An expert system for managing medical appropriateness criteria based on computer algebra techniques This article presents the development of an expert system for managing medical appropriateness criteria together with an outline of its theoretical foundations. Techniques borrowed from computer algebra (Grobner bases) are applied to this field of medicine. The steps of the expert system construction process are as follows. First, the knowledge provided in table format by experts in coronary diseases is translated into a set of production rules of a rule-based expert system (RBES). Kleene's three-valued logic augmented with modal operators is chosen in order to manage uncertainty. Once the rules are written, they are automatically translated into polynomials. A result that relates tautological consequences in logic with an ideal membership problem in a polynomial ring is the key for dealing with inference and verification in the RBES. The implementation of the (algebraic) inference engine is made in the CoCoA language. Indeed, the problems detected using CoCoA in the knowledge summarized in the table led to the redesign of the table. (C) 2001 Elsevier Science Ltd. All rights reserved.

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 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

medical informatics
expert systems verification
many-valued logics


Preventing dielectric damage of low-k organic siloxane by passivation treatment An organic SOG, the Hybird-Organic-Siloxane-Polymer (HOSP), has high applicability to ULSI processes, because of the low dielectric constant of about 2.5. However, the HOSP film will be damaged after photoresist removal. The function groups of HOSP will be destroyed by O2 plasma ashing and chemical wet stripper, which leads to electrical degradation. In order to avoid the issue, H2 plasma treatment is proposed to prevent HOSP film from photoresisit stripping damage. It is found that leakage current is decreased significantly and the dielectric constant is still maintained at a low k value even after photoresist stripping. Therefore, H2 plasma treatment is an effective technique to enhance the resistance of HOSP film against photoresist stripping damage.

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

hosp
photoresist removal
electrical degradation
stripping
h2 plasma


PDF simulations of a bluff-body stabilized flow Three different PDF algorithms have been applied to investigate a constant-density bluff-body stabilized flow using the same turbulence models and the same boundary conditions. The objectives of this paper are to compare the three algorithms in terms of numerical accuracy and efficiency and to demonstrate the ability of PDF methods to calculate this type of flow accurately. While one of the three algorithms is a standalone particle-mesh method, the other two are consistent hybrid algorithms, i.e., both are particle methods coupled with finite-volume schemes. The motivation for hybrid algorithms is to reduce the statistical and bias errors. Since the coupling between the finite-volume scheme and the particle method is a major numerical issue, different approaches have been investigated. It is shown that the results obtained from the three numerical algorithms are in good agreement with each other and with the experimental data. (C) 2001 Academic Press.

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

monte carlo
finite-volume
turbulence modeling
bluff-body stabilized flow


Performance of nonlinear degrading structures: Identification, validation, and prediction The lack of a fundamental theory of hysteresis is a major barrier to successful design of structures against deterioration associated with earthquakes, high winds, and sea waves. Development of a practical model of degrading structures that would match experimental observations is an important task. This paper has a twofold objective. First, a superior system identification algorithm is devised to estimate the unspecified parameters in a differential model of hysteresis from experimental loaddisplacement traces. This algorithm is based upon the latest theory of genetic evolution and it will be streamlined through global sensitivity analysis. Second, the utility of identification of hysteresis is demonstrated through nonlinear response prediction, which is important in structural design. Suppose a hysteretic model is generated with a given loaddisplacement trace. It will be shown experimentally that the model will predict the response of the same system driven by other cyclic loads. The requirements for accurate prediction will be addressed. Through identification of hysteresis, it becomes possible to assess, for the first time in analysis, the performance of a real-life structure that has previously been damaged. In the open literature, there is not any other method that can perform the same task.

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

system identification
hysteresis
degrading structures
nonlinear response


Ordering points for incremental TIN construction from DEMs The standard method of building compact triangulated surface approximations to terrain surfaces (TINS) from dense digital elevation models (DEMs) adds points to an initial sparse triangulation or removes points from a dense initial mesh. Typically, in each triangle in the current TIN, the worst fitting point, in terms of vertical distance, is selected. The order of insertion of the points is determined by the magnitude of the maximum vertical difference. This measure produces triangulations that minimize the maximum vertical distance between the TIN and the source DEM. Other approximation criteria are often used, however, including the root-mean-squared error or the mean absolute error, both for the vertical difference and normal difference, i.e., the distance in the direction of the normal to the triangular approximation. For these approximation criteria, we still select the worst fit point, but determine the insertion order by various sums of errors over the triangle. Experiments show that using these better evaluation measures significantly reduces the size of the TIN for a given approximation error.

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 B 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 B O O O B I

triangulated irregular network
digital elevation model
point selection
structural lines


Numerical simulation of a single bubble by compressible two-phase fluids The present work deals with the numerical investigation of a collapsing bubble in a liquid-gas fluid, which is modeled its a single compressible medium. The medium is characterized by the stiffened gas law using different material parameters for the two phases. For the discretization of the stiffened gas model, the approach of Saurel and Abgrall is employed where the flow equations, here the Euler equations, for the conserved quantities are approximated by a finite volume scheme, and an upwind discretization is used for the non-conservative transport equations of the pressure law coefficients. The original first-order discretization is extended to hi.-her order applying second-order ENO reconstruction to the primitive variables. The derivation of the non-conservative upwind discretization for the phase indicator, here the gas fraction, is presented for arbitrary unstructured grids. The efficiency of the numerical scheme is significantly improved by employing local grid adaptation. For this purpose, multiscale-based grid adaptation is used in combination with it multilevel time stepping strategy to avoid small time steps for coarse cells. The resulting numerical scheme is then applied to the numerical investigation of the 2-D axisymmetric collapse of a gas bubble in a free flow field and near to a rigid wall. The numerical investigation predicts physical features such as bubble collapse, bubble splitting and the formation of a liquid jet that can be observed in experiments with laser-induced cavitation bubbles. Opposite to the experiments, the computations reveal insight to the state inside the bubble clearly indicating that these features are caused by the acceleration of the gas Clue to shock wave focusing and reflection as well as wave interaction processes. While incompressible models have been used to provide useful predictions on the change of the bubble shape of a collapsing bubble near a solid boundary, we wish to study the effects of shock wave emissions into the ambient liquid on the bubble collapse, a phenomenon that may not be captured using an incompressible fluid model. Copyright (C) 2009 John Wiley & Sons, Ltd.

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

compressible two-phase flow
multiscale-based grid adaptation
bubble solid wall interference
finite volume schemes


Organizational climate in air traffic control: Innovative preparedness for implementation of new technology and organizational development in a rule governed organization A positive and innovative organizational climate is of great importance in order to manage and adapt to change. Such a climate seldom evolves in organizations closely governed by rules and regulations. Because of ongoing organizational and technical changes within the Swedish Air Navigation Services Provider, a study concerning the organizational climate for changes and innovations was conducted to investigate the organization's capacity to cope with changes. Study locations were the two Swedish main air traffic control centers and parts of the civil aviation administration headquarters. In the study 390 subjects took part and the CCQ questionnaire was used to measure the organizational climate. The results show that the organizational climate is quite positive despite the rule-governed work. The results also show that administrative personnel assess the organizational climate as more positive than operative personnel. Comparisons between management positions did not result in any differences.

