Hybrid Aeroacoustic Computations: State of Art and New Achievements

2019 ◽  
Vol 27 (04) ◽  
pp. 1950020
Author(s):  
Stefan Schoder ◽  
Manfred Kaltenbacher
Keyword(s):  
State Of The Art ◽  
Jet Noise ◽  
Hybrid Modeling ◽  
Fan Noise ◽  
Linearized Euler Equations ◽  
Vortex Sound ◽  
Tremendous Progress ◽  
Modeling Flow ◽  
State Of Art ◽  
Made In

This paper collects the state of the art and the tremendous progress that has been made in hybrid modeling of aeroacoustic sound. Hybrid modeling is defined such that flow and acoustics are modeled separate and connected by an aeroacoustic model. The contributions will be classified with respect to the aeroacoustic models being developed, covering Lighthill’s analogy, Ffowcs Williams and Hawkings, vortex sound, linearized Euler equations (LEE), and different perturbation equations modeling flow induced sound. Within each topic, specific applications, such as jet noise, aircraft noise, ground mobility, noise, fan noise and human phonation, are covered. We focus on the accomplishments and provide the authors’ contribution to aeroacoustic research. Eventually, a concise summary of the different methods and their capabilities is included.

Biological Production of (S)-acetoin: A State-of-the-Art Review

2019 ◽  
Vol 19 (25) ◽  
pp. 2348-2356 ◽  
Author(s):  
Neng-Zhong Xie ◽  
Jian-Xiu Li ◽  
Ri-Bo Huang
Keyword(s):  
Side Effects ◽  
Chemical Synthesis ◽  
State Of The Art ◽  
Optically Active ◽  
Considerable Progress ◽  
Future Prospects ◽  
Chiral Compound ◽  
Biological Production ◽  
Acetoin Production ◽  
Made In

Acetoin is an important four-carbon compound that has many applications in foods, chemical synthesis, cosmetics, cigarettes, soaps, and detergents. Its stereoisomer (S)-acetoin, a high-value chiral compound, can also be used to synthesize optically active drugs, which could enhance targeting properties and reduce side effects. Recently, considerable progress has been made in the development of biotechnological routes for (S)-acetoin production. In this review, various strategies for biological (S)- acetoin production are summarized, and their constraints and possible solutions are described. Furthermore, future prospects of biological production of (S)-acetoin are discussed.

Developments in Rechargeable Mno2Electrodes for Lithium Batteries

1988 ◽  
Vol 135 ◽  
Author(s):  
Michael M Thackeray
Keyword(s):  
Lithium Batteries ◽  
Lithium Battery ◽  
Electrode Materials ◽  
State Of The Art ◽  
Structural Features ◽  
Rechargeable Batteries ◽  
Current State ◽  
Alternative Systems ◽  
Battery Technology ◽  
Made In

AbstractConsiderable efforts are in progress to develop rechargeable batteries as alternative systems to the nickel-cadmium battery. In this regard, several advances have been made in ambient-temperature lithium battery technology, and specifically in the engineering of rechargeable lithium/manganese dioxide cells. This paper reviews the current state of the art in rechargeable Li/MnO2battery technology; particular attention is paid to the structural features of various MnO2electrode materials which influence their electrochemical and cycling behaviour in lithium cells.

State of the Art — 1973

1973 ◽  
Vol 18 (3) ◽  
pp. 175-183 ◽  
Author(s):  
Nathan B. Epstein ◽  
Duane S. Bishop
Keyword(s):  
State Of The Art ◽  
Therapeutic Process ◽  
Scientific Discipline ◽  
Therapeutic Approaches ◽  
Training And Education ◽  
Rigorous Approach ◽  
The Family ◽  
Process And Outcome ◽  
Scientific Approach ◽  
Made In

In summary, it can be said that progress is being made in the field, but slowly. The ‘art’ is vigorous, vital and exciting. The ranks of family therapists are swelling and they are coming from backgrounds of different theoretical persuasions and with varying degrees of sophistication in their training and education. This mélange does lead to excitement and turbulence but often detracts from the necessary rigour that a scientific discipline must develop in order to reach maturity. Systems theory allows for easy conceptualization of one another's behaviour in the system, and permits a much clearer understanding of the therapeutic process based upon it, in contrast to therapeutic approaches based on other models. The authors found negotiation to be therapeutically effective when made explicit. In addition they place the focus on the ‘here and now’ and encourage the increased labeling by family members of interactions (affective and behavioural) and their effects (affective and behavioural), according to the Family Categories Schema previously referred to. Efforts are directed especially towards dealing with the current resistances to problem solutions. Epstein et al. have reported on an ongoing program of research which attempts to examine the process and outcome of family therapy (7,10,21,22,25,26). What is needed now is a more rigorous approach to research and the development of a necessary theoretical base in order that a more systematic and scientific approach can be developed for treating families.

