Industrial manufacture of sugar-free chocolates: applicability of alternative sweeteners and carbohydrate polymers as raw materials in product development

Chocolate is dense suspension of solid particles comprising 60-70% sugar and non-fat cocoa solids. Until recently, it was rarely produced as a sugar-free product due to the multi-functional properties of sweetness, bulkiness and textural characteristics that sugar offers to products. Today's consumers are concerned about the high sugar levels, calories and cariogenicity effects in confectionery products, hence increasing popularity of 'light' and 'sugar-free' products. Development of sugar-free chocolates is most challenging since all sugar needs to be replaced. In-depth understanding of the applicability of alternative sweeteners and carbohydrate polymers as ingredients in sugar-free chocolate manufacture would therefore have significant industrial applications

Harmonic generation in gases using Bessel-gauss beams

The generation and propagation of harmonics in an atomic gas are described for the case of an incident Bessel-Gauss beam. Theoretical expressions are derived for the far-field amplitude of the harmonic field by solving the propagation equation using an elaborate integral formalism. We establish simple rules which determine the optimum Bessel-Gauss beam with respect to phase-matching as a function of the medium properties, such as the dispersion and the gas density. Target depletion due to photoionization and refractive index variations originating from both free electrons and dressed linear atomic susceptibilities are taken into account. The intensity-dependent complex atomic dipole moment is calculated using nonpertur- bative methods. Numerical propagation calculations for hydrogen, xenon and argon are presented. For hydrogen we consider the third harmonic of a 355-nm, 15-ps pump beam up to 3 X 10(^13) W/cm(^2) intensity, similarly for xenon, but at lower intensities. For argon we consider the 17th and 19th harmonic of a 810-nm, 30-fs pump beam around 10(^14) W/cm(^2) intensity. We compare conversion efficiencies and both spatial and temporal far-field profiles for an optimized Bessel-Gauss beam with respect to a Gaussian beam of same power and/or peak focal intensity. For the case of hydrogen, we investigate the effect of an ac-Stark-shift induced atomic resonance. We find all results in good agreement with our theoretical predictions. We conclude from our studies that Bessel-Gauss beams can perform better in terms of conversion efficiency than a comparable Gaussian beam. We find this to originate essentially from the more flexible phase-matching conditions for Bessel-Gauss beams. Bessel-Gauss beams also allow for spatial separation of the harmonic and the incident field in the far-field region, owing to the conical shape of their spatial far-field profile. Both features make Bessel-Gauss beams an attractive alternative to Gaussian beams in a limited but substantial number of experimental conditions

Temporal Constraint Satisfaction Problems and Difference Decision Diagrams: A Compilation Map

International audienceThe frameworks dedicated to the representation of quantitative temporal constraint satisfaction problems, as rich as they are in terms of expressiveness, define difficult requests - typically NP-complete decision problems. It is therefore adventurous to use them for an online resolution. Hence the idea to compile the original problem into a form that could be easily solved. Difference Decision Diagrams (DDDs) have been proposed by [1] as a possible way to cope with this difficulty, following a compilation-based approach. In this article, we draw a compilation map that evaluates the relative capabilities of these languages (TCSP, STP, DTP and DDD) in terms of algorithmic efficiency, succinctness and expressiveness

Four archetypes of process improvement: a Q-methodological study

This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Production Research on 11/07/2014, available online: http://www.tandfonline.com/doi/full/10.1080/00207543.2013.867086This paper explores the process improvement approaches of organisations. It seeks to identify process redesign principles and the combinations of these principles that are used successfully in industry. We use Q-methodology to explore the viewpoints of a range of highly-experienced process experts about the success of 16 improvement practices. Q-methodology enables the examination of the similarities and differences in the success of the improvement principles used by organisations in order to inform archetypes of process improvement. Overall, our findings suggest that process improvement is determined through the application of two foundational principles combined with one of four archetypes. ‘Remove non-value-adding tasks’ and ‘re-sequence tasks’ are described as foundational principles of process improvement, whilst outsourcing needs to be approached with caution. Furthermore, we articulate four distinctive archetypes comprising unique configurations of improvement principles that can be used to redesign operational processes. Based on this evidence we propose a typology of process improvement. This work suggests that rather than adopting generic improvement frameworks, managers should consult the typology to determine the archetype in closest proximity to their specific requirements. This study has several limitations including the small number of items populating the concourse and the fact that implementation problems are not taken into account

