• Title/Summary/Keyword: wave response

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Miniatured Planar Bandpass Filter Using Coupled Metamaterial Resonators

  • Kim, Gi-Rae
    • Journal of information and communication convergence engineering
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    • v.9 no.3
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    • pp.256-259
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    • 2011
  • In this article, new microstrip slow-wave bandpass filters using open loop resonator loaded with inter-digital capacitive fingers is proposed. The filter features not only compact in size, but also exhibits spurious stop-band rejection. Filters of this type with elliptic function and Chebyshev response are demonstrated. There is good agreement between experimental and full-wave electromagnetic (EM) simulation results.

Load simulation for offshore wind turbine (해상풍력터빈에 대한 하중 모사 방법 연구)

  • Suk, Sangmin;Lee, Sunggun;Chung, Chinhwa;Park, Hyunchul
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.58.1-58.1
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    • 2011
  • In this paper, the purpose is a study on structural analysis for offshore wind turbine using commercial code. Because offshore wind turbine is subjected to great wind and wave force, it is necessary to analyse the dynamics and minimize the response of wind turbine. The offshore wind turbine tower is modelled as a single degree of freedom and multi degree of freedom structure. It is assumed that the blades, nacelle are composed of concentrated masses.

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Response-Improved Electrochromic Display Device Based on Organic Materials (고응답성 유기계 전기변색성 소자의 제작과 특성)

  • 권태선
    • Journal of the Korean Graphic Arts Communication Society
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    • v.12 no.1
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    • pp.81.1-91
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    • 1994
  • Irradiation of aromatic diazonium salts resulted in an effcient elimination of nitrogen, yielding substitution products. This paper was not only studies about photolysis of aromatic diazonium with double salts but also coexistence of ion and radical when they was photolysis. Photolysis of aromatic diazonium was depend on excite wave length therefore photolysis products out put different absorption intensity such other. We also confirmed coexistence of ion and radical when they was accomplished photolysis. In case of BD, there are ion decomposition process about 90 percentage, decreased ion decomposition process the other side radical`s it was becomeing increased according to excite of short-wave length.

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On Long-term Prediction Scheme in Ocean Engineering

  • Kwon, Sun-Hong;Kim, Dea-Woong
    • International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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    • v.3 no.1
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    • pp.29-34
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    • 2000
  • This paper proposes a long-term prediction of offshore structures in ocean waves. All short-term statistics is generated by the simulation for all the combinations of significant wave heights and spectral peak periods. The simulation has been tested first on linear system, whose analytic solution is known, to verify if the simulation works accurately. Then the scheme was applied to the nonlinear system. This paper demonstrated that the proposed scheme could be an efficient tool in estimating the response of offshore structures.

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Design of Capacitive Displacement Sensor and Gap Measurement with High Precision Using Surface Acoustic Wave Device (표면 탄성파 장치를 응용한 용량 성 변위센서의 설계 및 초정밀 간극 측정)

  • Kim, Jae-Geun;Lee, Taek-Joo;Lim, Soo-Cheol;Park, No-Cheol;Park, Young-Pil;Park, Kyoung-Su
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.5
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    • pp.437-443
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    • 2010
  • SAW device is widely used as band pass filters, chemical or physical sensors, and actuators. In this paper, we propose the capacitive gap measurement system with high precision using SAW device. The research process is mainly composed of theoretical and experimental part. In the theoretical part, equivalent circuit model was used to predict the SAW response by the change of load impedance. In the experimental part, commercialized capacitor was used to see the SAW response by the change of load capacitance to check the feasibility as a sensor unit. After that, experimental setup to measure and adjust the gap was made and the SAW response by the change of gap which caused the capacitance change was measured. Finally, resolution and stroke was decided compared with the signal change and basic measurement noise level.

Earthquake response of isolated cable-stayed bridges under spatially varying ground motions

  • Ates, Sevket;Soyluk, Kurtulus;Dumanoglu, A. Aydin;Bayraktar, Alemdar
    • Structural Engineering and Mechanics
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    • v.31 no.6
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    • pp.639-662
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    • 2009
  • A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wave-passage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

Effect of Pretension on Moored Ship Response

  • Sajjan, Sharanabasappa C.;Surendran, S.
    • International Journal of Ocean System Engineering
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    • v.3 no.4
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    • pp.175-187
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    • 2013
  • Moonpools are vertical wells in a floating body used onboard many types of vessels like Exploration and drilling vessels, Production barges, Cable-laying vessels, Rock dumping vessels, Research and offshore support vessels. Moonpool gives passage to underwater activities for different types of ships as per their mission requirements. It is observed that inside a moonpool considerable relative motions may occur, depending on shape, depth of the moonpool and on the frequency range of the waves to which the ship is exposed. The vessel responses are entirely different in zero and non-zero Froude number. Former situation is paid attention in this study as the mission requirement of the platform is to be in the particular location for long period of operation. It is well known that there are two modes of responses depending on the shape of the moonpool viz., piston mode for square shape and sloshing mode for rectangular shapes with different aspect ratios of opening like 1:1.5 and 1:2 ratios. Circular shaped moonpool is also tested for measuring the responses. The vessel moored using heavy lines are modelled and tested in the wave basin. The pretensions of the lines are varied by altering the touchdown points and the dynamic tensions on the lines are measured. The different modes of oscillations of water column are measured using wave gauge and the vessel response at a particular situation is determined. RAOs calculated for various situations provide better insight to the designer.

