A new method for filling missing values by gray relational analysis

2011 ◽  
Author(s):  
Bingwei Han ◽  
Shuangjiu Xiao ◽  
Lu Liu ◽  
Zhijing Wu
Keyword(s):  
Missing Values ◽  
New Method ◽  
Gray Relational Analysis ◽  
Relational Analysis

Reason Analysis of Runway Incursions Based on Grey Theory

2011 ◽  
Vol 328-330 ◽  
pp. 2400-2404
Author(s):  
Zi Qi Ju
Keyword(s):  
Gray Relational Analysis ◽  
Grey Theory ◽  
Prevention Measures ◽  
Key Factors ◽  
Class Ab ◽  
Relational Analysis ◽  
Definition Of ◽  
Grey Relational ◽  
Runway Incursions ◽  
Runway Incursion

To prevent runway incursions, we should have the corresponding systematic prevent ideas. Based on the definition of runway incursions and classification of relevant criteria, it analyzed the runway incursion system, put forward the closed-loop management ideas to prevent runway incursions, and found the main contradictions of preventing runway incursions using the gray relational analysis. With the example of runway incursion dates of U.S.A, by means of Grey Relational Analysis of different severities and different factors for runway incursions, it have shown that the key factors leading to the class AB and class CD runway incursions are Vehicle/Pedestrian Deviations and Pilot Deviations respectively. Meanwhile, it proposed integrated prevention measures of runway incursions.

A MPTCP Path Selection Strategy Based on Improved Grey Relational Analysis

2013 ◽  
Vol 401-403 ◽  
pp. 1766-1771 ◽  
Author(s):  
Lan Kou ◽  
Si Rui Chen ◽  
Rui Wang
Keyword(s):  
Transmission Control Protocol ◽  
Path Selection ◽  
Transport Layer ◽  
Reference Sequence ◽  
Gray Relational Analysis ◽  
Selection Strategy ◽  
Relational Analysis ◽  
Multiple Paths ◽  
End To End ◽  
Grey Relational

Multipath Transmission Control Protocol (MPTCP), a transport layer protocol, proposed by the IETF working group in 2009, can provide multipath communication end to end. It also can improve the utilization of network resources and network transmission reliability. However, that how to select multiple paths to improve the end to end overall throughput, and how to avoid the throughput declining by the performance difference, become the focus of this study. We propose a path selection strategy based on improved gray relational analysis, and set the optimal values of the QoS parameters for the selected paths as the reference sequence. According to the value of improved grey relational degree (IGRD) which is compared with reference sequence, we select the paths with better performance, smaller difference for transmission.

OPTIMIZATION OF PROCESS PARAMETERS AFFECTING CUTTING FORCE, POWER CONSUMPTION AND SURFACE ROUGHNESS USING TAGUCHI-BASED GRAY RELATIONAL ANALYSIS IN TURNING AISI 1040 STEEL

2021 ◽  
Author(s):  
MAHIR AKGÜN
Keyword(s):  
Surface Roughness ◽  
Power Consumption ◽  
Cutting Force ◽  
Cutting Speed ◽  
System Optimization ◽  
Gray Relational Analysis ◽  
Depth Of Cut ◽  
Nose Radius ◽  
Significance Level ◽  
Relational Analysis

This study focuses on optimization of cutting conditions and modeling of cutting force ([Formula: see text]), power consumption ([Formula: see text]), and surface roughness ([Formula: see text]) in machining AISI 1040 steel using cutting tools with 0.4[Formula: see text]mm and 0.8[Formula: see text]mm nose radius. The turning experiments have been performed in CNC turning machining at three different cutting speeds [Formula: see text] (150, 210 and 270[Formula: see text]m/min), three different feed rates [Formula: see text] (0.12 0.18 and 0.24[Formula: see text]mm/rev), and constant depth of cut (1[Formula: see text]mm) according to Taguchi L18 orthogonal array. Kistler 9257A type dynamometer and equipment’s have been used in measuring the main cutting force ([Formula: see text]) in turning experiments. Taguchi-based gray relational analysis (GRA) was also applied to simultaneously optimize the output parameters ([Formula: see text], [Formula: see text] and [Formula: see text]). Moreover, analysis of variance (ANOVA) has been performed to determine the effect levels of the turning parameters on [Formula: see text], [Formula: see text] and [Formula: see text]. Then, the mathematical models for the output parameters ([Formula: see text], [Formula: see text] and [Formula: see text]) have been developed using linear and quadratic regression models. The analysis results indicate that the feed rate is the most important factor affecting [Formula: see text] and [Formula: see text], whereas the cutting speed is the most important factor affecting [Formula: see text]. Moreover, the validation tests indicate that the system optimization for the output parameters ([Formula: see text], [Formula: see text] and [Formula: see text]) is successfully completed with the Taguchi method at a significance level of 95%.

scholarly journals Copy Mean: A New Method to Impute Intermittent Missing Values in Longitudinal Studies

2013 ◽  
Vol 03 (04) ◽  
pp. 26-40 ◽  
Author(s):  
Christophe Genolini ◽  
René Écochard ◽  
Hélène Jacqmin-Gadda
Keyword(s):  
Longitudinal Studies ◽  
Missing Values ◽  
New Method

Improving the Quality Assessment band in Landsat cloud images for the application of cloud removal  

2021 ◽  
Author(s):  
Boli Yang ◽  
Yan Feng ◽  
Ruyin Cao
Keyword(s):  
Quality Assessment ◽  
Land Surface ◽  
Missing Values ◽  
Similarity Index ◽  
Visual Assessment ◽  
New Method ◽  
Landsat Data ◽  
Cloud Detection ◽  
Cloud Removal ◽  
Ultimate Objective

<p>Cloud contamination is a serious obstacle for the application of Landsat data. Thick clouds can completely block land surface information and lead to missing values. The reconstruction of missing values in a Landsat cloud image requires the cloud and cloud shadow mask. In this study, we raised the issue that the quality of the quality assessment (QA) band in current Landsat products cannot meet the requirement of thick-cloud removal. To address this issue, we developed a new method (called Auto-PCP) to preprocess the original QA band, with the ultimate objective to improve the performance of cloud removal on Landsat cloud images. We tested the new method at four test sites and compared cloud-removed images generated by using three different QA bands, including the original QA band, the modified QA band by a dilation of two pixels around cloud and cloud shadow edges, and the QA band processed by Auto-PCP (“QA_Auto-PCP”). Experimental results, from both actual and simulated Landsat cloud images, show that QA_Auto-PCP achieved the best visual assessment for the cloud-removed images, and had the smallest RMSE values and the largest Structure SIMilarity index (SSIM) values. The improvement for the performance of cloud removal by QA_Auto-PCP is because the new method substantially decreases omission errors of clouds and shadows in the original QA band, but meanwhile does not increase commission errors. Moreover, Auto-PCP is easy to implement and uses the same data as cloud removal without additional image collections. We expect that Auto-PCP can further popularize cloud removal and advance the application of Landsat data.     </p><p><strong> </strong></p><p><strong>Keywords: </strong>Cloud detection, Cloud shadows, Cloud simulation, Cloud removal, MODTRAN</p>

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