Electrodeposited nickel–manganese: an alloy for microsystem applications

A process has been developed, using LIGA fabrication techniques, for the electrodeposition of a high strength, heat resistant Ni–Mn alloy to meet the requirements of a mechanical microsystem component. The electrolyte bath chemistry consists of Ni sulfamate to which a small amount of manganese chloride is added. The Mn content for the electrodeposited alloys of interest is generally equal to or less than about 1 wt%. It is shown that its co-deposition with Ni is insensitive to feature aspect ratio and therefore not limited by mass transport effects, permitting uniform alloy deposition. While plating of this alloy at a constant current density yields a high strength deposit, it also results in a highly stressed film that makes the fabrication of thick section deposits problematic.To counter this, a pulsed deposition scheme is employed to fabricate a nanostructured film consisting of alternating nm-thick regions of low stress, relatively soft Ni, and high strength, and highly stressed, NiMn alloy. This moderates the high plating stress of the NiMn alloy and enables the deposition of thick deposits. Yield strengths of over 800 MPa are achievable in the pulse-plated material, with good as-plated ductility (6%). The material loses only about 15% of its original strength after a one hour, 600 °C anneal, and no embrittlement is observed since no sulfur-bearing additives are employed. To the contrary, ductility measured as strain to failure is improved.The authors thank the Sandia/California LIGA prototyping team for their assistance in the fabrication of the masks, molds and sample preparation needed to execute the work described here. Colleagues at Sandia/New Mexico are acknowledged as well for their contribution to some of the mechanical testing and microscopy.This work supported under contract DE-A04–94AL85000     

Measuring Toronto's vital signs – Comparing global and local ideal point analysis in an urban equity case study

Multi-Criteria Decision Analysis (MCDA) offers a unique analytical lens for examining socio-economic indicators within cities. Competing, interrelated criteria are combined to produce a single weighted score for each location or spatial unit. The Toronto Foundation's Vital Signs report provides an annual snapshot of Toronto's quality of life, using ten indicator categories. While the report is published at a city scale, a spatially explicit approach could offer a deeper interpretation of the results. While global MCDA methods can conceal geographic variation, novel local techniques account for spatial heterogeneity in relevant characteristics. In this paper, a localized ideal point method, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), was applied to the Vital Signs report. The results show more variation and less spatial autocorrelation than the global approach and a simplified representation of the report. GIS researchers are increasingly exploring local MCDA approaches using vector data, but the more complex techniques such as TOPSIS are relatively underdeveloped. This case study aims to fill this conceptual gap and illustrate the applicability of local ideal point analysis in an urban equity context.     

Comparing alternatives for analyzing requirements trade-offs – In the absence of numerical data

ContextChoosing a design solution most often involves dealing with trade-offs and conflicts among requirements and design objectives. Making such trade-offs during early stages of requirements and design is challenging because costs and benefits of alternatives are often hard to quantify.ObjectiveThe objective of this work is to develop a decision analysis method that assists in making trade-offs in the absence of quantitative data.MethodIn this method, stakeholders qualitatively compare consequences of alternatives on decision criteria. We propose an algorithm that generates all possible consequences of alternatives on requirements, according to the rough qualitative comparisons that stakeholders made. The possible consequences generated by the algorithm are then analyzed by the Even Swaps Multi-Criteria Decision Analysis method to determine the best solution. The Even Swaps method is a technique developed in management science to assist in multi-criteria decision making when explicit value trade-offs are not available.Results and conclusionsOur algorithm teases out the need to accurately measure or estimate costs and benefits of alternative design solutions. The algorithm automates the Even Swap process, and reuses stakeholders’ value trade-offs throughout the Even Swaps process. We applied the prototype tool in several case studies to evaluate the utility of the method. The results of case studies provide evidence that our decision aid method selects the optimum solution correctly compared to results of other similar quantitative methods, while our method does not rely on detailed numerical assessment of alternatives and importance weights of criteria.     

FraRI: an algorithm to account for the discontinuity at 60° N in MODIS temperature products

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra and Aqua satellites conducts continuous monitoring of the Earth's land surface and oceans. Recently, a sharp discontinuity (averaging 1.9°C) has been noticed at 60° N in both MODIS daytime and night-time land surface temperature (LST) products. This linear artefact arises because the CO₂ high cloud test in the operational code for the generation of the MODIS cloud mask product is used only in the non-polar region (between 60° N and 60° S). The resulting discontinuity clearly has negative implications for any statistical applications of these temperature data. In this technical note we present a new algorithm, which minimizes this discontinuity. The method uses edge detection and elimination based on a mixture of Sobel and non-linear Laplacian filters (edge detection and quantification), cubic splines (edge modelling), and a controllable power function for image restoration. The implementation of this algorithm is demonstrated on an image of average minimum night-time LST between 2001 and 2008.     

