Large qualitative models of complex chemical and bioengineering processes

1991 ◽  
Vol 56 (10) ◽  
pp. 2107-2141 ◽  
Author(s):  
Mirko Dohnal

Qualitative model is a theoretical background of commonsense. Complex qualitative models can have prohibitively many solutions (qualitative states). Therefore a qualitative analogy of such classical quantitative tools as e.g. the decomposition is developed. Practical applications of decomposition principle is nearly always ad hoc. Therefore two case studies are presented in details, a chemical process (mixer, chemical reactor, separator) and an anaerobic fermentor.

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 949
Author(s):  
Tomasz Okon ◽  
Kazimierz Wilkosz

The paper deals with voltage profiles in a power system. The analysis of these profiles is important due to the requirement that the Root-Mean-Squared (RMS) values of nodal voltages should be within certain ranges, as well as to ensure desired power flows in a power system. In both cases, it is desirable to indicate points in a power system where it is reasonable to apply remedial measures to meet the requirements for RMS values of nodal voltages, or to effectively control the power flows in a power system. In general, candidate nodes for remediation are established based on operational experience or measurement data from a certain time point (sometimes from several time points). The paper presents a method that provides a basis for determining the aforementioned candidate nodes based on the behavior of a system over a certain period of time, which is an unquestionable advantage of this proposal. In order to achieve the abovementioned goal, the method provides for the analysis of propagation of voltage RMS value deviations in a power system. The analysis of correlational relationships between the RMS values of nodal voltages is used for this. After presentation of the theoretical background, the new original method is described in the paper. Then, case studies showing the utilization of that method are presented. At the end of the paper, features of the proposed method are enumerated.


Author(s):  
Katarzyna Cegiełka ◽  
Piotr Dniestrzański ◽  
Janusz Łyko ◽  
Arkadiusz Maciuk ◽  
Maciej Szczeciński

AbstractOne of the main problems of practical applications of degressively proportional allocations of goods and burdens is lack of uniqueness of this principle. Even under given boundary conditions of allocation, i.e. determined minimal and maximal amounts of a good that can be assigned in a given allocation, there are usually many feasible solutions. The lack of formal rules of allocation is the reason why the allocation is typically a result of negotiations among its agents. A number of allocations favor some of agents or their groups, therefore other agents cannot accept them. The aim of this paper is to indicate a way of reducing the set of all feasible solutions exclusively to those that are neutral to all agents. As a result of the term of lexicographic preference of allocation agents defined on the basis of the relation theory followed by a numerical analysis of sets of all feasible solutions, it is possible to determine a core of this set in the form of a subset of all feasible solutions that are acceptable by all agents. In addition, this subset can be further divided into smaller subsets with regard to the degree of acceptance of their elements. Theoretical analysis is complemented by case studies, one of which is application of this idea to the allocation of seats in the European Parliament among the member states of the European Union.


MRS Bulletin ◽  
1993 ◽  
Vol 18 (7) ◽  
pp. 29-34 ◽  
Author(s):  
Shuichi Iwata

One of the requirements for an intelligent system is to construct a virtual reality in the computer. For materials development, the “reality” is a laboratory or a production line used to improve some aspect of a material by changing its composition, processing parameters, service conditions, etc. In the case of information in libraries, the reality is a search that uses a thesaurus and bibliographic (fact) databases. The greatest barrier faced by users of materials information is that of accessing necessary information through both a librarian's view and a scientific/technological expert's view. One of the objectives of a virtual production line is to reduce this barrier through user-friendly interfaces.In designing materials, two typical approaches are combined to solve a given problem. The first is a top-down approach, in which a number of requirements are resolved to a set of possible and practical solutions for satisfying these requirements to a certain level. Almost all alloy development has followed such an approach. The second approach is a bottom-up approach, where different materials properties are described on the basis of underlying theories, preferably using first principles and fundamental data. But the vast number of possible materials makes the bottom-up approach unrealistic on its own. Instead, semi-empirical approaches are needed to bridge the gap between ad hoc data sets for practical applications and results produced by the bottom-up approach using fundamental data and first-principle calculations.


