892 resultados para UAS sense and avoid
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Includes bibliography
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This mixed methods concurrent triangulation design study was predicated upon two models that advocated a connection between teaching presence and perceived learning: the Community of Inquiry Model of Online Learning developed by Garrison, Anderson, and Archer (2000); and the Online Interaction Learning Model by Benbunan-Fich, Hiltz, and Harasim (2005). The objective was to learn how teaching presence impacted students’ perceptions of learning and sense of community in intensive online distance education courses developed and taught by instructors at a regional comprehensive university. In the quantitative phase online surveys collected relevant data from participating students (N = 397) and selected instructional faculty (N = 32) during the second week of a three-week Winter Term. Student information included: demographics such as age, gender, employment status, and distance from campus; perceptions of teaching presence; sense of community; perceived learning; course length; and course type. The students claimed having positive relationships between teaching presence, perceived learning, and sense of community. The instructors showed similar positive relationships with no significant differences when the student and instructor data were compared. The qualitative phase consisted of interviews with 12 instructors who had completed the online survey and replied to all of the open-response questions. The two phases were integrated using a matrix generation, and the analysis allowed for conclusions regarding teaching presence, perceived learning, and sense of community. The findings were equivocal with regard to satisfaction with course length and the relative importance of the teaching presence components. A model was provided depicting relationships between and among teaching presence components, perceived learning, and sense of community in intensive online courses.
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Abstract Background A popular model for gene regulatory networks is the Boolean network model. In this paper, we propose an algorithm to perform an analysis of gene regulatory interactions using the Boolean network model and time-series data. Actually, the Boolean network is restricted in the sense that only a subset of all possible Boolean functions are considered. We explore some mathematical properties of the restricted Boolean networks in order to avoid the full search approach. The problem is modeled as a Constraint Satisfaction Problem (CSP) and CSP techniques are used to solve it. Results We applied the proposed algorithm in two data sets. First, we used an artificial dataset obtained from a model for the budding yeast cell cycle. The second data set is derived from experiments performed using HeLa cells. The results show that some interactions can be fully or, at least, partially determined under the Boolean model considered. Conclusions The algorithm proposed can be used as a first step for detection of gene/protein interactions. It is able to infer gene relationships from time-series data of gene expression, and this inference process can be aided by a priori knowledge available.
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One of the most interesting challenge of the next years will be the Air Space Systems automation. This process will involve different aspects as the Air Traffic Management, the Aircrafts and Airport Operations and the Guidance and Navigation Systems. The use of UAS (Uninhabited Aerial System) for civil mission will be one of the most important steps in this automation process. In civil air space, Air Traffic Controllers (ATC) manage the air traffic ensuring that a minimum separation between the controlled aircrafts is always provided. For this purpose ATCs use several operative avoidance techniques like holding patterns or rerouting. The use of UAS in these context will require the definition of strategies for a common management of piloted and piloted air traffic that allow the UAS to self separate. As a first employment in civil air space we consider a UAS surveillance mission that consists in departing from a ground base, taking pictures over a set of mission targets and coming back to the same ground base. During all mission a set of piloted aircrafts fly in the same airspace and thus the UAS has to self separate using the ATC avoidance as anticipated. We consider two objective, the first consists in the minimization of the air traffic impact over the mission, the second consists in the minimization of the impact of the mission over the air traffic. A particular version of the well known Travelling Salesman Problem (TSP) called Time-Dependant-TSP has been studied to deal with traffic problems in big urban areas. Its basic idea consists in a cost of the route between two clients depending on the period of the day in which it is crossed. Our thesis supports that such idea can be applied to the air traffic too using a convenient time horizon compatible with aircrafts operations. The cost of a UAS sub-route will depend on the air traffic that it will meet starting such route in a specific moment and consequently on the avoidance maneuver that it will use to avoid that conflict. The conflict avoidance is a topic that has been hardly developed in past years using different approaches. In this thesis we purpose a new approach based on the use of ATC operative techniques that makes it possible both to model the UAS problem using a TDTSP framework both to use an Air Traffic Management perspective. Starting from this kind of mission, the problem of the UAS insertion in civil air space is formalized as the UAS Routing Problem (URP). For this reason we introduce a new structure called Conflict Graph that makes it possible to model the avoidance maneuvers and to define the arc cost function of the departing time. Two Integer Linear Programming formulations of the problem are proposed. The first is based on a TDTSP formulation that, unfortunately, is weaker then the TSP formulation. Thus a new formulation based on a TSP variation that uses specific penalty to model the holdings is proposed. Different algorithms are presented: exact algorithms, simple heuristics used as Upper Bounds on the number of time steps used, and metaheuristic algorithms as Genetic Algorithm and Simulated Annealing. Finally an air traffic scenario has been simulated using real air traffic data in order to test our algorithms. Graphic Tools have been used to represent the Milano Linate air space and its air traffic during different days. Such data have been provided by ENAV S.p.A (Italian Agency for Air Navigation Services).
