低对比度环境下运动目标光学相关检测技术

在用光电混合联合变换相关器对运动目标进行检测的过程中,为了在提高运算速度的前提下解决运动目标在低对比度环境中所导致的低识别率问题,提出一种基于提升小波的边缘检测算法,该算法能在将目标边缘准确地从低对比度环境中提取的同时,将传统小波变换的计算量减少一倍,显著提高运算速度,满足运动目标检测在处理速度上的需求。将该算法应用于光学相关检测,并结合瞬态模板方法可改善目标的识别率,提高在低对比度环境下运动目标检测的效率。对大量具有低对比度特点的运动序列进行光学相关实验,验证了算法对低对比度环境下运动目标检测的可行性。

一个永恒的命题——我看《谁说我不在乎》

记得好些年前曾流行过“理解万岁” 这么一句充满着人文意义的话语,后来,不知为什么这句话渐渐地淡出了我们的生活,再后来,随着市场经济带来的交换法则的崛起,这句话似乎便有些销声匿迹了。但“理解万岁”从此却成了我心中的一个情结,我总对交换法则对情感世界的正当侵入抱着一种怀疑,我不相信我们的情感、我们的世界真的能离开理解。那天,当《谁说我不在乎》出现在我眼前的银幕上时,我鄂然,我惊喜:“理解万岁”并没有从我们的意识中消失。通过黄建新的眼光,“理解万岁” 虽然显得有些陌生,但却因沧桑的磨励却更加成熟与深刻了。只不过这种深刻与成熟是潜藏在一种荒诞之中的,如果不经意,也许便会在黑色的幽默间被笑声无意遮盖。 在表层,《谁说我不在乎》

Statistical Evaluation and Regression Analysis of Vehicle Sound Quality

A statistical approach to evaluate the subjective perception of the annoyance caused by the vehicle noise was presented in this paper. After recording the noises of Sanfeng, Huali and Xiali at speeds of 30, 40, 50, 60, 70 and 80 km/h respectively, the annoyance of the vehicle noises was evaluated in the testing room using paired comparison method, and the sound quality metrics and subjective annoyance were then distilled. Loudness, sharpness, roughness, periodicity and impulsiveness were selected for each of the vehicle noises. By correlation analysis method, it can be found that loudness has a higher correlation （0.91） with annoyance than other parameters. Meanwhile, sharpness, periodicity, roughness and impulsiveness have correlation with subjective perception with correlation coefficients being 0.84, -0.82, 0.62 and 0.87, respectively. The result of multiple regression analysis shows that calculated annoyance obtained by the regression equation can explain the perceptual annoyance and the regressed evaluation model is feasible to evaluate the sound quality of vehicle.

Neoproterozoic stratigraphic correlation of Subei-Huainan in China

Subei-Huainan in the southeastern margin of the North China platform is a key area of convergence of China’s north-south stratigraphic correlation of Neoproterozoic.Due to the lack of fossils,the Neoproterozoic stratigraphic correlation is still a difficulty in this area.The division of Neoproterozoic strata and the establishment of the correlation framework of the stratigraphic sequences have been done through recognizing the regularity of meter-scale cycles by measuring the outcrop of Neoproterozoic strata and using the Fischer diagram and the sea-level curve of transgressive-regressive by the maximum flooding sedimentary and molar teeth carbonate sedimentary.The maximum flooding sedimentary which becomes cycle sequence comparison of sign is isochronous in the same basin and is a key of cycle sequence comparison although paleogeographic environment and sedimentary sequence may be different in the sedimentary strata of the same geologic time.Molars carbonates,having specific geological distrution time and depositional environment and mainly developing in the ramp environment of the platform edge in the 1500-650 Ma,are the new symbol of the stratigraphic correlation in the Neoproterozoic.Because of the missing of the fossil record,the maximum flooding and the molar-teeth carbonate sedimentary,as the new research ideas,are used in stratigraphic division and correlation.

Success of native and invasive plant congeners depends on inorganic nitrogen compositions and levels

Aims Successful plant invaders usually exhibit three strategies:Jack-of-all-trades(more robust in stressful sites),Master-of-some(more responsive in favorable sites)and Jack-and-master(both robustness and responsiveness).To revisit these strategies,we examined how soil inorganic nitrogen(N)compositions and levels influence the success of native and invasive plant congeners in the context of plant communities.Methods We conducted an experiment involving three fixed factors:species origin,N composition and N level.Here,we selected 21 plant species(eight pairs of invasive and native congeners and five non-congeneric natives)to assemble plant communities,which were subject to nine N environments consisting of three N compositions(3:1,2:2 and 1:3 NO3−/NH4+)and three N levels(low,medium and high N).We determined the following metrics:total biomass,relative biomass(a proxy of species success),mortality rate and mortality time.Important Findings Across nine N environments,native and invasive congeners exhibited similar total biomass,relative biomass and mortality time,but invaders had a marginally lower mortality rate than natives.Similar success between native and invasive congeners was linked to their similar growth and tolerance.N compositions influenced mortality time and N levels affected the total biomass and relative biomass.Importantly,species origin,N composition and N level interactively affected the total biomass,relative biomass and mortality time.These findings suggest that native and invasive plant congeners may be similarly successful across different N environments,and that inorganic N compositions and levels both contribute to plant invasion success.

The effect of air exposure on device performance of flexible C8-BTBT organic thin-film transistors with hygroscopic insulators

Organic thin film transistors(OTFTs)are normally sensitive to ambient conditions and show performance degradation in air.On the contrary,the performance of flexible 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene(C8-BTBT)OTFTs using cross-linked polymer layer,poly(4-vinyl-phenol)-4,4’-(hexafluoroisopropylidene)diphthalic anhydride(PVP-HDA),as the dielectric layer can be improved in air conditions with 40%relative humidity.Under soaking in air with 40%relative humidity,the electrical behavior,surface morphology,and contact angle of the flexible C8-BTBT OTFTs using PVP-HAD as dielectric layer with three different thicknesses were investigated.It is found that,when the devices with 375 nm-thick PVP-HDA films are placed in 40%relative humidity air conditions for 6 h,the corrected average mobility(μ)can increase from 3.2 to 5.1 cm^2 V^-1 s^-1.Furthermore,the average threshold voltage(Vth)changes from-12.4 to-9.3 V while keeping a constant ratio of I on/Ioff=10^4.These results indicate that the flexible C8-BTBT OTFTs with PVP-HDA dielectric layer exhibit interesting application prospects.