基于PMF-FFT的伪码捕获算法分析

建立了PMF-FFT算法的数学模型,分析了相关器个数、相关积累长度和FFT点数对积累损失、扇贝损失和频率分辨率的影响。在此基础上,结合算法的效率和运算量,给出了PMF-FFT算法参数选择的原则和依据。     

Robust numerical approach to steady-state calibration of mean-value models

A numerically robust approach to steady-state calibration of nonlinear dynamic models is presented. The approach is based on explicit formulation of the constraints on validity of internal model signals by set of inequalities. The constrained optimization with feasible iterates guarantees that the model will never be evaluated with invalid internal signals. This overcomes numerical difficulties often encountered when dealing with highly nonlinear models. Because the approach uses a large number of slack variables, distributed least squares algorithm is proposed. The robustness of this approach is demonstrated on a steady-state calibration of turbocharged diesel engine model starting from grossly inaccurate initial estimates.     

Parameter estimation of permanent magnet stepper motors without mechanical sensors

The paper presents a new sensorless parameter identification method for permanent magnet stepper motors. Current sensors are assumed available, but mechanical sensors are not. Data is obtained with open-loop commands at multiple speeds. A new frame is proposed that presents advantages similar to the d–q frame, but without the need for a position sensor. The method exploits derived linear parameterizations and least-squares algorithms. In some cases, overparameterization is resolved using elimination theory. The parameters identified using the new procedure are found to be very close to those obtained with sensors. The approach is potentially applicable to other types of synchronous motors.     

浅析激冷气压缩机系统的联锁控制功能

研讨50万吨甲醇项目煤气化装置压缩机装备建设与开车运行工程。     

Testing for serial independence of panel errors

A test for the serial independence of errors in panel data models is proposed. The test is based on the difference between the joint empirical characteristic function of residuals at different lags and the product of their marginal empirical characteristic functions. The test is nuisance-parameter-free and powerful against any type of pairwise dependence at all lags. A simple random permutation procedure is used to approximate the limit distribution of the test. A Monte Carlo experiment illustrates the finite sample performance of the test, and supports that the test statistic based on the estimated residuals has the same asymptotic distribution as the corresponding statistic based on the unobservable true errors.     

“It’s Not Who You Know,but Who You Add:” An investigation into the differential impact of friend adding and self-disclosure on interpersonal perceptions on Facebook

This research seeks to understand how people perceive and respond to structural factors and different types of disclosure on Facebook when evaluating the profile of someone they have never met offline. Using a 2 × 3 × 2 between-subjects experimental design, this research explored the relationship between friend adding (add; no add), levels of self-disclosure (low, medium, high), and sex of the Facebook profile owner (male; female) on feelings of interpersonal liking, future behavioral intentions to interact, and homophily. Results indicated that friend adding and higher levels of self-disclosure led to greater feelings of interpersonal liking and homophily amongst both male and female participants. In addition, males tended to view other male profiles with moderate amounts of disclosure and female profiles with the highest amount of disclosure most favorably. Theoretical and practical implications are discussed.     

西门子变频器的应用 第2讲 MM440变频器在电梯控制中的应用

电梯是随着高层建筑的兴建而发展起来的一种垂直运输工具,其要求安全性、舒适性和经济性。在多年的实践之后,变频调速已经成为了电梯传动的主要控制方式。本文主要阐述了MM440变频器在电梯控制中的应用。     

Technological benefits of inulin-type fructans application in gluten-free products – A review

BackgroundAlthough cereals are used extensively in food products, ingestion of gluten-containing food has been associated with gluten-related disorders in susceptible individuals. Recently, the gluten-free (GF) products are one of the most dynamically growing branches of the food industry. However, many commercially available GF products provide lower level of proteins, dietary fibre, vitamins and minerals, compared with wheat products. To meet the growing demands of GF food consumers, efforts have been made to improve the overall quality of these products. Recently, inulin-type fructans (ITFs) were proposed as the beneficial ingredients of GF products.Scope and approachOver the last decade, the application of ITFs in GF products has been widely explored. Therefore, the aim of this review is to present the current application of ITFs as components of GF products by summarising the existing data concerning their effect on the technological properties and sensory quality of these products in the light of their physicochemical characteristics.Key findings and conclusionsITFs added to the GF products interact with other ingredients and additives. Generally, they have the potential to improve the technological properties and sensory perception of obtained products. The presented facts may provide an inspiration for further intensive work on the improvement of the quality of GF products for the growing number of people struggling with the problem of gluten intolerance.     

Identification of the thermal properties of concrete for the temperature calculation of concrete slabs and columns subjected to a standard fire—Methodology and proposal for simplified formulations

The fire resistance of concrete members is controlled by the temperature distribution of the considered cross section. The thermal analysis can be performed with the advanced temperature dependent physical properties provided by EN 1992-1-2. But the recalculation of laboratory tests on columns from TU Braunschweig shows, that there are deviations between the calculated and measured temperatures. Therefore it can be assumed, that the mathematical formulation of these thermal properties could be improved. A sensitivity analysis is performed to identify the governing parameters of the temperature calculation and a nonlinear optimization method is used to enhance the formulation of the thermal properties. The proposed simplified properties are partly validated by the recalculation of measured temperatures of concrete columns. These first results show, that the scatter of the differences from the calculated to the measured temperatures can be reduced by the proposed simple model for the thermal analysis of concrete.