Search results

FOV splicing optical remote sensing instruments have a strict requirement for the focal length consistency of the lens. In conventional optical-mechanical structure design, each optical element is equally distributed with high accuracy and everyone must have a high machining and assembly accuracy. For optical remote sensors with a large number of optical elements, this design brings great difficulties to lens manufacture and alignment.

Taking the relay lens in an optical remote sensing instrument with the field of view splicing as an example, errors of the system are redistributed to optical elements. Two optical elements, which have the greatest influence on modulation transfer function (MTF) of the system are mounted with high accuracy centering and the other elements are fixed by gland ring with common machining accuracy. The reduction ratio consistency difference among lenses is compensated by adjusting the optical spacing between the two elements.

Based on optical system simulation analysis, the optimized structure can compensate for the difference of reduction ratio among lens by grinding the washer thickness in the range of ±0.37 mm. The test data for the image quality of the lens show that the MTF value declined 0.043 within ±0.4 mm of space change between two barrels. The results indicate that the reduction ratio can be corrected by adjusting the washer thickness and the image quality will not obviously decline.

This paper confirms that this work is original and has not been published elsewhere nor is it currently under consideration for publication elsewhere. In this paper, the optimum structural design of the reduction relay lens for the field of view stitching applications is reported. The method of adjusting washer thickness is applied to compensate for the reduction ratio consistency difference of lenses. The optimized structure also greatly reduces the difficulty of lenses manufacture, alignment and improves the efficiency of assembly.

Purpose – To provide strategic management scholars, particularly graduate students and new faculty members, a novel approach, the lens model, to investigate emerging economies phenomena.

Design/methodology/approach – Based on a review of the strategic management literature and a search of the strategy databases and journals, I propose the lens model approach and discuss its origins, development, and designs since its introduction. It has been used extensively in such fields as cognitive psychology, social psychology, medicine, agriculture, human resources management, and organizational behavior. Besides the wide application, it has relevance for strategic management research.

Findings – An illustrative study and a summary of the approach from a previous study in one prominent journal are also provided as guides. I conclude by providing recommendations on what to consider in using the approach for the study of emerging economies.

Research limitations/implications – In addition to the strengths of the approach, its weaknesses are also discussed. Suggestions on maximizing the potential of the approach are also discussed.

Practical implications – The approach is an invaluable source particularly for graduate students of strategy who often are unfamiliar with microlevel approaches. They can use it to supplement approaches for strategic management.

Originality/value – To my knowledge, this chapter is the first to discuss the lens model approach in the strategic management literature. In that regard, it fills a gap in the research methodology literature. It can therefore help graduate students improve their careers.

This paper aims to explore a transdisciplinary approach to the careers and employability education of transnational education (TNE) students of higher education. It proposes that an approach which adopts three lenses of academic study, lived experience and career stage can provide maximum benefits to the TNE students' careers education, particularly in response to the modern workplace. The study aims illustrate the potential benefits of such an approach to multiple stakeholders within higher education.

This paper adopts a viewpoint approach drawing on higher education career service practitioner-based experience of using a specific approach to employability with TNE students studying with a large university based in the UK. Student evaluation data from this practice are referred to in the paper.

This paper provides insights into how this approach to employability was received by higher education TNE students who participated in a pilot project led by a higher education careers service, which adopted the three lenses approach.

This paper illustrates how a transdisciplinary approach to the careers and employability education of TNE students can be of significant value to the higher education students themselves, the institutions within which they study and the graduate recruiters looking to attract future employees for the workplaces of the future. It is hoped that by sharing this approach more stakeholders within the TNE and careers and employability communities within higher education will adopt a similar approach.

This article explicates the notion of using a “theoretical lens” to interpret research data, which has grown increasingly common in recent decades, often without a second thought about the implications of use of a mere metaphor in the pursuit of truth. Poets may not question that metaphors reveal truths, but should social scientists accept that?

