Top PDF Internal Decoupling in Nonlinear Process Control

Non-Linear Multivariable Predictive Control of an Alcoholic Fermentation Process Using Functional Link Networks

Non-Linear Multivariable Predictive Control of an Alcoholic Fermentation Process Using Functional Link Networks

In this work a MIMO non-linear predictive controller was developed for an extractive alcoholic fermentation process. The internal model of the controller was represented by two MISO Functional Link Networks (FLNs), identified using simulated data generated from a deterministic mathematical model whose kinetic parameters were determined experimentally. The FLN structure presents as advantages fast training and guaranteed convergence, since the estimation of the weights is a linear optimization problem. Besides, the elimination of non-significant weights generates parsimonious models, which allows for fast execution in an MPC-based algorithm. The proposed algorithm showed good potential in identification and control of non-linear processes.
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NEURO MODELING AND CONTROL STRATEGIES FOR A pH PROCESS

NEURO MODELING AND CONTROL STRATEGIES FOR A pH PROCESS

Modeling of the pH process is considered to be a difficult task because one needs to have knowledge about the components and their nature in the process stream in order to model its dynamics using conventional techniques. In the modeling aspect, rigorous models from first principles involving the material balance and equilibrium equations were established in [1] and later extended in [2] through the concept of the reaction invariant, and more complicated situations were considered in [3]. Due to the susceptibility to change in operating point, varying gain and load disturbances, the performance of the practical processes deviates from conventional modeling output [4]. The potential capability of neural networks in modeling and control of non-linear dynamics systems has been recognized since last decade [5], and research in this area has been intensively investigated. Neural network has the capacity to capture the nonlinear dynamics and model mismatch of the system. Hence, conventional model – based control strategies for dynamic processes, such as internal model control (IMC) and model inversion control has been redesigned using neural network [6]. The Levenberg – Marquardt (LM) algorithm is the fastest training algorithm reported in the literature for modeling. This is an extension to the standard back propagation algorithm.
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THE INTERNAL AUDIT AS COGNITIVE PROCESS

THE INTERNAL AUDIT AS COGNITIVE PROCESS

The term AUDIT generally comes from the Latin word "audire" to listen and to inform others, from today's Anglo-Saxon countries, this term has the meaning of a revision of the accounting information and of those of a different nature, realized by an independent professional, in view of expressing an opinion regarding the regularity and honesty of the audited information (1 Ştefan Cr ăciun, Audit financiar şi audit intern, The Economic Publishing House, Bucharest, 2004, page 22). In a general register, an audit has the purpose to grant an entity added value by a systematic and methodic approach, evaluating the risk management processes, the control processes and the governing processes, all of which are materialized within an objective and professional report.
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Research of internal control of Chinese enterprises based on Sarbanes-Oxley Act

Research of internal control of Chinese enterprises based on Sarbanes-Oxley Act

5. Strengthen internal auditing operations. Standards are required for making any judgment on whether the design of an internal control is appropriate or its implementation is effective. These are evaluation standards and apply to integral and operational aspects of the five factors for internal control listed by COSO. Regarding who should conduct internal control evaluations, the COSO report suggests that it primarily be enterprise management authorities or designated individuals, such as internal auditing committee. This group periodically conducts effective evaluations on the internal control design for the unit and issues an evaluation report. Next, registered accountants are required to examine and check thee evaluation report. The Sarbanes Act also has the same regulations. Corporate internal auditing plays an important role in developing corporate internal control evaluations. Within the Sarbanes Act is process of implementation, due to active participation from the IIA, defining and enabling roles for internal auditing and the obligations to be met under the terms of the regulation. Relevant guidelines within the Sarbanes Act and the American Securities and Trade Commission require senior managers within listed companies to submit a financial report and provide guarantees that the information is correct. Therefore, the executive managers are the responsible persons for control of the environment and financial materials. The external auditor notarizes the information for financial report and he needs to insure the financial report recipients that information in the report is accurately reflects the financial status of the organization. The internal auditors verify to the auditing commission that the internal control system set by the organization for the purpose of formulating the financial report is effective. Internal auditing executives should constantly communicate with the auditing commission in a timely manner. The auditing commission should evaluate the report’s coverage and adequacy from internal auditing executive directors.
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An Internal Audit Perspective on Differences between European Corporate Governance Codes and OECD Principles

An Internal Audit Perspective on Differences between European Corporate Governance Codes and OECD Principles

