982 resultados para PERSONAL COMPUTERS


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Modern sample surveys started to spread after statistician at the U.S. Bureau of the Census in the 1940s had developed a sampling design for the Current Population Survey (CPS). A significant factor was also that digital computers became available for statisticians. In the beginning of 1950s, the theory was documented in textbooks on survey sampling. This thesis is about the development of the statistical inference for sample surveys. For the first time the idea of statistical inference was enunciated by a French scientist, P. S. Laplace. In 1781, he published a plan for a partial investigation in which he determined the sample size needed to reach the desired accuracy in estimation. The plan was based on Laplace s Principle of Inverse Probability and on his derivation of the Central Limit Theorem. They were published in a memoir in 1774 which is one of the origins of statistical inference. Laplace s inference model was based on Bernoulli trials and binominal probabilities. He assumed that populations were changing constantly. It was depicted by assuming a priori distributions for parameters. Laplace s inference model dominated statistical thinking for a century. Sample selection in Laplace s investigations was purposive. In 1894 in the International Statistical Institute meeting, Norwegian Anders Kiaer presented the idea of the Representative Method to draw samples. Its idea was that the sample would be a miniature of the population. It is still prevailing. The virtues of random sampling were known but practical problems of sample selection and data collection hindered its use. Arhtur Bowley realized the potentials of Kiaer s method and in the beginning of the 20th century carried out several surveys in the UK. He also developed the theory of statistical inference for finite populations. It was based on Laplace s inference model. R. A. Fisher contributions in the 1920 s constitute a watershed in the statistical science He revolutionized the theory of statistics. In addition, he introduced a new statistical inference model which is still the prevailing paradigm. The essential idea is to draw repeatedly samples from the same population and the assumption that population parameters are constants. Fisher s theory did not include a priori probabilities. Jerzy Neyman adopted Fisher s inference model and applied it to finite populations with the difference that Neyman s inference model does not include any assumptions of the distributions of the study variables. Applying Fisher s fiducial argument he developed the theory for confidence intervals. Neyman s last contribution to survey sampling presented a theory for double sampling. This gave the central idea for statisticians at the U.S. Census Bureau to develop the complex survey design for the CPS. Important criterion was to have a method in which the costs of data collection were acceptable, and which provided approximately equal interviewer workloads, besides sufficient accuracy in estimation.

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"Fifty-six teachers, from four European countries, were interviewed to ascertain their attitudes to and beliefs about the Collaborative Learning Environments (CLEs) which were designed under the Innovative Technologies for Collaborative Learning Project. Their responses were analysed using categories based on a model from cultural-historical activity theory [Engestrom, Y. (1987). Learning by expanding.- An activity-theoretical approach to developmental research. Helsinki: Orienta-Konsultit; Engestrom, Y., Engestrom, R., & Suntio, A. (2002). Can a school community learn to master its own future? An activity-theoretical study of expansive learning among middle school teachers. In G. Wells & G. Claxton (Eds.), Learning for life in the 21st century. Oxford: Blackwell Publishers]. The teachers were positive about CLEs and their possible role in initiating pedagogical innovation and enhancing personal professional development. This positive perception held across cultures and national boundaries. Teachers were aware of the fact that demanding planning was needed for successful implementations of CLEs. However, the specific strategies through which the teachers can guide students' inquiries in CLEs and the assessment of new competencies that may characterize student performance in the CLEs were poorly represented in the teachers' reflections on CLEs. The attitudes and beliefs of the teachers from separate countries had many similarities, but there were also some clear differences, which are discussed in the article. (c) 2005 Elsevier Ltd. All rights reserved."

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The aged people in the target group of my study belong to generation, which has experienced the shift from agricultural society via industrial society up to the society which has been described as information society. They have grown up concurrently with the technological development, but during the recent years the technological development has accelerated. One can say that the older the target study group has come the more information technological skills they need to possess to be equal actors in our society. However, especially in case of aged people the learning and maintaining of skills in information technology has mainly been left dependent on their personal motivation. The purpose of this report is to study the use of computers in the life of the aged people. The report studies the will and ability of the aged people to learn the skill of using computers, and the new possibilities which this brings into their lives. The study questions are the following: 1) Why the aged people start to use computers? 2) How the aged people benefit information technology in their own life? 3) How computers have extended the environment of the aged people? 4) What kind of problems the aged people have experienced in use of computers? The research material consists of group interviews and individual interviews (total of 23 people). The interview material has been collected among the participants on information technology courses of the Senior University of Helsinki University during years 2004-2005. The research method used is theme interviewing. In addition, the material of opinions about information technology of people born in decades of 1920 and 1930, gathered as part of the Ikihyvä Päijät-Häme 2002 -research has been used. On basis of this research one can say that the aged people do have motivation to study the use of computers, although many interviewees commented that they also have met problems in use of computers. The motivation has grown also because the fear that without the skills to use computers they could drift into outsiders of the society, whereas instead as skilled computer users they felt to be equal citizens compared with the younger age groups, and that they can maintain their independence and autonomy. Especially, the independent use of banking routines over the Internet and use of emails seem to give them a position as modern actors. Many interview statements also underline that computers will bring both joy and benefit to the users. Studying the use of computers is a new and interesting hobby, which can fill the hole left in the life after leaving the working life. Using skills of text processing and processing of pictures one can, for example, record the traditional knowledge of the family and ancestry to the younger generations, and write articles or even books on the professional area of ones own. Single people emphasize that computers can even act as companionship substitutes. One can use Internet for virtual traveling, which provides a new dimension in use of computers. Internet can also be used to maintain family relationships, especially between grandparents and remote grandchildren. Typical problems in use of computers appeared to be that reaching the right professional helpdesk advisers of the service providers is difficult and requires lots of time and patience. However, the interviewees were not willing to give up their computers, because they had already used to these. Keywords: digital divide, aging, Internet, usability, motivation, information technology, information society.

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This correspondence presents an algorithm for microprogram control memory width minimization with the bit steering technique. The necessary and sufficient conditions to detect the steerability of two mutually exclusive sets of microcommands are established. The algorithm encodes the microcommands of the sets with a bit steering common part and also extends the theory to multiple (more than two) sets of microcommands.

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Resumen: Ciertamente, ningún dato biológico es por sí mismo suficiente para describir el milagro de la vida. Sin embargo, cuando la ciencia es entendida como un servicio a la humanidad, los científicos son capaces de brindarnos los conocimientos necesarios y suficientes para percibir una presencia personal desde el primer instante de la vida de cada embrión humano.

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Existing devices for communicating information to computers are bulky, slow to use, or unreliable. Dasher is a new interface incorporating language modelling and driven by continuous two-dimensional gestures, e.g. a mouse, touchscreen, or eye-tracker. Tests have shown that this device can be used to enter text at a rate of up to 34 words per minute, compared with typical ten-finger keyboard typing of 40-60 words per minute. Although the interface is slower than a conventional keyboard, it is small and simple, and could be used on personal data assistants and by motion-impaired computer users.

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Published as article in: Journal of Economic Methodology, 2010, vol. 17, issue 3, pages 261-275.

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Paper was revised on 2009-11-11.-- Published as article in: Rationality and Society (2009), 21(2), 1-24.