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基于机器视觉与机器学习的火龙果重量估计 被引量:1
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作者 梁英凯 商枫楠 +4 位作者 陈桥 肖明玮 罗陈迪 李文涛 周学成 《食品与机械》 CSCD 北大核心 2023年第7期99-103,共5页
目的:解决火龙果人工称重耗时、费力且成本高昂等问题,提出一种基于机器视觉和机器学习的自动化重量估计方法。方法:首先,对106个火龙果进行称重、记录重量并拍摄、构建火龙果图像。然后,对火龙果进行降噪和分割,得到火龙果的二值图像,... 目的:解决火龙果人工称重耗时、费力且成本高昂等问题,提出一种基于机器视觉和机器学习的自动化重量估计方法。方法:首先,对106个火龙果进行称重、记录重量并拍摄、构建火龙果图像。然后,对火龙果进行降噪和分割,得到火龙果的二值图像,并从中提取出火龙果像素面积、长轴像素长度和短轴像素长度3项图像特征。将以上图像特征与重量组合成数据集,按照7∶3比例将数据集划分为训练集和测试集。最后,将训练集输入梯度提升、随机森林、K近邻和人工神经机器模型中训练,并利用测试集进行模型评估。结果:人工神经网络评价指标相较于其他模型更优,决定系数为0.986,均方根误差为13.091。结论:该方法能够有效地完成火龙果重量估计,满足火龙果重量估计的要求。 展开更多
关键词 机器视觉 机器学习 火龙果 重量估计
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基于相似原理的液压泵重量估算方法研究
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作者 刘晓超 王振宇 +4 位作者 邱钟毅 齐鹏远 吴帅 尚耀星 焦宗夏 《液压与气动》 北大核心 2023年第2期117-124,共8页
液压系统是机载机电系统中的重要组成部分,飞机对液压系统的装机重量有严格要求。液压元件的重量直接影响到了液压系统的整体装机重量,提前对重要液压元件进行重量估计是元件设计阶段必须考虑的问题。提出了一种基于相似原理的液压泵重... 液压系统是机载机电系统中的重要组成部分,飞机对液压系统的装机重量有严格要求。液压元件的重量直接影响到了液压系统的整体装机重量,提前对重要液压元件进行重量估计是元件设计阶段必须考虑的问题。提出了一种基于相似原理的液压泵重量估计方法,利用pv值作为液压泵重量估计的重要约束条件,将液压泵重量估计的几何参数的相似比转换为性能参数的相似比,从而直观的进行任意参数液压泵的重量估计。通过对大量液压泵重量参数的统计,拟合出液压泵重量与功率和流量的匹配关系,并设计制造了液压泵进行试验称重,结果表明,基于相似原理的液压泵重量估计误差可以控制在4.8%以内,为机载液压系统重量估计提供了一种新的参考。 展开更多
关键词 机载液压系统 相似原理 重量估计 PV值 数据拟合
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基于机器视觉的水下鲆鲽鱼类质量估计 被引量:24
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作者 王文静 徐建瑜 +1 位作者 吕志敏 辛乃宏 《农业工程学报》 EI CAS CSCD 北大核心 2012年第16期153-157,共5页
为了更好地解决水下鲆鲽类等底栖鱼的质量估计问题,本研究获取了半滑舌鳎(Cynoglossus semilaevis)在不同生长阶段的图像和质量数据,利用图像处理技术测量出鱼的面积,并将面积与质量进行数据拟合建立模型。结果表明面积与质量的相关性... 为了更好地解决水下鲆鲽类等底栖鱼的质量估计问题,本研究获取了半滑舌鳎(Cynoglossus semilaevis)在不同生长阶段的图像和质量数据,利用图像处理技术测量出鱼的面积,并将面积与质量进行数据拟合建立模型。结果表明面积与质量的相关性可达到0.9682,测试平均相对误差为6.17%。由于鱼的质量还受其他形状参数的影响,同时测量了等效椭圆长短轴比和圆形度因子,对面积、等效椭圆长短轴比和质量,面积、圆形度因子和质量分别进行三维拟合,质量估计的平均相对误差分别为5.50%、5.62%。通过验证表明,对水底鱼拍摄的图像经过水底模板校准后的处理结果,与水外面拍摄处理后的结果一致,因此在不捕捞的情况下可以实现水底活体鲆鲽类鱼的质量估计。 展开更多
关键词 水产养殖 图像处理 摄像机 半滑舌鳎 重量估计 数据拟合
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民用飞机的重量设计 被引量:4
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作者 沈可正 《民用飞机设计与研究》 2001年第4期19-22,27,共5页
