1,723,387 research outputs found
The performance of subset response surface designs for estimating third order terms
No full textResponse surface designs are widely used in industries like chemicals, foods, pharmaceuticals, bioprocessing, agrochemicals, biology, biomedicine, agriculture and medicine. One of the major objectives of these designs is to study the functional relationship between one or more responses and a number of quantitative input factors. However, biological materials have more run to run variation than in many other experiments, leading to the conclusion that smaller response surface designs are inappropriate. Thus designs to be used in these research areas should have greater replication. Gilmour (2006) introduced a wide class of designs called "subset designs" which are useful in situations in which run to run variation is high. These designs allow the experimenter to fit the second order response surface model. However, there are situations in which the second order model representation proves to be inadequate and unrealistic due to the presence of lack of fit caused by third or higher order terms in the true response surface model. In such situations it becomes necessary for the experimenter to estimate these higher order terms. In this study, the properties of subset designs, in the context of the third order response surface model, are explored.</p
Customer Participation and Product Innovation in the Era of Industry 4.0 and 3D Printing: Evidence at Firm and Individual-Level
Full text linkMy PhD dissertation consists of two chapters which empirically analyse the impact of the modern technologies of Industry 4.0 on customer participation (CP) in new product development (NPD) process of firms in general, and the impact of 3D printing on individual-level innovation performance in particular. These studies aim to contribute to the debate on the evolution of CP from customers as passive recipients of products offered by firms to independent makers of their desired products.
Initially, customers had no input in what was offered to them, and they were the submissive recipients of firms’ products. The market was perceived as the aggregate of demand and value transfer, whereas companies were the points of value creation (Kotler, 2002; Vargo & Lusch, 2004). With the advent and omnipresence of the Internet, information asymmetry reduced between firms and customers. As a result, the customers started taking part in the NPD process as mere information providers to active partners. Consequently, active customers happened to appear as lead users (Von Hippel, 1986) whose opinion carried weight which could influence the changes in product features and subsequent adoption of products by other customers. Companies also realized the importance of customers’ feedback and opinion; hence, CP evolved further, and customers were provided with toolkits (Von Hippel, 2001b). “User toolkits for innovation” provided customers with a free environment within defined bounds related to specific products and allowed them to develop their customized products via trial-and-error. Customers also started forming virtual customer communities (Nambisan, 2002) to discuss the ideas and information regarding products and desired new features. But it is the recent work which has given formal recognition to CP in NPD (Chang & Taylor, 2016) by acknowledging various participation roles a customer can
7
take on in NPD, e.g. a customer as an information source, a co-developer and an innovator (Cui & Wu, 2016; 2017).
The world is forecasting the fourth industrial revolution prompted by advanced technologies, and the twenty-first century demands technological innovation and novel product development approach (L. Li, 2018a). The term ‘Industry 4.0’ (German: Industrie 4.0) – representing the much-anticipated fourth industrial revolution symbolising the increased use of modern technologies in the manufacturing process of firms – was coined at ‘Hannover Messe 2011’ in Germany as part of its high-tech strategy to sustain the competitive advantage and meet the requirements of future production. Other countries have also initiated similar ventures and use different terminologies like ‘Internet of Things’ in the United States and ‘Made-in-China 2025’ in China to represent the phenomenon of Industry 4.0. Consequently, there is an increasing trend of investment by firms in the technologies associated with Industry 4.0. Although some of these technologies like robotics, 3D printing, laser cutting are in use since over two decades, many of Industry 4.0 applications necessitate the combination of these technologies (Xu et al., 2018). However, the connectivity between these technologies is not extensively discussed before 2011. But now, the discussion has started as the technologies have reached a mature state of application and are materialized under the concept of Industry 4.0 (Santos et al., 2017). According to Gilchrist (2016), “Industry 4.0 is essentially a revised approach to manufacturing that makes use of the latest technological inventions and innovations, particularly in merging operational and information and communication technology.”
