Autonomous Vehicle Coordination with Wireless Sensor and Actuator Networks

A coordinated team of mobile wireless sensor and actuator nodes can bring numerous benefits for various applications in the field of cooperative surveillance, mapping unknown areas, disaster management, automated highway and space exploration. This article explores the idea of mobile nodes using vehicles on wheels, augmented with wireless, sensing, and control capabilities. One of the vehicles acts as a leader, being remotely driven by the user, the others represent the followers. Each vehicle has a low-power wireless sensor node attached, featuring a 3D accelerometer and a magnetic compass. Speed and orientation are computed in real time using inertial navigation techniques. The leader periodically transmits these measures to the followers, which implement a lightweight fuzzy logic controller for imitating the leader's movement pattern. We report in detail on all development phases, covering design, simulation, controller tuning, inertial sensor evaluation, calibration, scheduling, fixed-point computation, debugging, benchmarking, field experiments, and lessons learned

Can Hyperfine Excitation explain the Observed Oscillation-Puzzle of Nuclear Orbital Electron Capture of Hydrogen-like Ions?

Modulated in time orbital electron capture (EC) decays have been observed recently in stored H-like $^{140}$Pr$^{58+}$ and $^{142}$Pm$^{60+}$ ions. Although, the experimental results are extensively discussed in literature, a firm interpretation has still to be established. Periodic transitions between the hyperfine states could possible lead to the observed effect. Both selected nuclides decay to stable daughter nuclei via allowed Gamow-Teller transitions. Due to the conservation of total angular momentum, the allowed EC decay can only proceed from the hyperfine ground state of parent ions. In this work we argue that periodic transitions to the excited hyperfine state (sterile) in respect to the allowed EC decay ground state cannot explain the observed decay pattern

Improve OR-schedule to reduce number of required beds

After surgery most of the surgical patients have to be admitted in a ward in the hospital. Due to financial reasons and an decreasing number of available nurses in the Netherlands over the years, it is important to reduce the bed usage as much as possible. One possible way to achieve this is to create an operating room (OR) schedule that spreads the usage of beds nicely over time, and thereby minimizes the number of required beds. An OR-schedule is given by an assignment of OR-blocks to specific days in the planning horizon and has to fulfill several resource constraints. Due to the stochastic nature of the length of stay of patients, the analytic calculation of the number of required beds for a given OR-schedule is a complex task involving the convolution of discrete distributions. In this paper, two approaches to deal with this complexity are presented. First, a heuristic approach based on local search is given, which takes into account the detailed formulation of the objective. A second approach reduces the complexity by simplifying the objective function. This allows modeling and solving the resulting problem as an ILP. Both approaches are tested on data provided by Hagaziekenhuis in the Netherlands. Furthermore, several what-if scenarios are evaluated. The computational results show that the approach that uses the simplified objective function provides better solutions to the original problem. By using this approach, the number of required beds for the considered instance of HagaZiekenhuis can be reduced by almost 20%

The activity of supported vanadium oxide catalysts for the selective reduction of NO with ammonia

The activities of monolayer V2O5 catalysts for the selective reduction of NO with NH3 are compared with those of commercial available catalysts containing V and/or W. From steady state and pulse experiments it can be concluded that the reduction of surface sites proceeds either by NH3 + NO or by NH3 alone. The reoxidation of the reduced sites occurs by gaseous oxygen or NO. The experimental reaction stoichiometry can be explained in terms of suitable combinations of these four reactions

Structure and reactivity of titania-supported oxides. Part 1: vanadium oxide on titania in the sub- and super-monolayer regions

Vanadium oxide has been deposited on TiO2 (washed anatase, 10 m2g−1; Degussa P-25, 55 ±3 m2g−1; Eurotitania, 46 m2g−1) by aqueous impregnation of (NH4)2[VO(C2O4)2] and by reaction with VOCl3, VO(OR)3 (R=iBu) and VO(acac)2 in organic solvents. Single applications of the last tree reagents form not more than a monolayer of vanadium oxide VOx, a monolayer being defined as 0.10 wt.% V2O5 per m2 of surface. When less than about four monolayers of VOx are present, there is in most cases only a single TPR peak: Tmax values, which increase with V2O5 content, are almost independent of the method used but vary slightly with the support (P-25 < Eurotitania < washed anatase). The 995 cm−1 band, characteristic of V&z.dbnd;O in V2O5, only appears when more than a monolayer of VOx is present.\ud \ud In the sub-monolayer region, VOx is best formulated as an oxohydroxy species bonded to two surface oxygens. As the V2O5 content is increased, layers of disordered V2O5 are formed on limited areas of the surface, but crystalline V2O5 only occurs, probably on top of the disordered V2O5, when the V2O5 content exceeds about four monolayers, and takes the form of acicular crystals exposing only planes perpendicular to the a and b axes

Educació postural: avaluació dels coneixements de la salut de l'esquena en activitats de la vida diària en estudiants d'Educació Secundària

