Cognitive Strategies in HCI and Their Implications on User Error

Human error while performing well-learned tasks on a com-puter is an infrequent, but pervasive problem. Such errors areoften attributed to memory deficits, such as loss of activation orinterference with other tasks (Altmann & Trafton, 2002). Weare arguing that this view neglects the role of the environment.As embodied beings, humans make extensive use of externalcues during the planning and execution of tasks. In this paper,we study how the visual interaction with a computer interfaceis linked to user errors. Gaze recordings confirm our hypoth-esis that the use of the environment increases when memorybecomes weak. An existing cognitive model of sequential ac-tion and procedural error (Halbrügge, Quade, & Engelbrecht,2015) is extended to account for the observed gaze behavior

Current Trends and Challenges in Electronic Procurement: An Empirical Study

The following paper presents results from a longitudinal study on the use of ICT for B2B-related business processes in large Swiss companies. In an empirical survey, 68 questionnaires were personally collected from procurement heads and sub-sequently analysed. The findings show that reduction of purchase prices is the top priority when goal-setting in procurement. Electronic orders and invoices are the business documents that are most often exchanged electronically between partners. Electronic exchange of invoices (e-invoicing) is a current key topic for over 70 % of the companies. Procurement heads sense a lack of supplier involvement which makes the realisation of balanced B2B solution scenarios difficult. The study shows that IT, without doubt, plays a significant role in everyday procurement, but that the expectations of IT are rarely completely fulfilled

Bound states and local topological phase diagram of classical impurity spins coupled to a Chern insulator

The existence of bound states induced by local impurities coupled to an insulating host depends decisively on the global topological properties of the host's electronic structure. In this context, we consider magnetic impurities modelled as classical unit-length spins that are exchange-coupled to the spinful Haldane model on the honeycomb lattice. We investigate the spectral flow of bound states with the coupling strength $J$ in both the topologically trivial and Chern-insulating phases. In addition to conventional $k$-space topology, an additional, spatially local topological feature is available, based on the space of impurity-spin configurations forming, in case of $R$ impurities, an $R$-fold direct product of two-dimensional spheres. Global $k$-space and local $S$-space topology are represented by different topological invariants, the first ($k$-space) Chern number and the $R$-th ($S$-space) spin-Chern number. We demonstrate that there is a local $S$-space topological transition as a function of $J$ associated with a change in the spin Chern number and work out the implications of this for the $J$-dependent local electronic structure close to the impurities and, in particular, for in-gap bound states. The critical exchange couplings' dependence on the parameters of the Haldane model, and thus on the $k$-space topological state, is obtained numerically to construct local topological phase diagrams for systems with $R=1$ and $R=2$ impurity spins.Comment: 16 pages, 9 figure

Peritoneal Dissemination Complicating Morcellation of Uterine Mesenchymal Neoplasms

Background: Power morcellation has become a common technique for the minimally invasive resection of uterine leiomyomas. This technique is associated with dissemination of cellular material throughout the peritoneum. When morcellated uterine tumors are unexpectedly found to be leiomyosarcomas or tumors with atypical features (atypical leiomyoma, smooth muscle tumor of uncertain malignant potential), there may be significant clinical consequences. This study was undertaken to determine the frequency and clinical consequence of intraperitoneal dissemination of these neoplasms. Methodology/principal findings: From 2005–2010, 1091 instances of uterine morcellation were identified at BWH. Unexpected diagnoses of leiomyoma variants or atypical and malignant smooth muscle tumors occurred in 1.2% of cases using power morcellation for uterine masses clinically presumed to be “fibroids” over this period, including one endometrial stromal sarcoma (ESS), one cellular leiomyoma (CL), six atypical leiomyomas (AL), three smooth muscle tumor of uncertain malignant potential (STUMPs), and one leiomyosarcoma (LMS). The rate of unexpected sarcoma after the laparoscopic morcellation procedure was 0.09%, 9-fold higher than the rate currently quoted to patients during pre-procedure briefing, and this rate may increase over time as diagnostically challenging or under-sampled tumors manifest their biological potential. Furthermore, when examining follow-up laparoscopies, both from in-house and consultation cases, disseminated disease occurred in 64.3% of all tumors (zero of one ESS, one of one CL, zero of one AL, four of four STUMPs, and four of seven LMS). Only disseminated leiomyosarcoma, however, was associated with mortality. Procedures are proposed for pathologic evaluation of morcellation specimens and associated follow-up specimens. Conclusions/significance: While additional study is warranted, these data suggest uterine morcellation carries a risk of disseminating unexpected malignancy with apparent associated increase in mortality much higher than appreciated currently

The main geological factors influencing on formation of indices of coal quality (on the example of the coal deposit "Neryungrinskoye")

Genetic and epigenetic factors influencing on formation of a coal bed (its characteristics expressing by means of morphology, petrographic composition, degree of reducing, metamorphism, oxidation, and dislocation, physical properties and indices of coal quality) are considered. The main task of this research consisted in establishing of the significant factors influencing of the coal bed quality indices to a greater extent. Solution of the set task from positions of a system approach at study of rock massifs consisting in revealing and studying of many interconnected elements and estimation of their influence by means of alternate normalization of the main bounds is shown. The study was carry out in conditions of the bed «Moshny» of the coal deposit «Neryngrinskoye» of the Southern-Yakutia basin. The experimental data were treated with use of the correlation-regression methods. Results of researches allow to use geological information and geophysical methods for operative planning of geologic prospecting process and mining works in more total way

Water Resources Management In Support Of Raw Region Based On Decoupling Effect

It determines the presence of the decoupling effect in the Russians raw regions materials by using water. Developed models that explain the relationship between the gross regional product and water intake. It proved no effect on the growth of water consumption in most regions of the reference commodity. Recommendations for the decoupling effect development in support of Russians raw regions

On Fairness in Simulatability-based Cryptographic Systems

Simulatability constitutes the cryptographic notion of a secure refinement and has asserted its position as one of the fundamental concepts of modern cryptography. Although simulatability carefully captures that a distributed protocol does not behave any worse than an ideal specification, it however does not capture any form of liveness guarantees, i.e., that something good eventually happens in the protocol. We show how one can extend the notion of simulatability to comprise liveness guarantees by imposing specific fairness constraints on the adversary. As the common notion of fairness based on infinite runs and eventual message delivery is not suited for reasoning about polynomial-time, cryptographic systems, we propose a new definition of fairness that enforces the delivery of messages after a polynomial number of steps. We provide strengthened variants of this definition by granting the protocol parties explicit guarantees on the maximum delay of messages. The variants thus capture fairness with explicit timeout signals, and we further distinguish between fairness with local timeouts and fairness with global timeouts. We compare the resulting notions of fair simulatability, and provide separating examples that help to classify the strengths of the definitions and that show that the different definitions of fairness imply different variants of simulatability