scholarly journals Senescence in the aging process

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1219 ◽  
Author(s):  
Richard GA Faragher ◽  
Anne McArdle ◽  
Alison Willows ◽  
Elizabeth L. Ostler
Keyword(s):  
Aging Process ◽  
Molecular Mechanisms ◽  
Senescent Cell ◽  
Cell Phenotype ◽  
Direct Demonstration ◽  
Tremendous Progress ◽  
Made In

The accumulation of ‘senescent’ cells has long been proposed to act as an ageing mechanism. These cells display a radically altered transcriptome and degenerative phenotype compared with their growing counterparts. Tremendous progress has been made in recent years both in understanding the molecular mechanisms controlling entry into the senescent state and in the direct demonstration that senescent cells act as causal agents of mammalian ageing. The challenges now are to gain a better understanding of how the senescent cell phenotype varies between different individuals and tissues, discover how senescence predisposes to organismal frailty, and develop mechanisms by which the deleterious effects of senescent cells can be ameliorated.

scholarly journals Social and Solidarity Economy Web Information Systems

2014 ◽  
Vol 12 (1) ◽  
pp. 35-52 ◽  
Author(s):  
Mariana Curado Malta ◽  
Ana Alice Baptista ◽  
Cristina Parente
Keyword(s):  
Information Systems ◽  
State Of The Art ◽  
Bibliographic Databases ◽  
Sources Of Information ◽  
Solidarity Economy ◽  
Web Based ◽  
Web Information ◽  
The Social ◽  
Application Profile ◽  
Made In

This paper presents the state of the art on interoperability developments for the social and solidarity economy (SSE) community web based information systems (WIS); it also presents a framework of interoperability for the SSE' WIS and the developments made in a research-in-progress PhD project in the last 3 years. A search on the bibliographic databases showed that so far there are no papers on interoperability initiatives on the SSE, so it was necessary to have other sources of information: a preliminary analysis of the WIS that support SSE activities; and interviews with the representatives of some of the world's most important SSE organisations. The study showed that the WIS are still not interoperable yet. In order to become interoperable a group of the SSE community has been developing a Dublin Corre Application Profile to be used by the SSE community as reference and binding to describe their resources. This paper also describes this on-going process.

scholarly journals SetRank: A Setwise Bayesian Approach for Collaborative Ranking from Implicit Feedback

2020 ◽  
Vol 34 (04) ◽  
pp. 6127-6136
Author(s):  
Chao Wang ◽  
Hengshu Zhu ◽  
Chen Zhu ◽  
Chuan Qin ◽  
Hui Xiong
Keyword(s):  
Bayesian Approach ◽  
Posterior Probability ◽  
State Of The Art ◽  
User Preferences ◽  
Implicit Feedback ◽  
Pairwise Preference ◽  
Entire List ◽  
Collaborative Ranking ◽  
Real World Datasets ◽  
Made In

The recent development of online recommender systems has a focus on collaborative ranking from implicit feedback, such as user clicks and purchases. Different from explicit ratings, which reflect graded user preferences, the implicit feedback only generates positive and unobserved labels. While considerable efforts have been made in this direction, the well-known pairwise and listwise approaches have still been limited by various challenges. Specifically, for the pairwise approaches, the assumption of independent pairwise preference is not always held in practice. Also, the listwise approaches cannot efficiently accommodate “ties” due to the precondition of the entire list permutation. To this end, in this paper, we propose a novel setwise Bayesian approach for collaborative ranking, namely SetRank, to inherently accommodate the characteristics of implicit feedback in recommender system. Specifically, SetRank aims at maximizing the posterior probability of novel setwise preference comparisons and can be implemented with matrix factorization and neural networks. Meanwhile, we also present the theoretical analysis of SetRank to show that the bound of excess risk can be proportional to √M/N, where M and N are the numbers of items and users, respectively. Finally, extensive experiments on four real-world datasets clearly validate the superiority of SetRank compared with various state-of-the-art baselines.

