• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.577-583
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• 2014

In this study, we evaluated fermentation characteristics of microorganism with antimicrobial activity in makgeolli made from various kinds of koji and nuruk during fermentation. The pH of nuruk groups decreased compared to the koji groups after 3 days of fermentation. Acidity and alcohol contents of nuruk groups significantly increased compared to the koji groups. The total sugar contents of the koji groups were significantly higher than those of the nuruk groups after 15 days of fermentation. Sensory scores of koji groups (DKB) were higher than those of other samples. Antimicrobial activities of nuruk group (GND and ANF) against Salmonella enterica, Bacillus subtilis, Escherichia coli, and Bacillus cereus were significantly higher compared to the koji group. ST-1, isolated from (Geumjeonggu nuruk D), showed the highest antimicrobial activity and was identified as Paenibacillus polymyxa strain RCP6 based on 16S rRNA sequencing. Our result suggest that Paenibacillus polymyxa from nuruk group produces a bacteriocin-like substrate with antimicrobial activity.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1195-1196
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• 2008

It is difficult to solve PCB(Printed Circuit Board) Noise problem. Because Electronic circuit system operates very high frequency. Resonance analysis of PCB layout by PI(Power Integrity) Simulation method visualizes distribution of Switching noise between VDD and GND. By using de-cap, we reduce impedance and solve the EMI problems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1668-1670
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• 2012

In this paper, a satellite array antenna operates at 12.2GHz~12.75GHz was designed and fabricated. The lowest height and high gain electrical beam tilt was obtained by applying backed slot and sub-reflector widening the distance between the patch and the GND. The simulation and measurement showed good agreements, the electrical beam tilt was $10^{\circ}$, the gain was 26.5dBi, the VSWR was less than 3:1 and the return loss was less than -15dB.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.180-184
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• 2013

In this paper, a low power antenna switch controller IC is designed using a silicon-on-insulator (SOI) CMOS technology. To improve power handling capability and harmonic distortion performance of the antenna switch, the proposed antenna switch controller provides 3-state logic level such as +VDD, GND, and -VDD for the gate and body of switch of FETs according to decoder signal. By employing input-coupled current ring oscillator and hardware efficient level shifter, the proposed controller greatly reduces power consumption and hardware complexity. It consumes 135 ${\mu}A$ at a 2.5 V supply voltage in active mode, and occupies $1.3mm{\times}0.5mm$ in area. In addition, it shows fast start-up time of 10 ${\mu}s$.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.6
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• pp.665-670
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• 2015

In this paper, We proposed a broadband RF amplifier for Microwave band receiver. We also proposed a broadband RF amplifier, designed by using EM simulation for reliable amplification of the received signal. Connected to a source terminal to via, it minimizes those which are the active elements of source-side oscillation as the operating element in an ideal GND, and a constant gain characteristic in a broadband. The goal of this was to obtain stable amplification characteristics. For implementing this architecture, we designed the broadband(500 MHz ~ 7 GHz) RF amplifier by using commercial GaAs FET, which operate on 720 MHz, 4,595 MHz, and 6,035 MHz by impedance matching. The voltage gain is 10.635 dB ~ 14.407 dB(737.5 MHz ~ 6.0575 GHz), P1dB is 20 dBc of band(1st harmonic/2nd harmonic).

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.504-513
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• 2009

This paper proposes the new type LED driver modularization for illumination LED driver. The proposed LED driver circuit insulates a hot GND of AC input power and a cold GND of LED driver part by using a fly-back converter. In order to control easily the current of the LED, the fly-back converter is operated in the discontinuous mode with excellent dynamic characteristics, and the characteristics of the LED are verified after the closed loop control is performed using a KIA2431. The LED driver module allows the wide AC power input ranges and realizes the burst dimming function which directly regulates a PWM control IC. This paper describes the operation principle of the LED driver module and it is proved the usefulness through the real model with experimentation. Besides, this paper proposes the multi-channel LED driver which the miniaturized and modularized LED driver module are connected by parallel, and verified its propriety by experiments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.9-14
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• 2006

