Rectangle packing with additional restrictions

We formulate a generalization of the NP-complete rectangle packing problem by parameterizing it in terms of packing density, the ratio of rectangle areas, and the aspect ratio of individual rectangles. Then we show that almost all restrictions of this problem remain NP-complete and identify some cases where the answer to the decision problem can be found in constant time.     

基于TC35I的汽车空调温控系统的设计

应用TC35I模块和DS18B30单总线数字温度传感器模块,利用STC89C52RC微控制器和GSM移动通信网络中的短消息业务,设计一种基于TC35I的汽车空调温控系统,详细阐述了系统的基本组成和相关的软硬件方面的设计.系统具有实时性、操作简单、实用等优点.     

基于NRF905的无线温度数据采集系统

设计并实现了一种采用单片射频收发芯片nRF905、DS18B20和以单片机AT89C52为主控制器的无线数据采集系统.系统由一些相互独立的工作站构成,每站均包括数据处理模块、数据收发模块和数据采集模块三大模块.系统能够实现温度信息的采集、传送和LED显示,并且在温度超过最大值时,驱动蜂鸣器产生报警信号.     

基于单总线数字传感器的温度控制系统原理及应用

随着现代化生产和科学研究的发展,人们对温度过程控制的要求越来越高。文章介绍以单片机P89C668为核心的智能温度控制系统。它使用一线制数字温度传感器DS18B20采集温度,与传统测温装置相比,具有结构简单,测温精度高、应用面广等特点。另外,系统还扩展了和上位计算机的串行通信,实现远程监控。整个系统不但成本低廉、而且使用和扩展方便,可广泛应用于人们日常生活、工农业生产和科学研究领域,为广泛深入应用提供了借鉴。     

Nonsmooth optimization for multiband frequency domain control design

Multiband frequency domain synthesis consists in the minimization of a finite family of closed-loop transfer functions on prescribed frequency intervals. This is an algorithmically difficult problem due to its inherent nonsmoothness and nonconvexity. We extend our previous work on nonsmooth H_∞ synthesis to develop a nonsmooth optimization technique to compute local solutions to multiband synthesis problems. The proposed method is shown to perform well on illustrative examples.     

Comparison of the Hansen-Sengupta and the Frommer-Lang-Schnurr existence tests

The Krawczyk and the Hansen-Sengupta interval operators are closely related to the interval Newton operator. These interval operators can be used as existence tests to prove existence of solutions for systems of equations. It is well known that the Krawczyk operator existence test is less powerful that the Hansen-Sengupta operator existence test, the latter being less powerful than the interval Newton operator existence test. In 2004, Frommer et al. proposed an existence test based on the Poincaré-Miranda theorem and proved that it is more powerful than the Krawczyk existence test. In this paper, we complete the classification of these four existence tests showing that, in practice, the Hansen-Sengupta existence test is actually more powerful than the existence test proposed by Frommer et al.     

Estimation in a linear multivariate measurement error model with a change point in the data

A linear multivariate measurement error model AX=B is considered. The errors in are row-wise finite dependent, and within each row, the errors may be correlated. Some of the columns may be observed without errors, and in addition the error covariance matrix may differ from row to row. The columns of the error matrix are united into two uncorrelated blocks, and in each block, the total covariance structure is supposed to be known up to a corresponding scalar factor. Moreover the row data are clustered into two groups, according to the behavior of the rows of true A matrix. The change point is unknown and estimated in the paper. After that, based on the method of corrected objective function, strongly consistent estimators of the scalar factors and X are constructed, as the numbers of rows in the clusters tend to infinity. Since Toeplitz/Hankel structure is allowed, the results are applicable to system identification, with a change point in the input data.     

Models for Image Interpolation Based on the Optical Flow

Optical flow is the 2D motion that needs to be recovered from a video sequence. In this paper we study variational principles for the generation of interpolating sequences between two images. The basic assumption is that there exists an underlying video sequence that solves the optic flow equation and interpolates the two images. The numerical solution of the interpolation problem is reduced to the solution of a system of coupled partial differential equations. Some numerical simulations are presented. Received June 29, 2000; revised November 29, 2000     

基于PSoC的飞艇艇内温度采集系统设计

介绍基于PSoC、nRF24L01射频芯片和DS18B20数字温度传感器的智能无线温度采集系统在飞艇上的设计,并对系统实际运行的结果数据进行测试分析,实现温度的测量与数据传输。重点描述了系统采集端软硬件的设计与实现,阐述了软件与硬件的设计要求。本系统功耗低、结构简单、通信效率高,可实现飞艇范围内全方位的温度测量。     

L ∞-error estimates of higher order mixed finite element approximations for elliptic optimal control problems

In this paper, we investigate the L ^∞-error estimates of the numerical solutions of linear-quadratic elliptic control problems by using higher order mixed finite element methods. The state and co-state are approximated by the order k Raviart-Thomas mixed finite element spaces and the control variable is approximated by piecewise polynomials of order k (k≥1). Optimal L ^∞-error estimates are derived for both the control and the state approximations. These results are seemed to be new in the literature of the mixed finite element methods for optimal control problems.