Structural design of modern steam turbine blades using ADINA™

The present paper provides an overview of the structural design of modern steam turbine blades at Siemens power generation using the finite element code ADINA™. The different types of blades are described in detail regarding their geometry and loading. The modular building block approach of modelling is shown to be of essential importance. For the different analyses a fatigue post-processor has been implemented as well as an optimization tool. Both of these in-house codes will be briefly presented.     

Behavioural data in the design of ergonomic computer terminals and workstations—a case study

Abstract

Manufacturers of office automation equipment, in their design of ergonomic computer terminals and office furniture, are encountering needed design data which is sometimes weak, absent, erroneous or inapplicable to the office-worker situation under consideration. In some instances, office automation manufacturers simply follow standards. In others, manufacturers make assumptions as to the best design, and in others, design decisions were based on testing results and conclusions.This paper reviews the ergonomic tools and features incorporated into the design of one office automation manufacturer's terminals and workstations. The short fall of applicable design data relevant to comfort versus extremes of motion in biomechanics, to keyboard home row height and slope angle to viewing distance, as well as to reverse video and surface colour are presented, along with the design resolution of these parameters. Further, certain aspects of posture recently published are discussed.     

Exploring the costs of technical debt management – a case study

Technical debt is a metaphor for delayed software maintenance tasks. Incurring technical debt may bring short-term benefits to a project, but such benefits are often achieved at the cost of extra work in future, analogous to paying interest on the debt. Currently technical debt is managed implicitly, if at all. However, on large systems, it is too easy to lose track of delayed tasks or to misunderstand their impact. Therefore, we have proposed a new approach to managing technical debt, which we believe to be helpful for software managers to make informed decisions. In this study we explored the costs of the new approach by tracking the technical debt management activities in an on-going software project. The results from the study provided insights into the impact of technical debt management on software projects. In particular, we found that there is a significant start-up cost when beginning to track and monitor technical debt, but the cost of ongoing management soon declines to very reasonable levels.     

Optimizing a damped system – a case study

We consider a second-order damped-vibrational system described by the equation M ?+C(v) [xdot]+K x=0, where M, C(v), K are real, symmetric matrices of order n. We assume that the undamped eigenfrequencies (eigenvalues of (λ² M+K) x=0) ω₁, ω₂, …, ω _n , are multiple in the sense that ω₁=ω₂, ω₃=ω₄, …, ω _n?1=ω _n , or are given in close pairs ω₁ ≈ ω₂, ω₃ ≈ ω₄, …, ω _n?1 ≈ ω _n . We present a formula which gives the solution of the corresponding phase space Lyapunov equation, which then allows us to calculate the first and second derivatives of the trace of the solution, with no extra cost. It can serve for the efficient trace minimization.     

SOA in practice – a study of governance aspects

The academic literature on Service Oriented Architecture (SOA) governance is based on theories and assumptions rather than practices, whereas the SOA governance frameworks proposed by Information Technology (IT) vendors are made to suit their products. Research shows that the problems with SOA governance in practice are among the major reasons of SOA failures. An extensive literature review that covers SOA, IT governance and SOA governance has been carried out part of this research. The purpose of this research paper is to increase our understanding of SOA governance and to show which SOA aspects organizations should consider when adopting a SOA governance framework. Based on a literature review, this study first proposes a list of SOA aspects to be considered when implementing SOA governance. By adopting an interpretive research methodology – based on interviews with professionals and practitioners in the fields of IT governance and SOA governance – this research paper examines the importance of these aspects. The results provide a theoretical conceptualization of SOA aspects that can be used to assess SOA governance practices and provide guidance to improve them.     

Optimisation of maintenance concept choice using risk-decision factor – a case study

This article is concerned with the state estimation problem for a kind of non-uniform sampling dynamic system. The system is described at a certain sampling rate in discrete form. A sensor observes the target successively, while the samples are obtained non-uniformly and the sampling points in each sampling periods may be different. To generate the optimal state estimate, state prediction and innovation are carried out step-by-step similar to Kalman filter (KF), but before innovation in each sampling period, measurements should be properly disposed and augmented. It is shown that our main results improve and extend the existing KF for which the samples are obtained multirate non-uniformly. Measurements randomly missing with Bernoulli distribution are also considered in this article. Finally, the feasibility and efficiency of the presented algorithm is illustrated by a numerical simulation example.     

Potential of polarimetric Radarsat-2 data in geological mapping – a case study in parts of Dharwar craton,India

Polarimetry is a technique for quantitatively estimating the change in polarization in a backscattered electromagnetic signal (in this case a radar signal) with reference to the polarization of the incident signal for estimating the geophysical properties (roughness and dielectric constant) of surface elements. In this study, quadrapole Radarsat-2 data have been utilized for mapping geological elements in Archaean terrain based on their geophysical parameters preserved in the four polarization channels of Radarsat-2 data. The study illustrates how single-look complex polarimetric data can be processed to extract information on lithology, geological structure, and land covers (i.e. soil type, etc.) preferentially developed over each rock type. The study revealed that C-band polarization power images can be used indirectly to delineate lithounits provided each unit has characteristic surface roughness and moisture resulting from the surface cover or exposure pattern developed over each lithounit. Moreover, polarimetric data (inclusive of phase and amplitude) provide complementary information when we compare this information with the information derived from simple polarization composites, derived from the backscattered image of each polarization channel. It is also observed that structural imprints are enhanced in co-polarized (HH, VV) data, whereas the cross-polarized channel (HV, VH) provides information on land cover.     

