In this expository paper, we provide an intuition and illustration-driven overview of two recent results that tie the dynamics of certain homeomorphisms of infinite-type surfaces, called end-periodic homeomorphisms, to the geometry of their associated (compactified) mapping tori. These results are analogues of a theorem of Brock in the finite-type setting for mapping tori of pseudo-Anosov homeomorphisms.
We study smooth proper embeddings of compact orientable surfaces in compact orientable $4$-manifolds and elements in the mapping class group of that surface which are induced by diffeomorphisms of the ambient $4$-manifolds. We call such mapping classes extendible. An embedding for which all mapping classes are extendible is called flexible. We show that for most of the surfaces there exists no flexible embedding in a $4$-manifold with homology type of a $4$-ball or of a $4$-sphere. As an application of our method, we address a question of Etnyre and Lekili and show that there exists no simple open book decomposition of $S^5$ with a spin page where all $3$-dimensional open books admit open book embeddings. We also provide many constructions and criteria for extendible and non-extendible mapping classes, and discuss a connection between extendibility and sliceness of links in a homology $4$-ball with $S^3$ boundary. Finally, we give a new generating set of the group of extendible mapping classes for the trivial embedding of a closed genus $g$ surface in $S^4$, consisting of $3g$ generators. This improves a previous result of Hirose giving a generating set of size $6g-1$.
In the current conditions of development of the country’s market economy, the methodological support for cadastral land valuation requires effective modernization and improvement of the existing mechanisms for determining cadastral value for a fair distribution of land tax among landowners. In this regard, the aim of the study was to develop a methodology for taking into account the qualitative state of soils in the cadastral valuation of agricultural lands in the conditions of an active land market, as well as to modernize the method for taking into account the quality of soils within the framework of the income approach in the conditions of a depressed land market. The study was conducted based on a set of scientific methods: the analytical method was used to conduct an analysis of the scientific review of the problem area and to substantiate the relevance of the study, a cycle of laboratory experiments was conducted using mechanical and chemical analyses, the construction of thematic maps was carried out using the dispersion method, the regression modeling method was used to determine the cadastral value of garden plots, and the land rent capitalization method was used to calculate the cadastral value of agricultural land. Research results were as follows: Methodological recommendations were provided for taking into account the quality of soils in the form of an integral indicator of physical and chemical properties in the model for calculating the specific indicator of cadastral value (SICV) of garden and vegetable lands in the conditions of an active land market. The method of accounting for the qualitative state of soil fertility in the form of a weighted quality score of an agricultural land plot was modernized when determining the specific gross income within the framework of the land rent capitalization method used to calculate the SICV. Based on field work and laboratory experiments, current indicators of soil fertility status were obtained, and soil quality scores for Saint Petersburg were calculated. The possibility of using an integral indicator (soil quality score) as a cost factor instead of a large number of fertility status indicators was proven. Also, models for calculating the SICV of garden and vegetable plots were built for the conditions of an active land market, according to which the cadastral value of land plots in Saint Petersburg was calculated for subsequent land taxation. For agricultural lands, using the example of a land plot of a high-commodity agricultural enterprise (Leningrad Region), the cadastral value was also calculated using the proposed income approach method. The scientific significance of the study lies in the improvement of the methodological foundations of cadastral valuation, as well as the technology of taking into account the quality of soils when calculating the cadastral value. The practical significance of the study lies in the applicability of the results of soil quality assessment and models for calculating the SICV for land taxation; individual market valuation for lending, purchase, and sale; lease of agricultural land; and allocation of land plots on account of a land share. In the area of developing a set of melioration measures on agricultural lands, including the development and implementation of agricultural technologies and technical means to improve soil fertility, the results of laboratory studies to determine the physical and chemical properties of soils can be used. The obtained soil quality scores for Saint Petersburg are also applicable to identifying unused and degraded lands for their transfer to other types of use.
