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排序方式: 共有397条查询结果,搜索用时 31 毫秒
1.
基于LPC2214的嵌入式智能家居控制终端的设计 总被引:2,自引:0,他引:2
为进一步提高家居生活的智能化和便捷化,文中设计了一款嵌入式智能家居控制终端。该终端以NXP(恩智浦)公司的ARM7TDMI处理器LPC2214为核心,集多款家电操控和状态监控界面于一体,通过扩展RF模块组建家庭内部无线网络。该终端既可以伴随相应的语音提示,通过按键进行家电操控界面切换和相应功能的选择及遥控,又可通过Wi-Fi模块接收由平板电脑或智能手机上家电控制软件下发的控制命令编码,最终实现对家电的遥控。同时,家电状态的变化也会实时反馈给控制终端、平板电脑或智能手机进行状态显示更新。该方案解决了对家电远程遥控和状态的实时监控问题。经过实验测试,该终端具备轻巧便携、控制精准、速度快等特点,非常适宜在智能家居系统中应用。 相似文献
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An accurate chlorine bulk decay model is needed to ensure that potable water meets the microbial and the chemical safeties at the treatment plant and throughout the distribution. Among the mathematical models available,the general second-order chlorine bulk decay model( GBDM) is the most fundamentally sound.Application of the GBDM,however,has been hindered by its numerous fictive parameters and lack of an analytical solution. This theoretical work removes the two obstacles. The GBDM is solved through transformation and integration. The analytical solution provides deep insights into the GBDM and facilitates the parameterization and sensitivity analysis. The background natural organic matter( NOM) is characterized with the probabilistic distribution of functional groups. It reveals that the mean of the function group distribution is correlated with the initial chlorine decay rate coefficient( κ_0). A simple formula is developed to determine κ_0 directly from the initial chlorine decay. The theoretical treatment reduces the fictive parameters to a minimum. For the common lognormal distribution,the GBDM needs only three parameters,well defined as initial chlorine demand X_0,median rate coefficient km,and heterogeneity index σ. For more complicated scenarios,composite distributions are constructed through superposition of individual distributions. A highlighted example is to predict chlorine decay in blends of different waters. With the theoretical and mathematical advancement here,the GBDM can be applied effectively to any reactive background matter in any reaction systems. 相似文献
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为使Wi Fi位置指纹数据库,不在定位区域Wi Fi环境发生改变时,出现位置指纹过时现象,设计一种更新算法。该算法使用用户的反馈数据,考虑了AP信号不稳定情况下AP新增与撤销的检测问题;消除了手机热点等临时AP对传统更新算法的影响;最终通过检测AP位置移动等引起的RSS改变,加速位置指纹数据库的更新。实验结果表明,在实际环境中该算法在指纹数据库的更新效率上优于传统更新算法。 相似文献
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Owing to the recent proliferation of smartphones and the SNS, a large number of images taken by smartphones at various places have been uploaded to SNSs. In addition, smartphones are equipped with various sensors such as Wi-Fi modules that enable us to generate an image associated with the sensory information that represents the context in which the image was captured. This study demonstrates the benefits of images associated with Wi-Fi signals in the automated construction of a Wi-Fi-based indoor logical location classifier that predicts a semantic location label of a user’s position for shopping complexes. In this study, a logical location class refers to the store class label in a shopping complex, such as Starbucks and H&M. Given a collection of images associated with Wi-Fi signals taken at a shopping complex and the complex’s floor plan, the proposed method first estimates the store label at which an image was taken by analyzing the image and crawled online images of branch stores. Then, the 2D coordinates of the images taken at branch stores on the floor coordinate system can be estimated using the floor plan. Subsequently, by using the Wi-Fi signals of the branch store images and their estimated 2D coordinates, we construct a transformation function that maps Wi-Fi signals onto the 2D coordinates, and we adopt this function to predict an indoor location class of an observed Wi-Fi scan from a smartphone possessed by an end user. The proposed transformation function comprises an ensemble of sub-functions designed based on CVAEs. Finally, we demonstrate the effectiveness of the proposed method for three actual shopping complexes. 相似文献
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Sohaib Manzoor Hira Manzoor Saddaf Rubab Muhammad Attique Khan Majed Alhaisoni Abdullah Alqahtani Ye Jin Kim Byoungchol Chang 《计算机、材料和连续体(英文)》2023,75(2):2347-2363
Despite the planned installation and operations of the traditional IEEE 802.11 networks, they still experience degraded performance due to the number of inefficiencies. One of the main reasons is the received signal strength indicator (RSSI) association problem, in which the user remains connected to the access point (AP) unless the RSSI becomes too weak. In this paper, we propose a multi-criterion association (WiMA) scheme based on software defined networking (SDN) in Wi-Fi networks. An association solution based on multi-criterion such as AP load, RSSI, and channel occupancy is proposed to satisfy the quality of service (QoS). SDN having an overall view of the network takes the association and reassociation decisions making the handoffs smooth in throughput performance. To implement WiMA extensive simulations runs are carried out on Mininet-NS3-Wi-Fi network simulator. The performance evaluation shows that the WiMA significantly reduces the average number of retransmissions by 5%–30% and enhances the throughput by 20%–50%, hence maintaining user fairness and accommodating more wireless devices and traffic load in the network, when compared to traditional client-driven (CD) approach and state of the art Wi-Balance approach. 相似文献
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随着国家智能电网的建设,新一代配网自动化系统处于试点建设阶段。配电自动化和现代通信技术的结合,特别是无线通信技术,包括3G、WiMax、Wi-Fi等新技术,对于配网自动化,智能化的发展有着重要的意义。与传统通信系统的数据传输相比,无线专网具有低成本、高频谱利用率、高可靠性等优点。该文介绍了三种热门无线专网的技术特性并和传统通信方式进行了分析比较。 相似文献
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为了使人们在各种各样的室内环境中,也能享受到定位服务带来的便利,基于Android手机平台通过采用RSSI定位的方法,设计和实现了一个LBS系统平台.该平台整合了室内定位的功能以及时下最流行的微博功能,使其他用户可以通过调用平台的接口,基于该平台设计出各种应用于不同环境的购物辅助系统.当消费者购物时可以通过该系统更方便的进行购物,从而使人们在室内环境下也能享受到普适计算带来的便利.通过一个实例验证了该系统的可行性及实用性. 相似文献