scholarly journals Soft-Transition Sub-PCA Monitoring of Batch Processes

2022 ◽  
pp. 59-77
Author(s):  
Jing Wang ◽  
Jinglin Zhou ◽  
Xiaolu Chen
Keyword(s):  
Value Added ◽  
Batch Process ◽  
Batch Processes ◽  
Time Varying ◽  
Continuous Processes ◽  
Finite Duration ◽  
Monitoring Model ◽  
Highly Sensitive ◽  
The Common ◽  
Nonlinear Behaviors

AbstractBatch or semi-batch processes have been utilized to produce high-value-added products in the biological, food, semi-conductor industries. Batch process, such as fermentation, polymerization, and pharmacy, is highly sensitive to the abnormal changes in operating condition. Monitoring of such processes is extremely important in order to get higher productivity. However, it is more difficult to develop an exact monitoring model of batch processes than that of continuous processes, due to the common natures of batch process: non-steady, time-varying, finite duration, and nonlinear behaviors. The lack of exact monitoring model in most batch processes leads that an operator cannot identify the faults when they occurred. Therefore, effective techniques for monitoring batch process exactly are necessary in order to remind the operator to take some corrective actions before the situation becomes more dangerous.

scholarly journals Slow Time-Varying Batch Process Quality Prediction Based on Batch Augmentation Analysis

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 512
Author(s):  
Luping Zhao ◽  
Xin Huang
Keyword(s):  
Prediction Method ◽  
Batch Process ◽  
Batch Processes ◽  
Data Matrix ◽  
Injection Molding Process ◽  
Quality Prediction ◽  
Time Varying ◽  
Slow Time ◽  
Process Data ◽  
Molding Process

In this paper, focusing on the slow time-varying characteristics, a series of works have been conducted to implement an accurate quality prediction for batch processes. To deal with the time-varying characteristics along the batch direction, sliding windows can be constructed. Then, the start-up process is identified and the whole process is divided into two modes according to the steady-state identification. In the most important mode, the process data matrix, used to establish the regression model of the current batch, is expanded to involve the process data of previous batches, which is called batch augmentation. Thus, the process data of previous batches, which have an important influence on the quality of the current batch, will be identified and form a new batch augmentation matrix for modeling using the partial least squares (PLS) method. Moreover, considering the multiphase characteristic, batch augmentation analysis and modeling is conducted within each phase. Finally, the proposed method is applied to a typical batch process, the injection molding process. The quality prediction results are compared with those of the traditional quality prediction method based on PLS and the ridge regression method under the proposed batch augmentation analysis framework. The conclusion is obtained that the proposed method based on the batch augmentation analysis is superior.

scholarly journals Optimization of Synthetic Media Composition for Kluyveromyces marxianus Fed-Batch Cultivation

Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 62
Author(s):  
Konstantins Dubencovs ◽  
Janis Liepins ◽  
Arturs Suleiko ◽  
Anastasija Suleiko ◽  
Reinis Vangravs ◽  
...  
Keyword(s):  
Kluyveromyces Marxianus ◽  
Reaction Medium ◽  
Value Added ◽  
Batch Cultivation ◽  
Batch Processes ◽  
Biomass Growth ◽  
High Cell ◽  
Media Composition ◽  
Fed Batch ◽  
Fed Batch Cultivation

The Kluyveromyces marxianus yeast recently has gained considerable attention due to its applicability in high-value-added product manufacturing. In order to intensify the biosynthesis rate of a target product, reaching high biomass concentrations in the reaction medium is mandatory. Fed-batch processes are an attractive and efficient way how to achieve high cell densities. However, depending on the physiology of the particular microbial strain, an optimal media composition should be used to avoid by-product synthesis and, subsequently, a decrease in overall process effi-ciency. Thus, the aim of the present study was to optimise the synthetic growth medium and feeding solution compositions (in terms of carbon, nitrogen, phosphorous, magnesium, and calcium concentrations) for high cell density K. marxianus fed‑batch cultivations. Additionally, the biomass yields from the vitamin mixture and other macro/microelements were identified. A model predictive control algorithm was successfully applied for a fed-batch cultivation control. Biomass growth and substrate consumption kinetics were compared with the mathematical model predictions. Finally, 2‑phenylethanol biosynthesis was induced and its productivity was estimated. The determined optimal macronutrient ratio for K. marxianus biomass growth was identified as C:N:P = 1:0.07:0.011. The maximal attained yeast biomass concentration was close to 70 g·L-1 and the 2-PE biosynthesis rate was 0.372 g·L−1·h−1, with a yield of 74% from 2-phenylalanine.

scholarly journals Backstepping Methodology to Troubleshoot Plant-Wide Batch Processes in Data-Rich Industrial Environments

