5,184 research outputs found
Attacks on the Search-RLWE problem with small errors
The Ring Learning-With-Errors (RLWE) problem shows great promise for
post-quantum cryptography and homomorphic encryption. We describe a new attack
on the non-dual search RLWE problem with small error widths, using ring
homomorphisms to finite fields and the chi-squared statistical test. In
particular, we identify a "subfield vulnerability" (Section 5.2) and give a new
attack which finds this vulnerability by mapping to a finite field extension
and detecting non-uniformity with respect to the number of elements in the
subfield. We use this attack to give examples of vulnerable RLWE instances in
Galois number fields. We also extend the well-known search-to-decision
reduction result to Galois fields with any unramified prime modulus q,
regardless of the residue degree f of q, and we use this in our attacks. The
time complexity of our attack is O(nq2f), where n is the degree of K and f is
the residue degree of q in K. We also show an attack on the non-dual (resp.
dual) RLWE problem with narrow error distributions in prime cyclotomic rings
when the modulus is a ramified prime (resp. any integer). We demonstrate the
attacks in practice by finding many vulnerable instances and successfully
attacking them. We include the code for all attacks
Synaptic potentiation facilitates memory-like attractor dynamics in cultured in vitro hippocampal networks
Collective rhythmic dynamics from neurons is vital for cognitive functions
such as memory formation but how neurons self-organize to produce such activity
is not well understood. Attractor-based models have been successfully
implemented as a theoretical framework for memory storage in networks of
neurons. Activity-dependent modification of synaptic transmission is thought to
be the physiological basis of learning and memory. The goal of this study is to
demonstrate that using a pharmacological perturbation on in vitro networks of
hippocampal neurons that has been shown to increase synaptic strength follows
the dynamical postulates theorized by attractor models. We use a grid of
extracellular electrodes to study changes in network activity after this
perturbation and show that there is a persistent increase in overall spiking
and bursting activity after treatment. This increase in activity appears to
recruit more "errant" spikes into bursts. Lastly, phase plots indicate a
conserved activity pattern suggesting that the network is operating in a stable
dynamical state
Exciting Students About Materials Science and Engineering: A Project-Based, Service-Learning Museum Design Course
A new course was developed for Materials Engineering students to design, create, and install interactive, educational displays on Materials Science & Engineering for a science museum at a local K-6 charter school. The course grew out of an ASM Foundation grant “to excite young people in materials, science, and engineering careers,” and the challenge was put forth to Cal Poly students. A formal design sequence was applied to give the students the opportunity to learn about the design process, project management, and teamwork. User profiles were created for the stakeholders, and project values were established. The class partnered with the museum curator to develop functional and design requirements for the displays, and to gain valuable feedback during the project development. Guest lectures and discussions with museum exhibit developers, education specialists, and design experts assisted the class. Three different displays that highlighted materials were developed: “Metallic Trampoline” (amorphous metal), “Smart Materials” (NiTi shape memory alloys), and “Touch and See” (heat sensing liquid crystals). The final museum displays were well received by the client and end users. A survey at the end of the quarter revealed that the engineering students gained valuable design and project experiences
Point-contact tunneling spectroscopy measurement of CuTiSe: disorder-enhanced Coulomb effects
We performed point-contact spectroscopy tunneling measurements on
CuTiSe bulk with and at temperatures ranging from
K and observe a suppression in the density of states around zero-bias
that we attribute to enhanced Coulomb interactions due to disorder. We find
that the correlation gap associated with this suppression is related to the
zero-temperature resistivity. We use our results to estimate the disorder-free
transition temperature and find that the clean limit is close to the
experimentally observed .Comment: 4 pages, 4 figure
Silicon-based nanochannel glucose sensor
Silicon nanochannel biological field effect transistors have been developed
for glucose detection. The device is nanofabricated from a silicon-on-insulator
wafer with a top-down approach and surface functionalized with glucose oxidase.
The differential conductance of silicon nanowires, tuned with source-drain bias
voltage, is demonstrated to be sensitive to the biocatalyzed oxidation of
glucose. The glucose biosensor response is linear in the 0.5-8 mM concentration
range with 3-5 min response time. This silicon nanochannel-based glucose
biosensor technology offers the possibility of high density, high quality
glucose biosensor integration with silicon-based circuitry.Comment: 3 pages, 3 figures, two-column format. Related papers can be found at
http://nano.bu.ed
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Research Synthesis for the California Zero Traffic Fatalities Task Force
This research synthesis consists of a set of white papers that jointly provide a review of research on the current practicefor setting speed limits and future opportunities to improve roadway safety. This synthesis was developed to inform thework of the Zero Traffic Fatalities Task Force, which was formed in 2019 by the California State Transportation Agencyin response to California Assembly Bill 2363 (Friedman). The statutory goal of the Task Force is to develop a structured,coordinated process for early engagement of all parties to develop policies to reduce traffic fatalities to zero. Thisreport addresses the following critical issues related to the work of the Task Force: (i) the relationship between trafficspeed and safety; (ii) lack of empirical justification for continuing to use the 85th percentile rule; (iii) why we need toreconsider current speed limit setting practices; (iv) promising alternatives to current methods of setting speed limits;and (v) improving road designs to increase road user safety
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