It looks first at what theory means, then – and in greater detail – what the metaphor of a lens entails.

Drawing on the base analogy in optics, it identifies four mechanisms through which theory might act as a lens – adjustment, correction, distortion and augmentation-suppression, with examples based on theories of business strategy and organisation studies.

These four mechanisms involve two different ways of seeing – better and differently. With adjustment and correction see better what is, or perhaps what was. With distortion and especially augmentation-suppression, we see differently, which helps us imagine what might be, or what we might have overlooked. They help us escape narrow silos of thinking. Researchers and students alike need to be aware of all four lenses of theory and be ready to experiment.

It argues that if some theories try to help us see better, others push us to see differently, with implications for the practice and teaching of research methods.

The purpose of this study is to calibrate a microstructure-based fatigue model for its use in predicting fatigue life of additively manufactured (AM) Ti-6Al-4V. Fatigue models that are capable of better predicting the fatigue behavior of AM metals is required to further the adoption of such metals by various industries. The trustworthiness of AM metallic material is not well characterized, and fatigue models that consider unique microstructure and porosity inherent to AM parts are needed.

Various Ti-6Al-4V samples were additively manufactured using Laser Engineered Net Shaping (LENS), a direct laser deposition method. The porosity within the LENS samples, as well as their subsequent heat treatment, was varied to determine the effects of microstructure and defects on fatigue life. The as-built and heat-treated LENS samples, together with wrought Ti-6Al-4V samples, underwent fatigue testing and microstructure and fractographic inspection. The collected microstructure/defect statistics were used for calibrating a microstructure-sensitive fatigue model.

Fatigue lives of the LENS Ti-6Al-4V samples were found to be consistently less than those of the wrought Ti-6Al-4V samples, and this is attributed to the presence of pores/defects within the LENS material. Results further indicate that LENS Ti-6Al-4V fatigue lives, as predicted by the used microstructure-sensitive fatigue model, are in close agreement with experimental results. The used model could predict upper and lower prediction bounds based on defect statistics. All the fatigue data were found to be within the bounds predicted by the microstructure-sensitive fatigue model.

To further test the utility of microstructure-sensitive fatigue models for predicting fatigue life of AM samples, future studies on additional material types, additive manufacturing processes and heat treatments should be conducted.

This study shows the utility of a microstructure-sensitive fatigue model for use in predicting the fatigue life of LENS Ti-6Al-4V with various levels of porosity and while in a heat-treated condition.

This paper aims to present a comprehensive review of the laser engineered net shaping (LENS) process in an attempt to provide the reader with a deep understanding of the controllable and fixed build parameters of metallic parts. The authors discuss the effect and interplay between process parameters, including: laser power, scan speed and powder feed rate. Further, the authors show the interplay between process parameters is pivotal in achieving the desired microstructure, macrostructure, geometrical accuracy and mechanical properties.

In this manuscript, the authors review current research examining the process inputs and their influences on the final product when manufacturing with the LENS process. The authors also discuss how these parameters relate to important build aspects such as melt-pool dimensions, the volume of porosity and geometry accuracy.

The authors conclude that studies have greatly enriched the understanding of the LENS build process, however, much studies remains to be done. Importantly, the authors reveal that to date there are a number of detailed theoretical models that predict the end properties of deposition, however, much more study is necessary to allow for reasonable prediction of the build process for standard industrial parts, based on the synchronistic behavior of the input parameters.

This paper intends to raise questions about the possible research areas that could potentially promote the effectiveness of this LENS technology.

This paper uses practice theory to strengthen the theoretical relationship between customer engagement (CE) and value cocreation (VCC), thereby demonstrating how customers may become engaged and remain engaged through VCC practices.

The study adopts a problematization approach to identify shared assumptions evident in service-dominant logic (SDL) and CE research. Practice theory, as a higher-order perspective, is used to integrate the iterative and cyclical processes of VCC and CE, specifically through the theoretical mechanism of habitus.

