Qualitative path estimation: A fast and reliable algorithm for qualitative trend analysis

Abstract

in Wiley Online Library (wileyonlinelibrary.com)Fault detection and identification is challenged by a lack of detailed understanding of process dynamics under anomalous circumstances as well as a lack of historical data concerning rare events in a typical process. Qualitative trend analysis (QTA) techniques provide a way out by focusing on a coarse-grained representation of time series data. Such qualitative representations are valid in a larger set of operating conditions and thus provide a robust way to handle the detection and identification of rare events. Unfortunately, available methods fail when faced with moderate noise levels or result in rather large computational efforts. For this reason, this article provides a novel method for QTA. This leads to dramatic improvements in computational efficiency compared to the previously established shape constrained splines method while the accuracy remains high. V C 2015 American Institute of Chemical Engineers AIChE J, 61: 1535-1546, 2015The BCBC shape is clearly identified as the most likely over a wide range of kernel half-widths.

The Covid-19 Disease and Policy Response to Mitigate the Economic Impact in the Eu

“…The qualitative on-the-trend-based research concept has been applied here to study events and systems, which are unique, vague and multidimensional and thus cannot be described by current adequate data sets (Villez, 2015). The model takes into account a certain number of input variables and results in a set of scenarios and transitions between them.…”

“…Qualitative trend analysis (QTA) represents a technique how to deal with rare events which cannot be described by numerical data sets because these are not available or are incomplete (Villez, 2015). Many shallow knowledge items are available just as verbal descriptions based on trends: decreasing, constant, or increasing (Yan et al, 2013).…”

“…For instance, if an effective treatment of Covid-19 were found, then a sharp increase in GDP can be expected. Villez (2015) reports that a QTA consists of a two-step procedure. In the first step, an abstraction of the quantitative data series is outlined.…”

Novel Pattern-Matching Integrated KCVA with Adaptive Rank-Order Morphological Filter and Its Application to Fault Diagnosis

“…Data preprocessing: data noise elimination and the standardization of the original training and test data. A/C feed flow ratio changes, B content constant (stream 4) IDV (2) B component content change, A/C flow ratio unchanged (stream 4) IDV (3) D feed temperature changes (stream 2) IDV (4) reactor cooling water inlet temperature changes IDV (5) condenser cooling water inlet temperature changes IDV (6) A feed loss (stream 1) IDV (7) C header pressure loss/reduced availability (stream 4)…”

“…In our case, the step type faults IDV(1)− IDV (7) are selected for simulation, and detailed descriptions of the seven faults in the TEP are shown in Table 1. 4), (f) IDV( 5), (g) IDV (6), and (h) IDV (7). In the TEP, the run time of one simulation is 24 h, and the sample interval is 1.5 min; therefore, each simulation contains 960 samples.…”