3D GIS Modeling of Soft Geo-Objects: Taking Rainfall, Overland Flow, and Soil Erosion as an Example

In physics, objects can be divided into rigid and soft objects according to the object deformation capacity. Similarly, geo-object can also be classified into rigid geo-objects (e.g., building, urban) and soft geo-objects (e.g., mudflow, water, soil erosion). There are three types of approaches for 3D GIS modeling, i.e., surface-based, volume-based, and hybrids in terms of geometry. These approaches are suitable for representing rigid geo-objects, but they are not suitable to simulate the intrinsic properties of the soft geo-object, i.e., dynamics and deformation. And so far there are few GIS modeling methods for simulation of soft geo-objects. GIS flow elements (FEs) and GIS soft voxels (SVs) were proposed for 3D modeling of soft geo-objects. GIS flow elements can realistically represent the dynamics and stochastics of soft geo-objects, while GIS soft voxels simulate deformation of soft geo-objects. The authors discuss the implementation and computer programming of GIS flow elements and GIS soft voxels in this study. GIS FE and SV have been successfully applied in a case study toward the simulation of the process of rainfall, overland flow, and soil erosion. A software system has been designed and developed, which has the functions of data management, model computation, and 3D simulation

Indoor Particulate Matter Transfer in CNC Machining Workshop and The Influence of Ventilation Strategies—A Case Study

Particulate matter in Computer Numerical Control (CNC) machining workshop is harmful to workers’ health. This paper studies particulate matter transfer and the performance of various ventilation strategies in a CNC machining workshop. To obtain the boundary condition of the particle field, instruments were installed to obtain the particle size attenuation characteristics and source strength, respectively. The results show that the 99% cumulative mass concentration of particles is distributed within 1.5 μm, and the release rate of particles from the full enclosure. Next, the indoor flow field and particle field were simulated by numerical simulation with the measured boundary conditions. The working area’s age of air, particle concentration, and ventilation efficiency were compared between four displacement ventilation methods and one mixed ventilation method. The results show that the working area’s mean particle concentration and ventilation efficiency under longitudinal displacement ventilation is better than other methods. At the same time, the mean age of air is slightly worse. In addition, mixed ventilation can obtain lower mean age of air, but the particle concentration is higher in the working area. The bilateral longitudinal ventilation can be improved by placing axial circulation fans with vertical upward outlets in the center of the workshop

CBSeq: A Channel-level Behavior Sequence For Encrypted Malware Traffic Detection

Machine learning and neural networks have become increasingly popular solutions for encrypted malware traffic detection. They mine and learn complex traffic patterns, enabling detection by fitting boundaries between malware traffic and benign traffic. Compared with signature-based methods, they have higher scalability and flexibility. However, affected by the frequent variants and updates of malware, current methods suffer from a high false positive rate and do not work well for unknown malware traffic detection. It remains a critical task to achieve effective malware traffic detection. In this paper, we introduce CBSeq to address the above problems. CBSeq is a method that constructs a stable traffic representation, behavior sequence, to characterize attacking intent and achieve malware traffic detection. We novelly propose the channels with similar behavior as the detection object and extract side-channel content to construct behavior sequence. Unlike benign activities, the behavior sequences of malware and its variant's traffic exhibit solid internal correlations. Moreover, we design the MSFormer, a powerful Transformer-based multi-sequence fusion classifier. It captures the internal similarity of behavior sequence, thereby distinguishing malware traffic from benign traffic. Our evaluations demonstrate that CBSeq performs effectively in various known malware traffic detection and exhibits superior performance in unknown malware traffic detection, outperforming state-of-the-art methods.Comment: Submitted to IEEE TIF

A Dynamic Feature Interaction Framework for Multi-task Visual Perception

Multi-task visual perception has a wide range of applications in scene understanding such as autonomous driving. In this work, we devise an efficient unified framework to solve multiple common perception tasks, including instance segmentation, semantic segmentation, monocular 3D detection, and depth estimation. Simply sharing the same visual feature representations for these tasks impairs the performance of tasks, while independent task-specific feature extractors lead to parameter redundancy and latency. Thus, we design two feature-merge branches to learn feature basis, which can be useful to, and thus shared by, multiple perception tasks. Then, each task takes the corresponding feature basis as the input of the prediction task head to fulfill a specific task. In particular, one feature merge branch is designed for instance-level recognition the other for dense predictions. To enhance inter-branch communication, the instance branch passes pixel-wise spatial information of each instance to the dense branch using efficient dynamic convolution weighting. Moreover, a simple but effective dynamic routing mechanism is proposed to isolate task-specific features and leverage common properties among tasks. Our proposed framework, termed D2BNet, demonstrates a unique approach to parameter-efficient predictions for multi-task perception. In addition, as tasks benefit from co-training with each other, our solution achieves on par results on partially labeled settings on nuScenes and outperforms previous works for 3D detection and depth estimation on the Cityscapes dataset with full supervision.Comment: Accepted by International Journal of Computer Vision. arXiv admin note: text overlap with arXiv:2011.0979

The social and environmental costs associated with water management practices in state environmental protection projects in Xinjiang, China

