Operational space consensus of multiple heterogeneous robots without velocity measurements     

Carlos I. Aldana  Emmanuel Nuño  Luis Basañez  Eduardo Romero 《Journal of The Franklin Institute》2014

This paper proposes a control algorithm for networks of multiple heterogeneous robot manipulators, which solves the leader–follower and the leaderless consensus problems in the operational space. In the leader–follower scenario, the controller ensures that all the robots in the network asymptotically reach a given leader pose (position and orientation), provided that, at least, one follower robot has access to the leader pose. Without a leader pose, in the leaderless problem, the robots asymptotically reach a pose of consensus. The controller is a simple distributed proportional plus damping injection (P+d) scheme which does not require velocity measurements. A singularity-free representation, unit quaternions, is used to describe the orientation of each manipulator. The paper presents some simulations, with a network of six 6-Degrees-of-Freedom (DoF) manipulators, and experiments, with a network of three 6-DoF manipulators, to show the effectiveness of the proposed controller.  相似文献   

Systematized Discrimination: Linguistic,Racial and Cultural Differences Can Equal Mathematics Success     

Mosqueda  Eduardo  Maldonado  Saúl I.  Capraro  Mary M.  Capraro  Robert M. 《The Urban Review》2022,54(3):428-449

The Urban Review - Researchers analyzed quantitative data from the Education Longitudinal Study (2002–2004) to investigate the relationship between the highest mathematics course taken and...  相似文献   

Effects of AM3 (Inmunoferon®) on increased serum concentrations of interleukin-6 and tumour necrosis factor receptors I and II in cyclists     

Alfredo Cordova  Jorge Monserrat  Gerardo Villa  Eduardo Reyes  Melchor Alvarez-Mon Soto 《Journal of sports sciences》2013,31(6):565-573

Abstract

The aims of this study were to examine the changes in plasma concentrations of inflammatory cytokines induced by training and competition in professional cyclists. We report the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α), tumour necrosis factor receptors I and II (TNFR-I and -II) in a prospective, randomized, double-blind trial involving the administration of AM3 (Inmunoferon®), an oral booster immunomodulator, or placebo to 16 professional cyclists (n=8 in each group) for 65 consecutive days. Serum was collected just before treatment began (baseline), at the end of pre-competition training, before the mountain stage of the competition (60 days), 4 h after finishing this stage (62 days), and 18 h after the fifth and last day of competition (65 days). To determine the normal levels of cytokines and soluble TNF receptors, individual samples from 14 moderately trained healthy controls were studied. After 60 days of training, the serum concentrations of IL-6 did not differ significantly from those at the beginning of the study for either group of cyclists (placebo and AM3). A significant rise was seen in IL-6 concentrations in both the AM3 and placebo groups at 62 days, 4 h after finishing the mountain stage. The increase was significantly greater in the placebo group than in the AM3 group. At 65 days of treatment, 18 h after the fifth and last day of competition, IL-6 concentrations were similar to those recorded at the end of the training, but were significantly higher in the placebo group than in the AM3 group. At the end of training, serum TNFR-I concentrations in both groups of cyclists were significantly lower than at baseline. The concentrations of serum TNFR-I and -II both 4 h after finishing the mountain stage and 18 h after the fifth and last day of competition were significantly higher than those recorded after training in both groups. Professional cycling competition is associated with increases in serum IL-6 and TNFR-I and -II concentrations. Inmunoferon treatment reduced significantly the concentrations of IL-6 but not those of TNFR-I and -II.  相似文献   

Public narratives under intensified market conditions: Chile as a critical case     

Diego Santori 《Discourse: Studies in the Cultural Politics of Education》2018,39(1):53-68