一、概述 民用飞机的重量设计是民用飞机型号研制中一项重要设计工作.它贯穿于民机型号的前期论证到方案设计、详细设计、试制、试飞及营运的整个过程.且民用飞机的重量设计有其自身特点.本文主要就民用飞机重量设计的重要性、设计内容... 一、概述 民用飞机的重量设计是民用飞机型号研制中一项重要设计工作.它贯穿于民机型号的前期论证到方案设计、详细设计、试制、试飞及营运的整个过程.且民用飞机的重量设计有其自身特点.本文主要就民用飞机重量设计的重要性、设计内容并着重对民机的重量预测、重量控制等几个方面作分析和探讨. 展开更多
关键词 民用飞机 重量设计 重量控制 重量估计
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水轮机空化空蚀分析软件设计 被引量:4
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作者 林良有 张伟 吴玉林 《大电机技术》 北大核心 2007年第1期37-40,共4页
本文从数据的测试与存储管理、信号数据的分析、空蚀失重量估计等方面介绍了水轮机空化空蚀软件的设计思路和方法。介绍了两种分析空化噪声的有效方法:多维空化分析和叶片通道频率分析;通过修正J.L.Gordon空蚀率估计公式,并结合工况和... 本文从数据的测试与存储管理、信号数据的分析、空蚀失重量估计等方面介绍了水轮机空化空蚀软件的设计思路和方法。介绍了两种分析空化噪声的有效方法:多维空化分析和叶片通道频率分析;通过修正J.L.Gordon空蚀率估计公式,并结合工况和空化噪声的分析计算,提出了空蚀失重量估计的思路,并在软件上加以实现。 展开更多
关键词 水轮机状态监测 空化噪声 多维空化分析 叶片通道频率调制 空蚀失重量估计
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车身
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《汽车车辆:英文版》 2005年第1期33-35,共3页
[ 篇名 ] A hybrid method for vehicle axle noise simulation with experimental validation,[ 篇名 ] A linearized turbulent production in the k- ε model for engineering applications,[ 篇名 ] A Method for Estimating Axl... [ 篇名 ] A hybrid method for vehicle axle noise simulation with experimental validation,[ 篇名 ] A linearized turbulent production in the k- ε model for engineering applications,[ 篇名 ] A Method for Estimating Axle Weights of In-motion Vehicles and Its Evaluation,[ 篇名 ] A new concept for occupant deceleration control in a crash - part 2,[ 篇名 ] A new experimental methodology to estimate chassis force transmissibility and applications to road NVH improvement,[ 篇名 ] A SMART ECOBIKE WITH RIM-MOTOR,[ 篇名 ] A study on optimum design for thin-walled beam structures of vehicles,[ 篇名 ] A study on the distortion characteristic due to spot welding of body structure assembly for passenger car,[ 篇名 ] A VIBRO-ACOUSTICAL INVESTIGATION FOR CAR ROLLING NOISE CHARACTERIZATION AND OPTIMIZATION,[ 篇名 ] 780 N/mm{sup }2 grade hot-rolled high-strength steel sheet for automotive suspension system。 展开更多
关键词 车身 噪声 车轴 重量估计 自动控制
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钢丝绳在使用中出现“走油”现象怎么办?
