• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.61-68
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• 2018

This paper describes design of a 10.525 GHz self oscillating mixer semiconductor IC chip combining voltage controlled oscillator and frequency mixer using silicon CMOS technology for Doppler radar applications. The p-core type VCO included in the self oscillating mixer minimizes the noise contained in the transmitted signal. This noise minimization increases the sensing distance and acts in a direction favorable to the reaching distance and the sensitivity of the motion detection sensor. Simulation results for phase noise show that a VCO designed as a P-core has a noise characteristic of -106.008 dBc / Hz at 1 MHz offset and -140.735 dBc / Hz at 25 MHz offset compared to a VCO designed with N-core and NP-core showed excellent noise characteristics. If a self-oscillating mixer is implemented using a p-core designed VCO in this study, a motion sensor with excellent range and reach sensitivity will be produced.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.57.3-57.3
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• 2018

KVN 수신기는 22/43/86/129GHz 주파수 대역의 우주전파를 관측할 수 있는 4채널 동시 관측 시스템의 핵심으로 다수의 제어 및 모니터 항목이 존재한다. 대표적인 예로 Synthesizer, Pcal, LO, Vacuum, Cryogenic Temperature 등이 있으며 이와 관련된 여러 인스트루먼트가 21m 전파망원경의 하부단에 위치한 수신기실 내에 분산 배치되어 있다. 이에 대한 효율적인 제어를 위해서는 사용자 컴퓨터 관점에서 두 가지 조건이 충족되어야 한다. 첫째, 물리적으로 분산된 인스트루먼트에 대한 접근 및 변경이 용이해야 하고, 둘째는 단일 인터페이스 상에서 다양한 인스트루먼트를 하나로 통합하는 확장성이 보장되어야 한다. 이러한 요건을 고려하여 KVN은 산업 분야에서 널리 쓰이고 있는 프로피버스를 수신기 시스템의 제어를 위한 기반 인터페이스로 활용 중에 있고, 추가 기능 요구에 효율적으로 대처하고 있다. 본 발표에서는 먼저 KVN 수신기 시스템을 구성하는 인스트루먼트에 대해 살펴보고자 한다. 그리고 이를 효율적으로 제어하기 위한 기반 인터페이스로서 프로피버스 구축 및 활용 현황에 대해 논하고자 한다.

• The Journal of the Acoustical Society of Korea
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• v.29 no.3
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• pp.209-215
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• 2010

Recently portable terminal is received attention by wireless networks and mass capacity ROM. In this result, TTS(Text to Speech) system is inserted to portable terminal. Nevertheless high quality synthesis is difficult in portable terminal, users need high quality synthesis. In this paper, we proposed Distributed TTS (DTTS) that was composed of server and terminal. The DTTS on corpus based speech synthesis can be high quality synthesis. Synthesis system in server that generate optimized speech concatenation information after database search and transmit terminal. Synthesis system in terminal make high quality speech synthesis as low computation using transmitted speech concatenation information from server. The proposed method that can be reducing complexity, smaller power consumption and efficient maintenance.

• The Journal of the Acoustical Society of Korea
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• v.26 no.8
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• pp.403-408
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• 2007

In a large corpus-based speech synthesizer, a break, which is a parameter influencing the naturalness and intelligibility, is used as an important feature during a unit selection process. Japanese is a language having intonations, which ate indicated by the relative differences in pitch heights and the APs(Accentual Phrases) are placed according to the changes of the accents while a break occurs on a boundary of the APs. Although a break can be predicted by using J-ToBI(Japanese-Tones and Break Indices), which is a rule-based or statistical approach, it is very difficult to predict a break exactly due to the flexibility. Therefore, in this paper, a method is to conduct a unit search by dividing breaks into two types, such as a fixed break and a flexible break, in order to use the advantages of a large-scale corpus, which includes various types of prosodies. As a result of an experiment, the proposed unit selection method contributed itself to enhance the naturalness of synthesized speeches.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.26-29
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• 2011

