Vector Map Research Articles

Cadastral value of land taking into account geo-environmental factors

An urgent task is to determine the cadastral value of land, taking into account the geo-environmental factors affecting the production of environmentally friendly agricultural products and the health of citizens living in the respective territories. The contamination of the territory of the Novgorod region caused by natural and technogenic factors is considered. Natural factors include earth’s crust fractures and the associated infection of the territory with radon. Technogenic factors include the consequences of the accident at the Chernobyl nuclear power plant. Basic concepts from the field of measuring radiation contamination of a territory and human radiation doses are given. Radioecological disturbances are considered: earth’s crust fractures, territories with exceeded norms for the content of radon, cesium, potassium, thorium and uranium. Thematic mapping of radioecological violations was done in the environment of the Mapinfo program. Herewith, a schematic ecological map in raster format and a vector map of the region were used, on the basis of which thematic maps were created. On the basis of building norms and rules, as well as using the cost method of decontamination to reduce the radiation dose per 1 person-sievert, it was proved that the cadastral value of agricultural land should be reduced by fifty percent relative to its current values. The dependence of oncological morbidity in the region on the radiation infection of the territory is shown cartographically. Infection with cesium does not significantly affect the irradiation dose. It is necessary to monitor the state of radioactive potassium, and one-time measures should be taken to decontaminate the territory from thorium and uranium. The cost method justifies the cost of such measures per hectare of land.

An Analysis of the Benefits and Difficulties of Aerial Magnetic Vector Navigation

Recent successful flight tests have demonstrated scalar magnetic anomaly navigation to be a viable GPS-alternative navigation system. These flight tests matched magnetic field measurements to maps of the Earth's crustal magnetic field in order to navigate. Scalar magnetic navigation uses only the magnetic field intensity, not direction, in order to navigate. While it appears obvious to extend aerial magnetic navigation to use the full vector field, in practice there are substantial obstacles to doing so. This article explores the key challenges of magnetic vector navigation including current sensor limitations, lack of high frequency magnetic vector maps of the Earth's crust, and proper integration of the magnetic data with an inertial navigation system. In overcoming these challenges several key benefits of magnetic vector navigation over scalar magnetic navigation become apparent, including modestly improved navigation accuracy and greatly improved platform attitude.

A unified concept of approximate and quasi efficient solutions and associated subdifferentials in multiobjective optimization

In this paper, we introduce some new notions of quasi efficiency and quasi proper efficiency for multiobjective optimization problems that reduce to the most important concepts of approximate and quasi efficient solutions given up to now. We establish main properties and provide characterizations for these solutions by linear and nonlinear scalarizations. With the help of quasi efficient solutions, a generalized subdifferential of a vector mapping is introduced, which generates a number of approximate subdifferentials frequently used in optimization in a unifying way. The generalized subdifferential is related to the classical subdifferential of real functions by the method of scalarization. An application of generalized subdifferential to express optimality conditions for quasi efficient solutions is also given.

Optimum Municipal Solid Waste Disposal Site Selection Using Gis Based Multi-Criteria Decision Analysis: A Case of Nekemte Town, Oromia Regional State, Ethiopia

