scholarly journals Drift analysis in tilt-roll heliostats

Solar Energy ◽  
2020 ◽  
Vol 211 ◽  
pp. 1170-1183
Author(s):  
Alejandro Martínez-Hernández ◽  
Iván B. Gonzalo ◽  
Manuel Romero ◽  
José González-Aguilar
Keyword(s):  
Drift Analysis

scholarly journals Drift Analysis and Evolutionary Algorithms Revisited

2018 ◽  
Vol 27 (4) ◽  
pp. 643-666 ◽  
Author(s):  
J. LENGLER ◽  
A. STEGER
Keyword(s):  
Evolutionary Algorithms ◽  
Evolutionary Algorithm ◽  
Random Search ◽  
Optimization Algorithms ◽  
Simple Algorithm ◽  
Linear Functions ◽  
Search Point ◽  
Drift Analysis ◽  
Fixed Constant ◽  
Greedy Optimization

One of the easiest randomized greedy optimization algorithms is the following evolutionary algorithm which aims at maximizing a function f: {0,1}n → ℝ. The algorithm starts with a random search point ξ ∈ {0,1}n, and in each round it flips each bit of ξ with probability c/n independently at random, where c > 0 is a fixed constant. The thus created offspring ξ' replaces ξ if and only if f(ξ') ≥ f(ξ). The analysis of the runtime of this simple algorithm for monotone and for linear functions turned out to be highly non-trivial. In this paper we review known results and provide new and self-contained proofs of partly stronger results.

scholarly journals Multiplicative Drift Analysis

Algorithmica ◽  
2012 ◽  
Vol 64 (4) ◽  
pp. 673-697 ◽  
Author(s):  
Benjamin Doerr ◽  
Daniel Johannsen ◽  
Carola Winzen
Keyword(s):  
Drift Analysis

scholarly journals On the improved stability of the version 7 MIPAS ozone record

2018 ◽  
Vol 11 (8) ◽  
pp. 4693-4705 ◽  
Author(s):  
Alexandra Laeng ◽  
Ellen Eckert ◽  
Thomas von Clarmann ◽  
Michael Kiefer ◽  
Daan Hubert ◽  
...  
Keyword(s):  
Michelson Interferometer ◽  
European Space Agency ◽  
Detector Response ◽  
Ozone Level ◽  
Term Stability ◽  
Long Term Stability ◽  
Drift Analysis ◽  
Ground Based Lidar ◽  
Level 2

Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) was an infrared limb emission spectrometer on the Envisat platform. From 2002 to 2012, it performed pole-to-pole measurements during day and night, producing more than 1000 profiles per day. The European Space Agency (ESA) recently released the new version 7 of Level 1B MIPAS spectra, in which a new set of time-dependent correction coefficients for the nonlinearity in the detector response functions was implemented. This change is expected to reduce the long-term drift of the MIPAS Level 2 data. We evaluate the long-term stability of ozone Level 2 data retrieved from MIPAS v7 Level 1B spectra with the IMK/IAA scientific level 2 processor. For this, we compare MIPAS data with ozone measurements from the Microwave Limb Sounder (MLS) instrument on NASA's Aura satellite, ozonesondes and ground-based lidar instruments. The ozonesondes and lidars alone do not allow us to conclude with enough significance that the new version is more stable than the previous one, but a clear improvement in long-term stability is observed in the satellite-data-based drift analysis. The results of ozonesondes, lidars and satellite drift analysis are consistent: all indicate that the drifts of the new version are less negative/more positive nearly everywhere above 15 km. The 10-year MIPAS ozone trends calculated from the old and the new data versions are compared. The new trends are closer to old drift-corrected trends than the old uncorrected trends were. From this, we conclude that the nonlinearity correction performed on Level 1B data is an improvement. These results indicate that MIPAS data are now even more suited for trend studies, alone or as part of a merged data record.

scholarly journals Drift analysis and stabilization of a Fiber Bragg Grating interrogation device

2020 ◽  
Author(s):  
Marvin Friedemann ◽  
Sebastian Voigt ◽  
Marie-Luise Werner ◽  
Raoul Hecker ◽  
Jan Mehner
Keyword(s):  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Drift Analysis

Drift analysis of MH370 debris in the southern Indian Ocean

2018 ◽  
Vol 12 (3) ◽  
pp. 468-480 ◽  
Author(s):  
Jia Gao ◽  
Lin Mu ◽  
Xianwen Bao ◽  
Jun Song ◽  
Yang Ding
Keyword(s):  
Indian Ocean ◽  
Southern Indian Ocean ◽  
Drift Analysis

scholarly journals CONDA-PM—A Systematic Review and Framework for Concept Drift Analysis in Process Mining

Algorithms ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 161
Author(s):  
Ghada Elkhawaga ◽  
Mervat Abuelkheir ◽  
Sherif I. Barakat ◽  
Alaa M. Riad ◽  
Manfred Reichert
Keyword(s):  
Systematic Review ◽  
Business Process ◽  
Continuous Monitoring ◽  
Business Processes ◽  
Process Mining ◽  
Concept Drift ◽  
Business Environments ◽  
Drift Analysis ◽  
Comprehensive Framework ◽  
Over Time

Business processes evolve over time to adapt to changing business environments. This requires continuous monitoring of business processes to gain insights into whether they conform to the intended design or deviate from it. The situation when a business process changes while being analysed is denoted as Concept Drift. Its analysis is concerned with studying how a business process changes, in terms of detecting and localising changes and studying the effects of the latter. Concept drift analysis is crucial to enable early detection and management of changes, that is, whether to promote a change to become part of an improved process, or to reject the change and make decisions to mitigate its effects. Despite its importance, there exists no comprehensive framework for analysing concept drift types, affected process perspectives, and granularity levels of a business process. This article proposes the CONcept Drift Analysis in Process Mining (CONDA-PM) framework describing phases and requirements of a concept drift analysis approach. CONDA-PM was derived from a Systematic Literature Review (SLR) of current approaches analysing concept drift. We apply the CONDA-PM framework on current approaches to concept drift analysis and evaluate their maturity. Applying CONDA-PM framework highlights areas where research is needed to complement existing efforts.

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