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101.
Miguel Angel Sotelo Francisco Javier Rodriguez Luis Magdalena Luis Miguel Bergasa Luciano Boquete 《Autonomous Robots》2004,16(1):95-116
This work describes a color Vision-based System intended to perform stable autonomous driving on unmarked roads. Accordingly, this implies the development of an accurate road surface detection system that ensures vehicle stability. Although this topic has already been documented in the technical literature by different research groups, the vast majority of the already existing Intelligent Transportation Systems are devoted to assisted driving of vehicles on marked extra urban roads and highways. The complete system was tested on the BABIECA prototype vehicle, which was autonomously driven for hundred of kilometers accomplishing different navigation missions on a private circuit that emulates an urban quarter. During the tests, the navigation system demonstrated its robustness with regard to shadows, road texture, and weather and changing illumination conditions. 相似文献
102.
Antonio Lpez Rafael Molina Aggelos K. Katsaggelos Antonio Rodriguez Jos M. Lpez Jos M. Llamas 《International journal of imaging systems and technology》2004,14(1):21-27
Despite the adequacy of Bayesian methods to reconstruct nuclear medicine SPECT (single‐photon emission computed tomography) images, they are rarely used in everyday medical practice. This is primarily because of their computational cost and the need to appropriately select the prior model hyperparameters. We propose a simple procedure for the estimation of these hyperparameters and the reconstruction of the original image and test the procedure on both synthetic and real SPECT images. The experimental results demonstrate that the proposed hyperparameter estimation method produces satisfactory reconstructions. Although we have used generalized Gaussian Markov random fields (GGMRF) as prior models, the proposed estimation method can be applied to any priors with convex potential and tractable partition function with respect to the scale hyperparameter. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 21–27, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20003 相似文献
103.
This paper addresses the first generation benchmark problem on structural health monitoring developed by the ASCE Task Group on Structural Health Monitoring. The focus of the problem is a four-story model of an existing physical model at the University of British Columbia where simulated data are used for the system identification. Modal parameters were extracted using the frequency domain decomposition method. Rather than relying on data from the undamaged structure, a new proposed methodology based on ratios between stiffness and mass values from the eigenvalue problem is presented to identify the undamaged state of the structure. Once the structural identification is complete, the damage index method is used to detect the location and severity of damage. By not relying on undamaged structure information, this approach may be applicable to existing structures that may already incorporate some amount of damage. 相似文献
104.
Suominen Fuller M.L. Rodriguez Fernandez L. Massoumi G.R. Lennard W.N. Kasrai M. Bancroft G.M. 《Tribology Letters》2000,8(4):187-192
X‐ray absorption near edge structure (XANES) spectroscopy at the P K‐edge was used to monitor ZDDP antiwear film thickness
with rubbing time. Thermal immersion films of varying thickness were generated from the ZDDP and analysed using XANES spectroscopy
and the particle induced X‐ray emission (PIXE) technique. P K‐edge XANES edge jumps and (1s → np) peak heights of the spectra
were plotted against PIXE mass thickness values in order to establish calibration curves. Antiwear films were analysed using
XANES spectroscopy, and average mass thicknesses were extrapolated from the calibration curves. A set of antiwear films formed
in the presence of ZDDP and then further rubbed in base oil (no ZDDP) showed no significant decrease in film thickness. A
set of antiwear films rubbed in the presence of ZDDP for various lengths of time showed an increase in film thickness, followed
by thinning of the film. The decrease in film thickness is believed to be due to wear caused by the ZDDP solution decomposition
products acting as an abrasive in the contact region.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
105.
Angélica R. Jiménez‐Sánchez Israel Santillán Juvenal Rodriguez Resendiz Carlos A. Gonzalez‐Gutierrez Jorge D. Mendiola‐Santibañez 《International journal of imaging systems and technology》2012,22(2):137-144
In this article, a morphological contrast index based on the Weber's law is proposed to quantify the contrast in a processed image. This measure involves the contours of the image along with its background. The proposal made here is applied to detect the image with higher contrast, and also identify the enhanced image most similar to the original. Moreover, the contrast index is compared with other four indexes reported in the current literature. © 2012 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 22, 137–144, 2012 相似文献
106.
Aiming to fill a gap in traditional methods of source code documentation, which focus mainly on the API (application programming interface) documentation for other programmers, this article presents a new approach for business requirements, mapping them through a set of annotations. These annotations, in turn, are interpreted by the GaiaDoc tool, which is specified in this paper and is able to generate documentation in form of use case specifications in a language and format easily understandable by the project stakeholders. Along with the GaiaDoc tool proposal, a RUP (rational unified process) based requirements flow is developed to fit with its needs and it is validated through CMMI (capability maturity model integration) requirement process areas and a case study of the proposed methodology's application is presented before the final considerations. 相似文献
107.
