Novel permeable pavement systems utilising carbon-negative aggregate

The use of commercially produced Carbon-Negative aggregates from Carbon8 (a British company which applies patented Accelerated Carbonation Technology (ACT) to solidify waste residues producing useful eco-friendly aggregates) is being investigated in the Caribbean islands of Trinidad, Tobago and St. Lucia. Typical construction of the subbase layer of pavements in the Caribbean include layers of virgin aggregate material (gravel, pea gravel) on which the base course layer is located. These materials are usually unbound granular (crushed stone, crushed slag, crushed concrete, slate) or cement-bound. Permeable Pavement Systems (PPS) have emerged over the years using various quality of subbase materials including large pieces of rocks and concrete. For the first time in the Caribbean, the design, construction and implementation of such pavement systems is being carried out. The novel pavement systems consist of permeable or pervious concrete paving blocks and the Carbon-Negative aggregates in the sub-base as an innovative and effective method of providing structural pavements, whilst allowing urban stormwater runoff to infiltrate naturally into the pavements (mimicking the hydrologic cycle) into the base/sub-base reservoir for urban runoff attenuation and an overall reduction in stormwater discharge. These pavement systems are being considered to reduce the overall carbon footprint on the construction and implementation phase of pavements, in addition to reducing surface water flooding in several towns and cities across these Caribbean Small Island Developing States (SIDS). The project includes ongoing experimental assessment of the Permeable Pavement Systems (PPS) using Carbon-Negative aggregates versus conventional pervious pavements from a water quality, structural integrity and hydraulic perspective. Stormwater is being collected from various towns and cities across the islands and applied uniformly over the pilot scaled permeable pavements using a rainfall simulator. The permeable pavements stormwater treatment efficacies are being evaluated for the removal and retention of nutrients (total nitrogen and total phosphorus), heavy metals (zinc, lead, copper, cadmium), suspended solids and turbidity. The hydraulic performance, flow through and clogging patterns of these pavements are also being measured over a simulated 10-year period of sediment loading. Load bearing and deflection test are being carried out on the various pavement designs to assess its structural integrity and load bearing capacity. Static and dynamic loads applied representing the maximum contact pressure varying from 0.03 to 1.7 MPa over the cross-sectional area of 0.2 m2 (permeable pavement surface area). These contract pressures represent various loads from heavy vehicles, cars, pallets and handling equipment of industrial areas (ports)

Permeable pavement systems with low carbon and recycled materials for Caribbean Small Island Developing States

This PhD research project targets the utilisation of permeable pavement systems (PPS) as a long-term, sustainable urban drainage option for flood risk mitigation and improvement in stormwater runoff quality in Small Island Developing States (SIDS) across the Caribbean. Additionally, the research assesses the performance of PPS comprising of recycled and/or waste materials in the sub-base layer. These innovative pavements are being considered to reduce the overall carbon footprint on the construction phase of pavements and to reduce the volume of natural material used in the construction industry. The recycled materials considered are Crushed Concrete Aggregates (CCA), Carbon-Negative Aggregates (CNA) and expanded polystyrene (EPS) beads. The research methods explored combine experimental and modelling through a quantitative research design approach

Secure biometric authentication with improved accuracy

We propose a new hybrid protocol for cryptographically secure biometric authentication. The main advantages of the proposed protocol over previous solutions can be summarised as follows: (1) potential for much better accuracy using different types of biometric signals, including behavioural ones; and (2) improved user privacy, since user identities are not transmitted at any point in the protocol execution. The new protocol takes advantage of state-of-the-art identification classifiers, which provide not only better accuracy, but also the possibility to perform authentication without knowing who the user claims to be. Cryptographic security is based on the Paillier public key encryption scheme

Hiding in Plain Sight: A Longitudinal Study of Combosquatting Abuse

Domain squatting is a common adversarial practice where attackers register domain names that are purposefully similar to popular domains. In this work, we study a specific type of domain squatting called "combosquatting," in which attackers register domains that combine a popular trademark with one or more phrases (e.g., betterfacebook[.]com, youtube-live[.]com). We perform the first large-scale, empirical study of combosquatting by analyzing more than 468 billion DNS records---collected from passive and active DNS data sources over almost six years. We find that almost 60% of abusive combosquatting domains live for more than 1,000 days, and even worse, we observe increased activity associated with combosquatting year over year. Moreover, we show that combosquatting is used to perform a spectrum of different types of abuse including phishing, social engineering, affiliate abuse, trademark abuse, and even advanced persistent threats. Our results suggest that combosquatting is a real problem that requires increased scrutiny by the security community.Comment: ACM CCS 1

Towards Practical Fabrication Stage Attacks Using Interrupt-Resilient Hardware Trojans