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

organizational climate
innovative preparedness
air traffic control


User-Experience from an Inference Perspective In many situations, people make judgments on the basis of incomplete information, inferring unavailable attributes from available ones. These inference processes may also well operate when judgments about a product's user-experience are made. To examine this, an inference model of user-experience, based on Hassenzahl and Monk's [2010], was explored in three studies using Web sites. All studies supported the model's predictions and its stability, with hands-on experience, different products, and different usage modes (action mode versus goal mode). Within a unified framework of judgment as inference [Kruglanski et al. 2007], our approach allows for the integration of the effects of a wide range of information sources on judgments of user-experience.

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 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

experimentation
human factors
theory
user-experience
beauty
aesthetics


An Efficient Computation of Handle and Tunnel Loops via Reeb Graphs A special family of non-trivial loops on a surface called handle and tunnel loops associates closely to geometric features of "handles" and "tunnels" respectively in a 3D model. The identification of these handle and tunnel loops can benefit a broad range of applications from topology simplification/repair, and surface parameterization, to feature and shape recognition. Many of the existing efficient algorithms for computing non-trivial loops cannot be used to compute these special type of loops. The two algorithms known for computing handle and tunnel loops provably have a serious drawback that they both require a tessellation of the interior and exterior spaces bounded by the surface. Computing such a tessellation of three dimensional space around the surface is a non-trivial task and can be quite expensive. Furthermore, such a tessellation may need to refine the surface mesh, thus causing the undesirable side-effect of outputting the loops on an altered surface mesh. In this paper, we present an efficient algorithm to compute a basis for handle and tunnel loops without requiring any 3D tessellation. This saves time considerably for large meshes making the algorithm scalable while computing the loops on the original input mesh and not on some refined version of it. We use the concept of the Reeb graph which together with several key theoretical insights on linking number provide an initial set of loops that provably constitute a handle and a tunnel basis. We further develop a novel strategy to tighten these handle and tunnel basis loops to make them geometrically relevant. We demonstrate the efficiency and effectiveness of our algorithm as well as show its robustness against noise, and other anomalies in the input.

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


Merging covering arrays and compressing multiple sequence alignments Covering arrays have been extensively studied, in part because of their applications in testing interacting software components. In this setting, fast and flexible methods are needed to construct covering arrays of close-to-minimum size. However testing scenarios often impose additional structure on the tests that can be selected. We extend a greedy method to construct test suites for complex systems that have a hierarchical structure in which components combine to form subsystems, which in turn form larger subsystems, until the entire system is formed. The algorithm for merging covering arrays that we propose is then shown to have further potential application in the compression of multiple sequence alignments of genomic data.

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

mixed-level covering arrays
t t -way interaction coverage t t t t t
software interaction testing
multiple sequence alignment


Performance-guided load (un) balancing under autocorrelated flows Size-based policies have been shown in the literature to effectively balance the load and improve performance in cluster environments. Size-based policies assign jobs to servers based on the job size and their performance improvements are an outcome of separating "short" from "long" jobs, by avoiding having short jobs waiting behind long jobs for service. In this paper, we present evidence that performance improvements due to this separation quickly vanish if the arrival process to the cluster is autocorrelated. Based on our observations, we devise a new size-based policy called D_EQAL that still strives to separate jobs to servers according to job size but this separation is now biased by an effort to reduce performance loss due to autocorrelation in the arrival flows to each server. As a result of this bias, all servers may not be equally utilized (i. e., the load in the system may be "unbalanced"), but performance benefits become significant. D_EQAL can be used on-line as it does not assume any a priori knowledge of the incoming workload. Extensive simulations show the effectiveness of D_EQAL under autocorrelated and uncorrelated arrival streams and illustrate that the policy successfully self-adjusts the degree of load unbalancing based on monitored performance measures.

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

load balancing
autocorrelated arrivals
highly variable service times
self adaptive policies


An Extended Periodic Imperfect Preventive Maintenance Model With Age-Dependent Failure Type This paper presents a generalized periodic imperfect preventive maintenance (PM) model for a system with age-dependent failure type. The imperfect PM model proposed in this study incorporates improvement factors vis-a-vis the hazard-rate function, and effective age. As failures occur, the system experiences one of the two types of failure: type-I failure (minor), and type-II failure (catastrophic). Type-I failures are rectified with minimal repair. In a PM period, the system is preventively maintained following the occurrence of a type-II failure, or at age T, whichever takes place first. At the Nth PM, the system is replaced. An approach that generalizes the existing studies on the periodic PM policy is proposed. Taking age-dependent failure type into consideration, the objective consists of determining the optimal PM & replacement schedule that minimize the expected cost per unit of time, over an infinite horizon.

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 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

improvement factor
maintenance optimization
replacement policy


Managing e-Government: value positions and relationships Public sector managers take much of the responsibility for selecting, commissioning, implementing and realising benefits from information technology (IT) projects. However, e-Government initiatives often suffer from complexity, vision failure, lack of goal clarity and insufficient commitment. These problems may stem from value traditions that are deeply ingrained in managers' cultural environments but not always in harmony with each other. A first step towards working with value complexity is to understand it; we synthesise a model of value positions for e-Government derived from major traditions in the public administration literature. Four value positions relevant to e-Government together with their IT assumptions are identified; they reflect the ideals of professionalism, efficiency, service and engagement. A qualitative investigation of Danish local authority managers displays both value congruence and value divergence. The interpretive study results in a theoretical model that combines value positions and relationships, and the model's implications for researchers and practitioners in focusing successful e-Government initiatives are outlined.

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

e-government
bureaucracy
new public management
is management


Combining concept lattice with call graph for impact analysis Software change impact analysis (CIA) is a key technique to identify unexpected and potential effects caused by software changes. Given a changed entity, most of current CIA techniques compute the change effect composed of some potentially impacted entities. The generated results are often of no help to the maintainers in starting the analysis of impacted entities. In this article, we combine concept lattice with call graph together to obtain a ranked list of potentially impacted methods from the proposed changed methods and/or classes. These impacted methods are ranked based on the hierarchical feature of concept lattice, represented by an impact factor, which can then be used to prioritize these methods to be inspected. Case studies based on four real-world programs show that our approach can improve the precision of the impact result without severely decreasing its recall, when compared with results from either concept lattice or call graph used independently. In addition, the predicted impacted methods with higher impact factor values are also shown to have higher probability to be affected by the changes. Our study also shows that our approach is better than the JRipples CIA approach in removing the false-positives, but at the cost of losing more false-negatives and much more time overhead. (C) 2012 Elsevier Ltd. All rights reserved.

O O O O B I 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 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 B I 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

change impact analysis
call graph
impact factor

formal concept analysis
hierarchical impact results
case study


Constructions for q-ary constant-weight codes This paper introduces a new combinatorial construction for q-ary constant-weight codes which yields several families of optimal codes and asymptotically optimal codes. The construction reveals intimate connection between q-ary constant-weight codes and sets of pairwise disjoint combinatorial designs of various types.