Purpose: The general test method of the Korean Pharmacopeia specifies the test method on the clauses of quality control after manufacturing. According to KFDA Guidance for Medicines, standards of residual solvents regulates the maximum permissible dose of acetonitrile as 400 ppm, ethanol as 5,000 ppm, and acetic acid as 5,000 ppm. This study aims at identifying the type of resiual solvents in the final [F-18]FDG vial of an automatic synthesizer and measure its residual quantity. Materials and Methods: The center carried out residual solvents test of [F-18]FDG injection using Agilent Technologies 7890A with a Flame Ionization Detector. The column of Agilent Technologies 7890A used in measuring of residual solvents was CP WAX column ($30m{\times}0.53mm{\times}1.0{\mu}m$) and analysis condition was split mode 1:1 at the initial temperature $70^{\circ}C$ which was increased $20^{\circ}C/minute$ after two minutes and maintained at the final $140^{\circ}C$ for two minutes. The analysis method was as following: Firstly, ethanol-acetonitrile-acetic acid mixture was classified into four types of concentration (250-25-250 ppm, 1,000-100-1,000 ppm, 3,000-300-3,000 ppm, and 6,000-600-6,000 ppm), and $1.0{\mu}L$ of each type of concentration was injected into gas chromatography followed by an analysis of its peak domain. Then, a calibration-curve by the external standard method was drawn based on the analysis result. Results: While ethanol and acetonitrile were detected in TRACERlab MX, FASTlab had additional acetic acid. The residual quantity of the ethanol-acetonitrile-acetic acid mixture evaluated using the calibration-curve was average 72 ppm ethanol, 54 ppm acetonitrile, and 1030 ppm acetic acid for FASTlab, whereas average 439 ppm ethanol and 79 ppm acetonitrile for TRACERlab MX. This indicated that both of them were within the maximum permissible dose. Conclusion: Solvent residues in the [F-18]FDG injection were all within maximum permissible doses and proper to be used to examine a patient. The result indicated that types and quantities of solvent resides of radioactive pharmaceuticals vary depending on the automatic synthesizer.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.3-6
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• 2012

Purpose : Samsung medical ceter shall find a cause of the interference factor and suggest a solution for it. Materials and Methods : A sample of $^{18}F$-FDG, radioactive pharmaceuticals produced by TRACERlab MX and FASTlab synthesizer. Gel-clot method uses Positive control tube and single test tube. Kinetic chromogenic method uses ENDOSAFE-PTS produced by Charles River. Results : According to Gel clot method of Endotoxin Tests at FASTlab, both turbidity and viscosity increased at 40-fold dilution and Gel clot was detected. In case of TRACERlab MX, Gel clot was detected in most of samples but intermittently not in a few of them. When using ENDOSAFE-PTS, sample CV (Coefficient of Variation) of FASTlab is 0% at all dilution rates whereas spike CV is 0% at 1-fold dilution, 0~35% at 10-fold, 3.6~12.9% at 20-fold, 5.2~7.1% at 30-fold, 1.1~17.4% at 40-fold, spike recovery; 0% at one-fold, 25 ~ 58% at 10-fold, 50 ~ 86% at 20-fold, 70~92% at 30-fold, and 75~120% at 40-fold. Sample CV of TRACERlab MX, is 0% at all dilution rates whereas spike CV is 1.4~4.8% at one-fold dilution, 0.6~19.9% at 10-fold, spike recovery; 35~72% at one-fold dilution and 77~107% at 10-fold. Conclusion : Gel clot does not seem to occur probably to H3PO4 which engages in bonding with Mg2+ion contributing gelation inside PCT. Dilution which is identical to reducing the amount of H3PO4, could remove interfering effects accordingly. Spike recovery was obtained within 70~150% - recommended values of supplier - at 40-fold dilution even in kinetic chromogenic method.

• The Korean Journal of Nuclear Medicine Technology
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• v.26 no.2
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• pp.15-19
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• 2022

Purpose [⁶⁸Ga]PSMA-11 is needed the high reproducibility, excellent radiochemical yield and purity. In term of radiation safety, the radiation exposure of operator for its production also should be considered. In this work, we performed a comparative study for the fully automated synthesis of [⁶⁸Ga]PSMA-11 between non-cassette type and cassette type. Materials and Methods Two different type of modules (TRACERlab FX N pro for non-cassette type and BIKBox for cassette type) were used for the automated production of [⁶⁸Ga]PSMA-11. According to the previously identified elution profile, Only 2.5 ml with high radioactivity was used for the reaction. After adjusting the pH of the reaction solution with HEPES buffer solution, the precursor was added and reacted with at 95 ℃ for 15 minutes. The reaction mixture was separated and purified using a C18 light cartridge. The product was eluted with 50% EtOH/saline solution and diluted with saline. It was completed by sterilizing filter. In the non-cassette type, the aforementioned process must be prepared directly. However, in the cassette method, synthesis was possible simply by installing a kit that was already completed. Results Both total [⁶⁸Ga]PSMA-11 production time were 25±3(non-cassette type) and 23±3 minutes(cassette type). The radiochemical yield of the non-cassette type(65.5±5.7%) was higher than that of the cassette type(61.6±4.8%) after sterilization filter. The non-cassette type took about 120 minutes of preparation time before synthesis due to washing of synthesizer and reagent preparation. However, since the cassette type does not require washing and reagent preparation, it took about 20 minutes to prepare before synthesis. Both type of synthesizer had a radiochemical high purity(>99%). Conclusion The non-cassette type production of [⁶⁸Ga]PSMA-11 showed higher radiochemical yield and lower cost than the cassette type. However, The cassette type has an advantage in terms of preparation time, convenience, and equipment maintenance.

