scholarly journals Signal Diversity for Laser-Doppler Vibrometers with Raw-Signal Combination

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 998
Author(s):  
Marvin Schewe ◽  
Christian Rembe
Keyword(s):  
Laser Doppler Vibrometer ◽  
Laser Speckle ◽  
Laser Doppler ◽  
Practical Implementation ◽  
Velocity Signal ◽  
Signal Combination ◽  
Signal Diversity ◽  
The Individual ◽  
Signal Dropout

The intensity of the reflected measuring beam is greatly reduced for laser-Doppler vibrometer (LDV) measurements on rough surfaces since a considerable part of the light is scattered and cannot reach the photodetector (laser speckle effect). The low intensity of the reflected laser beam leads to a so-called signal dropout, which manifests as noise peaks in the demodulated velocity signal. In such cases, no light reaches the detector at a specific time and, therefore, no signal can be detected. Consequently, the overall quality of the signal decreases significantly. In the literature, first attempts and a practical implementation to reduce this effect by signal diversity can be found. In this article, a practical implementation with four measuring heads of a Multipoint Vibrometer (MPV) and an evaluation and optimization of an algorithm from the literature is presented. The limitations of the algorithm, which combines velocity signals, are shown by evaluating our measurements. We present a modified algorithm, which generates a combined detector signal from the raw signals of the individual channels, reducing the mean noise level in our measurement by more than 10 dB. By comparing the results of our new algorithm with the algorithms of the state-of-the-art, we can show an improvement of the noise reduction with our approach.

scholarly journals A Comparative Study of Laser Doppler Vibrometers for Vibration Measurements on Pavement Materials

2018 ◽  
Vol 3 (4) ◽  
pp. 47 ◽  
Author(s):  
Navid Hasheminejad ◽  
Cedric Vuye ◽  
Wim Van den bergh ◽  
Joris Dirckx ◽  
Steve Vanlanduit
Keyword(s):  
Modal Analysis ◽  
Asphalt Concrete ◽  
Optical Measurement ◽  
Signal To Noise Ratio ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Noise Floor ◽  
Surface Conditions ◽  
Pavement Materials

A laser Doppler vibrometer (LDV) is a noncontact optical measurement device to measure the vibration velocities of particular points on the surface of an object. Even though LDV has become more popular in road engineering in recent years, their signal-to-noise ratio (SNR) is strongly dependent on light scattering properties of the surface which, in some cases, needs to be properly conditioned. SNR is the main limitation in LDV instrumentation when measuring on low diffusive surfaces like pavements; therefore, an investigation on the SNR of different LDV devices on different surface conditions is of great importance. The objective of this research is to investigate the quality of two types of commercially available LDV systems—helium–neon (He–Ne)-based vibrometers and recently developed infrared vibrometers—on different surface conditions, i.e., retroreflective tape, white tape, black tape, and asphalt concrete. Both noise floor and modal analysis experiments are carried out on these surface conditions. It is shown that the noise floor of the He–Ne LDV is higher when dealing with a noncooperative dark surface, such as asphalt concrete, and it can be improved by improving the surface quality or by using an infrared LDV, which consequently improves the modal analysis experiments performed on pavement materials.

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

Manageable Self in the Early Hellenistic Era

2010 ◽  
Vol 39 (2) ◽  
pp. 34-36
Author(s):  
Vaia Touna
Keyword(s):  
Social Economic ◽  
Ancient Greece ◽  
The Self ◽  
Hellenistic Period ◽  
Political Conditions ◽  
The Individual

This paper argues that the rise of what is commonly termed "personal religion" during the Classic-Hellenistic period is not the result of an inner need or even quality of the self, as often argued by those who see in ancient Greece foreshadowing of Christianity, but rather was the result of social, economic, and political conditions that made it possible for Hellenistic Greeks to redefine the perception of the individual and its relationship to others.

Reflecting the Sky in Water

2017 ◽  
Vol 3 (1) ◽  
pp. 112-126 ◽  
Author(s):  
Ilaria Cristofaro
Keyword(s):  
The Unconscious ◽  
Related Case ◽  
Quality Of Water ◽  
Fluid Properties ◽  
Phenomenological Perspective ◽  
Auto Ethnography ◽  
The Individual ◽  
Artificial Water ◽  
Land Water

From a phenomenological perspective, the reflective quality of water has a visually dramatic impact, especially when combined with the light of celestial phenomena. However, the possible presence of water as a means for reflecting the sky is often undervalued when interpreting archaeoastronomical sites. From artificial water spaces, such as ditches, huacas and wells to natural ones such as rivers, lakes and puddles, water spaces add a layer of interacting reflections to landscapes. In the cosmological understanding of skyscapes and waterscapes, a cross-cultural metaphorical association between water spaces and the underworld is often revealed. In this research, water-skyscapes are explored through the practice of auto-ethnography and reflexive phenomenology. The mirroring of the sky in water opens up themes such as the continuity, delimitation and manipulation of sky phenomena on land: water spaces act as a continuation of the sky on earth; depending on water spaces’ spatial extension, selected celestial phenomena can be periodically reflected within architectures, so as to make the heavenly dimension easily accessible and a possible object of manipulation. Water-skyscapes appear as specular worlds, where water spaces are assumed to be doorways to the inner reality of the unconscious. The fluid properties of water have the visual effect of dissipating borders, of merging shapes, and, therefore, of dissolving identities; in the inner landscape, this process may represent symbolic death experiences and rituals of initiation, where the annihilation of the individual allows the creative process of a new life cycle. These contextually generalisable results aim to inspire new perspectives on sky-and-water related case studies and give value to the practice of reflexive phenomenology as crucial method of research.