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

disjoint codes
group divisible designs
incomplete group divisible designs
large sets of designs
probabilistic constructions
q-ary constant-weight codes
t-designs


Application of Lie groups to compressible model of two-phase flows This paper presents some exact solutions for the drift-flux model of two-phase flows using Lie group analysis. The analysis involves an isentropic no-slip conservation of mass for each phase and the conservation of momentum for the mixture. The present analysis employs a complete Lie algebra of infinitesimal symmetries. Subsequent to these theoretical analysis a symmetry group is established. The symmetry generators are used for constructing similarity variables which reduce the model equations to a system of ordinary differential equations (ODEs). In particular, a general framework is discussed for solving the model equations analytically. As a consequence of this, new classes of exact group-invariant solutions are developed. This provides new insights into the fundamental properties of weak discontinuities and helps one to understand better on existence of solutions.

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

drift-flux model
two-phase flows
no slip law
analytical solution
weak discontinuity


On using acoustic environment classification for statistical model-based speech enhancement In this paper, we present a statistical model-based speech enhancement technique using acoustic environment classification supported by a Gaussian mixture model (GMM). In the data training stage, the principal parameters of the statistical model-based speech enhancement algorithm such as the weighting parameter in the decision-directed (DD) method, the long-term smoothing parameter of the noise estimation, and the control parameter of the minimum gain value are uniquely set as optimal operating points according to the given noise information to ensure the best performance for each noise. These optimal operating points, which are specific to the different background noises, are estimated based on the composite measures, which are the objective quality measures representing the highest correlation with the actual speech quality processed by noise suppression algorithms. In the on-line environment-aware speech enhancement step, the noise classification is performed on a frame-by-frame basis using the maximum likelihood (ML)-based Gaussian mixture model (GMM). The speech absence probability (SAP) is used to detect the speech absence periods and to update the likelihood of the GMM. According to the classified noise information for each frame, we assign the optimal values to the aforementioned three parameters for speech enhancement. We evaluated the performances of the proposed methods using objective speech quality measures and subjective listening tests under various noise environments. Our experimental results showed that the proposed method yields better performances than does a conventional algorithm with fixed parameters.

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

speech enhancement
noise classification
gaussian mixture model


Combining precomputation and on-demand routing for multicast QoS routing In QoS routing, two types of computational approaches haste been studied: precomputation and on-demand computation. The precomputation approaches have the advantage of extreme efficiency in connection request processing, but they suffer from large storage overhead for the maintenance of precomputed QoS (route and potentially lower connection acceptance probability due to stale topology information. In contrast, the on-demand computation approaches enjoy higher connection acceptance probability but incur a large per-request computation cost and long join latency. In this paper, we try to combine the two approaches and strike a balance between the m in the design of a multicast routing protocol PPMRP (Probabilistic Precomputation Multicast Routing Protocol). PPMRP is the first attempt to include the precomputation technique in the design of multicast QoS routing protocols. It employs two innovative ideas to achieve a nice balance between cost and performance: scope-limited adverting of multicast tree information and probabilistic selection of precomputation routers. Through extensive simulations experiments, we demonstrate that PPMRP exhibits the low join latency characteristic of precomputation schemes without excessive computation on a large control message overhead. Meanwhile, it is able to construct low cost multicast trees with superior connection acceptance probability.

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

dynamic routing
scope-limited advertising


An efficient certificateless aggregate signature with constant pairing computations An aggregate signature scheme enables an algorithm to aggregate n signatures of n distinct messages from n users into a single short signature. This primitive is useful in resource-constrained environment since they allow bandwidth and computational savings. Recently, in order to eliminate the use of certificates in certified public key cryptography and the key-escrow problem in identity-based cryptography, the notion of certificateless public key cryptography was introduced. In this paper, we present an efficient certificateless aggregate signature scheme with constant pairing computations. The security of the proposed scheme can be proved to be equivalent to the standard computational DiffieHellman problem in the random oracle with a tight reduction. Furthermore, our scheme does not require synchronization for aggregating randomness, which makes it more suitable for ad hoc networks.

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

message authentication
certificateless cryptography


Enhanced sharing analysis techniques: a comprehensive evaluation Sharing, an abstract domain developed by D. Jacobs and A. Langen for the analysis of logic programs, derives useful aliasing information. It is well-known that a commonly used core of techniques, such as the integration of Sharing with freeness and linearity information, can significantly improve the precision of the analysis. However, a number of other proposals for refined domain combinations have been circulating for years. One feature that is common to these proposals is that they do not seem to have undergone a thorough experimental evaluation even with respect to the expected precision gains. In this paper we experimentally evaluate: helping Sharing with the definitely ground variables found using Pos, the domain of positive Boolean formulas; the incorporation of explicit structural information; a full implementation of the reduced product of Sharing and Pos; the issue of reordering the bindings in the computation of the abstract mgu; an original proposal for the addition of a new mode recording the set of variables that are deemed to be ground or free; a refilled way of using linearity to improve the analysis; the recovery of hidden information in the combination of Sharing with freeness information. Finally, we discuss the issue Of whether tracking compoundness allows the computation of more sharing information.

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 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

sharing analysis
experimental evaluation

abstract interpretation
logic programming


Supervised feature-based classification of multi-channel SAR images This paper describes a new method for a feature-based supervised classification of multi-channel SAR data. Classic feature selection and classification methods are inadequate due to the diverse statistical distributions of the input features. A method based on logistic regression (LR) and multinomial logistic regression (MNLR) for separating different classes is therefore proposed. Both methods, LR and MNLR, are less dependent on the statistical distribution of the input data. A new spatial regularization method is also introduced to increase consistency of the classification result. The classification method was applied to a project on humanitarian demining in which the relevant classes were defined by experts of a mine action center. A ground survey mission collected learning and validation samples for each class. Results of the proposed classification methods are shown and compared to a maximum likelihood classifier.

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

sar image classification
multinomial logistic regression
multi-channel sar


Stepwise decomposition approaches for large scale cell formation problems Cell formation is one of the major steps in cellular manufacturing system (CMS) design. In this paper, two stepwise decomposition approaches are proposed to solve large scale industrial problems. Both of them analyze the part-machine relations, decompose the original system to several large subsystems and then use an optimal solution technique to solve each. Several results are proved to show the conditions under which optimal solutions are obtained.

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

group technology
optimization
benders decomposition


Stable results and relative normalization In orthogonal expression reduction systems, a common generalization of term rewriting and X-calculus, we extend the concepts of normalization and needed reduction by considering, instead of the set of normal forms, a set S of 'results'. When S satisfies some simple axioms which we call stability, we prove the corresponding generalizations of some fundamental theorems: the existence of needed redexes, that needed reduction is normalizing, the existence of minimal normalizing reductions, and the optimality theorem.

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

rewrite systems
normalizing strategy
stable sets of results
minimal and optimal normalization
high-order rewriting


FirstSTEP process modeler - a CIMOSA-compliant modeling tool Since its market release in late 1994, the FirstSTEP toolset developed by Interfacing Technologies of Montreal, Canada has been proven to be one of the most practical solutions for business process management initiatives. Being a methodology independent enterprise modeling and simulation application, FirstSTEP has been adopted by industry leaders from such diversified sectors as manufacturing, finance, telecom, healthcare, public, and others. Its concept and approach are compatible to the CIMOSA framework. Most notably is the user front-end simplicity that has enabled its acceptance by the typical business manager who is not usually academic in his/her approach. The paper presents the FirstSTEP tool suite, its concept and approach and demonstrates its capabilities using an application with a most recent FirstSTEP user - America Online. (C) 1999 Published by Elsevier Science B.V. All rights reserved.

