scholarly journals A New Nested Array Configuration With Increased Degrees of Freedom

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 1490-1497 ◽  
Author(s):  
Huiping Huang ◽  
Bin Liao ◽  
Xiaoye Wang ◽  
Xiansheng Guo ◽  
Jianjun Huang
Keyword(s):  
Degrees Of Freedom ◽  
Array Configuration

A High Performance Voice Coil Actuator for Optomechatronic Applications

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Dion Hicks ◽  
Taufiq Rahman ◽  
Nicholas Krouglicof
Keyword(s):  
High Performance ◽  
Degrees Of Freedom ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
The Novel ◽  
Array Configuration ◽  
Halbach Array ◽  
Mechanical Devices ◽  
Kinematic Mechanisms ◽  
Voice Coil Actuator

Voice coil actuators (VCAs) are simple electro-mechanical devices, which are capable of generating linear motion in response to an electrical input. The generic cylindrical design of commercially available actuators imposes a large variety of limitations on the end user. The most prominent is the requirement to design and fit extra components to the actuator in order to increase functionality. To solve this issue, a novel voice coil actuator was created, which reconfigures the standard cylindrical design with one of a rectangular structure. The novel actuator incorporates planar magnets in a modified Halbach array configuration to ensure compactness and an exceptionally intense, uniform magnetic field. The moving coil is substituted with a printed circuit board (PCB) encompassing numerous current conducting traces. The board contains a miniature linear rail and bearing system, unified drive electronics, and highly adaptive position feedback circuitry resulting in a compact, highly dynamic and accurate device. In pursuit of optomechatronic applications, two distinct parallel kinematic mechanisms (PKMs) were developed to utilize the high dynamics and accuracy of the novel actuator. These devices were configured to function in only rotational degrees-of-freedom (DOF) and because of their underlying kinematic structures can be referred to as parallel orientation manipulators (POMs). In particular, two structures were defined, 2-PSS/U and 3-PSS/S, in order to constrain their payloads to two and three degrees of rotational freedom, respectively. The resultant manipulators are highly dynamic, precise and fulfill size, weight, and power requirements for many applications such as sense and avoidance and visual tracking.

scholarly journals DOA Estimation of a Novel Generalized Nested MIMO Radar with High Degrees of Freedom and Hole-Free Difference Coarray

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yule Zhang ◽  
Guoping Hu ◽  
Hao Zhou ◽  
Mingming Zhu ◽  
Fei Zhang
Keyword(s):  
Degrees Of Freedom ◽  
Multiple Input Multiple Output ◽  
Doa Estimation ◽  
Mimo Radar ◽  
Music Algorithm ◽  
Array Configuration ◽  
Matrix Reconstruction ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Array Aperture

A novel generalized nested multiple-input multiple-output (MIMO) radar for direction of arrival (DOA) estimation is proposed in this paper. The proposed structure utilizes the extended two-level nested array (ENA) as transmitter and receiver and adjusts the interelement spacing of the receiver with an expanding factor. By optimizing the array element configuration, we can obtain the best number of elements of the transmitter and receiver and the attainable degrees of freedom (DOF). Compared with the existing nested MIMO radar, the proposed MIMO array configuration not only has closed-form expressions for sensors’ positions and the number of maximum DOF, but also significantly improves the array aperture. It is verified that the sum-difference coarray (SDCA) of the proposed nested MIMO radar can get higher DOF without holes. MUSIC algorithm based on Toeplitz matrix reconstruction is employed to prove the rationality and superiority of the proposed MIMO structure.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Representing utility and deploying the body

2020 ◽  
Vol 43 ◽  
Author(s):  
David Spurrett
Keyword(s):  
Functional Activity ◽  
Degrees Of Freedom ◽  
The Body ◽  
Target Article ◽  
Processing Demands ◽  
The Many

Abstract Comprehensive accounts of resource-rational attempts to maximise utility shouldn't ignore the demands of constructing utility representations. This can be onerous when, as in humans, there are many rewarding modalities. Another thing best not ignored is the processing demands of making functional activity out of the many degrees of freedom of a body. The target article is almost silent on both.

Das Experten-Novizen-Paradigma und die Vertrauenskrise in der Psychologie

2016 ◽  
Vol 23 (4) ◽  
pp. 131-140 ◽  
Author(s):  
Philip Furley ◽  
Karsten Schul ◽  
Daniel Memmert
Keyword(s):  
Degrees Of Freedom

Zusammenfassung. Das Ziel des vorliegenden Beitrages ist es anhand eines vielverwendeten Paradigmas in der Sportwissenschaft – dem Experten-Novizen-Vergleich – zu prüfen, ob die momentane Vertrauenskrise in der Psychologie ebenfalls die Sportpsychologie betreffen könnte. Anhand einer exemplarischen Studie zeigen wir, dass es innerhalb dieses Paradigmas zu kontroversen Befunden kommt, welche durch die vermuteten Ursachen der Vertrauenskrise (Researcher Degrees of Freedom, kleine Stichprobengrößen) erklärt sein könnten. Zusätzlich argumentieren wir, dass weitere Faktoren (Konfundierung, Stichprobengrößen, Rosenthal Effekt, Expertise-Definition) innerhalb dieses Paradigmas die Reproduzierbarkeit von Erkenntnissen in Frage stellen. Wir diskutieren mögliche Maßnahmen, wie die dargestellten Probleme des Experten-Novizen-Paradigmas in zukünftigen Forschungsarbeiten gelöst werden können.

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