Review of Various Two-Phase Authentication Mechanisms on Ease of Use and Security Enhancement Parameters

Author(s):  
Himani Thakur ◽  
Anand Rajavat
2015 ◽  
Vol 32 (2) ◽  
pp. 109-123 ◽  
Author(s):  
A.K.M. Najmul Islam ◽  
Nasreen Azad

Purpose – The purpose of this paper is to compare the perceptions of educators and students with a learning management system (LMS). The comparison is based on survey data collected from 185 educators and 249 students in a Finnish university who use a popular LMS, Moodle. Design/methodology/approach – The analysis of the survey data follows a two-phase strategy. In the first phase, perceptions of educators and students regarding ease of use, result demonstrability, usefulness, access, reliability, compatibility, satisfaction, and continuance intention were compared using one way analysis of variance (ANOVA). In the second phase, partial least squares (PLS) technique is employed to compare the path values and explained variances of satisfaction, and continuance intention by putting relevant variables as predictors. Findings – The ANOVA results suggest that students have higher positive perceptions regarding ease of use, usefulness, access, reliability, and compatibility of the LMS than the educators. The PLS analysis results revealed that the amount of variance of students’ satisfaction explained by its predictors was 9 percentage points lower than that of educators. It also revealed that the variance of students’ continuance intention explained by satisfaction and usefulness was 12 percentage points lower than that of educators. Practical implications – The study concludes with both theoretical and managerial implications. Originality/value – While prior research has investigated either educators’ or students’ perspective, the authors have investigated both and presented a comparison. The authors have reported several differences that help practitioners make customized intervention plan.


2014 ◽  
Vol 52 ◽  
pp. 141-150 ◽  
Author(s):  
Mary Regina Boland ◽  
Alexander Rusanov ◽  
Yat So ◽  
Carlos Lopez-Jimenez ◽  
Linda Busacca ◽  
...  

2020 ◽  
pp. 175717742094858
Author(s):  
Mariusz Malinowski ◽  
Anna Serafin ◽  
Aleksandra Prazmowska-Wilanowska

Background: Most needlestick injuries (NSIs) result from unsafe needle devices. DropSafe safety pen needle (SPN) was designed to help prevent such injuries before, during and after use through a built-in sharps injury prevention feature (SIPF). Methods: A two-phase study was undertaken. For the pilot study, five non-healthcare users (NHCUs) performed evaluations. For the validation study, 30 evaluators comprising 10 healthcare professionals (HCPs) and 20 NHCUs performed evaluations. The aim of the study was to validate the performance of the SIPF of the SPN and to collect feedback from the evaluators on several aspects of the safety device. Participants performed simulated injections into an orange. Results: The results show that no device failures were observed, and all manipulations were performed without a needlestick or without contact with the needle after injection. The safety feature of the SPN was activated successfully. It was shown that: the label on the seal was legible; the SPNs were easy to attach to the pen injector; injections were easy to perform; it was clear when safety feature was activated; removing the SPN from the injection pen was easy; and the written instructions were easy to understand. Conclusion: The performance of the safety feature of SPN was successfully evaluated in terms of the prevention of NSIs. User feedback demonstrate that the device’s ease of use, handling and instructions for use ensure safety and effectiveness of the SPN when used as intended.


Author(s):  
K. P. Staudhammer ◽  
L. E. Murr

The effect of shock loading on a variety of steels has been reviewed recently by Leslie. It is generally observed that significant changes in microstructure and microhardness are produced by explosive shock deformation. While the effect of shock loading on austenitic, ferritic, martensitic, and pearlitic structures has been investigated, there have been no systematic studies of the shock-loading of microduplex structures.In the current investigation, the shock-loading response of millrolled and heat-treated Uniloy 326 (thickness 60 mil) having a residual grain size of 1 to 2μ before shock loading was studied. Uniloy 326 is a two phase (microduplex) alloy consisting of 30% austenite (γ) in a ferrite (α) matrix; with the composition.3% Ti, 1% Mn, .6% Si,.05% C, 6% Ni, 26% Cr, balance Fe.


Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


Author(s):  
Naresh N. Thadhani ◽  
Thad Vreeland ◽  
Thomas J. Ahrens

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.


Author(s):  
M.G. Burke ◽  
M.K. Miller

Interpretation of fine-scale microstructures containing high volume fractions of second phase is complex. In particular, microstructures developed through decomposition within low temperature miscibility gaps may be extremely fine. This paper compares the morphological interpretations of such complex microstructures by the high-resolution techniques of TEM and atom probe field-ion microscopy (APFIM).The Fe-25 at% Be alloy selected for this study was aged within the low temperature miscibility gap to form a <100> aligned two-phase microstructure. This triaxially modulated microstructure is composed of an Fe-rich ferrite phase and a B2-ordered Be-enriched phase. The microstructural characterization through conventional bright-field TEM is inadequate because of the many contributions to image contrast. The ordering reaction which accompanies spinodal decomposition in this alloy permits simplification of the image by the use of the centered dark field technique to image just one phase. A CDF image formed with a B2 superlattice reflection is shown in fig. 1. In this CDF micrograph, the the B2-ordered Be-enriched phase appears as bright regions in the darkly-imaging ferrite. By examining the specimen in a [001] orientation, the <100> nature of the modulations is evident.


Author(s):  
G. Mackiewicz Ludtka

Historically, metals exhibit superplasticity only while forming in a two-phase field because a two-phase microstructure helps ensure a fine, stable grain size. In the U-5.8 Nb alloy, superplastici ty exists for up to 2 h in the single phase field (γ1) at 670°C. This is above the equilibrium monotectoid temperature of 647°C. Utilizing dilatometry, the superplastic (SP) U-5.8 Nb alloy requires superheating to 658°C to initiate the α+γ2 → γ1 transformation at a heating rate of 1.5°C/s. Hence, the U-5.8 Nb alloy exhibits an anomolous superplastic behavior.


Author(s):  
R.W. Carpenter ◽  
Changhai Li ◽  
David J. Smith

Binary Nb-Hf alloys exhibit a wide bcc solid solution phase field at temperatures above the Hfα→ß transition (2023K) and a two phase bcc+hcp field at lower temperatures. The β solvus exhibits a small slope above about 1500K, suggesting the possible existence of a miscibility gap. An earlier investigation showed that two morphological forms of precipitate occur during the bcc→hcp transformation. The equilibrium morphology is rod-type with axes along <113> bcc. The crystallographic habit of the rod precipitate follows the Burgers relations: {110}||{0001}, <112> || <1010>. The earlier metastable form, transition α, occurs as thin discs with {100} habit. The {100} discs induce large strains in the matrix. Selected area diffraction examination of regions ∼2 microns in diameter containing many disc precipitates showed that, a diffuse intensity distribution whose symmetry resembled the distribution of equilibrium α Bragg spots was associated with the disc precipitate.


Author(s):  
U. Dahmen ◽  
K.H. Westmacott

Despite the increased use of convergent beam diffraction, symmetry concepts in their more general form are not commonly applied as a practical tool in electron microscopy. Crystal symmetry provides an abundance of information that can be used to facilitate and improve the TEM analysis of crystalline solids. This paper draws attention to some aspects of symmetry that can be put to practical use in the analysis of structures and morphologies of two-phase materials.It has been shown that the symmetry of the matrix that relates different variants of a precipitate can be used to determine the axis of needle- or lath-shaped precipitates or the habit plane of plate-shaped precipitates. By tilting to a special high symmetry orientation of the matrix and by measuring angles between symmetry-related variants of the precipitate it is possible to find their habit from a single micrograph.


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