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《江苏安全生产》 2008年第10期48-48,共1页
答:在起重作业中,如果事先对物件的重量估计不足,用了承载力较小的钢丝绳,那么钢丝绳就会出现“走油”现象。当出现这种现象时,表明钢丝绳已经严重,超载,产生了较大的变形,钢丝绳的钢丝向绳芯挤压,使绳芯中的油大量挤出。如果... 答:在起重作业中,如果事先对物件的重量估计不足,用了承载力较小的钢丝绳,那么钢丝绳就会出现“走油”现象。当出现这种现象时,表明钢丝绳已经严重,超载,产生了较大的变形,钢丝绳的钢丝向绳芯挤压,使绳芯中的油大量挤出。如果再继续使用,就有断裂危险。因此,在作业中,当钢丝绳出现“走油”现象时,应当立即更换。 展开更多
关键词 钢丝绳 起重作业 重量估计 承载力 绳芯 危险
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Development of a mass model in estimating weight-wise particle size distribution using digital image processing 被引量:4
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作者 Maiti Abhik Chakravarty Debashish +1 位作者 Biswas Kousik Halder Arpan 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第3期435-443,共9页
Particle size distribution of coarse aggregates through mechanical sieving gives results in terms of cumu- lative mass percent. But digital image processing generated size distribution of particles, while being fast a... Particle size distribution of coarse aggregates through mechanical sieving gives results in terms of cumu- lative mass percent. But digital image processing generated size distribution of particles, while being fast and accurate, is often expressed in terms of area function or number of particles. In this paper, a mass model is developed which converts the image obtained size distribution to mass-wise distribution, mak- ing it readily comparable to mechanical sieving data. The concept of weight/particle ratio is introduced for mass reconstruction from 2D images of particle aggregates. Using this mass model, the effects of several particle shape parameters (such as major axis, minor axis, and equivalent diameter) on sieve-size of the particles is studied. It is shown that the sieve-size of a particle strongly depend upon the shape param- eters, 91% of its variation being explained by major axis, minor axis, bounding box length and equivalent diameter. Furthermore, minor axis gives an overall accurate estimate of particle sieve-size, error in mean size (D-50) being just 0.4%. However, sieve-size of smaller particles (〈20 ram) strongly depends upon the length of the smaller arm of the bounding box enclosing them and sieve-sizes of larger particles (〉20 mm) are highly correlated to their equivalent diameters. Multiple linear regression analysis has been used to generate overall mass-wise particle size distribution, considering the influences of all these shape parameters on particle sieve-size. Multiple linear regression generated overall mass-wise particle size distribution shows a strong correlation with sieve generated data. The adjusted R-square value of the regression analysis is found to be 99 percent (w.r,t cumulative frequency). The method proposed in this paper provides a time-efficient way of producing accurate (up to 99%) mass-wise PSD using digital image processing and it can be used effectively to renlace the mechanical sieving. 展开更多
关键词 Particle size distribution Image analysis Particle shape parameters Weight/particle ratio Sieve analysis
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Underpad weight to estimate urine output in adult patients with urinary incontinence
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作者 Benjamin T Galen 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2015年第2期189-190,共2页
