Dividing Attention Between Tasks: Testing Whether Explicit Payoff Functions Elicit Optimal Dual-Task Performance

We test people's ability to optimize performance across two concurrent tasks. Participants performed a number entry task while controlling a randomly moving cursor with a joystick. Participants received explicit feedback on their performance on these tasks in the form of a single combined score. This payoff function was varied between conditions to change the value of one task relative to the other. We found that participants adapted their strategy for interleaving the two tasks, by varying how long they spent on one task before switching to the other, in order to achieve the near maximum payoff available in each condition. In a second experiment, we show that this behavior is learned quickly (within 2-3 min over several discrete trials) and remained stable for as long as the payoff function did not change. The results of this work show that people are adaptive and flexible in how they prioritize and allocate attention in a dual-task setting. However, it also demonstrates some of the limits regarding people's ability to optimize payoff functions

A Tale of Three Signatures: practical attack of ECDSA with wNAF

One way of attacking ECDSA with wNAF implementation for the scalar multiplication is to perform a side-channel analysis to collect information, then use a lattice based method to recover the secret key. In this paper, we reinvestigate the construction of the lattice used in one of these methods, the Extended Hidden Number Problem (EHNP). We find the secret key with only 3 signatures, thus reaching the theoretical bound given by Fan, Wang and Cheng, whereas best previous methods required at least 4 signatures in practice. Our attack is more efficient than previous attacks, in particular compared to times reported by Fan et al. at CCS 2016 and for most cases, has better probability of success. To obtain such results, we perform a detailed analysis of the parameters used in the attack and introduce a preprocessing method which reduces by a factor up to 7 the overall time to recover the secret key for some parameters. We perform an error resilience analysis which has never been done before in the setup of EHNP. Our construction is still able to find the secret key with a small amount of erroneous traces, up to 2% of false digits, and 4% with a specific type of error. We also investigate Coppersmith's methods as a potential alternative to EHNP and explain why, to the best of our knowledge, EHNP goes beyond the limitations of Coppersmith's methods

Physicians, Primary Caregivers and Topical Repellent: All Under-Utilised Resources in Stopping Dengue Virus Transmission in Affected Households

BACKGROUND: Primary health care facilities frequently manage dengue cases on an ambulatory basis for the duration of the patient’s illness. There is a great opportunity for specific messaging, aimed to reduce dengue virus (DENV) transmission in and around the home, to be directly targeted toward this high-risk ambulatory patient group, as part of an integrated approach to dengue management. The extent however, to which physicians understand, and can themselves effectively communicate strategies to stop focal DENV transmission around an ambulatory dengue case is unknown; the matter of patient comprehension and recollection then ensues. In addition, the effectiveness of N,N-diethyl-3-methylbenzamide (DEET)-based insect repellent in protecting dengue patients from Aedes aegypti mosquitoes’ bites has not been investigated. METHODOLOGY: A knowledge, attitude and practice (KAP) survey, focusing on the mechanisms of DENV transmission and prevention, was performed using semi-structured questionnaires. This survey was targeted towards the patients and family members providing supportive care, and physicians routinely involved in dengue patient management in Southern Vietnam. An additional clinical observational study was conducted to measure the efficacy of a widely-used 13% DEET-based insect repellent to repel Ae. aegypti mosquitoes from the forearms of dengue cases and matched healthy controls. PRINCIPAL FINDINGS: Among both the physician (n = 50) and patient (n = 49) groups there were several respondents lacking a coherent understanding of DENV transmission, leading to some inappropriate attitudes and inadequate acute preventive practices in the household. The application of insect repellent to protect patients and their relatives from mosquito bites was frequently recommended by majority of physicians (78%) participating in the survey. Nevertheless, our tested topical application of 13% DEET conferred only ~1hr median protection time from Ae. aegypti landing. This is notably shorter than that advertised on the manufacturer’s label. No differences in landing time between febrile dengue cases or matched healthy controls (n = 19 experiments) were observed. CONCLUSIONS/SIGNIFICANCE: Our study identifies missed opportunities for primary care physicians to improve public health through communication of strategies that could prevent focal dengue transmission in and around a case household. We advocate better access to more efficient communication methods for physicians and auxilliary health workers, supporting to educate those at high risk of DENV transmission. Our empirical testing of a widely-available 13% DEET-based repellent was limited in its protective efficacy against Ae. aegypti mosquito bites, and therefore DENV transmission, suggesting more frequent application is necessary to be beneficial

Carbon nanotube four-terminal devices for pressure sensing applications

Carbon nanotubes (CNTs) are of high interest for sensing applications,owing to their superior mechanical strength, high Young’s modulus and low density. In this work, we report on a facile approach for the fabrication of carbon nanotube devices using a four terminal configuration. Oriented carbon nanotube films were pulled out from a CNT forest wafer and then twisted into a yarn. Both the CNT film and yarn were arranged on elastomer membranes/diaphragms which were arranged on a laser cut acrylic frame to form pressure sensors. The sensors were calibrated using a precisely controlled pressure system, showing a large change of the output voltage of approximately 50 mV at a constant supply current of 100 μA and under a low applied pressure of 15 mbar. The results indicate the high potential of using CNT films and yarns for pressure sensing applications