Solid waste is a major global concern particularly in developing countries. Municipal landfill site selection is becoming the main challenge as a result of various factors. To make the site to be selected environmentally sound, socially acceptable and economically feasible, GIS based multi-criteria decision analysis ( MCDA ) method that has the capability to combine spatially referenced data with experts’ value judgment was used in this study. The analytic hierarchy process ( AHP ) was the major technique of MCDA used to derive the weights of the nine criteria considered – distance from road network, geology, distance from fault lines, soil permeability, slope, distance from rivers/streams, distance from lakes, distance from the built-up areas and land use/land cover types. After creating Multiple-ring Buffers for road network, fault lines, rivers/streams, lakes and built-up areas by reviewing various literatures, all the criteria were standardized by reclassifying them into suitability classes. The weights of the reclassified criteria were derived using AHP Pair-wise Comparison Matrix in Microsoft Excel and then combined together using the Weighted Overlay tool in ArcGIS to produce the composite suitability map of the study area. Accordingly, 0.43% and 0.02% of the study area are unsuitable and highly suitable, respectively. The remaining 41.64%, 51.12%, and 6.8% of the study area are poorly suitable, moderately suitable and suitable, respectively. The raster composite suitability map of study area was then converted into vector map to select candidate disposal sites. Accordingly, six candidate municipal solid waste disposal sites were selected, evaluated with respect to their area (size), distance from center and distance from the nearby built-up area. They were weighted with respect to these three evaluating criteria using AHP Pair-wise Comparison Matrix and finally mapped and ranked. The first, second and third ranked candidate disposal sites have an area of 46 ha, 29 ha and 35ha, respectively. The first and second candidate sites are located in Burka Jato sub-town, while the third one is located in Sorga sub-town. In order to reduce the adverse impact of surface water pollution in the downstream, runoff should not flow into and out of the MSW disposal sites. To minimize groundwater pollution, detailed investigation on sub-surface condition of the site should be made during design. Greenhouse gases collection should also be designed to reduce air pollution. Keywords: multi-criteria decision analysis; analytic hierarchy process; Pair-wise Comparison Matrix; Weight Overlay DOI: 10.7176/JEES/10-11-01 Publication date: November 30 th 2020

A method for analyzing the expansion and shrinkage of point pattern

AbstractThis article proposes a new method for analyzing the spatial expansion and shrinkage of point patterns. Spatial expansions of epidemic diseases and market areas are represented as the expansions of point patterns when disease cases and store customers are represented as points. The spatial expansion and shrinkage have been studied in many scientific fields. Existing analytical methods, however, are not sufficient for treating complicated spatiotemporal patterns. To answer this demand, this article develops a new method for analyzing the expansion and shrinkage of points. Three vector measures evaluate the degree and direction of expansion and shrinkage as functions of location and time. They are visualized as vector maps, which are valid for capturing the global spatiotemporal pattern as well as for discussing the local variation. Summary measures of these vectors allow us to grasp the overall spatiotemporal pattern efficiently. To test the validity of the proposed method, this article applies it to the analysis of visitors to Shinjuku and Ginza in Tokyo. The proposed measures permitted us to evaluate the spatiotemporal pattern of the visitors in detail and to consider its underlying structure from various perspectives, which indicated the soundness of the technique.

An end-to-end shape modeling framework for vectorized building outline generation from aerial images

The identification and annotation of buildings has long been a tedious and expensive part of high-precision vector map production. The deep learning techniques such as fully convolution network (FCN) have largely promoted the accuracy of automatic building segmentation from remote sensing images. However, compared with the deep-learning-based building segmentation methods that greatly benefit from data-driven feature learning, the building boundary vector representation generation techniques mainly rely on handcrafted features and high human intervention. These techniques continue to employ manual design and ignore the opportunity of using the rich feature information that can be learned from training data to directly generate vectorized boundary descriptions. Aiming to address this problem, we introduce PolygonCNN, a learnable end-to-end vector shape modeling framework for generating building outlines from aerial images. The framework first performs an FCN-like segmentation to extract initial building contours. Then, by encoding the vertices of the building polygons along with the pooled image features extracted from segmentation step, a modified PointNet is proposed to learn shape priors and predict a polygon vertex deformation to generate refined building vector results. Additionally, we propose 1) a simplify-and-densify sampling strategy to generate homogeneously sampled polygon with well-kept geometric signals for shape prior learning; and 2) a novel loss function for estimating shape similarity between building polygons with vastly different vertex numbers. The experiments on over 10,000 building samples verify that PolygonCNN can generate building vectors with higher vertex-based F1-score than the state-of-the-art method, and simultaneously well maintains the building segmentation accuracy achieved by the FCN-like model.

