Cross-Correlation-Function-Based Multipath Mitigation Method for Sine-BOC Signals

Global Navigation Satellite Systems (GNSS) positioning accuracy indoor and urban canyons environments are greatly affected by multipath due to distortions in its autocorrelation function. In this paper, a cross-correlation function between the received sine phased Binary Offset Carrier (sine-BOC) modulation signal and the local signal is studied firstly, and a new multipath mitigation method based on cross-correlation function for sine-BOC signal is proposed. This method is implemented to create a cross-correlation function by designing the modulated symbols of the local signal. The theoretical analysis and simulation results indicate that the proposed method exhibits better multipath mitigation performance compared with the traditional Double Delta Correlator (DDC) techniques, especially the medium/long delay multipath signals, and it is also convenient and flexible to implement by using only one correlator, which is the case of low-cost mass-market receivers

Prandtl number of lattice Bhatnagar-Gross-Krook fluid

The lattice Bhatnagar-Gross-Krook modeled fluid has an unchangeable unit Prandtl number. A simple method is introduced in this letter to formulate a flexible Prandtl number for the modeled fluid. The effectiveness was demonstrated by numerical simulations of the Couette flow.Comment: 4 pages, uuencoded postscript fil

Allowable silicon wafer thickness versus diameter for ingot rotation ID wafering

Inner diameter (ID) wafering of ingot rotation reduce the ID saw blade diameter was investigated. The blade thickness can be reduced, resulting in minimal kerf loss. However, significant breakage of wafers occurs during the rotation wafering as the wafer thickness decreases. Fracture mechanics was used to develop an equation relating wafer thickness, diameter and fracture behavior at the point of fracture by using a model of a wafer, supported by a center column and subjected to a cantilever force. It is indicated that the minimum allowable wafer thickness does not increase appreciably with increasing wafer diameter and that fracture through the thickness rather than through the center supporting column limits the minimum allowable wafer thickness. It is suggested that the minimum allowable wafer thickness can be reduced by using a vacuum chuck on the wafer surface to enhance cleavage fracture of the center core and by using 111 ingots

L&D in the ED: A Game-Based Approach to Learning High-Risk Obstetric Emergencies.

IntroductionTeaching emergency medicine residents the principles of obstetric emergencies is a challenging task, as these emergencies are uncommon in general practice and include specific maneuvers for difficult and precipitous deliveries. These requirements are not easy to satisfy in a standard lecture and are labor intensive for small groups. This resource is a board game that leverages near-peer teaching, engages student collaboration, and supports friendly competition.MethodsThe game was designed to be used by emergency medicine residents and emphasized the evaluation and management of acute issues related to labor and delivery (L&D). To play the game, three to four learners took turns answering questions. Each correct answer was awarded points for forward movement on the game board. The first person to reach the end of the game won. A faculty moderator circulated among the players to clarify questions or answers as needed.ResultsOur residents loved this resource. They were able to teach each other throughout the game while using reference materials. Participants rated the educational value of the L&D board game as 4.81 (out of 5), as compared to 4.37 for prior lectures covering the same topics. The game was rated similarly to delivery procedural skills workshops implemented in prior years (4.62-4.82).DiscussionGame-based exercises are low-tech, highly interactive teaching tools enabling students to learn from each other in a fun and engaging way. Although we did not assess knowledge retention, this activity's educational value was rated similarly to delivery procedural skills sessions

Direct measurement of the electron density of extended femtosecond laser pulse-induced filaments

We present direct time- and space- resolved measurements of the electron density of femtosecond laser pulse-induced plasma filaments. The dominant nonlinearity responsible for extended atmospheric filaments is shown to be field-induced rotation of air molecules.Comment: 12 pages, 5 figure