Contact Dynamics of Reconfigurable Space Systems With Numerical Verification Method

2001 ◽  
Author(s):  
Takashi Takahashi ◽  
Saburo Matunaga
Keyword(s):  
Numerical Computation ◽  
Contact Dynamics ◽  
Numerical Verification ◽  
Space Systems ◽  
Guaranteed Accuracy ◽  
Experiment System ◽  
Verification Method ◽  
Satellite Systems ◽  
Cluster Satellite ◽  
The Difference

Abstract In order to analyze dynamics of space systems, such as cluster satellite systems and the capturing process of damaged satellites, it is necessary to consider such space systems as reconfigurable multibody systems. In this paper, we discuss the numerical computation of the dynamics of the ground experiment system to simulate the capturing and berthing process of a satellite by a dual-manipulator on the flat floor as an example. We have previously discussed the efficient dynamics algorithm for reconfigurable multibody system with topological changes. However, the contact dynamics, which is one of the most difficult issues in our study, remains to be discussed. We introduce two types of the linear complementarity problem (LCP) concerned with contact dynamics. The difference between the two types of LCP is whether impacts can be considered. Dynamic systems with impacts and friction are non-conservation systems; moreover the LCP is not always solvable. Therefore we must check if the solutions of the numerical computation are correct, or how accurate they are. In this paper, we derive the method of numerical computation with guaranteed accuracy of the LCP for contact dynamics.

NUMERICAL REEXAMINATION OF SUPERSYMMETRIC AND NONSUPERSYMMETRIC SU(5)-LIKE GRAND UNIFIED MODELS

1989 ◽  
Vol 04 (10) ◽  
pp. 2531-2559 ◽  
Author(s):  
DARIUSZ K. GRECH
Keyword(s):  
Numerical Analysis ◽  
Numerical Computation ◽  
Numerical Results ◽  
Yukawa Couplings ◽  
Loop Level ◽  
Grand Unified Theories ◽  
Unified Theories ◽  
Supersymmetric Particles ◽  
The Difference

The significance of numerical analysis in both nonsupersymmetric and supersymmetric Grand Unified Theories is pointed out. The exact analytical and numerical analysis we present shows a need of larger corrections to the values of unifying parameters, i.e. sin 2 θw, Mx, τp than those often quoted in literature. When an unmodified nonsupersymmetric version of SU(5) is considered we show that numerical computation allows some of the models still to be experimentally admissible. The difference between analytical and numerical results for the supersymmetric SU(5) model is also stressed. In particular, corrections due to the mass threshold of additional generations or supersymmetric particles are calculated both analytically and numerically at the two-loop level. We found them far more important for the final values of sin 2 θw, Mx and τp than the effects of Higgs-Yukawa couplings between scalars and fermions.

scholarly journals Suitability of Unmanned Aerial Vehicles for Cadastral Surveys

2019 ◽  
Vol 19 (1) ◽  
pp. 1-8
Author(s):  
S. Mantey
Keyword(s):  
High Resolution ◽  
Unmanned Aerial Vehicles ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Aerial Vehicles ◽  
High Resolution Images ◽  
The Difference ◽  
Cadastral Surveying ◽  
Difficult Terrain ◽  
Global Navigation Satellite

Cadastral surveys in Ghana often employ well known surveying equipment such as Total Station andGNSSreceivers or a combination of both. These survey techniques are well-established and widely accepted. However, there are limitations in certain areas. In situations where difficult terrain and inaccessible areas and dense vegetation are encountered or when surveyor’s life may be at risk, Unmanned Aerial Vehicles (UAVs) could be used to overcome the limitations of these well-established survey instruments. This research used high resolution images from UAV (DJI Phantom 4) to survey plots within the University of Mines and Technology land area. Coordinates of the boundary points were extracted using Agisoft Photoscan.GNSSreceivers were also used to survey the land and the same boundary point coordinates obtained and compared. This enabled the establishment of accurate ground control points for georeferencing. The coordinates obtained from both UAV andGNSSSurveys were used to prepare cadastral plans and compared. The difference in Northings and Eastings from UAV andGNSSsurveys were +0.380 cmand +0.351 cmrespectively. These differences are well within tolerance of +/-0.9114 m(+/-3 ft) set by the Survey and Mapping Division (SMD) of the Lands Commission for cadastral plans production. This research therefore concludes that high resolution images from UAVs are suitable for cadastral surveying. Keywords: Unmanned Aerial Vehicles, Drones, Global Navigation Satellite Systems, Cadastral Surveys

scholarly journals Three Spatial Verification Techniques: Cluster Analysis, Variogram, and Optical Flow

