The rough representation and measurement of quotient structure in algebraic quotient space model

Granular computing is a very hot research field in recent years. In our previous work an algebraic quotient space model was proposed,where the quotient structure could not be deduced if the granulation was based on an equivalence relation. In this paper,definitions were given and formulas of the lower quotient congruence and upper quotient congruence were calculated to roughly represent the quotient structure. Then the accuracy and roughness were defined to measure the quotient structure in quantification. Finally,a numerical example was given to demonstrate that the rough representation and measuring methods are efficient and applicable. The work has greatly enriched the algebraic quotient space model and granular computing theory.

Beyond Public Spaces： Shared Spaces in the Contemporary City

The text aims to investigate the relevance of the concept of＂public space＂ and the continuous variations which have changed its meaning. Going beyond the concept of public space, the author can understand the semantic boundaries of this definition： Today, relational spaces and shared spaces are the forms with which people can express the concept of public space. The gradual spread of new forms of communication has transformed the static view of public space in a more dynamic condition, the distinction between square, street, garden has lost its meaning leaving space to fragments and residues. Contemporary public spaces are defined, as the residual places that come from the abandonment of industries. The large mono-functional voids, which originate from industrial dismantlement, should be strategically reconsidered as new shared public spaces, where the integration between different functions leads to reactivate new forms of re-using of built space.

A Relation of the Noncommutative Parameters in Generalized Noncommutative Phase Space

We introduce the deformed boson operators which satisfy a deformed boson algebra in some special types of generalized noncommutative phase space. Based on the deformed boson algebra, we construct coherent state representations. We calculate the variances of the coordinate operators on the coherent states and investigate the corresponding Heisenberg uncertainty relations. It is found that there are some restriction relations of the noncommutative parameters in these special types of noncommutative phase space.

An Evaluation of Crown Structure and Site Index to Determine Crown Closure in Eucalyptus urophylla × E. grandis Stands in Guangxi,China

Eucalyptus forests are grown in many parts of the world for their commercial value and use in construction projects. Density management becomes im- portant as a means to attain the management goals in these forests. Changes in canopy and tree crown structure were quantified for Eucalyptus urophylla x E. grandis forests at different ages to determine when canopy closure occurs and the onset of competition begins. Site index was developed for these forests to determine whether site quality affects the canopy structure. Site index had little effect in the forests sampled, with the forest canopy on the better sites becoming slightly more elongated. Based upon crown projection ratio and crown diameter： dbh （diameter at breast height） ratio, it appears that crown closure occurs by age 4 years in these forests. The age at which this occurs was also checked and verified with the evaluation of relative spacing, RS （the ratio of the mean distance between trees to the average dominant height of the stand）. The RS value displayed a rapid decline until age 4 years, and then became relatively flat through age 21 years. The rapid height growth during the first 3 years with no change in density accounted for this rapid decrease. By age 4 years, reductions in the number of trees due to mortality began to have more of an influence on this value, resulting in a more gradual de- cline. The implications for management are discussed.

文学空间:关系的建构

随着西方人文社科领域的"空间转向",空间、空间性、空间问题逐渐成为国内学术界的研究热点。在这场转向中,"文学空间"开始受到关注和深入探讨。现有的研究已涉及文学空间的许多方面,却也有不少问题还需做出系统讨论与理论建构。比如,这个空间应如何界定,有何特点,有着怎样的构成?文学空间是对关系的建构,关系性和建构性是其本质特征。这个空间既是各种关系的集合:时间关系、位置关系、权力关系、伦理关系、价值关系等,也是语言建构、心理建构与文化建构的结果,并置与重叠是空间建构的重要方式。作为关系建构的文学空间既具有抽象性和结构性,又强调视觉性与图像性,与现实空间既相关又不同。

