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Desirable Features (desirable + feature)
Selected AbstractsSecurity in distributed metadata cataloguesCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 17 2008Nuno Santos Abstract Catalogue services provide the discovery and location mechanisms that allow users and applications to locate data on Grids. Replication is a highly desirable feature in these services, since it provides the scalability and reliability required on large data Grids and is the basis for federating catalogues from different organizations. Grid catalogues are often used to store sensitive data and must have access control mechanisms to protect their data. Replication has to take this security policy into account, making sure that replicated information cannot be abused but allowing some flexibility such as selective replication for the sites depending on the level of trust in them. In this paper we discuss the security requirements and implications of several replication scenarios for Grid catalogues based on experiences gained within the EGEE project. Using the security infrastructure of the EGEE Grid as a basis, we then propose a security architecture for replicated Grid catalogues, which, among other features, supports partial and total replication of the security mechanisms on the master. The implementation of this architecture in the AMGA metadata catalogue of the EGEE project is then described including the application to a complex scenario in a biomedical application. Copyright © 2008 John Wiley & Sons, Ltd. [source] Consistent Regulation of Infrastructure Businesses: Some Economic Issues,ECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 1 2009Flavio M. Menezes L51 This article examines some important economic issues associated with the notion that consistency in the regulation of infrastructure businesses is a desirable feature. It makes two important points. First, it is not easy to measure consistency. In particular, one cannot simply point to different regulatory parameters as evidence of inconsistent regulatory policy. Second, even if one does observe consistency emerging from decisions made by different regulators, it does not necessarily mean that this consistency is desirable. It might be the result, at least partially, of career concerns of regulators. [source] LABOUR MOBILITY AND TRANS-TASMAN CURRENCY UNION,AUSTRALIAN ECONOMIC PAPERS, Issue 1 2006ADAM CREIGHTONArticle first published online: 7 MAR 200 The prospect of a common currency for Australia and New Zealand has been canvassed by senior poli-ticians and bureaucrats, and has been the subject of academic debate. According to Mundell (1961), a high degree of internal labour mobility is a desirable feature of currency unions. This study looks at the extent to which long-term migration between Australia and New Zealand responds to output shocks. Estimated VAR models and panel Granger-causality tests demonstrate that shocks to relative per capita output have a significant and symmetrical impact on migration flows between Australia and New Zealand, and most of the impact is felt after about one year. Separating the shocks to Australia and New Zealand shows that ,pull' effects are more important than ,push' effects. Additionally, the trajectory of the Australian economy proves particularly influential for the choice of New Zealand emigrants. Although permanent migration responds intuitively to the state of the economy in Australia and New Zealand, the level of these migration flows is low in comparison to Australian inter-state migration; yet it is high in relation to any third country. [source] Environmental Predictors of Geographic Variation in Human Mating PreferencesETHOLOGY, Issue 4 2002Kevin J. McGraw Sexual selection theory classically posits consistent and directional mate-preferences for male traits that provide benefits to females. However, flexible mate-choice tactics may persist within a species when males display multiple desirable features that confer different benefits to females under variable environmental conditions. Ecological factors such as population density, resource demand, and sex ratio can influence the value that female animals place on certain male characteristics across mating environments. In this study, I used human mate-preference data from `lonely hearts' advertisements in the newspapers of 23 cities in the USA to assess geographic differences in female preferences for male traits (e.g. physical attributes, resource-holding potential, emotional characteristics, personal interests) in relation to these ecological parameters. I found that females placed more emphasis on the resource-accruing ability of prospective mates in densely populated cities and cities having greater resource demands (higher cost of living). In contrast, women from densely populated or resource-demanding cities placed less emphasis on the emotional aspects or personal interests of males. Preferences for physical features were not environmentally linked, but instead were a function of the degree to which females advertised their own physical attractiveness. Collectively, these results suggest that certain mate-choice criteria employed by women are sensitive to variation in local environmental conditions and that variable levels of resource or mate availability may favor different mating tactics across human populations. [source] Connectionist symbolic rule encoding using a generalized phase-locking mechanismEXPERT SYSTEMS, Issue 1 2000Nam Seog Park This paper describes a connectionist inference architecture which performs standard symbolic inference on a subclass of first-order predicate calculus. This work first involves constructing efficient connectionist mechanisms to represent basic symbol components, dynamic bindings and basic symbolic inference procedures, and devising a set of algorithms which automatically translates input descriptions to localist neural networks. These connectionist mechanisms are built by taking an existing phase-locking mechanism and extending it further to obtain desirable features to represent and manipulate basic symbol structures. The existing phase-locking mechanism represents dynamic bindings very efficiently using temporal synchronous activity between neuron elements but has fundamental limitations in supporting standard symbolic inference. The extension addresses these limitations. The extended system encodes a significant subset of a Horn clause language in a connectionist style. [source] Spatially explicit fisheries simulation models for policy evaluationFISH AND FISHERIES, Issue 4 2005Dominique Pelletier Abstract This paper deals with the design of modelling