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991.
Knowledge conversion is a prominent theme within the knowledge management field and the question arises how knowledge creation processes can grow innovation capability maturity. This notion provides the platform for aligning knowledge creation processes to the requirements for innovation capability growth from one maturity level to the next. In order to achieve this alignment, the authors identified a knowledge creation path as a key enabler for maturity growth in each innovation capability area. Knowledge management tools and organisational facilitating conditions that support the specific knowledge processes highlighted in the identified path were identified through a literature study and subsequently synthesised to form a framework. This framework provides guidelines for the use of knowledge creation processes as a vehicle to improve innovation. The amount of time needed to practically test the framework does not allow for the practical implementation of the framework and the impact of the framework was demonstrated by discussing a practical organisational scenario. 相似文献
992.
Robert L. Crain 《The Urban Review》1981,13(2):121-127
Southern desegregated high schools with high levels of black or white student extracurricular participation have students who report more interracial contact, higher self-esteem, more positive attitudes toward school, more parent visits to schools, and more personal contact with teachers. The results are derived from regression equations based on responses from 10,000 students in 200 schools, controlling on student and school background factors. The author recommends that secondary schools place high priority on encouraging extracurricular participation and argues that this enhances the school's ability to teach because it increases student attachment to the school, reduces student alienation, provides alternative channels for students to develop self-esteem, and increases the opportunity for positive interracial contact. 相似文献
993.
What does No Child Left Behind (NCLB) have to do with higher education? Turns out plenty, according to Teniell L. Trolian and Kristin S. Fouts. They argue that NCLB has signifcant consequences for college learners. 相似文献
994.
Robert B. Anderson Julius A. Marshall Andrea L’Afflitto 《Journal of The Franklin Institute》2021,358(12):6281-6308
In classical model reference adaptive control (MRAC), the adaptive rates must be tuned to meet multiple competing objectives. Large adaptive rates guarantee rapid convergence of the trajectory tracking error to zero. However, large adaptive rates may also induce saturation of the actuators and excessive overshoots of the closed-loop system’s trajectory tracking error. Conversely, low adaptive rates may produce unsatisfactory trajectory tracking performances. To overcome these limitations, in the classical MRAC framework, the adaptive rates must be tuned through an iterative process. Alternative approaches require to modify the plant’s reference model or the reference command input. This paper presents the first MRAC laws for nonlinear dynamical systems affected by matched and parametric uncertainties that constrain both the closed-loop system’s trajectory tracking error and the control input at all times within user-defined bounds, and enforce a user-defined rate of convergence on the trajectory tracking error. By applying the proposed MRAC laws, the adaptive rates can be set arbitrarily large and both the plant’s reference model and the reference command input can be chosen arbitrarily. The user-defined rate of convergence of the closed-loop plant’s trajectory is enforced by introducing a user-defined auxiliary reference model, which converges to the trajectory tracking error obtained by applying the classical MRAC laws before its transient dynamics has decayed, and steering the trajectory tracking error to the auxiliary reference model at a rate of convergence that is higher than the rate of convergence of the plant’s reference model. The ability of the proposed MRAC laws to prescribe the performance of the closed-loop system’s trajectory tracking error and control input is guaranteed by barrier Lyapunov functions. Numerical simulations illustrate both the applicability of our theoretical results and their effectiveness compared to other techniques such as prescribed performance control, which allows to constrain both the rate of convergence and the maximum overshoot on the trajectory tracking error of uncertain systems. 相似文献
995.
Rocío L. Cecchini Carlos M. Lorenzetti Ana G. Maguitman Nlida Beatríz Brignole 《Information processing & management》2008,44(6):1863
Systems for searching the Web based on thematic contexts can be built on top of a conventional search engine and benefit from the huge amount of content as well as from the functionality available through the search engine interface. The quality of the material collected by such systems is highly dependant on the vocabulary used to generate the search queries. In this scenario, selecting good query terms can be seen as an optimization problem where the objective function to be optimized is based on the effectiveness of a query to retrieve relevant material. Some characteristics of this optimization problem are: (1) the high-dimensionality of the search space, where candidate solutions are queries and each term corresponds to a different dimension, (2) the existence of acceptable suboptimal solutions, (3) the possibility of finding multiple solutions, and in many cases (4) the quest for novelty. This article describes optimization techniques based on Genetic Algorithms to evolve “good query terms” in the context of a given topic. The proposed techniques place emphasis on searching for novel material that is related to the search context. We discuss the use of a mutation pool to allow the generation of queries with new terms, study the effect of different mutation rates on the exploration of query-space, and discuss the use of a especially developed fitness function that favors the construction of queries containing novel but related terms. 相似文献
996.
