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Article
Publication date: 23 November 2020

Leo Lukose and Tanmay Basak

This paper aims to investigate the role of shapes of containers (nine different containers) on entropy generation minimization involving identical cross-sectional area…

Abstract

Purpose

This paper aims to investigate the role of shapes of containers (nine different containers) on entropy generation minimization involving identical cross-sectional area (1 sq. unit) in the presence of identical heating (isothermal). The nine containers are categorized into three classes based on their geometric similarities (Class 1: square, tilted square and parallelogram; Class 2: trapezoidal type 1, trapezoidal type 2 and triangular; Class 3: convex, concave and curved triangular).

Design/methodology/approach

Galerkin finite element method is used to solve the governing equations for a representative fluid (engine oil: Pr = 155) at Ra = 103–105. In addition, finite element method is used to solve the streamfunction equation and evaluate the entropy generation terms (Sψ and Sθ). Average Nusselt number ( Nub¯) and average dimensionless spatial temperature ( θ^) are also evaluated via the finite element basis sets.

Findings

Based on larger Nub¯, larger θ^ and optimal Stotal values, containers from each class are preferred as follows: Class 1: parallelogrammic and square, Class 2: trapezoidal type 1 and Class 3: convex (larger θ^, optimum Stotal) and concave (larger Nub¯). Containers with curved walls lead to enhance the thermal performance or efficiency of convection processes.

Practical implications

Comparison of entropy generation, intensity of thermal mixing ( θ^) and average heat transfer rate give a clear picture for choosing the appropriate containers for processing of fluids at various ranges of Ra. The results based on this study may be useful to select a container (belonging to a specific class or containers with curved or plane walls), which can give optimal thermal performance from the given heat input, thereby leading to energy savings.

Originality/value

This study depicts that entropy generation associated with the convection process can be reduced via altering the shapes of containers to improve the thermal performance or efficiency for processing of identical mass with identical heat input. The comparative study of nine containers elucidates that the values of local maxima of Sψ (Sψ,max), Sθ (Sθ,max) and magnitude of Stotal vary with change in shapes of the containers (Classes 1–3) at fixed Pr and Ra. Such a comparative study based on entropy generation minimization on optimal heating during convection of fluid is yet to appear in the literature. The outcome of this study depicts that containers with curved walls are instrumental to optimize entropy generation with reasonable thermal processing rates.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 14 November 2019

Leo Lukose and Tanmay Basak

The purpose of this paper is to study thermal (natural) convection in nine different containers involving the same area (area= 1 sq. unit) and identical heat input at the…

Abstract

Purpose

The purpose of this paper is to study thermal (natural) convection in nine different containers involving the same area (area= 1 sq. unit) and identical heat input at the bottom wall (isothermal/sinusoidal heating). Containers are categorized into three classes based on geometric configurations [Class 1 (square, tilted square and parallelogram), Class 2 (trapezoidal type 1, trapezoidal type 2 and triangle) and Class 3 (convex, concave and triangle with curved hypotenuse)].

Design/methodology/approach

The governing equations are solved by using the Galerkin finite element method for various processing fluids (Pr = 0.025 and 155) and Rayleigh numbers (103 ≤ Ra ≤ 105) involving nine different containers. Finite element-based heat flow visualization via heatlines has been adopted to study heat distribution at various sections. Average Nusselt number at the bottom wall ( Nub¯) and spatially average temperature (θ^) have also been calculated based on finite element basis functions.

Findings

Based on enhanced heating criteria (higher Nub¯ and higher θ^), the containers are preferred as follows, Class 1: square and parallelogram, Class 2: trapezoidal type 1 and trapezoidal type 2 and Class 3: convex (higher θ^) and concave (higher Nub¯).

Practical implications

The comparison of heat flow distributions and isotherms in nine containers gives a clear perspective for choosing appropriate containers at various process parameters (Pr and Ra). The results for current work may be useful to obtain enhancement of the thermal processing rate in various process industries.

Originality/value

Heatlines provide a complete understanding of heat flow path and heat distribution within nine containers. Various cold zones and thermal mixing zones have been highlighted and these zones are found to be altered with various shapes of containers. The importance of containers with curved walls for enhanced thermal processing rate is clearly established.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 7
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 6 August 2018

Remigiusz Romuald Iwańkowicz and Michał Taraska

The purpose of the paper is to develop a method of automatic classification of the components of the assembly units. The method is crucial for developing an automatic ship…

Abstract

Purpose

The purpose of the paper is to develop a method of automatic classification of the components of the assembly units. The method is crucial for developing an automatic ship assembly planning tools. The proposed method takes into account the assumptions specific for shipbuilding technology processes: high complexity of structures, difficult expert-based classification of components, fixed priority relations between connections resulting from geometrical constraints and demands of welding processes.

