Search

为解决飓风来临前路径不确定时输电线路随机故障等带来的难题，提出了适用于含云计算 数据中心的电网韧性增强日前调度策略，并将其构建为两阶段风险规避的分布鲁棒优化问题。以 飓风对输电线路的时空影响为出发点，采用蒙特卡洛模拟获得飓风路径不确定时线路的离散故障 集合，并构建基于L1 距离度量的分布鲁棒模糊集合。然后，在日前调度中，对机组和数据中心进行优化以平衡经济性和电网韧性，并采用追索问题量化其对日间调度的影响，形成两阶段优化问题。随后，对优化问题进行确定性转换与解耦求解。最后，以含4 个数据中心的IEEE-RTS 系统为测试算例，验证了所提韧性增强策略应对模糊不确定性的有效性。 To manage the possible transmission line failures under uncertain hurricane tracks before its advent, a day-ahead resilience-enhanced scheduling scheme is proposed for power systems with cloud computing data centers. The scheme is formulated as a two-stage risk aversion distributionally robust optimization problem. Considering the spatial and temporal impacts of hurricanes on transmission lines, a discrete line failure set is generated by the Monte-Carlo simulation scheme, in which the hurricane path uncertainty is considered. This set is further formulated as a distributionally robust ambiguity set using L1 norm distance. In the day-ahead scheduling, the generators and data centers are scheduled to balance the operational efficiency and resilience, considering the impacts of day-ahead scheduling on intra-day scheduling, which is formulated as a recourse problem, and resulting in a two-stage optimization problem. It is reformulated to its robust counterpart and solved by decomposition algorithms. Finally, simulations are conducted on a modified IEEE reliability test system with 4 data centers, and the results verify the effectiveness of the proposed resilience-enhanced strategy in addressing the ambiguity uncertainty. Published version

Organic light-emitting devices based on molybdenum oxide(MoOx) doped 4,4’-bis(carbazol-9-yl)biphenyl(CBP) as a p-type doping hole injection layer was demonstrated.The devices comprise the following structure: ITO/MoOx/CBP∶MoOx/CBP/CBP:tris(2-phenylpyridine)iridium(III)(Ir(ppy)3)/4,7-diphenyl-1,10-phenanthroline(Bphen)/LiF/Al,where CBP acts as hole injection layer(HIL) and hole transport layer(HTL) as well as the host metarial of emitting layer(EML).The simple structure also has the the benefit of lowing the injection and transpotring barrier of holes.With the thickness of HIL increasing,the current density of device increases,indicating the p-type doping layer has a good performance of enhancing the holes injection.The performance of the device can be improved through optimizing the thickness of HIL and HTL.The maximum current efficiency of optimized device is 29.8 cd/A,which can be attributed to the more balanced distribution of carrier in EML.It is noteworthy that the efficiency roll-off of optimized device is only 17.7% between maximum and 20 000 cd/m2,comparing to that of conventional device(62.1%).The undoping CBP layer in optimized device can help to extend the distribution zone of excitons,reducing the possibility of triplet-triplet annihilation and triplet-polaron annihilation,this can be accounted for the improved efficiencies and reduced efficiency roll-off.

Ag was deposited onto Si/SiO2 substrate as anode,4,4,4-tris(3-methylphenylpheny-lamino)-triphenylamine(m-MTDATA):MoOx/m-MTDATA/N,N-bis-(1-naphthyl)-N,N-diphenyl-1,1-biphenyl-4,4-diamine(NPB) were used as hole-injected layer and hole-transporting layer,respectively.4,4-N,N-dicarbazole-biphenyl(CBP) doped with(1-(phenyl)isoquinoline) iridium(III) acetylanetonate(Ir(piq)2(acac)) was chosed as emitting layer.4,7-di-phenyl-1,10-phenanthroline(BPhen) worked as hole-blocking layer and electronic-transporting layer.LiF(1 nm)/Al(2 nm)/Ag(20 nm) were composite cathode.In order to improve the outcoupling character of the top-emitting device,an organic CBP layer was introduced above the cathode.Appropriate use of the optical outcoupling layer is helpful for improving the transmittance of the composit cathode film system,and caused the color of the emitting light moved to deep-red region.The angle-dependent properties of the devices were also investigated and the ones with optical outcoupling layer show better performance.And it is very meaningful to the production of high-quality displays.In further study,another 20 nm NPB doped with Ir(piq)2(acac) was introduced to form dual emitting-layer structure,and while the driving voltage of the devices did not significant increase due to the relative high hole mobility of NPB.Meanwhile efficient triplet energy transfer between the host and guest is obtained,the recombination zone is broadened and the non-radiative losses is reduced,seen from the experimental,the current efficiency and color purity are both improved for the dual emitting-layer devices compared with the single emitting-layer structures.

As existing filtering methods could not overcome the contradiction between noise removal and feature preserving for the light-spot signals on a CCD,the random error resulted from image noises has become a key constraint on the location accuracy of the light-spot images.Therefore,a filtering method named Attribute Distance Weighted Average(ADWA) is proposed to denoise the light-spot images.The method separates signals and noises based on their attributes,and alleviates the contradiction between noise removal and feature preserving of the signals progressively through introducing new attributes.Experimental results show that as compared with the bivariate ADWA based on "location" and "value"(2-ADWA/LV),the sub-pixel location accuracy of light-spot has been improved by more than 20% and the standard deviation of location reduced to 0.024 pixel by introducing a 3-ADWA/LVG formed by adding an attribute "gradient" to 2-ADWA/LV.It concludes that when the ADWA is used to denoise the light-spot image,the filtering performance can be further enhanced progressively in both noise removal and feature preserving through introducing new attributes.The ADWA gives a new effective way to further improve the sub-pixel location accuracy of the light-spot.

