Environmental and energy life cycle analyses of passenger vehicle systems using fossil fuel-derived hydrogen

Hydrogen energy utilization is expected due to its environmental and energy efficiencies. However, many issues remain to be solved in the social implementation of hydrogen energy through water electrolysis. This analyzes and compares the energy consumption and GHG emissions of fossil fuel-derived hydrogen and gasoline energy systems over their entire life cycle. The results demonstrate that for similar vehicle weights, the hydrogen energy system consumes 1.8 MJ/km less energy and emits 0.15 kg-CO 2 eq./km fewer GHG emissions than those of the gasoline energy system. Hydrogen derived from fossil fuels may contribute to future energy systems due to its stable energy supply and economic efficiency. Lowering the power source carbon content also improved the environmental and energy efficiencies of hydrogen energy derived from fossil fuels.     

高放废物地质处置战略讨论

概述了全球核电开发情况，介绍了高放废物地质处置国际态势及发展动向，对我国有关工作提出了意见和建议。     

二维码位流长度最小化算法

目的 快速响应矩阵码(quick response code,QR code)简称二维码,是一种由深色和浅色模块组成的正方形符号。给定输入数据,不同编码算法可能输出不同的位流。位流长度决定了二维码的版本,进而决定了二维码每条边上的模块数量。减小二维码的版本能够在不减小模块大小的前提下节省面积,或者在不改变面积的前提下增大模块大小。为了减小二维码面积、提高二维码识读率,本文提出了位流长度最小化算法。方法 首先,根据二维码位流可以分段切换编码模式的特点,归纳了6种编码状态;然后,根据二维码位流编码标准推导了状态转移关系,从而将位流长度最小化问题转换成动态规划问题;最后,通过求解动态规划问题,计算出最短位流。针对统一资源定位符(uniform resource locator,URL)类型数据,利用其部分字段对大小写不敏感、部分字段可以转义的性质,提出了统一资源定位符的最短位流计算算法,进一步缩短位流。结果 本文构建了一个测试集,包含603个编码了非URL数据的二维码,以及1 679个编码了URL数据的二维码。实验结果表明,本文算法与二维码标准相比,对于非URL测试集,位流长度减小的二维码占比9.1%,版本减小的二维码占比1.2%;对于URL测试集,位流长度减小的二维码占比98.4%,版本减小的二维码占比31.7%。结论 二维码位流长度最小化算法输出的位流长度最短,输出的二维码版本最小,能在兼容标准二维码解码器且不影响纠错能力的前提下提升二维码的数据容量。同时,本文算法运行速度快,易于使用,没有需要调节的参数。     

地基承载力的来龙去脉

本文阐述了地基承载力表的历史沿革 ,讨论了承载力表的问题 ,提出了今后工作的建议。     

Excavation cycle times recorded during sinking of a deep shaft in crystalline rock – A case example at Ventilation Shaft of Mizunami URL,Japan

Realistic and properly planned excavation cycle times developed prior to tunnel construction are an important issue for dependable project management, including cost estimation and time saving. Existing design studies, conducted to estimate the total cost for geological disposal, have been limited to estimates of approximate construction total time schedules. There were no case studies which compared the detailed excavation cycle time used in design studies with the actual results from an excavation taking into account each excavation cycle operation and task. In this paper, analyses of actual cycle time recorded during the sinking of the Ventilation Shaft of the Mizunami Underground Research Laboratory and comparison with the planned cycle time developed in the design stage are intended for an evaluation of the baseline work plan and schedule and for optimization of the calculations for application to shaft construction in any future repository in Japan. Actual times to perform three operations, drill and blast, muck removal and concrete lining emplacement were much larger than expected and represent the largest portion of the total excavation cycle time and had the largest impact on the efficiency of the excavation cycles and schedules. Operating at increasingly greater depths and excavating harder, more competent rock combined to significantly affect the shaft sinking speed. The underlying reasons for increases in actual times for the excavation cycle operations compared to their design estimates fall into three categories: constraints on construction; to ensure safety; and maintenance.     

日本公众参与社区规划研究之一:社区培育的概念、年表与启示

社区培育是日本公众参与社区规划的主要形式,这个词及其所代表的行动经过40多年的探索,已经深入人心.它是一种自下而上的、首先起源于居民为改善本地环境的活动,逐步得到专业人员、非政府组织、政府机构等的认同与合作.该系列研究拟从其起源、演变、模式等方面,对其发展过程及意义进行详细的梳理与分析.提出其对我国公众参与社区规划的启...     

高效的基于段模式的恶意URL检测方法

提出一种高效的基于段模式的检测恶意URL的方法,该方法首先解析已标注的恶意URL中的域名、路径名和文件名3个语义段,然后通过建立以三元组为词项的倒排索引快速计算恶意URL每个语义段的模式,最后基于倒排索引查找到的段模式来判定给定的URL是否是恶意URL。不仅如此,该方法还支持基于Jaccard的随机域名识别技术来判定包含随机域名的恶意URL。实验结果表明,与当前先进的基准方法相比,该方法具有较好的性能和可扩展性。     

Adjoint Monte Carlo neutron transport using cross-section probability table representation

The probability table representation of cross-sections is generally used to deal with neutron interactions in the unresolved energy range. In the frame of neutron transport methods, the capability of the probability table representation of cross-sections on the whole neutron energy range has been mentioned by Cullen (1974) and it has been already demonstrated for the Monte Carlo transport calculations by Zheng et al. (1998). Such an advantage is also illustrated here with a simple neutron propagation configuration dealt with the TRIPOLI-4 Monte Carlo transport code.     

Introducing functional classification theory to land use planning by means of decision tables

This paper contributes to the conceptualisation and analysis of double-sided matching problems, taking the land use planning problem as an example. It does so by introducing functional classification theory at the knowledge level, the symbol level and the system level of a DSS. This theory explicitly expresses the methodological viewpoint of relational realism. At the knowledge level this implies defining knowledge on the basis of matching the intension and extension of concepts. At the symbol level it deals with knowledge representation and here decision tables are advanced and formally introduced. At the system level the formalism used at the symbol level is implemented to develop a relational matching DSS.     

基于JPEG双量化特性的彩色伪造图像盲检测

现有的盲检测方法主要针对灰度图像和未压缩图像,很多算法都不能有效地检测彩色压缩伪造图像。本文提出了一种利用JPEG双量化失真特性实现彩色压缩伪造图像盲检测的方法。通过分析伪造图像的制作过程,可知由多幅JPEG图像拼接成的高质量彩色伪造图像中篡改区域和背景区域经历的双量化过程不同。根据这一特性,本文首先使用背景区域的初始量化表估计值对待检测图像进行再压缩处理,定义再压缩后图像各颜色分量的失真函数;然后根据各失真函数在图像不同区域的取值,由各颜色分量分别确定篡改区域;最后综合彩色图像各颜色分量的检测结果,最终识别出彩色图像篡改区域的位置和大小。仿真结果表明该方法不但可以有效地识别彩色伪造图像的篡改区域,而且比基于单一颜色分量的检测方法更加准确。