scholarly journals Geosynchronous Spaceborne-Airborne Bistatic Moving Target Indication System: Performance Analysis and Configuration Design

2020 ◽  
Vol 12 (11) ◽  
pp. 1810
Author(s):  
Xichao Dong ◽  
Chang Cui ◽  
Yuanhao Li ◽  
Cheng Hu
Keyword(s):  
Design Method ◽  
Configuration Design ◽  
Moving Target ◽  
Maximum Output ◽  
Sar Imaging ◽  
Long Time ◽  
Bistatic Synthetic Aperture Radar ◽  
Indication System ◽  
Imaging Performance ◽  
The Relationship

Geosynchronous spaceborne-airborne bistatic synthetic aperture radar (GEO SA-BSAR), consisting of GEO transmitter and airborne receiver, has stable coverage for a long time and benefits moving target detection. However, the performance of GEO SA-BSAR moving target indication (MTI) system varies widely between bistatic configurations. The traditional configuration design for GEO SA-BSAR system only considers the imaging performance, which may cause the poor MTI performance. In this paper, we propose a bistatic configuration design method to jointly optimize the MTI and SAR imaging performance for GEO SA-BSAR MTI system. The relationship between the MTI performance and bistatic configuration parameters is derived analytically and analyzed based on the maximum output signal to clutter and noise ratio (SCNR) criterion. Then, the MTI performance and SAR imaging performance are jointly considered to model the configuration design problem as a multi-objective optimization problem under the constrained condition. Finally, the optimal configuration for GEO SA-BSAR MTI system is given.

scholarly journals On the design of a novel fully compliant spherical four-bar mechanism

2019 ◽  
Vol 11 (9) ◽  
pp. 168781401987954
Author(s):  
Volkan Parlaktaş ◽  
Engin Tanık ◽  
Çağıl Merve Tanık
Keyword(s):  
Compliant Mechanism ◽  
Design Method ◽  
Optimization Method ◽  
Maximum Output ◽  
Element Analysis ◽  
Free Position ◽  
Flexural Hinges ◽  
Arc Lengths ◽  
The Relationship ◽  
Novel Design

In this article, a novel fully compliant spherical four-bar mechanism is introduced and its generalized design methodology is proposed. The original fully compliant mechanism lies on a plane at the free position (undeflected position); therefore, it has the advantages of ease of manufacturing, minimized parts, and no backlash. First, the mobility conditions of the mechanism are obtained. The dimensions of the mechanism are optimally calculated for maximum output rotation, while keeping the deflection of flexural hinges at an acceptable range. Using an optimization method, design tables are prepared to display the relationship between arc lengths and corresponding deflections of flexural hinges. Input–output torque relationship and stresses at compliant segments are obtained analytically. A mechanism dimensioned by this novel design method is analyzed by a finite element analysis method, and the analytical results are verified. Finally, the mechanism is manufactured and it is ensured that the deflections of the compliant segments are consistent with the theoretical results.

Based on STK and Matlab Satellite Formation's Configuration Design and Simulation

2013 ◽  
Vol 823 ◽  
pp. 411-416 ◽  
Author(s):  
Chang Ping Dang ◽  
Yuan Wen Cai ◽  
Tian Le ◽  
Yi Bin Zhao ◽  
Chao Jun Xin
Keyword(s):  
Design Method ◽  
Structural Characteristics ◽  
Configuration Design ◽  
Orbital Elements ◽  
General Process ◽  
Satellite Formation ◽  
Simulation Results ◽  
Typical Satellite ◽  
Configuration Simulation ◽  
The Relationship

According to the structural characteristics of satellite formation, and using the kinematic equations which expressed as fly-around form, designed a model for satellite formation configuration, analysed the relationship between fly-around parameters and the orbital elements, designed a method that meets the mission requirements of the satellite formation configuration, formulated a corresponding operation flow chart, listed several typical satellite formations of simple configuration and complex configuration. Finally, according to the general process of configuration design, obtaioned a configuration based on the requirments, and with the help of software STK and Matlab performed a formation configuration simulation that considering collision avoidance verification and adjustment. The simulation results show that the formation configuration design process and design method are basically right.

scholarly journals Comparison of Raw Data-Based and Complex Image-Based Sparse SAR Imaging Methods

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 320 ◽  
Author(s):  
Zhilin Xu ◽  
Bingchen Zhang ◽  
Hui Bi ◽  
Chenyang Wu ◽  
Zhonghao Wei
Keyword(s):  
Imaging Method ◽  
Signal Ratio ◽  
Raw Data ◽  
Imaging Model ◽  
Complex Image ◽  
Sar Imaging ◽  
Imaging Performance ◽  
The Relationship ◽  
Suppress Noise ◽  
Image Performance

Sparse signal processing has already been introduced to synthetic aperture radar (SAR), which shows potential in improving imaging performance based on raw data or a complex image. In this paper, the relationship between a raw data-based sparse SAR imaging method (RD-SIM) and a complex image-based sparse SAR imaging method (CI-SIM) is compared and analyzed in detail, which is important to select appropriate algorithms in different cases. It is found that they are equivalent when the raw data is fully sampled. Both of them can effectively suppress noise and sidelobes, and hence improve the image performance compared with a matched filtering (MF) method. In addition, the target-to-background ratio (TBR) or azimuth ambiguity-to-signal ratio (AASR) performance indicators of RD-SIM are superior to those of CI-SIM in down-sampling data-based imaging, nonuniform displace phase center sampling, and sparse SAR imaging model-based azimuth ambiguity suppression.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Psychology: Volume 5

2019 ◽  
Keyword(s):  
World View ◽  
Science Volume ◽  
Western World ◽  
Mental Life ◽  
Long Time ◽  
The Difference ◽  
New Perspective ◽  
Indian Setting ◽  
The Mind ◽  
The Relationship

