A current-mode based Field-Programmable Analog Array for signal processing applications

This paper presents a new approach to develop Field Programmable Analog Arrays (FPAAs),(1) which avoids excessive number of programming elements in the signal path, thus enhancing the performance. The paper also introduces a novel FPAA architecture, devoid of the conventional switching and connection modules. The proposed FPAA is based on simple current mode sub-circuits. An uncompounded methodology has been employed for the programming of the Configurable Analog Cell (CAC). Current mode approach has enabled the operation of the FPAA presented here, over almost three decades of frequency range. We have demonstrated the feasibility of the FPAA by implementing some signal processing functions.

Analysis of Abstracts Presented at the Prosthodontic Research Section of IADR General Sessions 2004-2005: Demographics, Publication Rates, and Factors Contributing to Publication

Purpose: The purposes of this study were to describe the demographics of abstracts presented at the prosthodontics section of IADR General Sessions from 2004 to 2005, evaluate the publication rate of abstracts, and analyze the relationship between variables in abstracts and publication.Materials and Methods: Prosthodontics research section abstracts from the IADR General Session in 2004 and 2005 were evaluated for: number of authors, presentation type, origin, affiliation, topic, study design, statistics, study outcome, and funding. The publication rate was calculated following a PubMed search. The journal of publication, year of publication, and the length of time before publication were analyzed. Descriptive statistics were used for the data analysis; the relationships between presentation type, study design, study outcome, statistics, funding, and publication were analyzed using logistic regression (alpha = 0.05).Results: From 346 abstracts, 37.0% were published. For oral presentations, 40.7% were published; 35.8% of poster presentations were published. The mean duration before publicationwas 26.4months. North America had themost abstracts, and Europe had the most publications. Fixed prosthodontic research had the highest number and proportion for publication. A significant association with publication was noted for neutral study outcomes (p = 0.018), studies with funding (p = 0.035), and abstracts from Europe (p = 0.001).Conclusions: The majority of abstracts from the prosthodontics research section of IADR General Sessions from 2004 and 2005 remain unpublished. A significant association for publication was noted with neutral outcomes, funding, and abstracts from Europe.

Factors Influencing Publication Rates of Abstracts Presented at the ADEA Annual Session & Exhibition

Factors related to the path of abstracts from presentation at a conference to publication as a full article have been analyzed in the medical field, but only a few studies have been performed in dentistry. This study investigated the rate of publication of articles based on abstracts presented at the American Dental Education Association (ADEA) Annual Session & Exhibition in 2002 and 2003 and the time lag to publication. This study also aimed to characterize the abstracts and subsequent articles and determine if there were any significant factors related to expansion of an abstract into a full manuscript. A total of 370 abstracts met the inclusion criteria and were examined for this study. Subsequent published articles were located using a standard PubMed search. Descriptive statistics and bivariate analyses were used to analyze the data collected (alpha=0.05). Results suggest that there was a low (19 percent) publication rate for articles based on abstracts presented at the meetings studied. The median time between abstract presentation and article publication was ten months. Factors that showed significant correlation to likelihood of article publication were multiple affiliations, presence of analytical statistics, and, to a lesser extent, funding. We suggest that presenters at these meetings should expand their abstracts into full manuscripts and seek to publish them in peer-reviewed journals for the benefit of the profession.

Classification and characterization of places for mapping of environment using hierarchical neural network and omnivision

Mobile robots need autonomy to fulfill their tasks. Such autonomy is related whith their capacity to explorer and to recognize their navigation environments. In this context, the present work considers techniques for the classification and extraction of features from images, using artificial neural networks. This images are used in the mapping and localization system of LACE (Automation and Evolutive Computing Laboratory) mobile robot. In this direction, the robot uses a sensorial system composed by ultrasound sensors and a catadioptric vision system equipped with a camera and a conical mirror. The mapping system is composed of three modules; two of them will be presented in this paper: the classifier and the characterizer modules. Results of these modules simulations are presented in this paper.

Nonlinear (2+1)-dimensional systems solvable through asymptotic modules

Some nonlinear differential systems in (2+1) dimensions are characterized by means of asymptotic modules involving two poles and a ring of linear differential operators with scalar coefficients.Rational and soliton-like are exhibited. If these coefficients are rational functions, the formalism leads to nonlinear evolution equations with constraints. © 1989.

