• 상하수도학회지
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• 제28권6호
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• pp.735-745
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• 2014

This paper presents PKES(PuKyung -Excel based Simulator) for WWTPs(wastewater treatment plants) by using MS Excel and VBA(Visual Basic for Application). PKES is a user-friendly simulator for the design and optimization of the whole plant including biological and physico-chemical processes for the wastewater and sludge treatment. PKES calculates the performance under steady or dynamic state and allows changing the mathematical model by the user. Mathematical model implemented in PKES is a improved integration model based on ASM2d and ADM1 for simulation of AS(activated sludge) and AD(anaerobic digestion). Gaseous components of $N_2$, $N_2O$, $CO_2$ and $CH_4$ are added for estimation of GHGs(greenhouse gases) emission. The simulation results for comparison between PKES and Aquasim(EAWAG) showed about the same effluent concentrations. As a result of verification using by measured data of BOD, TSS, TN and TP for 2 years of operation, calculated effluent concentrations were similar to measured effluent concentrations. The values of average RMSE(root mean square error) were 1.9, 0.8, 1.6 and 0.2 mg/L for BOD, TSS, TN and TP, respectively. Total GHGs emission of WWTP calculated by PKES was 138.5 ton-$CO_2$/day and GHGs emissions of $N_2O$, $CO_2$ and $CH_4$ were calculated at 21.7, 28.9 and 87.9 ton-$CO_2$/day, respectively. GHGs emission of activated sludge was 32.5 % and that of anaerobic digestion was 67.5 %.

• 한국초등과학교육학회지:초등과학교육
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• 제24권5호특별호
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• pp.558-570
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• 2005

The importance of teaching the nature of science (NOS) has been always emphasized in science education. However, the NOS is hardly taught in elementary science class. We are lacking in the strategies and materials for teaching NOS. So we designed the science drama teaching, and investigated the effects on pupils' perceptions about NOS. The subjects of this study were 185 third graders from a elementary school. The treatment group was provided with science drama lessons and the control group was provided with traditional lecture-type lessons. Their perceptions about NOS were investigated before/after the science lessons and after 3 months following them, and both of two groups were compared. The pretest results revealed that the pupils of both groups were found to have similar views on NOS. Dey had traditional views of the most items except for social construction of theories, mathematical knowledge and decision-making. After science lessons, they tended to change their views toward modem views, but the pupils of the treatment group showed more modem views than those of the control group on the observation, model, social construction of theories, predictions. After 3 months, the pupils of the control group tended to come back to their traditional views, but those of the treatment group showed tendencies that their changed views were kept up on the observation, scientific model, scientific knowledge, scientific methods, decision-making, social construction of theories, mathematical knowledge. Therefore this study suggests that science drama teaching could be one of the effective ways for teaching NOS.

• 한국수학교육학회지시리즈A:수학교육
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• 제59권1호
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• pp.31-45
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• 2020

시대적 흐름과 정부의 정책 시행 노력에도 불구하고 수학학습에 어려움을 호소하는 학생들이 많이 늘어나고 있다. 이를 반영하여 수학교육에서 수학학습부진아와 관련된 연구가 많이 시행되었다. 하지만 이러한 연구들의 대부분은 수학학습부진아의 원인을 밝혀내거나 교수학적 처치를 시행하고 그 효과를 알아보는 실험연구가 대부분이었다. 따라서 본 연구에서는 학위논문 및 학술지 논문 49편을 메타분석하여 수학학습부진에 대한 교수학적 처치가 학업성취도 향상에 얼마나 큰 효과크기를 갖는지 분석하였다. 이러한 분석의 결과 수학학습부진아에게 교수학적 처치는 전반적으로 중간 정도의 효과크기를 갖는다는 것을 알게 되었다. 또한 여러 중재요인을 분석하여 어떠한 환경에서 가장 큰 효과를 거둘 수 있는지에 대한 제안점도 얻을 수 있었다.