Parallel implementation of an efficient preconditioned linear solver for grid-based applications in chemical physics. III: Improved parallel scalability for sparse matrix–vector products

The linear solve problems arising in chemical physics and many other fields involve large sparse matrices with a certain block structure, for which special block Jacobi preconditioners are found to be very efficient. In two previous papers [W. Chen, B. Poirier, Parallel implementation of efficient preconditioned linear solver for grid-based applications in chemical physics. I. Block Jacobi diagonalization, J. Comput. Phys. 219 (1) (2006) 185–197; W. Chen, B. Poirier, Parallel implementation of efficient preconditioned linear solver for grid-based applications in chemical physics. II. QMR linear solver, J. Comput. Phys. 219 (1) (2006) 198–209], a parallel implementation was presented. Excellent parallel scalability was observed for preconditioner construction, but not for the matrix–vector product itself. In this paper, we introduce a new algorithm with (1) greatly improved parallel scalability and (2) generalization for arbitrary number of nodes and data sizes.     

Vibration in offshore structures: an analysis for the general nonlinear stochastic case – part I

The response of offshore structures to random wave excitation is studied for general nonstationary stochastic excitation, constant, time-dependent, or stochastic coefficients, and nonlinear forces without linearization, or averaging methods and closure approximations, or numerical methods. The method used yields physically realistic analytic solutions.     

Comparing different smoothing methods to detect double-cropping rice phenology based on LAI products – a case study in the Hunan province of China

ABSTRACT

Many studies have demonstrated the remarkable potential of assimilating remotely sensing leaf area index (LAI) products into crop models in estimating regional crop yield. To ensure the temporal consistency between crop models and remote-sensing system, it is prerequisite to derive the crop phenology information from the LAI products. However, previous studies mainly detected the phenology through the vegetation index (VI). Although some pieces of research applied LAI in phenology monitoring for trees and shrubs, fewer focused on crops, especially those with two or three growing seasons annually. Thus, which smoothing algorithm methods are suitable to obtain phenology of double-cropping rice and their difference in smoothing for crops are still unknown. Based on the Global Land Surface Satellite (GLASS)LAI products, we applied four favourite smoothing algorithms (Asymmetric Gaussian fitting, Double Logistic fitting, Savitzky–Golay filter, and Wavelet-based Filter method) to reduce noise and reconstruct the LAI profile and then detected the phenological information of double-cropping rice in Hunan Province. Compared with ground actual observations, we found that two fitting methods are not suitable to smooth double-cropping rice LAI, while the wavelet method performed the best. Based on the wavelet method, we estimated the phenological information of double-cropping rice at different regional scales as well and the results reflected that the accuracy of regional estimation is also acceptable. This study implied that the wavelet method is rather suitable to detect phenological information of crops from LAI products, which provides narrow gaps between two growing season. Our contribution can benefit researchers who focus on agriculture or remote sensing, especially those who would like to assimilate remotely sensed information into crop growth models.     

Computing the Duquenne–Guigues basis: an algorithm for choosing the order

This paper presents an algorithm for choosing the order in which pseudo-intents are enumerated when computing the Duquenne–Guigues basis of a formal context. Sets are constructed through the use of a spanning tree to ensure they are all found once. The time and space complexities of the algorithm are empirically evaluated using, respectively, the number of logical closures and the number of sets in memory as measures. It is found that only the space complexity depends on the enumeration order.     

Understanding online customer repurchasing intention and the mediating role of trust – an empirical investigation in two developed countries

Although e-commerce adoption and customers’ initial purchasing behavior have been well studied in the literature, repeat purchase intention and its antecedents remain understudied. This study proposes a model to understand the extent to which trust mediates the effects of vendor-specific factors on customers’ intention to repurchase from an online vendor. The model was tested and validated in two different country settings. We found that trust fully mediates the relationships between perceived reputation, perceived capability of order fulfillment, and repurchasing intention, and partially mediates the relationship between perceived website quality and repurchasing intention in both countries. Moreover, multi-group analysis reveals no significant between-country differences of the model with regards to the antecedents and outcomes of trust, except the effect of reputation on trust. Academic and practical implications and future research are discussed.     

Computing interval-valued statistical characteristics: what is the stumbling block for reliability applications?

The application of interval-valued statistical models is often hindered by the rapid growth in imprecision that occurs when intervals are propagated through models. Is this deficiency inherent in the models? If so, what is the underlying cause of imprecision in mathematical terms? What kind of additional information can be incorporated to make the bounds tighter? The present paper gives an account of the source of this imprecision that prevents interval-valued statistical models from being widely applied. Firstly, the mathematical approach to building interval-valued models (discrete and continuous) is delineated. Secondly, a degree of imprecision is demonstrated on some simple reliability models. Thirdly, the root mathematical cause of sizeable imprecision is elucidated and, finally, a method of making the intervals tighter is described. A number of examples are given throughout the paper.     

Older adults’ use of smart phones: an investigation of the factors influencing the acceptance of new functions

After adopting mobile phones, most older adults use them only for calling and SMS. The purpose of this study is to extend their usage of mobile phones to new functions. To understand older adults’ requirements of mobile phones, a questionnaire was constructed and 351 Chinese older adults were recruited to complete the questionnaires. Data collected through the questionnaires were analysed using explorative factor analysis. The results revealed that older adults’ requirements were composed of 10 factors: Find a Specific Function, Awareness and Attractiveness, Readability, Personal Concern, Soft Keys and Multi-tap, Hardware Capacity, Touch Screen, Concern of Learning, Connectivity, and Social Influence. Then, from the above 10 factors, the 6 most important factors were revealed using multiple linear regression analysis. The results imply that accepting new functions is different from accepting a product. Readability and Find a Specific Function, which are critical for older adults’ acceptance of feature phones, are not determinants of their acceptance of new functions in smart phones.     

