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1 – 10 of over 12000
Article
Publication date: 1 January 1984

Günther Haedrich and Dipl.‐Kfm. Edgar Kreilkamp

Einführung in das Portfolio‐Management Allgemein ist in den letzten 5–10 Jahren zunehmendes Interesse der Wirtschaft und Verwaltung für Probleme der strategischen Planung…

Abstract

Einführung in das Portfolio‐Management Allgemein ist in den letzten 5–10 Jahren zunehmendes Interesse der Wirtschaft und Verwaltung für Probleme der strategischen Planung festzustellen, nicht zuletzt aufgrund der Diskussion über das Portfolio‐Management. Dieses neue Planungsmodell rückt durch die Definition sogenannter Strategischer Geschäftsfelder (“business units”, vgl. Abschnitt 2 dieses Aufsatzes) als strategische Planung aus gesamtunternehmerischer Sicht in den Mittelpunkt der Betrachtung und löst sich damit los von der engen Funktionalorientierung, bei der jeder strategische Bereich als eigene und relativ unabhängige Planungseinheit auftritt. Abell/Hammond sprechen in diesem Zusammenhang von einem 3‐zyklischen Planungsprozess (Abell/Hammond 1979, S. 14) (vgl. Abb. 1); die Längeund Breite der einzelnen Planungsstufen geben gleichzeitig ihre zeitliche Dauer und ihre relative Bedeutung wieder.

Details

The Tourist Review, vol. 39 no. 1
Type: Research Article
ISSN: 0251-3102

Article
Publication date: 1 January 1989

Dr. Gottfried Langer

Die Anwendung strategischer Fhrungsmethoden in Hotelunternehmen ist durch zunehmende Turbulenz im gesamtgesellschaftlichen Umfeld und durch Intensivierung des Wettbewerbes in der…

Abstract

Die Anwendung strategischer Fhrungsmethoden in Hotelunternehmen ist durch zunehmende Turbulenz im gesamtgesellschaftlichen Umfeld und durch Intensivierung des Wettbewerbes in der Tourismusbranche wichtiger denn je. Unbefriedigend ist, dass die strategische Fhrung von Service‐unternehmen lange Zeit zu sehr unter dem Eindruck einer Theorie fr Unternehmen der Sachgterpro‐duktion gestanden hat. Erst in den letzten Jahren wurden in verstärktem Masse eigene Theorieansätze entwickelt, wobei bestimmte Besonderheiten von Dienstleistungen verstärkte Beachtung finden. Dazu zählt vornehmlich die “buyer/seller‐interaction”, mit simultanem Ablauf von Produktion und Konsum. Die von Gästen wahrgenommene Qualität persönlicher Dienstleistungen wird in dieser Situation massgeblich beeinflusst. Um eine strategische Managementfalle zu vermeiden, ist daher das Geschehen im Rahmen persönlicher Gästekontakte und das damit verbundene Problem einer präventiven Qualitäts‐sicherung im Rahmen von Stärken/Schwächen‐Ana‐lysen als zentraler Erfolgsfaktor zu beachten.

Details

The Tourist Review, vol. 44 no. 1
Type: Research Article
ISSN: 0251-3102

Article
Publication date: 1 February 1964

H. Friedmann and L. L.ès

OTHER TYPES OF LANGUAGE LABORATORY 1. Laboratories without student recording facilities. To this category belong the various types of ‘milking machine’. The programme is fed to…

Abstract

OTHER TYPES OF LANGUAGE LABORATORY 1. Laboratories without student recording facilities. To this category belong the various types of ‘milking machine’. The programme is fed to the students from the master tape recorder (or other source) via (‘audio‐active’) headsets with feed‐back from the students' microphones to their ears, although in the simplest form of this type of installation the student only possesses his headphones.

Details

Education + Training, vol. 6 no. 2
Type: Research Article
ISSN: 0040-0912

Article
Publication date: 20 November 2020

Sudeepa Das, Tirath Prasad Sahu and Rekh Ram Janghel

The purpose of this paper is to modify the crow search algorithm (CSA) to enhance both exploration and exploitation capability by including two novel approaches. The positions of…

Abstract

Purpose

The purpose of this paper is to modify the crow search algorithm (CSA) to enhance both exploration and exploitation capability by including two novel approaches. The positions of the crows are updated in two approaches based on awareness probability (AP). With AP, the position of a crow is updated by considering its velocity, calculated in a similar fashion to particle swarm optimization (PSO) to enhance the exploiting capability. Without AP, the crows are subdivided into groups by considering their weights, and the crows are updated by conceding leaders of the groups distributed over the search space to enhance the exploring capability. The performance of the proposed PSO-based group-oriented CSA (PGCSA) is realized by exploring the solution of benchmark equations. Further, the proposed PGCSA algorithm is validated over recently published algorithms by solving engineering problems.

