• 한국IT서비스학회지
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• 제14권1호
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• pp.129-143
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• 2015

This study has two goals. The first goal is to investigate whether worked examples are effective in the ill-defined domain with on-line learning and the second goal is to find out which components (conceptual or procedural knowledge) of worked examples are effective factor at the given learning environment. We carried out three experiments in which Korean undergraduate or graduate students were working in three or four conditions of worked examples (CWE, PWE, CPWE, or the control group). While experiment 1 conducted in on-line learning environment did not find any effect and difference among groups and also any logical reason for those results, experiment 2 conducted in completely controlled laboratory setting with less knowledgeable students showed the clear difference among groups by the order CPWE, PWE, and CWE. Experiment 3 in which highly knowledgeable and motivated students were presented the same materials in more controlled on-line learning environment indicated the difference among groups by the order CWE, CPWE, and PWE. The results were discussed within the framework of cognitive load theory.

• 한국학교수학회논문집
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• 제17권2호
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• pp.291-319
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• 2014

이 연구의 목적은 제곱근과 실수 단원에 대한 Worded-Out Examples을 활용하여 중학생들의 수학적 사고과정을 수학적 숙련도(mathematical proficiency)를 통해 규명하는 것이다. WOE는 "학생의 학습을 위하여 전문가의 풀이 과정을 상세히 제공하는 도구"로 학생들의 수학에 대한 과정과 구조의 학습을 돕기 위한 것이다. 이를 위해, WOE 문항을 개발하여 6명의 중학생들이 활용하도록 하고 2명의 학생을 대상으로 인터뷰를 실시하였다. 수집된 자료를 분석하였고 그 결과는 다음과 같다. 학생들의 사고과정은 이해한 내용을 활용하여 적절한 단계로 문제를 풀어가는 '이해 계산', '계산 추론', '이해 계산 추론'으로 나타났다. 또한 학생들 대부분이 '적용'하는 것에는 어려움을 겪는 것으로 나타났다.

• 한국임상수의학회지
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• 제31권4호
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• pp.288-292
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• 2014

A critical assumption of the standard sample size calculation is that the response (outcome) for an individual patient is completely independent to that for any other patient. However, this assumption no longer holds when there is a lack of statistical independence across subjects seen in cluster randomized designs. In this setting, patients within a cluster are more likely to respond in a similar manner; patient outcomes may correlate strongly within clusters. Thus, direct use of standard sample size formulae for cluster design, ignoring the clustering effect, may result in sample size that are too small, resulting in a study that is under-powered for detecting the desired level of difference between groups. This paper revisit worked examples for sample size calculation provided in a previous paper using nomogram to easy to access. Then we present the concept of cluster design illustrated with worked examples, and introduce design effect that is a factor to inflate the standard sample size estimates.

• 한국과학교육학회지
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• 제16권3호
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• pp.295-302
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• 1996

The purpose of this study was to investigate the effects of training and use of worked-example on chemical problem-solving learning. Schema acquisition and rule automation are the basic components of skilled problem-solving, which are dependent on appropriately focused attention and sufficient cognitive resources. Training and use of worked-example facilitate schema acquisition and rule automation, so improve problem-solving learning. The subjects of this study were 60 high school students. The average age was 17 years old. Then, they were randomly assigned to each groups and the chemical reaction problems used as experimental materials. The independent variables of this study were training and use of worked-examples and dependent variables were time for solution and the number of error. The results of this study were as follows; 1. The worked-example groups spent significantly less time on solution for acquisition problems than the conventional problem groups. 2. The long-acquisition groups spent significantly less time on solution for acquisition problems than the short-acquisition groups. 3. The modified worked-example groups did not spend significantly less time on solution for acquisition problems than the worked-example groups.

• 인지과학
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• 제21권4호
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• pp.627-653
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• 2010

본 연구에서는 수학 학습을 위한 평가 도구로 풀이 과정을 답지로 이용한 시험 방식이 제안되었고, 그 효과가 검증되었다. 풀이된 예제 연구에 따르면, 학생들에게 문제에 대한 단계적인 해결책인 풀이된 예제를 문제 사이에 제시할 경우, 문제만 풀 때보다 효과적으로 학습한다. 그러나 풀이된 예제의 단순한 제시는 학습 효과가 제한적이라는 최근의 발견들이 있었다. 이에 따라 본 연구에서는 학습자가 풀이된 예제를 더 적극적으로 탐구하게 하는 방법으로 풀이과정을 선다형의 답지로 제시하였다. 이 시험 방식은 컴퓨터화 시험으로 구현되었으며, 학생들이 컴퓨터에서 단답형으로 문제를 풀고 나서 답지를 요청하면 선다형 답지가 제시되었다. 이 때 실험 집단은 답지가 풀이 과정으로, 비교 집단은 전통적 선다형과 같이 최종 정답으로 구성되었다. 초등학교 6학년 학생들을 대상으로 실험이 수행되었다. 사후 검사 결과 실험집단의 평균 점수가 비교집단의 평균 점수보다 높았다. 이 결과는 풀이 과정을 답지로 이용한 시험 방식이 교실현장에서 학습을 촉진하기 위한 도구로 활용될 수 있음을 시사한다. 끝으로 후속 연구의 방향성이 논의되었다.