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In the framework of an international collaboration with South Africa CSIR, the structural design, manufacturing and testing of the new wing for the Modular UAS in composite materials has been performed.
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Throughout the twentieth century statistical methods have increasingly become part of experimental research. In particular, statistics has made quantification processes meaningful in the soft sciences, which had traditionally relied on activities such as collecting and describing diversity rather than timing variation. The thesis explores this change in relation to agriculture and biology, focusing on analysis of variance and experimental design, the statistical methods developed by the mathematician and geneticist Ronald Aylmer Fisher during the 1920s. The role that Fisher’s methods acquired as tools of scientific research, side by side with the laboratory equipment and the field practices adopted by research workers, is here investigated bottom-up, beginning with the computing instruments and the information technologies that were the tools of the trade for statisticians. Four case studies show under several perspectives the interaction of statistics, computing and information technologies, giving on the one hand an overview of the main tools – mechanical calculators, statistical tables, punched and index cards, standardised forms, digital computers – adopted in the period, and on the other pointing out how these tools complemented each other and were instrumental for the development and dissemination of analysis of variance and experimental design. The period considered is the half-century from the early 1920s to the late 1960s, the institutions investigated are Rothamsted Experimental Station and the Galton Laboratory, and the statisticians examined are Ronald Fisher and Frank Yates.
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Conflict has marked civilization from Biblical times to the present day. Each of us, with our different and competing interests, and our desires to pursue those interests, have over time wronged another person. Not surprisingly then, forgiveness is a concern of individuals and groups¿communities, countries, religious groups, races¿yet it is a complex idea that philosophers, theologians, political scientists, and psychologists have grappled with. Some have argued that forgiveness is a therapeutic means for overcoming guilt, pain, and anger. Forgiveness is often portrayed as a coping mechanism¿how often we hear the phrase, ¿forgive and forget,¿ as an arrangement to help two parties surmount the complications of disagreement. But forgiveness is not simply a modus vivendi; the ability to forgive and conversely to ask for forgiveness, is counted as an admirable trait and virtue. This essay will explore the nature of forgiveness, which in Christian dogma is often posited as an unqualified virtue. The secular world has appropriated the Christian notion of forgiveness as such a virtue¿but are there instances wherein offering forgiveness is morally inappropriate or dangerous? I will consider the situations in which forgiveness, understood in this essay as the overcoming of resentment, may not be a virtue¿when perhaps maintaining resentment is as virtuous, if not more virtuous, than forgiving. I will explain the various ethical frameworks involved in understanding forgiveness as a virtue, and the relationship between them. I will argue that within Divine Command Theory forgiveness is a virtue¿and thus morally right¿because God commands it. This ethical system has established forgiveness as unconditional, an idea which has been adopted into popular culture. With virtue ethics in mind, which holds virtues to be those traits which benefit the person who possesses them, contributing to the good life, I will argue unqualified forgiveness is not always a virtue, as it will not always benefit the victim. Because there is no way to avoid wrongdoing, humans are confronted with the question of forgiveness with every indiscretion. Its limits, its possibilities, its relationship to one¿s character¿forgiveness is a concern of all people at some time if for no other reason than the plain fact that the past cannot be undone. I will be evaluating the idea of forgiveness as a virtue, in contrast to its counterpart, resentment. How can forgiveness be a response to evil, a way to renounce resentment, and a means of creating a positive self-narrative? And what happens when a sense of moral responsibility is impossible to reconcile with the Christian (and now, secularized imperative of) forgiveness? Is it ever not virtuous to forgive? In an attempt to answer that question I will argue that there are indeed times when forgiveness is not a virtue, specifically: when forgiveness compromises one¿s own self-respect; when it is not compatible with respect for the moral community; and when the offender is unapologetic. The kind of offense I have in mind is a dehumanizing one, one that intends to diminish another person¿s worth or humanity. These are moral injuries, to which I will argue resentment is a better response than forgiveness when the three qualifications cannot be met.