Habitus acts as a customer value lens and provides a bridging concept to demonstrate how VCC and CE are joined via sensemaking processes. These processes determine how customers perceive, assess, and evaluate value, how they become engaged through VCC, and how their experience of engagement may lead to further VCC practice. The temporally bound experiences, states, and episodes are accumulated and aggregated through an enduring customer value lens comprised of habituated dispositions, interests, and attitudes.

This work responds to calls for research to strengthen the theoretical link between VCC and CE and to take account of customers' lived realities and their contextualized experiences. A key suggestion for future research is the use of a rope metaphor to stimulate thinking about the complex, temporally unfolding, and interrelated processes of VCC and CE.

The customer value lens and CE rope are introduced to simplify the complex, abstract, theoretical research on VCC and CE for a nonacademic audience. To understand how customers' value lenses are formed and change, and how a CE rope is strengthened, firms, service designers, and practitioners need to understand sensemaking processes through customer narratives and to use platforms and feedback to support and trigger sensemaking.

This paper provides a theoretical mechanism to explain the iterative and cyclical nature of VCC and CE processes and how accumulation and aggregation occur in these processes. In doing so, it demonstrates that CE occurs by virtue of, and is typified by, sensemaking processes that reproduce and shape a customer's habituated value lens, which perceives, assesses, and determines VCC and thus provides a basis for further customer engagement.

The aim of the research is to perform an accurate micromanipulation task, the assembly of a lens system, implementing safe procedures in a flexible microrobot‐based workstation for micromanipulation.

The approach to the micromanipulation research issue consists in designing and building a micromanipulation station based on mobile microrobots, with 5 degrees of freedom and a size of a few cm³, capable of moving and manipulating by the use of tube‐shaped and multilayered piezo‐actuators. Controlled by visual and force/tactile sensor information, the micro‐robot is able to perform manipulation with a motion resolution down to 10 nm in a telemanipulated or semi‐automated mode, thus freeing human operators from the difficult task of handling minuscule objects directly. Equipped with purposely‐developed grippers, the robot can take over high‐precise grasping, transport, manipulation and positioning of mechanical or biological micro‐objects. A computer system using PC‐compatible hardware components ensures the robot operation in real‐time.

The robots and the grippers described in this paper are highly interesting tools. Even if each specific application may require specific modifications, the proposed solution is extremely versatile, due to the ability to manipulate with a very large stroke (being the size of the base the robot works on) with a very high motion resolution. These positive aspects do make the robots very suitable also for working in a scanning electron microscope, for wafer inspection in a laboratory, and so on.

Future work will include modifications to the existing system in order to enhance the flexibility of the workstation: e.g. other robots and other tools with different characteristics will be designed and fabricated. Research efforts will be devoted in particular to further miniaturization of the actuators.

This workstation can be used as a platform for assembling novel prototypes, and as a test bench for testing new assembly procedures or new products, e.g. the lens assembly procedure described in this work, even if not suitable for mass production, was useful to assess the performance of the two‐lenses assembly system itself, compared to standard systems with just one lens.

The system proves that the development of mobile micro‐robots is a promising approach to realise very small and flexible tools useful for different applications. By means of its intuitive teleoperation mode, the system enables the user to work in the micro‐world; due to the force feedback the user is almost immersed into the micro‐world and gets a sense for the handled object.

An Autodesk Ember three-dimensional (3D) printer was used to print optical components from Clear PR48 photocurable resin. The cured PR48 was characterized by the per cent of light transmitted and the index of refraction, which was measured with a prism spectrometer. Lenses and diffraction gratings were also printed and characterized. The focal length of the printed lenses agreed with predictions based on the thin lens equation. The periodicity and effective slit width of the printed gratings were determined from both optical micrographs and fits to the Fraunhofer diffraction equation. This study aims to demonstrate the advantages offered by a layer-by-layer DLP printing process for the manufacture of optical components for use in the visible region of the electromagnetic spectrum.

