295 research outputs found
Fiber design for high-power low-cost Yb:Al-doped fiber laser operating at 980nm
No full textWe investigated an Yb:Al-doped depressed-clad hollow optical fiber (DCHOF) for cladding-pumped 980nm laser operation. With a careful design, the nonzero fundamental-mode cutoff characteristics of a DCHOF allows the competing 1030-1060nm emission to be filtered out, despite being quite close to 980nm. The laser yielded over 3W of output power in a diffraction limited beam (M -parameter degrades to 2.7, as a result of increased cladding-mode lasing, as the cladding thickness is reduced
Research of the Relationship between Li-ion Battery Charge Performance and SOH based on MIGA-Gpr Method
No full textAbstractOwing to the problem that it is difficult to measure State of Health (SOH) of Li-ion battery online, a method to estimate SOH of Li-ion battery using the charge performance under different SOH is put forward. By Grey Incidence Analysis (GIA), the correlation degree between the charge performance and SOH is measured. Based on Multi-island Genetic Algorithm (MIGA) and Gauss Process Regression (GPR), with charge performance as input, SOH is estimates and variance of estimation is also calculated. The result shows that the above-mentioned method can evaluate SOH well
Korean 'Chung-soh' and Australian contemporary dance : a practice based investigation
No full textThis project investigated a characteristic concept of Korean culture, "Chung-soh", to develop an understanding a 'Korean-ness' in dance and of how "Chung-soh" informs cross-cultural dance processes involving Korean and Australian artists. At the same time the author developed her artistic identity through investigating and understanding her dance practice. The DVDs contain 2 works choreographed by the author: Cross sections and Embryo
a review on the efforts for the post-2015 development agenda led by UN and UNESCO
No full textThesis(Master) --KDI School:Master of Public Policy,2015Before the international community adopted the Sustainable Development Goals (SDGs), the international educational community agreed on the Muscat Agreement, with some similar but ultimately different goal and targets. Based on a stakeholder analysis on accountability developed by Romzek and Dubnick (1987), this paper argues that while political accountability was primary and professional accountability was secondary in developing the post-2015 agendas for both UN and UNESCO, there was a stronger professional accountability for UNESCO, which resulted difference in input targets and the scope of the post-2015 educational agenda. The author argues this was possible due to the combination of both representatives of member states and international organizations participating in the discussion process as equal members, as well as an atmosphere where active debate was allowed during the consultation process.masterpublishedKi-Joon SOH
Possibilities and pitfalls in quantifying the extent of cysteine sulfenic acid modification of specific proteins within complex biofluids
No full textabstract: Background
Cysteine sulfenic acid (Cys-SOH) plays important roles in the redox regulation of numerous proteins. As a relatively unstable posttranslational protein modification it is difficult to quantify the degree to which any particular protein is modified by Cys-SOH within a complex biological environment. The goal of these studies was to move a step beyond detection and into the relative quantification of Cys-SOH within specific proteins found in a complex biological setting--namely, human plasma.
Results
This report describes the possibilities and limitations of performing such analyses based on the use of thionitrobenzoic acid and dimedone-based probes which are commonly employed to trap Cys-SOH. Results obtained by electrospray ionization-based mass spectrometric immunoassay reveal the optimal type of probe for such analyses as well as the reproducible relative quantification of Cys-SOH within albumin and transthyretin extracted from human plasma--the latter as a protein previously unknown to be modified by Cys-SOH.
