• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제27권1호
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• pp.37-55
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• 2023

In this paper we propose a new algorithm for detecting and counting flowers in a complex background based on digital images. The algorithm mainly includes the following parts: edge contour extraction of flowers, edge contour determination of overlapped flowers and flower counting. We use a contour detection technique in Computer Vision (CV) to extract the edge contours of flowers and propose an improved algorithm with a concave point detection technique to find accurate segmentation for overlapped flowers. In this process, we first use the polygon approximation to smooth edge contours and then adopt the second-order central moments to fit ellipse contours to determine whether edge contours overlap. To obtain accurate segmentation points, we calculate the curvature of each pixel point on the edge contours with an improved Curvature Scale Space (CSS) corner detector. Finally, we successively give three adaptive judgment criteria to detect and count flowers accurately and automatically. Both experimental results and the proposed evaluation indicators reveal that the proposed algorithm is more efficient for flower counting.

• Advances in nano research
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• 제15권1호
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• pp.15-23
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• 2023

Dynamics of protein filamentous has been an active area of research since the last few decades as the role of cytoskeletal components, microtubules, intermediate filaments and microfilaments is very important in cell functions. During cell functions, these components undergo the deformations like bending, buckling and vibrations. In the present paper, bending and buckling of microfilaments are studied by using Euler Bernoulli beam theory with nonlocal parametric effects in conjunction. The obtained results show that the nonlocal parametric effects are not ignorable and the applications of nonlocal parameters well agree with the experimental verifications.

• Advances in concrete construction
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• 제9권5호
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• pp.491-501
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• 2020

Microtubules buckle under bending and torsion and this property has been studied for free microtubules before using orthotropic elastic shell model. But as microtubules are embedded in other elastic filaments and it is experimentally showed that these elastic filaments affect the critical buckling moment and critical buckling torque of the microtubules. To prove that, we developed orthotropic Winkler like model and demonstrated that the critical buckling moment and critical buckling torque of the microtubules are orders of higher magnitude than those found for free microtubules. Our results show that Critical buckling moment is about 6.04 nNnm for which the corresponding curvature is about θ = 1.33 rad /㎛ for embedded MTs, and critical buckling torque is 0.9 nNnm for the angle of 1.33 rad/㎛. Our results well proved the experimental findings.

• East Asian mathematical journal
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• 제36권2호
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• pp.229-251
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• 2020

Problem Based learning(PBL) is a teaching and learning method to increase mathematical ability and help achieving mathematical concepts and principles through problem solving using the learner's mathematical prerequisite knowledge. In addition, the recent instructional situations or environments have focused on the learner's self construction of his learning and its process. In spite of such a quite attention, it is not easy to apply and execute PBL program actually in class. Especially, there are some difficulties in actually applying and practicing PBL in the areas of mathematics education in not only secondary school but also in college. Its reason is that in order to conduct PBL instruction constantly in real or experimental class there is no more concrete and detailed instructional content during the consistent and long period. However, to whom is related to mathematics education including instructors called scaffolders, investigation and recognition on the degree of the learner's acquisition of mathematical thinking skills and strategies is an very important work. By the reason, in this study, the instructional content was to be explored and developed to be conducted during 15 weeks in one semester, which was based on Problem Based Learning environment by the subject of the theories relevant to mathematics education in the college of education.

• Journal of applied mathematics & informatics
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• 제41권6호
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• pp.1257-1274
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• 2023

Rotating machines heavily rely on an intricate network of interconnected sub-components, with bearing failures accounting for a substantial proportion (40% to 90%) of all such failures. To address this issue, intelligent algorithms have been developed to evaluate vibrational signals and accurately detect faults, thereby reducing the reliance on expert knowledge and lowering maintenance costs. Within the field of machine learning, Artificial Immune Systems (AIS) have exhibited notable potential, with applications ranging from malware detection in computer systems to fault detection in bearings, which is the primary focus of this study. In pursuit of this objective, we propose a novel procedure for detecting novel instances of anomalies in varying operating conditions, utilizing only the signals derived from the healthy state of the analyzed machine. Our approach incorporates AIS augmented by Dynamic Time Warping (DTW). The experimental outcomes demonstrate that the AIS-DTW method yields a considerable improvement in anomaly detection rates (up to 53.83%) compared to the conventional AIS. In summary, our findings indicate that our method represents a significant advancement in enhancing the resilience of AIS-based novelty detection, thereby bolstering the reliability of rotating machines and reducing the need for expertise in bearing fault detection.

