• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.485-495
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• 1994

Several new symmetric and asymmetric homo and hetero dinuclear complexes of the type $[Cl(dppp)(NO)_2M({\mu}-pyz)M'(NO)_2(dppp)Cl][ClO_4]_2$ and $[Cl(phen)(NO)_2M({\mu}-pyz)M'(NO)_2(dppp)Cl][ClO_4]_2$(M,M'= Mo or W; phen = 1,10-phenanthroline; dppp = 1,3-bis(diphenylphosphino)propane; pyz = 1,4-pyrazine) were synthesized in three-steps starting from $[M(NO)_2Cl_2]_n(M = Mo, W)$. The final products were purified by eluting it through silica gel column ($2{\times}20$ cm) with acetone as the eluent. Characterization of these complexes and some related complexes was accomplished through UV-vis., $^1H$-NMR, $^{13}C$-NMR and IR spectroscopies as well as elemental analysis. The infrared spectra indicate that the NO groups occupy cis-positions of the octahedral. The $^1H$ and $^{13}C-NMR$ data for the new compounds revealed a dimeric structures with bridged pyz.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.2
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• pp.73-78
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• 2011

A frequency synthesizer for DAB applications is designed using $0.18{\mu}m$ CMOS process with 1.8V supply. NP-core type is chosen for VCO core to improve low power characteristic and symmetric characteristic of output waveform. VCO range is 1302.34 MHz - 1949.51 MHz using switchable capacitor bank and varactor bank. Varactor biases that improve varactor capacitance characteristics were minimized as two, $K_{vco}$(VCO gain) is maintained using technique of varactor bank switching. Intervals of $K_{vco}$ are maintained adding VCO frequency compensation logic. Each block of VCO and frequency synthesizer designed $0.18{\mu}m$ CMOS process with 1.8V supply is verified by Cadence Spectre, measured VCO consumes 9mA current, and is 39.8% tuning range, total power consumption of the frequency synthesizer is 18mW.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.2
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• pp.254-262
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• 1996

$Pb(Zr_{0.52}Ti_{0.48})O_{3}$ (PZT) ceramics were prepared with uniform particle size of $1~3\;\mu\textrm{m}$ by hydrothermal synthesis at various conditions, such as hydrothermal reaction temperature, concentration of mineralizer and reaction time. PZT ceramics were formed above $180^{\circ}C$ for 2 hrs reaction using 10 M KOH solution as a mineralizer, but reaction condition was slightly different by starting materials. Morphology and characterization of PZT powders were investigated by XRD and SEM. By increasing the reaction temperature, KOH concentration and reaction time, the composition of the PZT phase tended to be homogeneous phase.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.2
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• pp.33-40
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• 2000

The present invention relates to a absorption rotor for removed VOC(volatile organic compound) and humidity in semiconductor clean room system. A absorption rotor medium is made by NaX zeolite and TS-1 zeolite formed on a honeycomb matrix of ceramic papers. The crystallization of NaX zeolite was hydrothermal reaction, and NaX zeolite crystals of a uniform particle size of 5$\mu$m were synthesized that NaX zeolite seed crystals (2~3$\mu$m) added in a batch composition at levels of 3~15 wt$\%$. The seeding resulted in an increase in the fraction of large crystals compared with unseeded batches and successfully led to a uniform NaX zeolite crystal. The microporous zeolite-type titanosilicate(TS-1) was synthesized by different of the reactant solution pH. The pH range of reactant solution has been changed from 10.0 to 11.5 TS-1 zeolite (ETS-10), having a large pore(8~10 $\AA$), was synthesized at 10.4 of pH, since TS-1 zeolite (ETS-4), having a small pore(3~5$\AA$), was synthesized at 11.5 of pH.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.41-49
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• 1999

In this paper, we design a controller using the $\mu$-synthesis method and apply it for the spring-mass system with noncollocated sensors and actuators. We assume that the values of the spring stiffness and load mass of the plant are uncertain. The plant is modeled with parametric uncertainty by using the state space equation, especially the descriptor form. The $H_\infty$ controller designed by the $\mu$-synthesis method is compared with the standard $H_\infty$ controller To compare performances of two $H_\infty$ controllers, it is assumed that both controllers were designed with same weighting functions except that the $\mu$-synthesis controller has structured uncertainties. By compared with the standard $H_\infty$ controller, we show that the designed controller has satisfactory robust performance as well as robust stability by simulations and experiments.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.10
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• pp.3186-3198
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• 1996