Service delivery system design: characteristics and contingencies

publication-status: Publishedtypes: ArticleThis is an Accepted Manuscript of an article published in International Journal of Operations & Production Management, Vol. 31 (3), pp.324 – 349. DOI: 10.1108/01443571111111946 "This article is (c) Emerald Group Publishing and permission has been granted for this version to appear here: https://ore.exeter.ac.uk/repository/. Emerald does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Emerald Group Publishing Limited."Purpose: The aim of this paper is to explore and empirically investigate the characteristics and contingencies of service delivery system design. Design/methodology/approach: Informed by the service strategy triad, a single embedded case study was designed to explore empirical data on four target markets, four service concepts, and on the design characteristics of the corresponding four service delivery systems. Data was collected in a market leading organisation in the B2B sector within the power industry. The service delivery systems comprise processes that sell electricity contracts and processes that bill against those contracts. Findings: First, the findings indicate what design characteristics are contingent upon the degree of customisation of the service concept. We show how this contingency has implications for the extents of employee skills, employee discretion, task routineness, automation, and for front office – back office configurations. Second, we challenge the consensus that low customer-contact processes are designed for the purpose of efficiency. Third, our findings contradict Metters and Vargas (2000) who state that it is not possible to have different front office – back office configurations in a single organisation. Research limitations/implications: While there are major interactions between the four service delivery systems supporting each individual service concept, this research does not examine the trade-offs between the various possible designs of these service delivery systems. Practical implications: The study emphasises the importance of considering the complexity of the service offering, the customer relationship strategy, and of taking a process-orientation to address service delivery system design

Process design principles in service firms: Universal or context dependent? A literature review and new research directions

publication-status: Acceptedtypes: ArticleThis is an Accepted Manuscript of an article published by Taylor & Francis Group in Total Quality Management & Business Excellence on 16/01/2012, available online: http://www.tandfonline.com/doi/abs/10.1080/14783363.2011.637797#.VGxftZ1FDcsThe aim of this article is to assess whether process design principles derived from best practices are universally applicable to service organisations or context dependent. This is achieved through a comprehensive review of the business process management (BPM) and operations management (OM) literatures. Our comparison of the existing bodies of knowledge in these disciplines reveals major inconsistencies in how the topic of process design in service environments is addressed. Drawing on the more mature, contingency-oriented OM literature, we challenge the BPM discipline which prescribes that process design principles derived from best practices are universally applicable irrespective of the context in which the service organisation operates. The results strongly suggest that in the business process design area one size does not fit all service organisations and that some design principles fit better under certain contextual conditions. We then use these findings to develop a contingency conceptual framework and associated research propositions linking the firm's service strategy context to the use of particular business process design principles. This extends existing theory and provides a platform for future process design research in service organisations that is more closely aligned with the needs of practitioners

Context Aware Model-Checking for Embedded Software

Reactive systems are becoming extremely complex with the huge increase in high technologies. Despite technical improvements, the increasing size of the systems makes the introduction of a wide range of potential errors easier. Among reactive systems, the asynchronous systems communicating by exchanging messages via buffer queues are often characterized by a vast number of possible behaviors. To cope with this difficulty, manufacturers of industrial systems make significant efforts in testing and simulation to successfully pass the certification process. Nevertheless revealing errors and bugs in this huge number of behaviors remains a very difficult activity. An alternative method is to adopt formal methods, and to use exhaustive and automatic verification tools such as model-checkers. Model-checking algorithms can be used to verify requirements of a model formally and automatically. Several model checkers as (Berthomieu et al., 2004; Holzmann, 1997; Larsen et al., 1997), have been developed to help the verification of concurrent asynchronous systems. It is well known that an important issue that limits the application of model checking techniques in industrial software projects is the combinatorial explosion problem (Clarke et al., 1986; Holzmann & Peled, 1994; Park & Kwon, 2006). Because of the internal complexity of developed software, model checking of requirements over the system behavioral models could lead to an unmanageable state space. The approach described in this chapter presents an exploratory work to provide solutions to the problems mentioned above. It is based on two joint ideas: first, to reduce behaviors system to be validated during model-checking and secondly, help the user to specify the formal properties to check. For this, we propose to specify the behavior of the entities that compose the system environment. These entities interact with the system. Their behaviors are described by use cases (scenarios) called here contexts. They describe how the environment interacts with the system. Each context corresponds to an operational phase identified as system initialization, reconfiguration, graceful degradation, etc.. In addition, each context is associated with a set of properties to check. The aim is to guide the model-checker to focus on a restriction of the system behavior for verification of specific properties instead on exploring the global system automaton

Automatic insertion of a turbulence model in the finite element discretization of the Navier-Stokes equations

International audienceWe consider the finite element discretization of the Navier--Stokes equations locally coupled with the equation for the turbulent kinetic energy through an eddy viscosity. We prove a posteriori error estimates which allow to automatically determine the zone where the turbulent kinetic energy must be inserted in the Navier--Stokes equations and also to perform mesh adaptivity in order to optimize the discretization of these equations. Numerical results confirm the interest of such an approach