• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.333-346
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• 2018

This study presents a mathematical modeling approach for developing models based on non-ideal conditions related to the membrane structure including porous supporting layer and deformation under pressure. Comparison of the findings with experimental data reveal the importance of considering the resistance in porous supporting layer though the effect of concentration polarization in the permeate stream could be neglected. Investigations on deformation of fibers under pressure ascertain that at larger fiber inner radius to outer radius ratios, increasing driving force may lead to an initial increase in permeability. After that, the effects of deformation dominates and thus permeability may be decreased.

• 한국전산구조공학회논문집
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• 제25권4호
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• pp.363-372
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• 2012

본 논문에서는 수학적 구조 모델과 인공신경망 기법을 상호 유기적으로 결합하여 구조물의 거동 데이터로부터 부재모델 또는 재료모델의 정확도를 높이는 정보기반 하이브리드 모델 업데이트 기법을 개발하였다. 유한요소와 같은 수학적 모델을 사용하여 구조물의 거동을 모사하기 위해서는 재료, 부재, 그리고 시스템의 정확한 모델링이 우선하여야 한다. 그러나 재료, 부재의 각 레벨에서의 수학적인 모델은 이상화과정을 거치면서 중요한 특성을 생략하거나, 시스템 구성시 부재간의 상호작용이나 경계조건의 단순화로 인해 유한요소 모델은 실제 구조물의 거동과 차이를 보이게 된다. 본 논문에서 제시된 하이브리드 모델 업데이트 기법은 구조물의 거동과 수학적 모델의 해석결과 차이를 인공신경망 기법을 사용하여 보완함으로써 시스템 모델의 정확도를 높일 수 있다. 이때 시스템의 거동 데이터로부터 부재 또는 재료모델을 개선할 수 있는 데이터를 추출하여 부재 또는 재료모델을 개선한다. 제시된 기법은 보-기둥 접합부의 이력모델을 개선하는 것으로 검증하였으며, 복잡한 거동을 보이는 시스템 모델링에 광범위하게 사용될 수 있다.

• 대한수학교육학회지:학교수학
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• 제7권4호
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• pp.427-444
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• 2005

스프레드시트는 표, 그래프 기능 그리고 셀 참조 기능을 가지고 있고, 이러한 기능은 모델링 활동에서 중요한 역할을 한다. 이 글에서는 스프레드시트를 활용한 수학적 모델링 활동에서의 수학적 규칙의 발견과 이의 정당화 과정을 알아보고자 한다. 이를 위해 스프레드시트 환경이 특정 문제 상황의 해결에 어떻게 도움을 주는 지 알아보고, 어떻게 특정한 문제 상황을 일반적인 문제 상황으로 바꿀 수 있도록 하는지를 알아본다. 또한 문제 상황 속에 내재하는 수학적 규칙의 발견에 이르는 과정을 알아보고, 발견한 규칙의 정당화 유형과 스프레드시트가 정당화에 어떤 영향을 미치는지를 알아본다.

• 한국정보통신학회논문지
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• 제3권2호
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• pp.291-304
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• 1999

주 연구에서는 압전체에서의 IDT 변환기, 음향 반사기에 대한 전기 음향 모드의 결합 모드 방정식을 유도, 정리함으로써 SAW 공진기 필터의 결합 모드를 수학적으로 분석할 수 있는 모델링 방법을 소프트웨어 설계 모듈화하고, SAW 공진기 필터를 구성하고 있는 각 구성 요소에 대한 회로적인 결합 방법의 제안을 통하여 SAW 결합 모드 공진기 필터의 설계 및 시뮬레이션 방법을 제안하였다. 또한, 제작된 소프트웨어 설계 모듈을 시뮬레이션 소프트웨어 패키지화함으로써 설계자가 손쉽게 이동통신기기용 결합 모드 공진기 필터를 설계할 수 있도록 그래픽 사용자 인터페이스를 갖는 SAW 결합 모드 공진기 필터의 설계 시뮬레이터를 구현하였으며 이를 통하여 이동통신기기에서 사용할 수 있는 결합 모드 공진기 필터를 모의 설계하고 주파수 특성을 해석함으로써 그 응용 타당성을 제시하였다.

• 대한수의학회지
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• 제60권1호
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• pp.15-18
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• 2020

Canine heartworm disease is a vector-borne disease that is transmitted from dog to dog by mosquitoes. It causes epidemics that disrupt the health environments of dogs and are burdensome for many dog owners. Recent trends of changing temperatures and weather conditions in South Korea may have an impact on the population of mosquitoes, and it affects the population of dogs at risk of heartworm infection. Mathematical modeling has become an important measure for analyzing the epidemiological characteristics of infectious diseases. However, canine heartworm infection transmission has not been reported yet through mathematical modeling. We develop a mathematical model of canine heartworm infection to predict the population of infected dogs depending on the vector (mosquito) population using a susceptible, exposed, infected, and recovered model. Simulation results show that after 1 year, 3,289 dogs out of 73,602 (about 4.5%) are exposed and 134 (about 0.2%) are infected. Only 0.2% of susceptible dogs become infected after 1 year. However, if all exposed dogs are maintained in the same circumstances without any treatment, then the number of infected subjects will increase over time. This may increase the possibility of other dogs, especially dogs that live outside, being infected.

