scholarly journals Time Asymmetries in Pulsar Signals

1981 ◽  
Vol 95 ◽  
pp. 197-198
Author(s):  
Dan R. Stinebring ◽  
James M. Cordes
Keyword(s):  
Correlation Analysis ◽  
Decay Time ◽  
Time Scale ◽  
Temporal Modulation ◽  
Third Order ◽  
Emission Process ◽  
Symmetrical Distribution ◽  
Average Shape ◽  
Average Profile ◽  
The Difference

The average shape of micropulses in two pulsars is highly symmetric, unlike the subpulse emission which is skewed in the same sense as the average profiles. These conclusions stem from a third-order correlation analysis of the emission from PSR 0950+08 and PSR 2016+28. The symmetric micropulses may be produced either by temporal modulation or angular beaming of the radiation. If due to temporal modulation, this average symmetry implies a distribution of time-scales in the emission process: the difference between the rise time-scale (τr) and the decay time-scale (τd) must be small compared to δτr and/or δτd. Subpulses in PSR 0950+08 are narrower than and have the same sense of asymmetry as the average profile. In PSR 2016+28 the two subpulses typically present in a pulse are both tapered toward the outside edge of the pulse. In both pulsars, the skewness of the subpulses contributes significantly to the skewness of the average profile; a symmetrical distribution of these subpulses within the pulse window could then give rise to an asymmetrical profile.

scholarly journals Pulsar Microstructure: Periodicities, Polarization and Probes of Pulsar Magnetospheres

1979 ◽  
Vol 32 (2) ◽  
pp. 9 ◽  
Author(s):  
JM Cordes
Keyword(s):  
Frequency Dependence ◽  
Time Scale ◽  
Characteristic Time ◽  
Emission Region ◽  
Characteristic Time Scale ◽  
Temporal Modulation ◽  
Average Profile ◽  
Pulse Structure ◽  
Relationship Of ◽  
The Relationship

This paper discusses characteristic time scales, periodicities and polarization of microstructure in pulsar signals. The relationship of microstructure polarization to the polarization of subpulses and the average profile is analysed in detail for PSR2016+28. For this pulsar the contributions of micropulses to the variance of the intensity vary with radio frequency v approximately as V-I and the characteristic time scale varies as v-a, with 0�2 ;S IX ;S 0�3. In summarizing possible interpretations of microstructure, we distinguish between angular beaming and temporal modulation processes that can cause intensity variations. We outline, with regard to the frequency dependence of pulse structure, how micropulses can be used to probe the depth and variability of the emission region.

scholarly journals Fast Comparison of High-Precision Time Scales Using GNSS Receivers

2017 ◽  
Vol 2017 ◽  
pp. 1-4
Author(s):  
Vojtech Vigner ◽  
Jaroslav Roztocil
Keyword(s):  
Time Scales ◽  
Time Scale ◽  
High Performance ◽  
Data Format ◽  
Common View ◽  
Log Files ◽  
Gnss Receivers ◽  
Precision Time ◽  
The Common ◽  
The Difference

Comparison of high-performance time scales generated by atomic clocks in laboratories of time and frequency metrology is usually performed by means of the Common View method. Laboratories are equipped with specialized GNSS receivers which measure the difference between a local time scale and a time scale of the selected satellite. Every receiver generates log files in CGGTTS data format to record measured differences. In order to calculate time differences recorded by two receivers, it is necessary to obtain these logs from both receivers and process them. This paper deals with automation and speeding up of these processes.

Weak Coupling Strategy for Multi-Physics CFD Simulation in Engineering Problems

2011 ◽  
Author(s):  
Makoto Yamamoto ◽  
Masaya Suzuki
Keyword(s):  
Strong Coupling ◽  
Time Scale ◽  
Weak Coupling ◽  
Particle Deposition ◽  
Cfd Simulation ◽  
The Other ◽  
Cfd Simulations ◽  
Sand Erosion ◽  
Coupling Strategy ◽  
The Difference

Multi-Physics CFD Simulation will be one of key technologies in various engineering fields. There are two strategies to simulate a multi-physics phenomenon. One is “Strong Coupling”, and the other is “Weak Coupling”. Each can be employed, based on time-scales of physics embedded in a problem. That is, when a time-scale of one physics is nearly same as that of the other physics, we have to use Strong Coupling to take into account the interaction between two physics. On the other hand, when one time-scale is quite different from the other one, Weak Coupling can be applied. Considering the present computer performance, Strong Coupling is difficult to be used in engineering design processes now. Therefore, we are focusing on Weak Coupling, and it has been applied to a number of multi-physics CFD simulations in engineering. We have successfully simulated sand erosion, ice accretion, particle deposition, electro-chemical machining and so on, with using Weak Coupling method. In the present study, the difference between strong and weak couplings is briefly described, and two examples of our multi-physics CFD simulations are expressed. The numerical results indicate that Weak Coupling strategy is promising in a lot of multi-physics CFD simulations.

