• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.867-876
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• 2016

In accordance with the changing of society, remarkable increase in knowledge and information, the competencies to choose and use proper information in various domains are considered as an important skill. As one of the methods in developing these competencies, it is emphasized that a problem-based learning can make student understand and use knowledge by solving the contextualized problem. However, it is skeptical of learner's development of competencies to use knowledge by solving well-defined given problem. Therefore it is required that students be allowed to develop the competency to find problem through experiences to determine and evaluate the purpose of the problem and method. The purpose of this study is to understand how undergraduate students use science or technology in finding a problem. In this line, this study articulated four cases conducted by participants who engaged in convergence teaching-learning program. And this study investigated the participants' process of problem-finding, method and reason to apply science or technology. The results were drawn by analyzing interviews and written data, including their proposal, a poster, and final reports. Participants changed the form of problem from initial ill-structured one into a concrete one, where the participant could derive a detailed solution. Science or technology applied as the detailed example to convert problem into a concrete form, or as the analyzing tool or theoretical background of problem to make a link with other domain. Their reason of applying science or technology could be summarized in 'personal interest based on prior experience' and 'alternatives to resolve a dissatisfaction.' Based on the result, this study suggests holistic approach that is included in both intuitive thinking and logical thinking and metacognitive regulation to stimulate problem-finding in problem-based learning program.

• Journal of the Korean School Mathematics Society
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• v.12 no.4
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• pp.365-388
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• 2009

In this paper we solve various triangle construction problems given by three points(a midpoint of side and other two points). We investigate relation between these construction problems, draw out a base problem, and make hierarchy of solved construction problems. In detail we describe analysis for searching solving method, and construction procedure of required triangle.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.33-36
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• 2006

OR 기법이 현실에 성공적으로 적용된 분야 중 하나가 차량 경로 문제 풀이며 이 분야에 대한 연구는 꾸준히 진행되어 오고 있다. 시간대 제약이 있는 차량 수 배송 문제는 기존의 차량 배송 문제에서 더욱 진보된 형태의 문제이다. 많은 연구가 있어왔지만, 이러한 형태의 문제들은 NP-hard 형태의 문제이므로 meta-heuristic 기법들이 많이 사용되었다. 유전자 알고리즘에 비해 타부 서치 기법이 많이 사용되었는데, 이는 시간대 제약이 있는 차량 수 배송 문제의 경우 유전자 알고리즘의 근간인 염색체 형태로 표현하기가 쉽지 않기 때문이다. 이에 본 논문에서는 시간대 제약이 있는 차량 수 배송 문제를 다수의 차량을 사용하는 Grouping Genetic Algorithms을 적용하여 이러한 어려움을 해결하였다. 또한, 기존의 유전자 알고리즘들은 초기 해 집단을 임의 선택 방식으로 구성하였지만, 초기 해 집단 구성을 heuristic 기법을 사용하여 적합도 함수 값이 좋은 해들로 구성하여 기존에 사용된 알고리즘들과 성능을 비교 분석하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.1133-1138
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• 2000

최소비용 선형 망 흐름 문제가 동등한 할당 문제로 변환될 수 있으며, 또한 선형 망 흐름 문제를 해결하기 위한 전통적 방법은 단순 싸이클 흐름을 변환시킴으로서 원시 비용을 개선하는 방법이다. Auction 알고리즘이 각각의 반복에서 분산계산을 제시하는 개체와 초기의 대상 가격을 선택하기 위하여 몇 개의 특별한 법칙과 함께 동일한 문제에 적용이 될 때, 개체는 ${\varepsilon}$-이완법의 형태에서 획득할 수 있다. 본 논문은 할당 문제를 해결하기 위한 방법으로 최소비용 흐름 문제를 일반화 시켜, 전형적인 반복에 최소비용 흐름 문제, 수학적 등가에 의한 최소비용 흐름 문제를 연구하였고, 최소비용 흐름 측면에서 수송문제의 확장과 ${\varepsilon}$-이완법을 도출하여 이를 PCB 설계에 응용하고자 하였다.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.65-76
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• 2004

