Automated combination of probabilistic graphic models from multiple knowledge sources

Master'sMASTER OF SCIENC

PRESEE: An MDL/MML Algorithm to Time-Series Stream Segmenting

Time-series stream is one of the most common data types in data mining field. It is prevalent in fields such as stock market, ecology, and medical care. Segmentation is a key step to accelerate the processing speed of time-series stream mining. Previous algorithms for segmentingmainly focused on the issue of ameliorating precision instead of payingmuch attention to the efficiency. Moreover, the performance of these algorithms depends heavily on parameters, which are hard for the users to set. In this paper, we propose PRESEE (parameter-free, real-time, and scalable time-series stream segmenting algorithm), which greatly improves the efficiency of time-series stream segmenting. PRESEE is based on both MDL (minimum description length) and MML (minimum message length) methods, which could segment the data automatically. To evaluate the performance of PRESEE, we conduct several experiments on time-series streams of different types and compare it with the state-of-art algorithm. The empirical results show that PRESEE is very efficient for real-time stream datasets by improving segmenting speed nearly ten times. The novelty of this algorithm is further demonstrated by the application of PRESEE in segmenting real-time stream datasets from ChinaFLUX sensor networks data stream

PhD

dissertationDuring Drosophila metamorphosis, pulses of the steroid hormone ecdysone trigger the histolysis of larval tissues in a stage-specific manner, but the mechanism of this developmental response remains unclear. In these studies, we show that histolysis of both the larval midgut and salivary glands is accompanied by increased nuclei permeability, DNA fragmentation and caspase activation, indicative of apoptotic cell death. Two Drosophila cell death activators, reaper (rpr) and head involution defective (hid), are induced by ecdysone in the larval midgut and salivary glands immediately preceding their histolysis, suggesting that the larval tissues are destroyed through the activation of the same apoptotic pathway that is employed during Drosophila embryogenesis. In addition, the cell death inhibitor diap2 is transiently induced in mid-prepupal salivary glands, but repressed in late prepupae, as rpr and hid are induced. These expression patterns suggest that ecdysone directs salivary gland cell death by simultaneously repressing diap2 and inducing rpr and hid. This hypothesis is supported by the results of our molecular genetic analysis which indicates that ecdysone triggers the switch in death gene expression through the ecdysone receptor and ecdysone-regulated transcription factors. Two ecdysone-inducible orphan nuclear receptors, E75A and E75B, are sufficient to repress diap2. In addition, ecdysone induces the Broad-Complex (BR-C) and E74A, which function together with the ecdysone receptor to induce rpr and hid. Our preliminary studies also show that two stress-activated transcription factors, AP-1 and NF-kappa-B, may function as stage-specific activators of rpr and hid in larval salivary glands. Based on these studies, we propose that the ecdysone receptor, ecdysone-induced transcription factors and the stress-response pathways cooperate to precisely regulate larval salivary gland cell death

Optimal Control of Holding Motion by Nonprehensile Two-Cooperative-Arm Robot

Recently, more researchers have focused on nursing-care assistant robot and placed their hope on it to solve the shortage problem of the caregivers in hospital or nursing home. In this paper, a nonprehensile two-cooperative-arm robot is considered to realize holding motion to keep a two-rigid-link object (regarded as a care-receiver) stable on the robot arms. By applying Newton-Euler equations of motion, dynamic model of the object is obtained. In this model, for describing interaction behavior between object and robot arms in the normal direction, a viscoelastic model is employed to represent the normal forces. Considering existence of friction between object and robot arms, LuGre dynamic model is applied to describe the friction. Based on the obtained model, an optimal regulator is designed to control the holding motion of two-cooperative-arm robot. In order to verify the effectiveness of the proposed method, simulation results are shown

Design and Control of Advanced Mechatronics Systems

Research and experiments on mechatronics systems, which are a synergistic integration of mechanical engineering, electronic control, and systems concepts, have contributed significantly to the design of systems, devices, processes, and products [...

Design and Control of Advanced Mechatronics Systems

Research and experiments on mechatronics systems, which are a synergistic integration of mechanical engineering, electronic control, and systems concepts, have contributed significantly to the design of systems, devices, processes, and products [...