• Title/Summary/Keyword: M-Wave

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Estimation of Consolidation in Soft Clay by Field Velocity Probe (Field Velocity Probe를 활용한 연약지반 압밀 평가)

  • Lee, Jong-Sub;Kim, Youngseok;Hong, Seungseo;Yoon, Hyung-Koo
    • The Journal of Engineering Geology
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    • v.23 no.4
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    • pp.511-517
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    • 2013
  • The Field Velocity Probe (FVP) has been widely applied to determine the various characteristics of soils. This study seeks to estimate soil consolidation characteristics using an FVP and to increase its application in the field. The specimens were extracted from depths of 3 and 6 m at the study site, an area of soft clay in Incheon. In laboratory testing, the specimens were placed in an improved oedometer cell to measure shear wave velocity, and statistical analysis was performed to compare the results of effective stress and shear wave velocity. FVP enables increased resolution in the field because it measures the shear wave velocity every 20 cm. To estimate the condition of consolidation, we compared the results of shear wave velocities between those obtained in the laboratory and those in the field. The field conditions are used to analyze overconsolidated and normally consolidated soils at depths of 3 and 6 m, respectively. The results show that FVP is a suitable method for estimating the degree of consolidation.

Optimization of traveling-wave electroabsorption modulator using FDTD method (FDTD를 이용한 진행파형 전계 흡수 광 변조기 최적화)

  • Ok, Seung-Hae;Lee, Seung-Jin;Kong, Soon-Cheol;Yun, Young-Seol;Choi, Young-Wan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.7
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    • pp.37-45
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    • 2002
  • In this paper, the microwave characteristics of traveling-wave electroabsorption coplanar waveguide modulator have been analyzed and optimized precisely by using the 3-dimensional finite-difference time-domain method (FDTD). Microwave characteristics are affected by the thickness of intrinsic layer, the width of meas, and the distance between signal electrode and ground electrode on traveling-wave type structure. In case that intrinsic layers are composed of InAsP/InGaP (1.3Q), the optimized distance between signal electrode and ground electrode, the optimized intrinsic region thickness and the width of waveguide are founded to be $3{\mu}m,\;039{\mu}m\;and\;2{\mu}m$, respectively, to minimize microwave loss and to obtain velocity and impedance matched structure. By using the FDTD, we could design the traveling-wave electroabsorption modulator more precisely.

A Study on the Characteristic of Sea Wave (불규칙파(不規則波)의 특성(特性)에 관한(關) 연구(硏究))

  • Choi, Han-Kuy;Yun, Kang-Hun
    • Journal of Industrial Technology
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    • v.5
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    • pp.59-64
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    • 1985
  • The remarkable economic growth achived during 1960-1980 in Korea inevitablely demanded the expansion and maintenance of the harbors and their auxiliary seashore facilities. One of the most important elements in the basic besign for the expasion of a harbor and its auxiliary facilities is, of course, the proper determination of the design wave which reflects the major characteristics of the seashore under consideration. In this study, the parameters of significant waves for the industrial harbors on East Coast, Muck-Ho and Po-Hang, are first computed by means of computer programming using S.M.B and P.N.J methods, respectively. Then the design waves with the return periods of 5-200 years were estimated by frequency analysis of the significant waves. A comparison of the design waves with the observed wave data during the past 10 years made it possible to determine the optimum value of design wave at the two harbors. The important results of this study can be summarized as follows; 1) It seems appropriate to take the design wave hieghts with the return period of 50 years at Muck-Ho and Po-Hang as 6.9 and 5.8 meters respectively. 2) It was found that for the determination of design waves on East Coast of Korean Peninsula P.N.J method works better than S.M.B method in predicting the significant wave, and the Log-Normal distribution fits best to the wave data which were put to frequency analysis.

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A Millimeter-Wave LC Cross-Coupled VCO for 60 GHz WP AN Application in a 0.13-μm Si RF CMOS Technology

  • Kim, Nam-Hyung;Lee, Seung-Yong;Rieh, Jae-Sung
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.4
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    • pp.295-301
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    • 2008
  • Recently, the demand on mm-wave (millimeter-wave) applications has increased dramatically. While circuits operating in the mm-wave frequency band have been traditionally implemented in III-V or SiGe technologies, recent advances in Si MOSFET operation speed enabled mm-wave circuits realized in a Si CMOS technology. In this work, a 58 GHz CMOS LC cross-coupled VCO (Voltage Controlled Oscillator) was fabricated in a $0.13-{\mu}m$ Si RF CMOS technology. In the course of the circuit design, active device models were modified for improved accuracy in the mm-wave range and EM (electromagnetic) simulation was heavily employed for passive device performance predicttion and interconnection parasitic extraction. The measured operating frequency ranged from 56.5 to 58.5 GHz with a tuning voltage swept from 0 to 2.3 V. The minimum phase noise of -96 dBc/Hz at 5 MHz offset was achieved. The output power varied around -20 dBm over the measured tuning range. The circuit drew current (including buffer current) of 10 mA from 1.5 V supply voltage. The FOM (Figure-Of-Merit) was estimated to be -165.5 dBc/Hz.