• 한국학교수학회논문집
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• 제12권3호
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• pp.211-230
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• 2009

본 연구의 목적은 Skemp 이론에 따른 곱셈 놀이활동이 학생들의 수학학업성취도 및 수학적 태도에 미치는 효과를 알아보기 위한 것이었다. 학생들이 수학에 대한 자신감과 흥미를 잃지 않도록 곱셈을 좀 더 재미있고 효과적으로 가르치기 위한 방법의 하나로써 Skemp 이론에 따른 놀이활동을 재구성하여 초등학교 2학년 학생들을 대상으로 실험집단과 비교집단으로 나누어 적용해 보고 수학학업성취도 및 수학적 태도에 미치는 효과를 알아보았다. 연구 결과, 첫째, Skemp 이론에 따른 곱셈 놀이활동은 수학학업성취도면에서 큰 효과가 나타나지 않았고, 둘째, Skemp 이론에 따른 곱셈 놀이 활동은 수학학업성취도면에서 중 상위 그룹보다 하위 그룹의 학생들에게 상대적으로 더 효과적이었으며, 셋째, Skemp 이론에 따른 곱셈 놀이활동은 학생들의 수학적 태도에 긍정적인 영향을 주었음을 알 수 있었다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권2호
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• pp.269-281
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• 2014

This paper examines the suitability of using the Computational Fluid Dynamics (CFD) tools, ANSYS-CFX, as an initial analysis tool for predicting the drag and propulsion performance (thrust and torque) of a concept underwater vehicle design. In order to select an appropriate thruster that will achieve the required speed of the Underwater Disk Robot (UDR), the ANSYS-CFX tools were used to predict the drag force of the UDR. Vertical Planar Motion Mechanism (VPMM) test simulations (i.e. pure heaving and pure pitching motion) by CFD motion analysis were carried out with the CFD software. The CFD results reveal the distribution of hydrodynamic values (velocity, pressure, etc.) of the UDR for these motion studies. Finally, CFD bollard pull test simulations were performed and compared with the experimental bollard pull test results conducted in a model basin. The experimental results confirm the suitability of using the ANSYS-CFX tools for predicting the behavior of concept vehicles early on in their design process.

• Interaction and multiscale mechanics
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• 제1권2호
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• pp.231-250
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• 2008

The statistical two-order and two-scale method is developed for predicting the mechanics parameters, such as stiffness and strength of core-shell particle-filled polymer composites. The representation and simulation on meso-configuration of random particle-filled polymers are stated. And the major statistical two-order and two-scale analysis formulation is briefly given. The two-order and two-scale expressions for the strains and stresses of conventionally strength experimental components, including the tensional or compressive column, the twist bar and the bending beam, are developed by means of their classical solutions with orthogonal-anisotropic coefficients. Then a new effective mesh generation algorithm is presented. The mechanics parameters of core-shell particle-filled polymer composites, including the expected stiffness parameters, minimum stiffness parameters, and the expected elasticity limit strength and the minimum elasticity limit strength, are defined by means of the stiffness coefficients and elasticity strength criterions for core, shell and matrix. Finally, the numerical results for predicting both stiffness and elasticity limit strength parameters are compared with the experimental data.

• 대한수학교육학회지:수학교육학연구
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• 제8권2호
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• pp.709-722
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• 1998

This thesis is to see if the classes using problem posing is effective to improve the students' grades in math. So I set up research subjects as follow. 1. Do the classes focused on problem posing have any influence on the students' achievement\ulcorner 2. Do the classes focused on problem posing have any different influence on the students' achievement according to their levels\ulcorner 3. Do the classes focused on problem posing have any different influence on the students' achievement according to the categories in math\ulcorner I close four classes in the first grade of K middle school in Kangnung, Kangwon province for this thesis. First I divided them into two groups. Each group consisted of two classes. One is the experimental group. The other is the comparative group. The experimental group was taken classes using problem posing. The comparative group was taken classes by the traditional teaching method. And then I analyzed the difference of the achievement between two groups. As a result of this research, I came to the conclusion as follow. First, the classes focused on problem posing is more effective than traditional teaching method for the improvement of the students` achievement Second, both the classes using problem posing and the traditional teaching method doesn`t affect to the advanced students. Third, the classes using problem posing is more effective to the intermediate students and lower level students than the traditional teaching method. Especially it is very effective in teaching the students the linear equation.

• 한국초등수학교육학회지
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• 제12권1호
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• pp.27-46
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• 2008

본 연구에서는 초등학교 6-가 단계 수학 교과에 사이버가정학습을 적용한 후, 수학 학업성취도와 수학적 성향에 미치는 효과를 분석함으로써 학생들의 전반적인 수학 학습에 대한 학업성취도와 수학적 성향을 향상시킬 수 있는 방안을 모색하고자 하는데 그 목적이 있다.