• 한국해안·해양공학회논문집
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• 제36권4호
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• pp.138-148
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• 2024

다중공진 파력발전체는 파랑의 공진현상을 복합적으로 이용하여 실해역의 평상파 내습시에도 파랑을 증폭시켜 효율적인 발전이 가능하다. 공진에 의해 파랑이 증폭될수록 다중공진 파력발전체의 발전 효율이 증가하며, 발전 효율이 최대가 될 수 있도록 공진부의 형상 최적화가 필요하다. 다중공진 파력 발전체는 항만 공진부와 수로 공진부에서 파랑을 증폭시키며, 본 연구에서는 수로 공진부의 길이, 위치 등 다양한 조건에서 CFD 수치실험을 수행하여 조건 별 상관성을 분석하고 수로 공진부의 최적 형상을 도출하였다.

• 충청수학회지
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• 제25권3호
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• pp.425-443
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• 2012

Sufficient conditions for the existence of at least one solution of a class of multi-point boundary value problems of the fractional differential equations at resonance are established. The main theorem generalizes and improves those ones in [Liu, B., Solvability of multi-point boundary value problems at resonance(II), Appl. Math. Comput., 136(2003)353-377], see Remark 2.3. An example is presented to illustrate the main results.

• 전기학회논문지
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• 제60권2호
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• pp.431-434
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• 2011

In this paper, bandwidth enhanced design of dielectric resonator antenna fabricated in multi-layer substrate is introduced. The proposed dielectric resonator antenna is operating with fundamental TE101 mode and higher-order TM111 mode. Each resonance frequency is dependent on resonator dimensions. As increasing the height of radiating aperture, the higher-order TM111 mode resonance frequency approach the fundamental TE101 mode resonance frequency and the antenna bandwidth increase by double resonance. Three different aperture height size antennas that operated at 7GHz are fabricated in FR4 multi-layer substrate. Measured 10 dB matching bandwidth is 8 percent for single resonace antenna and 18 percent for double resonance antenna.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.57-62
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• 2007

A modeling method for the modal and the transient vibration analysis of a multi-packet blade system excited by nozzle jet forces is presented in this paper. Blades are idealized as cantilever beams and the elastic structures like disc and shroud connecting blades are modeled as coupling stiffnesses. A modified Campbell diagram is proposed to identify true resonance frequencies of the multi-packet blade system. Different from the SAFE diagram that employs three dimensional space, the modified Campbell diagram proposed in this study employs a plane to find the true resonance frequencies. To verify the existence of true resonance frequencies, nozzle jet forces are modeled as periodic forces and transient vibration analysis were performed with the modeling method.

• 한국소음진동공학회논문집
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• 제18권7호
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• pp.711-717
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• 2008

A modeling method for the modal and the transient vibration analysis of a multi-packet blade system excited by nozzle jet forces is presented in this paper. Blades are idealized as cantilever beams and the elastic structures like disc and shroud connecting blades are modeled as coupling stiffnesses. A modified Campbell diagram is proposed to identify true resonance frequencies of the multi-packet blade system. Different from the SAFE diagram that employs three dimensional space, the modified Campbell diagram Proposed in this study employs a plane to find the true resonance frequencies. To verify the existence of true resonance frequencies, nozzle jet forces are modeled as periodic forces and transient vibration analysis were performed with the modeling method.

• Journal of information and communication convergence engineering
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• 제1권4호
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• pp.199-204
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• 2003

In this paper, we present the thermal annealing effects of the W/$SiO_2$ multi-layer reflectors in ZnO-based FBAR devices with cobalt (Co) electrodes in comparison with those with aluminum (Al) electrodes. Various thermal annealing conditions have been implemented on the W/$SiO_2$ multi-layer reflectors formed on p-type (100) silicon substrates. The resonance characteristics could be significantly improved due to the thermal annealing and were observed to depend strongly on the annealing conditions applied to the reflectors. Particularly, the FBAR devices with the W/$SiO_2$ multi- layer reflectors annealed at $400^{\circ}C$/30min have shown superior resonance characteristics in terms of return loss and quality-factor (Q-factor). In addition, the use of Co electrodes has resulted in further improvement of the resonance characteristics as compared with the Al electrodes. As a result, the combined use of both the thermal annealing and Co electrodes seems very useful to more effectively improve the resonance characteristics of the FBAR devices with the W/$SiO_2$ multi-layer reflectors.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제16권2호
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• pp.213-225
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• 2009

This paper deals with the existence of positive solutions for a kind of multi-point nonlinear fractional differential boundary value problem at resonance. Our main approach is different from the ones existed and our main ingredient is the Leggett-Williams norm-type theorem for coincidences due to O'Regan and Zima. The most interesting point is the acquisition of positive solutions for fractional differential boundary value problem at resonance. And an example is constructed to show that our result here is valid.

• 센서학회지
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• 제15권5호
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• pp.347-351
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• 2006

A novel surface plasmon resonance sensor, which can measure 2-dimensional array of immobilized ligands without using imaging devices such as CCD, has been proposed. Regular surface plasmon resonance can be directly used due to the insertion of additional layers with different thickness, on which each ligands are immobilized. Surface plasmon resonance signals are separated depending on the thickness of additional layers. The possibility of multi-sensing capability of the proposed surface plasmon resonance sensor has been verified by the modeling that is based on Fresnel reflection model.

• 대한수학회보
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• 제49권4호
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• pp.815-827
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• 2012

The existence of $n$ positive solutions is established for second order multi-point boundary value problem at resonance where $n$ is an arbitrary natural number. The proof is based on a theory of fixed point index for A-proper semilinear operators defined on cones due to Cremins.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.882-887
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• 2001

This paper deals with the effect of mass-spring-mass resonance that is a characteristics of the multi-layered panels in order to enhance sound insulation performance. From theoretical and experimental investigation, it is evident that tuning mass-spring-mass resonance by controlling elastic modulus of the core materials is very important to improve the STC value without increasing the weight of panels, resulting in enhancing STC value more than 10 dB.