• Journal of IKEEE
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• v.9 no.2 s.17
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• pp.152-160
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• 2005

A prescaler is an essential building block for PLL-based frequency synthesizers and must satisfy high-speed and low-power characteristics. The design of D-flip flips used in the prescaler implementation is thus critical. Conventional TSPC D-flip flops suffer from glitches, unbalanced propagation delay, and unnecessary charge/discharge at internal nodes in precharge phase, which results in increased power consumption. In this paper a new dynamic D-flip flop is proposed to overcome these problems. Glitches are minimized using discharge suppression scheme, speed is improved by making balanced propagation delay, and low power consumption is achieved by removing unnecessary discharge. The proposed D-flip flop is employed in designing a 128/129 dual-modulus prescaler using $0.18{\mu}m$ CMOS process parameters. The designed prescaler operates up to 5GHz while conventional one can operate up to 4.5GHz under same conditions. It consumes 0.394mW at 4GHz that is a 34% improved result compared with conventional one.

• Applied Biological Chemistry
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• v.37 no.1
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• pp.56-63
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• 1994

Oligonucleotides for a conserved region of the coat protein gene of cucumber mosaic virus (CMV) and a hammerhead structure ribozyme against CMV RNA were synthesized using a DNA synthesizer. Both strands of oligonucleotides were annealed and restricted with BamHI/SacI, then cloned into a plasmid pBS SK (+). The cloned CMV substrate and ribozyme were sequenced to verify correct constructions. In vitro transcriptions were carried out by using T7 RNA polymerase with BssHII or SspI digests of $1\;{\mu}g$ of substrate and ribozyme clones. The size of substrate RNA was 176 nucleotides (nt) containing 50 nt of CMV RNA sequence, 6 nt of XbaI restriction site and 120 nt of vector-derived sequence in the case of BssHII digest. The size of ribozyme RNA was 164 nt containing 40 nt of ribozyme RNA sequence and same sequences of substrate. Substrate RNA was efficiently cleaved into two fragments (96 nt and 80 nt) by ribozyme RNA. This endonucleolytic cleavage occurred more efficiently at $55^{\circ}C$ than $37^{\circ}C$. SspI digest-derived substrate RNA (2234 nt) was also cleaved into two fragments by the same ribozyme. SspI digest-derived ribozyme RNA (2222 nt) cleaved the above substrate to two fragments. In vitro-tested ribozyme construct is being cloned into a plant transformation vector to develop virus-resistant plants.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.1
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• pp.126-142
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• 2016

This paper presents a wide-frequency-range, low-power transceiver with an automatic impedance-matching calibration for TV-white-space (TVWS) application. The wide-range automatic impedance matching calibration (AIMC) is proposed for the Drive Amplifier (DA) and LNA. The optimal $S_{22}$ and $S_{11}$ matching capacitances are selected in the DA and LNA, respectively. Also, the Single Pole Double Throw (SPDT) switch is integrated to share the antenna and matching network between the transmitter and receiver, thereby minimizing the systemic cost. An N-path filter is proposed to reject the large interferers in the TVWS frequency band. The current-driven mixer with a 25% duty LO generator is designed to achieve the high-gain and low-noise figures; also, the frequency synthesizer is designed to generate the wide-range LO signals, and it is used to implement the FSK modulation with a programmable loop bandwidth for multi-rate communication. The TVWS transceiver is implemented in $0.13{\mu}m$, 1-poly, 6-metal CMOS technology. The die area of the transceiver is $4mm{\times}3mm$. The power consumption levels of the transmitter and receiver are 64.35 mW and 39.8 mW, respectively, when the output-power level of the transmitter is +10 dBm at a supply voltage of 3.3 V. The phase noise of the PLL output at Band 2 is -128.3 dBc/Hz with a 1 MHz offset.