Fingerprint Reference Point Determination Based on Orientation Features

2010 ◽  
Author(s):  
Shan Juan Xie ◽  
Sook Yoon ◽  
Hui Gong ◽  
Jinwook Shin ◽  
Dong Sun Park
Keyword(s):  
Reference Point ◽  
Point Determination

scholarly journals ILRS Reference Point Determination Using Close Range Photogrammetry

2021 ◽  
Vol 11 (6) ◽  
pp. 2785
Author(s):  
Michael Lösler ◽  
Cornelia Eschelbach ◽  
Thomas Klügel ◽  
Stefan Riepl
Keyword(s):  
Reference Point ◽  
Reference Points ◽  
Geodetic Reference System ◽  
Unscented Transformation ◽  
Local Ties ◽  
Close Range Photogrammetry ◽  
Crucial Component ◽  
Space Geodetic Techniques ◽  
Close Range ◽  
Point Determination

A global geodetic reference system (GGRS) is realized by physical points on the Earth’s surface and is referred to as a global geodetic reference frame (GGRF). The GGRF is derived by combining several space geodetic techniques, and the reference points of these techniques are the physical points of such a realization. Due to the weak physical connection between the space geodetic techniques, so-called local ties are introduced to the combination procedure. A local tie is the spatial vector defined between the reference points of two space geodetic techniques. It is derivable by local measurements at multitechnique stations, which operate more than one space geodetic technique. Local ties are a crucial component within the intertechnique combination; therefore, erroneous or outdated vectors affect the global results. In order to reach the ambitious accuracy goal of 1 mm for a global position, the global geodetic observing system (GGOS) aims for strategies to improve local ties, and, thus, the reference point determination procedures. In this contribution, close range photogrammetry is applied for the first time to determine the reference point of a laser telescope used for satellite laser ranging (SLR) at Geodetic Observatory Wettzell (GOW). A measurement campaign using various configurations was performed at the Satellite Observing System Wettzell (SOS-W) to evaluate the achievable accuracy and the measurement effort. The bias of the estimates were studied using an unscented transformation. Biases occur if nonlinear functions are replaced and are solved by linear substitute problems. Moreover, the influence of the chosen stochastic model onto the estimates is studied by means of various dispersion matrices of the observations. It is shown that the resulting standard deviations are two to three times overestimated if stochastic dependencies are neglected.

scholarly journals Prospective study of high geodetic resolution to future VGOS reference point determination

2019 ◽  
Vol 10 (2) ◽  
pp. 163-171
Author(s):  
Zhibin Zhang ◽  
Guangli Wang ◽  
Dezhen Xu ◽  
Shize Song
Keyword(s):  
Prospective Study ◽  
Reference Point ◽  
Point Determination

scholarly journals An accurate fingerprint reference point determination method based on curvature estimation of separated ridges

2018 ◽  
Vol 28 (1) ◽  
pp. 209-225 ◽  
Author(s):  
Rafal Doroz ◽  
Krzysztof Wrobel ◽  
Piotr Porwik
Keyword(s):  
Reference Point ◽  
Reference Points ◽  
Second Step ◽  
Multi Stage ◽  
Stage System ◽  
Series Of Experiments ◽  
Curvature Estimation ◽  
Point Determination ◽  
Point Detection

AbstractThis paper presents an effective method for the detection of a fingerprint’s reference point by analyzing fingerprint ridges’ curvatures. The proposed approach is a multi-stage system. The first step extracts the fingerprint ridges from an image and transforms them into chains of discrete points. In the second step, the obtained chains of points are processed by a dedicated algorithm to detect corners and other points of highest curvature on their planar surface. In a series of experiments we demonstrate that the proposed method based on this algorithm allows effective determination of fingerprint reference points. Furthermore, the proposed method is relatively simple and achieves better results when compared with the approaches known from the literature. The reference point detection experiments were conducted using publicly available fingerprint databases FVC2000, FVC2002, FVC2004 and NIST

An Optimizing Method to Balance Aerodynamic Loading for Gas Turbine Engine Preliminary Design