• 설비공학논문집
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• 제15권6호
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• pp.533-542
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• 2003

This study aims to propose a simplified mathematical model for calculating vertical air temperature distribution in a four-sided atrium. In the first stage of the mathematical modeling, the computer model combined zonal model and solar radiation model using Monte Carlo method and Ray tracing technique went through a computer simulation with architectural variables applied to a four-sided atrium in summer. In the next stage, Curve Expert, a computer program that gets the most suitable solution ac-cording to the least squares method, is used to analyze the results of the computer simulation and to derive the mathematical model. The accuracy of the mathematical model was evaluated through a comparison of calculation results from a mathematical model and computer simulation. In this validation step using the least square method, the R2 value of the Zones 1, 2 and 3 showed higher than 0.945. Zone 4 has an R2 value of 0.911, lower than the previous three zones. However the relative error was below 0.5%, which is considered very small.

• The Korean Journal of Physiology and Pharmacology
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• 제23권5호
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• pp.305-310
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• 2019

The physiomic approach is now widely used in the diagnosis of cardiovascular diseases. There are two possible methods for cardiovascular physiome: the traditional mathematical model and the machine learning (ML) algorithm. ML is used in almost every area of society for various tasks formerly performed by humans. Specifically, various ML techniques in cardiovascular medicine are being developed and improved at unprecedented speed. The benefits of using ML for various tasks is that the inner working mechanism of the system does not need to be known, which can prove convenient in situations where determining the inner workings of the system can be difficult. The computation speed is also often higher than that of the traditional mathematical models. The limitations with ML are that it inherently leads to an approximation, and special care must be taken in cases where a high accuracy is required. Traditional mathematical models are, however, constructed based on underlying laws either proven or assumed. The results from the mathematical models are accurate as long as the model is. Combining the advantages of both the mathematical models and ML would increase both the accuracy and efficiency of the simulation for many problems. In this review, examples of cardiovascular physiome where approaches of mathematical modeling and ML can be combined are introduced.

• 제어로봇시스템학회논문지
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• 제13권10호
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• pp.927-932
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• 2007

The sophisticated mathematical model is required for the design and the database construction of the advanced flight control system of UAV. In this paper, flight test of KARI's research UAV, often called DURUMI-II, is implemented for the data acquisition from the maneuver flight. The flight path reconstruction is implemented to ensure that the measured data is consistent and error free. The nonlinear system identification for the refined mathematical modeling is implemented with the verified measurements from the flight path reconstruction. The simulation with the identified results have a good validation when the simulated responses were compared to the flight tested data.

• Communications for Statistical Applications and Methods
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• 제23권5호
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• pp.363-383
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• 2016

The Weibull family of lifetime distributions play a fundamental role in reliability engineering and life testing problems. This paper investigates the potential usefulness of transmuted new generalized Weibull (TNGW) distribution for modeling lifetime data. This distribution is an important competitive model that contains twenty-three lifetime distributions as special cases. We can obtain the TNGW distribution using the quadratic rank transmutation map (QRTM) technique. We derive the analytical shapes of the density and hazard functions for graphical illustrations. In addition, we explore some mathematical properties of the TNGW model including expressions for the quantile function, moments, entropies, mean deviation, Bonferroni and Lorenz curves and the moments of order statistics. The method of maximum likelihood is used to estimate the model parameters. Finally the applicability of the TNGW model is presented using nicotine in cigarettes data for illustration.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.431-431
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• 2000

The modeling of 5-bar linkage robot manipulator dynamics by means of a mathematical and neural architecture is presented. Such a model is applicable to the design of a feedforward controller or adjustment of controller parameters. The inverse model consists of two parts: a mathematical part and a compensation part. In the mathematical part, the subsystems of a 5-bar linkage robot manipulator are constructed by applying Kawato's Feedback-Error-Learning method, and trained by given training data. In the compensation part, MLP backpropagation algorithm is used to compensate the unmodeled dynamics. The forward model is realized from the inverse model using the inverse of inertia matrix and the compensation torque is decoupled in the input torque of the forward model. This scheme can use tile mathematical knowledge of the robot manipulator and analogize the robot characteristics. It is shown that the model is reasonable to be used for design and initial gain tuning of a controller.