基于语义相关的信息聚焦数学模型及方法研究

信息服务目前依然是一个研究热点。提出了基于语义关联的信息聚焦概念及数学模型。信息聚焦作为一种新的信息服务方式,利用信息之间的语义关联关系实现信息汇聚。首先给出了基于本体的元数模型以及信息、信息空间的数学模型和信息聚焦的数学描述,并在此基础上提出了基于本体的语义相关及信息聚焦的形式化描述。

基于语义关联的文本分类研究

传统的文本表示是在向量空间模型的基础上,采用特征选择方法降低文本的维数,这种方法认为文本中词语是相互独立的,没有考虑彼此之间的语义信息。文章提出一种新的基于语义特征选择的文本分类方法,在已有特征选择的基础上,利用词语之间的语义关联性,将那些与已选择的词语具有密切联系的词语加入词语特征空间。实验表明,该方法与已有的特征选择方法比较,提高了文本分类的精度。

基于不同尺度和模型的小秦岭谱系结构研究

为探索研究尺度、零模型与群落谱系结构的关系,在小秦岭自然保护区建立1 hm^2样地,运用约束型、非约束型零模型分别从10、20、25 m 3个研究尺度上分析群落谱系结构,结果表明:(1)非约束型模型下,谱系结构聚集;约束型模型下,10、20 m尺度上,谱系聚集,25 m尺度上谱系分散。对比发现,随研究尺度增大,谱系聚集程度降低,趋于分散,可能是由于环境异质性对物种分布的影响程度降低,密度制约作用增强所致。(2)空间因子对谱系结构的影响远远大于地形因子,随研究尺度增加,空间因子及地形因子的解释量逐渐增大。地形的不同营造了不同的空间差异,二者密切相关。因此,空间因子是影响谱系结构形成的直接因素,而地形因子是间接因素。

西部产业升级路径依赖抑或路径突破研判

以2009—2020年中国西部地区九省份的工业产业为研究对象,基于产品空间的方法可视化分析产业动态比较优势的发展现状、产业空间的演化路径和产业密度分布的变化趋势,实证检验技术关联对区域工业产业升级路径的作用机理。结果表明:(1)研究时段内,资源密集型产业始终处于保持比较优势状态,技术密集型产业尽管得到不断优化但大多仍处于升级未成功阶段,由资源密集型向技术密集型产业转变的趋势增强。(2)2009—2013年,技术关联对产业升级影响较小,产业升级体现出路径突破的演化过程;2014—2020年,产业升级受技术关联影响增强,更多体现出路径依赖的演化过程。(3)技术关联对产业升级的影响主要体现在促进新产业升级与发展方面,而在帮助现有产业保持优势方面效果并不显著。因此,西部地区应着力培育、发展与现有优势产业技术关联较强的新兴产业,全面融入丝绸之路经济带建设。

低维显式语义空间下的语义关联度计算方法

语义关联度计算是数据科学中的一个关键性基础问题,在信息检索及自然语言处理等方面有着广泛的应用.针对ESA(Explicit Semantic Analysis)算法存在的局限性,提出一种显式语义特征选择算法,并构建低维语义空间.在此基础上,根据特征概念在Wikipedia中的映射信息,提出一种低维显式语义空间下的语义关联度计算方法.该方法解决了ESA算法在后续语义关联度计算过程中,因高维稀疏空间导致计算效果不够准确的问题.实验结果表明,与当前其他方法相比,该方法的计算结果在皮尔逊相关系数(P)及斯皮尔曼相关系数(S)上与人们的认知判断之间具有更好的一致性.