Non-Target Soil Deformation Mapping by Photogrammetry for Underground Tunnel Model Test

A complex urban environment requires frequent underground tunneling to resolve heavy traffic congestion. With new underground lines being constructed close to existing underground lines the soil deformation around the underground tunnels should be studied and analyzed with proper tunnel model tests. Therefore, we conducted non-target soil deformation mapping using photogrammetry for two different underground tunnel models of sandy soil and clay. Self-calibrated cameras were used to acquire before and after images of the models with the loading test. With accurately estimated exterior orientation parameters (EOPs), the soil deformation was measured via image matchings between two images. Different image matching parameters were tested and the effect of filtering was investigated to produce soil deformation vectors on the images. Experimental results showed that sandy soil and clay required different matching window sizes for the best results. In addition, the deformation vector filtering was helpful to suppress outliers only when an image matching threshold was not applied. With proper matching parameter setup and filtering, the visually informative soil deformation vector map could be generated using photogrammetry.

A presentation and retrieval hash scheme of images based on principal component analysis

Image representation and approximate query is always a research challenge and is affected greatly by the dimension and size of images. Since hash-based methods and binary encodings in combination with other techniques, such as kernel tricks, a longer binary code and mapping vectors rotation, can maintain a linear query time and query accuracy, they have been used in this area broadly. This paper develops principal component analysis hashing (PCAH) and unequal length of binary coding to divide images into more categories, denoted as PCA-MD, to improve accuracy of the representation and lookup of images. This paper firstly proves that the eigenvector mapping is locality sensitive, which is the basis for more classes division. For the anisotropy of the eigenvectors, PCA-MD utilizes an unequal length of binary coding and fewer eigenvectors, rather than an equal code, to divide the images mapped on every eigenvector to more categories. Moreover, L1-norm distance is applied to measure the distances of images to avoid the enormous computation of Euclidean distance. Theoretical analysis and extensive experimental results demonstrate that the PCA-MD has a higher query performance and a slight longer run time than the state-of-the-art approaches based on the Hamming distance. This in turn verifies that PCAH is a locality sensitive hash and that partitioning into more categories rather than only two categories is reasonable.

High-resolution tunneling spin transport characteristics of topologically distinct magnetic skyrmionic textures from theoretical calculations

High-resolution tunneling electron spin transport properties (longitudinal spin current (LSC) and spin transfer torque (STT) maps) of topologically distinct real-space magnetic skyrmionic textures are reported by employing a 3D-WKB combined scalar charge and vector spin transport theory in the framework of spin-polarized scanning tunneling microscopy (SP-STM). For our theoretical investigation metastable skyrmionic spin structures with various topological charges (Q=-3,-2,-1,0,1,2) in the (Pt0.95Ir0.05)/Fe/Pd(111) ultrathin magnetic film are considered. Using an out-of-plane magnetized SP-STM tip it is found that the maps of the LSC vectors acting on the spins of the magnetic textures and all STT vector components exhibit the same topology as the skyrmionic objects. In contrast, an in-plane magnetized tip generally does not result in spin transport vector maps that are topologically equivalent to the underlying spin structure, except for the LSC vectors acting on the spins of the skyrmionic textures at a specific relation between the spin polarizations of the sample and the tip. The magnitudes of the spin transport vector quantities exhibit close relations to charge current SP-STM images irrespectively of the skyrmionic topologies. Moreover, we find that the STT efficiency (torque/current ratio) acting on the spins of the skyrmions can reach large values up to ~25 meV/μA (~0.97 h/e) above the rim of the magnetic objects, but it considerably varies between large and small values depending on the lateral position of the SP-STM tip above the topological spin textures. A simple expression for the STT efficiency is introduced to explain its variation. Our calculated spin transport vectors can be used for the investigation of spin-polarized tunneling-current-induced spin dynamics of topologically distinct surface magnetic skyrmionic textures.

UAV Navigation System Autonomous Correction Algorithm Based on Road and River Network Recognition

Abstract—The paper considers an original autonomous correction algorithm for UAV navigation system based on comparison between terrain images obtained by onboard machine vision system and vector topographic map images. Comparison is performed by calculating the homography of vision system images segmented using the convolutional neural network and the vector map images. The presented results of mathematical and flight experiments confirm the algorithm effectiveness for navigation applications.

