Being a Serial Transnational Activist

Transnational activism endures as a political practice turning a mirror onto the world's powerbrokers. We analyse a variety of transnational activism best characterized as serial by virtue of an observed systematic time and border‐spanning commitment to protest communication. Following statistical disambiguation of a dataset of 2.5 million unique Twitter users, we identified a subset of exceptionally prolific communicators and interviewed 21 of them. We show that a noted prominence in networked communication of otherwise unremarkable Twitter users may be an upshot of purposive strategies intended to publicize, support or help orchestrate collective action. Accordingly, we propose the term “engagement compass” to address the relationship between activists' life‐patterns and their personal investment in protest over time.     

ACOUSTIC STUDIES OF INTERFACIAL EFFECTS IN AIRLIFT REACTORS

Rational design of airlift reactors for the culture of plant and animal cells is impeded by a lack of understanding of the causes of loss of viability. Some recent speculations in the literature suggest that gas-liquid interfacial phenomena have played prominent roles in observed instances of loss of viability in both insect and animal cell cultures. The important interfacial events may include bubble formation and detachment at the sparger, bubble coalescence and breakage, and bubble disengagement at the free surface-entailing film thinning, film rupture, and film droplet ejection.

We have carried out an experimental investigation of interfacial phenomena using macrovideography and acoustic signals recorded at both the sparger and the free surface. Data have been collected for several liquid media including distilled water, distilled water with electrolyte (NaCl), and aqueous solutions of glycerol (μ = 3 to 9.5 cP). The studies were conducted in a 3-liter, acrylic plastic, split-column airlift reactor, and air was introduced through interchangeable sieve plates (with hole diameters of 1, 2, and 3 mm). Time-series data collected from the microphone were processed for mean and root-mean-square values, and Fourier transforms were computed to identify important signal energies. A sequence of experiments was also conducted that was designed to relate specific interfacial phenomena to the frequencies of the noises produced.     

Facilitation of reaction times with GAP paradigm: comparison of manual and saccadic responses

Manual and saccadic reaction times (RTs) were measured to peripheral target onsets. Previous researchers reported marked decrement in saccadic latencies when the central fixation mark offset preceded the target onset by a short interval (a gap paradigm). The first experiment ascertained whether a similar RT facilitation would occur with a manual RT task. It was found that, in line with previous studies, a majority of saccades was less than 150 ms when a gap of 200 ms was inserted between the fixation offset and the target onset. These short latency saccades were executed virtually without error. Manual RTs were also facilitated, but the amount of facilitation was modest, and it was bargained for at the expense of increased errors.

To compare these two response modes under the gap paradigm, two additional experiments were conducted. First, to check the possibility that the facilitation of manual RTs was due to the prolonged experience with the gap paradigm, 36 naive subjects were recruited, and their manual RTs were measured under one of two gap durations (100 or 200 ms). Both gap durations were successful in bringing about RT facilitation, suggesting that naive subjects could utilize the gap paradigm to speed up their responses. The gap durations of 100 and 200 ms were equally effective in the facilitation of RTs.

In the final experiment, three subjects were observed in manual and saccadic RT tasks under 13 gap-overlap intervals (— 1000 to + 1000ms, of which a negative sign indicates a delayed fixation mark offset relative to target onset or overlap condition). Both saccadic and manual RTs were shortened in the gap range 100-300 ms, while they were increased under the short (less than 300 ms) overlap condition. These effects were more conspicuous for the saccade. Prolonged fixation mark presentation (overlaps of more than 500 ms) caused delayed response initiations only for the saccade.     

Analysis of Autopilot Disengagements Occurring During Autonomous Vehicle Testing

In present-day highly-automated vehicles, there are occasions when the driving system disengages and the human driver is required to take-over. This is of great importance to a vehicle's safety and ride comfort. In the U.S state of California, the Autonomous Vehicle Testing Regulations require every manufacturer testing autonomous vehicles on public roads to submit an annual report summarizing the disengagements of the technology experienced during testing. On 1 January 2016, seven manufacturers submitted their first disengagement reports:Bosch, Delphi, Google, Nissan, Mercedes-Benz, Volkswagen, and Tesla Motors. This work analyses the data from these disengagement reports with the aim of gaining abetter understanding of the situations in which a driver is required to takeover, as this is potentially useful in improving the Society of Automotive Engineers (SAE) Level 2 and Level 3 automation technologies. Disengagement events from testing are classified into different groups based on attributes and the causes of disengagement are investigated and compared in detail. The mechanisms and time taken for take-over transition occurred in disengagements are studied. Finally, recommendations for OEMs, manufacturers, and government organizations are also discussed.      

膜片弹簧离合器分离特性的分析计算与仿真

简要介绍了电控机械式自动变速器(AMT)中膜片弹簧离合器的性能特点。在此基础上,根据已有的膜片弹簧计算公式对膜片弹簧从自由状态到接合状态再到分离状态进行了深入的分析与计算,得出了压力与形变的函数关系。通过MATLAB软件对推导出的4组函数关系进行仿真,从仿真曲线可以清晰地看出压力与变形的线性关系,从而可以实现离合器的分离控制。