We introduce a new class of hardware trojans called interrupt-resilient trojans (IRTs). Our work is motivated by the observation that hardware trojan attacks on CPUs, even under favorable attack scenarios (e.g., an attacker with local system access), are affected by unpredictability due to non-deterministic context switching events. As we confirm experimentally, these events can lead to race conditions between trigger signals and the CPU events targeted by the trojan payloads (e.g., a CPU memory access), thus affecting the reliability of the attacks. Our work shows that interrupt-resilient trojans can successfully address the problem of non-deterministic triggering in CPUs, thereby providing high reliability guarantees in the implementation of sophisticated hardware trojan attacks. Specifically, we successfully utilize IRTs in different attack scenarios against a Linux-capable CPU design and showcase its resilience against context-switching events. More importantly, we show that our design allows for seamless integration during fabrication stage attacks.We evaluate different strategies for the implementation of our attacks on a tape-out ready high-speed RISC-V microarchitecture in a 28nm commercial technology process and successfully implement them with an average overhead delay of only 20 picoseconds, while leaving the sign-off characteristics of the layout intact. In doing so, we challenge the common wisdom regarding the low flexibility of late supply chain stages (e.g., fabrication) for the insertion of powerful trojans. To promote further research on microprocessor trojans, we open-source our designs and provide the accompanying supporting software logic

A New Distribution-Sensitive Secure Sketch and Popularity-Proportional Hashing

Motivated by typo correction in password authentication, we investigate cryptographic error-correction of secrets in settings where the distribution of secrets is a priori (approximately) known. We refer to this as the distribution-sensitive setting. We design a new secure sketch called the layer-hiding hash (LHH) that offers the best security to date. Roughly speaking, we show that LHH saves an additional log H_0(W) bits of entropy compared to the recent layered sketch construction due to Fuller, Reyzin, and Smith (FRS). Here H_0(W) is the size of the support of the distribution W. When supports are large, as with passwords, our new construction offers a substantial security improvement. We provide two new constructions of typo-tolerant password-based authentication schemes. The first combines a LHH or FRS sketch with a standard slow-to-compute hash function, and the second avoids secure sketches entirely, correcting typos instead by checking all nearby passwords. Unlike the previous such brute-force-checking construction, due to Chatterjee et al., our new construction uses a hash function whose run-time is proportional to the popularity of the password (forcing a longer hashing time on more popular, lower entropy passwords). We refer to this as popularity-proportional hashing (PPH). We then introduce a frame-work for comparing different typo-tolerant authentication approaches. We show that PPH always offers a better time / security trade-off than the LHH and FRS constructions, and for certain distributions outperforms the Chatterjee et al. construction. Elsewhere, this latter construction offers the best trade-off. In aggregate our results suggest that the best known secure sketches are still inferior to simpler brute-force based approaches

Cancer screening information at community health fairs: What the participants do with information they receive

Background. To assess participants’ reasons for seeking cancer screening information at community health fairs and what they do with the information they receive. Design and methods. Mixed quantitative and qualitative approach was used. Community health fairs are organized in underserved New York City neighbourhoods. From June 14, 2016 to August 26, 2016, cancer prevention tables providing information about various cancer screenings were established at 12 local community health fairs in New York City. In-person and follow up telephone surveys assessing interest in the cancer prevention table, personal cancer screening adherence rates, information-sharing behaviours and demographic variables have been taken into account. Statistical analyses were performed using IBM SPSS 22.0: frequencies, descriptive, cross tabulations. All qualitative data was coded by theme so that it could be analysed through SPSS. For example, Were you interested in a specific cancer? may be coded as 2 for yes, breast cancer. Results. One hundred and sixteen patrons participated in the initial survey. Of those, 88 (78%) agreed to give their contact information for the follow-up survey and 60 follow-up surveys were completed (68%). Of those who reported reading the material, 45% shared the information; 15% subsequently spoke to a provider about cancer screenings and 40% intended to speak to a provider. Conclusions. Participants disseminated information without prompting; suggesting the reach of these fairs extends beyond the people who visit our table. Future studies should look at whether patrons would share information at higher rates when they are explicitly encouraged to share the information

Effects of Early Childhood Education on Kindergarten Readiness Scores

The purpose of this correlational study, which took place in a Central Florida school district, was to investigate the relationship between the quality of the early childhood education (ECE) programs and students\u27 kindergarten readiness scores. Vygotsky\u27s sociocultural theory, which states that a child\u27s environment, culture, and language are related to academic and social development, was the theoretical framework for this study. Many ECE centers have been rated using the Early Childhood Environment Rating Scale (ECERS). Additionally, some children in those centers have been rated for kindergarten readiness using the Florida Kindergarten Readiness Screener (FLKRS) developed by the Florida Department of Education (FLDOE). The sample included 55 ECE centers that had an ECERS rating with students who had FLKRS scores. This study addressed whether FLKRS scores were positively correlated with ECERS ratings. Data were analyzed using the Pearson product moment correlation. Results indicated a positive and significant correlation between ECERS ratings and FLKRS scores. A white paper was prepared to raise awareness regarding the availability of quality ECE centers to young learners. Implications for social change include an increased number of quality ECE programs in local neighborhoods as well as increased awareness of the importance of an environmental rating scale to monitor program quality