• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.107-114
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• 2021

By analyzing the voice communication performance of the existing tactical FM radios, the performance target of the newly developing TICN combat network radio system VHF band tactical voice communication waveform was derived. In addition, a vocoder and modulation method that can satisfy the performance target and additional requirements are presented, and the expected voice communication quality is analyzed.

• Journal of the Korean Chemical Society
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• v.45 no.4
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• pp.312-317
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• 2001

7'-Aldehyde-nucleosides analogue (2a, 2c) were synthesized from 6-N-benzoyl-2',3'-O-isopropylideneadenosine and uridine. The condensation of 2 with ethoxycarbonylmethylene Wittig reagent produced the adenosine and uridine analogues containing extended conjugated diene and ethoxycarbonyl group, ethyl-1',5',6',7',8'-pentadeoxy-1'-(adenin-9-yl)-$\beta$-D-ribo-nona-5'(E),7'(E)-dienofuranuronate (4b) and ethyl-1'. 5',6',7',8'-pentadeoxy-1'-(uracil-1-yl)-$\beta$-D-ribo-nona-5'(E),7'-(E)-dienofuranuronate (4c). 9-[8',8'-dibromo-5',6',7',8' -tetradeoxy-$\beta$-D-ribo-octa-5'(E),7'(E)-diene]nucleosides (6b, 6c) were also prepared from 2 with similar method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.10
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• pp.1051-1062
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• 1992

Design of a continuous-time fifth-order OTA-C Eiliptic filter for operation at 4MHz is presented. The filter has been realize by five OTAs, eight capacitors and a buffer as an OTA-C structure. To prevent decreasing of characteristics due to the parastic capacitance of OTA and loading a buffer and a capacitor have been connected to the next of second section. As the result the frequency characteristics were found to be essentially within specifications : less than 0.2dB passband attenuation, 30dB stopband attenuation and 4Mz cut-off frequency have been obtained and the characteristic of cut-off region has been improved about 7dB compared with it of the theoretical case.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.151-155
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• 1999

We proposed the beam tilted antenna by aperture coupled microstrip array, found out the values of design parameters by using Ensemble 5.1 of Ansoft Co., and analysed the performance of fabricated antenna. In order to point to the fixed satellite on the nothern hemisphere, 3 dB beamwidth of this antenna is 25$^{\circ}C$ to 65$^{\circ}C$. Operation bandwidth is 2.51GHz to 2.59GHz. The structure of this antenna is composed by 3 types of squared patches; reflector, driver, and director. The maximum antenna gain is 6.2dB at 2.56GHz and elevation angle of 42$^{\circ}C$. Front-to-Back ratio is more than 13dB at the same condition.

• Bulletin of the Korean Chemical Society
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• v.7 no.1
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• pp.29-35
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• 1986

An empirical formula for semiconductive metal oxides is proposed relating nonstoichiometric value x to a temperature or an oxygen partial pressure such that experimental data can be represented more accurately by the formula than by the well-known Arrhenius-type equation. The proposed empirical formula is log x = A + $B{\cdot}1000/T\;+\;C{\cdot}$exp$(-D{\cdot}1000/T)$ for a temperature dependence and $log\;{\times}\;=a\;+b{\cdot}log\;Po_2\;+\;c{\cdot}$exp$(-d{\cdot}log\;Po_2)$ for an oxygen partial pressure dependence. The A, B, C, D and a, b, c, d are parameters which are evaluated by means of a best-fitting method to experimental data. Subsequently, this empirical formula has been applied to the n-type metal oxides of $Zn_{1+x}O,\; Cd_{1+x}O,\;and\;PrO_{1.8003-x}$, and the p-type metal oxides of $CoO_{1+x},\; FeO_{1+x},\;and\;Cu_2O_{1+x}$. It gives a very good agreement with the experimental data through the best-fitted parameters within 6% of relative error. It is also possible to explain approximately qualitative characters of the parameters A, B, C, D and a, b, c, d from theoretical bases.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.181-190
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• 2019

In this study, four reinforced concrete coupling beams were subjected to cyclic lateral loading test to evaluate the structural performance of coupling beam according to volume fraction of steel fiber. For this purpose, the volume fraction of steel fiber(0%, 1%, 2%) and transverse reinforcement spacing were determined as the main parameter. According to the test results, the maximum strength of D-40C-s100-0 was 1.15, 1.13, 1.05 times higher than D-40C-s300-0, D-40C-s300-1, D-40C-s300-2, respectively. The maximum strength of coupling beams with mitigated rebar details increases as the volume fraction of steel fiber increases. Although steel fiber 2% reinforced specimen(D-40C-s300-2) did not satisfy the amount of transverse reinforcement required for seismic design of coupling beam, the overall performance including to maximum strength, ductility and energy dissipation capacity was similar to the control specimen(D-40C-s100-0). As a result, the use of steel fiber with 2% reinforcement can partially replace the transverse reinforcement in diagonally reinforced concrete coupling beam.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.951-965
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• 2024

Lactiplantibacillus plantarum is a valuable potential probiotic species with various proven health-beneficial effects. L. plantarum LM1001 strain was selected among ten strains of L. plantarum based on proteolytic activity on whey proteins. L. plantarum LM1001 produced higher concentrations of total free amino acids and branched-chain amino acids (Ile, Leu, and Val) than other L. plantarum strains. Treatment of C2C12 myotubes with whey protein culture supernatant (1%, 2% and 3%, v/v) using L. plantarum LM1001 significantly increased the expression of myogenic regulatory factors, such as Myf-5, MyoD, and myogenin, reflecting the promotion of myotubes formation (p<0.05). L. plantarum LM1001 displayed β-galactosidase activity but did not produce harmful β-glucuronidase. Thus, the intake of whey protein together with L. plantarum LM1001 has the potential to aid protein digestion and utilization.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.9
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• pp.685-697
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• 2017

In this paper, it is presented the result of design and fabrication for C-band solid state high power amplifier unit and components using in search radar. The solid state power amplifier(SSPA) assembly was fabricated using GaN(Gallium Nitride), which is semiconductor device, and the transmit signal output power of the solid state high power amplifier unit is generated by combining the transmit signal power of the solid state power amplifier configured in parallel through a design and fabricated waveguide type transmit signal combine assembler. Designed solid state high power amplifier unit demonstrated C-band 500 MHz bandwidth, maximum 10.5% duty cycle, transmit pulse width from $0.0{\mu}s{\sim}000{\mu}s$, and transmit signal power is 44.98 kW(76.53 dBm).

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.21-26
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• 2013

In this paper, we introduced various 3D printing technology and it's application on tissue engineering and regenerative medicine. Using the 3D printing technology, Korea Institute of Machinery and Materials (KIMM) has developed 3D bio-printing system. Various 3D tissue engineered scaffolds have been fabricated by the 3D bio-printing system. Cell printing system has been also developed and it is the fundamental technology for organ regeneration in tissue engineering and regenerative medicine.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.230-232
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• 2013

본 논문에서는 실내 음영지역에서 사용되는 모바일 와이맥스의 펨토셀 기지국(WFAP; WiMAX Femtocell AP)에 대한 성능을 분석하였다. 시뮬레이션을 통해 와이맥스 펨토셀 기지국의 패킷에러율(PER), Outage, throughput을 확인하였다.