• 제목/요약/키워드: Mixed method approach

검색결과 346건 처리시간 0.023초

Analysis of Stratified Lake using an Eddy Diffusion and a Mixed-layer Models

  • Kim, Kyung-sub
    • Korean Journal of Hydrosciences
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    • 제8권
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    • pp.111-123
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    • 1997
  • A one-dimensional eddy diffusion model and a mixed-layer model are developed and applied to simulate the vertical temperature profiles in lakes. Also the running result of each method are compared and analyzed. In an eddy diffusion model, molecular diffusivity is neglected and eddy diffusivity which does not need lake-specific fitting parameter and constant lake's level are applied. The heat exchanges at the water surface and the bottom are formulated by the energy balance and zero energy gradient, respectively. In a mixed-layer model, two layers approach which has a constant thickness is adopted. The application of these models which use explicit finite difference and Runge-Kutta methods respectively demonstrates that the models simulate water temperatures efficiently.

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진화알고리듬을 이용한 혼합모델 U라인의 작업할당과 투입순서 결정 (Balancing and sequencing mixed-model U-lines using evolutionary algorithm)

  • 김재윤;김여근
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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    • pp.930-935
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    • 2002
  • This paper presents a new method that can efficiently solve the integrated problem of line balancing and model sequencing in mixed-model U-lines (MMULs). Balancing and sequencing problem are important for an efficient use of MMULs and are tightly related with each other. However, in almost all the existing researches on mixed­model production lines, the two problems have been considered separately. In 1his research, an endosymbiotic evolutionary algorithm, which is a kind of evolutionary algorithm, is adopted as a methodology in order to solve the two problems simultaneously. Some evolutionary search capability, rapidity of convergence and population diversity. The proposed algorithm is compared with the existing evolutionary algorithm in terms of solution quality. The experimental results confirm the effectiveness of our approach.

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혼합모델 조립라인에서 부품사용의 일정률 유지를 위한 생산순서 결정 : 유전알고리즘 적용 (Sequencing Problem to Keep a Constant Rate of Part Usage In Mixed Model Assembly Lines : A Genetic Algorithm Approach)

  • 현철주
    • 대한안전경영과학회지
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    • 제9권4호
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    • pp.129-136
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    • 2007
  • This paper considers the sequencing of products in mixed model assembly lines under Just-In-Time (JIT) systems. Under JIT systems, the most important goal for the sequencing problem is to keep a constant rate of usage every part used by the systems. The sequencing problem is solved using Genetic Algorithm Genetic Algorithm is a heuristic method which can provide a near optimal solution in real time. The performance of proposed technique is compared with existing heuristic methods in terms of solution quality. Various examples are presented and experimental results are reported to demonstrate the efficiency of the technique.

Mixed Methods Research on the Intercultural Sensitivity of Summer Program Participants; Comparison of US Participants and Korean Language Partners

  • Soyoung Jeong
    • International Journal of Advanced Culture Technology
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    • 제11권4호
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    • pp.112-122
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    • 2023
  • This study was conducted as part of a summer Korean language and culture program at a university in Korea, aimed at examining the changes in intercultural sensitivity among American students who participated in the program, as well as the Korean students who served as their language partners. The research utilized a mixed-method approach combining qualitative and quantitative analysis. To derive research findings, pre- and post-program Intercultural Sensitivity Scale surveys were administered to participating students and semi-structured interview data were collected from a randomly selected group of six students. The research findings indicated that among a total of twenty-seven students including both American and Korean students, significant changes in intercultural sensitivity were observed in the domain of Interaction Engagement. Furthermore, fourteen American students showed significant changes in their Interaction Confidence, while the Korean students who participated as language partners did not exhibit significant changes in the five subdomains of intercultural sensitivity.

Multiple Mixed Modes: Single-Channel Blind Image Separation

  • Tiantian Yin;Yina Guo;Ningning Zhang
    • Journal of Information Processing Systems
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    • 제19권6호
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    • pp.858-869
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    • 2023
  • As one of the pivotal techniques of image restoration, single-channel blind source separation (SCBSS) is capable of converting a visual-only image into multi-source images. However, image degradation often results from multiple mixing methods. Therefore, this paper introduces an innovative SCBSS algorithm to effectively separate source images from a composite image in various mixed modes. The cornerstone of this approach is a novel triple generative adversarial network (TriGAN), designed based on dual learning principles. The TriGAN redefines the discriminator's function to optimize the separation process. Extensive experiments have demonstrated the algorithm's capability to distinctly separate source images from a composite image in diverse mixed modes and to facilitate effective image restoration. The effectiveness of the proposed method is quantitatively supported by achieving an average peak signal-to-noise ratio exceeding 30 dB, and the average structural similarity index surpassing 0.95 across multiple datasets.