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The outbreak of foot and mouth disease (FMD) in Great Britain in 2001 let to discussions and especially emergency vaccination was deemed as an alternative to the culling of vast numbers of healthy animals. The project emergency vaccination for FMD in Switzerland was conducted to compare the effectiveness of conventional control strategies during a FMD outbreak alone and with ring vaccination of 3 km and 10 km, respectively. The results of this project showed that emergency vaccination conducted at the beginning of an epidemic was not favorable compared to conventional disease control strategy in Switzerland. In case of an advanced FMD epidemic, a 10 km ring vaccination could support the disease control in a positive way. However, the goal of emergency vaccination to save animal live can hardly be achieved due to actual legal basis and the consequent restriction measures within vaccination zones which will lead to welfare culling.
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Objective: past research has shown relationship problems associated with narcissists’ excessive self-centeredness and lacking concern for others. Using romantic relationships as opportunities to self-enhance rather than caring about intimacy, narcissists are sensitive to shortcomings in their partners and quick to withdraw investment once relationships turn out to be less than perfect. Our research aimed to reveal whether narcissists are aware of their destructive relationship behavior or tend to put the blame for a failed relationship on their ex-partners. Conversely, do ex-partners of narcissists take the blame and feel responsible for the breakup or walk away convinced their narcissistic ex-partners’ behavior was just too unbearable? Method: 120 participants (19-59 yrs) who reported a recent romantic breakup completed a battery of questionnaires online, including measures of narcissism and self-esteem, as well as newly created scales assessing attributions for breakup. In addition to self-reports, participants retrospectively rated their ex-partners on adapted versions of the same measures. Results: narcissists made attributions to lacking relationship investment mostly in themselves and to a lesser extent in their partners. However, this pattern was reversed when self-esteem was controlled, with attributions to partner shortcomings outnumbering aspects of own destructive behavior. Narcissism perceived in the ex-partner was related to reports of lacking investment in oneself as well as the ex-partner, but controlling for self-esteem reduced the number of attributions to own shortcomings. Conclusion: our analyses revealed that narcissists do show some awareness of their contribution to a failed relationship, although controlling for self-esteem increased their blame of the ex-partner. In contrast, associations between perceived partner-narcissism and aspects of own lacking relationship investment became fewer when self-esteem was controlled for.
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Plasmacytoid dendritic cells (pDCs) are a rare population of circulating cells, which selectively express intracellular Toll-like receptors (TLR)-7 and TLR-9 and have the capacity to produce large amounts of type I IFNs (IFN-a/b) in response to viruses or host derived nucleic acid containing complexes. pDCs are normally absent in skin but accumulate in the skin of psoriasis patients where their chronic activation to produce IFN-a/b drives the disease formation. Whether pDCs and their activation to produce IFN-a/b play a functional role in healthy skin is unknown. Here we show that pDCs are rapidly and transiently recruited into healthy human and mouse skin upon epidermal injury. Infiltrating pDCs were found to sense nucleic acids in wounded skin via TLRs, leading to the production of IFN-a/b. The production of IFN-a/b was paralleled by a short lived expression of cathelicidins, which form complexes with extracellular nucleic acids and activated pDCs to produce IFN-a/b in vitro. In vivo, cathelicidins were sufficient but not necessary for the induction of IFN-a/b in wounded skin, suggesting redundancy of this pathway. Depletion of pDCs or inhibition of IFN-a/bR signaling significantly impaired the inflammatory response and delayed re-epithelialization of skin wounds. Thus we uncover a novel role of pDCs in sensing skin injury via TLR mediated recognition of nucleic acids and demonstrate their involvement in the early inflammatory process and wound healing response through the production of IFN-a/b.
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Food security is important. A rising world population coupled with climate change creates growing pressure on global world food supplies. States alleviate this pressure domestically by attracting agri-foreign direct investment (agri-FDI). This is a high-risk strategy for weak states: the state may gain valuable foreign currency, technology and debt-free growth; but equally, investors may fail to deliver on their commitments and exploit weak domestic legal infrastructure to ‘grab’ large areas of prime agricultural land, leaving only marginal land for domestic production. A net loss to local food security and to the national economy results. This is problematic because the state must continue to guarantee its citizens’ right to food and property. Agri-FDI needs close regulation to maximise its benefit. This article maps the multilevel system of governance covering agri-FDI. We show how this system creates asymmetric rights in favour of the investor to the detriment of the host state’s food security and how these problems might be alleviated.