This paper aims to extend existing theorisations around the notion of public narratives by analysing their regulatory effects under intensified market conditions. My analysis suggests that public narratives constitute a liminal space, one that it is not exclusively real or imaginary, factual or normative, but that simultaneously affects and is affected by vernacular practices and wider discursive structures. However, this paper argues that, under extreme conditions, these public narratives become a rigidifying space with homogenising/normalising effects. To do this I look at a set of ‘obligatory scenes’ captured in tales of success and struggle of teachers, parents and students in popular newspapers and fringe media in Chile. These accounts share a common ground: national assessment as a framework of intelligibility for the practices of parents, teachers and students. The central claim of this paper is that under intensified market conditions the scenes captured in these publicly available stories become ‘obligatory’ storylines, and their protagonists idealised policy subjects.  相似文献   

Prediction of peak V˙O2 in Children and Adolescents With HIV From an Incremental Cycle Ergometer Test     

Luiz Rodrigo Augustemak de Lima  Diego Augusto Santos Silva  Paulo Cesar do Nascimento Salvador  Carlos Alencar Souza Alves Junior  Priscila Custódio Martins  João Antônio Chula de Castro 《Research quarterly for exercise and sport》2019,90(2):163-171

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Creating survival strategies: what can be learned from a science class?     

Maria Inês Mafra Goulart  Eduardo Sarquis Soares 《Cultural Studies of Science Education》2009,4(3):587-594

Elementary science teaching has been considered by recent researchers as a process in which students should be engaged in a variety of activities to develop science concepts, science process skills and scientific attitudes. From this perspective, hands-on activities are prominent in this approach because it leads the students to both reflect on the natural and physical world, and understand the social role of science in society. In Upadhyay’s article we follow an elementary teacher who struggles to implement a participatory method of science teaching in an environment that prioritizes high-stakes tests as the benchmarks for teachers’ and students’ success. In so doing, the teacher negotiates her identities in order to engage the students in the process of learning science even though the environment requires a teaching methodology that is against her beliefs. In our commentary on Upadhyay’s article we argue that (a) the tensions experienced by teachers create the core of the process of fluidity identity; (b) the different forms of external control over the teaching are inherent in educational systems and also a demand of parents and society; and (c) the possibility for social mobility of minority students is a complex process that goes beyond the dichotomy identified in Upadhyay’s article, namely that either the students learn to think scientifically, or the students learn tricks that enable them to succeed in the tests.

Eduardo Sarquis Soares (Corresponding author)Email:

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Costs and benefits of bilingual education in Guatemala: A partial analysis   总被引：1，自引：0，他引：1  

Harry Anthony Patrinos  Eduardo Velez   《International Journal of Educational Development》2009,29(6):594-598

The benefits of bilingual education for a disadvantaged indigenous population as an investment in human capital are significant. Students of bilingual schools in Guatemala have higher attendance and promotion rates, and lower repetition and dropout rates. Bilingual students receive higher scores on all subject matters, including mastery of Spanish. The efficiency of bilingual education is confirmed by a crude cost–benefit exercise. A shift to bilingual schooling would result in considerable cost savings because of reduced repetition. The higher quality of education generating higher promotion rates will help students complete primary education and will substantially increase completion rates at low cost. The costs saving due to bilingual education is estimated at $5 million, equal to the cost of primary education for 100,000 students.  相似文献   

Does Educational Preparation Match Professional Practice: The Case of Higher Education Policy Analysts     

Eduardo C. Arellano  Mario C. Martinez 《Innovative Higher Education》2009,34(2):105-116

