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Article
Publication date: 1 January 1992

B.J. Garner, C.L. Forrester and D. Lukose

The concept of a knowledge interface for library users is developed as an extension of intelligent knowledge‐base system (IKBS) concepts. Contemporary directions in intelligent…

Abstract

The concept of a knowledge interface for library users is developed as an extension of intelligent knowledge‐base system (IKBS) concepts. Contemporary directions in intelligent decision support, particularly in the role of search intermediaries, are then examined to identify the significance of intelligent intermediaries as a solution to unstructured decision support requirements of library users. A DISCOURSE SCRIPT is given to illustrate one form of intelligent intermediary.

Details

Library Hi Tech, vol. 10 no. 1/2
Type: Research Article
ISSN: 0737-8831

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 (1 sq…

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 bottom…

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: 19 December 2022

Damodara Priyanka, Pratibha Biswal and Tanmay Basak

This study aims to elucidate the role of curved walls in the presence of identical mass of porous bed with identical heating at a wall for two heating objectives: enhancement of…

Abstract

Purpose

This study aims to elucidate the role of curved walls in the presence of identical mass of porous bed with identical heating at a wall for two heating objectives: enhancement of heat transfer to fluid saturated porous beds and reduction of entropy production for thermal and flow irreversibilities.

Design/methodology/approach

Two heating configurations have been proposed: Case 1: isothermal heating at bottom straight wall with cold side curved walls and Case 2: isothermal heating at left straight wall with cold horizontal curved walls. Galerkin finite element method is used to obtain the streamfunctions and heatfunctions associated with local entropy generation terms.

Findings

The flow and thermal maps show significant variation from Case 1 to Case 2 arrangements. Case 1 configuration may be the optimal strategy as it offers larger heat transfer rates at larger values of Darcy number, Dam. However, Case 2 may be the optimal strategy as it provides moderate heat transfer rates involving savings on entropy production at larger values of Dam. On the other hand, at lower values of Dam (Dam ≤ 10−3), Case 1 or 2 exhibits almost similar heat transfer rates, while Case 1 is preferred for savings of entropy production.

Originality/value

The concave wall is found to be effective to enhance heat transfer rates to promote convection, while convex wall exhibits reduction of entropy production rate. Comparison between Case 1 and Case 2 heating strategies enlightens efficient heating strategies involving concave or convex walls for various values of Dam.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

Book part
Publication date: 10 December 2018

Thomas Keil, Pasi Kuusela and Nils Stieglitz

How do organizations respond to negative feedback regarding their innovation activities? In this chapter, the authors reconcile contradictory predictions stemming from behavioral…

Abstract

How do organizations respond to negative feedback regarding their innovation activities? In this chapter, the authors reconcile contradictory predictions stemming from behavioral learning and from the escalation of commitment (EoC) perspectives regarding persistence under negative performance feedback. The authors core argument suggests that the seemingly contradictory psychological processes indicated by these two perspectives occur simultaneously in decision makers but that the design of organizational roles and reward systems affects their prevalence in decision-making tasks. Specifically, the authors argue that for decision makers responsible for an individual project, responses given to negative performance feedback regarding a project are dominated by self-justification and loss-avoidance mechanisms predicted by the EoC literature, while for decision makers responsible for a portfolio of projects, responses to negative performance regarding a project are dominated by an under-sampling of poorly performing alternatives that behavioral learning theory predicts. In addition to assigning decision-making authority to different organizational roles, organizational designers shape the strength of these mechanisms through the design of reward systems and specifically by setting more or less ambiguous goals, aspiration levels, time horizons of incentives provided, and levels of failure tolerance.

Article
Publication date: 6 August 2018

Yanwu Yang, Xin Li, Daniel Zeng and Bernard J. Jansen

The purpose of this paper is to model group advertising decisions, which are the collective decisions of every single advertiser within the set of advertisers who are competing in…

1351

Abstract

Purpose

The purpose of this paper is to model group advertising decisions, which are the collective decisions of every single advertiser within the set of advertisers who are competing in the same auction or vertical industry, and examine resulting market outcomes, via a proposed simulation framework named Experimental Platform for Search Engine Advertising (EXP-SEA) supporting experimental studies of collective behaviors in the context of search engine advertising.