Design/methodology/approach

The set of ex post determined liaisons and assembly sequences constitutes the database of structures which have been made-up earlier. The components classification problem is solved using matrix coding of graphs. Information in such form is stored in the database. The minimization of number of cycles in the graph of classes sequence and minimization of diversity of classes within all constructions has been proposed as criteria of optimization. The genetic algorithm has been proposed as a solution method.

Findings

The proposed method solves the problem of components’ classifications. It allows setting the pattern of priorities between classes of various connections. This gives a chance to determine the relationship constraints between the connections of new structures for which assembly sequences are not established.

Research limitations/implications

Mathematical formulation of the database is quite laborious. The possibility of partial automation of this process should be considered. Owing to the complexity of the problem, a relatively simple objective function has been proposed. During a ship hull assembly, additional criteria should be taken into account, what will be the direction of further research.

Practical implications

Automatic classification of components is dedicated for implementation in shipyards and similar assembly systems. Tests performed by the authors confirm efficiency of presented method in supporting management of the database and assembly of new structures planning. Suggested activity-oriented approach allows for easy conversion of any assembly unit structure to the form of a matrix.

Originality/value

The new approach for components classification according to its assembly features distinguishes the proposed method from others. The use of nilpotent matrix theory in an acyclicity of graphs analysis is also a unique achievement. Original crossover and mutation operators for assembly sequence were proposed in the article.

Details

Assembly Automation, vol. 38 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

Book part
Publication date: 18 April 2015

Pavel Illich Popov

This chapter offers the first full translation from Russian to English of the Balance of the National Economy of the USSR, 192426’s first chapter. Involving 12 authors…

Abstract

This chapter offers the first full translation from Russian to English of the Balance of the National Economy of the USSR, 192426’s first chapter. Involving 12 authors and composed of 21 chapters, the Balance is a collective work published in June 1926 in Moscow by the Soviet Central Statistical Administration under the scientific supervision of its former director, Pavel Illich Popov (1872–1950). In this first chapter, titled ‘Studying the Balance of the National Economy: An Introduction’, Popov set the theoretical foundations of what might be considered as the first modern national accounting system and paved the way to multisector macroeconometric modelling.

Article
Publication date: 22 March 2019

Rakesh Venkitasubramony and Gajendra Kumar Adil

This paper aims to develop an approach to design a warehouse that uses class-based storage policy in a way that minimizes both space cost and material handling cost.

Abstract

Purpose

This paper aims to develop an approach to design a warehouse that uses class-based storage policy in a way that minimizes both space cost and material handling cost.

Design/methodology/approach

The authors argue for and develop an optimization model for joint determination of lane depth, lateral width and product partitions for minimizing the sum of handling and space costs. In doing so, the assumption of perfect sharing is also relaxed. Using computational experiments, the authors characterize the operating conditions based on pick density and cost ratio. The authors further outline an approach to decide the conditions under which it is advantageous to implement multiple classes.

Findings

More classes are preferred when both the pick density and cost ratio are higher and vice versa. Factors such as demand skewness, lane depth and stacking height affect the space-sharing dynamics.

Practical implications

The paper gives the practical insights on when the conditions under which it is advisable to partition a warehouse into a certain number of classes instead of maintaining and when to maintain as a single-class block. It also gives a method to estimate the space-sharing factor, given a combination of operating parameters.

Originality/value

Very few studies have seen class-based storage policy in the context of block stacked warehouse layout. Further, block stacking designs have mostly been approached with the objective of minimizing just the space cost. This study contributes to the literature by developing an integrated model, which has the practical utility.

Details

Facilities, vol. 37 no. 13/14
Type: Research Article
ISSN: 0263-2772

Keywords

Article
Publication date: 2 August 2022

Ahmet Aytekin, Ömer Faruk Görçün, Fatih Ecer, Dragan Pamucar and Çağlar Karamaşa

The present study aims to provide a practical and robust assessment technique for assessing countries' investability in global supply chains to practitioners. Thus, the…

Abstract

Purpose

The present study aims to provide a practical and robust assessment technique for assessing countries' investability in global supply chains to practitioners. Thus, the proposed approach can help decision-makers evaluate and select appropriate countries in the expansion process of the global supply chains and reduce risks concerning country (market) selection.

