A sensor classification strategy for robotic manipulators

In practice the robotic manipulators present some degree of unwanted vibrations. The advent of lightweight arm manipulators, mainly in the aerospace industry, where weight is an important issue, leads to the problem of intense vibrations. On the other hand, robots interacting with the environment often generate impacts that propagate through the mechanical structure and produce also vibrations. In order to analyze these phenomena a robot signal acquisition system was developed. The manipulator motion produces vibrations, either from the structural modes or from endeffector impacts. The instrumentation system acquires signals from several sensors that capture the joint positions, mass accelerations, forces and moments, and electrical currents in the motors. Afterwards, an analysis package, running off-line, reads the data recorded by the acquisition system and extracts the signal characteristics. Due to the multiplicity of sensors, the data obtained can be redundant because the same type of information may be seen by two or more sensors. Because of the price of the sensors, this aspect can be considered in order to reduce the cost of the system. On the other hand, the placement of the sensors is an important issue in order to obtain the suitable signals of the vibration phenomenon. Moreover, the study of these issues can help in the design optimization of the acquisition system. In this line of thought a sensor classification scheme is presented. Several authors have addressed the subject of the sensor classification scheme. White (White, 1987) presents a flexible and comprehensive categorizing scheme that is useful for describing and comparing sensors. The author organizes the sensors according to several aspects: measurands, technological aspects, detection means, conversion phenomena, sensor materials and fields of application. Michahelles and Schiele (Michahelles & Schiele, 2003) systematize the use of sensor technology. They identified several dimensions of sensing that represent the sensing goals for physical interaction. A conceptual framework is introduced that allows categorizing existing sensors and evaluates their utility in various applications. This framework not only guides application designers for choosing meaningful sensor subsets, but also can inspire new systems and leads to the evaluation of existing applications. Today’s technology offers a wide variety of sensors. In order to use all the data from the diversity of sensors a framework of integration is needed. Sensor fusion, fuzzy logic, and neural networks are often mentioned when dealing with problem of combing information from several sensors to get a more general picture of a given situation. The study of data fusion has been receiving considerable attention (Esteban et al., 2005; Luo & Kay, 1990). A survey of the state of the art in sensor fusion for robotics can be found in (Hackett & Shah, 1990). Henderson and Shilcrat (Henderson & Shilcrat, 1984) introduced the concept of logic sensor that defines an abstract specification of the sensors to integrate in a multisensor system. The recent developments of micro electro mechanical sensors (MEMS) with unwired communication capabilities allow a sensor network with interesting capacity. This technology was applied in several applications (Arampatzis & Manesis, 2005), including robotics. Cheekiralla and Engels (Cheekiralla & Engels, 2005) propose a classification of the unwired sensor networks according to its functionalities and properties. This paper presents a development of a sensor classification scheme based on the frequency spectrum of the signals and on a statistical metrics. Bearing these ideas in mind, this paper is organized as follows. Section 2 describes briefly the robotic system enhanced with the instrumentation setup. Section 3 presents the experimental results. Finally, section 4 draws the main conclusions and points out future work.

Electronic books

Este documento de trabalho visa apresentar o conceito de electronic book e discutir questões relacionadas com este novo género de publicação e sua aceitação pelo mercado, as vantagens, alguns desafios e principais dificuldades enfrentadas pelos produtores. Com o desenvolvimento das novas tecnologias, emergem novas expectativas em relação às potencialidades do ambiente digital ao que se verifica no meio impresso: custos reduzidos, facilitando a replicação de cópias e a quase livre e imediata distribuição de cópias no mundo inteiro através da Internet.

Picture marks semiotics between ontwerpen and vormgeving

This project seeks to implement and operationalize an analytical and schematic tool proposed in the doctoral thesis of Eduardo Aires applied to the first pages of newspapers (FBAUP: 2006), to the study of the symbol within the visual identity – the picture mark – starting with its semiotic analysis. Our research has the main objective to contribute to providing guidelines to facilitate both the communication and the methodology used by students and professionals of graphic design, translating, in a graphic way, implicit phenomena that is still in the spectrum of intuition, concerning Identity Design (specifically, the design of the graphic mark), and bringing them to the field of scientific definitions. It is our intention to provide the design of a picture mark, a graphic sign which is intended to synthesize, identify and bring positive values about an entity, with an educational tool that would constitute itself as knowledge so far nonexistent.

The logo is not flat: evolving picture marks

From the boom of corporate identity in the 50s, 60 years have passed, and we now see picture marks become more complex and question axioms of identity design, like simplicity or bidimensionality. In these changing times, where access to technology and to information makes it possible for one to see the world as a ‘flat’ place [1], where virtually anyone with a computer can create, it is worth considering how much has changed and how much remains the same in picture marks design. Are the silent designers [2] — the technology and software — growing louder? Are picture marks mimicking each other? Are graphic marks following trendy solutions? It is clear the change of paradigms the new technologies have over the graphic zeitgeist. However, what are the consequences of the transformation in the modus operandi and its result in picture marks evolving solutions? And what does this evolution say about us? Being both a condensation of meaning about a corporation or institution and a rhetorical instrument by which to persuade an audience that a product or entity has distinctive and desirable qualities, picture marks are, therefore, a condensed representation of social identity. They are signs full of signification beyond themselves, representing ourselves and our world and by means of its analysis we can learn a bit more about our role as designers, our relation towards new technologies and foresee our role as designers in the future.