tools suitable for investigating the consequences of alternative policies on the dynamics of resources and fisheries, such as the evaluation of marine protected areas (MPA). We first review the numerous models that have been developed for this purpose, and compare them from several standpoints: population modelling, exploitation modelling and management measure modelling. We then present a generic fisheries simulation model, Integration of Spatial Information for FISHeries simulation (ISIS-Fish). This spatially explicit model allows quantitative policy screening for fisheries with mixed-species harvests. It may be used to investigate the effects of combined management scenarios including a variety of policies: total allowable catch (TAC), licenses, gear restrictions, MPA, etc. Fisher's response to management may be accounted for by means of decision rules conditioned on population and exploitation parameters. An application to a simple example illustrates the relevance of this kind of tool for policy screening, particularly in the case of mixed fisheries. Finally, the reviewed models and ISIS-Fish are discussed and confronted in the light of the underlying assumptions and model objectives. In the light of this discussion, we identify desirable features for fisheries simulation models aimed at policy evaluation, and particularly MPA evaluation. [source] Designing sexual health services for young people: a methodology for capturing the user voiceHEALTH & SOCIAL CARE IN THE COMMUNITY, Issue 4 2009Sally Jerome MSc Abstract The aim of the study was to assess the suitability of the Thurstone paired comparison method for capturing the user voice, through a survey of young people's views on the most salient priorities for a sexual health service. A convenience sample of 161 12,24 year olds was used. A psychometrically robust questionnaire was developed from a review of the relevant literature and from the information provided by three focus groups. The data derived from both stages were distilled into seven themes, and adapted to a Thurstone paired comparison format, in which each theme was paired with every other theme, with an 8-point scale between each pairing (21 pairings in total). Respondents were required to indicate their preference for one theme over the other in each pairing. The questionnaire was completed by 161 young people between April and July 2007, and the results were analysed using the Kendall coefficient of concordance to establish the degree of within-group agreement. The results suggested that there was significant agreement as to the essential desirable features of a sexual health service, both within the whole sample as well as within sub-samples (i.e. gender, age group and previous sexual health service use). The priorities were privacy, and a dedicated service close to home, with a drop-in facility and male and female staff being next most important, and an informal service and young staff being lowest priorities. The feedback from the pilot study, the 40% return and absence of spoiled questionnaires together indicated that the respondents found the method acceptable, while the actual findings corroborated those from other studies. Taken together, these results suggest that the Thurstone method offers a quick and simple method of capturing the user voice, with the results having sufficient validity to inform the planning of a local sexual health service. [source] Optimal design and optimal control of structures undergoing finite rotations and elastic deformationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 14 2004A. Ibrahimbegovic Abstract In this work, we deal with the optimal design and optimal control of structures undergoing large rotations and large elastic deformations. In other words, we show how to find the corresponding initial configuration through optimal design or the corresponding set of multiple load parameters through optimal control, in order to recover a desired deformed configuration or some desirable features of the deformed configuration as specified more precisely by the objective or cost function. The model problem chosen to illustrate the proposed optimal design and optimal control methodologies is the one of geometrically exact beam. First, we present a non-standard formulation of the optimal design and optimal control problems, relying on the method of Lagrange multipliers in order to make the mechanics state variables independent from either design or control variables and thus provide the most general basis for developing the best possible solution procedure. Two different solution procedures are then explored, one based on the diffuse approximation of response function and gradient method and the other one based on genetic algorithm. A number of numerical examples are given in order to illustrate both the advantages and potential drawbacks of each of the presented procedures. Copyright © 2004 John Wiley & Sons, Ltd. [source] Modelling the dynamics of log-domain circuitsINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 1 2007Alon Ascoli Abstract Log-domain filters are an intriguing form of externally linear, internally nonlinear current-mode circuits, in which a compression stage is first used to convert the input currents to the logarithmic domain, then analogue processing is carried out on the resulting voltages, and finally input,output linearity is restored by mapping the output voltages to current form through an expansion stage. The compressing and expanding operations confer on log-domain filters a number of desirable features, but they may be responsible for the loss of external linearity. In this paper, sufficient conditions for the external linearity of log-domain LC-ladders are established, and the local nature of this external linearity is highlighted. Certain log-domain LC-ladders employing floating capacitors may exhibit externally nonlinear behaviour even for zero input and very small initial conditions. We show how transistor parasitic capacitances are central to the emergence of this behaviour, and must be incorporated in the circuit model. Copyright © 2006 John Wiley & Sons, Ltd. [source] Generational incidence of savings taxation versus capital-income taxationINTERNATIONAL JOURNAL OF ECONOMIC THEORY, Issue 2 2007Alan Krause D5; D6; D9; H2 This paper examines the incidence of capital taxation in a model in which the taxation of capital is clearly justifiable and using analytical techniques from the tax reform literature. The taxation of capital has long been a controversial issue, with much of the literature concluding that savings/capital-income should not be taxed. Recently, however, Blackorby and Brett have shown in