• Journal of Educational Research in Mathematics
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• v.24 no.3
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• pp.359-374
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• 2014

Students' difficulties and errors in relation to mathematical proofs are worth while to say one of the dilemmas in mathematics education. The potential elements of their difficulty are scattered over the process of proving in geometry as well as algebra. This study aims to investigate whether middle school students understand the context of algebraic proof including literal expressions. We applied 24 third-grade middle school students a test item which shows a proof including a literal expression and missing the conclusion. Over the half of them responded wrong answers based on only the literal expression without considering its context. Three of them were interviewed individually to show their thinking. As a result, we could find some characteristics of their thinking including the perspective on proof as checking the validity of algebraic expression and the gap between proving and understanding of proof etc. From these, we also discussed about several didactical implications.

• School Mathematics
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• v.18 no.3
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• pp.441-455
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• 2016

The position as saying that the math learning needs to begin from what diversely presents concrete object or familiar situation is well known as a name dubbed CSA(Concrete-Semiconcrete-Abstract). Compared to this, a recent research by Kaminski, et al. asserts that learning an abstract concept first may be more effective in the aspect of knowledge transfer than learning a mathematical concept with concrete object of having various contexts. The purpose of this study was to analyze a class, which differently applied a guidance sequence of concrete object, semi-concrete object, and abstract concept in consideration of this conflicting perspective, and to confirm its educational implication. As a result of research, a class with the application of a concept starting from the concrete object showed what made it have positive attitude toward mathematics, but wasn't continued its effect, and didn't indicate significant difference even in achievement. Even a case of showing error was observed rather owing to the excessive concreteness that the concrete object has. This error wasn't found in a class that adopted a concept as semi-concrete object. This suggests that the semi-concrete object, which was thought a non-essential element, can be efficiently used in learning an abstract concept.

• Journal of Educational Research in Mathematics
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• v.23 no.3
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• pp.389-406
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• 2013

The purpose of this study is to analyze eighth grade students' errors in the constructed-response items to improve teaching and learning of mathematics in schools. By analyzing 99 students' responses to nine constructed-response items, we found several types of students' errors in their responses to the assessment items involving with mathematical reasoning and representations, problems within realistic contexts, and mathematical connections. Not only a single error but also multiple errors (a combination of two or more types of errors) were discovered. In particular, high achieving students showed more simple errors than multiple errors while low achieving students had more multiple errors in various kinds.

• School Mathematics
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• v.19 no.3
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• pp.553-570
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• 2017

The purpose of this study was to gain insights into investigating the feasibility on integrating computational thinking(CT) into school mathematics. Definitions and the components of CT were varied among studies. In this study, CT in mathematics was focused on thinking related with mathematical problem solving under ICT supportive environment where computing tools are available to students to solve problems and verify their answers. The focus is not given on the computing environment itself but on CT in mathematics education. For integrating CT into mathematical problem solving, providing computing environment, understanding of tools and supportive curriculum revisions for integration are essential. Coding with language specially developed for mathematics education such as LOGO, and solving realistic mathematical problems using S/W such as Excel in mathematics classrooms, or integrating CT into math under STEAM contexts are suggested for integration CT into math education. Several conditions for the integration were discussed in this paper.

• School Mathematics
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• v.19 no.4
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• pp.795-817
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• 2017

Whereas noticing with relation to teacher expertise has been steadily studied in international contexts, there have been very few studies in Korea in this area. Given this, this paper reviewed the meanings of noticing based on Sherin and van Es as well as Jacobs et al. who provided foundational work and then analyzed recent studies on teacher noticing. A review of literature showed that recent international studies on noticing tend to elaborate the theoretical framework of noticing, diversify the methods of research on noticing, and extend to the range of noticing. This paper also included an analysis of domestic studies dealing with noticing either explicitly or implicitly. This paper is expected to serve as a basis to foster conceptual understanding of teacher noticing and to derive follow-up studies in Korea.

• School Mathematics
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• v.19 no.4
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• pp.731-749
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• 2017

The purpose of this study is to find out whether the current mathematics textbooks are structured so as to cultivate students' statistical literacy. To do this, we analyzed the problems of the statistics units of 9 kinds of middle school 3rd grade mathematics textbook according to 2009 revised mathematics curriculum based on four types of context and statistical problem solving process. As a result of the analysis, among the four types of context, the problems that correspond to the type of personal context was the highest in 67% and among statistical problem solving process, the data analysis process was the highest in 72.85%. According to the results of this study, it is necessary to include the problems that can recognize the necessity of statistics through the use of various contexts and that can develop the statistical literacy through the activities that from the process of collecting data to guessing reasonable conclusions from the presented data.

