搜索结果: 1-15 共查到“知识库 理学 k-means”相关记录130条 . 查询时间(0.031 秒)
基于逻辑回归函数的加权K-means聚类算法
欧式距离 特征加权的K-means算法 逻辑回归函数 初始聚类中心
2021/3/28
传统K-means聚类算法通过欧式距离计算样本的相似度，将数据所有的属性特征均平等对待，忽略每个属性特征的不同贡献，导致样本相似度计算的准确率不高。针对这个不足，提出一种特征加权的K-means算法进行优化。首先，运用Softmax和Sigmoid逻辑回归函数计算特征权重，使得加权的欧式距离更能准确地表示样本相似度；其次，优化初始聚类中心选择策略，选择距离较大的K个样本作为初始聚类中心，可有效避免...
MULTI-PATCHES IRIS BASED PERSON AUTHENTICATION SYSTEM USING PARTICLE SWARM OPTIMIZATION AND FUZZY C-MEANS CLUSTERING
Particle swarm optimization Fuzzy c-means Taylor’s series expansion weighted mean Hamming distance Iris recognition system
2017/5/15
Locating the boundary parameters of pupil and iris and segmenting the noise free iris portion are the most challenging phases of an automated iris recognition system. In this paper, we have presented ...
3D BUILDING MODELS SEGMENTATION BASED ON K-MEANS++ CLUSTER ANALYSIS
3D model segmentation cluster segmentation 3D building model K-means++ cluster
2016/10/5
3D mesh model segmentation is drawing increasing attentions from digital geometry processing field in recent years. The original 3D mesh model need to be divided into separate meaningful parts or surf...
Tests atternative to higher criticism for high dimensional means under sparsity and column-wise dependence
Large deviation Large p, small n Optimal detection boundary Sparse signal Thresholding Weak dependence
2016/1/25
We consider two alternative tests to the Higher Criticism test of Donoho and Jin (2004) for high dimensional means under the spar-sity of the non-zero means for sub-Gaussian distributed data with unkn...
Aerosol optical thickness of Mt. Etna volcanic plume retrieved by means of the Airborne Multispectral Imaging Spectrometer (MIVIS)
aerosol optical thickness volcanic plume MIVIS DEM radiative transfer model 6S inversion technique
2015/9/16
Within the framework of the European MVRRS project (Mitigation of Volcanic Risk by Remote Sensing
Techniques), in June 1997 an airborne campaign was organised on Mt. Etna to study different character...
Ionospheric Doppler measurements by means of HF-radar techniques
shift Doppler ionosphere plasma drift
2015/9/10
Studies of the dynamics of the ionosphere and its related phenomena are mainly based on Doppler Drift measurements. The time variation (ionisation/recombination) of plasma density, thermospheric wind ...
Validation of a method for ionospheric electron density reconstruction by means of vertical incidence data during quiet and storm periods
electron density model vertical incidence ionograms ionospheric data ingestion
2015/9/10
A preliminary validation of the technique developed using the NeQuick ionospheric model and the 玡ffective ionization
parameter?Az, based on vertical total electron content data ingestion, was carried...
Perspectives of 2D and 3D mapping of atmospheric pollutants over urban areas by means of airborne DOAS spectrometers
DOAS applications in urban areas atmospheric pollutants tomography aircraft measurements of atmospheric trace gases
2015/9/7
In the field of air quality control, optical remote sensing systems can measure the spatial distribution of gas pollutants, offering numerous advantages over conventional networks of in situ analysers...
Memories of the past contribute to prevention: photography as a direct means for public understanding of science
Memories Prevention Historical images
2015/8/26
There are thousands of ways to achieve a sustainable future for our Planet. Some of these follow high-value scientific research activities, while others simply aim to increase people’s awareness of wh...
Focus maps:a means of prioritizing data collection for efficient geo-risk assessment
Geo-risk assessment Vulnerability Data collection Sampling
2015/8/17
Efficient Disaster Risk Reduction (DRR) management constantly calls upon high-quality information to be collected or updated for vulnerability monitoring and risk assessment. This process is often res...
Focus maps: a means of prioritizing data collection for efficient geo-risk assessment
Geo-risk assessment Vulnerability Data collection Sampling
2015/8/14
Efficient Disaster Risk Reduction (DRR) management constantly calls upon high-quality information to be collected or updated for vulnerability monitoring and risk assessment. This process is often res...
Methodological aspects of a pattern-scaling approach to produce global fields of monthly means of daily maximum and minimum temperature
produce global fi elds daily maximum
2014/12/18
A Climate Pattern-Scaling Model (CPSM) that
simulates global patterns of climate change, for a prescribed
emissions scenario, is described. A CPSM works by quantitatively establishing the statistica...
Krakatau caldera deposits: revisited and verification by geophysical means
Krakatau caldera Parasitic cones Caldera deposit Drillings at calderas S-wave attenuation Vp/Vs ratio
2014/5/18
One of the differences between volcanic craters and calderas is that the latter bottoms are flatways filled with caldera deposit with lower density in comparison to country rocks. The 1883 Krakatau er...
Inversion of circular means and the wave equation on general planar domains
Inversion of circular equation general planar domains Analysis of PDEs
2012/6/6
We study the problem of recovering the initial data of the two dimensional wave equation from values of its solution on an arbitrarily shaped bounded domain $\Omega \subset \R^2$. As a main result we ...
Approximation of functions from Lp(w)b by matrix means of their Fourier series
Rate of approximation summability of Fourier series Lipschitz classes
2012/4/13
We formulate some special conditions for the integrable functions and moduli of continuity. We give the results on rate of approximation of such functions by matrix means of their Fourier series, wher...