This paper develops a complete methodology for the mitigation of ionosphere spatial anomalies by GBAS systems fielded in the Conterminous U.S. (CONUS). It defines an ionosphere anomaly threat model based on validated observations of unusual ionosphere events in CONUS impacting GBAS sites in the form of a linear ‘wave front’ of constant slope and velocity. It then develops a simulation-based methodology for selecting the worst-case ionosphere wave front impact impacting two satellites simultaneously for a given GBAS site and satellite geometry, taking into account the mitigating effects of code-carrier divergence monitoring within the GBAS ground station. The resulting maximum ionosphere error in vertical position (MIEV) is calculated and compared to a unique vertical alert limit, or $VAL_{H2,I}$, that applies to the special situation of worst-case ionosphere gradients. If MIEV exceeds $VAL_{H2,I}$ for one or more otherwise-usable subset geometries (i.e., geometries for which the 'normal' vertical protection level, or $VPL_{H0}$, is less than the 'normal' VAL), the broadcast ${\sigma}_{pr_{-}gnd}$ and/or ${\sigma}_{vig}$ must be increased such that all such potentially-threatening geometries have VPL$_{H0}$ > VAL and thus become unavailable. In addition to surveying all aspects of the methods used to generate the required ${\sigma}_{pr_{-}gnd}$ and ${\sigma}_{vig}$ inflation factors for CONUS GBAS sites, related methods for deriving similar results for GBAS sites outside CONUS are suggested.

• Food Science of Animal Resources
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• v.42 no.6
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• pp.928-941
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• 2022

This study aimed to analyze the microbiological composition and sensory characterization of fermented sausage using strains isolated from Kimchi (GK1, Pediococcus pentosaceus SMFM2016-GK1; NK3, P. pentosaceus SMFM2016-NK3), Doenjang (D1, Debaryomyces hansenii SMFM2021-D1), and spontaneously fermented sausage (S8, D. hansenii SMFM2021-S8; S6, Penicillium nalgiovense SMFM2021-S6). The control was commercial starter culture. Nine treatments were applied [GD (GK1+D1), GS (GK1+S8), GDS (GK1+D1+S8), ND (NK3+D1), NS (NK3+S8), NDS (NK3+D1+S8), GND (GK1+NK3+D1), GNS (GK1+NK3+S8), and GNDS (GK1+NK3+D1+S8)] by mixing lactic acid bacteria and yeast, and S6 was sprayed. The microbial composition of fermented sausage was analyzed [aerobic bacteria (AC), Lactobacillus spp. (LABC), Staphylococcus spp. (STPC), and yeast and mold (YMC)], and pH and electronic nose and tongue measurements were taken. The AC, LABC, STPC, and YMC values of the control and treatment groups tended to increase during fermentation (p>0.05). The STPC values of the GD, GS, ND, and GDS groups were similar to that of the control on day 3. The pH of the control on day 3 was significantly lower than that of the GD, ND, and GND groups (p<0.05). Higher levels of 4-methylpentanol, 2-furanmethanol, and propyl nonanoate, which provide a "fermented" flavor, were detected in the GD group compared to in the control and other treatment groups. GD and ND groups showed higher umami values than the control and other treatment groups. Therefore, it is expected that GD can be valuable as a starter culture unique to Korea when manufacturing fermented sausage.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1660-1661
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• 2011

본 논문에서는 7중 대역 (GSM850, GSM900, DCS1800, PCS1900, UMTS850, UMTS1900, UMTS2100) 을 지원하는 LPF 내장형 LTCC 프런트 엔드 모듈 (FEM) 을 설계, 제작 및 측정하였다. 제작된 FEM은 효과적인 고조파 제거를 위해 수동소자를 LTCC 기판에 내장하여 저역 통과 필터(LPF)를 구현하였다. 본 논문에서 제안하는 FEM은 송수신 신호를 선택하기 위한 flip-chip 형태의 CMOS RF SP9T switch, Rx 신호의 수신을 위한 dual type의 SAW filter, 매칭 및 ESD 보호 회로를 위한 0603 크기의 칩소자가 부품 외부에 실장되어 구현된다. 전체 크기는 $4.5{\times}3.2{\times}1.2\;mm^3$의 초소형으로 내부 GND 2개 층을 포함하여 총 16층으로 구성된다. 측정결과는 송신단과 수신단의 삽입손실이 각각 1.7 dB, 3.6 dB 이하의 우수한 특성을 보였다.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.310-311
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• 2011

기존의 모바일 디바이스용 AC/DC 어댑터는 단순한 밧데리 충전기로서 기능적인 측면보다는 가격적인 측면의 접근이 많이 이루어졌다. 하지만 최근 스마트폰과 타블렛 PC 같은 다양한 모바일 디바이스의 출현으로 출력단 GND 잡음 및 누설전류에 대한 새로운 사양들이 대두되고 있다. 더불어 하나의 어댑터를 이용하여 여러 디바이스에 대응하기 위한 새로운 어댑터에 대한 요구가 커지고 있다. 본 논문에서는 AC/DC 어댑터의 새롭게 요구되는 사양들에 대해 간략히 살펴보고 기술적 문제점에 대해 기술하였다.