浅谈基于大数据背景下的数字经济发展——以数字电网为例

我们已经进入了一个全新的大数据信息化时代,充满了更多的机遇与挑战。大数据及数字经济的出现极大程度地改变了传统技术及工作思维的方式。数字经济是继工业和农业之后的又一大经济形态,为社会的经济增长提供了新的动力。通过分析电网行业传统的科学技术及作业方式,论文简要阐述了基于大数据信息化发展下电网的影响,并认为信息化技术的发展对于数字经济有着至关重要的影响及重要性。最后论文讨论了数字经济发展存在的问题及方向。     

跳频信号的归一化多普勒频差最大似然估计

针对双站定位涉及的跳频信号多普勒频差估计问题，提出了归一化的频差最大似然估计算法，利用两个定位站接收到的跳频脉冲串信号，构建一个关于基准跳频频率多普勒频差的似然函数，通过网格搜索得到使似然函数最大的多普勒频差估计，既解决了跳频信号在不同跳频频率上多普勒频差不一致的问题，又充分利用在不同频率的脉冲串信号提高了多普勒频差估计精度。通过仿真对算法的性能进行了评估，结果表明，与基于子空间的算法比较，在脉冲数达到240个时，所提算法执行效率提升30%以上。     

Optimal investment with vintage capital: Equilibrium distributions

The paper concerns the study of equilibrium points, or steady states, of economic systems arising in modeling optimal investment with vintage capital, namely, systems where all key variables (capitals, investments, prices) are indexed not only by time but also by age. Capital accumulation is hence described as a partial differential equation (briefly, PDE), and equilibrium points are in fact equilibrium distributions in the variable of ages. A general method is developed to compute and study equilibrium points of a wide range of infinite dimensional, infinite horizon, optimal control problems. We apply the method to optimal investment with vintage capital, for a variety of data, deriving existence and uniqueness of equilibrium distribution, as well as analytic formulas for optimal controls and trajectories in the long run. The examples suggest that the same method can be applied to other economic problems displaying heterogeneity. This shows how effective the theoretical machinery of optimal control in infinite dimension is in computing explicitly equilibrium distributions. To this extent, the results of this work constitute a first crucial step towards a thorough understanding of the behavior of optimal paths in the long run.     

Comparison of dimension reduction methods for DEA under big data via Monte Carlo simulation

Data with large dimensions will bring various problems to the application of data envelopment analysis (DEA). In this study, we focus on a “big data” problem related to the considerably large dimensions of the input-output data. The four most widely used approaches to guide dimension reduction in DEA are compared via Monte Carlo simulation, including principal component analysis (PCA-DEA), which is based on the idea of aggregating input and output, efficiency contribution measurement (ECM), average efficiency measure (AEC), and regression-based detection (RB), which is based on the idea of variable selection. We compare the performance of these methods under different scenarios and a brand-new comparison benchmark for the simulation test. In addition, we discuss the effect of initial variable selection in RB for the first time. Based on the results, we offer guidelines that are more reliable on how to choose an appropriate method.     

电子商务需要网格计算

网格是继传统因特网和web之后的第三代因特网。传统因特网实现了计算机硬件的连通,web实现了网页的连通,而网格将要实现因特网上所有资源的全面连通。虽然网格计算还处在起步期,但是企业已经把它看作是下一阶段电子商务的基础设施。企业通过网格获取来自全球的计算资源,利用网格这个虚拟的、强大的计算平台,企业会降低总体的计算成本。网格带给企业的将不仅仅是经济利益,还有竞争力的提升。     

The Ethical Dimensions of Decision Processes of Employees

The influence of stakeholders, organisational commitment, personal values, goals of the organisation and socio-demographic characteristics of individuals on the ethical dimension of behavioural intentions of employees in various organisations are investigated. The research results show that employees working for the public sector or in educational institutions take more ethical aspects into account than employees working in the "private" sector. The influence of stakeholders and organisational commitment do not significantly affect the ethical behaviour of employees, and only some personal values and goals of the organisation have a significant influence on ethical behaviour. The most significant explanatory factor of ethical decision making seems to be what may be called "stage in the career of the employee": "ethical" employees can be described as young, with a relatively low income, limited work experience and a low level of responsibility in the company.     

基于分形理论的广西城市体系空间结构研究

城市是人口和经济的聚集地,城市体系空间结构具有分形几何特征。将分形理论与中心地理论相结合,通过城市体系的关联维数模型计算出广西城市体系空间结构的分维值,发现广西城市体系的空间分布是具有分形特征,城市体系自组织演化在空间结构方面具有优化趋势,可以强化中心、极化南宁核心地位,重点扶持桂林、柳州、北海三个副中心建设,构建"一枢纽、二港口、三通道、四辐射"大通道体系和点轴面相结合发展的广西城市体系空间结构。     

What Are the Characteristics That Software Development Project Team Members Associate With a Good Project Manager?

In this study we investigate what software development project team members consider to be a good project manager. Previous research has been carried out using project manager self‐assessments, other project stakeholder views, or recruiters’ views. This qualitative study used the repertory grid technique to identify the characteristics that project team members associate with a good project manager. This technique has been adopted because of its strength in eliciting personal constructs. Among the 18 characteristics identified, the seven most relevant were classified and compared with previous findings, which reveals differences between the team members’ and project managers’ and other stakeholders’ perceptions. Those findings complement the existing skill set and could be considered when recruiting and training project managers and staffing projects.     

输变电技术在智能电网中的应用研究

输变电技术具有资金投入大、技术含量高、建设周期长、协作程度高、系统可靠度强等特点,满足智能电网建设需要,在实际工作中的应用比较广泛。主要包括质量优化技术、能源转换技术、特高压输电技术、柔性输电技术、智能感应技术、智能设备和智能装置技术等,并发挥着重要作用。今后为促进输变电技术在智能电网中得到更好应用,需要根据实际工作采取相应对策,注重技术研究和创新、加大资金投入力度、培养专业人才队伍,并重视日常检查和维修、确保设备安全与可靠。     

智能电网实现低碳效益的作用机理

通过分析智能电网低碳效益的内涵,确定了碳的减排对于智能电网的重要性。分别从清洁发电、降低损耗及负荷整形三个方面探讨了智能电网低碳效益的实现路径。