• 인지과학
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• 제1권1호
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• pp.103-127
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• 1989

예를 이용하여 학습하는 방법은 ALEX,LP,LEX 에 이르기까지 각각 특유의 방법을 가지면서 발전해 왔다.특히 Silver 의 LP 시스템은 방정식(Symbolic Equation)을 푸는데 있어, 과거에 풀었던 예로부터 이에 적용된 일련의 연산자들을 이용하는 방법으로 구축되어 있다. 본논문에서는 기존의 학습시스템 LEX,LP를 보다 일반화시킨 새로운 학습시스템 LRD를 제안한다. LRD에서는 연구된 예에서의 연산자 활용을 이와 유사한 모든 문제에까지 적용시킬 수 있도록 하기위하여 일반화 과정과 세분화 과정을 설정하여 학습하는 방법을 제시한다.초월함수의 치역을 구하는 예를 통하여 LRD의 학습기법을 설명하고,기존의 LEX및 LP시스템 에서 다루어지는 문제들을 통해 LEX및 LP시스템과 LRD 시스템이 비교 되어진다.

• Educational Technology International
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• 제11권1호
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• pp.93-117
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• 2010

The purpose of this study was to develop the problem solving instruction facilitating novice learner to represent the problem. For the purpose, we mainly focused on three aspects of problem solving. First, learner should represent the targeted problem and its solutions for problem solving. Second, from crucial notions of cognitive load theory, learner's mental load should be optimized for problem representation. Third, for optimizing students' mental load, experts may support making their thinking more visible and mapping from their intuition to expert practice. We drew the design principles as follows. First, since providing worked examples for the targeted problem has been considered to minimize analogical errors as well as reduce cognitive load in problem representation at line of problem solving and instructional research, it is needed to elaborate the way of designing. The worked example alternatively corresponds to expert schema that consists of domain knowledge as well as strategies for expert-like problem representation and solution. Thus, it may help learner to represent what the problem is and how to solve it in problem space. Second, principle can be that expert should scaffold learner's self-explanations. Because the students are unable to elicit the rationale from worked example, the expert's triggering scaffold may be critical in that process. The unexplained and incomplete parts of the example should be completed not by expert's scaffold but by themselves. Critical portion of the expert's scaffold is to explain about how to apply and represent the given problem, since students' initial representations may be reached at superficial or passive pattern of example elaboration. Finally, learner's mental model on the designated problem domain should be externalized or visualized for one's reflection as well as expert's scaffolding activities. The visualization helps learner to identify one's partial or incorrect model. The correct model of learner could be constructed by expert's help.

• Structural Engineering and Mechanics
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• 제6권5호
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• pp.517-527
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• 1998

This paper describes an exact method of analysis for natural vibration of diagonal networks by considering an equivalent cyclic periodic structure and adopting the double U-transformation technique. Both a lumped mass system and a distributed mass system are considered to investigate the diagonal networks. The exact solution for the frequency equations and the natural modes of the networks can be derived. As numerical examples, square diagonal cable networks with different meshes are worked out.

• 한국전산유체공학회지
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• 제12권3호
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• pp.20-28
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• 2007

A fast and robust method of grid generation to multiple functions has been developed for flow analysis in three dimensional space. It is based on the Non-Uniform Rational B-Spline(NURBS) of an approximation method. Many of NURBS intrinsic properties are introduced and much more easily understood. The grid generation method, details of numerical implementation. examples of application, and potential extensions of the current method are illustrated in this paper. The object of this study is to develop the surface grid generation and the grid cluster techniques capable of resolving complex flows with shock waves, expansion waves, shear layers. The knot insert method of Non-Uniform Rational B-Spline seems well worked. In addition, NURBS has been widely utilized to generate grids in the computational fluid dynamics community. Computational examples associated with practical configurations have shown the utilization of the algorithm.

• Journal of applied mathematics & informatics
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• 제33권1_2호
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• pp.61-76
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• 2015

In this paper, a fifth order extension of Potra's third order iterative method is proposed for solving nonlinear equations. A convergence theorem along with the error bounds is established. The method takes three functions and one derivative evaluations giving its efficiency index equals to 1.495. Some numerical examples are also solved and the results obtained are compared with some other existing fifth order methods. Next, the interval extension of both third and fifth order Potra's method are developed by using the concepts of interval analysis. Convergence analysis of these methods are discussed to establish their third and fifth orders respectively. A number of numerical examples are worked out using INTLAB in order to demonstrate the efficacy of the methods. The results of the proposed methods are compared with the results of the interval Newton method.