• 한국수학교육학회지시리즈D:수학교육연구
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• 제23권1호
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• pp.1-12
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• 2020

In this case study, a professor was observed to investigate use of instructional examples when teaching the Intermediate Value Theorem in a calculus course. Video-recorded lessons were analyzed with constant comparison to video-stimulated recall interviews and field notes. The professor employed multiple instructional examples, which was initiated by students and modified by the professor. The professor asked students to build non-existing examples as an informal proof of the Intermediate Value Theorem and assessment of students' previous knowledge. Use of incorrect examples on instructional purpose can be an appropriate way for formative assessment as well as a bridge between informal and formal proofs in college mathematics.

• 대한수학교육학회지:수학교육학연구
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• 제15권4호
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• pp.401-417
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• 2005

이 연구는 새롭게 전달될 내용이 학습자의 기존 도식을 상회하는 고차적인 경우, 예와 반례를 통해 학습되는 것이 효과적이라는 영국의 수학교육자 Skemp의 이론을 근간으로 하여, 우리나라의 실정에 맞는 도형 개념 지도방안을 구안하고자 한다. 이를 위해 범례 제시법에 관련된 선행 연구가 고찰되었으며, 개념 학습을 위한 원형모형 이론이 고찰되었다. 또한 우리나라 7차 수학과 교과서의 도형 단원이 분석되었다. 이러한 고찰을 토대로 이 연구에서는 예와 반례를 통한 6단계 수업 모형을 고안하였으며, 4학년 아동을 대상으로 도형 영역의 수업을 실시하였다 수업 결과, 예와 반례를 통한 지도는 아동의 성취 수준에 관계없이 도형 개념을 형성하고, 개념간의 위계 관계를 이해하는 데 적합하였으며, 의사소통을 촉진시키는 것으로 나타났다

• 대한수학교육학회지:학교수학
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• 제15권4호
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• pp.743-758
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• 2013

본 연구는 2009 개정교육과정 중학교 1학년 교과서 13종을 대상으로 다각형에 관한 예를 분석하여 교과서에서 예를 어떻게 제시하고 있는지 살펴보고자 하였다. 교과서의 예를 일반적인 예, 비예, 반례라는 하나의 관점과 개념의 예와 절차 적용의 예라는 다른 관점으로 분류하고 사례를 분석하였다. 그리고 같은 개념이나 절차와 관련된 예를 제시할 때 교과서에 따라 어떤 방법으로 제시하고 있는가를 분석하였다. 그 결과 교과서에 제시되는 예는 일반적인 예에 편중되어 있었고, 개념의 예와 절차 적용의 예도 교과서에 따라 제시된 비율의 편차가 큰 편이었다. 또한 여러 교과서에서 다각형의 배치나 모양을 다양하게 제시하지 못하고 있었다. 학생들의 예 공간을 확장시키기 위해서 교과서에서는 적절하고 다양한 예를 제시할 필요가 있다.

• Communications for Statistical Applications and Methods
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• 제26권6호
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• pp.583-589
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• 2019

Counterexamples of a skew-normal distribution are developed to improve our understanding of this distribution. Two examples on bivariate non-skew-normal distribution owning marginal skew-normal distributions are first provided. Sum of dependent skew-normal and normal variables does not follow a skew-normal distribution. Continuous bivariate density with discontinuous marginal density also exists in skew-normal distribution. An example presents that the range of possible correlations for bivariate skew-normal distribution is constrained in a relatively small set. For unified skew-normal variables, an example about converging in law are discussed. Convergence in distribution is involved in two separate examples for skew-normal variables. The point estimation problem, which is not a counterexample, is provided because of its importance in understanding the skew-normal distribution. These materials are useful for undergraduate and/or graduate teaching courses.

• 한국정밀공학회지
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• 제15권12호
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• pp.202-211
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• 1998

The present paper proposes a modal analysis procedure to obtain exact modal parameters (natural frequencies, damping ratios, eigenvectors) for general, non-uniform beam-like structures. The proposed method includes a derivation of the system dynamic matrix for a Timoshenko beam element. The proposed method provides not only exact modal parameters but also exact frequency response functions (FRFs) for general beam structures. A time domain analysis method is also proposed. Two examples are provided for validating and illustrating the proposed method. The first numerical example compares the proposed method with FEM. The second example deals with a non-uniform beam structure supported in joints with damping property. The numerical study proves that the proposed method is useful for the dynamic analysis of continuous systems consisting of beam-like structures.

