scholarly journals Impact sound synthesis method of complex structures and the experimental verification

2014 ◽  
Vol 63 (22) ◽  
pp. 224303
Author(s):  
Zhang Bing-Rui ◽  
Chen Ke-An ◽  
Ding Shao-Hu
Keyword(s):  
Experimental Verification ◽  
Synthesis Method ◽  
Sound Synthesis ◽  
Complex Structures

Discovery of a Difluoroglycine Synthesis Method through Quantum Chemical Calculations

2020 ◽  
Author(s):  
Tsuyoshi Mita ◽  
Yu Harabuchi ◽  
Satoshi Maeda
Keyword(s):  
Quantum Chemical Calculations ◽  
Experimental Verification ◽  
Quantum Chemical ◽  
Synthesis Method ◽  
Target Product ◽  
Systematic Exploration ◽  
Hands On ◽  
Retrosynthetic Analysis ◽  
Synthetic Routes ◽  
Verification Process

The systematic exploration of synthetic pathways to afford a desired product through quantum chemical calculations remains a considerable challenge. In 2013, Maeda et al. introduced ‘quantum chemistry aided retrosynthetic analysis’ (QCaRA), which uses quantum chemical calculations to search systematically for decomposition paths of the target product and propose a synthesis method. However, until now, no new reactions suggested by QCaRA have been reported to lead to experimental discoveries. Using a difluoroglycine derivative as a target, this study investigated the ability of QCaRA to suggest various synthetic paths to the target without relying on previous data or the knowledge and experience of chemists. Furthermore, experimental verification of the seemingly most promising path led to the discovery of a synthesis method for the difluoroglycine derivative. The extent of the hands-on expertise of chemists required during the verification process was also evaluated. These insights are expected to advance the applicability of QCaRA to the discovery of viable experimental synthetic routes.

Discovery of a Difluoroglycine Synthesis Method through Quantum Chemical Calculations

2020 ◽  
Author(s):  
Tsuyoshi Mita ◽  
Yu Harabuchi ◽  
Satoshi Maeda
Keyword(s):  
Quantum Chemical Calculations ◽  
Experimental Verification ◽  
Quantum Chemical ◽  
Synthesis Method ◽  
Target Product ◽  
Systematic Exploration ◽  
Hands On ◽  
Retrosynthetic Analysis ◽  
Synthetic Routes ◽  
Verification Process

The systematic exploration of synthetic pathways to afford a desired product through quantum chemical calculations remains a considerable challenge. In 2013, Maeda et al. introduced ‘quantum chemistry aided retrosynthetic analysis’ (QCaRA), which uses quantum chemical calculations to search systematically for decomposition paths of the target product and propose a synthesis method. However, until now, no new reactions suggested by QCaRA have been reported to lead to experimental discoveries. Using a difluoroglycine derivative as a target, this study investigated the ability of QCaRA to suggest various synthetic paths to the target without relying on previous data or the knowledge and experience of chemists. Furthermore, experimental verification of the seemingly most promising path led to the discovery of a synthesis method for the difluoroglycine derivative. The extent of the hands-on expertise of chemists required during the verification process was also evaluated. These insights are expected to advance the applicability of QCaRA to the discovery of viable experimental synthetic routes.

Partial timbre sound synthesis method and instrument

1986 ◽  
Vol 79 (4) ◽  
pp. 1201-1201
Author(s):  
Sydney A. Alonso ◽  
Cameron W. Jones
Keyword(s):  
Synthesis Method ◽  
Sound Synthesis

scholarly journals Sample-level sound synthesis with recurrent neural networks and conceptors

2018 ◽  
Author(s):  
Chris Kiefer
Keyword(s):  
Neural Networks ◽  
Recurrent Neural Networks ◽  
Frequency Control ◽  
Synthesis Method ◽  
Sound Synthesis ◽  
Boolean Logic ◽  
Training Data ◽  
Reservoir Computing ◽  
Research Questions ◽  
Granular Synthesis

Conceptors are a recent development in the field of reservoir computing; they can be used to influence the dynamics of recurrent neural networks (RNNs), enabling generation of arbitrary patterns based on training data. Conceptors allow interpolation and extrapolation between patterns, and also provide a system of boolean logic for combining patterns together. Generation and manipulation of arbitrary patterns using conceptors has significant potential as a sound synthesis method for applications in computer music and procedural audio but has yet to be explored. Two novel methods of sound synthesis based on conceptors are introduced. Conceptular Synthesis is based on granular synthesis; sets of conceptors are trained to recall varying patterns from a single RNN, then a runtime mechanism switches between them, generating short patterns which are recombined into a longer sound. Conceptillators are trainable, pitch-controlled oscillators for harmonically rich waveforms, commonly used in a variety of sound synthesis applications. Both systems can exploit conceptor pattern morphing, boolean logic and manipulation of RNN dynamics, enabling new creative sonic possibilities. Experiments reveal how RNN runtime parameters can be used for pitch-independent timestretching and for precise frequency control of cyclic waveforms. They show how these techniques can create highly malleable sound synthesis models, trainable using short sound samples. Limitations are revealed with regards to reproduction quality, and pragmatic limitations are also shown, where exponential rises in computation and memory requirements preclude the use of these models for training with longer sound samples. The techniques presented here represent an initial exploration of the sound synthesis potential of conceptors; future possibilities and research questions are outlined, including possibilities in generative sound.

Simulation and Optimization of Nonlinear Structures on Low Frequency Vibration and Noise of Lightweight Car Body

2021 ◽  
pp. 2140005
Author(s):  
X. P. Xie ◽  
T. Chai ◽  
Q. Sun
Keyword(s):  
Synthesis Method ◽  
Low Frequency ◽  
Combination Method ◽  
Good Effect ◽  
Frequency Noise ◽  
Complex Structures ◽  
Modal Strain Energy ◽  
Nonlinear Materials ◽  
Simulation And Optimization ◽  
Low Frequency Vibration

Accurate models, optimization methods and improvement measures are three key issues in the design and optimization of complex structures in the field of vibration and noise. Due to the increase of passenger vehicle structure complexity and lightweight demand, nonlinear materials and structures increase obviously in the whole system. Not only different structural adhesives are used to strong body structures under the lightweight requirement, but also the influence of the windshield should be considered in the structural design process. The first point of this paper is to use the model matching method to build an accurate finite element model that takes into account nonlinear materials and structures for the next optimization. Although the optimization method can also achieve structural improvement, it cannot find the regular conclusion that has a significant impact on the performance of the structure inherently. The second innovation is to propose a combination method of sensitivity analysis and modal strain energy (MSE) indication. The method not only finds a specific weak structure, but also summarizes viewpoints that the whole stiffness mismatch characters and the weak local structure destroyed balance of the whole structure. These conclusions provide the basis for further improvement. It is a difficult problem to solve low-frequency vibration and noise problem because of their long wavelength and strong penetration ability. As the third innovation point, three-dimensional phononic crystal simulation is done to optimize the low-frequency noise of structure in this paper. The synthesis method including the above three key points has a very good effect in suppressing low-frequency vibration and noise in the vehicle. This method is also suitable for simulation and optimization of other complex structures.

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