The first chapter of this thesis is a firm-level analysis which focuses on analysing the impact of Industry 4.0 technologies on CP in firms’ NPD process where customers work as co-developers. Customer participation is defined as the magnitude of the customer’s engagement in
8
the company’s NPD process (Fang, 2008). Scholars consider the investment in modern technologies a significant internal factor to cater to customized demand of consumers (Kotha, 1996). Industry 4.0 technologies are interactive because of the digital connectivity of tools and remote inputs and have the potential to take the magnitude of customer’s participation to a higher level and engage them in the product design and production process. Hence, it is essential to empirically investigate this claim as the Industry 4.0 technologies will not only help to develop new products and services (Lee et al., 2014), but the provision of customized products will also help to reduce the number of goods returned. For empirical analysis, we collected the data from 123 North Italian firms by using a structured questionnaire targeted to chief operating officers or managers in charge of technological and manufacturing processes. The firms were currently using Industry 4.0 technologies like 3D scanner, additive manufacturing, IoT and intelligent products, robotics, big data and cloud, augmented reality and laser cutting.
Another facet of recent technological scenario is that it takes the empowerment of customers and end-users one step further from toolkits and customer communities. Now some technologies are in direct reach and use of individuals. One potentiality linked with such technologies, especially 3D printing (3DP), is the transformation of customers into real “makers” (Anderson, 2012). 3DP is “a process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies” (ASTM, 2012). A computer-aided design (CAD) file of the object idea is generated by using a software which contains all the information of the physical object. To develop the physical object, the 3D printer receives the print command and based on the digital file, transforms the information in the arrangement of material layers upon layers. As the material layers bind together directly from a CAD file, it reduces the product development time and intensity of physical flows (Holmström et
9
al., 2017). The additive style of manufacturing also eliminates many intermediaries like labour (Ford & Despeisse, 2016) and expensive and time-consuming tools. 3DP is ideal for the economies-of-one and is not resource-intensive. These features make 3DP ideal for end-user and open innovation. Subsequently, 3DP aids firms as well as individual makers to execute a project from the design stage to final output (Rayna & Striukova, 2016a).
Apart from knowledge creation and social exchange, the use of technology forms the basis of the relationship of makers movement with entrepreneurship (Browder et al., 2019). The prices have decreased considerably, and 3DP is in access to end-user and makers. Recent research shows that makerspaces are significant platforms for 3DP spread and adoption (Woodson ey al., 2019). 3DP has the potential to empower makers and boost end-user innovation and entrepreneurship linked with the maker movement. Despite the increasing importance and relevance of 3DP, very little is known about the factors affecting the acceptance and use of 3DP among the exiting users. More importantly, the impact of the use of 3DP on innovation performance is not empirically acknowledged at individual-level.
The second chapter is an individual-level empirical analysis of the factors affecting the acceptance and use of 3DP by makers in makerspaces. Makerspaces have been used as local places of shared resources and provision of manufacturing technologies that are not as commonly available as internet connectivity and computers (Kostakis et al., 2015). This chapter uses an extended model of the unified theory of acceptance and use of technology 2 (UTAUT2) (Venkatesh et al., 2012) to explore the factors affecting the acceptance and use of 3DP by makers. The model is extended on the outcome side to analyse the impact of the use by incorporating a new construct, ‘innovation performance’ as a consequence of use. For empirical analysis, I developed a survey, using the scales validated by exiting studies and distributed it to the visitors
10
of makerspaces registered on three platforms; hackerspaces.org, makerspaces.make.co and fabfoundattion.org and had the facilities of 3DP. In total, 338 responses were used for the empirical analysis of the study.
