Quantitative Analysis of DoS Attacks and Client Puzzles in IoT Systems

Denial of Service (DoS) attacks constitute a major security threat to today's Internet. This challenge is especially pertinent to the Internet of Things (IoT) as devices have less computing power, memory and security mechanisms to mitigate DoS attacks. This paper presents a model that mimics the unique characteristics of a network of IoT devices, including components of the system implementing `Crypto Puzzles' - a DoS mitigation technique. We created an imitation of a DoS attack on the system, and conducted a quantitative analysis to simulate the impact such an attack may potentially exert upon the system, assessing the trade off between security and throughput in the IoT system. We model this through stochastic model checking in PRISM and provide evidence that supports this as a valuable method to compare the efficiency of different implementations of IoT systems, exemplified by a case study

Resampling technique applied to statistics of microsegregation characterization

Characterization of chemical heterogeneities at the dendrite scale is of practical importance for understanding phase transformation either during solidification or during subsequent solid-state treatment. Spot analysis with electron probe is definitely well-suited to investigate such heterogeneities at the micron scale that is relevant for most solidified products. However, very few has been done about the statistics of experimental solute distributions gained from such analyses when they are now more and more used for validating simulation data. There are two main sources generating discrepancies between estimated and actual solute distributions in an alloy: i) data sampling with a limited number of measurements to keep analysis within a reasonable time length; and ii) uncertainty linked to the measurement process, namely the physical noise that accompanies X-ray emission. Focusing on the first of these sources, a few 2-D composition images have been generated by phase field modelling of a Mg-Al alloy. These images were then used to obtain "true" solute distributions to which to compare coarse grid analyses as generally performed with a microanalyser. Resampling, i.e. generating several distributions by grid analyses with limited number of picked-up values, was then used to get statistics of estimates of solute distribution. The discussion of the present results deals first with estimating the average solute content and then focuses on the distribution in the primary phase

Ambient dose equivalent versus effective dose for quantifying stray radiation exposures to a patient receiving proton therapy for prostate cancer

The purpose of this study was to evaluate the suitability of the quantity ambient dose equivalent H*(10) as a conservative estimate of effective dose E for estimating stray radiation exposures to patients receiving passively scattered proton radiotherapy for cancer of the prostate. H*(10), which is determined from fluence free-in-air, is potentially useful because it is simpler to measure or calculate because it avoids the complexities associated with phantoms or patient anatomy. However, the suitability of H*(10) as a surrogate for E has not been demonstrated for exposures to high-energy neutrons emanating from radiation treatments with proton beams. The suitability was tested by calculating H*(10) and E for a proton treatment using a Monte Carlo model of a double-scattering treatment machine and a computerized anthropomorphic phantom. The calculated E for the simulated treatment was 5.5 mSv/Gy, while the calculated H*(10) at the isocenter was 10 mSv/Gy. A sensitivity analysis revealed that H*(10) conservatively estimated E for the interval of treatment parameters common in proton therapy for prostate cancer. However, sensitivity analysis of a broader interval of parameters suggested that H*(10) may underestimate E for treatments of other sites, particularly those that require large field sizes. Simulations revealed that while E was predominated by neutrons generated in the nozzle, neutrons produced in the patient contributed up to 40% to dose equivalent in near-field organs

Engage D5.1 University programme database (initial version)

This document describes the methodology applied to the design and population of the initial version of the university programme database. The database contains information on postgraduate degree and research opportunities. Please note that a later report (D3.9) describes the final database content, as used in the Engage wiki

Engage D5.3 Postgraduate research and events database (initial version)

This document describes the methodology applied to the design and population of the initial version of the postgraduate research and events database. The database contains information on European and international conferences, workshops, summer schools, training courses and other relevant events. Please note that a later report (D3.9) describes the final database content, as used in the Engage wiki

Alkali activation of dif ferent type of ash as a production of combustion process