Conclusions
The relative quantification of Cys-SOH within specific proteins in a complex biological setting can be accomplished, but several analytical precautions related to trapping, detecting, and quantifying Cys-SOH must be taken into account prior to pursuing its study in such matrices.The electronic version of this article is the complete one and can be found online at: http://bmcbiochem.biomedcentral.com/articles/10.1186/1471-2091-11-2
A Wideband Four-Way Doherty Bits-In RF-Out CMOS Transmitter
No full textWe present a wideband, 12-bit four-way Doherty Cartesian digital transmitter (DTX) featuring an innovative 50%-LO signed I/Q interleaved up-conversion technique that enables close to perfect orthogonal I/Q summation. The DTX incorporates a compact four-way lumped-element Doherty power combining network to enhance its average efficiency at deep power back-off (DPBO). It comprises a signed second-order hold (SOH) interpolation filter to suppress the sampling spectral replicas significantly. The proposed DTX is realized in a 40-nm bulk CMOS and delivers a peak output power of 27.54 dBm with drain and system efficiencies of 46.35% and 30.77%, respectively, at 5.3 GHz. At 12 dB DPBO, the realized DTX demonstrates a drain efficiency (DE) of 41.74%-39.27% in a 5.2-5.5 GHz band, respectively. Its intrinsic I/Q image, LO leakage, and C-IMD3/H 3BB for a 200 MHz tone spacing over a 4.8-6.2 GHz band are-64,-65, and-69 dBc, respectively, without calibration. Applying a simple memoryless 2× 1-D digital pre-distortion, its error vector magnitude and adjacent channel leakage ratio are lower than-31 dB and-39 dBc, respectively, for a six-carrier '40 MHz 256-QAM OFDM' signal with 18 dBm average output power and a 41% average DE. The signed SOH functionality is verified employing a four-carrier '80 MHz 512-QAM OFDM' signal with spectral purity of better than-35 dBc, while its baseband sampling frequency is 675 MHz.Accepted author manuscriptElectronic
Multi-objective Optimal Energy Management Strategy and Economic Analysis for an Range-Extended Electric Bus
No full textAbstractAn optimal energy management strategy is proposed to match engine fuel consumption and battery SOH of REEB. Models of APU fuel consumption and battery SOH loss are established and multi-objective performance function is provided. DP algorithm is adopted to solve the optimization problem. Under the conditions of different drive cycles, different SOH penalty coefficients are analyzed to reveal its effects. Considering the total life-cycle costs, simulations prove that when battery is not to be replaced, and the capacity configuration and SOH penalty coefficient of battery are both taken the minimum, the best economical results can be achieved
Measures of falls efficacy, balance confidence, or balance recovery confidence for perturbation-based balance training
No full textFrom Frontiers via Jisc Publications RouterHistory: collection 2022, received 2022-08-22, accepted 2022-09-28, epub 2022-10-12Peer reviewed: TrueAcknowledgements: The Balance Recovery Confidence Scale was developed as part of the author's PhD studies under the tutelage of Dr Judith Lane, Dr Chee-Wee Tan, and Prof Nigel Gleeson. The author was awarded a PhD scholarship by the Singapore Institute of Technology.Publication status: PublishedShawn Leng-Hsien Soh - ORCID: 0000-0002-8725-5182
https://orcid.org/0000-0002-8725-5182There is a growing interest in using perturbation-based balance training (PBT) to reduce falls. The efficacy of PBT has been largely attributed to improved physical ability to arrest falls, such as improved recovery step length and trunk velocity. While PBT is likely to influence psychological factors, the impact on this aspect remains unclear. Several studies have found a limited influence of PBT on falls efficacy or balance confidence. Given that falls is a complex phenomenon, the role of PBT on psychological factors needs to be elucidated adequately. Recently, falls efficacy has been proposed to encompass four domains: balance confidence, balance recovery confidence, safe-landing confidence, and post-fall recovery confidence, alongside the appropriate use of falls efficacy measures. This commentary aims to feature some falls efficacy-related measurement instruments so that researchers and clinicians can choose the most suitable measures for PBT.pubpu
Modelling and Experiment-Based Methods for Lithium-Ion Batteries SoH estimation
No full text2020 - 2021This thesis addresses multiple issues regarding the on-board implementation of Lithium-Ion (Li-ion) batteries
State-of-Health (SoH) estimation. Even if in the literature multiple model- and experiment-based SoH
estimation methods are very well explored under laboratory conditions, their suitability for implementation
in the framework of Battery Management Systems (BMSs) or battery chargers is still an open research topic.
