Uncertainty in Additive Feature Attribution methods

In this work, we explore various topics that fall under the umbrella of Uncertainty in post-hoc Explainable AI (XAI) methods. We in particular focus on the class of additive feature attribution explanation methods. We first describe our specifications of uncertainty and compare various statistical and recent methods to quantify the same. Next, for a particular instance, we study the relationship between a feature's attribution and its uncertainty and observe little correlation. As a result, we propose a modification in the distribution from which perturbations are sampled in LIME-based algorithms such that the important features have minimal uncertainty without an increase in computational cost. Next, while studying how the uncertainty in explanations varies across the feature space of a classifier, we observe that a fraction of instances show near-zero uncertainty. We coin the term "stable instances" for such instances and diagnose factors that make an instance stable. Next, we study how an XAI algorithm's uncertainty varies with the size and complexity of the underlying model. We observe that the more complex the model, the more inherent uncertainty is exhibited by it. As a result, we propose a measure to quantify the relative complexity of a blackbox classifier. This could be incorporated, for example, in LIME-based algorithms' sampling densities, to help different explanation algorithms achieve tighter confidence levels. Together, the above measures would have a strong impact on making XAI models relatively trustworthy for the end-user as well as aiding scientific discovery.Comment: 1

In-situ characterization of the thermal state of resonant optical interferometers via tracking of their higher-order mode resonances

Thermal lensing in resonant optical interferometers such as those used for gravitational wave detection is a concern due to the negative impact on control signals and instrument sensitivity. In this paper we describe a method for monitoring the thermal state of such interferometers by probing the higher-order spatial mode resonances of the cavities within them. We demonstrate the use of this technique to measure changes in the Advanced LIGO input mode cleaner cavity geometry as a function of input power, and subsequently infer the optical absorption at the mirror surfaces at the level of 1 ppm per mirror. We also demonstrate the generation of a useful error signal for thermal state of the Advanced LIGO power recycling cavity by continuously tracking the first order spatial mode resonance frequency. Such an error signal could be used as an input to thermal compensation systems to maintain the interferometer cavity geometries in the presence of transients in circulating light power levels, thereby maintaining optimal sensitivity and maximizing the duty-cycle of the detectors

Transitioning young adults from paediatric to adult care and the HIV care continuum in Atlanta, Georgia, USA: a retrospective cohort study

Introduction: The transition from paediatric to adult HIV care is a particularly highâ risk time for disengagement among young adults; however, empirical data are lacking.Methods: We reviewed medical records of 72 youth seen in both the paediatric and the adult clinics of the Grady Infectious Disease Program in Atlanta, Georgia, USA, from 2004 to 2014. We abstracted clinical data on linkage, retention and virologic suppression from the last two years in the paediatric clinic through the first two years in the adult clinic.Results: Of patients with at least one visit scheduled in adult clinic, 97% were eventually seen by an adult provider (median time between last paediatric and first adult clinic visit = 10 months, interquartile range 2â 18 months). Half of the patients were enrolled in paediatric care immediately prior to transition, while the other half experienced a gap in paediatric care and reâ enrolled in the clinic as adults. A total of 89% of patients were retained (at least two visits at least three months apart) in the first year and 56% in the second year after transition. Patients who were seen in adult clinic within three months of their last paediatric visit were more likely to be virologically suppressed after transition than those who took longer (Relative risk (RR): 1.76; 95% confidence interval (CI): 1.07â 2.9; p = 0.03). Patients with virologic suppression (HIVâ 1 RNA below the level of detection of the assay) at the last paediatric visit were also more likely to be suppressed at the most recent adult visit (RR: 2.3; 95% CI: 1.34â 3.9; p = 0.002).Conclusions: Retention rates once in adult care, though high initially, declined significantly by the second year after transition. Preâ transition viral suppression and shorter linkage time between paediatric and adult clinic were associated with better outcomes postâ transition. Optimizing transition will require intensive transition support for patients who are not virologically controlled, as well as support for youth beyond the first year in the adult setting.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138343/1/jia21848.pd