Gravity observation at continental borderlands (Russia, Primorie, Cape Shults)

The paper is focused on different kinds of gravity results obtained in Shults Cape Observatory for 2010 -2015. Gravity observation is interpreted together with GPS observation data which was obtained from 2012 to 2015 at the same station, The station is situated on Gamov peninsular （42.58° N, 131.15° E, Russia） at the coast of Japan Sea, This region constitutes the eastern boundary of Eurasia. This major continental tectonic feature is associated with a seismic activity, high heat flow and anomalous thickness of earth＇s crust. The goal of the observation was the investigation of gravity variation with time and seismicity situation monitoring. Gravity observation was developed at special basement by absolute gravimeter （GABL type） and by spring gravimeter （SCINREX CG-5and gPhone type）. Tidal models were tested by results of observation with spring gravimeters. Reduction task was solved, as the experimental data received from different points of Shults Cape Observatory was used. Applied reduction coefficient is 203.3 12Gal m l, and agrees with theoretical calculation. Next goal was studying structure of earth＇s crust by means of gravity models. Gravity anomaly varied from 30 mGal to 46 mGal, which also depend on difference reference system, Experimental results were used for testing of the structure of continental boundary, which also depends on the sea bottom flexion. Thickness of elastic layer was estimated from 12 km to 18 km by using different models.

Review of space relative navigation based on angles-only measurements

Relative navigation is a key enabling technology for space missions such as on-orbit servicing and space situational awareness.Given that there are several special advantages of space relative navigation using angles-only measurements from passive optical sensors,angles-only relative navigation is considered as one of the best potential approaches in the field of space relative navigation.However,angles-only relative navigation is well-known for its range observability problem.To overcome this observability problem,many studies have been conducted over the past decades.In this study,we present a comprehensive review of state-of-the-art space relative navigation based on angles-only measurements.The emphasis is on the observability problem and solutions to angles-only relative navigation,where the review of the solutions is categorized into four classes based on the intrinsic principle:complicated dynamics approach,multi-line of sight(multi-LOS)approach,sensor offset center-of-mass approach,and orbit maneuver approach.Then,the fight demonstration results of angles-only relative navigation in the two projects are briefly reviewed.Finally,conclusions of this study and recommendations for further research are presented.

Fixed Point Theorems in Relational Metric Spaces with an Application to Boundary Value Problems

In this paper,we establish fixed point theorems for generalized nonlinear contractive mappings using the concept of w-distance in relational metric spaces.Thus we generalize the recent results of Senapati and Dey[J.Fixed Point Theory Appl.19,2945-2961(2017)]and many other important results relevant to this literature.In order to revel the usefulness of such investigations,an application to first order periodic boundary value problem are given.Moreover,we furnish a non-trivial example to demonstrate the validity of our generalization over previous existing results.

On the Space bv_p(F) of Sequences of p-bounded Variation of Fuzzy Numbers

Recently, the space bvp of real or complex numbers consisting of all sequences whose differences are in the space lp has been studied by Basar, Altay [Ukrainian Math. J. 55（1）（2003）, 136-147], where 1 ≤ p ≤ ∞. The main purpose of the present paper is to introduce the space bvp（F） of sequences of p-bounded variation of fuzzy numbers. Moreover, it is proved that the space bvp（F） includes the space lp（F） and also shown that the spaces bvp（F） and lp（F） axe isomorphic for 1 ≤ p ≤∞. Furthermore, some inclusion relations have been given.

中国对外贸易产品空间路径演化

地区经济发展与其生产结构紧密相联。演化经济地理学认为,地区生产结构的演化受技术关联的影响,是一个路径依赖过程;一些研究也认为产业和区域政策等因素可能创造新路径,实现路径突破。本文沿用Hidalgo等定义的贸易产品空间方法,基于2001-2013年中国31个省区市的产品贸易数据,对中国出口产品空间(Product Space)的演化路径进行探讨。结果发现:中国四大区域—东部、中部、西部和东北地区的出口产品经历了较为明显的结构转型,不同区域的转型方向与路径各异。在2001-2007年间,四大区域的出口产品空间演化受到技术关联的显著影响,体现为路径依赖的过程。在2008-2013年间,东部、中部与东北地区的产品空间演化仍受技术关联的影响,而西部地区则更多受到产业和区域政策的推动,体现了路径突破的演化过程。本文研究启示,虽然中国区域生产结构演化一定程度上受制于现有区域能力、技术和知识积累,但是区域性制度政策创新可以突破原有路径,为区域发展创造新的机会。

