Nowadays, more and sensors are equipped on robots to increase robustness autonomous ability. We have seen various sensor suites different platforms, such as stereo cameras ground vehicles, a monocular camera with an IMU (Inertial Measurement Unit) mobile phones, aerial robots. Although many algorithms for state estimation been proposed in the past, they usually applied single or specific suite. Few of them can be employed multiple choices. In this paper, we general optimization-based...

Recent advances in trajectory replanning have enabled quadrotor to navigate autonomously unknown environments. However, high-speed navigation still remains a significant challenge. Given very limited time, existing methods no strong guarantee on the feasibility or quality of solutions. Moreover, most do not consider environment perception, which is key bottleneck fast flight. In this article, we present RAPTOR, robust and perception-aware framework support safe flight, addresses these issues...

Recently several different deep learning architectures have been proposed that take a string of characters as the raw input signal and automatically derive features for text classification. Few studies are available compare effectiveness these approaches character based classification with each other. In this paper we perform such an empirical comparison important cybersecurity problem DGA detection: classifying domain names either benign vs. produced by malware (i.e., Domain Generation...

In this article, we propose a complete and robust system for the aggressive flight of autonomous quadrotors. The proposed is built upon on classical teach-and-repeat framework, which widely adopted in infrastructure inspection, aerial transportation, search-and-rescue. For these applications, human's intention essential deciding topological structure trajectory drone. However, poor teaching trajectories changing environments prevent simple from being applied flexibly robustly. instead...

In recent years, small, inexpensive UAV - also known as drone has made great progress, which brings privacy and security issues. Drone detection is one of the important methods to solve these problems. The main challenges are: (1) A very confusing with other flying objects such a bird, (2) low-flying occlusion happens frequent, (3) existing surveillance coverage limited. Camera array can be used for large-scale airspace observation. this paper, we propose modular camera system audio...

Domain generation algorithms (DGAs) automatically generate large numbers of domain names in DNS fluxing for the purpose command-and-control (C&C) communication. DGAs are immune to static prevention methods like blacklisting and sinkholing. Detection a live stream queries server is referred as inline detection. Most previous approaches literature on DGA detection either: (i) based small synthetic data sets training, rather than collected from real traffic or (ii) require contextual...

Gradient-based trajectory optimization (GTO) has gained wide popularity for quadrotor replanning. However, it suffers from local minima, which is not only fatal to safety but also unfavorable smooth navigation. In this paper, we propose a replanning method based on GTO addressing issue systematically. A path-guided (PGO) approach devised tackle infeasible improves the success rate significantly. topological path searching algorithm developed capture collection of distinct useful paths in 3-D...

The condition assessment of road surfaces is essential to ensure their serviceability while still providing maximum traffic safety. This paper presents a robust stereo vision system embedded in an unmanned aerial vehicle (UAV). perspective view the target image first transformed into reference view, and this not only improves disparity accuracy, but also reduces algorithm's computational complexity. cost volumes generated from matching are then filtered using bilateral filter. latter has...

Drones are enabling new forms of cinematography. Aerial filming via drones in action scenes is difficult because it requires users to understand the dynamic scenarios and operate drone camera simultaneously. Existing systems allow user manually specify shots guide capture footage, while none them employ aesthetic objectives automate aerial scenes. Meanwhile, these cinematography depend on external motion perceive human action, which limited indoor environment. In this paper, we propose an...

Accurate and robust calibration is crucial to a multisensor fusion-based system. The of heterogeneous sensors particularly challenging because the huge difference captured sensor data. On other hand, many approaches ignore temporal that in fact as important spatial calibration. In this article, we focus on sensors, corresponding extrinsic rotation also derived. Most existing methods are specialized for certain combination, such an inertial measurement unit (IMU) camera or camera-Lidar...

The development of a nonparametric and versatile clustering algorithm has been longstanding challenge in unsupervised learning due to the exploratory nature problem. This study presents novel algorithm, named Gauging-, which can handle diverse cluster shapes operate manner. employs hierarchical merging process that starts from individual data points until no further clusters be merged. central component Gauging- is adaptive mergeability function, progressively determines if two are mergeable...

Abstract. The global near-surface soil freeze-thaw (FT) states are crucial for understanding complex interactions with hydrological, ecological, and climatic processes. However, current remote sensing of FT primarily relies on passive microwave sensing, which, despite its all-weather monitoring capabilities, suffers from low spatial resolution. This limitation restricts application to hydroclimatological scales, precluding use in finer-scale studies such as erosion hydrometeorological...

In this paper, we present a framework to do optimal time allocation for quadrotor trajectory generation. Using method, can generate minimum-time piecewise polynomial trajectories flights. We decouple the generation problem into two folds. Firstly smooth and safe curve which is parameterized by virtual variable. This named spatial independent of has fixed properties. Then mapping function decides how moves along respecting kinodynamic limits found minimizing total time. The maps variable...

Domain generation algorithms (DGAs) have become commonplace in malware that seeks to establish command and control communication between an infected machine the botmaster. DGAs dynamically consistently generate large volumes of malicious domain names, only a few which are registered by botmaster, within short time window around their time, subsequently resolved when on tries access them. Deep neural networks can classify names as benign or great interest real-time defense against DGAs. In...

Phosphorus is one of the major constraints to karst grassland productivity. Understanding effects different fertilization practices on soil phosphorus dynamics essential for enhancing bioavailability and rational management in grasslands. Here, we investigated fertilizers manures fractions explored relationship between properties fractions. The four fertilizer application designs were as follows: control (CK; no or manure); (F); manure (M); (FM). results showed that total (TP) concentration...

Abstract Automatic generation of high-quality meshes is a base CAD/CAE systems. The element extraction major mesh method for its capabilities to generate around the domain boundary and control local densities. However, widespread applications have been inhibited by difficulties in generating satisfactory interior or even complete mesh. method's primary challenge define rules achieving both geometric with complex shapes. This paper presents self-learning system, FreeMesh-S, that can...

In this paper, we present a new moving objects detection method in dynamic scenes to meet the real-time requirements. method, propose an improved SURF algorithm for feature extraction. The is via limiting number of detected points, and adopting fast reduce repeated calculation when calculating point's dominant orientation. This improves speed precision original SURF. To computation complexity global-search matching proposed. reduces time matching. Experimental results demonstrate that our...

Recent advances in trajectory replanning have enabled quadrotor to navigate autonomously unknown environments. However, high-speed navigation still remains a significant challenge. Given very limited time, existing methods no strong guarantee on the feasibility or quality of solutions. Moreover, most do not consider environment perception, which is key bottleneck fast flight. In this paper, we present RAPTOR, robust and perception-aware framework support safe A path-guided optimization (PGO)...

This paper investigates a finite-time disturbance observer (FTDO) based nonsingular terminal sliding mode control (NTSMC) approach for DC-DC boost converter system. By using exact feedback linearization theory and method to solve the output voltage regulation problem under load resistance changes external input variations. Integrating estimated by FTDO into design of nonlinear dynamic surface, NTSMC is developed reject effects mismatched disturbances achieve tracking performance. As compared...