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自适应视野的人工鱼群算法求解最短路径问题简 总被引:1,自引:0,他引:1
针对基本人工鱼群算法的参数视野固定不变导致算法后期收敛速度慢、运算量大、易陷入局部最优等问题,提出自适应视野的改进人工鱼群算法。改进后的算法只对人工鱼的觅食行为的视野进行调整,使其随着算法的迭代次数的增加而逐渐减小,但当视野小于初始值的一半时,停止减小,使其等于初始值的一半。将提出的改进型人工鱼群算法应用到求解基于道路网络的最短路径问题中,并通过实验证明了改进后的人工鱼群算法比基本人工鱼群算法及蚁群优化算法收敛速度快、计算量小,而且更加准确和稳定。 相似文献
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本文提出了一种基于改进人工鱼群算法的无线传感器网络覆盖优化策略.通过对人工鱼群视野范围和步长的自适应调整,提高了算法的寻优精度、收敛速度以及稳定性;再结合WSN网络覆盖的性能,使网络覆盖得以优化.仿真结果表明,改进的人工鱼群算法优化的网络覆盖率比基本人工鱼群算法的网络覆盖率提高了17%. 相似文献
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目前现行的电力系统无功优化所用的人工智能算法都会存在易局部收敛和收敛速度慢等问题。为了克服上述问题,文中选取人工鱼群算法并对算法中一些参数进行调整,在步长选择上采取变尺度,并引入评价函数,对于视野范围和拥挤度因子上采用动态调整。文中将系统有功网损作为目标函数,利用改进的人工鱼群算法实现电力系统无功优化。通过IEEE-30节点仿真系统计算,证明改进的人工鱼群算法在电力系统无功优化上的可行性和有效性。 相似文献
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针对标准人工鱼群算法解精度不高的缺点,文章提出了动态自适应人工鱼群算法,使人工鱼群算法的两个重要参数—步长和视野实现动态自适应调整,使鱼群中的个体在早期具有较大的步长和较宽阔的视野,以保证算法具有较快的收敛速度和较广阔的搜索范围,而在后期逐渐转入精细的局部搜索,使算法的解精度得以提高。并通过实验对比证明动态自适应人工鱼群算法的解精度优于标准人工鱼群算法。 相似文献
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无人机(UAV)路径规划的目标是在考虑地形威胁和高度约束的条件下,得到一条尽可能高效的安全飞行路径。袋獾优化算法是一种模拟袋獾进食的两种行为来寻求最优解的元启发式算法。在袋獾优化算法(TDO)的基础上,结合自适应权重方式减少陷入局部最优的情况,还引入limit阈值思想,可以更好地平衡全局搜索和局部收敛。首先通过六个测试函数,将改进后的算法与多种算法进行对比实验,验证算法的高效性。然后建立两个不同的地图模型,将三维路径的长度视为适应度函数,通过与粒子群算法、人工鱼群算法及蚁群算法共同求解三维路径规划问题,验证改进算法的可行性。实验结果表明,改进后的算法有更快的收敛速度和更高的收敛精度,不易陷入局部最优,而且在三维路径规划问题中具有更好的求解能力。 相似文献
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为了提高路径覆盖测试数据生成效率,研究了路径自动分割方法并结合人工鱼群算法提出了一种路径覆盖测试数据生成方法.首先在分析变量与节点关系、变量与路径关系的基础上提出了路径分割的自动判定及分离算法,实现了变量对子路径有无影响的自动判定;其次引入Levy飞行策略和共轭梯度法对人工鱼群算法进行了改进;然后结合路径分离的结果和改进的人工鱼群算法实现路径覆盖测试数据的生成.在利用人工鱼生成测试数据的过程中,判断是否有人工鱼穿越分离的子路径.如果有,则记录人工鱼中穿越子路径相应的分量并在人工鱼的觅食、聚群及追尾等行为中固定这些分量,从而使得搜索空间不断减少.最后将提出的方法实现程序的测试数据生成,并与相关方法进行了比较.实验结果表明,本文方法在时间开销、成功率及算法稳定性等方面均具有优越性. 相似文献
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Meihua Shen Wilfred Pau Nicolas Gani Jianping Wen Shashank Deshmukh Thorsten Lill Jian Zhang Hanming Wu Guqing Xing 《半导体技术》2004,29(8)
This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration. 相似文献
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White organic light-emitting devices based on fac tris(2- phenylpyridine) iridium sensitized 5,6,11,12-tetraphenylnap -hthacene 总被引:1,自引:0,他引:1
We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure is ITO/2T-NATA (20 nm)/NPBX (20 nm)/CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/NPBX (5 nm)/DPVBi (30 nm)/Alq(30 nm)/LiF(0.5 nm)/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)- N,N' -diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir (PPY)3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V. 相似文献
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Complete approach to automatic identification and subpixel center location for ellipse feature 总被引:1,自引:0,他引:1
XUE Ting WU Bin SUN Mei YE Sheng-hua 《光电子快报》2008,4(1):51-54
To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction. 相似文献
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In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy. 相似文献
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High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center. 相似文献
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This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors. 相似文献
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Credence Systems Corporation 《半导体技术》2004,29(9)
Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V. 相似文献
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YUXiao-hua XIANGYu-qun 《半导体技术》2005,30(2):30-32,37
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB. 相似文献
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It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer (LDV). 相似文献