Flexible Recipe Research Articles

Use-up day and flexible recipes: Reducing household food waste by helping families prepare food they already have

In two 5-week randomized-controlled field studies, Canadian and US households were invited to make one meal per week from food that might otherwise be discarded, using flexible recipes. In the first study (Canada), tools to increase the salience of unused food (storage basket, clips to tag, or whiteboard) were also explored. A second study (US) examined a shorter program and the addition of follow-up reminders. Food waste was assessed with a self-reported food waste measure. Intervention groups reduced their food waste significantly versus baseline by 33% (Canada) and 46% (US) and versus control by 27% (Canada) and 33% (US). The salience tools (study 1) or duration (study 2) had no impact. Eight weeks after the intervention food saving continued although the intervention conditions no longer differed significantly from control. In the US, change in Perceived Behavioral Control partially mediated the impact of the intervention on food waste reduction.

Within-Firm Productivity Dispersion: Estimates and Implications

This paper develops a flexible recipe for identifying unobserved input allocations, as well as quantity- and revenue-based total factor productivity (TFP) across product lines, for multiproduct producers, using demand- and supply-side information. Applying variants of this recipe to a panel of plants manufacturing machinery in India from 2000–2007 yields sizable within-plant TFP differences. Removing an average plant’s lowest-performing product increases the unweighted average of plant-level revenue-based productivity by 10%–65%. A 1 standard deviation decline in product-level revenue-based TFP generates around a 6 percentage point increase in the probability of dropping that product.

So You’ve Provincialized the Canon. Now What?

Sociologists are engaging in a long-overdue reckoning about the place of the traditional canon in social theory courses and pedagogy. Instructors are revising their syllabi to include a more diverse set of authors while “provincializing” classics that have long been taught as universal. We confront the question of how to teach contested canonical works after an instructor has committed to this work. We argue that progressive reforms to theory syllabi can raise new problems associated with teaching “canonical” works and propose one way to address them with a flexible recipe designed to resolve tensions between pedagogical imperatives. An extended example from our experience teaching Durkheim’s The Elementary Forms of Religious Life is employed to illustrate our proposal. Our aim is to contribute to an ongoing disciplinary dialogue that will maintain theory’s central place in sociology’s identity while constantly asking what, and whom, it is for.

Which attenuation curves for star-forming galaxies?

AbstractDust attenuation shapes the spectral energy distributions of galaxies and any modelling and fitting procedure of their spectral energy distributions must account for this process. We present results of two recent works dedicated at measuring the dust attenuation curves in star forming galaxies at redshift from 0.5 to 3, by fitting continuum (photometric) and line (spectroscopic) measurements simultaneously with CIGALE using variable attenuation laws based on flexible recipes. Both studies conclude to a large variety of effective attenuation laws with an attenuation law flattening when the obscuration increases. An extra attenuation is found for nebular lines. The comparison with radiative transfer models implies a flattening of the attenuation law up to near infrared wavelengths, which is well reproduced with a power-laws recipe inspired by the Charlot and Fall recipe. Here we propose a global modification of the Calzetti attenuation law to better reproduce the results of radiative transfer models.

Flexible Recipe Method and Decomposition Algorithm for Integrating Production Operations and Dynamic Optimization of Continuous Manufacturing Processes

Flexible Recipe Method and Decomposition Algorithm for Integrating Production Operations and Dynamic Optimization of Continuous Manufacturing Processes

Novel Optimization Model and Efficient Solution Method for Integrating Dynamic Optimization with Process Operations of Continuous Manufacturing Processes

