47 research outputs found
Stability of Multi-Dimensional Switched Systems with an Application to Open Multi-Agent Systems
Extended from the classic switched system, themulti-dimensional switched
system (MDSS) allows for subsystems(switching modes) with different state
dimensions. In this work,we study the stability problem of the MDSS, whose
state transi-tion at each switching instant is characterized by the
dimensionvariation and the state jump, without extra constraint imposed.Based
on the proposed transition-dependent average dwell time(TDADT) and the
piecewise TDADT methods, along with the pro-posed parametric multiple Lyapunov
functions (MLFs), sufficientconditions for the practical and the asymptotical
stabilities of theMDSS are respectively derived for the MDSS in the presenceof
unstable subsystems. The stability results for the MDSS areapplied to the
consensus problem of the open multi-agent system(MAS) which exhibits dynamic
circulation behaviors. It is shownthat the (practical) consensus of the open
MAS with disconnectedswitching topologies can be ensured by (practically)
stabilizingthe corresponding MDSS with unstable switching modes via theproposed
TDADT and parametric MLF methods.Comment: 12 pages, 9 figure
Is ProtoPNet Really Explainable? Evaluating and Improving the Interpretability of Prototypes
ProtoPNet and its follow-up variants (ProtoPNets) have attracted broad
research interest for their intrinsic interpretability from prototypes and
comparable accuracy to non-interpretable counterparts. However, it has been
recently found that the interpretability of prototypes can be corrupted due to
the semantic gap between similarity in latent space and that in input space. In
this work, we make the first attempt to quantitatively evaluate the
interpretability of prototype-based explanations, rather than solely
qualitative evaluations by some visualization examples, which can be easily
misled by cherry picks. To this end, we propose two evaluation metrics, termed
consistency score and stability score, to evaluate the explanation consistency
cross images and the explanation robustness against perturbations, both of
which are essential for explanations taken into practice. Furthermore, we
propose a shallow-deep feature alignment (SDFA) module and a score aggregation
(SA) module to improve the interpretability of prototypes. We conduct
systematical evaluation experiments and substantial discussions to uncover the
interpretability of existing ProtoPNets. Experiments demonstrate that our
method achieves significantly superior performance to the state-of-the-arts,
under both the conventional qualitative evaluations and the proposed
quantitative evaluations, in both accuracy and interpretability. Codes are
available at https://github.com/hqhQAQ/EvalProtoPNet
A Survey of Neural Trees
Neural networks (NNs) and decision trees (DTs) are both popular models of
machine learning, yet coming with mutually exclusive advantages and
limitations. To bring the best of the two worlds, a variety of approaches are
proposed to integrate NNs and DTs explicitly or implicitly. In this survey,
these approaches are organized in a school which we term as neural trees (NTs).
This survey aims to present a comprehensive review of NTs and attempts to
identify how they enhance the model interpretability. We first propose a
thorough taxonomy of NTs that expresses the gradual integration and
co-evolution of NNs and DTs. Afterward, we analyze NTs in terms of their
interpretability and performance, and suggest possible solutions to the
remaining challenges. Finally, this survey concludes with a discussion about
other considerations like conditional computation and promising directions
towards this field. A list of papers reviewed in this survey, along with their
corresponding codes, is available at:
https://github.com/zju-vipa/awesome-neural-treesComment: 35 pages, 7 figures and 1 tabl
Analysis of the Spatial Differentiation and Development Optimization of Towns’ Livable Quality in Aksu, China
With the proposal of the United Nations Sustainable Development Goals (SDGs), how to effectively improve the quality of human settlements has become a hot spot. Governments and scholars around the world pay attention to reasonable improvement of livability, which is conducive to improving the happiness level of residents and is closely related to human well-being. Due to the lack of rural statistical data in Xinjiang, this study established a new comprehensive evaluation system, which selected 21 indicators from the natural and humanistic aspects. The results show that the overall ecological security of Aksu prefecture is good, and Kuche city has the best humanistic livability performance. In terms of the livable quality of towns, Kuche Urban Area performs best. The towns with excellent and good livable quality are concentrated, but their spatial connections are weak. Based on the analysis and survey results, we put forward zoning optimization suggestions for the livable quality in Aksu prefecture. The results of this study would provide directional guidance for the improvement of livable quality in Aksu prefecture. At the same time, we expect that it can provide a methodological supplement for the relevant evaluation in other similar regions
A Survey of Deep Learning for Low-Shot Object Detection
Object detection has achieved a huge breakthrough with deep neural networks
and massive annotated data. However, current detection methods cannot be
directly transferred to the scenario where the annotated data is scarce due to