To the Editor Monitoring urine output remains essential to the care of adult patients admitted to the hospital. In acute, decompen- sated heart failure, ongoing assessment of urine output is required to adjust diureti... To the Editor Monitoring urine output remains essential to the care of adult patients admitted to the hospital. In acute, decompen- sated heart failure, ongoing assessment of urine output is required to adjust diuretic dosing in keeping with current recommendations for hospitalized patients, In patients with acute kidney injury, assessment of urine output is essential for diagnosis and management. The diagnosis of circulatory shock is supported by renal hypoperfusion as measured by low urine output. Indwelling urinary cathe- ters are routinely used for the "strict" monitoring of urine output, which is an accepted indication. 展开更多
关键词 Heart failure: Urinary catheters Urine output
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Estimation of Fat-tail Weight by External Fat-tail Dimensions in Lori-Bakhtiari Sheep
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作者 M. A. Talebi M. Vatankhah 《Journal of Agricultural Science and Technology(A)》 2011年第8期1241-1244,共4页
In this study fat-tail weight was estimated by external fat-tail dimensions. External fat-tail dimensions included upper, middle and lower width, length, length of gap, depth, upper and middle circumference recorded o... In this study fat-tail weight was estimated by external fat-tail dimensions. External fat-tail dimensions included upper, middle and lower width, length, length of gap, depth, upper and middle circumference recorded on 1,482 head of Lori-Bakhtiari lambs at 6 months. Of these about 311 lambs were slaughtered at the age of six months. Prediction equations were derived for fat-tail weight by multiple regression analyses with two methods. The results showed that the measure of middle circumference fat-tail was as most important measure in estimation of fat-tail weight. The measure of middle circumference fat-tail accounted for 76 percent of variation in fat-tail weight. The regression equations for predicting fat-tail weight using external fat-tail dimensions obtained from stepwise regression procedure can be estimated only with using from the lower width, length, middle circumference fat-tail and body weight with high acc, uracy (0.92). Average of fat-tail weight estimated in the age of six months in lambs was 2.39 kg. The highest regression coefficient of external fat-tail dimensions on fat-tail weight observed for the length of fat-tail (0.095 kg). Results of the present investigation showed that fat-tail weight in live sheep of Lori-Bakhtiari, could be estimated by measuring external fat-tail dimensions. 展开更多
关键词 External dimensions fat-tail regression Lori-Bakhtiari SHEEP
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春节探源 猪年话猪
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作者 江梅 江舟 《中小学管理》 北大核心 1995年第1期47-47,共1页
春节探源猪年话猪春节是农历的新年。春,《前汉书·律历志》、《风俗通》诸书的解释为“春蠢也”。“蠢”是昆虫活动的意思,春来虫动,幼苗吐绿,万物兴旺,《公羊传》又注说:“春者,天地开辟之端,养生之道,法象所出,昏斗指... 春节探源猪年话猪春节是农历的新年。春,《前汉书·律历志》、《风俗通》诸书的解释为“春蠢也”。“蠢”是昆虫活动的意思,春来虫动,幼苗吐绿,万物兴旺,《公羊传》又注说:“春者,天地开辟之端,养生之道,法象所出,昏斗指东方日春。”春又被神化成为春神东君执掌... 展开更多
关键词 辛亥革命 大混战 青藏高原 《史记》 《公羊传》 二十四节气 季节变化 摩尔达维亚 估计重量 我国古代
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已亥话猪趣
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作者 江舟 《四川劳动保障》 1995年第1期19-19,共1页
最小的猪美国有一种与人同居,喜欢和人挨近,有如家中宠物的迷你猪,这种猪即使长成后也只有40多磅。最大的猪浙江省金华县山坑乡西坞村舒吉基养的一头猪,长得有黄牛那么高,估计重量达500公斤。产仔最多的猪山东省蒙阴县城郊乡一位农民喂... 最小的猪美国有一种与人同居,喜欢和人挨近,有如家中宠物的迷你猪,这种猪即使长成后也只有40多磅。最大的猪浙江省金华县山坑乡西坞村舒吉基养的一头猪,长得有黄牛那么高,估计重量达500公斤。产仔最多的猪山东省蒙阴县城郊乡一位农民喂养的一头母猪,曾一胎生下27只小猪仔,但这还不算是最多的。前苏联摩尔达维亚共和国一个育种国营农场饲养的一头母猪,曾一胎生28只小猪仔。香猪我国青藏高原上饲养的一种猪,由于跟随牧民不断搬家、奔走,所以肥肉少而瘦肉多,肉味特别香,被称为"香猪",它的外表极象野猪,毛蓬乱,在冬天猪鬃下面还会长出一层厚厚的绒毛,能抗高原的严寒和遮挡强烈紫外线的照射。 展开更多
关键词 种猪 青藏高原 摩尔达维亚 母猪 估计重量 国营农场 紫外线 香猪 浙江省 饲养
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Comparison of daily physical activity parameters using objective methods between overweight and normal-weight children