a model with several desirable features that it can be optimal to tax capital, and they provide a simple yet compelling argument in favor of both savings taxation and capital-income taxation. We use the Blackorby,Brett model (i.e. a model in which the taxation of capital can be justified) to revisit the question of the incidence of capital taxation. We focus on the generational incidence of capital taxation; that is, the incidence on a young generation and an old generation. However, an interpretation in terms of the incidence on "capital" versus "labor" (as is traditional in the tax incidence literature) is also provided. [source] Amplitude estimation for near-sinusoidal oscillators by using a modified Barkhausen criterionINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 6 2005H. Jardón-Aguilar Abstract By using an approach based on the Taylor/Volterra series, nonlinear amplifier characteristics can be introduced into the Barkhausen criterion in order to estimate the amplitude for near-sinusoidal oscillators. The characteristic equation is similar to the 1st -order determining equation obtained by Chua. This new method includes all desirable features of Chua's equation and lets us generalize the linear approach directly to a nonlinear one without losing the mathematical simplicity of the Barkhausen criterion. It also allows us to determine the oscillation amplitude with a desired accuracy. Moreover, this method investigates the influence of the feedback factor and the voltage supply on the oscillation amplitude. Employing only the 3rd -order nonlinearity of the amplifying element, the amplitude of the oscillation predicted by the modified Barkhausen criterion was compared to the one estimated using the transient analysis of SPICE, the harmonic balance analysis of Serenade, and by measurements. The amplitudes obtained by these four approaches for several feedback factors and supply voltages are in good agreement. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source] RF MEMS-based tunable filtersINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2001James Brank Abstract This paper overviews the application of RF MEMS switches in tunable filters as well as circuit developments for bandpass filters covering 110 MHz to 2.8 GHz. RF MEMS have several desirable features, including small size, low power requirements, and low loss. The basic operation of Raytheon's RF MEMS capacitive membrane switch is described. An overview of the technique used to integrate the switch into a variable capacitor structure with sixteen capacitance states is provided. Variable capacitor structures are used to construct multipole lumped bandpass filter designs, each with sixteen states. Finally, measured data from two representative five- and six-pole bandpass filters are presented. Characterization data demonstrates that the insertion loss for the five-pole filter using on-chip inductors was between 6.6 and 7.3 dB, and between 3.7 and 4.2 dB for the six-pole filter using off-chip inductors. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 276,284, 2001 [source] The Deliberative Model of Democracy: Two Critical RemarksRATIO JURIS, Issue 3 2007RAF GEENENS However, since it overemphasises the epistemic facet of decision-making, the model is unable to take into account other valuable aspects of democracy. This is shown in reference to two concrete phenomena from political reality: majority voting and the problem of the dissenter. In each case, the deliberative model inevitably fails to account for several normatively desirable features of democracy, such as formal political equality and proper respect for the judgement of each citizen. [source] Polarized light out-coupling from lightguides for LCDsTHE CHEMICAL RECORD, Issue 2 2005C. M. van Heesch Abstract New designs of lightguide systems, which emit linear polarized light with a high efficiency for transmissive and transflective LCD applications, are presented. These systems are equipped with nano- and/or micro-structured films or coatings, which emit highly collimated or diffuse linearly polarized light with a high efficiency. The films are based on polarization-selective scattering, reflection, or diffraction of light and their properties can be tuned to a large extent dependent on their envisioned application. For instance, edge-lit lightguide systems are discussed, which combine a range of desirable features such as a high transparency in direct view, a direct emission of light at normal angles to the plane of the lightguide, and a purely unidirectional out-coupling of light towards the LCD-side. © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 59,69; 2005: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20034 [source] On multidimensional convolutional codes and controllability properties of multidimensional systems over finite ringsASIAN JOURNAL OF CONTROL, Issue 2 2010Eva Zerz Abstract Using the behavior-code duality pointed out by Rosenthal et al., we study the relations between certain desirable features of a code and the corresponding controllability properties of its behavior. Module-theoretic characterizations are provided as well. The coefficients of the codes and behaviors are taken to be integers modulo m, where m is not necessarily prime. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] Mixture Generalized Linear Models for Multiple Interval Mapping of Quantitative Trait Loci in Experimental CrossesBIOMETRICS, Issue 2 2009Zehua Chen Summary Quantitative trait loci mapping in experimental organisms is of great scientific and economic importance. There has been a rapid advancement in statistical methods for quantitative trait loci mapping. Various methods for normally distributed traits have been well established. Some of them have also been adapted for other types of traits such as binary, count, and categorical traits. In this article, we consider a unified mixture generalized linear model (GLIM) for multiple interval mapping in experimental crosses. The multiple interval mapping approach was proposed by Kao, Zeng, and Teasdale (1999, Genetics152, 1203,1216) for normally distributed traits. However, its application to nonnormally distributed traits has been hindered largely by the lack of an efficient computation algorithm and an appropriate mapping procedure. In this article, an effective expectation,maximization algorithm for the computation of the mixture GLIM and an epistasis-effect-adjusted multiple interval mapping procedure is developed. A real data set, Radiata Pine data, is analyzed and the data structure is used in simulation studies to demonstrate the desirable features of the developed method. [source] | |||||||||||||