In this paper, we propose a novel mathematical model for the integrated optimization for production planning, scheduling, and dynamic optimization of continuous manufacturing processes. With a novel approach to estimate the inventory cost, the integrated problem is first formulated as a mixed-integer dynamic optimization (MIDO) problem, which is then reformulated into a large scale mixed-integer nonlinear program (MINLP). By using metamodeling to characterize the detailed linking information between different decision layers, we develop an efficient solution method to decompose the integrated MINLP into a mixed-integer linear program (MILP) for an integrated planning and scheduling problem with flexible recipes, and a set of dynamic optimization problems for generating metamodels. We further apply a bilevel decomposition algorithm to improve the computational efficiency of solving the integrated planning and scheduling problem with flexible recipes. The proposed models and algorithms are demonstrated through case studies of methyl methacrylate (MMA) polymerization processes. The results show that the proposed methods reduce the computational time by more than 2 orders of magnitude compared with the approach of solving the entire integrated optimization problem directly.

What is Arts Entrepreneurship? Tracking the Development of its Definition in Scholarly Journals

In this study, we investigate the ways in which arts entrepreneurship has been operationalized and defined in the literature. We identify eight scholarly journals in arts administration and policy, in business administration, and in nonprofit marketing published during 2003-2013 and review articles published in these journals. Our review found that the scholarly literature on arts entrepreneurship has in fact been quite scarce. We also examine all articles in Artivate, a journal that specializes in arts entrepreneurship. Taking the literature as a whole, we found a plethora of meanings used in the literature, indicating an, as yet, unsettled definition. We suggest that some analytical clarity can be obtained by grouping the many meanings of arts entrepreneurship into five analytical “levels”: Personal Character traits, Goals, Strategies, Tactics, and Context. We also suggest a possible general definition: “arts entrepreneurship” is a management process through which cultural workers seek to support their creativity and autonomy, advance their capacity for adaptability, and create artistic as well as economic and social value. This management process involves an ongoing set of innovative choices and risks intended to recombine resources and pursue new opportunities to produce artistic, economic, and social value. Identifying the emerging clusters from the meanings found in the literature, we conclude that to understand arts entrepreneurs, one must focus on the innovative combinations of strategy, individual skills, and mindset operating in each case of arts entrepreneurship and its context. As arts entrepreneurship is a constant exercise in recombination of skillsets, the possibility of flexible recipes begins to reveal what might be regarded as the recombinant DNA of arts entrepreneurship.

Implementation of a Process Orchestration Model in a Service Oriented Holonic Manufacturing System

Process models are usually represented by linear sequences, where the order of the conforming operations is fixed a priori. In a FMS, flexibility can be considered as proportional to the number of alternatives the system has when a decision needs to be made. Considering only flexibility related to the choice and the order in which the products are treated on machines is therefore limitative when the design of the products could enable flexible recipes, where groups of operations could be permuted according to the state of the system. The objective of this paper is to describe the implementation of service and process models as well as the orchestration of such processes at a product level.

Integrated Scheduling and Dynamic Optimization of Sequential Batch Processes with Online Implementation

An efficient decomposition method to solve the integrated problem of scheduling and dynamic optimization for sequential batch processes is proposed. The integrated problem is formulated as a mixed‐integer dynamic optimization problem or a large‐scale mixed‐integer nonlinear programming (MINLP) problem by discretizing the dynamic models. To reduce the computational complexity, we first decompose all dynamic models from the integrated problem, which is then approximated by a scheduling problem based on the flexible recipe. The recipe candidates are expressed by Pareto frontiers, which are determined offline by using multiobjective dynamic optimization to minimize the processing cost and processing time. The operational recipe is then optimized simultaneously with the scheduling decisions online. Because the dynamic models are encapsulated by the Pareto frontiers, the online problem is a mixed‐integer programming problem which is much more computationally efficient than the original MINLP problem, and allows the online implementation to deal with uncertainties. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2379–2406, 2013

