线性-动态规划改进模型及其应用

Becker和Yeh于1974年提出的线性(LP-DP)模型是一种功能很强的优化模型。然而该模型是针对梯级发电库群实时调度提出的,对并联系统并不适用。且该模型在理论上还不够严密,需进一步完善。本文所提出的LP-DP改进模型不但在理论上比较完整,而且扩展了应用范围,提高了优化效益。该模型现已成功地应用于江西省水火电力系统实时优化调度之中。     

水泥土搅拌桩复合地基的优化设计

运用双层地基模型的线弹性有限元程序对不同类型水泥土搅拌桩复合地基的沉降进行计算,分析了水泥土搅拌桩的桩长、置换率、桩身刚度对地基沉降的影响,同此确定了搅拌桩的有效桩长、最优置换率、最优桩身刚度。     

一种由微机控制的波浪数据采集系统

该波浪数据采集系统应用重力测波仪作传感器,由IBM—PC/XT微型计算机控制,将模拟信号经过A/D转换器进行波浪数据采集。采集到的数据按设计格式存入软盘,以便用处理程序进行统计和谱分析。本系统的数据采集程序在1987年9—11月西太平洋热带海域考察中得到应用,取得了较好的效果。     

Control and Recovery of Environment after the Construction

The Taiwan Strait Tunnel Project will bring very deep, far, and long lasting influence on the environment inevitably. This article focuses on what shall be done considering environmental issues after the construction. Herein an environmental protection program with a four-step procedure is particularly illustrated, including setting environmental objectives, formulation of environment protection program, plan of environmental survey, and management of environmental event. This procedure based on the outcome of environmental impact assessment formulates an environment protection program to control and recover environmental problems after the project completed. Two case studies will illustrate the special design and considerations adopted that make the project coexist with the environment successfully, peacefully, and friendly.     

一种增设于Waverider测波仪的数据自记系统

本文介绍一种用MCS-51单片微机作为控制器,用大容量静态RAM作为存储器,以纯电子线路组成硬件线路,配合相应的控制软件,联合构成稳定可靠、低功耗的自记式波浪数据采集系统。该系统增设在Waverider浮标(67780系列)中,使之成为自记与遥测并存的双制式测波浮标,海上实地投放使用已获得成功.     

Predicting the capability-polar-plots for dynamic positioning systems for offshore platforms using artificial neural networks

As the capability of polar plots becomes better understood, improved dynamic positioning (DP) systems are possible as the control algorithms greatly depend on the accuracy of the aerodynamic and hydrodynamic models. The measurements and estimation of the environmental disturbances have an important role in the optimal design and selection of a DP system for offshore platforms. The main objective of this work is to present a new method of predicting the Capability-Polar-Plots for offshore platforms using the combination of the artificial neural networks (NNs) and the capability polar plots program (CPPP). The estimated results from a case study for a scientific drilling vessel are presented. A trained artificial NN is designed in this work and is able to predict the maximum wind speed at which the DP thrusters are able to maintain the offshore platform in a station-keeping mode in the field site. This prediction for the maximum wind speed will be a helpful tool for DP operators in managing station-keeping for offshore platforms in an emergency situation where the automation of the DP systems is disabled. It is obvious from the obtained results that the developed technique has potential for the estimation of the capability-polar-plots for offshore platforms. This tool would be suitable for DP operators to predict the maximum wind speed and direction in a very short period of time.     

某测区GPS水准拟合算法的研究及程序实现

首先介绍了GPS水准高程的拟合原理及方法,并对其一次曲面拟合、不完全二次曲面拟合以及二次曲面拟合高程模型进行详细的介绍;然后用最小二乘原理进行参数估计,将其3种模型用自己编写的C语言程序进行精度评定及可靠性的验证;最后选取了工程中的测量数据进行精度评定和模型之间的对比,并将两种方案进行分析进而得出结论。     

Contribution of REDD+ payments to the economy of rural households in Nepal

Reducing Emissions from Deforestation and forest Degradation (REDD+) is a global climate change mitigation strategy. Under the proposed REDD+ framework, financial incentives are provided, primarily to developing countries, for forest conservation to reduce carbon emissions. Projects labelled as REDD are being implemented in a wide variety of settings in different countries. Developing an effective benefit-distribution mechanism between implementing agencies and local communities is a key challenge for the implementation of REDD+. We examined whether the REDD+ payment mechanism adopted in a REDD+ pilot project in Nepal is beneficial to the local forest users. We estimated economic contribution of the REDD+ payments to the total household income, calculated the role of payment in reducing income inequality at the household level and examined socio-economic heterogeneity represented by wealth and ethnicity among the payment recipient households. REDD+ payment provided economic benefits to the poorest households but the economic contribution of the payment to the household economy is very nominal and is insufficient to invest in livelihood enhancement activities. REDD+ payment to some extent helps to reduce income inequality among the households. Social heterogeneity of a household overshadowed household wealth status during the payment distribution among the sampled households creating social tension. Therefore, either alternative payment models or investment in community projects might yield better outcomes.     

Mean and Temporal Variability in Kuroshio Geostrophic Transport South of Taiwan (1993–2001)

Observations of the Kuroshio south of Taiwan have been carried out on a quarterly basis since late 1992 as part of the basin-wide High Resolution expendable bathythermograph/expendable conductivity-temperature-depth (XBT/XCTD) network. Mean geostrophic transport in the Kuroshio, 0–800 m, from 34 cruises is 22.0 Sv ± 1.5, consistent with previous results from moorings and geostrophic calculations in the upstream Kuroshio region. The mean core of the current has speed about 90 cm s⁻¹ and is located close to Taiwan. At this location the Kuroshio appears to be confined mainly to the upper 700 m, and there is no evident tight recirculation of the current. Eddy variability is substantial, and large eddies can be seen propagating westward for thousands of kilometers in TOPEX/Poseidon altimetric data, impinging on the current and altering its structure and transport. The annual range in transport is about 8 Sv ± 6, with maximum in summer. Interannual variability is about 12 Sv ± 6, with transport maxima in 1995 and 2000 and a minimum in 1997–1998. Interannual variability in the upstream Kuroshio may be uncorrelated with that in the downstream region south of Japan, where the transport is much greater. Our quarterly sampling aliases high frequency variability of the current, and an improved boundary-current observation program would include more frequent transects and occasional deeper measurements. This revised version was published online in August 2006 with corrections to the Cover Date.     

The stream hydrology response of converting a headwater pasture catchment to Pinus radiata plantation

ABSTRACT

The planting of degraded land with tree plantations may be effective at improving land use sustainability and profitability but it can also have significant effects on stream hydrology. In this paired catchment study, we report the stream hydrological response to partial (62%) afforestation of a steep pastoral catchment in the western Waikato Region, North Island, New Zealand. We comprehensively analyse the hydrological regime changes over a 23-year period (including eight years before pine planting) with reference to a native-forested ‘control’ catchment. Our results show that afforestation has markedly affected stream hydrology. Seven years after planting, the total annual runoff was 380?mm lower than predicted for the catchment in pasture. Two phases of plantation thinning resulted in the difference between measured and predicted runoff reducing to only 129?mm. Peak flows reduced by ～50% while total stormflow reduced by ～30% – which we attribute to canopy interception attenuating and delaying water yield. The impact of plantation establishment on low flows is not so clear, although afforestation appears to have reduced low flows by ～25%. This study provides information on the hydrological impact of afforestation within a hitherto poorly-represented New Zealand environment (i.e. high rainfall, sedimentary lithology-based, North Island hill country).