解析无线网络弊病化解无线安全威胁

伴随着低档次无线网络设备的价格不断走低,以及操作上的越来越简便,低档次无线局域网网络在最近几年得到了快速普及.为了方便进行资源共享、无线打印、移动办公操作,我们只要耗费几百元钱购买一台普通的无线路由器和一块无线网卡设备,就可以快速地搭建好一个简易的无线局域网网络了.不过,低档次无线局域网网络的不断普及,也容易给单位的信息安全带来不小的威胁.在这种情形下,我们该如何才能化解低档次无线网络的安全威胁,享受组网的快捷、便利呢?     

Coupling agent-based models of subsistence farming with individual-based forest models and dynamic models of water distribution

Subsistence farming communities are dependent on the landscape to provide the resource base upon which their societies can be built. A key component of this is the role of climate and the feedback between rainfall, crop growth, land clearance and their coupling to the hydrological cycle. Temporal fluctuations in rainfall alter the spatial distribution of water availability, which in turn is mediated by soil-type, slope and landcover. This pattern ultimately determines the locations within the landscape that can support agriculture and controls sustainability of farming practices. The representation of such a system requires us to couple together the dynamics of human and ecological systems and landscape change, each of which constitutes a significant modelling challenge on its own. Here we present a proto-type coupled modelling system to simulate land-use change by bringing together three simple process models: (a) an agent-based model of subsistence farming; (b) an individual-based model of forest dynamics; and (c) a spatially explicit hydrological model which predicts distributed soil moisture and basin scale water fluxes. Using this modelling system we investigate how demographic changes influence deforestation and assess its impact on forest ecology, stream hydrology and changes in water availability.     

Digital Intuition: Applying Common Sense Using Dimensionality Reduction

Understanding the world we live in requires access to a large amount of background knowledge: the commonsense knowledge that most people have and most computer systems don't. Many of the limitations of artificial intelligence today relate to the problem of acquiring and understanding common sense. The Open Mind Common Sense project began to collect common sense from volunteers on the Internet starting in 2000. The collected information is converted to a semantic network called ConceptNet. Reducing the dimensionality of ConceptNet's graph structure gives a matrix representation called AnalogySpace, which reveals large-scale patterns in the data, smoothes over noise, and predicts new knowledge. Extending this work, we have created a method that uses singular value decomposition to aid in the integration of systems or representations. This technique, called blending, can be harnessed to find and exploit correlations between different resources, enabling commonsense reasoning over a broader domain.     

Measurements of NOx, acyl peroxynitrates, and NOy with automatic interference corrections using a NO2 analyzer and gas phase titration

NO(2) analyzers are much more valuable if they can also measure NO since the two (NO+NO(2)=NO(x)) are often found together. NO can be quantitatively converted to NO(2) by reaction with ozone and subsequent thermal decomposition of the N(2)O(5) that may form from further oxidation. The conversion of NO, along with decomposition of N(2)O(5) and removal of the remaining unreacted ozone with a heated chamber, allows for quantitative determination of NO(x) using a NO(2) analyzer and the determination of decomposed acyl peroxynitrates. Ambient tests are performed to demonstrate these methods.     

Attraction ofCarpophilus spp. (Coleoptera: Nitidulidae) to synthetic aggregation pheromones and host-related coattractants in Australian stone fruit orchards: Beetle phenology and pheromone dose studies

Synthetic aggregation pheromones ofCarpophilus hemipterus (L.) andCarpophilus mutilatus Erichson were field tested during a 10-month period in southern New South Wales stone fruit orchards to determineCarpophilus spp. phenology and the effect of two pheromone doses on attraction. Aggregation pheromones synergize the attraction of host volatiles toCarpophilus spp. Four major species,C. hemipterus, C. mutilatus, C. davidsoni Dobson andC. (Urophorus) humeralis (F.), were trapped, with greater numbers of each species inC. hemipterus pheromone/fermenting whole-wheat breaddough-baited traps, than in dough-only-traps. InC. mutilatus pheromone/ fermenting-dough-baited traps, onlyC. mutilatus andC. davidsoni responded in greater numbers than to dough-only traps. Beetles first appeared in traps in late September (early spring) when daily maximum temperatures averaged 17.5C. Trappings reached a peak during October and declined to very low levels in November–December (late spring-early summer). Numbers trapped of all species increased during February–March (late summer–early autumn), presumably due to the presence of abundant host resources (ripening and fallen fruit), and continued at high levels until May (late autumn). An 18-week study demonstrated significantly greater responses byCarpophilus spp. to 5000-g than to 500-g doses of C.hemipterus andC. mutilatus pheromones. Greatest responses to 5000g were recorded forC. hemipterus andC. mutilatus responding to their own pheromones (increased attraction over dough alone of 259x and 21.2x respectively). Implications of the study and the potential for using synthetic aggregation pheromones for managingCarpophilus spp. populations in Australian stone fruit are discussed.     

Selective toxicity of hydroxyl-rich carbon nanodots for cancer research

Nano Research - The toxicity of nanoparticles in a biological system is an integration of effects arising from surface functionality, particle size, ionic dissolution, etc. This complexity suggests...     

Community resources for clients with mobility problems

Clients are leaving the hospital "quicker and sicker," and they frequently have acute care needs that must be met by resources outside the hospital setting. Community resources are diverse, vary widely from place to place, and have no central administration. Thus, using them can be challenging for both the nurse, client, and family. Reimbursement mechanisms underlie a person's ability to use resources and receive health care. By presenting two actual case scenarios where clients have mobility problems commonly seen by orthopaedic nurses, the authors discuss the community resources available, avenues of access to them, and their reimbursement mechanisms.