bluuebunny/crossref_metadata_2025 huggingface dataset:
Beilinson-Flach elements and Euler systems II: The Birch-Swinnerton-Dyer conjecture for Hasse-Weil-Artin 𝐿-series
Authors: Bertolini Massimo , Darmon Henri , Rotger Victor
Published: March 2015

Let

E
E

be an elliptic curve over

Q

\mathbb {Q}

and let

ϱ
\varrho

be an odd, irreducible two-dimensional Artin representation. This article proves the Birch and Swinnerton-Dyer conjecture in analytic rank zero for the Hasse-Weil-Artin

L
L

-series

L
(
E
,
ϱ
,
s
)

L(E,\varrho ,s)

, namely, the implication
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper L left-parenthesis upper E comma rho comma 1 right-parenthesis not-equals 0 right double arrow left-parenthesis upper E left-parenthesis upper H right-parenthesis circled-times rho right-parenthesis Superscript normal upper G normal a normal l left-parenthesis upper H slash double-struck upper Q right-parenthesis Baseline equals 0 comma">

L
(
E
,
ϱ
,
1
)
≠
0

⇒

(
E
(
H
)
⊗
ϱ

)

G
a
l

(
H

/

Q

)

=
0
,

L(E,\varrho ,1) \ne 0\quad \Rightarrow \quad (E(H)\otimes \varrho )^{\mathrm {Gal}(H/\mathbb {Q})} = 0,

\]
where

H
H

is the finite extension of

Q

\mathbb {Q}

cut out by

ϱ
\varrho

. The proof relies on

p
p

-adic families of global Galois cohomology classes arising from Beilinson-Flach elements in a tower of products of modular curves.
Water Security
Authors: Mukhtarov Farhad , Cherp Aleh
Published: March 2015

In the post–Cold War era, the concept of water security referred to the potential dangers of conflict over water resources and safety of drinking water infrastructure from attacks by military enemies or terrorists. By the 1990s, water security increasingly became discussed together with human security and such concerns as economic security, environmental security, energy security, and food security. The use of security jargon in the field of water resources signaled the importance of this resource for the survival of nations. Definitions of water security prominent in the 1990s focused on the quantity and quality of water supply for human welfare and economic development. More recently, an additional requirement for water management emerged, namely, the functioning of the biosphere as the basis for human well-being. The most recent definitions of water security embrace both human and ecosystem access to water, most often in the form of the so-called water-food-energy nexus with the emphasis on the links between these resources. However defined, the use of the “water security” concept is clearly on the rise in the circles of academics, government officials, and policymakers. However, it is not without its critics who challenge “water security” as failing to add value to the discussions of water governance. Indeed, the pre-eminence of intricate links between water, food, energy, and eco- and social systems has already been widely marked within the integrated water resources management (IWRM) discourse. The proponents of “water security,” in turn, argue for the complementarity of these two concepts. Another major debate running throughout the emerging “water security” literature is on whether it should be defined and operationalized in a broad sense as a framework for water management at multiple levels, or in a narrow sense, as a quantifiable index or a set of indicators.
Energy Security
Authors: Cherp Aleh , Mukhtarov Farhad
Published: March 2015

Energy security is a multidisciplinary field which overlaps with engineering and energy systems analysis, earth sciences, economics, technology studies, political science, international relations, and security and military studies. Though discussions of energy security have been around for most of the 20th century, a systematic “energy security science” has emerged only recently and is still a young and dynamic field. The structure and the borders of the area are widely debated and contested. Contemporary debates on energy security include dilemmas such as whether energy security is a “socially constructed concept” or an objective property of energy systems, whether it is primarily a national-level issue or whether it also exists at different scales (household, local, regional, and global), whether it relates only to conventional or also to “human security,” whether it is a generic or context-dependent idea, and how it relates to other energy policy issues (e.g., environmental and social impacts). The key outcomes of this debate include the idea that energy security relates to both shocks and stresses, includes both physical and economic aspects, and relates to the “vital energy systems” which underpin the stability and functioning of societies.
Environmental Ethics
Authors: Nelson Michael Paul , Ryan Leslie A.
Published: March 2015