Evaluating the Performance of Three Popular Web Mapping Libraries: A Case Study Using Argentina’s Life Quality Index

Recent Web technologies such as HTML5, JavaScript, and WebGL have enabled powerful and highly dynamic Web mapping applications executing on standard Web browsers. Despite the complexity for developing such applications has been greatly reduced by Web mapping libraries, developers face many choices to achieve optimal performance and network usage. This scenario is even more complex when considering different representations of geographical data (raster, raw data or vector) and variety of devices (tablets, smartphones, and personal computers). This paper compares the performance and network usage of three popular JavaScript Web mapping libraries for implementing a Web map using different representations for geodata, and executing on different devices. In the experiments, Mapbox GL JS achieved the best overall performance on mid and high end devices for displaying raster or vector maps, while OpenLayers was the best for raster maps on all devices. Vector-based maps are a safe bet for new Web maps, since performance is on par with raster maps on mid-end smartphones, with significant less network bandwidth requirements.

Integrally Cooperative Spatio-Temporal Feature Representation of Motion Joints for Action Recognition

In contemporary research on human action recognition, most methods separately consider the movement features of each joint. However, they ignore that human action is a result of integrally cooperative movement of each joint. Regarding the problem, this paper proposes an action feature representation, called Motion Collaborative Spatio-Temporal Vector (MCSTV) and Motion Spatio-Temporal Map (MSTM). MCSTV comprehensively considers the integral and cooperative between the motion joints. MCSTV weighted accumulates limbs’ motion vector to form a new vector to account for the movement features of human action. To describe the action more comprehensively and accurately, we extract key motion energy by key information extraction based on inter-frame energy fluctuation, project the energy to three orthogonal axes and stitch them in temporal series to construct the MSTM. To combine the advantages of MSTM and MCSTV, we propose Multi-Target Subspace Learning (MTSL). MTSL projects MSTM and MCSTV into a common subspace and makes them complement each other. The results on MSR-Action3D and UTD-MHAD show that our method has higher recognition accuracy than most existing human action recognition algorithms.

Beyond Euclidean Distance for Error Measurement in Pedestrian Indoor Location

Indoor positioning systems (IPSs) suffer from a lack of standard evaluation procedures enabling credible comparisons: this is one of the main challenges hindering their widespread market adoption. Traditionally, accuracy evaluation is based on positioning errors defined as the Euclidean distance between the true positions and the estimated positions. While Euclidean is simple, it ignores obstacles and floor transitions. In this article, we describe procedures that measure a positioning error defined as the length of the pedestrian path that connects the estimated position to the true position. The procedures apply pathfinding on floor maps using visibility graphs (VGs) or navigational meshes (NMs) for vector maps and fast marching (FM) for raster maps. Multifloor and multibuilding paths use the information on vertical in-building communication ways and outdoor paths. The proposed measurement procedures are applied to position estimates provided by the IPSs that participated in the EvAAL-ETRI 2015 competition. Procedures are compared in terms of pedestrian path realism, indoor model complexity, path computation time, and error magnitudes. The VGs algorithm computes shortest distance paths; NMs produce very similar paths with significantly shorter computation time; and FM computes longer, more natural-looking paths at the expense of longer computation time and memory size. The 75th percentile of the measured error differs among the methods from 2.2 to 3.7 m across the evaluation sets.

4D FLOW Magnetic Resonance Imaging in the Study of Blood Flow in Patients With Aortic Coarctation in the Long-Term After Surgery

