Effect of M and M-Ca Substitution on the Structure and Superconductivity of GdBa2Cu3O7?δ [M = Mo, Hf ]

The structural and superconducting properties of (Gd_1–x–y Ca _y M _x )Ba₂Cu₃O _z with M = Mo, Hf are investigated using X-ray diffraction, electrical resistivity, and oxygen content measurements. The effect of increasing the Mo concentration in (Gd_1–x Mo _x )Ba₂Cu₃O _z changes the structure from orthorhombic to tetragonal accompanied by a large increase in resistivity and a fast decrease in T _c at the rate of 1.9 K per at.% of Mo, unlike that of Hf substitution in (Gd_1–x Hf _x )Ba₂Cu₃O _z , which maintains the orthorhombic structure and decreases T _c very slowly at the rate of 0.6 K per atm.% of Hf with nearly no change in resistivity. The suppression of T _c by M = Mo, Hf can be counterbalanced by hole doping by Ca which increases T _c with increasing Ca content showing maximum compensation for Mo. A comparative study of M = Mo, Hf doped samples in (Gd_1–x–y Ca _y M _x )Ba₂Cu₃O _z indicates that the valence of the dopant M = Mo^4+,6+, Hf⁴⁺ and its ionic radius play an important role in controlling the structural and superconducting properties of the systems.     

Web assurance seal services,trust and consumers’ concerns: an investigation of e-commerce transaction intentions across two nations

Trust is considered as a critical enabler in reducing consumer concerns regarding e-commerce transactions. Another enabler that helps reduce consumers’ concerns is Web Assurance Seal Services (WASS). We suggest that both factors help in the reduction of a critical hindrance to e-commerce, namely consumer concerns, and foster e-commerce transactions. Prior research has focused on trust in e-commerce, and separately, on the effectiveness of WASS within certain nations or cultures. However, given that e-commerce is now a global phenomenon we contend that the national or cultural characteristics of consumers are important to understand. This comparative national research attempts to fill this gap. This study makes the following contributions: It identifies a hindrance (i.e., consumers’ concerns), and two enablers (i.e., effectiveness of WASS and trust) in e-commerce technologies as a shopping channel (i.e., trust in e-Channel). It proposes consumers’ concerns for e-commerce as a second-order three-dimensional construct (i.e., security, privacy, and business integrity concern) and compares the effects of trust in e-Channel and WASS on consumers’ e-commerce transaction intention in two different national/cultural contexts (i.e., the U.S.A. and South Korea). The results of the study indicate that the perceived effectiveness of WASS of the U.S. consumers has a strong positive impact on their transaction intention and has a strong negative influence on their concerns for e-commerce. In contrast, Korean consumers’ perceived effectiveness of WASS does not significantly influence their transaction intention and their concerns for e-commerce. The results of group comparison analysis confirm that the strength of perceived effectiveness of WASS of the U.S. consumers is significantly stronger than that of Korean consumers. Interpretations from a cross-national perspective, theoretical and practical implications as well as limitations are discussed.     

Protection motivation and deterrence: a framework for security policy compliance in organisations

Enterprises establish computer security policies to ensure the security of information resources; however, if employees and end-users of organisational information systems (IS) are not keen or are unwilling to follow security policies, then these efforts are in vain. Our study is informed by the literature on IS adoption, protection-motivation theory, deterrence theory, and organisational behaviour, and is motivated by the fundamental premise that the adoption of information security practices and policies is affected by organisational, environmental, and behavioural factors. We develop an Integrated Protection Motivation and Deterrence model of security policy compliance under the umbrella of Taylor-Todd's Decomposed Theory of Planned Behaviour. Furthermore, we evaluate the effect of organisational commitment on employee security compliance intentions. Finally, we empirically test the theoretical model with a data set representing the survey responses of 312 employees from 78 organisations. Our results suggest that (a) threat perceptions about the severity of breaches and response perceptions of response efficacy, self-efficacy, and response costs are likely to affect policy attitudes; (b) organisational commitment and social influence have a significant impact on compliance intentions; and (c) resource availability is a significant factor in enhancing self-efficacy, which in turn, is a significant predictor of policy compliance intentions. We find that employees in our sample underestimate the probability of security breaches.     

Nonconvex/nonsmooth economic load dispatch using modified time‐varying particle swarm optimization

In this paper, a modified time‐varying particle swarm optimization (MTVPSO) is proposed for solving nonconvex economic load dispatch problems. It is a variant of the traditional particle swarm optimization (PSO) algorithm. In an MTVPSO, novel acceleration coefficients for cognitive and social components are presented as linear time‐varying parameters in the velocity update equation of the PSO algorithm. In the early stages of the optimization process, it improves the global search capability of particles and directs the global optima at the end stage. Additionally, a linearly decreased inertia weight is introduced in an MTVPSO, instead of a fixed constant value, which helps improve the diversity of the population. Through this modification mechanism in PSO, the proposed algorithm has a higher probability of avoiding local optima, and it is likely to find global optima more quickly. Six complex benchmark functions have been used to validate the effectiveness of the proposed algorithm. Furthermore, to demonstrate its efficiency, feasibility, and fastness, six different cases (3‐, 6‐, 13‐, 15‐, and 40‐unit systems and one large‐scale Korean power 140‐unit system) of the economic load dispatch problem are solved by an MTVPSO. The results of the proposed algorithm have been compared with state‐of‐the‐art algorithms. It was found that the proposed MTVPSO can deliver better results in terms of solution quality, convergence characteristics, and robustness.     

