基于UML的图书管理系统分析与设计

图书管理系统是信息化时代有效管理图书的重要手段,根据不同的权限,读者、管理员、系统管理员可以完成各自的操作。文中借助UML技术对图书管理系统进行了面向对象分析与设计,在需求分析阶段给出了系统用例图,在类设计阶段给出了系统类图,在交互性设计阶段给出了借书时序图。     

A web application for follow-up of results from a mobile device test battery for Parkinson's disease patients

Contrast-enhanced ultrasound (CEU) is an ultrasound imaging technique used to assess tissue perfusion. Analysis of microvascular recruitment necessitates the definition of a region of interest (ROI) containing exclusively the tissues to be studied. Conventional ROI selection requires examining the images and drawing the ROI by hand, making the analysis of CEU images non-reproducible and analyst-dependent. We have designed a systematic ROI selection method that is both reproducible and analyst-independent. Microvascular blood volume (MBV) assessed in 21 sequences of images was used to correlate the systematic ROI selection method with the conventional method performed by two independent analysts (correlation of 0.88 and 0.87 respectively) and the MBV sample distribution from the systematic method was not significantly different from those obtained from the conventional one. Using the systematic method, we found no significant insulin-induced capillary recruitment in subjects with type 1 diabetes mellitus, which might be related to the observed low glucose uptake during the hyperinsulinemic euglycemic clamp compared to healthy patients.     

Evaluating your obligations for employee training according to the Food Safety Modernization Act

The signing of the Food and Drug Administration's (FDA) Food Safety Modernization Act (FSMA) into law in 2011 elevated the FDA into a significantly higher, international operational role to implement a new, prevention-oriented, systems-wide approaches to food safety for the entire spectrum of non-meat foods. After decades of failed regulatory attempts to “inspect food safety into” the nation's food supply, FSMA puts the responsibility for food safety where the liability resides, with the food producers and processors. FSMA has been called the most sweeping change in food safety in the past 70 years with the potential to significantly reduce the burden of foodborne illness while saving a potential billion dollars a year in associated health care costs. When fully implemented, FSMA legislation will depend on a risk-based food safety assessment to require food producers to control their environment and train their employees to minimize risk of food borne illness to their consumers. FDA has noted that between 1999 and 2003 more than 1/3 of all food recalls were related to ineffective employee training. There will be substantial benefits for companies who begin early to write and implement employee training programs because preventing foodborne illness is most effectively address at the local, plant level. In this new regulation the establishment of training programs for personnel and documentation of training are couched in the regulatory language of “shall” rather than the former “should”, meaning they are now required and civil and criminal penalties could be assessed if companies do not comply.     

Instream flows and the decline of riparian cottonwoods along the Yakima River,Washington, USA

Under pre‐settlement conditions the Yakima River in Washington state, USA was characterized by multiple channels, complex aquifers and extensive riparian cottonwood forests. Subsequent implementation of headwater dams to supply irrigation water has altered river and floodplain processes critical to the cottonwoods and associated riparian vegetation. In this study, we analysed hydrology and floodplain forests and especially the dominant black cottonwoods (Populus trichocarpa) along sequential reaches of the Yakima River. Elevations were surveyed and vegetation inventoried along cross‐sectional belt transects, and cottonwood tree ring interpretations investigated historic associations between river hydrology and cottonwood establishment and growth. We analysed hydrographs relative to the apparent episodes of cottonwood recruitment and applied a quantitative model for seedling colonization that required: (1) floods, disturbance flows to produce barren nursery sites, and subsequent flows for seedling (2) establishment and (3) survival. In contrast to earlier conditions, flow patterns after the 1960s have generally been unfavourable for cottonwood recruitment although some cottonwood colonization has occurred in association with physical disturbance from gravel mining. With recent flow regimes, regulated flows along upper reaches maintain the river near bank‐full throughout the growing season, thus inundating suitable seedling recruitment sites. Downstream, irrigation withdrawals reduce the river stage, resulting in seedling establishment at low elevations that are lethally scoured by subsequent high flows. These regulated flow regimes have not hindered growth of established trees, but have reduced the recruitment of cottonwoods, and particularly disfavoured females, thus altering sex ratios and producing skewed cottonwood population age and gender structures. The cottonwood decline has also been associated with other changes in riparian plant community composition, including the encroachment of invasive weeds. Based on this ecohydrologic analysis we discuss flow adjustments that could rejuvenate cottonwood forests along the Yakima River. Copyright © 2007 John Wiley & Sons, Ltd.     

