• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.3
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• pp.244-252
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• 2003

In this paper, we propose a new subblock division method(SDM) for PAPR reduction in the OFDM communication system. The SDM divides the OFDM symbol into the several subblocks. If the PAPR is high, the some of the data subblocks are replaced by the dummy zero padding blocks. We propose SDM 1 and SDM 2 according to the structure. Even though the transmission efficiency may be partially lowered, the proposed SDM can considerably reduce the computational burden while maintaining similar PAPR reduction performance, compared with the PTS which is known to be the best in the conventional methods.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.685-692
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• 2009

This paper dealt with the development of the Framework for Multidisciplinary Design Optimization for the rotorcraft design concept and the building process of KHP(Korea Helicopter Project) - SDM(Simulation Data Management) system to manage various analysis data, which are used in the rotorcraft development phase. KHP-SDM RMDO(Rotorcraft Multidisciplinary Design Optimization) framework, which applied optimization modules of KHP-SDM and integrated the developed Multidisciplinary analysis modules, was constructed in the KHP-SDM. The results of the rotorcraft conceptual design using KHP-SDM RMDO showed that the framework was evaluated to be successfully constructed.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.33-43
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• 2011

This study is to make snowfall distribution map for the 4 heavy snowfall events of January 2001, March of 2004, December of 2005 and January of 2010, and compare the results for three cases of construction methods. The cases are to generate the map by applying IDW(Inverse Distance Weighting) interpolation to 76 ground measured snowfall point data (Snow Depth Map; SDM), mask out the SDM with the MODIS snow cover area (MODIS SCA) of Terra MODIS (MODerate resolution Imaging Spectroradiometer) (SDM+MODIS SCA; SDM_M), and consider the snowdepth lapse rate of snowfall by elevation (Digital Elevation Model; DEM) to the second case (SDM_M+DEM; SDM_MD). By applying the MODIS SCA, the SCA of 4 events was 62.9%, 44.1%, 52.0%, and 69.0% for the area of South Korea. For the average snow depth, the SDM_M decreased 0.9cm, 1.9cm, 0.8cm, and 1.5cm compared to SDM and the SDM_MD increased 1.3cm, 0.9cm, 0.4cm, and 1.2cm respectively.

• Journal of IKEEE
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• v.17 no.4
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• pp.511-516
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• 2013

This paper presents a SDM using the FDPA technique. The FDPA technique is the added feedback path which is the delayed path of DAC output. The designed SDM increases the SNR by adding the delayed digital feedback path. The proposed SDM is easily implemented by eliminating the analog feedback path. Through the MATLAB modeling, the optimized coefficients are obtained to design the SDM. The designed SDM has a power consumption of $220{\mu}W$ and SNR(signal to noise ratio) of 81dB at the signal-bandwidth of 20KHz and sampling frequency of 2.56MHz. The SDM is designed using the $0.18{\mu}m$ standard CMOS process.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.601-609
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• 2000

An enzyme linked immunosorbent assay (ELISA) was developed to screen residues of sulfadimethoxine (SDM) in edible animal products. An indirect competitive ELISA was allowed to compete with rabbit anti-SDM for binding to a limited amount of SDM-gelatin conjugate and SDM in serum samples. Sera was diluted 20 times with phosphate buffered saline (PBS) and boiled for 5 minutes to destruct immunoglobulins of serum. Detection limit of this competitive ELISA for SDM was 0.1 ppb or less. Among eight sulfonamide analogues tested for specifity, only sulfamonomethoxine showed significant cross-reaction in the assay. The EC-50 value for sulfamonomethoxine was 3.5 ppm. Recovery of SDM in spiked serum samples between 100 ppb and 500 ppb ranged from 110.7% to 128.9%.

