Automated Structural-level Alignment of Multi-view TLS and ALS Point Clouds in Forestry

Access to highly detailed models of heterogeneous forests from the near surface to above the tree canopy at varying scales is of increasing demand as it enables more advanced computational tools for analysis, planning, and ecosystem management. LiDAR sensors available through different scanning platforms including terrestrial, mobile and aerial have become established as one of the primary technologies for forest mapping due to their inherited capability to collect direct, precise and rapid 3D information of a scene. However, their scalability to large forest areas is highly dependent upon use of effective and efficient methods of co-registration of multiple scan sources. Surprisingly, work in forestry in GPS denied areas has mostly resorted to methods of co-registration that use reference based targets (e.g., reflective, marked trees), a process far from scalable in practice. In this work, we propose an effective, targetless and fully automatic method based on an incremental co-registration strategy matching and grouping points according to levels of structural complexity. Empirical evidence shows the method's effectiveness in aligning both TLS-to-TLS and TLS-to-ALS scans under a variety of ecosystem conditions including pre/post fire treatment effects, of interest to forest inventory surveyors

On the Importance to Economic Success of Property Rights in Finance and Innovation

This Essay surveys recent developments across the fields of finance and innovation to highlight some common themes concerning the importance of property rights to economic success. Society regularly makes choices when shaping the precise contours of the legal institutions that govern the behavior of market actors, often in response to high profile issues like the collapse of Enron and the patenting of life-saving AIDS drugs. Recognizing that no set of legal institutions or related enforcement mechanisms will be perfect, this Essay explores some particularly helpful institutional features based on property rights that too often are overlooked by policy makers and commentators, even though these property-based institutional features have long been associated with economic success in a number of diverse settings

On the Importance to Economic Success of Property Rights in Finance and Innovation

This Essay surveys recent developments across the fields of finance and innovation to highlight some common themes concerning the importance of property rights to economic success. Society regularly makes choices when shaping the precise contours of the legal institutions that govern the behavior of market actors, often in response to high profile issues like the collapse of Enron and the patenting of life-saving AIDS drugs. Recognizing that no set of legal institutions or related enforcement mechanisms will be perfect, this Essay explores some particularly helpful institutional features based on property rights that too often are overlooked by policy makers and commentators, even though these property-based institutional features have long been associated with economic success in a number of diverse settings

On the Importance to Economic Success of Property Rights in Finance and Innovation

This Essay surveys recent developments across the fields of finance and innovation to highlight some common themes concerning the importance of property rights to economic success. Society regularly makes choices when shaping the precise contours of the legal institutions that govern the behavior of market actors, often in response to high profile issues like the collapse of Enron and the patenting of life-saving AIDS drugs. Recognizing that no set of legal institutions or related enforcement mechanisms will be perfect, this Essay explores some particularly helpful institutional features based on property rights that too often are overlooked by policy makers and commentators, even though these property-based institutional features have long been associated with economic success in a number of diverse settings

Procedurally Generating Biologically Driven Bird and Non-Avian Dinosaur Feathers

A key element in computer-graphics research is representing the world around us, and immense inspiration may be found in nature. Algorithms and procedural models may be developed that can describe the three-dimensional shape of objects and how they interact with light. This thesis focuses particularly on bird and other dinosaur feathers and their structure. More specifically, it addresses the problem of procedurally generating biologically driven geometry for modeling feathers in computer graphics. As opposed to previously published methods for generated feather geometry, data is derived from a myriad of real-world specimens of feathers and used in creating graphical models of feathers. Modeling feathers is of interest both for media production and also for various fields of research such as ornithology, paleontology, and material science. In order to create realistic, computer-graphics feathers, the anatomy of feathers is analyzed in detail with the aim of understanding their structure and variation in order to apply that understanding to modeling. Data concerning the shape of actual feathers was collected and analyzed to drive attribute parameters for modeling accurate synthetic feathers, during which methods for generating geometry informed by the data were investigated. Synthesized image results, capabilities, limitations, and extensions of the developed techniques are presented

Three Dimensional Simulations of Vertical Magnetic Flux in the Immediate Vicinity of Black Holes