A case study of applying data mining techniques in an outfitter’s customer value analysis

This study applies K-means method, fuzzy c-means clustering method and bagged clustering algorithm to the analysis of customer value for an outfitter in Taipei, Taiwan. These three techniques bear similar philosophy for data classification. Thus, it would be of interest to know which clustering technique performs best in a real world case of evaluating customer value. Using cluster quality assessment, this study concludes that bagged clustering algorithm outperforms the other two methods. To conclude the analyses, this study also suggests marketing strategies for each cluster based on the results generated by bagged clustering technique.     

Modular product design with grouping genetic algorithm—a case study

Modular products are products that fulfill various functions through the combination of distinct modules. These detachable modules are constructed both according to the maximum physical and functional relations among components and maximizing the similarity of specifically modular driving forces. Accordingly, a non-linear programming is proposed to identify separable modules and simultaneously optimize the number of modules. This paper presents a systematic approach to accomplish modular product design in four major phases. Phase 1 is by means of functional and physical interaction analysis to format a component-to-component correlation matrix. Phase 2 is the exploration of design requirements to evaluate the relative importance of each modular driver. In phase 3, non-linear programming is used to formulate the objective function. In the final phase, a heuristic grouping genetic algorithm is adopted to search for the optimal or near-optimal modular architecture. This process and its application are illustrated by a real case of an electrical consumer product provided by an Original Design Manufacturer. The results demonstrate that the designer could direct a new approach to establish product modules according to the relative importance of modular drivers and the interaction among components.     

Conceptualizing task-technology fit and the effect on adoption – A case study of a digital textbook service

Although information technology has revolutionized virtually every aspect of how we interact with products and services, it has changed learning to a surprisingly small degree. In a study of a digital textbook service, we provide a new conceptual definition and measurement of technology fit. We conceptualize task-technology fit as how well a technology is integrated with a set of interrelated tasks included in achieving the goal of the behavior where the technology is used. Whereas research on technology adoption typically explains around 40 percent of the variance in motivation to adopt, our model explains as much as 76 percent.     

An analysis of the most cited articles in software engineering journals – 2002

Citations and related work are crucial in any research to position the work and to build on the work of others. A high citation count is an indication of the influence of specific articles. The importance of citations means that it is interesting to analyze which articles are cited the most. Such an analysis has been conducted using the ISI Web of Science to identify the most cited software engineering journal articles published in 2002. The objective of the analysis is to identify and list the articles that have influenced others the most as measured by citation count. An understanding of which research is viewed by the research community as most valuable to build upon may provide valuable insights into what research to focus on now and in the future. Based on the analysis, a list of the 20 most cited articles is presented here. The intention of the analysis is twofold. First, to identify the most cited articles, and second, to invite the authors of the most cited articles in 2002 to contribute to a special section of Information and Software Technology. Six authors have accepted the invitation and their articles appear in this special section.     

Network neutrality in the era of 5G – a matter of faith,hope, and design?

The article addresses the relationship of network neutrality (NN) and 5G, while abandoning technological determinism. Contrary to recent developments in the US, current EU law includes NN rules which imply non-discrimination and equal treatment of all internet traffic with specific exceptions, including in the case of congestion prevention. For their part, visions of 5G include tailored solutions for individual use cases, while prioritisation or guarantees for time-critical applications, such as autonomous vehicles, will become crucial. This means that differentiation rather than equality lies at the core of 5G. At the outset, NN and 5G seem to collide and contradict. Indeed, telecom operators have expressed concerns on the feasibility of EU regulation in terms of investments and innovation. However, viewed from the perspective of end-to-end (E2E) design principles, NN and 5G are not inevitably (merely) at odds. Moreover, network design, including the principle of neutrality, is a matter of choice. For its part, embracing diversity presents an alternative to promoting neutrality. The article thus promotes a societal debate on NN in the era of 5G which considers various dimensions from technology and economics to law and policy.     

Ergonomic design interventions – a case study involving portable ladders

Portable ladders are one of the most ancient tools conceived by man. They remain ubiquitous and indispensable even today. It is interesting to note that there is little difference between the makeshift portable ladders used throughout history and some still used today. The design of portable ladders seems to have simply evolved, rather than been subject to formal design process, including ergonomic criteria. An analysis of 277 fatalities associated with ladders was conducted to describe the pattern of ladder fatalities and identify and assess ergonomic design controls. All ladder fatalities analysed were found to contain multiple human, equipment (ladder) and environmental causative factors. It is hypothesized that significant gains with regard to reducing future fatalities can be achieved by applying ergonomic design principles to ladders to accommodate predictable and undesirable human behaviour. Without effective future change, the only prediction that can be made is that the pattern of ladder fatalities will simply continue.     

