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红外通信IrDA标准与应用   总被引:12,自引:1,他引:11  
红外光是有许多优势的通信媒介,红外通信IrDA标准是目前IT和通讯业普遍支持的近距离无线数据传输规范。本文介绍了红外通信IrDA标准的内容以及它的物理层协议,脉冲调制的必要性,不同传输速率下不同的脉冲调制方式,连接建立协议层的帧结构。给出了符合IrDA标准的芯片TOIM32325和TFDS4500在高电压环境下调试实验设备的应用。  相似文献   
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The role of geriatrics and geriatricians in family medicine remains unsettled. Despite a rapidly aging population, a tremendous shortage now exists of faculty with interest and expertise in geriatrics. Relatively few family practice residents choose to enter geriatric fellowship programs, and federal funding for such programs has been reduced. Despite accreditation requirements, residency programs are not always able to provide the range of geriatric experiences needed to properly prepare graduates to provide care for the broad range of older patients. Medical students' exposure to geriatrics remains limited. The Group on Geriatric Education of the Society of Teachers of Family Medicine believes that family medicine faculty must recognize and be committed to the notion that geriatrics is integral to family medicine. Both undergraduate and residency training programs should emphasize experience with geriatric patients in multiple settings. In particular, the nursing home should not be the main focus of geriatric training. The small number of certified geriatric faculty will be able to provide leadership, but a broad range of faculty must become involved in teaching geriatrics. Faculty development activities and continuing education programs to foster the necessary expertise will be essential to the accomplishment of this task.  相似文献   
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In this paper, we study the design problem of PID controllers for networked control systems (NCSs) with polyhedral uncertainties. The load disturbance and measurement noise are both taken into account in the modeling to better reflect the practical scenario. By using a novel technique, the design problem of PID controllers is converted into a design problem of output feedback controllers. Our goal of this paper is two‐fold: (1) To design the robust PID tracking controllers for practical models; (2) To develop the robust ?? PID control such that load and reference disturbances can be attenuated with a prescribed level. Sufficient conditions are derived by employing advanced techniques for achieving delay dependence. The proposed controller can be readily designed based on iterative suboptimal algorithms. Finally, four examples are presented to show the effectiveness of the proposed methods. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
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We present the results of our investigation on the use of predicate-argument structures for contextual opinion retrieval. The use of predicate-argument structure for opinion retrieval is a novel approach that exploits the grammatical derivation of sentences to show contextual and subjective relevance. We do not use frequency of certain keywords as it is usually done in keyword-based opinion retrieval approaches. Rather, our novel solution is based on frequency of contextually relevant and subjective sentences. We use a linear relevance model that leverages semantic similarities among predicate-argument structures of sentences. Thus, this paper presents the evaluation results of the linear relevance model. The model does a linear combination of a popular relevance model, our proposed transformed terms similarity model, and the absolute value of a sentence subjectivity scoring scheme. The predicate-argument structures are derived from the grammatical derivations of natural language query topics and the well formed sentences from blog documents. The derived predicate-argument structures are then semantically compared to compute an opinion relevance score. Our scoring technique uses the highest frequency of semantically related predicate-argument structures enriched with the total subjectivity score from sentences. Evaluation and experimental results show that predicate-argument structures can indeed be used for contextual opinion retrieval as it improves performance of opinion retrieval task by 15% over the popular TREC baselines.  相似文献   
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The Journal of Supercomputing - Smart services are a concept that provides services to the citizens in an efficient manner. The online shopping and recommender system can play an important role for...  相似文献   
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The Journal of Supercomputing - The main challenge in database-as-a-service is the security and privacy of data because service providers are not usually considered as trustworthy. So, the data...  相似文献   
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Stochastic Dynamic Programming (SDP) is widely used in reservoir operation problems. Besides its advantages, a few drawbacks have leaded many studies to improve its structure. Handling the infeasible conditions and curse of dimensionality are two major challenges in this method. The main goal of this paper is proposing a new method to avoid infeasible conditions and enhance the solution efficiency with new discretization procedure. For this purpose, an optimization module is incorporated into regular SDP structure, so that, near optimal values of state variables are determined based on the available constraints. The new method (RISDP) employs reliability concept to maximize the reservoir releases to satisfy the downstream demands. Applying the proposed technique improves the reservoir operating policies compared to regular SDP policies with the same assumptions of discretization. Simulation of reservoir operation in a real case study indicates about 15% improvement in objective function value and elimination of infeasible conditions by using RISDP operating policies.  相似文献   
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