RFID系统优化模型与智能算法研究

射频识别技术（Radio Frequency Identification, RFID）作为采集与处理信息的高新技术和信息化标准的基础，被列为本世纪十大重要技术之一。但是，RFID技术的大规模实际应用仍处于探索阶段，RFID系统的应用基础技术还存在着大量尚未解决的关键问题，其中RFID系统优化是RFID技术研究和应用的重要课题。由于RFID系统本身的动态性和不确定性， RFID系统优化面对的一般是非线性、多目标、大规模的复杂优化问题，传统的数学优化算法在处理这些问题时，存在困难。为此，研究新的优化算法成为RFID技术实际应用和理论研究中必须解决的课题。 智能计算方法是求解复杂RFID系统优化问题的一种可供选择的算法。智能计算作为一个新兴领域，其发展已引起了多个学科领域研究人员的关注，目前已经成为人工智能、经济、社会、生物等交叉学科的研究热点和前沿领域。智能计算的各类算法已在传统NP问题求解及诸多实际应用领域中展现出其优异的性能和巨大的发展潜力。 本文旨在对RFID系统的各种优化问题进行深入研究和探讨，面向RFID技术的实际应用需求构建其优化模型，并基于智能计算思想设计能够有效求解这些复杂模型的新型智能优化算法。具体研究内容包括： 首先，进行了RFID读写器网络的调度问题研究。在深入分析RFID网络中读写器冲突类型和成因的基础上，考虑RFID网络中的读写器冲突约束，以最小化系统中的频道数量、时隙分配以及总处理时间建立了RFID读写器网络调度的数学优化模型。从生物学的角度出发提出基于生态捕食模型的改进PSO算法（Particle Swarm Optimizer based on Predator-prey Coevolution, PSOPC），在一定程度上解决了PSO算法在迭代后期随着多样性丧失而陷入局部最优的缺点。应用PSOPC设计了求解RFID读写器网络调度模型的智能求解算法，分别给出算法的求解框架、关键步骤的实现机制。通过在不同规模的RFID读写器网络上进行实例仿真，验证了算法的有效性和模型的正确性。 其次，进行了基于菌群自适应觅食算法RFID网络规划问题的研究。考虑RFID系统在不同应用环境下的系统需求，建立了RFID网络规化的数学模型，其目标函数分别为：RFID网络标签覆盖率的最大化目标函数、RFID读写器冲突的最小化目标函数、RFID网络运行的经济效益最大化目标函数、RFID网络运行的负载平衡目标函数以及同时考虑全局目标的混合目标函数。将自然界生物觅食所采用的自适应搜索策略与细菌的趋化行为和群体感应机制相集成，提出了适合求解复杂RFID网络规划问题的菌群自适应觅食算法（Adaptive Bacterial Foraging Optimization, ABFO）。通过仿真实验基于ABFO算法分别对RFID网络规划模型中的五个目标函数进行了实例求解和分析，测试结果与标准PSO算法和遗传算法进行了比较分析。 再次，进行了基于系统智能方法的RFID网络规划分布式决策模型研究。采用分布式决策的思想建立了RFID网络规划的层次模型，在一定程度上缓解、分散了RFID网络规划问题的复杂性，以解决具有混合变量（包括离散变量和连续变量）的多目标RFID网络规划问题。针对层次模型求解的复杂性，以复杂适应系统理论为指导思想设计了一种新型系统智能优化算法对RFID网络规划的层次模型进行求解。系统智能算法将群体智能中的单层群体系统概念扩展为多层涌现系统，仿真实验表明新提出的算法显著提高了智能计算方法的寻优能力，以及算法的适应性、鲁棒性和平衡性等性能。 最后，进行了RFID网络目标跟踪系统中的数据融合研究。以基于RFID技术的目标定位与跟踪系统为应用背景，提出了基于模糊聚类方法的多RFID读写器数据融合模型框架。通过深入分析蜜蜂采蜜的基本生物学规律，对蜜蜂的个体行为及群体行为进行模拟，提出了一类新型群体智能优化算法-蜂群优化算法（Bee Swarm Optimization, BSO），并将BSO算法嵌入RFID目标定位跟踪系统，作为其模糊聚类的基本算法。仿真研究表明，提出的融合模型能够有效的过滤读写器对跟踪目标的错误监测数据，显著提高目标定位与跟踪的精度。

Changes of Leptodora kindti abundance (1957-1996) in a planktivorous fishes-dominated subtropical Chinese lake (Lake Donghu)

