SOLVING SPATIAL CONSTRAINTS WITH GLOBAL DISTANCE COORDINATE SYSTEM

2006 ◽  
Vol 16 (05n06) ◽  
pp. 533-547 ◽  
Author(s):  
LU YANG
Keyword(s):  
Coordinate System ◽  
Systematic Approach ◽  
Distance Geometry ◽  
Spatial Constraints ◽  
Constraint Equations ◽  
System A ◽  
Short Program ◽  
Complete Set ◽  
Point Line ◽  
Made In

A systematic approach making use of distance geometry to solve spatial constraints is introduced. We demonstrate how to create the constraint equations by means of a relevant distance coordinate system. A short program is made (in Maple) which implements the algorithm producing automatically a complete set of constraint equations for a given point-plane configuration. The point-line-plane configurations are converted into point-plane ones beforehand.

scholarly journals Study and Analysis of Interference Signals of the LTE System of the GNSS Receiver

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4901
Author(s):  
Lucjan Setlak ◽  
Rafał Kowalik
Keyword(s):  
End User ◽  
Current Time ◽  
Gnss Receiver ◽  
System A ◽  
Telecommunication Systems ◽  
Depth Analysis ◽  
Gnss Receivers ◽  
Interference Signals ◽  
The Subject ◽  
Made In

Sometimes, it is impossible to conduct tests with the use of the GNSS system, or the obtained results of the measurements made differ significantly from the predicted accuracy. The most common cause of the problems (external factors, faulty results) are interference disturbances from other radio telecommunication systems. The subject of this paper is to conduct research, the essence of which is an in-depth analysis in the field of elimination of LTE interference signals of the GNSS receiver, that is based on the developed effective methods on counteracting the phenomenon of interference signals coming from this system and transmitted on the same frequency. Interference signals are signals transmitted in the GNSS operating band, and unwanted signals may cause incorrect processing of the information provided to the end-user about his position, speed, and current time. This article presents methods of identifying and detecting interference signals, with particular emphasis on methods based on spatial processing of signals transmitted by the LTE system. A comparative analysis of the methods of detecting an unwanted signal was made in terms of their effectiveness and complexity of their implementation. Moreover, the concept of a new comprehensive anti-interference solution was proposed. It includes, among others, information on the various stages of GNSS signal processing in the proposed system, in relation to the algorithms used in traditional GNSS receivers. The final part of the article presents the obtained research results and the resulting significant observations and practical conclusions.

scholarly journals Zur exakten Behandlung von kollektiven Rotationen Teil A: Theorie / On the Exact Treatment of Collective Rotations Part A: Theory

1973 ◽  
Vol 28 (2) ◽  
pp. 206-215
Author(s):  
Hanns Ruder
Keyword(s):  
Coordinate System ◽  
Perturbation Expansion ◽  
Rotational Energy ◽  
The Body ◽  
System A ◽  
N Body Problem ◽  
Definition Of ◽  
Fixed System ◽  
Body Fixed Coordinate System ◽  
Groundstate Energy

Basic in the treatment of collective rotations is the definition of a body-fixed coordinate system. A kinematical method is derived to obtain the Hamiltonian of a n-body problem for a given definition of the body-fixed system. From this exact Hamiltonian, a consequent perturbation expansion in terms of the total angular momentum leads to two exact expressions: one for the collective rotational energy which has to be added to the groundstate energy in this order of perturbation and a second one for the effective inertia tensor in the groundstate. The discussion of these results leads to two criteria how to define the best body-fixed coordinate system, namely a differential equation and a variational principle. The equivalence of both is shown.

"A FESTIVAL OF BRIGANDS": IN SEARCH OF DEMOCRACY AND POLITICAL LEGITIMACY IN MALI

2020 ◽  
Vol 35 (2) ◽  
Author(s):  
Bruce Whitehouse
Keyword(s):  
Political Legitimacy ◽  
Warning Signs ◽  
Democratic Transitions ◽  
Weak State ◽  
Coup D'etat ◽  
State Institutions ◽  
System A ◽  
The Government ◽  
Systemic Corruption ◽  
Made In

Mali's coup d'état in March 2012 and the subsequent occupation of northern Mali by Islamist and separatist rebels took many observers by surprise. How could an erstwhile model of peaceful democratic transition collapse so swiftly? Why did so few ordinary Malians stand up in defence of their 20-year-old democracy? Combining accounts from Malian and foreign journalists with observations made in Bamako leading up to and during the dramatic events of early 2012, this article assesses the failures of Mali's pre-coup political system. A combination of the tenuous rule of law, weak state institutions, and perceptions of systemic corruption deeply eroded Malians' faith in their democracy. The junta that ousted Mali's elected president in March 2012, despite its international isolation, skillfully manipulated public frustrations with the government as well as local symbols and discourses pertaining to heroic leaders to gain support and legitimacy at home. The crisis in Mali was preceded by certain warning signs, some of which might be applied to gauge the health of democratic transitions elsewhere in Africa.