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作者 Jonghoon Park Kazuko Ishikawa-Takata +5 位作者 Sangjik Lee Eunkyung Kim Kiwon Lim Hyungryul Kim In-Sook Lee Shigeho Tanaka 《Journal of Sport and Health Science》 SCIE 2018年第2期210-217,共8页
Purpose: The purpose of the present study was to determine if there were any differences in various aspects of physical activity such as energy expenditure, intensity, and type of activity between normal-weight and ov... Purpose: The purpose of the present study was to determine if there were any differences in various aspects of physical activity such as energy expenditure, intensity, and type of activity between normal-weight and overweight boys.Methods: Children aged 9—12 years were recruited from 2 elementary schools located in different urban districts in Republic of Korea. The present study included 45 Korean boys, of which 19 were normal-weight and 26 were overweight. Daily physical activity was estimated over the same 1-week study period under free-living conditions using the doubly labeled water(DLW) method and a tri-axial accelerometer. Resting metabolic rate(RMR) was measured using the Douglas bag method and open-circuit indirect calorimetry. We calculated the physical activity level(PAL) as the total energy expenditure(TEE)/RMR.Results: PAL was not significantly different between the groups. In the accelerometer data, time spent in locomotive moderate-to-vigorous physical activity(MVPA) was significantly lower in overweight boys than in normal-weight subjects, whereas other variables including non-locomotive activity did not differ between groups. In addition, among all participants, time spent in total locomotive activity was significantly associated with PAL. Time spent in locomotive MVPA was significantly associated with PAL.Conclusion: Overweight boys may be less physically active based on locomotive MVPA, which was positively related with PAL. Our findings suggest that the contribution of locomotive MVPA to the increase in PAL was relatively significant. 展开更多
关键词 Accelerometer Doubly labeled water Korean elementary boys Locomotive moderate-to-vigorous physical activity Obesity Physical activity level
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Preliminary Analysis for Ground Structure around Source Region of 2008 Iwate-Miyagi Nairiku Earthquake
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作者 Hitoshi Morikawa Masachika Tanigawa +1 位作者 Taiyo Kobayashi Hiroko Matsuo 《Journal of Civil Engineering and Architecture》 2011年第2期175-179,共5页
To obtain a detailed model of the three-dimensional ground structure, the microtoremor and gravity surveys were carried out around Kurikoma area, Japan, where is the source reagion of 2008 Iwate-Miyagi nairiku earthqu... To obtain a detailed model of the three-dimensional ground structure, the microtoremor and gravity surveys were carried out around Kurikoma area, Japan, where is the source reagion of 2008 Iwate-Miyagi nairiku earthquake and is located about 90 km north of Sendai. Using the microtremor data, velocity structures of shallow sediments are estimated and the results at some of the sites are reported preliminarily. We could not find the detailed velocity structure to bedrock, because small arrays for the microtremor observation were applied, However, significant structures are observed for shallow velocity structure at some sites. Furthermore, gravity data provided Bouguer anomaly, which is one of gravity anomalies, around the target area. From the Bouguer anomaly, area with low anomaly is tbund around the south-eastern area of the fault plane. 展开更多
关键词 Gravity survey microtremor array observation ground structure 2008 Iwate-Miyagi Nairiku Earthquake.