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

business process management
enterprise modeling
firststep
modeling tool
cimosa


Feature-based surface parameterization and texture mapping Surface parameterization is necessary for many graphics tasks: texture-preserving simplification, remeshing, surface painting, and precomputation of solid textures. The stretch caused by a given parameterization determines the sampling rate on the surface. In this article, we present an automatic parameterization method for segmenting a surface into patches that are then flattened with little stretch. Many objects consist of regions of relatively simple shapes, each of which has a natural parameterization. Based on this observation, we describe a three-stage feature-based patch creation method for manifold surfaces. The first two stages, genus reduction and feature identification, are performed with the help of distance-based surface functions. In the last stage, we create one or two patches for each feature region based on a covariance matrix of the feature's surface points. To reduce stretch during patch unfolding, we notice that stretch is a 2 x 2 tensor, which in ideal situations is the identity. Therefore, we use the Green-Lagrange tensor to measure and to guide the optimization process. Furthermore, we allow the boundary vertices of a patch to be optimized by adding scaffold triangles. We demonstrate our feature-based patch creation and patch unfolding methods for several textured models. Finally, to evaluate the quality of a given parameterization, we describe an image-based error measure that takes into account stretch, seams, smoothness, packing efficiency, and surface visibility.

O B I O B I 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

surface parameterization
texture mapping


Modifying the shape of NURBS surfaces with geometric constraints NURBS surfaces are among the most commonly used parametric surfaces in CAGD and Computer Graphics. This paper investigates shape modification of NURBS surfaces with geometric constraints, such as point, normal vector, and curve constraints. Two new methods are presented by constrained optimization and energy minimization. The former is based on minimizing changes in control net of surfaces, whereas the latter is based on strain energy minimization. By these two methods, we change control points and weights of an original surface, such that the modified surface satisfies the given constraints. Comparison results and practical examples are also given.

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

shape modification
nurbs
energy minimization
constrained optimization


A standardised graphic method for describing data privacy frameworks in primary care research using a flexible zone model Easy model to display policies and rules for data privacy. Novel concept of privacy zones for research data flow. A risk gradient runs from high risk to low risk for patient identification. The zone model is presented for important research scenarios. Different types of research are considered in each of the three zones.

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 B 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 O O O O O O O O B

medical research
confidentiality
pseudonymisation
anonymisation
data linkage


Resource-Optimal Heterogeneous Machine-to-Machine Communications in Software Defined Networking Cyber-Physical Systems Cyber-physical systems (CPS), emerging as the most promising approach for extensive computing, processing, and remote control to physical entities, rely on reliable and heterogeneous (real-time and non-real-time) data exchanges among machines. However, for CPS exploiting shared network infrastructures, communication links may suffer from various vulnerabilities to harm real-time data exchanges. Providing robustness against link vulnerabilities consequently becomes the most critical requirement. By installing software defined networking (SDN) functions in existing network infrastructures, multiple communication paths can be practically formed to provide robustness if replicates of real-time data are simultaneously forwarded via multiple paths. Furthermore, if each non-real-time data packet is forwarded via distinct paths, packet congestion in certain paths can be avoided. However, the key to practice such SDN robust communications relies on an efficient resource utilization both in the time and the spatial domains. To further support high mobile machines, the efficient resource utilization shall be achieved by a low complexity scheme to rapidly adapt to varying environments. In this paper, we shall consequently develop mathematical foundations of a resource-optimal design for CPS. Achieving the minimum resource usage to support real-time data exchanges, our design further avoids the worst case packet congestion to trace the performance of non-real-time data exchanges to the optimum. By providing the most efficient and low complexity resource management, our design successfully practice robust big data exchanges in CPS.

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

heterogeneous machine-to-machine (m2m) communications


Laws of Attraction: From Perceived Forces to Conceptual Similarity Many of the pressing questions in information visualization deal with how exactly a user reads a collection of visual marks as information about relationships between entities. Previous research has suggested that people see parts of a visualization as objects, and may metaphorically interpret apparent physical relationships between these objects as suggestive of data relationships. We explored this hypothesis in detail in a series of user experiments. Inspired by the concept of implied dynamics in psychology, we first studied whether perceived gravity acting on a mark in a scatterplot can lead to errors in a participant's recall of the mark's position. The results of this study suggested that such position errors exist, but may be more strongly influenced by attraction between marks. We hypothesized that such apparent attraction may be influenced by elements used to suggest relationship between objects, such as connecting lines, grouping elements, and visual similarity. We further studied what visual elements are most likely to cause this attraction effect, and whether the elements that best predicted attraction errors were also those which suggested conceptual relationships most strongly. Our findings show a correlation between attraction errors and intuitions about relatedness, pointing towards a possible mechanism by which the perception of visual marks becomes an interpretation of data relationships.

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

perceptual cognition
visualization models
laboratory studies
cognition theory


self-predicted and actual performance in an introductory programming course Students in a large introductory programming course were asked twice to predict their scores on the final exam: once at the beginning of a six-week module, and once at the end. In between, students in only one of the two lecture streams recorded subjective confidence in their answers to individual questions on weekly quizzes. Students' predictions were moderately correlated with their scores. Students who attended more quizzes had not only higher exam scores, but improved their predictions more than those who attended fewer quizzes. Practice recording confidence on individual quiz questions did not yield significantly more improvement in exam predictions. Several findings from previous work are confirmed, including that women were significantly more underconfident than men.

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


Software Effort Estimation as a Multiobjective Learning Problem Ensembles of learning machines are promising for software effort estimation (SEE), but need to be tailored for this task to have their potential exploited. A key issue when creating ensembles is to produce diverse and accurate base models. Depending on how differently different performance measures behave for SEE, they could be used as a natural way of creating SEE ensembles. We propose to view SEE model creation as a multiobjective learning problem. A multiobjective evolutionary algorithm (MOEA) is used to better understand the tradeoff among different performance-measures by creating SEE models through the simultaneous optimisation of these measures. We show that the performance measures behave very differently, presenting sometimes even opposite trends. They are then used as a source of diversity for creating SEE ensembles. A good tradeoff among different measures can be obtained by using an ensemble of MOEA solutions. This ensemble performs similarly or better than a model that does not consider these measures explicitly. Besides, MOEA is also flexible, allowing emphasis of a particular measure if desired. In conclusion, MOEA can be used to better understand the relationship among performance measures and has shown to be very effective in creating SEE models.

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

software effort estimation
ensembles of learning machines

experimentation
algorithms
management
multi-objective evolutionary algorithms


A bounded distance metric for comparing tree structure Comparing tree-structured data for structural similarity is a recurring theme and one on which much effort has been spent. Most approaches so far are grounded, implicitly or explicitly, in algorithmic information theory, being approximations to an information distance derived from Kolmogorov complexity. In this paper we propose a novel complexity metric, also grounded in information theory, but calculated via Shannon's entropy equations. This is used to formulate a directly and efficiently computable metric for the structural difference between unordered trees. The paper explains the derivation of the metric in terms of information theory, and proves the essential property that it is a distance metric. The property of boundedness means that the metric can be used in contexts such as clustering, where second-order comparisons are required. The distance metric property means that the metric can be used in the context of similarity search and metric spaces in general, allowing trees to be indexed and stored within this domain. We are not aware of any other tree similarity metric with these properties.