The results of the first chapter confirm that the use of Industry 4.0 technologies does have a positive impact on CP in the development of product design and production process of the firms. The effect is stronger for CP in design than CP in the production process. The firms which report product flexibility as their competitive advantage, are more like to allow CP in the product design and production process. The findings of the second chapter, focused at the individual-level adoption and impact of 3DP on innovation performance, show that the makers are adopting 3DP printing because they expect an increase in their performance and the opinion of the important people around them also matters in the adoption decision. Empirical results indicate that the adoption of 3DP also depends on the availability of facilitating conditions and the hedonic motivation extracted from the use of 3DP. The results also provide empirical evidence of the impact of the use of 3DP on makers’ innovation performance
Industry 4.0 and co-creation in new product development
No full textThe value delivered to consumers depends on providing superior and reliable service using
technology. The technologies of Industry 4.0 are interactive in nature, but literature lacks
the studies focusing on analyzing their impact on new product development and customer
participation therein. This empirical work on made in Italy firms is aimed at extending the
implication of customer participation in product development in Industry 4.0 settings. The
results show that Robotics, Laser Cutting and Augmented reality have positive impact on
customer participation and the companies with increased use of Industry 4.0 technologies
allow more customer participation in product development. Study also offers practical
implications for managers and a guideline for the firms which have already invested or
planning to invest in Industry 4.0 technologies
Customer participation in new product development: an Industry 4.0 perspective
Full text linkPurpose – The use of modern technologies of the fourth industrial revolution, commonly known as “Industry 4.0” (I4.0), is believed to have considerable potential for product customisation. In this context, this paper aims to explore whether or not using these technologies impacts customer participation (CP) in a firm’s new product development (NPD) process.
Design/methodology/approach – To empirically test the proposed relationships, the authors collected the North Italian manufacturing firms’ data and applied regression analysis.
Findings – Empirical results indicate that, on the one hand, the technologies have their specific and individual impacts, and on the other hand, the firms which use more I4.0 technologies allow more customer participation in their product design and production process. This positive impact is more robust in product design than in the production process.
Practical implications – Managers aiming to benefit from CP should broaden the scope of adopting I4.0 technologies and consider different roles concerning the design and production phases of the new product development process. Recognising the importance and allowing CP in NPD will enable firms to meet the customised demands.
Originality/value – To the best of the authors’ knowledge, the proposed relationships of this study have been extensively debated theoretically in the I4.0 context but never empirically tested before. It is one of the few studies which discusses the strategic adoption and the combined use of I4.0 technologies to create more opportunities for product customisation
Thermal management of electronics: An experimental analysis of triangular, rectangular and circular pin-fin heat sinks for various PCMs
No full textThis study implies experimental investigation for optimization of heat transfer in electronic integrated circuits using close packed phase change materials (PCMs) filled pin-fin heat sinks. The aim of this study is to find the most efficient pin-fin configuration filled with optimum PCM to extend the operating range of electronic circuits. The experimental methodology is based upon variation of pin-fin configurations in rectangular, round and triangular cross-sections. Each configuration is allowed a pin-fin volumetric percentage of 9%. For analysis using PCM a volume fraction of 90% is maintained and six PCMs with different thermo-physical properties (varying melting temperatures, latent heats and heat capacities) are selected. These include paraffin wax, RT-54, RT-44, RT-35HC, SP-31 and n-eicosane. Moreover, the power levels mimicking heat input range between 5 W and 8 W. The resulting information is analyzed for the performance of a heat sink with and without PCM. Besides that, PCM ascendency is manipulated in terms of operational time, enhancement ratios, Stefan number and storage ratio. The outcomes suggest that triangular pin-fins are found to be the most effective pin-fin configuration for heat transfer both with and without PCM
Elektronik kutular için bir eksenel akış fanının performans karakterizasyonu ve optimizasyonu
