Wyniki wyszukiwania - BazTech

1

A Deep Q-Learning Network for ship stowage planning problem

Shen Y., Zhao N., Xia M., Du X.

Polish Maritime Research

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2017

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S 3

102--109

EN

Ship stowage plan is the management connection of quae crane scheduling and yard crane scheduling. The quality of ship stowage plan affects the productivity greatly. Previous studies mainly focuses on solving stowage planning problem with online searching algorithm, efficiency of which is significantly affected by case size. In this study, a Deep Q-Learning Network (DQN) is proposed to solve ship stowage planning problem. With DQN, massive calculation and training is done in pre-training stage, while in application stage stowage plan can be made in seconds. To formulate network input, decision factors are analyzed to compose feature vector of stowage plan. States subject to constraints, available action and reward function of Q-value are designed. With these information and design, an 8-layer DQN is formulated with an evaluation function of mean square error is composed to learn stowage planning. At the end of this study, several production cases are solved with proposed DQN to validate the effectiveness and generalization ability. Result shows a good availability of DQN to solve ship stowage planning problem.

2

Storage allocation in automated container terminals: the upper level

Xia M., Zhao N., Mi W.

Polish Maritime Research

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2016

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S 1

160--174

EN

Nowadays automation is a trend of container terminals all over the world. Although not applied in current automated container terminals, storage allocation is indispensable in conventional container terminals, and promising for automated container terminals in future. This paper seeks into the storage allocation problem in automated container terminals and proposed a two level structure for the problem. A mixed integer programming model is built for the upper level, and a modified Particle Swarm Optimization (PSO) algorithm is applied to solve the model. The applicable conditions of the model is investigated by numerical experiments, so as the performance of the algorithm in different problem scales. It is left to future research the lower level of the problem and the potential benefit of storage allocation to automated container terminals.

3

Polarization properties of Gaussian–Schell model quantization field in a turbulent marine-atmosphere

Zhao Y., Xia M., Wang Q., Li Y., Hu Z., Sun H., Zhang Y.

Optica Applicata

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2016

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Vol. 46, nr 3

335--345

EN

Polarization properties of Gaussian–Schell model quantization field propagating through the Kolmogorov turbulence of a marine-atmosphere channel are studied based on the degree of quantum polarization. The effective photon annihilation and creation operators of Gaussian–Schell model quantization field propagation in a marine-atmosphere are developed by making use of the extended Huygens–Fresnel integral of quantum field. The effects of the outer scale on the degree of polarization can be neglected. As the source transverse coherent width, the number of received photons, the inner scale of turbulent eddies, and the source transverse radius decrease or the re- fractive index structure parameter increases, the degree of polarization decreases. In theory, we find that the polarization fade of marine-atmosphere turbulence channels is larger than that of terrene-atmosphere turbulence channels under same transport parameters and the channel with a stronger turbulence strength will possess a larger detection area of a polarization signal, which have potentially important implications for free-space quantum key distribution.

4

A Novel Adaptive Fuzzy Controller Approach of Brushless DC Motors without Hall and Position Sensors

Liu Y., Xia M., Zhao J.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 12a

290-294

EN

This paper presents a novel adaptive fuzzy controller approach of brushless DC motors (BLDCM) without hall sensors. The fuzzy controller adopts fuzzy logic to retune the PID parameters online. Based on the mathematical model of BLDCM introduced, a novel adaptive fuzzy control strategies have been designed in MATLAB/SIMULINK. The results have been recorded under various operating conditions. The simulation results showed that the fuzzy PID controller made much better performance than the traditional PID controller in speed responses and system performance.

PL

W artykule opisano nową metodę sterowania bez szczotkowym silnikiem DC bez czujnika Hall'a, z wykorzystaniem regulatora adaptacyjnego opartego na logice rozmytej. Algorytm na bieżąco dostraja nastawy regulatora PID. Badania symulacyjne maszyny, przeprowadzone w programie Matlab-Simulink, wykazały znaczne polepszenie odpowiedzi regulatora PID, dla zadanych zmian.

5

Super-resolution reconstruction for underwater imaging

Chen Y., Li W., Xia M., Li Q., Yang K.

Optica Applicata

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2011

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Vol. 41, nr 4

841--853

EN

In order to enhance the visual quality of images obtained by underwater imaging systems, super resolution (SR) reconstruction is introduced, including single-frame and multi-frame SR algorithms. Experimental images from a range-gated pulsed laser imaging system are processed by SR algorithms, results are evaluated and compared by blind, objective quality metrics. Results show that the image quality of underwater imaging can be effectively enhanced if the appropriate SR reconstruction algorithm is chosen.

6

Analysis of uniform illumination system with imperfect Lambertian LEDs

Tan J., Yang K., Xia M., Yang Y.

Optica Applicata

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2011

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Vol. 41, nr 3

507--517

EN

This paper offers a novel algorithm to better design LEDs arrays for illumination systems. First, the illuminance distribution of LED arrays is studied through theoretical analysis. Second, we present the algorithm criterion and steps. And finally, we use computer to simulate and verify this method. The results show that the illumination uniformity is significantly affected by the spacing of each light in the LED array. The analysis method presented here in this thesis can be usefully applied in LED in the illumination engineering.