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 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 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 B I 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

distance metric
algorithmic information theory
information distance
entropy

unordered tree
tree comparison
information content


Client-side enhancements using portable interceptors Interceptors are a useful technique for extending the basic functionality provided by an Object Request Broker without changing its implementation, or affecting clients' code. The recently proposed CORBA standard includes a new definition of portable interceptors. This definition is very powerful, yet not trivial to use. In this paper we review this definition, and discuss how it can be applied to provide client side enhancement for caching, load-balancing, flow control (quality of service), and fault-tolerant soft real-time. A recommendation to the OMG for a very minor change in the standard that could greatly simplify its usability is also provided.

O O O O B B 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 B 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 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

interceptors
object request broker
corba
client side enhancement


A Fuzzy Decision Support System for irrigation and water conservation in agriculture We describe a Fuzzy Decision Support System to decide the irrigation based on soil moisture and rain forecast. Its rules are easily editable and can be specialized for each crop and agricultural condition. The system provided improved irrigation suggestions in terms of timing and water saving.

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

decision support systems
irrigation management
climate changes
fuzzy inference systems
fuzzy modelling


Cooperative advertising in a distribution channel with fairness concerns Cooperative (co-op) advertising has been widely used in practice and employed as a strategy to improve the performance of a distribution channel. It is known from the existing models that co-op advertising could not achieve the channel coordination (i.e., maximize the total channel profit). In this paper, we consider a distribution channel consisting of a single manufacturer and a single retailer, and investigate the effect of the retailers fairness concerns. Applying the equilibrium analysis, we obtain the following results: (1) Channel coordination can be achieved if the retailer has fairness concerns and model parameters satisfy certain conditions. (2) Although both channel members become better off with co-op advertising if neither channel member has fairness concerns, we find situations where co-op advertising brings detrimental effects to the retailer if the retailer has fairness concerns. (3) The retailers fairness concerns may increase or decrease the equilibrium participation rate, the equilibrium advertising effort, and the equilibrium profit of the manufacturer and the whole channel. (4) We identify the conditions under which the effectiveness of co-op advertising can be improved or reduced by the retailers fairness concerns. As long as co-op advertising can bring extra profit to the manufacturer, the retailers fairness concerns could improve the effectiveness of the co-op advertising. (5) There exists a Pareto improvement for the profits of both the manufacturer and the retailer when a retailer without fairness concerns becomes fair-minded.

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

cooperative advertising
fairness concerns
channel coordination


Fast buffering for FPGA implementation of vision-based object recognition systems Real-time frame rate is an important factor for practical deployment of computer vision systems. Field programmable gate array (FPGA) technology has been considered for many applications due to its parallel computing capability. FPGA implementations of computer vision algorithms normally involve buffering data on external memory devices, which could slow down the whole system. This paper proposes a buffering scheme suitable for implementing real-time vision-based systems on an FPGA that does not require external memory to buffer data. A stop sign detection system implemented on an FPGA employing the proposed buffering scheme is presented as an example system. This system is capable of processing over 200fps at the frame size of 480752 pixels.

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


Image edge sharpening with phase correction An image edge sharpening technique with phase correction for digital image is presented. In this paper the point spread functions of a typical standard single focal lens and zoom lens are investigated with a several different apertures. And from this investigation the Fourier phase figure pattern of the point-spread function is identified. The technique here includes a traditional one (a Laplacian operator) and phase-only synthesis with the corrected Fourier phase. The Fourier phase of the original non-blurred image is estimated recursively and it is utilized for implementation of the phase-only synthesis, which is powerful for image edge sharpening. A human visual property is also introduced as a weight function in order to maintain the natural smoothness in the gray level of the resulting processed image. Simulation examples show that the proposed technique is superior to the traditional one.

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

edge-sharpening
fourier phase-only synthesis


Enabling opportunistic storage for mobile DTNs Delay-tolerant Networking (DTN) can enable ad-hoc communication within (sparse) mobile user communities and multi-hop Internet access where IP-based end-to-end communication would fail. DTN message forwarding in ad-hoc networks may lead to message replication and messages remaining stored on several nodes for some time. We leverage these characteristics and provide application support in intermediate nodes: we enable them to understand the resources contained in forwarded and locally stored DTN messages to perform application-specific processing. Based upon this, we create an opportunistic distributed storage for cooperative content caching and retrieval using the nodes buffers.

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 B O O O B O O O O O O

delay-tolerant networking (dtn)
mobile ad-hoc


A Lightweight Authentication Protocol for Low-Cost RFID As low-cost RFIDs with limited resources will dominate most of the RFID market, it is imperative to design lightweight RFID authentication protocols for these low-cost RFIDs. However, most of existing RFID authentication protocols either suffer from some security weaknesses or require costly operations that are not available on low-cost tags. In this paper, we analyze the security vulnerabilities of a lightweight authentication protocol recently proposed by Li et al. (2006), and then propose a new lightweight protocol to improve the security and to reduce the computational cost for identifying a tag from O(n) to O(1).

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

low-cost cryptography
dos attack
forward secrecy


Stochastic Exploration of Ambiguities for Nonrigid Shape Recovery Recovering the 3D shape of deformable surfaces from single images is known to be a highly ambiguous problem because many different shapes may have very similar projections. This is commonly addressed by restricting the set of possible shapes to linear combinations of deformation modes and by imposing additional geometric constraints. Unfortunately, because image measurements are noisy, such constraints do not always guarantee that the correct shape will be recovered. To overcome this limitation, we introduce a stochastic sampling approach to efficiently explore the set of solutions of an objective function based on point correspondences. This allows us to propose a small set of ambiguous candidate 3D shapes and then use additional image information to choose the best one. As a proof of concept, we use either motion or shading cues to this end and show that we can handle a complex objective function without having to solve a difficult nonlinear minimization problem. The advantages of our method are demonstrated on a variety of problems including both real and synthetic data.

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


Fitting a least squares piecewise linear continuous curve in two dimensions An optimal piecewise linear continuous fit to a given set of n data points D = {(x(i),yi) : 1 less than or equal to i less than or equal to n} in two dimensions consists of a continuous curve defined by k linear segments {L-1, L-2,..., L-k} which minimizes a weighted least squares error function with weight w(i) at (x(i),y(i)), where k greater than or equal to 1 is a given integer. A key difficulty here is the fact that the linear segment L-j, which approximates a subset of consecutive data points D-j subset of D in an optimal solution, is not necessarily an optimal fit in itself for the points D-j. We solve the problem for the special case k = 2 by showing that an optimal solution essentially consists of two least squares linear regression lines in which the weight w(j) of some data point (x(j), y(j)) is split into the weights lambdaw(j) and (1 - lambda )w(j), 0 less than or equal to lambda less than or equal to 1, for computations of these lines. This gives an algorithm of worst-case complexity O(n) for finding an optimal solution for the case k = 2. (C) 2001 Elsevier Science Ltd. All rights reserved.