There are several different methods in laser scanning technology including terrestrial laser scanner (TLS), airborne laser scanner (ALS), and mobile laser scanner (MLS). In addition to these scanners, there are personal laser scanners (PLS). PLS are examined under two main categories as handheld personal laser scanner (HPLS) and backpack personal laser scanner (BPLS) which are the latest additions to these laser scanning technologies. Today, the use of personal laser scanner technology is a popular research and application topics. The primary advantage of PLS lies in its high mobility in different topography conditions and rapid data acquisition. Unlike TLS and MLS, the operator carries the PLS device in the work area at standard walking speed, which is sufficient to collect data. Also, PLS technology eliminates the limitations of moving TLS equipment from one station point to another station point during the data collection process and installing instruments on a tripod again. In this paper, a case study was conducted using the LiBackpack DGC50 Mobile Scanner, which is the PLS technique, for the cadastral updating surveying in the Karaağaç District of Edirne province. It has been concluded that backpack laser scanners provide sufficient accuracy for cadastral studies in the study area.
Let $\mathbb{A}$ and $\mathbb{B}$ be circular annuli in the complex plane and consider the Dirichlet energy integral of $j-$degree mappings between $\mathbb{A}$ and $\mathbb{B}$. Then we minimize this energy integral. The minimizer is a $j-$degree harmonic mapping between annuli $\mathbb{A}$ and $\mathbb{B}$ provided it exits. If such a harmonic mapping does not exist, then the minimizer is still a $j-$degree mapping which is harmonic in $\mathbb{A}'\subset \mathbb{A}$ and it is a squeezing mapping in its complementary annulus $\mathbb{A}''=\mathbb{A}\setminus \mathbb{A}$. Such a result is an extension of the certain result of Astala, Iwaniec and Martin \cite{astala2010}.
In this paper, we introduce Vox-Fusion++, a multi-maps-based robust dense tracking and mapping system that seamlessly fuses neural implicit representations with traditional volumetric fusion techniques. Building upon the concept of implicit mapping and positioning systems, our approach extends its applicability to real-world scenarios. Our system employs a voxel-based neural implicit surface representation, enabling efficient encoding and optimization of the scene within each voxel. To handle diverse environments without prior knowledge, we incorporate an octree-based structure for scene division and dynamic expansion. To achieve real-time performance, we propose a high-performance multi-process framework. This ensures the system's suitability for applications with stringent time constraints. Additionally, we adopt the idea of multi-maps to handle large-scale scenes, and leverage loop detection and hierarchical pose optimization strategies to reduce long-term pose drift and remove duplicate geometry. Through comprehensive evaluations, we demonstrate that our method outperforms previous methods in terms of reconstruction quality and accuracy across various scenarios. We also show that our Vox-Fusion++ can be used in augmented reality and collaborative mapping applications. Our source code will be publicly available at \url{https://github.com/zju3dv/Vox-Fusion_Plus_Plus}
Tudor Alinei-Poiana, David Rete, Davian Martinovici
et al.
We propose a low-cost laboratory platform for development and validation of underwater mapping techniques, using the BlueROV2 Remotely Operated Vehicle (ROV). Both the ROV and the objects to be mapped are placed in a pool that is imaged via an overhead camera. In our prototype mapping application, the ROV's pose is found using extended Kalman filtering on measurements from the overhead camera, inertial, and pressure sensors; while objects are detected with a deep neural network in the ROV camera stream. Validation experiments are performed for pose estimation, detection, and mapping. The litter detection dataset and code are made publicly available.
The availability of low-cost GNSS receivers opens up new possibilities for performing precision topographic surveys.
To achieve acceptable survey precision, it is necessary to use the services provided by a network of permanent stations.
The services consist of a stream of differential correction data of the detected positions, transmitted in the RTCM format (Radio Technical Commission for Maritime Services, international standard) which are received through the NTRIP protocol following an authenticated connection to the network site.
