• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.353-356
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• 2000

Multi-bias parameter extraction technique for HEMT small signa] equivalent circuits is presented in this paper. The technique in this paper uses S-parameters measured at various bias points in the active region to construct one optimization problem, of which the vector of unknowns contains only a set of bias-independent elements. Tests are peformed on measured S-parameters of a pHEMT at 30 bias points. Results indicate that the calculated S-parameters is similar to the measured data.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.217-219
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• 2005

This paper describes implicit restated arnoldi method algorithm and Its application to small size power systems In order to observe the salient features of IRAM algorithm. Two area system with 36 state variables and England 39-bus system with 150 state variables have been tested using IRAM, and the eigenvalue results of IRAM are compared with those of the results obtained from QR method.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.353-355
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• 1993

A single-mode fiber-optic interferometer for measuring small vibrations was constructed. The interferometer is based on the Fabry-Perot configuration that uses a single mode bidirectional fiber coupler as a beam splitter and employs peak detection scheme in the signal processing. The instrument was used to measure the displacement of the translator clamped to a piezo crystal.

• Journal of Ocean Engineering and Technology
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• v.16 no.6
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• pp.32-36
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• 2002

This paper presents the results of wave profile detection from video image using the Mexican hat function. The Mexican hat function has been extensively used in the field of signal processing to detect discontinuity in the images. The analysis was done on the numerical image and video images of waves that were taken in the small wave flume. The results show that the Mexican hat function is an excellent tool for wave profile detection.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.365-370
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• 1998

This paper reports on the measurement of the vane motion in a positive displacement small vane pump. The capacitive method using ceramic vane is proposed to measure the vane motion. This method enables us to measure only radial motion of the vane regardless of the motions of other directions. With simple experiments and solutions of simultaneous equations, the indirect compensation of measured signal was performed.

• Journal of Biomedical Engineering Research
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• v.13 no.3
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• pp.201-208
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• 1992

In the indirect optical bio-telemetry, high frequency response and low minimum detectable optical power can be achieved by using photodiode with small light receiving area which minimizes junction capacitance. But, on the other hand, S/N ratio becomes low because the optical signal current is small. To solve such a problem, we attach plato-convex lens in front of photo diode, The results of comput- er simulation and experiments suggest promotion of light receiving efficiency and possibility of multi- telemetry system through directivity of convex lens in one room.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.5
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• pp.762-768
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• 1987

The capacitive transducers, which are used of the principle of capacitance changes by means of the variation of distance between electrodes, are usually utilized for measurement of small displacements. But the measurement ranges of this method are limited. In this study, the measurement ranges are extended by using the variation method of the surface area of electrodes. Thus the capacitive transducer and signal conditioner, which are having the capability of measurement range of 25mm and resolution of 0.1\ulcorner, have developed, and its environmental characteristics are also tested.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.48-58
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• 2023

Interferon regulatory factor 3 (IRF3) integrates both immunological and non-immunological inputs to control cell survival and death. Small GTPases are versatile functional switches that lie on the very upstream in signal transduction pathways, of which duration of activation is very transient. The large number of homologous proteins and the requirement for site-directed mutagenesis have hindered attempts to investigate the link between small GTPases and IRF3. Here, we constructed a constitutively active mutant expression library for small GTPase expression using Gibson assembly cloning. Small-scale screening identified multiple GTPases capable of promoting IRF3 phosphorylation. Intriguingly, 27 of 152 GTPases, including ARF1, RHEB, RHEBL1, and RAN, were found to increase IRF3 phosphorylation. Unbiased screening enabled us to investigate the sequence-activity relationship between the GTPases and IRF3. We found that the regulation of IRF3 by small GTPases was dependent on TBK1. Our work reveals the significant contribution of GTPases in IRF3 signaling and the potential role of IRF3 in GTPase function, providing a novel therapeutic approach against diseases with GTPase overexpression or active mutations, such as cancer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.4
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• pp.396-405
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• 2009

This paper describes playback downlink and telecommand uplink channel design performed for a transportable small-sized KOMPSAT(Korea Multi-Purpose Satellite) ground station. As a result of downlink channel design, required receiving performance was calculated from the threshold signal-to-noise ratio of playback signal and it was revealed that this performance can be guaranteed in 1.5 m ground station with 6.5 dB/K of G/T. For the uplink channel design, 40 dBW of EIRP was derived from the threshold signal-to-noise ratio of telecommand signal received at on-board receiver. The implemented small-sized ground station based on design was evaluated to be fully acceptable for KOMPSAT TT&C(Telemetry, Tracking and Command) system and playback downlink design without taking account of additional 3 dB system link margin was shown to be effective because it had provided constantly initial channel performance without any remarkable degradation over several years of tests with KOMPSAT and KOMPSAT-2, for both uplink and playback downlink in the elevation angle above $10^{\circ}$.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.338-343
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• 2007

BOLD T2*-weighted MR images reflects cortical blood flow and oxygenation alterations. fMRI study relies on the detection of localized changes in BOLD signal intensity. Since fMRI measures the very small modulations in BOLD signal intensity that occur during changes in brain activity, it is also very sensitive to small signal intensity variations caused by physiologic noise during the scan. Due to the complexity of movement of various organs associated with heart beat, it is important to reduce cardiac related noise rather than other physiological noise which could be required with relatively simple method. Therefore, a number of methods have been developed for the estimation and reduction of cardiac noise in fMRI study. But, each method has limitation. In this study, we proposed a new estimation method for brain activities influenced by blood pulsation effect using regression analysis with blood pulsation signal and the correspond slice of fMRI. We could find out that the right anterior cingulate cortex and right olfactory cortex and left olfactory cortex were largely influenced by blood pulsation effect for new method. These observed areas are mostly on the structure of anterior cerebral artery in the brain. That is convinced with that our method would be valid and our new method is easier to apply in practice and reduce computational burden than the retrospective method.