Objectiu: Dissenyar i validar un qüestionari sobre coneixements de la salut i la cura de l’esquena en activitats de la vida diària en joves També analizar diferents models de puntuació de les respostes. Metodologia: Es va seguir un mètode general de prospectiva (Delphi), amb el consens d’un grup de sis experts. Estudi de consistencia interna i fiabilitat en una mostra de 89 xics i 80 xiques. Amb les dades obteses aplicació de cinc models de puntuació basats en donar un pes diferent a les respostes. Consistència interna del qüestionari calculada amb l'Alfa de Cronbach amb cadascú dels models. Estudi de la fiabilitat amb l'anàlisi de mesures repetides test-retest i l’estudi de l’error de mesura amb la representació gràfica dels valors descrita per Bland i Altman. Es calcularen les desviacions estàndard de les diferències, la prova t per a una mostra amb les diferències, els coeficients de correlació intraclasse i els seus intervals de confiança del 95%, l’error estàndard de mesura, el canvi mínim detectable i el coeficient de reproductibilitat. Efecte sòl/sostre calculat amb els percentatges de resposta més alts i més baixos en les puntuacions del primer passe. Per a l'anàlisi de la capacitat discriminatòria de les puntuacions obtingudes es van utilitzar les mitjanes totals del primer passe, es va reagrupar la variable en quatre grups per quartils i es va aplicar una ANOVA d'un factor entres el quartil 1 y el quartil 4. Resultats: Anàlisi de la validesa tots els valors obtesos sobre la consistència interna són iguals o majors a .6 Als diferents models, l'Alfa de Cronbach va oscil·lar entre .6 i .7. En la representació de les puntuacions mitjanes de totes dues passades i el càlcul del pendent de la seua funció lineal hi ha una relació positiva entre les mesures. El valor del pendent, en tots els models al voltant de .7 excepte en el model C que va ser de .56. L’índex de determinació va mostrar un nivell de coherència de les mesures reals amb les teòriques moderat Coeficient de correlació entre les puntuacions i el coeficient de correlació intraclasse igual o major a .75. Error de mesura i límits d'acord de les puntuacions calculats a partir de la desviació típica de la diferència de les mitjanes van indicar una probabilitat molt baixa de ser diferents entre ells. L'efecte sòl/sostre va indicar que aquest efecte no es va produir L'anàlisi de regressió de les mitjanes i diferències de les puntuacions totals de tots els models va indicar un augment significatiu de les diferències en les puntuacions a mesura que el valor mitjà d'aquestes va augmentar. Les diferències entre tots els models van ser significatives. Conclusions: Es presenta un qüestionari per a mesurar els coneixements sobre la postura corporal i la cura de l'esquena en activitats de la vida diària en adolescents validat. Es determina que les mateixes dades, es poden analitzar utilitzant diferents models, proporcionant cadascun d#aquests informació diferent

Public Perspectives on Project Success – Influenced by National Culture?

AbstractProject success, both the determination and the achievement, is a widely discussed subject. Literature seems to agree on one thing: whether a project is considered a success depends on the perspective taken to judge it. But how the public project manager determines the success of his project is not clearly discussed in literature. In 2013 we conducted a research using Q-methodology to reveal which success criteria are important to Dutch public project managers who are in charge of construction projects. In the follow up research, described in this paper, we will extend the research to several European countries. Within the European Union national governments are the largest initiators and clients of large infrastructure projects, which are put up for tender in an international market. In this international context it is essential for private companies, consultancies or contractors, to better understand their public client, in order to come up with internationally competitive bids, successfully collaborate and complete complex projects. The objective of this follow up research is to expose managerial viewpoints on project success in different European countries. The respondents in the research performed early 2014 are governmental project managers, who are responsible for the execution of an internal assignment and who are the representative of the client to the contractor. The position of the respondents in the government organization is similar to the research already carried out in the Netherlands. Based on the research (Hofstede, 2001) into differences in the national culture of countries variations between these countries can be expected. This paper describes the set-up of the study and hypotheses, based on literature, influences of culture on the perception of project success

Fusion of Smartphone Motion Sensors for Physical Activity Recognition

For physical activity recognition, smartphone sensors, such as an accelerometer and a gyroscope, are being utilized in many research studies. So far, particularly, the accelerometer has been extensively studied. In a few recent studies, a combination of a gyroscope, a magnetometer (in a supporting role) and an accelerometer (in a lead role) has been used with the aim to improve the recognition performance. How and when are various motion sensors, which are available on a smartphone, best used for better recognition performance, either individually or in combination? This is yet to be explored. In order to investigate this question, in this paper, we explore how these various motion sensors behave in different situations in the activity recognition process. For this purpose, we designed a data collection experiment where ten participants performed seven different activities carrying smart phones at different positions. Based on the analysis of this data set, we show that these sensors, except the magnetometer, are each capable of taking the lead roles individually, depending on the type of activity being recognized, the body position, the used data features and the classification method employed (personalized or generalized). We also show that their combination only improves the overall recognition performance when their individual performances are not very high, so that there is room for performance improvement. We have made our data set and our data collection application publicly available, thereby making our experiments reproducible