Large-scale semantic mapping is crucial for outdoor autonomous agents to fulfill high-level tasks such as planning and navigation. This paper proposes a novel method for large-scale 3D semantic reconstruction through implicit representations from posed LiDAR measurements alone. We first leverage an octree-based and hierarchical structure to store implicit features, then these implicit features are decoded to semantic information and signed distance value through shallow Multilayer Perceptrons (MLPs). We adopt off-the-shelf algorithms to predict the semantic labels and instance IDs of point clouds. We then jointly optimize the feature embeddings and MLPs parameters with a self-supervision paradigm for point cloud geometry and a pseudo-supervision paradigm for semantic and panoptic labels. Subsequently, categories and geometric structures for novel points are regressed, and marching cubes are exploited to subdivide and visualize the scenes in the inferring stage. For scenarios with memory constraints, a map stitching strategy is also developed to merge sub-maps into a complete map. Experiments on two real-world datasets, SemanticKITTI and SemanticPOSS, demonstrate the superior segmentation efficiency and mapping effectiveness of our framework compared to current state-of-the-art 3D LiDAR mapping methods.
Wajnryb proved that the mapping class group of a closed oriented surface is generated by two elements. We proved that the mapping class group is generated by two pseudo-Anosov elements. In particular, if the genus is greater than or equal to nine, we can take the generators to two conjugate pseudo-Anosov elements with arbitrarily large dilatations. Another result we prove is that the mapping class group is generated by two conjugate reducible but not periodic elements if the genus is greater than or equal to eight. We also give similar results to the first and third results for the hyperelliptic mapping class group when the genus is greater than or equal to one.
In Italy, the repression of forest fires also involves virtual reality, thanks to the Forest Fire Area Simulator (FFAS), a unique technological platform of its kind, with which the “Arma dei Carabinieri” trains soldiers specialized in investigations
post forest fire.
Realized at the headquarters of the “Scuola Forestale Carabinieri di Castel Volturno”, the system is able to generate immersive and interactive scenarios of forest ecosystems attacked by fire and allows the simulated execution of the technical activities
of the judicial police.
This paper presents a real-time 3D mapping framework based on global matching cost minimization and LiDAR-IMU tight coupling. The proposed framework comprises a preprocessing module and three estimation modules: odometry estimation, local mapping, and global mapping, which are all based on the tight coupling of the GPU-accelerated voxelized GICP matching cost factor and the IMU preintegration factor. The odometry estimation module employs a keyframe-based fixed-lag smoothing approach for efficient and low-drift trajectory estimation, with a bounded computation cost. The global mapping module constructs a factor graph that minimizes the global registration error over the entire map with the support of IMU constraints, ensuring robust optimization in feature-less environments. The evaluation results on the Newer College dataset and KAIST urban dataset show that the proposed framework enables accurate and robust localization and mapping in challenging environments.
Nonostante il pervasivo e fondamentale ruolo dei sistemi globali di navigazione via satellite (“Global Navigation Satellite Systems, GNSSs”) in praticamente tutte le infrastrutture economiche ed industriali della nostra società, cresce la preoccupazione per la troppa dipendenza da sistemi altamente affidabili, ma al contempo anche intrinsecamente vulnerabili.
Imperial hegemony established by the Habsburg Monarchy relied upon proper mapping during its conquests. The need for the development of geodesy and establishing reference frames was important. Until the end of the First World War, Vojvodina belonged to the Austrian-Hungarian Empire, so all of its surveys were carried out as part of many organized land surveys in the Monarchy. Today, more than 100 years after Vojvodina became the Autonomous Province of Serbia, the network developed by the Monarchy and cadastral plans from that period are still in use. In this paper, in addition to a historical overview of military and cadastral surveys in Vojvodina, we will show data that have historical significance and are available on the Internet and in historical archives. We will also emphasize how the maps available in historical archives of the neighbouring countries could have been used to set up Serbian national spatial data infrastructure.