In the view of the latest economic environment evolution punctuated by financial scandals (national, European and international ones) the concept of corporate governance, has become more and more visible. As defined by The Institute of Internal Auditors, governance is “the combination of processes and structures implemented by the board of directors in order to inform, direct, manage and monitor the activities of the organization toward achieving is objectives”. In the IIA 2100 Standard – Nature of Work, we have a clear punctuation: „the internal audit activity must evaluate and contribute to the improuvement of governance, risck management and control process using a systematic and discipined aproach” (IIA standards, 2012).
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Optimal Robust Nonlinear LQG/LTR Control with Application to Longitudinal Flight Control

Optimal Robust Nonlinear LQG/LTR Control with Application to Longitudinal Flight Control

Due to the complexity and rhythm of the nowadays life in this modern age, time is becoming increasingly scarce in order to keep up the pace with all the demands. And though, advancements in automation procedures and systems had largely helped to reduce workload and improve schedules, there is still an important gap that must be fulfilled. For instance, whilst actual flight plan fulfilment requires 4D navigation, existing autonomous navigation procedures are mostly done in 3D because of the stringent certification requirements for 4D flight and due to the complexity in coping with time of arrival at waypoints. Therefore, there is a need for the development and testing of an algorithm that, when implemented on an aircraft’s autopilot system, will enable the aircraft to autonomously fulfil its scheduled time- of-arrival at a designated waypoint. As an initial step on that development process, the present work focuses on the simulated testing of improved and up-to-date optimal control and filtering methodologies that will be implemented in the aforementioned algorithm. More precisely it presents the background theory and simulated results of an LQG/LTR controller method when applied to a Classical Atmospheric Disturbances Simulation Test of an UAV on stable levelled flight.
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Sistema de control interno en el proceso general de la auditoria / Internal control system in the general audit process

Sistema de control interno en el proceso general de la auditoria / Internal control system in the general audit process

La gerencia debe llevar a cabo la revisión y evaluación sistemática de los componentes y elementos que forman parte de los sistemas de control. Lo anterior no significa que tengan que revisarse todos los componentes y elementos, como tampoco que deba hacerse al mismo tiempo. Ello dependerá de las condiciones específicas de cada organización, de los distintos niveles de riesgos existentes y del grado de efectividad mostrado por los distintos componentes y elementos de control. La evaluación debe conducir a la identificación de los controles débiles, insuficientes o innecesarios, para promover con el apoyo decidido de la gerencia, su robustecimiento e implantación. Esta evaluación puede llevarse a cabo de tres formas: durante la realización de las actividades diarias en los distintos niveles de la organización; de manera separada por personal que no es responsable directo de la ejecución de las actividades (incluidas las de control) y mediante la combinación de las dos formas anteriores.
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Characterizing the nonlinear internal wave climate in the northeastern South China Sea

Characterizing the nonlinear internal wave climate in the northeastern South China Sea

One location where ISWs are particularly clear and energetic is the northeastern South China Sea. Both synthetic aperture radar (Liu et al., 1998, 2004; Hsu and Liu, 2000) and ocean color (Kao et al., 2007) images have shown well-defined fields of ISWs propagating WNW across the sea from west of Luzon Strait to the Chinese continental shelf. The radar data reveal that the ISWs are depression waves in the open sea, changing to elevation waves in depths less than about 120–150 m on the continental shelf (Hsu and Liu, 2000). Most of the waves fit the expected surface signatures for mode-1 waves, but mode-2 waves have also been observed occasionally (Yang et al., 2004, 2009). The collective sea surface imagery suggests a few curious features. First, there seems to be a distinct lack of eastward- propagating waves on the Pacific side of the Luzon Ridge. This has recently been attributed to asymmetries in the tidal flux, thermal structure, and bottom topography across the ridge (Buijsman et al., 2010b) although observations on the Pacific side are lacking. Second, westward-propagating features generally do not appear in the surface imagery until a point west of the western (Heng-Chun) Ridge. This suggests that the Heng-Chun Ridge plays some role in the wave generation process. While this may be the case (Chao et al., 2007; Buijsman et al., 2010b) others have successfully modeled this result without the presence of a western ridge (Shaw et al., 2009; Zhang, 2010). Both show that the nonlinear internal tide requires a finite time to steepen to the point where ISWs develop on the leading edge of the bore, at a distance which approximately coincides with the location
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INTERNAL CONTROL MECHANISMS IN THE CONTEXT OF THE CHALENGE FINANCIAL CRISIS

