• Korean Journal of Optics and Photonics
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• v.22 no.3
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• pp.122-128
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• 2011

The AWG-filtering effect was investigated on a bidirectional 100-GHz-channel-spacing WDM-PON link using spectrum-sliced and RSOA-amplified light sources for downstream signals and a wavelength reuse technique for upstream signals. Signal performances of three different filtering AWGs, including Gaussian, trapezoidal, and rectangular types, were compared on link transmission with fiber nonlinear effects. As an extinction ratio of a downstream signal varied, the effect for both directional signals was analyzed and optimized. It was found that there was an optimal pass bandwidth of an AWG for the balance between relative intensity noise decrement and cross phase modulation noise increment as the bandwidth got wider.

• MALSORI
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• no.57
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• pp.85-97
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• 2006

This paper suggests an algorithm that can estimate the direction of the sound source in real time. The algorithm uses the time difference and sound intensity information among the recorded sound source by four microphones. Also, to deal with noise of robot itself, the Kalman filter is implemented. The proposed method can take shorter execution time than that of an existing algorithm to fit the real-time service robot. Also, using the Kalman filter, signal ratio relative to background noise, SNR, is approximately improved to 8 dB. And the estimation result of azimuth shows relatively small error within the range of ${\pm}7$ degree.

• Journal of the Korean Vacuum Society
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• v.12 no.2
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• pp.123-129
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• 2003

Thin transparent Cu films in the thickness range of 10 ~ 40 nm are deposited by rf-magnetron sputtering on porous silicon (PS) anodized on p-type silicon in dark. Microstructural features of the Cu films are investigated using SEM, AFM and XRD techniques. The RMS roughness of the Cu films is found to be around 1.47 nm and the grain growth is columnar with a (111) preferred orientation and follows the Volmer-Weber mode. The photoluminescence studies showed that a broad luminiscence peak of PS near the blue-green region gets blue shifted (~0.05 eV) with a small reduction in intensity and therefore, Cu-related PL quenching is absent. The FTIR absorption spectra on the PS/Cu structure revealed no major change of the native PS peaks but only a reduction in the relative intensity. The I-V characteristic curves further establish the Schottky nature of the diode with an ideality factor of 2.77 and a barrier height of 0.678 eV. An electroluminiscence (EL) signal of small intensity could be detected for the above diode.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.105-110
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• 2012

A europium (III)-sensitized, spectrofluorimetric (FL) method is presented for the determination of sparfloxacin (SPAR) using an anionic surfactant, sodium dodecyl benzene sulphonate (SDBS). The method is based on the strong fluorescence (FL) enhancement of SPAR after the addition of $Eu^{3+}$ ions as fluorescence probes. The experimental results indicated that the FL intensity of the SPAR-$Eu^{3+}$ system was enhanced markedly by SDBS. The maximum FL emission signal was obtained at about 615 nm when excited at 372 nm. The experimental conditions that affected the FL intensity of the SPAR-$Eu^{3+}$-SDBS system were optimized systematically. The enhanced FL intensity of the system exhibited a good linear relationship with the SPAR concentration over the range of $1.5{\times}10^{-9}-1.2{\times}10^{-7}mol\;L^{-1}$ with a correlation coefficient (r) of 0.9987. The limit of detection ($3{\delta}$) was $4.15{\times}10^{-10}mol\;L^{-1}$ with a relative standard deviation (RSD) of 1.65%. This method was successfully applied for the determination of SPAR in pharmaceuticals, and human serum and urine samples with higher sensitivity, wide dynamic range and better stability. The possible interaction mechanism of the system is also discussed in detail by ultraviolet absorption spectra and FL spectra.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.153-160
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• 2020

The kinetic energy of the rain drops was predicted in a relation between the rain rate and rain quantity, derived directly from the rain drop size distribution (DSD), which had been measured by a disdrometer located in the eastern state of Alagoas-Brazil. The equation in the form of exponential form suppressed the effects of large drops at low rainfall intensity observed at the beginning and end of the rainfall. The kinetic energy of the raindrop was underestimated in almost rain intensity ranges and was considered acceptable by the performance indicators such as coefficient of determination, average absolute error, percent relative error, mean absolute error, root mean square error, Willmott's concordance index and confidence index.

• Korean Journal of Optics and Photonics
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• v.23 no.1
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• pp.42-51
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• 2012

In this paper, injection-locking characteristics versus active layer structures in Fabry-Perot laser diodes (FP-LD) are compared. TE and TM gain spectra and peak gains versus carrier density in polarized and unpolarized multiple quantum well structures and in an unpolarized bulk structure are calculated. The calculated gain parameters are applied to a time-domain large-signal model to simulate the injection-locking characteristics. The results show that RIN in unpolarized FD-LDs is about 3 dB lower than that in a polarized FP-LD and that the eye characteristics of the unpolarized FP-LD are much better than those of the polarized FP-LD.

