Seungjin Kim

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This brief presents a low-voltage and low-noise ring voltage-controlled oscillator (VCO) where the phase noise performance is improved by reducing the total channel thermal noise injected into the output node of the VCO during the transition period of the output voltage swing. Implemented in a 65-nm CMOS technology, the proposed ring VCO operates from 485.7(More)
The purpose of this study was to enhance the efficiency of anaerobic co-digestion with sewage sludge using pretreatment technologies and food waste. We studied the effects of various pretreatment methods (thermal, chemical, ultrasonic, and their combination) on hydrogen production and the characteristics of volatile fatty acids (VFAs) using sewage sludge(More)
The degradation rates of toluene and trichloroethylene (TCE) by Pseudomonas putida and Bacillus spp. that were encapsulated in polyethylene glycol (PEG) polymers were evaluated in comparison with the results of exposure to suspended cultures. PEG monomers were polymerized together with TCE-degrading microorganisms, such that the cells were encapsulated in(More)
This study exploited the concept of the minimum/maximum substrate concentrations (MSC values) for identifying proper start-up conditions and achieving stable and low effluent total ammonium nitrogen (TAN) concentrations in suspended-growth short-cut biological nitrogen removal (SSBNR). Calculations based on the MSC concept indicated that S(Dmax), the TAN(More)
This study was carried out to determine the possibility of autotrophic denitritation using thiosulfate as an electron donor, compare the kinetics of autotrophic denitrification and denitritation, and to study the effects of pH and sulfur/nitrogen (S/N) ratio on the denitrification rate of nitrite. Both nitrate and nitrite were removed by autotrophic(More)
The application of effective remediation technologies can benefit from adequate preliminary testing, such as in lab-scale and Pilot-scale systems. Bioremediation technologies have demonstrated tremendous potential with regards to cost, but they cannot be used for all contaminated sites due to limitations in biological activity. The purpose of this study was(More)
In this paper, an accurate, low power CMOS temperature sensor for attachable medical devices (AMDs) is presented. The proposed temperature sensor consists of a highslope proportional to absolute temperature (PTAT) current and reference voltage generator, a current controlled relaxation oscillator (ICRO), a digital counter, and a reference clock generator.(More)
This communication introduces a non-intrusive method for void fraction measurement and identification of two-phase flow regimes, based on ultrasonic sensing. The underlying algorithm is built upon the recently reported theory of a statistical pattern recognition method called symbolic dynamic filtering (SDF). The results of experimental validation,(More)
This paper presents a UHF-band RFID transmitter with a robust spur reduction technique using a DLL-based SSCG. By adopting an 8-bit DLL and Hershey-kiss modulated profile together, the SSCG shows more than a 20dB EMI reduction while providing up-, down-, and center-spread modes. Implemented in a 0.18μm CMOS process, the proposed transmitter achieves(More)
According to the IPCC (Intergovernmental Panel on Climate Change) guidelines, when calculating CO2 emissions, CO2 emissions from biomass should be excluded from the total amount of CO2 emissions and should be separately reported due to their “carbon neutrality”. Sewage sludge is one of the representative biomass fuels. It is mixed with fossil fuels to(More)