农业规模经营模式分析

本文在文献研究和案例分析的基础上 ,首次将当前我国农业规模经营模式总结为土地集中型、契约型和市场激励型三种形式 ,并分别对其进行了分析。本文结论认为 ,我国农业规模经营应该主要依靠市场配置资源 ,依靠政府纠正市场失灵 ;各地区应该结合自己的经济发展状况、自然条件、产业结构及其调整方向、市场发育程度以及社会传统等实际情况 。

猪规模养殖中主要疫病的防治对策

生猪是我国人民主要的肉类食物,为了确保人们的生命安全,必须加强猪规模养殖场中的猪疫病防治。鉴于此,本文对猪规模养殖中主要疫病的防治对策及相关问题进行了探讨。

基于倾斜摄影和激光雷达的大规模城市(深圳)三维建模探索

近年来,虽然实景三维建模技术高速发展,然而城市级高精度三维模型构建仍面临多传感器融合、点云语义分割和结构化三维重构等技术难点,制约了城市实景三维发展。本文以深圳市全市域三维建模工程为案例,介绍基于倾斜摄影和激光雷达的大规模城市三维建模技术路线和生产工艺,分析工程实践中的难点和解决思路,探讨实景三维产品标准和未来发展方向。

基于联锁分块的大规模地形建模方法研究

针对已有MRLoD算法生成的地形三角形网不稳定等缺点,提出了一种新的基于联锁分块的大规模地形建模方法,在对地形进行分块调度的基础上通过预先建立分块模板和分块联锁模板,渲染时动态匹配各模板建立平滑完整的分块模型,在分块调度及附加计算策略下,拼接各分块以完成整块地形的多分辨率建模,并以高效的方式将模型数据传入渲染硬件。实验表明,在满足了精度要求的同时提高了模型的稳定性,有效减少了实时计算量,在渲染效率上取得了令人满意的结果,能够满足用户对大规模地形的实时漫游的要求。

3dsmax环境下大规模城市建模研究

高效率的大规模城市建模是虚拟现实、城市规划、数字娱乐中重要的技术支持。本文首先以3dsmax为平台,通过获取平面网格的节点的位置作为坐标,复制建筑模型。并建立自动删除机制。重点研究了删除参数的设置。将模型视作顶点集合,根据模型顶点分布,采用高斯分布加权。实现了根据模型的形状进行变化的动态删除参数。有效的完成了对重叠模型的清理。

形式复环上的规范内积模

考察内积模的内积象性质。抽象出形式复环与Ｇ·Ｓ同构概念，并给出形式复环一些判定。

基于概率因子图模型的医疗社会网络用户健康状态检测方法

社会网络应用已无处不在,在健康医疗领域也是如此.同时,传感器网络的发展也面临新的形势.在真实世界中,有许多因素(如社会关系、历史健康状态和个人属性信息)都能对健康状态检测?预测结果产生影响.然而,却很少有相关文献能够系统阐述新形势下在一个动态社会网络中节点用户健康状态如何进行检测?预测以及不同因素对用户健康状态影响到何种程度.首先描述一种新颖的医疗物联网:医疗社会网络(medical social networks,MSNs);然后统一考虑社会关系、历史健康状态和用户属性对网络用户健康状态检测结果的影响,提出一种新的基于时-空概率因子图模型(temporal-spatial factorgraph model,TS-FGM)的网络用户健康状态检测?预测方法.在Twitter数据集上对所提出的模型进行了验证,并在一个真实的临床医疗数据集上与SVM基线算法进行了对比实验.实验结果表明所提出的TS-FGM模型是有效的,健康状态检测方法也在一定程度上优于基线方法.

新型三维地质建模方法及其在成都—昌都区域建模的应用

在地质研究不断深入和地理空间信息科学蓬勃发展的背景下,三维可视化地质建模技术已成为信息科学与地球科学交叉领域的研究热点。笔者对传统的三维地质建模方法进行研究、改进,形成一种新型的三维地质建模新方法。新型三维地质建模方法主要应用于地质领域,在多源异构地质数据融合、大规模高精度建模、地质网格细分、属性建模技术和遥感图像融合等方面取得了新的进展。笔者以成都—昌都区域为例,以地质钻孔数据、成都图幅、昌都图幅、遥感数据为数据源,利用新一代三维地质建模技术,进行了三维地质建模和可视化显示。成都—昌都区域的三维可视化验证了新型三维地质建模方法的可行性和有效性。同时也为全国重要地质钻孔数据服务平台对社会公开发布覆盖全国31个省(区、市),累计进尺达2.75亿m的110万个重要钻孔数据三维地质建模提供了重要方法。