Initially, the thesis explores the topic of on-board implementation and identification of battery impedance
models. First the issue of impedance models fitting from Electrochemical Impedance Spectroscopy (EIS) data
is addressed, by proposing an identification method with a suitable procedure for setting the initial values of
the impedance model parameters. When tested using experimental EIS data, the method guaranties the
convergence of the identification process, which is not always the case when considering fixed initial
conditions, as it is typical in the literature.
Then, discrete time representations for three approaches for time domain response approximation of
fractional-order battery models are proposed and evaluated in terms of performance and suitability for onboard implementation. Comparisons between the methods are made in terms of accuracy, computational
burden and suitability for the identification of impedance parameters from time domain measurements. The
study was performed in a simulation framework and focused on a set of ZARC elements, representing the
middle frequency range of Li-ion batteries’ impedance. It was found that the multiple RC approach offers the
best accuracy-complexity compromise, making it the most interesting approach for real-time battery
simulation applications. As for applications requiring the identification of impedance parameters, the
Oustaloup approach offers the best compromise between the goodness of the obtained frequency response
and the accuracy–complexity requirements.
Then, the Incremental Capacity (IC) analysis is proposed for characterising the capacity and the SoH of
batteries aged by using cycling patterns built from current pulses with randomly selected levels and
durations. The batteries are periodically characterised using a 1C charge, which is a high value with respect
to the typical IC tests in pseudo-equilibrium condition. The high-current IC curves generation from raw
voltage/current data includes two filtering stages, one for the input voltage and one for the IC curve
smoothing, which are optimised for the application on the basis of the data characteristics. The correlations
between the IC main peak features and the battery full capacity, for 28 Lithium-Cobalt oxide batteries with
18650 packaging, were evaluated, finding that the main peak area is a general feature for the evaluation of
the SoH under high current tests and random usage patterns, and, therefore, it can be used as a battery
health indicator in practical applications. The effects of the computational parameters on the relationship
between the peak area and the battery capacity are also investigated. The results are confirmed by a further
analysis performed over two additional sets of cells with different technologies, aged with a fixed driving
profile and using fast charging regimes. Additionally, the performance of the peak area as a health indicator
was compared with an ohmic resistance-based estimation approach.
Finally, several linear multifeature models for battery SoH estimation are proposed and their performance is
evaluated. The models combine high current IC and dynamic resistance features, obtainable during partial
constant current charges and discharges respectively. The models are constructed by including fixed sets of
features or by applying features selection procedures based on statistical criteria. The proposed models are
fitted and evaluated with data from two publicly available battery datasets, including batteries cycled using
driving and randomised profiles. During the test process, the estimation improvement introduced by each
multifeature model is evaluated by computing the reduction on the mean squared error for the SoH
estimation with respect to two reference single-feature models already used in recent literature. The
collinearity for each model is quantified through the variance inflation factor to indicate the prediction
reliability of each model. As main result of this analysis, a simple two-features model is proposed as the best
compromise between estimation improvement, with respect to single feature models, and collinearity
reduction. [edited by Author]Questa tesi affronta molteplici questioni riguardanti l'implementazione a bordo della stima dello stato di
salute (SoH) delle batterie agli ioni di litio (Li-ion). Anche se in letteratura molteplici metodi di stima dello SoH
basati su modelli ed esperimenti sono molto ben esplorati in condizioni di laboratorio, la loro idoneità
all'implementazione nell'ambito dei sistemi di gestione delle batterie (BMS) o dei caricabatteria è ancora un
soggetto di ricerca aperto.
Inizialmente, la tesi esplora i temi dell'implementazione e identificazione a bordo dei modelli di impedenza
della batteria. In primo luogo viene affrontata la questione del fitting dei modelli di impedenza ai dati della
spettroscopia di impedenza elettrochimica (EIS), proponendo un metodo di identificazione con una
procedura adeguata per impostare i valori iniziali dei parametri del modello di impedenza. Quando testato
utilizzando dati di EIS sperimentali, il metodo garantisce la convergenza del processo di identificazione, cosa
che non sempre avviene quando si considerano condizioni iniziali fisse, come è tipico in letteratura.
