An unconditionally positive definite finite difference scheme termed as UPFD has been derived to approximate a linear advection-diffusion-reaction equation which models…
Abstract
Purpose
An unconditionally positive definite finite difference scheme termed as UPFD has been derived to approximate a linear advection-diffusion-reaction equation which models exponential travelling waves and the coefficients of advection, diffusion and reactive terms have been chosen as one (Chen-Charpentier and Kojouharov, 2013). In this work, the author tests UPFD scheme under some other different regimes of advection, diffusion and reaction. The author considers the case when the coefficient of advection, diffusion and reaction are all equal to one and also cases under which advection or diffusion or reaction is more important. Some errors such as L1 error, dispersion, dissipation errors and relative errors are tabulated. Moreover, the author compares some spectral properties of the method under different regimes. The author obtains the variation of the following quantities with respect to the phase angle: modulus of exact amplification factor, modulus of amplification factor of the scheme and relative phase error.
Design/methodology/approach
Difficulties can arise in stability analysis. It is important to have a full understanding of whether the conditions obtained for stability are sufficient, necessary or necessary and sufficient. The advection-diffusion-reaction is quite similar to the advection-diffusion equation, it has an extra reaction term and therefore obtaining stability of numerical methods discretizing advection-diffusion-reaction equation is not easy as is the case with numerical methods discretizing advection-diffusion equations. To avoid difficulty involved with obtaining region of stability, the author shall consider unconditionally stable finite difference schemes discretizing advection-diffusion-reaction equations.
Findings
The UPFD scheme is unconditionally stable but not unconditionally consistent. The scheme was tested on an advection-diffusion-reaction equation which models exponential travelling waves, and the author computed various errors such as L1 error, dispersion and dissipation errors, relative errors under some different regimes of advection, diffusion and reaction. The scheme works best for very small values of k as k → 0 (for instance, k = 0.00025, 0.0005) and performs satisfactorily at other values of k such as 0.001 for two regimes; a = 1, D = 1, κ = 1 and a = 1, D = 1, κ = 5. When a = 5, D = 1, κ = 1, the scheme performs quite well at k = 0.00025 and satisfactorily at k = 0.0005 but is not efficient at larger values of k. For the diffusive case (a = 1, D = 5, κ = 1), the scheme does not perform well. In general, the author can conclude that the choice of k is very important, as it affects to a great extent the performance of the method.
Originality/value
The UPFD scheme is effective to solve advection-diffusion-reaction problems when advection or reactive regime is dominant and for the case, a = 1, D = 1, κ = 1, especially at low values of k. Moreover, the magnitude of the dispersion and dissipation errors using UPFD are of the same order for all the four regimes considered as seen from Tables 1 to 4. This indicates that if the author is to optimize the temporal step size at a given value of the spatial step size, the optimization function must consist of both the AFM and RPE. Some related work on optimization can be seen in Appadu (2013). Higher-order unconditionally stable schemes can be constructed for the regimes for which UPFD is not efficient enough for instance when advection and diffusion are dominant.
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Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects…
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Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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The personnel function has not, in general, been involved in the high‐level strategic decision‐taking activities of the firm. This lack of involvement seems largely to be caused…
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The personnel function has not, in general, been involved in the high‐level strategic decision‐taking activities of the firm. This lack of involvement seems largely to be caused by an inability on the part of the personnel manager to present information regarding the enterprise in its labour market and by an inability on the part of general management to appreciate the significance of such information.
Lucrezia Songini, Chiara Morelli and Paola Vola
Notwithstanding the relevance of managerial control systems (MCS) in any organization, as well the distinctive role they can play in family business, due to its specific features…
Abstract
Notwithstanding the relevance of managerial control systems (MCS) in any organization, as well the distinctive role they can play in family business, due to its specific features, the literature rarely dealt with the role and characteristics of MCS in family business. Taking into account previous contributions from different disciplines (organization, management accounting, and family business), the current work aims to better understand the state of the art about research in the field of MCS in family business in order to identify main research gaps and propose future research directions.
Forty-five articles have been analyzed, which were issued in 29 sources. Research findings show that the literature on MCS in family business is limited and not very conclusive. Some authors focused on the type of controls, other authors outlined the role of MCS in managerialization and the relation with professionalization. A few studies focused on some specific mechanisms, especially strategic planning and compensation. Some contributes dealt with MCS’ determinants and impacts. Differences between family and non-family firms were proposed. However, a clear and organized picture of the features of MCS in family firms, their determinants, and impacts has not yet been developed. Particularly, the impact of the distinctive features of family business on MCS represents an underdeveloped research field along with how MCS can be differently developed and used in different kinds of family firms. In the light of findings of the literature review, we propose a reference research framework on MCS in family business.
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We deal here with some problems of superimposed random coding that arise when marking codes into the codefield. Our investigations are concerned with a general model. Systems used…
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We deal here with some problems of superimposed random coding that arise when marking codes into the codefield. Our investigations are concerned with a general model. Systems used in practice are special cases of this, and may be deduced from it by making appropriate simplifying assumptions. We give exact formulas for the distribution of the marked sites in a codefield and for the distribution of multiple marking of a site. These results are obtained by applying a general theorem in probability due to K. Jordan. Some acquaintance with superimposed random coding and knowledge of basic combinatorial and probability theory are assumed.
Loizos Heracleous and Luh Luh Lan
Concentrated ownership implies greater alignment between ownership and control, mitigating the agency problem. However, it may also engender governance challenges such as funds…
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Concentrated ownership implies greater alignment between ownership and control, mitigating the agency problem. However, it may also engender governance challenges such as funds appropriation through related party transactions and the oppression of minority shareholders, especially in the context of weak legal systems. We draw from legal theory (the tradeoff controlling shareholder model and private benefits of control) and from organization theory (socioemotional wealth), to suggest that concentrated ownership can be beneficial in both robust and weak legal systems for different reasons. We advance theory on the effects of controlling shareholders and suggest that the longer-term outlook associated with engaged concentrated ownership can aid the shift of the corporation toward Berle and Means' (1932, p. 355) “third possibility” of corporations serving the interests of not just the stockholders or management but also of society.
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Examines the ninth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects…
Abstract
Examines the ninth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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Olof Brunninge and Anders Melander
In this chapter, we explore the impact of socioemotional and financial wealth on the resource management of family firms. We use MoDo, a Swedish pulp and paper firm, covering…
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In this chapter, we explore the impact of socioemotional and financial wealth on the resource management of family firms. We use MoDo, a Swedish pulp and paper firm, covering three generations of owner-managers from 1873 to 1991, to grasp the shifting emphases on socioemotional and financial wealth in the management of the company. Identifying four strategic issues of decisive importance for the development of MoDo, we analyze the organizational values that guided the management of these issues. We propose that financial and socioemotional wealth stand for two different rationalities that infuse organizational values. The MoDo case illustrates how these rationalities go hand in hand for extended periods of time, safeguarding both financial success and socioemotional endowments. However, in a situation where the rationalities are no longer in line with the development of the industry context, the conflict arising between the two rationalities may have fatal consequences for the firm in question.
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Examines the thirteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…
Abstract
Examines the thirteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…
Abstract
Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.