Förnyelse av äldre arbetsområden i Göteborg

Törnqvist, Anders: Förnyelse av äldre arbetsområden i Göteborg. Geografisk Tidsskrift 83: 60–64. May 1., 1983.

A recently started research and development project at Chalmers Institute of Technology in cooperation with the City of Gothenburg is presented. Background research on the physical and economic status of old industrial districts in Sweden shows the need for renewal. Difficulties and possibilities are analysed. A two-phase negotiation strategy involving the landowners, the firms, the employees and local government branches is outlined.     

基于云环境的云南地震灾害快速评估与信息服务系统在巧家MS5.0地震中的应用

基于云南地震灾害快速评估系统现状与使用中发现的问题,对其在空间算法、动态集群分布式并行计算、信息服务模式等多方面进行优化,设计了云环境下的云南地震灾害快速评估与信息服务系统,并结合系统在巧家MS5.0地震中的使用情况进行综合分析.结果表明:新的地震灾害应急指挥技术系统产出的应急产品,在时效性与准确性方面均得到较大提高,...     

Pesticides in export and domestic agriculture: Reconsidering market orientation and pesticide use in Costa Rica

The environmental impact of agro-export production in developing countries remains an important research topic. The political economy-inspired literature on developing country agro-exports maintains that export crops are pesticide intensive – or, more generally, environmentally destructive – while local and national market crops are less pesticide intensive, or environmentally benign. If used to draw conclusions about the impact of national market versus export market expansion, this view has significant limitations, most importantly the comparison of high-commodity value export crops with low-commodity value crops for national market. To overcome this and other limitations of prior analyses, this paper addresses the question: how does market orientation influence pesticide intensity where the same crops are grown for both the national market and for export? Data from a survey of Costa Rican vegetable farmers are used to compare pesticide intensity of 27 vegetable crops, five of which are produced for both national and export markets. The general pattern that emerges is that national market vegetables are more pesticide intensive than export vegetables in the area. Yet, controlling more for the crop variable is important, and specific comparisons of the five vegetables grown for both markets – carrot, chayote, corn, green beans, and squash – illustrate that market orientation alone does not determine pesticide intensity, but that it is jointly influenced by regulatory risk, crop value, and pest susceptibility, among other factors. Continued attention to both political economy and ecological processes in “second nature” will allow political ecology to make important contributions to understanding pesticide problems and implementing agroecological solutions.     

Machine learning for accelerating 2D flood models: Potential and challenges

Two-dimensional hydrodynamic models numerically solve full Shallow Water Equations (SWEs). Despite their high accuracy, these models have long simulation run times and therefore are of limited use for exploratory or real-time flood predictions. We investigated the possibility of improving flood modelling speed using Machine Learning (ML). We propose a new method that replaces the computationally expensive parts of the hydrodynamic models with simple and efficient data-driven approximations. Our hypothesis is that by integrating ML with physics-based numerical methods, we can achieve improved generalization performance: that is, the trained model for one case study can be used in other studies without the need for new training. We tested two ML approaches: for the first, we integrated curve fitting, and, for the second, artificial neural networks (ANN) with a finite volume scheme to solve the local inertial approximation of the SWEs. The data-driven models approximated the Momentum Equation, which explicitly solved the time derivative of flow rates. Water depths were then updated by applying a water balance equation. We also tested two different training datasets: the simulated dataset, generated from the results of hydrodynamic model, and the random dataset, generated by directly solving the momentum equation on randomly sampled input data. Various combinations of input features, for example, water slope and depth, were explored. The proposed models were trained in a small hypothetical case and tested in a different hypothetical and in two real case studies. Results showed that the curve-fitting method can be implemented successfully, given sufficient training and input data. The ANN model trained with a random dataset was substantially more accurate than that of the model trained with the simulated dataset. However, it was not successful in the real case studies. The curve-fitting method resulted in better generalization performance and increased the simulation speed of the local inertial model by 23%. Future research should test the performance of ML in terms of an increase in stable time step size and approximation of the full SWEs.     

省级基础地理信息快速更新方法研究

传统省级基础地理信息更新模式,无法保证数据的现势性,直接影响其使用价值和使用范围,因此本文研究了一种省级基础地理信息快速更新方法。首先利用互联网地理分析、影像和矢量数据变化检测等技术实现变化地理信息的快速发现;接着通过无人机遥感测量系统、车载移动测量系统、内外业一体化采集平台等实施变化地理信息的快速采集;最后根据增量信息形成新的现势数据库和历史数据库。实施成果表明,该技术可以灵活地应用于特定要素或指定区域信息的快速更新,对于推进省级基础地理信息数据快速更新机制的完善具有重要作用。     

耐高压高精度快速时间响应温度传感器的封装技术

文章详细阐述了耐高压高精度快速时间响应温度传感器的设计方法和封装工艺,并给出了温度传感器测试时间响应的方法以及目前达到的水平。对该项技术应用作了介绍。     

工程毁伤快速观测与标定系统研究

针对战时毁伤工程快速抢修,提出采用车载式全站仪测量系统,快速观测遭袭工程的毁伤范围、弹坑位置、直径及深度等信息,利用CASS数字成图软件实时标定成图,并准确计算毁伤面积、计算汇总各个修复方案的抢修工程量,为确定最小的抢修工程量和选择最佳的修复方案提供技术依据。本文从快速观测系统功能设计入手,介绍了观测系统的组成、系统快速定位技术与毁伤数据快速采集方法、弹坑轮廓边界的确定、抢修工程量的计算,并通过对模拟弹坑的实测试验,证明了方法的可行性与先进性。     

Farmers and fallowing: agricultural change in Kigezi District, Uganda

Focusing on the area of Kigezi, in south-western Uganda, this article examines land use change over a 50-year period. It shows that Kigezi, an area long considered to be suffering the effects of overpopulation, has never suffered the environmental catastrophes that have long been predicted. Instead, research suggests that farmers have successfully managed their land and maintained productivity.     

地震动强度与地震烈度速报研究

本在总结了美、日等国家和我国大陆与台湾地区基于实时或近实时强震台网的地震动强度（烈度）速报方法的基础上,对我国地震动强度（烈度）速报及计算机软件编制中的关键技术问题进行了讨论。     

用Kaula线性摄动方法恢复CHAMP重力场模型

介绍了Kau la线性摄动方法的基本原理和算法,基于CHAMP几何法轨道和动力法轨道,给出了利用该方法恢复地球重力场模型的实现过程,分析了Kau la线性摄动方法在实际应用中需要注意的问题。基于德国慕尼黑技术大学提供的一个月的CHAMP几何法轨道和德国GFZ数据中心提供的快速科学轨道,计算出了50×50阶地球重力场模型CHAMP-Kau la1S,并与EIGEN-CG03C、EIGEN-CHAMP03S、EIGEN2、ENIGN1S、EGM96模型进行了比较。结果表明:X ISM-CHAMP1S模型精度明显优于相同阶次EIGEN1S模型,前40阶明显优于EGM96模型,而低于同阶次的EIGEN2和EIGEN-CHAMP03S模型精度。