Aim Comprehensive evaluation of blood flow in the thoracic aorta using a software for 4D processing of magnetic resonance (MR) images of the heart and blood vessels (4D Flow) in patients with aortic coarctation in the late postoperative period.Materials and methods The MR study of the heart was performed for 10 patients (7 boys and 3 girls) aged 8 to 13 years (median, 9.5 [8.3; 10.8] years) who underwent resection with end-to-end anastomosis for aortic coarctation at age of 2 weeks to 10 months. MR tomography was performed on a 1.5 T MR scanner using a multichannel surface coil for scanning, electrocardiographic synchronization, and a specialized package of pulse sequences for scanning of the heart. Blood flow was evaluated with a 4D data handling software for processing of MR images of heart and blood vessels (4D Flow). The following blood flow parameters were analyzed: blood flow volume per second, peak blood flow velocity, peak and minimum blood flow area at the levels of ascending aorta, arch, isthmus, and descending aorta, and pressure gradient at the level of maximum narrowing of the aorta. 3D-MR images were used for evaluation of aortic geometry. Blood flow formation, distribution, and trajectories were analyzed by maps of vectors, particle trace, and stream lines. Statistical analysis was performed with a Statistica (v. 6.0 StatSoft Inc.) package.Results Accelerated flow in the region of residual aortic stenosis in systole was observed in all patients; 4 patients had an additional vortex flow below the aortic stenosis and a spiral flow in the descending aorta. The pressure gradient on the aortic isthmus was directly correlated with the left ventricular myocardial mass index (r=0.65; р=0.04) and indexes of blood flow in the ascending and descending aorta (р=0.03; р=0.026). No significant correlation was found for blood flow indexes and geometry of the aortic arch (H / L). Delayed contrast enhancement MR imaging did not detect any fibrotic changes in the myocardium in only one patient. The fibrosis severity inversely correlated with the right ventricular ejection fraction (r=0.65; р=0.04) and directly correlated with the pressure gradient at the aortic isthmus (r=0.63; p=0.05).Conclusion The 4D MR image processing software for the heart and blood vessels allows studying the blood flow in detail under natural conditions, provides potential advantages in comprehensive evaluation of patients with aortic coarctation during a dynamic follow-up. For a definitive conclusion about the relationship between the altered blood flow in the thoracic aorta and markers of residual, post-correction pathology, larger studies are required as well as long-term follow-up of patients with documented pathological patterns of blood flow (changes in blood flow velocity and volume throughout the entire thoracic aorta in combination with disorders in the normal flow geometry during the cardiac cycle).

A novel multi-stage watermarking scheme of vector maps

Vector maps are distributed frequently among various departments and subscribers, and traditional single-stage watermarking technology cannot provide powerful multi-copyright protection of them. In this paper, a novel multi-stage watermarking algorithm is proposed for vector maps, aiming at robustness enhancement and maximum-supported watermark capacity improvement. A watermark generation method is designed based on QR code to shorten watermark length, and watermarks are embedded into polar coordinates of map vertices so as to improve the robustness of the proposed scheme. Another method of copyright information combination is raised to keep watermark length invariant along with the increasing of the total stages of watermark data, and the maximum-supported stages of watermarks can be thus improved without affecting the robustness of watermarking algorithm. Moreover, each stage of copyright information occupies a specified space within the final watermark data, and non-interference among various watermarks can be guaranteed and different copyright data can be efficiently distinguished after watermark extraction. Compared with the existing researches, the proposed scheme can increase effectively the size of maximum-supported watermark capacity, and it has strong robustness under common geometric and non-geometric attacks, which have been validated by both theoretical analysis and comprehensive experiments.

Vector conjugation and subdifferential of vector topical function in complete lattice

In our previous work, we introduced a vector topical function which takes values in a general ordered Banach space. With some weak versions of supremum, a set-valued mapping was proposed to build the envelope for it. In this paper, regarding the image space as a complete lattice, we present a vector mapping as the support to study the abstract convex framework of the vector topical function. This framework provides a dual space consisting of vector mappings. Based on that, we obtain the global Lipschitz of the vector topical mapping, discussing the abstract convex conjugation and subdifferential. Further more, we investigate how the vector topical feature behaves from the dual point of view. Some dual characterizations of vector topical mapping are also established.

