海洋调查船业务化运行保障关键技术进展

海洋科学的发展和海洋战略重要性的日益凸显对海洋调查船的业务化运行提出了新的要求。从国内外海洋调查船运行和关键技术两方面的发展现状和趋势出发,提出了我国"十三五"期间海洋调查船业务化运行保障关键技术的发展建议。为解决海洋调查船需求不断增大与船舶建造运行成本限制的矛盾,世界各主要海洋国家均采取措施提高调查船的使用效率,组建海洋调查船队,实行船时统一调配。另一方面,多学科多任务的海洋调查方式的发展,以及新型调查观测设备的应用,促使调查船运行保障关键技术趋向于普适性和更强的现场支持功能。据此,在我国海洋调查船业务化运行发展原则、关键技术发展方向等方面提出了建议。     

支撑刚度对水平板波浪冲击压力影响

上部结构位于浪溅区及由弹性桩腿支撑的海洋结构物,如海上栈桥和海洋平台等,在恶劣海况下会受到强烈的波浪冲击作用并产生振动响应。通过物理模型实验研究了波浪对三种不同支撑刚度的结构物冲击作用。分析了不同支撑刚度结构物底面冲击压力和冲击力的变化特性。讨论了支撑刚度对结构波浪冲击力的影响,给出了冲击压力和冲击力随相对净空(s/H)和相对板长(B/L)的变化规律。实验分析结果表明:水平板底面波浪冲击压力与冲击力均随弹性支撑刚度K的增大而增大;随相对净空(s/H)的增大先增大后减小;随相对板长(B/L)的增大而减小。     

Carbon Reduction Policies: A Regional Comparison of Their Contributions to CO2 Abatement in Six Carbon Trading Pilot Schemes in China

The contributions of carbon reduction policies were evaluated and compared for six carbon trading pilot schemes in China, in four municipalities(Beijing, Shanghai, Tianjin, and Chongqing) and two provinces(Guangdong and Hubei). The carbon emissions accounting method of the Intergovernmental Panel on Climate Change was used to calculate the actual CO2 and the support vector machine model was used to predict CO2. Chinese carbon reduction policies abated CO2 in the six carbon trading pilot schemes after the comprehensive policies came into force. However, the contribution of policies to CO2 abatement varied among regions, and the effect of carbon reduction policy on municipality pilot schemes was greater than on provincial pilot schemes. The largest contribution of carbon reduction policy to CO2 abatement was 28.3%, for the pilot carbon trading scheme in Beijing, and the smallest contribution was 3.7%, for that in Hubei. It is crucial to consider “carbon leakage” and a carbon trading linking program in order to evaluate the effects of carbon reduction policies.     

A recurrent support vector regression model in rainfall forecasting

To minimize potential loss of life and property caused by rainfall during typhoon seasons, precise rainfall forecasts have been one of the key subjects in hydrological research. However, rainfall forecast is made difficult by some very complicated and unforeseen physical factors associated with rainfall. Recently, support vector regression (SVR) models and recurrent SVR (RSVR) models have been successfully employed to solve time‐series problems in some fields. Nevertheless, the use of RSVR models in rainfall forecasting has not been investigated widely. This study attempts to improve the forecasting accuracy of rainfall by taking advantage of the unique strength of the SVR model, genetic algorithms, and the recurrent network architecture. The performance of genetic algorithms with different mutation rates and crossover rates in SVR parameter selection is examined. Simulation results identify the RSVR with genetic algorithms model as being an effective means of forecasting rainfall amount. Copyright © 2006 John Wiley & Sons, Ltd.     

