Generalized difference control of parallel streams temperatures

A furnace with multiple parallel passes and multiple burners is commonly seen in petroleum refineries. In order to maintain the furnace running in a safe, stable, and high-efficiency state it is necessary to control the outlet temperatures of the multiple passes to be the same. Due to the fact that the process of the oil heating in such furnace is nonlinear, multivariable, time varying, has serious coupling among passes, has frequent dynamic changes and a large time delay, traditional control methods have trouble in controlling these temperatures, and some advanced control methods, including predictive control, adaptive control, and robust control, are usually too complex for convenient use. In this paper, a control technique, called differences control technique (DsCT), is proposed to distribute the stream flowrates such that the stream temperatures are as identical as possible. The principle of the proposed technique is explained and demonstrated, and the results of its application to a real-life petroleum refinery furnace are also reported. The DsCT technique has the following advantages: it does not need complicated design procedures, the controller structure is simple, it is easy to apply, and it can be canonically applied to furnaces with different number of passes.     

基于像素差异的金属腐蚀区域分割仿真研究

研究基于图像的金属腐蚀区域分割问题,提高分割区域的准确性。针对传统基于金属本身与腐蚀颜色的区别,利用像素差异的变化进行腐蚀区域的分割,因当腐蚀颜色与金属的本体颜色相差不是很大,或者在边沿发生像素的混淆时,利用差异边缘像素相减的方法很难完整分割腐蚀区域的问题。为了解决上述问题,提出利用空间像素差异距离聚类的金属腐蚀区域图像分割算法。通过计算差异像素之间的差异距离概率,将差异像素特征进行严格划分,对划分后的结果进行排序计算,详细描述混淆边沿信息,对腐蚀区域进行完整分割。实验证明,改进方法能够对金属腐蚀造成的细微区域完整分割,取得了满意的效果,为金属腐蚀区检测提供了参考。     

Media Niche of Electronic Communication Channels in Friendship: A Meta‐Analysis

The current landscape of communication technologies is characterized by a wide variety of choices. As each medium provides different affordances, each may occupy a different niche and be used in different relationships. Drawing on the theory of the niche, we did a meta‐analysis involving 27 effect sizes from 22 independent samples to test the correlation between media selection/use and friendship closeness. Results showed that the 5 communication channels filled 2 different friendship closeness niches. Mobile phone calls and texting had stronger positive correlations with friendship closeness than instant messaging, social network sites, and online gaming. Culture, but not gender, moderated some of these correlations: Friendship closeness had a stronger positive association with SNS use and online gaming in collectivist cultures.     

Tariff reduction as a tool to increase the efficiency of electricity distributors: A case study in southern Brazil

The article aims to evaluate the consumer response to a reduction in the electricity tariffs as a hourly economic signal for the case of an electric utility in the state of Rio Grande do Sul, southern Brazil. Using Differences-in-differences method, the results were robust in showing that the change in the economic signal increased up to 81.01% the consumption at the time influenced by the change, improving the way in which the company's assets are used, in addition to reducing fuel oil consumption by users.     

Individual differences,exercise and leisure activity in predicting affective well-being in young adults

This study focuses on the prevalence of exercise and health-related leisure activities (smoking, drinking), across groups of subjects, defined by personality and gender, in relation to subjective well-being. Results from a cross-sectional survey of 187 participants are reported. Males (n = 80) reported more drinking (p < 0.001) and smoking (p < 0.001) than females, though they also reported higher habitual physical activity levels (p < 0.001). Females (n = 107) reported more frequent use of social support coping (p < 0.01). There was a positive association between extraversion and self-reported habitual physical activity as well as alcohol consumption (even when controlling for gender). Neuroticism was not related to any of the exercise and leisure activity variables. Multiple regression analyses predicted 34% of variance for the depression-enthusiasm and 39% of the variance for the anxiety-contentment measures of affective well-being. Neuroticism (p < 0.001) and avoidance coping (p < 0.05) were the only significant predictors of both anxiety-contentment and depression-enthusiasm. It is concluded that the influence of individual differences such as personality and gender on coping behaviour and well-being is consistent with social learning theory research. Limitations of cross-sectional research designs necessitate caution with inferring causal paths. Recommendations for future research are presented concerning the use and value of repeated measures designs within research into exercise and well-being.     

An Iterative Method for Solving Nonlinear Operator Equations Using Generalized Divided Differences

An iterative method that uses generalized divided differences to solve nonlinear operator equations is proposed. Local and semi local convergence of the proposed method is shown. Numerical examples are also presented to demonstrate the efficiency of the method.     

On-Line Approximate String Searching Algorithms: Survey and Experimental Results

The problem of approximate string searching comprises two classes of problems: string searching with k mismatches and string searching with k differences. In this paper we present a short survey and experimental results for well known sequential approximate string searching algorithms. We consider algorithms based on different approaches including dynamic programming, deterministic finite automata, filtering, counting and bit parallelism. We compare these algorithms in terms of running time against pattern length and for several values of k for four different kinds of text: binary alphabet, alphabet of size 8, English alphabet and DNA alphabet. Finally, we compare the experimental results of the algorithms with their theoretical complexities.     

GB4706.1-2005与GB4706.1-1998第30章的主要差异浅析

本文列出了GB4706.1-2005与GB4706.1-1998在第30章的主要差异,并对这些差异进行了分析。     

浅析清代南北方造园风格差异——以留园和避暑山庄为例

中国古典园林发展到清朝已进入成熟时期。这一时期的北方皇家园林和江南私家园林同为中国后期园林发展史上的两个高峰,代表着中国风景式园林的最高水平。由于自然、人文、地方情感等方面的因素,使得北方皇家园林和江南私家园林在造园风格上有着截然不同的特点,这些差异在空间布局、建筑外观和景观组织等方面均有显著反映。     

对中国古典园林与英国自然风景园之综合分析比较

英国自然风景园与中国古典园林具有相似之处,但是区别无疑是巨大的。该文试从哲学基础及审美差异、设计观念和关于“自然”概念的理解等几方面比较深入地阐释两者的本质不同。