产品动态技术关联与中国出口产业地理共聚

伴随着区域产业分工不断深化,不同空间尺度上的产业集聚尤其是不同产业间的共聚现象日益凸显。本文使用2000—2016年中国海关贸易数据库,引入产品动态技术关联构建中国出口产品空间网络,刻画其演化过程及网络结构特征,在此基础上,考察产品技术关联对中国出口产业空间共聚的影响及其变动趋势,并从产品异质性视角补充相关实证证据。描述性分析发现:①中国出口产品空间具有典型的“核心-边缘”结构,2000—2016年期间,中国出口产品空间网络结构由松散扁平向复杂紧密演化。②强关联产品在地理上高度共聚。③中国出口产品空间网络表现出产品间更集聚、联系更紧密、网络结构更复杂的特征,形成了一个密集而复杂的强关联核心。实证检验表明:①产品技术关联对中国出口产业地理共聚存在显著的正向影响,但这一影响的边际效应在研究期内逐渐递减。②同行业与跨行业产品、高/低技术复杂度产品在产品技术关联影响产业共聚中具有差异化作用。其中,同行业产品关联对地理邻近的促进作用要强于跨行业关联;低复杂度产品无论与何种复杂度产品关联均能够显著提升其在地理空间上共聚的概率,高复杂度的关联产品则并未表现出共聚特征。本研究有利于为中国区域产业布局调整和产业结构升级提供理论支撑和政策指引。

中国地级城市职业空间演化的技能关联机制研究

采用2000年全国人口普查和2015年全国人口抽样调查微观数据集提供的分地级城市分职业小类的从业人员数据,运用社会网络分析方法,构建中国地级城市职业空间、可视化职业之间的技能关联性,并从职业进入、职业退出和就业增长三方面分析技能关联对职业空间演化的影响。结果表明:①中国地级城市职业空间网络异质性明显,技能关联度高的工作群主要集中在网络中心,且有显著的跨技能关联特征,技能关联度低的工作群零散分布于外围。②2000—2015年,专业人员的技能关联率提高最多,在农业生产人员上有专业化优势的城市一直最多,机电装配人员和生产操作人员的遍在性提高最多,管理人员、专业人员和技术人员等高技能水平职业类的遍在性明显降低。③技能关联对职业进入和就业增长具有显著促进作用,对职业退出具有显著抑制作用,影响程度在不同规模等级的城市之间存在明显的差异性。可以认为,各地区可大力吸引与本地技能关联度高的劳动力,以提高劳动力市场的匹配程度,稳定就业增长。

双边贸易、产品关联与中国产品内分工升级

文章基于产品空间视角,结合2001—2019年中国与130多个国家(地区)HS(1996)六分位双边贸易数据,创新引入区分出口目的地和进口来源地密度指标,考察中国与伙伴国(地区)双边产品内分工格局及产品空间结构关系,并采用两步系统GMM法实证检验出口关联、进口关联对双边产品内分工深化和升级的影响。研究表明:①虽然2008年金融危机后全球价值链分工发展趋缓,但中国与各伙伴国间的产品内分工程度、产品空间关系仍呈上升趋势,其中“一带一路”沿线国家表现突出;②无论是对总产品内分工还是高端型产品内分工水平,出口关联发挥了积极促进作用,但进口关联不利于双边产品内分工深化与升级,稳健性检验也得到一致结论;③出口关联、进口关联的作用机制迥然不同,作用效应在2008年金融危机前后以及伴随伙伴国收入水平、贸易关系的不同存在差异性,其中“一带一路”沿线国家的出口关联与进口关联更为有效地促进了中国产品内分工深化与升级。