Design/methodology/approach

In this paper, two novel approaches are implemented in two phases of CSA (with and without AP), which have been entitled the PGCSA algorithm to solve engineering benchmark problems.

Findings

The proposed algorithm is applied with two types of problems such as eight benchmark equations without constraint and six engineering problems.

Originality/value

The PGCSA algorithm is proposed with superior competence to solve engineering problems. The proposed algorithm is substantiated hypothetically by using a paired t-test.

Details

Engineering Computations, vol. 38 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 8 November 2022

Manoj Kumar Imrith, Satyadev Rosunee and Roshan Unmar

The thermophysiological comfort of fabrics is prerequisite as customers covet adequate moisture, heat management-supported and UV protective clothing that measure up to their…

Abstract

Purpose

The thermophysiological comfort of fabrics is prerequisite as customers covet adequate moisture, heat management-supported and UV protective clothing that measure up to their levels of activities and environmental conditions. Hitherto, scant tasks have been reported with the purpose of engineering both comfort and UV protection simultaneously. From that vantage point, the objective of this work is to develop a model for optimum UPF, air permeability, water-vapour resistance, thermal resistance, thermal absorptivity and areal density of knitted fabrics.

Design/methodology/approach

Weft knitted fabrics of various compositions were investigated. UPF was tested using the Labsphere UV transmittance analyser. The FX 3300 (Textest instruments) air permeability tester was used to test air permeability. Thermal comfort and water-vapour resistance were evaluated using the Alambeta and Permetest instruments, respectively. Based on image processing, the porosity was measured. Fabrics thickness and areal density were measured according to standard methods. Furthermore, parametric and non-parametric statistical test methods were applied to the data for analysis.

Findings

Linear regression was substantiated by Kolmogorov-Smirnov test. Then multiple linear regression of porosity and thickness together on UPF and comfort parameters were visually depicted by virtue of 3D linear plots. Residual analysis with quantile-quantile and probability plots, advocated the tests using the Shapiro-Wilk test. The result was validated by comparison with experimental data tested. The samples gave satisfactory relative errors and were supported by the z-test method. All tests indicated failure to reject the null hypothesis.

Originality/value

The predictive models were embedded into an interactive computer program. Fabric thickness and porosity are the inputs needed to run the program. It will predict the optimum UPF, areal density and thermophysiological comfort parameters. In a nutshell, knitters may use the program to determine optimum structural parameters for diverse permutations of UPF and thermophysiological comfort parameters; scilicet high UV protection together with low thermal insulation combined with low water-vapour resistance and high air permeability.

Details

Research Journal of Textile and Apparel, vol. 27 no. 3
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 29 July 2019

Vishweshwara P.S., Harsha Kumar M.K., N. Gnanasekaran and Arun M.

Many a times, the information about the boundary heat flux is obtained only through inverse approach by locating the thermocouple or temperature sensor in accessible boundary…

Abstract

Purpose

Many a times, the information about the boundary heat flux is obtained only through inverse approach by locating the thermocouple or temperature sensor in accessible boundary. Most of the work reported in literature for the estimation of unknown parameters is based on heat conduction model. Inverse approach using conjugate heat transfer is found inadequate in literature. Therefore, the purpose of the paper is to develop a 3D conjugate heat transfer model without model reduction for the estimation of heat flux and heat transfer coefficient from the measured temperatures.

Design/methodology/approach

A 3 D conjugate fin heat transfer model is solved using commercial software for the known boundary conditions. Navier–Stokes equation is solved to obtain the necessary temperature distribution of the fin. Later, the complete model is replaced with neural network to expedite the computations of the forward problem. For the inverse approach, genetic algorithm (GA) and particle swarm optimization (PSO) are applied to estimate the unknown parameters. Eventually, a hybrid algorithm is proposed by combining PSO with Broyden–Fletcher–Goldfarb–Shanno (BFGS) method that outperforms GA and PSO.

Findings

The authors demonstrate that the evolutionary algorithms can be used to obtain accurate results from simulated measurements. Efficacy of the hybrid algorithm is established using real time measurements. The hybrid algorithm (PSO-BFGS) is more efficient in the estimation of unknown parameters for experimentally measured temperature data compared to GA and PSO algorithms.

