scholarly journals Characterization of Multitermination CG Flashes Using a 3D Lightning Mapping System (FALMA)

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 625 ◽  
Author(s):  
Gao ◽  
Wang ◽  
Shi ◽  
Wu ◽  
Takagi
Keyword(s):  
High Probability ◽  
Arithmetic Mean ◽  
Time Difference ◽  
Return Stroke ◽  
Mapping System ◽  
Mapping Array ◽  
Cg Lightning

We characterized 205 multiple-termination negative cloud-to-ground (CG) lightning flashes that were imaged by the Fast Antenna Lightning Mapping Array (FALMA) in Japan during the summer of 2017. The parameters we used included termination number, termination distance, fork height, return stroke (RS) number, the interval between the first RS of each termination, the shortest time difference between the strokes at different terminations, and the first RS intensities separated by termination occurrence orders. It was found that the multiple-termination flashes (MTFs) had a termination number ranging from 2 to 5, with the majority (148/205) at 2. The termination distance (with high probability) was between 2 and 4 km, with 10 out of 359 MTF termination distances being longer than 10 km. For most MTFs (146/205), their leader forks for different terminations occurred at a height between 4 and 6 km, indicating that the fork process mainly occurred inside the cloud. The RS number of the MTFs ranged from 2 to 18, with an arithmetic mean (AM) value of 5.8. The interval between the first RS of each termination in the MTFs ranged from 0.5 to 965.3 ms, with an AM value of 225.6 ms, while the shortest time difference between the strokes at different terminations had an AM value of 189.6 ms. The intensity of the first stroke in each termination tended to decrease with increasing termination occurrence orders.

Microwave Dielectric Loss Characterization of Silicon Carbide Wafers

2006 ◽  
Vol 527-529 ◽  
pp. 733-736
Author(s):  
Timothy Bogart ◽  
W.J. Everson ◽  
Rick D. Gamble ◽  
Ed Oslosky ◽  
David Snyder ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Dielectric Loss ◽  
Microwave Cavity ◽  
High Yield ◽  
Microwave Dielectric ◽  
Mapping System ◽  
High Frequency Devices ◽  
Nondestructive Characterization ◽  
Initial Results

Semi-insulating silicon carbide (SiC) wafers are important as substrates for high frequency devices such as AlGaN-GaN HEMT’s. A nondestructive characterization technique has been developed to measure the dielectric properties of SiC wafers in the GHz frequency range where the devices will operate in order to validate wafers for high yield working devices. The dielectric loss is measured at approximately 16 GHz in a split microwave cavity. Initial results show a correlation where the dielectric loss decreases as the resistivity increases, where the resistivity was measured using a Contactless Resistivity Mapping system (COREMA). The uniformity of dielectric loss across SiC wafers was evaluated using a split post dielectric resonator cavity fixed at 5.5GHz to measure the dielectric loss at five points on a wafer. Dielectric loss as a function of temperature from room temperature to 400°C was also studied.

Characterization of lightning return stroke electric and magnetic fields from simultaneous two-station measurements

1979 ◽  
Vol 84 (C10) ◽  
pp. 6307 ◽  
Author(s):  
Y. T. Lin ◽  
M. A. Uman ◽  
J. A. Tiller ◽  
R. D. Brantley ◽  
W. H. Beasley ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Return Stroke ◽  
Electric And Magnetic Fields

Characterization of superconducting rings using an in-field hall probe magnetic mapping system

2003 ◽  
Vol 13 (2) ◽  
pp. 3667-3670 ◽  
Author(s):  
X. Granados ◽  
S. Sena ◽  
E. Bartolome ◽  
A. Palau ◽  
T. Puig ◽  
...  
Keyword(s):  
Hall Probe ◽  
Mapping System ◽  
Superconducting Rings

scholarly journals Generalized Kings and Single-Elimination Winners in Random Tournaments

2021 ◽  
Author(s):  
Pasin Manurangsi ◽  
Warut Suksompong
Keyword(s):  
High Probability ◽  
Complete Characterization ◽  
Directed Path ◽  
Tight Bound ◽  
Random Models ◽  
Natural Notion ◽  
Probability Threshold

Tournaments can be used to model a variety of practical scenarios including sports competitions and elections. A natural notion of strength of alternatives in a tournament is a generalized king: an alternative is said to be a k-king if it can reach every other alternative in the tournament via a directed path of length at most k. In this paper, we provide an almost complete characterization of the probability threshold such that all, a large number, or a small number of alternatives are k-kings with high probability in two random models. We show that, perhaps surprisingly, all changes in the threshold occur in the regime of constant k, with the biggest change being between k = 2 and k = 3. In addition, we establish an asymptotically tight bound on the probability threshold for which all alternatives are likely able to win a single-elimination tournament under some bracket.

Osteological characterization of four putative species of the genus Adenomera (Anura: Leptodactylidae), with comments on intra- and interspecific variation

Zootaxa ◽  
2007 ◽  
Vol 1403 (1) ◽  
pp. 37 ◽  
Author(s):  
MARÍA LAURA PONSSA ◽  
W. RONALD HEYER
Keyword(s):  
High Probability ◽  
Interspecific Variation ◽  
Putative Species ◽  
Cladistic Analyses

Previous osteological characterizations of members of the frog genus Adenomera have been based on selected features. The purpose of this study is to establish a detailed osteological description of four putative species of the genus Adenomera. There is considerable variation, which we postulate corresponds to both intra- and interspecific variation. Osteology should provide a set of characters appropriate for cladistic analyses to help elucidate relationships within the Subfamily Leptodactylinae. Much of the adult osteological variation has a high probability of having evolved through the process of heterochrony.

Review and Evaluation of Characterization First Return Stroke in the Measured Lightning Electric Fields on Malaysia Data

2015 ◽  
Vol 793 ◽  
pp. 44-48
Author(s):  
S.N.M. Arshad ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Mahdi Izadi ◽  
A.M. Ariffen ◽  
M.N. Hamzah ◽  
...  
Keyword(s):  
Electric Fields ◽  
Rise Time ◽  
Statistical Correlation ◽  
Peak Time ◽  
Return Stroke ◽  
Zero Crossing ◽  
Time To Peak ◽  
Lightning Channel ◽  
Crossing Time

In this paper, the characterization of measured electric fields on first return stroke due to lightning channel was studied done. Likewise, previous studies on this case were discussed and reviewed accordingly. Furthermore, the first return stroke was analyzed done in detailed and was indicated on the real measured electric fields. Later the results were discussed appropriately. The behaviorsof first return stroke signal has beencharacterized from previous researchers. This study shows themeasured data in detailed, which include there are slow front time, first return stroke peak, time to peak, zero crossing time and 10% to 90% rise time. The characteristic of first return stroke signal data in Malaysia was compared with data gathered in Sweden. Moreover In addition, the statistical correlation between electric field zero times and corresponding rise times was also been studied.

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