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11.
Smart card technology has evolved over the last few years following notable improvements in the underlying hardware and software platforms. Advanced smart card microprocessors, along with robust smart card operating systems and platforms, contribute towards a broader acceptance of the technology. These improvements have eliminated some of the traditional smart card security concerns. However, researchers and hackers are constantly looking for new issues and vulnerabilities. In this article we provide a brief overview of the main smart card attack categories and their corresponding countermeasures. We also provide examples of well-documented attacks on systems that use smart card technology (e.g. satellite TV, EMV, proximity identification) in an attempt to highlight the importance of the security of the overall system rather than just the smart card. 相似文献
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Dimitrios Tzovaras Konstantinos Moustakas Georgios Nikolakis Michael G. Strintzis 《Personal and Ubiquitous Computing》2009,13(1):51-58
This paper presents a mixed reality tool developed for the training of the visually impaired based on haptic and auditory
feedback. The proposed approach focuses on the development of a highly interactive and extensible Haptic Mixed Reality training
system that allows visually impaired to navigate into real size Virtual Reality environments. The system is based on the use
of the CyberGrasp™ haptic device. An efficient collision detection algorithm based on superquadrics is also integrated into
the system so as to allow real time collision detection in complex environments. A set of evaluation tests is designed in
order to identify the importance of haptic, auditory and multimodal feedback and to compare the MR cane against the existing
Virtual Reality cane simulation system. 相似文献
14.
Segkouli Sofia Giakoumis Dimitrios Votis Konstantinos Triantafyllidis Andreas Paliokas Ioannis Tzovaras Dimitrios 《Universal Access in the Information Society》2023,22(1):37-49
Universal Access in the Information Society - Pervasive technologies such as Artificial Intelligence, Virtual Reality and the Internet of Things, despite their great potential for improved... 相似文献
15.
This paper investigates the effect of microwave curing on the bond strength of steel reinforcement in concrete repair. Pull-out tests on plain mild steel reinforcement bars embedded in four repair materials in 100 mm cube specimens were performed to determine the interfacial bond strength. The porosity and pore structure of the matrix at the steel interface, which influence the bond strength, were also determined. Test results show that microwave curing significantly reduces the bond strength of plain steel reinforcement. The reduction relative to normally cured (20 °C, 60% RH) specimens is between 21 and 40% with low density repair materials and about 10% for normal density cementitious mortars. The corresponding compressive strength of the matrix also recorded similar reduction and microwave curing resulted in increased porosity at the interface transition zone of the steel reinforcement. A unique relationship exists between bond strength and both compressive strength and porosity of all matrix materials. Microwave curing reduced shrinkage but despite the wide variation in the shrinkage of the repair mortars, its effect on the bond strength was small. The paper provides clear correlations between the three parameters (compressive strength, bond strength and porosity), which are common to both the microwave and conventionally cured mortars. Therefore, bond-compressive strength relationships used in the design of reinforced concrete structures will be also valid for microwave cured elements. 相似文献
16.
Konstantinos Agathos Eleni Chatzi Stéphane P. A. Bordas Demosthenes Talaslidis 《International journal for numerical methods in engineering》2016,105(9):643-677
A variation of the extended finite element method for three‐dimensional fracture mechanics is proposed. It utilizes a novel form of enrichment and point‐wise and integral matching of displacements of the standard and enriched elements in order to achieve higher accuracy, optimal convergence rates, and improved conditioning for two‐dimensional and three‐dimensional crack problems. A bespoke benchmark problem is introduced to determine the method's accuracy in the general three‐dimensional case where it is demonstrated that the proposed approach improves the accuracy and reduces the number of iterations required for the iterative solution of the resulting system of equations by 40% for moderately refined meshes and topological enrichment. Moreover, when a fixed enrichment volume is used, the number of iterations required grows at a rate which is reduced by a factor of 2 compared with standard extended finite element method, diminishing the number of iterations by almost one order of magnitude. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
17.
ROSy+: 3D Object Pose Normalization Based on PCA and Reflective Object Symmetry with Application in 3D Object Retrieval 总被引:1,自引:0,他引:1
Konstantinos Sfikas Theoharis Theoharis Ioannis Pratikakis 《International Journal of Computer Vision》2011,91(3):262-279
A novel pose normalization method based on 3D object reflective symmetry is presented. It is a general purpose global pose
normalization method; in this paper it is used to enhance the performance of a 3D object retrieval pipeline. Initially, the
axis-aligned minimum bounding box of a rigid 3D object is modified by requiring that the 3D object is also in minimum angular
difference with respect to the normals to the faces of its bounding box. To estimate the modified axis-aligned bounding box,
a set of predefined planes of symmetry are used and a combined spatial and angular distance, between the 3D object and its
symmetric object, is calculated. By minimizing the combined distance, the 3D object fits inside its modified axis-aligned
bounding box and alignment with the coordinate system is achieved. The proposed method is incorporated in a hybrid scheme,
that serves as the alignment method in a 3D object retrieval system. The effectiveness of the 3D object retrieval system,
using the hybrid pose normalization scheme, is evaluated in terms of retrieval accuracy and demonstrated using both quantitative
and qualitative measures via an extensive consistent evaluation on standard benchmarks. The results clearly show performance
boost against current approaches. 相似文献
18.
The Data Exchange for Visualizing Security Events (DEViSE) is an open-source architecture designed to enable data sharing between security visualization tools. The security visualization market currently lacks interoperability between different applications, which tend to be constrained to certain log formats. DEViSE is a middleware layer that manages these interactions so one visualization tool can transfer security-related information to another application. DEViSE uses XML for all communication purposes. This allows a much greater level of freedom for application integration. To demonstrate DEViSE, the authors have created several security visualization tools that adhere to different visualization paradigms. 相似文献
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Athanasios Karagiannidis Konstantinos Lagouvardos Vassiliki Kotroni Nikos Mazarakis 《International journal of remote sensing》2016,37(20):5001-5020
An analysis of selected spatiotemporal characteristics of isolated thunderstorms in relation to cloud-to-ground (CG) lightning over part of the eastern Mediterranean is performed. The purpose of the study is twofold: to better understand and improve the basic knowledge of the physical mechanisms of the phenomenon and to offer new means of nowcasting the lightning activity in such thunderstorms. Meteosat Second Generation (MSG) Rapid Scan Service (RSS) infrared imagery which offers the option of tracking the examined storms with a time frequency of 5 minutes is one of the two utilized datasets, the other being ZEUS very low frequency (VLF) lightning detection system’s CG discharge data. It was shown that a cloud top temperature of about ?20°C is required for the onset of lightning activity. A rapid drop of the cloud-top temperature of about 11°C in 5 minutes on average is observed a few minutes before or during lightning initiation. The maximization of the activity is usually quite close to the overall minimum cloud-top temperature of the cell. A temperature increase of 3.5°C from this overall minimum can mark the end of the activity, which is also associated to the time evolution of the cell’s horizontal extent. In fact, after the cell’s horizontal area stops to increase and/or starts to gradually diminish, CG lightning activity is expected to stop. 相似文献