118,252 research outputs found
Recommended from our members
Use of 3D body motion to freeform surface design
This paper presents a novel surface modelling approach by utilising a 3D motion capture system. For designing a large-sized surface, a network of splines is initially set up. Artists or designers wearing motion markers on their hands can then change shapes of the splines with their hands. Literarily they can move their bodies freely to any positions to perform their tasks. They can also move their hands in 3D free space to detail surface characteristics by their gestures. All their design motions are recorded in the motion capturing system and transferred into 3D curves and surfaces correspondingly. This paper reports this novel surface design method and some case studies
Recommended from our members
Re-evaluation of the first synthetic estrogen, 1-keto-1,2,3,4-tetrahydrophenanthrene, and bisphenol A, using both the ovariectomised rat model used in 1933 and additional assays
1-Keto-1,2,3,4-tetrahydrophenanthrene (THP-1) was reported by Cook et al in 1933 as the first synthetic estrogen. Estrogenic activity was assessed by the induction of vaginal cornification in ovariectomised rats. The corresponding 4-isomer (THP-4) was shown to be inactive. Both chemicals have been re-synthesised and assessed for hormonal activity. Each chemical bound weakly and to the same extent to isolated estrogen receptors, but only at high concentrations. However, they each lacked estrogenic or anti-estrogenic activity when evaluated in vitro using a yeast hER assay, and both failed to induce vaginal cornification or uterotrophic effects in ovariectomised rats. THP-1, and to a lesser extent THP-4, were shown to possess weak androgenic and anti-androgenic activity in vitro when evaluated using an hAR yeast assay. Estrogenic activity for bisphenol A (BPA) was subsequently demonstrated by Dodds and Lawson (1936) using the same ovariectomised rat protocol, and this activity has been confirmed and supplemented by positive uterotrophic effects for BPA in the same bioassays.
The present results illustrate the complexity of deriving conclusions regarding the hormonal activities of chemicals. First, some activities observed in isolated hormonal receptor binding assays may not be expressed in functional hormonal assays. This indicates the need for functional hormonal assays in any screening programme. Second, that activities observed for a chemical in one hormonal assay may not be reflected in related hormonal assays. This indicates the need to define assay protocols with some precision when incorporating them into screening batteries. Finally, that some literature reports of hormonal activity for chemicals may not be capable of independent confirmation under apparently identical conditions of test. This illustrates the need to use lists of hormonally active chemicals with car
Study of Histamine Forming Bacteria in Commercial fish samples of Kalyan city
Histamine food poisoning is found to be associated with consumption of scombroid fish containing unusually high levels of histamine. Fish belonging to non-scombroid group may also cause histamine poisoning. In this study, histamine forming bacteria in the commercial fish samples of local markets of Kalyan region were investigated. Among 54 isolates 24 were found to be prominent histamine producers. A simple and rapid colorimetric method for the quantification of histamine in fish was used. Histamine level in fresh mackerel samples was found to be around 20 mg/100 g, which was much above the defect action level (5 mg/100 g) given by FDA indicating potential risk for histamine poisoning. The study suggest that practice of more hygienic and sanitary conditions during handling and processing of fish are required to minimize the contamination of such histamine producing bacteri
Bearing-only acoustic tracking of moving speakers for robot audition
This paper focuses on speaker tracking in robot audition for human-robot interaction. Using only acoustic signals, speaker tracking in enclosed spaces is subject to missing detections and spurious clutter measurements due to speech inactivity, reverberation and interference. Furthermore, many acoustic localization approaches estimate speaker direction, hence providing bearing-only measurements without range information. This paper presents a probability hypothesis density (PHD) tracker that augments the bearing-only speaker directions of arrival with a cloud of range hypotheses at speaker initiation and propagates the random variates through time. Furthermore, due to their formulation PHD filters explicitly model, and hence provide robustness against, clutter and missing detections. The approach is verified using experimental results
Performance evaluation of an emergency call center: tropical polynomial systems applied to timed Petri nets
We analyze a timed Petri net model of an emergency call center which
processes calls with different levels of priority. The counter variables of the
Petri net represent the cumulated number of events as a function of time. We
show that these variables are determined by a piecewise linear dynamical
system. We also prove that computing the stationary regimes of the associated
fluid dynamics reduces to solving a polynomial system over a tropical
(min-plus) semifield of germs. This leads to explicit formul{\ae} expressing
the throughput of the fluid system as a piecewise linear function of the
resources, revealing the existence of different congestion phases. Numerical
experiments show that the analysis of the fluid dynamics yields a good
approximation of the real throughput.Comment: 21 pages, 4 figures. A shorter version can be found in the
proceedings of the conference FORMATS 201
- …