• Journal of Biosystems Engineering
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• v.17 no.4
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• pp.344-353
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• 1992

This study was carried out to develop a fully-controlled plant growth system for studying the effects of environmental factors on plant growth. The plant growth system consists of the growth chamber, the measurement system for sensing and signal conditioning the environmental factors and the control system which includes control algorithm required for optimum operation and on-line monitoring. The results of the study on the performance of the controlled plant growth system are summarized as follows : 1. Under the light intensity of 18,000~20,000 lux, the temperature was controlled in the range of $22{\pm}0.4^{\circ}C$, the relative humidity of $70{\pm}5%$ respectively. 2. The $CO_2$ concentration was controlled in the range of $1,000{\pm}40ppm$(from 1st to 4th day) and $1,500{\pm}40ppm$(from 4th to 9th day). 3. The electric conductivity(EC) and pH of the nutrient solution were controlled in the range of $1.9{\pm}0.2mS/cm$ and $6.8{\pm}0.5pH$ respectively. 4. Under the above environmental conditions, the average fresh weight of leaf lettuce increased from 10g to 74g in 9 days with 24 hour lighting.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.121-122
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• 1998

To induce perturbed magnetic field variations in the range of auto prescans permitted, we chose artificially shim values and applied manualy as DC offsets to X, Y, Z gradient amplifiers. The STEAM spectra were obtained from a localized region (8ml) of phantom's center and a Marquart Algorithm is employed to quantify MRS spectra. Results indicated that Creatine (Cr) which had a good correlation between a signal intensity and an area, changed little bit and showed extremly a stabilized state in perturbed magnetic field variations. Therefore, during the MRS experiments, to minimize the SNR reduction by means of unavoidable inhomogeneous magnetic fields, the present study suggested that the quantification method of relative ratios produced by replacing Cr concentration with standard quantify was most desirable.

• ETRI Journal
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• v.38 no.1
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• pp.1-8
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• 2016

A large incoherent crosstalk (IC) caused by amplified spontaneous emission (ASE) noise power from Tx-disabled optical network units and a differential path loss has been shown to degrade upstream transmission performance in time-division multiplexing passive optical networks. This paper considers the IC-induced power penalty of an upstream signal both in an XG-PON and in a TWDM-PON. We investigate the degradation of the extinction ratio and relative intensity noise through a simulation and experiments. For the XG-PON case, we observe a 9.6 dB difference in the level of ASE noise power from Tx-disabled ONUs (hereafter known simply as ASE noise) between our result and the ITU-T XG-PON PMD recommendation. We propose an optical filtering method to mitigate an IC-induced power penalty. In the TWDM-PON case, the IC-induced power penalty is naturally negligible because the ASE noise is filtered by a wavelength multiplexer at the optical line terminal. The results provide design guidelines for the level of ASE noise in both XG-PONs and TWDM-PONs.

• Journal of Microbiology
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• v.33 no.4
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• pp.328-333
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• 1995

$\^$31/ P-NMR experiment was performed to detect phophonates (Pn) utilization and degradation in the several different C-P lyase mutants of E. coli and in E. aerogenes and the recombinants. The relative peak intensity (RPI) for the standard samples of 0.5 mM methylphosphonate (MPn) and 1.0 mM aminoethylphosphonate in glucose-MOPS medium showed 0.5 : 1.0 ratio. In the case of BW14329 (.DELTA.phnC-P, .delta.phoA), RPI did not change significantly after 24 hrs culturing, which means it nearly could not utilize Pn. In vivo $\^$31/ P-NMR spectrum of E. aerogens (BWKL 16627) during 3 hrs starvation showed two intense peaks at 0-2 ppm and at near-10 ppm which indicate intracellular orthophosphate (Pi) and pyrophosphate (PPi), respectively. Both of them might be released by degradation of inorganic polyphosphate pool. When MPn is supplied to the medium as an unique P source, Pi content in the cell has the constant, but PPi seems to be slightly decreased. Recombinants (BWKL 16954) grew slower than E. aerogenes in the glucose-MOPS media with various P sources. In vivo $\^$31/ P-NMR spectrum of recombinant did not show any intense signal in the cell. Surprisingly, under the cultivation adding with MPn, a few intense peaks in the region of Pi AND phospate monoester were detected.