scholarly journals An algebraic approach for simultaneous solution of process and molecular design problems

2010 ◽  
Vol 27 (3) ◽  
pp. 441-450 ◽  
Author(s):  
S. Bommareddy ◽  
N. G. Chemmangattuvalappil ◽  
C. C. Solvason ◽  
M. R. Eden
2010 ◽  
Vol 34 (9) ◽  
pp. 1481-1486 ◽  
Author(s):  
Susilpa Bommareddy ◽  
Nishanth G. Chemmangattuvalappil ◽  
Charles C. Solvason ◽  
Mario R. Eden

Author(s):  
Susilpa Bommareddy ◽  
Nishanth Chemmangattuvalappil ◽  
Charles Solvason ◽  
Mario Eden

1985 ◽  
Vol 107 (1) ◽  
pp. 131-140 ◽  
Author(s):  
A. C. Wang ◽  
T. W. Lee

This paper presents a general theory for the dwell characteristics and for the synthesis of momentary-dwell mechanisms. Dwell conditions are obtained from the simultaneous solution of a set of equations derived recursively through the differentiations of a general form of displacement equation. A general synthesis approach is presented. It involves the use of analytical solutions of the lower-order dwell criteria as initial estimates and the development of a computer-aided procedure to subsequently readjust the mechanism proportions by heuristic optimization. The proportions thus obtained represent tradeoffs among higher orders of dwell and various prescribed kinematic and dynamic characteristics. For most practical purposes, such a solution is useful and acceptable. The coupler-dwell mechanism is used to illustrate the theory and approach. In particular, two mechanisms design problems are investigated. One deals with the kinematic synthesis of a six-bar coupler mechanism with shockless dwell and with prescribed unlimited crank rotations as well as optimum transmission; and the other concerns the design of a chain-linkage drive, including an analysis on the effect of the chain dynamics.


2021 ◽  
Author(s):  
Jeff Guo ◽  
Vendy Fialková ◽  
Juan Diego Arango ◽  
Christian Margreitter ◽  
Jon Paul Janet ◽  
...  

Abstract Reinforcement learning (RL) is a powerful paradigm that has gained popularity across multiple domains. However, applying RL may come at a cost of multiple interactions between the agent and the environment. This cost can be especially pronounced when the single feedback from the environment is slow or computationally expensive, causing extensive periods of nonproductivity. Curriculum learning (CL) provides a suitable alternative by arranging a sequence of tasks of increasing complexity with the aim of reducing the overall cost of learning. Here, we demonstrate the application of CL for drug discovery. We implement CL in the de novo design platform, REINVENT, and apply it on illustrative de novo molecular design problems of different complexity. The results show both accelerated learning and a positive impact on the quality of the output when compared to standard policy based RL. To our knowledge, this is the first application of CL for the purposes of de novo molecular design. The code is freely available at https://github.com/MolecularAI/Reinvent.


2018 ◽  
Vol 63 (1) ◽  
pp. 210-225 ◽  
Author(s):  
Gyula Dörgő ◽  
János Abonyi

We propose an efficient algorithm to generate Pareto optimal set of reliable molecular structures represented by group contribution methods. To effectively handle structural constraints we introduce goal oriented genetic operators to the multi-objective Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The constraints are defined based on the hierarchical categorisation of the molecular fragments. The efficiency of the approach is tested on several benchmark problems. The proposed approach is highly efficient to solve the molecular design problems, as proven by the presented benchmark and refrigerant design problems.


2021 ◽  
Author(s):  
Jeff Guo ◽  
Vendy Fialková ◽  
Juan Diego Arango ◽  
Christian Margreitter ◽  
Jon Paul Janet ◽  
...  

Reinforcement learning (RL) is a powerful paradigm that has gained popularity across multiple domains. However, applying RL may come at a cost of multiple interactions between the agent and the environment. This cost can be especially pronounced when the single feedback from the environment is slow or computationally expensive, causing extensive periods of nonproductivity. Curriculum learning (CL) provides a suitable alternative by arranging a sequence of tasks of increasing complexity with the aim of reducing the overall cost of learning. Here, we demonstrate the application of CL for drug discovery. We implement CL in the de novo design platform, REINVENT, and apply it on illustrative de novo molecular design problems of different complexity. The results show both accelerated learning and a positive impact on the quality of the output when compared to standard policy based RL. To our knowledge, this is the first application of CL for the purposes of de novo molecular design. The code is freely available at https://github.com/MolecularAI/Reinvent.


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