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Novel fuzzy logic controllers with self-tuning capability
No full textTwo controllers which extend the PD+I fuzzy logic controller to deal with the plant having time varying nonlinear dynamics are proposed. The adaptation ability of the first self tuning PD+I fuzzy logic controller (STPD+I_31) is achieved by adjusting the output scaling factor automatically thereby contributing to significant improvement in performance. Second controller (STPD+I_9) is the simplified version of STPD+I_31 which is designed under the imposed constraint that allows only minimum number of rules in the rule bases. The proposed controllers are compared with two classical nonlinear controllers: the pole placement self tuning PID controller and sliding mode controller. All the controllers are applied to the two-links revolute robot for the tracking control. The tracking performance of STPD+I_31 and STPD+I_9 are much better than the pole placement self tuning PID controller during high speed motions while the performance are comparable at low and medium speed. In addition, STPD+I_31 and STPD+I_9 outperform sliding mode controller using same method of comparison study
The Integration of IVUS and OCT
No full textUltrasound and optical coherence tomography (OCT) provide complementary capabilities-ultrasound has high penetration depth but low resolution; OCT has high resolution but low penetration depth. The integration of these two technologies enable superior imaging capabilities for intravascular applications.Jiawen Li, Teng Ma, Qifa Zhou and Zhongping Che
Division and Unity: The History and Historiography of the Pennsylvania Constitution
No full textAbout the author:
Wen Li Teng is pursuing a double major in History and Political Science at the University of Chicago
Electrospun PVDF/aromatic HBP of 4th gen based flexible and self-powered TENG for wearable energy harvesting and health monitoring
No full textAbstract In recent times, high-performance wearable electronic devices that can transform mechanical force into electrical energy for biomedical monitoring applications are receiving an increasing amount of attention. In the present study, we focused on a flexible, self-powered and wearable triboelectric nanogenerator (TENG) based on electrospun polyvinylidene fluoride (PVDF)/aromatic hyperbranched polyester of 4th generation (Ar.HBP-G4, 0–40 wt.-% w.r.t. PVDF content) blend nanoweb as tribo-negative layer and melt-blown thermoplastic polyurethane (TPU) as tribo-positive layer for energy harvesting and human health monitoring applications. Among the varying Ar.HBP-G4 content used, incorporation of Ar.HBP-G4 (10 wt.-%) in PVDF (P-Ar.HBP-G4-10) showed higher increase in the triboelectric output voltage when compared to pristine PVDF and other Ar.HBP-G4 weight ratios. The optimized P-Ar.HBP-G4-10/TPU based TENG exhibited a peak-to-peak voltage (V p-p ) of 124.4 V under an applied load of 9.8 N and frequency 1 Hz which is superior to many other TENGs reported elsewhere. Higher triboelectric performance of P-Ar.HBP-G4 blend based TENG compared to that of neat PVDF is attributed to the effect of Ar.HBP-G4-10 in enhancing the degree of crystallinity and polar β-crystalline phase content (98.3%) in PVDF. The ability of the TENG to power up portable electronic devices is demonstrated when it is powered for 750 s while connected through a capacitor and a rectifier, and the TENG was able to operate 45 light-emitting diodes directly. Evaluation of the triboelectric output of the TENG device attached to different parts of the human body reveal significantly better output voltage and sensitivity for human health monitoring. The results of this work pave a new way to develop TENG based on P-Ar.HBP-G4 nanowebs for sustainable energy generation and wearable healthcare monitoring systems
The Menkaure Triad, Numerical Thinking, and Divine Configurations in Ancient Egypt
No full textAbout the Author
Formerly an undergraduate at the University of California, Los Angeles, Wen Li Teng is a transfer student at the University of Chicago. Wen Li is currently pursuing a major in History
Civilization and Nature: A Reading of Ancient Texts
No full textAbout the Author
Hailing from Singapore, Wen Li Teng is a first-year student at the University of California, Los Angeles. She intends to declare a major in History
Robustness and classification capabilities of MRI radiomic features in identifying carotid plaque vulnerability