No full textThermal management of high power electronic components have become a challenging and critical issue for thermal engineers. Forced convection electronic enclosures comprises of fans to provide fluid flow through the system to remove heat efficiently. In this study, performance characterization of an axial fan for electronic enclosures has been performed computationally and experimentally. For this purpose, by using the three-dimensional CAD model of a fan with Computational Fluid Dynamics (CFD) are evaluated in comparision with the experimental data. An experimental system was designed and built for the validation of numerical models. All the measurements were carrried out in a wind tunnel which was designed and manufactured according to the Air Movement Control Assosciation (AMCA) standard 210-99, 1999. In order to make relevant comparisions, a detailed computational model of the wind tunnel setup along with the fan were modeled. Moving Reference Frame (MRF) technique is used for the modelling of an axial fan and the simulations were performed by utilizing realizable k–ε turbulence model with enhanced wall function to determine flow and pressure fields over a range of flow rates. Experimental investigation in the wind tunnel by measuring the pressure rise and flow rate through the fan by using multiple nozzles which was also designed and manufactured according to the Air Movement Control Assosciation (AMCA) standard 210-99, 1999. Understanding of the overall fan efficiency as a function of the volumetric flow rate and th improvement concerning with the losses occur across the fan are described. In the second phase of the study, power losses of an axial fan are investigated to determine the effect different components on the overall efficiency. Moreover, it deals with the modeling of mechanical, electrical, thermal and electromagnetic losses which focus especially on an outer rotor brushless DC motor. Efficiency of a fan depends on its electrical and mechanical designs as well as the environmental conditions that the fan is exposed to. Typically, the overall efficiency of an axial fan varies between 15 to 40 percent. Power losses may be due to electrical, aerodynamic or mechanical design components. Losses occurring in an axial fan motor have become a critical issue in which high inertial effects, low power, low cost and high efficiency are desired. In order to design an efficient motor, it is important to accurately predict the power losses which are usually dissipated in the form of heat. Reduction of these losses leads to a decrease in the motor temperature and, therefore, has a positive effect on the fan reliability. Expressions for calculating the inverter losses, motor losses and mechanical losses are derived. The power losses obtained are then used as heat sources when evaluating the thermal performance of the motor. By using a two-dimensional model, computational fluid dynamics (CFD) simulations are performed to analyze the core loss distribution across the motor. The results are utilized to determine evaluate the overall efficiency of the system.Yüksek güçlü elektronik komponentlerin ısıl yönetimi, termal mühendisler için zorlayıcı ve kritik bir problem haline gelmiştir. Zorlanmış taşınımlı elektronik mahfazalar, sistemdeki ısıyı verimli bir şekilde ortadan kaldırmak için akış yaratan fanlardan oluşmaktadır. Bu çalışma kapsamında, elektronik mahfazalarda kullanılan eksenel bir fanın performans karakterizasyonu üzerine sayısal ve deneysel çalışmalar gerçekleştirilmiştir. Bu amaç ile bir fanın üç boyutlu CAD modeli kullanılarak hesaplamalı akışkanlar dinamiği ile deneysel veriler ile karşılaştırılması yapılmıştır. Sayısal modellerin doğrulamasını yapmak amacıyla bir deneysel düzenek tasarlanmış ve kurulmuştur. Tüm ölçümler, Air Movement and Control Association (AMCA- Hava Hareket ve Kontrol Kurumu) 210-99,1999 standardına uygun olarak tasarlanmış ve üretilmiş bir rüzgar tüneli içerisinde gerçekleştirilmiştir. Tutarlı karşılaştırmalar yapmak adına, fan ile birlikte rüzgar tüneli düzeneğinin sayısal modeli hazırlanmıştır. Eksenel bir fanın modellemesi sırasında Hareketli Referans Çerçevesi (Moving Reference Frame) tekniği kullanılır. Akış hızları aralığı üzerine, akış ve basınç alanlarına karar vermek için geliştirilmiş duvar fonksiyonu ile gerçekleştirilebilir k–ε türbülans modeli kullanılarak simülasyonlar yapılmıştır. Rüzgar tünelinde yapılan deneysel araştırmalar, fandan kaynaklanan basınç artışı ve akış hızı ölçülerek tamamlanmıştır. Bu ölçümler sırasında AMCA 210-99, 1999 standardına uygun olarak tasarlanmış ve üretilmiş birden fazla çıkış ağzı (nozzle) kullanılmıştır. Fanın toplam verimlilik kavramı, hacimsel debiye ve fan boyunca oluşan kayıplar ile ilgili gelişmelere bağlı bir fonksiyon olarak tanımlanmaktadır. Çalışmanın ikinci fazında, farklı komponentlerin genel verim üzerindeki etkisini görmek amacıyla eksenel fanın güç kayıpları araştırılmaktadır. Dahası, güç kayıpları özellikle fırçasız doğru akım motorunun dış rotoruna odaklı mekanik, elektriksel, termal ve elektromanyetik kayıpların modellemesi ile bağlantılıdır. Bir