Managing risk through a flexible recipe framework

Managing risk through a flexible recipe framework

Managing risk through a flexible recipe framework

AbstractA novel approach is proposed that exploits the use of a flexible recipe framework as a better way to handle the risk associated with the scheduling under uncertainty of batch chemical plants. The proposed solution strategy relies on a novel two‐stage stochastic formulation that explicitly includes the trade‐off between risk and profit at the decision‐making level. The model uses a continuous‐time domain representation and the generalized notion of precedence. Management of risk is explicitly addressed by including a control measure (i.e., the profit in the worst scenario), as an additional objective to be considered, thus, leading to a multiobjective optimization problem. To overcome the numerical difficulties associated with such mathematical formulation, a decomposition strategy based on the sample average approximation (SAA) is introduced. The main advantages of this approach are illustrated through a case study, in which a set of solutions appealing to decision makers with different attitudes toward risk are obtained. The potential benefits of the proposed flexible recipe framework as a way of managing the risk associated with the plant operation under demand uncertainty are highlighted through comparison with the conventional approach that considers nominal operating conditions. Numerical results corroborate the advantages of exploiting the capabilities of the proposed flexible recipe framework for risk management purposes. © 2008 American Institute of Chemical Engineers AIChE J, 2008

Optimal Reactive Scheduling of Manufacturing Plants with Flexible Batch Recipes

The inherent dynamic nature of industrial environments often needs not only the cyclic revision of scheduling decisions (typical rescheduling actions) but also an efficient adjustment of the production recipe to the current process conditions. Therefore, the concept of flexible recipe becomes an important part of the rescheduling framework that allows full exploitation of the process flexibility in batch plants. This work introduces a rigorous mathematical approach that incorporates the concept of recipe flexibility to plantwide batch operation rescheduling. The proposed mixed-integer linear programming (MILP)-based approach is able to address the rescheduling problem of multistage, multipurpose batch plants involving different storage policies, nonzero transfer times, and flexible batch product recipes. This model relies on the concept of general precedence, which reduces the number of binary variables and, therefore, the computational effort. Flexible-recipe constraints are incorporated in this model to account for the possibility of changing the processing time of some tasks, tweaking the rest of the parameters of the product recipe. The cost for modifying these process variables from their optimal economic conditions is taken into account to represent how productivity is increased despite the cost of altering the nominal plant conditions. Different incidences, such as insertion of new orders, equipment failures, due-date changes, maintenance tasks, and delay in arrivals, variations in the cost, and quality of the raw materials or products, taking place throughout the scheduling horizon, are considered to evaluate the effectiveness of the proposed approach.

Influence of model validation on proper selection of process models—an industrial case study

This paper considers the design and validation of a model of an industrial batch process in TiO 2 production. The model will be used for flexible recipe control, which is a model-based approach used in control and optimisation of batch processes. Because of insufficient knowledge and a lack of proper data, different process models were developed: a semi-empirical dynamic model based on chemical kinetics laws, and several experimental black-box models. In the paper the models are validated and mutually compared. Validation of models has shown that besides comparing the model and the process output behaviour, additional measures considering also the model input error should be introduced for proper model validation related to the model use. In our case, introducing additional measures also contributed to improvement of the model design procedure, so that a simple yet satisfactory black-box model was obtained despite a small amount of process data.

A New Framework for Batch Process Optimization Using the Flexible Recipe

Batch processes are characterized by a high degree of flexibility that can be appropriately exploited to obtain a maximum production profit. In principle, the nominal production recipe assumes an optimum balance between quality and costs for batches of products. However, in practice, this optimum performance is achieved only when this balance is extended to management of the entire batch plant. In this work, a framework is presented that fully exploits this inner flexibility of batch processes at the plant level. The framework considers a batch recipe model that interacts with a plant-wide model to constitute the so-called flexible recipe model. First, the potential use of this framework is shown by integrating a general multipurpose batch process scheduling algorithm into a general linear recipe model. Next, this framework is illustrated in practice using a real industrial scenario that exhibits complex recipe behavior. Finally, the benefits of considering the flexible recipe concept for the scheduling of batch processes are discussed.

