904 research outputs found
Investing in New Technology - A Case Study of a Food Processing Company
The increased turbulence, complexity and competitiveness of organizational environments have made identification, evaluation and implementation of new technological investments critical determinants of organizational productivity, competition and survival. This paper examines new technology investment decision-making process on two levels combining traditional innovation adoption and diffusion approaches by network and interaction approach of IMP-Group. Conducting this we aim to crossfertilize the chosen approaches and produce more comprehensive and integrated understanding to conceptualize investment decision-making processes on new technology. The empirical part of the study investigates an investment process in which a food processing company invested in a new microbiological quality assurance method. The internationalization of food processing industry combined with a growing amount of global raw material sourcing is posing increasing challenges for companies, authorities and governments in terms of guaranteeing the safety of food. Since improved food safety is both time consuming and expensive, food producers find it difficult to cover the resulting costs of testing. These circumstances offer an interesting and fruitful context in which to study investment decision-making process on new technology
Comparing Innovation Adoption and Organizational Buying Behavior Approaches in a Context of Technological Investment Decision-Making
The statement by Cyert, Simon and Trow [1, p. 237] that “Decision-Making – choosing one course of action rather than another, finding an appropriate solution to a new problem posed by a changing world – is commonly asserted to be the heart of executive activity in business.” holds true still after fifty years although a lot has changed in business from those days. New products are launched more frequently to markets and technological innovations alter structures of competition and disturb equilibrium of markets. These dynamics can pose not only opportunities but also threats for firms, depending upon the timing of adoption. The most innovative companies may gain competitive advantage over competitors by adopting and implementing performance improving technologies. On the other hand, the non-adopters may suffer from the improved performance of the adopters. This paper examines conceptually a process of decision-making on new technology discussing organizational buying behavior approach and innovation adoption approach in regard to general decision-making approach and finally combines these fields in order to conceptualize and understand better the process of decision-making on new technological investment
Social media adoption in higher education: a case study involving IT/IS students
This paper discusses the adoption and use of social media in Higher Education (HE). The aim of the research reported in this paper was to identify the main factors and problem areas in the adoption and use of social media in HE. Our study included a survey involving students of Information Technology and Information Systems in Greece and in Finland. In order to verify the findings from the survey, a follow-up survey was also undertaken. The unified technology adoption approach was identified to be a suitable underlying theory for this study. The analysis of viewpoints of students was needed in order to understand converging and diverging viewpoints. The results showed that infrastructure is the most important issue in the planning of learning/teaching activities based on social media, followed by the role of social influence. Based on the analysis, guidelines for planning social-media-based learning activities are proposed. Indications of further work complete the paper
Energetics of positron states trapped at vacancies in solids
We report a computational first-principles study of positron trapping at
vacancy defects in metals and semiconductors. The main emphasis is on the
energetics of the trapping process including the interplay between the positron
state and the defect's ionic structure and on the ensuing annihilation
characteristics of the trapped state. For vacancies in covalent semiconductors
the ion relaxation is a crucial part of the positron trapping process enabling
the localization of the positron state. However, positron trapping does not
strongly affect the characteristic features of the electronic structure, e.g.,
the ionization levels change only moderately. Also in the case of metal
vacancies the positron-induced ion relaxation has a noticeable effect on the
calculated positron lifetime and momentum distribution of annihilating
electron-positron pairs.Comment: Submitted to Physical Review B on 17 April 2007. Revised version
submitted on 6 July 200
Modeling the momentum distributions of annihilating electron-positron pairs in solids
Measuring the Doppler broadening of the positron annihilation radiation or
the angular correlation between the two annihilation gamma quanta reflects the
momentum distribution of electrons seen by positrons in the
material.Vacancy-type defects in solids localize positrons and the measured
spectra are sensitive to the detailed chemical and geometric environments of
the defects. However, the measured information is indirect and when using it in
defect identification comparisons with theoretically predicted spectra is
indispensable. In this article we present a computational scheme for
calculating momentum distributions of electron-positron pairs annihilating in
solids. Valence electron states and their interaction with ion cores are
described using the all-electron projector augmented-wave method, and atomic
orbitals are used to describe the core states. We apply our numerical scheme to
selected systems and compare three different enhancement (electron-positron
correlation) schemes previously used in the calculation of momentum
distributions of annihilating electron-positron pairs within the
density-functional theory. We show that the use of a state-dependent
enhancement scheme leads to better results than a position-dependent
enhancement factor in the case of ratios of Doppler spectra between different
systems. Further, we demonstrate the applicability of our scheme for studying
vacancy-type defects in metals and semiconductors. Especially we study the
effect of forces due to a positron localized at a vacancy-type defect on the
ionic relaxations.Comment: Submitted to Physical Review B on September 1 2005. Revised
manuscript submitted on November 14 200
Quantum Monte Carlo Study of Positron Lifetimes in Solids
Publisher Copyright: © 2022 American Physical Society.We present an analysis of positron lifetimes in solids with unprecedented depth. Instead of modeling correlation effects with density functionals, we study positron-electron wave functions with long-range correlations included. This gives new insight in understanding positron annihilation in metals, insulators, and semiconductors. By using a new quantum Monte Carlo approach for computation of positron lifetimes, an improved accuracy compared to previous computations is obtained for a representative set of materials when compared with experiment. Thus, we present a method without free parameters as a useful alternative to the already existing methods for modeling positrons in solids.Peer reviewe
Quantum Monte Carlo Study of Positron Lifetimes in Solids
Publisher Copyright: © 2022 American Physical Society.We present an analysis of positron lifetimes in solids with unprecedented depth. Instead of modeling correlation effects with density functionals, we study positron-electron wave functions with long-range correlations included. This gives new insight in understanding positron annihilation in metals, insulators, and semiconductors. By using a new quantum Monte Carlo approach for computation of positron lifetimes, an improved accuracy compared to previous computations is obtained for a representative set of materials when compared with experiment. Thus, we present a method without free parameters as a useful alternative to the already existing methods for modeling positrons in solids.Peer reviewe
Development of a test device for the evaluation of journal bearings
Journal and thrust bearings are widely used in heavy industry. Today, there is a growing need for studying different kinds of new bearing material and coating solutions in operating conditions where full film lubrication cannot be achieved or sustained. A test device for the evaluation of journal bearings was developed. The device consists of a rotating shaft and four stationary test bearings. This scheme eliminates the need for support bearings, allowing an accurate measurement of friction. The initial tests were carried out with a variety of loads and sliding speeds in mixed and full film regimes. The friction results in the form of a Stribeck curve were obtained and found to be in line with general trends. The results also indicate that the bearing lift-off speed occurs when the value of the non-dimensional ηen / ppro - parameter is in the range of 0.5·10-8 - 1.0·10-8
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