Coastline evolution monitoring and estimation—a case study in the region of Nouakchott,Mauritania

Since the construction of a harbour, Port de l'Amitié, an important importation gate for Nouakchott, northwestern Africa in 1987, the previous coast dynamic equilibrium has been destroyed and thus a significant littoral geomorphologic change has occurred, which has produced a severe degradation of the littoral and urban environment. This research is focused on coastline evolution monitoring and its potential change estimation by remote sensing techniques using multi‐temporal Satellite pour l'Observation de la Terre (SPOT) images and Markov chain analysis. It is the objectives of the study to measure and estimate the coastal current hydrodynamics, coastline evolution rates, harbour life‐span and to provide useful reference for the local authorities to make decisions for their future coastal management. The results show that the north beach of the harbour has extended by 0.92 km² (92 ha) from 1989 to 2001 and the accretion will probably reach its maximum limit in about 13 years±6 months (in 2014–2015) while the harbour will gradually arrive at the end of service. The south sandbar has been eroded by 1.34 km² (134 ha) and the coastline has retreated landwards by 362 m at the maximum point. Another 0.91 km² of land will be eroded in the next 10 years from 2001 to 2011. This erosion has caused several inundations to the suburb and urban areas, provoking a deterioration of the urban environment.     

Monitoring intense dust storms over the Indian region using satellite data – a case study

Dust storms are normally considered to be natural hazards. During such events, dust aerosol is loaded into the atmosphere, directly reducing visibility and effectively reflecting solar radiation back to space. In the present study, an intense dust storm was monitored during the first week of June 2010 using Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua data over the Indian region. A dust cloud was detected using a combination of MODIS reflective and emissive channels and moving trace/spread monitored by its multi-temporal data. The MODIS Terra-derived aerosol optical depth at 550 nm (AOD₅₅₀) and the aerosol index (AI) obtained from the Ozone Monitoring Instrument (OMI) were used in conjunction with National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis wind fields for the monitoring of dust clouds. The study reveals that the movement of a high concentration of dust clouds coincided with the NCEP/NCAR reanalysis meridional and zonal wind fields (>8 m s^?1) at pressure levels of 700 hPa. The Cloud–Aerosol Lidar Pathfinder Satellite Observations (CALIPSOs) that derive vertical feature mask images also suggested that the vertical extent of the dust aerosol layer was at a height of about 6 km over northern India on 2 June 2010. The roles of long-range transport of dust over the entire Gangetic plane are analysed using back trajectories from the National Oceanic and Atmospheric Administration (NOAA) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Back trajectory analysis suggests that dust clouds moving over long distances entered from the western side of India on 1 June 2010.     

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.     

Social intelligence design in online chat communication: a psychological study on the effects of “congestion”

Social intelligence design (SID) is an essential concept for constructing electronic communities or computer-supported communication systems which effectively support various intelligent activities. This study is focused on one example of such systems, that is, online chat for real-time computer-mediated communication. We examined various dimensions of human information processing in online chat sessions from both the cognitive and social perspectives within psychology. A key variable which affects the process of a chat session is what we call communication congestion. We regard this quality as characterizing online chat sessions and are experimentally exploring its effects on chat performance and cognition processing by participants. Results of this experimental study suggest that medium-density congestion with a relevant topic might activate communication, particularly for experienced participants. Based on our findings, we discuss some suggestions regarding future innovations for chat systems.

What could they have been thinking? How sociotechnical system design influences cognition: a case study of the Stockwell shooting

Understanding why an individual acted in a certain way is of fundamental importance to the human factors community, especially when the choice of action results in an undesirable outcome. This challenge is typically tackled by applying retrospective interview techniques to generate models of what happened, recording deviations from a 'correct procedure'. While such approaches may have great utility in tightly constrained procedural environments, they are less applicable in complex sociotechnical systems that require individuals to modify procedures in real time to respond to a changing environment. For complex sociotechnical systems, a formative approach is required that maps the information available to the individual and considers its impact on performance and action. A context-specific, activity-independent, constraint-based model forms the basis of this approach. To illustrate, an example of the Stockwell shooting is used, where an innocent man, mistaken for a suicide bomber, was shot dead. Transferable findings are then presented. STATEMENT OF RELEVANCE: This paper presents a new approach that can be applied proactively to consider how sociotechnical system design, and the information available to an individual, can affect their performance. The approach is proposed to be complementary to the existing tools in the mental models phase of the cognitive work analysis framework.     

Drawing evaluation into design for mobile computing: a case study of the Renwick Gallery’s Hand Held Education Project

We present a detailed case study of the design, launch, and evaluation of a handheld mobile computing guide for visitors to the Smithsonian American Art Museums Renwick Gallery. Of particular emphasis is integrating methods and tools of evaluation into the process of designing for new visitor experiences. Using a method of reflective design and evaluation incorporating interviews, surveys, observation, and clickstream analysis, we uncover assumptions and hypothesis for further testing. Finally, we discuss the cross-over between physical navigation of museum spaces and information navigation of online museum data.