This article reports on three-dimensional (3-D) MHD simulations of non-rotating and rapidly rotating black holes and the adjacent black hole accretion disk magnetospheres. A particular emphasis is placed on the vertical magnetic flux that is advected inward from large radii and threads the equatorial plane near the event horizon. In both cases of non-rotating and rotating black holes, the existence of a significant vertical magnetic field in this region is like a switch that creates powerful jets. There are many similarities in the vertical flux dynamics in these two cases in spite of the tremendous enhancement of azimuthal twisting of the field lines and enhancement of the jet power because of an "ergospheric disk" in the Kerr metric. A 3-D approach is essential because two-dimensional axisymmetric flows are incapable of revealing the nature of vertical flux near a black hole. Poloidal field lines from the ergospheric accretion region have been visualized in 3-D and much of the article is devoted to a formal classification of the different manifestations of vertical flux in the Kerr case.Comment: To appear in ApJ. The referenced movies can be found in the electronic on-line journal or http://85.20.11.14/punsly/PHI/movies

Virtuaalse proovikabiini 3D kehakujude ja roboti juhtimisalgoritmide uurimine

Väitekirja elektrooniline versioon ei sisalda publikatsiooneVirtuaalne riiete proovimine on üks põhilistest teenustest, mille pakkumine võib suurendada rõivapoodide edukust, sest tänu sellele lahendusele väheneb füüsilise töö vajadus proovimise faasis ning riiete proovimine muutub kasutaja jaoks mugavamaks. Samas pole enamikel varem välja pakutud masinnägemise ja graafika meetoditel õnnestunud inimkeha realistlik modelleerimine, eriti terve keha 3D modelleerimine, mis vajab suurt kogust andmeid ja palju arvutuslikku ressurssi. Varasemad katsed on ebaõnnestunud põhiliselt seetõttu, et ei ole suudetud korralikult arvesse võtta samaaegseid muutusi keha pinnal. Lisaks pole varasemad meetodid enamasti suutnud kujutiste liikumisi realistlikult reaalajas visualiseerida. Käesolev projekt kavatseb kõrvaldada eelmainitud puudused nii, et rahuldada virtuaalse proovikabiini vajadusi. Välja pakutud meetod seisneb nii kasutaja keha kui ka riiete skaneerimises, analüüsimises, modelleerimises, mõõtmete arvutamises, orientiiride paigutamises, mannekeenidelt võetud 3D visuaalsete andmete segmenteerimises ning riiete mudeli paigutamises ja visualiseerimises kasutaja kehal. Selle projekti käigus koguti visuaalseid andmeid kasutades 3D laserskannerit ja Kinecti optilist kaamerat ning koostati nendest andmebaas. Neid andmeid kasutati välja töötatud algoritmide testimiseks, mis peamiselt tegelevad riiete realistliku visuaalse kujutamisega inimkehal ja suuruse pakkumise süsteemi täiendamisega virtuaalse proovikabiini kontekstis.Virtual fitting constitutes a fundamental element of the developments expected to rise the commercial prosperity of online garment retailers to a new level, as it is expected to reduce the load of the manual labor and physical efforts required. Nevertheless, most of the previously proposed computer vision and graphics methods have failed to accurately and realistically model the human body, especially, when it comes to the 3D modeling of the whole human body. The failure is largely related to the huge data and calculations required, which in reality is caused mainly by inability to properly account for the simultaneous variations in the body surface. In addition, most of the foregoing techniques cannot render realistic movement representations in real-time. This project intends to overcome the aforementioned shortcomings so as to satisfy the requirements of a virtual fitting room. The proposed methodology consists in scanning and performing some specific analyses of both the user's body and the prospective garment to be virtually fitted, modeling, extracting measurements and assigning reference points on them, and segmenting the 3D visual data imported from the mannequins. Finally, superimposing, adopting and depicting the resulting garment model on the user's body. The project is intended to gather sufficient amounts of visual data using a 3D laser scanner and the Kinect optical camera, to manage it in form of a usable database, in order to experimentally implement the algorithms devised. The latter will provide a realistic visual representation of the garment on the body, and enhance the size-advisor system in the context of the virtual fitting room under study