Adaptive neuro-fuzzy inference system for prediction of water level in reservoir

Accurate prediction of the water level in a reservoir is crucial to optimizing the management of water resources. A neuro-fuzzy hybrid approach was used to construct a water level forecasting system during flood periods. In particular, we used the adaptive network-based fuzzy inference system (ANFIS) to build a prediction model for reservoir management. To illustrate the applicability and capability of the ANFIS, the Shihmen reservoir, Taiwan, was used as a case study. A large number (132) of typhoon and heavy rainfall events with 8640 hourly data sets collected in past 31 years were used. To investigate whether this neuro-fuzzy model can be cleverer (accurate) if human knowledge, i.e. current reservoir operation outflow, is provided, we developed two ANFIS models: one with human decision as input, another without. The results demonstrate that the ANFIS can be applied successfully and provide high accuracy and reliability for reservoir water level forecasting in the next three hours. Furthermore, the model with human decision as input variable has consistently superior performance with regard to all used indexes than the model without this input.     

Two-stage decision-making under uncertainty and stochasticity: Bayesian Programming

This paper develops a new method for decision-making under uncertainty. The method, Bayesian Programming (BP), addresses a class of two-stage decision problems with features that are common in environmental and water resources. BP is applicable to two-stage combinatorial problems characterized by uncertainty in unobservable parameters, only some of which is resolved upon observation of the outcome of the first-stage decision. The framework also naturally accommodates stochastic behavior, which has the effect of impeding uncertainty resolution. With the incorporation of systematic methods for decision search and Monte Carlo methods for Bayesian analysis, BP addresses limitations of other decision-analytic approaches for this class of problems, including conventional decision tree analysis and stochastic programming. The methodology is demonstrated with an illustrative problem of water quality pollution control. Its effectiveness for this problem is compared to alternative approaches, including a single-stage model in which expected costs are minimized and a deterministic model in which uncertain parameters are replaced by their mean values. A new term, the expected value of including uncertainty resolution, or EVIUR, is introduced and evaluated for the illustrative problem. It is a measure of the worth of incorporating the experimental value of decisions into an optimal decision-making framework. For the illustrative problem, the two-stage adaptive management framework extracted up to approximately 50% of the gains of perfect information. The strength and limitations of the method are discussed and conclusions are presented.     

渐消滤波原理及其理论分析

动态导航与定位的质量取决于对动态载体扰动和观测异常扰动的认知和控制。本文首先分析了渐消滤波的理论背景和基本原则；基于其基本原则，推导了渐消滤波解；然后从理论模型、极值原则全面分析了渐消滤波理论存在的问题。分析认为，理论上，渐消滤波具有控制状态模型误差影响的能力；现有渐消因子的求解在实践中可能出现负定现象，求解时必须附加条件。     

基于VRS系统建立城市三维大地测量基准

介绍了以VRS技术为基础的苏州GPS连续参考站系统的建设,并结合(似)大地水准面精化的成果与EGM96,建成了高精度、动态的三维基准,实现了苏州地区的坐标基准的统一。     

Views from the vulnerable: Understanding climatic and other stressors in the Sahel

In much of sub-Saharan Africa, considerable research exists on the impacts of climate change on social-ecological systems. Recent adaptation studies emphasize sectoral vulnerability and largely physical adaptation strategies that mirror anti-desertification plans. The adaptive role of subsistence farmers, the vulnerable ‘target’ population, is largely overlooked. This article aims to fill this gap by putting the views from the vulnerable in the center of the analysis. Drawing from participatory risk ranking and scoring among smallholders in central Senegal, data on multiple hazards indicate that farmers’ adaptive capacity to climate change is undermined by poor health, rural unemployment, and inadequate village infrastructure. Results from conceptual mapping reveal incomplete understanding of causes and consequences of climate change. Yet, shared knowledge and lessons learned from previous climatic stresses provide vital entry points for social learning and enhanced adaptive capacity to both wetter and drier periods now and in the future.     

