31 research outputs found
Structuurplan westelijke waddenzee
No full textBestuudeerd wordt in het hydraulisch deel: Wijziging in hoogte, freqentie van stormvloeden in het betreffende waddengebied en de afleiding voor dit onderzoek noodzakelijke formules. Uitvoering van de gedtijberekeningen. In the technisch deel: het tracee en profiel van de dam in het Eijerlandse gat, en de scheidingsdam, de sluitgatern en een kostenvergelijking. Beschouwing over de wijze van uitvoeringHydraulic EngineeringCivil Engineering and Geoscience
Effective weld length of beam to column connections with and without stiffeners (twee versies)
No full textCivil Engineering and GeosciencesStructural Engineerin
When Beauty Hides a Beast
No full textWe present a 43-year old female patient, admitted to the intensive care unit, recovering from a Bentall procedure because of a supra-coronary aneurysm and unicuspid aortic valve. Few hours following surgery,a marked lactic acidosis, hypoxemia and increased central venous pressure developed. Pulmonary angio-CT was performed to exclude pulmonary embolism. Because of severe peripheral vasoconstriction, iodine contrast could only be administered through a narrow lumen central venous catheter, which limited the maximum flow rate to 1.5 ml/s. Images were performed with triggering in the pulmonary trunk. Review of the images showed no evidence for pulmonary embolism. Despite the low flow rate, a clear enhancement of the pulmonary artery was observed (up to 460 HU) (Fig. 1). Such an enhancement of the pulmonary artery is normally only achieved when injecting contrast at a flow rate of 4-5 ml/s. These perfect images, obtained at a low contrast flow rate in fact indicate severely impaired right ventricular function
Monte Carlo Simulation of Partially Confined Flexible Polymers
No full textWe have studied conformational properties of flexible polymers partially confined to narrow pores of different size using configurational biased Monte Carlo simulations under athermal conditions. The asphericity of the chain has been studied as a function of its center of mass position along the pore axis and as a function of the degree of penetration, or fraction of confined segments. The asphericity passes through a maximum well before all segments are located inside the pore. Rather than deforming gradually, we find that at intermediate penetration degrees, where the center of mass is within distances of approximately one radius of gyration away from the pore entry, the chain part inside the pore stretches out considerably while the remaining part outside the pore is coillike ("flower conformations"). When the center of mass is located further inside the pore, this strong chain extension along the pore axis diminishes, and the average conformation becomes that of a deformed coil. Introduction of weakly attractive monomer-wall interactions does not affect these observations significantly
A comparison of decision making criteria and optimization methods for active robotic sensing
No full textThis work presents a comparison of decision making criteria and optimization methods for active sensing in robotics. Active sensing incorporates the following aspects: (i ) where to position sensors, and (ii ) how to make decisions for next actions, in order to maximize information gain and minimize costs. We concentrate on the second aspect: “Where should the robot move at the next time step?”. Pros and cons of the most often used statistical decision making strategies are discussed. Simulation results from a new multisine approach for active sensing of a nonholonomic mobile robot are given
Magnetic resonance imaging of the adrenal glands in the diagnosis of primary hyperaldosteronism
No full textGemcitabine and cisplatin with or without sorafenib in urothelial carcinoma (AUO-AB 31/05).
No full textImpact of attenuation and scatter correction on the quantification in cardiac pinhole MicroSPECT/CT of laboratory animals
No full textRevised Force Control Using a Compliant Sensor with a Position Controlled Robot
No full textA different way of force control is presented, that is specially advantageous for position controlled robots. Instead of usual force control laws we rely on the well tuned position control loop and just use the force sensor to measure the target pose or to predict the desired trajectory. In combination with a compliant sensor we
introduce an inherently stable framework of force control which almost inhibits all control errors. After an unexpected impact the force error is reduced independently from the sensor's bandwidth or delays in signal processing. Thus the (inevitable) impact force is more significant than the measured force control errors. The special case of a sensor that is mounted far away from a vertex-face contact is discussed, too
On Kalman Filtering with Nonlinear Equality Constraints
No full textThe state space description of some physical systems possess nonlinear equality constraints between some state variables. In this paper, we consider the problem of applying a Kalman filter-type estimator in the presence of such constraints. We categorize previous approaches into pseudo-observation and projection methods and identify two types of constraints-those that act on the entire distribution and those that act on the mean of the distribution. We argue that the pseudo-observation approach enforces neither type of constraint and that the projection method enforces the first type of constraint only. We propose a new method that utilizes the projection method twice-once to constrain the entire distribution and once to constrain the statistics of the distribution. We illustrate these algorithms in a tracking system that uses unit quaternions to encode orientation
