Search results for "graphics"
showing 10 items of 1223 documents
Conservative swept volume boundary approximation
2010
We present a novel technique for approximating the boundary of a swept volume. The generator given by an input triangle mesh is rendered under all rigid transformations of a discrete trajectory. We use a special shader program that creates offset geometry of each triangle on the fly, thus guaranteeing a conservative rasterization and correct depth values. Utilizing rasterization mechanisms and the depth buffer we then get a conservative voxelization of the swept volume (SV) and can extract a triangle mesh from its surface. This mesh is simplified maintaining conservativeness as well as an error bound measured in terms of the one-sided Hausdorff distance. For this we introduce a new techniqu…
Decision-making Tool for Moving from 3-axes to 5-axes CNC Machine-tool
2016
Abstract Nowadays most of the parts within machine-building industry are machines on CNC machine-tools. According to their mechanical and kinematic structure, CNC machine-tools can be divided into 3-axes and 5-axes ones. Each type has its advantages and drawbacks and choosing between them could be a very difficult process. This paper presents a decision support tool for aiding the process of selecting between using and/or buying either a 3-axes CNC milling machine or a 5-axes milling machine, based upon fuzzy logic. The tool was built using the Fuzzy Logic Toolbox and the fuzzy graphical user interface (GUI) within Matlab software package.
Dental anatomy portrayed with microscopic volume investigations
1993
The clinical treatment of the root canal of teeth--called endodontics--assumes a precise idea of the spatial arrangement of the anatomy of teeth and their inner structure. By using computer-assisted data acquisition from filmed sequences of histologic serial sections and a special kind of magnetic resonance microscope--the Stray Field Imaging (STRAFI)--volume investigations were carried out using special functions of a newly developed 3D software. Possible applications and future perspectives are discussed.
Metal Cutting Operations and Terminology
2008
This chapter presents a general description of the machining processes and machining operations using various classification criteria. The classification of machining processes is based on the energy source used and the type of generating mechanisms, whereas the classification of machining operations utilizes characteristic motions describing their kinematics. Some examples of turning, milling, hole making, broaching and threading operations are provided. Kinematics of typical cutting operations and appropriate standardized cutting parameters are described. The geometry of cutting tools in the tool-in-hand and tool-in-use systems, including relevant tool angles, is characterized.
Building 3D Geometric and Kinematic Models of Five-Axis Machine-Tools for Manufacturing Prosthetic Devices
2015
The paper presents the process of building and testing a geometric and kinematic model of a five-axis machining center, which can be used for accurate cutting processes simulation of complex parts. After building the model, it was be tested by simulating the machining process of a hip joint prosthetic device. The prosthetic device was chosen because of its complex shape and because it was obtained by a 3D scanning process, which means that the part was reconstructed using meshes, instead of surfaces, which makes the toolpath control more difficult.
Computer-assisted orientation and drawing of archaeological pottery.
2018
Archaeologists spend considerable time orienting and drawing ceramic fragments by hand for documentation, to infer their manufacture, the nature of the discovery site and its chronology, and to develop hypotheses about commercial and cultural exchanges, social organisation, resource exploitation, and taphonomic processes. This study presents a survey of existing solutions to the time-consuming problem of orienting and drawing pottery fragments. Orientation is based on the 3D geometry of pottery models, which can now be acquired in minutes with low-cost 3D scanners. Several methods are presented: they are based on normal vectors, or circle fittings, or profile fittings. All these methods see…
Digital Palaeography of Hieratic
2020
After a short history of research into hieratic palaeography, the first experiences with digital methods to conduct the study of handwritten documents, in Egyptology as well as in other fields, are presented. The needs and goals of a future digital palaeography are then explained in detail. Such a palaeography is expected to become a modern research tool for ancient Egyptian handwritings that allows the depiction, description, classification, and encoding of cursive signs and that includes information about the entire manuscripts and their materiality. In constructing such a tool, some questions are essential, for instance: How should the signs be represented—as image sections from a scan o…
On the impact of within-die process variation in GALS-Based NoC Performance
2012
[EN] Current integration scales allow designing chip multiprocessors (CMP), where cores are interconnected by means of a network-on-chip (NoC). Unfortunately, the small feature size of current integration scales causes some unpredictability in manufactured devices because of process variation. In NoCs, variability may affect links and routers causing them not to match the parameters established at design time. In this paper, we first analyze the way that manufacturing deviations affect the components of a NoC by applying a new comprehensive and detailed within-die variability model to 200 instances of an 8¿8 mesh NoC synthesized using 45 nm technology. Later, we show that GALS-based NoCs pr…
THE METAMODEL: A STARTING POINT FOR DESIGN PROCESSES CONSTRUCTION
2010
The construction of ad-hoc design processes following the Situational Method Engineering (SME) paradigm is currently carried out by adopting a set of phases for which, until now, no well defined techniques and guidelines have been established. The consequence is that organizations are very dependent on method designers' skills. In this paper, we propose an approach based on SME for constructing customized agent oriented design processes. Our approach adopts the metamodel as the most important factor leading to the selection and assembly of method fragments and an algorithm for establishing the instantiation order of metamodel elements. The algorithm makes the proposed approach repeatable a…
UMTS radio networks
2006
Publisher Summary This chapter reviews the contributions to the UMTS radio network planning, with the optimization being provided from COST 273 and the real-time tuning, which is related to RRM. The results on UTRAN performance evaluation by the means of simulation tools are also discussed. The UMTS planning includes processes like: the propagation and traffic models, the aspects of parameter planning, and the automatic planning algorithms. An accurate ray-tracing model integrated in a UMTS-capable planning tool allows the radio network planner to reach optimal numbers for the BS deployment and configuration while meeting the service level requirements. Ray tracing can identify the problem …