Environmental ethics focuses on questions concerning how we ought to inhabit the world; what constitutes a good life or a good society; and who, where, or what merits moral standing. The field emerged most significantly in the 1960s from an increasing awareness of the global environmental condition, although its multiple roots stretch back through the conservation legacy of Roosevelt and Leopold, the transcendentalism of Thoreau and Muir, a growing wilderness movement, insights from the ecological sciences and their precursors, and 19th-century Arcadian sentiments. The field of environmental ethics emerged as a reaction to the perception of growing environmental crises, such as the transformation of Australian forests into pine plantations, rivers afire in the industrialized regions of the United States, the pressure of population growth on natural resources, and the preservation of wild lands. In the United States these concerns led to legislative action such as the Wilderness Act (1964) and the formulation of several key pieces of legislation reflecting concern for environmental health and well-being, such as the Clean Water Act (1972) the Endangered Species Act (1973), and the establishment of both Earth Day and the Environmental Protection Agency in 1970. These events and others have most frequently been read through the lens of Western philosophy, with Aristotle, Hume, Spinoza, and others serving as theoretical guides, and Western science functioning as both source of and solution to environmental problems. Contributions from non-Western cultures illuminate other forms of relating to the land, based on very different metaphysical understandings. There is often a fine line, for example, between the animate and inanimate, or communal and individual—a line of moral considerability found in other cultures that some Western philosophers seek to blur. Rather than establishing separate categories for non-Western environmental ethics, or those offered by feminists, we have focused on the arguments and investigations within the field. Through creating constellations of individuals with similar concerns, we have created a taxonomy of discourse on selected topics. This article opens with general overviews of environmental ethics in single-author monographs and edited anthologies. Foundational texts from philosophy, science, and the humanities provide an interdisciplinary context for the concepts explored in sections on the human place in nature, moral consideration, putting environmental ethics into practice, and issues of and for the future.
Cline coupling and uncoupling in a stickleback hybrid zone
Authors: Vines Tim , Dalziel Anne , Albert Arianne , Veen Thor , Schulte Patricia , Schluter Dolph
Published: March 2015

Strong ecological selection on a genetic locus can maintain allele frequency differences between populations in different environments, even in the face of hybridization. When alleles at divergent loci come into tight linkage disequilibria, selection acts on them as a unit and can significantly reduce gene flow. For populations interbreeding across a hybrid zone, linkage disequilibria between loci can force clines to share the same slopes and centers. However, strong ecological selection can push clines away from the others, reducing linkage disequilibria and weakening the barrier to gene flow. We looked for this ‘cline uncoupling’ effect in a hybrid zone between stream resident and anadromous sticklebacks at two genes known to be under divergent natural selection (Eda and ATP1a1) and five morphological traits that repeatedly evolve in freshwater stickleback. We used 10 anonymous SNPs to characterize the shape of the zone. We found that the clines at Eda, ATP1a1, and four morphological traits were concordant and coincident, suggesting that direct selection on each is outweighed by the indirect selection generated by linkage disequilibria. Interestingly, the cline for pectoral fin length was much steeper and displaced 200m downstream, and two anonymous SNPs also had steep clines.
The advent of genome-wide association studies for bacteria
Authors: Chen Peter E. , Jesse Shapiro B.
Published: March 2015

Highlights

• The advent of the genome-wide association study (GWAS) approach provides a promising framework for dissecting the genetic basis of bacterial or archaeal phenotypes.

• Bacterial genomes tend to be shaped by stronger positive selection, stronger linkage disequilibrium and stronger population stratification than humans, with implications for GWAS power and resolution.

• An example GWAS inMycobacterium tuberculosisgenomes highlights the potentially confounding effects of linkage disequilibrium and population stratification.

• A comparison of the traditional GWAS approach versus a somewhat orthogonal method based upon evolutionary convergence (phyC) shows strengths and weaknesses of both approaches.

Significant advances in sequencing technologies and genome-wide association studies (GWAS) have revealed substantial insight into the genetic architecture of human phenotypes. In recent years, the application of this approach in bacteria has begun to reveal the genetic basis of bacterial host preference, antibiotic resistance, and virulence. Here, we consider relevant differences between bacterial and human genome dynamics, apply GWAS to a global sample ofMycobacterium tuberculosisgenomes to highlight the impacts of linkage disequilibrium, population stratification, and natural selection, and finally compare the traditional GWAS against phyC, a contrasting method of mapping genotype to phenotype based upon evolutionary convergence. We discuss strengths and weaknesses of both methods, and make suggestions for factors to be considered in future bacterial GWAS.
In situcharacterization of β′′ precipitation in an Al–Mg–Si alloy by anisotropic small-angle neutron scattering on a single crystal
Authors: Chang Cynthia Sin Ting , De Geuser Frédéric , Banhart John
Published: March 2015

A single crystal of an Al–Mg–Si alloy (Mg: 0.43 wt%, Si: 0.47 wt%) was aged at 453 K while small-angle neutron scattering experiments were carried outin situ. The scattering data recorded on a two-dimensional detector show the symmetry typical for needle-shaped β′′ precipitates oriented in the three [100] directions of the aluminium lattice and allow the calculation of the length, diameter and number density of the precipitates assuming cylindrical scattering objects of equal size and composition. The repetition time of the experiments was ∼12 min. The values obtained for the three quantities agree well with values measured by transmission electron microscopy (TEM) on a similar alloy. The impact of one week of natural ageing before artificial ageing on the evolution of the size and number density of precipitates is found to be pronounced, as expected from published TEM data.
Scattering functions of polyhedra
Authors: Senesi Andrew , Lee Byeongdu
Published: March 2015

