连铸温度场数值模拟及冷却水参数优化

由于用实验方法来研究工艺参数对铸坯温度场的影响较困难,故而提出了一种在冶金冷却条件指导下的启发式GA(遗传算法)数值模拟优化方法,为优化工艺参数提供了理论依据,并在优化基础上采用MIMO(多输入多输出)系统PID(比例积分微分)控制器实现了二冷段配水的优化控制,改善了铸坯的质量.     

Planar-shape prototype generation using a tree-based random greedy algorithm.

A prototype is representative of a set of similar objects. This paper proposes an approach that formulates the problem of prototype generation as finding the mean from a given set of objects, where the prototype solution must satisfy certain constraints. These constraints describe the important perceptual features of the sample shapes that the proposed prototype must retain. The contour prototype generated from a set of planar objects was used as an example of the approach, and the corners were used as the perceptual features to be preserved in the proposed prototype shape. However, finding a prototype solution for more than two contours is computationally intractable. A tree-based approach is therefore proposed in which an efficient greedy random algorithm is used to obtain a good approximation of the proposed prototype and analyze the expected complexity of the algorithm. The proposed prototype-generation process for hand-drawn patterns is described and discussed in this paper.     

Centrifugal Casting of High Speed Steel/Nodular Cast Iron Compound Roll Collar

Ｈｉｇｈ ｓｐｅｅｄｓｔｅｅｌ (ＨＳＳ) ,ｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｅｘ ｃｅｌｌｅｎｔｈａｒｄｎｅｓｓ ,ｗｅａｒｒｅｓｉｓｔａｎｃｅ ,ａｎｄ ｇｏｏｄｒｅｄｈａｒｄｎｅｓｓ .Ｒｅｃｅｎｔｌｙ ,ＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｈｏｔｒｏｌｌｉｎｇｒｏｌｌｓｔｏｐｒｏｄｕｃｅｓｔｒｉｐｓｏｆｇｏｏｄｓｈａｐｅａｎｄｓｍａｌｌｃｒｏｗｎｗｉｔｈｅｘｔｅｎｄｅｄｒｏｌｌｓｅｒｖｉｃｅｌｉｆｅ[1,2 ] .ＴｈｅＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｒｏｌｌｃｏｌｌａｒｆｏｒ…     

Analysis of ATSC field test results in Taiwan

Field tests of the transmission performance of the ATSC DTV system have been conducted in Taiwan. The test results as well as comparisons against the NTSC system performance are reported and analyzed. From the measured results the reception characteristics of the DTV can be deduced and can provide guidelines for television stations to design the transmission system, schedule equipment deployment, plan service coverage areas, and improve the reception quality of the digital signal     

面向共同配送的建模仿真研究

分析了共同配送的工作程序、建模方法及相关算法。采用基于面向对象的结构化的建模分析方法和eM-plant仿真平台,建立了共同配送的仿真模型。将电子地图导入仿真模型,并运用启发式算法自动规划出车辆配送路线,同时考虑各种确定性与不确定性因素对模型的影响。选用实例验证了该仿真方法。     

QRS feature extraction using linear prediction

This communication proposes a method called linear prediction (a high performant technique in digital speech processing) for analyzing digital ECG signals. There are several significant properties indicating that ECG signals have an important feature in the residual error signal obtained after processing by Durbin's linear prediction algorithm. This communication also indicates that the prediction order need not be more than two for fast arrhythmia detection. The ECG signal classification puts an emphasis on the residual error signal. For each ECG's QRS complex, the feature for recognition is obtained from a nonlinear transformation which transforms every residual error signal to a set of three states pulse-code train relative to the original ECG signal. The pulse-code train has the advantage of easy implementation in digital hardware circuits to achieve automated ECG diagnosis. The algorithm performs very well in feature extraction in arrhythmia detection. Using this method, our studies indicate that the PVC (premature ventricular contraction) detection has at least a 92 percent sensitivity for MIT/BIH arrhythmia database.     

Modeling phosphorus in the upper Etowah River basin: identifying sources under uncertainty.

The Uniform Covering by Probabilistic Rejection (UCPR) algorithm was used, in conjunction with the Soil and Water Assessment Tool (SWAT) model, to identify P loads from point source and nonpoint source polluters in the upper Etowah River basin (UERB) in Georgia. The key findings of the research are as follows. The mean absolute error was preferred over the root mean square error as a search criterion for the UCPR algorithm when water quality observations are scarce. The undocumented P load from point sources in the UERB was consistently estimated as about 43 kg/d by the proposed method; but the method was not able to identify the broiler litter application rate to the poultry/beef operation pastures. Point sources (both documented and undocumented), poultry/beef operation pastures, and forests are the three major contributors of P. During 1992-1996, on average they accounted for 36.4, 31.7, and 17.2% of P load from the UERB, respectively.     

OFDM-MIMO系统及其频率同步分析

多媒体业务对无线通信的带宽与品质提出了更高的要求，OFDM和MIMO由于满足了这一需求被越来越多的无线通信标准采用所为底层的调制和传输技术。频率同步问题是OFDM—MIMO物理层设计中正确解调的前提和基础，本文介绍了OFDM—MIMO的原理、特点和频率同步问题的研究现状。     

静态电子轨道衡组成部分解析及其合理选择

阐述静态电子轨道衡诸多优点;工作原理、允许误差及误差分配;轨道衡的结构组成部分、解析各部分的工作特性及技术指标要求;合理选配及推荐实例.     

论国有企业激励机制和约束机制的设计

本文通过对建立国有企业激励机制和约束机制的过程中存在的问题进行分析，找出其产生的原因，并尝试提出国有企业激励和约束机制设计思路与对策。