394 research outputs found
A Procedure for Characterizing Tactile Sensors
We describe a methodology for the characterization of tactile sensors. We address the questions of verification of manufacturer\u27s claims about the output of a sensor, reliability of the output and robustness of the sensor over time.
In our work with tactile sensors, it has become apparent that there is a need for a rigorous methodology of characterizing sensor quality.
We implement this as a procedure which is specific for the Lord LTS-200 sensor [ref 1] With some modifications, this methodology could be applied to other tactile sensors
A Real-Time Display for Tactile Images
The tactile array sensor is a key component of the multi-sensory integration work at the General Robotics and Active Sensory Perception Laboratory (GRASP Lab) at the University of Pennsylvania.
In our work, tactile sensors provide information about the nature of the contact between an actuated tool, such as a robotic gripper, and its physical domain. This information is used for feedback control of the gripper and robot manipulator to which it is attached, and for tactile perception.
The sensor we currently use, LTS-200 from Lord Corp. [r@. I], consists of a two separate modules (see figure 1):
• a 10 x 16 tactile array, which measures displacement (or deflection) via optical technology.
• a 6 degree of freedom force/torque module using strain gauge technology. The force/ torque module is mounted under the tactile array. This is not an array, its output is scalar.
The interface and signal processing circuitry is located in an external box.
The data obtained from the LTS-200 tactile array describes the amount of deformation of the sensor cover. The sensor cover, made from a synthetic rubber, can deform, up to a point, to comply with the surface of the object under investigation (see figure 2). The sensing array samples this surface and data is obtained describing the texture and local shape of the contact area.
This tactile sensor can be compared to a range finder, but with very limited span.
The second module of the LTS-200 provides overall force, in x, y and z direction, and overall moments, around the x, y and z direction, which result from pressing the sensor against an object.
In the course of using the LTS-200, or evaluating new sensors, we felt a need for visualizing the tactile information obtained. We looked for a format that provides insight into the tactile image and is suitable for further post-processing
La Route de l’esclave et de l’engagé dans les îles et pays du Sud-Ouest de l’océan Indien
Le système esclavagiste a longtemps été au centre des sociétés pré-coloniales et coloniales qui se sont développées dans les pays bordiers et insulaires du sud-ouest de l’océan Indien. Chaque étape de la Route de l’esclave et de l’engagé dans l’océan Indien, un programme Unesco, conduit par la Chaire Unesco de l’Université de La Réunion et l’association Historun dirigées par Sudel Fuma, est marquée, depuis 2004, par une stèle qui répond symboliquement au drame de la rupture mémorielle après les abolitions de l’esclavage.The slave system was for a long time in the center of the pre-colonial and colonial societies which developed in bordiers countries and islanders of the southwest of the Indian Ocean. Every stage of the Road of the Slave and the Indentured in the Indian Ocean, an Unesco program, driven by the Unesco Pulpit of the University of Reunion and the Historun association managed by Sudel Fuma, is marked, since 2004, by a stele which answers symbolically the drama of the memory gap, after abolitions of slavery
Numerical investigation on sand erosion phenomenon of coated and uncoated vanes in low-pressure gas turbine
For energy saving and less environmental impact, efficient energy utilization is of importance. In a gas-turbine engine, its performance increases as increasing temperature of the turbine inlet flow. However, turbine components are required to be protected from the high temperature flows. Recently, ceramic matrix composite (referred as CMC, hereafter) is expected to be utilized as protecting the gas-turbine components due to the excellent properties of CMC in high temperature conditions: low density, high strength and high rigidity. Therefore, the CMC allows us to increase the inlet temperature and leads to high performance of gas-turbine engines. On the other hand, sand erosion phenomenon is one of serious problems in gas-turbine engines. Sand particles ingested from the engine inlet impinge and erode the wall surfaces, which can cause engine failure. In order to prevent the sand erosion phenomenon, anti-erosion coatings have been developed and adopted for gas-turbines, although the anti-erosion characteristics of the CMC coating have not completely been clarified. The objective of the present paper is to perform numerical simulations of sand erosion phenomenon on the coated and the uncoated T106 CMC vanes in a low-pressure gas turbine. We investigate the flow field, particle trajectories and the eroded shape of the CMC turbine vanes. The results show that the erosion occurs near the leading edge and at the 90 percent axial chord on the pressure surface in both of the coated and uncoated cases. In the uncoated case, the severe erosion phenomenon is observed especially. Accordingly, we have concluded that the coating obviously played an important role in protecting the CMC vanes from sand erosion
Políticas públicas em educação: Papel e contribuição da igreja católica no processo de sistema educativo Guineense
O trabalho realizado é uma compilação dos dados obtidos utilizando vários métodos
de investigação, e permitiu-se analisar as políticas públicas da educação e refletir
sobre a contribuição da Igreja Católica no processo de sistema educativo da Guiné-
Bissau, portanto, este estudo proporcionou uma compreensão mais ampla acerca
das políticas de educação, e a missão da Igreja Católica nesse processo na Guiné-
Bissau. Como é do conhecimento geral, a educação na Guiné-Bissau,
historicamente, nunca fora exclusivamente da responsabilidade de uma única
instituição. Ainda no presente trabalho mostra quanto às missões católicas foram/
serão muito importantes para a sociedade guineense, agora, com a dificuldade que
o Estado tem enfrentado nos últimos anos, temos visto a sua participação ainda
maior e com mais frequência em todo o território nacional. De ponto de vista
estrutural e organização, a igreja católica apresenta uma forma de trabalho bem
estruturado e de maior consistência em relação aos outros parceiros. Através dos
métodos utilizados na investigação deste trabalho permitiu diferenciar os métodos de
ensino administrado pelo Estado, e aqueles que são coordenadas pela Igreja
católica. Ainda, nos levou a ter uma ideia das instituições religiosas, ou seja, a Igreja