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1074
Author(s):  
Federico Zuecco ◽  
Matteo Cicciotti ◽  
Pierantonio Facco ◽  
Fabrizio Bezzo ◽  
Massimiliano Barolo
Keyword(s):  
Production Capacity ◽  
Batch Process ◽  
Batch Processes ◽  
Flow Diagram ◽  
Production Cycle ◽  
Multivariate Statistical ◽  
Process Flow Diagram ◽  
Root Cause ◽  
Industrial Batch ◽  
Specialty Chemical

Troubleshooting batch processes at a plant-wide level requires first finding the unit causing the fault, and then understanding why the fault occurs in that unit. Whereas in the literature case studies discussing the latter issue abound, little attention has been given so far to the former, which is complex for several reasons: the processing units are often operated in a non-sequential way, with unusual series-parallel arrangements; holding vessels may be required to compensate for lack of production capacity, and reacting phenomena can occur in these vessels; and the evidence of batch abnormality may be available only from the end unit and at the end of the production cycle. We propose a structured methodology to assist the troubleshooting of plant-wide batch processes in data-rich environments where multivariate statistical techniques can be exploited. Namely, we first analyze the last unit wherein the fault manifests itself, and we then step back across the units through the process flow diagram (according to the manufacturing recipe) until the fault cannot be detected by the available field sensors any more. That enables us to isolate the unit wherefrom the fault originates. Interrogation of multivariate statistical models for that unit coupled to engineering judgement allow identifying the most likely root cause of the fault. We apply the proposed methodology to troubleshoot a complex industrial batch process that manufactures a specialty chemical, where productivity was originally limited by unexplained variability of the final product quality. Correction of the fault allowed for a significant increase in productivity.

scholarly journals Streptococcus pyogenes vulvovaginitis in children in Nottingham

1991 ◽  
Vol 106 (3) ◽  
pp. 459-465 ◽  
Author(s):  
F. E. Donald ◽  
R. C. B. Slack ◽  
G. Colman
Keyword(s):  
Public Health ◽  
Streptococcus Pyogenes ◽  
Public Health Laboratory ◽  
Large Numbers ◽  
Highly Sensitive ◽  
Vaginal Swabs ◽  
Different Types ◽  
Winter Peak ◽  
The Common

SUMMARYIsolates of Streptococcus pyogenes from vaginal swabs of children with vulvovaginitis received at Nottingham Public Health Laboratory during 1986–9 were studied. A total of 159 isolates was made during the 4 years, increasing from 17 in 1986 to 64 in 1989 and accounting for 11% of all vaginal swabs received from children. The numbers of throat swabs yielding S. pyogenes also showed an increase from 974 in 1986 to 1519 in 1989. A winter peak of isolates was noted for both vaginal swabs and throat swabs. A total of 98 strains from vaginal swabs were serotyped: 22 different types were identified, 61% of which were the common types M4, M6, R28 and M12. Erythromycin sensitivity was done on 89 strains; 84% were highly sensitive (MIC < 0·03 mg/1). There are no other reports of such large numbers in the literature; the reason for seeing this increase in Nottingham is unclear.

Optimization of Model Training Based on Iterative Minimum Covariance Determinant In Motor-Imagery BCI

2021 ◽  
pp. 2150030
Author(s):  
Jing Jin ◽  
Hua Fang ◽  
Ian Daly ◽  
Ruocheng Xiao ◽  
Yangyang Miao ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Classification Performance ◽  
Minimum Covariance Determinant ◽  
Fisher Score ◽  
Practical Applications ◽  
Computer Interfaces ◽  
Highly Sensitive ◽  
Feature Optimization ◽  
The Common ◽  
Model Training

The common spatial patterns (CSP) algorithm is one of the most frequently used and effective spatial filtering methods for extracting relevant features for use in motor imagery brain–computer interfaces (MI-BCIs). However, the inherent defect of the traditional CSP algorithm is that it is highly sensitive to potential outliers, which adversely affects its performance in practical applications. In this work, we propose a novel feature optimization and outlier detection method for the CSP algorithm. Specifically, we use the minimum covariance determinant (MCD) to detect and remove outliers in the dataset, then we use the Fisher score to evaluate and select features. In addition, in order to prevent the emergence of new outliers, we propose an iterative minimum covariance determinant (IMCD) algorithm. We evaluate our proposed algorithm in terms of iteration times, classification accuracy and feature distribution using two BCI competition datasets. The experimental results show that the average classification performance of our proposed method is 12% and 22.9% higher than that of the traditional CSP method in two datasets ([Formula: see text]), and our proposed method obtains better performance in comparison with other competing methods. The results show that our method improves the performance of MI-BCI systems.

