• 한국광학회지
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• 제4권2호
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• pp.233-241
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• 1993

슈뢰딩거에 의해서 거론되기 시작한 량자적 중첩상태를 광학적 측면에서 고찰한다. 양자중첩 상태의 생성, 양자 중첩상태의 비고전적 성질을 살펴보고, 거시적 중첩상태를 관측하기 어려운 이유를 알아본다.

• Korea-Australia Rheology Journal
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• 제21권1호
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• pp.13-16
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• 2009

We investigate time-temperature superposition from the viewpoint of geometry. The arc length of viscoelastic plots provides powerful resolution for check of the validity of time-temperature superposition. We also suggest a new algorithm for determination of shift factor which is base on the minimization of the total arc length and does not assume any functional form of viscoelastic function.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.373-375
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• 1997

In this study, we designed multiple mesh circuit consisting of 3-6 meshes and pulse superposition one consisting of a 3 mesh, and fabricated the electrical power supply and the single elliptical resonator. We developed the two pulse superposition technique forming the step pulse shapes of pulsed Nd:YAG laser with single shot multivibrator and 2 SCRs. Laser beam generated by multiple mesh circuit and superposition one respectively irradiated target surface to analyze process state of surface with spark and vapor. And it was obtained experimental results that all superposition meshes had common points which the best efficiency was obtained at delay time 0[${\mu}s$], followed by, no superposition and obtained at delay time 250[${\mu}s$].

• Advances in aircraft and spacecraft science
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• 제5권2호
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• pp.259-275
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• 2018

In mechanical analysis of spacecraft structures situations appear where static and dynamic loads must be considered simultaneously. This could be necessary either by load definition or preloaded structures. The superposition of these environments has an impact on the load and stress distribution of the analysed structures. However, this superposition cannot be done by adding both load contributions directly. As an example, to compute equivalent Von Mises stresses, the phase information must be taken into account in the stress tensor superposition. Finite Element based frequency response solvers do not allow the calculation of superposed static and dynamic responses. A manual combination of loads in a post-processing task is required. In this paper, procedures for static and harmonic loads superposition are presented and supported by analytical and finite element-based examples. The aim of the paper is to provide evidence of the risks of using different superposition techniques. Real application examples such as preloaded mechanism structures and propulsion system tubing assemblies are provided. This study has been performed by the Structural Engineering department of Airbus Defence and Space GmbH Friedrichshafen.

• 디지털산업정보학회논문지
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• 제6권3호
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• pp.9-17
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• 2010

Decision problem called an optimal release policies, after testing a software system in development phase and transfer it to the user, is studied. The applied model of release time exploited infinite non-homogeneous Poisson process. This infinite non-homogeneous Poisson process is a model which reflects the possibility of introducing new faults when correcting or modifying the software. The failure life-cycle distribution used superposition which has various intensity, if the system is complicated. Thus, software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement becomes an optimal release policies. In a numerical example, after trend test applied and estimated the parameters using maximum likelihood estimation of inter-failure time data, estimated software optimal release time. Through this study, in terms of superposition model and simply model, the optimal time to using superposition model release the software developer to determine how much could count will help.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2001년도 학술대회논문집
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• pp.163-166
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• 2001

In this paper, the superposition of ultrasonic signals which were generated by multi-source in a transformer was presented. For analysis of ultrasonic superposition, V$_{peak-peak}$ and pulse number of ultra-sonic signal were used. As a result, the wave form of ultrasonic superposition was classified into three types ; First type was the wave form whose V$_{peak-peak}$ was increased by the superposition of each signal's V$_{peak-peak}$. Second type was wave form whose V$_{peak-peak}$ was decreased by the superposition of each signal's V$_{peak-peak}$. And the other type was wave form whose peals were two or mere. And V$_{peak-peak}$ of superposed ultrasonic wave wads mostlv increased or decreased and pulse number of supe게osed u1trasonic wave was mostly increased.y increased.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.172-181
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• 2003

In this study, the stress intensity factor of center crack tip is calculated by the superposition method when it is surrounded by symmetrically distributed small cracks. The values of stress intensity factors of center crack tips are compared with those of the center crack tips calculated by the superposition method. These compared errors are influenced by the locations of distributed small cracks. These errors are inspected. When small cracks overlap and approach near the center crack tip, the effect of interaction caused by these cracks becomes noticeable and these errors become larger. In case of multiple distributed small cracks except this case, the stress intensity factor of the center crack tip is easily calculated by the superposition method.

