Minimum Jerk Trajectory Planning for Trajectory Constrained Redundant Robots

In this dissertation, we develop an efficient method of generating minimal jerk trajectories for redundant robots in trajectory following problems. We show that high jerk is a local phenomenon, and therefore focus on optimizing regions of high jerk that occur when using traditional trajectory generation methods. The optimal trajectory is shown to be located on the foliation of self-motion manifolds, and this property is exploited to express the problem as a minimal dimension Bolza optimal control problem. A numerical algorithm based on ideas from pseudo-spectral optimization methods is proposed and applied to two example planar robot structures with two redundant degrees of freedom. When compared with existing trajectory generation methods, the proposed algorithm reduces the integral jerk of the examples by 75% and 13%. Peak jerk is reduced by 98% and 33%. Finally a real time controller is proposed to accurately track the planned trajectory given real-time measurements of the tool-tip\u27s following error

Labor Law - Extortion as Defined by the Hobbs Act and Its Relation to Legitimate Labor Objectives

In a 5-4 decision, the Supreme Court of the United States held that extortion as defined by the Hobbs Act does not proscribe violence committed during a lawful strike for the purpose of inducing an employer\u27s agreement to legitimate collective bargaining demands. United States v. Enmons, 410 U.S. 396 (1973)

Paper Session III-C - A SAREX Case Study- Getting Teachers Interested in Amateur Radio and Space Education

SAREX, the Shuttle Amateur Radio Experiment, is flown primarily as part of NASA\u27s education program. Any school or educational group can submit a proposal for a prescheduled SAREX contact. It\u27s hoped that schools will get interested in the space program and amateur radio, and make these activities part of the normal curriculum. Sometimes a SAREX contact is incredibly exciting, but forgotten soon after the shuttle mission is over. But in many cases SAREX does leave a lasting impression on the students and teachers. Co-author Joan Freeman is a teacher at South Seminole Middle School in Casselberry Florida. Three years ago she watched television and read the newspaper to find out about the space program. Now she uSes amateur radio every day in her class and completed a SAREX educational contact with the shuttle during the STS-65 mission. This paper will show what has been done, and suggestions for how to increase awareness about ham radio, SAREX, and the shuttle program in schools

