Lei Ma

Dr. Lei Ma

Department of Geographic Information Science, Nanjing University, Nanjing 210046, China
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2019 in ISPRS Journal of Photogrammetry and Remote Sensing
Verified
Journal Article
Open access
Lei MaLei Ma
Lei Ma
YLYu Liu
Yu Liu
XZXueliang Zhang
Xueliang Zhang
YYYuanxin Ye
Yuanxin Ye
GYGaofei Yin
Gaofei Yin
Brian Alan JohnsonBrian Alan Johnson
Brian Alan Johnson

1 August 2017 in ISPRS Journal of Photogrammetry and Remote Sensing
Verified
Journal Article
Open access
Lei MaLei Ma
Lei Ma
MLManchun Li
Manchun Li
XMXiaoxue Ma
Xiaoxue Ma
LCLiang Cheng
Liang Cheng
PDPeijun Du
Peijun Du
YLYongxue Liu
Yongxue Liu

6 September 2013 in International Journal of Geographical Information Science
Verified
Journal Article
Closed access
XLXiaoping Liu
Xiaoping Liu
Lei MaLei Ma
Lei Ma
XLXia Li
Xia Li
BABin Ai
Bin Ai
SLShaoying Li
Shaoying Li
ZHZhijian He
Zhijian He
Traditional urban cellular automata CA model can effectively simulate infilling and edge-expansion growth patterns. However, most of these models are incapable of simulating the outlying growth. This paper proposed a novel model called LEI-CA which incorporates landscape expansion index LEI with CA to simulate urban growth. Urban growth type is identified by calculating the LEI index of each cell. Case-based reasoning technique is used to discover different transition rules for the adjacent growth type and the outlying growth type, respectively. We applied the LEI-CA model to the simulation of urban growth in Dongguan in southern China. The comparison between logistic-based CA and LEI-CA indicates that the latter can yield a better performance. The LEI-CA model can improve urban simulation accuracy over logistic-based CA by 13.8%, 10.8% and 6.9% in 1993, 1999 and 2005, respectively. Moreover, the outlying growth type hardly exists in the simulation by logistic-based CA, while the proposed LEI-CA model performs well in simulating different urban growth patterns. Our experiments illustrate that the LEI-CA model not only overcomes the deficiencies of traditional CA but might also better understand urban evolution process.

Verified
Journal Article
Open access
PDF file
Lei MaLei Ma
Lei Ma
TFTengyu Fu
Tengyu Fu
Thomas BlaschkeThomas Blaschke
Thomas Blaschke
MLManchun Li
Manchun Li
Dirk TiedeDirk Tiede
Dirk Tiede
DCDeliang Chen
Deliang Chen
The increased feature space available in object-based classification environments (e.g., extended spectral feature sets per object, shape properties, or textural features) has a high potential of improving classifications. However, the availability of a large number of derived features per segmented object can also lead to a time-consuming and subjective process of optimizing the feature subset. The objectives of this study are to evaluate the effect of the advanced feature selection methods of popular supervised classifiers (Support Vector Machines (SVM) and Random Forest (RF)) for the example of object-based mapping of an agricultural area using Unmanned Aerial Vehicle (UAV) imagery, in order to optimize their usage for object-based agriculture pattern recognition tasks. In this study, several advanced feature selection methods were divided into both types of classifiers (SVM and RF) to conduct further evaluations using five feature-importance-evaluation methods and three feature-subset-evaluation methods. A visualization method was used to measure the change pattern of mean classification accuracy with the increase of features used, and a two-tailed t-test was used to determine the difference between two population means for both repeated ten classification accuracies. This study mainly contribute to the uncertainty analysis of feature selection for object-based classification instead of the per-pixel method. The results highlight that the RF classifier is relatively insensitive to the number of input features, even for a small training set size, whereby a negative impact of feature set size on the classification accuracy of the SVM classifier was observed. Overall, the SVM Recursive Feature Elimination (SVM-RFE) seems to be an appropriate method for both groups of classifiers, while the Correlation-based Feature Selection (CFS) is the best feature-subset-evaluation method. Most importantly, this study verified that feature selection for both classifiers is crucial for the evolving field of Object-based Image Analysis (OBIA): It is highly advisable for feature selection to be performed before object-based classification, even though an adverse impact could sometimes be observed from the wrapper methods.

1 April 2015 in ISPRS Journal of Photogrammetry and Remote Sensing
Verified
Journal Article
Closed access
Lei MaLei Ma
Lei Ma
LCLiang Cheng
Liang Cheng
MLManchun Li
Manchun Li
YLYongxue Liu
Yongxue Liu
XMXiaoxue Ma
Xiaoxue Ma

14 April 2023 in Remote Sensing of Environment
Verified
Journal Article
Closed access
FHFan Huang
Fan Huang
SJSida Jiang
Sida Jiang
Wenfeng ZhanWenfeng Zhan
Wenfeng Zhan
BBBenjamin Bechtel
Benjamin Bechtel
ZLZihan Liu
Zihan Liu
JCJike Chen
Jike Chen