Herein, a general method to calculate the scattering functions of polyhedra, including both regular and semi-regular polyhedra, is presented. These calculations may be achieved by breaking a polyhedron into sets of congruent pieces, thereby reducing computation time by taking advantage of Fourier transforms and inversion symmetry. Each piece belonging to a set or subunit can be generated by either rotation or translation. Further, general strategies to compute truncated, concave and stellated polyhedra are provided. Using this method, the asymptotic behaviors of the polyhedral scattering functions are compared with that of a sphere. It is shown that, for a regular polyhedron, the form factor oscillation at highqis correlated with the face-to-face distance. In addition, polydispersity affects the Porod constant. The ideas presented herein will be important for the characterization of nanomaterials using small-angle scattering.
Determination of the melting and freezing temperatures of Pb nanoparticles embedded in a PbO–B2O3–SnO2glass by using only the SAXS method
Authors: Kellermann G. , Gorgeski A. , Craievich A. F. , Montoro L. A.
Published: March 2015

Melting and freezing of metallic nanoparticles embedded in glass matrices usually occur at temperatures lower than for the same metal in the bulk state.In situsmall-angle X-ray scattering (SAXS) measurements using a synchrotron beamline and a specially designed high-temperature chamber allowed the determination of the temperature dependence of the SAXS intensity produced by a dilute and nearly monodisperse set of spherical Pb nanoparticles, with an average radius 〈R〉 = 16.1 nm, embedded in a homogeneous lead–borate oxide glass. The temperature dependences of the nanoparticle volumeV(T) and nanoparticle radius of gyrationRg(T) derived from SAXS results exhibit clear discontinuities during the cooling and during the heating processes, thus allowing for precise determinations of the melting and freezing temperatures of the studied Pb nanoparticles. Additional features observed in bothV(T) andRg(T) curves showed that during the heating cycle the frozen Pb nanoparticles suffer a transition to a more compact phase at 433 K before melting at 580 K. The results of this work demonstrate that the melting and freezing temperatures of nanoparticles in a very diluted state – for which the X-ray diffraction technique is not sensitive enough – can be precisely determined by applying only the SAXS method.
Matrix effects in white-beam X-ray fluorescence holography
Authors: Dul D. T. , Korecki P.
Published: March 2015

Recently, it has been shown that atomic structure determination with X-ray fluorescence holography (XFH) can be hindered by matrix effects,i.e.beam attenuation and indirect excitation. The analysis was limited to the monochromatic regime. In this work, the description of matrix effects is extended to the polychromatic case. It is shown that matrix effects affect the element sensitivity of white-beam XFH by introducing distortions in the holographic signal which may lead to spurious maxima in the reconstructed image. For high energies of the X-ray beam it is found that the effect of beam attenuation is very weak and indirect excitation mainly contributes to the distortions. A correction for matrix effects is proposed in the high-energy range, which allows one to remove the distortions and retrieve pure element-sensitive information. Numerical model calculations are performed to visualize the reduction of element sensitivity and its implications on local structure imaging.
Structural investigation ofN,N′-methylenebisacrylamideviaX-ray diffraction assisted by crystal structure prediction
Authors: Graiff Claudia , Pontiroli Daniele , Bergamonti Laura , Cavallari Chiara , Lottici Pier Paolo , Predieri Giovanni
Published: March 2015

The crystal structure ofN,N′-methylenebisacrylamide was determined through the geometry optimization of the molecular unit with density functional theory and conformational analysis, and then through the calculation of the packingviaa crystal structure prediction protocol, based on lattice energy minimization. All the calculated structures were ranked, comparing their powder pattern with the laboratory low-quality X-ray diffraction data. Rietveld refinement of the best three proposed structures allowed the most probable crystal arrangement of the molecules to be obtained. This approach was essential for disentangling the twinning problems affecting the single-crystal X-ray diffraction data, collected on samples obtainedviarecrystallization of powder, which definitely confirmed the predicted model. It was found thatN,N′-methylenebisacrylamide shows a monoclinic structure in the space groupC2/c, with lattice parametersa= 17.822 (12),b= 4.850 (3),c= 19.783 (14) Å, β = 102.370 (9)°,V= 1670 (2) Å3. Two strong interactions between the amide protons and the carbonyl groups of neighbouring molecules were found along thebaxis, determining the crystal growth in the form of wires in this direction. This work provides a further example of how computational methods may help to investigate low-quality molecular crystals with standard diffraction techniques.
Non linear models and the load of an electricity distributor
Authors: Simões Mario Domingues , Klotzle Marcelo Cabus , Pinto Antonio Carlos Figueiredo , Gomes Leonardo Lima
Published: March 2015

Purpose

– The purpose of this study is to ascertain whether nonlinearities could be present in electricity loads observed in subtropical environments, where none or little heating is required, and whether threshold autoregressive (TAR)-type regime switching models could be advantageous in the modeling of those loads.

