Active speaker detection (ASD) and virtual cinematography (VC) can significantly improve the experience of a video conference by automatically panning, tilting and zooming of a camera: subjectively users rate an expert video cinematographer significantly higher than the unedited video. We describe a new automated ASD and VC that performs within 0.3 MOS of an expert cinematographer based on subjective ratings with a 1-5 scale. This system uses a 4K wide-FOV camera, a depth camera, and a microphone array, extracts features from each modality and trains an ASD using an AdaBoost machine learning system that is very efficient and runs in real-time. A VC is similarly trained using machine learning. To avoid distracting the room participants the system has no moving parts - the VC works by cropping and zooming the 4K wide-FOV video stream. The system was tuned and evaluated using extensive crowdsourcing techniques and evaluated on a system with N=100 meetings, each 2-5 minutes in length.

User surveys for Quality of Experience (QoE) are a critical source of information for application developers. In addition to the common “star rating” used to estimate Mean Opinion Score (MOS), more detailed survey questions (problem tokens) about specific areas provide valuable insight into the factors impacting QoE. This paper explores two aspects of problem token questionnaire design. First, we study the bias introduced by fixed question order, and second, we provide a methodology to manage the size of the survey while keeping it informative. Based on 900,000 calls gathered using a randomized controlled experiment from Skype, we find that token selections can be strongly biased due to token positions and display design. This selection bias can be significantly reduced by randomizing the display order of tokens. It is worth noting that users respond to the randomized-order variant at levels that are comparable to the fixed-order variant. The effective selection of a subset of tokens is achieved by extracting tokens that provide the highest information gain over user ratings. This selection is known to be in the class of NP-hard problems. We apply a well-known greedy submodular maximization method on our dataset to capture 94% of the information using just 30% of thequestions.

User-perceived quality-of-experience (QoE) in internet telephony systems is commonly evaluated using subjective ratings computed as a Mean Opinion Score (MOS). In such systems, while user MOS can be tracked on an ongoing basis, it does not give insight into which factors of a call induced any perceived degradation in QoE - it does not tell us what caused a user to have a sub-optimal experience. For effective planning of product improvements, we are interested in understanding the impact of each of these degrading factors, allowing the estimation of the return (i.e., the improvement in user QoE) for a given investment. To obtain such insights, we advocate the use of an end-of-call “problem token questionnaire” (PTQ) which probes the user about common call quality issues (e.g., distorted audio or frozen video) which they may have experienced. In this paper, we show the efficacy of this questionnaire using data gathered from over 700,000 end-of-call surveys gathered from Skype (a large commercial VoIP application). We present a method to rank call quality and reliability issues and address the challenge of isolating independent factors impacting the QoE. Finally, we present representative examples of how these problem tokens have proven to be useful in practice.

A method of calculating a similarity measure between first and second image patches, which include respective first and second intensity values associated with respective elements of the first and second image patches, and which have a corresponding size and shape such that each element of the first image patch corresponds to an element on the second image patch. The method: determines a set of sub-regions on the second image patch corresponding to elements of the first image patch and having first intensity values within a range defined for that sub-region; calculates variance, for each sub-region of the set over all of the elements of that sub-region, of a function of the second intensity value associated with that element and the first intensity value associated with the corresponding element of the first image patch; and calculates similarity measure as the sum over all sub-regions of the calculated variances.

We have developed a “Space Weather Buoy” for measuring upper atmospheric radiation from cosmic rays and solar storms. The Buoy, which is carried to the stratosphere by helium balloons, is relatively inexpensive and uses off-the-shelf technology accessible to small colleges and high schools. Using this device, we have measured two Forbush Decreases and a small surge in atmospheric radiation during the St. Patrick's Day geomagnetic storm of March 2015.

Background: Cefixime trihydrate is a third generation cephalosporin with a broad spectrum bactericidal activity. It usually requires frequent dosing due to its short biological half life, poor bioavailability, and first pass metabolism. Methods: Oral floating tablets of cefixime trihydrate was formulated using cross-linked polymers like chitosan and sodium alginate, gas generating agent sodium bicarbonate, Xanthan gum, lactose, and carbopol. The tablets were compressed by potassium bromide press and evaluated with different parameters like average weight, thickness, diameter, hardness, friability, drug content, in-vitro buoyancy study, swelling characteristics, scanning electron microscopy, and kinetic release data. Results: The formulated floating tablets showed good physiochemical properties. The kinetic profile show that the drug release follow a mixed zero order and first order kinetics and well fits with Higuchis model and followed by non-Fickian diffusion mechanism. The formulations F8 and F9 showed higher swelling index and maximum drug release compared to others. Formulations F9 was found to be stable at 45oC and 75% RH for a period of 21 days. Conclusion: From the study, it is evident that a promising gas-powered controlled release floating tablets of Cefixime can be developed to increase gastric residence time and thereby increasing its bioavailability.