the severe overfitting problem. Although few-shot learning and zero-shot
learning have been extensively explored in the field of image classification,
it is indispensable to design new methods for object detection in the
data-scarce scenario since object detection has an additional challenging
localization task. Low-Shot Object Detection (LSOD) is an emerging research
topic of detecting objects from a few or even no annotated samples, consisting
of One-Shot Object Detection (OSOD), Few-Shot Object Detection (FSOD) and
Zero-Shot Object Detection (ZSD). This survey provides a comprehensive review
of LSOD methods. First, we propose a thorough taxonomy of LSOD methods and
analyze them systematically, comprising some extensional topics of LSOD
(semi-supervised LSOD, weakly-supervised LSOD and incremental LSOD). Then, we
indicate the pros and cons of current LSOD methods with a comparison of their
performance. Finally, we discuss the challenges and promising directions of
LSOD to provide guidance for future works
Spatial Characteristics of Land Use Multifunctionality and Their Trade-Off/Synergy in Urumqi, China: Implication for Land Space Zoning Management
Identifying and exploring the spatial characteristics of land use multifunctionality (LUMF) and their trade-off/synergy are the basis for promoting the coordinated development of LUMF, and have significant implications for land space zoning management. In this study, we integrated multi-source data to construct a multi-functional identification system of land use, and quantitatively identified agricultural production function (APF), urban life function (ULF), and ecological function (EF) from grid units. We used the mechanical equilibrium model and Spearman correlation variable analysis to explore the trade-off/synergy between the primary and secondary function of land use. The results show that LUMF has obvious spatial differentiation characteristics and significant composite characteristics. Functionality interweaves and overlaps spatially, creating trade-off/synergy between LUMF. Urumqi as a whole was at a coordinated level (73%). High urban life–low agricultural production and high ecology–low agricultural production were the main types of trade-off/synergy. APF and EF were dominant functions, and there was a significant synergistic relationship. APF and urban life-bearing function had a trade-off relationship. Based on the research results, zoning attempts were made as a reference. Finally, under the framework of regional function theory, we considered the sequential selection process and competition process of LUMF, and put forward proposals for land space zoning management
Spatial Characteristics of Land Use Multifunctionality and Their Trade-Off/Synergy in Urumqi, China: Implication for Land Space Zoning Management
Identifying and exploring the spatial characteristics of land use multifunctionality (LUMF) and their trade-off/synergy are the basis for promoting the coordinated development of LUMF, and have significant implications for land space zoning management. In this study, we integrated multi-source data to construct a multi-functional identification system of land use, and quantitatively identified agricultural production function (APF), urban life function (ULF), and ecological function (EF) from grid units. We used the mechanical equilibrium model and Spearman correlation variable analysis to explore the trade-off/synergy between the primary and secondary function of land use. The results show that LUMF has obvious spatial differentiation characteristics and significant composite characteristics. Functionality interweaves and overlaps spatially, creating trade-off/synergy between LUMF. Urumqi as a whole was at a coordinated level (73%). High urban life–low agricultural production and high ecology–low agricultural production were the main types of trade-off/synergy. APF and EF were dominant functions, and there was a significant synergistic relationship. APF and urban life-bearing function had a trade-off relationship. Based on the research results, zoning attempts were made as a reference. Finally, under the framework of regional function theory, we considered the sequential selection process and competition process of LUMF, and put forward proposals for land space zoning management
Spatial and Temporal Evolution of Land Use and the Response of Habitat Quality in Wusu, China
Understanding land use change and its impact on habitat quality (HQ) is conducive to land use management and ecological protection. We used the InVEST model and the GeoDetector model to explore the land use and HQ of Wusu from 1980 to 2020. We found that the spatial distribution of land use in Wusu had the most dramatic change from 2000 to 2010, and accordingly, the habitat quality deteriorated seriously from 2000 to 2010. Via correlation analysis, the response of HQ to land use change is obvious, among which the negative effect of forest land to construction land is the largest, and the positive effect of construction land to water is the largest. However, the overall HQ had the largest negative response to the change of grassland to arable land, and the largest positive response to the change of unused land to grassland. Of the driving factors that cause land use change and thus affect HQ, the human factors are the strongest, and the negative impact on HQ is more irreversible. This study can provide a scientific basis for land use management and ecological protection in Wusu, and can help to further promote the exploration of human activities and ecological responses in arid and semi-arid areas