scholarly journals Assessment of Educational Game Materials and Poster Practices with Rubrics by Expert Educators and Students

2018 ◽  
Vol 5 (13) ◽  
pp. 79
Author(s):  
Figen Altay ◽  
Kevser Bozkurt
Keyword(s):  
Correlation Analysis ◽  
Educational Games ◽  
Educational Game ◽  
Test Results ◽  
Knowledge Test ◽  
Significant Difference ◽  
Scoring Rubrics ◽  
Sample Test ◽  
The Difference ◽  
Poster Presentations

The purpose of this study was to investigate the difference between evaluations of the educational game materials and poster practices by students’ own peers and by expert educators using the rubrics created by expert educators and students together. Study included 10 students and 3 educators attended educational game materials course. Students were informed about basic skills of movement, game, game types, game equipment, analytical rubric, and educational game lectures were given to the students for 6 weeks and 80 minutes each week. 12-question knowledge test was used regarding educational games, analytical scoring rubrics, developing game materials and preparing posters. Materials and posters presented in the course were recorded. Evaluation scales were selected by students and expert teachers. Selected peers and educators evaluated 25 videos. One-way analysis of variance and correlation analysis were used for the reliability and repeatability measurements of the students and teachers. R values of 0.96-0.92 were found between students and 0.78-0.86 between educators. For knowledge tests of the groups, according to Wilcoxon paired two-sample test, there was a significant difference in test results (p<.05). The t test was used in the results of the student and educator video evaluations and there was no significant difference between the scores given by the expert educators and the students to the material and poster presentations (p>.05). In conclusion, this study showed that students could make evaluations as good as expert educators when given an answer key such as a scoring rubric that will help them in the evaluation.

scholarly journals Six-year analysis of traumatic injuries of the craniomaxillofacial area: relation between maxillofacial and traumatic brain injuries

2021 ◽  
Vol 105 (1) ◽  
pp. 56-60
Author(s):  
E. Shuminsky ◽  
◽  
A. Kopchak ◽  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Correlation Analysis ◽  
Brain Injuries ◽  
Statistical Significance ◽  
Maxillofacial Trauma ◽  
Traumatic Injuries ◽  
The Face ◽  
The Difference ◽  
Panfacial Fractures

Summary. Craniofacial trauma is one of the most difficult types of injuries. There is disagreement among various authors about the relationship between maxillofacial trauma (MFT) and traumatic brain injury (TBI). Purpose. Retrospectively evaluate the epidemiology of traumatic injuries of the craniomaxillofacial area and determine whether there is a relationship between different isolated or combined fractures of the facial bones and brain damage. Materials and methods. The case histories of three groups of patients with isolated fractures of the mandible (I group), isolated fractures of the midface zone (II group) and combined fractures of all areas of the face (III group), who were hospitalized in the period from 2012 to 2017, were analyzed. The main epidemiological indicators were determined. The analysis of indicators of severity of MFT and TBI is carried out. Correlation analysis of indicators, analysis using the Kruskal- Wallis test and Steel-Dwass test for pairwise comparisons was performed. Results. Were treated519 patients. 457 men (88 %) and 62 women (12 %). The main causes of injuries were assaults (40 %). Correlation analysis did not reveal the dependence of MFT and TBI. The difference in severity of isolated fractures of the mandible and midface bones was statistically significant, and there is a statistical significance between the severity of TBI in case of isolated fractures of midface bones and panfacial fractures (p < 0.05). Conclusions. The severity of maxillofacial trauma in the case of panfacial fractures is on average 3 times higher than in the case of isolated fractures of the lower jaw or midface bones. The severity of TBI is largely consistent with concussion in all groups, but in the group with panfacial fractures, the median rate is lower comparing to other groups. Key words: Glasgow coma scale, fracture, Le Fort, traumatic brain injury

scholarly journals Theoretical Light Curves of Recurrent Novae

1993 ◽  
Vol 155 ◽  
pp. 408-408
Author(s):  
M. Kato
Keyword(s):  
Decay Time ◽  
Time Scale ◽  
Light Curves ◽  
Decay Phase ◽  
Wind Theory

Theoretical light curves for the decay phase of recurrent novae are obtained using optically thick wind theory. With the OPAL opacity tables the decay time scale is drastically shortened.

scholarly journals On Third Order Stable Difference Scheme for Hyperbolic Multipoint Nonlocal Boundary Value Problem

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Ozgur Yildirim ◽  
Meltem Uzun
Keyword(s):  
Boundary Value Problem ◽  
Difference Scheme ◽  
Boundary Value ◽  
Nonlocal Boundary ◽  
Stability Estimates ◽  
Nonlocal Boundary Value Problem ◽  
Third Order ◽  
Order Of Accuracy ◽  
Definite Operator ◽  
The Difference

This paper presents a third order of accuracy stable difference scheme for the approximate solution of multipoint nonlocal boundary value problem of the hyperbolic type in a Hilbert space with self-adjoint positive definite operator. Stability estimates for solution of the difference scheme are obtained. Some results of numerical experiments that support theoretical statements are presented.