Winter wheat varieties require an extended low temperature period to initiate or accelerate the flowering process(vernalization).Spring wheat varieties do not have the vernalization requirement,and they would be exposed to a high risk of cold injury if sowed in low temperature.Correct evaluation of the winterness is the prerequisite to study and utilization of wheat germplasm,wheat production,and minimizing the cold injury.It also has certain theoretical significance when explaining the ecotype of wheat.Therefore,it′s of great importance to build an accurate method to evaluate vernalization characteristic of different wheat varieties.To address this issue,we investigated the growth characters of 12 wheat varieties under natural or artificial vernalization conditions,and proposed two reliable standards to evaluate the winterness of wheat. Twelve varieties,including Shannong8355,Jimai20,Jimai22,Shangnong14,Shannong15,Taishan008,Shannong664,Jimai19,Shannong16,Zimai12,Yannong19 and Shannong2413,were sowed every month from October to the following February.They experienced the winter and acquired vernalization naturally.For comparison,these twelve varieties were sowed every month from March to May after an artificial low temperature treatment was appllied from March to May next year.The temperature of artificial vernalization was set to 3℃,and the durations were 0d,10d,20d,30d,40d,50d,and 60d,respectively.The experiment was repeated twice in two years. The characters related to vernalization,such as number of spikes,spikelets and stem tillers,and thousand seed weight,were investigated.The datasets obtained from wheat that have been naturally or artificially vernalized were statistically compared.In addition,the growth cones of vernalized wheat planted in May were dissected and checked on the 20th day after emergence. The data was normalized first,followed by variance test and cluster analysis.The results showed,that the character of number of stem tillers,spikelets and thousand seed weight,were overlapping among different kinds of cultivars under natural and artificial vernalization,therefore the indexes above are not suitable to evaluate the strength of winterness of wheat.Neither can the number of wheat spikes under condition of natural vernalization,because it was affected by many factors,such as planting time and seeding rate.By contrast,the number of wheat spikes,under artificial vernalization that the effect of natural low temperature was eliminated,can serve as a good indicator to evaluate the strength of winterness.In addition,the shape of growth cone,which grows up about 20 days after emergence,is another indicator as good as the numbers of spikes. Based on the cluster analysis of the numbers of spikes under the conditions of artificial vernalization,the twelve wheat varieties surveyed here were divided into three categories,namely weak winterness,winterness and strong winterness.Shannong8355,Jimai20,Jimai22 and Shangnong14 belonged to weak winterness cultivars.Shannong15,Taishan008,Shannong664 and Jimai19 were winterness cultivars,and the strong winterness cultivars included Shannong16,Zimai12,Yannong19 and Shannong2413.This result is largely consistent with that obtained from observation of morphology characteristics,but the former gives more accurate evaluation for some varieties. As a conclusion,the number of spikes and shape of growth cone under artificial vernalization are two indicators of wheat winterness.When using this method,to avoid influence of natural low temperature,the daily maximum temperature should be higher than 12℃ at sowing stage.Meanwhile,the days of daily minimum temperature below 3℃ should be less than 4 days after planting.For evaluating vernalization characteristic of wheat in Shandong province,the temperature in April is suitable to sow after different time of artificial low temperature treatment.In other area,optimum planting date can be determined to satisfy the above temperature requirements.

An improved block density fast algorithm for steadying shaking image was presented.The jitter of camera system was measured by gyro,while the local motion vectors was estimated by the small area fast block-matching algorithm,and the global motion vector was calculated by least square method.Small area fast block-matching algorithm,which has high calculating precision,is good at calculating the local motion vectors.So the least square method can exactly calculate global motion vector by using parts of the local motion vectors.For this reason,the black density can be improved to speed up the algorithm and retain the precision of the global motion vector at the same time.The small area fast block-matching algorithm was optimized by analyzing the block gridding,and then the fast sensor electronic stabilization algorithm was designed.The simulation and experiment show that the algorithm is slightly more accurate and about 89% faster than the small area fast algorithm.

A novel scanning image stabilizing algorithm,predicting scanning motion and jumping in advance,is proposed based on sensor electronic image stabilization to process active scanning and passive scanning problems in a camera system.Firstly,it uses a gyro to detect the motion situation of the camera system and estimate the offset of image sequences.Then,it judges whether the scanning motion is in the camera system based on the estimated offsets.If the scanning motion exists,the reference frame will be converted into the predicting frame which is a image after scanning.Finally,the electronic image stabilization is used to process the motion vectors of image sequences.The algorithm is different from traditional image stabilizing algorithm.It transforms the image stabilization from scanning model to un-scanning model,so it greatly simplifies the image stabilizing process and reduces the complexity of algorithm.Furthermore,the proper step size and cache reference frame improve the accuracy and reliability of the algorithm.The experimental result shows that the algorithm can output stable images,meanwhile can display the scanning motions of image sequences correctly.