An examination of private intermediaries’ roles in software vulnerabilities disclosure

Software vulnerability disclosure has generated much interest and debate. Recently some private intermediaries have entered this market. This paper examines the effects of such private intermediaries on optimal timing of disclosure policy made by public intermediaries and vendors’ reactions. Our analysis of private intermediaries’ role suggests that public intermediary’s optimal disclosure time does not change with private intermediary’s participation. However, a vendor’s patch time increases when the probability of information leakage is low, if not non-existent. In other words, private intermediaries’ service decreases a vendor’s willingness to deliver quick patches. Empirical evidence with 1493 vulnerability observations from CERT/CC and other 326 different vulnerability observations from iDefense provided support for our analytical results.

Reduction of unsaturated fatty acids and fatty alcohols with diimide from hydroxylamine-ethyl acetate

Hydroxylamine has been recently found to react with ethyl acetate to generate diimide in situ. This reaction was used to reduce 10-undecenoic, oleic, linoleic, stearolic, concentrates of ricinoleic, cyclopentene and cyclopropene fatty acids (FA), dehydrated castor oil FA, 10-undecen-1-ol, oleyl alcohol and castor fatty alcohols. Unsaturated FA and their corresponding alcohols reacted in a similar manner. Terminally unsaturated, cyclopropene and cyclopentene FA were more reactive than oleic acid, which, in turn, was more reactive than hydroxymonoenoic acids. Conjugated dienoic FA reduced faster than nonconjugated dienoic acids. Partial hydrogenation using this reagent is particularly advantageous in determining geometry and the position of double bonds in the polyunsaturated FA, as it can be carried out in the absence of oxygen or oxidizing agents unlike hydrazine reductions.     

Coded excitation for infrared non-destructive testing of carbon fiber reinforced plastics

This paper proposes a Barker coded excitation for defect detection using infrared non-destructive testing. Capability of the proposed excitation scheme is highlighted with recently introduced correlation based post processing approach and compared with the existing phase based analysis by taking the signal to noise ratio into consideration. Applicability of the proposed scheme has been experimentally validated on a carbon fiber reinforced plastic specimen containing flat bottom holes located at different depths.     

Closed-form solutions to image flow equations for 3D structure and motion

A major source of three-dimensional (3D) information about objects in the world is available to the observer in the form of time-varying imagery. Relative motion between textured objects and the observer generates a time-varying optic array at the image, from which image motion of contours, edge fragments, and feature points can be extracted. These dynamic features serve to sample the underlying image flow field. New, closed-form solutions are given for the structure and motion of planar and curved surface patches from monocular image flow and its derivatives through second order. Both planar and curved surface solutions require at most, the solution of a cubic equation. The analytic solution for curved surface patches combines the transformation of Longuet-Higgins and Prazdny [25] with the planar surface solution of Subbarao and Waxman [43]. New insights regarding uniqueness of solutions also emerge. Thus, the structure-motion coincidence of Waxman and Ullman [54] is interpreted as the duality of tangent plane solutions. The multiplicity of transformation angles (up to three) is related to the sign of the Gaussian curvature of the surface patch. Ovoid patches (i.e., bowls) are shown to possess a unique transform angle, though they are subject to the local structure-motion coincidence. Thus, ovoid patches almost always yield a unique 3D interpretation. In general, ambiguous solutions can be resolved by requiring continuity of the solution over time.The support of the Defense Advanced Research Projects Agency and the U.S. Army Night Vision Laboratory under Contract DAAK70-83-K-0018 (DARPA Order 3206) is gratefully acknowledged.     

An empirical investigation into the validity of transitivity andnon-satiety assumptions in partial order structures: a note

Research in the area of information acquisition has been based on two key assumptions, namely, nonsatiety (implying more is preferable to less) and transitivity (implying that if A is preferred to B and B to C then A will be preferred to C). While at first glance these assumptions do not seem altogether unjustifiable, they do, in practice, constrain the empirical application of the research models. The primary purpose of the paper is to test the validity of these two key assumptions underlying most theoretical research in information acquisition and resource allocation. We begin by introducing four partial order structures and highlight the assumptions upon which they have been based. We then discuss how these structures could be used in estimating consumer preferences. We also provide a statistical methodology to implement such estimation. In later sections, we implement the empirical model on two data sets and discuss the results and propose generalizations