• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.3
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• pp.323-328
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• 2001

Multicarrier modulation is a promising technique for mobile communications system, since it has a strong immunity to multipath fading and increasing bandwidth efficiency. In this paper, the performance of MC DS-CDMA/MPSK has been analyzed with that of DS-CDMA/MPSK system using MRC diversity in the same frequency bandwidth. The results show that with no diversity we can see that the BER of about $10^{-5}$ is achieved at $E_b/N_o$ = 25 dB, with diversity is reachable up to 12 dB.

• Journal of the Korean Geophysical Society
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• v.8 no.1
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• pp.7-14
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• 2005

Early detection in real-time response of slope movements ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of slope-stabilizing structures such as Rock bolt, Nail and Pile during or after installation. We developed a novel monitoring system using Fiber Bragg Grating (FBG) sensor. It's advantages are highly sensitivity, small dimension and electro-magnetic immunity. capability of multiplexing, system integrity, remote sensing - these serve real-time health monitoring of the structures. Real-time strain measurement by the signal processing program is shown graphically and it gives a warning sound when the monitored strain state exceeds a given threshold level so that any sign of abnormal disturbance on the spot can be easily perceived.

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.203-205
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• 2004

A soft error rate neutrons is a growing problem for terrestrial integrated circuits with technology scaling. In the acceleration test with high-density neutron beam, a latch-up prohibits accurate estimations of the soft error rate (SER). This paper presents results of analysis for the latch-up characteristics in the circumstance corresponding to the acceleration SER test for SRAM. Simulation results, using a two-dimensional device simulator, show that the deep p-well structure has better latch-up immunity compared to normal twin and triple well structures. In addition, it is more effective to minimize the distance to ground power compared with controlling a path to the $V_{DD}$ power.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.2
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• pp.233-240
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• 2019

High-altitude ElectroMagnetic Pulse(HEMP) is a high-power electromagnetic pulse caused by nuclear explosions at altitudes above 30 km. This pulse can cause serious damage to the electrical/electronic device. Therefore, there are a lot of studies on the effects of HEMP in the literature. When conducting studies on the effects of HEMP, it is essential to measure the simulated HEMP. Depending on the need for measurement, this paper focuses on the HEMP measurement method. This paper proposes a measurement method using frequency domain compensation to extract the correct waveform and solves the offset problem more efficiently than the conventional methods. The proposed method is verified by experiment using HEMP simulator and measurement system in ADD.

• Electronics and Telecommunications Trends
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• v.33 no.6
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• pp.118-128
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• 2018

With the massive increase in bandwidth for wireless communications, free space optical (FSO) communication has attracted significant interest owing to its outstanding strengths over conventional radio frequency wireless communication such as a wide bandwidth, unlicensed spectrum, low power consumption, small size, electromagnetic interference immunity, long-range propagation, and improved security. In recent years, FSO technology has been studied intensively for use in terrestrial and underwater autonomous and unmanned mobile systems, a rapidly growing application area, including robots, drones, unmanned aerial vehicles, autonomous vehicles, unmanned trains, and unmanned submarines. In this report, we review the recent trends and key technologies for the mobile FSO system, and introduce our drone-based mobile FSO system, which is currently under development.

• IMMUNE NETWORK
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• v.16 no.1
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• pp.52-60
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• 2016

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that bridge innate and adaptive immune responses, thereby leading to immune activation. DCs have been known to recognize pathogen-associated molecular patterns such as lipopolysaccharides (LPS) and nucleic acids via their pattern recognition receptors, which trigger signaling of their maturation and effector functions. Furthermore, DCs take up and process antigens as a form of peptide loaded on the major histocompatibility complex (MHC) and present them to T cells, which are responsible for the adaptive immune response. Conversely, DCs can also play a role in inducing immune suppression under specific circumstances. From this perspective, the role of DCs is related to tolerance rather than immunity. Immunologists refer to these special DCs as tolerogenic DCs (tolDCs). However, the definition of tolDCs is controversial, and there is limited information on their development and characteristics. In this review, we discuss the current concept of tolDCs, cutting-edge methods for generating tolDCs in vitro, and future applications of tolDCs, including clinical use.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.339-342
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• 2005

