Model Predictive Engine Air-Ratio Control Using Online Sequential Relevance Vector Machine

Engine power, brake-specific fuel consumption, and emissions relate closely to air ratio (i.e., lambda) among all the engine variables. An accurate and adaptive model for lambda prediction is essential to effective lambda control for long term. This paper utilizes an emerging technique, relevance vector machine (RVM), to build a reliable time-dependent lambda model which can be continually updated whenever a sample is added to, or removed from, the estimated lambda model. The paper also presents a new model predictive control (MPC) algorithm for air-ratio regulation based on RVM. This study shows that the accuracy, training, and updating time of the RVM model are superior to the latest modelling methods, such as diagonal recurrent neural network (DRNN) and decremental least-squares support vector machine (DLSSVM). Moreover, the control algorithm has been implemented on a real car to test. Experimental results reveal that the control performance of the proposed relevance vector machine model predictive controller (RVMMPC) is also superior to DRNNMPC, support vector machine-based MPC, and conventional proportional-integral (PI) controller in production cars. Therefore, the proposed RVMMPC is a promising scheme to replace conventional PI controller for engine air-ratio control

Numerical Modeling and Control of Rotating Plate with Coupled Self-Sensing and Frequency-Dependent Active Constrained Layer Damping

This work proposes a coupled finite element model for actively controlled constrained layer damped (CLD) rotating plate with self-sensing technique and frequency-dependent material property in both the time and frequency domain analyses. Constrained layer damping with viscoelastic material can effectively reduce the vibration in rotating structures. However, most existing research models use complex modulus approach to model the viscoelastic material, but it limits to frequency domain analysis and the frequency dependency of the viscoelastic material is not well-included as well. It is meaningful use of the anelastic displacement fields (ADFs) that is done in order to include the frequency dependency of the material for both the time and frequency domains. Also, unlike previous ones, all types of damping are taken into account by this finite element model. Thus, in this work, a single layer finite element is adopted to model a three-layer active constrained layer damped rotating plate in which the constraining layer is made of piezoelectric material to work as both the self-sensing sensor and actuator. This newly proposed finite element model is validated, and then, as shown in numerical studies, this proposed approach can achieve effective vibration reduction in both the frequency and time domains

Genome sequence and genetic linkage analysis of Shiitake mushroom _Lentinula edodes_

_Lentinula edodes_ (Shiitake/Xianggu) is an important cultivated mushroom. Understanding the genomics and functional genomics of _L. edodes_ allows us to improve its cultivation and quality. Genome sequence is a key to develop molecular genetic markers for breeding and genetic manipulation. We sequenced the genome of _L. edodes_ monokaryon L54A using Roche 454 and ABI SOLiD genome sequencing. Sequencing reads of about 1400Mb were de novo assembled into a 40.2 Mb genome sequence. We compiled the genome sequence into a searchable database with which we have been annotating the genes and analyzing the metabolic pathways. In addition, we have been using many molecular techniques to analyze genes differentially expressed during development. Gene ortholog groups of _L. edodes_ genome sequence compared across genomes of several fungi including mushrooms identified gene families unique to mushroom-forming fungi. We used a mapping population of haploid basidiospores of dikaryon L54 for genetic linkage analysis. High-quality variations such as single nucleotide polymorphisms, insertions, and deletions of the mapping population formed a high-density genetic linkage map. We compared the linkage map to the _L. edodes_ L54A genome sequence and located selected quantitative trait loci. The Shiitake community will benefit from these resources for genetic studies and breeding.
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MiR-133b Targets Antiapoptotic Genes and Enhances Death Receptor-Induced Apoptosis

Despite the importance of microRNAs (miRs) for regulation of the delicate balance between cell proliferation and death, evidence for their specific involvement during death receptor (DR)-mediated apoptosis is scarce. Transfection with miR-133b rendered resistant HeLa cells sensitive to tumor necrosis factor-alpha (TNFα)-induced cell death. Similarly, miR-133b caused exacerbated proapoptotic responses to TNF-related apoptosis-inducing ligand (TRAIL) or an activating antibody to Fas/CD95. Comprehensive analysis, encompassing global RNA or protein expression profiling performed by microarray experiments and pulsed stable isotope labeling with amino acids in cell culture (pSILAC), led to the discovery of the antiapoptotic protein Fas apoptosis inhibitory molecule (FAIM) as immediate miR-133b target. Moreover, miR-133b impaired the expression of the detoxifying protein glutathione-S-transferase pi (GSTP1). Expression of miR-133b in tumor specimens of prostate cancer patients was significantly downregulated in 75% of the cases, when compared with matched healthy tissue. Furthermore, introduction of synthetic miR-133b into an ex-vivo model of prostate cancer resulted in impaired proliferation and cellular metabolic activity. PC3 cells were also sensitized to apoptotic stimuli after transfection with miR-133b similar to HeLa cells. These data reveal the ability of a single miR to influence major apoptosis pathways, suggesting an essential role for this molecule during cellular transformation, tumorigenesis and tissue homeostasis

Implementation of problem-based learning in junior secondary science curriculum

Recent curriculum reforms in Hong Kong emphasize learning how to learn, inquiry, collaboration, and similar capabilities. Problem-based learning (PBL) seems an appropriate approach for addressing these new requirements. However, little is known about the use of PBL in secondary (middle) schools, particularly in East-Asian countries in which Confucian-heritage values influence learning approaches. Therefore, the goal of this research was to provide a systematic account of an attempt to implement PBL in Form 1 (Grade 7) Integrated Science classes. The study investigated the teachers’ pedagogical actions, the aspects of the PBL environment that helped to motivate students in science learning, their pattern of discourse for science development and the possible differences of their learning outcomes compared with PBL and conventional learning conditions. A quasi-experimental and mixed-method approach was employed to gather data from two experimental classes (n = 62) and two control classes (n = 63). Data sources included field notes of classroom observations, audio recordings of students working in small groups on their PBL problems, interviews with teachers and students, and science tests administered immediately prior to each instructional unit (pre-test), at the conclusion of each unit (post-test), and before the school term ended (delayed post-test). The study has five main findings: (1) PBL teachers used different strategies to help students who were new to PBL to adapt to the new pedagogical practice, to facilitate group confrontation, and to help students become self-directed learners. (2) Choice, challenge, control and collaboration seem to have motivated students’ learning in the PBL classrooms. (3) Disagreements about the problem situations stimulated task-related cognitive activity and resulted in academic progress. (4) Students’ questions during collaboration facilitated learning by directing their’ inquiry and expanding their thinking. (5) Science test results show that the PBL group performed at least as well as the traditional learning group in knowledge acquisition, and that PBL helped the high achievers to retain information better than their peers in the traditional learning group. The study provides valuable information that shows how PBL can work in secondary school science classrooms. Implications for future research on PBL, and its practice in secondary school science, are also outlined.published_or_final_versionEducationDoctoralDoctor of Philosoph