• 상하수도학회지
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• 제18권4호
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• pp.453-460
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• 2004

The objective of this research is to develop the water quality management model to achieve the water quality goal and the minimization of the waste load abatement cost. Most of existing water quality management model can calculate BOD and DO. In addition to those variables, N and P are included in the management model of this study. With a genetic algorithm, calculation results from the mathematical water quality model can be used directly in this management model. Developed management model using genetic algorithm was applicated for the Youngsan River basin. To verify the management model, water quality and pollution source of the Youngsan River had been investigated. Treatment types and optimum treatment costs of the existing and planned WWTPs in the baisn were calculated from the model. The results of genetic algorithm indicate that Kwangju and Naju WWTP have to do the advanced treatment to achieve the water quality goal about BOD, DO and TP. Total annual treatment cost including the upgrade cost of existing WWTPs in the Youngsan River basin was about 50.3 billion Won.

• Fibers and Polymers
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• 제7권4호
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• pp.414-419
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• 2006

The paper presents information concerning metrological and technical characteristics of KTU-Griff-Tester device, the optimization of its parameters and the cases of its application. It was defined that the behaviour of textile material during its extraction through a rounded hole depends upon its structure. Variations of geometrical shape of woven and knitted specimens can be described by mathematical expressions of shortened epicycloids and Cassini ovals. It is shown that waving process of disc shaped specimen can be predicted on the basis of the law of sine curve. The examples of textiles treatment with different types of commercial softeners are presented, herewith showing the suitability (sensitiveness) of the new device to detect the changes of textile hand. Meantime it is shown that the level of materials anisotropy can be decided on the basis of transformations of specimen's geometrical shape.

• 대한수학회보
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• 제50권2호
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• pp.559-581
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• 2013

This paper is motivated by a 2001 paper of Choie and Kim and a 2006 paper of Bump and Choie. The paper of Choie and Kim extends an earlier result of Bol for elliptic modular forms to the setting of Siegel and Jacobi forms. The paper of Bump and Choie provides a representation theoretic interpretation of the phenomenon, and shows how a natural generalization of Choie and Kim's result on Siegel modular forms follows from a natural conjecture regarding ($g$, K)-modules. In this paper, it is shown that the conjecture of Bump and Choie follows from work of Boe. A second proof which is along the lines of the proof given by Bump and Choie in the genus 2 case is also included, as is a similar treatment of the result of Choie and Kim on Jacobi forms.

• Environmental Engineering Research
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• 제14권3호
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• pp.143-149
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• 2009

In this paper, review of stormwater quality and quantity in the urban environment is presented. The review is presented in three parts. This second part reviews the mathematical techiques used in the stromwater quality modelling and has been undertaken by examining a number of models that are in current use. The important features of models are discussed.

• International Journal of Reliability and Applications
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• 제16권2호
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• pp.81-98
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• 2015

The Exponentiated Gamma (EG) distribution is one of the important families of distributions in lifetime tests. In this paper, a new generalized version of this distribution which is called kumaraswamy Exponentiated Gamma (KEG) distribution is introduced. A new distribution is more flexible and has some interesting properties. A comprehensive mathematical treatment of the KEG distribution is provided. We derive the $r^{th}$ moment and moment generating function of this distribution. Moreover, we discuss the maximum likelihood estimation of the distribution parameters. Finally, an application to real data sets is illustrated.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제19권2호
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• pp.147-169
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• 2012

We introduce a Heaviside-function formulation of the interaction between incompressible two-phase fluid and a non-deformable solid. Fluid and solid interact in two ways : fluid satises the Dirichlet boundary condition imposed by the velocity field of solid, and solid is accelerated by the surface traction exerted by fluid. The two-way couplings are formulated by the Heaviside function to the interface between solid and fluid. The cumbersome treatment of interface is taken care of by the Heaviside function, and the interaction is discretized in a simple manner. The discretization results in a stable and accurate projection method.

• Communications for Statistical Applications and Methods
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• 제24권4호
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• pp.353-365
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• 2017

In this article, we proposed a new three-parameter distribution called generalized half-logistic Poisson distribution with a failure rate function that can be increasing, decreasing or upside-down bathtub-shaped depending on its parameters. The new model extends the half-logistic Poisson distribution and has exponentiated half-logistic as its limiting distribution. A comprehensive mathematical and statistical treatment of the new distribution is provided. We provide an explicit expression for the $r^{th}$ moment, moment generating function, Shannon entropy and $R{\acute{e}}nyi$ entropy. The model parameter estimation was conducted via a maximum likelihood method; in addition, the existence and uniqueness of maximum likelihood estimations are analyzed under potential conditions. Finally, an application of the new distribution to a real dataset shows the flexibility and potentiality of the proposed distribution.