• Journal of Environmental Impact Assessment
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• v.14 no.5
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• pp.247-254
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• 2005

Road traffic noise has increasing broader effects on urban areas as well as rural areas because of rapidly increasing traffic volume and newly-constructed roads. 10 sites in building development areas were selected and the noise level were measured by the apartment floors and by the various block plans of apartment complex. Analysis result, about correction factor, in the case of right angle arrangement, apply - 2.5dB(A). In the case of apartment house correlation of each floor apply 1st floors 0dB(A), 2st floors 1.2dB(A), 3st floors 2.1dB(A), 4st floors 2.6dB(A), 5st floors 2.7dB(A), 6st floors 2.7dB(A), 7st floors 2.4dB(A), 8st floors 2.0dB(A), 9st floors 1.6dB(A), 10st floors 1.1dB(A), 13st floors 0.2dB(A), 15st floors 0.5dB(A). The level of road traffic noise in the arrangement construction of right angle was about 3.0dB(A) at N-4 point and 2.1dB(A) at N-6 point lower than that of a plan figure, respectively. The results suggested that application of correction coefficient obtained by the apartment floor and by the arrangement construction can be improved in road traffic noise. The results suggested that application of correction coefficient obtained by the apartment floor and by the arrangement construction can be improved in road traffic noise.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.107-114
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• 1996

The in situ target strength for the anchovy (Engraulis japonica) were measured by the split beam echo sounder system at 38 kHz. This study allowed us to detect the single echos from anchovy shoals which were dispersed during trawling operation in day time. The results of our study were as fellows: We found that the anchouy occupied about $95\%$ of the total catch from the detected shoals from which target strength data were collected. Length distribution of anchovy showed a mode and ranged from 13.6 to 15.4cm with a mean of 14.4cm and a standard deviation of 0.45cm, and weight distribution showed a mode and ranged from 16 to 28 g witha mean of 21.9 g and a standard deviation of 2.7 g. The target strength distribution of anchovy ranged from -40.7 dB to -69.2 dB in the water layer of ,$10\~30\;m$ -42.19 to -67.7 dB in the $30\~50\;m$ and -42.2 to -67.7 dB in $10\~50\;m$, showing 2 modes in each layer, respectively. Overall mean target strengths were -49.7 dB/fish and -33.1 dB/kg, averaged by area backscattering cross section $(\sigma)$, and the confidence interval for target strength was less than 1 dB. With the mean total length and the mean target strength, we drived the target strength-length relationship as $TS(\sigma)=20\;Log\;L-72.9$.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.229-232
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• 2000

In this study, An active band grass filter for 2.14GHz have been designed with MMIC using negative resistance circuit. The negative resistance element was realized with a common-drain FET with series inductive feedback. The designed active filter showed an insertion loss of 0dB at 2.14GHz and a 3-dB bandwidth of 125MHz.

• Journal of Magnetics
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• v.14 no.1
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• pp.11-14
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• 2009

We investigated the I-V curves and differential tunneling conductance of two, CoFeB/MgO/CoFeB-based, magnetic tunnel junctions (MTJs): one with a low tunneling magnetoresistance (TMR; 22%) and the other with a high TMR (352%). This huge TMR difference was achieved by different MgO sputter conditions rather than by different annealing or deposition temperature. In addition to the TMR difference, the junction resistances were much higher in the low-TMR MTJ than in the high-TMR MTJ. The low-TMR MTJ showed a clear parabolic behavior in the dI/dV-V curve. This high resistance and parabolic behavior were well explained by the Simmons' simple barrier model. However, the tunneling properties of the high-TMR MTJ could not be explained by this model. The characteristic tunneling properties of the high-TMR MTJ were a relatively low junction resistance, a linear relation in the I-V curve, and conduction dips in the differential tunneling conductance. We explained these features by applying the coherent tunneling model.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.12 s.115
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• pp.1240-1248
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• 2006

This paper presents an UHF band(911 MHz) RFID tag antenna which has near-isotropic radiation pattern and easy conjugate impedance matching characteristics to any commercial chips of usual practice through the application of an inductively-coupled feeding. The proposed antenna of compact size $40{\times}46mm\;(0.12{\times}0.14{\lambda})$ has, at normal incidence, the maximum RCS of $-18.5dBm^2$ and the 3 dB RCS bandwidth of 9 MHz(1 %) in case of short chip load. It has the maximum and minimum RCS' of $-16.9dBm^2\;and\;-21.4dBm^2$ depending on the incident angles. The difference of about 4.5 dB is relatively small compared with that (about 70 dB) of a pure dipole antenna. The designed antenna has been fabricated and its RCS' have been measured varying the angles of incidence. The measured RCS' have been found to have good agreement with the simulated ones.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.2
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• pp.9-16
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• 2006

FAA AC120-40B Level D flight dynamics model for T-50 Full Mission Trainer was successfully developed. Since AC120-40B Level D requires the quantitative validation tests for simulation model compared with flight test data, T-50 flight test data for each validation test item was gathered, and also automatic test environments which include AFT (Automatic Fidelity Tester) and STA (Simulation Test Analyzer) were developed. The final test results after the iterative test-tuning processes were all within the tolerances specified in AC120-40B Level D. Qualification Test Guide, QTG contains the detail test processes and results.

