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Article
Publication date: 1 December 2003

Seda Ozmutlu, Huseyin C. Ozmutlu and Amanda Spink

Recent studies show that many Web users only submit short queries and conduct short search sessions. This paper examines aspects of users’ attempting longer more complex…

Abstract

Recent studies show that many Web users only submit short queries and conduct short search sessions. This paper examines aspects of users’ attempting longer more complex queries. Web search services such as Ask Jeeves – publicly accessible question and answer (Q&A) search engines – encourage queries in question or request format. In light of this trend, this study examines whether general Web queries are shifting towards a more question/request format. Previous studies show that some users were submitting question or request format queries to general non‐Q&A Web search engines. This paper re‐examines this issue by analysing large‐scale Web query data from two different (US and European) Web query data sets, including 1.2 million Excite queries (www.excite.com) and 1.2 million AlltheWeb.com (http://AlltheWeb.com) queries from 2001.

Details

Online Information Review, vol. 27 no. 6
Type: Research Article
ISSN: 1468-4527

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Article
Publication date: 12 July 2013

Cun‐Cen Li, Ming Yang, Ya‐Fei Pang and Shi‐Yang Li

The purpose of this paper is to propose an optimization method by combining artificial immune algorithm and finite element analysis to find the optimal exciting electrode…

Abstract

Purpose

The purpose of this paper is to propose an optimization method by combining artificial immune algorithm and finite element analysis to find the optimal exciting electrode of a piezoceramic plate type ultrasonic motor vibrator.

Design/methodology/approach

The artificial immune algorithm is selected as optimizer for its merit of fast convergence to global optimal solution. The finite element analysis is used to calculate the motion trajectory of contact point. The objective function is the work that the vibrator does to rotor. The design variables are the boundaries of exciting electrode on piezoceramic plate vibrator surface.

Findings

The calculated results and the experimental results show that using this method, both the position and the size of optimal exciting electrode of this ultrasonic motor can be quickly and accurately determined.

Originality/value

In order to successfully design an ultrasonic motor, both the position and the size of the exciting electrode must be investigated, so as to change more electric energy into mechanical energy. In this paper, an optimization method by combining artificial immune algorithm and finite element analysis is proposed for the exciting location optimization of a piezoceramic plate type ultrasonic motor to obtain large power output.

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Article
Publication date: 1 May 1999

Amanda Spink, Judy Bateman and Bernard J. Jansen

Web search services are now a major source of information for a growing number of people. We need to know more about how users search Web search engines to improve the…

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Abstract

Web search services are now a major source of information for a growing number of people. We need to know more about how users search Web search engines to improve the effectiveness of their information retrieval. This paper reports results from a major study exploring users’ information searching behavior on the EXCITE Web search engine. The study is the first to investigate Web users’ successive searching behavior as they conduct related searches

Details

Internet Research, vol. 9 no. 2
Type: Research Article
ISSN: 1066-2243

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Article
Publication date: 1 October 2000

Amanda Spink, Bernard J. Jansen and H. Cenk Ozmultu

Examines the use of query reformulation, and particularly the use of relevance feedback by users of the Excite Web search engine. A total of 985 user search sessions from…

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1561

Abstract

Examines the use of query reformulation, and particularly the use of relevance feedback by users of the Excite Web search engine. A total of 985 user search sessions from a data set of 18,113 user search sessions containing 51,473 queries were examined. Includes a qualitative and quantitative analysis of 191 user sessions including more than one query, to examine patterns of user query reformulation; and second, all 804 user sessions including relevance feedback were examined. Results show limited use of query reformulation and relevance feedback by Excite users – only one in five users reformulated queries. Most relevance feedback sessions were successful. Identifies the most common pattern of searching and discusses implications for Web search system design.

Details

Internet Research, vol. 10 no. 4
Type: Research Article
ISSN: 1066-2243

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Article
Publication date: 1 April 1960

D.J. Mead

The modes of fuselage vibration that could be excited by jet‐efflux pressure fields are first discussed, and consideration is given to (he initial acoustic and structural…

Abstract

The modes of fuselage vibration that could be excited by jet‐efflux pressure fields are first discussed, and consideration is given to (he initial acoustic and structural damping of the modes. A simplified theory is presented for the acoustic damping of flat (or nearly flat) panels set in a much larger body, such as a fuselage. Using the results of Part I, an estimate is then made of the effect of Aquaplas damping compound on the vibration stresses, amplitudes and rivet loads of a structure subjected to random jet‐efflux excitation. It is assumed that the structure and the damping compound together constitute a linear system. In the two particular cases considered, the maximum possible reduction of rivet load is found to be about 40 per cent and 70 per cent respectively, and it is concluded that this is insufficient to outweigh the possible adverse effects of certain factors which cannot be introduced into a simplified investigation.

