产业集群的增长经济学解释

产业集群作为一种独特的产业组织形式,在区域经济增长中起着重要的促进作用,研究产业集群作用于经济增长的机理是经济理论工作者的重要任务。本文以Solow经济增长理论为基础,结合产业集群形成的内在原因,运用定量分析的方法从理论上解释了产业集群与经济增长的关系。     

User community detection via embedding of social network structure and temporal content

Identifying and extracting user communities is an important step towards understanding social network dynamics from a macro perspective. For this reason, the work in this paper explores various aspects related to the identification of user communities. To date, user community detection methods employ either explicit links between users (link analysis), or users’ topics of interest in posted content (content analysis), or in tandem. Little work has considered temporal evolution when identifying user communities in a way to group together those users who share not only similar topical interests but also similar temporal behavior towards their topics of interest. In this paper, we identify user communities through multimodal feature learning (embeddings). Our core contributions can be enumerated as (a) we propose a new method for learning neural embeddings for users based on their temporal content similarity; (b) we learn user embeddings based on their social network connections (links) through neural graph embeddings; (c) we systematically interpolate temporal content-based embeddings and social link-based embeddings to capture both social network connections and temporal content evolution for representing users, and (d) we systematically evaluate the quality of each embedding type in isolation and also when interpolated together and demonstrate their performance on a Twitter dataset under two different application scenarios, namely news recommendation and user prediction. We find that (1) content-based methods produce higher quality communities compared to link-based methods; (2) methods that consider temporal evolution of content, our proposed method in particular, show better performance compared to their non-temporal counter-parts; (3) communities that are produced when time is explicitly incorporated in user vector representations have higher quality than the ones produced when time is incorporated into a generative process, and finally (4) while link-based methods are weaker than content-based methods, their interpolation with content-based methods leads to improved quality of the identified communities.     

E-Mail as Spectroscopy: Automated Discovery of Community Structure within Organizations

We describe a method for the automatic identification of communities of practice from e-mail logs within an organization. We use a betweenness centrality algorithm that can rapidly find communities within a graph representing information flows. We apply this algorithm to an initial e-mail corpus of nearly 1 million messages collected over a 2-month span, and show that the method is effective at identifying true communities, both formal and informal, within these scale-free graphs. This approach also enables the identification of leadership roles within the communities. These studies are complemented by a qualitative evaluation of the results in the field.     

E-Mail as Spectroscopy: Automated Discovery of Community Structure within Organizations

We describe a method for the automatic identification of communities of practice from e-mail logs within an organization. We use a betweenness centrality algorithm that can rapidly find communities within a graph representing information flows. We apply this algorithm to an initial e-mail corpus of nearly 1 million messages collected over a 2-month span, and show that the method is effective at identifying true communities, both formal and informal, within these scale-free graphs. This approach also enables the identification of leadership roles within the communities. These studies are complemented by a qualitative evaluation of the results in the field.     

Group Behavior and Learning in Electronic Forums: A Sociotechnical Approach

The term community is widely and often uncritically used to characterize groupings of people who meet in electronic forums (e-forums). The research reported here shows how the casual use of the term community to characterize these groups can actually undermine their transformation into forms of social organization that are justifiably characterized as communities. This article examines how transforming a group into a community is a major accomplishment that requires special processes and practices. Primary data come from a particular project, the Inquiry Learning Forum (ILF), that aimed to develop "communities of practice" (CoPs) among high school science and mathematics teachers through an elaborate dedicated web site. We examine participants' behaviors in some of the differently structured forums within the ILF web site. While the project's developers expected CoPs to develop autonomously, there was no evidence of CoP formation in open public online forums. The article contrasts two approaches to building online communities that differ sharply: "IT-led community development" and "IT-supported community development." The experience of the ILF project shows that IT-led strategies community development strategies are much more difficult to make workable than are the "IT-supported" strategies.     

