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Article
Publication date: 1 March 1992

B.S. Siegal

Thermal characterisation of surface mount devices (SMDs) has become a growing concern as these components have increased in use—a situation aggravated by the lack of accepted…

Abstract

Thermal characterisation of surface mount devices (SMDs) has become a growing concern as these components have increased in use—a situation aggravated by the lack of accepted industry standards for making thermal measurements. This paper attempts to provide better understanding of thermal resistance terminology, and to summarise some of the existing problems with current standards and common practices. A defined methodology for obtaining SMD thermal characteristics is proposed, involving measurement by vendors and confirmation by users, and suitable for use in meeting application‐oriented requirements. The importance of providing a clear and complete set of test condition information is also emphasised.

Details

Soldering & Surface Mount Technology, vol. 4 no. 3
Type: Research Article
ISSN: 0954-0911

Article
Publication date: 9 October 2017

Ali Sohaib, Laurence Broadbent, Abdul Rehman Farooq, Lyndon Neal Smith and Melvyn Lionel Smith

Significant research has been carried out in terms of development of new bidirectional reflectance distribution function (BRDF) instruments; however, there is still little…

Abstract

Purpose

Significant research has been carried out in terms of development of new bidirectional reflectance distribution function (BRDF) instruments; however, there is still little research available regarding spectral BRDF measurements of human skin. This study aims to investigate the variation in human skin reflectance using a new fibre optic-based spectral-BRDF measurement device.

Design/methodology/approach

Design of this system mainly involves use of multiple fibre optics to illuminate and detect light reflected from a sample, whereas a hemispherical dome was 3D printed to mount the fibres at various slant/tilt angles. To investigate the spectral differences in BRDF of human skin, 3 narrowband filters in the visible spectrum were used, whereas measurements were taken from the back of the hand for Caucasian and Asian skin types.

Findings

The experiments demonstrate that the BRDF of human skin varies with wavelengths in the visible spectrum and it is also different for Caucasian and Asian skin types. Both skin types exhibit off-specular reflection with increase in angle of incidence and show less variation with respect to viewing angles when the angle of incidence is normal to the surface.

Research implications

A database of spectral BRDF measurements of human skin will help not only in creating realistic skin renderings but also in development of novel skin reflectance models for biomedical and machine vision applications. The measurements would also provide means to validate the predictions from existing light transport/spectral simulation models for human skin and will ultimately help in the accurate diagnosis and simulation of various skin disorders.

Originality/value

The proposed system provides fast scatter measurements by utilising multiple fibres to detect light simultaneously at different angles while also allowing easy switching between incident light directions. Due to its flexible design and contact-based measurements, the device is independent of errors due to sample movements and does not require any image registration. Also, measurements taken from the device show that the BRDF of skin varies significantly in the visible spectrum and it is different for Caucasian and Asian skin types.

Details

Sensor Review, vol. 37 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 9 April 2019

Faisal L. Kadri

The purpose of this study is to investigate the possibility of soft science measurement of motivation under strict hard science criteria from observations of individual animals…

Abstract

Purpose

The purpose of this study is to investigate the possibility of soft science measurement of motivation under strict hard science criteria from observations of individual animals and to suggest the conditions under which an observation can be classified as a measurement.

Design/methodology/approach

The methodology starts from reconciling second-order cybernetics/radical constructivism (SOC/RC) understanding of the central role of the observer with physical measurements, which accepts the existence of a mind-independent reality. As a result of the reconciliation, parallels were identified between the SOC/RC experiences of as_is and as_if, on the one hand, and the measurement concepts of accuracy and resolution, on the other hand. The scales of physical measurement are defined by criteria of varying strictness, and the scales that meet the strict criterion of concatenation are generally considered hard science and lead to well-defined accuracy and precision. The similarity between SOC/RC and physical measurement suggests that if accuracy and precision can be computed from observations, then the observations can be classified as measurements in a strict hard science fashion; otherwise, the observations are just observations.

Findings

A nonlinear dynamic model of motivation is reintroduced as an example for reference in measurements of motivation. If there was an agreement on its use among observers (Ethologists), which in reality is not the case, then empirical data may be collected, and the averages and spreads of parameter estimations will define a reference for an animal species. Later, observers with their own data will calibrate with the reference model, so that new observers will have calculated values of accuracy and precision for their data.

Research limitations/implications

Unlike hard science whose scales of measurement are practically unambiguous, measuring the purpose of behaviour of an animal has inherent ambiguity according to the reintroduced model. The ambiguity cannot be resolved from instantaneous readings. The necessary existence of ambiguity renders the criticism of hard science invalid, that of expecting to measure motivation with a static scale as if it were temperature.

Practical implications

Human observers can be treated as measuring devices of motivation from observing behaviour. Each observer can have characteristic accuracy/precision, or validity/reliability, calculated from empirical data.