Kinematic Fixturing With Respect to a Plane Using Contact Sensing

1998 ◽  
Author(s):  
Walter W. Nederbragt ◽  
Bahram Ravani
Keyword(s):  
Spatial Constraint ◽  
Spatial Constraints ◽  
Constraint Equations ◽  
Contact Sensing ◽  
Geometric Elements ◽  
Work Cells

Abstract This paper presents a method for determining the location of geometric elements that compose the external features of referencing fixtures. Since in most applications parts that are handled in robotic work-cells are on a worktable or a floor, this paper focuses on fixture geometries that reside on a plane of known location. The location of the unknown geometric elements are found using contacts to the geometric elements and spatial constraints between the geometric elements. Geometric equations for contacts between lines, planes, points, spheres, and cylinders are derived. Spatial constraint equations are also derived. An algorithm is given for locating the geometric elements that form the fixture. The algorithm uses the contact equations and spatial constraint equations to locate the geometric elements. To illustrate the use of this algorithm, two examples are described in detail.

EFFECT OF ADDED TIP MASS ON THE NONLINEAR FLAPWISE AND CHORDWISE VIBRATION OF CANTILEVER COMPOSITE BEAM UNDER BASE EXCITATION

2012 ◽  
Vol 12 (02) ◽  
pp. 285-310 ◽  
Author(s):  
M. EFTEKHARI ◽  
M. MAHZOON ◽  
S. ZIAEI-RAD
Keyword(s):  
Cantilever Beam ◽  
Multiple Scales ◽  
Equilibrium Points ◽  
Laminated Composite ◽  
Base Excitation ◽  
System A ◽  
Autoparametric Resonance ◽  
The Stability ◽  
Tip Mass ◽  
Made In

In this paper, a comparative study is performed for a symmetrically laminated composite cantilever beam with and without a tip mass under harmonic base excitation. The base is subjected to both flapwise and chordwise excitations tuned to the primary resonances of the two directions and conditions of 2:1 autoparametric resonance. In the literature, the governing nonlinear equations of the same problem without tip mass have been derived using the extended Hamilton's principle. Extension is made in this study to include the effect of a tip mass on the response of the beam. The natural frequencies are obtained numerically using the diversity guided evolutionary algorithm (DGEA). Next, the multiple scales method is applied to determine the nonlinear response and stability of the system. A set of four first-order differential equations describing the modulation of the amplitudes and phases of interacting modes are derived for the perturbation analysis. For verification, the above equations are reduced to the special case of the cantilever beam without tip mass for comparison with existing results. Finally, the effect of the tip mass on the stability of the fixed points and on the amplitude of oscillation about the equilibrium points in both the frequency and force modulation responses is examined.

A Sensor-Driven Approach to Distributed Shop Floor Planning and Control

2003 ◽  
Author(s):  
Lihui Wang ◽  
Weiming Shen ◽  
Xiaoqian Li ◽  
Sherman Lang
Keyword(s):  
Shop Floor ◽  
Seamless Integration ◽  
Intelligent Sensor ◽  
Planning And Control ◽  
Intelligent Sensors ◽  
System A ◽  
Floor Planning ◽  
High Level ◽  
And Control ◽  
Made In

The objective of this research is to develop methodology and framework for distributed shop floor planning, real-time monitoring, and remote device control supported by intelligent sensors. An intelligent sensor serves runtime data from bottom up to facilitate high-level decision-making. It assures that correct decisions are made in a timely manner, if compared with the best estimations of engineers. Being an adaptive system, a so-designed framework will improve the flexibility and dynamism of shop floor operations, and provide a seamless integration among process planning, resource scheduling, job execution, process monitoring, and device control. This paper presents principles of the methodology, details in architecture design, module interactions, information flow, and a proof-of-concept prototype implementation.

The magnetotelluric impedance tensor properties with respect to rotations

Geophysics ◽  
1985 ◽  
Vol 50 (10) ◽  
pp. 1610-1617 ◽  
Author(s):  
Simon Spitz
Keyword(s):  
Data Analysis ◽  
Coordinate System ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Impedance Tensor ◽  
Coordinate Systems ◽  
Magnetotelluric Data ◽  
Conventional Analysis ◽  
Complete Set ◽  
The Relationship

A serious limitation to conventional data analysis is that the data refer mainly to elongated bodies. When three‐dimensional distortions are present, quantitative interpretation based only on the off‐diagonal elements of the conventionally rotated impedance tensor is inadequate, because these off‐diagonal elements are insensitive to the tensor trace. The impedance tensor eigenstate formulation proposed in the literature defines a complete set of parameters suitable for recognition of three‐dimensionality. Generally, though, the eigenvalues do not stand for the off‐diagonal elements of an impedance tensor measured in a physical coordinate system. It is shown how the eigenvalues are modified when the relationship between coordinate system rotations and the eigenstate formulation is clarified. A generalization of the conventional analysis results, but the rotation angle obtained is neither unique nor complete To improve the situation, two new analytical rotation angles are proposed. These angles define two complete intrinsic coordinate systems suitable for magnetotelluric data analysis when a general three‐dimensional structure is involved.

Sign in / Sign up

Export Citation Format

Share Document