Experimental testing of flexible recipe control based on a hybrid model

Flexible recipe control is aimed at improving the performance of batch processes by changing the recipe parameters. Compensation is effected with the aid of the process model and optimisation. This strategy was used for the quality control of an industrial process in TiO 2 pigment production. The control algorithm was based on a hybrid model in order to use all the information about the process (knowledge, data, experience) and to design the model from a small number of real-plant experiments. When testing on the real process the algorithm was able to move the process output closer to the desired value.

Balancing stocks, flexible recipe costs and high service level requirements in a batch process industry: A study of a small scale model

Process industries often obtain their raw materials from mining or agricultural industries. These raw materials usually have variations in quality which often lead to variations in the recipes used for manufacturing a product. Another reason for varying the recipe is to minimize production costs by using the cheapest materials that still lead to a satisfactory quality in the product. A third reason for using recipe flexibility is that it may occur that not all materials for the standard recipe are available. If variations in supply and demand are large, keeping sufficient safety stock to cope with these variations may incur prohibitive high costs. This means that the costs of keeping safety stock should be balanced with the costs of sometimes using more expensive recipes. The question now is for what situations and to what extent the use of recipe flexibility is justified. In this paper we study this question by means of a small scale model. For this simple situation we derive a decision procedure to balance safety stock costs and flexibility costs. This procedure is applied to a range of different situations, that are characterized by a set of parameter values, in order to determine for which situations recipe flexibility should be used.

Integration of Business and Production Levels in Process Industries

Process control systems are operated more or less in isolation from business systems relating to the same plant. As the potential benefits of integration have become clearer. there have been several attempts to link process control and business control systems. One aspect of linking is described in this paper. A primary function of a process control system, which was in 1996 successfully installed in a Slovenian brick/work, is efficient control of the drying process in the factory. and so far this system is conceived as classic computer-based process control systenl. With regard to the possible need to incorporate this control system into a future CIM information system, a concept of flexible recipes was applied as a possible integration link between planning. which is a typical business-level activity, and process control which is a production-level activity. Flexible recipes thus may provide a modest contribution to the integration of shop floor control and logistical functions.

A Semi-Empirical and a Neural Network Model of a Batch Plant Dynamics for Flexible Recipes Control

In order to apply a model based control strategy such as flexible recipes control to an industrial batch process, a model of the process dynamics is needed. This paper presents the modelling procedure for two such models: a semi-empirical and an artificial neural network model. Both models predict precipitation rates of TiO2 particles in an industrial hydrolysis process. Model properties and their prediction accuracy is compared. The artificial neural network is trained using the augmented training data set approach. A simulator has been designed to study the application Of flexible recipe instructions.

Applying artificial neural network models to control a time variant chemical plant

Control of an industrial hydrolysis batch process using a model-based control strategy is described. For this purpose, non-linear artificial neural network models of the process dynamics are identified with the aid of a semi-empirical model. Neural networks are trained using an augmented training data set. Neural network models predict the TiO 2 precipitation rate for each batch. Using this prediction, some of the process parameters can be optimised through the application of the flexible recipes concept to control the quality of the intermediate product and the duration of each batch. A simulator has been designed to study the application of flexible recipe instructions. Different adaptation mechanisms which use on-line process measurements are discussed to improve model accuracy and to counteract changes in process dynamics.

Derivation of the Lattice Boltzmann Method by Means of the Discrete Ordinate Method for the Boltzmann Equation

In this note, we show that the lattice Boltzmann BGK method in common use can be derived from the Boltzmann equation itself. According to the present derivation, it is apparent that the equation thus derived can be reduced to the Navier-Stokes equation at a limit of small Knudsen number since the equation thus derived is the Boltzmann equation itself. Hence the present derivation method gives us a simple and flexible recipe to construct the lattice Boltzmann method, and makes it easy to construct an extended lattice Boltzmann method in various ways. 15 refs., 1 fig.