In order to support ultrawide-band signal generation for low rate WPAN, several types of signal generation mechanisms are suggested such as Chaos, Impluse, and Chirp signals by the activity of IEEE 802.15.4a. The communication system applied chaos theory may have ultrawide-band characteristics with spread spectrum and immunity from multipath effect. In order to use the advantage of chaotic signal generation, we introduce the system implementation of communication and networking systems with the chaos UWB signal. This system may be composed of mainly three parts in hardware architecture : RF transmission with chaotic signal generation, signal receiver using amplifiers and filters, and 8051 & FPGA unit. The most difficult part is to implement the chaotic signal generator and build transceiver with it. The implementation of the system is devidced into two parts i.e. RF blocks and digital blocks with amplifiers, filters, ADC, 8051 processor, and FPGA. In this paper, we introduce the system block diagram for chaotic communications. Mainly the RF block is important for the system to have good performance based on the chaotic signal generator. And the main control board functions for controlling RF blocks, processing Tx and Rx data, and networking in MAC layer.

• Journal of Sensor Science and Technology
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• v.15 no.1
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• pp.40-46
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• 2006

This paper presents a novel fiber optic accelerometer system for monitoring vibration of large-size structures. The system is composed of one (or multiple) sensor head, a light control unit and a signal processing unit. The sensing mechanism of the sensor head is based on a novel integration of the moire fringe phenomenon with fiber optics to achieve a robust performance in addition to its immunity to EM interference, easy cabling, and low cost. In this paper, a prototype of the fiber optic accelerometer system has been developed successfully. A low-cost light control unit has been developed to drive the system's optic and electronic components. A unique algorithm has also been developed to derive the sensor's acceleration from the raw signals of the light control unit; it is implemented via a separate signal processing unit. Finally, the shaking table tests successfully demonstrate the performance and the potential of the moire fringe fiber optic sensor system to monitor the health of civil infrastructures.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.423-435
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• 2013

The Codonopsis pilosula is traditional oriental herb associated with immune-modulatory functions and has anti-inflammatory properties and antioxidative activity. The present study was conducted to investigate the effects of dietary supplementation of Codonopsis pilosula extract powder (CEP) on the immunity and productivity in sows and piglets. A total of 20 pregnant sows were randomly assigned to two dietary treatments, which was given a corn-soybean meal diet with 0% and 0.5% CEP from 40 days prepartum to weaning (25 days postpartum). The immune system of piglets was expected to build up, because the feeding of CEP might increase the colostrum contents in sows. We also predicted that the growth performance of piglets also could be increased by some compensation effects due to the increased immunity of piglets. In results, immunities of sows and piglets as well as growth performance of piglets were not affected by the supplementation of CEP. The correlation between the colostrum and the serum on the IgG contents tended to have a positive correlation, although there was no significant (coefficient, 0.435; P=0.102). This result suggests that the supplementation of CEP may increase IgG contents in sows and piglets and contribute to improve immunity of piglets. In conclusion, it is thought that the physiologically active substances of CEP did not influence to the immune synergic effects in vivo of sows. Thus, the metabolic and action mechanism of the physiologically active substances of CEP should be explored to evaluate the availability of CEP as a feed additive for the immunomodulator.

• Applied Chemistry for Engineering
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• v.35 no.1
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• pp.54-60
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• 2024

The present study was aimed to evaluate the removal of the trace pollutants (heavy metals and microplastics) in the sewage treatment plant by using the jellyfish Extract at Immunity reaction (JEI) of Aurelia coerulea. The experiment was conducted on two different scales: the lab scale using a Jar-tester and the Pilot system scale equipped with two newly developed devices in the laboratory, the active tube connection mixed system and the concentration integrated separation device. Compared to anionic polymers currently used in the field, JEI showed similar or higher efficiency to remove the trace pollutants. When JEI was added to the effluent through the Pilot system, the combination of JEI and the trace pollutants was maximized through two mixing processes, and as a result, the removal rate of the trace pollutants was greatly improved. Based on these results, we propose the present technology as an alternative to removing trace pollutants that can reduce ecosystem risk and minimize the generation of inorganic waste, away from the existing method.