A class of S-restricted compositions

2019 ◽  
Vol 15 (02) ◽  
pp. 361-371
Author(s):  
Matko Glunčić ◽  
Ivica Martinjak
Keyword(s):  
Combinatorial Interpretation ◽  
Third Order ◽  
Recursive Sequences ◽  
The Difference

In this paper, we introduce a class of restricted compositions. We prove that this class appears as a combinatorial interpretation of a generalized third-order recursive sequences. Further identities are also proved. In particular, we show that the difference of the [Formula: see text]th [Formula: see text]-tribonacci number and the sum of its three predecessors is the [Formula: see text]th regular polytopic number.

scholarly journals Comparing Semantic Differential Methods in Affective Engineering Processes: A Case Study on Vehicle Instrument Panels

2020 ◽  
Vol 10 (14) ◽  
pp. 4751
Author(s):  
Gee Won Shin ◽  
Sunghwan Park ◽  
Yong Min Kim ◽  
Yushin Lee ◽  
Myung Hwan Yun
Keyword(s):  
Correlation Analysis ◽  
Repeated Measures ◽  
Evaluation Method ◽  
Correlation Coefficients ◽  
Semantic Differential ◽  
Affective Evaluation ◽  
Relative Evaluation ◽  
The Difference ◽  
Sample Pair

When developing a user-oriented product, it is crucial to consider users’ affective needs. Various semantic differential (SD) methods have been used to identify affect regarding materials, and this is the most important property in products. This study aims to determine which of the three conventional SD methods (absolute evaluation 1 [AE 1], absolute evaluation 2 [AE 2], or relative evaluation [RE]) is most effective for affective evaluation. Affective evaluation was performed for vehicle instrument panels by each of these three SD methods. Two quantitative analysis methods (correlation analysis and repeated-measures ANOVA) were used to examine the performance (sample distinguishability) of each evaluation method, and it was found that both AE 2 and RE produced better results than AE 1. The correlation coefficients and p-values in correlation analysis were slightly better for RE than for AE 2. In conclusion, an affective evaluation produced better results when pairwise samples (especially one sample pair) were presented, indicating that maintaining distinct samples is very important. The clearer the difference in comparison targets is, the more accurate the evaluation results.

Compressibility to 7 GPa at 298 K of the protonated octahedral framework mineral burtite, CaSn(OH)6

2002 ◽  
Vol 66 (3) ◽  
pp. 431-440 ◽  
Author(s):  
M. D. Welch ◽  
W. A. Crichton
Keyword(s):  
Hydrogen Bonding ◽  
Equation Of State ◽  
Major Effect ◽  
Third Order ◽  
Space Group ◽  
X Ray ◽  
The Difference ◽  
Murnaghan Equation ◽  
Hydrogen Bonded

AbstractThe equation of state of synthetic deuterated burtite, CaSn(OD)6, has been determined to 7.25 GPa at 298 K by synchrotron X-ray powder diffraction. Fitting to a third-order Birch-Murnaghan equation of state gives K0 = 44.7(9) GPa and K0′ = 5.3(4). A second-order fit gives K0 = 47.4(4) GPa. Within experimental error the two fits are indistinguishable over the pressure range studied. The decrease in the a parameter with pressure is smooth and no phase transitions were observed. Burtite is much more compressible (by a factor of three or four) than CaSnO3 and CdSnO3 perovskites, indicating that the absence of a cavity cation has a major effect upon the compressibility of the octahedral framework. Burtite is also markedly more compressible than the closely-related mineral stottite FeGe(OH)6 (K0 = 78 GPa). Their different compressibilities correlate with the relative compressibilities of stannate and germanate perovskites. Although different octahedral compressions are likely to be the primary reason for the different compressibilities of burtite and stottite, we also consider the possible secondary role of hydrogen-bonding topology in affecting the compressibilities of protonated octahedral frameworks. Burtite and stottite have different hydrogen-bonding topologies due to their different octahedral-tilt system. Burtite, space group Pn3̄ and tilt system a+a+a+, has a hydrogen-bonded network of linked four-membered rings of O-H…O linkages, whereas stottite, space group P42/n and tilt system a+a+c−, has <100> O-H…O crankshafts and isolated four-membered rings. These different hydrogen-bonded configurations lead to different bracing of the empty cavity sites by the O-H…O linkages and very different hydrogen-bonding connectivities in these two minerals that may also enhance the difference between their compressibilities.

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