数控自动编程技术现状和发展方向

数控程序作为将设计转化成现实的信息载体,直接控制机床的切削动作,是数控加工的关键。随着计算机技术的迅速发展,计算机数控与CAD/CAM软件不断推陈出新,性能越来越完善,功能越来越强大,并且代表了以后机械制造业的发展方向。但我国制造业中数控技术与CAD/CAM技术应用水平仍然非常低。     

专利实物期权定价的蒙特卡罗模拟方法及其改进技术

专利作为现代企业重要的无形资产,对企业募集发展资金、扩大收益回流、形成竞争优势发挥着巨大的作用,因此专利定价问题也成为现代企业管理决策中的重要内容.本文基于专利的实物期权特征,运用蒙特卡罗模拟方法对专利的实物期权定价问题进行研究与探讨.首先,分析探讨专利投资项目的决策过程及其实物期权特征;在此基础上,建立专利定价的实物期权蒙特卡罗模拟模型,并引入对偶变量技术用以提高蒙特卡罗模拟的效率;最后,以生物医药企业专利定价为例进行实证模拟.研究结论认为,引入适当方差减少技术的蒙特卡罗模拟则成为专利实物期权定价的一种有效的分析方法.     

超宽带盘锥天线的设计

介绍了盘锥天线的性能、设计原理,分析了各个参数对天线性能的影响。通过改变 天线结构,即在圆盘和下锥体之间引入一个上锥体,将盘锥天线和双锥天线结合起来,既保 持了盘锥天线的特性,又减少了圆盘和下锥体的分布电容,从而有效地增加了其带宽。在理 论计算的基础上利用ANSOFT HFSS软件对设计出的新型盘锥天线进行仿真优化,优化的结果 表明天线覆盖了从300 MHz到10 GHz的频带,在33∶1的带宽范围内驻波比基本小于 3,该方法有效地展宽了带宽。     

基于QualNet的战术数据链三维动态仿真

基于QualNet仿真软 件设计并实现了战术数据链在模拟环境下的三维动态仿真。将战术数据链仿真拓展到三维空 间,加入目标的机动性因素,给出了三维仿真的动态模型及其满足的更普遍关系式,具有一 定的参考价值和指导意义。     

基于地理加权和元胞自动机的建设用地发展模拟

为了防止建设用地的肆意扩张,缓解经济和生态平衡之间的矛盾,为政府部门的前期规划工作提供更合理的借鉴。为此以大连市某区域为研究区,将地理加权回归的思想融入到元胞自动机中,实现了城市空间发展的模拟,并与二次logistic回归模型作了对比。结果表明,在土地利用格局与影响因素建模过程中,存在着不同程度的空间自相关性,并在空间结构上不是单一趋势分布的,体现着空间不稳定性。将地理加权回归和元胞自动机的结合,不仅体现了空间分异特征,而且模拟精度也有所提高。     

Research on e-commerce transaction networks using multi-agent modelling and open application programming interface

We provide a formal definition of an e-commerce transaction network. Agent-based modelling is used to simulate e-commerce transaction networks. For real-world analysis, we studied the open application programming interfaces (APIs) from eBay and Taobao e-commerce websites and captured real transaction data. Pajek is used to visualise the agent relationships in the transaction network. We derived one-mode networks from the transaction network and analysed them using degree and betweenness centrality. Integrating multi-agent modelling, open APIs and social network analysis, we propose a new way to study large-scale e-commerce systems.     

MONOPOLISTIC LOCATION CHOICE IN A TWO‐SIDED HOTELLING MODEL

We analyse the optimal location choice of a monopolistic firm that operates two arbitrarily located platforms on a two‐sided market. By extending the traditional Hotelling framework, we show that the optimal platform locations are equivalent to the one‐sided benchmark if both sides are either restricted to single‐ or multi‐homing. In the mixed case (one side single‐homes, the other one multi‐homes), the optimal platform locations are in line with the respective symmetric case. If the monopolist is restricted to choosing the same location on either side of the market, the optimal locations are determined by the relative profitability of the market sides.     

Where to vacation? An agent-based approach to modelling tourist decision-making process

Agent-based models (ABMs) are becoming more relevant in social simulation due to the potential to model complex phenomena that emerge from individual interactions. In tourism research, complexity is a subject of growing interest and researchers start to analyse the tourism system as a complex phenomenon. However, there is little application of ABMs as a tool to explore and predict tourism patterns. The purpose of the paper is to develop an ABM that increases knowledge in tourism research by (i) considering the complexity of tourism phenomenon, (ii) providing tools to explore the complex relations between system components and (iii) giving insights on the functioning of the system and the tourist decision-making process. A theoretical ABM is developed to improve knowledge on tourist decision-making in the selection of a destination to vacation. Tourists’ behaviour, such as individual motivation, and social network influence in the vacation decision-making process are hereby discussed.     

Establishing the validity of cycle path capacity assumptions in the Highway Capacity Manual

Cycle mode share increase is widely desired, but highway design practitioners lack the numerical tools to deliver infrastructure, instead relying on design standards and intuition, with little literature basis. As a case in point, the US Highway Capacity Manual (which is well used internationally) has developed levels of service for cycle infrastructure that are, at their core, based on an assumption of noninteraction between multiple cyclists. This paper uses a modified implementation of the Social Force Model to test the validity of this assumption. Necessary changes such as the consideration of acceleration characteristics and minimum maintainable speed are included. The resulting model produces valid outcomes in keeping with established traffic flow properties, reflecting three-phase traffic flow theory and the ability for the stochastic elements in traffic flow to cause flow breakdown. The developed simulation indicates that there is a fundamental difference in outcome if cyclists are assumed to have a fixed speed versus one they can change given their surroundings. This difference in outcomes is found to exist within the range of literature design flow capacities for bicycle infrastructure and also yields emergent outcomes that align closely with those known behaviors of highway vehicles, which intuitively transfer to cyclists. These findings reinforce the standing need for large-scale empirical studies to determine the basic numerical and behavioral parameters for cyclists, upon which all design ultimately rests.     

数控技术应用型人才调研及其岗位群分析

职业院校的数控技术应用专业,已经建设了近二十年,通过深入调研,了解机械制造企业人才状况,细致分析任职岗位群,掌握企业未来数控人才需求,为学院深入开展教学改革提供了可靠依据。