교통망설계문제란, 교통시스템을 최적상태로 만들기 위한 최적의 설계변수를 결정하는 문제이다. 대표적인 교통망설계문제로는 도로를 신설하거나 확장하는 문제가 있으며, 이외에 교통신호시간의 결정, 교통정보의 제공, 혼잡통행료 부과, 새로운 교통수단의 도입 등 여러 교통정책분야가 교통망설계문제에 포함된다고 볼 수 있다. 일반적으로 교통망설계문제는 bi-level 구조로 구축되는데, 기존 대부분의 연구들은 상위문제와 하위문제를 서로 협력없이(Noncooperative) 자신들만의 목적을 최적화시키는 Cournot-Nash게임형태로 구성하여 풀고 있으나, 실제 교통분야에서 다루는 문제들은 리더(leader)와 추종자(follower)가 존재하는 Stackelberg게임에 가깝다고 할 수 있다. 기존 bi-level 문제들이 Cournot-Nash게임형태로 구성되어 풀고 있는 이유는 Stackelberg게임으로 구성할 경우 풀기가 어렵기 때문이다. 이런 측면에서 본 연구는 리더와 추종자가 존재하는 Stackelberg게임으로 교통망설계문제를 구성하며, 설계 변수값에 따른 통행자의 행태변화도 인지오차(perceived error)를 고려한 확률적 통행배정문제로 구성하여 좀더 현실적인 결과를 도출하도록 한다. 제시된 모형을 풀기 위하여 민감도분석(Sensitivity analysis)을 이용하며, 설계문제의 해를 구하는 알고리듬도 제시한다. 또한, 이 기법을 일반 도로교통망(general transportation road network)에 적용할 수 있도록 민감도(sensitivity) 유도과정을 자세히 기술하였다. 개발된 모형을 평가하기 위하여 2개의 예제 교통망을 대상으로 모형을 적용한 결과, 합리적인 값들을 도출하고 있음을 확인할 수 있었다.

• School Mathematics
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• v.12 no.3
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• pp.259-271
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• 2010

This study involves investigating problem posing practices for mathematically gifted first year middle school students in Korea. The overall purpose of this study is twofold: to examine the students' preferences on problem posing resources on the division algorithm and to analyze the approaches of the students' posing problems related to specific solution methods. To this end, the patterns of the problems are classified into 6 types such as 'routine' and 'nonroutine' problems associated with 3 levels of the original version of problems. Based on the analysis on the problems, we provide some implications about the nature of mathematically gifted students' problem posing practices in gifted education.

• Journal of Gifted/Talented Education
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• v.23 no.2
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• pp.289-310
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• 2013

The purpose of the study is to investigate science process skills and suggest several considerations about developing scientific inquiries for secondary science gifted students. To do this, we analyzed scientific inquiries of science gifted programs and evaluated them on the quantity of problem perception, problem finding and inquiry planning that are regarded as high level science process skills, then revised each inquiry to include those high level skills. The result was that the first, there were differences in frequencies and types of science process skills among those inquiries. The second, there were very few problem perception and problem finding and were not many inquiry planning. The third, some of the revised inquiries showed those high level skills. From this, we would like to suggest we should construct scientific inquiries of science gifted program out of many and various themes. And there should be more high level science process skills such as problem perception, problem finding, and inquiry planning. For this, scientific inquiry developers should have intentions to involve such science process skills which is appropriate for science gifted student.

• Management & Information Systems Review
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• v.29 no.4
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• pp.109-121
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• 2010

In this study, we propose a solution procedure to solve travelling salesman problem(TSP) with special cost function, route dependent travelling salesman problem(RDTSP). First, we develop an integer programming model to describe the problem. In the model, a variable means a possible route. And, the number of variables in this model are extremely large. So, we develop a LP relaxation problem of the IP model and solve the relaxation problem by a column generation technique. The relaxation problem does not guarantee the optimal solution. If we get an integer solution in the ralaxation problem, then the solution is an optimal one. But, if not, we cannot get an optimal solution. So, we approach a branch and price technique. The overall solution procedure can be applied a printed circuit board(PCB) assembly process.

• Journal of Korean Society of Transportation
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• v.18 no.2
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• pp.63-71
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• 2000

One Problem of the choice Property in logit model is interpreted as the Problem of common links and common nodes in choice set. Common node Problem Plays important role in deciding the efficiency of network loading and common link problem is connected with choice Problem, both of which are to be solved to improve the logit choice model. Although much need has been pointed out for research on the topic, however, no Paper as yet considers these two factors at the same time. In the Paper we develop a new logit formulation, which is able to ease the logit Problem, widely known as the Problem of IIA(Independence of Irrelevant Alternatives). An example network is used to assess the Proposed model and compare it with other conventional models. From the results, we find out that the model is superior to others.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.495-505
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• 2015

The purpose of the study is to investigate the problem solving abilities of nursing students in case of simulation-based emergency care for respiratory distress patients. For this study, 117 third year nursing students participated in the adult simulation practice from April 22 to May 31, 2013. The results of the study revealed that problem solving abilities after simulation practice were significantly greater than those after self-directed learning(t=2.59, p=.010). In the analysis of subcategories of problem solving abilities, there were significant differences in the definition of problem solving (t=2.95, p=.004), the device of problem solutions(t=2.10, p=.0.37), and the review of problem resolutions(t=3.06, p=.002). Based on these results, the study confirmed that the simulation practice was an effective teaching method for problem solving skills.