scholarly journals Uncertainty-Based Vibration/Gyro Composite Planetary Terrain Mapping

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2681 ◽  
Author(s):  
Chengchao Bai ◽  
Jifeng Guo
Keyword(s):  
Environmental Changes ◽  
Estimation Method ◽  
Dust Storms ◽  
Simulation Environment ◽  
Terrain Mapping ◽  
Soil Environment ◽  
Reconstruction Accuracy ◽  
Mapping Accuracy ◽  
Accuracy Test ◽  
Accurate Perception

Accurate perception of the detected terrain is a precondition for the planetary rover to perform its own mission. However, terrain measurement based on vision and LIDAR is subject to environmental changes such as strong illumination and dust storms. In this paper, considering the influence of uncertainty in the detection process, a vibration/gyro coupled terrain estimation method based on multipoint ranging information is proposed. The terrain update model is derived by analyzing the measurement uncertainty and motion uncertainty. Combined with Clearpath Jackal unmanned vehicle—the terrain mapping accuracy test based on ROS (Robot Operating System) simulation environment—indoor Optitrack auxiliary environment and outdoor soil environment was completed. The results show that the proposed algorithm has high reconstruction ability for a given scale terrain. The reconstruction accuracy in the above test environments is within 1 cm, 2 cm, and 6 cm, respectively.

Climatic and Environmental Changes in the Source Areas of Dust Storms in Xinjiang, China, during the Last 50 Years

2005 ◽  
Vol 5 (3-6) ◽  
pp. 207-216 ◽  
Author(s):  
Wenshou Wei ◽  
Hongfei Zhou ◽  
Yuguang Shi ◽  
Osamu Abe ◽  
Kenji Kai
Keyword(s):  
Environmental Changes ◽  
Dust Storms ◽  
Source Areas

Parameter Estimation of the Mechanical Behavior of the Artery Using a Nonlinear Least Square Method With a Noise Model

2008 ◽  
Author(s):  
Shahrokh Zeinali ◽  
Jongeun Choi ◽  
Seungik Baek
Keyword(s):  
Parameter Estimation ◽  
Blood Vessel ◽  
Mechanical Behavior ◽  
Constitutive Relation ◽  
Environmental Changes ◽  
Constitutive Relations ◽  
Estimation Method ◽  
Least Square ◽  
Noise Model ◽  
Bias Error

Although it is well known that blood vessels adapt and remodel in response to various biomechanical stimuli, quantifying changes in constitutive relation corresponding to environmental changes is still challenging. Especially, when the dimension of blood vessel is small, the uncertainties in experimental measurements become significant and make it difficult to precisely estimate parameters of constitutive relations for mechanical behavior of the blood vessel. Hence without considering measurement error in displacement, a conventional nonlinear least square (NLS) method results in a biased parameter estimation. In this paper, we propose a new parameter estimation method to eliminate such bias error and provide more accurate estimated parameters for a constitutive relation using a weighted nonlinear least square (WNLS) method with a noise model. We first applied the proposed technique to a set of synthesized data with computer generated white noises and compared the fitting results to those of the NLS method without the noise model. We also applied our method to experimental data sets from mechanical tests of rabbit basilar and mouse carotid arteries and studied parameter sensitivity of the constitutive model.

Mineral Dust Cycle

2016 ◽  
Author(s):  
Irina Sokolik
Keyword(s):  
Atmospheric Aerosols ◽  
Environmental Changes ◽  
Mineral Dust ◽  
Global Climate ◽  
Dust Emission ◽  
Northern China ◽  
Dust Storms ◽  
Atmospheric Composition ◽  
System Response ◽  
Beneficial Effects

There is scientific consensus that human activities have been altering the atmospheric composition and are a key driver of global climate and environmental changes since pre-industrial times (IPCC, 2013). It is a pressing priority to understand the Earth system response to atmospheric aerosol input from diverse sources, which so far remain one of the largest uncertainties in climate studies (Boucher et al., 2014; Forster et al., 2007). As the second most abundant component (in terms of mass) of atmospheric aerosols, mineral dust exerts tremendous impacts on Earth’s climate and environment through various interaction and feedback processes. Dust can also have beneficial effects where it deposits: Central and South American rain forests get most of their mineral nutrients from the Sahara; iron-poor ocean regions get iron; and dust in Hawaii increases plantain growth. In northern China as well as the midwestern United States, ancient dust storm deposits known as loess are highly fertile soils, but they are also a significant source of contemporary dust storms when soil-securing vegetation is disturbed. Accurate assessments of dust emission are of great importance to improvements in quantifying the diverse dust impacts.