This survey of research on psychology in five volumes is a part of a series undertaken by the ICSSR since 1969, which covers various disciplines under social science. Volume Five of this survey, Explorations into Psyche and Psychology: Some Emerging Perspectives, examines the future of psychology in India. For a very long time, intellectual investments in understanding mental life have led to varied formulations about mind and its functions across the word. However, a critical reflection of the state of the disciplinary affairs indicates the dominance of Euro-American theories and methods, which offer an understanding coloured by a Western world view, which fails to do justice with many non-Western cultural settings. The chapters in this volume expand the scope of psychology to encompass indigenous knowledge available in the Indian tradition and invite engaging with emancipatory concerns as well as broadening the disciplinary base. The contributors situate the difference between the Eastern and Western conceptions of the mind in the practice of psychology. They look at this discipline as shaped by and shaping between systems like yoga. They also analyse animal behaviour through the lens of psychology and bring out insights about evolution of individual and social behaviour. This volume offers critique the contemporary psychological practices in India and offers a new perspective called ‘public psychology’ to construe and analyse the relationship between psychologists and their objects of study. Finally, some paradigmatic, pedagogical, and substantive issues are highlighted to restructure the practice of psychology in the Indian setting.

scholarly journals The impacts of mediating the work environment on the mode choice in work trips

2021 ◽  
Vol 11 (1) ◽  
pp. 592-605
Author(s):  
Melchior Bria ◽  
Ludfi Djakfar ◽  
Achmad Wicaksono
Keyword(s):  
Work Environment ◽  
Public Transportation ◽  
Travel Behavior ◽  
Structural Equation ◽  
Mode Choice ◽  
Equation Modeling ◽  
Rapid Transit ◽  
Long Time ◽  
Socio Economic Variables ◽  
The Relationship

Abstract The impacts of work characteristics on travel mode choice behavior has been studied for a long time, focusing on the work type, income, duration, and working time. However, there are no comprehensive studies on the influence of travel behavior. Therefore, this study examines the influence of work environment as a mediator of socio-economic variables, trip characteristics, transportation infrastructure and services, the environment and choice of transportation mode on work trips. The mode of transportation consists of three variables, including public transportation (bus rapid transit and mass rapid transit), private vehicles (cars and motorbikes), and online transportation (online taxis and motorbike taxis online). Multivariate analysis using the partial least squares-structural equation modeling method was used to explain the relationship between variables in the model. According to the results, the mediating impact of work environment is significant on transportation choices only for environmental variables. The mediating mode choice effect is negative for public transportation and complimentary for private vehicles and online transportation. Other variables directly affect mode choice, including the influence of work environment.

scholarly journals Dynamics of life expectancy and life span equality

2020 ◽  
Vol 117 (10) ◽  
pp. 5250-5259 ◽  
Author(s):  
José Manuel Aburto ◽  
Francisco Villavicencio ◽  
Ugofilippo Basellini ◽  
Søren Kjærgaard ◽  
James W. Vaupel
Keyword(s):  
Life Expectancy ◽  
Life Span ◽  
Health Policies ◽  
Public Health Policies ◽  
Dynamic Relationship ◽  
Mortality Increase ◽  
Long Time ◽  
Underlying Causes ◽  
The Relationship ◽  
Over Time

As people live longer, ages at death are becoming more similar. This dual advance over the last two centuries, a central aim of public health policies, is a major achievement of modern civilization. Some recent exceptions to the joint rise of life expectancy and life span equality, however, make it difficult to determine the underlying causes of this relationship. Here, we develop a unifying framework to study life expectancy and life span equality over time, relying on concepts about the pace and shape of aging. We study the dynamic relationship between life expectancy and life span equality with reliable data from the Human Mortality Database for 49 countries and regions with emphasis on the long time series from Sweden. Our results demonstrate that both changes in life expectancy and life span equality are weighted totals of rates of progress in reducing mortality. This finding holds for three different measures of the variability of life spans. The weights evolve over time and indicate the ages at which reductions in mortality increase life expectancy and life span equality: the more progress at the youngest ages, the tighter the relationship. The link between life expectancy and life span equality is especially strong when life expectancy is less than 70 y. In recent decades, life expectancy and life span equality have occasionally moved in opposite directions due to larger improvements in mortality at older ages or a slowdown in declines in midlife mortality. Saving lives at ages below life expectancy is the key to increasing both life expectancy and life span equality.

A Research on the Morphology and Composition of Flocs (Part 1: Floc Breaage Disregarded)

2013 ◽  
Vol 726-731 ◽  
pp. 1566-1572 ◽  
Author(s):  
Shi Qiang Ding ◽  
Qing Na Li ◽  
Xin Rong Pang ◽  
Ji Run Xu
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
New Classification ◽  
Suspension Viscosity ◽  
Primary Particles ◽  
Long Time ◽  
Relationship Of ◽  
The Relationship ◽  
Three Dimensional Space ◽  
Floc Breakage

The characteristics of flocs aggregated in flocculation have been paid more and more attention for a long time. In this paper, a new classification and analyses method dealing with the flocs is developed. The flocs formed after flocculation is divided into four kinds, including the left primary particles, linear flocs with all component particles in a line, planar flocs with all component particles on a plane and volumetric flocs with all component particles in a three-dimensional space. By analyzing the formation approaches of different kind of flocs regardless of the floc breakage, the number of every kind of floc is analyzed to be related with the suspension concentration mathematically. After comparing the different items in the models describing the relationship of floc number and concentration, a series of simplified expressions are presented. Lastly, a mathematical equation relating the measurable suspension viscosity with the numbers of different flocs is obtained.

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