With rapid growth of urban environments worldwide, there is an increasing need to develop more innovative and efficient land administration systems. In Australia, various jurisdictions are currently in the process of implementing 3D cadastre to support better land administration services to the wider community. The ‘Cadastre 2034 Strategy’ published by the Intergovernmental Committee on Surveying and Mapping (ICSM) for Australia in 2014 indicates that a digital cadastre will be implemented as part of that strategy. As part of development of 3D cadastre, State of New South Wales has used the ePlan model based on LandXML for digital lodgement and validation of cadastral plans. This initiative aims to replace PDF cadastral plans with the digital format of LandXML. However, with the introduction of LandXML as the chosen formats for digital cadastral plans in NSW, there has been a significantly low level of Strata Plan digital capture and submission in LandXML format by the surveying industry. The research aims to identify the main challenges and explore a suitable method to improve the adoption of the digital format for Strata Plan submission and development of 3D cadastre in NSW. In this research paper, a mixed method research approach has been used by integrating both qualitative and quantitative data. The primary data was collected using online questionnaires and surveys of different stakeholders from government and the private surveying industry. The data allowed for the assessment of the effectiveness and implications of the digital system currently maintained by the NSW LRS (Land Registry Services). A case study was used for the creation, validation and lodgement of an existing strata plan using LandXML format. This paper demonstrates that implementation of 3D digital cadastral plans needs to be more structured in order to satisfy all stakeholders involved. More investment into the representation of complex 3D geometric models and classification for validation will improve the uptake by surveyors. The paper concludes with a discussion on the implications of the proposed strata plan implementation strategy and proposes future research within the topic of strata plan validation in NSW, Australia.
The human ability to flexibly reason using analogies with domain-general content depends on mechanisms for identifying relations between concepts, and for mapping concepts and their relations across analogs. Building on a recent model of how semantic relations can be learned from non-relational word embeddings, we present a new computational model of mapping between two analogs. The model adopts a Bayesian framework for probabilistic graph matching, operating on semantic relation networks constructed from distributed representations of individual concepts and of relations between concepts. Through comparisons of model predictions with human performance in a novel mapping task requiring integration of multiple relations, as well as in several classic studies, we demonstrate that the model accounts for a broad range of phenomena involving analogical mapping by both adults and children. We also show the potential for extending the model to deal with analog retrieval. Our approach demonstrates that human-like analogical mapping can emerge from comparison mechanisms applied to rich semantic representations of individual concepts and relations.
Hua Deng, Jinjing Qiao, Saminathan Ponnusamy
et al.
In this paper, we investigate properties of harmonic entire mappings. Firstly, we give the characterizations of the order and the type for a harmonic entire mapping $f=h+\overline{g}$, respectively, and also consider the relationship between the order and the type of $f$, $h$, and $g$. Secondly, we investigate the harmonic mappings $f=h+\overline{g}$ such that $f^{(n_p)}=h^{(n_p)}+\overline{g^{(n_p)}}$ are univalent in the unit disk, where $\{n_p\}_{p=1}^{\infty}$ be a strictly increasing sequence of nonnegative integers. In terms of the sequence $\{n_p\}_{p=1}^{\infty}$, we derive several necessary conditions for these mappings to be entire and also establish an upper bound for the order of these mappings.
The peculiarities of the free market of agricultural lands are described. The consequences of opening the land market in terms of economic, land and legal components in the system of land relations are presented. The list of conditions for the purchase and sale of agricultural land is highlighted. The specifics of the functioning of the free market of agricultural lands are substantiated. The characteristic of basic normative-legal acts in the sphere of functioning of the land market is given. A comparative analysis of the current state of purchase and sale of land by farms and agricultural holdings. A comparison of the indicators of the number of concluded agreements of purchase and sale of agricultural land, the average value of rent per 1 hectare of land, respectively, by region and price fluctuations per 1 hectare of land when concluding purchase and sale agreements. The foreign experience of land market function with the detailing of the factors influencing the further development is analyzed. In particular, the problems and needs in the functioning of the land market of Poland, Brazil, the United States and the United Kingdom are considered. The possibility of introducing an electronic system such as EMBRAESP, which monitors the main indicators of the efficiency of the urban real estate market, together with city legislation, land regulations and large public works projects that may affect the behavior of real estate markets.
Key words: land relations, land market, land lease, land legislation.
AbstractThe article addresses the issues of maintaining the landscape and ecological balance of the regions, increasing land productivity, improving land cadastre in accordance with modern technologies and rapid monitoring on the basis of GIS (geographic information systems) technologies. The work also provides information on land cadastre indicators in the new century of technologies, ways of their collection, the role of GIS technologies, principles, methods of cadastral mapping and problems related to their improvement and development. In addition, the article includes an inventory of district land resources and the creation of cadastral maps, as well as a qualitative analysis of existing agricultural land.