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

piecewise linear continuous curve
complexity

least squares regression
nonlinear regression
convexity
optimization
algorithms


Retrograde adaptive resonance theory based on the role of nitric oxide in long-term potentiation Adaptive resonance theory (ART) demonstrates how the brain learns to recognize and categorize vast amounts of information by using topdown expectations and attentional focusing. ART 3, one member of the ART family, embeds the computational properties of the chemical synapse in its search process, but it converges slowly and is lack of stability when being applied in pattern recognition and analysis. To overcome these problems, Nitric Oxide (NO), which serves as a newly discovered retrograde messenger in Long-Term Potentiation (LTP), is introduced in retrograde adaptive resonance theory (ReART) model presented in this paper. In the presented model a novel search hypothesis is proposed to incorporate angle and amplitude information of an external input vector to decide whether the input matches the long-term memory (LTM) weights of an active node or not, and the embedded NO retrograde mechanism makes the search procedure a closed loop, which improves the stability and convergence speed of the transmitter releasing mechanism in a synapse. To make the model more adaptive and practical, a forgetting mechanism is built to improve the weights updating process. Experimental results indicate that the proposed ReART model achieves low error rate, fast convergence and self-organizing weights regulation.

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

adaptive resonance theory
nitric oxide
forgetting mechanism

neural networks
retrograde art (reart)
long-term potentiation


Functional gradient ascent for Probit regression This paper proposes two gradient based methods to fit a Probit regression model by maximizing the sample log-likelihood function. Using the property of the Hessian of the objective function, the first method performs weighted least square regression in each iteration of the NewtonRaphson framework, resulting in ProbitBoost, a boosting-like algorithm. Motivated by the gradient boosting algorithm [10], the second proposed approach maximizes the sample log-likelihood function by updating the fitted function a small step in the gradient direction, performing gradient ascent in functional space, resulting in Gradient ProbitBoost. We also generalize the algorithms to multi-class problems by two strategies, one of which is to use the gradient ascent to maximize the multi-class sample log-likelihood function for fitting all the classifiers simultaneously, and the second approach uses the one-versus-all scheme to reduce the multi-class problem to a series of binary classification problems. The proposed algorithms are tested on typical classification problems including face detection, cancer classification, and handwritten digit recognition. The results show that compared to the alternative methods, the proposed algorithms perform similar or better in terms of testing error rates.

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

probit regression
classification
functional gradient ascent
boosting


A time-memory trade-off approach for the solution of nonlinear equation systems We propose a memory-based method for the solution of a specific type of nonlinear equation systems. We observe that when the equations in a system can be separated into 2 parts, where each subset contains fewer parameters than the whole set of equations, the system can be solved faster with a preprocessing phase. We show that reduced rounds of AES produce such a system under a chosen plaintext scenario. This observation enables us to solve that system within a practically applicable complexity of 2(37) operations where a brute force approach requires 2(72) trials. The method can be used for the solution of other equation systems of the same structure. In the optimal case where we can divide the equations into 2, a problem that contains n binary variables can be solved at time O(n/2 . 2(n/2)) operations and using O(2(n/2)) units of memory rather than O(2(n)) trials of the equation system.

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

time-memory trade-off
solution of nonlinear equations
cryptanalysis


Multiquadric and Chebyshev approximation to three-dimensional thermoelasticity with arbitrary body forces In this paper, analytical particular solutions of multiquadrics and Chebyshev polynomials associated with problems of three-dimensional thermoelasticity are derived, which provides a supplement to the review article of Cheng, Chen, Golberg and Rashed (Engineering Analysis with Boundary Elements 25 (2001), 377). In the derivation, the three coupled second-order partial differential equations (PDEs) are converted into a biharmonic equation. Then, the multiquadric and polynomial particular solutions of the biharmonic equation are obtained respectively by straight integrations and referring to the first authors recent study. For the multiquadric particular solutions, they are set to be infinitely differentiable by suitably arranging the coefficients of its Laurent series. And for the polynomial particular solutions, they can be represented explicitly and implemented without any book keeping. Numerical experiments are carried out to validate the derived particular solutions.

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

elasticity
dual reciprocity method
method of particular solutions
chebyshev polynomial


Interactive Visualizations of Blowups of the Plane Blowups are an important technique in algebraic geometry that permit the smoothing of singular algebraic varieties. It is a challenge to visualize this process even in the case of blowups of points X in the affine plane AA 2 A(R)(2). First results were obtained by Brodmann with the aid of the so-called toroidal blowup, a compact embedding of the blowup into affine 3-space. In fact, Brodmann provides a rational parametrization of the toroidal blowup, but its visualization fails in the neighborhood of X because the parametrization tends to indefinite terms of the form 0/0. Our approach is based on implicitization of the parametric form. By methods from commutative algebra we are able to reduce the implicitization to the computation of a single, fairly simple resultant. This provides an algebraic equation of the implicit surface of the toroidal blowup including the so-called exceptional fiber associated with X. Surprisingly, the degree of the equation grows only linearly with the degree of the parametrization. By applying additional clipping techniques to the implicit surface we are able to visualize the toroidal blowup as well as its deformations by several parameters interactively in real time using GPU-based ray casting techniques. The methods of the paper provide insights in the structure of blowups of points, even if the points are interactively moved or tend to degenerations.

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

real-time ray tracing
interactive surface deformation


DYNAMICALLY FORMED CLUSTERS OF AGENTS IN ECO-GRAMMAR SYSTEMS In this paper we extend the conditions of dynamic team constitution in simple eco-grammar systems, motivated by the bottom-up-clustering algorithm. The relationships of simple eco-grammar systems formed according to the newly introduced conditions to each other as well as to certain language classes of the Chomsky hierarchy and L systems are established. We prove that any recursively enumerable language can be obtained as the intersection of a regular language and the language of simple eco-grammar systems where the active teams are organized according to different conditions of team constitution. We also propose some further research directions.

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

bottom-up-clustering algorithm
simple eco-grammar systems
recursively enumerable languages
lindenmayer systems


Computing the stationary distribution of an SRBM in an orthant with applications to queueing networks In [15], a BNAfm (Brownian network analyzer with finite element method) algorithm was developed for computing the stationary distribution of a semimartingale reflecting Brownian motion (SRBM) in a hypercube. In this companion paper, that BNAfm algorithm is extended to computing the stationary distribution of an SRBM in an orthant, which is achieved by constructing a converging sequence of SRBMs in hypercubes. The SRBM in the orthant serves as an approximation model of queueing networks with infinite buffers. We show that the constructed sequence of SRBMs in the hypercubes converges weakly to the SRBM in the orthant as the hypercubes approach the orthant. Under the conjecture that the set of the stationary distributions of the SRBMs in the hypercubes is relatively compact, we prove that the sequence of the stationary distributions of the SRBMs in the hypercubes converges weakly to the stationary distribution of the SRBM in the orthant. A three-machine job shop example is presented to illustrate the effectiveness of the SRBM approximation model and our BNAfm algorithm. The BNAfm algorithm is shown to produce good estimates for stationary probabilities of queueing networks.

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

semimartingale reflecting brownian motion

brownian approximation
heavy traffic
performance analysis
finite buffer
infinite buffer
bnasm
basic adjoint relationship
numerical algorithm


Second-order nonlinear dynamics of catenary pipelines: A frequency domain approach The double frequency nonlinear dynamic behavior of catenary pipelines is investigated. The original nonlinear system is treated using a perturbation technique. The seafloor interaction phenomenon is approximated through a Taylor series expansion. The discrete mathematical models are solved numerically using a centered difference scheme. The calculations demonstrate the significant contribution of the second-order components.

