• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3653-3664
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• 2021

In PWR three-dimensional transient coupling calculation software CORCA-K, the nodal Green's function method and diagonal implicit Runge Kutta method are used to solve the spatiotemporal neutron dynamic diffusion equation, and the single-phase closed channel model and one-dimensional cylindrical heat conduction transient model are used to calculate the coolant temperature and fuel temperature. The LMW, NEACRP and PWR MOX/UO₂ benchmarks and FangJiaShan (FJS) nuclear power plant (NPP) transient control rod move cases are used to verify the CORCA-K. The effects of burnup, fuel effective temperature and ejection rate on the control rod ejection process of PWR are analyzed. The conclusions are as follows: (1) core relative power and fuel Doppler temperature are in good agreement with the results of benchmark and ADPRES, and the deviation between with the reference results is within 3.0% in LMW and NEACRP benchmarks; 2) the variation trend of FJS NPP core transient parameters is consistent with the results of SMART and ADPRES. And the core relative power is in better agreement with the SMART when weighting coefficient is 0.7. Compared with SMART, the maximum deviation is -5.08% in the rod ejection condition and while -5.09% in the control rod complex movement condition.

• 전자공학회논문지A
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• 제29A권11호
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• pp.49-56
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• 1992

In this paper a band-pass filter using dielectric resonators with tuning screw and spacer at Ku-band is designed and constructed. For the filter design and construction, the coupling coefficient K between two resonators is numberically evaluated. The external quality factor Q$_{ex}$ is also calculated with a microstrip line which is necessary for the field excitation of dielectric resonator. The coupling between dielectric resonator and microstrip line depends mainly upon the magnetic field and is principal parameter in band-pass filter. The Q$_{ex}$ and K data which are evaluated by numberical analysis are practically applied to the filter construction. The theoretical Band-pass filter responses are given by Chebyshev approximation and they are nearly similar to the experimental results.

• 전자공학회논문지D
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• 제35D권9호
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• pp.87-92
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• 1998

확장된 새로운 층 방법을 이용하여 사다리꼴과 삼각형 형태의 회절격자 구조를 가지는 5층의 DFB 구조 소자의 TM 모드의 결합계수를 계산하였다. TM 모드의 unperturbed 필드 분포를 쉽게 계산하기 위하여 회절격자 영역의 비유전상수의 역수를 종축과 횡축 양 방향으로 평균값을 취하여 새로이 설정하는 층의 비유전상수의 역수가 되도록 설정하였다. 확장된 새로운 층 방법이 TM 모드의 결합계수 계산에도 유용하게 사용될 수 있음을 회절격자 영역의 등분할 층수를 6층까지 늘려가며 self-consistent하게 검증하였다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 2호
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• pp.415-420
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• 1999

본 연구의 목적은 SEA모델링 기법을 이용하여 시스템 응답 특성을 예측 하는데 있어서 연견 손실 계수(coupling loss factor). 내부 손실 계수(internal loss factor)와 같은 주요 변수의 값을 압전 지능 구조물을 이용하여 도출 하는 .것이다. 관심 주파수 대역에서 임피던스(impedance) 해석기를 이용해 압전 지능 구조물의 임피던스를 측정하고 랜덤 가진 시 압전 지능 구조물의 부하전압을 측정, 시스템에 가해지는 전기적 파워를 구하였다. 이 값을 전기-기계적 연결 계수(electro-mechanical coupling coefficient)를 이용 기계적 파워로 상사 시키고 이때 시스템에 저장되는 에너지를 가속도계를 이용해 측정 하였다. 이 결과 값을 이용하여 연결 손실 계수와 내부 손실 계수를 구하여 보았다. 또한 이론식을 이용하여 얻은 이론 값과 기존의 가진기(shaker)를 이용하여 얻은 실험 값과 비교 분석 하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.1215-1218
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• 1998