Design/methodology/approach

– The actual observed load of a Brazilian regional electricity distributor from January 2013 to August 2012 was modeled using a popularly employed ARMA model for reference, and smooth and non-smooth TAR transition (non-linear) models were used as non-linear regime switching models.

Findings

– Evidence of nonlinearities were found in the load series, and evidence was also found on the intrinsic resistance of this type of models to structural breaks in the data. Additionally, to reacting well to asymmetries in the data, these models avoid the use of exogenous variables. Altogether, this could prove to be a definite advantage of the use of such model alternatives.

Research limitations/implications

– However, even if the present work may have been limited by the observation frequency of the available data, it appears TAR models appear to be a viable alternative to forecasting short-term electricity loads. Nonetheless, additional research is required to achieve a higher accuracy of forecast data.

Practical implications

– If such models can be successfully used, it will be a great advantage for electricity generators, as the computational effort involved in the use of such models is not significantly larger than regular linear ones.

Originality/value

– To our knowledge, this type of research has not yet been made with subtropical/tropical electricity load data.
The relationship between energy consumption and GDP in emerging countries
Authors: Al-mulali Usama , Mohammed Abdul Hakim
Published: March 2015

Purpose

– This paper aims to investigate the relationship between gross domestic product (GDP) by sector and energy consumption by type in 16 emerging countries.

Design/methodology/approach

– The panel model was utilized taking the period 1980-2010.

Findings

– The results revealed that GDP by sector and energy consumption by type are cointegrated. Moreover, the Granger causality concluded a bi-directional causal relationship between oil, natural gas and renewable energy consumption and the value of the manufacturing, industrial and services sector. Furthermore, a bi-directional causal relationship was also found between coal consumption and the value of the services sector. Furthermore, a one-way causal relationship was found from oil consumption to the value of the agriculture sector, the value of the agriculture sector to coal consumption, and coal consumption to the value of the manufacturing and the industrial sectors.

Practical implications

– This study recommended that these countries should increase their renewable energy consumption to achieve their GDP growth.

Originality/value

– This study is different from the previous studies, as it disaggregated the GDP into four sectors, namely, agriculture, manufacturing, industrial and the services sector. In addition, this study will disaggregate energy consumption into oil consumption, gas consumption, coal consumption and electricity consumption.
Sustainability in the car-based mobility: the case of the electric vehicle Editha
Authors: Heinicke Matthias , Wagenhaus Gerd
Published: March 2015

Purpose

– Considering the well-known finiteness of resources and particularly in the light of previous concepts to ensure car-based mobility, this paper aims to outline to what extent the cost structure for sustainable mobility is still acceptable in the foreseeable future for the majority of people. The production and use of energy for mobility is a decisive factor for the future development of entire regions. This can be directly derived from the dramatically evolving energy cost in the recent years rooted in an increasing scarcity of known resources.

Design/methodology/approach

– On the basis of available new technology components, researchers from the University of Magdeburg (Germany) have converted a conventional car into an electric vehicle. Hereby, energy efficiency and sustainability were in the direct focus of the product redesign. Furthermore, a LCC analysis complements the qualitative analysis.

Findings

– Thus, a driving concept for electric mobility in the urban environment was drawn up which meets the criterion of suitability for everyday use due to an e-conversion. Moreover, the outstanding efficiency of the designed powertrain is demonstrated.

Research limitations/implications

– Using the research electric vehicle Editha, the researchers point out which technical options can be inferred from available components for the creation of mobility in the urban environment. However, the source of energy is crucial to assess if the claim for sustainability is fulfilled.

Social implications

– The paper illustrates that a monetary advantage of electric vehicles, such as the prototype Editha, arises after seven years due to disproportional purchase costs.

Originality/value

– In this context, the proposed driving concept of the prototype represents a transitional solution from vehicles with central engine to hub wheel electric engines. In addition, Editha is the first roadworthy and suitable for daily use research vehicle using an individual electric motor for each rear wheel without manual gearbox.
Shipping sulphur regulation, freight transportation prices and diesel markets in the Baltic Sea region
Authors: Hilmola Olli-Pekka
Published: March 2015

Purpose

– Purpose of this research is to shed light on the changes caused by shipping sulphur regulation, which will globally take off during years 2015 and 2020. It has significant effects on diesel markets globally, but especially in regions, where demanding 0.1 per cent level is required. One of these regions is the Baltic Sea. It is relatively undealt issue, how this forthcoming change will affect these specific sub-regions of stiff 0.1 per cent sulphur level demand and their transportation modes with different tax obligations.

Design/methodology/approach

– The authors use second-hand data from various different sources, earlier research as well as simulation to estimate the effects on the diesel markets and transportation prices in the Baltic Sea region. Different transportation modes have diverging taxation treatment on diesel oil use, which complicates analysis further.