Quindi, le rappresentazioni del tempo discreto per tre approcci per l'approssimazione della risposta nel
dominio del tempo di modelli di batterie di ordine frazionario vengono proposte e valutate in termini di
prestazioni e idoneità per l'implementazione a bordo. I confronti tra i metodi sono effettuati in termini di
accuratezza, onere computazionale e idoneità per l'identificazione di parametri di impedenza da misurazioni
nel dominio del tempo. Lo studio è stato condotto in un quadro di simulazione e si è concentrato su un
insieme di elementi ZARC, che rappresentano la gamma di frequenze medie dell'impedenza delle batterie
agli ioni di litio. È stato riscontrato che l'approccio RC multiplo offre il miglior compromesso tra precisione e
complessità, rendendolo l'approccio più interessante per le applicazioni di simulazione della batteria in
tempo reale. Per quanto riguarda le applicazioni che richiedono l'identificazione di parametri di impedenza,
l'approccio di Oustaloup offre il miglior compromesso tra la bontà della risposta in frequenza ottenuta ei
requisiti di accuratezza-complessità.
Quindi, viene proposta l'analisi della capacità incrementale (IC) per caratterizzare la capacità e il SoH delle
batterie invecchiate utilizzando schemi di ciclo costruiti da impulsi di corrente con livelli e durate selezionati
casualmente. Le batterie vengono periodicamente caratterizzate utilizzando una carica a 1C, che è un valore
elevato rispetto ai tipici test IC in condizioni di pseudo-equilibrio. La generazione di curve IC ad alta corrente
dai dati di tensione/corrente include due stadi di filtraggio, uno per la tensione e uno per il livellamento della
curva IC, che sono ottimizzati per l'applicazione sulla base delle caratteristiche dei dati. Per 28 batterie
all'ossido di litio-cobalto con confezione 18650, sono state valutate le correlazioni tra le caratteristiche del
picco principale della curva IC e la capacità della batteria. È stato riscontrato che l'area di picco principale è
una caratteristica generale per la valutazione del SoH in test di corrente elevata e modelli di utilizzo casuali
e, pertanto, può essere utilizzata come indicatore della salute della batteria in applicazioni pratiche. Vengono
inoltre studiati gli effetti dei parametri computazionali sulla relazione tra l'area di picco e la capacità della
batteria. I risultati sono confermati da un'ulteriore analisi eseguita su altre due set di celle con tecnologie
diverse, invecchiate con un profilo di guida fisso e utilizzando regimi di ricarica rapida. Inoltre, le prestazioni
dell'area di picco come indicatore di salute sono state confrontate con un approccio di stima basato sulla
resistenza ohmica.
Infine, vengono proposti diversi modelli lineari multifeature per la stima dello SoH della batteria e ne vengono
valutate le prestazioni. I modelli combinano caratteristiche de IC ad alta corrente e de resistenza dinamica,
ottenibili rispettivamente durante cariche e scariche parziali a corrente costante. I modelli sono costruiti
includendo insiemi fissi di caratteristiche o applicando procedure di selezione delle caratteristiche basate su
criteri statistici. I modelli proposti sono parametrizzati e valutati con i dati di due datasets di batterie
pubblicamente disponibili, che includono batterie ciclate utilizzando profili di guida e randomizzati. Durante
il processo di test, il miglioramento di stima introdotto da ciascun modello multifeature viene valutato
calcolando la riduzione dell'errore quadratico medio per la stima dello SoH rispetto a due modelli di
riferimento single-feature già utilizzati nella letteratura recente. La collinearità per ciascun modello viene
quantificata attraverso il fattore di inflazione della varianza per indicare l'affidabilità di previsione di ciascun
modello. Come risultato principale di questa analisi, un semplice modello a due caratteristiche viene
proposto come miglior compromesso tra il miglioramento della stima, rispetto ai modelli di riferimento, e la
riduzione della collinearità. [a cura dell'Autore]XXXIV cicl
Author Correction: Transcription Factor HOXA9 is Linked to the Calcification and Invasion of Papillary Thyroid Carcinoma
No full textAn amendment to this paper has been published and can be accessed via a link at the top of the paper
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