2006年度天文学科科学基金面上项目

介绍了2006年度天文学科科学基金申请、资助的基本情况并对其结果进行了分析。     

Using GIS and a digital elevation model to assess the effectiveness of variable grade flow diversion terraces in reducing soil erosion in northwestern New Brunswick,Canada

Flow diversion terraces (FDT) are commonly used beneficial management practice (BMP) for soil conservation on sloped terrain susceptible to water erosion. A simple GIS‐based soil erosion model was designed to assess the effectiveness of the FDT system under different climatic, topographic, and soil conditions at a sub‐basin level. The model was used to estimate the soil conservation support practice factor (P‐factor), which inherently considered two major outcomes with its implementation, namely (1) reduced slope length, and (2) sediment deposition in terraced channels. A benchmark site, the agriculture‐dominated watershed in northwestern New Brunswick (NB), was selected to test the performance of the model and estimated P‐factors. The estimated P‐factors ranged from 0·38–1·0 for soil conservation planning objectives and ranged from 0·001 to 0·45 in sediment yield calculations for water‐quality assessment. The model estimated that the average annual sediment yield was 773 kg ha^?1 yr ^?1 compared with a measured value of 641 kg ha^?1 yr^?1. The P‐factors estimated in this study were comparable with predicted values obtained with the revised universal soil loss equation (RUSLE2). The P‐factors from this study have the potential to be directly used as input in hydrological models, such as the soil and water assessment tool (SWAT), or in soil conservation planning where only conventional digital elevation models (DEMs) are available. Copyright © 2009 John Wiley & Sons, Ltd.     

A new measure for assessing the efficiency of hydrological data-driven forecasting models

Abstract

There is a lack of consistency and generality in assessing the performance of hydrological data-driven forecasting models, and this paper presents a new measure for evaluating that performance. Despite the fact that the objectives of hydrological data-driven forecasting models differ from those of the conventional hydrological simulation models, criteria designed to evaluate the latter models have been used until now to assess the performance of the former. Thus, the objectives of this paper are, firstly, to examine the limitations in applying conventional methods for evaluating the data-driven forecasting model performance, and, secondly, to present new performance evaluation methods that can be used to evaluate hydrological data-driven forecasting models with consistency and objectivity. The relative correlation coefficient (RCC) is used to estimate the forecasting efficiency relative to the naïve model (unchanged situation) in data-driven forecasting. A case study with 12 artificial data sets was performed to assess the evaluation measures of Persistence Index (PI), Nash-Sutcliffe coefficient of efficiency (NSC) and RCC. In particular, for six of the data sets with strong persistence and autocorrelation coefficients of 0.966–0.713 at correlation coefficients of 0.977–0.989, the PIs varied markedly from 0.368 to 0.930 and the NSCs were almost constant in the range 0.943–0.972, irrespective of the autocorrelation coefficients and correlation coefficients. However, the RCCs represented an increase of forecasting efficiency from 2.1% to 37.8% according to the persistence. The study results show that RCC is more useful than conventional evaluation methods as the latter do not provide a metric rating of model improvement relative to naïve models in data-driven forecasting.

Editor D. Koutsoyiannis, Associate editor D. Yang

Citation Hwang, S.H., Ham, D.H., and Kim, J.H., 2012. A new measure for assessing the efficiency of hydrological data-driven forecasting models. Hydrological Sciences Journal, 57 (7), 1257–1274.     

橡胶隔震支座力学性能试验研究

在自行研制的压剪试验装置上进行了橡胶隔震支座水平刚度和竖向刚度等力学性能的检测试验研究,试验结果为建筑结构基础隔震设计和橡胶支座设计改进提供了依据。试验检测的产品已用于多个建筑工程。     

数据仓库及其在城市规划决策支持系统中的应用探讨

在分析传统决策支持系统在城市规划决策应用中存在的问题的基础上 ,初步提出一种基于数据仓库的城市规划决策支持系统的基本框架 ,探讨了该系统建立中数据仓库的数据组织、数据挖掘、知识发现方法等关键技术问题 ,并进一步阐述城市规划决策支持系统的建立方法 ,最后以荆州市环境规划为例 ,说明数据仓库在城市规划决策支持系统中的具体应用。     

重力式幕墙加预应力锚杆及钻孔小桩组合基坑支护体系

采用重力式幕墙加预应力锚杆及钻孔小桩组合基坑支护体系 ,方法简单 ,既节省投资 ,又可保证工期 ,且止水效果相当好。