Group Behavior and Learning in Electronic Forums: A Sociotechnical Approach

The term community is widely and often uncritically used to characterize groupings of people who meet in electronic forums (e-forums). The research reported here shows how the casual use of the term community to characterize these groups can actually undermine their transformation into forms of social organization that are justifiably characterized as communities. This article examines how transforming a group into a community is a major accomplishment that requires special processes and practices. Primary data come from a particular project, the Inquiry Learning Forum (ILF), that aimed to develop "communities of practice" (CoPs) among high school science and mathematics teachers through an elaborate dedicated web site. We examine participants' behaviors in some of the differently structured forums within the ILF web site. While the project's developers expected CoPs to develop autonomously, there was no evidence of CoP formation in open public online forums. The article contrasts two approaches to building online communities that differ sharply: "IT-led community development" and "IT-supported community development." The experience of the ILF project shows that IT-led strategies community development strategies are much more difficult to make workable than are the "IT-supported" strategies.     

Looking for a general for some modern major models

Computer climate models are some of the most complex scientific structures ever conceived. Consisting of hundreds of thousands of equations and running on supercomputers capable of trillions of operations per second, they chart the evolution of past and future climates across thousands of years. These simulations are breathtaking in their qualitative detail and vastly ambitious in their quantitative exactitude. However, their progress has recently been challenged by the very size and complexity of the models, factors that are also paralleled in the communities of scientists that build them. This complex co-evolution of computers and scientific communities gives us insight into the promise and limits of sciences driven by exponential increases in computing power.     

资源型城市经济增长:基于生态约束的分析

提出了新型的产业组织模式——生态产业组织模式,但新的产业组织模式是否能够实现经济增长需要进一步加以证明。为此,把生态约束引入经济系统,构建包含生产部门和R&D部门两部门的生态约束下的经济增长模型,运用最优控制方法研究稳态时经济最优增长路径问题。研究发现,生态约束下资源型城市经济系统的最优增长路径是存在的,在不同的发展阶段,资源型城市生态系统的相关变量变化不同。在资源型城市的繁荣期将其转向生态产业组织模式,可以协调经济增长与生态环境,促进城市的可持续发展。     

Managing the investment in information security technology by use of a quantitative modeling

This paper presents a mathematical model for an optimal security-technology investment evaluation and decision-making processes based on a quantitative analysis of the security risks and a digital-assets assessment in an organization. The model makes use of a quantitative analysis of different security measures that counteract individual risks by identifying the information-system processes in an enterprise and the potential threats. The model comprises the target security levels for all the identified core business processes and the probability of a security accident together with the possible loss the organization may suffer. The model allows in-depth analyses and computations providing quantitative assessments of different options for investments, which translate into recommendations that facilitate the selection of the best solution and the associated decision-making. The model was tested using empirical examples and mathematical simulations with data from a real business environment.     

非营利组织绩效评估理论综述

对非营利组织绩效评估的准则、指标和方法进行了综述,发现非营利组织绩效评估越来越重视定量与定性相结合以及结果与过程相结合的评估方式,同时对评估中的问题和难点进行了分析,得出进一步研究的展望,力图呈现出非营利组织绩效评估的发展趋势。     

旅游虚拟社区成员的参加动机对其契合行为的影响——以户外旅行俱乐部为例

虚拟社区已成为当代旅游者的重要活动空间,他们在社区中展开发布信息、组织活动、寻求帮助、分享生活等非交易行为（即契合行为）,厘清旅游虚拟社区的参加动机及其与契合行为间的关系对于旅游虚拟社区的经营与发展具有重要意义。本文采用定量研究方法,对呼和浩特户外旅游虚拟社区进行了问卷调查,尝试明晰人们参加旅游虚拟社区的主要心理动因,并探索户外旅游虚拟社区中参加动机对于成员契合行为的影响。研究结果表明：旅游虚拟社区参加动机可划分为4种：自我成就、社交、学习和实际好处;虚拟社区参加动机对于契合行为具有显著影响,但仅对态度契合具有直接影响;群体认同是虚拟社区参加动机对契合行为产生影响的重要路径;契合行为的完全实现,必须要以达成态度契合为前提;旅游虚拟社区成员“参加动机-群体认同-态度契合-行为契合”的关系链条得以明晰,探索出从参加动机到契合行为的一般性普适路径。本文丰富了旅游虚拟社区契合行为研究,对旅游虚拟社区的经营管理者具有一定的借鉴和参考价值。     