Presented study deals with the final struc ture and radiological properties of different fly-ash based geopolymers. Lig nite fly-ash (lignite Kolubara – Ser bia) and wood fly ash were obtained in combustion process together with commercial fly-ash. Synthesis of the geopolymers was con ducted by mixing fly-ash, sodium silicate solution, NaOH and water. The sam ples were strength ened 60 °C for 48 hours af ter stay ing at room temperature in covering mold for 24 hours. The X-ray dif frac tion, Fou rier trans form in fra red and SAM mea sure ments were conducted on the sam ples af ter 28 days of geopolymerization pro cess. The X-ray dif frac tion measurements of lignite fly-ash sam ples show anhydrite as the main constituent, while wood fly-ash samples consist of cal cite, albite and gypsum minerals. Besides determination of physicochemical properties, the aim of this study was radiological characterization of lignite fly-ash, wood fly-ash and the obtained geopolymer products. Ac tiv ity con cen tra tion of 40 K and radionuclides from the 238 U and 232 Th decay series, in ash sam ples and fly-ash based geopolymers, were determined by means of gamma-ray spectrometry, and the absorbed dose rate, D, and the annual effective dose rate, E, were calcu lated in accordance with the UNSCEAR 2000 report

Real-time grammar processing by native and non-native speakers : constructions unique to the second language

We investigated second language (L2) comprehension of grammatical structures that are unique to the L2, and which are known to cause persistent difficulties in production. A visual-world eye-tracking experiment focused on online comprehension of English articles by speakers of the article-lacking Mandarin, and a control group of English native speakers. The results show that non-native speakers from article-lacking backgrounds can incrementally utilise the information signalled by L2 articles in real time to constrain referential domains and resolve reference more efficiently. The findings support the hypothesis that L2 processing does not always over-rely on pragmatic affordances, and that some morphosyntactic structures unique to the target language can be processed in a targetlike manner in comprehension – despite persistent difficulties with their production. A novel proposal, based on multiple meaning-to-form, but consistent form-to-meaning mappings, is developed to account for such comprehension–production asymmetries

Integrating Top-down and Bottom-up Requirements in eHealth Development:The Case of a Mobile Self-compassion Intervention for People with Newly Diagnosed Cancer

Background: Psychosocial eHealth interventions for people with cancer are promising in reducing distress; however, their results in terms of effects and adherence rates are quite mixed. Developing interventions with a solid evidence base while still ensuring adaptation to user wishes and needs is recommended to overcome this. As most models of eHealth development are based primarily on examining user experiences (so-called bottom-up requirements), it is not clear how theory and evidence (so-called top-down requirements) may best be integrated into the development process. Objective: This study aims to investigate the integration of top-down and bottom-up requirements in the co-design of eHealth applications by building on the development of a mobile self-compassion intervention for people with newly diagnosed cancer. Methods: Four co-design tasks were formulated at the start of the project and adjusted and evaluated throughout: explore bottom-up experiences, reassess top-down content, incorporate bottom-up and top-down input into concrete features and design, and synergize bottom-up and top-down input into the intervention context. These tasks were executed iteratively during a series of co-design sessions over the course of 2 years, in which 15 people with cancer and 7 nurses (recruited from 2 hospitals) participated. On the basis of the sessions, a list of requirements, a final intervention design, and an evaluation of the co-design process and tasks were yielded. Results: The final list of requirements included intervention content (eg, major topics of compassionate mind training such as psychoeducation about 3 emotion systems and main issues that people with cancer encounter after diagnosis such as regulating information consumption), navigation, visual design, implementation strategies, and persuasive elements. The final intervention, Compas-Y, is a mobile self-compassion training comprising 6 training modules and several supportive functionalities such as a mood tracker and persuasive elements such as push notifications. The 4 co-design tasks helped overcome challenges in the development process such as dealing with conflicting top-down and bottom-up requirements and enabled the integration of all main requirements into the design. Conclusions: This study addressed the necessary integration of top-down and bottom-up requirements into eHealth development by examining a preliminary model of 4 co-design tasks. Broader considerations regarding the design of a mobile intervention based on traditional intervention formats and merging the scientific disciplines of psychology and design research are discussed