• Journal of Internet Computing and Services
• /
• v.10 no.5
• /
• pp.33-39
• /
• 2009

In this paper, the Window based dual-mode audio receiver of DAB and DAB+(Digital Audio Broadcasting Plus) is designed, and audio performance of it is analyzed. DAB+ can be composed of DAB and AAC(Advanced Audio Coding) for more effective audio services in the limited channel bandwidth. In the result of thesis, the Window based receiver can simultaneously be decoded for DAB/DAB+ dual-mode audio.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.4
• /
• pp.289-295
• /
• 2008

In this paper, we designed the off-line PWM(Pulse width modulation) control IC for flyback type power converter to reduce the standby power consumption. In normal state, this off-line PWM IC generates the output pulse with $40\sim60kHz$ frequency and duty ratio of $20\sim88%$. When SMPS operates in standby mode, this IC generates the output pulse with 33kHz frequency and duty ratio of 1 %. SPICE simulation was performed to verify the standby power consumption of the power converter with designed of-line PWM IC. Power converter with designed off-line PWM IC consumes less than 0.3W when it operates in standby mode condition.

• Journal of electromagnetic engineering and science
• /
• v.17 no.1
• /
• pp.29-33
• /
• 2017

This paper proposes a half-mode substrate integrated waveguide (HMSIW) amplifier using lumped-element transition. The input and output impedances of this amplifier are matched by the lumped-element transition structure. This structure provides compact impedance and mode matching circuits between the HMSIW and a stand-alone amplifier. Surface mount technology inductors and capacitors are implemented to realize the lumped-element transition. A prototype of the proposed HMSIW amplifier shows 15 dB gain with 3 dB bandwidth of 4 to 7.05 GHz in a simulation and measurement.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.34C no.6
• /
• pp.58-70
• /
• 1997

In this paper, an 8bit CMOS low power, high-speed current-mode folding and interpolation A/D converter is designed with te LG semicon $0.8\mu\textrm{m}$ N-well single-poly/double-metal CMOS process to be integrated into a portable image signal processing system such as a digital camcoder. For good linearity and low power consumption, folding amplifiers and for high speed performance of the A/D converter, analog circuitries including folding block, current-mode interpolation circuit and current comparator are designed as a differential-mode. The fabricated 8 bit A/D converter occupies the active chip area of TEX>$2.2mm \times 1.6mm$ and shows DNL of $\pm0.2LSB$, INL of <$\pm0.5LSB$, conversion rate of 40M samples/s, and the measured maximum power dissipation of 33.6mW at single +5V supply voltage.

• Progress in Superconductivity and Cryogenics
• /
• v.11 no.2
• /
• pp.33-36
• /
• 2009

A 1 MW class HTS (High-Temperature Superconducting) synchronous motor has been developed. This motor is aimed to be utilized for industrial application such as large motors operating in large plants. The HTS field coil of the developed motor is cooled by way of neon thermo siphonmechanism and the stator (armature) coil is cooled by water through hollow copper conductor. This paper also describes evaluation of some electrical parameters from performance test results of our motor, which was conducted at steady state in generator mode and motor mode. Open and short circuit tests were conducted in generator mode while a 1.1 MW rated induction machine was rotating the HTS machine. Electrical parameters such as mutual inductance and synchronous inductance are deduced from these tests. Load test was done upto rating torque during motor mode and efficiency was measured at each load torque.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.5
• /
• pp.1571-1576
• /
• 2012

A diarylurea compound 1 possessing pyrrolo[3,2-$c$]pyridine nucleus was designed and synthesized with structure similarity to Sorafenib. Compound 1 was tested over 60-cancer cell line panel at a single dose concentration of 10 ${\mu}M$ and showed high activity. It was further tested in a five-dose mode to determine its $IC_{50}$, TGI, and $LC_{50}$ values over the 60 cell lines. Compound 1 showed high potency and good efficacy, and was accordingly tested at a single dose concentration of 10 ${\mu}M$ over a panel of 40 kinases. At this concentration, it completely inhibited the enzymatic activities of a number of oncogenic kinases, including ABL, ALK, c-RAF, FLT3, KDR, and TrkB. The target compound was subsequently tested over these 6 kinases in 10-dose testing mode in order to determine its $IC_{50}$ values.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.5
• /
• pp.1597-1602
• /
• 2012

In this study, we determined the 3D-structure of Arabidopsis thaliana KAPAS by homology modeling. We then investigated the binding mode of compounds obtained from in-house library using computational docking methods. From the flexible docking study, we achieved high dock scores for the active compounds denoted in this study as compound $\mathbf{3}$ and compound $\mathbf{4}$. Thus, we highlight the flexibility of specific residues, Lys 312 and Phe 172, when used in active sites.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.2
• /
• pp.613-619
• /
• 2012

We applied several machine learning methods for developing QSAR models for prediction of acute toxicity to fathead minnow. The multiple linear regression (MLR) and artificial neural network (ANN) method were applied to predict 96 h $LC_{50}$ (median lethal concentration) of 555 chemical compounds. Molecular descriptors based on 2D chemical structure were calculated by PreADMET program. The recursive partitioning (RP) model was used for grouping of mode of actions as reactive or narcosis, followed by MLR method of chemicals within the same mode of action. The MLR, ANN, and two RP-MLR models possessed correlation coefficients ($R^2$) as 0.553, 0.618, 0.632, and 0.605 on test set, respectively. The consensus model of ANN and two RP-MLR models was used as the best model on training set and showed good predictivity ($R^2$=0.663) on the test set.

• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.1
• /
• pp.175-182
• /
• 2009

This paper summarizes a solution procedure for a large cylindrical structure mounted underneath a ship as a sonar. Vibration analysis of the water loaded structure is required to enhance the structural reliability as well as acoustic performance of the sonar. It is, however, often very difficult to solve such structures since they have many DOFs, considering the frequency of interest and the water-loading. The mode mapping method is proposed and verified to take into account the water-loading with the minimum DOF for the analysis. The cyclic symmetric method is then reviewed to show how the eigen properties of the full model can be obtained from the representative segment model. The solution procedure is finally proposed and applied successfully for a simplified water-loaded cylindrical array structure.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.33 no.9
• /
• pp.722-727
• /
• 2009

The effect of the intake flow on the spray structure of a high pressure 11-hole fuel injector were examined in a single cylinder optical direct injection spark ignition (DISI) engine. The effects of injection timing and in-cylinder charge motion were investigated using the 2-dimensional Mie scattering technique. It was confirmed that in the homogeneous charge mode, the in-cylinder swirl charge motion played a major role in the fuel spray distribution during the induction stroke rather than the tumble flow. But, in the stratified charge mode, the effect of the in-cylinder charge was not so large that the injected spray pattern was nearly maintained and the increase of in-cylinder pressure by the upward moving piston reduced the fuel spray penetration.