Social implications

This is an inductive, rather than deductive, study of individual animal behaviour; the author believes it is extensible to individual human behaviour and personality studies. However, group behaviour studies are beyond its scope.

Originality/value

The author believes that the suggestion of ambiguity of scales of animal motivation is original, and the suggested link between SOC/RC and a mainstream hard science is new.

Details

Kybernetes, vol. 48 no. 4
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 18 September 2007

Wenjun Liu and Bozhi Yang

The goal of this review paper is to provide information on several commonly used thermography techniques in semiconductor and micro‐device industry and research today.

1710

Abstract

Purpose

The goal of this review paper is to provide information on several commonly used thermography techniques in semiconductor and micro‐device industry and research today.

Design/methodology/approach

The temperature imaging or mapping techniques include thin coating methods such as liquid crystal thermography and fluorescence microthermography, contact mechanical methods such as scanning thermal microscopy, and optical techniques such as infrared microscopy and thermoreflectance. Their principles, characteristics and applications are discussed.

Findings

Thermal issues play an important part in optimizing the performance and reliability of high‐frequency and high‐packing density electronic circuits. To improve the performance and reliability of microelectronic devices and also to validate thermal models, accurate knowledge of local temperatures and thermal properties is required.

Originality/value

The paper provides readers, especially technical engineers in industry, a general knowledge of several commonly used thermography techniques in the semiconductor and micro‐device industries.

Details

Sensor Review, vol. 27 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 6 February 2009

Henna Heinilä, Jarno Riistama, Pekka Heino and Jukka Lekkala

The purpose of this paper is to present the stages for manufacturing a low‐cost miniaturized prototype device, which observes the restrictions of implantable medical devices. The…

Abstract

Purpose

The purpose of this paper is to present the stages for manufacturing a low‐cost miniaturized prototype device, which observes the restrictions of implantable medical devices. The device measures the electrocardiography. The power for the implant is received passively as the same magnetic field as data is transferred to the reader device.

Design/methodology/approach

In this manufacturing technique, only easily attachable commercial available components are used, etching is used to simply produce a low‐cost double‐sided flexible printed circuit board which is converted to 3D by folding.

Findings

The circuit board was folded into the final shape after component attachment and the final result was a compact 3D package within the specifications determined by the electronics designer. The miniaturized prototype device was successfully tested both in vitro and in vivo.

Originality/value

The manufacturing technique of the sensing device can be readily adapted to other devices that need to be miniaturized. The coatings used for electrical insulation and chemical protection and the type of adhesives used for folded packages are easily utilized in similar miniaturization prototypes. By using bare chips, the final product would have been even smaller but for prototyping it is cheaper and faster to use easily acquired and attached components. In the case of mass production, the whole new design, where bare chips with flip chip attachments, integrated passives and/or stacked 3D packages with design considerations such as electrical, thermal and mechanical engineering is justified.

Details

Circuit World, vol. 35 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 24 July 2020

Keita Matsuo and Leonard Barolli

Recently, Internet of Things (IoT) devices and sensors are rapidly increasing in the word. They are connecting to the internet and are generating vast packets in the network…

Abstract

Purpose

Recently, Internet of Things (IoT) devices and sensors are rapidly increasing in the word. They are connecting to the internet and are generating vast packets in the network. Thus, the networks could be congested, and the performance will degrade. For this reason, it is important to decrease the number of transmitted packets. Agile is a technique to develop the software and manage the work efficiently. Kanban is a method to support Agile development. The purpose of this paper is to propose an IoT sensors management system considering Agile–Kanban and show its application for weather measurement and electric wheelchair management.

Design/methodology/approach

The authors present the design and implementation of two systems and show the measurement device, data communication failure and experimental results.

Findings

The proposed Agile–Kanban system can manage a large amount of IoT sensors and can decrease the IoT sensor’s consumption power thus increasing the IoT sensor lifetime.

Originality/value

By experimental results, the authors have shown that the proposed systems have good performance and can control the IoT devices efficiently.

Details

International Journal of Web Information Systems, vol. 16 no. 3
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 16 November 2021

Krzysztof Posobkiewicz and Krzysztof Górecki

The purpose of this study is to investigate the validation of the usefulness of cooling systems containing Peltier modules for cooling power devices based on measurements of the…

Abstract

Purpose

The purpose of this study is to investigate the validation of the usefulness of cooling systems containing Peltier modules for cooling power devices based on measurements of the influence of selected factors on the value of thermal resistance of such a cooling system.

Design/methodology/approach

A cooling system containing a heat-sink, a Peltier module and a fan was built by the authors and the measurements of temperatures and thermal resistance in various supply conditions of the Peltier module and the fan were carried out and discussed.

Findings

Conclusions from the research carried out answer the question if the use of Peltier modules in active cooling systems provides any benefits comparing with cooling systems containing just passive heat-sinks or conventional active heat-sinks constructed of a heat-sink and a fan.

Research limitations/implications

The research carried out is the preliminary stage to asses if a compact thermal model of the investigated cooling system can be formulated.

