Influence of Threshold Stress on the Estimation of the Weibull Statistics

The influence of threshold stress on the estimation of the Weibull statistics is discussed in terms of the Akaike information criterion. Numerical simulations show that, if sample data are limited in number and threshold stress is not too large, the two-parameter Weibull distribution is still a preferred choice. For example, the fit of strength data of glass and ceramics to the two- and three-parameter Weibull distributions is compared.     

Decisive arrival law parameters and a general finite capacity queueing problem

This paper addresses the problem of finding the parameters of the arrival law which most significantly influence expected occupation and loss of a finite capacity queue. The input process is supposed to be ergodic and wide sense stationary. We show that it is mostly possible to fit an MMPP(2) to the decisive parameters of observational data. Numerical examples illustrate the importance of the decisive parameters, called key parameters, and also show the accuracy of the proposed fitting procedure. Finally, in the appendix we present the solution of the finite capacity queueing problem with Special Semi Markov Process (SSMP) arrivals and a general service strategy.     

Dynamic testing.

This article evaluatively reviews the literature on dynamic testing, a collection of testing procedures designed to quantify not only the products or even the processes of learning but also the potential to learn. The article considers a variety of approaches to dynamic testing and the strengths and weaknesses of each. Moreover, the literature on each approach is reviewed and analyzed in terms of the extent to which it fulfills the claims made for it. In all of these approaches, testing involves learning at the time of test, rather than just static testing of what has been learned before. It is concluded that dynamic testing has great potential for helping to understand people's potentials but that its potential has yet to be realized fully. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis Routes and Characterization of High-Purity, Single-Phase Gallium Nitride Powders

Synthesis of high-purity, single-phase gallium nitride powder has been achieved in a hot-wall tube furnace via (i) the reaction of gallium with ammonia (NH₃) and (ii) the conversion of gallium oxide (Ga₂O₃). For complete reaction, the optimum temperatures, NH₃ flow rates, and boat positions relative to the NH₃ inlet were 975°C, 400 standard cubic centimeters per minute (sccm), and 50 cm, respectively, for the gallium-NH₃ reaction, and 1050°C, 500 sccm, and 50 cm, respectively, for the Ga₂O₃ conversion. Polyhedra of various shapes were obtained from both processes; some rod-shaped crystals also were observed in the material derived from Ga₂O₃.     

IT strategies: beyond competitive advantage

During the 1980s, we saw considerable energy being expended in the search for the Holy Grail of competitive advantage from information technology (IT). There were many academic papers published on the topic and consultants grew rich from their efforts to persuade companies to invest in strategic information systems. The topic itself rose to become one of the top two information systems management issues identified by IT directors and senior IT executives in the USA, and many organizations sought to replicate the success stories of American and United Airlines, Thomson Holidays, Frito-Lay, Otis Elevators, Mrs Field's Cookies and all the other celebrated cases that have entered the information systems mythology.In the cold light of the 1990s, however, much of this mythology has begun to pale. Were the success stories as real as they were first reported? Where is the sustainable advantage from IT? And if the stories were indeed real, to what extent were they planned or merely serendipitous?This editorial reflects on some of the more recent evidence available and raises some key points for debate in this important aspect of information systems management. It attempts to answer the question: What comes after competitive advantage? in terms of the on-going development of the topic ‘IT strategy’.     

Information cut for clustering using a gradient descent approach

We introduce a new graph cut for clustering which we call the Information Cut. It is derived using Parzen windowing to estimate an information theoretic distance measure between probability density functions. We propose to optimize the Information Cut using a gradient descent-based approach. Our algorithm has several advantages compared to many other graph-based methods in terms of determining an appropriate affinity measure, computational complexity, memory requirements and coping with different data scales. We show that our method may produce clustering and image segmentation results comparable or better than the state-of-the art graph-based methods.     

Intelligent Medical Record--entry (IMR-E)

This paper describes an automated medical record designed to allow providers to enter patient data at the point of care. The system runs on PCs and Macintoshes and uses a graphical user interface and object-oriented programming to take advantage of current mouse and pen technologies. The provider acquires all relevant patient data by pointing and clicking at selections on input screens, many of which contain anatomical drawings to help the provider quickly and accurately describe patient findings. The system also generates a grammatically correct progress note using the problem-oriented structure. Furthermore, items identified in the assessment and plans portion of the program can be ported to expert systems for medical decisions assistance or to billing systems. The system allows the provider to obtain the necessary information on a focused patient visit in less than 5 min or to enter a complete history and physical.