The Complexity of Scheduling for p-norms of Flow and Stretch

We consider computing optimal k-norm preemptive schedules of jobs that arrive over time. In particular, we show that computing the optimal k-norm of flow schedule, is strongly NP-hard for k in (0, 1) and integers k in (1, infinity). Further we show that computing the optimal k-norm of stretch schedule, is strongly NP-hard for k in (0, 1) and integers k in (1, infinity).Comment: Conference version accepted to IPCO 201

Video Highlight Prediction Using Audience Chat Reactions

Sports channel video portals offer an exciting domain for research on multimodal, multilingual analysis. We present methods addressing the problem of automatic video highlight prediction based on joint visual features and textual analysis of the real-world audience discourse with complex slang, in both English and traditional Chinese. We present a novel dataset based on League of Legends championships recorded from North American and Taiwanese Twitch.tv channels (will be released for further research), and demonstrate strong results on these using multimodal, character-level CNN-RNN model architectures.Comment: EMNLP 201

Phases and phase stabilities of Fe3X alloys (X=Al, As, Ge, In, Sb, Si, Sn, Zn) prepared by mechanical alloying

Mechanical alloying with a Spex 8000 mixer/mill was used to prepare several alloys of the Fe3X composition, where the solutes X were from groups IIB, IIIB, IVB, and VB of the periodic table. Using x-ray diffractometry and Mössbauer spectrometry, we determined the steady-state phases after milling for long times. The tendencies of the alloys to form the bcc phase after milling are predicted well with the modified usage of a Darken–Gurry plot of electronegativity versus metallic radius. Thermal stabilities of some of these phases were studied. In the cases of Fe3Ge and Fe3Sn, there was the formation of transient D03 and B2 order during annealing, although this ordered structure was replaced by equilibrium phases upon further annealing

Your Code Is My Code: Exploiting a Common Weakness in OAuth 2.0 Implementations

Many millions of users routinely use their Google, Facebook and Microsoft accounts to log in to websites supporting OAuth 2.0-based single sign on. The security of OAuth 2.0 is therefore of critical importance, and it has been widely examined both in theory and in practice. In this paper we disclose a new class of practical attacks on OAuth 2.0 implementations, which we call Partial Redirection URI Manipulation Attacks. An attack of this type can be used by an attacker to gain a victim user’s OAuth 2.0 code (a token representing a right to access user data) without the user’s knowledge; this code can then be used to impersonate the user to the relevant relying party website. We examined 27 leading OAuth 2.0 identity providers, and found that 19 of them are vulnerable to these attacks

Thermodynamic properties of interstitial elements in the refractory metals Semiannual report, 1 Dec. 1967 - 31 May 1968

Thermodynamic behavior of interstitial elements in Mo, W, Nb, and T

Nd-142/Nd-144 in SNCs and early differentiation of a heterogeneous Martian mantle

Sm/Nd correlated variations in Nd-142/Nd-144 have been observed for mineral phases of achondrites from decay of live Sm-146 in the early solar system. Crystallization ages of shergottites-nakhlites-Chassigny (SNC) meteorites are less than or = 1.3 Ga, so variations of Nd-142/Nd-144 among mineral phases of the SNC's are not expected. However, if SNC's were derived from source reservoirs of differing Sm/Nd ratios, established while Sm-146 was still alive, and which remained isolated except for magma extraction, then variations in Nd-142/Nd-144 would exist among individual SNC meteorites. Rb-Sr and U-Pb isotopic data for the shergottites imply differentiation of their parent planet approximately 4.6 Ga ago. The confirmation of the conclusion that the nakhlites and shergottites were derived from different source regions, and that, consequently, the shergottite parent body (SPB) mantle was heterogeneous is presented

Performance evaluation of multiquadrant DC drive using fuzzy- genetic approach

This paper presents the simulation of multiquadrant DC drive using Fuzzy Logic Control (FLC) for various operating conditions. Genetic Algorithm (GA) has been used in the design of membership functions and rule sets for eliminating the need of human input in the design loop. Performance analysis is performed through mathematical simulation for the stable operation of the drive. Simulated results validate the proposed control techniqu

A New Simulation Metric to Determine Safe Environments and Controllers for Systems with Unknown Dynamics

We consider the problem of extracting safe environments and controllers for reach-avoid objectives for systems with known state and control spaces, but unknown dynamics. In a given environment, a common approach is to synthesize a controller from an abstraction or a model of the system (potentially learned from data). However, in many situations, the relationship between the dynamics of the model and the \textit{actual system} is not known; and hence it is difficult to provide safety guarantees for the system. In such cases, the Standard Simulation Metric (SSM), defined as the worst-case norm distance between the model and the system output trajectories, can be used to modify a reach-avoid specification for the system into a more stringent specification for the abstraction. Nevertheless, the obtained distance, and hence the modified specification, can be quite conservative. This limits the set of environments for which a safe controller can be obtained. We propose SPEC, a specification-centric simulation metric, which overcomes these limitations by computing the distance using only the trajectories that violate the specification for the system. We show that modifying a reach-avoid specification with SPEC allows us to synthesize a safe controller for a larger set of environments compared to SSM. We also propose a probabilistic method to compute SPEC for a general class of systems. Case studies using simulators for quadrotors and autonomous cars illustrate the advantages of the proposed metric for determining safe environment sets and controllers.Comment: 22nd ACM International Conference on Hybrid Systems: Computation and Control (2019

Large-scale exact diagonalizations reveal low-momentum scales of nuclei

Ab initio methods aim to solve the nuclear many-body problem with controlled approximations. Virtually exact numerical solutions for realistic interactions can only be obtained for certain special cases such as few-nucleon systems. Here we extend the reach of exact diagonalization methods to handle model spaces with dimension exceeding $10^{10}$ on a single compute node. This allows us to perform no-core shell model (NCSM) calculations for 6Li in model spaces up to $N_\mathrm{max} = 22$ and to reveal the 4He+d halo structure of this nucleus. Still, the use of a finite harmonic-oscillator basis implies truncations in both infrared (IR) and ultraviolet (UV) length scales. These truncations impose finite-size corrections on observables computed in this basis. We perform IR extrapolations of energies and radii computed in the NCSM and with the coupled-cluster method at several fixed UV cutoffs. It is shown that this strategy enables information gain also from data that is not fully UV converged. IR extrapolations improve the accuracy of relevant bound-state observables for a range of UV cutoffs, thus making them profitable tools. We relate the momentum scale that governs the exponential IR convergence to the threshold energy for the first open decay channel. Using large-scale NCSM calculations we numerically verify this small-momentum scale of finite nuclei.Comment: Minor revisions.Accepted for publication in Physical Review