Temperature control of optical focal planes comes with the intrinsic challenge of creating a pathway that is both extremely flexible mechanically and highly conductive thermally. The task is further complicated because science-caliber optical focal planes are extremely delicate, yet time, cost, and their unique nature means that their mechanical resiliency is rarely tested and documented. The mechanical engineer tasked with the thermo-mechanical design must then create a highly conductive thermal link that minimizes the tensile and shear stresses transmitted to the focal plane without design parameters on an acceptable stiffness and without data on the stiffness of previously implemented thermal links.This paper describes the development and testing of the thermal link developed for the Portable Remote Imaging Spectrometer (PRISM) instrument. It will provide experimentally determined mechanical stiffness plots in the three axes of interest. Analytical and experimental thermal conductance results for the two-arm focal-plane thermal strap (TAFTS), from cryogenic to room temperatures, are also presented. The paper also briefly describes some elements of the fabrication process followed in developing a novel design solution, which provides high conductance and symmetrical mechanical loading, while providing enhanced flexibility in all three dimensions. 相似文献
108.
In this paper, we illustrate specific power savings obtained from exploiting a reconfigurable mobile terminal under the 3GPP LTE standard. Building on traditional link adaptation towards maximum throughput and extended towards minimal power consumption, we add two flexible baseband components: the turbo decoder and the multiple input multiple output (MIMO) detector. Optimizing their configuration leads to larger power savings when compared to non-flexible systems only performing link adaptation. The gain observed strongly depends on the scenario. For low-activity set-ups with a few minutes of voice per day, the idle power dominates and the active data rate is relatively low. This makes analog front-end and time-domain processing dominant given their constant power consumption while MIMO detection and turbo decoding that scale with data rate play a smaller role. Still, because of its ability to improve the system spectral efficiency and hence reduce its duty cycle, an advanced MIMO detector can save 10% in power consumption, on the condition that the network requires to use MIMO. Otherwise single input single output is more power-efficient in downlink. In high-throughput scenarios, larger gains are obtained. The flexible MIMO detector can save up to 35% of average power consumption. The turbo decoding also brings some gain, saving up to 12% of power when the full bandwidth is allocated to a single user. 相似文献
109.
Josephine L. P. Soh Feng Wang Nathan Boersen Rodolfo Pinal Garnet E. Peck 《Drug development and industrial pharmacy》2013,39(10):1022-1035
This article aimed to model the effects of raw material properties and roller compactor operating parameters (OPs) on the properties of roller compacted ribbons and granules with the aid of principal component analysis (PCA) and partial least squares (PLS) projection. A database of raw material properties was established through extensive physical and mechanical characterization of several microcrystalline cellulose (MCC) and lactose grades and their blends. A design of experiment (DoE) was used for ribbon production. PLS models constructed with only OP-modeled roller compaction (RC) responded poorly. Inclusion of raw material properties markedly improved the goodness of fit (R2?=?.897) and model predictability (Q2?=?0.72). 相似文献
110.
Denise Aparecida Delgado Anderson de Souza Sant’AnaDaniel Granato Pilar Rodriguez de Massaguer 《Food Control》2012,23(1):165-170
This study reports on the influence of heat and hydrogen peroxide combination on the inactivation kinetics of two heat resistant molds: Neosartorya fischeri and Paecilomyces variotii. Spores of different ages (1 and 4 months) of these molds were prepared and D-values (the time required at certain temperature/hydrogen peroxide combination to inactivate 90% of the mold ascospores) were determined using thermal death tubes. D-values found for P. variotii ranged from 1.2 to 25.1 s after exposure to different combinations of heat (40 or 60 °C) and hydrogen peroxide (35 or 40% w/w) while for N. fischeri they varied from 2.7 to 14.3 s after exposure to the same hydrogen peroxide concentrations and higher temperatures (60 or 70 °C). The influence of temperature and hydrogen peroxide concentration on the d-values varied with the genus of mold and their ages. A synergistic effect of heat and hydrogen peroxide in reducing D-values of Paecilomyces variotti and N. fischeri has been observed. In addition to strict control of temperature, time and hydrogen concentration, hygienic storage and handling of laminated paperboard material must be considered to reduce the probability of package’s contamination. All these measures together will ensure package’s sterility that is imperative for the effectiveness of aseptic processing and consequently to ensure the microbiological stability of processed foods during shelf-life. 相似文献