2018 ◽  
Vol 12 (1) ◽  
pp. 19-35
Author(s):  
Cam Thi Hong Khuong ◽  
Ly Thi Tran

Purpose Tourism is one of the most notable features of the contemporary globalised world. The tourism industry is becoming increasingly vital to the economy of many developing and developed countries around the globe. The demand of the tourism industry has posed a challenge for tourism training providers to move towards a more responsive and internationalised curriculum to enhance work readiness for tourism graduates who are expected to work with an increased number of international tourists. The purpose of this paper is analyse whether and how internationalisation has been implemented in the tourism training programmes across six institutions in Vietnam. Design/methodology/approach The research deployed case studies as research strategy with interviews and document analysis as two instruments of data collection. Findings The major findings show that even though the tourism industry demands graduates to possess global competency, knowledge and skills, the curriculum does not prioritise the internationalisation dimensions and the faculty members are not facilitated to be internationally active in their roles. Overall, internationalisation is still fragmented and ad hoc in these institutions even though the private institutions in this research appear to be more responsive to the trend of internationalisation in education than their public counterparts. Research limitations/implications The paper provides recommendations on how to effectively embed internationalisation components into local tourism training programs in Vietnam. Originality/value The research bridges the gap in the literature on internationalisation of the local tourism programme in non-English-speaking countries.


2014 ◽  
Vol 17 (4) ◽  
pp. 319-335 ◽  
Author(s):  
Alessio Cavicchi ◽  
Cristina Santini ◽  
Lucia Bailetti

Purpose – This purpose of this paper is to introduce a research model inspired by the basic principles of experiential research and apply it to the food and beverage industry. Thinkers and doers often do not speak the same language: many scholars have pursued the goal of reducing the gap between academicians and practitioners by introducing new research models or adapting existing ones. Two case studies with wine and olive oil producers illustrate how the model works and highlight its applicability. Background literature is provided to support the model. Design/methodology/approach – In defining the model, we have followed several steps. First, we searched the literature to identify research needs and insights that might be useful in formulating the model. Second, we constructed a model following some procedural steps suggested in the literature. Third, we tested a model to verify its applicability and functionality. The paper is structured as follows: the first section explores the issue of academic–practitioner collaboration to identify the obstacles to effective collaboration and to define possible benefits from reducing the gap. The second section presents background literature on methodologies for enhancing cross-profession collaboration. Finally, the model is described and two case studies are described to flesh out how the model works. Findings – According to our experience and research results, this model is, paraphrasing Phillips (1987), “warrantable” because it proposes continuous reflection to improve the alignment between thinkers and doers: this method of conducting research is objective and bridges the gap between researchers and practitioners. Because this model centres on experience, participant behaviours and beliefs can be elicited about a host of nondurable goods. Having entrepreneurs put themselves in the consumers’ position, and providing them the results of their experiment can be considered the real value added of this approach. The model proposed in this paper opens a wider perspective in qualitative research, and the two case studies demonstrate that it is particularly flexible for adaptation to various businesses. Research limitations/implications – More case studies could be useful to demonstrate the validity of this model. Particularly, a longitudinal case study aiming at collecting data about the participants’ feedback in the long run could help in understanding the deep value of the proposed model. Practical implications – While this paper illustrates two applications of the model with entrepreneurs and managers of the wine and olive oil industry, this model offers potential for analysis not only in the food and beverage sector but all fast-moving consumer goods sectors, as it can be adapted to techniques other than sensory analysis once researchers have confirmed that they fit with the aim of the research and the peculiarities of the problem observed. Social implications – Tools and methodologies must be chosen according to the type of business the problem refers to, and, while this presents a considerable challenge in organizing ad hoc research teams, it also offers an opportunity for an interdisciplinary approach and an exchange of knowledge and skills from different research fields. In this case, the choice of research methodology is much more driven by the real needs that emerge from the phenomenon observed, rather than by the researchers’ specific skills. Originality/value – This paper has helped us broaden our perspective on research and has encouraged us to reflect on critical issues such as validity of a research process and usefulness of research. Some questions about the role of research in relation to practitioners are still open, but we think that this work has the merit of further highlighting the importance of bridging the gap between researchers and practitioners during research, and the usefulness being flexible and open-minded when carrying out an investigation.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1274-C1274
Author(s):  
Annalisa Guerri ◽  
Giovanna Scapin ◽  
Paola Spadon