Big Data in Food: Systematic Literature Review and Future Directions

The growing importance of Big Data in the food industry enables businesses to leverage information to gain a competitive advantage. This paper provides a systematic literature review (SLR) to provide an insight into the use of state-of-art of Big Data applications in the food industry. The SLR relies on available literature that provides the context, theoretical construct and identifies gaps. Based on the findings, we suggest recommendations, identify limitations and suggest policy implications and future directions. Using search databases were examined and 38 relevant studies were identified for retrospective analysis. The review shows that Big Data supports the food industry in ways that enable using Artificial Intelligence to manage restaurants and mobile based applications in supporting consumers with restaurant selection. This SLR open new avenues for future research in the importance of Big Data in the food industry, which will surely help researchers/practitioners in effective utilization of Big DataBig Data

Tuned mass damper effects on the response of multi-storied structures observed in geotechnical centrifuge tests

Tuned mass dampers (TMDs) are widely used to reduce vibrations in structures. However, very little research is available on the experimental investigation of TMDs and their performance in soilstructure systems. In this paper, a series of geotechnical centrifuge tests was conducted to investigate the effects of TMDs on the response of a multiple-storey sway frame structure undergoing dynamic soil-structure interaction (SSI). Structural responses were recorded for a wide range of input motion characteristics, damper configurations and soil profiles. The practicality associated with the use of TMDs in the damping of resonant structures in light of unexpected earthquake characteristics different from design earthquakes was experimentally demonstrated. Tuning a TMD to soil-structure system properties rather than fixed-base structural properties was found to double the improvement in damping and reduce the original peak response by nearly half. The potential effectiveness of a detuned mass damper in light of significant SSI was also demonstrated.The financial help during the course of the study was extended by the Engineering and Physical Sciences Research Council (EPSRC).This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.soildyn.2015.06.01

Investigating the Intention of Tourists to Travel to the World Heritage Destination: The Mediating Role of Familiarity

This study investigates the intention of tourists to travel to the Great Himalayan National Park (GHNP) in India, a conservation area of natural bio-diversity that was accorded World Heritage Site status in 2014. The main constructs that have been used in the study are an image of the destination, homestay preference, destination familiarity and intention to travel. The S-O-R framework has been further used to find the tourists’ intention to travel to GHNP. A closed-ended questionnaire was administered to 1,020 respondents in India. The results show that path coefficients for all constructs are statistically significant. Tourists’ intention to travel is likely to be influenced by the destination image and the preference for a local homestay, which is mediated by destination familiarity. The study is not longitudinal and sheds light on respondents’ perceptions for a specific time period. Policymakers must design policies that focus on developing campaigns that promote lesser-known destinations, thus ensuring a positive destination image and enhancing destination familiarity by providing authentic information. Such a shift in tourism will foster employment in rural and less-known areas of natural beauty. Further, tourists’ preference to stay in homestay arrangements allows them to experience local hospitality

Melatonin: the placental antioxidant and anti-inflammatory

Melatonin (N-acetyl-5-methoxytryptamine) is an indolamine hormone with many physiological and biological roles. Melatonin is an antioxidant, anti-inflammatory, free radical scavenger, circadian rhythm regulator, and sleep hormone. However, its most popular role is the ability to regulate sleep through the circadian rhythm. Interestingly, recent studies have shown that melatonin is an important and essential hormone during pregnancy, specifically in the placenta. This is primarily due to the placenta’s ability to synthesize its own melatonin rather than depending on the pineal gland. During pregnancy, melatonin acts as an antioxidant and anti-inflammatory, which is necessary to ensure a stable environment for both the mother and the fetus. It is an essential antioxidant in the placenta because it reduces oxidative stress by constantly scavenging for free radicals, i.e., maintain the placenta’s integrity. In a healthy pregnancy, the maternal immune system is constantly altered to accommodate the needs of the growing fetus, and melatonin acts as a key anti-inflammatory by regulating immune homeostasis during early and late gestation. This literature review aims to identify and summarize melatonin’s role as a powerful antioxidant and anti-inflammatory that reduces oxidative stress and inflammation to maintain a favorable homeostatic environment in the placenta throughout gestation

Non-linear electromagnetic response of graphene

It is shown that the massless energy spectrum of electrons and holes in graphene leads to the strongly non-linear electromagnetic response of this system. We predict that the graphene layer, irradiated by electromagnetic waves, emits radiation at higher frequency harmonics and can work as a frequency multiplier. The operating frequency of the graphene frequency multiplier can lie in a broad range from microwaves to the infrared.Comment: 5 pages, 3 figure