Design/methodology/approach

The authors implement the EXP-SEA to validate the proposed simulation framework, also conduct three experimental studies on the aggregate impact of electronic word-of-mouth (eWOM), the competition level and strategic bidding behaviors. EXP-SEA supports heterogeneous participants, various auction mechanisms and also ranking and pricing algorithms.

Findings

Findings from the three experiments show that both the market profit and advertising indexes such as number of impressions and number of clicks are larger when the eWOM effect is present, meaning social media certainly has some effect on search engine advertising outcomes, the competition level has a monotonic increasing effect on the market performance, thus search engines have an incentive to encourage both the eWOM among search users and competition among advertisers, and given the market-level effect of the percentage of advertisers employing a dynamic greedy bidding strategy, there is a cut-off point for strategic bidding behaviors.

Originality/value

This is one of the first research works to explore collective group decisions and resulting phenomena in the complex context of search engine advertising via developing and validating a simulation framework that supports assessments of various advertising strategies and estimations of the impact of mechanisms on the search market.

Details

Internet Research, vol. 28 no. 4
Type: Research Article
ISSN: 1066-2243

Keywords

Article
Publication date: 1 February 2013

Maarten E.J. Rutten, André G. Dorée and Johannes I.M. Halman

The purpose of this article is to explore the ability of a novel psychological theory of how people make decisions, narrative‐based decision theory, to help explain people's…

2325

Abstract

Purpose

The purpose of this article is to explore the ability of a novel psychological theory of how people make decisions, narrative‐based decision theory, to help explain people's decisions about whether to continue investment in a research and development (R&D) project (R&D progress decisions).

Design/methodology/approach

The paper applies the new theory to an empirical finding of existing research on R&D progress decisions; the finding that instruction in the sunk cost principle seems to mitigate the sunk cost effect in R&D progress decision‐making.

Findings

By interpreting the empirical finding in terms of narrative‐based decision theory, the paper is able to clarify and extend an earlier explanation for the empirical finding. More specifically, by drawing on narrative‐based decision theory the paper is able to provide a more detailed explanation of how the predictor variable (sunk cost) and the moderator variable (instruction in the sunk cost principle) may exert an influence.

Research limitations/implications

Based on the result of the exploration, the authors call for further investigations into narrative‐based decision theory's value in explaining R&D progress decisions, and other management decisions.

Practical implications

Furthermore, the authors call for investigations into how narrative‐based decision theory may help decision‐makers in improving the quality of R&D progress decisions.

Originality/value

Narrative‐based decision theory is a recent theory from the field of naturalistic decision‐making. To the authors' knowledge, this is the first article that, by using an example, illustrates how the theory may help in explaining the findings of empirical research on management decisions.

Book part
Publication date: 13 June 2013

Helge Löbler and Marco Hahn

Purpose – Service-dominant logic (S-D logic) has conceptualized value as value-in-context where context is defined as a “set of unique actors with unique reciprocal links among…

Abstract

Purpose – Service-dominant logic (S-D logic) has conceptualized value as value-in-context where context is defined as a “set of unique actors with unique reciprocal links among them” (Chandler & Vargo, 2011, p. 40). The chapter proposes a means of measuring value-in-context as experienced by an actor while integrating resources, called the ValConRIA model (value-in-context of resource integrating activities).Design/methodology/approach – Value emerges from experiencing interactions in a service-for-service exchange. The actor perceives value as emerging with his activities and hence experiences the emerging value as connected to either his activities or the items supporting his activities or the people he is interacting with. We call these realms of experience the I (–Me) realm, the I–It and It–I realm, and the I–You and You–I realm, composing five dimensions. An exploratory principal component analysis supports this structure. The measurement process has been tested for reliability and validity and applied to different activities: using a laptop, using cigarettes (=smoking), using a smartphone, and using Facebook.Findings – According to where the actor mostly experiences the value emergence, five dimensions of value-in-context have been identified using principal component analysis. The measurement scale shows high construct reliability and discriminant validity.Implications – Being able to measure value-in-context as proposed by S-D logic brings S-D logic into practice. Practitioners can use the measurement process to identify value their customers co-create. The proposed means of measuring value-in-context does not measure the value of things but instead values as it emerges from an actor’s activities, exchanging service for service.Value/originality – To our knowledge this chapter is the first to propose a means of measuring value-in-context, which is based on S-D logic.