Characteristics of Pulse Wave Velocity by the Simultaneously Measured ECG Waveform and Hall Device Radial Artery Waveform (ECG 파형과 홀소자 맥진파형으로 동시 측정한 맥파전달속도 특성 연구)

  • Yoo, Jae-Young;Choi, Suel-Gi;Kim, Dam-Bee;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
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    • v.22 no.4
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    • pp.136-141
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    • 2012
  • In the this research, two simultaneous peaks of radial artery pulse wave and ECG pulse wave measured by using clip-type pulsimeter and ECG were investigated in order to analyze pulse wave velocity. The measured value of a pulse wave velocity is about 5~7 m/s, it is proved one new method to measure an exact value of pulse wave velocity more than the typical biomedical signal monitoring system. This result implies that data measured by the oriental medical diagnosis apparatus as pulsimeter is clinically used in future.

Effect of Wave Load on the Member Force of Steel Structure of Floating Buildings

  • Lee, Young-Wook;Park, Tae-Jun
    • International journal of steel structures
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    • v.18 no.4
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    • pp.1431-1439
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    • 2018
  • For floating buildings may fl oat on the water for a long time, they are constantly affected by various environmental loads such as wind and wave loads. In this study to find the wave effect on the floating building, five models are designed using steel moment resisting frame. It is assumed that the lower part of the floating building is a reinforced concrete pontoon, while the upper part is a three-story steel frame. To analyze floating buildings affected by wind and wave loads, hydro-dynamic and substructure analysis are performed. As input loads, this study set limits that the mean wind velocity is 35 m/s and the significant wave height is 0.5 m for the residential building. From the hydrodynamic analysis, the time-history acceleration of building is obtained and transformed into a base ground input for a substructure analysis of the superstructure of the building. Finally the mean of the maximum from 30 dynamic analysis of the floating buildings are used to be compared with the results of the same model on the ground. It was shown that the dynamic results with wind and wave loads are not always lesser than the static results which are calculated with static equivalent wind load for a building that is located on the ground.

Development of a Probabilistic Model for the Estimation of Yearly Workable Wave Condition Period for Offshore Operations - Centering on the Sea off the Ulsan Harbor (해상작업 가능기간 산정을 위한 확률모형 개발 - 울산항 전면 해역을 중심으로)

  • Choi, Se Ho;Cho, Yong Jun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.3
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    • pp.115-128
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    • 2019
  • In this study, a probabilistic model for the estimation of yearly workable wave condition period for offshore operations is developed. In doing so, we first hindcast the significant wave heights and peak periods off the Ulsan every hour from 2003.1.1 to 2017.12.31 based on the meteorological data by JMA (Japan Meterological Agency) and NOAA (National Oceanic and Atmospheric Administration), and SWAN. Then, we proceed to derive the long term significant wave height distribution from the simulated time series using a least square method. It was shown that the agreements are more remarkable in the distribution in line with the Modified Glukhovskiy Distribution than in the three parameters Weibull distribution which has been preferred in the literature. In an effort to develop a more comprehensive probabilistic model for the estimation of yearly workable wave condition period for offshore operations, wave height distribution over the 15 years with individual waves occurring within the unit simulation period (1 hour) being fully taken into account is also derived based on the Borgman Convolution Integral. It is shown that the coefficients of the Modified Glukhovskiy distribution are $A_p=15.92$, $H_p=4.374m$, ${\kappa}_p=1.824$, and the yearly workable wave condition period for offshore work is estimated to be 319 days when a threshold wave height for offshore work is $H_S=1.5m$. In search of a way to validate the probabilistic model derived in this study, we also carry out the wave by wave analysis of the entire time series of numerically simulated significant wave heights over the 15 years to collect every duration periods of waves the height of which are surpassing the threshold height which has been reported to be $H_S=1.5m$ in the field practice in South Korea. It turns out that the average duration period is 45.5 days from 2003 to 2017, which is very close to 46 days from the probabilistic model derived in this study.

