浅谈E时代下的计算机及网络安全

简要概述了在网络时代,测绘网络存在的几点安全隐患并根据现有条件在组织和技术方面如何保障网络信息安全的几点措施。     

影响社区的常见气象因素分析与防范

通过对影响人们日常生活的风、雨、温度、雷电等常见气象因素的分析。提出社区有效防御气象灾害的措施,以提高社区管理的质量和水平。     

隆林县西贡蕉种植的气象条件分析

根据西贡蕉的生物学特性,结合隆林县气候特点进行分析,得出：隆林县栽种季节温度适宜,生长旺盛期雨水充沛,光温配合好,有利提高西贡蕉产量,是种植西贡蕉理想的区域.但干旱、低温冻害、大风、冰雹等气象灾害影响西贡蕉的产量和质量,应采取措施,以求达到西贡蕉种植优质增产目的.     

Trajectory analysis at intersections for traffic rule identification

In this paper,we focus on trajectories at intersections regulated by various regulation types such as traffic lights,priority/yield signs,and right-of-way rules.We test some methods to detect and recognize movement patterns from GPS trajectories,in terms of their geometrical and spatio-temporal components.In particular,we first find out the main paths that vehicles follow at such locations.We then investigate the way that vehicles follow these geometric paths(how do they move along them).For these scopes,machine learning methods are used and the performance of some known methods for trajectory similarity measurement(DTW,Hausdorff,and Fréchet distance)and clustering(Affinity propagation and Agglomerative clustering)are compared based on clustering accuracy.Afterward,the movement behavior observed at six different intersections is analyzed by identifying certain movement patterns in the speed-and time-profiles of trajectories.We show that depending on the regulation type,different movement patterns are observed at intersections.This finding can be useful for intersection categorization according to traffic regulations.The practicality of automatically identifying traffic rules from GPS tracks is the enrichment of modern maps with additional navigation-related information(traffic signs,traffic lights,etc.).     

Post-2012 climate policy dilemmas: a review of proposals

This article assesses a wide range of alternative proposals for post-2012 international climate policy regimes. We believe that these proposals will serve as a basis for debates about how to configure post-2012 climate policy. The article characterizes and assesses the policy proposals along the lines of five key policy dilemmas. We argue that (1) many proposals have ideas on how to reduce emissions, but fewer have a solution on how to stimulate technical innovation; (2) many proposals formulate climate policy in isolation, while there are fewer proposals that try to mainstream climate policies in other policy areas; (3) many proposals advocate market-based solutions, while fewer realize that there are certain drawbacks to this solution especially at the international level; (4) most proposals have a preference for a UN-based regime, while a more fragmented regime, based on regional and sectoral arrangements may be emerging; and (5) most proposals have ideas about mitigation, but not many have creative ideas on how to integrate mitigation with adaptation.     

Performance of renewable energy technologies under the CDM

While many different greenhouse gas (GHG) mitigation technologies can be implemented under the Clean Development Mechanism (CDM), renewable energy technologies (RETs), in particular, are often viewed as one of the key solutions for achieving the CDM's goals: host-country sustainable development and cost-efficient emissions reductions. However, the viability of emission reduction projects like RETs is technology- and country-specific. To improve the CDM with respect to the diffusion of RETs, it is crucial to understand the factors that ultimately drive or hinder investments in these technologies. This study develops a methodology based on project-level, regional and global variables that can systematically assess the financial and environmental performance of CDM projects in different country contexts. We quantitatively show how six RETs (PV, wind, hydro, biomass, sewage, landfill) are impacted differently by the CDM and how this impact depends on regional conditions. While sewage and landfill are strongly affected independently of their location; wind, hydro and biomass projects experience small to medium impacts through the carbon price, and strongly depend on regional conditions. PV depends more on regional conditions than on the carbon price but is always unprofitable. Furthermore, we determine the carbon prices necessary to push these six RETs to profitability under various regional conditions. Based on these results, we derive policy recommendations to advance the interplay between international and domestic climate policy to further incentivize GHG emission reductions from RETs.     

Measuring the goodness-of-fit of decision-tree models of discrete and continuous activity-travel choice: methods and empirical illustration

The use of decision tree models for predicting activity-travel choice is receiving increasing attention, but raises two related problems that are considered in this study. First, commonly used deterministic action-assignment rules should be replaced by probabilistic action-assignment rules. We develop such probabilistic rules for both discrete and continuous choice problems. Second, common goodness-of-fit measures such as the hit-ratio need to be replaced by likelihood measures. In this paper, we develop and empirically illustrate the interrelated methods and measures. The findings suggest that the new measures add information to existing statistics for discrete as well as the continuous choice.     

浅析GPS导航对抗技术

对GPS导航作了简单概述,介绍了国内外GPS导航对抗的技术,对各种GPS干扰与抗干扰技术作了较为全面的分析,提出应加快我军GPS对抗战术、技术研究。     

石河子总场"5·27"雷灾事故现场调查和成因背景分析

通过对"5·27"雷灾事故的调查分析,在掌握雷电产生原理的基础上,只要人们不违背防雷技术规范,对建筑物或构筑物等防雷场所建立安全合理的防雷设施,雷灾是可以防范的.     

Qinghai-Tibet Expressway experimental research

As one part of the National Highway Network Planning in China, the Qinghai-Tibet Expressway （QTE） from Golmud to Lhasa will be built in the interior of the Qinghai-Tibet Plateau （QTP） across about 630 km of permafrost lands. Due to the problematic interactions between the engineering foundations and permafrost, the frozen-soil roadbed of the QTE will be subjected to the more intense thermal disturbances due to the wider black surface. The design and construction for long-term thermal and mechanical stability will face more severe challenges than those in ordinary highways and railways in the same region. In order to provide scientific support for cold regions engineering practices, the QTE Experimental Demonstration Project （EDP） was constructed in situ in the vicinity of the Beilu＇he Permafrost Station in the interior of the QTP. In this paper, the anticipated problems of the proposed QTE project are enumerated, and the structures of the test sections for QTE EDP are described. Through numerical simulations, it was found that the heat transfer processes occurring in each specific road structure are significantly different. The heat accumulation in the highway embankment is mainly due to the black bituminous pavement, but in the railway embankment with its gravel surfaces, it mainly comes from the side slopes. As a result, the net heat accumulation of the highway embankment is three times higher than that in the railway. In expressway, the heat accumulation is further increased because of the wider pavement so that significantly more heat will be accumulated in the roadbed beneath the centerline area. Thus, the thermal stability of the fro- zen-soil roadbed and the underlying permafrost of the QTE can be seriously threatened without proper engineering measures protection against thawing. Based on research and practical experiences from the operating Qinghai-Tibet Railway （QTR） and the Qinghai-Tibet Highway （QTH）, combined with the predicted characteristics of heat transfer in an expressway embankment, nine kinds of engineering measures for mitigating the thaw settlement of foundation soils through the cooling the roadbed soils were built and are being tested in the EDP. The design of the monitoring system for the EDP and the observed parameters were also described.