高校数字图书馆混合型存储系统的设计

存储系统作为数字图书馆的支撑平台,是数字图书馆建设的一个基础和重要组成部分.文章叙述了数字化图书馆中存储的特点,介绍了新型存储技术的分类和各自的特性,结合高校图书馆建设实例,提出高校数字图书馆存储系统的解决方案.     

数字时代的图书馆——从传统到现代的转变

介绍了传统图书馆服务模式的特点,阐述了网络环境下数字图书馆服务模式的转变,提出了网络环境下搞好图书馆服务工作的对策。     

土地利用结构熵变化分析

选取上海市嘉定区1984--2002年的土地利用分类统计数据，应用信息熵概念计算该区域土地利用结构熵．根据熵值变化量对区域土地利用结构变化进行阶段划分，分析该地区的土地利用结构演变规律及变化形成动因．结果表明，嘉定区工业经济快速发展和产业结构的调整是促使土地利用变化的主要推动力量，持续快速的工业化、城市化进程对建设用地的需求会不断加大，土地利用结构将进一步调整，若不实施严格管理、科学规划和合理调控，该地区土地利用结构熵将继续增长．     

数字地形和景观数据的可视化

数字地形是指将地球表面的形态以数字的形式进行表达，它通过对地面坐标和高程的数字描述来实现。景观数据的可视化在这里主要指地球表面的一些自然要素，如植被、气候、水等要素在计算机环境下的2维和3维描述。     

Problems in wavelet analysis of hydrologic series and some suggestions on improvement

Applying the wavelet theory and methods to investigate the hydrologic processes such as precipitation and runoff is a hot field. However, several aspects in research are usually ignored: the effect of admissible condition of wavelet functions and the disturbance of noises for the detection of periods, the effect of the length of a hydrologic time-series on the final result, and the choice between the anomaly and the original time series for wavelet analysis. In this paper, these issues are fully discussed. Precipitation data from Lanzhou Precipitation Station are taken for case study. The result indicates that in the wavelet analysis of hydrologic series, denoise methods should be used to eliminate the influence of noises. The MexHat wavelet function satisfies the admissible condition, which ensures that the periodic properties of hydrologic processes can be well represented by using the MexHat wavelet for decomposition. The affected range of hydro-logic series which should be discarded before analysis is given. It is also suggested that the anomaly series should be used to highlight the actual undulation of the hydrologic series.     

Exchange-coupling interaction, effective anisotropy and magnetic property of nano-magnetic materials

The theories and models of exchange-coupling interaction between grains in nanocrystalline magnetic materials are introduced here. Their insufficiencies and distinctions from the experimental results are pointed out, and some revisions are made. The effects of the phase component ratio, the grain size and microstructure on the effective anisotropy and magnetic properties in the nanocomposite permanent materials and the improved models are discussed in detail.     

Metallogenic epoch and genesis of the gold deposits in Jiaodong Peninsula, Eastern China: a regional review

Gold deposits are characterized by multi-sources, superimposition, large scale and temporal-spatial concentration in Jiaodong Peninsula, Eastern China. In this paper, we review the history and the development of the study on metallogenic chronology and genesis of gold deposits, summarize the main features of superimposed metallogenesis, provide evidence of the Mesozoic complex metallogenic system, and point out some problems for further research of Jiaodong gold deposit cluster from a regional view. Although gold deposits are different in genetic types, ore-forming materials and geological settings, our research indicates that the accumulation and emplacement of the ore-forming materials are temporally-spatially concentrated on a large scale, and the main metallogenic epoch of Jiaodong gold deposits was concentrated in Mesozoic. Metallogenic chronology and geological-geochemical data indicate that there are two periods of gold mineralizations occurred in 130-110 Ma and 90-80 Ma respectively in Jiaodong ore cluster. The gold deposit cluster results from the superimposition of the polygenetic mineralization, and further study is needed to investigate the formation and evolution of the Mesozoic complex metallogenic system.     

Stability analysis of BAM neural networks with time-varying delays

Some new criteria for the global asymptotic stability of the equilibrium point for the bi-directional associative memory neural networks with time varying delays are presented. The obtained results present the structure of linear matrix inequality which can be solved efficiently. The comparison with some previously reported results in the literature demonstrates that the results in this paper provide one more set of criteria for determining the stability of the bi-directional associative memory neural networks with delays.     

P systems based multi-objective optimization algorithm

Based on P systems, this paper proposes a new multi-objective optimization algorithm (PMOA). Similar to P systems, PMOA has a cell-like structure. The structure is dynamic and its membranes merge and divide at different stages. The key rule of a membrane is the communication rule which is derived from P systems. Mutation rules are important for the algorithm, which has different ranges of mutation in different membranes. The cooperation of the two rules contributes to the diversity of the population, the conquest of the muhimodality of objective function and the convergence of algorithm. Moreover, the unique structure divides the whole population into several sub populations, which decreases the computational complexity. Almost a dozen popular algorithms are compared using several test problems. Simulation results illustrate that the PMOA has the best performance. Its solutions are closer to the true Pareto-optimal front