Article
Publication date: 5 August 2022

N. Keerthi Reddy and M. Sankar

This study aims to numerically study the buoyant convective flow of two different nanofluids in a porous annular domain. A uniformly heated inner cylinder, cooled outer…

Abstract

Purpose

This study aims to numerically study the buoyant convective flow of two different nanofluids in a porous annular domain. A uniformly heated inner cylinder, cooled outer cylindrical boundary and adiabatic horizontal surfaces are considered because of many industrial applications of this geometry. The analysis also addresses the comparative study of different porous media models governing fluid flow and heat transport.

Design/methodology/approach

The finite difference method has been used in the current simulation work to obtain the numerical solution of coupled partial differential equations. In particular, the alternating direction implicit method is used for solving transient equations, and the successive line over relaxation iterative method is used to solve time-independent equation by choosing an optimum value for relaxation parameter. Simpson’s rule is adopted to estimate average Nusselt number involving numerical integration. Various grid sensitivity checks have been performed to assess the sufficiency of grid size to obtain accurate results. In this analysis, a general porous media model has been considered, and a comparative study between three different models has been investigated.

Findings

Numerical simulations are performed for different combinations of the control parameters and interesting results are obtained. It has been found that the an increase in Darcy and Rayleigh numbers enhances the thermal transport rate and strengthens the nanofluid movement in porous annulus. Also, higher flow circulation rate and thermal transport has been detected for Darcy model as compared to non-Darcy models. Thermal mixing could be enhanced by considering a non-Darcy model.

Research limitations/implications

The present results could be effectively used in many practical applications under the limiting conditions of two-dimensionality and axi-symmetry conditions. The only drawback of the current study is it does not include the three-dimensional effects.

Practical implications

The results could be used as a first-hand information for the design of any thermal systems. This will help the design engineer to have fewer trial-and-run cases for the new design.

Originality/value

A pioneering numerical investigation on the buoyant convective flow of two different nanofluids in an annular porous domain has been carried out by using a general Darcy–Brinkman–Forchheimer model to govern fluid flow in porous matrix. The results obtained from current investigation are novel and original, with numerous practical applications of nanofluid saturated porous annular enclosure in the modern industry.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 17 October 2018

A.S. Dogonchi, Mikhail A. Sheremet, Ioan Pop and D.D. Ganji

The purpose of this study is to investigate free convection of copper-water nanofluid in an upper half of circular horizontal cylinder with a local triangular heater under the…

Abstract

Purpose

The purpose of this study is to investigate free convection of copper-water nanofluid in an upper half of circular horizontal cylinder with a local triangular heater under the effects of uniform magnetic field and cold cylinder shell using control volume finite element method (CVFEM).

Design/methodology/approach

Governing equations formulated in dimensionless stream function, vorticity and temperature variables using the single-phase nanofluid model with Brinkman correlation for the effective dynamic viscosity and Hamilton and Crosser model for the effective thermal conductivity have been solved numerically by CVFEM.

Findings

The impacts of control parameters such as the Rayleigh number, Hartmann number, nanoparticles volume fraction, local triangular heater size, shape factor on streamlines and isotherms as well as local and average Nusselt numbers have been examined. The outcomes indicate that the average Nusselt number is an increasing function of the Rayleigh number, shape factor and nanoparticles volume fraction, while it is a decreasing function of the Hartmann number.

Originality/value

A complete study of the free convection of copper-water nanofluid in an upper half of circular horizontal cylinder with a local triangular heater under the effects of uniform magnetic field and cold cylinder shell using CVFEM is addressed.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 28 no. 12
Type: Research Article
ISSN: 0961-5539

Keywords

1 – 10 of 125