Consumer Selection of E-Commerce Websites in a B2C Environment: A Discrete Decision Choice Model

Despite the suggestions of friction-free information availability, considerable price dispersions for the same product are not uncommon across online retailers in the business-to-consumer (B2C) segment. Online customers do not necessarily always buy from the site with the lowest price, suggesting that other forces are at work. This paper presents and empirically examines a model that proposes that Web site value in terms of (perceived) Web site quality as well as awareness of the site and consumer differences (on price sensitivity) are key variables in explaining online consumer behavior in their choice of Web site despite the existence of price dispersions. Two hundred ninety-three students participated in a series of controlled laboratory experiments making use of two different types of products in terms of complexity and expensiveness (Canon digital camera Powershot S400 and digital versatile disc full-screen edition of Star Wars: Episodes I and II) that required them to interact with three different real-world Web sites offering each of these two branded products and make their decision on which of the three Web sites they will chose to buy the product from. The prices varied across the Web sites, as did the quality of the sites on various dimensions and site awareness of the participants. Conditional logit models of discrete choice for each of the two product types indicate differential influences of Web site quality dimensions and price sensitivity. A number of interesting implications emerge, and pointers to further extensions of the research theme are discussed.     

One-step route to a hybrid TiO2/TixW1?xN nanocomposite by in situ selective carbothermal nitridation

Metal oxide/nitride nanocomposites have many existing and potential applications, e.g. in energy conversion or ammonia synthesis. Here, a hybrid oxide/nitride nanocomposite (anatase/Ti_xW_1−xN) was synthesized by an ammonia-free sol–gel route. Synchrotron x-ray diffraction, complemented with electron microscopy and thermogravimetric analysis, was used to study the structure, composition and mechanism of formation of the nanocomposite. The nanocomposite contained nanoparticles (<5 nm diameter) of two highly intermixed phases. This was found to arise from controlled nucleation and growth of a single oxide intermediate from the gel precursor, followed by phase separation and in situ selective carbothermal nitridation. Depending on the preparation conditions, the composition varied from anatase/Ti_xW_1−xN at low W content to an isostructural mixture of Ti-rich and W-rich Ti_xW_1−xN at high W content. In situ selective carbothermal nitridation offers a facile route to the synthesis of nitride-oxide nanocomposites. This conceptually new approach is a significant advance from previous methods, which generally require ammonolysis of a pre-synthesized oxide.     

Recruitment of low threshold motor-units in the trapezius muscle in different static arm positions

A prevailing hypothesis for development of myalgia symptoms in the trapezius muscle is based on observations that in stereotypic activation of muscle the same low-threshold motor-units are the first ones to be recruited, and that these units are active throughout the contraction, until total relaxation. The theory suggests that these units are the first ones in monotonous repetitive work to be subject to degenerative processes, causing pain. The present project was undertaken to evaluate to what extent recruitment of motor-units in the trapezius muscle is position-specific, i.e. if there are motor-units that are recruited over a wide range of arm postures. Fine wire electrode pairs, inserted 2 cm lateral to the midpoint between the acromion and the C7 spinous processus, were used for signal acquisition. Methods for decomposition of the interference patterns were developed, allowing identification of single motor-units in signals registered in different arm positions. Voluntary recruitment of motor-units in the descending portion of the trapezius muscle was studied in 24 different arm positions (0-90 degrees shoulder flexion, 0-45 degrees humeral abduction, and 45-135 degrees elbow flexion) in three subjects. The results showed that the wire electrode technique and the signal processing algorithm employed allowed motor-unit identification in non-isometric conditions. It was found that low threshold motor-units in the trapezius muscle, active over a wide range of arm positions, could be identified in all three subjects. We refer to those as Cinderella, or C, units. These results support the research hypothesis addressed.     

