نتایج جستجو برای: collision frequency

تعداد نتایج: 529466  

2017
Ya-ning Yan Jian Xiong

Dynamic frame slotted ALOHA (DFSA) has been widely adopted to reduce tag collisions in Ultra High Frequency (UHF) radio frequency identification (RFID) system. In the existing DFSA algorithms, the reader needs to accurately estimate tag backlog and set a new frame length which is equal to the backlog to close to the theoretical maximum throughput 36.8% of the framed ALOHA. To overcome throughpu...

2010
Andrew D. Sutton James A. Sherwood

Hollow nonwood baseball bats have performance advantages over wooden bats. The hollow barrel bats act as a spring or trampoline during the bat-ball collision. The trampoline effect can occur at different natural frequencies known as hoop modes. To examine the effect of the hoop mode on the bat-ball collision, modal analysis and performance measurements were performed on a sample of hollow nonwo...

2017
Alejandro Luque

We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer colli...

Journal: :archives of trauma research 0
rebecca stier department of cranio maxillofacial surgery, hannover medical school, hannover, germany; department of cranio maxillofacial surgery, hannover medical school (mhh), carl-neuberg-strasse 1, d-30625 hannover, germany. tel: +49-5115324748, fax: +49-5115324740 dietmar otte department for accident research, hannover medical school, hannover, germany christian müller trauma department, hannover medical school, hannover, germany maximilian petri trauma department, hannover medical school, hannover, germany ralph gaulke trauma department, hannover medical school, hannover, germany christian krettek trauma department, hannover medical school, hannover, germany

conclusions higher age of cyclists and increasing speed of the accident opponent significantly increase the likelihood of sustaining facial fractures. the use of bicycle helmets does not significantly reduce the incidence of mid-facial fractures, while being correlated with an even increased incidence of mandibular fractures. background the effectiveness of bicycle safety helmets in preventing ...

2009
Gregory C. McLaskey Steven D. Glaser

Experimental studies were performed using high-fidelity broadband Glaser-NIST conical transducers to quantify stress waves produced by the elastic collision of a tiny ball and a massive plate. These sensors are sensitive to surface-normal displacements down to picometers in amplitude, in a frequency range of 20 kHz to over 1 MHz. Both the collision and the resulting transient elastic waves are ...

2007
C. Adolphsen C. Beard L. Bellantoni G. Burt R. Carter B. Chase M. Church A. Dexter M. Dykes H. Edwards P. Goudket R. Jenkins R. M. Jones A. Kalinin T. Khabiboulline K. Ko A. Latina Z. Li L. Ma P. McIntosh C. Ng A. Seryi D. Schulte N. Solyak I. Tahir L. Xiao

The International Linear Collider (ILC) has a 14 mrad crossing angle in order to aid extraction of spent bunches. As a result of the bunch shape at the interaction point, this crossing angle at the collision causes a large luminosity loss which can be recovered by rotating the bunches prior to collision using a crab cavity. The ILC baseline crab cavity is a 9-cell superconducting dipole cavity ...

Journal: :Computer Communications 2006
Dong-Her Shih Po-Ling Sun David C. Yen Shi-Ming Huang

Due to the limitless possibilities and low cost, Radio Frequency Identification (RFID) systems are used in a variety of applications to uniquely identify physical objects. The operation of RFID systems often involves a situation in which numerous tags are present in the interrogation zone of a single reader at the same time. The tags can collide and cancel each other out, leading to retransmiss...

Journal: :IJAHUC 2014
Ming-Kuei Yeh Jehn-Ruey Jiang Shing-Tsaan Huang

In an RFID system, tags can be identified by a reader when they are within the interrogation zone of the reader. Collisions occur when tags using backscatter technology report their IDs to the reader at the same carrier frequency simultaneously. The performance of tag identification is degraded by collisions, so it is important to address the tag collision problem. Several anti-collision protoc...

Journal: :Physical review letters 2012
Marko Cetina Andrew T Grier Vladan Vuletić

We present, and derive analytic expressions for, a fundamental limit to the sympathetic cooling of ions in radio-frequency traps using cold atoms. The limit arises from the work done by the trap electric field during a long-range ion-atom collision and applies even to cooling by a zero-temperature atomic gas in a perfectly compensated trap. We conclude that in current experimental implementatio...

2007
Jae-Dong Shin Sang-Soo Yeo Tai-Hoon Kim Sung Kwon Kim

RFID, Radio Frequency Identification, technology is a contactless automatic identification technology about which a lot of researches and developments are recently progressing. For this RFID technology to be widely spread, the problem of multiple tag identification, which a reader identifies a multiple number of tags in a very short time, has to be solved. So far, several anti-collision algorit...

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