997.
ABSTRACTThe metaphor of the leaking pipeline is sometimes used to suggest that some students are lost for STEM as they advance through the educational system. This paper follows a cohort of upper-secondary school students with an interest in STEM from 18 months before their completion of upper-secondary until three years after their completion. Adopting a mixed-methods design, it follows the students' reflections and interests concerning their choice of higher education programme within and/or outside STEM. Only 22% of the students expressed the same interest during the whole period, and 56% changed between different groups of studies, e.g. between STEM and HEALTH. The students' trajectories showed that the leaking-pipeline metaphor is misleading because it suggests a linear and one-way movement, while there were students moving in as well as out of STEM trajectories. The students’ reflections showed identity issues at the level of ego identity, the personal identity and the social identity (Coté and Levine). Particular incidents in the students’ lives and in the outreach programme they were involved in sparked interests and reflections. These incidents should be considered as elements in a continuous reflection concerning who they are and where they would like to go rather than as critical moments. 相似文献
998.
Richard J. Viken Danny L. Moore John F. Knutson David J. Fordyce 《Learning & behavior》1982,10(2):135-140
The effects of isolation and handling on the reactivity of rats to two tactile stimuli were assessed in two experiments. In the first experiment, reactivity to more intense footshock was increased in rats raised in isolation but was not affected by handling by an experimenter. In the second experiment, increased reactivity to airpuff stimuli presented to the dorsal surface of isolation-reared rats was reduced by handling. The data suggest that the effects of handling on shock-motivated behaviors are not due to altered reactivity to shock and that the effect of housing or handling must be considered in behavioral tests in which reactivity to tactile stimulation might play a role as dependent or independent variables. 相似文献
999.
The aim of this study was to assess the effect of time of day on physiological responses to running at the speed at the lactate threshold. After determination of the lactate threshold, using a standard incremental protocol, nine male runners (age 26.3 - 5.7 years, height 1.77 - 0.07 m, mass 73.1 - 6.5 kg, lactate threshold speed 13.6 - 1.6 km· h -1 ; mean - s ) completed a standardized 30 min run at lactate threshold speed, twice within 24 h (07:00- 09:00 h and 18:00-21:00 h). Core body temperature, heart rate, minute ventilation, oxygen uptake, carbon dioxide expired, respiratory exchange ratio and capillary blood lactate were measured at rest, after a warm-up and at 10, 20 and 30 min during the run. In addition, the rating of perceived exertion was reported every 10 min during the run. Significant diurnal variation was observed only for body temperature (36.9 - 0.9°C vs 37.3 - 0.3°C) and respiratory exchange ratio at rest (0.86 - 0.01 vs 0.89 - 0.07) ( P ? 0.05). Diurnal variation persisted for body temperature throughout the warm-up (37.1 - 0.2°C vs 37.5 - 0.3°C) and during exercise (36.2 - 0.6°C vs 38.6 - 0.4°C), but only during the warm-up for the respiratory exchange ratio (0.85 - 0.05 vs 0.87 - 0.02) ( P ? 0.05). The rating of perceived exertion was significantly elevated during the morning trial (12.7 - 0.9 vs 11.9 - 1.2) ( P ? 0.05). These findings suggest that, despite the diurnal variation in body temperature, other physiological responses to running at lactate threshold speed are largely unaffected. However, a longer warm-up may be required in morning trials because of a slower increase in body temperature, which could have an impact on ventilation responses and ratings of perceived exertion. 相似文献
1000.
We present a straightforward and rapid surface acoustic wave (SAW) atomization-based technique for encapsulating proteins into 10 μm order particles composed of a biodegradable polymeric excipient, using bovine serum albumin (BSA) as an exemplar. Scans obtained from confocal microscopy provide qualitative proof of encapsulation and show the fluorescent conjugated protein to be distributed in a relatively uniform manner within the polymer shell. An ELISA assay of the collected particles demonstrates that the BSA survives the atomization, particle formation, and collection process with a yield of approximately 55%. The SAW atomization universally gave particles with a textured morphology, and increasing the frequency and polymer concentration generally gave smaller particles (to 3 μm average) with reduced porosity. 相似文献