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51.
52.
Oliver Bimber Daisuke Iwai Gordon Wetzstein Anselm Grundhöfer 《Computer Graphics Forum》2008,27(8):2219-2245
This article focuses on real‐time image correction techniques that enable projector‐camera systems to display images onto screens that are not optimized for projections, such as geometrically complex, coloured and textured surfaces. It reviews hardware‐accelerated methods like pixel‐precise geometric warping, radiometric compensation, multi‐focal projection and the correction of general light modulation effects. Online and offline calibration as well as invisible coding methods are explained. Novel attempts in super‐resolution, high‐dynamic range and high‐speed projection are discussed. These techniques open a variety of new applications for projection displays. Some of them will also be presented in this report. 相似文献
53.
This paper presents a cooperative decentralized path-planning algorithm for a group of autonomous agents that provides guaranteed collision-free trajectories in real-time. The algorithm is robust with respect to arbitrary delays in the wireless traffic, possible sources being transmission time and error correction. Agents move on reserved areas which are guaranteed not to intersect, therefore ensuring safety. A handshaking procedure guarantees recent information states for the agents. Conflicts between agents are resolved by a cost-based negotiation process. The basic algorithm is augmented by the introduction of waypoints, which increase performance at the cost of additional wireless traffic. An implementation of the algorithm is tested in simulation and successfully applied to a real system of autonomous robots. The results are presented and discussed. 相似文献
54.
Dipl.-Wirt.-Inform. Daniel Beverungen Dr. Ralf Knackstedt Dipl.-Wirt.-Inform. Oliver Müller 《WIRTSCHAFTSINFORMATIK》2008,50(3):220-234
Offering product-service bundles (consisting of products and services) is becoming more important for companies. Modifying the organizational structure of the cooperation as well as adapting to changing customer demands requires versatile information systems. Implementing Service Oriented Architectures (SOA) is one attempt to provide this flexibility. Currently, there is little methodical guidance for the identification, specification and implementation of services as building blocks of Service Oriented Architectures. Accounting for this need, a conceptual approach is designed, which adapts approaches of customer integration, and combines a business and IT analysis. The applicability of the method is demonstrated by designing a Service Oriented Architecture for the recycling of electronic equipment. Implementing services for other product-service bundles will support additional integration scenarios. By standardizing services, a sound integration of products and services can be backed by providing a reference architecture. 相似文献
55.
Predicting weekly defect inflow in large software projects based on project planning and test status
Defects discovered during the testing phase in software projects need to be removed before the software is shipped to the customers. The removal of defects can constitute a significant amount of effort in a project and project managers are faced with a decision whether to continue development or shift some resources to cope with defect removal. The goal of this research is to improve the practice of project management by providing a method for predicting the number of defects reported into the defect database in the project. In this paper we present a method for predicting the number of defects reported into the defect database in a large software project on a weekly basis. The method is based on using project progress data, in particular the information about the test progress, to predict defect inflow in the next three coming weeks. The results show that the prediction accuracy of our models is up to 72% (mean magnitude of relative error for predictions of 1 week in advance is 28%) when used in ongoing large software projects. The method is intended to support project managers in more accurate adjusting resources in the project, since they are notified in advance about the potentially large effort needed to correct defects. 相似文献
56.
