The South East Regional Marine Plan: Implementing Australia's Oceans Policy     

Joanna Vince 《Marine Policy》2006

In 1998, the Australian Government released Australia's Oceans Policy (AOP), a world first policy initiative focused on providing a framework for integrated ecosystem-based management of Australia's vast marine domain. The South East Regional Marine Plan, the first regional marine plan to be implemented under AOP, was released on 21 May 2004. This paper argues that although full integration across sectors and jurisdictions has not occurred, new AOP initiatives, institutions and governance processes have considerably increased sectoral and jurisdictional coordination in the South East region.  相似文献   

High parallelization efficiency in barotropic-mode computation of ocean models based on multi-grid boundary ghost area   总被引：1，自引：0，他引：1  

Hiroshi Ishizaki  Ichiro Ishikawa 《Ocean Modelling》2006,13(3-4):238-254

In general, barotropic-mode computation requires the largest communication time in ocean models because of its iterative nature, when parallel computation is performed based on regional partitioning. In this study, reduction in the overhead time included in the communication in the parallel computation of the barotropic mode is considered to achieve a high parallelization efficiency of ocean models. We verify that the reduction in the communication frequency based on the multi-grid boundary ghost area reduces the total communication time. We find that this is because the sum of several kinds of overhead time for communication occupies a fairly large part of the total communication time. We discuss the trade-off between the decrease in communication time and the increase in computation time due to increased boundary area in such cases, leading to a determination of a suitable width of the multi-grid boundary that minimizes the total required time. We also discuss the efficiencies of the one- and two-dimensional partitioning of the model domain, when a multi-grid boundary is used. In general, two-dimensional partitioning is more efficient than one-dimensional for large partitioning numbers.  相似文献   

Efficient GOCE satellite gravity field recovery based on least-squares using QR decomposition   总被引：3，自引：0，他引：3  

Oliver Baur  Gerrit Austen  Jürgen Kusche 《Journal of Geodesy》2008,82(4-5):207-221

We develop and apply an efficient strategy for Earth gravity field recovery from satellite gravity gradiometry data. Our approach is based upon the Paige-Saunders iterative least-squares method using QR decomposition (LSQR). We modify the original algorithm for space-geodetic applications: firstly, we investigate how convergence can be accelerated by means of both subspace and block-diagonal preconditioning. The efficiency of the latter dominates if the design matrix exhibits block-dominant structure. Secondly, we address Tikhonov-Phillips regularization in general. Thirdly, we demonstrate an effective implementation of the algorithm in a high-performance computing environment. In this context, an important issue is to avoid the twofold computation of the design matrix in each iteration. The computational platform is a 64-processor shared-memory supercomputer. The runtime results prove the successful parallelization of the LSQR solver. The numerical examples are chosen in view of the forthcoming satellite mission GOCE (Gravity field and steady-state Ocean Circulation Explorer). The closed-loop scenario covers 1 month of simulated data with 5 s sampling. We focus exclusively on the analysis of radial components of satellite accelerations and gravity gradients. Our extensions to the basic algorithm enable the method to be competitive with well-established inversion strategies in satellite geodesy, such as conjugate gradient methods or the brute-force approach. In its current development stage, the LSQR method appears ready to deal with real-data applications.  相似文献   

应用改进并行遗传算法反求水文地质参数研究   总被引：1，自引：0，他引：1  

孔祥龙  朱国荣  江思珉 《高校地质学报》2008,14(1):126-132

利用单纯形法局部搜索速度快和遗传算法全局寻优的特点,同时为了克服两种方法各自的弊病,提出采用混合单纯形技术的并行遗传算法(Hybrid Simplex Parallel Genetic Algorithm,SPGA)进行水文地质逆问题的求解。详细阐述了SPGA算法的具体操作和实现,并将该方法应用于水源地的地下水模拟反演中。计算结果表明,SPGA算法在水文地质参数寻优计算中具有比较好的可靠性和计算效率。  相似文献   

建筑物沉降监测专家分析系统设计与开发     

董春来  吴雪燕  蒋廷臣 《测绘与空间地理信息》2008,31(6)

