys a set of proxy servers called replicas and improves the content delivery performance by replicating the content to multiple replicas in the Internet. These issues motivate us to do research in how to efficiently place replicas in the network, and then propose a cost-based replica placement algorithm which selects replica locations using a greedy fashion iteratively. We evaluated that it can yield close to optimal performance at low management and computation cost among several replica placement strategies. The key contributions of this paper are threefold: A practical cost function from the game theoretic perspective is designed, and is limited by various parameters and constraints. It can minimize either its clients' latency or its total bandwidth consumption. A cost-based replica placement integrating a greedy algorithm is proposed, which can provide CDNs with the performance close to optimal. The performance of the diversified replica placement algorithms is evaluated by simulating their behavior on synthetic and real network topologies. To the best of our knowledge, there are few studies on this subject. In summary, we study the online problem of placing web replicas in CDNs to minimize the cost for clients to access data replicated from the original web servers. The novel cost-based replica placement is designed combining with the minimum k-median heuristic greedy algorithm. We evaluate the performance of the different replica placement algorithms by simulating their behavior on both synthetic and real network topologies. Based upon simulation results, we conclude that our cost-based greedy algorithm for web server replica placement can provide CDNs with performance that is close to optimal. Although the greedy algorithm depends upon estimation, we find it is a viable and practical algorithm to use in the general Internet environment. As for future work, we are interested in exploring incremental versions of the placement algorithms that also take into account the cost of changing the set of replica sites. Ideally, for placement strategies with similar performance, we prefer the one that incurs the least amount of perturbation to the system.

O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

cost function
replica placement algorithm

access frequency
content distribution network (cdn)
web replica


Crack detection in simply supported beams without baseline modal parameters by stationary wavelet transform There are significant changes in the vibration responses of cracked structures when the crack depth is significant in comparison to the depth of the structure. This fact enables the identification of cracks in structures from their vibration response data. However when the crack is relatively small, it is difficult to identify the presence of the crack by a mere observation of the vibration response data. A new approach for crack detection in beam-like structures is presented and applied to cracked simply supported beams in this paper. The approach is based on finding the difference between two sets of detail coefficients obtained by the use of the stationary wavelet transform (SWT) of two sets of mode shape data of the beam-like structure. These two sets of mode shape data, which constitute two new signal series, are obtained and reconstructed from the modal displacement data of a cracked simply supported beam. They represent the left half and the modified right half of the modal data of the simply supported beam. SWT is a redundant transform that doubles the number of input samples at each iteration. It provides a more accurate estimate of the variances at each scale and facilitates the identification of salient features in a signal, especially for recognising noise or signal rupture. It is well known that the mode shape of a beam containing a small crack is apparently a single smooth curve like that of an uncracked beam. However, the mode shape of the cracked beam actually exhibits a local peak or discontinuity in the region of damage. Therefore, the mode shape signal of a cracked beam can be approximately considered as that of the uncracked beam contaminated by noise, which consists of response noise and the additional response due to the crack. Thus, the modal data can be decomposed by SWT into a smooth curve, called the approximation coefficient, and a detail coefficient. The difference of the detail coefficients of the two new signal series includes crack information that is useful for damage detection. The modal responses of the damaged simply supported beams used are computed using the finite element method. For real cases, mode shape data are affected by experimental noise. Therefore, mode shape data with a normally distributed random noise are also studied. The results show that the proposed method has great potential in crack detection of beam-like structures as it does not require the modal parameters of an uncracked beam as a baseline for crack detection. The effects of crack size, depth and location, and the effects of sampling interval are examined.

B I O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O

cracks
crack detection
damage detection
stationary wavelet transform


Two-way successively refined joint source-channel coding Consider a source, {X-i, Y-i}(i=1)(infinity) producing independent copies of a pair of jointly distributed random variables (RVs). The {X-i} part of the process is observed at some location, say A, and is supposed to be reproduced at a different location, say B, where the {Y-i} part of the process is observed. Similarly, {Y-i} should be reproduced at location A. The communication between the two locations is carried out across two memoryless channels in K iterative bi-directional rounds. In each round, the source components are reconstructed at the other locations based on the information exchanged in all previous rounds and the source component known at that location, and it is desired to find the amount of information that should be exchanged between the two locations in each round, so that the distortions incurred (in each round) will not exceed given thresholds. Our setting extends the results of Steinberg and Merhav as well as Kaspi, combining the notion of successive refinement with this of two-way interactive communication. We first derive a single-letter characterization of achievable rates for a pure source-coding problem with successive refinement. Then, for a joint source-channel coding setting, we prove a separation theorem, asserting that in the limit of long blocks, no optimality is lost by first applying lossy (two-way) successive-refinement source coding, regardless of the channels, and then applying good channel codes to each one of the resulting bitstreams, regardless of the source.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O

channel capacity
joint source-channel coding
two-way communication


Optimal design of chemical processes with chance constraints Generally, chemical processes (CP) are designed with the use of inaccurate mathematical models. Therefore, it is important to create a chemical process that guarantees satisfaction of all design specifications either exactly or with some probability. The paper considers the issue of chemical process optimization when at the operation stage the design specification should be met with some probability and the control variables can be changed. We have developed a common approach for solving the broad class of optimization problems with normally distributed uncertain parameters. This class includes the one-stage and two-stage optimization problems with chance constraints. This approach is based on approximate transformation of chance constraints into deterministic ones. (C) 2013 Elsevier Ltd. All rights reserved.

O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O

systems engineering
uncertainty
normal distribution


Slip flow and convective heat transfer of nanofluids over a permeable stretching surface This article presents a numerical investigation on the convective heat transfer performance of nanofluids over a permeable stretching surface in the presence of partial slip, thermal buoyancy and temperature dependent internal heat generation or absorption. Two different types of nanoparticles, namely Cu and Al2O3 are considered by using water-based fluid with Prandtl number P-r = 6.785 for simulating the heat transfer and flow behavior of nanofluids. The proposed model is validated with the available experimental data and correlations. The similarity solutions which depend on nanoparticle volume fraction phi (0 <= phi <= 0.2), slip parameter, suction/injection parameter, etc. are presented through graphs and tables and discussed in detail. (C) 2012 Elsevier Ltd. All rights reserved.

O O O B I I O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

cu-water nanofluid
al2o3-water nanofluid
slip velocity
suction/injection


An approximation result for a periodic allocation problem In this paper we study a periodic allocation problem which is a generalization of the dynamic storage allocation problem to the case in which the arrival and departure time of each item is periodically repeated. These problems are equivalent to the interval coloring problem on weighted graphs in which each feasible solution corresponds to an acyclic orientation, and the solution value is equal to the length of the longest weighted path of the oriented graph. Optimal solutions correspond to acyclic orientations having the length of longest weighted path as small as possible. We prove that for the interval coloring problem on a class of circular arc graphs, and hence for a periodic allocation problem, there exists an approximation algorithm that finds a feasible solution whose value is at most two times the optimal.

O B I O O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O B I I O O O O B I O O O O O O O O O O O O O O O O O O O O

periodic allocation
interval coloring
circular arc graphs
approximation result

multiprocessor task scheduling
helly property
clique partition