Tropospheric Mineral Dust Study by High Spectral Resolution Infrared Satellite during intense dust storms

2021 ◽  
Author(s):  
Perla Alalam ◽  
Hervé Herbin
Keyword(s):  
Mineral Dust ◽  
Complex Refractive Index ◽  
Estimation Method ◽  
Dust Storms ◽  
High Spectral Resolution ◽  
Dust Particles ◽  
Physical Parameters ◽  
Chemical Compositions ◽  
Storm Events ◽  
Atmospheric Measurements

<p>Large desert lands such as Sahara, Gobi or Australia present main sources of atmospheric mineral dust caused by intense dust storms. Transported dust particles undergo physical and chemical changes affecting their microphysical and optical properties. This modifies their scattering and absorption properties and alters the global atmospheric radiative budget.</p><p>Currently, remote sensing techniques represent a powerful tool for quantitative atmospheric measurements and the only means of analyzing its evolution from local to global scale. In order to improve the knowledge of atmospheric aerosol distributions, many efforts were made particularly in the development of hyperspectral infrared spectrometers and processing algorithms. However, to fully exploit these measurements, a perfect knowledge of Complex Refractive Index (CRI) is required.</p><p>In that purpose, a new methodology <sup></sup>based on laboratory measurements of mineral dust in suspension coupled with an optimal estimation method has been developed. This approach allows getting access to CRI of several desert samples with various chemical compositions.</p><p>Here, we present the first results of the physical parameters (effective radius and concentration) retrievals using Infrared Atmospheric Sounding Interferometer IASI data, during dust storm events. The latter use the CRI of different desert samples obtained in laboratory and a new radiative transfer algorithm (ARAHMIS) developed at Laboratoire d’Optique Atmosphérique LOA.</p>

Research on data fusion method of multi-source complex system

2021 ◽  
Author(s):  
Yuxiang Cai
Keyword(s):  
Data Fusion ◽  
Estimation Method ◽  
Fuzzy Neural ◽  
Accurate Perception ◽  
Value Estimation ◽  
Null Value ◽  
Neural Network Algorithm ◽  
Basic Technology ◽  
Power And Energy ◽  
The Internet Of Things

Multi source fusion of data collected by various sensors to realize accurate perception is the key basic technology of the Internet of things. At present, there are many problems in the fusion of various kinds of data collected by sensors, such as more noise and more null values. In this paper, the fuzzy neural network algorithm is proposed to establish the model, combined with the Delphi method and the null value estimation method based on the prediction value to construct the data fusion system. This method has rich application scenarios in the construction of IOT system in the field of power and energy.

DOES PERCEPTUAL ACUITY MATTER? — AN INVESTIGATION OF ENTREPRENEURIAL ORIENTATION, PERCEPTUAL ACUITY, AND FIRM PERFORMANCE

2009 ◽  
Vol 17 (01) ◽  
pp. 79-102 ◽  
Author(s):  
ZHI TANG ◽  
SANDRA ROTHENBERG
Keyword(s):  
Firm Performance ◽  
Organizational Performance ◽  
Organizational Effectiveness ◽  
Entrepreneurial Orientation ◽  
Environmental Changes ◽  
Management Research ◽  
Top Managers ◽  
Accurate Perception ◽  
Perceptual Mode ◽  
Perceptual Acuity

One critical proposition in normative strategic management research is that an accurate perception of the environment by top managers is a prerequisite to attaining better organizational performance. However, recent entrepreneurship studies suggest that entrepreneurs are often leading or even causing environmental changes, and thus they may perceive greater industrial instability than there actually is. In this project, we examine if an over-perception of industrial instability exists among entrepreneurs. If it does, which perceptual mode (accurate perception versus over-perception) will benefit firm performance? We conducted the study in a highly volatile environment — China — and found that entrepreneurial orientation (EO) had an inverse U-shape relationship with perceptual acuity of industrial instability, indicating that a greater level of EO indeed led to an over-perception of industrial instability. However, we found that although perceptual acuity of industrial instability improved firm sales, it was negatively associated with organizational effectiveness evaluated by top managers. Additional analyses were conducted and implications were provided in the end.

