93 research outputs found
Homography-based ground plane detection using a single on-board camera
This study presents a robust method for ground plane detection in vision-based systems with a non-stationary camera. The proposed method is based on the reliable estimation of the homography between ground planes in successive images. This homography is computed using a feature matching approach, which in contrast to classical approaches to on-board motion estimation does not require explicit ego-motion calculation. As opposed to it, a novel homography calculation method based on a linear estimation framework is presented. This framework provides predictions of the ground plane transformation matrix that are dynamically updated with new measurements. The method is specially suited for challenging environments, in particular traffic scenarios, in which the information is scarce and the homography computed from the images is usually inaccurate or erroneous. The proposed estimation framework is able to remove erroneous measurements and to correct those that are inaccurate, hence producing a reliable homography estimate at each instant. It is based on the evaluation of the difference between the predicted and the observed transformations, measured according to the spectral norm of the associated matrix of differences. Moreover, an example is provided on how to use the information extracted from ground plane estimation to achieve object detection and tracking. The method has been successfully demonstrated for the detection of moving vehicles in traffic environments
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The ErbB2ÎEx16 splice variant is a major oncogenic driver in breast cancer that promotes a pro-metastatic tumor microenvironment.
Amplification and overexpression of erbB2/neu proto-oncogene is observed in 20-30% human breast cancer and is inversely correlated with the survival of the patient. Despite this, somatic activating mutations within erbB2 in human breast cancers are rare. However, we have previously reported that a splice isoform of erbB2, containing an in-frame deletion of exon 16 (herein referred to as ErbB2ÎEx16), results in oncogenic activation of erbB2 because of constitutive dimerization of the ErbB2 receptor. Here, we demonstrate that the ErbB2ÎEx16 is a major oncogenic driver in breast cancer that constitutively signals from the cell surface. We further show that inducible expression of the ErbB2ÎEx16 variant in mammary gland of transgenic mice results in the rapid development of metastatic multifocal mammary tumors. Genetic and biochemical characterization of the ErbB2ÎEx16-derived mammary tumors exhibit several unique features that distinguish this model from the conventional ErbB2 ones expressing the erbB2 proto-oncogene in mammary epithelium. Unlike the wild-type ErbB2-derived tumors that express luminal keratins, ErbB2ÎEx16-derived tumors exhibit high degree of intratumoral heterogeneity co-expressing both basal and luminal keratins. Consistent with these distinct pathological features, the ErbB2ÎEx16 tumors exhibit distinct signaling and gene expression profiles that correlate with activation of number of key transcription factors implicated in breast cancer metastasis and cancer stem cell renewal
Digital transient torque measurement for rotating or linear AC machines (real time measurement)
The digital transient torque measuring device presented in this paper is able to make a "real time" calculation in steady-state and transient conditions of the electromagnetic torque or force of an extremely wide range of ac electrical machines supplied with sinusoidal voltages or through frequency converters with frequencies up to 30 kHz. The device needs no shaft position or speed sensors, it uses exclusively the acquisition of the stator currents and voltages. The main fields of applications are: test shop, control, measurement, integration in a control or regulation unit, element of a monitoring system
Fully automated parameter identification for synchronous machines.
The article presents a fully automated identification method for the determination of the sub-subtransient, subtransient and transient characteristic parameters of large synchronous machines. The software allows for an identification of the parameters based on the measurements of the terminal currents during a three-phase short-circuit as defined in the international standards. Based on the identified parameters the equivalent circuit diagram (ecd) is established and it can be used as model of the synchronous machine for numerical simulations to be performed later
Vector Control of an Induction Machine in a Stator Flux Reference Frame.
