Experimental study on turbulence characteristics of a slot jet impingement on semi-circular surfaces

2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A diagrammatic approach to search for minimum sampling frequency and quantization resolution for digital control of power converters

A diagrammatic approach to find out the minimum sampling frequency and quantization resolution for digital control of power converters is proposed. The proposed solution algorithm combines consideration on both time sampling and quantization resolution axes to search for the minimum required digital controller settings. Experiments results are presented to justify the proposed algorithm. © 2007 IEEE.published_or_final_versio

Least coupling paths model for non-contact EMI base on lump element approach in switch mode converter

A simplified physical model concludes a minimum of six equivalent physical coupling paths, Least Coupling Paths (LCP), using lump elements approach through non-contact EMI coupling mechanism to the terminals of LISN. Simulation shows both inductive and capacitive coupling through each path may produce substantial EMI measured by a LISN. This physical model is good for understanding, diagnosis and emission estimation.published_or_final_versio

Monetary Policy Transparency and Pass-Through of retail interest rates

This paper examines the degree of pass-through and adjustment speed of retail interest rates in response to changes in benchmark wholesale rates in New Zealand during the period 1994 to 2004. We consider the effect of policy transparency and financial structure in the transmission mechanism. New Zealand is the first OECD country to adopt a formal inflation targeting regime with specific accountability and transparency provisions. Policy transparency was further enhanced by a shift from quantity (settlement cash) to price (interest rate) operating targets in 1999. We find complete long-term pass-through for some but not all retail rates. Our results also show that the introduction of the Official Cash Rate (OCR) increased the pass-through of floating and deposit rates but not fixed mortgage rates. Overall, our results confirm that monetary policy rate has more influence on short-term interest rates and that increased transparency has lowered instrument volatility and enhanced the efficacy of policy

Analysis of the resonance modes of PZT/epoxy 1-3 composite rings

Author name used is this publication: C. P. ChongRefereed conference paper2001-2002 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

A novel high frequency current-driven synchronous rectifier applicable to most switching topologies

A novel current-driven synchronous rectifier is presented in this paper. With the help of current sensing energy recovery circuit, the proposed current-driven synchronous rectifier can operate at high switching frequency with high efficiency. Compared with those voltage-driven synchronous rectification solutions, this current-driven synchronous rectifier has several outstanding characteristics. It can be easily applied to most switching topologies like an ideal diode. Constant gate drive voltage can be obtained regardless of line and load fluctuation. This makes it desirable in high input range application. Converters designed with this synchronous rectifier are also capable of being connected in parallel without taking the risk of reverse power sinking. Principle of operation is given in the paper. A series of experiments verify the analysis and demonstrate the merits.published_or_final_versio

Sufu and Gli3 repressor mediate the temporal basal-to-apical progression of hair cell differentiation in mammalian cochleae

Poster presentation - Theme 3: Development & stem cellsThe Sonic Hedgehog pathway plays important roles in mammalian inner ear development. Mutations of Shh, Smo and Gli3 lead to severe defects in mouse inner ear morphogenesis. However, knockout of Gli2 does not affect inner ear morphology or cochlear hair cell differentiation, suggesting that the Gli repressor function may be required for Hedgehog signaling during inner ear development. Sufu is a negative regulator of Hedgehog signaling and it functions to repress Gli activator and enhance Gli repressor ...postprin

Synthesis of input-rectifierless AC-DC converters

This paper discusses the basic construction procedure and topological possibilities of creating ac/dc converters out of simple dc/dc conveners. It is shown that two separately controlled dc/dc conveners are sufficient for producing a regulated dc output and shaping the input current, from an ac voltage source, without the need for input rectifiers. Some design constraints are discussed, emanating from the limitation of the conversion ratios that can be achieved by particular dc/dc converters. Selected topologies are verified experimentally.published_or_final_versio

Passive PT -symmetric couplers without complex optical potentials

© 2015 American Physical Society. In addition to the implementation of parity-time-(PT-) symmetric optical systems by carefully and actively controlling the gain and loss, we show that a 2×2 PT-symmetric Hamiltonian has a unitarily equivalent representation without complex optical potentials in the resulting optical coupler. Through the Naimark dilation in operator algebra, passive PT-symmetric couplers can thus be implemented with a refractive index of real values and asymmetric coupling coefficients. This opens up the possibility to implement general PT-symmetric systems with state-of-the-art asymmetric slab waveguides, dissimilar optical fibers, or cavities with chiral mirrors

Loss analysis of a single phase fast transient VRM converter

This paper analyzes the losses of a stepping inductor converter in the presence of load transients. Stepping inductor converter is a buck VRM topology which only employs a single phase. Stepping inductor converter is very effective in dealing with fast transient and at the same time it can give better steady state efficiency. Occurrences of transient load current changes are measured in a PC and data are used for the comparison to evaluate the real world performance of the stepping inductor converter and the multiphase interleaved buck converter.published_or_final_versio