The term user experience (UX) encompasses the concepts of usability and affective engineering. However, UX has not been defined clearly. In this study, a literature survey, user interview and indirect observation were conducted to develop definitions of UX and its elements. A literature survey investigated 127 articles that were considered to be helpful to define the concept of UX. An in‐depth interview targeted 14 hands‐on workers in the Korean mobile phone industry. An indirect observation captured daily experiences of eight end‐users with mobile phones. This study collected various views on UX from academia, industry, and end‐users using these three approaches. As a result, this article proposes definitions of UX and its elements: usability, affect, and user value. These results are expected to help design products or services with greater levels of UX. © 2011 Wiley Periodicals, Inc.This article was published online on 20 October 2011. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 13 June 2013.

New sensitive and reliable methods for assessing alterations in regional lung structure and function are critically important for the investigation and treatment of pulmonary diseases. Accurate identification of the airway tree will provide an assessment of airway structure and will provide a means by which multiple volumetric images of the lung at the same lung volume over time can be used to assess regional parenchymal changes. The authors describe a novel rule-based method for the segmentation of airway trees from three-dimensional (3-D) sets of computed tomography (CT) images, and its validation. The presented method takes advantage of a priori anatomical knowledge about pulmonary airway and vascular trees and their interrelationships. The method is based on a combination of 3-D seeded region growing that is used to identify large airways, rule-based two-dimensional (2-D) segmentation of individual CT slices to identify probable locations of smaller diameter airways, and merging of airway regions across the 3-D set of slices resulting in a tree-like airway structure. The method was validated in 40 3-mm-thick CT sections from five data sets of canine lungs scanned via electron beam CT in vivo with lung volume held at a constant pressure. The method's performance was compared with that of the conventional 3-D region growing method. The method substantially outperformed an existing conventional approach to airway tree detection.

While interacting with a product or a service, people have diverse experiences, which constitute user experience (UX). In this study, the hierarchical dimensions of UX were considered, including overall UX, its elements (usability, affect, and user value) and their subelements. To determine how UX changes over time, the temporal changes of the influence of each element and subelement were analyzed. Twenty subjects participated in a longitudinal experiment by using a social network service (SNS). The most important element of UX changed from usability to user value after one week of use. These results suggest that adoption of an SNS occurs in two phases: a phase of affected by usability and a phase affected by user value. Identification of these phases and the systematic approach used in the study are expected to contribute to design and evaluation of new SNSs and other products and services. C 2014 Wiley Periodicals, Inc.

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Heavily tellurium (Te)-doped GaAs layers with diethyltellurium (DETe) grown by metalorganic chemical vapor deposition (MOCVD) were investigated. The existence of Te-rich microprecipitates might degrade both the electrical and optical properties. Compared to Si doping, the tunnel junction diode doped with Te doping revealed lower tunneling resistance. A comparative study using both Si and Te doping in the GaAs tunnel junction of GaInP/GaAs tandem solar cells showed a higher efficiency for Te doping. Therefore, the GaAs tunnel junction with Te doping can be considered to improve the device performance of GaAs-based multi-junction solar cells.