No full textObjectives To assess how radiomic features may be combined with plaque morphological and compositional features identified by multi-contrast MRI to improve upon conventional risk assessment models in determining culprit carotid artery lesions.Methods Fifty-five patients (mean age: 62.6; 35 males) with bilateral carotid stenosis who experienced transient ischaemic attack (TIA) or stroke were included from the CARE-II multi-centre carotid imaging trial (ClinicalTrials.gov Identifier: NCT02017756). They underwent MRI within 2 weeks of the event. Classification capability in distinguishing culprit lesions was assessed by machine learning. Repeatability and reproducibility of the results were investigated by assessing the robustness of the radiomic features.Results Radiomics combined with a relatively conventional plaque morphological and compositional metric-based model provided incremental value over a conventional model alone (area under curve [AUC], 0.819 +/- 0.002 vs 0.689 +/- 0.019, respectively, P = .014). The radiomic model alone also provided value over the conventional model (AUC, 0.805 +/- 0.003 vs 0.689 +/- 0.019, respectively, P = .031). T2-weighted imaging-based radiomic features had consistently higher robustness and classification capabilities compared with T1-weighted images. Higher-dimensional radiomic features outperformed first-order features. Grey Level Co-occurrence Matrix, Grey Level Dependence Matrix, and Grey Level Size Zone Matrix sub-types were particularly useful in identifying textures which could detect vulnerable lesions.Conclusions The combination of MRI-based radiomic features and lesion morphological and compositional parameters provided added value to the reference-standard risk assessment for carotid atherosclerosis. This may improve future risk stratification for individuals at risk of major adverse ischaemic cerebrovascular events.Advances in knowledge The clinical relevance of this work is that it addresses the need for a more comprehensive method of risk assessment for patients at risk of ischaemic stroke, beyond conventional stenosis measurement. This paper shows that in the case of carotid stroke, high-dimensional radiomics features can improve classification capabilities compared with stenosis measurement alone
TENG implant for monitoring blood flow through a vascular graft
No full textTato bakalářská práce se zabývá problematikou triboelektrických nanogenerátorů se snahou jejich využití jako implantátů pro monitorování průchodnosti krve cévní protézou. Práce je rozdělena na teoretickou část zaměřenou na triboelektrický jev, principy fungování TENG v jednotlivých režimech a přehled jejich využití v oblasti medicíny. Dále popisuje elektrickou charakterizaci TENG. Experimentální část popisuje výrobu a měření vlastností vzorků složených z elektrod a naneseného materiálu. Následně pojednává o teoretických návrzích těchto implantátů. V praktické části této bakalářské práce je popsána výroba těchto návrhů, spolu s jejich postupnou optimalizací a testováním. V závěru práce jsou zhodnoceny dosažené výsledky.This bachelor thesis deals with issue of triboelectric nanogenerators with an attempt to use them as implants for monitoring blood flow through vascular graft. The thesis is divided into a theoretical part focusing on the triboelectric effect, the principles of operation of TENGs in different modes and an overview of their medical applications. It also describes the electrical characterization of TENG. The experimental part describes the fabrication and measurement of the properties of samples composed of electrodes and deposited material. Then discusses the theoretical designs of these implants. In the practical part of this bachelor thesis, the fabrication of these designs is described, along with their step-by-step optimization and testing. The thesis concludes with an evaluation of the results obtained.
The Advances in Conversion Techniques in Triboelectric Energy Harvesting: A Review
No full textA triboelectric nanogenerator (TENG) is a new transducer utilizing contact electrification and electrostatic induction to transform mechanical energy into electric energy. Due to its high energy density and flexibility, it can be employed to make electronic devices self-powered by harvesting ambient mechanical energy in many application scenarios, such as biomedical devices, wearable electronics, and Internet-of-Things (IoT) sensors. However, due to the time-varying and low internal capacitance of a TENG, it is challenging to extract electrical energy from it. Hence, good power conversion techniques are crucial in TENG energy harvesting systems. Currently, studies on dedicated integrated power conversion techniques are very limited. Due to the exponentially increasing research interests in TENG, a comprehensive study on the TENG energy harvesting system, emphasizing integrated-circuit (IC) power conversion techniques, is urgently needed. This paper summarizes and compares the state-of-the-art triboelectric energy harvesting systems, focusing on different power conversion techniques for output power enhancement. Some techniques, which have been widely used in other relevant energy harvesting systems, are also mentioned to inspire innovative design strategies for TENG systems.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and MaterialsElectronic Instrumentatio
Site selection, structural design, construction, management and production of floating cage culture system in Malaysia
No full textThe success of cage culture system is largely determined by correct selection of favourable sites, suitable cage size and facilities and management of the system. These three elements are considered in this paper in relation to culture systems in Malaysia
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