期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
Trends in Markets for Forest-Based Products and Consequences for Selected Countries
1
作者 Olena Maksymets Lars Lonnstedt 《Open Journal of Forestry》 2015年第7期697-710,共14页
The forest sectors in many regions and countries are facing a need to change their structure, due to the development of new markets, emergence of new competitors, and shifts in production and consumption patterns for ... The forest sectors in many regions and countries are facing a need to change their structure, due to the development of new markets, emergence of new competitors, and shifts in production and consumption patterns for forest products. This article focuses on recent changes in the trade in these products, on imports and exports of four countries (USA, Sweden, Ukraine and, to a lesser extent, China) during the period from 1995 to 2011. For this purpose we use explanatory data analysis, time series analysis, benchmarking, meta-synthesis and content analysis of scientific and business publications concerning national and global trends in forest product industries. Data sources are various organizations’ databases of international trade in forest-based products in both monetary and physical terms (cubic meters and tons). The results show that the US and Swedish forest sectors are adversely affected by downturns in both their domestic and foreign markets during the study period, while the Ukrainian sector maintains exports of low value-added products at roughly constant levels (except that particle-board exports increase). China maintains production quantities of low value-added forest-based products, but also substantially increases exports of high-value added products. The results may facilitate efforts to forecast future trends and provide useful information and methodological approaches for future studies of interest to industry representatives, policy-makers and researchers. 展开更多
关键词 New Markets forest-Based Products Competition international Trade in forest Products forest Products Companies
下载PDF
A New Finding in Forest
2
作者 Lucy 曹阳 《小学生导刊(中年级版)》 2017年第6期32-33,共2页
关键词 A New Finding in forest
原文传递
基于大数据的前科人员犯罪预警模型构建研究 被引量:11
3
作者 张蕾华 牛红太 +1 位作者 王仲妮 刘雪红 《信息网络安全》 CSCD 北大核心 2019年第4期82-89,共8页
犯罪预警研究是大数据时代公安机关实施数据警务的有益探索,是数据挖掘技术和人工智能技术在公安领域的运用,对公安机关实现犯罪的前馈控制具有重要意义。基于现有的犯罪数据,通过人工智能分析平台构建前科人员再次犯罪预测模型,从而提... 犯罪预警研究是大数据时代公安机关实施数据警务的有益探索,是数据挖掘技术和人工智能技术在公安领域的运用,对公安机关实现犯罪的前馈控制具有重要意义。基于现有的犯罪数据,通过人工智能分析平台构建前科人员再次犯罪预测模型,从而提高犯罪预测的准确性,并且可以为事先防控犯罪提供科学的参考依据。搜集前科人员基本属性信息、劣迹信息、活动轨迹等数据,通过数据清洗、特征构造、模型建立、模型评估与优化,构建科学合理的感知预警分析模型,选取随机森林算法作为模型的训练算法,其正样本的精确率为0.85、召回率为0.86。研究表明,犯罪数据不仅可以用来预防犯罪,而且能够帮助我们从一个更高的层面理解犯罪发生的原因。 展开更多
关键词 前科人员 犯罪预测 数据挖掘 随机森林
下载PDF
矗立在辽蒙边界的绿色长城——辽西北边界防护林工程建设
4
作者 冯双霞 焦大志 李明 《内蒙古林业调查设计》 2009年第5期12-14,共3页
辽西北防护林工程建设是一个区域性的生态建设系统工程,它应用了系统工程技术、先进造林技术和科学造林模式,是30 a来林业科技成果和宝贵经验的结晶。辽西北防护林工程建设将会极大地改善全省的生态环境,对辽宁省经济可持续发展与构建... 辽西北防护林工程建设是一个区域性的生态建设系统工程,它应用了系统工程技术、先进造林技术和科学造林模式,是30 a来林业科技成果和宝贵经验的结晶。辽西北防护林工程建设将会极大地改善全省的生态环境,对辽宁省经济可持续发展与构建和谐社会具有深远意义。 展开更多
关键词 辽蒙边界 绿色长城 辽西北边界防护林工程建设
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部