this paper demonstrates a new lossless compression framework. the (A-M) code is a hybrid technique of three major components. the first component is a fixed dictionary (A-M dictionary) of gathered symbols where the wo...
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ISBN:
(纸本)9781467358149;9781467358125
this paper demonstrates a new lossless compression framework. the (A-M) code is a hybrid technique of three major components. the first component is a fixed dictionary (A-M dictionary) of gathered symbols where the word length might one of three lengths;8, 10 or 12 bits each. the second component is the AM transform that applies over the input text file in order to generate the A-M intermediate code with a compression ration up to 25% of the original file. the third component is used to apply a customized variable-length code such as Huffman algorithm in order to achieve the final output. After illustrating each part of the algorithm;two case studies with comparison to famous lossless compression techniques are shown with results. Finally, next steps for enhancement and open research issues to improve the A-M algorithm are discussed.
Purpose the purpose of this study is to present a hybrid approach to model and predict long-term energy peak load using Bayesian and Holt-Winters (HW) exponential smoothing techniques. Design/methodology/approach Baye...
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Purpose the purpose of this study is to present a hybrid approach to model and predict long-term energy peak load using Bayesian and Holt-Winters (HW) exponential smoothing techniques. Design/methodology/approach Bayesian inference is administered by Markov chain Monte Carlo (MCMC) sampling techniques. Machine learning tools are used to calibrate the values of the HW model parameters. Hybridization is conducted to reduce modeling uncertainty. the technique is applied to real load data. Monthly peak load forecasts are calculated as weighted averages of HW and MCMC estimates. Mean absolute percentage error and the coefficient of determination (R-2) indices are used to evaluate forecasts. Findings the developed hybrid methodology offers advantages over both individual combined techniques and reveals more accurate and impressive results with R-2 above 0.97. the new technique can be used to assist energy networks in planning and implementing production projects that can ensure access to reliable and modern energy services to meet the sustainable development goal in this sector. Originality/value this is original research.
Large scale megawatt wind farms like the Adama wind farm and Ashegoda is being integrated into the Ethiopian Electric Power System. the location of Adama wind farm is about 95 km from Addis Ababa (the capital city of ...
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ISBN:
(纸本)9781467366014
Large scale megawatt wind farms like the Adama wind farm and Ashegoda is being integrated into the Ethiopian Electric Power System. the location of Adama wind farm is about 95 km from Addis Ababa (the capital city of Ethiopia) and 3km from Adama town, with an altitude elevation of 1824 similar to 1976m. the central geographical position of the wind farm is 39 degrees 13'48 '' E, 8 degrees 32'41 '' N. the Adama wind farm has two parts named by Phase-1 and Phase-2 with installed capacity of 51 MW and 153 MW respectively. Both Wind farms use variable speed wind turbines. However, the wind turbine type of Adama Phase-1 wind farm is a permanent magnet synchronous generator direct derive wind turbine (PMSG WT) while Adama phase-2 wind turbine is doubly fed induction generator wind turbine (DFIG WT). In this study the dynamic behavior of these wind turbines under fault conditions is discussed. the dynamic modeling of major components involved in wind energy conversion systems like aerodynamic modeling of the turbine rotor, dynamic modeling of generator, shaft system, drive train, controllers, converters, and other components that are involved in wind energy conversion process is done. modeling and simulation of wind turbines (both PMSG WT and DFIG WT) are done by the DigSILENT PowerFactory simulation tool. the wind farms (both phase-1 and phase-2) are modeled by aggregated modeling approach and tested for Fault Ride-through capability during three phase short circuit fault on the electric grid near to the wind farms. the simulation results showed that the integration of the wind farms to Ethiopian Electric Power Utility (EEU) network is feasible with respect Fault ride-through capability.
Digital production and logistic enterprise systems are complex systems, in terms of layout variability, control strategies, business processes and system parameter. All of these aspects are not independent and even du...
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ISBN:
(纸本)9781450366199
Digital production and logistic enterprise systems are complex systems, in terms of layout variability, control strategies, business processes and system parameter. All of these aspects are not independent and even due to the system dynamics the optimal solution may differ depending on the actual situation applying specific requirements. the planning, optimization and operation of these complex systems requires modern, data and simulation driven multi criteria decision approaches. simulation based analyses can be uses through all phases on different planning and operating levels. In order to improve operative decision making in production and logistic enterprises the digital twin concept, using virtual clones of real systems or subsystems, can be applied. Due to improved network and computing power operative simulation concepts are starting now to be realized in industrial practice.
In order to verify whether the building can meet the requirements of safe evacuation during a fire or not, finding an optimum design of the smoke exhaust system, the author used Pyrosim software to establish the fire ...
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ISBN:
(纸本)9781450366199
In order to verify whether the building can meet the requirements of safe evacuation during a fire or not, finding an optimum design of the smoke exhaust system, the author used Pyrosim software to establish the fire model for the Dongyuan Building, a crowd-intensive public commercial space glutted with restaurants. the fire simulation model was used to simulate to simulate the performance of three types of air vents, each is in 5 different air velocities when two most likely kinds of fire source are on fire respectively. Using the temperature area proportional method of proposed an optimization scheme for the simulation results and verifying its optimization effect. the appropriate air vent position, the air flowrate and a feasible optimization scheme, which can enhance the requirement for the safe evacuation of personnel in the fire event.
this paper presents an adaptive control scheme for a hyper-redundant robot articulated nimble adaptable trunk (ANAT) subject to spatial constraints. An optimization scheme is applied to avoid obstacles in 3D space pre...
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this paper presents an adaptive control scheme for a hyper-redundant robot articulated nimble adaptable trunk (ANAT) subject to spatial constraints. An optimization scheme is applied to avoid obstacles in 3D space present in the robot's trajectory by using redundancy, and to prevent the robot from retracting and crashing into the base by setting a security envelop. the generation of the trajectory with obstacles avoidance is performed by calculating the differential inverse kinematics of the robot based on the generalized inverse function. the obstacles are modeled by hyper-surfaces in order to reduce calculations and improve the computation time. When the optimal trajectory is attained in presence of the imposed constraints, an adaptive control law is applied to the robot. simulation results showed the effectiveness of the proposed approach. (c) 2006 IMACS. Published by Elsevier B.V. All rights reserved.
In this paper, the unmanned surface vehicle (USV) turning test and zig-zag test are performed and the test data are acquired. the identification mathematical model of the turning and zig-zag test has been established ...
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ISBN:
(纸本)9781450366199
In this paper, the unmanned surface vehicle (USV) turning test and zig-zag test are performed and the test data are acquired. the identification mathematical model of the turning and zig-zag test has been established respectively, which has been connected withoptimization algorithms including roulette genetic algorithm and growth mechanism genetic algorithm. Optimal identification results are achieved by means of the identification computation. the fitting turning diameter formula and the fitting turning index and the rudder index formula are obtained conclusively, which can provide reference for the investigation of the maneuvering motion mode of USV.
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