次同步振荡误差评估与建模

次同步振荡传统建模方法不能确保所建立的模型分析结果能够满足工程实际的精度需求。本文基于39节点算例模型研究了不同建模规模和负荷模型两类因素对次同步振荡的作用,发现不同负荷模型和建模规模均会导致次同步振荡模态发生变化。本文考虑到上述两类因素是导致次同步振荡传统建模误差较大的本质原因,提出通过逐渐扩大区域的误差指标迭代来建立合适的系统次同步振荡模型。最后,应用算例模型评估了传统建模方法误差,验证了该方法的有效性。

领域本体组织的自助式零件库

针对目前已有基于Web的开放零件库在使用上自主性和自助性的不足,建立了一套领域本体组织的、基于HTML5技术的开放式零件库系统,该系统能够提供自助零件发布、零件语义信息检索、跨设备跨平台的零件数据浏览等功能。建立了领域本体,负责组织整个零件库资源,并使用推理机对该领域本体进行概念一致性检查;借助可扩展标记语言的转化,实现供应商的自助零件信息发布和本体属性及实例的维护;利用语义相似度算法扩展用户检索关键字,得到符合意图的零件检索结果。整个系统利用HTML5技术实现,支持在不同移动设备的不同操作系统中进行无插件的查看和操作,同时借助异步JavaScript与可扩展标记语言技术实现自助式零件上传和交互式零件选型。实现了领域本体组织下的跨平台零件库原型系统,有效提升了开放零件库使用的自助性和灵活性,对语义相似度算法的实验证明了领域本体定义的合理性,可以满足语义检索的扩展性要求。

Construction of Risk Assessment Application Model of Epidemic Disease in Large-scale Pig Farms

The application model of epidemic disease assessment technology for Web-based large-scale pig farm was expounded from the identification of epidemic disease risk factors, construction of risk assessment model and development of risk assessment system. The assessed pig farm uploaded the epidemic disease risk data information through on-line answering evaluating questionnaire to get the immediate evaluation report. The model could enhance the risk communication between pig farm veterinarian, manager and veterinary experts to help farm system understand and find disease risk factors, assess and report the potential high risk items of the pig farm in the three systems of engineering epidemic disease prevention technology, biological safety and immune monitoring, and promote the improvement and perfection of epidemic disease prevention and control measures.

Fuzzy programming approach solution for multi-objective solid transportation problem

Based on recent research developments in multi-objective solid transportation problem (MOSTP), this paper presents a fuzzy programming approach to determine the optimal compromise solution of MOSTP. The characteristic feature of the proposed approach is that various objectives are synthetically considered with marginal evaluation for individual objectives and global evaluation for all objectives. The decision-maker's preference is taken into account by his/her assigning weights to the objectives. With global evaluation for all objectives, a compromise programming model is formulated. As a generic aggregation operator is adopted, several solution methods proposed earlier become special cases of this approach, and the solution process also becomes more flexible and realistic. An illustrative numerical example is provided to demonstrate the approach.

SPN中网状路径研究和性能解算

以往的关于SPN中路径寻找的研究都基于SPN中仅存在链状路径的假设,事实上由于变迁之间复杂的逻辑关系SPN中存在着复杂的网状路径。关于随机Petri网中网状路径还未有深入研究。文中把链状路径看作网状路径的一个特例,给出了SPN中网状路径的定义和网状路径的寻找和路径性能解算的方法。大幅改进了ACO和SPN,使变迁和蚂蚁都具有选择和记忆能力,增强了ACO的灵活性,使之成功找出网状路径;结合可靠性相关理论给出了变迁可靠性和效率服从指数分布的复杂路径性能和系统综合性能的求解的方法。该方法突破了模拟方法应用于大规模复杂系统的瓶颈,为模拟方法的广泛应用铺平了道路。

Mathematical Model and Simulation of Harmful Invasive Plant Control

Plant invasion refers to the phenomenon that some plants grow too fast due to they are far away from the original living environment or predators, affecting the local environment. With the development of tourism and trade, the harm caused by invasive plants will be more and more serious. Therefore, it is necessary to ex- plore an effective method for controlling plant invasion through qualitative and quan- titative research. In this paper, the models were established for the early and late harmful plant invasion control. The huge computation was completed by the com- puter programming to obtain the optimal solutions of the models. The real meaning of the optimal solution was further discussed. Through numerical simulations and discussion, it could be concluded that the quantitative research on the invasive plant control had a certain application value.