细菌菌膜的致病性及防治策略

细菌菌膜是细菌吸附于惰性物体如医学材料或机体黏膜表面后形成的一种特殊的生存形式,由于其对抗生素耐药性使得菌膜成为许多慢性感染性疾病反复发作和难以控制的主要原因之一。本文介绍了细菌菌膜的致病性及其防治的研究进展,对寻找有效控制手段有重要意义。     

自我职业生涯管理与经理人职业成长——劳动关系氛围与组织结构的权变影响

从宏观政策视角分析加快我国"职业经理人阶层"形成的研究已较多,但微观视角的分析也不容忽视。本研究以映像理论为基础,以企业中、基层经理为研究对象,将自我职业生涯管理、劳动关系氛围、组织结构和职业成长整合在一个理论模型中,运用286组配套数据实证探究了四者间的关系。结果表明自我职业生涯管理对经理人职业成长有显著的正向预测作用;在和谐、积极的劳动关系氛围中,那些自我职业生涯管理效率更高的经理人能获得更快的职业成长;在有机组织结构中,那些更注重自我职业生涯管理的经理人也能获得更快的职业成长。     

Coercion or empowerment? Moderation of content in Wikipedia as ‘essentially contested’ bureaucratic rules

In communities of user-generated content, systems for the management of content and/or their contributors are usually accepted without much protest. Not so, however, in the case of Wikipedia, in which the proposal to introduce a system of review for new edits (in order to counter vandalism) led to heated discussions. This debate is analysed, and arguments of both supporters and opponents (of English, German and French tongue) are extracted from Wikipedian archives. In order to better understand this division of the minds, an analogy is drawn with theories of bureaucracy as developed for real-life organizations. From these it transpires that bureaucratic rules may be perceived as springing from either a control logic or an enabling logic. In Wikipedia, then, both perceptions were at work, depending on the underlying views of participants. Wikipedians either rejected the proposed scheme (because it is antithetical to their conception of Wikipedia as a community) or endorsed it (because it is consonant with their conception of Wikipedia as an organization with clearly defined boundaries). Are other open-content communities susceptible to the same kind of ??essential contestation???     

Bacterial aggregation and biofilm formation in a vortical flow

Bacterial aggregation and patchiness play an important role in a variety of ecological processes such as competition, adaptation, epidemics, and succession. Here, we demonstrate that hydrodynamics of their environment can lead to their aggregation. This is specially important since microbial habitats are rarely at rest (e.g., ocean, blood stream, flow in porous media, and flow through membrane filtration processes). In order to study the dynamics of bacterial collection in a vortical flow, we utilize a microfluidic system to mimic some of the important microbial conditions at ecologically relevant spatiotemporal scales. We experimentally demonstrate the formation of “ring”-shaped bacterial collection patterns and subsequently the formation of biofilm streamers in a microfluidic system. Acoustic streaming of a microbubble is used to generate a vortical flow in a microchannel. Due to bacteria''s finite-size, the microorganisms are directed to closed streamlines and trapped in the vortical flow. The collection of bacteria in the vortices occurs in a matter of seconds, and unexpectedly, triggers the formation of biofilm streamers within minutes. Swimming bacteria have a competitive advantage to respond to their environmental conditions. In order to investigate the role of bacterial motility on the rate of collection, two strains of Escherichia coli bacteria with different motilities are used. We show that the bacterial collection in a vortical flow is strongly pronounced for high motile bacteria.     