Findings

– Based on research findings, it is rather probable that diesel markets for sulphur-free diesel oil shall face price spike in the beginning of 2015 in the Baltic Sea region. This is mostly explained with needed large-scale scrubber investment and short-time span to complete these (there are both technical and financial challenges). Therefore, numerous ships shall enter sulphur-free diesel oil market. Based on the simulation study, freight transportation will mostly be hurt in shipping, whereas road and rail shall face smaller price increases. Results are mostly explained with taxation treatment, where shipping is still using tax-free diesel oil, and no fixed taxes are hedging this transportation mode from sudden price changes.

Research limitations/implications

– Analysis concerns only Baltic Sea region, and effects and changes in the entire Europe from sulphur regulation change in 2015 are unknown. This would mean to extent study to North Sea. In addition, taxation system harmonization is not yet complete in Europe, and differences exist between member states. Research work was completed with diesel oil tax treatment regarding different transportation modes in Finland.

Practical implications

– Based on this study, short sea shipping will be hurt by regulation change in 2015. However, in the future, this transportation mode shall face additional cost increases, as most probably, tax harmonization in diesel markets shall lead to fixed taxes added on shipping diesel. So, transportation mode shall face difficult and challenging times ahead.

Originality/value

– Research is seminal study from possible sulphur regulation change implications in transportation mode level. It takes into account taxation treatment, cost share of diesel in transportation mode level and possible diesel price change. Until today, no other study exists in this detailed level.
Mobile social network in proximity: taxonomy, approaches and open challenges
Authors: Chang Chii , Srirama Satish Narayana , Ling Sea
Published: March 2015

Purpose

– Recent smart mobile devices are capable of letting users produce various digital content, and share/upload the content to many social network services (SNS) directly via wireless network connections. The phenomenon has increased the number of people using mobile SNS applications. Although the applications have become more popular, mobile users have been restricted in the virtual communities of online SNS and are not aware of the social opportunities available to them in real-time surrounding. While they spend most of their time accessing online SNS, they have missed many opportunities to interact with others for new friendships, business opportunities or information sharing. Consequently, a new breed of mobile social network (MSN) system has arisen to assist mobile users to interact with proximal people and perform various social activities. Such a proximal-based MSN environment is termed a Mobile Social Network in Proximity (MSNP).

Design/methodology/approach

– Developing an MSNP system needs to address a number of issues and challenges, such as heterogeneity, content/service discovery, privacy and trust, resource management, and so on. This paper identifies and describes these challenges, and reviews a number of related solutions from existing literature. In the follow up, this paper addresses a number of open challenges in the MSNP domain.

Findings

– Although various works have been proposed to enable and overcome challenges in MSNP, there are still many unsolved open challenges in terms of identification, content management, social-aware discovery, trust in public environment, adaptation, quality of service and the development of MSNP. We have addressed these challenges in this paper as future research directions in the MSNP domain.

Originality/value

– This paper provides an original literature review in MSNP and identifies a number of open challenges as research direction in the MSNP domain.
Competition versus interaction as a way to promote innovation in the construction industry
Authors: Havenvid Malena Ingemansson
Published: March 2015

Purpose

– The purpose of this paper is to discuss the link between economic thinking and public policy, two ways of promoting innovation are reviewed – competition and interaction. The competition perspective is illustrated by Schumpeterian-inspired growth economics, while the role of inter-organisational interaction is shown by the industrial network theory.

Design/methodology/approach

– The construction sector is used as an example of a politically critiqued industry regarding low innovativeness and productivity, through which the two different views are outlined and compared. The main differences of these two perspectives are outlined as: the organisational unit of analysis (the firm vs the relationship and network), how knowledge is created and spread (exogenous vs endogenous to economic exchange), and the value-creation processes (internal vs external focus).

Findings

– The two views are essential different and therefore should cancel each other out if implemented simultaneously. Consequently, a conscious choice as to which view should be used within a public policy for promoting innovation must be made. It is concluded that, while both types of economic thinking can be used to promote innovation in this industry, a fundamental difference could arise if construction firms continue to pursue mainly competitive strategies at the expense of addressing its interactional problems.

Practical implications

– Finally, a set of questions that policymakers need to consider in relation to the three fundamental issues addressed above is discussed.

Originality/value

– The paper adds to the discussion of how to increase the innovativeness in the construction industry in a novel way by comparing two distinctly different theoretical perspectives on how this is best handled.
The diversity of systemic innovation thinking
Authors: Eklund Magnus , Waluszewski Alexandra
Published: March 2015

Purpose

– The purpose of this paper is to analyze the different assessments of a particular industry and its ability to innovative, renew and prosper, but also to look into the underlying assumptions that are hiding behind the systemic approaches utilized in these assessments. The point of departure is an empirical puzzle: one group of studies presents a rather optimistic view of the Swedish life science industry and its ability to economize on research, policy and industrial investments. Another group of studies presents much a darker view, questioning the capacity of new companies to reach economic endurance, as well as the possibility of keeping the actually successful companies within the country. At a first sight it appears as if the two groups of studies are resting on a common theoretical ground: all seem to depart from a systemic innovation perspective that challenges the idea of an independent business landscape.