A Spatial Quantile Regression Hedonic Model of Agricultural Land Prices

Abstract Land price studies typically employ hedonic analysis to identify the impact of land characteristics on price. Owing to the spatial fixity of land, however, the question of possible spatial dependence in agricultural land prices arises. The presence of spatial dependence in agricultural land prices can have serious consequences for the hedonic model analysis. Ignoring spatial autocorrelation can lead to biased estimates in land price hedonic models. We propose using a flexible quantile regression-based estimation of the spatial lag hedonic model allowing for varying effects of the characteristics and, more importantly, varying degrees of spatial autocorrelation. In applying this approach to a sample of agricultural land sales in Northern Ireland we find that the market effectively consists of two relatively separate segments. The larger of these two segments conforms to the conventional hedonic model with no spatial lag dependence, while the smaller, much thinner market segment exhibits considerable spatial lag dependence. Un mod�le h�donique � r�gression quantile spatiale des prix des terrains agricoles R�sum� Les �tudes sur le prix des terrains font g�n�ralement usage d'une analyse h�donique pour identifier l'impact des caract�ristiques des terrains sur le prix. Toutefois, du fait de la fixit� spatiale des terrains, la question d'une �ventuelle d�pendance spatiale sur la valeur des terrains agricoles se pose. L'existence d'une d�pendance spatiale dans le prix des terrains agricoles peut avoir des cons�quences importantes sur l'analyse du mod�le h�donique. En ignorant cette corr�lation s�rielle, on s'expose au risque d'�valuations biais�es des mod�les h�doniques du prix des terrains. Nous proposons l'emploi d'une estimation � base de r�gression flexible du mod�le h�donique � d�calage spatial, tenant compte de diff�rents effets des caract�ristiques, et surtout de diff�rents degr�s de corr�lations s�rielles spatiales. En appliquant ce principe � un �chantillon de ventes de terrains agricoles en Irlande du Nord, nous d�couvrons que le march� se compose de deux segments relativement distincts. Le plus important de ces deux segments est conforme au mod�le h�donique traditionnel, sans d�pendance du d�calage spatial, tandis que le deuxi�me segment du march�, plus petit et beaucoup plus �troit, pr�sente une d�pendance consid�rable du d�calage spatial. Un modelo hed�nico de regresi�n cuantil espacial de los precios del terreno agr�cola Resumen T�picamente, los estudios del precio de la tierra emplean un an�lisis hed�nico para identificar el impacto de las caracter�sticas de la tierra sobre el precio. No obstante, debido a la fijeza espacial de la tierra, surge la cuesti�n de una posible dependencia espacial en los precios del terreno agr�cola. La presencia de dependencia espacial en los precios del terreno agr�cola puede tener consecuencias graves para el modelo de an�lisis hed�nico. Ignorar la autocorrelaci�n espacial puede conducir a estimados parciales en los modelos hed�nicos del precio de la tierra. Proponemos el uso de una valoraci�n basada en una regresi�n cuantil flexible del modelo hed�nico del lapso espacial que tenga en cuenta los diversos efectos de las caracter�sticas y, particularmente, los diversos grados de autocorrelaci�n espacial. Al aplicar este planteamiento a una muestra de ventas de terreno agr�cola en Irlanda del Norte, descubrimos que el mercado consiste efectivamente de dos segmento relativamente separados. El m�s grande de estos dos segmentos se ajusta al modelo hed�nico convencional sin dependencia del lapso espacial, mientras que el segmento m�s peque�o, y mucho m�s fino, muestra una dependencia considerable del lapso espacial.Spatial lag, quantile regression, hedonic model, C13, C14, C21, Q24,

Local variance of atmospheric 14C concentrations around Fukushima Dai-ichi Nuclear Power Plant from 2010 to 2012

Radiocarbon (14C) has been measured in single tree ring samples collected from the southwest of the Fukushima Dai-ichi Nuclear Power Plant. Our data indicate south-westwards dispersion of radiocarbon and the highest 14C activity observed so far in the local environment during the 2011 accident. The abnormally high 14C activity in the late wood of 2011 ring may imply an unknown source of radiocarbon nearby after the accident. The influence of 14C shrank from 30 km during normal reactor operation to 14 km for the accident in the northwest of FDNPP, but remains unclear in the southwest

The influence of nitric oxide and nitrite on coronary vascular resistance, platelet function and inflammation in patients undergoing revascularisation after NSTEMI and stable angina