본 논문은 Digital Audio Compression(AC-3) Standard 인 A-52를 기반으로 하였으며 Borland C++3.1 Compiler를 사용하여 AC-3 Decoding Algorithm 구현하였다. Input Stream은 DVD VOB File에서 AC-3 Stream만을 분리하여 사용하며 최종 출력은 16 Bit PCM File이다. AC-3의 Frame구조는 Synchronization Information, Bit Stream Information, Audio Block, Auxiliary Data, Error Check로 구성된다. Aduio Block 은 모두 6개의 Block으로 나뉘어져 있다. BSI와 Side Information을 참조하여 Exponent를 추출하여 Exponent Strategy에 따라 Exponent를 복원한다. 복원된 Exponent 정보를 이용하여 Bit Allocation을 수행하여 각각의 Mantissa에 할당된 Bit수를 계산하고 Stream으로부터 Mantissa를 추출한다. Coupling Parameter를 참조하ㅕ Coupling Channel을 Original Channel로 복원시킨다. Stereo Mode에 대해서는 Rematrixing을 수행한다. Dynamic Range는 Mantissa와 Exponent의 Magnitude를 바꾸는 것으로 선택적으로 사용할 수 있다. Mantissa와 Exponent를 결합하여 Floating Point coefficient로 만든 후 Inverse Transform을 수행하면 PCM Data를 얻을 수 있다. PC에서 듣기 위해서는 Multi Channel을 Stereo나 Mono로 Downmix를 수행한다. 이렇게 만들어진 PCM data는 PCM Data를 재생하는 프로그램으로 재생할 수 있다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.824-828
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• 2007

In this paper Statistical Energy Analysis has been considered to predict middle, high frequency air borne interior noise. PIM method is used for verification. Damping loss factor and coupling loss factor have been derived from the response(SPL) of sub systems when the power is applied. The airborne SEA model of vehicle is modeled through AutoSea2. Insulation material's absorption coefficient and transmission loss are acquired from closed form solution and experiment.

• 전기학회논문지
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• 제61권10호
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• pp.1454-1460
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• 2012

In order to develop an new electric insulation material for heavy electric equipments, epoxy/micro/nano composite (EMNC) was prepared by mixing micro-silica with nano layered silicate, where the nano layered silicate was synthesized by our electric field dispersion method, EMNSC was prepared by treating the EMNC with a silane coupling agent. Thermal properties such as glass transition temperature (Tg) and thermal expansion coefficient, and DMA characteristics were studied, and mechanicla properties such as tensile and flexural tests were performed. AC electrical insulation strength was also tested. All properties of EMNSC were modified by treating EMNC with silane coupling agent and it was confirmed that our new developed composites could be used in the heavy electric equipments.

• 소음진동
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• 제9권4호
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• pp.822-827
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• 1999

The reduction of booming noise level and improvement of sound quality in the vehicle interior have been major fields of vehicle NVH for many years. In order to reduce the booming noise this paper proposed a system variable, which takes account of mode shapes and natural frequencies of the structural-acoustic system, measurement points and excitation frequency. By simplifying the system variable, the major contributors of panels inculding roof, roof lining, wind shield glasses, doors and floor to booming noise at a specific frequency was experimentally found. Also the relationships between structural modes of roof lining, one of the major contributors, and acoustic modes of compartment cavity were investigated from the viewpoint fo structure-borne noise. In addition, the roof lining was modified structurally by applying marble sponge to the gap between roof and roof lining. Asthe result of structural modification, the booming noise was reduce at target frequency.

• 전자공학회논문지A
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• 제33A권10호
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• pp.61-70
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• 1996

In this paper, we find the values of near-end crosstalk coefficient in striplines of a FR-4 multilayer PCB by an analytic method and a HSPICE simulation method, and define calcualtion errors in an analytic method and define the application range, and simualte near-end crosstalk coefficients of the FCT (fast CMOS TTL) in complicated striplines by HSPICE and analyze near-en crosstalk coefficients in relation to dielectric thickness and trace spaces of striplines. As a result, we analyze coupling structure of the near-end crosstalk in the coplicated sstriplines that are impedance matched and define a coupling formula of near-end crosstalk coefficients in general complicated striplines. Especially, it is approximated in the layout grade rule.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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• pp.413-415
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• 2000

마이크로스트립 안테나의 일반적인 특징중의 하나는 좁은 대역폭이다. 이 좁은 대역폭은 안테나의 입력 임피던스에 의해서 제한될 뿐 방사 패턴이나 이득의 변화에 의해서는 아니다. 그래서 안테나에서 결합계수를 조절하여 over-coupling을 만든 후 임피던스의 허수성분을 제거하는 경합회로를 사용하여 안테나의 임피던스 대역폭을 증가 시켰다.