Details

Aircraft Engineering and Aerospace Technology, vol. 32 no. 4
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 2 March 2012

Mohammad Sedigh Toulabi, Hossein Torkaman and Ebrahim Afjei

The purpose of this paper is to propose a combination of two novel switched reluctance generators (SRG) as a suitable prototype to produce electrical energy using natural…

Abstract

Purpose

The purpose of this paper is to propose a combination of two novel switched reluctance generators (SRG) as a suitable prototype to produce electrical energy using natural, renewable and variable speed energy resource. The paper focuses on the voltage generation analysis of two special SRGs.

Design/methodology/approach

To evaluate the proposed configurations, their structures are introduced firstly, and the output voltages of both two generators are analyzed numerically via three dimensional finite element method. After that the obtained results are validated on laboratory set up. Moreover, the main parameters of each one causing the output voltages are studied. The proposed generators have been manufactured within a common physical framework. This framework consists of two magnetically independent stator and rotor sets (layers), where each stator set includes four salient poles, while the rotor comprises of two salient poles with almost equal arc lengths and no windings. The first generator called Field assisted SRG which has a stationary reel, and so the field coil wrapped around it, and it is placed between the two‐stator sets, whereas in the second type named Self excited SRG, there is no field coil.

Findings

Via experimental and numerical analysis, it is substantiated that this interesting combination can help users to produce electrical energy from low speeds to high speeds of performance through employing each of these generators in special case of study and application separately.

Originality/value

This beneficial characteristic of two proposed SRGs can be noticed as a suitable trait in different industries such as aerospace, automobile and production of electrical energy via windmills.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 7 March 2016

I.A.A. Afinowi, Z.Q. Zhu, Y. Guan, Jean-Claude Mipo and P. Farah

– The purpose of this paper is to comparatively study the conventional, i.e. single magnet, and novel hybrid-magnet switched-flux permanent-magnet (HMSFPM) machines.

Abstract

Purpose

The purpose of this paper is to comparatively study the conventional, i.e. single magnet, and novel hybrid-magnet switched-flux permanent-magnet (HMSFPM) machines.

Design/methodology/approach

The HMSFPM machines utilize two magnet types, i.e. low-cost ferrites and NdFeB. Thus, a set of magnet ratios (?), defined as the quotient of the NdFeB volume to the total PM volume, is introduced. This allows any desired performance and cost trade-off to be designed. Series- and parallel-excited magnet configurations are investigated using 2-dimensional finite element analysis.

Findings

The torque of the HMSFPM machines is lower than the NdFeB SFPM machine but the flux-weakening performance is improved for similar machine efficiency. If the machine dimensions are unconstrained, the HMSFPM machines can have the same torque for reduced material costs and a moderate increase in machine dimensions. Ferrite SFPM machines have the lowest cost for the same torque but a significant increase in machine dimensions is required. Finally, the series-excited HMSFPM machine is the preferred over the parallel-excited HMSFPM machine because it has superior demagnetization withstand capability.

Research limitations/implications

Mechanical and winding eddy current losses are not considered in the efficiency map calculations.

Originality/value

The NdFeB SFPM, ferrite SFPM, series-excited HMSFPM, and the parallel-excited HMSFPM machines are compared for their electromagnetic performance, flux-weakening, PM demagnetization, efficiency, and material costs.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 14 June 2011

Andrew Adamatzky

Delaunay triangulations provide a good alternative to existing approaches of modelling unstructured unconventional computers. Experimental research in novel and emerging…

Abstract

Purpose

Delaunay triangulations provide a good alternative to existing approaches of modelling unstructured unconventional computers. Experimental research in novel and emerging computing paradigms and materials shows a great progress in designing laboratory prototypes of spatially extended computing devices. In these devices, computation is implemented by excitation waves and localisations in reaction‐diffusion chemical media, geometrically constrained and compartmentalized excitable substrates, organic molecular assemblies, and gas‐discharge systems. These unconventional computing substrates can be formally represented by Delaunay triangulations with excitable nodes. Thus, it is important to uncover most common types of excitation dynamics on the Delaunay diagrams. The purpose of this paper is to define excitable automata on Delaunay triangulation and demonstrate how to control a space‐time dynamics of excitation on the triangulation using absolute and relative excitability thresholds.