2009 ◽  
Vol 24 (6) ◽  
pp. 1457-1471 ◽  
Author(s):  
Caren Marzban ◽  
Scott Sandgathe ◽  
Hilary Lyons ◽  
Nicholas Lederer
Keyword(s):  
Cluster Analysis ◽  
Optical Flow ◽  
Covariance Structure ◽  
Object Oriented ◽  
False Alarms ◽  
Verification Method ◽  
Field Displacement ◽  
The Difference ◽  
Verification Techniques ◽  
Spatial Verification

Abstract Three spatial verification techniques are applied to three datasets. The datasets consist of a mixture of real and artificial forecasts, and corresponding observations, designed to aid in better understanding the effects of global (i.e., across the entire field) displacement and intensity errors. The three verification techniques, each based on well-known statistical methods, have little in common and, so, present different facets of forecast quality. It is shown that a verification method based on cluster analysis can identify “objects” in a forecast and an observation field, thereby allowing for object-oriented verification in the sense that it considers displacement, missed forecasts, and false alarms. A second method compares the observed and forecast fields, not in terms of the objects within them, but in terms of the covariance structure of the fields, as summarized by their variogram. The last method addresses the agreement between the two fields by inferring the function that maps one to the other. The map—generally called optical flow—provides a (visual) summary of the “difference” between the two fields. A further summary measure of that map is found to yield useful information on the distortion error in the forecasts.

scholarly journals LEADER MEMBER EXCHANGE DAN KEPRIBADIAN UNTUK MENINGKATKAN EMPLOYEE VOICE KOPONTREN DT

2017 ◽  
Vol 16 (2) ◽  
pp. 38
Author(s):  
Putri Rahmawati ◽  
Sumiyati Sumiyati ◽  
Masharyono Masharyono
Keyword(s):  
Research Result ◽  
Sampling Technique ◽  
Employee Voice ◽  
Leader Member Exchange ◽  
Voice Communication ◽  
Verification Method ◽  
Organization Effectiveness ◽  
Member Exchange ◽  
Research Population ◽  
The Difference

ABSTRACTPurpose – this study was conducted to see how much influence leader member exchange and personality to employee voiceDesign/methodology/approach – this type of research This research uses descriptive and  verification method, with explanatory survey. Saturated sample of nonprobability sampling was used in sampling technique which amounted to 47 people. Multiple correlation was used in data anlysis technique.Findings – based on the result of research that the employee voice is affected by leader member exchange and personality.Orisinality – the difference in this study with other study located from independent variable, the object of research, population and sample, measurment, and as well as research result, the resource of theory from journals and books, so the theory used is different. Keywords              : Leader Member Exchange, personality,, Employee Voice, communication, employee relation, organization effectiveness.

scholarly journals A Digital Camera-Based Rotation-Invariant Fingerprint Verification Method

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Sajid Khan ◽  
Dong-Ho Lee ◽  
Asif Khan ◽  
Ahmad Waqas ◽  
Abdul Rehman Gilal ◽  
...  
Keyword(s):  
Feature Matching ◽  
Digital Camera ◽  
Reference Image ◽  
Digital Cameras ◽  
Scale Invariant ◽  
Image Capture ◽  
Verification Method ◽  
Reference Images ◽  
Binary Segmentation ◽  
The Difference

Fingerprint registration and verification is an active area of research in the field of image processing. Usually, fingerprints are obtained from sensors; however, there is recent interest in using images of fingers obtained from digital cameras instead of scanners. An unaddressed issue in the processing of fingerprints extracted from digital images is the angle of the finger during image capture. To match a fingerprint with 100% accuracy, the angles of the matching features should be similar. This paper proposes a rotation and scale-invariant decision-making method for the intelligent registration and recognition of fingerprints. A digital image of a finger is taken as the input and compared with a reference image for derotation. Derotation is performed by applying binary segmentation on both images, followed by the application of speeded up robust feature (SURF) extraction and then feature matching. Potential inliers are extracted from matched features by applying the M-estimator. Matched inlier points are used to form a homography matrix, the difference in the rotation angles of the finger in both the input and reference images is calculated, and finally, derotation is performed. Input fingerprint features are extracted and compared or stored based on the decision support system required for the situation.

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