This study compares the extent to which higher education policy analysts and master’s and doctoral faculty of higher education and public affairs programs match on a set of competencies thought to be important to higher education policy analysis. Analysts matched master’s faculty in three competencies while analysts and doctoral faculty matched in five competencies. The findings suggest possible reasons why analysts and graduate faculty agree or differ on various competencies. Also, the findings raise important questions regarding the preparation of higher education policy analysts and the graduate programs that educate them. This study is an addition to the body of competency literature. Eduardo C. Arellano  obtained a B.A. in Political Science and an M.P.A from the University of Texas at El Paso, and he holds the Ph.D. in Educational Administration from New Mexico State University. He is an assistant professor at New Mexico State University in the Department of Educational Management and Development. His special interests are interactional diversity, competency, and US–Mexico border studies. Mario C. Martinez  has a B.A. in Electrical Engineering from New Mexico State University, an M.B.A. from the University of Texas at Austin, and a Ph.D. in Educational Policy and Leadership from Arizona State University. He is an associate professor at the University of Nevada-Las Vegas in the department of Educational Leadership. His special interests are higher education policy, governance, finance, competency modeling, and strategy.  相似文献   

Cross-curricular skills development in final-year dissertation by active and collaborative methodologies     

Iñaki Etaio  Itziar Churruca  Diego Rada  Jonatan Miranda  Amaia Saracibar  Fernando Sarrionandia 《Interactive Learning Environments》2018,26(2):175-188

European Frame for Higher Education has led universities to adapt their teaching schemes. Degrees must train students in competences including specific and cross-curricular skills. Nevertheless, there are important limitations to follow skill improvement through the consecutive academic years. Final-year dissertation (FYD) offers the opportunity to assess these aspects so linked to the professional requirements. The experience reported here offers an alternative methodology for the FYD in order to reinforce cross-curricular skills and substitute the classic final evaluation schemes. A new protocol for the FYD was defined and tested in the Degree in Human Nutrition and Dietetics, with the participation of students and lecturers from different disciplines. The new methodology included collaborative activities that required students active implication and participation. New cross-curricular skills not considered before were included and evaluated in a continuous way: analysis and critical attitude, as well as team working. Obtained data revealed an improvement over cross-curricular skills. Student–student cooperation resulted in significant contributions to enhance FYD quality. The new methodology was satisfactorily valued by students. The main keys for the successful implementation of this protocol were the followings: encouragement of teachers and students, coordination, information and communication technologies, and clear guidelines.  相似文献   

Oxidative stress in elite athletes training at moderate altitude and at sea level     

Josefa León-López  Carmen Calderón-Soto  Matías Pérez-Sánchez  Belén Feriche  Xavier Iglesias  Diego Chaverri 《European Journal of Sport Science》2018,18(6):832-841

Using a controlled parallel group longitudinal trial design, we investigated the effects of different training interventions on the prooxidant/antioxidant status of elite athletes: living and training at moderate altitude for 3 (Hi-Hi3) and 4 weeks (Hi-Hi), and for 4 weeks too, living high and training high and low (Hi-HiLo) and living and training at sea level (Lo-Lo). From 61 swimmers, 54 completed the study. Nitrites, carbonyls, and lipid peroxidation (LPO) levels were assessed in plasma. Enzymatic antioxidants glutathione peroxidase (GPx) and glutathione reductase (GRd), and non-enzymatic antioxidants total glutathione (GST), reduced glutathione (GSH) and oxidized glutathione (GSSG) were analysed in the erythrocyte fraction. At the end of the intervention, nitrites levels were similar in all altitude groups but higher than in the Lo-Lo controls (P?=?.02). Hi-HiLo had greater GPx activity than Hi-Hi and Hi-Hi3 during most of the intervention (P?≤?.001). GRd activity was higher in Lo-Lo than in Hi-Hi at the end of the training camp (P?≤?.001). All groups showed increased levels of LPO, except Lo-Lo, and carbonyls at the end of the study (P?≤?.001). Training at altitude for 3 or 4 weeks drives oxidative stress leading to cellular damage mainly by worsening the antioxidant capacities. The GSSG/GSH ratio appears to be related to perceived exertion and fatigue. The stronger antioxidant defence showed by the Hi-HiLo group suggests an inverse relationship between redox alterations and performance. Further studies are required to investigate the role of oxidative stress in acclimatization, performance, and health.  相似文献