Design/methodology/approach

The paper modifies classical Greenberg‐Hasting model to topology of Delaunay triangulations and considers not only a threshold of excitation but also a ratio of excited neighbours as an essential factor of nodes' activation. Delaunay triangulations for various densities of nodes packaging are considered.

Findings

The paper defines excitable automata on Delaunay triangulation and demonstrates how to control a space‐time dynamics of excitation on the triangulation using absolute and relative excitability thresholds. The paper uncovers several interesting phenomena ranging from reaction of excitation waves by edge of triangulation to branching domains of activity guided by travelling localized excitations.

Originality/value

The findings reported in the paper will contribute towards designs of novel computing substrates in non‐crystalline structure. Also, automaton interpretation of activity dynamics on Delaunay triangulation can make a viable model of automaton‐network approaches to design of nano‐computing devices.

Details

Kybernetes, vol. 40 no. 5/6
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 2 March 2012

Xiaojun Zhao, Lin Li, Junwei Lu, Zhiguang Cheng and Tiebing Lu

This paper aims to introduce the decomposed harmonic balance finite element method (HBFEM) to decrease the memory requirement in large‐scale computation of the DC‐biasing…

Abstract

Purpose

This paper aims to introduce the decomposed harmonic balance finite element method (HBFEM) to decrease the memory requirement in large‐scale computation of the DC‐biasing magnetic field. Harmonic analysis of the flux density and flux distribution was carried out to investigate the DC biased problem in a laminated core model (LCM).

Design/methodology/approach

Based on the DC bias test on a LCM, the decomposed HBFEM is applied to accurately calculate the DC‐biasing magnetic field. External electric circuits are coupled with the magnetic field in the harmonic domain. The reluctivity matrix is decomposed and the block Gauss‐Seidel algorithm solves each harmonic solution of magnetic field and exciting current sequentially.

Findings

The calculated exciting currents and flux density are compared with that obtained from measurement and time domain finite element analysis, respectively, which demonstrates consistency. The DC bias leads to the significant saturation of the magnetic core and serious distortion of the exciting current. The flux density varies nonlinearly with DC bias excitation.

Research limitations/implications

The harmonic balance method is only applicable in solving the steady state magnetic field. Future improvements in the method are necessary in order to manage the hysteresis effects in magnetic material.

Originality/value

The proposed method to solve the DC biased problem significantly reduces the memory requirement compared to the conventional HBFEM. The decomposed harmonic balance equations are solved efficiently by the block Gauss‐Seidel algorithm combined with the relaxation iterative scheme. An investigation on DC bias phenomena is carried out through the harmonic solution of the magnetic field. The decomposed HBFEM can also be applied to solve 3‐D DC‐biasing magnetic field and eddy current nonlinear problems in a practical power transformer.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 13 November 2017

Brian Handley, Tekle Shanka and Fazlul K. Rabbanee

The purpose of this paper is to explore Australasian students’ current perception towards a sales career.

Abstract

Purpose

The purpose of this paper is to explore Australasian students’ current perception towards a sales career.

Design/methodology/approach

Data were collected through a self-administered survey from 431 students enrolled in a Sales Management unit in a large Australian university and its Asian campuses.

Findings

The study reveals a four-factor solution with factors labeled as “exciting,” “deceptive,” “taxing,” and “challenging,” with “exciting” being the only factor to significantly predict likelihood of pursuing a sales career. Although no differences of perception were found between males and females, Asian students were found to perceive sales career as more exciting, innovative and fun than Australian students.

Research limitations/implications

Although significant difference was noted between Australian and Asian students’ perceptions towards sales as an exciting career, it is prudent to interpret and generalize the finding with caution as Asia is the largest continent with different cultures, religions and races.

Practical implications

The four factors that were found to influence students’ perception towards a sales career are novel, psychometrically sound, and are pertinent for businesses conducting graduate recruitment. This study indicates how sales education at university level assist in changing students’ views towards a sales career from negative to positive.

Originality/value

While previous research has reported negative perceptions about sales as a career, this study reveals that students consider sales to be an “exciting” career.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 29 no. 5
Type: Research Article
ISSN: 1355-5855

Keywords

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