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排序方式: 共有422条查询结果,搜索用时 15 毫秒
91.
Harun Kemal Ozturk Olcay Ersel Canyurt Arif Hepbasli Zafer Utlu 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2013,35(8):715-725
Since 1975, there has been a great deal of interest, particularly during the past decade, in the promising genetic algorithm (GA) and its application to various disciplines from medicine to cogeneration. However, the studies performed on energy-related GA modeling are relatively low in numbers. The main objective of the present study is to develop the exergy input/output estimation equations in order to estimate the future projections based on the GA notion. In this regard, the GA Future Total EXergy Input/Output Estimation Models (GAFTEXIEM/GAFTEXOEM) are used to estimate total exergy input/output demand of Turkey, which is selected as an application country, based on the economic and social indicators of gross domestic product (GDP), population, import, export and house production figures. The future prediction of Turkey's total exergy input/output values are projected between 2003 and 2023. It may be concluded that the models proposed here can be used as an alternative solution and estimation techniques to available estimation techniques. It is also expected that this study will be helpful in developing highly applicable and productive planning for energy policies. 相似文献
92.
İbrahim Uslu Arda Aytimur Mustafa Kemal Öztürk Serhat Koçyiğit 《Ceramics International》2012,38(6):4943-4951
In this study, a new method to synthesize neodymium doped ceria ceramic nanopowders by the electrospinning of the hybrid polymers solution of their composite precursor was put forward. Calcined and sintered nanopowders were characterized by FT-IR, XRD, BET, SEM, and AFM techniques. According to the XRD analysis, the obtained powders are single phase and independent of the dopant concentration in the range investigated. The crystallite sizes were calculated using Scherrer equation. Moreover, lattice parameters, dislocation densities and microstrain values were calculated. BET results show that the increase of the neodymium doped content decrease the surface area of the composite powders, confirming the highly ordered micro and mesostructure. SEM and AFM results show that the samples have spherical grains. According to the surface roughness measurements, the increase in the amount of neodymium and the decrease in the amount of cerium decreased the surface roughness. 相似文献
93.
This paper shows how to embed complete binary trees in products of complete binary trees, products of shuffle‐exchange graphs,
and products of de Bruijn graphs with small dilation and congestion. In the embedding results presented here the size of the
host graph can be fixed to an arbitrary size, while we define no bound on the size of the guest graph. This is motivated by
the fact that the host architecture has a fixed number of processors due to its physical design, while the guest graph can
grow arbitrarily large depending on the application. The results of this paper widen the class of computations that can be
performed on these product graphs which are often cited as being low‐cost alternatives for hypercubes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
94.
Kadir Kavaklioglu Halim Ceylan Harun Kemal Ozturk Olcay Ersel Canyurt 《Energy Conversion and Management》2009,50(11):2719-2727
Artificial Neural Networks are proposed to model and predict electricity consumption of Turkey. Multi layer perceptron with backpropagation training algorithm is used as the neural network topology. Tangent-sigmoid and pure-linear transfer functions are selected in the hidden and output layer processing elements, respectively. These input–output network models are a result of relationships that exist among electricity consumption and several other socioeconomic variables. Electricity consumption is modeled as a function of economic indicators such as population, gross national product, imports and exports. It is also modeled using export–import ratio and time input only. Performance comparison among different models is made based on absolute and percentage mean square error. Electricity consumption of Turkey is predicted until 2027 using data from 1975 to 2006 along with other economic indicators. The results show that electricity consumption can be modeled using Artificial Neural Networks, and the models can be used to predict future electricity consumption. 相似文献
95.
Ali Kemal Şehirlioğlu Cenk Özler 《The International Journal of Advanced Manufacturing Technology》2008,35(7-8):769-777
The response surface methodology (RSM) approach can be used to determine the optimal component tolerances in an assembly.
Frequently, response surface designs such as Box-Behnken design and central composite design are used in tolerance allocation
problems. In this article, mixture experiments, which are essentially constructed for designing a blend composition, are proposed
instead of response surface designs in order to observe the cost values. Also some advantages and disadvantages of mixture
designs are discussed. 相似文献
96.