The changes of L. kindti density from 1957 to 1996 were studied in a shallow, eutrophic Chinese lake, Lake Donghu. Despite the fact that the fish yield of planktivorous fish (silver carp and bighead carp) has increased steadily, the population density of L. kindti has also increased since 1957 and peaked in 1982/1983, The increase of both fish and L. kindti densities during this period may have benefitted from a considerable increase in the densities of their zooplankton prey. and fish predation on L. kindti might have been minor. As the fish yield increased further, their predation began to suppress most zooplankton prey including L. kindti. The largely increased fish predation on L. kindti is also evidenced by the remarkable decline of their body length after 1984. The density of L. kindti was significantly higher at the pelagic station (II) than at the littoral station (I), although for L. kindti, the littoral zone was significantly more resource profitable than the pelagic zone. The gradient of fish predation (more fish in the littoral zone) is the most likely explanation, since L. kindti is reported to be a preferred prey for many planktivorous fishes. The maximum density of L. kindti was 1.78 ind./I (on Aug. 17, 1984) at Station I and 1.55 ind./I (on Sep. 13, 1985) at Station II, respectively, which are close to those in several other eutrophic lakes.

Changes in the structure of a zooplankton community during a Ceratium (dinoflagellate) bloom in a eutrophic fishless pond

The community structure of zooplankton was studied in a eutrophic, fishless Japanese pond. The ecosystem was dominated by a dinoflagellate, Ceratium hirundinella, two filter-feeding cladocerans, Daphnia rosea and Ceriodaphnia reticulata, and an invertebrate predator, the dipteran Chaoborus flavicans. The midsummer zooplankton community showed a large change in species composition (the Daphnia population crashed) when a heavy Ceratium bloom occurred. It is shown that (i) the rapid density decline of D.rosea in mid-May was mainly caused by a shortage of edible phytoplankton, which was facilitated by the rapid increase in C.hirundinella abundance; (ii) the low density of D.rosea in June-July was considered to be mainly caused by the blooming of Ceratium hirundinella (which may inhibit the feeding process of D.rosea), while predation by C.flavicans larvae, the changing temperature, the interspecific competition and the scarcity of edible algae were not judged to be important; (iii) the high summer biomass of the planktonic C.flavicans larvae was maintained by the bloom of C.hirundinella, because >90% of the crop contents of C.flavicans larvae were C.hirundinella during this period. The present study indicates that the large-sized cells or colonies of phytoplankton are not only inedible by most cladocerans, but the selective effect of the blooming of these algae can also influence the composition and dominance of the zooplankton community, especially for the filter-feeding Cladocera, in a similar way as the selective predation by planktivorous fish. The large-sized phytoplankton can also be an important alternative food for ominivorous invertebrate predators such as Chaoborus larvae, and thus may affect the interactions between these predators and their zooplanktonic prey. In this way, such phytoplankton may play a very important role in regulating the dynamics of the aquatic food web, and become a driving force in shaping the community structure of zooplankton.