The Changing – and Unchanging – Face of the Digital Divide: an Application of Kohonen Self-Organizing Maps

The goal of this study is to trace the evolution of the digital divide, to begin to understand whether and how the divide is widening or closing, and in achieving this, begin to identify implications and further research moving forward. We are able to do this by using longitudinal data over a period of nine years (1999–2007). We employ the Kohonen self-organizing maps approach. This exploratory approach allows for clear visualization and interpretations of country's positions on the map and illustrates any changes that may have occurred over a given time period. We identify five clusters of countries, based on their digital development; economical; demographic and risk indicators. Our results indicate that a number of Eastern European countries such as Slovakia and Lithuania have made significant progress in the period 1995–2003, while we find that most African countries have made little or no improvement during this period – an issue requiring urgent attention. Overall, this study provides a clear visualization of the progression of digital development indicators alongside economic, demographic, infrastructural and risk factors in 179 countries over a nine-year time frame. These results are relevant as a basis for policy discussions as they highlight the success stories of some countries relative to others.     

Untangling the ‘Dark Web’: an emerging technological challenge for the criminal law

The Dark Web, and the technology which underpins it, is fundamentally changing how crime is conducted. It is an enabler of cross-border, truly international crime where each of the major actors, evidence, and the proceeds of crime can all be in different jurisdictions. The technologies utilised mask the identity of individuals and the nature of the crimes committed. It is these complexities, and law’s inability to deal with them, which this paper will focus on. It critically analyses six intersecting and overlapping themes in order to highlight the technological challenges posed by the Dark Web to the criminal law. The paper argues that the current approaches, regulatory structures, legislation and investigative methods are all unfit for purpose. There is little to suggest the law is any closer to restricting Dark Web crime, particularly given a substantial amount of the challenges posed are unsolved traditional issues, in a new form.     

Design of an H∞ controller for the Delta robot: experimental results

This paper deals with an efficient implementation of an H∞ multi-variable controller on the three degrees of freedom (DOF) parallel robot namely the ‘Delta robot’. The H∞ controller is designed by the mixed sensitivity approach in which the sensitivity function matrix S and the complementary sensitivity function matrix T are taken into account. For this purpose, a nonlinear analytical dynamic state model is developed and a tangent linearization procedure is used to obtain a multi-variable linear model around a functional point. Real-time experiments were performed to compare the centralized H∞ controller with a classical decentralized Proportional Integral Derivative (PID) controller. Experimental tracking results show that the performances of the PID compared to those of the H∞ decrease when the movement dynamic is increased. At high dynamic (12 Ge), it is shown that the maximum tracking error and the error around the stop positions of the H∞ are, respectively, 80 and 60% of the PID. The experiments of the load variation have proven that the H∞ is more robust than the PID. The steady-state root mean square error of the H∞ is less than 60% of the one obtained using the PID controller.     

IT induced business transformation in higher education: an analysis of the UniCafé experience and its implications

This paper is concerned with the changes in the business processes of higher education that may result from the introduction of IT enabled, either eLocalised or eDistributed, learning methods. It provides a framework based on the issues of commercial business transformation that can be linked to changes in the teaching and learning process and learner markets. Evidence from a case study of the UniCafé project based at the University of Surrey and other surrounding projects and initiatives is considered in the light of this matrix in order to highlight some of the key organizational challenges facing future development.     

The Unavoidable Nature of Population Ageing and the Ageing-Driven End of Growth – an Update for New Zealand

Despite overwhelming evidence to the contrary, many people still question the extent to which population ageing and the ageing-driven ending of growth will unfold more or less as projected. This is particularly so in New Zealand, where the population is still relatively youthful due to near-replacement fertility and many years of high per capita net migration gains. As elsewhere, however, the picture differs markedly at subnational level, with the populations of one-quarter of the nation’s 67 territorial authority areas (TAs) already (in 2017) having more than 20% aged 65+ years. Accompanying this trend, one-third of the nation’s TAs declined in population between 1996 and 2013, primarily because of net migration loss at young adult ages, but in the process accelerating their structural ageing. Taking a subnational approach, this paper explores the dynamics of population ageing across New Zealand’s TAs. We demonstrate that structural ageing is accelerating and that even excessively high levels of net international migration gain cannot be expected to appreciably reduce future structural ageing. We also show that over the period 2013–43 the majority of declining TAs will move from the old form of decline, caused by net migration loss exceeding natural increase, to a new form caused by the combined effects of net migration loss and natural decrease. The findings reinforce our central argument that the phenomenon of population ageing and the ageing-driven end of growth will not ‘go away’ and has urgent implications for matters such as rate-based local government infrastructure funding.