Coronary blood flow (CBF) is principally controlled by changes in coronary vascular resistance (CVR). Low CVR helps to maintain myocardial perfusion in the presence of epicardial stenosis, therefore factors that impair the reduction of CVR will have a direct effect on CBF leading to either a narrower “effective” perfusion pressure range or reduced ability to compensate for increased demand on myocardial contraction. There are several mechanisms which may be important in the control CVR in humans including both endothelial dependent production of NO and reduction of the simple anion inorganic nitrite (a metabolite of NO) back to NO (via several putative mechanisms). The synthesis of NO by both nitric oxide synthase (NOS) and the reduction of nitrite in the coronary circulation has been the subject of many animal and human clinical studies. Reduced systemic endothelial dependent production of NO has an association with worse cardiovascular outcomes in humans, the number of potential mechanisms are large and perhaps central is the effect on CVR. The reduction of nitrite to NO is seen, in some ways, to be the perfect compensatory mechanism, particularly when endothelial function is impaired. It is easy to hypothesise that this stoichiometric balance of NO production might be responsible for the perfect regulation of CVR and thus CBF. Methods This thesis investigates the influence and effect of both endothelial production of NO and the reduction of nitrite to NO on CVR in man. First, an observational study assessing the impact of these mechanisms in patients undergoing percutaneous coronary intervention (PCI), in the treatment of both non-ST-elevation myocardial infarction and stable angina. Specifically, the metabolites of NO were measured from aortic root to coronary sinus together with the associated CVR both before and after PCI. Second, using a systemic infusion of sodium nitrite (NaNO2) in NSTEMI patients to assess the effect of nitrite reduction on CVR during PCI. The systemic nitrite concentration was increased 8-fold in the same experimental conditions as the observational study. Third, beyond CVR control the influence of NO and nitrite was also assessed in terms of platelet reactivity and systemic inflammatory cytokines in the NSTEMI cohort both with and without NaNO2 infusion. Results NSTEMI patients have a net increase in NO metabolites across the coronary circulation unlike healthy controls (historical data) and stable angina patients. This net increase is lost following PCI and is associated with a significant rise in CVR. Stable angina patients appear to compensate with increase collateral circulation and not NO synthesis. An 8-fold increase in nitrite concentration has no effect on CVR or platelet reactivity in NSTEMI patients. Conclusions In NSTEMI patients a net aorta to coronary sinus NO synthesis appears to be important to maintain a low CVR and thus CBF when haemodynamically significant epicardial disease is present. After the epicardial disease is treated this net increase in NOx (Nitric Oxide metabolites), is lost and is associated with an acute increase in CVR. Stable angina patients have no net increase in NOx across the coronary circulation and after revascularisation have no change in CVR, this may reflect an alternate mechanism of compensation and microvascular perfusion maintained by collateral circulation as evident by the increase CFI. Despite the perfect environment for the reduction of nitrite to NO we saw no influence of an 8-fold increase in serum nitrite concentration on CVR in patients with NSTEMI either before or after PCI, suggesting that nitrite reduction to NO plays no role in CBF regulation in NSTEMI patients. Nitrite reduction depends on conditions that are found predominantly in the capillary bed or venules, thus any mechanism would need to rely on a feedback mechanism to signal back to the arterioles (where much of resistance change is created). Despite hypotheses by others that this may occur by the close arrangement of venules to arterioles, this appears not to be the case in NSTEMI patients. Other clinically relevant and important mechanisms also appear to be unaffected by this increase in serum nitrite, residual platelet function and cytokine concentrations at 24 hours

Diffuse reflectance imaging with astronomical applications

Diffuse objects generally tell us little about the surrounding lighting, since the radiance they reflect blurs together incident lighting from many directions. In this paper we discuss how occlusion geometry can help invert diffuse reflectance to recover lighting or surface albedo. Self-occlusion in the scene can be regarded as a form of coding, creating high frequencies that improve the conditioning of diffuse light transport. Our analysis builds on a basic observation that diffuse reflectors with sufficiently detailed geometry can fully resolve the incident lighting. Using a Bayesian framework, we propose a novel reconstruction method based on high-resolution photography, taking advantage of visibility changes near occlusion boundaries. We also explore the limits of single-pixel observations as the diffuse reflector (and potentially the lighting) vary over time. Diffuse reflectance imaging is particularly relevant for astronomy applications, where diffuse reflectors arise naturally but the incident lighting and camera position cannot be controlled. To test our approaches, we first study the feasibility of using the moon as a diffuse reflector to observe the earth as seen from space. Next we present a reconstruction of Mars using historical photometry measurements not previously used for this purpose. As our results suggest, diffuse reflectance imaging expands our notion of what can qualify as a camera.Natural Sciences and Engineering Research Council of Canada (NSERC) (Postdoctoral Fellowship)United States-Israel Binational Science Foundation (Grant 2008155)United States. National Geospatial-Intelligence Agency (NEGI-1582-04-0004)United States. Multidisciplinary University Research Initiative (Grant N00014-06-1-0734