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51.
E-Government diffusion is of interest to both researchers and practitioners. The purpose of this study is to investigate electronic government maturity and its determinants. We use the Fit-Viability Framework to assess e-Government Maturity in diverse countries. We empirically test the impact of task-technology fit (TTF) and viability on e-government maturity at the country level. The results of partial least squares (PLS) analysis indicate that TTF characteristics along with a country’s viable resources and level of e-government development have a significant impact on e-government maturity. Implications for research and practice are discussed.  相似文献   
52.
The current study examined the relationships between learners’ (\(N = 123\)) personality traits, the emotions they typically experience while studying (trait studying emotions), and the emotions they reported experiencing as a result of interacting with four pedagogical agents (agent-directed emotions) in MetaTutor, an advanced multi-agent learning environment. Overall, significant relationships between a subset of trait emotions (trait anger, trait anxiety) and personality traits (agreeableness, conscientiousness, and neuroticism) were found for four agent-directed emotions (enjoyment, pride, boredom, and neutral) though the relationships differed between pedagogical agents. These results demonstrate that some trait emotions and personality traits can be used to predict learners’ emotions directed toward specific pedagogical agents (with different roles). Results provide suggestions for adapting pedagogical agents to support learners’ (with certain characteristics; e.g., high in neuroticism or agreeableness) experience of adaptive emotions (e.g., enjoyment) and minimize their experience on non-adaptive emotions (e.g., boredom). Such an approach presents a scalable and easily implementable method for creating emotionally-adaptive, agent-based learning environments, and improving learner-pedagogical agent interactions in order to support learning.  相似文献   
53.
Increases in instruction level parallelism are needed to exploit the potential parallelism available in future wide issue architectures. Predicated execution is an architectural mechanism that increases instruction level parallelism by removing branches and allowing simultaneous execution of multiple paths of control, only committing instructions from the correct path. In order for the compiler to expose and use such parallelism, traditional compiler data-flow and path analysis needs to be extended to predicated code. In this paper, we motivate the need for renaming and for predicates that reflect path information. We present Predicated Static Single Assignment (PSSA) which uses renaming and introduces Full -Path Predicates to remove false dependences and enable aggressive predicated optimization and instruction scheduling. We demonstrate the usefulness of PSSA for Predicated Speculation and Control Height Reduction. These two predicated code optimizations used during instruction scheduling reduce the dependence length of the critical paths through a predicated region. Our results show that using PSSA to enable speculation and control height reduction reduces execution time from 12 to 68%.  相似文献   
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55.
BACKGROUND: Exogenous antigenic peptides are presented to T cells by class II major histocompatibility complex (Ia) molecules on the surface of antigen-presenting cells. Class II-associated invariant chain (Ii) is also required for effective antigen presentation. Because messenger RNAs (mRNAs) for Ii chain and for class II I-A beta chain appear in the mouse intestinal epithelium after weaning, experiments were conducted to test the effect of age of weaning and diet on the appearance of Ia and Ii mRNA. METHODS: Four litters were split at day 17; one half was weaned and the other remained with the mother until day 24. On day 23, 25, 27, and 29, enterocytes were isolated from full-length small intestine by vascular perfusion with 30 mmol/L ethylenediaminetetraacetic acid, and the RNA was extracted. RESULTS: Appearance of Ii and I-A beta was significantly delayed by late weaning, as judged by RNA hybridization blots (Ii chain) and complementary DNA amplification (I-A beta chain). In mice on elemental diets, the appearance of Ii and I-A beta chain was delayed compared with littermates reared on standard chow. Ii mRNA failed to appear in mice maintained on the elemental diet by day 40, despite normal growth. CONCLUSIONS: Appearance of mRNA for both Ia and Ii depends on the introduction of a complex diet and not the "stress" of weaning or elimination of breast milk. Introduction of foreign dietary antigens or development of an altered intestinal flora may contribute to this process.  相似文献   
56.
Sucha GD  Carter WH 《Applied optics》1984,23(23):4345-4347
The beam radius along a focused, unapertured Gaussian beam was measured and used to calculate the dependence of the geometrical Fresnel number on the effective Fresnel number of the beam as it emerged from the focusing lens. The resulting data clearly demonstrate a focal shift away from the focal plane given by geometrical optics. The data agree very well with a theory due to Carter. This theory indicates that a significant focal shift occurs in these beams if the focusing lens is placed within the near field of the focal plane.  相似文献   
57.
In part 11 a series of implicit finite element algorithms for the geometrically nonlinear structural problem were proposed. These algorithms were shown to be computationally efficient because they require the solution of a linear system rather than a nonlinear system at each time point. In addition, because of the conservative nature of the algorithms, their stability properties are easily assessed. One algorithm was shown to be unconditionally stable.In part 2 the convergence of the proposed algorithms is demonstrated. It is shown that for the consistent algorithm, additional conditions must be satisfied to insure convergence. In fact, one of the proposed algorithms is shown to be unconditionally stable but conditionally convergent.  相似文献   
58.
We have followed the growth of stature, sitting height, skinfolds, muscle widths measured radiologically, and skeletal maturity in growth hormone-deficient patients in whom hGH was given and withheld in alternating three-month periods throughout puberty (referred to as "off-hGH" and "on-hGH" periods). Six boys and four girls had true isolated GH deficiency and developed puberty spontaneously. Two boys had gonadotrophin deficiency plus GH deficiency, and five boys had multiple deficiencies; in these boys the signs of puberty were induced by hormone treatment. Boys with true isolated deficiency grew about two-thirds as much in height in the off-hGH periods as in the on-hGH periods; their total gain in height during the adolescent spurt would have been about 20 cm, instead of 30 cm, if hGH had been discontinued at the beginning of puberty. The effect of hGH was entirely on growth in leg-length, however, which virtually ceased during the off-hGH periods. Growth in sitting height altered little when hGH was withdrawn. Growth in limb muscles, however, was GH dependent throughout puberty; during the majority of periods when hGH was withheld, muscle was actually lost; this occurred in the boys who were receiving large doses of testosterone as well as in those producing their own normal amounts. Subcutaneous fat diminished when hGH was given and increased when it was withdrawn; this occurred independently of administration of testosterone. There was little evidence that growth of pubic and axillary hair progressed faster during on-hGH periods, except perhaps in patients with multiple deficiencies. There was some evidence, however, that bone age progressed less rapidly during on-hGH periods than during off-hGH periods in the patients with isolated deficiency. The results in the girls agreed with those in boys so far as stature was concerned, but the relationship with sitting height and leg length appeared to be different; the reasons for this are discussed. We conclude that all children with GH deficiency should continue on treatment with hGH throughout puberty, ideally until growth ceases.  相似文献   
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60.
Nanoparticles and nanoparticle-based devices are of interest in numerous industrial applications due to their unique and often advantageous properties. However, a major obstacle to the full exploitation of nanoscale materials is the lack of production processes that yield specific materials reproducibly. A fundamental understanding of nanoparticle formation in candidate production systems is critical to achieving both product specificity and uniformity. The present work uses observations from transmission electron microscopy to elucidate the formation processes occurring for silicon and titanium nanoparticles produced from a thermal plasma process. The structure, chemistry, and defect morphology of the nanoparticles are consistent with a rapid cooling and crystallization from a liquid droplet. The observation of surface faceting on some nanoparticles suggests a transition between different crystalline growth regimes.  相似文献   
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