Specific depth cone resistivity measurements to determine soil engineering properties

The University of British Columbia (UBC) began performing piezocone penetration tests (CPTU) with electrical resistivity measurements (RCPTU) in 1989. Since then, RCPTU research at UBC has focused on obtaining geo-environmental parameters such as fluid resistivity and soil engineering properties such as porosity and degree of saturation from measurements of bulk soil electrical resistivity using the empirical relationship proposed by Archie (1942). Within this framework, the paper illustrates and discusses important design and calibration issues for resistivity modules such as the use of isolated circuitry to achieve linear calibrations over large ranges of resistivity. The suitability of RCPTU measurements for determination of geo-environmental and geotechnical parameters are assessed using typical ranges of soil and groundwater properties and methods of isolating individual factors for study are discussed. Illustrative examples of RCPTU research efforts including the environmental characterization of mine tailings, delineation of saline water intrusions in fresh water aquifers and the quality control of geotechnical ground densification are presented throughout the text. It is shown that groundwater temperature and hence ion mobility is not significantly altered by frictional heat generated during piezocone penetration and that ratio-based approaches to monitoring soil porosity can be used to eliminate the requirement for extensive groundwater sampling programs. Lastly, it is shown that RCPTU measurements above the water table can only be made using resistivity modules that are stable over a large range of resistivities and that such measurements are the most difficult to interpret because of grain surface conduction effects and generally unknown fluid resistivities.

Tele-education environment and didactic iconography in sexual transmitted diseases

The field of advertising has developed techniques of mass communication and rapid transmission of information. Among these techniques are slogans and iconographies. This work used such tools for educational purposes and was divided into three modules. Module 1 evaluated the use of simplified textual communication (slogans) about the subject Sexually Transmitted Diseases. It was applied to third-year medical students, which had not taken the course on this theme. To evaluate the impact of the textual communication form (slogans), long phrases were elaborated in scientific language containing 15 topics. From these long phrases, compact phrases were developed using techniques of the advertising area for elaboration of slogans. Three forms of didactic material about that theme were developed. The first form consisted of long phrases in descriptive topics, using scientific language. The second was constituted exclusively of compact phrases in the form of slogans, and the third was composed of the combination of the two previous forms. Then, 10 multiple-choice questions were elaborated and applied in two phases. In the first phase, application occurred immediately after the reading of didactic texts; in the second phase, it happened 60 days after the reading. For statistical analysis, Snedcor's F test was used for analysis of variance, at 5% significance level. There was an increase in memorization by students who read the material containing the association between long phrases and slogans, which indicates that the latter, when used as an auxiliary model of learning, can bring significant benefits for education. Module 2 consisted of analyzing the elaboration of educational videos produced in graphic computing (called iconographies) for development of dynamic communication means. The theme Hair Cycle was utilized. Viability of high quantities of information in few minutes of animation could be demonstrated together with the advantage of presenting the process in a dynamic form without wasting scientific details. Module 3 presented the inclusion of slogans in educational videos produced in graphic computing about the Hair Cycle, showing a new tool for rapid and efficient transference of data. Slogans and iconographies, when utilized in educational material, can bring significant benefits for the student's learning.

Environment mapping for mobile robots navigation using hierarchical neural network and omnivision

Autonomous robots must be able to learn and maintain models of their environments. In this context, the present work considers techniques for the classification and extraction of features from images in joined with artificial neural networks in order to use them in the system of mapping and localization of the mobile robot of Laboratory of Automation and Evolutive Computer (LACE). To do this, the robot uses a sensorial system composed for ultrasound sensors and a catadioptric vision system formed by a camera and a conical mirror. The mapping system is composed by three modules. Two of them will be presented in this paper: the classifier and the characterizer module. The first module uses a hierarchical neural network to do the classification; the second uses techiniques of extraction of attributes of images and recognition of invariant patterns extracted from the places images set. The neural network of the classifier module is structured in two layers, reason and intuition, and is trained to classify each place explored for the robot amongst four predefine classes. The final result of the exploration is the construction of a topological map of the explored environment. Results gotten through the simulation of the both modules of the mapping system will be presented in this paper. © 2008 IEEE.

Methodology proposal for acquisition of biotelemetric data in a real time

This work presents a methodological proposal for acquisition of biometric data through telemetry basing its development on a research-action and a case study. Nowadays, the qualified professionals of physical evaluation have to use specific devices to obtain biometric signals and data. These devices in the most of the time are high cost and difficult to use and handling. Therefore, the methodological proposal was elaborate in order to develop, conceptually, a bio telemetric device which could acquire the desirable biometric signals: oxymetry, biometrics, corporal temperature and pedometry which are essential for the area of physical evaluation. It was researched the existent biometrics sensors, the possible ways for the remote transmission of signals and the computer systems available so that the acquisition of data could be possible. This methodological proposal of remote acquisition of biometrical signals is structured in four modules: Acquisitor of biometrics data; Converser and transmitter of biometric signals; Receiver and Processor of biometrics signals and Generator of Interpretative Graphs. The modules aim the obtention of interpretative graphics of human biometric signals. In order to validate this proposal a functional prototype was developed and it is presented in the development of this work.

