大地震前体应变临震异常现象

本文对2011年1月至2014年4月间全球发生的80次MS≥7.0级地震前,二张营台和天堂河台Sacks体应变临震异常现象进行了研究,针对复杂震例提出了异常识别的前提条件。统计结果显示,体应变观测对震中距为8000km范围内的MS≥7.0级地震映震和前兆异常反映较好。同时,对异常现象进行了分类和描述,划分了三种异常类型：即固体潮畸变型、突变型和慢地震型,并对各种类型作了统计分析,进行了力学性质初步探讨。从研究结果来看,体应变异常信息对未来全球强震的发生具有一定的预示意义。     

Computing cross-isotherm volume transports from ocean temperature observations and surface heat fluxes,with application to the Barents Sea inflow

A method for determining the cross-isotherm ocean transport from surface heat flux and ocean temperature data is derived. By computing the volume flux through the isotherm that extend from 19°E, 74°N to the eastern part of the Kola Peninsula, the flow through the western entrance of the Barents Sea south of 74°N is estimated. Using three different surface heat flux datasets, the inflow is found to range from 2.9 to 4.5 Sv in winter (October–March) and from 0.4 to 1.4 Sv in summer (April–September; 1 Sv=10⁶ m³ s⁻¹). The seasonal variations are stronger than indicated by results from direct current measurements, probably because the seasonal cycle of the surface heat fluxes is overestimated along the considered isotherm. The annual mean inflow ranges from 1.9 to 2.2 Sv during a cold period (1986–1988), and from 2.4 to 3.0 Sv during a warm period (1990–1992), close to reported observations.     

Experimental evaluation of design methods for in-site detention ponds

In this study,the detention rate of detention pond was defined to include both reduction and delay of peak flow.Flood routing experiments,with various combinations of inflow hydrographs and outlet devices in an in-site detention pond,were performed to examine the effectiveness of two analysis methods,namely the simplified method and the hydrological routing method;and to compare the detention rate of two types of outlet,namely the rectangular sharp-crested weir and the rectangular orifice.Comparison between...     

神经网络理论在河道洪水预报中的应用

本文将神经网络用于松花江干流河道汇流计算和河道洪峰水位的预报.对各种转移函数的效果进行了比较,线性函数和双正切函的精度较好超过传统的马斯京根法,其中线性转移函数最好,说明对于大江大河线性转移函数最好.由上游断面洪峰水位预报下游断面洪峰水位也取得了良好的效果.     

A Voronoi neighborhood-based search heuristic for distance/capacity constrained very large vehicle routing problems

Local search heuristics for very large-scale vehicle routing problems (VRPs) have made remarkable advances in recent years. However, few local search heuristics have focused on the use of the spatial neighborhood in Voronoi diagrams to improve local searches. Based on the concept of a k-ring shaped Voronoi neighbor, we propose a Voronoi spatial neighborhood-based search heuristic and algorithm to solve very large-scale VRPs. In this algorithm, k-ring Voronoi neighbors of a customer are limited to building and updating local routings, and rearranging local routings with improper links. This algorithm was evaluated using four sets of benchmark tests for 200–8683 customers. Solutions were compared with specific examples in the literature, such as the one-depot VRP. This algorithm produced better solutions than some of the best-known benchmark VRP solutions and requires less computational time. The algorithm outperformed previous methods used to solve very large-scale, real-world distance constrained capacitated VRP.     

Validation of methods to estimate design discharge flow rates for dam spillways with large regulating capacity

Abstract

The estimation and review of discharge flow rates in hydraulic works is a fundamental problem in water management. In the case of dams with large regulating capacity, in order to estimate return periods of discharge flow rates from the spillways, it becomes necessary to consider both peak flow and volume of the incoming floods. In this paper, the results of the validation for several methods of assessing design floods for spillways of dams with a large flood control capacity are presented; the validation is performed by comparing the maximum outflows (or the maximum levels reached in the reservoir) obtained from the routing of the design floods with those obtained from the routing of the historical annual maximum floods. The basin of Malpaso Dam, Mexico, is used as the case study.

Editor D. Koutsoyiannis

Citation Domínguez, M.R. and Arganis, J.M.L., 2012. Validation of methods to estimate design discharge flow rates for dam spillways with large regulating capacity. Hydrological Sciences Journal, 57 (3), 460–478.     

BIBLIOGRAPHY—BIBLIOGRAPHIE

Abstract

The Coupled Routing and Excess STorage model (CREST, jointly developed by the University of Oklahoma and NASA SERVIR) is a distributed hydrological model developed to simulate the spatial and temporal variation of land surface, and subsurface water fluxes and storages by cell-to-cell simulation. CREST's distinguishing characteristics include: (1) distributed rainfall–runoff generation and cell-to-cell routing; (2) coupled runoff generation and routing via three feedback mechanisms; and (3) representation of sub-grid cell variability of soil moisture storage capacity and sub-grid cell routing (via linear reservoirs). The coupling between the runoff generation and routing mechanisms allows detailed and realistic treatment of hydrological variables such as soil moisture. Furthermore, the representation of soil moisture variability and routing processes at the sub-grid scale enables the CREST model to be readily scalable to multi-scale modelling research. This paper presents the model development and demonstrates its applicability for a case study in the Nzoia basin located in Lake Victoria, Africa.

Citation Wang, J., Yang, H., Li, L., Gourley, J. J., Sadiq, I. K., Yilmaz, K. K., Adler, R. F., Policelli, F. S., Habib, S., Irwn, D., Limaye, A. S., Korme, T. &; Okello, L. (2011) The coupled routing and excess storage (CREST) distributed hydrological model. Hydrol. Sci. J. 56(1), 84–98.     

Defending against wormhole attack in OLSR

OLSR (optimal link state routing) is one of the four basic routing protocols used in mobile ad hoc Networks by the MANET working group of IETF (Internet engineering task force). OLSR, a proactive routing protocol, is based on a multipoint relaying flooding technique to reduce the number of topology broadcast. OLSR uses periodic HELLO packets to neighbor detection. As introduced in Reference [1], the wormhole attack can form a serious threat in wireless Networks, especially against many ad hoc Network routing protocols and location-based wireless security systems. Here, a trust model to handle this attack in OLSR is provided and simulated in NS2.     

Formal definition of a user-adaptive and length-optimal routing graph for complex indoor environments

Car routing solutions are omnipresent and solutions for pedestrians also exist.Furthermore,public or commercial buildings are getting bigger and the complexity of their internal structure has increased.Consequently,the need for indoor routing solutions has emerged.Some prototypes are available,but they still lack semantically-enriched modelling (e.g.,access constraints,labels,etc.) and are not suitable for providing user-adaptive length-optimal routing in complex buildings.Previous approaches consider simple rooms,concave rooms,and corridors,but important characteristics such as distinct areas in huge rooms and solid obstacles inside rooms are not considered at all,although such details can increase navigation accuracy.By formally defining a weighted indoor routing graph,it is possible to create a detailed and user-adaptive model for route computation.The defined graph also contains semantic information such as room labels,door accessibility constraints,etc.Furthermore,one-way paths inside buildings are considered,as well as three-dimensional building parts,e.g.,elevators or stairways.A hierarchical structure is also possible with the presented graph model.