• 수산해양교육연구
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• 제24권5호
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• pp.699-711
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• 2012

An undergraduate course named computational structural analysis becomes more significant in recent years because of its important role in industries and the recent innovation in computer technology. Typically, the course consists of introduction to finite element method, utilization of general purpose finite element software, and examples focusing on static and linear analyses on various structural members such as a beam, truss, frame, arch, and cable. However, in addition to the static and linear analyses, current industries ask graduates to acquire basic knowledge on structural dynamics and nonlinear analysis, which are not listed in the conventional syllabus of the computational structural analysis. Therefore, this study develops geometrically nonlinear examples, which can help students to easily capture the fundamental nonlinear theory, software manipulation, and problem solving skills. For the purpose, five different examples are found, developed for the analyses of cables and cable nets, which naturally have strong geometrical non-linearity. In the paper, these examples are presented, discussed, and finally compared for a better subject development.

• Bulletin of the Korean Chemical Society
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• 제19권1호
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• pp.5-21
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• 1998

The purpose of this paper is to show that X-ray absorption spectroscopy (XANES and EXAFS) is a powerful technique for characterizing both crystalline and amorphous solids from structural (local order) and electronic point of view. The principle of this technique is briefly described by showing the main factors which must be considered for recording and fitting the experimental results. Some non-trivial examples have been selected for demonstrating that XAS spectroscopy is the only technique for bringing a definitive answer as for example: the determination of the local distortion of the $NiO_6$ octahedra in the $Li_{1-z}Ni_{1+z}O_2$ layered oxides and the evidence of the presence of copper pairs in the NASICON-type phosphate $CuZr_2 (PO_4)_3$. Are also reported some significant examples for which XAS spectroscopy is decisive with other characterization methods as (i) Raman spectroscopy for glasses (ii) Mossbauer spectroscopy for $LiNi_{1+z-t}Fe_To_2$ oxides (iii) magnetic measurements for Ce-based intermetallic compounds.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2024년도 춘계학술발표대회
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• pp.885-887
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• 2024

딥러닝 모델이 다양한 분야에 적용되면서, 딥러닝 모델에 대한 보안이 큰 이슈가 되고 있다. 특히, 입력 데이터에 섭동(perturbation)을 추가하여 모델의 정상적인 추론을 방해하는 적대적 공격(Adversarial Attack)에 대한 연구가 활발하게 진행되고 있다. 본 논문에서는 객체 탐지 모델의 NMS(Non-Maximum Suppression) 알고리즘에 대한 적대적 공격 기법 중 하나인 Phantom Sponges 공격을 수행하여 적대적 예제(Adversarial Example)를 생성하고, 원본 이미지와의 유사성을 측정하여 분석하고자 한다.

• 한국수학교육학회지시리즈A:수학교육
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• 제57권4호
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• pp.371-391
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• 2018

The purpose of this study is to analyze manifestation examples and effects of group creativity in mathematical modeling and to discuss teaching and learning methods for group creativity. The following two points were examined from the theoretical background. First, we examined the possibility of group activity in mathematical modeling. Second, we examined the meaning and characteristics of group creativity. Six students in the second grade of high school participated in this study in two groups of three each. Mathematical modeling task was "What are your own strategies to prevent or cope with blackouts?". Unit of analysis was the observed types of interaction at each stage of mathematical modeling. Especially, it was confirmed that group creativity can be developed through repetitive occurrences of mutually complementary, conflict-based, metacognitive interactions. The conclusion is as follows. First, examples of mutually complementary interaction, conflict-based interaction, and metacognitive interaction were observed in the real-world inquiry and the factor-finding stage, the simplification stage, and the mathematical model derivation stage, respectively. And the positive effect of group creativity on mathematical modeling were confirmed. Second, example of non interaction was observed, and it was confirmed that there were limitations on students' interaction object and interaction participation, and teacher's failure on appropriate intervention. Third, as teaching learning methods for group creativity, we proposed students' role play and teachers' questioning in the direction of promoting interaction.

• Journal of Information Processing Systems
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• 제8권4호
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• pp.575-588
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• 2012

Exploiting unlabeled text data with a relatively small labeled corpus has been an active and challenging research topic in text mining, due to the recent growth of the amount of biomedical literature. Biomedical named-entity recognition is an essential prerequisite task before effective text mining of biomedical literature can begin. This paper proposes an Active Co-Training (ACT) algorithm for biomedical named-entity recognition. ACT is a semi-supervised learning method in which two classifiers based on two different feature sets iteratively learn from informative examples that have been queried from the unlabeled data. We design a new classification problem to measure the informativeness of an example in unlabeled data. In this classification problem, the examples are classified based on a joint view of a feature set to be informative/non-informative to both classifiers. To form the training data for the classification problem, we adopt a query-by-committee method. Therefore, in the ACT, both classifiers are considered to be one committee, which is used on the labeled data to give the informativeness label to each example. The ACT method outperforms the traditional co-training algorithm in terms of f-measure as well as the number of training iterations performed to build a good classification model. The proposed method tends to efficiently exploit a large amount of unlabeled data by selecting a small number of examples having not only useful information but also a comprehensive pattern.