• Journal of Power Electronics
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• v.9 no.5
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• pp.667-678
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• 2009

The PWM (Pulse Width Modulation) control signals have a drawback in that their power spectrum tends to be concentrated around the switching frequency and the resulting harmonic spikes cause an EMI (Electromagnetic Interference) and switching losses in semiconductors, etc. The SDM (Sigma-Delta Modulation) is a type of switching modulation used to reduce these harmonic spikes, and several SDM schemes are investigated in this paper. In the DSDM (Dithered SDM), the SDSDM (Space-Dithered SDM) and TDSDM (Time-Dithered SDM), the signals are classified by the location of their random dither additions. In these schemes, the switching frequency is spread by a random dither generator placed on the input or the output parts. Experimental results are presented where the advantages of the new proposed CDSDM (Combined Dithered SDM) are confirmed by applying to a buck converter.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.365-368
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• 2004

This paper describes a MATLAB based SDM software embodied in a GUI environment (SDMTool), which is a technical high-end tool for structural dynamics modification (SDM) problems. The software is composed of four modules: 1) FE model linker module; 2) FE model updating module; 3) SDM forward problem module; 4) SDM structural optimization module. The software can be useful to engineers performing researches on structural dynamics modification and FE model updating.

• Journal of IKEEE
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• v.18 no.2
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• pp.192-197
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• 2014

In this paper, $3^{rd}$ SDM with FDPA(Feedback Delay Pass Addition) technique to improve the input range is proposed. Conventional architecture with $3^{rd}$ transfer function is just made as adding a digital delay path in $2^{nd}$ SDM architecture. But the input range is very small because feedback path into the first integrator is increased. But, proposed architecture change feedback path into the first integrator to the second integrator, so input range could be improved about 9dB. The $3^{rd}$ SC SDM with only one operational amplifier was implemented using double-sampling technique. Simulation results for the proposed SDM designed in $0.18{\mu}m$ CMOS technology with power supply voltage 1.8V, signal bandwidth 20KHz and audible sampling frequency 2.8224MHz show SNR(Signal to Noise Ratio) of 83.8dB, the power consumption of $700{\mu}W$ and Dynamic Range of 82.8dB.

• Journal of fish pathology
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• v.25 no.2
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• pp.95-101
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• 2012

The residue levels of sulfadimethoxine (SDM) was studied after oral administration to cultured olive flounder, Paralichthys olivaceus at $20{\pm}1.0^{\circ}C$. The concentrations of SDM in the plasma and liver were determined by HPLC-UV detector after a single dosage of 400 mg/kg body weight. The average recoveries of SDM in spiked samples between 2~50 ppm were 92.24~93.62% for plasma and 88.34~91.90% for liver. Limit of detection for SDM was 0.05 ppm by using this method. Samples were taken at 1 h, 6 h, 12 h, 24 h, 48 h, 72 h, 168 h, 240 h, 336 h and 480 h post-dose. The peak plasma and liver concentrations of SDM, which attained at 1 h post-dose, was $402.64{\pm}59.66{\mu}g/ml$ and $238.18{\pm}54{\mu}g/g$, respectively. Thereafter, it's elimination from both tissues was considerably faster following process of time. Their concentrations of SDM were not measurable at 480 h post-dose. Based on this results, dosage and withdrawal times for SDM could be used when it is prescribed with SDM in olive flounder.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.108-117
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• 2024

In this study, simulations based on computational fluid dynamics were performed for self-propulsion performance prediction of a catamaran that has asymmetrical inside and outside hull form and numerous knuckle lines. In the simulations, the Moving Reference Frame (MRF) or Sliding Mesh (SDM) techniques were used, and the rotation angle of the propeller per time step was different to identify the difference using the analysis technique and condition. The propeller rotation angle used in the MRF technique was 1˚ and those used in the SDM technique were 1˚, 5˚, or 10˚. The torque of the propeller was similar in both the techniques; however, the thrust and resistance of the hull were computed lower when the SDM technique was applied than when the MRF technique was applied, and higher as the rotation angle of the propeller per time step in the SDM technique was smaller in the simulations for several revolutions of the propeller to estimate the self-propulsion condition. The revolutions, thrust, and torque of the propeller in the self-propulsion condition obtained using linear interpolation and the delivered power, wake fraction, thrust deduction factor, and revolutions of the propeller obtained using the full-scale prediction method showed the same trend for both the techniques; however, most of the self-propulsion efficiency showed the opposite trend for these techniques. The accuracy of the propeller wake was low in the simulations when the MRF technique was applied, and slight difference existed in the expression of the wake according to the rotation angle of the propeller per time step when the SDM technique was applied.