When a robot is to have contact with its enviornment, such as a medi-care robot, it would be advantageous for the robot to have a high compliance. For this reason, a robot having not only a flexible link but also an actuator with compliance, is desirable. This paper is concerned with the position and vibration control of 1 degree of freedom flexible robot using a pneumatic artificial muscle actuator. The dynamics of the manipulator assumed to be and Euler-Bernoulli beam are derived on the basis of the linear mathematical modle. Although this pneumatic artifical muscle actuator has many merits for the compliance robot, it is difficult to make an effective control scheme of this system because of ths nonlinearity and uncertainty on the dynamics of the actuator. By designing a controller using .mu.-synthesis, robust performance against measurement noise, various modeling uncertainties on the dynamics of the servo valve, actuator and mainpulator, is achieved. The effectiveness of the proposed control method is illustrated through simulations and experiments.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.378-379
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• 2012

ITO 만큼 높은 전도성과 광학적 투과성을 갖는 Al-doped ZnO (AZO) 박막을 DC-Pulse magnetron sputtering을 이용하여 40 nm 두께로 증착 후 리소그라피 공정을 통해 $30{\mu}m$ 간격으로 패터닝 하였다. 간격 30 ${\mu}m$로 배열된 AZO를 촉매층으로 하는 수열합성법을 리사이클 공정을 반복하여 수행하여 ZnO 나노선을 성장시켰다. 이와 같이 AZO 전극 사이에 길이 $30{\mu}m$의 ZnO 나노선이 래터럴 구조로 연결된 소자의 $NH_3$ 가스감지 특성을 조사하였다. 합성된 나노선의 전기적, 광학적, 구조적인 특성을 분석하여 높은 가스 감지도를 예상할 수 있는 특성을 확인하였다. 제작된 가스센서를 진공 챔버에 설치 후 양 전극간에 동작전압(Operating voltage)을 1 V로 인가하여 고정한 후에 $NH_3$를 주입(Injection)과 퍼지(Purge)를 반복하며 그 주입량(10 ppm, 20 ppm, 40 ppm, 60 ppm)에 변화를 주었고, 그에 따른 전류변화를 관찰하여 $NH_3$ 가스감지특성을 평가하였다.

• YAKHAK HOEJI
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• v.15 no.3_4
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• pp.83-86
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• 1971

Nine novel compounds, namely, 2-(p-aminobenzenesulfonamideo)-6-sulfamylbenzothiozle, 2-benzamido-6-sulfamylbenzothiazole, 2-(p-toluenesulfonamide)-6-sulfamylbenzothiazole, 2-(3,5-dinitrobenzamido)-6-sulfamylbenzothiazole, 2-benzamido-6-nitrobenzothiazole, 2-(p-toluene-sulfonamido)-6-nitrobenzothiazole, 2-(3,5-dinitrobenzamido)-6-nitrobenzothiazole, 2-(p-toluenesulfonamido)-6-chlorobenzothiazole, 2-(3,5-dinitrobenzamido)-6-chlorobenzothiazole were synthesized and evaluated for their in vitro antimicrobial activity against Staphylococcus aureus wood 46, $\betha$-Streptococcus S86, Escherichia coli and antitubercular activity against Mycobacterium tuberculosis H$_{37}$ /Rv. 2-(p-Toluenesulfonamido)-6-chlorobenzothiazole showed antimicrobial activity at 25 $\mu$g/ml against $\betha$-Streptococcus S/86, 2-(3,5-Dinitrobenzamido)-6-sulfamylbenzothiazole was active at 5 $\mu$g/ml and 2-(3,5-dinitrobenzamido)-6-nitrobenzothiazole was consderably active at 1$\mu$g/ml against Mycobacterium tuberculosis H$_{37}$Rv.

• Proceedings of the Materials Research Society of Korea Conference
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• 2004.05a
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• pp.50-50
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• 2004

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.4
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• pp.150-154
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• 2016

Method for synthesizing a $K_2Ti_6O_{13}$ whisker is a solid-state method, hydrothermal synthesis method, calcination method, flux method, slow-cooling method, melting method, kneading-drying-calcination method, sol-gel method etc. $K_2Ti_6O_{13}$ whisker have been synthesized by a flux method. The average size and distribution of the synthesized $K_2Ti_6O_{13}$ whisker can be controlled by a kind of potassium precursors and reaction temperature and time. The average size of the synthesized $K_2Ti_6O_{13}$ whisker was about in the size range of 500 nm to $2{\mu}m$. The effect of synthesis parameters, such as the molar ratio of KOH to $TiO_2$, pH, reaction temperature and time, are discussed. The synthesized $K_2Ti_6O_{13}$ whisker were characterized by x-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM).