scholarly journals Computation of domains of analyticity for the dissipative standard map in the limit of small dissipation

2019 ◽  
Vol 395 ◽  
pp. 15-23
Author(s):  
Adrián P. Bustamante ◽  
Renato C. Calleja
Keyword(s):  
Standard Map ◽  
Small Dissipation

scholarly journals Analysis of Low Probability of Detection Capability for Chaotic Standard Map-Based FH-OFDMA System

2021 ◽  
Vol 11 (5) ◽  
pp. 2198
Author(s):  
Junwoo Jung ◽  
Jaesung Lim ◽  
Sungyeol Park ◽  
Haengik Kang ◽  
Seungbok Kwon
Keyword(s):  
Detection Probability ◽  
Probability Of Detection ◽  
Lower Probability ◽  
Symbol Sequence ◽  
Ofdma System ◽  
Standard Map ◽  
Detection Probabilities ◽  
Low Probability ◽  
Transmitted Symbol ◽  
Basic Symbol

A frequency hopping orthogonal frequency division multiple access (FH-OFDMA) can provide low probability of detection (LPD) and anti-jamming capabilities to users against adversary detectors. To obtain an extreme LPD capability that cannot be provided by the basic symbol-by-symbol (SBS)-based FH pattern, we proposed two FH patterns, namely chaotic standard map (CSM) and cat map for FH-OFDMA systems. In our previous work, through analysis of complexity to regenerate the transmitted symbol sequence, at the point of adversary detectors, we found that the CSM had a lower probability of intercept than the cat map and SBS. It is possible when a detector already knows symbol and frame structures, and the detector has been synchronized to the FH-OFDMA system. Unlike the previous work, here, we analyze whether the CSM provides greater LPD capability than the cat map and SBS by detection probability using spectrum sensing technique. We analyze the detection probability of the CSM and provide detection probabilities of the cat map and SBS compared to the CSM. Based on our analysis of the detection probability and numerical results, it is evident that the CSM provides greater LPD capability than both the cat map and SBS-based FH-OFDMA systems.

Comment on ‘Propagation of solitary waves and shock wavelength in the pair plasma (J. Plasma Phys. 78, 525–529, 2012)’

2014 ◽  
Vol 80 (3) ◽  
pp. 513-516
Author(s):  
Frank Verheest
Keyword(s):  
Shock Wave ◽  
Solitary Wave ◽  
Solitary Waves ◽  
Plasma Phys ◽  
Theoretical Underpinning ◽  
Pair Plasma ◽  
Electrons And Positrons ◽  
Small Dissipation ◽  
Pseudopotential Approach ◽  
Wave Properties

In a recent paper ‘Propagation of solitary waves and shock wavelength in the pair plasma (J. Plasma Phys. 78, 525–529, 2012)’, Malekolkalami and Mohammadi investigate nonlinear electrostatic solitary waves in a plasma comprising adiabatic electrons and positrons, and a stationary ion background. The paper contains two parts: First, the solitary wave properties are discussed through a pseudopotential approach, and then the influence of a small dissipation is intuitively sketched without theoretical underpinning. Small dissipation is claimed to lead to a shock wave whose wavelength is determined by linear oscillator analysis. Unfortunately, there are errors and inconsistencies in both the parts, and their combination is incoherent.

scholarly journals Labels on the maps of the Third Military Survey of Austria-Hungary and on the survey maps of the Military Geographical Institute (Wojskowy Instytut Geograficzny) in Warsaw in the light of survey manuals

2015 ◽  
Vol 47 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Wojciech Włoskowicz
Keyword(s):  
The Other ◽  
Standard Map ◽  
The Third ◽  
Last Stage ◽  
The Right ◽  
The Military ◽  
Topographic Surveys ◽  
The Way

Abstract Materials from topographic surveys had a serious impact on the labels on the maps that were based on these surveys. Collecting toponyms and information that were to be placed as labels on a final map, was an additional duty the survey officers were tasked with. Regulations concerning labels were included in survey manuals issued by the Austro-Hungarian Militärgeographisches Institut in Vienna and the Polish Wojskowy Instytut Geograficzny in Warsaw. The analyzed Austro-Hungarian regulations date from the years 1875, 1887, 1894, 1903 (2nd ed.). The oldest manual was issued during the Third Military Survey of Austria-Hungary (1:25,000) and regulated the way it was conducted (it is to be supposed that the issued manual was mainly a collection of regulations issued prior to the survey launch). The Third Survey was the basis for the 1:75,000 Spezialkarte map. The other manuals regulated the field revisions of the survey. The analyzed Polish manuals date from the years 1925, 1936, and 1937. The properties of the labels resulted from the military purpose of the maps. The geographical names’ function was to facilitate land navigation whereas other labels were meant to provide a military map user with information that could not be otherwise transmitted with standard map symbols. A concern for not overloading the maps with labels is to be observed in the manuals: a survey officer was supposed to conduct a preliminary generalization of geographical names. During a survey both an Austro-Hungarian and a Polish survey officer marked labels on a separate “label sheet”. The most important difference between the procedures in the two institutes was that in the last stage of work an Austro-Hungarian officer transferred the labels (that were to be placed on a printed map) from the “label sheet” to the hand-drawn survey map, which made a cartographer not responsible for placing them in the right places. In the case of the Polish institute the labels remained only on the “label sheets”.