Originality/value

In the paper, the original results of measurements and calculations of parameters of a cooling system containing a Peltier module and an active heat-sink are presented and discussed. An influence of power dissipated in the components of the cooling system on its efficiency is investigated.

Details

Microelectronics International, vol. 39 no. 4
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 5 July 2021

Rodrigo Magana Carranza, Joseph Robinson, Ian Ashton, Peter Fox, Christopher Sutcliffe and Eann Patterson

The purpose of this paper is to detail the design and first use of a force transducer device to study the development of forces during the laser-powder bed fusion (L-PBF) process…

Abstract

Purpose

The purpose of this paper is to detail the design and first use of a force transducer device to study the development of forces during the laser-powder bed fusion (L-PBF) process from which residual stresses can be inferred.

Design/methodology/approach

The proposed novel device consists of an array of load cells for in-situ measurement of forces over time during the L-PBF additive manufacturing process. Measurements of the developed forces layer by layer were recorded in a first build using a 67-degree rotating scan strategy using Inconel 625 build material.

Findings

Preliminary experimental results from in-situ measurements using a 67-degree rotating scan strategy showed that the forces induced in the first five layers represented approximately 80% of the maximum on completion of the build and were distributed such as to induce concave deformation of the part, i.e. tension in the centre and compression at the edges of the part.

Originality/value

This paper describes a novel device for in-process measurement of the spatial distribution and time-varying nature of the forces induced during the L-PBF process as well as an evaluation of the residual forces following the completion of the build.

Details

Rapid Prototyping Journal, vol. 27 no. 7
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 March 2005

D. Desideri, M. Bagatin, M. Spolaore, V. Antoni, R. Cavazzana, E. Martines, G. Serianni and M. Zuin

The aim of this paper is to obtain an extensive experimental characterization of a DC magnetron sputtering device used for plasma processing of materials.

1659

Abstract

Purpose

The aim of this paper is to obtain an extensive experimental characterization of a DC magnetron sputtering device used for plasma processing of materials.

Design/methodology/approach

Models and measurements are combined for an interdisciplinary characterization of a DC magnetron sputtering device. Langmuir probes are used for the plasma characterization; the magnetic field is measured by using Hall probes and the data are used to validate a magnetostatic three‐dimensional numerical analysis of the device; precision mechanical measurements are done for the target erosion profile and the results are related to a simple estimation formula; a simple model is proposed for the target heating.

Findings

Data on magnetic and electric fields, electron temperature and density, plasma potential and target erosion are provided. An estimation of the target heating is proposed. Finally, an application concerning thin film deposition is reported.

Research limitations/implications

Measurement of the target surface temperature for the validation of the proposed target heating estimation has not been done.

Originality/value

In the field of the electromagnetic processing of materials, the reported extensive device characterization is a valuable set of information for an optimized utilization of DC magnetron sputtering devices.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 24 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Open Access
Article
Publication date: 14 July 2023

David S. Bedford, Markus Granlund and Kari Lukka

The authors examine how performance measurement systems (PMSs) and academic agency influence the meaning of research quality in practice. The worries are that the notion of…

Abstract

Purpose

The authors examine how performance measurement systems (PMSs) and academic agency influence the meaning of research quality in practice. The worries are that the notion of research quality is becoming too simplistically and narrowly determined by research quality's measurable proxies and that academics, especially manager-academics, do not sufficiently realise this risk. Whilst prior literature has covered the effects of performance measurement in the university sector broadly and how PMSs are mobilised locally, there is only little understanding of whether and how PMSs affect the meaning of research quality in practice.

Design/methodology/approach

The study is designed as a comparative case study of two university faculties in Finland. The role of conceptual analysis plays a notable role in the study, too.

Findings

The authors find that manager-academics of the two examined faculties have rather similar conceptual understandings of research quality. However, there were differences in the degree of slippage between the “espoused-meaning” of research quality and “meaning-in-practice” of research quality. The authors traced these differences to how the local PMS and manager-academics’ agency relate to one another within the context of increasing global and national performance pressures. The authors developed a tentative framework for the various “styles of agency”. This suggests how the relationship between the local PMS and manager-academics’ exerted agency shapes the “degrees of freedom” of the meaning of research quality in practice.

Originality/value

Given that research quality lies at the heart of academic work, the authors' paper indicates that exploring the three matters – performance measurement, the agency of manager-academics and the meaning of research quality in practice – in combination is crucial for the sustainability of the academe. The authors contribute to the literature by detailing the way in which local PMS and manager-academics' agency have material impacts on what research quality means in practice. The authors conclude by highlighting the pressing need for manager-academics to exercise the agency in efforts to safeguard a broad and pluralistic understanding of research quality in practice.

Details

Accounting, Auditing & Accountability Journal, vol. 36 no. 9
Type: Research Article
ISSN: 0951-3574

Keywords

1 – 10 of over 29000