• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.21-23
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• 2011

Uniformity of plasma etching processes critically depends on the wafer temperature and its distribution. The wafer temperature is affected by plasma, chucking force, He back side pressure and the surface temperature of ESC(electrostatic chuck). In this work, 3D mathematical modeling is used to investigate the influence of the geometry of coolant path and the temperature distribution of the ESC surface. The model that has the coolant path with less change of the cross-sectional area and the curvature shows low standard deviation of the ESC surface temperature distribution than the model with the coolant path of the larger surface area and more geometric change.

• 동력기계공학회지
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• 제18권2호
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• pp.77-82
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• 2014

The air spring is widely used in various fields such as a suspension system and an anti-vibration system because the natural frequency is kept constant regardless of the change in the load, spring constant is easy to change, and, vibration and shock isolation performance are excellent. The purpose of this study is to derive a nonlinear governing equation of an air spring, to analyze the effect of the various parameters on the dynamic stiffness of the air spring, and, to suggest a more efficient design method of an air spring system. In order to do so, this study investigates the impact of all the parameters that could affect the dynamic stiffness of the air spring while changing the excitation amplitude and the frequency with a developed governing equation.

• 대한안전경영과학회지
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• 제12권4호
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• pp.153-160
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• 2010

In this paper, effects of information sharing in multi-level supply chain management have been studied through simulation. The simulation model consists of a manufacturing company as a center, three suppliers, two logistic centers, and three different retail supply lines of each logistics centers. The mathematical model and the simulation were developed when real-time information sharing occurs and does not occur in supply chain under the assumption that each company applies (s, S) inventory policies. In addition, this paper analyzed the effects of the change of variables related to total costs, which compose of total ordering cost, total transportation cost, total carrying cost and shortage cost that are caused by the change of demand of three different patterns with the way of information sharing.

• 한국지능시스템학회논문지
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• 제11권8호
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• pp.736-741
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• 2001

변형된 영상을 다시금 최적영상을 복원하는 것은 여러 영상변환의 복합적인 변환, 그 것의 역변환과 많은 다중 해의 계산을 요구하게 된다. 본 연구에서는 가공기의 운전 전이나 운전 중에 가공기의 외란-진동, 이동, 기계적 특성-에 능동적으로 대치하고 동시에 복잡한 수학적인 수식전개를 피하고, 인공지능인 기법인 퍼지논리(Fuzzy Logic)를 적용하여 전문가적인 경험지식을 바탕으로 보정이 가능함을 보였다.

• Journal of Advanced Marine Engineering and Technology
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• 제24권4호
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• pp.502-508
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• 2000

The amount of container freight is continuously increasing recently, but freight congestion problem frequently occurs at ports due to low efficiency of container crane in transportation and cargo handling. In this paper, a method for designing a fuzzy controller of the container crane system is presented. In this scheme a mathematical model for the system is obtained in state space representation. The response of the proposed fuzzy controller is compared with that of the optimal controller at the same condition. Through the simulation results, the performance of the fuzzy controller was observed better than that of optimal controller in respect of reference change, disturbances and parameter change. The fuzzy controller was also more stable and robust than the optimal controller.

• Kyungpook Mathematical Journal
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• 제46권1호
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• pp.145-152
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• 2006

In this paper, we study a class of strongly nonlinear implicit complementarity problems in the setting of Hilbert spaces H (not necessarily Hilbert lattices). By using the property of the projection and a suitable change of variables, we establish the equivalence between the strongly nonlinear implicit complementarity problem and the fixed point problem in H. Moreover, we use this equivalence and the fixed point theorem of Boyd and Wong to prove the existence and uniqueness of solutions for the strongly nonlinear implicit complementarity problem in H.

• 한국포장학회지
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• 제4권1호
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• pp.23-32
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• 1997

The change in moisture content of moisture sensitive products in moisture-semipermeable packages was investigated for the purpose of predicting the shelf life of a product-package combination. A mathematical model, and a computer program based on the physiochemical properties of the product and the moisture permeability of the package was developed. The moisture content for products in moisture-semipermeable packages was determined under various environmental conditions and the results were compared with the predicted values by means of the simulation model. These experimental studies demonstrated that the prediction of the change in moisture content of packaged products over time by the simulation model is accurate, within a practical range of temperature and relative humidity values. The developed semi-empirical model is considered to have applications in industry, since it provides product shelf life information for a range of temperature and relative humidity conditions, with a limited number of experimentally obtained data points.

• Advances in nano research
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• 제13권6호
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• pp.561-574
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• 2022

The stability of protein tissues and protein fibers in the human muscle is investigated in the presented paper. The protein fibers are modeled via tube structures embedded in others proteins fibers like the elastic substrate. Physical sport and physical exercise play an important role in the stability of synthesis and strength of the protein tissues. In physical exercise, the temperature of the body increases, and this temperature change impacts the stability of the protein tissues, which is the aim of the current study. The mathematical simulation of the protein tissues is done based on the mechanical sciences, and the protein fibers are modeled via wire structures according to the high-order theory beams. The thermal stress due to the conditions of the sport is applied to the nanoscale protein fibers, then the stability regarding the frequency analysis is investigated. Finally, the impact of temperature change, physical exercise, and small-scale parameters on the stability of the protein tissues are examined in detail.

• Journal of applied mathematics & informatics
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• 제41권3호
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• pp.553-567
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• 2023

There are real life situations in our lives where the things are changing continuously or from time to time. It is a very important problem for one whether to continue the existing relationship or to form a new one after some occasions. That is, people, companies, cities, countries, etc. may change their opinion or position rapidly. In this work, we think of the problem of changing relationships from a mathematical point of view and think of an answer. In some sense, we comment these changes as power changes. Our number theoretical model will be based on this idea. Using the convolution sum of the restricted divisor function E, we obtain the answer to this problem.

• 대한수학교육학회지:수학교육학연구
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• 제14권3호
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• pp.221-237
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• 2004

본 연구는 개념적 은유의 분석을 통해 RME 기반 대학 미분방정식 수업에 참여한 학생들의 개념적 모델의 변환을 탐구하였다. 분석 결과 학기초 이산적이고 양적인 개념적 모델이 학생들의 수학적 토의 맥락에서 지배적이었으나 맥락문제탐구에 기반한 수학적 의미의 재조정 과정을 통해 연속적이고 질적인 사고를 반영하는 개념적 모델이 발생하여 기존의 개념적 모델이 확장됨이 밝혀졌다. 이와 같은 개념적 모델의 변환은 본 프로젝트 교실 참여가 학생들의 미분방정식에 대한 문제해결적 사고의 유연성을 증대시키는데 기여하였음을 보여준다. 이와 같은 분석 결과에 기초하여, 본 논문은 학생들의 개념적 모델의 변환을 촉발한 교수학적 요소에 대한 논의를 통해 학생들의 개념적 모델 변환이 가지는 사회문화적 의미를 조명하고 RME 기반 수학 수업 모델의 학교 현장 적용에 유용한 시사점을 제공하였다.