Design/methodology/approach

– The difference between the assessments becomes comprehensible once the authors allow for a variety of systemic approaches in innovation thinking. The authors propose an ideal-typical distinction between two types of system perspectives; those that view technology as entangled in its environment and those that view technology as disentangled from its environment. The authors use the national innovation system (NIS) and the industrial network (IMP) approaches to exemplify the two perspectives.

Findings

– An implication of the study is that the term “systemic perspective” is very broad and encompassing, something that in turn points to the importance of being clear about what the authors mean with a system, but also with what the theoretical assumptions focus on and abstract away from.

Originality/value

– The ideal-typical distinction between two types of system perspectives; those that view technology as entangled in its environment and those that view technology as disentangled from its environment. The authors use the NIS and the IMP approaches to exemplify the two perspectives.
Explaining the operation of a home care system
Authors: Turner Kenneth J.
Published: March 2015

Purpose

– The purpose of this paper is to devise a general solution that allows a policy-based (i.e. rule-based) management system to explain its operation. In particular, a solution has been developed and evaluated in the context of an automated home care system.

Design/methodology/approach

– The work has built on an existing policy-based management system called Advanced Component Control Enhancing Network Technologies (ACCENT). This includes automated management of home care using two forms of rules: higher-level (user) goals and lower-level (system) policies. These rules can be defined by users (typically carers) to personalise how the system should support the resident. In new work, the system has been extended to include an explanation facility that allows the user to understand the past and future behaviour of the system.

Findings

– An explanation facility has been created to explain the past and future behaviour of the system. An initial evaluation of this has been carried out with carers. The participants in this evaluation found the facility to be understandable and were able to use it effectively.

Research limitations/implications

– The work has made a useful extension to the design of policy-based systems in general. The initial evaluation with a limited group of users identified small weaknesses in the explanation facility that will be addressed in future work. The updated approach will then be evaluated with a larger group of users.

Practical implications

– The enhanced home care system is now more usable and comprehensible, and so will be easier to deploy and maintain.

Social implications

– The explanation facility has made the home care system more usable and comprehensible for users, and so will enhance its acceptability in future deployment.

Originality/value

– Although expert systems have long been able to explain their operation, this kind of solution has not previously been attempted for policy-based management systems. The value to end users is that the approach makes automated support of home care more understandable and thus more acceptable and usable.
Assistive technology in dementia care: methodological issues in research design
Authors: Altendorf Annette , Schreiber Jason
Published: March 2015

Purpose

– The purpose of this paper is to illustrate some of the ethical issues and methodological obstacles encountered when trialling and using safer walking technologies and monitoring devices in dementia care.

Design/methodology/approach

– Using a number of recent studies as examples statistical, methodological and ethical issues are illustrated, which impact on the feasibility of randomised controlled trials or quasi-experimental designs.

Findings

– Much has already been achieved in using technology to aid people with memory and related problems. However, statistical evidence for the effectiveness of safer walking and monitoring devices in dementia care is still lacking. Careful considerations such as “treat the client as you would like to be treated” should be applied, when making a decision about a particular device.

Originality/value

– Safer walking and monitoring technology for people with memory and related problems is a rapidly advancing field of research. This is an updated discussion on methodological, statistical and ethical issues.
Playing for time: the Fed’s attempt to mange the crisis as a liquidity problem
Authors: Eisenbeis Robert A. , Herring Richard J.
Published: March 2015

Purpose

– The purpose of this paper is to examine the events leading up to the Great Recession, the US Federal Reserve’s response to what it perceived to be a short-term liquidity problem, and the programs it put in place to address liquidity needs from 2007 through the third quarter of 2008.

Design/methodology/approach

– These programs were designed to channel liquidity to some of the largest institutions, most of which were primary dealers. We describe these programs, examine available evidence regarding their effectiveness and detail which institutions received the largest amounts under each program.

Findings

– We argue that increasing financial fragility and potential insolvencies in several major institutions were evident prior to the crisis. While it is inherently difficult to disentangle issues of illiquidity from issues of insolvency, failure to recognize and address those insolvency problems delayed necessary adjustments, undermined confidence in the financial system and may have exacerbated the crisis.

Research limitations/implications

– Disentangling issues of illiquidity from issues of insolvency is inherently difficult and so it is not possible to specify a definitive counterfactual scenario. Nonetheless, failure to recognize and address the insolvency problems in several major institutions until more than a year after the crisis had begun delayed the necessary adjustment and undermined confidence in the financial system.