Since the late 1970s the central government of China has initiated several ecological environmental protection projects. The most significant of these has been the tui geng huan lin (returning cultivated land to forest and pasture) project in operation since the late 1990s. China's northwest region is characterized by lack of water resources, yet such resources are of vital importance. There is scant discussion in the literature (including in China) on the linkages between the environmental protection projects and water management practices. This paper analyses how central government environmental protection projects are interpreted in the local setting, and how local water management policies and practices correspond to the projects. The conclusion is that local water management policies and practices are interlinked with both central government and local government policies on the environmental protection projects, and a new process for the redistribution of water has been established. When equity and social costs are not factored into the planning of new environmental protection projects, the social costs may be as high as the environmental costs. (C) 2009 Elsevier Ltd. All rights reserved

Amorphous-Like Ultralow Thermal Transport in Crystalline Argyrodite Cu7PS6

Due to their amorphous-like ultralow lattice thermal conductivity both below and above the superionic phase transition, crystalline Cu- and Ag-based superionic argyrodites have garnered widespread attention as promising thermoelectric materials. However, despite their intriguing properties, quantifying their lattice thermal conductivities and a comprehensive understanding of the microscopic dynamics that drive these extraordinary properties are still lacking. Here, an integrated experimental and theoretical approach is adopted to reveal the presence of Cu-dominated low-energy optical phonons in the Cu-based argyrodite Cu7PS6. These phonons yield strong acoustic-optical phonon scattering through avoided crossing, enabling ultralow lattice thermal conductivity. The Unified Theory of thermal transport is employed to analyze heat conduction and successfully reproduce the experimental amorphous-like ultralow lattice thermal conductivities, ranging from 0.43 to 0.58 W m−1 K−1, in the temperature range of 100–400 K. The study reveals that the amorphous-like ultralow thermal conductivity of Cu7PS6 stems from a significantly dominant wave-like conduction mechanism. Moreover, the simulations elucidate the wave-like thermal transport mainly results from the contribution of Cu-associated low-energy overlapping optical phonons. This study highlights the crucial role of low-energy and overlapping optical modes in facilitating amorphous-like ultralow thermal transport, providing a thorough understanding of the underlying complex dynamics of argyrodites

Mantle reflectivity structure beneath oceanic hotspots

This study applies high-resolution Radon transform to a large set of SS precursors and explores the mantle reflectivity structure beneath 17 potentially ‘deep-rooted’ hotspots. The combined reduced time (Τ) and ray parameter ( p ) information effectively constrains the depth, spatial distribution and sharpness of upper-/mid-mantle reflectors. The olivine to wadsleyite phase boundary is deeper than the ocean and global averages and produces a dominant Τ– p domain signal. Laterally coherent observations of the deep 410-km seismic discontinuity, thin upper mantle transition zone and weak/absent 520-km reflector beneath hotspots make compelling arguments for large-scale, hot thermal anomalies in the top 400–600 km of the mantle. On the other hand, a relatively ‘flat’ and weak reflector at ∼653 km is inconsistent with ringwoodite to silicate perovskite + magnesiowÜstite transformation at temperatures greater than 2000 K. The lack of a negative correlation between topography and temperature implies (1) average or below-average temperatures at 600–700 km depths or (2) high temperatures and a dominating majorite garnet to Ca perovskite phase transformation. The proper choice between these two scenarios will directly impact the origin and depth of mantle plumes beneath hotspots. We further identify lower-mantle reflectors at 800–950 and 1100–1350 km depths beneath a number of the hotspots. Their presence implies that the chemistry and thermodynamics of the mid-mantle may be more complex than suggested by seismic tomography.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74768/1/j.1365-246X.2009.04242.x.pd

Global genome expression analysis of rice in response to drought and high-salinity stresses in shoot, flag leaf, and panicle

To elucidate genome-level responses to drought and high-salinity stress in rice, a 70mer oligomer microarray covering 36,926 unique genes or gene models was used to profile genome expression changes in rice shoot, flag leaf and panicle under drought or high-salinity conditions. While patterns of gene expression in response to drought or high-salinity stress within a particular organ type showed significant overlap, comparison of expression profiles among different organs showed largely organ-specific patterns of regulation. Moreover, both stresses appear to alter the expression patterns of a significant number of genes involved in transcription and cell signaling in a largely organ-specific manner. The promoter regions of genes induced by both stresses or induced by one stress in more than one organ types possess relative enrichment of two cis-elements (ABRE core and DRE core) known to be associated with water stress. An initial computational analysis indicated that novel promoter motifs are present in the promoters of genes involved in rehydration after drought. This analysis suggested that rice might possess a mechanism that actively detects rehydration and facilitates rapid recovery. Overall, our data supports a notion that organ-specific gene regulation in response to the two abiotic stresses may primarily be mediated by organ-specific transcription responses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11103-006-9111-1) contains supplementary material, which is available to authorized users

Loss of susceptibility as a novel breeding strategy for durable and broad-spectrum resistance

Recent studies on plant immunity have suggested that a pathogen should suppress induced plant defense in order to infect a plant species, which otherwise would have been a nonhost to the pathogen. For this purpose, pathogens exploit effector molecules to interfere with different layers of plant defense responses. In this review, we summarize the latest findings on plant factors that are activated by pathogen effectors to suppress plant immunity. By looking from a different point of view into host and nonhost resistance, we propose a novel breeding strategy: disabling plant disease susceptibility genes (S-genes) to achieve durable and broad-spectrum resistance