若尔盖湿地3种两栖类的种间竞争及畜牧业对其食性的影响

从空间、时间、食物3个方面研究了若尔盖湿地3种两栖类的种间竞争，运用生态位理论探讨了3种两栖类利用环境资源的能力以及它们之间的共存模式，研究了3种两栖类年周期食性，并考察了畜牧业对3种两栖类食性及食物竞争格局的影响；此外，还通过实验室研究对2种两栖类幼体的种间竞争策略进行了考察。主要结果如下： 1、两栖类的空间资源利用状况：在3种两栖类成体生态位宽度的比较中，岷山蟾蜍（Bufo minshanicus）成体在牧场性质(0.41)、牛粪数量(0.42)、植被盖度(0.20)、地表温度(0.50)、地表湿度(0.51) 5个维度上的生态位宽度最窄；而倭蛙（Nanorana pleskei）成体在牛粪数量(0.81)、植被高度(0.63)、植被盖度(0.47)、小水体距离(0.68) 4个维度上的生态位宽度最宽。在3种两栖类亚成体生态位宽度的比较中，岷山蟾蜍亚成体在牧场性质(0.66)、牛粪数量(0.58)、植被高度(0.64)、小水体距离(0.51)、地表湿度(0.79) 5个维度的上生态位宽度最宽；倭蛙亚成体在牧场性质(0.39)、牛粪数量(0.30)、地表温度(0.18)、地表湿度(0.33) 4个维度上的生态位宽度最窄。高原林蛙（Rana kukunoris）在地表温度（成体：0.62；亚成体：0.56）、地表湿度（成体：0.84；亚成体：0.60）两个维度上具有较大的生态位宽度值，而在小水体距离维度上（成体：0.27；亚成体：0.14）的生态位宽度值则很小。比较3种无尾两栖类在不同生长阶段（成体、亚成体）的生态位宽度，发现高原林蛙和倭蛙的亚成体对栖息环境的要求更高。3种两栖类空间资源利用的相似程度很高，高原林蛙与倭蛙之间的生态重叠度(0.87)较之它与岷山蟾蜍(0.81)的生态位重叠度更大。 2、两栖类的日活动节律：高原林蛙成体、亚成体、岷山蟾蜍亚成体活动的最低气温为0℃、2℃、8℃；岷山蟾蜍和高原林蛙亚成体出现的数量与气温成极显著的正相关（r=0.797, p<0.001；r=0.794, p<0.001），高原林蛙成体出现的数量与气温有一定相关性（r=0.456, p<0.05）；晴天时两栖类的活动性明显高于阴天（p<0.001）；多云转晴天气，高原林蛙和岷山蟾蜍亚成体出现两次日活动高峰，分别为中午12:30左右和下午15:30～16:30之间；多云天气，高原林蛙和岷山蟾蜍亚成体出现两次日活动高峰，分别为9:30～10:30之间和15:30～16:30之间。 3、两栖类的食物资源利用状况：春、秋两季，高原林蛙最主要的食物是蜉金龟科(Aphodiidae)昆虫，相对重要性指数(IRI)最高（春季：35.28%，秋季：28.57%），其次为昆虫的幼虫，以及双翅目的毛蚊科(Bibionidae)、蝇科(Muscidae)、丽蝇科(Calliphoridae)昆虫，秋季，蝗虫是高原林蛙食物组成中的重要部分；岷山蟾蜍最主要的食物是蚂蚁(IRI，春季：85.54%，秋季：49.70%)，其次为蜉金龟科、象甲科(Curculionidae)、步甲科(Carabidae)、粪金龟科(Geotrupidae) 等鞘翅目昆虫；倭蛙春季的最主要食物也是蜉金龟科昆虫(IRI，春季：13.41%)，其次为蚂蚁、毛蚊科昆虫、昆虫的幼虫以及狼蛛科(Lycosidae)。3种两栖类中，倭蛙的食性生态位宽度相对较宽（0.43），而岷山蟾蜍（0.09）和高原林蛙（0.22）的生态位宽度较窄，与春季相比，两栖类在秋季的食谱更宽。以利用食物种类为标准，春季高原林蛙与倭蛙的生态位重叠度(0.40)比它与岷山蟾蜍的生态位重叠度（0.33）更大。 4、畜牧业对两栖类食性及食物竞争格局的影响：以藏牦牛粪为食物或寄居场所的昆虫，如蜉金龟科、粪金龟科、毛蚊科、蝇科、丽蝇科昆虫和某些昆虫幼虫，是3种两栖类食物谱中最主要的组成部分，蜉金龟科昆虫在高原林蛙食谱中的比例更高，高原林蛙可能从畜牧业发展中获得更多的好处，使之在食物竞争方面处于优势地位。与无放牧样地相比，在有放牧样地的中，两栖类食谱中的蜉金龟科昆虫数量更多(有放牧：31.94%；无放牧：21.32%)、出现频率更高(有放牧：76.38%；无放牧：44%)。然而在不同样地上（有放牧/无放牧），两栖类的食物组成无显著性差异(P=0.188)，两栖类的数量(P=0.075)、肥满度(P=0.537)均没有显著差别。 5、两栖类幼体的竞争策略：实验室条件下，通过活动性水平，变态时的体重、增长率和完成变态所需时间考察自然条件下常同水塘分布的中华蟾蜍（Bufo gargarizans）和高原林蛙蝌蚪的竞争策略。结果表明：中华蟾蜍蝌蚪在不同食物资源条件下，所选择的生存策略可能不同，即食物资源充足时，增加活动性获取更多食物，食物资源有限时，降低活动性且提前完成变态；与中华蟾蜍蝌蚪相比，在食物资源有限时高原林蛙蝌蚪获取食物能力可能更强。 This paper presented the study of competition of three amphibians (Rana kukunoris, Nanorana pleskei, Bufo minshanicus) based on spatial, temporal and dietary scales in Zoige wetland. We measured coexistence patterns of three amphibians and analyzed their ability of exploiting resource. Effects of grazing on the diet composition and diet competition of amphibians were analyzed by their diet composition during spring and autumn. Furthermore, we examined the competitive ability of larval common frogs (Rana kukunoris)and common toads(Bufo gargarizans) in a laboratory experiment, and analyzed their competitive strategies respectively. The results were as follows: 1 .The status of using spatial resource Niche breadths of B. minshanicus adults on 5 dimensional axes including character of pasture(0.41), number of yaks dung(0.42), vegetation coverage(0.20), temperature (0.50)and humidity(0.51) of ground surface were narrower than adults of R. kukunoris and N. pleskei. Niche breadths of B. minshanicus subadults were broader than R.kukunoris subadults and N.pleskei subadults on 5 dimensional axes including character of pasture (0.66), number of yaks dung (0.58), vegetation height (0.64), distance to small waterbodies (0.51), humidity of ground surface (0.79). Niche breadths of N. pleskei subadults were the narrowest in three anurans subadults on 4 dimensional axes including character of pasture (0.39), number of yaks dung (0.30), temperature (0.18) and humidity (0.33) of ground surface, niche breadths of N. pleskei adults were the broadest in three anurans adults on 4 dimensional axes including number of yaks dung (0.81), vegetation height (0.63) and coverage(0.47), distance to small waterbodies(0.68).Comparatively, niche breadths of R. kukunoris were broader on the two microclimate factors including temperature(adults：0.62；subadults：0.56) and humidity (adults：0.84；subadults：0.60)of ground surface, but was narrow on distance to small waterbodies(adults：0.27；subadults：0.14). Strategies for using habitat resource of adults and subadults of the three species anuran were different. Generally, subadults of R. kukunoris and N. pleskei needs better habitat condition. It was quite similar that three anurans exploited spatial resource, Niche overlap between R. kukunoris and N. pleskei (0.87) was greater than that between R. kukunoris and B.minshanicus(0.81). 