Changes in EEG According to Attention and Concentration Training Programs with Performed Difference Tasks (주의·집중훈련 프로그램의 두 가지 과제수행에 따른 뇌파 변화)

  • Chae, Jung-Byung
    • PNF and Movement
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    • v.12 no.2
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    • pp.97-106
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    • 2014
  • Purpose: The purpose of this study was to investigate changes in EEG through attention. Concentration training and performing tasks are important factors in the improvement of motor learning ability. Methods: In the experiment, 22 healthy people were divided into two groups: the trail making test (TMT) group and the computerized neurocognitive function test (CNT) group. A one-way Neuro Harmony M test to see whether there was a significant difference among the groups. Results: The TMT group showed a significant increase in ${\alpha}$ wave, ${\alpha}$ wave sequence, and ${\beta}$ wave sequence; however, there were no significant differences in SMR wave, SMR wave sequence, and ${\beta}$ wave. The CNT group showed increases in ${\alpha}$ wave, ${\alpha}$ wave sequence, SMR wave, SMR wave sequence, and ${\beta}$ wave sequence; however, there was no significant difference in ${\beta}$ wave. In EEGs before and after two performance tasks were changed, there were significant differences in ${\beta}$ wave, SMR wave, SMR wave sequence; however, there were no significant differences in ${\alpha}$ wave sequence, ${\beta}$ wave, and ${\beta}$ wave sequence. Conclusion: Attention training and concentration training offer feedback and repetition for constant stimulus and response. Moreover, attention training and concentration training can contribute to new studies and motivation by developing fast sensory and motor skills through acceptable visual and auditory stimulation.

Design of the 60 GHz Single Balanced Mixer Integrated with 180° Hybrid Coupler Using MEMS Technology (HEMS 기술을 이용한 180° 하이브리드 결합기가 집적된 단일 평형 혼합기의 설계 및 제작에 관한 연구)

  • Kim Sung-Chan;Lim Byeong-Ok;Baek Tae-Jong;Ko Baek-Seok;An Dan;Kim Soon-Koo;Shin Dong-Hoon;Rhee Jin-Koo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.7 s.98
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    • pp.753-759
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    • 2005
  • In this paper, we have developed a new type of single balanced mixer with the RF MEMS $180^{\circ}$ hybrid coupler using surface micromachining technology. The $180^{\circ}$ hybrid coupler in this mixer is composed of the dielectric-supported air gapped microstriplines(DAMLs) which have signal line with $10{\mu}m$ height to reduce substrate dielectric loss and dielectric posts with size of $20{\mu}m{\times}20{\mu}m$ to elevate the signal line on air with stability At LO power of 7.2 dBm, the conversion loss was 15.5 dB f3r RF frequency or 57 GHz and RF power of -15 dBm. Also, we obtained the good RF to LO isolation of -40 dB at LO frequency of 58 GHz and LO power of 7.2 dBm. The main advantage of this type of mixer is that we are able to reduce the size of the chips due to integrating the MEMS passive components.

Research on Broadband Millimeter-wave Cascode Amplifier using MHEMT (MHEMT를 이용한 광대역 특성의 밀리미터파 Cascode 증폭기 연구)

  • Baek, Yong-Hyun;Lee, Sang-Jin;Baek, Tae-Jong;Choi, Seok-Gyu;Yoon, Jin-Seob;Rhee, Jin-Koo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.4
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    • pp.1-6
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    • 2008
  • In this paper, millimeter-wave broadband MHEMT (Metamorphic High Electron Mobility Transistor) cascode amplifiers were designed and fabricated. The $0.1{\mu}m$ InGaAs/InAlAs/GaAs MHEMT was fabricated for cascode amplifiers. The DC characteristics of MHEMT are 670 mA/mm of drain current density, 588 mS/mm of maximum transconductance. The current gain cut-off frequency($f_T$) is 139 GHz and the maximum oscillation frequency($f_{max}$) is 266 GHz. To prevent oscillation of the designed cascode amplifiers, a parallel resistor and capacitor were connected to the drain of common gate device. By using the CPW (Coplanar Waveguide) transmission line, the cascode amplifier was designed and matched for the broadband characteristics. The designed amplifier was fabricated by the MHEMT MMIC process that was developed through this research. As the results of measurement, the amplifier was obtained 3 dB bandwidth of 50.37 GHz between 20.76 to 71.13 GHz. Also, this amplifier represents the S21 gain with the average 7.07 dB gain in bandwidth and the maximum gain of 10.3 dB at 30 GHz.