scholarly journals Relativistic equations of motion of massive bodies

2009 ◽  
Vol 5 (S261) ◽  
pp. 102-102
Author(s):  
Luc Blanchet

AbstractHighly relativistic equations of motions will play a crucial role for the detection and analysis of gravitational waves emitted by inspiralling compact binaries in detectors LIGO/VIRGO on ground and LISA in space. Indeed these very relativistic systems (with orbital velocities of the order of half the speed of light in the last orbital rotations) require the application of a high-order post-Newtonian formalism in general relativity for accurate description of their motion and gravitational radiation [1]. In this contribution the current state of the art which has reached the third post-Newtonian approximation for the equations of motion [2–6] and gravitational waveform [7–9] has been described (see [10] for an exhaustive review). We have also emphasized the successful matching of the post-Newtonian templates to numerically generated predictions for the merger and ring-down in the case of black-hole binaries [11].

2021 ◽  
pp. 147821032110627
Author(s):  
Petar Jandrić ◽  
Jeremy Knox

This article develops a post-determinist and a post-instrumentalist understanding of education and educational research through the lens of postdigital theory. We begin with historicizing current postdigital research by showing its intellectual ancestry and recognizing its rapidly changing nature. We move on to current state of the art, which we present in three wide themes. The first theme is the great convergence of various lower-level techno-scientific convergences, such as analogue–digital, physics–biology, and biology–information, which results in new epistemologies, ontologies and practices. The second theme is some consequences of the great convergence for education and pedagogy, which result in new postdigital ecopedagogies. The third theme is postdigital research, which is reconfigured by the great convergence towards a closer collaboration between traditional scientific fields and disciplines. We briefly outline four such reconfigurations (multidisciplinary, interdisciplinarity, transdisciplinarity, and antidisciplinarity) and their implications. The article concludes with a brief list of directions for future work in the field.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Junfeng Yang ◽  
Yuwen Huang ◽  
Fuxian Huang ◽  
Gongping Yang

Photoplethysmography (PPG) biometric recognition has recently received considerable attention and is considered to be a promising biometric trait. Although some promising results on PPG biometric recognition have been reported, challenges in noise sensitivity and poor robustness remain. To address these issues, a PPG biometric recognition framework is presented in this article, that is, a PPG biometric recognition model based on a sparse softmax vector and k-nearest neighbor. First, raw PPG data are rerepresented by sliding window scanning. Second, three-layer features are extracted, and the features of each layer are represented by a sparse softmax vector. In the first layer, the features are extracted by PPG data as a whole. In the second layer, all the PPG data are divided into four subregions, then four subfeatures are generated by extracting features from the four subregions, and finally, the four subfeatures are averaged as the second layer features. In the third layer, all the PPG data are divided into 16 subregions, then 16 subfeatures are generated by extracting features from the 16 subregions, and finally, the 16 subfeatures are averaged as the third layer features. Finally, the features with first, second, and third layers are combined into three-layer features. Extensive experiments were conducted on three PPG datasets, and it was found that the proposed method can achieve a recognition rate of 99.95%, 97.21%, and 99.92% on the respective sets. The results demonstrate that the proposed method can outperform current state-of-the-art methods in terms of accuracy.


2004 ◽  
Vol 93 (9) ◽  
Author(s):  
Luc Blanchet ◽  
Thibault Damour ◽  
Gilles Esposito-Farèse ◽  
Bala R. Iyer

2005 ◽  
Vol 21 (3-4) ◽  
pp. 615-671
Author(s):  
Jean Goulet

This paper deals primarily with computer-assisted legal research. It attempts to sketch the current state of the art, mainly in the United States and Canada, with special reference to systems oriented towards the processing of legislative data. The author suggests a checklist of the main requirements the systems of the 80's will have to answer to, in order to fulfill the growing needs of the new computer-minded generations of law graduates. Along these lines, this paper deals also with the second generation systems dedicated to automated legal research ; these could be expected to show some form, albeit elementary, of humanlike intelligence. Four prototypes of such systems are considered; they are the American Bar Foundation's and Jeffrey Meldman's systems, as well as the well-known JUDITH and TAXMAN systems. The paper concludes on a glimpse of the Third Wave of computerized legal research, in the belief that the legal profession will meet the challenge of the computer age, will learn to live and work with this new technology, and will master the artificial but sometimes acute intelligence of our new friend, the Robot.


