• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.1135-1138
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• 1999

In this paper, The Split Model Analysis Algorithm, which can generate the wideband speech signal from the spectral information of narrowband signal, is developed. The Split Model Analysis Algorithm deals with the separation of the 10$\^$th/ order LPC model into five cascade-connected 2$\^$nd/ order model. The use of the less complex 2$\^$nd/ order models allows for the exclusion of the complicated nonlinear relationships between model parameters and all the poles of the LPC model. The relationships between the model parameters and its corresponding analog poles is proved and applied to each 2$\^$nd/ order model. The wideband speech signal is obtained by changing only the sampling rate.

• Journal of Photoscience
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• v.9 no.2
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• pp.47-50
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• 2002

Raft is a distinctive membrane domain enriched in a certain class of lipids, cholesterol, and proteins observed on the plasma membrane. Growing evidence has revealed that such membrane domains play key roles in signal transduction, fertilization, development, transmitter release, and so on. Recently, we have isolated raft-like detergent-resistant membrane (DRM) fraction from bovine photoreceptor rod outer segments. Transducin and its effecter, cGMP-phosphodiesterase, elicited stimulus-dependent translocation between detergent-soluble membrane and DRM. This suggested potential importance of such distinct membrane domains in vertebrate phototransduction. Here, we will discuss physiological meaning of the translocation of major components of cGMP cascade to raft-like membrane in phototransduction. We would like to propose a hypothesis that raft-like membrane domains on the disk membrane are the place where cGMP cascade system could be quenched.

• ETRI Journal
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• v.30 no.4
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• pp.535-545
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• 2008

This paper introduces a systematic top-down and bottom-up design methodology to assist the designer in the implementation of continuous-time (CT) cascade sigma-delta (${\Sigma}{\Delta}$) modulators. The salient features of this methodology are (a) flexible behavioral modeling for optimum accuracy-efficiency trade-offs at different stages of the top-down synthesis process, (b) direct synthesis in the continuous-time domain for minimum circuit complexity and sensitivity, (c) mixed knowledge-based and optimization-based architectural exploration and specification transmission for enhanced circuit performance, and (d) use of Pareto-optimal fronts of building blocks to reduce re-design iterations. The applicability of this methodology will be illustrated via the design of a 12-bit 20 MHz CT ${\Sigma}{\Delta}$ modulator in a 1.2 V 130 nm CMOS technology.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.81-84
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• 1998

For ANC systems applied to aircrafts or passenger ships, engines from which reference signals are usually measured are located so far from seats where main part of controllers are placed. It can make feedforward ANC scheme difficult to implement or very costly. Feedback ANC algorithms which do not require reference signals and use error signals alone to update the filter, are usually sensitive to measurement noise ' and impulse noise. In this paper, reference signal needed for the feedforward control is not measured directly but generated with the estimated frequencies. Cascade adaptive notch filter (ANF), which has the low computational burden, is used to implement ANC system in real time. Several ANFs of order 2 are connected in series to estimate multiple sinusoids. Computer simulations and experiments in the laboratory for verifying efficacy of the proposed algorithm are carried out.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.1-7
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• 2012

In this paper, An X-band solid state power amplifier(SSPA) for pulse compressed microwave signal with 60Watt power and power added efficiency(PAE) above 30% is described. Designed 60Watt high power amplifier(HPA) was implemented by cascade coupled amplifiers, and it is consisted on three stage drive amplifiers with internally matched GaAs FET and one stage main power amplifier with an internally matched GaN HEMT. The designed SSPA has performance with more than total power gain 37dB and output power 48dBm(60-W) in condition of frequency range $9.41{\pm}0.03GHz$, pulse period width under 1ms and duty cycle under 10%. The implemented SSPA can apply to high quality digital marine radar applications with pulse compression technique.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.923-930
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• 2018

In the wireless communication system based on an array antenna, the angle of arrival (AOA) information of signal is very important element and various AOA estimation algorithms have been studied. Although most AOA estimation algorithms employ the uniform linear array (ULA), some algorithms apply the planar array (PA) antenna. In this paper, we present an algorithm for efficiently estimating AOAs of adjacent multiple signals, based on the uniform rectangular array antenna. This approach has two steps; after approximately estimating AOA groups consisting of the closely located signal sources using CAPON, accurately estimating the individual AOA of each signal in the estimated AOA group using Beamsapce MUSIC. The estimation performance of the presented cascade AOA algorithm is illustrated through the computer simulation example.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1254-1258
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• 2004

