最速下降和共轭梯度混合算法在波束形成中的应用     

赵翠芹  段艳明  包玉珍 《河池学院学报》2011,31(5):97-100

介绍了一种最速下降法和共轭梯度法的混合算法,并将这种混合算法应用到自适应波束形成中。该方法根据最小均方(LMS)准则推导出代价函数,结合共轭梯度法和最速下降法产生搜索方向,既提高了共轭梯度算法的收敛速度,又解决了最速下降法下降缓慢的问题。计算机仿真表明,混合算法所需迭代次数少于最速下降法,且显著减少计算量,缩短运行时间。  相似文献   

标话的形成     

杨璧菀 《贺州学院学报》2011,27(4):80-82

标话、上坊话和下坊话三种语言应在1000多前就在怀集共存了。原始标话与汉语方言长期交流融合,逐渐发展成为今天各地的标话。这种语言吸收了很多汉语的成分,但少数民族语言的底子没有变。  相似文献   

Teaching,teacher formation,and specialised professional practice     

Jim Hordern 《欧洲师范教育杂志》2015,38(4):431-444

This paper starts by exploring the relevance of Bernstein’s work on vertical and horizontal discourses and the constitution of professional knowledge for conceptualisation of the knowledge needed for teaching practice. Building on arguments for the differentiated nature of knowledge, and drawing on the work of Winch, Young and Muller on expertise, and the sociology of the professions, this paper advances a conception of teaching as a ‘specialised professional practice’ that requires the support of particular socio-epistemic arrangements and conditions embedded in professional communities. Prevalent notions of teaching and teacher education that find favour in some European countries are examined in the light of these arguments, with particular reference to recent reforms in England.  相似文献   

Socio-demographic and practice-oriented factors related to proficiency in problem solving: a lifelong learning perspective     

Richard Desjardins 《International Journal of Lifelong Education》2015,34(4):468-486

This article explores the relative importance of different socio-demographic and practice-oriented factors that are related to proficiency in problem solving in technology-rich environments (PSTREs) and by extension may be related to complex problem solving (CPS). The empirical analysis focuses on the proficiency measurements of PSTRE made available by the Programme for the International Assessment of Adult Competencies, which is relevant for gaining insight on some of the factors related to CPS. The purpose was to examine the relationship between the broad information processing experience that individuals gather in different contexts over the lifespan, and the chances to develop problem-solving skills that adults receive in different socio-demographic profiles. Results reveal that socio-demographic factors such as age, education and immigration status as well as practice-oriented factors such as ICT use and reading practice at and outside work are strongly related to proficiency.  相似文献   

Expert group formation using facility location analysis     

Mahmood Neshati  Hamid Beigy  Djoerd Hiemstra 《Information processing & management》2014

In this paper, we propose an optimization framework to retrieve an optimal group of experts to perform a multi-aspect task. While a diverse set of skills are needed to perform a multi-aspect task, the group of assigned experts should be able to collectively cover all these required skills. We consider three types of multi-aspect expert group formation problems and propose a unified framework to solve these problems accurately and efficiently. The first problem is concerned with finding the top k experts for a given task, while the required skills of the task are implicitly described. In the second problem, the required skills of the tasks are explicitly described using some keywords but each expert has a limited capacity to perform these tasks and therefore should be assigned to a limited number of them. Finally, the third problem is the combination of the first and the second problems. Our proposed optimization framework is based on the Facility Location Analysis which is a well known branch of the Operation Research. In our experiments, we compare the accuracy and efficiency of the proposed framework with the state-of-the-art approaches for the group formation problems. The experiment results show the effectiveness of our proposed methods in comparison with state-of-the-art approaches.  相似文献   

南通市城乡建设用地演变时空特征与形成机理   总被引：5，自引：0，他引：5  

蔡芳芳  濮励杰 《资源科学》2014,36(4):731-740

本文选择东部沿海"国家两大发展战略"交汇城市——南通市作为研究区,面对其新形势下的用地需求与矛盾,综合运用建设用地变化测度指标、城乡建设用地协调评价模型、地理探测器等多种研究方法,分析了2001-2011年南通市城乡建设用地演变时空特征及形成机理,结果表明:①南通市城镇用地扩张速度具有明显的阶段性与波动性,空间分布呈现"北高南低、西高东低、沿江高于沿海"的特征,同时其扩张弹性系数总体处于较高水平,未达到理想集约利用状态;②南通市农村居民点用地在城镇化推进下并未与农村人口非农化减少相挂钩,在研究期内基本处于加速增长态势,空间分布表现为"中部沿海扩展、南北沿江减少"的特征,过半数区、县(市)农村居民点用地增长模式属于人减地增粗放型;③全市城乡建设用地变化不甚协调,多数区、县(市)农村居民点用地增加量大于城镇用地增加量,且城镇发展不能较好满足城镇人口增长需要,在一定程度上影响了城镇化质量;④城乡建设用地变化形成机理差异显著,城镇用地增长受控于多种复杂因素,影响力最高的为城镇居民社会生活状况,而农村居民点用地变化则更多依赖于区位因素条件的影响,表现出其用地变化的先天依赖性与变化单一性。  相似文献   

云南特有少数民族武术的形成及其发展战略建构简     

汪雄  冯艳琼  李俊恒 《吉林体育学院学报》2014,(1):95-97

从社会学、文化学、人类学等角度,剖析云南特有少数民族武术的形成与发展过程,并进一步探讨其未来发展路径。研究结果认为：云南特有少数民族武术运动的发展是其各民族在长期的生产生活习俗以及历史文化的积淀过程中逐渐形成的,与其生产、生活、战争以及宗教祭祀活动等有着密切的关联;树立科学合理的认知方式、建立合理的价值取向、实施开发与保护并举将成为发展云南特有少数民族武术的必然选择。  相似文献   

“352”足球比赛阵型训练的探讨     

罗代 《湖北体育科技》2014,(4):319-320

采用文献综述法对"352"阵型的特点以及训练方法进行研究,认为阵型练习时教练员应注意与队员沟通、扬长避短,培养运动员的团队意识。  相似文献   

Placement and frequency of powerless talk and impression formation     

Craig Johnson  Larry Vinson 《Communication quarterly》2013,61(4):325-333

Study One examined the influence of initial use of hesitations and hedges on evaluations of witnesses and their persuasiveness in a budget hearing context. Results indicate that the negative attributions generated by the use of powerless language cannot be overcome by subsequent use of powerful talk. Study Two examined the relationship between the frequency of powerless language use and impression formation. For award/character and dynamism a perceptual threshold appeared to operate. The results of both studies suggest that auditors are very sensitive to the influence of powerless talk in formal settings.  相似文献   

我国星级酒店业知识转化与核心能力形成的相关性研究   总被引：1，自引：1，他引：0  

张同建  吕宝林 《软科学》2010,24(2):19-25

通过对我国星级酒店业知识转化与核心能力培育实践的现实性调查,借助于结构方程模型,揭示了我国星级酒店业知识转化在核心能力培育过程中的微观激励性机理,从而为我国星级酒店业进一步实施知识转化战略、有效地促进核心能力的培育提供了理论上的借鉴。  相似文献