A Comprehensive Taxonomy of Dynamic Texture Representation

2023 ◽  
Vol 55 (1) ◽  
pp. 1-39
Author(s):  
Thanh Tuan Nguyen ◽  
Thanh Phuong Nguyen
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
State Of The Art ◽  
The State ◽  
Future Research ◽  
Research Activities ◽  
Potential Applications ◽  
Benchmark Datasets ◽  
Negative Impacts ◽  
Made In

Representing dynamic textures (DTs) plays an important role in many real implementations in the computer vision community. Due to the turbulent and non-directional motions of DTs along with the negative impacts of different factors (e.g., environmental changes, noise, illumination, etc.), efficiently analyzing DTs has raised considerable challenges for the state-of-the-art approaches. For 20 years, many different techniques have been introduced to handle the above well-known issues for enhancing the performance. Those methods have shown valuable contributions, but the problems have been incompletely dealt with, particularly recognizing DTs on large-scale datasets. In this article, we present a comprehensive taxonomy of DT representation in order to purposefully give a thorough overview of the existing methods along with overall evaluations of their obtained performances. Accordingly, we arrange the methods into six canonical categories. Each of them is then taken in a brief presentation of its principal methodology stream and various related variants. The effectiveness levels of the state-of-the-art methods are then investigated and thoroughly discussed with respect to quantitative and qualitative evaluations in classifying DTs on benchmark datasets. Finally, we point out several potential applications and the remaining challenges that should be addressed in further directions. In comparison with two existing shallow DT surveys (i.e., the first one is out of date as it was made in 2005, while the newer one (published in 2016) is an inadequate overview), we believe that our proposed comprehensive taxonomy not only provides a better view of DT representation for the target readers but also stimulates future research activities.

Optimal Passive Damper Positioning Techniques

2013 ◽  
pp. 85-111 ◽  
Author(s):  
Arun M. Puthanpurayil ◽  
Rajesh P Dhakal ◽  
Athol J. Carr
Keyword(s):  
Seismic Event ◽  
State Of The Art ◽  
Sensitivity Study ◽  
Optimal Distribution ◽  
Comparative Sensitivity ◽  
Numerical Studies ◽  
Current State ◽  
Passive Damper ◽  
Damping Model ◽  
Made In

A consolidated review of the current-state-of-the-art on optimal damper positioning techniques is presented in this chapter. The inherent assumptions made in previous research are discussed and substantiated with numerical studies. Earlier studies have shown that optimal distribution of dampers is sensitive to in-structure damping. In this chapter the significance of optimal distribution of dampers coupled with the necessity for the use of a more realistic in-structure damping model is qualitatively illustrated using a comparative sensitivity study. The effect of inherent assumption of linearity of the parent frame on the ‘optimality’ is also investigated. It is shown that linearity assumption imposed on the parent frame in a major seismic event may not be justified; thereby raising doubts on the scope of optimality techniques proposed in literature.

scholarly journals Progress in Cooling Nanoelectronic Devices to Ultra-Low Temperatures

2020 ◽  
Vol 201 (5-6) ◽  
pp. 772-802 ◽  
Author(s):  
A. T. Jones ◽  
C. P. Scheller ◽  
J. R. Prance ◽  
Y. B. Kalyoncu ◽  
D. M. Zumbühl ◽  
...  
Keyword(s):  
State Of The Art ◽  
Electronic Devices ◽  
Bulk Materials ◽  
Nanoelectronic Devices ◽  
Current State ◽  
Physical Effects ◽  
On Chip ◽  
Nanoscale Physics ◽  
A Current ◽  
Made In

AbstractHere we review recent progress in cooling micro-/nanoelectronic devices significantly below 10 mK. A number of groups worldwide are working to produce sub-millikelvin on-chip electron temperatures, motivated by the possibility of observing new physical effects and improving the performance of quantum technologies, sensors and metrological standards. The challenge is a longstanding one, with the lowest reported on-chip electron temperature having remained around 4 mK for more than 15 years. This is despite the fact that microkelvin temperatures have been accessible in bulk materials since the mid-twentieth century. In this review, we describe progress made in the last 5 years using new cooling techniques. Developments have been driven by improvements in the understanding of nanoscale physics, material properties and heat flow in electronic devices at ultralow temperatures and have involved collaboration between universities and institutes, physicists and engineers. We hope that this review will serve as a summary of the current state of the art and provide a roadmap for future developments. We focus on techniques that have shown, in experiment, the potential to reach sub-millikelvin electron temperatures. In particular, we focus on on-chip demagnetisation refrigeration. Multiple groups have used this technique to reach temperatures around 1 mK, with a current lowest temperature below 0.5 mK.

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