共查询到20条相似文献,搜索用时 203 毫秒
1.
双水相萃取技术在生物、医药方面的应用 总被引:3,自引:0,他引:3
讨论了双水相萃取技术的作用原理,分析了影响双水相萃取的因素,介绍了双水相萃取技术的特点及这一技术在生物和药物提取领域的应用,针对双水相萃取技术的特点及局限性对其应用前景进行了展望。 相似文献
2.
3.
基于系统动力学基本原理对煤炭企业人力资源现状进行分析,并以某企业为例,构建其人才结构的系统动力学模型。在通过有效性检验后,对模型进行为期50年的仿真运行,最终得出该企业人才需求及结构预测结果。 相似文献
4.
5.
煤炭资源型城市可持续发展的系统动力学模型及应用 总被引:1,自引:0,他引:1
我国煤炭资源型城市凭借本地区优越的资源禀赋,对国民经济的发展起着非常重要的作用。由于煤炭资源型城市的复杂性,要实现可持续发展,系统动力学建模的方法能充分反映该类城市的非线性结构和动态变化趋势。在应用系统动力学模型至某一具体城市过程中,本文采用计量经济学方法对历史数据的分析上,确定模型的主要流位变量,利用灰色关联度分析方法来确定模型的辅助变量,从而建立起具有某城市特征的系统动力学模型。在应用历史数据对该模型进行了基本模拟和政策模拟,并对模拟结果进行了分析,为后续对煤炭资源型城市的研究提供了支持。 相似文献
6.
7.
8.
9.
软件产业是信息产业的核心和灵魂.本文在对江西软件产业进行定性分析的基础上,以系统动力学为主要工具,利用系统动力学流率基本入树建模法构建了江西软件产业系统动力学流率基本入树模型,并对模型进行计算机仿真分析. 相似文献
10.
11.
12.
为了解决短文本稀疏性问题,提高主题模型的性能,提出了一种词向量嵌入的主题模型。首先,假设一篇文档只包含一个主题;其次,利用词向量对每一轮迭代的主题进行扩充与调整,即对每一个主题,利用一种非参数化的概率采样方法得到一些词,再用词向量找出相似词,提升该主题下相似词的权重;最后,用拉普拉斯近似主题分布,使其更好地运用在变分自动编码器训练中,从而加快训练速度。实验结果表明,本文模型训练出的主题具有较好的解释性,并优于其他主流的模型,可为短文本的主题提取提供更多的可能。在主题模型训练的过程中,利用词向量干预主题词分布可以得到较好的主题质量,并可以通过变分自动编码器加快训练速度,对自然语言处理问题的研究具有一定的创新性和参考价值。 相似文献
13.
利用光谱复制技术提高颜色复制精度,减少同色异谱现象,是目前颜色高保真复制方法研究的一个主流方向。本文总结回顾了各经典光谱模型,并对打印机适用的基于回归的经典光谱模型和基于物理过程的关键光谱模型进行介绍。其中打印机适用的基于回归的经典光谱模型包括适用于单色打印机的MmTay-Davies模型、适用于网目调多色印刷的Neugebauer模型、添加n值优化的Yule-Nielsen光谱反射率模型、Clapper-Yule光谱反射率模型、细胞化Neugebauer模型、细胞化Yule-Nielsen光谱模型、YNSN光谱模型以及细胞化YNSN模型。通过控制模型中的各可变参数,不断优化模型,可提高光谱颜色复制的精度。 相似文献
14.
This article develops a real options model for valuing natural resource exploration investments (e.g. oil or copper) when there is joint price and geological‐technical uncertainty. After a successful several‐stage exploration phase, there is a development investment and an extraction phase. All phases are optimized contingent on price and geological‐technical uncertainty.
Several real options are considered. There are flexible investment schedules for all exploration stages and a timing option for the development investment. Once the mine is developed, there are closure, opening and abandonment options for the extraction phase. Our model maintains a relatively simple valuation structure by collapsing price and geological‐technical uncertainty into a one‐factor model.
We apply the model to a copper exploration prospect and find that a significant fraction of total project value is due to the operational, development and exploration options available to project managers. 相似文献
Several real options are considered. There are flexible investment schedules for all exploration stages and a timing option for the development investment. Once the mine is developed, there are closure, opening and abandonment options for the extraction phase. Our model maintains a relatively simple valuation structure by collapsing price and geological‐technical uncertainty into a one‐factor model.
We apply the model to a copper exploration prospect and find that a significant fraction of total project value is due to the operational, development and exploration options available to project managers. 相似文献
15.
孟艳春 《地质技术经济管理》2010,(9):56-58
以经济保障责任主体来划分,养老模式可分为家庭养老、自我养老和社会养老三种基本模式。目前在中国,家庭养老逐步弱化,自我养老难成现实,社会养老难以完全到位。因此,吸收以上几种养老模式之长,兼容的居家养老模式应是我们解决养老问题的最佳选择。 相似文献
16.
17.
Firms engage increasingly in open business models. While most research has previously focused on typologies or challenges of open business models, their specific antecedents have not been studied so far. We use data from eight open business model cases to explore this question and identify five main antecedents of open business models: (1) business model inconsistency, (2) need to create and capture new value, (3) previous experience with collaboration, (4) open business model patterns, and (5) industry convergence. Based on openness characteristics from the existing literature, we differentiate four basic types of open business models and develop an initial understanding of the relevance of the identified antecedents for each of them. We thereby provide first guidelines for practitioners in choosing the right form of business model openness for their company. 相似文献
18.
能源经济环境模型是研究宏观政策影响、能源经济环境综合评价等的重要分析工具。介绍了能源经济环境模型中应用最为广泛的一般均衡(CGE)模型、技术模型及混合模型。结合文献着重分析了模型的发展趋势,包括开发综合评价模型、处理不确定性问题及技术变化内生模拟、细化重要部门等方面。最后指出应重视基本模型的能力建设,积极参与国际合作。 相似文献
19.
This article examines existing models of the regulation of international labor standards in the context of international trade. The article first focuses on conceptual and theoretical notions of the international regulation of labor standards. Four existing models of international labor regulations are then examined: the legislative model, the trade sanctions model, the multilateral enforcement model, and the voluntary standards model. The theoretical issues raised and the characteristics of the four models are then used to develop a suggested structure for the international regulation of labor standards in a world of free trade. 相似文献
20.
This study analyzes Industrial Internet of Things (IIoT) business models in the machine-to-machine (M2M) context. Thereby, it develops a conceptual framework to categorize different types of business model innovation for companies operating in the M2M business space. Business model innovations tend to cross multiple industries and drive ecosystems in which smart objects facilitate business models and service applications that are incrementally or radically novel in terms of their modularity or architecture. Our framework identifies four distinct types of IIoT business models: (I) Company-specific business models, (II) Systemic business models, (III) Value designs, and (IV) Systemic value designs. Moreover, it sheds light on different abstraction levels of business model building blocks and exposes the characteristics and differences in the value potential between the four business models. Finally, we advance the idea of ‘value design’ referring to business models of multiple actors coupled together, ultimately resulting in complex networks and ecosystems of diverse things, processes, and companies. 相似文献