• Communications of Mathematical Education
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• v.25 no.1
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• pp.63-78
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• 2011

The purpose of this study is to explore a teaching method of limits of functions with more intuitive and visual of CAS graphing calculators rather than with the rigorous ${\epsilon}-{\delta}$ method. Texas Instruments Voyage200 CAS graphing calculators are used for studying the possibility of the use of technology in calculus course. For this, various related theoretical constructs are reviewed: concept image, concept definition, cognitive conflict, the use of visualization of technology for calculus concepts, the theory of APOS, and local straightness. Based on such theoretical constructs this study suggests a teaching method of limits of functions with embodied visualization of CAS graphing calculators.

• Journal of the Korean Chemical Society
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• v.61 no.5
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• pp.277-285
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• 2017

The purpose of this study is to investigate the perspective of pre-service chemistry teachers on the learning situations of visually impaired students through scientific inquiry in a darkroom and to propose a teaching and learning method for students with visual impairments. Twenty-one pre-service chemistry teachers from college of education in Gyeongbuk were encouraged to explore individually hands-on model for the molecular structure of ice freely, and had a discussion with a one of the researchers during the activity. All the conversation and discussion were audio-taped and transcribed for analysis. As a result, pre-service chemistry teachers realized that learning situation of the visually impaired students was quite different with their perception while exploring and figuring out hands-on model of the molecular structure of ice in the darkroom. They already learned and could see this model by themselves but also recognized that visually impaired students had inconvenience and difficulty in learning science concepts. Based on these reflections, some pre-service chemistry teachers suggested directions for modification to fit visually impaired students' needs more.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.4
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• pp.624-632
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• 2022

Relationship networks such as an interpersonal relationship network or navigation route search can be expressed in graph form. However, as the amount of data increase, there is a problem that it is difficult to search for the desired data when it is displayed on one screen. In this paper, we propose a visualization method for searching for people, searching for the shortest path between people, and using graphs to express an interpersonal relationship network with many nodes. Unlike the search for the shortest path in the routing table, the shortest path in the interpersonal relationship network should be changeable according to the intension or importance of the researcher or user who is analyzing it. To this end, the BFS algorithm was modified to apply the characteristics of the interpersonal relationship network. For the verification of the results, the data in the character relationship information of the Korean Classics DB in the Korean Classics Translation Institute was used.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.296-303
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• 2014

In this paper, we propose an algorithm to visualize radio wave environment based on the measured Received Signal Strength Indication( RSSI) and 3D geographic information. We estimate the source position using the circumcenter of the triangle and visualize the radio wave environment using the empirical propagation models. A mode seeking algorithm(mean-shift clustering) is used to seek the peak points and the center of gravity is utilized to reduce the estimation errors. Our approach finds its applications in the radio wave monitoring systems for the efficient utilization of radio resources.

• Archives of design research
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• v.17 no.1
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• pp.299-308
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• 2004

The methods of presenting information are more variable with advanced computer media technology. However, when we visualize information of database, it is more difficult to understand data meaning by complex date, which is not required by user. To compose new information, user needs to combine own his memory and new information presenting result. To be quickly explored new information and be exactly understood relationship of data structure, the data presenting of visualized information is more structured and presented with meaning form. It is possible to make information visualization system, which users can explore database by oneself, with supporting interaction to be able to control and combine relationship of three-dimensional scene graphic structure, presenting factors of animation and data structure of database. There are several diagrams, such as VR diagram, Form structure diagram and simulated diagram as the case study.