Design of a new three-degree of freedom spherical motor for photovoltaic-tracking systems 总被引:1,自引:0,他引:1
Photovoltaic (PV) panels directly convert the solar energy to electrical energy. The amount of electrical energy converted by PV panels mainly depends on incident solar radiation. Sun tracking systems can be used to maximize energy production since they ensure keeping the photovoltaic panels perpendicular to the incoming solar radiation. Spherical motors, which have the linear and circular movement ability in three independent dimensions, can be used for precisely tracking the sun as a solution. In this study, a spherical motor controlled by a micro-controller is designed for a PV-tracking system with the ability to move on two axes. Performance of PV-tracking system over a fixed tilted one is evaluated for the climate condition of Denizli, Turkey. The designed sun tracking system is observed to be improving this performance apparently using the output voltages obtained for one day. 相似文献
97.
Functionality of electronic commerce enabling technologies is dependent upon pervasive networks that a large number of applications share. Given the scarcity of network resources, it is imperative to allocate existing resources based on the actual needs of its users. In this paper, we study a two sided matching algorithm that enables such an allocation using tools from matching literature. Network system deploys intelligent agents that negotiate terms of allocation assignments with other intelligent agents that represent the users. We report the time complexity of the algorithm and give an example on how the mechanism performs. 相似文献
98.
99.
Karal-Yilmaz O Kayaman-Apohan N Misirli Z Baysal K Baysal BM 《Journal of materials science. Materials in medicine》2006,17(3):213-227
Multiblock terpolymer of poly(L-lactic acid)/ poly(ethylene oxide)/poly(L-aspartic acid), (PLLA/PEO/ PAsp) was synthesized
by ring opening polymerization of β -benzyl L-aspartate N-carboxyanhydride, Asp(OBzl)-NCA with α-ω -hydroxy terminated triblock
PLLA/PEO/PLLA copolymer.
The resulting multiblock terpolymer was characterized by several techniques including Fourier transform infrared spectroscopy
and differential scanning calorimetry.1H nuclear magnetic resonance spectra indicated the molar ratio of PLLA/PEO/PAsp (OBzl) to be 86/10/4.
Thermal gravimetric analysis and environmental scanning electron microscopy data showed that PLLA/PEO/PAsp had crystalline
and brittle structure. In order to improve its mechanical and physical properties, the terpolymer was blended with high molecular
weight poly(L-lactic-co-glycolic acid) copolymer, PLGA(85/15) (Mw: 95000 gmol− 1) in 25/75 and 50/50 mole ratios.
The hydrolytical degradation properties of these polymers were studied. Degradation experiments were performed during a 48-day
period in pH:7.4 phosphate-buffered saline (PBS) at 37∘C. The observed molecular weight losses were 91% and 67% for the 25/75 and 50/50 mixtures, respectively. In vitro attachment
and growth of L929 mouse fibroblasts on these biopolymers were also investigated. Cell growth experiments indicated that the
copolymer blend allowed the attachment and growth of cells. 相似文献
100.
Toughening of unmodified polyvinylchloride through the addition of nanoparticulate calcium carbonate
PVC/CaCO3 polymer nanocomposites of differing compositions were produced using a two-roll mill and compression molding. The morphology was observed using transmission electron microscopy, and the static and dynamic mechanical and fracture properties determined. The presence of nanometer-sized CaCO3 particles led to a slight decrease in the tensile strength but improved the impact energy, the storage modulus and the fracture toughness. Fracture surface examination by scanning electron microscopy indicated that the enhanced fracture properties in the nanocomposites were caused by the assisted void formation at the particles. This hypothesis is supported by a microstructure-based finite element modeling based upon elastic-plastic deformation around a weakly bonded particle. Hence, this provides an explanation of both the uniaxial tensile behavior and enhanced toughness of the nanocomposites. 相似文献