Pathologies of Neural Models Make Interpretations Difficult

One way to interpret neural model predictions is to highlight the most important input features---for example, a heatmap visualization over the words in an input sentence. In existing interpretation methods for NLP, a word's importance is determined by either input perturbation---measuring the decrease in model confidence when that word is removed---or by the gradient with respect to that word. To understand the limitations of these methods, we use input reduction, which iteratively removes the least important word from the input. This exposes pathological behaviors of neural models: the remaining words appear nonsensical to humans and are not the ones determined as important by interpretation methods. As we confirm with human experiments, the reduced examples lack information to support the prediction of any label, but models still make the same predictions with high confidence. To explain these counterintuitive results, we draw connections to adversarial examples and confidence calibration: pathological behaviors reveal difficulties in interpreting neural models trained with maximum likelihood. To mitigate their deficiencies, we fine-tune the models by encouraging high entropy outputs on reduced examples. Fine-tuned models become more interpretable under input reduction without accuracy loss on regular examples.Comment: EMNLP 2018 camera read

Fast Sequence Component Analysis for Attack Detection in Synchrophasor Networks

Modern power systems have begun integrating synchrophasor technologies into part of daily operations. Given the amount of solutions offered and the maturity rate of application development it is not a matter of "if" but a matter of "when" in regards to these technologies becoming ubiquitous in control centers around the world. While the benefits are numerous, the functionality of operator-level applications can easily be nullified by injection of deceptive data signals disguised as genuine measurements. Such deceptive action is a common precursor to nefarious, often malicious activity. A correlation coefficient characterization and machine learning methodology are proposed to detect and identify injection of spoofed data signals. The proposed method utilizes statistical relationships intrinsic to power system parameters, which are quantified and presented. Several spoofing schemes have been developed to qualitatively and quantitatively demonstrate detection capabilities.Comment: 8 pages, 4 figures, submitted to IEEE Transaction

Capturing Heat from Spent Nuclear Fuel

ME450 Capstone Design and Manufacturing Experience: Winter 2021Spent Nuclear Fuel can be placed in dry cask storage, where it emits waste heat into the atmosphere. Our sponsor, Dr. Marianna Coulentianos, identified an opportunity to capture this heat for a beneficial application. Our team evaluated the feasibility of our sponsor’s previously proposed solutions and designed a system that could transfer heat from the dry cask. We focused specifically on quantifying the amount of heat that would be available for a therothecial application. In order to determine how much heat would theoretically be available, we constructed both mathematical and computational simulations of heat transfer through a duct system. The system we propose includes a square funnel feature at the cask interface, connected to a round, rigid duct system extending over the perimeter fence. It was observed that the outlet temperature of our proposed system is around 36-65℃, which we determined is most suitable for a greenhouse application. We calculated a return on investment of 5 years by growing tomatoes in a greenhouse of 1800 ft2. We are confident that our design is feasible and does not violate any regulations set forth by the Nuclear Regulatory Commission. However, more analysis is needed to further examine discrepancies between field data and our assumptions, as well as the scalability of our proposed solution. We also considered the social context of this solution. Eating fruits and vegetables grown on a nuclear site is likely to cause skepticism around our solution. While we believe that the radiation levels of this waste heat are too low to realistically affect horticultural applications, all food that is intended for human or animal consumption in the United States must register with the FDA before beginning these activities.Dr. Marianna Coulentianos: UM Mechanical Engineering Departmenthttp://deepblue.lib.umich.edu/bitstream/2027.42/167636/1/Team_17-Capturing_Heat_from_Spent_Nuclear_Fuel.pd

Fuselage Pressures Measured on the Bell X-1 Research Airplane in Transonic Flight

Pressure-distribution measurements have been made on the fus elage of the Bell X- 1 research airplane. Data are presented for angles of attack from 2 deg. to 8 deg. during pull-ups at Mach numbers of about 0.78, 0.85, 0.88, and 1.02. The results of the investigation indicated that a large portion of the load carried by the fuselage was in the vicinity of the wing and may be attributed to wing-to-fuselage carryover. The presence of the wing from the 41 to 60 percent fuselage stations influenced the fuselage pressures from about 30 to 65 percent fuselage length at Mach numbers of approximat ely 0.78, 0.85, and 0.88, and from about 35 to 80 percent fuselage length at a Mach number of approximately 1.02. The fuselage contributed about 20 percent of the total airplane normal-force coefficient. The center of pressure of the fuselage load throughout the tests was located from 41 to 51 percent fuselage length, which corresponds to the forward half of the wing root-chord location

Static and dynamic tendon pull-out test research at the University of Wollongong

Tendon technology is widely used for strata control in underground coal mines, in both primary and secondary support systems. The understanding of how they work is crucial to effective strata reinforcement design. Research on tendon technology is an evolving study and this paper is aiming at maintaining this evolution by continuing research on load transfer mechanisms under both static and dynamic conditions, which was reported initially by (Anzanpour, 2021) in ROC2021. This programme of study includes testing of different strength capacity cable bolts, which have been important in the stabilisation of the ground around mining excavations affected by rock bursts and ground seismicity. The aim of the study was to evaluate tendon performance in different loading environments. From a series of tests carried out in the most recent study, it was found that in pull testing, the load transfer characteristics vary with respect to the type of testing. The required dynamic energy for pulling-out a cable bolt can be between 50-80% lower than the static load, based on the cable type and its geometry (Plain or Bulbed). Debonding and pullout mechanisms regardless of loading rate, seem to be similar in both static and dynamic tests, however, plain cable bolts behave differently from bulbed cable bolts in reaction to pull-out load