Bulk and bubble-scale experimental studies of influence of nanoparticles on foam stability

Influence of silicon oxide(SiO_2) and aluminum oxide(Al_2O_3) nanoparticles on the stability of nanoparticles and sodium dodecyl sulfate(SDS) mixed solution foams was studied at bulk and bubble-scale. Foam apparent viscosity was also determined in Hele-Shaw cell In order to investigate the foam performance at static and dynamic conditions. Results show that the maximum adsorption of surfactant on the nanoparticles occurs at 3 wt% surfactant concentration. Foam stability increases while the foamability decreases with the increasing nanoparticle concentration. However, optimum nanoparticle concentration corresponding to maximum foam stability was obtained at 1.0 wt% nanoparticle concentration for the hydrophilic SiO_2/SDS and Al_2O_3/SDS foams. Foam performance was enhanced with increasing nanoparticles hydrophobicity. Air-foams were generally more stable than CO_2 foams.Foam apparent viscosity increased in the presence of nanoparticles from 20.34 mPa·s to 84.84 mPa·s while the film thickness increased from 27.5 μm to 136 μm. This study suggests that the static and dynamic stability of conventional foams could be improved with addition of appropriate concentration of nanoparticles into the surfactant solution. The nanoparticles improve foam stability by their adsorption and aggregation at the foam lamellae to increase film thickness and dilational viscoelasticity. This prevents liquid drainage and film thinning and improves foam stability both at the bulk and bubble scale.

Study on Growth and Development Rules and Growth Curve Fitting of Minghua Black Minks

Growth curves of Minghua black minks at 0-180 days old were fitted and analyzed by using two growth models Logistic and Gompertz. The results showed that the growth curves of Minghua black minks could be fitted very well by Logistic model and Gompertz model （the degree of fitting FF≥0.99）, but Gompertz model was better at fitting and predicting their weight.

Experimental and CFD Study on the Role of Fluid Flow Pattern on Membrane Permeate Flux

This paper reports a study on the role of fluid flow pattern and dynamic pressure on the permeate flux through a micro filtration membrane in laboratory scale.For this purpose,a dead-end membrane cell equipped with a marine type impeller was used.The impeller was set to rotate in the clockwise and counter clockwise directions with the same angular velocities in order to illustrate the effect of rotation direction on permeate flux.Consequently, permeate fluxes were measured at various impeller rotational speeds.The computational fluid dynamics（CFD）predicted dynamic pressure was related to the fluxes obtained in the experiments.Using the CFD modeling,it is proven that the change in dynamic pressure upon the membrane surface has direct effect on the permeate flux.

Data Flow&Transaction Mode Classification and An Explorative Estimation on Data Storage&Transaction Volume

The public has shown great interest in the data factor and data transactions,but the current attention is overly focused on personal behavioral data and transactions happening at Data Exchanges.To deliver a complete picture of data flaw and transaction,this paper presents a systematic overview of the flow and transaction of personal,corporate and public data on the basis of data factor classification from various perspectives.By utilizing various sources of information,this paper estimates the volume of data generation&storage and the volume&trend of data market transactions for major economies in the world with the following findings:(i)Data classification is diverse due to a broad variety of applying scenarios,and data transaction and profit distribution are complex due to heterogenous entities,ownerships,information density and other attributes of different data types.(ii)Global data transaction has presented with the characteristics of productization,servitization and platform-based mode.(iii)For major economies,there is a commonly observed disequilibrium between data generation scale and storage scale,which is particularly striking for China.(i^v)The global data market is in a nascent stage of rapid development with a transaction volume of about 100 billion US dollars,and China s data market is even more underdeveloped and only accounts for some 10%of the world total.All sectors of the society should be flly aware of the diversity and complexity of data factor classification and data transactions,as well as the arduous and long-term nature of developing and improving relevant institutional systems.Adapting to such features,efforts should be made to improve data classification,enhance computing infrastructure development,foster professional data transaction and development institutions,and perfect the data governance system.

Model of wind-generated ambient noise in stratified shallow water

In order to build a rapid ocean ambient noise model adapted for a stratified shallow water, a hybrid model of normal mode method (for far field) and ray method (for near field) is suggested which combines the advantages of both methods. Since the near field of wind-generated noise is not sensitive to the sound speed pro- file, the sound speed profile is regarded as a constant; which makes the model rapid and accurate. The simulation results are in agreement with those of the wave model.