The Tennessee Eastman Challenge Process (TECP) represents an interesting case study within PSE fo... more The Tennessee Eastman Challenge Process (TECP) represents an interesting case study within PSE for process control and process optimization purposes. It has been widely addressed by the chemical engineering research community since its publication. The TECP is an open-loop unstable recycle reactor. The eigenvalues of the Jacobean matrix of the system at the base-case steady-state conditions, range from –1968 to +3.07. In absence of feed-back, small perturbations cause large transients reaching shut-down limits within an hour. Operation at open-loop unstable steady-states, even if feasible with feed-back control, is undesirable and should be avoided by proper design. In this contribution, the re-design problem of the TECP is addressed in order to generate an open-loop stable operating condition, by making use of eigenvalue optimization techniques. The objective is to find a new steady state point, such that the whole spectrum of the Jacobean matrix of the system lies in the left half...
In the last decades the chemical engineering scientific research community has largely addressed ... more In the last decades the chemical engineering scientific research community has largely addressed the design-for-operability problem. Such an interest responds to the fact that the operability quality of a process is determined by design, becoming evident the convenience of considering operability issues in early design stages rather than later when the impact of modifications is less effective and more expensive. The necessity of integrating design and operability is dictated by the increasing complexity of the processes as result of progressively stringent economic, quality, safety and environmental constraints. Although the design-for-operability problem concerns to practically every technical discipline, it has achieved a particular identity within the chemical engineering field due to the economic magnitude of the involved processes. The work on design and analysis for operability in chemical engineering is really vast and a complete review in terms of papers is beyond the scope...
La actividad agronómica actual presenta importantes desafíos asociados a la compleja ecuación cos... more La actividad agronómica actual presenta importantes desafíos asociados a la compleja ecuación costo/beneficio de la producción primaria y al creciente impacto ambiental resultante del empleo intensivo de agroquímicos. El SO Bonaerense, evidencia marcadas limitaciones agroecológicas asociadas a problemas de erosión eólica de diversa magnitud y a la irregularidad en el patrón anual de precipitaciones.
Avena fatua is an invasive weed affecting winter cereal crops of the semiarid temperate region of... more Avena fatua is an invasive weed affecting winter cereal crops of the semiarid temperate region of Argentina. Seedling emergence patterns show great variability between years mainly due to a highly unpredictable annual precipitation regime and a fluctuating thermal environment. Artificial feedforward neural networks (AFNN) are powerful tools for modeling non-linear relationships between variables thus showing a high potential applicability in ecological systems [1]. The quality of AFNN models depends on a proper setting of neural network architecture and other influential parameters (i.e. learning algorithm, transfer functions, number of neurons in hidden layers, etc.) [2]. The objective of the present work was to compare different AFNN architectures in order to obtain a model with the best capability to predict the proportion of daily emerged seedlings in the field as a function of meteorological data. Three input variables were considered for the network configuration: time (Julian...
La actividad agronómica actual presenta importantes desafíos asociados a la compleja ecuación cos... more La actividad agronómica actual presenta importantes desafíos asociados a la compleja ecuación costo/beneficio de la producción primaria y al creciente impacto ambiental resultante del empleo intensivo de agroquímicos. La zona del sudoeste de la provincia de Buenos Aires, en especial la región semiárida templada, evidencia una declinación progresiva de las pequeñas y medianas empresas debido a la imprevisibilidad del mercado agropecuario, el aumento de los costos de producción y la necesidad de incrementar la superficie de producción, a fin de poder disponer de una unidad económicamente rentable. La complejidad del contexto socio-económico expuesto, plantea un escenario donde la disponibilidad de herramientas computacionales de asistencia en la toma de decisiones podría jugar un rol fundamental en los diversos sistemas de la producción agronómica. Estas herramientas asumen habitualmente la forma de modelos de planeamiento óptimo. En términos generales, los modelos de planeamiento con...
Typical Fruit Industry Supply Chains are highly interconnected networks conformed by farms, packa... more Typical Fruit Industry Supply Chains are highly interconnected networks conformed by farms, packaging plants, cold storage facilities and concentrated juice plants along with clients and third party raw material and services suppliers. The operational planning of such a chain should seek to respond to the before-the-season established product delivery commitments rather than to react in the face of “on-line” customer
ABSTRACT The spread of infections is commonly represented through the so-called Susceptible – Inf... more ABSTRACT The spread of infections is commonly represented through the so-called Susceptible – Infectious – Recovered models (SIR). Treatment based on isolation of infected individuals is often applied to decrease the spread of certain diseases. Such situation is considered in the SIR model through a constant removal rate term. It has been shown that in such cases, the outcome of the disease spread may depend on the position of the initial states for certain range of the model parameters. The estimation of the domains of attraction of the equilibrium points may therefore be useful to understand the dynamic behavior of the infection spread as a function of the initial population distribution. In this contribution, a Lyapunov based approach to estimate the domain of attraction of the endemic steady state point in SIR models is proposed.
