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Learning-Driven Exploration for Reinforcement Learning
Muhammad Usama,Dong Eui Chang 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10
Effective and intelligent exploration remains an unresolved problem for reinforcement learning. Most contemporary reinforcement learning relies on simple heuristic strategies which are unable to intelligently distinguish the well-explored and the unexplored regions of state space, which can lead to inefficient use of training time. We introduce entropy-based exploration (EBE) that enables an agent to explore efficiently the unexplored regions of state space. EBE quantifies the agent’s learning in a state using state-dependent action values and adaptively explores the state space, i.e. more exploration for the unexplored region of the state space. We perform experiments on a diverse set of environments and demonstrate that EBE enables efficient exploration that ultimately results in faster learning without having to tune any hyperparameter. The code to reproduce the experiments is given at https://github.com/Usama1002/EBE-Exploration and the supplementary video is given at https://youtu.be/nJggIjjzKic.
Bioactive Anthraquinones from Endophytic Fungus Aspergillus versicolor Isolated from Red Sea Algae
Usama W. Hawas,Ahmed Atef El-Beih,Ali M. El-Halawany 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.10
The marine fungus Aspergillus versicolor was isolated from the inner tissue of the Red Sea green alga Halimeda opuntia. The fungus was identified by its morphology and 18s rDNA. Cultivation of this fungal strain led to a new metabolite named isorhodoptilometrin-1-methyl ether (1) along with the known compounds emodin (2), 1-methyl emodin (3), evariquinone (4), 7-hydroxyemodin 6,8-methyl ether (5), siderin (6), arugosin C (7), and variculanol (8). The structures were elucidated on the basis of NMR spectroscopic analysis and mass spectrometry. The biological properties of ethyl acetate extract and compounds 1-3 and 6-8 were explored for antimicrobial activity, anti-cancer activity and inhibition of Hepatitis C virus (HCV) protease.
Estimation of Hybrid Vigor of Some Egyptian Single Local Hybrids of Mulberry Silkworm, Bombyx mori L
( Usama Mohamed ),( Mohamed Ghazy ) 한국잠사학회 2012 International Journal of Industrial Entomology Vol.25 No.2
Fifteen races resulted from silkworm breeding programat Sericulture Research Department (SRD) were used for hybridization. Fourteen hybrids were obtained and coded as; Giza C, D, R, S, T, U, A, V, W, P, H, L and Qanater 1, 2. The traits of cocoon weight, cocoon shell weight, pupal weight, cocoon shell ratio, silk productivity, fifth instar duration, total larval duration, number of cocoon per liter and pupation ratio were evaluated. Data were analyzed by using three formulae of heterosis over better, mid and checkparent values. Hybrids of Giza V, C, N, Qanater 1 and2 are promising and could be used in commercial cocoon production. Generally, there are some new hybrids can be exploited in commercial scale. Also, the local races can be evolved using the hybridization, inbreeding and selection program.
Usama Al-Mulali,Chor Foon Tang,Bee Wah Tan,Ilhan Ozturk 한국자원공학회 2019 Geosystem engineering Vol.22 No.1
This paper investigates the electricity-growth nexus of Gulf Cooperation Council (GCC) member countries from 1980 to 2014. To achieve the goal of this research, both panel cointegration and causality approaches are utilised to examine the long-term and causal relationships between variables. Empirical results confirm the presence of cointegration between variables. Moreover, this study finds that electricity consumption affects the long-term economic growth. Given that GCC member countries are energy-dependent economies, policies that aim to conserve energy consumption may jeopardise economic growth.
( Usama M. Ghazy ),( Tahia A. Fouad ) 한국잠사학회 2021 International Journal of Industrial Entomology Vol.42 No.2
Many researchers are using the heterosis, heterobeltiosis and hybrid vigour over check parent value formulae to determine the hybrid vigour for animals, plants and silkworm breeding. These formulae are ideal for determine the hybrid vigour for the positive direction of single trait. It is difficult using these formulae for multiple traits. Suggested modification for cardinal formulae were made as well as suggestion new formula for determines hybrid vigour for multiple traits. Modifications of hybrid vigour were made to facilitate judgment of best hybrids under study for multiple traits. Nineteen local hybrids of mulberry silkworm were prepared for these investigations in addition the imported Bulgarian hybrid. Comparison between the cardinal and the modifications formulae were applied for thirteen economic characters. Nine positive and four negative direction characters were observed. Modified formulae make the judgment of heterobeltiosis, heterosis and hybrid vigour over check parent value very facilitate for positive and negative traits.
Analysis of the machinability of GFRE composites in drilling processes
Usama. A. Khashaba,Mohamed S. Abd-Elwahed,Khaled I. Ahmed,Ismail Najjar,Ammar Melaibari,Mohamed A Eltaher 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.4
Drilling processes in fiber-reinforced polymer composites are essential for the assembly and fabrication of composite structural parts. The economic impact of rejecting the drilled part is significant considering the associated loss when it reaches the assembly stage. Therefore, this article tends to illustrate the effect of cutting conditions (feed and speed), and laminate thickness on thrust force, torque, and delamination in drilling woven E-glass fiber reinforced epoxy (GFRE) composites. Four feeds (0.025, 0.05, 0.1, and 0.2 mm/r) and three speeds (400, 800, and 1600 RPM) are exploited to drill square specimens of 36.6x36.6 mm, by using CNC machine model “Deckel Maho DMG DMC 1035 V, ecoline”. The composite laminates with thicknesses of 2.6 mm, 5.3 mm, and 7.7 mm are constructed respectively from 8, 16, and 24 glass fiber layers with a fiber volume fraction of about 40%. The drilled specimen is scanned using a high-resolution flatbed color scanner, then, the image is analyzed using CorelDraw software to evaluate the delamination factor. Multi-variable regression analysis is performed to present the significant coefficients and contribution of each variable on the thrust force and delamination. Results illustrate that the drilling parameters and laminate thickness have significant effects on thrust force, torque, and delamination factor.