Mechanisms of plastic deformation of zirconium-based alloys upon uniaxial compression under different temperature-rate conditions

Based on the results of X-ray diffraction analysis of texture of the Zr-1% Nb and Zr-2.5% Nb model alloys compressed uniaxially at temperature corresponding to the β and α + β fields of the phase diagram, the mechanisms responsible for plastic deformation have been determined. These are the crystallographic slip in the β-Zr and α-Zr grains and also the diffusional mechanism of mutual displacement of crystallites along interphase boundaries, which is activated upon the α ? β phase transformations and is the basis of superplasticity. The contribution of each mechanism to the formation of specimen texture depends on the temperature-rate regime of compression.     

Bronchiolitis obliterans organizing pneumonia

Idiopathic BOOP is a clinicopathological entity defined histopathologically by the presence of granulation tissue in bronchioles, alveolar ducts and alveoli. 2 men and 6 women (mean age 47.2 years, range 22-66) with idiopathic BOOP have been observed, the mean period of observation being 31.1 months. In 7 cases the disease started with fever, cough and in 6 with progressive dyspnea. The interval between the onset of symptoms and the beginning of treatment ranged from 2 to 10 months. One woman was asymptomatic. The initial findings were: tachypnoea (6), crackles (7), decreased VC (6), reduced diffusing capacity (6), raised erythrocyte sedimentation rate (7). In 6 cases chest radiographs showed multiple alveolar patchy opacities of various size predominantly in the middle and lower lung zones. HRCT demonstrates peripheral distribution of changes. In one case diffuse reticulonodular infiltrates and in one case solitary tumor-like opacity with cavitation were observed. Seven subjects were given prednisone. Three subjects recovered completely, in 1 clinical and radiological improvement was observed. In 3 cases relapse occurred. The woman with the solitary tumor-like opacity was cured by surgical excision of the lesion.     

Reflecting on Social Influence in Networks

In many social contexts, social influence seems to be inescapable: the behavior of others influences us to modify ours, and vice-versa. However, social psychology is full of examples of phenomena where individuals experience a discrepancy between their public behavior and their private opinion. This raises two central questions. First, how does an individual reason about the behavior of others and their private opinions in situations of social influence? And second, what are the laws of the resulting information dynamics? In this paper, we address these questions by introducing a formal framework for representing reasoning about an individual’s private opinions and public behavior under the dynamics of social influence in social networks. Moreover, we dig deeper into the involved information dynamics by modeling how individuals can learn about each other based on this reasoning. This compels us to introduce a new formal notion of reflective social influence. Finally, we initialize the work on proof theory and automated reasoning for our framework by introducing a sound and complete tableaux system for a fragment of our logic. Furthermore, this constitutes the first tableau system for the “Facebook logic” of J. Seligman, F. Liu, and P. Girard.     

Impact of Cooperative R&D Projects on ICT‐Based Technology Convergence

This study examines how the characteristics of cooperative research and development (R&D) projects in the public domain impact information and communication technology (ICT) convergence. Based on the analysis of 416 cooperative R&D projects under the ICT‐based industry convergence R&D program in Korea, the study finds that the characteristics of cooperative R&D projects significantly impact ICT convergence. Moreover, the participation of public research institutes and universities is critical for ICT convergence compared with that of firms. However, in firm‐to‐firm cooperation, the participation of small and medium enterprises contributes to cross‐sectional convergence, while the participation of large firms leads to overall and longitudinal convergence. R&D inputs such as the number of partners and government subsidies exhibit an inverted U‐shaped relationship (negative quadratic effect) with technology convergence. Project duration and homogeneous partners are also critical factors for ICT convergence. The results indicate several implications and guidelines on how to effectively organize cooperative R&D projects to facilitate technology convergence.     

基于主动队列管理的互联网拥塞控制研究

针对现有AQM算法所遇到的问题,将神经网络理论和控制理论的思想相结合,采取了RED、P/PI和PID的AQM控制策略,设计了单神经元自适应PID控制器的AQM算法.仿真结果表明,该算法控制的路由器队列长度具有良好的性能.