TACL - a timeshared hybrid system for control laboratories

A generalized control-system model encompassing a wide variety of systems has been programmed on the analog portion of a hybrid computation system. Five terminals with storage oscilloscopes are con nected to the hybrid computer and are serviced on a round-robin basis. The generalized system can be configured in milliseconds to a specific problem by setting the values of the digital coefficient units and switches of the analog system. A library of specific problems is kept on the system's digital disk. Students use the system by referencing a problem in the library and entering parameter values to define the problem from their terminals. The per-solution time varies with the time scale seZect ed, but averages around a few hundred milliseconds. A user-oriented compiler helps the instructor define new problems to be added. Digital values are assigned by the student to select ed parameters of specific problems, and families of curves representing system performance as a function of control settings may be displayed on the student's terminal. The terminals also display digital data and alphanumerical information.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68305/2/10.1177_003754977502500203.pd

Remote inspection system for hazardous sites

Long term storage of special nuclear materials poses a number of problems. One of these is a need to inspect the items being stored from time to time. Yet the environment is hostile to man, with significant radiation exposure resulting from prolonged presence in the storage facility. This paper describes research to provide a remote inspection capability, which could lead to eliminating the need for humans to enter a nuclear storage facility. While there are many ways in which an RI system might be created, this paper describes the development of a prototype remote inspection system, which utilizes virtual reality technology along with robotics. The purpose of this system is to allow the operator to establish a safe and realistic telepresence in a remote environment. In addition, it was desired that the user interface for the system be as intuitive to use as possible, thus eliminating the need for extensive training. The goal of this system is to provide a robotic platform with two cameras, which are capable of providing accurate and reliable stereographic images of the remote environment. One application for the system is that it might be driven down the corridors of a nuclear storage facility and utilized to inspect the drums inside, all without the need for physical human presence. Thus, it is not a true virtual reality system providing simulated graphics, but rather an augmented reality system, which performs remote inspection of an existing, real environment

Steering Evolution with Sequential Therapy to Prevent the Emergence of Bacterial Antibiotic Resistance

The increasing rate of antibiotic resistance and slowing discovery of novel antibiotic treatments presents a growing threat to public health. Here, we consider a simple model of evolution in asexually reproducing populations which considers adaptation as a biased random walk on a fitness landscape. This model associates the global properties of the fitness landscape with the algebraic properties of a Markov chain transition matrix and allows us to derive general results on the non-commutativity and irreversibility of natural selection as well as antibiotic cycling strategies. Using this formalism, we analyze 15 empirical fitness landscapes of E. coli under selection by different β-lactam antibiotics and demonstrate that the emergence of resistance to a given antibiotic can be either hindered or promoted by different sequences of drug application. Specifically, we demonstrate that the majority, approximately 70%, of sequential drug treatments with 2–4 drugs promote resistance to the final antibiotic. Further, we derive optimal drug application sequences with which we can probabilistically ‘steer’ the population through genotype space to avoid the emergence of resistance. This suggests a new strategy in the war against antibiotic–resistant organisms: drug sequencing to shepherd evolution through genotype space to states from which resistance cannot emerge and by which to maximize the chance of successful therapy

The Psychological Science Accelerator’s COVID-19 rapid-response dataset

In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

The Psychological Science Accelerator’s COVID-19 rapid-response dataset

In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

Some problems in distributing real-time Ada programs across machines

http://deepblue.lib.umich.edu/bitstream/2027.42/8133/5/bad3609.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/8133/4/bad3609.0001.001.tx