INTERNAL CONTROL MECHANISMS IN THE CONTEXT OF THE CHALENGE FINANCIAL CRISIS

Prevention and earlier detection of fraudulent financial reporting must start with the entity that prepares financial reports. Thus the first focus of the Sarbannes-Oxley Act’s recommendations is the public company. These recommendations, taken together, will improve a company's overall financial reporting process and increase the likelihood of preventing fraudulent financial reporting and detecting it earlier when it occurs. For some companies, implementing these recommendations will require little or even no change from current practices; for other companies, it will mean adding or improving a recommended practice. Whether it means adding or improving a practice, the benefits justify the costs. The Sarbanes-Oxley Act is a direct response to the recent scandals in the US corporate world. Governance, compliance, risks and internal controls are mounting concerns for almost all organizations. As the numbers of rules, regulations and contractual obligations steadily rise, management is growing more and more concerned about their exposure on day-to-day operational decisions!
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The role of a company’s internal control system in fraud prevention

The role of a company’s internal control system in fraud prevention

Financial statements based on Internaional Accouning Standards should present correct data as the basis for the decision making process. Without qualitaive inancial reporing it is not possible to manage the company adequately, atract potenial investors, procure desired loans, inluence share prices at stock exchanges, etc. Managers usually receive a ixed salary and a premium if owners expectaions are achieved. There is a risk that managers might abuse their posiion by seing their own interests before the interests of their company, which may lead to undesirable consequences for the shareholders, investors, other stakeholders, the capital market and society in general. Almost all business scandals in the last years were the result of fraud in inancial statements. A large number of inancial scandals in the USA (Wordcom, Enron) and in Europe (Parmalat, Ahold) demonstrated that even in developed market economies scandals can negaively inluence the status of employees, pensioners, business partners and other paries which are not protected from the risk of fraud. Globalized, inancial markets detect frequent frauds at naional as well as at the internaional level. Large disorders in regional capital markets caused by frauds in inancial reports have iniiated serious monetary shocks, especially in developing countries, since they are very sensiive to internaional inancial frauds. Frauds in inancial statements could be deined as conscious violaion of accouning standards while making inancial reports and presening false data. Such frauds exist as long as inancial reporing is oriented toward the achievement of a manager’s short-term goals. They are present not only in transiion countries but also in countries with developed economies and tradiional inancial reporing. Frauds in inancial reports in the recent past have caused devastaing efects in developed countries leading to the emergence of global inancial crises. Pursuant to Internaional Audit Standards (IAS) frauds in inancial reports are considered criminal aciviies of intenional wrong data presentaion (Međunarodni standardi i saopštenja revizije“, Savez računovođa i revizora Srbije, Beograd, 2005, p. 277) Associaion of Ceriied Fraud Examiners (ACFE) deines inancial report frauds as “the intenional, deliberate, misstatement or omission of material facts, or accouning data which is misleading and, when considered with
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Decoupling multivariable GPC with reference observation and feed-forward compensation method Case Study: Neonate incubator

Decoupling multivariable GPC with reference observation and feed-forward compensation method Case Study: Neonate incubator

The progressive technological evolution of servo controlled incubators has created a need constantly to increase the capacity of these incubators to reach and maintain the desired temperature[1][2]. Consequently, the temperature is one of the most important factors that must be maintained with minimal variation to keep constant internal temperature. According to the study conducted in the Center Maternity and Neonatology of Tunisia (CMNT)[3], we noted that the infant is often exposed to disruption because of successive interventions of the medical team, which requires the presence of a controller more efficient. The newest incubators, such as Drager Isolette C2000 [3][4], uses a controller based on Proportional- Integral- Derivative (PID) to control internal temperature and a ON-OFF controller to increases the moisture by vaporization water [1][15]. However, the design of an active humidification system, modeling and implementation of a controller for a multi input multi- output, highly coupled constitute a real scientific challenge[1][15][16][17].. The contribution of this paper
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Securing Cloud System via Internal Control Management

Securing Cloud System via Internal Control Management

of your own data remotely in the supervision of a cloud server. This means one can store their data in the database of the server and can be retrieved whenever needed. But the question arises whether the data stored is secure enough or not, how it is being processed, who is going to process your data, what control are applied to make your data secure and several other questions are there that has to be answered. There are lots of research work has been done in this area but following are some issues that are still untouched:

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Predictive functional control of temperature in a pharmaceutical hybrid nonlinear batch reactor

Predictive functional control of temperature in a pharmaceutical hybrid nonlinear batch reactor