A 3D printer was used to print both lenses and diffraction gratings from Standard Clear PR48 photocurable resin. The manufacturing process of the lenses and the diffraction gratings differ mainly in the printing angle with respect to the printer x-y-axes. The transmission diffraction gratings studied here were manufactured with nominal periodicities of 10, 25 and 50 µm. The aim of this study was to optically determine the effective values for the distance between slits, d, and the effective width of the slits, w, and to compare these values with the printed layer thickness.

The normalized diffraction patterns measured in this experiment for the printed gratings with layer thickness of 10, 25 and 50 µm are shown by the solid dots in Figures 8(a)-(c). Also shown as a red solid line are the fits to the experimental diffraction data. The effective values of d and w obtained from fitting the data are compared to the nominal layer thickness of the printed gratings. The effective distance between slits required to fit the diffraction patterns are well approximated by the printed layer thickness to within 14, 4 and 16 per cent for gratings with a nominal 10, 25 and 50 µm layer thickness, respectively.

Chromatic aberration is present in all polymer lenses, and the authors have not attempted to characterize it in this study. These materials could be used for achromatic lenses if paired with a crown-type material in an achromatic doublet configuration, because this would correct the chromatic aberration issues. It is worthwhile to compare the per cent transmission in cured PR48 resin (approximately 80 per cent) to the percent transmission found in common optical materials like BK7 (approximately 92 per cent) over the visible region. The authors attribute the lower transmission in PR48 to a combination of surface scattering and increased absorption. At the present time, the authors do not know what fraction of the lower transmission is related to the surface quality resulting from sample polishing.

There are inherent limitations to the 3D manufacturing process that affect the performance of lenses. Approximations to a curved surface in the design software, the printing resolution of the Autodesk Ember printer and the anisotropy due to printing in layers are believed to be the main issues. The performance of the lenses is also affected by internal imperfections in the printed material, in particular the presence of bubbles and the inclusion of debris like dust or fibers suspended in air. In addition, the absorption of wavelengths in the blue/ultraviolet produces an undesirable yellowing in any printed part.

One of the most interesting results from this study was the manufacture of diffraction gratings using 3D printing. An analysis of the diffraction pattern produced by these printed gratings yielded estimates for the slit periodicity and effective slit width. These gratings are unique because the effective slit width fills the entire volume of the printed part. This aspect makes it possible to integrate two or more optical devices in a single printed part. For example, a lens combined with a diffraction grating now becomes possible.

The purpose of this paper is to review customer experience formation (CXF) by first locating and analyzing how researchers approach CXF in the service literature and the theoretical underpinnings of these approaches, and then assessing which approaches are best suited for understanding, facilitating, and examining CXF in today’s service landscape.

This study systematically reviews 163 articles published between 1998 and 2015 in the service field.

This study illustrates how researchers approach CXF on the individual level by applying stimulus- interaction- or sense-making-based perspectives. These reflect researchers’ theoretical underpinnings for how individuals realize the customer experience within environmental, social, and temporal contexts through intermediation. Researchers further apply contextual lenses, including the dyadic and service- or customer-ecosystem lenses, which reflect their theoretical underpinnings for explaining how various actor constellations and contextual boundaries frame individual-level CXF. Finally, this study shows why the sense-making-based perspective, together with a service- or customer-ecosystem lens, is particularly suitable for approaching complex CXF in today’s service settings.

To advance theory, researchers should choose the approaches resonant with their research problem and worldview but also consider that today’s complex service landscape favors holistic and systemic approaches over atomistic and dyadic ones.

This study provides managers with recommendations for understanding, facilitating, and evaluating contemporary CXF.

This study advances the understanding of CXF by systematically reviewing its multiple layers, approaches, and dimensions and the opportunities and challenges of each approach.