Time-Varying Uncertainty of the Federal Reserve's Output Gap Estimate

2021 ◽  
pp. 1-38
Author(s):  
Travis J. Berge
Keyword(s):  
Aggregate Demand ◽  
Stochastic Volatility Model ◽  
Output Gap ◽  
Time Varying ◽  
Common Component ◽  
Macroeconomic Variables ◽  
Macroeconomic Uncertainty ◽  
Volatility Model ◽  
The Common ◽  
Gap Estimate

Abstract A factor stochastic volatility model estimates the common component to output gap estimates produced by the staff of the Federal Reserve, its time-varying volatility, and time-varying, horizon-specific forecast uncertainty. The output gap estimates are uncertain even well after the fact. Nevertheless, the common component is clearly procyclical, and positive innovations to the common component produce movements in macroeconomic variables consistent with an increase in aggregate demand. Heightened macroeconomic uncertainty, as measured by the common component's volatility, leads to persistently negative economic responses.

Seeking transparency makes one blind: how to rethink disclosure, account for nature and make corporations sustainable

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Paolo Quattrone
Keyword(s):  
Social Inequality ◽  
Common Good ◽  
Design Methodology ◽  
Value Added ◽  
Institutional Arrangements ◽  
Content Type ◽  
Corporate Behavior ◽  
Income Statement ◽  
The Common ◽  
Human Actors

PurposeFinancial and nonfinancial disclosures are still anchored to conventional notions of transparency, whereby corporations “push” information out to various stakeholders. Such information is now “pulled” from various sources and addresses aspects of corporate behavior that go well beyond those envisioned by the disclosure framework. This shift makes notions of values, measurement and accountability more fragmented, complex and difficult. The paper aims to bring the accounting scholarly debate back to what and how transparency can be achieved especially in relation to issues of social inequality and sustainability.Design/methodology/approachAfter an analysis of the limitations of current approaches to disclosure, the paper proposes a shift toward normative policies that profit of years of critique of positivism.FindingsDrawing on the notion of value-added, the paper ends with a new income statement design, labeled as Value-Added Statement for Nature, which recognizes Nature as a further stakeholder and forces human stakeholders to give voice, or at least acknowledge the lack of voice, for non-human actors.Originality/valueThe author proposes a shift in the perspective, practice and institutional arrangements in which disclosure occurs. Measurement and transparency need to happen in communication exercises, which do not presuppose what needs to be made transparent once and for good but define procedures on how to make fragmented, complex, multiple and volatile notions of value transparent. Income statements and accounting more in general is to be reconceived as a platform where stakeholders will have to continuously negotiate what counts as the common good in the interest of all, including Nature.

Conventional Legal Regulation of Value-Added Taxation by the Member States of the Gulf Cooperation Counci

2021 ◽  
pp. 232-238
Author(s):  
Dmitry G. Bachurin ◽  
Keyword(s):  
Persian Gulf ◽  
Value Added ◽  
Legal Framework ◽  
Legal Regulation ◽  
Gulf Cooperation Council ◽  
Legal Aspects ◽  
Gulf Countries ◽  
The Common ◽  
National Tax ◽  
The Persian Gulf

The article discusses the legal aspects of supranational legal regulation of value added taxation in the Persian Gulf countries. The novelty of the research lies in the comparative aspect of the legal study of supranational law on the value-added tax in the Gulf countries, which allows formulating fundamentally new characteristics and interpretations that extend the theoretical and legal views on the legal mechanism of VAT, and analyzing the key provisions of the legal regulation of VAT of the states that are parties to the Common VAT Agreement. The issues of the Agreement for the countries of the Gulf Cooperation Council, as well as acts of national legislation on this tax, were studied. The analysis of the provisions of the Agreement allows concluding that the tax instrument this Agreement regulates can be classified as a type of neutral legal regulation of value-added taxation. Its peculiarity is that the country for one reason or another introduces VAT into the national tax system with minimal tax rates and continues to keep it at a low level that does not have a restraining effect on the development of its own industry. This is the reference point for the Common VAT Agreement for the countries of the Gulf Cooperation Council. The research shows that the supranational legislation of the Persian Gulf countries covers the most complex and fundamentally significant issues of legal regulation of value-added taxation, which developed taking into account the accumulated world experience in the administration of this tax. Conclusions have been obtained that the main direction of the adopted supranational legislation is the creation of a unified legal framework for the development of a coordinated legal regulation of VAT in each of the six Arab states of the Persian Gulf. The definitions of concepts that are crucial for VAT regulation are given, among which the following can be distinguished: reverse VAT accrual, input tax, deductible tax, net tax, mandatory registration threshold, voluntary registration threshold, and tax group. In the final part of the work, it is concluded that the second regional system of legal regulation of value-added taxation after the European one is being created, which begins its development on the basis of supranational legislation. Within its framework, the states that are parties to the Agreement shall organize administrative cooperation in the following areas: (1) exchange of information necessary for determining tax accuracy; (2) coordination of synchronized audit procedures and participation in audits; (3) assistance in tax collection and adoption of necessary procedures related to VAT collection.

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