O O O O O B O B I 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

second-order
perturbations
bottom interaction


Phase difference-based multichannel phase unwrapping This work addresses the derivation of the phase difference-based maximum likelihood (ML) phase unwrapping algorithm. To this end, we derive the joint statistics of the phase differences on a two-dimensional grid for the multichannel case, where several scaled wrapped phase values are available. Subsequently, we determine and study the structure of the phase difference-based ML estimator and compare it to known phase unwrapping techniques. This work allows us to frame single and multichannel algorithms in a common formulation. Moreover, among the known single-channel phase difference-based procedures, we identify those attaining an ML solution. We also show that multichannel phase difference-based and, recently proposed, phase-based ML algorithms achieve equivalent solutions.

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

maximum likelihood (ml)
multiple acquisitions
phase unwrapping (phu)


Sparse HDLSS discrimination with constrained data piling Regularization is a key component in high dimensional data analyses. In high dimensional discrimination with binary classes, the phenomenon of data piling occurs when the projection of data onto a discriminant vector is dichotomous, one for each class. Regularizing the degree of data piling yields a new class of discrimination rules for high dimensionlow sample size data. A discrimination method that regularizes the degree of data piling while achieving sparsity is proposed and solved via a linear programming. Computational efficiency is further improved by a sign-preserving regularization that forces the signs of the estimator to be the same as the mean difference. The proposed classifier shows competitive performances for simulated and real data examples including speech recognition and gene expressions.

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 B I 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 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

high-dimensionlow sample-size
linear discriminant analysis
sparse discrimination


techniques for interactive three dimensional design An experimental graphics system for three dimensional design is described. Emphasis is placed on 3D interaction techniques used in the design of the system, together with the overall user-interface. The techniques used involved two-dimensional input devices and displays only. A 3D cursor is used to manipulate objects consisting of lines and geometric representations, appropriate for free-form design. The associative transformation structure combines with high level data generation directives to provide a flexible and powerful design environment. The system operates in a dual-minicomputer configuration involving a dynamic, on-line software package distributed between an IMLAC PDS-1 and a DEC PDP 11/40.

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

generation
design
graphics
interaction
input devices
software
structure
dynamic
data
3d
distributed

interaction technique
association
graphical interaction
object
direct
flexibility
three-dimensional interactive graphics
interactive programming
design environment
systems
experimentation
computer graphics
packaging
user interface
configurability
display


exploring technologies for building collaborative learning communities among diverse student populations Collaborative learning has long been recognized as an effective approach to enhance the learning process. The purpose of this research was to investigate mechanisms for building an inclusive collaborative learning community outside the classroom that connects students with diverse backgrounds and ultimately enhances students' learning experience. To accomplish this, we conducted a study using blogs and user groups to support virtual collaborative communities in our upper division computer science courses. Our results show that blogs are an effective tool for bringing together these diverse student groups to create an inclusive learning environment.

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


Sifted Disks We introduce the Sifted Disk technique for locally resampling a point cloud in order to reduce the number of points. Two neighboring points are removed and we attempt to find a single random point that is sufficient to replace them both. The resampling respects the original sizing function; In that sense it is not a coarsening. The angle and edge length guarantees of a Delaunay triangulation of the points are preserved. The sifted point cloud is still suitable for texture synthesis because the Fourier spectrum is largely unchanged. We provide an efficient algorithm, and demonstrate that sifting uniform Maximal Poisson-disk Sampling (MPS) and Delaunay Refinement (DR) points reduces the number of points by about 25%, and achieves a density about 1/3 more than the theoretical minimum. We show two-dimensional stippling and meshing applications to demonstrate the significance of the concept.

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

5 [computing methodologies]: computer graphicscomputational geometry and object modeling


LIS: Localization based on an intelligent distributed fuzzy system applied to a WSN The localization of the sensor nodes is a fundamental problem in wireless sensor networks. There are a lot of different kinds of solutions in the literature. Some of them use external devices like GPS, while others use special hardware or implicit parameters in wireless communications. In applications like wildlife localization in a natural environment, where the power available and the weight are big restrictions, the use of hungry energy devices like GPS or hardware that add extra weight like mobile directional antenna is not a good solution. Due to these reasons it would be better to use the localizations implicit characteristics in communications, such as connectivity, number of hops or RSSI. The measurement related to these parameters are currently integrated in most radio devices. These measurement techniques are based on the beacons transmissions between the devices. In the current study, a novel tracking distributed method, called LIS, for localization of the sensor nodes using moving devices in a network of static nodes, which have no additional hardware requirements is proposed. The position is obtained with the combination of two algorithms; one based on a local node using a fuzzy system to obtain a partial solution and the other based on a centralized method which merges all the partial solutions. The centralized algorithm is based on the calculation of the centroid of the partial solutions. Advantages of using fuzzy system versus the classical Centroid Localization (CL) algorithm without fuzzy preprocessing are compared with an ad hoc simulator made for testing localization algorithms. With this simulator, it is demonstrated that the proposed method obtains less localization errors and better accuracy than the centroid algorithm.

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

fuzzy system
wsn
localization
rssi
centroid
cl


Inferring cell cycle feedback regulation from gene expression data Feedback control is an important regulatory process in biological systems, which confers robustness against external and internal disturbances. Genes involved in feedback structures are therefore likely to have a major role in regulating cellular processes. Here we rely on a dynamic Bayesian network approach to identify feedback loops in cell cycle regulation. We analyzed the transcriptional profile of the cell cycle in HeLa cancer cells and identified a feedback loop structure composed of 10 genes. In silico analyses showed that these genes hold important roles in systems dynamics. The results of published experimental assays confirmed the central role of 8 of the identified feedback loop genes in cell cycle regulation. In conclusion, we provide a novel approach to identify critical genes for the dynamics of biological processes. This may lead to the identification of therapeutic targets in diseases that involve perturbations of these dynamics.

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

gene expression
cell cycle
dynamic bayesian network
feedback


static cache partitioning robustness analysis for embedded on-chip multi-processors In this paper we analyze the robustness of multi-tasking applications when mapped on an on-chip multiprocessor platform. We assume a multiprocesso structure which embeds a hierarchical cache organization with two levels. The first one is private to the processor cores while the second one is shared among the processors. To enable compositionality, i.e, to be able to evaluate the system's performance out of the individual task's performance, the second level of cache (L2) is partitioned per task basis. Two robustness aspects are relevant in this context: internal (performance deviations are caused by the tasks comprising the application) and external (performance variations are caused by external stimuli). First we introduce two metrics to quantify the robustness. The internal robustness is estimated by a sensitivity function which measures the performance variations induced by the \%private inter-task cache interference. The external robustness is quantified by a stability function which reflects the variations induced by different input data on the partitioned L2 behavior. Subsequently, we exercise our method on two applications (H.264 and picture-in-picture TV) running on a CAKE multi-processor platform. Our experiments indicate that, if the cache is partitioned, the sensitivity is 8\% and 5\% for the H.264 and PiPTV, respectively. For the shared cache scenario the sensitivity is 40\% and 50\% for the H.264 and PiPTV, respectively. The variations induced in the L2 behavior by various input data sets are at most 4\% for the PiPTV application, respectively 9\% for the H.264 decoder. This accounts for a stability of at least 96\%, respectively 91\%, therefore, for the investigated applications, we can conclude that the static cache partitioning is quite robust to input stimuli.