建筑物沉降监测数据分析与处理是一项较复杂的系统工程,本文从自动化处理观点出发,介绍了设计沉降监测专家分析系统的咨询新理念和主体思想,探讨了开发选用的数学模型与开发过程,以期为相关变形监测与分析提供帮助和启示.  相似文献   

Electrical aerosol spectrometer of Tartu University     

H. Tammet  A. Mirme  E. Tamm   《Atmospheric Research》2002,62(3-4)

The electrical aerosol spectrometer (EAS) of the parallel measuring principle at Tartu University is an efficient instrument for rapid measurement of the unstable size spectrum of aerosol particles. The measuring range from 10 nm to 10 μm is achieved by simultaneously using a pair of differential mobility analyzers with two different particle chargers. The particle spectrum is calculated and measurement errors are estimated in real time by using a least-squares method. Experimental calibration ensures reliability of measurement. The instrument is well suited for continuous monitoring of atmospheric aerosol.  相似文献   

Agents of Eviction: The Squatter Control and Clearance Division of Hong Kong's Housing Department     

Alan Smart 《Singapore journal of tropical geography》2002,23(3):333-347

More is known about the policies that produce forced evictions and their consequences than about the agencies whose responsibility it is to conduct them. Understanding the nature of forced evictions requires greater comprehension of responsible agencies since the ways in which they implement policies may be a crucial intervening variable influencing the outcomes. In this paper, I use documentary and ethnographic research to describe the Squatter Control and Clearance Division of the Hong Kong Housing Department. Responsible both for evicting squatters and for controlling squatter areas that are permitted to remain for the time being, officers must respond to the conflicts and challenges of their twin, partially conflicting, mandates. Examination of changes in squatter control and clearance practices since 1954 is followed by a brief case study of the most recent squatter clearance that occurred in July 2001.  相似文献   

一种在异构系统中实现负载平衡的方法   总被引：2，自引：3，他引：2       下载免费PDF全文

金之雁  王鼎兴 《应用气象学报》2003,14(4):410-418

提出了在异构系统实现负载平衡的区域分解算法和实现负载平衡的计算方法，利用它的负反馈性质解决了异构系统处理机计算速度测量误差造成的负载测量不准问题，并对处理机速度变化，速度测量误差、处理机数量、网格点计算量的分布等因素的影响进行了计算，结果表明本方法具有很强的平衡负载能力和较强的适应性；根据计算结果提出了解决模式网格点计算量不易测量问题的解决方案，并用扩散方程和模拟物理过程进行试验，试验表明这种方法是可行的，平衡负载的效果十分显著。  相似文献   

一种符合视觉规律的,基于地图数据的虚拟地景仿真   总被引：5，自引：1，他引：5  

陈刚 《测绘学报》1997,26(3):241-246

本文分析和解决了两个关键性问题，使计算机所生成的虚拟地景符合人的“越近看得越清”视觉规律，并通过实例对该方法的实现过程给予了详细的描述。  相似文献   

Fast space-domain evaluation of geodetic surface integrals     

R. Lehmann 《Journal of Geodesy》1997,71(9):533-540

Geodetic surface integrals play an important role in the numerical solution of geodetic boundary-value problems. In many cases they can be evaluated using fast methods in the frequency domain (FFT). However, this is not possible in general, because the domain of integration may be non-trivial (as is the surface of the Earth), the kernel function may not be of convolution type, or the data distribution may be heterogeneous. Therefore, fast evaluation strategies are also required in the space domain. They are more difficult to design because only one property is left where a more or less fast evaluation strategy can be built upon: the potential type of the kernel function. Consequently, the idea is not to replace well-established frequency domain techniques, but to supplement them. Our approach to this problem goes in two directions: (1) we use advanced cubature methods where the integration nodes automatically densify in the vicinity of the evaluation points; (2) we use powerful computer hardware, namely MIMD computers with distributed memory. This enables us to evaluate geodetic surface integrals of any practical complexity in reasonable time and accuracy. This is shown in a numerical example. Received: 7 May 1996 / Accepted:17 March 1997  相似文献