구조적 불확실성 접근을 이용한 RTP 시스템의 견실제어기 설계 (Robust controller design for RTP system using structured uncertainty approach)

  • 이상경;김종해;김해근;박홍배
    • 제어로봇시스템학회논문지
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    • 제5권6호
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    • pp.667-675
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    • 1999
  • In this paper, we propose a robust controller design of RTP(Rapid Thermal Processing) system using structured uncertainty approach. Using the weighted mixed sensitivity function, we solve the robust stability problem against disturbance and temperature variation, and design a $\mu$ controller using curve fitting method against structured uncertainty. Also the reduction method should be requried because of the difficulty of implementaion with the obtained high order controller. We dal with robust stability and performance of RTP system by the design of $\mu$ controller for original model and Schur balanced reduced model. Finally the simulation results are proposed to show the validity of the proposed method.

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초등수학교육에 적용된 혼합연구법의 특성 및 시사점에 대한 연구 (Analysis on Mixed Methods Research in Mathematics Education: A Qualitative Approach)

  • 나장함;김진호
    • 한국수학교육학회지시리즈C:초등수학교육
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    • 제20권2호
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    • pp.177-192
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    • 2017
  • 본 연구는 수학교육연구에서 적용되고 있는 혼합연구법이 질적연구와 양적연구를 어떻게 결합하여 활용하고 있는가를 탐색해 보고자 한다. 구체적으로 수학교육분야에서 질적연구와 양적연구의 혼합이 방법론적으로 어떠한 시사점과 과제를 줄 수 있는가를 탐구하고자 한다. 이와 같은 연구 목적을 달성하기 위하여, 본 연구에서는 한국초등수학교육학회에서 발간하는 '초등수학교육학회지'에 2015년 게재된 전체 32편의 논문 중, 혼합연구법을 적용한 4편의 논문을 분석 대상으로 선정하였다. 기존의 선행연구들에서는 혼합연구에 대한 분석 결과를, 일반적인 양적연구의 결과와 유사하게 비교 항목별로 수치화시키며 양적인 정보를 중심으로 간략하게 설명하는 경향이 있어 왔다. 이와는 대조적으로, 본 연구에서는 질적 연구자의 관점에서 질적연구와 양적연구의 장점을 최적화할 수 있는 방안을 상세하게 논의하는 형식으로 분석 결과와 시사점을 제시하고 있다.

시간지연과 불확실성을 가지는 위상동기루프의 루프필터에 대한 혼합 $H_2/H_{\infty}$ 출력궤환 제어기 설계 (Mixed $H_2/H_{\infty}$ Output Feedback Controller Design for PLL Loop Filter with Uncertainties and Time-delay)

  • 이경호;한정엽;박홍배
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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    • pp.2589-2592
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    • 2003
  • In this paper, a robust mixed H$_2$/H$\_$$\infty$/ output feedback control method is applied to the design of loop filter for PLL carrier phase tracking. The proposed method successfully copes with large S-curve slope uncertainty and a significant decision delay in the closed-loop that may exist In modern receivers due to a convolutional decoder or an equalizer. The objective is to design an output feedback controller which minimizes the H$_2$performance while satisfying the H$\_$$\infty$/ performance to guarantee the gain margin and phase margin for linear time invariant(LTI) polytopic uncertain systems. LMIs based approach is given to solve this problem. We can verify the H$\_$$\infty$/ performance satisfaction and minimize the phase detector error through the simulation result.

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준비시간이 있는 혼합모델 조립라인의 제품투입순서 결정 : Tabu Search 기법 적용 (Sequencing in Mixed Model Assembly Lines with Setup Time : A Tabu Search Approach)

  • 김여근;현철주
    • 한국경영과학회지
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    • 제13권1호
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    • pp.13-13
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    • 1988
  • This paper considers the sequencing problem in mixed model assembly lines with hybrid workstation types and sequence-dependent setup times. Computation time is often a critical factor in choosing a method of determining the sequence. We develop a mathematical formulation of the problem to minimize the overall length of a line, and present a tabu search technique which can provide a near optimal solution in real time. The proposed technique is compared with a genetic algorithm and a branch-and-bound method. Experimental results are reported to demonstrate the efficiency of the technique.

Comparing the Bayesian Estimates of Hazard Rate of Mixed Distribution and Hazard Rates by the MLE Method

  • Suneung Ahn;Kim, Hyunmook
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2003년도 추계학술대회 및 정기총회
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    • pp.263-266
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    • 2003
  • This paper is intended to compare between the Bayesian estimates of hazard rate and the hazard rates of mixed distributions. In estimating hazard rates, especially when the MLE method is used, such difficulties as a lack of data and the existence of censored data make it difficult to estimate the rates. For this reason, the estimates of hazard rate based on the Bayesian approach are introduced. For the simplicity, the exponential and gamma distributions are adopted as a sampling distribution and its natural conjugate prior distribution, respectively.

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