This paper describes a stator flux oriented control strategy using state space controllers. The optimal determination of the different controllers parameters leads to an independent control of the stator flux and the torque. The effects of undesired offsets on the calculated stator flux are discussed and a solution for eliminating these offset is presented Verification by computer simulation and results of the control implementation on a Motorola DSP 56002 are presente
12-Pulse LCI synchronous drive for a 20 MW compressor : modeling, simulation and measurements
Abstract â The current source thyristor inverter is still today a suitable choice for supplying high power adjustable speed drives for pumps or compressors. This paper presents a 12-pulse LCI (load commutated inverter) synchronous drive for a 20 MW compressor, it focuses on the following main aspects: modeling of the complete drive system, numerical simulation and comparison between calculated and measured values of the pulsating torque components in steady-state operations. The modeling of the six- phase synchronous motor is obtained by using a new virtual test- platform for large electrical machines. The pulsating torque components are measured in real time with a digital transient torque measurement device
On the Identification of the Synchronous Machine Parameters Using Standstill DC Decay Test.
This paper presents a refined approach to obtain the parameters of synchronous machine equivalent circuits from standstill DC decay tests. A dedicated program for the time- constants and reactances identification was developed and applied for both d- and q- axis, as well as for a random position of the rotor, with good results
TLSim: A software for Electrical Public Transportation Systems
The Laboratory of Electrical Machines of the Swiss Federal Institute of Technology (Lausanne) has developed a software (TLSim) for the simulation of electrical urban transportation systems. This program can simulate the behaviour of the power supply network (current and voltage level at any point of the topology) comprising uni- and bi- directionnal sub-stations. In the network the vehicules (trolleybus) may run along any defined path through different electrical supply sectors. Several models of trolleybus are available, one of these allowing for the injection of current back in the supply network. The operating schedule of the buses as well as the geographical data of the network are provided by the user. This program is a perfect tool for system planning as ascertained by its use by a Swiss transportation operator. A comparison of simulation and measurements on a real network has been performed with satisfactory results. This software evolved from a specific study to a flexible program still being extended with new developments. The latest of such developments being the study of the influence of capacitors in helping the system to keep voltages over a specified level mainly by supplying the surge current during the acceleration of the trolleybuses
Mechanical properties of porous asphalt, recommendations for standardization
Porous Asphalt (PA) is used worldwide for its favorable splash and spray properties and its reduction of aquaplaning under rainy conditions as well as its noise reduction properties. Switzerland started using PA in 1979 with mixed results. According to a survey taken in 2004, nine of the 26 cantons use PA. In particular, canton Vaud in western Switzerland is known as one of the leaders in promoting and using PA. Currently, 1/3 of the Vaud motorways are covered with porous asphalt and the use of PA is planned to be extended to most of the motorway surfaces in the canton Vaud up to an altitude of 600m. In addition, there are several bridge trial sections with PA. After the initial survey of the literature appropriate mechanical tests for porous asphalt were chosen (Table 8. 1). At the same time a survey of current experience with porous asphalt in Switzerland was conducted (Appendix 2). Tests were performed on laboratory prepared specimens (AG1, AG4, AG5, VD7, VD8, VD9) and cores (VD2, VD3, VD4, VD5, VS6, AG2, AG3, VD10) taken from selected pavements chosen based on the feedback from various cantons. The behavior of the selected materials was also assessed using an analytical model. Laboratory tests allowed the comparison of core performance with that of laboratory prepared specimen as well as comparison with field performance. Based on the results two mixes were optimized (VD9, AG5) and recommendations for mechanical tests appropriate for porous asphalt were made
Edukasi Literasi Digital dan Kecakapan Perawat dalam Penggunaan Media Sosial
Nurses frequently utilize social media in their professional activities in the digital era. However, there are concerns that some nurses engage in behaviours that breach ethical and legal standards when using social media, potentially impacting patient safety and legal repercussions. One approach to mitigate these impacts is through digital literacy training. This training aims to enhance nurses' knowledge, attitudes, and skills in responsibly utilizing social media for improved patient care. The training was delivered in lectures, simulations, and case studies over 8 hours. A total of 38 nurses participated in this training. After attending the training, the nurses' knowledge scores improved from 24% to 88%. Additionally, their attitudes towards the use of social media showed a positive increase, with 96.4% having a positive attitude post-training. Competence in using social media also improved, from 63.43% to 84.6%. Digital literacy training is vital in enhancing nurses' understanding and proficiency in using social media ethically and responsibly
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