A Framework to Measure Reliance of Acoustic Latency on Smartphone Status

Audio latency, defined as the time duration when an audio signal travels from the microphone to an app or from an app to the speakers, significantly influences the performance of many mobile sensing applications including acoustic based localization and speech recognition. It is well known within the mobile app development community that audio latencies can be significant (up to hundreds of milliseconds) and vary from smartphone to smartphone and from time to time. Therefore, it is essential to study the causes and effects of the audio latency in smartphones. To the best of our knowledge, there exist mobile apps that can measure audio latency but not the corresponding status of smartphones such as available RAM, CPU loads, battery level, and number of files and folders. In this paper, we are the first to propose a framework that can simultaneously log both the audio latency and the status of smartphones. The proposed framework does not require time synchronization or firmware reprogramming and can run on a standalone device. Since the framework is designed to study the latency causality, the status of smartphones are deliberately and randomly varied as maximum as possible. To evaluate the framework, we present a case study with Android devices. We design and implement a latency app that simultaneously measures the latency and the status of smartphones. The preliminary results show that the latency values have large means (50 - 150 ms) and variances (4-40 ms). The effect of latency can be considerably reduced by just simply subtracting the offset. In order to achieve improved latency prediction that can cope with the variances an advanced regression model would be preferred

Ambient Sound-Based Collaborative Localization of Indeterministic Devices

Localization is essential in wireless sensor networks. To our knowledge, no prior work has utilized low-cost devices for collaborative localization based on only ambient sound, without the support of local infrastructure. The reason may be the fact that most low-cost devices are indeterministic and suffer from uncertain input latencies. This uncertainty makes accurate localization challenging. Therefore, we present a collaborative localization algorithm (Cooperative Localization on Android with ambient Sound Sources (CLASS)) that simultaneously localizes the position of indeterministic devices and ambient sound sources without local infrastructure. The CLASS algorithm deals with the uncertainty by splitting the devices into subsets so that outliers can be removed from the time difference of arrival values and localization results. Since Android is indeterministic, we select Android devices to evaluate our approach. The algorithm is evaluated with an outdoor experiment and achieves a mean Root Mean Square Error (RMSE) of 2.18 m with a standard deviation of 0.22 m. Estimated directions towards the sound sources have a mean RMSE of 17.5 ° and a standard deviation of 2.3 °. These results show that it is feasible to simultaneously achieve a relative positioning of both devices and sound sources with sufficient accuracy, even when using non-deterministic devices and platforms, such as Android

Contact Angle & Electrochemical Measurements of Metallic Atmospheric Corrosion on Copper and Carbon Steel

Understanding atmospheric corrosion has been incredibly challenging due to the complex interplay between surface microstructures, environmental variables, and electrochemical processes. The methodology presented is being developed to apply to atmospheric corrosion models of metals and other advanced materials by observing the change in contact angle in situ as a function of corrosion parameters. Performed contact angle measurements on two industrially relevant metals (copper and carbon steel) over a 1 min to 30-day time span to track the change in wettability due to the formation of an air-formed oxide layer (aged) as a function of surface roughness

The binge-watcher’s journey: Investigating motivations, contexts, and affective states surrounding Netflix viewing

The growth of Internet-distributed TV services has transformed video consumption, enhancing the level of control that viewers have over what they watch. Along with the release of entire seasons of programming at once, this has led to the phenomenon of ‘binge-watching’, in which several episodes of a program are viewed in one sitting. This article presents the results of a novel exploratory study focused on 40 Netflix viewing sessions from 11 millennials in their homes. Methodologically, we employed a novel mixed-methods approach that combines objective data (collected through a browser extension) and subjective data (collected via questionnaires completed before and after viewing). This novel approach allowed us to describe the binge-watcher’s experience in a holistic fashion. Results suggest that binge-watching is an individual activity mainly performed at the end of the day to relax, for boredom relief purposes, or for escapism. Furthermore, a binge-watching session lasts for an average of 2 h and 10 min, and variations on binge-watchers’ affective states were identified after Netflix exposure. Participants’ levels of valence (unhappy–happy) significantly decreased after binge-watching; their positive affect values increased primarily after watching sci-fi, while their negative affect values decreased after watching comedy and slightly increased after watching drama. However, the levels of arousal (relaxed–stimulated) remained the same. This study extends our current understanding of binge-watching in terms of viewer motivations, how it affects their viewing experiences, and participants’ subjective affective states. The investigation contributes, thus

Vector boson Pair Production at Supercolliders; useful approximate helicity amplitudes

We study vector boson pair production at $LHC$ and $SSC$, taking into account the effects generated by the anomalous vector boson and Higgs couplings induced by the operators ${\cal O}_W$ and ${\cal O}_{UW}$, which are the only dim=6 operators preserving $SU(2)_c$. These operators lead to enhanced production of transverse vector bosons, as opposed to the enhanced production of longitudinal gauge bosons, induced in case M_H\gsim 1\ TeV, by dim=4 terms already existing in the Standard Model lagrangian. For vector boson pair masses larger than $1\ TeV$, we establish very simple approximate expressions for the standard as well as the non-standard helicity amplitudes for $q\bar q$ annihilation and vector boson fusion, which accurately describe the physics. These expressions should simplify the experimental search for such interactions. We finally discuss the observability and the disentangling of these interactions.Comment: 22 pages, 6 figures avaible by air mail upon request , (e-mail [email protected] PM/93-26 THES-TP 93/

Angiotensin II type 2 receptors and cardiac hypertrophy in women with hypertrophic cardiomyopathy

The development of left ventricular hypertrophy in subjects with hypertrophic cardiomyopathy (HCM) is variable, suggesting a ro