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Monitoring Media Velocity Variations with Coda Wave Interferometry
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作者 Zhang Jinchuan Wang Qincai +1 位作者 Xue Bing Ding Lisha 《Earthquake Research in China》 CSCD 2015年第2期190-202,共13页
Multiply scattered waves are sensitive to media changes owing to the effect of repeated sampling,superposition and amplification. Based on this characteristic,small-medium changes could be detected by using coda wave ... Multiply scattered waves are sensitive to media changes owing to the effect of repeated sampling,superposition and amplification. Based on this characteristic,small-medium changes could be detected by using coda wave interferometry. In recent years,coda wave interferometry has been widely used in estimating velocity variation with high precision in areas such as seismology and non-destructive testing. This paper systematically presents the principle and research status of coda wave interferometry,and especial focus is placed on the research of media velocity variations by using repeating earthquakes,artificial sources,and ambient noise. Applications of coda wave interferometry can contribute to the more subtle understanding of dynamic evolution process in the medium. 展开更多
关键词 Coda wave interferometry Cross-correlation Velocity variationsRepeating earthquake Ambient seismic noise
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海洋里的塑料垃圾产生了大量问题
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《中学科技》 2016年第4期32-32,共1页
如果你能把全球海洋中漂浮的所有塑料垃圾称重,那么它们大约相当于3.8万头非洲大象的重量。这个估计数字来源于一项对海洋漂浮塑料垃圾的新的全球性的研究。经过6年的研究,科学家们估算出海洋中大约有5_25万亿片这类垃圾,总重量估... 如果你能把全球海洋中漂浮的所有塑料垃圾称重,那么它们大约相当于3.8万头非洲大象的重量。这个估计数字来源于一项对海洋漂浮塑料垃圾的新的全球性的研究。经过6年的研究,科学家们估算出海洋中大约有5_25万亿片这类垃圾,总重量估计达到26.9万吨。 展开更多
关键词 塑料垃圾 全球海洋 重量估计 非洲大象 科学家 漂浮
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遛了半小时 压断一杆秤——我钓的草鱼十四千克重
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作者 张建勇 《中国钓鱼》 2002年第9期6-6,共1页
喜逢“五一”节长假,我约了两位朋友于4月30日到位于石家庄市西北75公里的横山岭水库游钓。钓位选在库区北岸的一个半岛尖部,钓点水深近4米,距岸约6米。
关键词 草鱼 半小时 杆秤 石家庄市 重量估计 降小雨 绕线轮 钓位 拉锯战 千克重
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“四无”友谊赛
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作者 黄仰萱 《中国钓鱼》 1998年第6期35-35,共1页
关键词 “四无” 三合一 友谊赛 比赛期 重量估计 大型水库 铁丝网 时间限定 迎春花 土豆泥
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Combining GPS carrier phase and Doppler observations for precise velocity determination 被引量:5
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作者 WANG QianXin XU TianHe 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第6期1022-1028,共7页
The truncation error and propagation error are analyzed for velocity determination through differential GPS carrier phase observations,and an approach for the choice of the best number of points for the central differ... The truncation error and propagation error are analyzed for velocity determination through differential GPS carrier phase observations,and an approach for the choice of the best number of points for the central difference method is developed.In order to overcome the disadvantages of existing GPS velocity determination methods,a new velocity determination algorithm is presented,based on combining carrier phase and Doppler observations.The basic idea is that two types of observation are combined by adding their normal equations,and their weights are evaluated by strict Helmet variance-components estimation.In order to control the influence of outliers,a bifactor equivalent weights strategy is adopted.To validate this method,GPS data of the airborne gravimetry campaign MEXAGE2001 is tested.The results show that the precision and reliability of velocity determination are obviously improved by using the proposed method. 展开更多
关键词 GPS velocity determination central difference data fusion variance components estimation
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偶获大鲂
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作者 王树础 《中国钓鱼》 1998年第11期17-17,共1页
关键词 估计重量 红枫湖 低压槽 贵州省 小康村 贵阳市 大石头 收线 水库 可看到
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