fanın verimliliği, elektriksel ve mekanik tasarımına bağlı olmakla birlikte fanın maruz kaldığı çevre koşullarına da bağlıdır. Genellikle, bir eksenel fanın toplam verimliliği %15 ila %40 arasında çeşitlilik göstermektedir. Güç kayıpları; elektriksel, aerodinamik veya mekanik tasarım parçalarından kaynaklanabilir. Yüksek atalet etkisi, düşük güç, düşük maliyet ve yüksek verim beklendiğinde, eksenel fanlar üzerinde oluşan kayıplar kritik bir problem haline gelir. Verimli bir motor tasarlamak için genellikle ısı formunda oluşan güç kayıplarını doğru olarak öngörmek önemlidir. Bu kayıpların giderilmesi motor sıcaklığının düşmesine yol açar ve bu sayede, fanın güvenilirliğini arttırır. Evirici kayıpları, motor kayıpları ve mekanik kayıpları hesaplamak için formüller türetilmiştir. Güç kayıpları belirlenmiş ve sonra motorun termal performansını değerlendirmek için güç kaynağı olarak kullanılmıştır. İki boyutlu bir model kullanılarak, motor üzerindeki çekirdek kaybı dağılımını analiz edebilmek amacı ile hesaplamalı akışkanlar dinamiği (HAD) simülasyonları üzerine çalışılmıştır. Sonuçlar, sistemin genel verimliliğine karar verebilmek için kullanılmıştır
An investigation into performance characteristics of an axial flow Fan using CFD for electronic devices
No full textDue to copyright restrictions, the access to the full text of this article is only available via subscription.Rotating fans are widely utilized in thermal management applications and their accurate characterization has recently become even a more critical issue for thermofluids engineers. The present study investigates the characterization of an axial fan computationally and experimentally. Using the three-dimensional CAD models of the fan, a series of computational fluid dynamics (CFD) simulations were performed to determine the flow and pressure fields produced by the axial mover over a range of flow rates. In order to validate the computational model findings, experiments were conducted to obtain the pressure drop values at different flow rates in an AMCA (Air Movement and Control Association) standard 210-99, 1999 wind tunnel. These data sets were also compared with the fan vendor’s published testing data. A reasonably good agreement was obtained among the data from these three separate sources. Furthermore, an attempt was made to understand the overall fan efficiency as a function of the volumetric flow rate. It was determined that the maximum overall fan efficiency was less than 27% correlating well with the computational results
Phase change material applications in thermal management of electronics and electrical systems
No full textThe escalating power densities and shrinking size of electronic devices present formidable challenges in achieving effective thermal management, particularly for high-performance chips. The failure rate of electronic devices exhibits an exponential rise with escalating operating temperatures. The prevailing design trend in modern electronics, characterized by smaller and faster components, engenders elevated power densities, heightened operating temperatures, and compromised performance and longevity of electronic devices. In light of these challenges, researchers have been actively investigating the applicability of phase change materials in electronic cooling. This chapter provides an exposition of these materials as a prospective solution for electronic cooling, with a particular focus on passive and hybrid cooling methodologies. Passive cooling methods include phase change material-enhanced heat sinks, heat pipes, and phase change material-integrated thermal interface materials. Hybrid cooling systems, on the other hand, involve the integration of phase change materials in conjunction with air, liquid, and thermoelectric cooling techniques. These cooling methodologies hold immense promise in augmenting heat dissipation and averting overheating, thereby ensuring the attainment of optimal performance and prolonged lifespan for electronic devices
A flexible resistive Read-Out Circuit suitable to multi-purpose ZnO nanostructured transducers for robotic applications
No full textAugmented box-behnken designs for fitting third-order response surfaces
No full textBox-Behnken designs are popular with experimenters who wish to estimate a second-order model, due to their having three levels, their simplicity and their high efficiency for the second-order model. However, there are situations in which the model is inadequate due to lack of fit caused by higher-order terms. These designs have little ability to estimate third-order terms. Using combinations of factorial points, axial points, and complementary design points, we augment these designs and develop catalogues of third-order designs for 3–12 factors. These augmented designs can be used to estimate the parameters of a third-order response surface model. Since the aim is to make the most of a situation in which the experiment was designed for an inadequate model, the designs are clearly suboptimal and not rotatable for the third-order model, but can still provide useful information
- …