TORP: An open standard framework for humanoid robots

Humanoid robots are an extremely complex interdisciplinary research field. Particularly, the development of high size humanoid robots usually requires joint efforts and skills from groups that are in many different research centers around the world. However, there are serious constraints in this kind of collaborative development. Some efforts have been made in order to propose new software frameworks that can allow distributed development with also some degree of hardware abstraction, allowing software reuse in successive projects. However, computation represents only one of the dimensions in robotics tasks, and the need for reuse and exchange of full robot modules between groups are growing. Large advances could be reached if physical parts of a robot could be reused in a different robot constructed with other technologies by other researcher or group. This paper proposes a new robot framework, from now on called TORP (The Open Robot Project), that aims to provide a standard architecture in all dimensions (electrical, mechanical and computational) for this collaborative development. This methodology also represents an open project that is fully shared. In this paper, the first robot constructed following the TORP specification set is presented as well as the advances proposed for its improvement. © 2010 IEEE.

Single stage converters for low power stand-alone and grid-connected PV systems

This work presents the evaluation of different power electronic integrated converters suitable for photovoltaic applications, in order to reduce complexity and improve reliability. The rated voltages available in Photovoltaic (PV) modules have usually low values for applications such as regulated output voltages in stand-alone or grid-connected configurations. In these cases, a boost stage or a transformer will be necessary. Transformers have low efficiencies, heavy weights and have been used only when galvanic isolation is mandatory. Furthermore, high-frequency transformers increase the converter complexity. Therefore, the most usual topologies use a boost stage and one inverter stage cascaded. However, the complexity, size, weight, cost and lifetime might be improved considering the integration of both stages. In this context, some integrated converters are analyzed and compared in this paper in order to support future evaluations and trends for low power single-phase inverters for PV systems. Power decoupling, MPPT and Tri-State modulations are also considered. Finally, simulation and experimental results are presented and compared for the analyzed topologies. © 2011 IEEE.

Discrepancies between abstracts presented at international association for dental research annual sessions from 2004 to 2005 and full-text publication

Purpose. The purpose of this study was to evaluate the discrepancies between abstracts presented at the IADR meeting (2004-2005) and their full-text publication. Material and Methods. Abstracts from the Prosthodontic Section of IADR meeting were obtained. The following information was collected: abstract title, number of authors, study design, statistical analysis, outcome, and funding source. PubMed was used to identify the full-text publication of the abstracts. The discrepancies between the abstract and the full-text publication were examined, categorized as major and minor discrepancies, and quantified. The data were collected and analyzed using descriptive analysis. Frequency and percentage of major and minor discrepancies were calculated. Results. A total of 109 (95.6%) articles showed changes from their abstracts. Seventy-four (65.0%) and 105 (92.0%) publications had at least one major and one minor discrepancies, respectively. Minor discrepancies were more prevalent (92.0%) than major discrepancies (65.0%). The most common minor discrepancy was observed in the title (80.7%), and most common major discrepancies were seen in results (48.2%). Conclusion. Minor discrepancies were more prevalent than major discrepancies. The data presented in this study may be useful to establish a more comprehensive structured abstract requirement for future meetings. © 2012 Soni Prasad et al.

Stable singularities of co-rank one quasi homogeneous map germs from (ℂn+1, 0) to (ℂn, 0), n = 2, 3

In this article, we investigate the geometry of quasi homogeneous corank one finitely determined map germs from (ℂn+1, 0) to (ℂn, 0) with n = 2, 3. We give a complete description, in terms of the weights and degrees, of the invariants that are associated to all stable singularities which appear in the discriminant of such map germs. The first class of invariants which we study are the isolated singularities, called 0-stable singularities because they are the 0-dimensional singularities. First, we give a formula to compute the number of An points which appear in any stable deformation of a quasi homogeneous co-rank one map germ from (ℂn+1, 0) to (ℂn, 0) with n = 2, 3. To get such a formula, we apply the Hilbert's syzygy theorem to determine the graded free resolution given by the syzygy modules of the associated iterated Jacobian ideal. Then we show how to obtain the other 0-stable singularities, these isolated singularities are formed by multiple points and here we use the relation among them and the Fitting ideals of the discriminant. For n = 2, there exists only the germ of double points set and for n = 3 there are the triple points, named points A1,1,1 and the normal crossing between a germ of a cuspidal edge and a germ of a plane, named A2,1. For n = 3, there appear also the one-dimensional singularities, which are of two types: germs of cuspidal edges or germs of double points curves. For these singularities, we show how to compute the polar multiplicities and also the local Euler obstruction at the origin in terms of the weights and degrees. © 2013 Pushpa Publishing House.