Originality/value

Surrogate model using ANN based on computational fluid dynamics simulations and in-house steady state fin experiments to estimate the heat flux and heat transfer coefficient separately using GA, PSO and PSO-BFGS.

Details

Engineering Computations, vol. 36 no. 9
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 November 2011

B.R. Das, S.M. Ishtiaque and R.S. Rengasamy

The tensile properties of spun yarns are accepted as one of the most important parameters for the assessment of yarn quality. Tensile properties contribute to the performance of…

Abstract

The tensile properties of spun yarns are accepted as one of the most important parameters for the assessment of yarn quality. Tensile properties contribute to the performance of post spinning operations; warping, weaving and knitting, hence their accurate technical evaluation carries much importance in industrial applications. This article presents a novel approach of classification of tensile properties into static and dynamic, based on the disposition of yarns during tensile testing. The definition of dynamic tensile properties and instruments utilized for their assessment are briefly discussed. Several theoretical and experimental work pursued on the static and dynamic tensile properties of ring, rotor, air-jet and friction spun staple yarns are critically reviewed. The article also throws light on the significance of exploitation of spun yarn dynamic tensile properties in industrial applications. The various material, spinning and testing parameters that influence static and dynamic tensile properties are summarized. The reported empirical equivalence of static and dynamic yarn strength of spun yarns is revealed. Current research work in the thrust area of spun yarns that are subjected to dynamic conditions is introduced.

Details

Research Journal of Textile and Apparel, vol. 15 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 1 August 2011

B.R. Das, S.M. Ishtiaque, R.S. Rengasamy and S. Hati

Warp yarns undergo various types of complex stress during the weaving process; namely tensile, cyclic-extension, compression, bending and abrasion. The capacity of the yarns to…

Abstract

Warp yarns undergo various types of complex stress during the weaving process; namely tensile, cyclic-extension, compression, bending and abrasion. The capacity of the yarns to withstand these stresses is termed as their weavability. The prediction of weavability is exploited to extract first-hand information about the expected performance of yarns in weaving. This critical review article discusses several approaches that are adopted by the researchers for the prediction of warp breakages in weaving; namely, empirical, statistical and instrumental. The recent developments in the field of prediction of warp breakage rate in weaving are summarized. The research work that is currently being pursued in the attachment of a microprocessor based shedding device in a constant tension transport (CTT) instrument for the prediction of the weavability of spun yarns is highlighted.

Details

Research Journal of Textile and Apparel, vol. 15 no. 3
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 1 February 2010

B.R. Das, S.M. Ishtiaque, R.S. Rengasamy, S. Hati and A. Kumar

The incidences of skin cancer have been rising worldwide due to excessive exposure to sunlight. Increase in exposure to ultraviolet (UV) radiation from sunlight results in skin…

Abstract

The incidences of skin cancer have been rising worldwide due to excessive exposure to sunlight. Increase in exposure to ultraviolet (UV) radiation from sunlight results in skin damage such as sunburn, premature skin ageing, allergies and skin cancer. Medical experts suggest several means of protection against ultraviolet radiation, including use of sunscreens, avoidance of the sun at its highest intensities, and wearing clothing that covers as much of the skin surface as possible. This paper provides insight on how UV absorbers can be efficiently used with textile material to protect human skin from harmful UV radiation. The manufacturers of various UV absorbers and their commercial products are reviewed and discussed. The interacting mechanism of UV absorbers with textile clothing for providing UV protection and an evaluation of the performance of UV absorbers are summarized.

Details

Research Journal of Textile and Apparel, vol. 14 no. 1
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 20 November 2009

Kichan Bae and Hyunsoo Yoon

The purpose of this paper is to find a practical method to minimize unnecessary rebroadcasts for ad hoc networks in a remote area.

Abstract

Purpose

The purpose of this paper is to find a practical method to minimize unnecessary rebroadcasts for ad hoc networks in a remote area.

Design/methodology/approach

The authors design a theoretical coverage estimation model for autonomous broadcast pruning. To verify the effect of the model, simulations are performed to evaluate the effect of confidence level and the actual performance by using ns2 network simulator.

Findings

The algorithm used to predict the coverage area of broadcasts can minimize unnecessary rebroadcasts.

Originality/value

Autonomous broadcast pruning scheme based on the local prediction of a remained coverage area in the on‐going broadcast process brings us beneficial results in terms of energy savings and limited bandwidth preservation.

Details

International Journal of Pervasive Computing and Communications, vol. 5 no. 4
Type: Research Article
ISSN: 1742-7371

Keywords

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