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991.
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Interviews with 25 nurses in this grounded theory study show that when nurses recognized that a child's death was inevitable, they struggled with both grief distress and moral distress. Their distress occurred within the context of the nurse-patient relationship. Nurses employed a range of strategies to manage their distress. Several conditions facilitated or constrained nurses' strategies, and resulted in far-reaching implications both professionally and personally.  相似文献   
993.
An approach to computer-aided interpretation of parametric test data for integrated circuit process-problem diagnosis is presented. In contrast to a conventional expert system, which reasons with a knowledge base consisting of rules acquired from human experts, the system presented centers its knowledge around analytic device equations. By using equations as the basis of the system knowledge, a more universal, well-organized, and concise level of knowledge is encoded. With the use of objects to present this knowledge, a great deal of useful information outside that described by only the symbolic expressions can be represented, and extension to qualitative or numeric models should be straightforward. The result is an expressive, well-organized, easily built, and easily maintained knowledge base. The authors describe the system's interactive graphical displays and the automatic data interpretation algorithms. Examples evaluating n-channel metal oxide semiconductor (NMOS) parameter variations, interconnect parameter variations, and interconnect yields are used for illustration  相似文献   
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Buildings are usually subject to a variety of stochastic influences. Though the deterministic approach to building thermal modelling is widespread, it cannot easily model the effects of such influences, and a different approach might be better. In this study, stochastic models are derived which describe the thermal behaviour of a full-scale room exposed to the naturally occurring disturbances of climate (temperature, solar irradiance, infiltration), occupancy and appliance usage. A Box-Jenkins time series analysis technique is employed, and univariate stochastic models are fitted to the internal and external air temperature series. The models are validated by comparing the observed temperature with values forecasted ahead (in steps of 1 h) by the models, over a 36-h period; agreement was found to be good. It is concluded that the stochastic modelling approach can be applied successfully to the thermal analysis of a building's behaviour, thereby affording a method which accounts for random influences in a compact model format. The technique has particular relevance to advanced model-based control implemented via ‘intelligent’ digital controllers and building energy management systems, and its application in this respect is discussed.  相似文献   
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999.
We have investigated gate oxide degradation in metal-oxide-semiconductor (MOS) devices as a function of high-field constant-current stress for charge injection from both gate and substrate. The two polarities are asymmetric: gate injection, where the substrate Si-SiO2 interface is the collecting electrode for the energetic electrons, shows a higher rate of interface-state generation (ΔDit) and lower charge-to-breakdown Qbd. Thus the collecting electrode interface, which suffers primary damage, emerges as a critical degradation site in addition to the injecting electrode interface, which has been the traditional focus. Consistent with a physical-damage model of breakdown, we demonstrate that interfacial degradation is an important precursor of breakdown, and that the nature of breakdown-related damage is physical, such as trap-generation by broken bonds  相似文献   
1000.
The recent trends in portable computing technologies have established the need for energy efficient design strategies. To achieve minimum energy design goals, system designers need a technique to accurately model the energy consumption of their design alternatives without performing a full physical design and full-circuit simulation. This paper presents and compares five approaches for modeling the energy consumption of CMOS circuits. These five modeling approaches have been chosen to represent the various levels of model complexity and accuracy found in the current literature. These modeling approaches are applied to the energy consumption of SRAM's to provide examples of their use and to allow for the comparison of their modeling qualities. It was found that a mixed characterization model-using a CV2 prediction for digital subsections and fitted simulation results for the analog subsections-is satisfactory (within ±1 process variation) for predicting the absolute energy consumed per cycle. This same model is also very good (within 2%) for predicting an optimum organization for the internal structures of the SRAM. Several common architectures and circuit designs for SRAM's are analyzed with these models. This analysis shows that global, rather than local improvements, produce the largest energy savings  相似文献   
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