This chapter proposes an overview of the main urban goods transport movement approaches in more than 40 years of research in the field. A state of the art on urban goods transport modelling is proposed in the form of a chronology to examine the main four periods in urban goods transport modelling, the main approaches, and the main schools of thinking. After that, the main dominant approaches are defined and presented. The author observes that, although in literature there is the feeling that no unified approach is dominating the field, several dominant approaches can be found: the first concerns demand generation models, the second the way generation is linked to route definition and construction, the third to the units used, and the fourth to the use of origin-destination synthesis when few data are available and classical models are not able to be deployed. Finally, as a conclusion, the paper shows on the current state of the field, which has achieved various advances, shows the capacity to innovate in the near future.


1974 ◽  
Vol 11 (02) ◽  
pp. 159-172
Author(s):  
John D. Burroughs ◽  
Raymond C. Benz

Since 1965 the authors' company has developed, assembled, and applied a computer simulation to the problem of analyzing the static and dynamic behavior of underwater towed systems. As a result of a recent survey [16]3 of towed system dynamic analysis literature, it became apparent that other investigators in the field of towed system analysis were either completely unaware of this work or had only a very superficial knowledge of it. It is a purpose of this paper to describe the modeling approach taken for the towed system and to present the methods used to derive the equations of motion for the model. Assumptions that were made in order to achieve practical solutions to the equations of motion also are discussed. A high degree of correlation with actual towing trials has been achieved by this analysis and it has been demonstrated that practical engineering problems can be solved using such a simulation tool. The computer support provided in 1970 to underway sea trials of a hydrofoil towed system is presented and discussed. It is believed that this simulation represents the current state of the art in towed system simulation.


2021 ◽  
Vol 12 ◽  
Author(s):  
Federica De Lise ◽  
Andrea Strazzulli ◽  
Roberta Iacono ◽  
Nicola Curci ◽  
Mauro Di Fenza ◽  
...  

Genetic code decoding, initially considered to be universal and immutable, is now known to be flexible. In fact, in specific genes, ribosomes deviate from the standard translational rules in a programmed way, a phenomenon globally termed recoding. Translational recoding, which has been found in all domains of life, includes a group of events occurring during gene translation, namely stop codon readthrough, programmed ± 1 frameshifting, and ribosome bypassing. These events regulate protein expression at translational level and their mechanisms are well known and characterized in viruses, bacteria and eukaryotes. In this review we summarize the current state-of-the-art of recoding in the third domain of life. In Archaea, it was demonstrated and extensively studied that translational recoding regulates the decoding of the 21st and the 22nd amino acids selenocysteine and pyrrolysine, respectively, and only one case of programmed –1 frameshifting has been reported so far in Saccharolobus solfataricus P2. However, further putative events of translational recoding have been hypothesized in other archaeal species, but not extensively studied and confirmed yet. Although this phenomenon could have some implication for the physiology and adaptation of life in extreme environments, this field is still underexplored and genes whose expression could be regulated by recoding are still poorly characterized. The study of these recoding episodes in Archaea is urgently needed.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3342 ◽  
Author(s):  
Maged AL-Quraishi ◽  
Irraivan Elamvazuthi ◽  
Siti Daud ◽  
S. Parasuraman ◽  
Alberto Borboni

Electroencephalography (EEG) signals have great impact on the development of assistive rehabilitation devices. These signals are used as a popular tool to investigate the functions and the behavior of the human motion in recent research. The study of EEG-based control of assistive devices is still in early stages. Although the EEG-based control of assistive devices has attracted a considerable level of attention over the last few years, few studies have been carried out to systematically review these studies, as a means of offering researchers and experts a comprehensive summary of the present, state-of-the-art EEG-based control techniques used for assistive technology. Therefore, this research has three main goals. The first aim is to systematically gather, summarize, evaluate and synthesize information regarding the accuracy and the value of previous research published in the literature between 2011 and 2018. The second goal is to extensively report on the holistic, experimental outcomes of this domain in relation to current research. It is systematically performed to provide a wealthy image and grounded evidence of the current state of research covering EEG-based control for assistive rehabilitation devices to all the experts and scientists. The third goal is to recognize the gap of knowledge that demands further investigation and to recommend directions for future research in this area.


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