2013 ◽  
Author(s):  
Qiuye Tu ◽  
Xianzhong Huang ◽  
Yang Shi ◽  
Kun Yang ◽  
Li Zhou
Keyword(s):  
Reference Point ◽  
Second Step ◽  
Preliminary Design ◽  
Aerodynamic Optimization ◽  
Turbine Engine ◽  
Axial Compressors ◽  
Aerodynamic Loading ◽  
Dimensional Parameters ◽  
Point Determination ◽  
Set Up

This paper presents a method to balance aerodynamic loading by optimizing the combined efficiencies of co-axial compressors and turbines for engine preliminary design. Relationships between the aerodynamic and dimensional parameters for co-axial compressors and turbines were set up by nonlinear equations. And the boundary conditions of the equations are thermodynamic parameters and Smith Charts of compressors and turbines. The process of the method includes the initial value guess, reference point determination and aerodynamic optimization. The first step solves approximate stage numbers for co-axial compressors and turbines, and other initial values used in the second step. In the second step, an appropriate solution of the equations determines a reference point on the Smith Chart. The first step is required for a better convergence in the second step due to the nature of the Newton-Raphson solver. In the third step, the combined efficiencies of co-axial compressors and turbines are optimized under the specified constraints. An optimizing tool was developed based on the proposed method. An example of a core engine was analyzed by using this tool. The results showed the reliability and high fidelity of the method.

A modified approach for automated reference point determination of SLR and VLBI telescopes

2018 ◽  
Vol 85 (10) ◽  
pp. 616-626 ◽  
Author(s):  
Michael Lösler ◽  
Cornelia Eschelbach ◽  
Stefan Riepl
Keyword(s):  
Reference Point ◽  
Terrestrial Reference Frame ◽  
Reference Points ◽  
Combination Process ◽  
Local Ties ◽  
Synchronization Errors ◽  
Space Geodetic Techniques ◽  
Point Determination ◽  
Technical Effort

AbstractThe International Terrestrial Reference Frame (ITRF) is derived by combining several space geodetic techniques. Basically, a meaningful combination of the geodesic space techniques is impossible without further geometrical information, i. e. local-ties. Local-tie vectors are defined between the geometrical reference points of space geodetic techniques at co-location stations. These local-ties are introduced during the inter-technique combination process, to overcome the weak physical connection between the space geodetic techniques. In particular, the determination of the reference point of radio telescopes or laser telescopes is a challenging task and requires indirect methods. Moreover, the Global Geodetic Observing System (GGOS) strives for an automated and continued reference point determination with sub-millimeter accuracy, because deviations in local-ties bias global results.This investigation presents a modified approach for automated reference point determination. The new approach extends the prior work of Lösler but evades the synchronization between the terrestrial instrument and the telescope. Thus, synchronization errors are omitted and the technical effort is reduced. A proof of concept was carried out at Geodetic Observatory Wettzell in 2018. Using a high-precision, mobile laser-tracker, the reference point of the Satellite Observing System Wettzell (SOS-W) was derived. An extended version of the in-house developed software package HEIMDALL was employed for a mostly automated data collection. To evaluate the estimated reference point, the derived results are compared with the results of two approved models.

Cognitive Reflection Effects on Time Discounting

2018 ◽  
Vol 39 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Michał Białek ◽  
Przemysław Sawicki
Keyword(s):  
Individual Differences ◽  
Individual Difference ◽  
Delay Discounting ◽  
Reference Point ◽  
Reference Points ◽  
Cognitive Reflection Test ◽  
Process Information ◽  
Time Discounting ◽  
Cognitive Reflection ◽  
The Way

Abstract. In this work, we investigated individual differences in cognitive reflection effects on delay discounting – a preference for smaller sooner over larger later payoff. People are claimed to prefer more these alternatives they considered first – so-called reference point – over the alternatives they considered later. Cognitive reflection affects the way individuals process information, with less reflective individuals relying predominantly on the first information they consider, thus, being more susceptible to reference points as compared to more reflective individuals. In Experiment 1, we confirmed that individuals who scored high on the Cognitive Reflection Test discount less strongly than less reflective individuals, but we also show that such individuals are less susceptible to imposed reference points. Experiment 2 replicated these findings additionally providing evidence that cognitive reflection predicts discounting strength and (in)dependency to reference points over and above individual difference in numeracy.

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