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Our emphasis in this paper has been on the knowledge-based and cognitive issues pertinent for improved interactions between workers and manufacturing computer systems. We believe that these techniques are as necessary and applicable to manufacturing as to any other vocation, especially as the difference in collar color of shop people becomes less noticeable in their increasing role as knowledge workers. 相似文献
74.
Ngoc-Anh T. Nguyen Mickey L. Wells David C. Cooper 《Drug development and industrial pharmacy》1995,21(14):1671-1682
To identify factors affecting the chemical stability and preservative efficacy of lamivudine oral liquid formulations, an optimization study using a central composite design was performed. In this design, five factors, each at three levels, were investigated: pH (4.5, 5.5, and 73, sucrose (5%, 20%. and 50% w/v), propylene glycol (0% 2%, and 5% w/v), glycerin (4% 8%, and 12% w/v). and EDTA (0.100. 0.175, and 0.250 mg/mL). All formulations contained a constant concentration of lamivudine, parabens, and artificial strawberry and banana flavors. All formulations were evaluated for preservative effectiveness against USP and BP standards and for chemical stability at 30°C and 40°C for three months. All formulations were effective against bacteria and yeasts, but indicated reduced preservative effectiveness against the mold Aspergillus niger. Preservative effectiveness improved with increasing pH (4.5 to 7.5) and to a lesser extent with increasing EDTA concentration (0.100 to 0.250 mg/mL). Increasing glycerin concentration (4% to 12% w/v) slightly decreased preservative effectiveness. Over the concentration ranges tested, no change in preservative effectiveness was noted with concentration changes in sucrose or propylene glycol. The pH was the main factor influencing the chemical stability of the drug and preservatives in this study. Lamivudine chemical stability increased with increasing pH from 4.5 to 7.5. Methyl and propylparaben showed extensive degradation at pH 7.5. 相似文献
75.
The transition from basic automation to flexible manufacturing is an expensive and tedious procedure. It requires meticulous planning and almost clairvoyant forecasting to insure that the initial flexibility obtained is sufficient to allow growth and expansion in the future. This paper will suggest a systematic and methodological approach to achieve optimal flexibility and describe the present results of its application to an ongoing system transformation.
Conclusions based on existing levels of completion are presented along with identification of critical and non critical flexibility requirements. The considerations and steps taken are summarized in a procedural format which may then be applied to a wide variety of system transformations. 相似文献
76.
77.
Allen M. Johnson Michael A. Schoenfelder David J. Lebold 《Quality and Reliability Engineering International》1993,9(1):55-62
The Rainbow net simulation technique is applied to modelling the impact of system load and fault handling on the availability of a fault-tolerant multiprocessor architecture. Rainbow nets are described along with the motivation for creating this modelling technique. A Rainbow net fault-handling model is created for the fault-tolerant multiprocessor architecture and the topology is shown to remain constant in size, independent of the number of processor, memory and I/O elements configured in the system. Simulation is performed with a varying load in terms of the number of active jobs the system must support. Results are given showing how the fault-tolerant capability varies with load. Two new metrics for evaluating fault tolerance are introduced; namely full fault-tolerability and partial fault-tolerability. They are based on simple observations in the model. 相似文献
78.
M. Schedl Dipl.-Ing. E. Pampalk Dipl.-Ind. G. Widmer Univ.-Prof. Dr. 《e & i Elektrotechnik und Informationstechnik》2005,122(7-8):232-237
In this paper we present a general approach to the automatic content-based organization and visualization of large digital music collections. The general methodology consists in extracting musically and perceptually relevant patterns (‘features’) from the given audio recordings (e.g., mp3 files), using topology-preserving data projection methods to map the entire music collection onto two-dimensional visualization planes (possibly in a hierarchical fashion), and using a new display metaphor (the ‘Islands of Music’) to display the inherent structure of the music collection to the user. It is shown how arbitrary meta-data can be integrated into the visualization process, and how similarity according to different viewpoints can be defined and exploited. The basic methodology is briefly described, three prototype systems are presented, and a general discussion of the practical application possibilities of such technologies is offered. 相似文献
79.
Many organisations suspect that their internal security threat is more pressing than their external security threat. The internal threat is predominantly the result of poor user security behaviour. Yet, despite that, security awareness programmes often seem more likely to put users to sleep than to improve their behaviour. This article discusses the influences that affect a user's security behaviour and outlines how a well structured approach focused on improving behaviour could be an excellent way to take security slack out of an organisation and to achieve a high return for a modest, low-risk investment. 相似文献
80.
Jens‐Peter Heinß Dr. 《真空研究与实践》2007,19(5):20-23
Hydrogen free amorphous carbon coatings ‐ deposited with plasma‐activated high‐rate evaporation By using the technology of the plasmaactivated electron beam evaporation we deposited hydrogen free amorphous carbon coatings with deposition rates of up to 100 μm/h. The results of the mechanical and tribological investigations show the potential of these layers for the use in case of wear resistance. Hardnesses of up to 16GPa were proved. The actual state of the characterisation of the coatings is described and the outlook onto possibilities of further optimisation is given. 相似文献