Near-infrared study of Titan's resolved disk in spectro-imaging with CFHT/OASIS

We present observations of Titan taken on November 17, 2000, with the near-infrared spectro-imaging system OASIS, mounted downstream of the CFHT/PUEO adaptive optics system. We have spatially resolved Titan's disk at Greatest Eastern Elongation. Our spectra cover the 0.86- range with a spectral resolution of 1800. By studying Titan at these wavelengths, we have recovered several pieces of information on the vertical and latitudinal structure of the atmosphere and surface of the satellite. The observing conditions were sufficiently good (AO-corrected seeing of 0.34”) so as to allow us to separate the disk into 7 independent elements. From the flux contained in the methane band, we find that at higher altitudes on Titan, the North-South asymmetry is undergoing changes with respect to previous years when the South was much brighter than the North. This asymmetry still prevails in the troposphere, but at higher levels the well-known “Titan smile”—previously reported—disappears. We believe that we even have evidence for a reversal. The year 2000 may then represent the beginning of a seasonal change in Titan's haze distribution in the near-infrared, something which has been confirmed since but was not visible in the previous years. By comparing regions on Titan's disk with similar surface and stratospheric characteristics, we find an differences in the latitudinal distribution of the aerosol content in the intermediate altitude levels. Reflectivity measurements derived in the window (and hence pertaining to the surface conditions) show that the equatorial regions of the leading side are brighter than the surrounding areas, due to the presence of the large bright zone observed since 1994. Given our spatial resolution, we find this region to be 6% brighter than northern latitudes, 7% brighter than the South pole and in total we have a contrast of 9% between the darker and the brighter areas distinguishable on our images. The methane window yields a geometric albedo of about 0.26 for the bright center of Titan's disk. This region is affected by a strong H₂O telluric absorption and therefore we could not derive any precise information on the surface composition from the original spectrum. We have, however, been able to correct for the telluric lines by using a stellar spectrum taken just before our Titan observations. We were then able to apply our radiative transfer code and after modeling surface albedo values of about 0.37 and 0.29 for the brightest and darkest areas respectively were found. We investigate possible surface components, compatible with our data, such as water ice, hydrocarbon liquid, tholin deposits or silicates.     

煤矿井水位观测资料中微弱孕震信息的提取

采用自适应技术，从陶庄煤矿区鲁１５井的水位观测资料中提取了ＭＬ＝１－２矿震前微弱的前兆信息，为矿震预报提供了有用方法。     

钨铅矿在我国的发现及其晶体结构的精细修正

湖南瑶岗仙钨铝矿发现于1948年,但一直未作正式报道。最近笔者用里特弗尔德法对其进行了晶体结构的修正。瑶岗仙钨铅矿的a=b=0.544503(3)nm;c=1.20495(1)nm;α=β=γ=90°。经笔者对瑶岗仙钨铅矿晶体结构修正得到的氧原子坐标为:X=0.2637,Y=0.1137,Z=0.0706;W-O的键长为0.17826nm,O-W-O键角为123°和103°。     

地球物理中的反问题与不适定问题

本文讨论地球物理中的某些反问题与不适定问题。其内容如下:场的延拓与偏微分方程的不适定Cauchy问题;不适定问题稳定性的性态;线性不适定问题的正则化算法。     

Refinement of thrust faulting models for the Central New Madrid seismic zone

We present the results of the joint relocation of events recorded during 1989–1992 by the PANDA network in the central New Madrid seismic zone. The near-surface material in the study area is a gently-dipping layer of poorly consolidated sediments with low P-wave velocity and high V_p/V_s (estimated values: 1.8 km s⁻¹ and 3). The sediments are underlain by high-velocity Paleozoic rocks. Under the network the difference in sediment thickness is only 0.6 km, but because of the low velocities the location of the events using layered models is affected by errors. Application of the joint hypocentral determination (JHD) technique to a subset of 580 events shows that the single-event locations may be in error by as much as 1 km in depth, depending on where the events are located. Analysis of synthetic data generated for a realistic 3-D velocity model supports the JHD results. The analysis of synthetic data also suggests that a V_p/V_s≤ 2.3 is more appropriate for the post-Paleozoic Mississippi embayment sediments. Based on the JHD locations we present a new interpretation of the seismicity, with two en-echelon SW-dipping thrust faults connected by a west-dipping thrust fault. These faults appear associated with the Reelfoot scarp and its northern extension, the Kentucky bend scarp.