In this thesis closed-loop control strategies over a communication network with multiple clients are developed. To accomplish this objective, a steel-ball magnetic-levitation system, a DC motor speed-control system, and an autonomous wheelchair robot referred to as Clients 1, 2, and 3, respectively were used as Networked-Based-control (NCS) test beds to validate the proposed strategies. For real-time operation, Linux with Real-Time Application Interface (RTAI) and Control and Measurement Interface (Comedi) were used as the operating system for Clients 1 and 2. Client 3's software was written in Microsoft Visual Basic 6.0 on the Windows XP operating system (OS). User datagram protocol (UDP) was used as the communication network protocol in this research due to its better real-time performance instead of transmission control protocol (TCP). Although UDP has no guarantee for transferring data, it has smaller overheads and less time delay than TCP. Since the robotic wheelchair and the server are run on different OSs, Samba was used to put both systems into the same LAN with a fast data-transmission speed. Using Samba, the round-trip communication time between the robotic wheelchair and the server is only 11.2 ms whereas 30.8 ms is taken without using Samba. When the server receives the sensor data from multiple clients at the same time, the NCS stability may be deteriorated due to the limitation of the system bandwidth. The NCS stability is affected by the sampling period of the system, and the reduction of the sampling period improves the control loop's performance. However, a shorter sampling period requires more network bandwidth to transmit more sensor data or control data, which increases the network traffic load. Using the PING test, the transmission time for each control loop was measured. The processing time for each system was also measured by a time-stamp function, and the operation time for each control loop was obtained. In order to maintain the NCS stable, several combinations of the sampling periods for each client are suggested and verified. The bandwidth utilization of Client 1 is set to be 43.5% and the range of the bandwidth utilization of Client 2 with guaranteed stability was found to be between 9.1% and 45.3%. Thus, the bandwidth utilization of Client 3 is from 11.8% to 46.8%. The multiple-client NCS test bed could maintain its stability within these ranges of the bandwidth utilizations of all clients.

Multiple sequence alignment is an important bioinformatics problem, with applications in diverse types of biological analysis, such as structure prediction, phylogenetic analysis and critical sites identification. In recent years, the quality of multiple sequence alignment was improved a lot by newly developed methods, although it remains a difficult task for constructing accurate alignments, especially for divergent sequences. In this dissertation, we propose three new methods (PSAlign, ISPAlign, and NRAlign) for further improving the quality of multiple sequences alignment. In PSAlign, we propose an alternative formulation of multiple sequence alignment based on the idea of finding a multiple alignment which preserves all the pairwise alignments specified by edges of a given tree. In contrast with traditional NP-hard formulations, our preserving alignment formulation can be solved in polynomial time without using a heuristic, while still retaining very good performance when compared to traditional heuristics. In ISPAlign, by using additional hits from database search of the input sequences, a few strategies have been proposed to significantly improve alignment accuracy, including the construction of profiles from the hits while performing profile alignment, the inclusion of high scoring hits into the input sequences, the use of intermediate sequence search to link distant homologs, and the use of secondary structure information. In NRAlign, we observe that it is possible to further improve alignment accuracy by taking into account alignment of neighboring residues when aligning two residues, thus making better use of horizontal information. By modifying existing multiple alignment algorithms to make use of horizontal information, we show that this strategy is able to consistently improve over existing algorithms on all the benchmarks that are commonly used to measure alignment accuracy.

Multiple polymerase chain reaction (multiple PCR) is one of the most important techniques in molecular biology. The selection of a suitable set of primers is very important for multiple PCR experiments. The primer selection problem is to minimize the number of primers required to amplify a set of DNA sequences. If the minimum set can be used to amplify the entire target DNA sequences, the experimental costs and time will be reduced. But the primer selection problem was proved to be an NP-complete problem. In this thesis, we develop an efficient heuristic algorithm for selecting a set of primer candidates, each may be able to amplify more than one target sequence. Those primers are called universal primers. The universal primer finding can be viewed as the local motif finding in our method. We modify the score function of the original Gibbs sampler method to find local motifs. The new score function is added a new parameter, weight parameter. The weight parameter can guide the Gibbs sampler method to find local motifs with the local view. Then, the complementary sequences of those local motifs are input into the binary integer programming. Thus we can reduce the size of the solution space. We also test our method on some artificial domains and two gene families. All the results show that we get some improvements on the problem.

The family Pegasidae is found composed of 5 species in two genera, Eurypegasus Bleeker and Pegasus Linnaeus. They contain two (E. draconis (Linnaeus) and E. papilio (Gilbert)) and. three species (P. laternarius Cuvier, P. volitans Linnaeus and P. Lancifer Kaup) , respectively these species are all small, benthic, and covered with plastron from head to tail. Three species have been recorded in Taiwan, but there are many differences between the species names and the specimen illustrations in other foreign publication studies. Recision on the records in Taiwan indicated that three species occur in this region , namely, E. draconis, P. laternarius and P. volitans. According to some osteological and external characters, a hypothesis on the phylogenetic relationship was arrived : P. laternarius is not the sister group of P. volitans and P. lancifer, but the sister group of Eurypegasus species. It is suggested that these five species should be classified in only genus, the Pegasus. Bottom-trawl samplings were made between April 2001 to April 2002 in area of the Kaohsiung coastal at depth around 30 meters. 32 specimens of P. volitans were captured. P. volitans captured its prey by means of oral suction. Guts of the majority of the preserved specimens, including those died right after landed, were empty. Besides some fine granules of sand, one specimen¡¦s gut included caprellideans (Crustacea, Amphoipoda). Skin-shedding was observed numerous times in the aquarium. Unlike other seamoths, only part of the skin was shedded at one time; no regular cycle of skin-sheding was noticed. No social pairing of the sexes and reproductive activity during this study was not noticed. Specimens collected in November tended to be largerin size. The smallest specimens with large ovary was 55mm in length, whereas the largest dry female specimens with a 1.2mm egg was 70mm.. Histological evidence (individual female had eggs in various developmental stages at the same time) indicates that this species is a multiple spawner.

Abridged Thesis (doctoral)--Universität, Hannover, 2000.

Reproduction de : Thèse de doctorat : Lettres et arts : Lyon 2 : 2007. / Titre provenant de l'écran-titre. Bibliogr.

Thesis (Honors)--College of William and Mary, 2009. / Includes bibliographical references (leaves 62-68). Also available via the World Wide Web.

Models for mediation are widely used in psychology, behavior science and education because they help researchers understand how a causal effect happens through one or several mediating variables. And more complex mediation models that incorporate multiple mediators are increasingly being assessed. This report uses a generated dataset to provide an overview of the assessment of direct effects and indirect effects in multiple mediator models. Use of a multiple comparison-based procedure for testing a set of hypotheses simultaneously while controlling the experiment-wise type I error rate is used to calculate a confidence interval for each pairwise contrast of mediated effects. Three approaches will be used to test hypotheses concerning the contrast between pairs of mediator effects. These approaches include 1) an assumption of zero covariance between parameters from different models, 2) assumption of a non-zero covariance between parameters from different models and 3) use of bootstrapping. Results are provided and discussed. / text

No description available.

No description available.