These days, in times of recession, we are forced by competitiveness and the optimization of production to lower the costs of the temperature control in phar- maceutical batch reactors and increase the quantity and quality of the pro- duced pharmaceutical product (active pharmaceutical substances). Therefore, a control algorithm is needed that provides us rapid and precise temperature control. This paper deals with the development of a control algorithm, where two predictive functional controllers are connected in a cascade for heating and cooling the content of the hybrid batch reactor. The algorithm has to be designed to cope with the constraints and the mixed discrete and continuous nature of the process of heating and cooling. The main goal of the control law is to achieve rapid and exact tracking of the reference temperature, good dis- turbance rejection and, in particular, a small number of heating and cooling medium switchings. The simulation results of the proposed algorithm gave a much better performance compared to a conventional cascade PI algorithm.
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Augusto Internal Control

Augusto Internal Control

Thus, one can say that Internal Control consists of an iterative and dynamic process including ongoing tasks and activities, acting as a mean to an end, and not as an end in itself. This process is effected by people at every level of an organization, as well as policy manuals, systems and forms previously written by the board and top management. It exists to provide a somewhat reasonable assurance to an entity’s senior management and board by trying to detect and prevent frauds and errors. Consequently, internal controls work as a way of a business to accomplish its objectives by performing operations that were established at the beginning, while protecting its assets and maintaining or enhancing its market value.
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CONTROL OF NONLINEAR PROCESS USING NEURAL NETWORK BASED MODEL PREDICTIVE CONTROL

CONTROL OF NONLINEAR PROCESS USING NEURAL NETWORK BASED MODEL PREDICTIVE CONTROL

That is, first a control time series u  is chosen. Using a model we look at what would happen if this series of control signals is used: the plant output ˆy can be predicted, then next a cost function (1) is used which shows how good or bad the outcome is. Then let the optimization algorithm choose a new control time series u  that is better by means of the cost function (1). Then number of iterations of these steps is done in order to find a series of control signals that is optimal with respect to the cost function (1).

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Rolls of the internal gravity waves in the Earth's  atmosphere

Rolls of the internal gravity waves in the Earth's atmosphere

The energy transfer from the Earth’s lithosphere to the at- mosphere and ionosphere is a fundamental problem of geo- physics and applied research. Internal gravity waves (IGWs) play an important role in such a process. For example, IGWs, propagating upward from the Earth’s surface to the upper at- mosphere and ionosphere, are able to carry a large amount of energy and momentum. These waves are crucial in atmo- sphere convection, generation of atmospheric turbulence and may affect global circulation. IGWs and related nonlinear structures are widely observed in the upper and lower lay- ers of the atmosphere as well as in the lower ionosphere, (see Fritts and Alexander, 2003; Swenson and Espy, 1995; Picard et al., 1998; Lu et al., 2009; Mitchell and Howells, 1998; Šindeláˇrová et al., 2009, for details).
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Simple Methods for Stability Analysis of Nonlinear Control Systems

Simple Methods for Stability Analysis of Nonlinear Control Systems

Abstract — Three methods for stability analysis of nonlinear control systems are introduced in this contribution: method of linearization, Lyapunov direct method and Popov criterion. Since stability analysis of nonlinear control systems is difficult task in engineering practice, these methods are made easier and tabulated. Method of linearization: The table includes the nonlinear equations and their linear approximation. Lyapunov direct method: The table contains Lyapunov functions for usu- ally used equations second order. Popov criterion: The table will allow us to directly determine the stability of the nonlinear circuit with the transfer function G(s) and the nonlinearity that satisfies the slope k.
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Nonlinear Finite Element Program for Reinforced Concrete Structural Control

Nonlinear Finite Element Program for Reinforced Concrete Structural Control

Two basically different approaches have been used so far for the analysis of RC slabs by the finite element method: the modified stiffness approach and the layer approach. The former is based on an average moment-curvature relationship which reflects the various stages of material behavior, while the latter subdivides the finite element into imaginary concrete and steel layers with idealized stress- strain relations for concrete and reinforcing steel. Dotroppe et al. (1973) used a layered finite element procedure in which slab elements were divided into layers to account for the progressive cracking through the slab thickness. Scanlon and Murray (1974) have developed a method of incorporating both cracking and time-dependent effects of creep and shrinkage in slabs. They used layered rectangular slab elements which could be cracked progressively layer by layer, and assumed that cracks propagate only parallel and perpendicular to orthogonal reinforcement. Lin and Scordelis (1975) utilized layered triangular finite elements in RC shell analysis and included the coupling between
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