Chong Hyun Lee

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Tetrodotoxin (TTX) is a potent toxin that specifically binds to voltage-gated sodium channels (NaV). TTX binding physically blocks the flow of sodium ions through NaV, thereby preventing action potential generation and propagation. TTX has different binding affinities for different NaV isoforms. These differences are imparted by amino acid substitutions in(More)
Tetrodotoxin (TTX) is a potent toxin that specifically binds to voltage gated sodium channels. TTX binding physically blocks the flow of sodium ions through the channel, thereby preventing action potential (AP) generation and propagation. TTX has different binding affinities for different sodium channel isoforms. These differences are imparted by amino acid(More)
This article develops the mathematical models needed to describe the key issues in using an array of antennas for receiving spacecraft signals for DSN applications. The detrimental effects of nearby interfering sources, such as other spacecraft transmissions or natural radio sources within the array’s field of view, on signal-to noise ratio (SNR) are(More)
A novel information-reduced carrier-synchronization system has been evaluated by means of both analysis and simulation. The idea is to use preliminary estimates of the received binary symbols to reduce the number of transitions before attempting to track the carrier phase, in order to minimize the effects of squaring loss on loop performance. It is shown(More)
The objective of this work is to develop discrete-time demodulator architectures for broadband optical pulse-position modulation (PPM) that are capable of processing Nyquist or near-Nyquist data rates. These architectures are motivated by the numerous advantages of realizing communications demodulators in digital very large scale integrated (VLSI) circuits.(More)
The concept of a generalized data pre-processor for preliminary estimates of block and convolutionally encoded symbols is described and evaluated. Preliminary data estimates are envisioned to have application in removing binary phase-shift-keyed (BPSK) modulated data from the received carrier prior to phase estimation, particularly in low signal-to-noise(More)
In this article, we describe a slot-synchronization algorithm for optical signals transmitted using pulse-position modulation (PPM). This algorithm utilizes PPM symbol decisions in order to generate a slot-timing error signal without the use of guard time around the transmitted laser pulse or synchronization symbols. We derive expressions for the open-loop(More)
The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order(More)