Crystal Structures, Local Atomic Environments, and Ion Diffusion Mechanisms of Scandium-Substituted Sodium Superionic Conductor (NASICON) Solid Electrolytes

The importance of exploring new solid electrolytes for all-solid-state batteries has led to significant interest in NASICON-type materials. Here, the Sc3+-substituted NASICON compositions Na3ScxZr2-x(SiO4)2-x(PO4)1+x (termed N3) and Na2ScyZr2-y(SiO4)1-y(PO4)2+y (termed N2) (x, y = 0 – 1) are studied as model Na+-ion conducting electrolytes for solid-state batteries. The influence of Sc3+ substitution on the crystal structures and local atomic environments has been characterized by powder X-ray diffraction (XRD) and neutron powder diffraction (NPD), as well as solid-state 23Na, 31P, and 29Si nuclear magnetic resonance (NMR) spectroscopy. A phase transition between 295 and 473 K from monoclinic C2/c to rhombohedral R c is observed for the N3 compositions, while N2 compositions crystallize in a rhombohedral R c unit cell in this temperature range. Alternating current (AC) impedance spectroscopy, molecular dynamics (MD) and high temperature 23Na NMR are in good agreement, showing that with a higher Sc3+ concentration, the ionic conductivity (about 10-4 S/cm at 473 K) decreases and the activation energy for ion diffusion increases. 23Na NMR experiments indicate that the nature of the Na+-ion motion is two-dimensional on the local atomic scale of NMR though the long-range diffusion pathways are three-dimensional. In addition, a combination of MD, bond valence, maximum entropy/Rietveld and van Hove correlation methods has been used, to reveal that the Na+-ion diffusion in these NASICON materials is three-dimensional and that there is a continuous exchange of sodium between Na(1) and Na(2) sites

Anonymous Single-Sign-On for n designated services with traceability

Anonymous Single-Sign-On authentication schemes have been proposed to allow users to access a service protected by a verifier without revealing their identity which has become more important due to the introduction of strong privacy regulations. In this paper we describe a new approach whereby anonymous authentication to different verifiers is achieved via authorisation tags and pseudonyms. The particular innovation of our scheme is authentication can only occur between a user and its designated verifier for a service, and the verification cannot be performed by any other verifier. The benefit of this authentication approach is that it prevents information leakage of a user's service access information, even if the verifiers for these services collude which each other. Our scheme also supports a trusted third party who is authorised to de-anonymise the user and reveal her whole services access information if required. Furthermore, our scheme is lightweight because it does not rely on attribute or policy-based signature schemes to enable access to multiple services. The scheme's security model is given together with a security proof, an implementation and a performance evaluation.Comment: 3

Clinical and Virological Features of Dengue in Vietnamese Infants

Dengue is a major public health problem in tropical and subtropical countries, including Vietnam. Dengue cases occur in children and young adults; however, severe dengue also occurs in infants less than 1 year of age. Prompt recognition of dengue is important for appropriate case management, particularly in infants in whom febrile illness from other causes is common. We describe the clinical picture, virological and immunological characteristics of infants with dengue admitted to three hospitals in southern Vietnam, compared with infants admitted with fever not due to dengue. We show that infants with dengue are difficult to distinguish from those with other febrile illnesses based on signs and symptoms at presentation, and so laboratory tests to confirm dengue virus infection may be useful for diagnosis and management. Conventional diagnostic methods for dengue have low sensitivity early in infection, and we show that an alternative antigen-detection assay that has demonstrated good sensitivity and specificity in older age groups also performs well in infants. This study will help to inform the diagnosis and management of dengue in infants

Faster Enumeration-based Lattice Reduction:Root Hermite Factor k1/(2k) Time kk/8+o(k)

International audienc

A Tale of Three Signatures: practical attack of ECDSA with wNAF

International audienceAttacking ECDSA with wNAF implementation for the scalar multiplication first requires some side channel analysis to collect information, then lattice based methods to recover the secret key. In this paper, we reinvestigate the construction of the lattice used in one of these methods, the Extended Hidden Number Problem (EHNP). We find the secret key with only 3 signatures, thus reaching a known theoretical bound, whereas best previous methods required at least 4 signatures in practice. Given a specifoc leakage model, our attack is more efficient than previous attacks, and for most cases, has better probability of success. To obtain such results, we perform a detailed analysis of the parameters used in the attack and introduce a preprocessing method which reduces by a factor up to 7 the total time to recover the secret key for some parameters. We perform an error resilience analysis which has never been done before in the setup of EHNP. Our construction find the secret key with a small amount of erroneous traces, up to 2% of false digits, and 4% with a specific type of error