scholarly journals Use of RNA and DNA to Identify Mechanisms of Microbial Community Homogenization

2018 ◽  
Author(s):  
Kyle M Meyer ◽  
Ian A.B. Petersen ◽  
Elie Tobi ◽  
Lisa Korte ◽  
Brendan Bohannan
Keyword(s):  
Land Use ◽  
Community Structure ◽  
Microbial Community ◽  
Environmental Changes ◽  
Environmental Variability ◽  
Congo Basin ◽  
Active Fraction ◽  
Soil Environment ◽  
Inference Methods ◽  
Rna And Dna

Biotic homogenization is a commonly observed response following conversion of native ecosystems to agriculture, but our mechanistic understanding of this process is limited for microbial communities. In the case of rapid environmental changes, inference of homogenization mechanisms may be confounded by the fact that only a minority of taxa is active at any given point. RNA- and DNA-based community inference may help to distinguish the active fraction of a community from inactive taxa. Using these two community inference methods, we asked how soil prokaryotic communities respond to land use change following transition from rainforest to agriculture in the Congo Basin. Our results indicate that the magnitude of community homogenization is larger in the RNA-inferred community than the DNA-inferred perspective. We show that as the soil environment changes, the RNA-inferred community structure tracks environmental variation and loses spatial structure. The DNA-inferred community loses its association with environmental variability. Homogenization of the DNA-inferred community appears to instead be driven by the range expansion of a minority of taxa shared between the forest and conversion sites, which is also seen in the RNA-inferred community. Our results suggest that complementing DNA-based surveys with RNA can provide unique perspectives on community responses to environmental change.

Dust storms, blackouts and 50°C in the shade: Exploring the Roots of Humankind with MATLAB

2020 ◽  
Author(s):  
Martin H. Trauth
Keyword(s):  
Summer School ◽  
Environmental Changes ◽  
Homo Sapiens ◽  
Single Species ◽  
Dust Storms ◽  
Environmental Data ◽  
Data Sets ◽  
Large Lakes ◽  
Braided Rivers ◽  
Climate Time Series

<p>Geoscientists from the University of Potsdam reconstruct environmental changes in East Africa over the past five million years. Micro-organisms such as diatoms and rotifers, clay minerals and pollen, thousands of years old, help to reconstruct large lakes and braided rivers, dense forests and hot deserts, high mountains and deep valleys. This is the habitat of our ancestors, members of a complicated family tree or network, of which only one single species, <em>Homo sapiens</em>, has survived. MATLAB is the tool of choice for analyzing these complicated and extensive data sets, extracted from up to 300 m long drill cores, from satellite images, and from the fossil remains of humans and other animals. The software is used to analyze to detect and classify important climate transitions in climate time series, to detect objects and quantify materials in microscope and satellite imagery, to predict river networks from digital terrain models, and to model lake-level fluctuations from environmental data. The advantage of MATLAB is the use of multiple methods with one single tool. Not least because of this, the software is also becoming increasingly popular in Africa, as shown by the program of an international summer school series in Africa and Germany for collecting, processing, and presenting geo-bio-information.</p>

scholarly journals Akurasi Citra Data Foto Udara UAV Quadcopter Persimpangan Lalu Lintas Kota Kendari

2020 ◽  
Vol 14 (1) ◽  
pp. 51-59
Author(s):  
La Ode M. Nurrakhmad Arsyad ◽  
◽  
Statiswaty Statiswaty ◽  
Laode M. Iradat ◽  
◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Field Measurement ◽  
Highway Traffic ◽  
Mapping Accuracy ◽  
Field Surveys ◽  
Accuracy Test ◽  
Measurement Results ◽  
Aerial Vehicle ◽  
The Difference ◽  
Field Planning

The use of the Unnamed Aerial Vehicle (UAV) called “Drone” has been widely used in various areas of planning, one of them by mapping the highway traffic junction. The range of remote roaming, adjustable spatial resolution greatly gives flexibility in the effectiveness of field surveys. The mapping accuracy test conducted on 7 (seven) Unsignaling junction in Kendari City by Omisi and Komisi Equation method gives significant output and quite accurate to serve as further planning data. The difference between image and field measurement results, obtained accuracy of 96%, so that the use of UAV in supporting mapping, survey and field planning still prioritize effectiveness and accuracy of the measurement.

Sign in / Sign up

Export Citation Format

Share Document