Originality/value

– This paper is among the first to analyze data showing the amounts of lending and the distribution of these loans across institutions under the Fed’s special liquidity facilities during the first 18 months of the financial crisis.
Upper Level of a Sustainability Assessment Framework for Power System Planning
Authors: Cano-Andrade Sergio , von Spakovsky Michael R. , Fuentes Alejandro , Lo Prete Chiara , Mili Lamine
Published: March 2015

This paper describes the upper level of a two-tiered sustainability assessment framework (SAF) for determining the optimal synthesis/design and operation of a power network and its associated energy production and storage technologies. The upper-level framework is described, and results for its application to a test bed scenario given by the Northwest European electricity power network presented. A brief description of the lower level of the SAF is given as well. In order to analyze the impact of microgrids (MGs) in the main network, two different scenarios are considered in the analysis, i.e., a network without MGs and a network with MGs. The optimization is carried out in a multi-objective, quasi-stationary manner with producer partial-load behavior taken into account via nonlinear functions for efficiency, cost, and emissions that depend on the electricity generated by each nonrenewable or renewable producer technology. Results indicate for the particular problem posed and for the optimal configurations found that including MGs improves the network relative to reductions in capital and operating costs and to increases in network resiliency. On the other hand, total daily SO2 emissions and network exergetic efficiency are not improved for the case when MGs are included.
Bistable Behavior of the Cylindrical Origami Structure With Kresling Pattern
Authors: Jianguo Cai , Xiaowei Deng , Ya Zhou , Jian Feng , Yongming Tu
Published: March 2015

The deployment of a cylinder based on origami with Kresling pattern, whose basic mechanisms are formed by the buckling of a thin cylindrical shell under torsional loading, is studied in this paper. The model consists of identical triangular panels with cyclic symmetry and has a small displacement internal inextensional mechanism. First, geometric formulation of the design problem is presented. Then, assuming that the deployment and folding process is uniform, the bistable behavior of the cylinder is discussed. It can be found that, during the deployment, the dimensionless strain energy increases first and then reduces to zero but followed by another sharp increase. Moreover, the limit condition of geometry parameters for the bistable phenomenon is also discussed. Finally, the bistable behavior is also studied by using numerical simulations for simple and more complex case of the cylinder with multistory. The numerical results agree well with the analytical predictions. Therefore, comparisons with finite element predictions have shown that the analytical solutions given in this paper are accurate and have validated the assumptions made in the derivations.
A Data-Driven Network Analysis Approach to Predicting Customer Choice Sets for Choice Modeling in Engineering Design
Authors: Wang Mingxian , Chen Wei
Published: March 2015

In this paper, we propose a data-driven network analysis based approach to predict individual choice sets for customer choice modeling in engineering design. We apply data analytics to mine existing data of customer choice sets, which is then used to predict choice sets for individual customers in a new choice modeling scenario where choice set information is lacking. Product association network is constructed to identify product communities based on existing data of customer choice sets, where links between products reflect the proximity or similarity of two products in customers' perceptual space. To account for customer heterogeneity, customers are classified into clusters (segments) based on their profile attributes and for each cluster the product consideration frequency is computed. For predicting choice sets in a new choice modeling scenario, a probabilistic sampling approach is proposed to integrate product associations, customer segments, and the link strengths in the product association network. In case studies, we first implement the approach using an example with simulated choice set data. The quality of predicted choice sets is examined by assessing the estimation bias of the developed choice model. We then demonstrate the proposed approach using actual survey data of vehicle choice, illustrating the benefits of improving a choice model through choice set prediction and the potential of using such choice models to support engineering design decisions. This research also highlights the benefits and potentials of using network techniques for understanding customer preferences in product design.
Products' Shared Visual Features Do Not Cancel in Consumer Decisions
Authors: Du Ping , MacDonald Erin F.
Published: March 2015

