Dynamic green self-configuration of 3G base stations using fuzzy cognitive maps

Cellular networks are rapidly evolving towards the fourth generation, thus providing a global infrastructure for wideband mobile network access. Currently, most of the energy consumption of such technology is by cellular base stations, which are not energy efficient—at least in terms of the transmission energy to “from-the-socket” energy consumption ratio. This paper addresses the problem of energy efficiency in cellular networks by taking advantage of the principles of cognitive networking, which promotes the creation of intelligent networks capable of self-configuration with minimal human intervention. In particular, this paper uses the concept of fuzzy cognitive maps to decide upon opportunistic traffic and user reallocations between radio network equipment operating in different spectrum bands to enable power saving modes by some subsets of the radio network equipment, and to utilize spectrum of more appropriate propagation characteristics to save transmission energy. The feasibility and performance of the proposed approach is investigated through simulations. Significant energy savings of some 25–30% are shown over a 72-h period, and blocking rate under the concept is shown to remain reasonable albeit exhibiting a high variance.     

Integrated topology optimization and optimal control for vibration suppression in structural design

This paper presents a topology design methodology for structures with active vibration control. The methodology takes into account the structural effect of the control forces and includes the modal control design. Location points for the actuation forces are chosen a priori. Structural topology optimization is used for distributing material on a fixed domain, using continuum finite element discretization for the static and free vibration analyses. Optimal control for transient response in modal space is used to derive the control force. The cost function for the optimization combines the strain energy and the control energy. Results of the numerical simulations validates the proposed methodology.     

Applicability of position-based routing for VANET in highways and urban environment

In the last years many routing protocols proposals have been made considering the particular VANET characteristics. From the many proposals that came up, the protocols based on the vehicles positions were found to be the most adequate to VANETs due to their resilience to handling the nodes position variation. In this study we will survey the existing position-based routing protocols. Unlike other studies we will emphasise on their applicability to different environments. We start by characterising the vehicular network environment, namely the urban and the highway environments. Afterwards, topology-based protocols are compared to position-based protocols and to the latter are identified the different used strategies and their performances are qualitatively evaluated relatively to different metrics. The different position-based routing proposals are described including a pseudo-code specification, and a comparison is made based on different perspectives. To conclude, the main constrains to urban and highway environments are characterised and the adaptability of each protocol to each of the environments is evaluated.     

Full-Information Lookups for Peer-to-Peer Overlays

Most peer-to-peer lookup schemes keep a small amount of routing state per node, typically logarithmic in the number of overlay nodes. This design assumes that routing information at each member node must be kept small so that the bookkeeping required to respond to system membership changes is also small, given that aggressive membership dynamics are expected. As a consequence, lookups have high latency as each lookup requires contacting several nodes in sequence. In this paper, we question these assumptions by presenting a peer-to-peer routing algorithm with small lookup paths. Our algorithm, called “OneHop,” maintains full information about the system membership at each node, routing in a single hop whenever that information is up to date and in a small number of hops otherwise. We show how to disseminate information about membership changes quickly enough so that nodes maintain accurate complete membership information. We also present analytic bandwidth requirements for our scheme that demonstrate that it could be deployed in systems with hundreds of thousands of nodes and high churn. We validate our analytic model using a simulated environment and a real implementation. Our results confirm that OneHop is able to achieve high efficiency, usually reaching the correct node directly 99 percent of the time.     