• Food Engineering Progress
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• v.21 no.2
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• pp.103-109
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• 2017

Alginate lyase from Streptomyces violaceoruber was purified by DEAE sephacel chromatography and SP sepharose chromatography. The specific activity of the purified enzyme was 14.6 units/mg protein, representing a 40.6-fold purification of the crude extract. The final preparation thus obtained showed a single band on Tricine-SDS polyacrylamide gel electrophoresis whose molecular weight was determined to be 23.3 kDa. The polyMG block of sodium alginate was hydrolyzed by the purified alginate lyase and then separated by activated carbon column chromatography and bio gel P-2 gel filtration. The main hydrolysates were composed of hetero type M/G-oligosaccharides with the degrees of polymerization (D.P.) being 6 and 8. To investigate the effects of hetero type M/G-oligosaccharides from the sodium alginate on the growth of some intestinal bacteria, cells were cultivated individually on the modified-MRS medium containing D.P. 6 and 8 M/G-oligosaccharides. B. longumgrew 4.25-fold and 6.44-fold more effectively by the treatment of D.P. 6 and 8 M/G-oligosaccharides compared with those of standard MRS medium. In addition, B. bifidumgrew 3.3-fold and 5.4-fold more effectively by the treatment of D.P. 6 and 8 M/G-oligosaccharides. In conclusion, D.P. 8 was more effective than D.P. 6 hetero M/G-oligosaccharides as regards the growth of Bifidobacteriumspp. and Lactobacillus spp.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.5
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• pp.504-514
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• 2014

An MMIC multi-function chip with a low DC power consumption for an X-band active phased array radar system has been designed and fabricated using a 0.5 ${\mu}m$ GaAs p-HEMT commercial process. The multi-function chip provides several functions: 6-bit phase shifting, 6-bit attenuation, transmit/receive switching, and signal amplification. The fabricated multi-function chip with a compact size of $16mm^2(4mm{\times}4mm)$ exhibits a gain of 10 dB and a P1dB of 14 dBm from 7 GHz to 11 GHz with a DC low power consumption of only 0.6 W. The RMS(Root Mean Square) errors for the 64 states of the 6-bit phase shift and attenuation were measured to $3^{\circ}$ and 0.6 dB, respectively over the frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.25-33
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• 1998

In this paper, we describe a single-gate MESFET mixer at PCS(Personal Communication Service) frequency band. The PCS frequency band is 1965~2025 MHz in FR and 140 MHz in IF irrespectly. The design of the mixer was executed by microwave simulator, EEsof Libra. The matching network is consisted of rectangular inductor, MIM capacitor and open stub. The ma- nufacture work was accomplished by the micro-pen and wedge-bonder. The mixer showed $6.69\pm0.65$ dB of conversion gain, $-14.9\pm3.5$dB of RF reflection coefficient and 57.83 dB of LO/IF isolation at 10 dBm of LO power when LO frequency is 1855 MHz. When this mixer is used at PCS terminal, IF-amplifier which compensates the conversion loss of diode mixer may be omitted.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.45-53
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• 2018

Purpose: The purpose of this study was to investigate the effects of muscle activity and muscle strength according to verbal command volume during isokinetic and isometric quadricep exercises. Methods: To measure muscle activity and muscle strength, surface electrodes were attached to the participants, as they sat on a Biodex chair. The isometric exercise was performed three times, with maximum exercise at $30^{\circ}$ bending angle, based on a maximum extension state of the knee at $0^{\circ}$. The average holding time was unified to three seconds. In addition, the isokinetic exercise was performed three times, at $60^{\circ}/sec$. The verbal command ranged between 0∾60 dB and 0∾75 dB. Muscle activity was measured using surface electromyography (4D-MT, Relive, Gimhae, Korea). The Biodex System 4 was used to measure the isometric and isokinetic strength of the nodal line, and 4D-MT was used to measure muscle activity. Results: There were significant improvements in the maximal and relative muscle strengths, when the 0∾ 60 dB and 0∾75 dB verbal commands were applied with isokinetic extension/flexion (p<.05). The isokinetic exercise (0∾75 dB) group showed a significant difference in the vastus medialis oblique muscle activity change (p<.05), while the isometric exercise (0∾75 dB) group showed a significant difference in the rectus femoris muscle activity change (p<.05). Conclusions: Our results reveal that verbal commands effectively improve muscle activity and muscle strength during isokinetic and isometric quadricep exercises.