Design/methodology/approach

The present study proposes a novel decision-making approach, namely the REF-Sort technique. The proposed approach has many valuable contributions to the literature. First, it has an efficient basic algorithm and can be applied to solve highly complicated decision-making problems without requiring advanced mathematical knowledge. Besides, some characteristics differentiate REF-Sort apart from other techniques. REF-Sort employs the value or value range that reflects the most typical characteristic of the relevant class in assignment processes. The reference values in REF-Sort and center profiles are similar in this regard. On the other hand, class references can be defined as ranges in REF-Sort. Secondary values, called successors, can also be employed to assign a value to the appropriate class. REF-Sort can also determine the reference and successor values/ranges independently of the decision matrix. In addition, the proposed model is a maximally stable and consistent decision-making tool, as it is resistant to the rank reversal problem.

Findings

The current papers' findings indicate that countries have different features concerning investment. Hence, the current paper pointed out that only 22% of the 95 countries are investable, whereas 19% are risky. Thus, decision-makers should make detailed evaluations using robust, powerful, and practical decision-making tools to make more reasonable and logical decisions concerning country selection.

Originality/value

The current paper proposes a novel decision-making approach to evaluate. According to the authors' information, the proposed model has been applied to evaluate investable countries for the global supply chains for the first time.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 3 April 2017

Douglas Rafael Veit, Daniel Pacheco Lacerda, Luis Felipe Riehs Camargo, Liane Mahlmann Kipper and Aline Dresch

Research in business processes has been developed around a disciplinary approach toward the production of traditional knowledge, known as Mode 1. The problems studied with…

Abstract

Purpose

Research in business processes has been developed around a disciplinary approach toward the production of traditional knowledge, known as Mode 1. The problems studied with this approach are solved in a context in which academic knowledge prevails, with no major concerns regarding its practical applicability. Thus, the purpose of this paper is to propose a structure for knowledge production based on Mode 2 for business process researches.

Design/methodology/approach

A bibliometric research was conducted to define and conceptualize the classes of disciplinary problems, by assessing the years 2007-2012 of the Business Process Management Journal publications.

Findings

A framework for the Mode 2 knowledge production was proposed in the development of research in business process and conceptualized classes of problems related to this issue.

Research limitations/implications

This work was carried out with specific focus on research in business process, so the defined classes of problems cannot be generalized.

Originality/value

The studies identified by this research are in the form of a disciplinary approach toward the production of traditional knowledge, known as Mode 1. This paper aims to fill the gap of a transdisciplinary production of knowledge and practical application, known as Mode 2 in the context of business process.

Details

Business Process Management Journal, vol. 23 no. 2
Type: Research Article
ISSN: 1463-7154

Keywords

Abstract

Details

Mathematical and Economic Theory of Road Pricing
Type: Book
ISBN: 978-0-08-045671-3

Book part
Publication date: 31 January 2015

Stephane Hess and Caspar G. Chorus

This chapter proposes a new mixture model which allows for heterogeneity in sensitivities and decision rules across decision makers and attributes.

Abstract

Purpose

This chapter proposes a new mixture model which allows for heterogeneity in sensitivities and decision rules across decision makers and attributes.

Theory

A new mixture model is put forward in which the different latent classes make use of different decision rules, where the use of generalised random regret minimisation kernel allows for within class heterogeneity in the decision rules applied across attributes.

Findings

Our theoretical developments are supported by the findings of an empirical application using data from a typical stated choice survey.

Originality and value

Existing work has looked at heterogeneity in decision rules and sensitivities across respondents. Other work has focused on the possibility that different decision rules apply to different attributes. This chapter puts forward a model that combines these two directions of research and does so in a way that lets the optimal specification be driven by the data rather than being imposed by the analyst.

Details

Bounded Rational Choice Behaviour: Applications in Transport
Type: Book
ISBN: 978-1-78441-071-1

Keywords

Book part
Publication date: 22 April 2015

Paul Caruana-Galizia

This paper constructs real wage series for nineteenth-century Algeria and Tunisia, and compares them with existing Egyptian and Syrian series. Archival sources are used…

Abstract

This paper constructs real wage series for nineteenth-century Algeria and Tunisia, and compares them with existing Egyptian and Syrian series. Archival sources are used for price and nominal wage data. Following Allen (2001), nominal wages are deflated with a consumer price index. The series are tested for robustness. Real wages were initially dispersed, but converged to similar levels by the end of the period. There is no evidence of a broad-based improvement in living standards over the period, with real wage series declining in Algeria, and stagnating in Egypt, Tunisia and Syria. The findings paint a less optimistic picture of living standards compared to other measures like GDP per capita and compared to some of the historical literature. Data for the Maghreb are scarce, and more work will need to be done on finding more wage and price observations.

Details

Research in Economic History
Type: Book
ISBN: 978-1-78441-782-6

Keywords

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