Multi metric evaluation of leaf wetness models for large-area application of plant disease models

Leaf wetness (LW) is one of the most important input variables of disease simulation models because of its fundamental role in the development of the infection process of many fungal pathogens. The low reliability of LW sensors and/or their rare use in standard weather stations has led to an increasing demand for reliable models that are able to estimate LW from other meteorological variables. When working on large databases in which data are interpolated in grids starting from weather stations, LW estimation is often penalized by the lack of hourly inputs (e.g., air relative humidity and air temperature), leading researchers to generate such variables from the daily values of the available weather data.Although it is possible to find several papers about models for the estimation of LW, the behavior and reliability of these models were never assessed by running them with inputs at different time resolutions aiming at large-area applications. Furthermore, only a limited number of papers have assessed the suitability of different LW models when used to provide inputs to simulate the development of the infection process of fungal pathogens. In this paper, six LW models were compared using data collected at 12 sites across the U.S. and Italy between 2002 and 2008 using an integrated, multi metric and fuzzy-based expert system developed ad hoc. The models were evaluated for their capability to estimate LW and for their impact on the simulation of the infection process for three pathogens through the use of a potential infection model. This study indicated that some empirical LW models performed better than physically based LW models. The classification and regression tree (CART) model performed better than the other models in most of the conditions tested. Finally, the estimate of LW using hourly inputs from daily data led to a decline of the LW models performances, which should still be considered acceptable. However, this estimate may require further work in data collection and model evaluation for applications at finer spatial resolutions aimed at decision support systems.     

Mathematical modeling and an application of the filled function method in entomology

Macrosiphum rosae (L.) is one of the most destructive pests for Rosa damascena (Miller) when it is found in high numbers. In order to understand the population dynamics of this pest, our priority should be the determination of what extent environmental factors affect the pest population. In this study, we apply fuzzy logic modeling to visualize the population variations, which depends on the environmental factors (temperature and humidity), by using the data obtained from the field studies. After that, we determine the values of temperature and humidity that makes the number of M. rosae maximum by using the filled function method as a global optimization technique.     

法理与政治双视角下土地使用权届满后的策略选择

温州房屋20年土地使用权到期事件引发了社会各界对土地使用权到期后该怎么续期、怎么缴费等问题的思考。该研究在对该事件以及相关知识了解的基础上,通过对土地使用权相关的法理梳理,分析了当前我国土地使用权的法理制度层面的问题;通过对土地使用权内在的政治逻辑分析,得出在土地使用权续期问题的处理中应该要在国家"少取多予"的政治理念的指导下,充分考虑代际公平和人与人之间公平公正。最后,在法理梳理和政治逻辑分析的基础上提出完善土地使用权续期的建议。     

基于单片机的太阳能热水器模糊控制系统的设计

本文设计基于AT89S51单片机的太阳能热水器模糊控制系统,其模糊控制规则能够比较有效地模仿人的经验,合理解决输出的强关联性问题。给出了模糊控制查询的单片机实现方法及模糊控制系统的核心控制部分的硬件电路和软件流程。     

基于内模型的知识遗忘

在多Agent系统下,根据遗忘理论和经典知识逻辑建立基于内模型的知识逻辑,并且提出相应的互模拟关系,定义出知识逻辑;讨论了知识遗忘的相关性质.     

A fuzzy logic multicasting algorithm for ad hoc networks

To increase the multicasting efficiency of Ad hoc networks, a fuzzy logic multicasting algorithm (FLMA) is proposed. FLMA adopts the fuzzy logic to tolerate the imprecise information caused by dynamic network topology. The two input variables of the fuzzy logic system are the relative degree of the additional coverage node number and the relative degree of the residual energy. The deferring time of rebroadcast is the output variable of the fuzzy logic system, which is used to optimize the priority of the nodes to rebroadcast. FLMA reduces the redundant retransmission and the chance of the contention and collision, while balances the energy consumption of the nodes. Simulation results reveal that the FLMA achieves better performance than BCAST in terms of the network lifetime, average end-to-end delay, the average number of drops per node and the throughput.     

基于Excel函数应用的森林资源二类调查数据逻辑检查

以海南省保亭和昌江二县森林资源二类调查小班数据录入后的逻辑检查为例,比较了应用Excel函数编程进行检查与利用森林资源二类调查数据处理软件进行检查的工作效率,结果认为,采用Excel可极大地提高数据录入效率.分析了数据录入过程中可能产生的几种逻辑错误,有针对性地编写了Excel函数逻辑检查程序.     

粮仓窗户远程自动控制系统设计

设计出一种粮仓窗户远程自动控制系统。根据仓内外的温度和湿度变化,自动开启或关闭窗户及通风机械,实现粮仓的自动通风,自动控制。该系统可与粮情检测系统、通风控制系统等结合,组成粮仓自动化管理系统。     

汽车电动助力转向系统回正特性控制逻辑分析

以汽车转向系转向特性为研究对象和目标,为了探讨汽车转向回正特性对汽车行驶安全和操纵稳定性的影响,降低驾驶员施加于方向盘的转向力矩,并使驾驶员获得良好的路感,改善汽车转向系的回正特性,提出了一种电动助力转向系统回正控制算法以提高转向盘的回正特性,开发了一种基于转向盘转角估计的PID控制策略.为了分析获得汽车转向回正特性和回正控制逻辑,通过分析和物理模型简化建立了电动助力转向系统的动力学模型,并根据建立的模型,对提出的控制策略进行了仿真分析,结果表明此控制策略可提高转向盘的回正特性和稳定性,利于提高汽车行驶的安全性和操纵稳定性.