A new vector map watermarking technique in frequency domain based on LCA-transform

Two-dimensional vector maps are vulnerable to issues related to copyright owner’s protection, which have an impact on the vector-data usage in different applications. Watermarking schemes are required in order to prevent this type of attack rotation, uniform scaling and translation (RST), invariance property, embedding distortion control and a high level of capacity in their concealment of a digital vector map’s information. This process typically involves transforming an original map and embedding the watermark. In this paper, a new approach to copyright protection for vector maps is proposed using a linear cellular automata (LCA) algorithm. The approach taken is as follows: (1) an original map, which is LCA-transformed, is obtained; (2) the watermark bit insertion process is conducted on the coefficient of the transformation result frequency into the LSB pattern; and (3) the inverse LCA transformation of the map is employed to obtain the watermarked map. Subsequent analysis has found that this approach provides desirable levels of fidelity, invisibility, capacity and computational complexity. It is also resistant to geometric and signal-operations attacks and provides multi-frequency domains for digital watermarking.

Combinational spatial and frequency domains watermarking for 2D vector maps

Watermarking plays an import role in digital copyright protection. It enables copyright owners to embed invisible watermarks within copies of data before distribution. However, most existing watermarking algorithms for 2D vector maps use either spatial domain methods, e.g., the Least Significant Bit or frequency domain methods, e.g., discrete Fourier transform (DFT), and very few algorithms combine the two domains. In order to improve the robustness of watermarks to against more common attacks, a novel algorithm using a combination of spatial and frequency domains is presented. Both the spatial domain and the frequency domain can be used for watermark embedding. Obviously, the advantages of each method are retained and the disadvantages of each method are offset by complementation. The watermark was also shuffled before embedding. A one-way hash function was used to map the watermark and 2D vector map. By using two different methods, one part of the watermark was embedded into the spatial domain first and another part of the watermark was embedded into the DFT domain. Additionally, the watermark was embedded multiple times. No original map data are required for the watermark extraction procedure. Analysis shows that the distortions of the watermarked data are extremely small, and the algorithm is more robust than methods using a single domain. It can resist the most common attacks, such as vertex insertion and removal, cropping, compression, reordering, and data format conversion attacks. It is also robust against rotation scaling and translation attacks.

THE ASSESSMENT OF CURVED CENTERLINE GENERATION IN HDMAPS BASED ON POINT CLOUDS

Abstract. Over the decades, autonomous driving technology has attracted a lot of attention and is under rapid development. However, it still suffers from inadequate accuracy in a certain area, such as the urban area, Global Navigation Satellite System (GNSS) hostile area, due to the multipath interference or Non-Line-of-Sight (NLOS) reception. In order to realize fully autonomous applications, High Definition Maps (HD Maps) become extra assisted information for autonomous vehicles to improve road safety in recent years. Compared with the conventional navigation maps, the accuracy requirement in HD Maps, which is 20 cm in the horizontal direction and 30 cm in 3D space, is considerably higher than the conventional one. Additionally, HD Maps consist of rich and high accurate road traffic information and road elements. For the requirement of high accuracy, conducting a Mobile Laser Scanning (MLS) system is an appropriate method to collect the geospatial data accurately and efficiently. Nowadays, digital vector maps are constructed by digitalizing manually on the collected data. However, the manual process spends a lot of manpower and is not efficient and practical for a large field. Therefore, this paper proposes to automatically construct the crucial road elements, such as road edge, lane line, and centerline, to generate the HD Maps based on point clouds collected by the MMS from the surveying company. The RMSEs in the horizontal direction of the road edge, lane line, and centerline are all lower than 30 cm in 3D space.

Voltage-driven displacement of magnetic vortex cores

Magnetic vortex cores in polycrystalline Ni discs underwent non-volatile displacements due to voltage-driven ferroelectric domain switching in single-crystal BaTiO3. This behaviour was observed using photoemission electron microscopy to image both the ferromagnetism and ferroelectricity, while varying in-plane sample orientation. The resulting vector maps of disc magnetization match well with micromagnetic simulations, which show that the vortex core is translated by the transit of a ferroelectric domain wall, and thus the inhomogeneous strain with which it is associated. The non-volatility is attributed to pinning inside the discs. Voltage-driven displacement of magnetic vortex cores is novel, and opens the way for studying voltage-driven vortex dynamics.