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


Branching-time logics with path relativisation We relativise path quantifier in branching-time logics using ?-languages. The extended logics are based on CTL, CTL+, CTL?, and ?PDL. We study expressivity and complexity of satisfiability and model checking. Path relativisation captures abstractions and refinements of large systems. Logics with non-regular relativisations may be useful for software synthesis.

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

temporal logic
ctl?
formal languages
expressive power


A 2D wavelet-based multiscale approach with applications to the analysis of digital mammograms A wavelet-based multifractal spectrum (MFS) for the analysis of images that possess an erratically changing oscillatory behavior at various scales is constructed and estimated. The methodology is applied to the analysis of mammograms. The key contribution is that the analysis is not focused on microcalcifications, but on the background of the image, thus presenting a new modality to be combined with other diagnostic tools. Differences in image backgrounds between malignant and normal cases are found, in terms of multifractal descriptors. The new tool is compared with another spectral method, based on monofractal descriptors.1

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

breast cancer diagnostic
image multifractal analysis
wavelet transform


An adaptive control method for time-varying systems Fuzzy set theory has grown to become a major scientific domain collectively referred to as fuzzy systems. It has been shown that there are a lot of applications in almost all sub-areas of fuzzy systems. However, the most successful application has been in fuzzy control. Fuzzy control algorithms have been extensively used in business and industry. In this paper, an adaptive control technique based on the fuzzy parameter identification is presented. The application of this technique includes an example in agriculture.

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


Object-oriented crop mapping and monitoring using multi-temporal polarimetric RADARSAT-2 data The aim of this paper is to assess the accuracy of an object-oriented classification of polarimetric Synthetic Aperture Radar (PolSAR) data to map and monitor crops using 19 RADARSAT-2 fine beam polarimetric (FQ) images of an agricultural area in North-eastern Ontario, Canada. Polarimetric images and field data were acquired during the 2011 and 2012 growing seasons. The classification and field data collection focused on the main crop types grown in the region, which include: wheat, oat, soybean, canola and forage. The polarimetric parameters were extracted with PolSAR analysis using both the CloudePottier and FreemanDurden decompositions. The object-oriented classification, with a single date of PolSAR data, was able to classify all five crop types with an accuracy of 95% and Kappa of 0.93; a 6% improvement in comparison with linear-polarization only classification. However, the time of acquisition is crucial. The larger biomass crops of canola and soybean were most accurately mapped, whereas the identification of oat and wheat were more variable. The multi-temporal data using the CloudePottier decomposition parameters provided the best classification accuracy compared to the linear polarizations and the FreemanDurden decomposition parameters. In general, the object-oriented classifications were able to accurately map crop types by reducing the noise inherent in the SAR data. Furthermore, using the crop classification maps we were able to monitor crop growth stage based on a trend analysis of the radar response. Based on field data from canola crops, there was a strong relationship between the phenological growth stage based on the BBCH scale, and the HV backscatter and entropy.

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

object-oriented classification
polarimetric decomposition
phenological monitoring


Information-Theoretic Key Agreement of Multiple Terminals-Part I We study the problem of information-theoretically secure secret key agreement under the well-known source model and channel model. In both of these models, multiple terminals wish to create a shared secret key that is secure from a passive eavesdropper. The terminals have access to a noiseless public communication channel and an additional resource that depends on the model. In the source model, the resource is an external source that repeatedly beams correlated randomness to the terminals; whereas in the channel model, the resource is a secure but noisy discrete memoryless broadcast channel. We derive new lower and upper bounds on the secret key capacity under both the source model and the channel model. The technique used for deriving our bound for the source model is to find certain properties of functions of joint probability distributions which, applied to the joint distribution of the source, will imply that they dominate the secret key capacity, and then prove the bound by a verification argument. A similar technique is used for the channel model. Finally, we also define a problem of communication for omniscience by a neutral observer and establish the equivalence between this new problem and the problem of secret key agreement. This generalizes an earlier result of Csiszar and Narayan.

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

channel model
communication for omniscience
secret key agreement
secret key capacity
source model

common randomness
public discussion
security
unconditional security


Gender and cultural differences in Internet use: A study of China and the UK This study investigates differences in use of, and attitudes toward the Internet and computers generally for Chinese and British students, and gender differences in this cross-cultural context. Two hundred and twenty Chinese and 245 British students' responses to a self-report survey questionnaire are discussed. Significant differences were found in Internet experience, attitudes, usage, and self-confidence between Chinese and British students. British students were more likely to use computers for study purposes than Chinese students, but Chinese students were more self-confident about their advanced computer skills. Significant gender differences were also found in both national groups. Men in both countries were more likely than women to use email or 'chat' rooms. Men played more computer games than women; Chinese men being the most active games players. Men in both countries were more self-confident about their computer skills than women, and were more likely to express the opinion that using computers was a male activity and skill than were women. Gender differences were higher in the British group than the Chinese group. The present study illustrates the continued significance of gender in students' attitudes towards, and use of computers, within different cultural contexts. (c) 2005 Elsevier Ltd. All rights reserved.

B 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 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 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 B 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


Cultural kinship as a computational system: from bottom-up to top-down forms of social organization A key change in the evolution of our species from a common ancestor with the chimpanzees was the shift to a field of social interaction no longer dependent upon face-to-face interaction for the maintenance of social coherency. Our hunter-gatherers ancestors made a radical shift to social relations based on a culturally constructed system of kinship relations. Unlike biological kinship that reflects the facts of biological reproduction, cultural kinship is a constructed, computational system that enables symbolic computation of kinship relations that are expressed through the kin terms of a kinship terminology. The system of kin terms is analogous to arithmetic as a computational system for computing quantities with symbols instantiated by the counting numbers. The internal logic of a kinship terminology ensures consistency both in kinship relation computations and translation of kin term computations to the perspective of each person who culturally shares the same kinship terminology. The constraint of internal and external consistency does not lead to a single kinship terminology computational system, hence there are a variety of kinship terminology systems across human societies. In this paper I outline a theory for the generative structure of kinship terminology systems and briefly discuss the implications this for explaining structural differences between kinship terminologies and how structure relates to social organization.

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

cultural evolution
primate social systems
hunter-gatherer social systems
cultural computational systems


Medical informatics education needs information system practicums in health care settings - Experiences and lessons learned from 32 practicums at four universities in two countries Objectives: To report about the themes and about experiences with procticums in the management of information systems in health care settings (health information management) for medical informatics students. Methods: We first summarize the topics of the health information management procticums/projects that the authors organized between 1990 and 2003 for the medical informatics programs at Heidelberg/Heilbronn, Germany, LIMIT, Austria, as well as for the informatics program at the University of Leipzig, Germany. Experiences and lessons learned, obtained from the faculty that organized the practicums in the past 14 years, are reported. Results:Thirty (of 32) health information management practicums focused on the analysis of health information systems. These took place inside university medical centers. Although the procticums were time-intensive and required intensively tutoring students with regard to health information management and project management, feedback from the students and graduates was mainly positive. Discussion: It is clearly recommended that students specializing in medical informatics need to be confronted with real-world problems of health information systems during their studies.

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

medical informatics
health information systems
education

health informatics
hospital information systems