Marketing plan for Snack Books

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

A private library in the Mateus Palace (Vila Real). The D. Luís António de Sousa Botelho Mourão (1722-1798) Books Collection

Fundação para a Ciência e Tecnologia no âmbito de Bolsa de Doutoramento (SFRH/BD/86280/2012)

Microscopy- or DNA-based analyses: Which methodology gives a truer picture of stream-dwelling decomposer fungal diversity?

We assessed aquatic hyphomycete diversity in autumn and spring on oak leaves decomposing in five streams along a gradient of eutrophication in the Northwest of Portugal. Diversity was assessed through microscopy-based (identification by spore morphology) and DNA-based techniques (Denaturing Gradient Gel Electrophoresis and 454 pyrosequencing). Pyrosequencing revealed five times greater diversity than DGGE. About 21% of all aquatic hyphomycete species were exclusively detected by pyrosequencing and 26% exclusively by spore identification. In some streams, more than half of the recorded species would have remained undetected if we had relied only on spore identification. Nevertheless, in spring aquatic hyphomycete diversity was higher based on spore identification, probably because many species occurring in this season are not yet connected to ITS barcodes in genetic databases. Pyrosequencing was a powerful tool for revealing aquatic hyphomycete diversity on decomposing plant litter in streams and we strongly encourage researchers to continue the effort in barcoding fungal species.

Brazilian norms for the International Affective Picture System (IAPS): comparison of the affective ratings for new stimuli between Brazilian and North-American subjects

OBJECTIVE: The study presents the Brazilian norms for 240 new stimuli from International Affective Picture System (IAPS), a database of affective images widely used in research, compared to the North-American normative ratings. METHODS: The participants were 448 Brazilian university students from several courses (269 women and 179 men) with mean age of 24.2 (SD = 7.8), that evaluated the IAPS pictures in the valence, arousal and dominance dimensions by the Self-Assessment Manikin (SAM) scales. Data were compared across the populations by Pearson linear correlation and Student's t-tests. RESULTS: Correlations were highly significant for all dimensions; however, Brazilians' averages for arousal were higher than North-Americans'. CONCLUSIONS: The results show stability in relation to the first part of the Brazilian standardization and they are also consistent with the North-American standards, despite minor differences relating to interpretation of the arousal dimension, demonstrating that IAPS is a reliable instrument for experimental studies in the Brazilian population.

Behavior of inflammatory markers of myocardial injury in cardiac surgery: laboratory correlation with the clinical picture of postpericardiotomy syndrome

OBJECTIVE: To verify the association of serum markers of myocardial injury, such as troponin I, creatinine kinase, and creatinine kinase isoenzyme MB, and inflammatory markers, such as tumor necrosis factor alpha (TNF-alpha), C-reactive protein, and the erythrocyte sedimentation rate in the perioperative period of cardiac surgery, with the occurrence of possible postpericardiotomy syndrome. METHODS: This was a cohort study with 96 patients undergoing cardiac surgery assessed at the following 4 different time periods: the day before surgery (D0); the 3rd postoperative day (D3); between the 7th and 10th postoperative days (D7-10); and the 30th postoperative day (D30). During each period, we evaluated demographic variables (sex and age), surgical variables (type and duration , extracorporeal circulation), and serum dosages of the markers of myocardial injury and inflammatory response. RESULTS: Of all patients, 12 (12.5%) met the clinical criteria for a diagnosis of postpericardiotomy syndrome, and their mean age was 10.3 years lower than the age of the others (P=0.02). The results of the serum markers for tissue injury and inflammatory response were not significantly different between the 2 assessed groups. No significant difference existed regarding either surgery duration or extracorporeal circulation. CONCLUSION: The patients who met the clinical criteria for postpericardiotomy syndrome were significantly younger than the others were. Serum markers for tissue injury and inflammatory response were not different in the clinically affected group, and did not correlate with the different types and duration of surgery or with extracorporeal circulation.

Catalogus Plantarum :tum exotiarum tum domesticarum, quae in hortis haud procul a Londino sitis in venditionem propagantur = A Catalogue of trees, shrubs, plants, and flowers, both exotic and domestic, which are propagated for sale, in the gardens near London :divided, accorded to their different degrees of hardiness, into particular books, or parts; in each of which the plants are ranged in an alphabetical order. by a Society of Gardeners

1730

Catalogue of the books, manuscripts, maps and drawings in the British museum (Natural history) ....

v.3:L-O (1910)

Catalogue of the books, manuscripts, maps and drawings in the British museum (Natural history) ....

v.8:suppl.P-Z (1940)

Catalogue of the books, manuscripts, maps and drawings in the British museum (Natural history) ....

v.7:suppl.J-O (1933)