A hierarchical approach to position-based multicast for mobile ad-hoc networks

In this paper we present Scalable Position-Based Multicast (SPBM), a multicast routing protocol for ad-hoc networks. SPBM uses the geographic position of nodes to provide a highly scalable group membership scheme and to forward data packets in a way that is very robust to changes in the topology of the network. SPBM bases the forwarding decision on whether or not there are group members located in a given direction, allowing a hierarchical aggregation of membership information. The farther away a region is from an intermediate node, the higher the level of aggregation for this region should be. Because of aggregation, the overhead for group membership management scales logarithmically with the number of nodes and is independent of the number of multicast senders for a given multicast group. Furthermore, we show that group management overhead is bounded by a constant if the frequency of membership updates is scaled down with the aggregation level. This scaling of the update frequency is reasonable since the higher the level of aggregation is, the lower the number of membership changes for the aggregate will be. The performance of SPBM is investigated by means of simulation, including a comparison with ODMRP, and through mathematical analysis. We also describe an open source kernel implementation of SPBM that has been successfully deployed on hand-held computers.     

模型飞机蓝牙遥控系统的设计

在该系统中,一个运行在本地PC上的Java程序,读取游戏杆的数据,通过蓝牙连接来控制一个装有4只发动机的模型飞机的飞行.作为设计的第一步,模型飞机是在一台远端PC上仿真的,两台PC以蓝牙方式连接.文中建立了系统的控制原型,定义了应用层的协议,给出了系统的流程图,并对程序包进行了简单的描述.这一设计可用于模型飞机的实际控制,只要将远端程序移植到模型飞机上的微控制器,而本地程序无需作多大的修改.     

Examining psychokinesis: The interaction of human intention with random number generators--A meta-analysis.

Séance-room and other large-scale psychokinetic phenomena have fascinated humankind for decades. Experimental research has reduced these phenomena to attempts to influence (a) the fall of dice and, later, (b) the output of random number generators (RNGs). The meta-analysis combined 380 studies that assessed whether RNG output correlated with human intention and found a significant but very small overall effect size. The study effect sizes were strongly and inversely related to sample size and were extremely heterogeneous. A Monte Carlo simulation revealed that the small effect size, the relation between sample size and effect size, and the extreme effect size heterogeneity found could in principle be a result of publication bias. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

In the eye of the beholder: Reply to Wilson and Shadish (2006) and Radin, Nelson, Dobyns, and Houtkooper (2006).

H. B?sch, F. Steinkamp, and E. Boller's (see record 2006-08436-001) meta-analysis, which demonstrated (a) a small but highly significant overall effect, (b) a small-study effect, and (c) extreme heterogeneity, has provoked widely differing responses. After considering D. B. Wilson and W. R. Shadish's see record 2006-08436-002) and D. Radin, R. Nelson, Y. Dobyns, and J. Houtkooper's see record 2006-08436-003) concerns about the possible effects of psychological moderator variables, the potential for missing data, and the difficulties inherent in any meta-analytic data, the authors reaffirm their view that publication bias is the most parsimonious model to account for all 3 findings. However, until compulsory registration of trials occurs, it cannot be proven that the effect is in fact attributable to publication bias, and it remains up to the individual reader to decide how the results are best and most parsimoniously interpreted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fluorescence Lifetime Imaging of Quantum Dot Labeled DNA Microarrays

Quantum dot (QD) labeling combined with fluorescence lifetime imaging microscopy is proposed as a powerful transduction technique for the detection of DNA hybridization events. Fluorescence lifetime analysis of DNA microarray spots of hybridized QD labeled target indicated a characteristic lifetime value of 18.8 ns, compared to 13.3 ns obtained for spots of free QD solution, revealing that QD labels are sensitive to the spot microenvironment. Additionally, time gated detection was shown to improve the microarray image contrast ratio by 1.8, achieving femtomolar target sensitivity. Finally, lifetime multiplexing based on Qdot525 and Alexa430 was demonstrated using a single excitation-detection readout channel.     

Suspension plasma spraying of TiO2 for the manufacture of photovoltaic cells

Highly porous TiO₂ coatings have been produced by suspension plasma spraying on ITO coated glass substrates. The deposition process could be optimized so that fine/nano grained highly porous coatings were obtained. Mean crystallite sizes well below 50 nm could be achieved in the coatings for the anatase phase.Special emphasis was on the establishment of a high volume fraction of the desired anatase phase. The best coatings showed values of about 90% of anatase phase.With these coatings photovoltaic cells could be produced. Different levels of layer thickness and porosity as well as contents of anatase phase have been investigated.In the paper details on the microstructure of the cells as well as the photovoltaic performance will be given.     

Tool Building on the Shoulders of Others

At the first International Workshop on Advanced Software Development Tools and Techniques, four emerging trends in academic tool building were evident. First, tools are increasingly constructed on the basis of external code, reusing, for instance, existing frameworks and integrated development environments. Second, researchers often choose dynamic languages such as Smalltalk to implement prototype tools. Third, Web-based tools are starting to incorporate Web 2.0 technologies to improve user interaction. Finally, increasing computational resources allow tools to tackle larger, real-world code bases.     

Rapid assay processing by integration of dual-color fluorescence cross-correlation spectroscopy: high throughput screening for enzyme activity

Dual-color fluorescence cross-correlation spectroscopy (dual-color FCS) has previously been shown to be a suitable tool not only for binding but also for catalytic rate studies. In this work, its application as a rapid method for high-throughput screening (HTS) and evolutionary biotechnology is described. This application is called RAPID FCS (rapid assay processing by integration of dual-color FCS) and does not depend on the characterization of diffusion parameters that is the prerequisite for conventional fluorescence correlation spectroscopy. Dual-color FCS parameters were optimized to achieve the shortest analysis times. A simulated HTS with homogeneous assays for different restriction endonucleases (EcoRI, BamHI, SspI, and HindIII) achieved precise yes-or-no decisions within analysis times of about 1 s per sample. RAPID FCS combines these short analysis times with the development of fast and flexible assays resulting in sensitive, homogeneous fluorescence-based assays, where a chemical linkage between different fluorophores is either cleaved or formed, or where differently labeled molecules interact by noncovalent binding. In principle, assay volumes can be reduced to submicroliters without decreasing the signal strength, making RAPID FCS an ideal tool for ultra-HTS when combined with nanotechnology. RAPID FCS can accurately probe 10(4) to 10(5) samples per day, and possibly more. In addition, this method has the potential to be an efficient tool for selection strategies in evolutionary biotechnology, where rare and specific binding or catalytic properties have to be screened in large numbers of samples.