The impact of small and large impoundments on freshwater mussel distribution in the Hawkesbury‐Nepean River,southeastern Australia

The influence of weirs on the distribution of freshwater mussels was investigated in the Hawkesbury‐Nepean River, Australia. Distribution of species and densities of size classes were strongly correlated with catchment level factors (e.g. location around a major impoundment, stream order). At catchment scale, weir height, presence of a fish barrier, fish ladder type and position above or below small weirs did not influence the presence/absence of mussel populations. Lower mussel densities in the upper catchment may therefore reflect inhibition of host fish migration. Where present, weir height and geomorphic reach type were linked to differences in densities among species. Geomorphic reach‐based differences were reflected by the Hyridella species, but not Velesunio ambiguus. When population structure was described by size class distribution, there were significant differences between densities of small and medium mussels from weirs above, compared to weirs below, a major impoundment, but not for large mussels. Upstream populations may therefore be functionally extinct. Distribution of mussel size classes differed among geomorphic reach types with highest densities for each class found in the least human‐impacted reaches. Small mussels were almost invariably found below the major impoundment, most frequently below weirs. Distribution patterns were inconsistent across species, suggesting habitat preference. V. ambiguus and Hyridella australis were most abundant in shale reaches, where assemblages were influenced by fish ladder type. Hyridella depressa and H. australis dominated in sandstone gorges and straights with assemblage density related to weir height. In upper catchment sandstone reaches, mussel assemblages comprising predominantly V. ambiguus were influenced by fish ladder type and weir height. While multiple factors defined localized distribution, large impoundments were linked with reduced population densities. The probable mechanism is the restriction of host fish movement and resulting lack of recruitment. In the Hawkesbury‐Nepean River, smaller weirs also seriously impacted recruitment. Copyright © 2008 John Wiley & Sons, Ltd.     

Shell-free Biomass and Population Dynamics of Dreissenids in Offshore Lake Michigan, 2001–2003

The USGS-Great Lakes Science Center has collected dreissenid mussels annually from Lake Michigan since zebra mussels (Dreissena polymorpha) became a significant portion of the bottomtrawl catch in 1999. For this study, we investigated dreissenid distribution, body mass, and recruitment at different depths in Lake Michigan during 2001–2003. The highest densities of dreissenid biomass were observed from depths of 27 to 46 m. The biomass of quagga mussels (Dreissena bugensis) increased exponentially during 2001–2003, while that of zebra mussels did not change significantly. Body mass (standardized for a given shell length) of both species was lowest from depths of 27 to 37m, highest from 55 to 64 m, and declined linearly at deeper depths during 2001–2003. Recruitment in 2003, as characterized by the proportion of mussels < 11 mm in the catch, varied with depth and lake region. For quagga mussels, recruitment declined linearly with depth, and was highest in northern Lake Michigan. For zebra mussels, recruitment generally declined non-linearly with depth, although the pattern was different for north, mid, and southern Lake Michigan. Our analyses suggest that quagga mussels could overtake zebra mussels and become the most abundant mollusk in terms of biomass in Lake Michigan.     

招生规模与就业现状矛盾之我见

本文从教育消费的投入与就业理想的矛盾、招生带来的教育质量滑坡与单位用人质量标准的矛盾、国民经济发展与用人需求的矛盾三个方面,全面阐述了高等学校招生规模与就业现状的矛盾,旨在为解决该问题做出一些有意义的尝试与探索。     

Web招聘信息抽取中命名实体识别的研究

命名实体识别是文本信息处理的重要基础,已逐步成为自然语言处理的一项关键技术。文章分析了Web招聘信息抽取中的命名实体识别方法,研究了基于自然语言理解方式识别组织机构名、职位名,并实现了一个Web招聘信息抽取原型系统。经测试,本系统在命名实体识别方面取得了较满意的实验结果。正确率和召回率都在77％以上。     

基于B/S与C/S结构的招生管理系统的实现

随着全国普通高等学校网上录取工作的全面实施,高校招生管理工作必须适应信息化发展要求。本文针对目前国内高校招生信息管理系统的种种不足,提出了基于《全国普通高校招生网上录取系统院校系统》二次开发的解决方案,解决了系统间的数据共享问题,实现了推荐生跟踪管理、招生决策分析等重要功能。     

Relations between complex hydraulics and the localized distribution of mussels in three regulated rivers

A stratified random sampling design was used to examine the relations between selected hydraulic variables and the density of unionids at five sites on the Green, Licking, and Rough Rivers of Kentucky. We located the strata to ensure that samples occurred in a wide range of hydraulic conditions at each site. Eight 0.25 m² quadrat samples were collected from each 25 m² stratum. We measured mean water column velocity, depth, and substrate roughness before we sampled each quadrat. ‘Fliesswasserstammtisch’ (FST) hemispheres were used to estimate shear stress. In all, we collected 798 individuals of 28 species of freshwater mussels. Simple hydraulic characteristics of our study sites were not correlated consistently with mussel density. For instance, water depth and mussel density were positively correlated in the Green River, negatively correlated in the Rough River, and not significantly correlated in the Licking River. In contrast, we found consistent negative correlations in all rivers between mussel density and complex hydraulic variables, such as shear velocity and FST hemisphere number. We believe that the limited recruitment observed in these rivers may have resulted from operation of upstream flood control dams that altered flow regimes seasonally. We suspect that the increased discharge during spring and early summer resulted in shear forces sufficiently high on mussel beds to prevent settlement of newly metamorphosed juveniles. Copyright © 2001 John Wiley & Sons, Ltd.