Abstract 9934: High Mean Arterial Pressure Aggravates Cerebral Hemodynamics After Extracorporeal Resuscitation in Swine

Circulation ◽  
2021 ◽  
Vol 144 (Suppl_2) ◽  
Author(s):  
Yael Levy ◽  
Alice Hutin ◽  
Nicolas Polge ◽  
fanny lidouren ◽  
Matthias Kohlhauer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Arrest ◽  
Oxygen Consumption ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Cerebral Hemodynamics ◽  
Reactivity Index ◽  
Extracorporeal Cardiopulmonary Resuscitation ◽  
Standard Map ◽  
Arterial Blood

Introduction: Extracorporeal cardiopulmonary resuscitation (E-CPR) is used for the treatment of refractory cardiac arrest but the optimal target to reach for mean arterial pressure (MAP) remains to be determined. Hypothesis: We hypothesized that MAP levels modify cerebral hemodynamics during E-CPR. Accordingly, we tested two MAP targets (65-75 vs 80-90 mmHg) in a porcine model of E-CPR. Methods: Pigs were anesthetized and instrumented for the evaluation of cerebral and systemic hemodynamics. They were submitted to 15 min of untreated ventricular fibrillation followed by 30 min of E-CPR. Electric attempts of defibrillation were then delivered until resumption of spontaneous circulation (ROSC). Extracorporeal circulation was initially set to an average flow of 40 ml/kg/min with a standardized volume expansion in both groups. The dose of epinephrine was set to reach either a standard or a high MAP target level (65-75 vs 80-90 mmHg, respectively). Animals were followed during 120 min after ROSC. Results: Six animals were included in both groups. After cardiac arrest, MAP was maintained at the expected level (Figure). During E-CPR, high MAP transiently improved carotid blood flow as compared to standard MAP. This blood flow progressively decreased after ROSC in high vs standard MAP, while intra-cranial pressure increased. Interestingly, this was associated with a significant decrease in cerebral oxygen consumption (26±8 vs 54±6 L O 2 /min/kg at 120 min after ROSC, respectively; p<0.01) (Figure). The pressure reactivity index (PRx), which is the correlation coefficient between arterial blood pressure and intracranial pressure, became positive in high MAP (0.47±0.02) vs standard MAP group (-0.16±0.10), demonstrating altered cerebral autoregulation with high MAP. Conclusion: Increasing MAP above 80 mmHg with epinephrine aggravates cerebral hemodynamics after E-CPR. Figure: Mean arterial pressure (MAP), cerebral blood flow and oxygen consumption (*, p<0.05)

Periodic orbits in the dissipative standard map

1991 ◽  
Vol 43 (12) ◽  
pp. 6550-6557 ◽  
Author(s):  
Wolfgang Wenzel ◽  
Ofer Biham ◽  
C. Jayaprakash
Keyword(s):  
Periodic Orbits ◽  
Standard Map

Chaos dynamique des particules relativistes accélérées dans un paquet d'ondes électrostatiques

2004 ◽  
Vol 82 (6) ◽  
pp. 467-479
Author(s):  
A Raouak ◽  
D Saifaoui ◽  
A Dezairi
Keyword(s):  
Numerical Simulation ◽  
Electromagnetic Wave ◽  
Wave Packet ◽  
Numerical Results ◽  
Theoretical Computation ◽  
Stochastic Diffusion ◽  
Standard Map ◽  
Stochastic Parameter ◽  
Accelerated Particles

In this work, we study the diffusion of particle accelerated in an electromagnetic wave packet, through a numerical simulation of the relativistic standard map. We contribute to the field of stochastic diffusion of accelerated particles as a function of the stochastic parameter K, specially the transition between partial and global stochasticity, and we also compare our theoretical computation of the diffusion with numerical results.

Badly ordered periodic orbits of the standard map

1986 ◽  
Vol 118 (6) ◽  
pp. 274-278 ◽  
Author(s):  
I. Leage ◽  
R.S. Mackay
Keyword(s):  
Periodic Orbits ◽  
Standard Map
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