This paper presents of position control of Permanent Magnet Synchronous Motor (PMSM) the implementation with Field Programmable Gate Array (FPGA) is proposed. Cascade control with inner loop as a current control and an outer loop as a position control is chosen for simplicity and fast response. FPGA is a single chip (single processing unit), which will perform the following tasks: receive and convert control signal, create a reference current signal, control current and create switch signal and act as position controller in a addition of zero form. The 10 kHz sampling frequency and 25 bit of floating point data are defined in this implementation.The experimental results show that the performance of FPGA based position control is comparable with the hardware based position control, with the advantage of control algorithm flexibility

• Proceedings of the Botanical Society of Korea Conference
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• 1998.07a
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• pp.83-96
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• 1998

The plant pigment proteins phytochromes are a molecular light sensor or switch for photomorphogenesis involving a variety of growth and developmental responses of plants to red and far-red wavelength light. Underscoring the photomorphogenesis mediated by phytochromes is the light signal transduction at molecular and cellular levels. For example, a number of genes activated by the phytochrome-mediated signal transduction cascade have been identified and characterized, especially in Arabidopsis thaliana. The light sensor/switch function of phytochromes are based on photochromism of the covalently linked tetrapyrrole chromophore between the two photoreversible forms, Pr and Pfr. The photochromism of phytochromes involves photoisomerization of the tetrapyrrole chromophore. The "photosensor" Pr-form ("switch off" conformation) of phytochromes strongly absorbs 660 nm red light, whereas the "switch on" Pfr-conformation preferentially absorbs 730 nm far-red light. The latter is generally considered to be responsible for eliciting transduction cascades of the red light signal for various responses of plants to red light including positive or negative expression of light-responsive genes in plant nuclei and chloroplasts. In this paper, we discuss the structure-function of phytochromes in plant growth and development, with a few examples of biotechnological implications.

• Journal of Life Science
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• v.26 no.2
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• pp.147-154
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• 2016

Osteosarcoma (OS) is the most common and malignant bone tumors. Although many types of resection surgery and experimental agents were developed, median survival and clinical prognosis are poorly investigated. Recently, several researches have reported that Eucheuma cottonii has potent as protective effects of coal dust-induced lung damage via inhibition of malondialdehyde (MDA) and oxidative stress in bronchoalveolar lavage fluids (BALF). However, anti-cancer effects and specific molecular mechanism of extract from Eucheuma cottonii (EE) has not been clearly studied yet. This study evaluated that anti-cancer potential of EE in human osteosarcoma Saos-2 cells. EE indicated cytotoxicity on Saos-2 cells in a dose-dependent manner. Morphological degradation and nucleic condensation were also observed under the EE treatment. However, it did not significantly affect on non-cancerous kidney HEK-293 cells under the same concentration which is shown cytotoxicity on Saos-2 cells. The phosphorylation of Fas-Associated Death Domain (FADD) and expression of cleaved caspase-8, -7 and -3 were upregulated in a dose-dependent manner. In immunofluorescence staining, expression level of Fas and cleaved PARP were upregulated by EE treatment. Furthermore, treatment of EE induces upregulation of sub G1 phase by flow cytometry analysis. The results demonstrated that EE has a therapeutic potential against osteosarcoma via FADD mediated caspase cascade apoptosis signal pathway.

• BMB Reports
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• v.32 no.3
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• pp.215-225
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• 1999

Phytochromes (with gene family members phyA, B, C, D, and E) are a wavelength-dependent light sensor or switch for gene regulation that underscore a number of photo responsive developmental and morphogenic processes in plants. Recently, phytochrome-like pigment proteins have also been discovered in prokaryotes, possibly functioning as an auto-phosphorylating/phosphate-relaying two-component signaling system (Yeh et al., 1997). Phytochromes are photochromically convertible between the light sensing Pr and regulatory active Pfr forms. Red light converts Pr to Pfr, the latter having a "switch-on" conformation. The Pfr form triggers signal transduction pathways to the downstream responses including the expression of photosynthetic and other growth-regulating genes. The components involved in and the molecular mechanisms of the light signal transduction pathways are largely unknown, although G-proteins, protein kinases, and secondary messengers such as $Ca^{2+}$ ions and cGMP are implicated. The 124-127 kDa phytochromes form homodimeric structures. The N-terminal half contains the tetrapyrrolic phytochromobilin for red/far-red light absorption. The C-terminal half includes both a dimerization motif and regulatory box where the red light signal perceived by the chromophore-domain is recognized and transduced to initiate the signal transduction cascade. A working model for the inter-domain signal communication within the phytochrome molecule is proposed in this Review.