QUALITY OF INDIVIDUAL AND GROUP LEVEL INTERVENTIONS FOR FIRST EPISODE PSYCHOSIS AT THE TERTIARY PSYCHIATRIC HOSPITAL IN UGANDA.

2020 ◽  
Author(s):  
Emmanuel Kiiza Mwesiga ◽  
Noeline Nakasujja ◽  
Lawrence Nankaba ◽  
Juliet Nakku ◽  
Seggane Musisi
Keyword(s):  
Psychiatric Hospital ◽  
Psychotic Disorders ◽  
First Episode Psychosis ◽  
First Episode ◽  
Group Level ◽  
Group Interventions ◽  
Episode Psychosis ◽  
Essential Components ◽  
The Individual

Introduction: Individual and group level interventions have the largest effect on outcomes in patients with the first episode of psychosis. The quality of these individual and group level interventions provided to first-episode psychosis patients in Uganda is unclear.Methods: The study was performed at Butabika National Psychiatric Teaching and referral hospital in Uganda. A retrospective chart review of recently discharged adult in-patients with the first episode of psychosis was first performed to determine the proportion of participants who received the different essential components for individual and group level interventions. From the different proportions, the quality of the services across the individual and group interventions was determined using the first-Episode Psychosis Services Fidelity Scale (FEPS-FS). The FEPS-FS assigns a grade of 1-5 on a Likert scale depending on the proportion of patients received the different components of the intervention. Results: The final sample included 156 first-episode psychosis patients. The median age was 27 years [IOR (24-36)] with 55% of participants of the female gender. 13 essential components across the individual and group interventions were assessed and their quality quantified. All 13 essential components had poor quality with the range of scores on the FEPS-FS of 1-3. Only one essential component assessed (use of single antipsychotics) had moderate quality.Discussion: Among current services at the National psychiatric hospital of Uganda, the essential for individual and group level interventions for psychotic disorders are of low quality. Further studies are required on how the quality of these interventions can be improved.

THE VALUE OF LOVE IN THE SYSTEM OF FORMATION OF THE PROFESSIONAL MATURITY OF THE EDUCATOR

2020 ◽  
Vol 1 (10(79)) ◽  
pp. 12-18
Author(s):  
G. Bubyreva
Keyword(s):  
Russian Federation ◽  
The State ◽  
Educational Process ◽  
Wide Range ◽  
The Family ◽  
The Russian Federation ◽  
The Government ◽  
The Individual ◽  
The Right

The existing legislation determines the education as "an integral and focused process of teaching and upbringing, which represents a socially important value and shall be implemented so as to meet the interests of the individual, the family, the society and the state". However, even in this part, the meaning of the notion ‘socially significant benefit is not specified and allows for a wide range of interpretation [2]. Yet the more inconcrete is the answer to the question – "who and how should determine the interests of the individual, the family and even the state?" The national doctrine of education in the Russian Federation, which determined the goals of teaching and upbringing, the ways to attain them by means of the state policy regulating the field of education, the target achievements of the development of the educational system for the period up to 2025, approved by the Decree of the Government of the Russian Federation of October 4, 2000 #751, was abrogated by the Decree of the Government of the Russian Federation of March 29, 2014 #245 [7]. The new doctrine has not been developed so far. The RAE Academician A.B. Khutorsky believes that the absence of the national doctrine of education presents a threat to national security and a violation of the right of citizens to quality education. Accordingly, the teacher has to solve the problem of achieving the harmony of interests of the individual, the family, the society and the government on their own, which, however, judging by the officially published results, is the task that exceeds the abilities of the participants of the educational process.  The particular concern about the results of the patriotic upbringing served as a basis for the legislative initiative of the RF President V. V. Putin, who introduced the project of an amendment to the Law of RF "About Education of the Russian Federation" to the State Duma in 2020, regarding the quality of patriotic upbringing [3]. Patriotism, considered by the President of RF V. V. Putin as the only possible idea to unite the nation is "THE FEELING OF LOVE OF THE MOTHERLAND" and the readiness for every sacrifice and heroic deed for the sake of the interests of your Motherland. However, the practicing educators experience shortfalls in efficient methodologies of patriotic upbringing, which should let them bring up citizens, loving their Motherland more than themselves. The article is dedicated to solution to this problem based on the Value-sense paradigm of upbringing educational dynasty of the Kurbatovs [15].

A Human/Computer Learning Network to Improve Biodiversity Conservation and Research

AI Magazine ◽  
2012 ◽  
Vol 34 (1) ◽  
pp. 10 ◽  
Author(s):  
Steve Kelling ◽  
Jeff Gerbracht ◽  
Daniel Fink ◽  
Carl Lagoze ◽  
Weng-Keen Wong ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Feedback Loop ◽  
Human Computation ◽  
Computational Power ◽  
Learning Networks ◽  
Learning Network ◽  
Computer Learning ◽  
The Individual ◽  
Citizen Science Project

In this paper we describe eBird, a citizen-science project that takes advantage of the human observational capacity to identify birds to species, which is then used to accurately represent patterns of bird occurrences across broad spatial and temporal extents. eBird employs artificial intelligence techniques such as machine learning to improve data quality by taking advantage of the synergies between human computation and mechanical computation. We call this a Human-Computer Learning Network, whose core is an active learning feedback loop between humans and machines that dramatically improves the quality of both, and thereby continually improves the effectiveness of the network as a whole. In this paper we explore how Human-Computer Learning Networks can leverage the contributions of a broad recruitment of human observers and processes their contributed data with Artificial Intelligence algorithms leading to a computational power that far exceeds the sum of the individual parts.

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