No abstract

Every year, millions of letters/parcels containing illicit goods are detected by customs authorities, which use traditional security screening equipment. However this equipment cannot detect all kinds of illicit goods and the detection procedure heavily depends on the attention of the customs officer. In order to achieve sufficiently fast intelligent screening of the large volumes of letters/parcels and detect all common kinds of threats, this paper proposes a highly innovative architecture well-beyond the state-of–art. In particular the proposed architecture monitors every letter/parcel by incorporating: (a) terahertz/X-ray sensors, (b) chemical, biological, radiological and nuclear (CBNR) sensors, (c) artificial robot-noses for narcotics, explosives etc., (d) magnetometers for weapons, firearms, banknotes etc., (e) acoustic sensors for liquids/gases/solids, (f) weight/pressure sensors to measure weight distribution, size and shape. Sensory information can be: (a) used to create a “Spectral Signatures Dictionary of Illicit Goods and Threats”, (b) fused to segment/isolate illicit goods and (c) visualized in the form of annotated high-resolution tensor-structured (3D/4D) multisensory image data. The proposed solution also gathers available information for the sender/recipient from various resources, while it also analyzes data from the dark web. All information is forwarded to an AI-based knowledge infrastructure.

Critical infrastructures are assets of invaluable importance, essential for the whole world. Since they serve core functions of our societies, they often become targets of terrorists. Many critical infrastructures are vulnerable, due to their short distance from public roads and in the past years, several vehicle-bomb incidents have been recorded. This paper focuses on the case of truck-bombs, which can either be created from scratch, or terrorists can easily hijack truck cargos carrying dangerous goods and turn them into bombs. The latter are typically called ADR truck cargos, according to the respective agreement of the 30th of September 1957, concerning the international carriage of dangerous goods by road. The proposed scheme performs threat assessment of neighboring critical infrastructures, aiming at preventing explosions of truck-bombs. To do so, each crucial point of a critical infrastructure is initially associated with a level of importance. Next, three scenarios are analyzed: (a) single-attack single-infrastructure, (b) multiple-attack single-infrastructure, and (c) multiple-attack multiple-infrastructure. To reduce computational complexity, the third scenario is simplified to one of the two other scenarios, by introducing a novel fusion technique for the non-overlapping segments of the Voronoi tessellation. By this way, an area of threat assessment is estimated for each critical infrastructure. Then, the threat level is assessed in real time by an innovative algorithm, which: (a) estimates the impact of multiple consecutive explosions, (b) uses five adapted threat levels and (c) introduces multiple criteria and minimum classification conditions based on the number of crucial points and their levels of importance. Extensive real world experimental results and comparisons to other works, exhibit the pros and cons of the proposed scheme. In particular the proposed scheme improves: (a) computational time by 74.5%, compared to [69], (b) threat notification time by 86.9% compared to [70] and (c) estimated surveillance cost by 98.6% compared to [71].

This paper focuses on the use of new technologies in educational practice. Despite the notion that students' familiarity with technological tools is essential for their learning development, the main question is still the following: does the utilization of technology affects the learning process ?The impact of using new technologies and tools on students’ learning achievements can be determined based on students’ progress in individual cognitive subjects, on students’ commitment, as well as on the attitudes, perceptions and readiness of teachers towards the utilization of technology. This paper explores whether and to what extent new technologies contribute to the strengthening of general education, special education and intercultural education (Roma students) students’ knowledge and skills. It appears that new technologies in classrooms seem to support educational practices. Teachers realize that their students use ICT as sources of reference, investigation and communication, while the frequent use of these tools effectively motivates students' commitment to learning and development.

In this paper, the parameters that shape online reputation of a company and the two-way relation between the effect reputation has on consumer behavior and the effect consumer behavior has on reputation are examined. The contribution of this work lies in the fact that it concerns Greek consumers. Moreover, it is important to highlight the particularities of Greek consumers and to confirm or disprove international trends in their case. At the same time, issues related to the extraction and classification of elements related to reputation are highlighted. The answers given through this research and the questions that arise contribute to the formulation of effective strategies for the management of online reputation by the companies, even in cases of attacks and threats.