• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.85-87
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• 2000

In real-time power system control, it is essential to measure the power system variables which are voltage. current, real and reactive power, power factor, system frequency and etc. this variables can be estimated or calculated by the synchronized phasor informations of voltage and current. Therefore, the synchronized phasor measurement of voltage and current is very important to real-time power system control. So, we develop SPMD(Synchronized Phasor Measurement Device) for synchronized phasor measurement of voltage and current. In this paper, we present the design and implementation of SPMD for real-time phasor measurement and prove its performance by the test results.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.104-116
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• 2010

With several advantages such as flexible downlink-to-uplink(DL-to-UL) ratio and flexible spectrum usage, Time Division Duplexing(TDD) is emerging as an alternate to Frequency Division Duplexing(FDD), especially in wireless broadband systems. We already have at least four different TDD systems in the industry: Time Division-Synchronous Code Division Multiple Access(TD-SCDMA), IEEE 802.16e-TDD, IEEE 802.16m-TDD, and Time Division-Long Term Evolution(TD-LTE). A disadvantage of TDD is that tight coordination such as time synchronization between adjacent operators is required to prevent interference between the adjacent TDD systems. In this paper, we investigate coexistence scenarios among the above four well-known TDD systems and calculate spectral efficiency(SE) loss in each scenario. Our findings are that SE loss can be significant if TDD ratios of the adjacent operators are considerably different. However, as long as the TDD ratios of the adjacent operators are similar, configurations in the systems permit perfect time synchronization between the two heterogeneous TDD systems, and the resulting SE loss is zero or reasonably low. We believe that the above findings and the configurations of the TDD systems recommended tominimize SE loss will be helpful for operators who deploy TDD systems in system parameter determination and cross-operator coordination.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.85-90
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• 2004

The effect of the hydraulic residence time (HRT) for the removal of aquarium waste, such as protein, total suspended solids (TSS) and turbidity were investigated by using a foam separator Protein, TSS and turbidity removal efficiencies were increased with the increase of hydraulic residence time. The optimum hydraulic residence time was 0.5 min, and the highest protein and TSS removal rates were $14.4\;g/L{\cdot}day\;and\;38.9\;g/L{\cdot}day,$ respectively. The tendency of turbidity removal rate and efficiency was similar to that of protein.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.155-159
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• 2001

In this paper, an on-line dead-time compensation method based on a time delay control approach is presented. The disturbance voltages caused by the dead time are estimated in an on-line manner by the time delay control without any additional circuits and off-line experimental measurements. And the estimated disturbance voltages are fed to voltage references in order to compensate the dead-time effects. The proposed method is applied to a PM synchronous motor drive system and implemented by using software of a digital signal processor (DSP) TMS320C31. Experiments are carried out for this system and the results well demonstrate the effectiveness of the proposed method.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.501-506
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• 2022

Long turn-off time limits high frequency operation of Bipolar Junction Transistors (BJTs). Turn-off time decreases with increases in the recombination rate of minority carriers at switching transients. Fast neutron irradiation on a Si BJT incurs lattice damages owing to the displacement of silicon atoms. The lattice damages increase the recombination rate of injected holes with electrons, and decrease the hole lifetime in the base region of pnp Si BJT. Fast neutrons generated from a beryllium target with 30 MeV protons by an MC-50 cyclotron were irradiated onto pnp Si BJTs in experiment. The experimental results show that the turn-off time, including the storage time and fall time, decreases with increases in fast neutron fluence. Additionally, it is confirmed that the base current increases, and the collector current and base-to-collector current amplification ratio decrease due to fast neutron irradiation.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.597-600
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• 2005

The software streaming technology enables telematics software to be automatically updated through a wireless network. When the software starts running, software streaming system inspects its version and then, automatically download latest one. The software streaming system breaks the software into several pieces that are streamed to the user as needed. In this way, software streaming system can improves the telematics application load time while updating the software through wireless network. In our experiments, the application load time was reduced about 7 times compared to downloading whole software at best case.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.287-290
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• 1999

In the transmitter of optical fiber transmission systems, a time-division multiplexer combines several parallel data streams into a single data stream with a high bit rate. In this paper, we design a 2:1 (2-channels) time-division multiplexer using SiGe HBT with emitter size of 2$\times$8${\mu}{\textrm}{m}$$^2$. The operation speed is 10Gbps, the rise and fall times of 20-80% are 34ps and 35ps, respectively and the dissipation of power is 0.86W.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05b
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• pp.54-57
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• 2003

This study proposes that the Phase Linearization Interpolation is higher efficency than the existed Orthogonal Frequency Division Multiplexing system in the Multipath channels time-varient. Also, it showed that time domain equalization is better than the existed frequency domain equalization about the calculation and efficency for clear Inter Carrier Interference of the doppler effect.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.418-423
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• 2007

Meats with alginate binders including sodium alginate, glucono-delta-lactone and calcium carbonate were tested in restructured steaks made from M. pectoralis profundus of beef steers in terms of meat quality and binding ability by tumbling time. The treatment with 25 min tumbling time was significantly lower (p<0.05) for crude protein than 5 and 15 min, while higher (p<0.05) for moisture content. This corresponded with sensory panel juiciness ratings, which showed the treatment for longer tumbling times to be significantly juicier (p<0.05) than that for a shorter time. Cooking loss decreased (p<0.05) linearly with an increased tumbling time, and Kramer shear force also significant decreased (p<0.05) with tumbling time. This corresponded with sensory panel tenderness ratings, which showed that the treatment for longer tumbling times was more tender (p<0.05). The texture results indicated that longer tumbling time had lower (p<0.05) hardness and chewiness values. Sensory panels ranked binding ability in the order 5 min, 15 min and 25 min from best to worst, and the overall acceptability for slices from roasts of treatments for 5 and 15 min were rated by the sensory panelists as moderate to very acceptable, but those for 25 min were rated as fair to moderate.

• Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.205-208
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• 2008

The mixotrophic dinoflagellate Cochlodinium polykrikoides was reported to be linked to major fish kills in Korea and Japan since the 1990s. Rapid and sensitive detection of microalgae has been problematic because morphological identification of dinoflagellates requires light microscopic and scanning electron microscopic observations that are time consuming and laborious compared to real-time PCR. To address this issue, a real-time PCR probe targeting the ITS2 rRNA gene was used for rapid detection and quantification of C. polykrikoides. PCR inhibitors in water column samples were removed by dilution of template DNA for elimination of false-negative reactions. A strong association between cell quantification using real-time PCR and microscopic counts suggests that the real-time PCR assay is an alternative method for cell estimation of C. polykrikoides in environment samples.