Measurements of the Influence of Acceleration and Temperature of Bodies on their Weight

A brief review of experimental research of the influence of acceleration and temperatures of test mass upon gravitation force, executed between the 1990s and the beginning of 2000 is provided.Results of weighing a rotor of a mechanical gyroscope with a horizontal axis, an anisotropic crystal with the big difference of the speed of longitudinal acoustic waves, measurements of temperature dependence of weight of metal bars of non-magnetic materials, and also measurement of restitution coefficients at quasi-elastic impact of a steel ball about a massive plate are given. A negative temperature dependence of the weight of a brass core was measured. All observably experimental effects, have probably a general physical reason connected with the weight change dependent upon acceleration of a body or at thermal movement of its microparticles.Comment: 7 pages, 6 figures. Presented at the 5-th Symposium on New Frontiers and Future Concepts (STAIF-2008

EyeScout: Active Eye Tracking for Position and Movement Independent Gaze Interaction with Large Public Displays

While gaze holds a lot of promise for hands-free interaction with public displays, remote eye trackers with their confined tracking box restrict users to a single stationary position in front of the display. We present EyeScout, an active eye tracking system that combines an eye tracker mounted on a rail system with a computational method to automatically detect and align the tracker with the user's lateral movement. EyeScout addresses key limitations of current gaze-enabled large public displays by offering two novel gaze-interaction modes for a single user: In "Walk then Interact" the user can walk up to an arbitrary position in front of the display and interact, while in "Walk and Interact" the user can interact even while on the move. We report on a user study that shows that EyeScout is well perceived by users, extends a public display's sweet spot into a sweet line, and reduces gaze interaction kick-off time to 3.5 seconds -- a 62% improvement over state of the art solutions. We discuss sample applications that demonstrate how EyeScout can enable position and movement-independent gaze interaction with large public displays

A New Amplification Regime for Traveling Wave Tubes with Third Order Modal Degeneracy

Engineering of the eigenmode dispersion of slow-wave structures (SWSs) to achieve desired modal characteristics, is an effective approach to enhance the performance of high power traveling wave tube (TWT) amplifiers or oscillators. We investigate here for the first time a new synchronization regime in TWTs based on SWSs operating near a third order degeneracy condition in their dispersion. This special three-eigenmode synchronization is associated with a stationary inflection point (SIP) that is manifested by the coalescence of three Floquet-Bloch eigenmodes in the SWS. We demonstrate the special features of "cold" (without electron beam) periodic SWSs with SIP modeled as coupled transmission lines (CTLs) and investigate resonances of SWSs of finite length. We also show that by tuning parameters of a periodic SWS one can achieve an SIP with nearly ideal flat dispersion relationship with zero group velocity or a slightly slanted one with a very small (positive or negative) group velocity leading to different operating schemes. When the SIP structure is synchronized with the electron beam potential benefits for amplification include (i) gain enhancement, (ii) gain-bandwidth product improvement, and (iii) higher power efficiency, when compared to conventional Pierce-like TWTs. The proposed theory paves the way for a new approach for potential improvements in gain, power efficiency and gain-bandwidth product in high power microwave amplifiers.Comment: 15 pages, 11 figure

Continuous Time-Delay Estimation From Sampled Measurements

An algorithm for continuous time-delay estimation from sampled output data and known input of finite energy is presented. The continuous time-delay modeling allows for the estimation of subsample delays. The proposed estimation algorithm consists of two steps. First, the continuous Laguerre spectrum of the output signal is estimated from discrete-time (sampled) noisy measurements. Second, an estimate of the delay value is obtained in Laguerre domain given a continuous-time description of the input. The second step of the algorithm is shown to be intrinsically biased, the bias sources are established, and the bias itself is modeled. The proposed delay estimation approach is compared in a Monte-Carlo simulation with state-of-the-art methods implemented in time, frequency, and Laguerre domain demonstrating comparable or higher accuracy for the considered case

Design and Preliminary Testing of Demand-Responsive Transverse Rumble Strips

Transverse rumble strips are common practice to alert drivers by engaging their auditory and tactile senses in addition to visual senses by traffic signals. However, continuous exposure to noise and vibration by transverse rumble strips often results in diminished effectiveness and erratic behaviors, leading to additional safety challenges. In response, demand-responsive transverse rumble strips were developed as traffic safety countermeasures that reduce unnecessary noise and vibration associated with transverse rumble strips by incorporating active control of the rumble strips. Rather than staying static, demand-responsive transverse rumble strips are activated based on the presence of pedestrians, at predesignated times, or in response to abrupt changes in traffic flow. To evaluate the effectiveness of demand-responsive transverse rumble strips, the research team assessed noise and vibration data, both inside the vehicles and on the roadside, for various types of vehicles traveling at different speeds. The test data indicate that demand-responsive transverse rumble strips produced noticeable in-vehicle noise and vibration that could alert drivers to downstream events. Furthermore, demand-responsive transverse rumble strips generated sufficient noise to alert roadside pedestrians to vehicle presence but at low enough level to be considered as acceptable for a residential neighborhood use. Accordingly, demand-responsive transverse rumble strips could address the challenges that static transverse rumble strips face, by providing a design with relatively limited noise while enhancing safety

Water in the Arab World

This volume is intended to serve as a water handbook. It represents the collective knowledge about water resources management acquired over recent years, both within the World Bank water team and with counterparts working in the Arab countries of North Africa and the Middle East (MNA). The chapters offer a cornucopia of ideas and themes. Some chapters are based on background papers prepared for the 2007 "MNA Development Report on Water." Others draw on sector work prepared at the request of client countries. Yet others summarize observations based on study tours or other learning events sponsored by the World Bank. Upon reviewing this lodestone of embedded knowledge, we realized that bringing together our observations and analyses could serve a useful purpose for public officials, other practitioners, academics, and students who are interested in learning more about the complexities of managing water resources management in one of the driest parts of the world