Paternity analysis in Excel

Paternity analysis using microsatellite information is a well-studied subject. These markers are ideal for parentage studies and fingerprinting, due to their high-discrimination power. This type of data is used to assign paternity, to compute the average selfing and outcrossing rates and to estimate the biparental inbreeding. There are several public domain programs that compute all this information from data. Most of the time, it is necessary to export data to some sort of format, feed it to the program and import the output to an Excel book for further processing. In this article we briefly describe a program referred from now on as Paternity Analysis in Excel (PAE), developed at IST and IBET (see the acknowledgments) that computes paternity candidates from data, and other information, from within Excel. In practice this means that the end user provides the data in an Excel sheet and, by pressing an appropriate button, obtains the results in another Excel sheet. For convenience PAE is divided into two modules. The first one is a filtering module that selects data from the sequencer and reorganizes it in a format appropriate to process paternity analysis, assuming certain conventions for the names of parents and offspring from the sequencer. The second module carries out the paternity analysis assuming that one parent is known. Both modules are written in Excel-VBA and can be obtained at the address (www.math.ist.utl.pt/~fmd/pa/pa.zip). They are free for non-commercial purposes and have been tested with different data and against different software (Cervus, FaMoz, and MLTR).     

Assessing the Certainty of Locations Produced by an Address Geocoding System

Addresses are the most common georeferencing resource people use to communicate to others a location within a city. Urban GIS applications that receive data directly from citizens, or from legacy information systems, need to be able to quickly and efficiently obtain a spatial location from addresses. In this paper we understand addresses in a broader perspective, in which not only the conventional elements of postal addresses are considered, but other kinds of direct or indirect references to places, such as building names, postal codes, or telephone area codes, which are also valuable as locators to urban places. This broader view on addresses allows us to work with two perspectives. First, in the ontological definition, modeling, and implementation of an addressing database that is flexible enough to accommodate the variety of concepts and address formats used worldwide, along with direct and indirect references to places. Second, in the definition of an indicator that is able to quantify the degree of certainty that could be reached when a user-given, semi-structured address is geocoded into a spatial position, as a function of the type and completeness of the available addressing data and of the geocoding method that has been employed. This indicator, which we call Geocoding Certainty Indicator (GCI), can be used as a threshold, beyond which the geocoded event should be left out of any statistical analysis, or as a weight that allows spatial analysis methods to reduce the influence of events that have been less reliably located. In order to support geocoding activities and the determination of the GCI, we propose a conceptual schema for addressing databases. The schema is flexible enough to accommodate a variety of addressing systems, at various levels of detail, and in different countries. Our intention is to depart from the usual geocoding strategy employed in commercial GIS products, which is usually limited to the average American or British address format. The schema also extends the notion of postal address to something broader, including popular names for places, building names, reference places, and other concepts. This approach extends Simpson’s and Yu’s Comput. Environ. Urban Syst., 27: 283–307, 2003 work on postal codes to records of any kind, including place names and loosely formatted addresses.     

Adsorption of SO2 using vanadium and vanadium–copper supported on activated carbon

Activated carbon impregnated with precursor salts of Ba, Co, Cu, Fe, Mg, Mn, Ni, Pb and V and their binary mixtures was used for adsorption of SO₂ at 20 °C. The most promising materials for SO₂ removal are carbons doped with V, Cu and mainly their binary mixtures, which show a synergetic effect. Kinetic curves and isotherms of SO₂ adsorption were obtained at 20 °C. These isotherms are reasonably well fitted by the Langmuir model and the respective parameters were determined. TPD experiments show that adsorption of SO₂ increases the oxygenated groups on the carbon surface. The sample doped with V, after SO₂ adsorption at 20 °C, presents an increase of basic oxygenated groups, which may be responsible for the observed extra adsorption of SO₂.     

The social-cognitive model of achievement motivation and the 2 × 2 achievement goal framework.

Two studies examined hypotheses drawn from a proposed modification of the social-cognitive model of achievement motivation that centered on the 2 × 2 achievement goal framework. Implicit theories of ability were shown to be direct predictors of performance attainment and intrinsic motivation, and the goals of the 2 × 2 framework were shown to account for these direct relations. Perceived competence was shown to be a direct predictor of achievement goals, not a moderator of relations implicit theory or achievement goal effects. The results highlight the utility of attending to the approach-avoidance distinction in conceptual models of achievement motivation and are fully in line with the hierarchical model of achievement motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)