Ivan Martinovic Paul Pichota Matthias Wilhelm Frank A. Zdarsky Jens B. Schmitt 《Pervasive and Mobile Computing》2009,5(5):510-525
To improve the tarnished reputation of WLAN security, the new IEEE 802.11i standard provides means for mutual user authentication and assures confidentiality of user data. However, the IEEE 802.11 link-layer is still highly vulnerable to a plethora of simple, yet effective attacks which further jeopardize the already fragile security of wireless communications.Some of these vulnerabilities are related to limited hardware capabilities of access points and their abuse may result in serious degradation of control over the wireless connection, which, especially in the case of broadcast communication, allows for client hijacking attacks. Although these issues are known and their impact is expected to be less prevalent on modern equipment, this work demonstrates the opposite. In our experimental analysis, we tested frequently used access points, and by forcing them to operate on their performance limits, we identified significant operational anomalies and demonstrated their impact on security by implementing a novel version of the Man-In-The-Middle attack, to which we refer as the Muzzle attack.Secondly, this work describes DiscoSec, a solution for “patching” WLANs against a variety of such link-layer attacks. DiscoSec provides DoS-resilient key exchange, an efficient frame authentication, and a performance-oriented implementation. By means of extensive real-world measurements DiscoSec is evaluated, showing that even on very resource-limited devices the network throughput is decreased by only 22% compared to the throughput without any authentication, and by 6% on more performance-capable hardware. To demonstrate its effectiveness, DiscoSec is available as an open-source IEEE 802.11 device driver utilizing well-established cryptographic primitives provided by the Linux Crypto API and OpenSSL library. 相似文献
57.
Wilhelm Dolle 《Datenschutz und Datensicherheit - DuD》2009,33(3):183-188
Zusammenfassung Im Zeitalter der Informationstechnologie und der umfassenden Vernetzung vieler Systeme ben?tigt ein Dieb weder eine Brechstange
noch muss er im Schutze der Dunkelheit vorgehen. Vielmehr kann er über das Internet, oder lokale Netzwerke, kommen und gehen
wann er will, ohne sich der Gefahr einer Entdeckung und Verhaftung auszusetzen. In vielen F?llen ist ein solcher Einbrecher
l?ngst über alle Berge, bevor seine Tat überhaupt bemerkt wird. Trotzdem hinterl?sst er Spuren — deren Aufspürung und Analyse
die Aufgabe des Computer-Forensikers ist. Zur Unterstützung dieser Arbeit existiert eine Vielzahl an Open-Source-Werkzeugen,
die es durchaus mit ihrer kommerziellen Konkurrenz aufnehmen k?nnen. 相似文献
58.
We present an enhancement towards adaptive video training for PhoneGuide, a digital museum guidance system for ordinary camera-equipped
mobile phones. It enables museum visitors to identify exhibits by capturing photos of them. In this article, a combined solution
of object recognition and pervasive tracking is extended to a client–server-system for improving data acquisition and for
supporting scale-invariant object recognition. A static as well as a dynamic training technique are presented that preprocess
the collected object data differently and apply two types of neural networks (NN) for classification. Furthermore, the system
enables a temporal adaptation for ensuring a continuous data acquisition to improve the recognition rate over time. A formal
field experiment reveals current recognition rates and indicates the practicability of both methods under realistic conditions
in a museum.
相似文献
Erich BrunsEmail: |
Oliver Bimber (Corresponding author)Email: |
59.
Mohammad Farhan Tanzim Nuno Fortunato Ilias Samathrakis Ruiwen Xie Ingo Opahle Oliver Gutfleisch Hongbin Zhang 《Advanced functional materials》2023,33(28):2214967
All-d Heuslers are a category of novel compounds combining versatile functionalities such as caloric responses and spintronics with enhanced mechanical properties. Despite the promising transport properties (anomalous Hall (AHC) and anomalous Nernst (ANC) conductivities) shown in the conventional Co2XY Heuslers with p-d hybridization, the all-d Heuslers with only d-d hybridization open a new horizon to search for new candidates with outstanding transport properties. In this work, the AHC and ANC are evaluated for thermodynamically stable ferro/ferri-magnetic all-d-metal regular Heusler compounds based on high-throughput first-principles calculations. It is observed that quite a few materials exhibit giant AHCs and ANCs, such as cubic Re2TaMn with an AHC of 2011 S cm-1, and tetragonal Pt2CrRh with an AHC of 1966 S cm-1 and an ANC of 7.50 A m-1K-1. Comprehensive analysis on the electronic structure reveals that the high AHC can be attributed to the occurrence of the Weyl nodes or gapped nodal lines in the neighborhood of the Fermi level. The correlations between such transport properties and the number of valence electrons are also thoroughly investigated, which provides a practical guidance to tailor AHC and ANC via chemical doping for transverse thermoelectric applications. 相似文献
60.