Screen-Printing of Cotton with Natural Pigments: Evaluation of Color and Fastness Properties of the Prints

Eleven natural pigments were selected for the production of environment-friendly cotton prints. Physicochemical properties pH, conductivity, viscosity of the printing pastes were measured in order to evaluate their stability and suitability for printing. Quality control standard tests and color measurements were carried out for all the prints with their fastness properties ranging from poor to very good in some cases.     

Product intelligence in industrial control: Theory and practice

This paper explores the evolving industrial control paradigm of product intelligence. The approach seeks to give a customer greater control over the processing of an order – by integrating technologies which allow for greater tracking of the order and methodologies which allow the customer [via the order] to dynamically influence the way the order is produced, stored or transported. The paper examines developments from four distinct perspectives: conceptual developments, theoretical issues, practical deployment and business opportunities. In each area, existing work is reviewed and open challenges for research are identified. The paper concludes by identifying four key obstacles to be overcome in order to successfully deploy product intelligence in an industrial application.     

Organizational adoption of open source software

Organizations and individuals can use open source software (OSS) for free, they can study its internal workings, and they can even fix it or modify it to make it suit their particular needs. These attributes make OSS an enticing technological choice for a company. Unfortunately, because most enterprises view technology as a proprietary differentiating element of their operation, little is known about the extent of OSS adoption in industry and the key drivers behind adoption decisions. In this article we examine factors and behaviors associated with the adoption of OSS and provide empirical findings through data gathered from the US Fortune-1000 companies. The data come from each company's web browsing and serving activities, gathered by sifting through more than 278 million web server log records and analyzing the results of thousands of network probes. We show that the adoption of OSS in large US companies is significant and is increasing over time through a low-churn transition, advancing from applications to platforms. Its adoption is a pragmatic decision influenced by network effects. It is likelier in larger organizations and those with many less productive employees, and is associated with IT and knowledge-intensive work and operating efficiencies.     

Performance issues of bandwidth management in ATM networks

In our days, efficient management of the available network resources becomes a critical issue, both from a functional point of view (so that users can be provided with the bandwidth they need), and an economical point of view (so that carriers can satisfactorily and efficiently serve as many customers as possible and at the same time increase their revenue). In this paper we consider a bandwidth control scheme (i.e. managed bandwidth service) for an ATM network infrastructure which is applied to the Greek research and technology network (GRNET). We present some methods that we have tested (in a simulation setting) in order to increase the efficiency of the system and the utilization of the available bandwidth. More specifically, we consider a bandwidth‐resizing algorithm for virtual paths, in order to keep the allocated bandwidth very close to the bandwidth actually used. This leads to an increased number of accepted requests and better network utilization. We, also, use the simulation results in order to get an estimation of the effective bandwidth for VBR paths that can be used in call admission. Finally, we consider a semi‐offline scheme where requests are gathered and considered for acceptance in regular intervals. Simulation results show an increase in the utilization of resources. As a further improvement, we allow connections to be allocated a little before or after the time initially requested. This leads to further improvement in network utilization. All the improvement schemes were tested with the ATM‐TN simulator and the results look promising. Copyright © 2003 John Wiley & Sons, Ltd.     

Uncertainty and method limitations in a short-time measurement of the effective thermal transmittance on a building envelope using an infrared camera

Buildings' thermal insulation has received a lot of attention these past years, in an effort to reduce the sector's high energy consumptions. A number of non-destructive methods have been used in order to evaluate in situ the building envelope's effective thermal transmittance, characterised, however, by long-lasting measurement periods. This paper examines the uncertainty and method limitations to use short-time measurements using an infrared camera for this purpose, but also within real environmental conditions that are inevitably unsteady during the measurement series. Experimental measurements were realised with three different infrared cameras, and the results show that a value of effective thermal transmittance could be estimated in situ by a relative uncertainty that does not exceed 20% (coverage factor?=?2), a reliable estimation as long as all systematic errors are identified and diminished through calculations.     

Modeling users’ acceptance of mobile services

The success of mobile services adoption hinges on their ability to cover user needs and attract consumer interest. The extant literature focuses on understanding the factors that might affect consumers’ actual adoption of such services through their effect on behavioral intention; these studies are mostly based on behavioral intention theories, such as Technology Acceptance Model, Diffusion of Innovation and Unified Theory of Acceptance and Use of Technology. In this work, new theoretical constructs are combined with existing evidence in order to extend the Technology Acceptance Model (TAM) as it was initially established by Davis and later further enriched by other researchers. The proposed model includes behavioral intention, perceived usefulness, perceived ease of use, trust, innovativeness, relationship drivers, and functionality. Within this approach, relationship drivers introduce a marketing perspective to the original models of technology adoption by building emotional connections between the users and the mobile services. The hypothesized model is empirically tested using data collected from a survey on m-commerce consumers. Structural Equation Modelling (SEM) was used to evaluate the causal model and Confirmatory Factor Analysis (CFA) was performed to examine the reliability and validity of the measurement model. It is briefly concluded that behavioral intention is directly affected by perceived usefulness, innovativeness and relationship drivers; the findings provide interesting insights and useful hints to practitioners and researchers.     

Suppliers’ behavior on the post-adoption stage of business-to-business e-reverse auctions: An empirical study

Reverse e-auctions are increasingly being used as an alternative business-to-business e-procurement model to exchange products and services among enterprises. Despite their high interest from the academic community, there has been limited empirical study focusing on their post-adoption stage. Based on extant literature dealing with their e-business model and building on emerging concepts in B2B e-commerce, this paper intends to investigate the impact of various factors on suppliers’ level of use of e-reverse auctions by examining their internal and external environment. A relevant conceptual framework is developed and examined on data collected from 60 supplying firms that currently utilize e-reverse auctions. These are analyzed through factor analysis and multiple discriminant analysis. Findings show that firms get influenced to a greater extent by their top management strategic practices and competitors’ business actions. The results also provide interesting insights and useful hints to both researchers and practitioners.     

Scalable rate control for video transmission over UMTS

This paper proposes a mechanism for the congestion control for video transmission over Universal Mobile Telecommunications System (UMTS). Our scheme is applied when the mobile user experiences real time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation‐based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Through a number of simulations and experiments we validate the correctness and measure the performance and efficiency of the mechanism. A first level of evaluation is carried out using the ns‐2 simulator. A second level then validates the proposed mechanism in real world traffic scenarios by performing experiments in a commercial UMTS network. Copyright © 2006 John Wiley & Sons, Ltd.     

Power management adaptation techniques for video transmission over TFRC

In this paper, we describe power management adaptation techniques for wireless video transmission using the TCP Friendly Rate Control (TFRC) protocol that take into account feedback about the received video quality and try to intelligently adapt transmitting power accordingly. The purpose of the mechanisms is to utilize TFRC feedback and thus achieve a beneficial balance between power consumption and the received video quality. There are two power adaptation mechanisms proposed, each one with its own advantages. They both offer significant improvements when used in terms of both power consumption and received video quality. We use simulation in order to compare and evaluate our approach. Copyright © 2011 John Wiley & Sons, Ltd.     

Review of some fundamental approaches for power control in wireless networks

An advanced tutorial on power control issues in wireless networks is provided, covering work published since circa 1992, the beginning of the systematic study of the area, to this date. We present and comment on what we consider are the most fundamental contributions in the area pointing out relationships and differences in approaches and their consequences and applicability. We consider wireless networks as collections of directly interfering wireless links. I.e., we consider single hop configurations, but we do not assume that there is necessarily a centralized control, or a single common goal for the network. We explicitly deal with voice and “data” networks, which have differences in perspective that lead to different methodologies.