católica tem sido parceiro em diferentes áreas sociais. Entretanto, o estudo contribui
para esclarecer o papel que a igreja católica tem desempenhado na área de
educação e, em particular, no contexto de sistema educativo da Guiné-Bissau.The work carried out is a compilation of data obtained using various research
methods, and allowed to analyze public education policies and reflect on the
contribution of the Catholic Church in the process of the educational system of
Guinea-Bissau, therefore, this study provided an understanding broader view of
education policies, and the mission of the Catholic Church in this process in Guinea-
Bissau. As is well known, education in Guinea-Bissau, historically, has never been
exclusively the responsibility of a single institution. Still in the present work, it shows
how the Catholic missions were / will be very important for Guinean society, now,
with the difficulty that the State has faced in recent years, we have seen its
participation even greater and more frequently throughout the national territory. From
a structural and organizational point of view, the Catholic Church has a well-structured
and more consistent way of working in relation to other partners. Through
the methods used in the investigation of this work, it allowed to differentiate the
teaching methods administered by the State, and those that are coordinated by the
Catholic Church. Still, it led us to have an idea of religious institutions, that is, the
Catholic Church has been a partner in different social areas. However, the study
contributes to clarify the role that the Catholic Church has played in the area of
education and, in particular, in the context of the educational system in Guinea-
Bissau
The Multiphase Flow CFD Analysis in Journal Bearings Considering Surface Tension and Oil-Filler Port Flow
This chapter presents the multiphase computational fluid dynamics (CFD) analysis on oil-lubricated high-speed journal bearings considering the oil-filler port. Journal bearings are widely used for high-speed rotating machinery such as turbines, compressors, pumps, automobiles, and so on. They can support the rotating shaft utilizing the oil lubrication film wedge effects used in the bearing clearance. Previously, in the analysis of journal bearings, which clearance is very narrow compared with shaft diameter, the Reynolds equation has been used on journal bearing analysis because of its applicability on the narrow space calculation and its low calculation cost. However, the gaseous-phase area generated in the journal bearing and the effect of oil-filler port cannot be reproduced accurately using the method. Under these backgrounds, some researchers use the CFD analysis to calculate the journal bearing characteristics in recent years. In this chapter, the authors describe the multiphase flow CFD analysis on journal bearing based on our previous studies . At first, the multiphase CFD calculation model on journal bearing and the experimental method are explained. Then, four types of calculation results under flooded and starved lubrication conditions are compared to the experimental ones. Additionally, the effect of surface tension on journal bearing characteristics is discussed. Finally, the CFD thermal analysis results under two types of supply oil conditions are shown
Isotopic evidence of plutonium release into the environment from the Fukushima DNPP accident
The Fukushima Daiichi nuclear power plant (DNPP) accident caused massive releases of radioactivity into the environment. The released highly volatile fission products, such as 129mTe, 131I, 134Cs, 136Cs and 137Cs were found to be widely distributed in Fukushima and its adjacent prefectures in eastern Japan. However, the release of non-volatile actinides, in particular, Pu isotopes remains uncertain almost one year after the accident. Here we report the isotopic evidence for the release of Pu into the atmosphere and deposition on the ground in northwest and south of the Fukushima DNPP in the 20–30 km zones. The high activity ratio of 241Pu/239+240Pu (> 100) from the Fukushima DNPP accident highlights the need for long-term 241Pu dose assessment, and the ingrowth of 241Am. The results are important for the estimation of reactor damage and have significant implication in the strategy of decontamination
Attorney on trial: When lawyers met phony lawyers in republican Beijing
China underwent tremendous changes in social systems during the Republican period. Among
these changes was the government’s introduction into Chinese society of a new legal profession
based on Western ideology. Relying mainly on Shanghai archival records, previous scholarship
has suggested that, unlike the traditional litigation masters who had always been
despised by the authorities, the new Chinese lawyers quickly rose to respectable social and
economic status. However, the historical findings presented in the current article challenge
this perception by showing that in a city with a more deeply rooted indigenous legal tradition
and less influence from Western lawyers, as in Beijing, the new Chinese lawyers faced resistance
from the legacy of the old legal culture that permeated the new system. For a considerable
period of time after the establishment of the Republic, the people of Beijing still continued to hire
unqualified, “phony” lawyers in lawsuits, and some of these phony lawyers had previously
been litigation masters under the Qing dynasty. Although legal reform was instigated by
the central government as a unified policy, its implementation was bound to vary in different
regions according to the influence of the traditional legal culture. It is clear that the situation in
Shanghai and other treaty ports does not represent the situation throughout the entire country,
nor even in other coastal regions. Therefore, to make more sense of legal reform in China, one
should evaluate the development of legal reform in a particular city or region against its social
and ideological backdrop. This approach may provide insights not only into the legal reform of
the Republican period, but also into the post-Mao era when once again a modern legal system
based on the Western model has been introduced, this time within a socialist system.published_or_final_versio
Saint-Paul – Cimetière Marin
Le Cimetière Marin est localisé sur le littoral de la baie de Saint-Paul (fig 1). Ce cimetière historique de la fin du XVIIIe s. et ses agrandissements successifs sont bien connus. Entre son mur de clôture et l’estran, s’étendait sur plusieurs dizaines de mètres vers l’océan une esplanade, dont la fonction funéraire était oubliée. Fig. 1 – Vue aérienne du Cimetière Marin en 2012 Cliché : Dac Océan Indien. En 2007, la moitié de cet espace a été emportée par le cyclone Gamède (fig. 2), et dans..
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