2.Daily activity rhythm R. kukunoris audlts were active when air temperatures were as low as 0℃, R. kukunoris subadults were active at 2℃, B.minshanicus subaudlts were active at 8℃. Positive correlation was found between activities of amphibians and air temperature, Subadults of R.kukunoris, (r=0.797, p<0.001), Subadults,of,B.minshanicus, (r=0.794, p<0.001), andbadults,of,R.kukunoris(r=0.456, p<0.05).Amphibians were more active during sunny days than cloudy days. In cloudy turning into sunny, R. kukunoris and B.minshanicus subadults had two active peak: at noon about 12:30 and 15:30～16:30 pm; in cloudy, R. kukunoris and B.minshanicus subadult had two active peak too : 9:30～10:30am,15:30～16:30pm. 3.Diet analysis Aphodiidae was the most commonly consumed food item by R. kukunoris based on index of relative importance (IRI) during spring (35.28%) and autumn (28.57%) in Zogie wetland. Besides Aphodiidae, larval insect, dipterans such as Bibionidae, Muscidae, Calliphoridae also were important food item for R. kukunoris, in autumn, locust was one of important food item for R. kukunoris. The most important food item for B.minshanicus during spring (IRI:85.54%) and autumn (IRI:49.70%) was ants, following, was coleopterans, such as Aphodiidae, dung beetle. Aphodiidae (IRI:13.41%) were the most important consumed food item by N. pleskei during spring too, following, was ants and Bibionidae. Dietary breadth of N. pleskei (0.43) were greater than R. kukunoris (0.22) and B. minshanicus (0.09). As a whole, Dietary breadth of amphibians during aurumn were greater than spring. Based on prey item, dietary overlap between R. kukunoris and N. pleskei (0.40) was greater than that between R. kukunoris and B.minshanicus (0.33) during spring. 4.Effects of grazing on the diet composition and diet competition of amphibians Amphibians are an important part of the pasture ecosystems as prey and predator. In Zogie wetland, major diet of amphibians was closely associated with dung of yaks, for example, Aphodiidae, Bibionidae, Muscidae, dung beetle. Dung of yaks was major diet and habitat of these insects. Proportion of Aphodiidae was higher in diet composition of R. kukunoris than N. pleskei and B.minshanicus, with development of pasturage, R. kukunoris may have a diet competitive advantage over N. pleskei and B.minshanicus. Number of Aphodiidae in diet composition of amphibians was higher in samples with grazing (31.94%) than in those without grazing (21.32%). Occurrence Frequency of Aphodiidae in diet composition of amphibians was higher in samples with grazing (76.38%) than in those without grazing (44%). However, There was not significantly different on diet composition (P=0.188), and number (P=0.075) and the relative fatness (P=0.537) of amphibians between grazing samples and without grazing. 5.Competitive strategies of amphibian larvae I examined the competitive ability of larval toads (Bufo gargarizans) and frogs (Rana kukunoris) which co-occur in the nature pond by activity level, the growth rate and mass at metamorphosis and larval period in a laboratory experiment. The results suggest: In laborary, B.gargarizans adapted himself to different food level by changing activity. At high food level, B. gargarizans increased activity to gain more diet. At low food level, B. gargarizans decreased activity and achieved early metamorphosis. When food resource was limit, R. kukunoris could gain more food than B. gargarizans.