The production of fresh fruit (apples and pears) and concentrated juice is one of the major regio... more The production of fresh fruit (apples and pears) and concentrated juice is one of the major regional economic activities of Argentina, which has traditionally been one of the world’s main fresh fruit and concentrated juice producers. Due to market reasons, there is a strong need to count with reliable decision tools to manage the whole business. In order to tackle
ABSTRACT Design-for-operability is a field of active research in process systems engineering beca... more ABSTRACT Design-for-operability is a field of active research in process systems engineering because of the high economic impact of design on operability. Dynamic operability has been widely studied by means of the so-called (open-loop) controllability and resiliency indices, which are mostly based on linearized (Laplace/frequency domains) models of the dynamic systems. In particular, the minimum singular value of the transfer function matrix is a fair measure of resilience to disturbances. Among the plethora of approaches to design for dynamic operability, a multiple-objective formulation between cost and controllability naturally arises because of the conflicting characters of the two objectives. In this contribution the cost/minimum-singular-value multiple-objective design problem is solved for the meaningful reactor−separator−recycle system and two different control strategies. The generation of the noninferior solution set is performed here within the framework of an eigenvalue optimization approach.
ABSTRACT In this paper, an optimization-based methodology is applied to the design of a reactor–s... more ABSTRACT In this paper, an optimization-based methodology is applied to the design of a reactor–separator–recycle system based on a measure of the extension of the domain of attraction of the operating equilibrium. The approach consists in maximizing the radius of a ball in the state space contained in the region of negative definiteness of the time derivative of a quadratic Lyapunov function. A two-level optimization strategy is proposed that solves a deterministic nonconvex global optimization problem at the inner level. To cope with the non-differentiability introduced by the inner problem, we applied a stochastic algorithm to manipulate the design variables at the outer level.
The Tennessee Eastman Challenge Process (TECP) represents an interesting case study within PSE fo... more The Tennessee Eastman Challenge Process (TECP) represents an interesting case study within PSE for process control and process optimization purposes. It has been widely addressed by the chemical engineering research community since its publication. The TECP is an open-loop unstable recycle reactor. The eigenvalues of the Jacobean matrix of the system at the base-case steady-state conditions, range from –1968 to +3.07. In absence of feed-back, small perturbations cause large transients reaching shut-down limits within an hour. Operation at open-loop unstable steady-states, even if feasible with feed-back control, is undesirable and should be avoided by proper design. In this contribution, the re-design problem of the TECP is addressed in order to generate an open-loop stable operating condition, by making use of eigenvalue optimization techniques. The objective is to find a new steady state point, such that the whole spectrum of the Jacobean matrix of the system lies in the left half...
In the last decades the chemical engineering scientific research community has largely addressed ... more In the last decades the chemical engineering scientific research community has largely addressed the design-for-operability problem. Such an interest responds to the fact that the operability quality of a process is determined by design, becoming evident the convenience of considering operability issues in early design stages rather than later when the impact of modifications is less effective and more expensive. The necessity of integrating design and operability is dictated by the increasing complexity of the processes as result of progressively stringent economic, quality, safety and environmental constraints. Although the design-for-operability problem concerns to practically every technical discipline, it has achieved a particular identity within the chemical engineering field due to the economic magnitude of the involved processes. The work on design and analysis for operability in chemical engineering is really vast and a complete review in terms of papers is beyond the scope...
La actividad agronómica actual presenta importantes desafíos asociados a la compleja ecuación cos... more La actividad agronómica actual presenta importantes desafíos asociados a la compleja ecuación costo/beneficio de la producción primaria y al creciente impacto ambiental resultante del empleo intensivo de agroquímicos. El SO Bonaerense, evidencia marcadas limitaciones agroecológicas asociadas a problemas de erosión eólica de diversa magnitud y a la irregularidad en el patrón anual de precipitaciones.
