A Method For Detecting Scheduled-Service Vehicles By Crowdsensing Of On-Board Beacons

The technology detects scheduled-service vehicles using a model generated based on onboard beacon location data. A trajectory of the onboard beacon may be determined by correlating the beacon detection data with the location data of the detecting devices. The trajectory may be analyzed to derive features of the beacon trajectory that correlate with a periodic motion typical of scheduled-service vehicles. Such features may be used to train a machine capable of learning patterns from data to generate a model that classifies whether a beacon trajectory is that of a scheduled-service vehicle. Various beacon trajectories may be classified by the generated model as either a scheduled-service vehicle or not. Once certain beacons are identified as onboard scheduled-service vehicles, further trajectory data may be gathered on such beacons to map out accurate public-transit routes and schedules, as well as to provide real-time locations and changes to routes and schedules

Measuring Offline Advertisement Conversion

This disclosure describes techniques to measure the impact of exposure to an offline advertisement on subsequent online and offline actions. The system utilizes advertisement data, historical location data and user behavior data to estimate a test spatiotemporal region in which users are likely exposed to a particular offline advertisement and a control spatiotemporal region in which users are likely not exposed to the particular offline advertisement. The system uses statistical techniques to determine the impact of the particular advertisement by comparison of the behavior of the test population and the control population

Three-dimensional steep wave impact on a vertical plate with an open rectangular section

The present study treats the three-dimensional hydrodynamic slamming problem on a vertical plate subjected to the impact of a steep wave moving towards the plate with a constant velocity. The problem is complicated significantly by assuming that there is a rectangular opening on the plate which allows a discharge of the liquid. The analysis is conducted analytically assuming linear potential theory. The examined configuration determines two boundary value problems with mixed conditions which fully are taken into account. The mathematical process assimilates the plate with a degenerate elliptical cylinder allowing the employment of elliptical harmonics that ensure the satisfaction of the free-surface boundary condition of the front face of the steep wave, away from the plate. This assumption leads to an additional boundary value problem with mixed conditions in the vertical direction. The associated problem involves triple trigonometrical series and it is solved through a transformation into integral equations. To tackle the boundary value problem in the vertical direction a perturbation technique is employed. Extensive numerical calculations are presented as regards the variation of the velocity potential on the plate at the instant of the impact which reveals the influence of the opening. The theory is extended to the computation of the total impulse exerted on the plate using pressure-impulse theory

Three-dimensional steep wave impact on a vertical cylinder

In the present study we investigate the 3-D hydrodynamic slamming problem on a vertical cylinder due to the impact of a steep wave that is moving with a steady velocity. The linear theory of the velocity potential is employed by assuming inviscid, incompressible fluid and irrotational flow. As the problem is set in 3-D space, the employment of the Wagner condition is essential. The set of equations we pose, is presented as a mixed boundary value problem for Laplace's equation in 3-D. Apart from the mixed-type of boundary conditions, the problem is complicated by considering that the region of wetted surface of the cylinder is a set whose boundary depends on the vertical coordinate on the cylinder up to the free-surface. We make some simple assumptions at the start but otherwise we proceed analytically. We find closed-form relations for the hydrodynamic variables, namely the time dependent potential, the pressure impulse, the shape of the wave front (from the contact point to beyond the cylinder) and the slamming force

Visual analytics for sets over time and space

This report documents the program and the outcomes of Dagstuhl Seminar 19192 “Visual Analytics for Sets over Time and Space”, which brought together 29 researchers working on visualization(i) from a theoretical point of view (graphdrawing, computational geometry, and cognition (ii) from a temporal point of view (visual analytics and information visualization overtime, HCI), and (iii) from a space-time point of view (cartography, GIScience). The goal of the seminar was to identify specific theoretical and practical problems that need to be solved in order to create dynamic and interactive set visualizations that take into account time and space, and to begin working on these problems. The first 1.5 days were reserved for overview presentations from representatives of the different communities, for presenting open problems, and for forming interdisciplinary working groups that would focus on some of the identified open problems as a group. There were three survey talks, ten short talks, and one panel with three contributors. The remaining three days consisted of open mic sessions, working-group meetings, and progress reports. Five working groups were formed that investigated several of the open research questions. Abstracts of the talks and a report from each working group are included in this report

Palladium-Catalyzed Carbonylation of Aryl Chlorides to Electrophilic Aroyl-DMAP Salts

The palladium-catalyzed carbonylative coupling of aryl chlorides and 4-dimethylaminopyridine (DMAP) to generate electrophilic aroyl-DMAP salts is described. In contrast to classical carbonylation reactions, which often require nucleophiles to react with weakly electrophilic palladium-acyl intermediates, the high electrophilicity of aroyl-DMAP salts allows the acylation of a broad range of substrates. This transformation is mediated by a palladium-Xantphos catalyst, and mechanistic studies suggest the combination of ligand steric strain together with Pd(0) stabilization allows both the reductive elimination of a reactive ArCO–DMAP product and oxidative addition of the strong aryl-chloride bond. Overall, this transformation allows the generation of amides and esters from aryl chlorides with an array of nucleophiles and with good functional group compatibility

Stereotactic Radiation for Intracranial Arteriovenous Malformations

To the Editor: In recent months the Journal has devoted substantial space to the crisis in American medicine and to various proposals for its solution. Most agree that some form of cost containment is necessary, including the rationing of medical care, particularly with regard to "high-technology" medicine. The article by Steinberg et al. (July 12 issue) 1 describes the use of heavy-charged-particle irradiation under stereotactic control for the treatment of intracranial arteriovenous malformations. The Synchrocyclotron and Bevatron at the University of California clearly qualify as high-technology facilities, and we are assured that the cost (not specified) of maintaining them is supported . .