• Korean Institute of Interior Design Journal
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• v.21 no.5
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• pp.145-152
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• 2012

Since 1966 when James Turrell completed his studies on Art, he has been working on the consistent theme of Art. For the 46 years of time, site contexts, scales, methods of light have been changed and they made Turrell's unique 'project series'. Each series has different spatial, visual-perceptual forms and characteristics from other series. The differences were caused by the given situations, but also Turrell intentionally pursued it. However, there are essential theme of art that has not changed in most of Turrell's projects. Target of this paper is to study the unchanged theme as well as the differences. The study starts with three questions: first, what is the geometrical space composition?, second, what is the visual-perceptual phenomenon?, third, what is the hidden consistent theme? This research focuses on three case projects: Wedgework, Space Division Constructions, Skyspaces. These project series are in between the early small object-like installations and the late mega-scale outdoor projects. The study found that geometrical space composition has important role to give visual-perceptual dynamism to the viewer. The phenomenological perception is connected to the questions of relationship between human and space, ultimately human and the world. Although the Merleau-Ponty's philosophy has been related to the work of Turrell in various previous studies, Cartesian 3-dimensional geometry has also crucial role to experiment a viewer's perceptual boundaries. Image of infinity is another aspect of three cases, especially Space Division Constructions and Skyspaces. Through these structure, Turrell's work lead to an ultimate question of meaning for human existence in infinite space. It is hoped that this paper is helpful for Architecture and Interior design field in which light and space are essential.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.353-358
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• 2017

This study aims to propose an assessment tool of port service quality (PSQ) in the context of container transport logistics (CTLs), by taking the perspectives from port users. The CTLs defined in this study are the relevant activities of serving the physical flows of a container box from a point of origin via a container port to a point of destination. To address the ports' role in collaboration between its channel members in CTLs, the PSQ measures for all port user groups (i.e. common PSQ measures) are selected based on the relevant CTLs activities involved by port, and its users within terminal/port area as well as throughout the CTLs chain. An importance-performance analysis (IPA) is applied as a diagnostic tool to analyse the status quo of Busan Port in CTLs contexts, by comparing the importance and performance (IP ) scores against each individual CTLs criterion. The findings from the IPA reveal that port managers and policy makers at the Busan Port should concentrate on six PSQ measures (i.e. SR1, SR4, ITS1, VAS1, VAS4, ICI3) to enhance PSQ in CTLs. However, four measures (i.e. ITS2, ITS3, ITS4, VAS2) are identified as a possible overkill, indicating an area of inefficiency where a remedial action of the cost-cutting decision is necessary. On the other hand, the Busan port shows an outstanding performance on four measures such as SR2, SR3, ICI1 and ICI2. The measures are not only important but also high performance. The study findings provide managerial guidance to port managers in Busan Port, in view of searching for managerial and operational strategies for sustainable port growth.

• KIISE Transactions on Computing Practices
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• v.22 no.5
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• pp.225-234
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• 2016

The emergence of diverse medical Internet of Things (IoT) devices has facilitated the collection and analysis of medical contexts to assess health conditions. However, the complexity of IoT-based systems for health assessment is quiet high and it requires high development cost, since the designs of the systems highly depend on the heath aspects to be evaluated. In this paper, we propose a design of the platform that provides generic functionalities to various health evaluation applications. We first define a metric for computing a health index, which is a generic health assessment model. And, based on the proposed generic health index, we propose a design of the platform to evaluate diverse aspects of the health including its hardware architecture, software architecture and database design. We describe the result of developing Rainbow Toilet System based on the proposed platform, and assess the practical applicability.

• Journal of KIISE
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• v.43 no.7
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• pp.801-811
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• 2016

Self-adaptive systems (SASs) can change their goals and behaviors to achieve its ultimate goal in a dynamic execution environment. Existing approaches have designed, at the design time, utility functions to evaluate and predict the goal satisfaction, and set policies that are crucial to achieve each goal. The systems can be adapted to various runtime environments by utilizing the pre-defined utility functions and policies. These approaches, however, may or may not guarantee the proper adaptability, because system designers cannot assume and predict all system environment perfectly at the design time. To cope with this problem, this paper proposes a new method of dynamic decision making, which takes the following steps: firstly we design a Dynamic Decision Network (DDN) with environmental data and goal model that reflect system contexts; secondly, the goal satisfaction is evaluated and predicted with the designed DDN and real-time environmental information. We furthermore propose a dynamic reflection method that changes the model by using newly generated data in real-time. The proposed method was actually applied to ROBOCODE, and verified its effectiveness by comparing to conventional static decision making.