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排序方式: 共有193条查询结果,搜索用时 187 毫秒
41.
在对色彩心理学、色彩工学等各种现代色彩理论进行了研究后,比较和分析了现在国内外路面机械,特别是路面机械的外观现状,并结合经济、成本以及工学等多方面因素,提出了铣刨机色彩方案的设计原则和主要思路.进而考虑环境对产品的影响,路面机械色彩对人的心理作用,提出色彩效果与涂装质量并重,考虑效果的色彩和产品实际效果的差异等,最终给出铣刨机色彩方案的解决方法. 相似文献
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针对基于固定颜色集的直方图方法计算量与存储量过大,对亮度、噪声较敏感,参考颜色(reference colortable)方法受限于图像色彩分布的先验知识等弊端,提出了一种基于主颜色(domaincolor)的检索图像检索算法,在保持了较高的检索精度的同时,能够大大降低特征空间维度,提高检索性能。 相似文献
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Achallengingtaskoffutureintelligentvehiclesisroadfollowing .Itincludeslanedetection (whichmainlystudiesthelocalizationoftheroad ,thede terminationoftherelativepositionbetweenvehicleandroad ,andtheanalysisofthevehicle’sheadingdirection) ,andobstacledetection (whichmainlystudieslocalizationofpossibleobstaclesonthevehi cle’spath) .Lanedetectionistheproblemoflocat inglaneboundarieswithoutpriorknowledgeoftheroadgeometry .Moregenerally ,however,lanede tectionhasbeenreducedtothelocalizationofspecif… 相似文献
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应用两维彩色多普勤超声心动图诊断大动脉炎性心脏损害38例,发现这些患者存在心脏扩大、向心性左室肥厚、主动脉瓣关闭不全、二尖瓣返流、升主动脉瘤样扩张、冠状动脉损害、心肌梗塞并左室室壁瘤、二尖瓣狭窄、二尖瓣脱垂、心包积液、肺动脉高压等心脏病变。并伴有体动脉系统的狭窄、闭塞、扩张、动脉瘤改变。两维彩色多普勤超声心动图诊断大动脉炎性心脏损害简便、安全、准确、迅速,值得临床推广使用。 相似文献
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玻化砖色差的形成及克服 总被引:1,自引:0,他引:1
喻乐华 《华东交通大学学报》2001,18(1):52-54
比较系统地阐述了玻化砖主要缺陷之一-色差的类型、产生原因、影响因素及相应的克服办法。 相似文献
49.
为解决山区公路中驾驶视觉信息量难以量化的问题,对驾驶视野图像进行分割,根 据HSV颜色模型,提取视野图像的色调、饱和度、亮度值,再结合车速值,在驾驶视觉心理负荷的基础上,提出山区公路路域环境下的驾驶视觉信息量计算方法.通过实车实验,进行数据采集,并验证计算方法.计算结果表明,在半郁闭型空间行驶时,接收的视觉信息量最大;在郁闭型空间中,接收的信息量最小.计算结果与被试实际感受具有一致性,说明本文提出的驾驶视觉信息量计算方法具有可行性,可为路域环境的合理布设提供一定的技术参考. 相似文献
50.
O. V. Kopelevich S. V. Sheberstov O. Yunev O. Basturk Z. Z. Finenko S. Nikonov V. I. Vedernikov 《Journal of Marine Systems》2002,36(3-4)
Absolute values of chlorophyll a concentration and its spatial and seasonal variations in the Black Sea were assessed by using satellite CZCS and in situ data. Since the satellite CZCS had operated for the 1978–1986 period, CZCS data was used for assessing the past state of the Black Sea just before the onset of drastic changes observed in late 1980s. The approach used for the calculation of the absolute values of chlorophyll a concentration from CZCS data was based on the direct comparison of in situ chlorophyll a data and those of CZCS and by applying the algorithm developed for the transformation of CZCS data into chlorophyll a values. CZCS Level 2 data related with pigment concentration having a spatial resolution of 1 km at nadir were used. The daily Level 3 files were derived by binning Level 2 values into 4-km grid cells and the monthly and seasonal Level 3 files were created by averaging the daily Level 3 files over the corresponding period. In situ chlorophyll a data were obtained by spectrophotometric and fluorometric methods in 15 scientific cruises over the 1978–1986 period. Total number of ship-measured data used for the comparison with those CZCS values was 590.Chlorophyll a concentration (Chl) was derived from CZCS values (C) with regression equations Chl=kC; the coefficient of transformation k was calculated from six different data sets by taking into account distinctions between subregions and seasons. The reasons for difference in the k values have been analyzed.Statistical comparison of the chlorophyll a values measured in situ and those derived from CZCS data was based on log-transformed data and gave the following results: regression SLOPE=0.842, regression INTERCEPT=−0.081, coefficient of determination (R2)=0.806, root–mean–square ERROR=0.195. The mean monthly chlorophyll a distributions derived from CZCS data over 1978–1986 have been constructed and the mean seasonal chlorophyll a values in different regions have been calculated and analyzed. The significant difference in chlorophyll concentration between the western shelf regions and the open part of the Black Sea has been demonstrated, especially in warm season. At almost all seasons, the highest chlorophyll concentration is observed in the western interior shelf region which is under strong influence of Danube. The summer mean chlorophyll concentration in this region is 18 times higher than that in the open parts and about nine times higher than in the eastern shelf region. The greatest seasonal variations are observed in the open part of the Black Sea: chlorophyll concentration in cold season is four to six times higher than in summer and three to five times higher than in April and October. To the contrary, in the western interior shelf regions, the concentration is higher in May–October (about twice than that in November–March). Seasonal variations in the western outer shelf regions are smoothed out as compared with both the western interior shelf and the open regions. 相似文献