2014 has been declared by UNESCO the International Year of Crystallography. Following the declaration, many initiatives have flourished with the intent of spreading the science and culture of crystallography, since among the major objectives of the IYCr2014 are increase of public awareness on the science of crystallography, promotion of education and research in all fields of crystallography and fostering of international collaborations. The International School of Crystallography is an internationally recognized meeting that was started in 1974 by Prof. Riva di Sanseverino, with the similar goals of promoting high level crystallographic education, scientific exchanges and collaborations. In 2014 the school celebrates its 40th year of activity. During these forty years, courses have been held on many different topics addressing all aspects of crystallography, from crystal growth theory to practical applications in drug discovery to the use of cutting edge technologies; students and teachers have been brought together in an environment that fostered high level scientific discussions as well as unique interpersonal relationships. Many of the students moved on to become well known personality in the crystallographic community, while retaining collaborations and friendships started during the School. Through these years the School teaching methods have also evolved, taking advantage of the fast technological progress of the past 10 years or so. The School offers both traditional lectures and practical computer-based workshops, to guarantee the students not only a theoretical background, but also hands-on experiences on applied crystallography. The dedication of the organizers and lecturers, the unconditioned support of the local staff, and the unique location of the School have made it a great success and a very popular meeting for generations of crystallographers.


2015 ◽  
Vol 34 (3) ◽  
pp. 260-267 ◽  
Author(s):  
Štěpán Veselý ◽  
Mirko Dohnal

Abstract The paper presents a simple qualitative model of environmental consequences of wildlife tourism. Qualitative models use just three values: Positive/Increasing, Zero/Constant and Negative/Decreasing. Such quantifiers of trends are the least information intensive. Qualitative models can be useful, since models of wildlife tourism include such variables as, for example, Biodiversity (BIO), Animals’ habituation to tourists (HAB) or Plant composition change (PLA) that are sometimes difficult or costly to quantify. Hence, a significant fraction of available information about wildlife tourism and its consequences is not of numerical nature, for example, if HAB is increasing then BIO is decreasing. Such equationless relations are studied in this paper. The model has 10 variables and 20 equationless pairwise interrelations among them. The model is solved and 15 solutions, that is, scenarios are obtained. All qualitative states, including the first and second qualitative derivatives with respect to time, of all variables are specified for each scenario.


This volume offers a range of synchronic and diachronic case studies in comparative Germanic and Romance morphosyntax. These two language families, spoken by over a billion people today, have been of central importance throughout the development linguistics, yet many significant questions about the relationship between the two families remain. Following an introduction that sets out the methodological, empirical, and theoretical background to the book, the volume is divided into three parts which deal with the morphosyntax of subjects and the inflectional layer inversion, discourse pragmatics, and the left periphery, and continuity and variation beyond the clause. The approaches used by the authors of individual chapters are diverse, making use of the latest digitized corpora and presenting a mixture of well-known and understudied data from standard and non-standard Germanic and Romance languages. Many of the chapters challenge received wisdom about the relationship between these two important language families. This volume will be an indispensable tool to researchers and students in Germanic and Romance linguistics, historical linguistics, grammatical theory, and language relationships.


2021 ◽  
pp. 1-53
Author(s):  
Mitchell R. Grams ◽  
Patricio F. Mendez

Abstract Manufacturing processes involving moving heat sources include additive manufacturing, welding, laser processing (cladding and heat treatment), machining, and grinding. These processes involve high local thermal stresses that induce plasticity and result in permanent residual stress and distortion. The residual stresses are typically calculated numerically at great computational expense despite the fact that the inelastic fraction of the domain is very small. Efforts to decouple the small plastic part from the large elastic part have led to the development of the tendon force concept. The tendon force can be predicted analytically for the case of infinitely rigid components; however, this limitation has prevented the broader use of the concept in practical applications. This work presents a rigorous mathematical treatment using dimensional analysis, asymptotics, and blending which demonstrates that the effect of geometric compliance depends on a single dimensionless group, the Okerblom number. Closed-form expressions are derived to predict the effect of compliance without the need for empirical ad-hoc fitting or calibration. The proposed expressions require input of only material properties and tabulated process parameters, and are thus ideally suited for use in metamodels and design calculations, as well as incorporation into engineering codes and standards.


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