• International Journal of Internet, Broadcasting and Communication
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• 제13권3호
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• pp.17-24
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• 2021

Recently, a lossless non-orthogonal multiple access (NOMA) implementation without successive interference cancellation (SIC) has been proposed in the literature of NOMA. This lossless non-SIC NOMA was achieved via correlated superposition coding (CSC), in contrast to conventional independent superposition coding (ISC). However, only the achievable data rates for CSC NOMA were investigated. Thus, this paper proposes a practical CSC NOMA scheme under Rayleigh fading channel environments. First, we design the practical CSC NOMA scheme, namely quadrature correlated superposition modulation (CSM) NOMA, without channel coding, i.e., uncoded systems. In addition, we calculate the symbol error rates (SERs) for this quadrature CSM NOMA scheme. Then, simulations demonstrate that for the weak channel gain's user, the SER performance of the proposed quadrature CSM NOMA is shown to be improved greatly, compared to that of the conventional quadrature amplitude modulation (QAM) NOMA, whereas for the strong channel gain's user, the SER performance of the proposed quadrature CSM NOMA degrades a little, compared to that of the conventional QAM NOMA. As a result, the proposed quadrature CSM NOMA scheme could be considered as a practical NOMA scheme for CSC NOMA schemes toward the fifth-generation (5G) and next generation communications.

• 한국통신학회논문지
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• 제35권2B호
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• pp.325-333
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• 2010

Wibro를 포함한 많은 시스템에서 순환 치환 행렬(circulant)로 구성된 준 순환 LDPC(low-density parity-check) 부호를 사용하고 있다. 하지만 준 순환 부호의 기저 행렬 크기의 제약으로 인해 계층 복호(layered decoding)가 가능하고 일정 값 이상의 거스(girth)를 만족하면서 동시에 최적의 차수 분포를 갖도록 하는 것은 매우 힘들다. 본 논문에서는 이러한 문제점을 극복하기 위해 중첩 행렬(superposition matrix) 구조를 가지는 준 순환 LDPC 부호를 제안한다. 중첩 행렬을 이용할 경우에 특화된 거스 점검 조건들을 유도하고, 기존 행렬 구조와 중첩 행렬 구조 두 가지 모두에 대해 계층 복호를 수행할 수 있는 새로운 LDPC 복호기 구조를 제안한다. 모의실험을 통하여 중첩 행렬 구조를 가지는 LDPC 부호는 복호 시 수렴 속도가 개선되고 오류 정정율이 향상됨을 보인다.

• 한국정보통신학회논문지
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• 제22권10호
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• pp.1379-1385
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• 2018

기존의 다중사용자 중첩 전송은 순시 채널 전력의 조건에 따라 데이터 심벌의 전력 할당 계수와 사용자별 수신 신호 처리 방법을 결정한다. 그러나 순시 채널 전력의 이용은 시스템의 복잡도를 증가시킬 수 있기 때문에 본 논문에서는 평균 채널 전력을 이용하는 고정적 다중사용자 중첩 전송을 고려한다. 고정적 다중사용자 중첩 전송 기법은 시간에 따라 느리게 변화하는 평균 채널 전력의 조건을 기반으로 데이터 심벌의 전력 할당 계수와 사용자별 수신 신호 처리 방법을 결정하기 때문에 시스템 복잡도를 감소시킬 수 있다. 본 논문에서는 고정적 다중사용자 중첩 전송에 대한 평균 심벌 오차율을 분석한다. 특히, 레일레이 페이딩 채널을 가정하여 M-ary 직교 진폭 변조에 대한 평균 심벌 오차율의 표현식을 유도한다. 또한, 수치적 결과를 통하여 열악한 채널 환경에 있는 사용자에서 고정적 다중사용자 중첩전송과 기존의 다중사용자 중첩 전송의 평균 심벌 오차율 성능이 유사함을 보였다.