• Science of Emotion and Sensibility
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• v.23 no.1
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• pp.29-40
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• 2020

Visually impaired people use tactile maps to get spatial information about their surrounding environment, find their way, and improve their independent mobility. However, classical tactile maps that make use of braille to describe the location within the map have several limitations, such as the lack of information due to constraints on space and limited feedback possibilities. This study describes the development of a new multi-modal interactive tactile map interface that addresses the challenges of tactile maps to improve the usability and independence of visually impaired people when using tactile maps. This interface adds touch gesture recognition to the surface of tactile maps and enables the users to verbally interact with a voice agent to receive feedback and information about navigation routes and points of interest. A low-cost prototype was developed to conduct usability tests that evaluated the interface through a survey and interview given to blind participants after using the prototype. The test results show that this interactive tactile map prototype provides improved usability for people over traditional tactile maps that use braille only. Participants reported that it was easier to find the starting point and points of interest they wished to navigate to with the prototype. Also, it improved self-reported independence and confidence compared with traditional tactile maps. Future work includes further development of the mobility solution based on the feedback received and an extensive quantitative study.

• Journal of the Korean Society for information Management
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• v.28 no.2
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• pp.135-158
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• 2011

The ability of the searcher to express their information problem to an information retrieval system is fundamental to the retrieval process. Query by visual example is the principal query paradigm for expressing queries in a content-based image retrieval environment yet there is little empirical evidence to support its efficacy in facilitating query formulation. The aim of this research was to investigate the usability of the query by colour method in supporting a range of information problems in order to contribute to the gap in knowledge regarding the relationship between searchers' information problems and the query methods required to support efficient and effective visual query formulation. The results strongly suggest that the query method does not support visual query formulation and that there is a significant mismatch between the searchers information problems and the expressive power of the retrieval paradigm.

• Journal of the Korean Geographical Society
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• v.40 no.3 s.108
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• pp.310-320
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• 2005

This study attempts at prototyping and evaluating a geovisualization tool that summarizes and explores human activity patterns using spatio-temporal trajectory data collected from GPS receiver. A set of core conceptualization developed in 'time geography' is successfully represented by our prototype based on the notion of 'space-time cube.' The notions of 'temporal dispersion cylinder' and 'parallel plane plot' are also implemented to allow funker analyses of human activity pattern on the space-time trajectory. The capabilities of the geovisualization environment we proposed include the interactive and dynamic functions that support a variety of explorations on the three components of spatio-temporal data : space(where), time(when), and object(what).

• Journal of the Korea Computer Graphics Society
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• v.16 no.4
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• pp.25-33
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• 2010

With the popularization of digital photography, people are now capturing and storing far more photos than ever before. However, the enormous number of photos often discourages the users to identify desired photos. In this paper, we present a novel method for fast and intuitive browsing through large collections of geo-referenced photographs. Given a set of photos, we construct a hierarchical structure of clusters such that each cluster includes a set of spatially adjacent photos and its sub-clusters divide the photo set disjointly. For each cluster, we pre-compute its convex hull and the corresponding polygon area. At run-time, this pre-computed data allows us to efficiently visualize only a fraction of the clusters that are inside the current view and have easily recognizable sizes with respect to the current zoom level. Each cluster is displayed as a single polygon representing its convex hull instead of every photo location included in the cluster. The users can quickly transfer from clusters to clusters by simply selecting any interesting clusters. Our system automatically pans and zooms the view until the currently selected cluster fits precisely into the view with a moderate size. Our user study demonstrates that these new visualization and interaction techniques can significantly improve the capability of navigating over large collections of geo-referenced photos.

• Journal of Agricultural Extension & Community Development
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• v.19 no.1
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• pp.179-194
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• 2012

본 논문은 조직이론 가운데 주로 신제도주의경제학의 기본이론으로 다음 세 가지 내용을 탐색했다. 첫째, 50년대 이후 중국 농촌조직의 발전성과에 대해 개괄했다. 둘째, 2001년 중국의 WTO 가입 전후 농촌조직개혁의 방향에 대한 신제도주의경제학의 시각을 탐색했다. 셋째, 2006년 <사회주의신농촌건설>의 시작과 <농민전업합작사법> 공표 이후 중국 농촌합작조직의 발전 방향에 대해 탐색했다. 본문은 주로 신제도주의경제학의 기본이론으로 중국 농촌합작조직의 변화와 전망에 대한 저자의 시각에 대해 서술했다.