Avena fatua is an invasive weed affecting winter cereal crops of the semiarid temperate region of... more Avena fatua is an invasive weed affecting winter cereal crops of the semiarid temperate region of Argentina. Seedling emergence patterns show great variability between years mainly due to a highly unpredictable annual precipitation regime and a fluctuating thermal environment. Artificial feedforward neural networks (AFNN) are powerful tools for modeling non-linear relationships between variables thus showing a high potential applicability in ecological systems [1]. The quality of AFNN models depends on a proper setting of neural network architecture and other influential parameters (i.e. learning algorithm, transfer functions, number of neurons in hidden layers, etc.) [2]. The objective of the present work was to compare different AFNN architectures in order to obtain a model with the best capability to predict the proportion of daily emerged seedlings in the field as a function of meteorological data. Three input variables were considered for the network configuration: time (Julian...
La actividad agronómica actual presenta importantes desafíos asociados a la compleja ecuación cos... more La actividad agronómica actual presenta importantes desafíos asociados a la compleja ecuación costo/beneficio de la producción primaria y al creciente impacto ambiental resultante del empleo intensivo de agroquímicos. La zona del sudoeste de la provincia de Buenos Aires, en especial la región semiárida templada, evidencia una declinación progresiva de las pequeñas y medianas empresas debido a la imprevisibilidad del mercado agropecuario, el aumento de los costos de producción y la necesidad de incrementar la superficie de producción, a fin de poder disponer de una unidad económicamente rentable. La complejidad del contexto socio-económico expuesto, plantea un escenario donde la disponibilidad de herramientas computacionales de asistencia en la toma de decisiones podría jugar un rol fundamental en los diversos sistemas de la producción agronómica. Estas herramientas asumen habitualmente la forma de modelos de planeamiento óptimo. En términos generales, los modelos de planeamiento con...
Typical Fruit Industry Supply Chains are highly interconnected networks conformed by farms, packa... more Typical Fruit Industry Supply Chains are highly interconnected networks conformed by farms, packaging plants, cold storage facilities and concentrated juice plants along with clients and third party raw material and services suppliers. The operational planning of such a chain should seek to respond to the before-the-season established product delivery commitments rather than to react in the face of “on-line” customer
ABSTRACT The spread of infections is commonly represented through the so-called Susceptible – Inf... more ABSTRACT The spread of infections is commonly represented through the so-called Susceptible – Infectious – Recovered models (SIR). Treatment based on isolation of infected individuals is often applied to decrease the spread of certain diseases. Such situation is considered in the SIR model through a constant removal rate term. It has been shown that in such cases, the outcome of the disease spread may depend on the position of the initial states for certain range of the model parameters. The estimation of the domains of attraction of the equilibrium points may therefore be useful to understand the dynamic behavior of the infection spread as a function of the initial population distribution. In this contribution, a Lyapunov based approach to estimate the domain of attraction of the endemic steady state point in SIR models is proposed.
The production of fresh fruit (apples and pears) and concentrated juice is one of the major regio... more The production of fresh fruit (apples and pears) and concentrated juice is one of the major regional economic activities of Argentina, which has traditionally been one of the world’s main fresh fruit and concentrated juice producers. Due to market reasons, there is a strong need to count with reliable decision tools to manage the whole business. In order to tackle
ABSTRACT Design-for-operability is a field of active research in process systems engineering beca... more ABSTRACT Design-for-operability is a field of active research in process systems engineering because of the high economic impact of design on operability. Dynamic operability has been widely studied by means of the so-called (open-loop) controllability and resiliency indices, which are mostly based on linearized (Laplace/frequency domains) models of the dynamic systems. In particular, the minimum singular value of the transfer function matrix is a fair measure of resilience to disturbances. Among the plethora of approaches to design for dynamic operability, a multiple-objective formulation between cost and controllability naturally arises because of the conflicting characters of the two objectives. In this contribution the cost/minimum-singular-value multiple-objective design problem is solved for the meaningful reactor−separator−recycle system and two different control strategies. The generation of the noninferior solution set is performed here within the framework of an eigenvalue optimization approach.
ABSTRACT In this paper, an optimization-based methodology is applied to the design of a reactor–s... more ABSTRACT In this paper, an optimization-based methodology is applied to the design of a reactor–separator–recycle system based on a measure of the extension of the domain of attraction of the operating equilibrium. The approach consists in maximizing the radius of a ball in the state space contained in the region of negative definiteness of the time derivative of a quadratic Lyapunov function. A two-level optimization strategy is proposed that solves a deterministic nonconvex global optimization problem at the inner level. To cope with the non-differentiability introduced by the inner problem, we applied a stochastic algorithm to manipulate the design variables at the outer level.
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Papers by Anibal Blanco