Effects of the Photic Stimulation on Electroencephalogram in Pediatric Epilepsy Patients

  • Yoon, Joong Soo;Choi, Hyun Ju
    • Biomedical Science Letters
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    • v.18 no.4
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    • pp.428-434
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    • 2012
  • Epilepsy is a chronic neurological disease showing a symptom of repeated seizures without any other physical disorders. Among the diagnostic examination for epilepsy, the electroencephalogram (EEG) has been known as an important test. This study aimed to investigate the EEG with photic stimulation in the pediatric epilepsy patients. They underwent digital sleep and waking EEGs or waking EEGs with photic stimulation. Epilepsy type, seizure history, and season of occurring seizure were analyzed. Epilepsy patients showed more response during the period of photic-on and eye close at the frequency of 10~20 Hz during the EEG activation procedure. Photoparoxysmal response (PPR) was shown in 206 patients out of total 1,551 epilepsy patients. PPR was appeared more frequently during summer and winter seasons, and especially in the patients who had a history of seizure. During the PPR, EEG pattern showed spike (77.18%), theta (9.71%), and spike + theta (13.11%). On the other hand, beta and theta waves were not significantly changed by photic stimulation. However, alpha wave was decreased and delta wave was increased by photic stimulation (P<0.05). These changes may be due to temporarily altered electrophysiological function of the epileptic patient's brain by the photic stimulation. There was no difference in the EEG pattern between the left and right side in the brain. In conclusion, condition of photic-on with closed eyes and frequency of 10~20 Hz during the procedure of EEG activation could be appropriate for obtaining a definite photoparoxysmal response in the electroencephalogram of the pediatric epilepsy patients.

Seismic Performance Evaluation of Cone-type Friction Pendulum Bearing System Using Shaking Table Test (진동대실험을 통한 원추형 마찰진자베어링의 내진성능 평가)

  • Jeon, Bub-Gyu;Chang, Sung-Jin;Kim, Nam-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.04a
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    • pp.389-394
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    • 2011
  • Existing FPS(Friction Pendulum System) is isolation system which is possible to isolate structures by pendulum characteristic from ground vibration. Structural natural frequency could be decided by designing the radius of curvature of FPS. Thus, response vibration could be reduced by changing natural frequency of structures from FPS. But effective periods of recorded seismic wave were various and estimation of earthquake characteristic could be difficult. If effective periods of seismic wave correspond to natural frequency of structures with FPS, resonance can be occurred. Therefore, CFPBS(Cone-type Friction Pendulum Bearing System) was developed for controlling the response acceleration and displacement by the slope of friction surfaces. Structural natural frequency with CFPBS can be changed according to position of ball on the friction surface which was designed cone-type. Therefore, Divergence of response could be controlled by CFPBS which had constantly changing natural frequency with low modal participation factor in wide-range. In this study, Seismic performance of CFPBS was evaluated by numerical analysis and shaking table test.

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Physiological Response of Human Body by Temperature Change -Part 2: In Priority to Pulse wave- (온도변동에 따른 인체 생리적 반응 -제2보: 맥파를 중심으로-)

  • Kang, Suk-Jung;Kum, Jong-Soo;Kim, Dong-Gyu;Chung, Yong-Hyun;Lee, Nak-Bum
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.23-28
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    • 2007
  • In most existing research, it is difficult to evaluate thermal comfort exactly because of reflecting individual ideal or psychological response by subjective questions. Physiological variable was selected in this study to evaluate objectively thermal comfort. MST was appeared very sensitively in indoor temperature and can express correctly thermal comfort of human body. The results of CSV are different each individual feeling sensation, so is difficult to evaluate detailedly thermal comfort unlike TSV. But the results of PP, AIx, ED, SEVR are greatly related to temperature change. So thermal comfort is evaluated more objectively by using PP, AIx, ED, SEVR on behalf of TSV, CSV. Human body was presented physiological feedback by temperature impetus and specially, tendency of heart rate agree with temperature change. Physiological reaction was showed sufficient possibility availing evaluation index of thermal comfort. In the future another one needs to review beside the selected physiological variable.

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