A microfluidic device to apply shear stresses to polarizing ciliated airway epithelium using air flow

Organization of airway epithelium determines ciliary beat direction and coordination for proper mucociliary clearance. Fluidic shear stresses have the potential to influence ciliary organization. Here, an in vitro fluidic flow system was developed for inducing long-term airflow shear stresses on airway epithelium with a view to influencing epithelial organization. Our system consists of a fluidic device for cell culture, integrated into a humidified airflow circuit. The fluidic device has a modular design and is made from a combination of polystyrene and adhesive components incorporated into a 6-well filter membrane insert. We demonstrate the system operates within physiologically relevant shear and pressure ranges and estimate the shear stress exerted on the epithelial cell layer as a result of air flow using a computational model. For both the bronchial epithelial cell line BEAS2B and primary human tracheal airway epithelial cells, we demonstrate that cells remain viable within the device when exposed to airflow for 24 h and that normal differentiation and cilia formation occurs. Furthermore, we demonstrate the utility of our device for exploring the impact of exposing cells to airflow: our tool enables quantification of cytoskeletal organization, and is compatible with in situ bead assays to assess the orientation of cilia beating.     

科学共同体测度方法的改进与实证研究

将社会网络分析中的位置分析引入作者同被引分析,改进科学共同体测度方法.实证得出我国经济学领域存在四大科学共同体,并分析了共同体之间的关系.认为,基于个体的统计分析与基于关系的网络分析相融合的新方法能够更本质地揭示科学共同体的形成与发展,在避免数据信息丢失,提取作者同被引行为模式,区分共同体层次结构,识别特殊团体,细分团体以及范式可视化方面具有优势.     

The Meaning of the Web

Speculation about the meaning of the Net (the Internet and potentially associated networks) and its most rapidly developing dimension, the Web (the World Wide Web), are both symptoms and components of a broader reshaping of world politics, economy, and culture. These changes challenge many of the categories within which we have grown used to thinking about the shape and meaning of society and its future. For individuals and local communities, the promises, hopes, and fears associated with the growth of the Web have particular poignancy as they face the challenge of establishing and asserting their identity in a ever more complicated and interdependent world and, through that, finding a strategy for achieving the sort of future they would like to live. The Net and the Web are technologies that promise us access to the world, but they and their associated social and economic trends challenge many of the premises upon which our identity is forged. The Net facilitates the development of new forms of transnational community organization, opening up the promise of more effective ways of acting as citizens across the broader social terrains in which it must be expressed. This article reconsiders the traditional theoretical tools that we have available to understand these issues. It addresses some of the central difficulties and possibilities available to us in rethinking identity, exploring the new promising cultural potential of the Web and Net in a more integrated and simultaneously fragmenting world.     

Early bacterial biofilm colonizers in the coastal waters of Mauritius

BackgroundThe past years have witnessed a growing number of researches in biofilm forming communities due to their environmental and maritime industrial implications. To gain a better understanding of the early bacterial biofilm community, microfiber nets were used as artificial substrates and incubated for a period of 24 h in Mauritian coastal waters. Next-generation sequencing technologies were employed as a tool for identification of early bacterial communities. Different genes associated with quorum sensing and cell motility were further investigated.ResultsProteobacteria were identified as the predominant bacterial microorganisms in the biofilm within the 24 h incubation, of which members affiliated to Gammaproteobacteria, Alphaproteobacteria and Betaproteobacteria were among the most abundant classes. The biofilm community patterns were also driven by phyla such as Firmicutes, Bacteroidetes, Chloroflexi, Actinobacteria and Verrucomicrobia. The functional analysis based on KEGG classification indicated high activities in carbohydrate, lipid and amino acids metabolism. Different genes encoding for luxI, lasI, agrC, flhA, cheA and cheB showed the involvement of microbial members in quorum sensing and cell motility.ConclusionThis study provides both an insight on the early bacterial biofilm forming community and the genes involved in quorum sensing and bacterial cell motility.     

城市社区信息化的信息整合机制

城市社区信息化是城市信息化的一个重要组成部分.随着城市社区建设的不断深入,城市社区信息化建设中的一些问题逐渐暴露出来.文章分析了城市社区信息"条块分割"问题的成因及危害,进而提出解决这一问题的具体方法,即建立一个完整的城市社区信息整合机制;同时指出了这一机制正常运转所需的组织结构保障.