Consumers' product purchase decisions typically involve comparing competing products' visual features and functional attributes. Companies strive for “product differentiation” (Liu et al., 2013, “Product Family Design Through Ontology-Based Faceted Component Analysis, Selection, and Optimization,” ASME J. Mech. Des., 135(8), p. 081007; Thevenot and Simpson, 2009, “A Product Dissection-Based Methodology to Benchmark Product Family Design Alternatives,” ASME J. Mech. Des., 131(4), p. 041002; Kota et al., 2000, “A Metric for Evaluating Design Commonality in Product Families,” ASME J. Mech. Des., 122(4), pp. 403–410; Orfi et al. 2011, “Harnessing Product Complexity: Step 1—Establishing Product Complexity Dimensions and Indicators,” Eng. Econ., 56(1), pp. 59–79; and Shooter et al. 2005, “Toward a Multi-Agent Information Management Infrastructure for Product Family Planning and Mass Customisation,” Int. J. Mass Customisation, 1(1), pp. 134–155), which makes consumers' product comparisons fruitful but also sometimes challenging. Psychologists who study decision-making have created models of choice such as the cancellation-and-focus (C&F) model. C&F explains and predicts how people decide between choice alternatives with both shared and unique attributes: The shared attributes are “canceled” (ignored) while the unique ones have greater weight in decisions. However, this behavior has only been tested with text descriptions of choice alternatives. To be useful to designers, C&F must be tested with product visuals. This study tests C&F under six conditions defined by: The representation mode (text-only, image-only, and image-with-text) and presentation (sequentially or side-by-side) of choice alternatives. For the products tested, C&F holds for only limited situations. Survey and eye-tracking data suggest different cognitive responses to shared text attributes versus shared image features: In text-only, an attribute's repetition cancels its importance in decisions, while in images, repetition of a feature reinforces its importance. Generally, product differences prove to attract more attention than commonalities, demonstrating product differentiation's importance in forming consumer preferences.
Lift and Drag Characteristics of an Air-Cooled Heat Exchanger Axial Flow Fan
Authors: Louw Francois G. , von Backström Theodore W. , van der Spuy Sybrand J.
Published: March 2015

Actuator-disk models (ADMs) use blade element theory to numerically simulate the flow field induced by axial fans. These models give a fair approximation at near design flow rates, but are of poor accuracy at low flow rates. Therefore, the lift/drag (LD) characteristics of two-dimensional (2D) sections along the span of an air-cooled heat exchanger (ACHE) axial fan are numerically investigated, with the future prospect of improving ADMs at these flow conditions. It is found that the blade sectional LD characteristics are similar in shape, but offset from the 2D LD characteristics of the reference airfoil (NASA LS 413 profile) at small angles of attack (αatt<5deg). A deviation between these characteristics is observed at higher angles of attack. The blade sectional lift coefficients for αatt>5deg always remain lower compared to the maximum lift coefficient of the reference airfoil. Conversely, the blade sectional drag coefficients are always higher compared to that of the reference airfoil for αatt>5deg.
Breakdown of a Pressurized Fingerlike Crack in a Permeable Solid
Authors: Sarvaramini Erfan , Garagash Dmitry I.
Published: March 2015

This paper is concerned with the analysis of a low-viscosity fluid injection into a pre-existing, fingerlike crack within a linear elastic, permeable rock, and of the conditions leading to the onset of the fracture propagation (i.e., the breakdown). The problem is of interest in reservoir waterflooding, supercritical CO2 injection for geological storage, and other subsurface fluid injection applications. Fluid injection into a stationary crack leads to its elastic dilation and pressurization, buffered by the fluid leak-off into the surrounding rock. The solution of the problem, therefore, requires coupling of the crack deformation and the full-space pore-fluid pressure diffusion in the permeable rock. Contrary to the case of propagating hydraulic fractures, when significant part of the energy input is dissipated in the viscous fluid flow in the fracture, we find that the viscous fluid pressure drop inside a stationary fracture can be often neglected (we establish the conditions when one can do so). This, in turn, allows for a semi-analytical solution of the problem using the Green's function method, and, furthermore, for the full analytical treatment of the small/large injection time asymptotics. We apply the transient pressurization solution to predict the onset of the propagation based on the criteria derived from the energy considerations for a fingerlike crack.
Organic Fluid Turbines for Various Engine Power Level Turbochargers
Authors: Cerri Giovanni
Published: March 2015

Engine exhaust thermal power can be recovered with bottoming Rankine cycle turbine used to drive the engine charging compressor. This paper describes the turbine design concepts and performance analysis of organic fluid turbines for various size turbochargers to be employed with diesel engines of different power levels. Such designs result in monostage full admission turbines with supersonic exit stator nozzles and low degrees of reaction. Turbine expansion efficiencies from 77% to 79% and overall organic fluid turbocharger efficiencies from 53% to 63% are projected with engine power levels ranging from 100 kW to 20 MW. Design problems such as sealing are discussed.
Three Dimensional Flow in Radial-Inflow Turbines
Authors: Zangeneh-Kazemi M. , Dawes W. N. , Hawthorne W. R.
Published: March 2015

The flow through an impeller of a low speed radial-inflow turbine has been analysed using a fully three-dimensional viscous program and good correlations with instantaneous measurements of casing static pressure and exit flow distribution have been obtained. The flow at the exit of the turbine shows a pronounced non-uniformity with a wake region of high absolute flow angle near the casing. The predictions show that the flow is fully attached inside the impeller, while secondary flows can be observed especially in the exducer moving low momentum fluid towards the casing-suction corner. The presence of these secondary flows is discussed with reference to classical secondary flow theory. However, the comparison of measurements and numerical predictions indicate that the wake flow pattern is only partly due to the secondary flow. It is shown that in fact the tip leakage flow also plays a significant role in the wake generation and correspondingly some modelling of the leakage flow is essential in any attempted numerical simulations.