• Journal of Intelligence and Information Systems
• /
• v.21 no.1
• /
• pp.99-118
• /
• 2015

Object-oriented programming languages have been widely selected for developing modern information systems. The use of concepts relating to object-oriented (OO, in short) programming has reduced efforts of reusing pre-existing codes, and the OO concepts have been proved to be a useful in interpreting system requirements. In line with this, we have witnessed that a modern conceptual modeling approach supports features of object-oriented programming. Unified Modeling Language or UML becomes one of de-facto standards for information system designers since the language provides a set of visual diagrams, comprehensive frameworks and flexible expressions. In a modeling process, UML users need to consider relationships between classes. Based on an explicit and clear representation of classes, the conceptual model from UML garners necessarily attributes and methods for guiding software engineers. Especially, identifying an association between a class of part and a class of whole is included in the standard grammar of UML. The representation of part-whole relationship is natural in a real world domain since many physical objects are perceived as part-whole relationship. In addition, even abstract concepts such as roles are easily identified by part-whole perception. It seems that a representation of part-whole in UML is reasonable and useful. However, it should be admitted that the use of UML is limited due to the lack of practical guidelines on how to identify a part-whole relationship and how to classify it into an aggregate- or a composite-association. Research efforts on developing the procedure knowledge is meaningful and timely in that misleading perception to part-whole relationship is hard to be filtered out in an initial conceptual modeling thus resulting in deterioration of system usability. The current method on identifying and classifying part-whole relationships is mainly counting on linguistic expression. This simple approach is rooted in the idea that a phrase of representing has-a constructs a par-whole perception between objects. If the relationship is strong, the association is classified as a composite association of part-whole relationship. In other cases, the relationship is an aggregate association. Admittedly, linguistic expressions contain clues for part-whole relationships; therefore, the approach is reasonable and cost-effective in general. Nevertheless, it does not cover concerns on accuracy and theoretical legitimacy. Research efforts on developing guidelines for part-whole identification and classification has not been accumulated sufficient achievements to solve this issue. The purpose of this study is to provide step-by-step guidelines for identifying and classifying part-whole relationships in the context of UML use. Based on the theoretical work on Meta-model Formalization, self-check forms that help conceptual modelers work on part-whole classes are developed. To evaluate the performance of suggested idea, an experiment approach was adopted. The findings show that UML users obtain better results with the guidelines based on Meta-model Formalization compared to a natural language classification scheme conventionally recommended by UML theorists. This study contributed to the stream of research effort about part-whole relationships by extending applicability of Meta-model Formalization. Compared to traditional approaches that target to establish criterion for evaluating a result of conceptual modeling, this study expands the scope to a process of modeling. Traditional theories on evaluation of part-whole relationship in the context of conceptual modeling aim to rule out incomplete or wrong representations. It is posed that qualification is still important; but, the lack of consideration on providing a practical alternative may reduce appropriateness of posterior inspection for modelers who want to reduce errors or misperceptions about part-whole identification and classification. The findings of this study can be further developed by introducing more comprehensive variables and real-world settings. In addition, it is highly recommended to replicate and extend the suggested idea of utilizing Meta-model formalization by creating different alternative forms of guidelines including plugins for integrated development environments.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.3
• /
• pp.23-28
• /
• 2018

Next generation displays show a trend of evolving from the display device environment (represented by existing televisions) to the mobile environment. The mobile display corresponding to the personal display is similar to a home theatre; however, they are advantageous because they are small and have a relatively lower weight. Therefore, the display industry has an interest in diverse product applications of displays, reproducing more accurate colours, and offering improved image quality from display devices of various sizes. To address these interests, a psychophysical experiment was conducted in this research. The experiment compared the size of the colour stimulation corresponding to foveal vision by gradually increasing the lightness of the background. This was based on the assumption of possible differences in colours being recognized by the lightness of the background and the size of the colour stimulation. Contrary to the results of previous studies, where the colours are identified more clearly as the size of the colour stimulation increases (assuming that the lightness of the background is not considered) here the results of the experiment showed that the attributes of the identified colours were different depending on the lightness of the background and the size of the colour stimulation. Based on the experimental results, it is possible to resolve errors in colour conversion that can occur when the input image is switched from a large screen size to a mobile size display, and to reproduce the colours more accurately and improve the image quality.

• Journal of Science Education
• /
• v.44 no.1
• /
• pp.1-14
• /
• 2020

In this study, we analyzed the written and drawn explanations of thirty elementary school pre-service teachers in order to examine their perception on the seasonal length of day and night. The main findings are as follows: First, pre-service teachers used the most common term in the description of the texts, such as meridian altitude, axis of rotation, and revolution, and there were more misconceptions in the drawn explanation than in the written explanation. Second, by analyzing the pre-service teachers' perceptions by combining written and drawn explanations, it is possible to detect scientific errors that the distance between the Earth and the Sun is closer when the axis of rotation is tilted in relation to the revolution and seasonal changes due to changes in the orbital radius of the Earth. In addition, there have been types of explanations such as seasonally changing meridian altitudes related to the rotation of the Earth but no change in the location of the Sun. Based on the results of the analysis, we discussed the lack of experience in constructing an explanatory system of specific phenomena using scientific knowledge, lack of observational experiences about natural phenomena, and lack of exposure to other explanatory systems that cause cognitive conflicts. We hope that it will be concrete and practical help to improve the understanding of pre-service teachers in the science domain of primary teacher training program.

• Archives of design research
• /
• v.20
• /
• pp.199-208
• /
• 1997

The emphasis of simplicity in design is because of the desire to deliver much content with a simplest way. Since in general, a simple form is outstanding in its symbolical nature and the relief of plastic beauty is easy by it, it is usually applied to a form of a symbol mark. However, in the meantime, if any local autonomous group or enterprise which has not tried to give efforts to its advertisement than they might expect and might be disadvantageous in competition. For consumers, when they experienced several, forms of simple, symbol mark, would not remember the special features of each mark. Rather, for the psychology of perception, they might remember only the formative, common features, there by grouping the marks by their common features. In this study, some symbol marks in Dobong-gu Ward Office and Wonju city were inspected, reviewed, and analized. And its is a finding that the subjects of this study could not distinguish or identify any of marks from another mark having a similar image of it: the reason is that the simplicity of a symbol mark made or allowed them to recognize it identical with the other imaged: it proves that the mistakes, defects of memory, and accumulated errors are oriented to the identical image. After all, the appearented image and perceived image are differnt. Any of symbolmarks which takes a simple form does not mean the perceived image is also simple. As a final conclusion, designers, in order to produce any of competitive symbolmarks, need to thoroughly understand psychology of gestalt.

• The Mathematical Education
• /
• v.27 no.1
• /
• pp.15-23
• /
• 1988

We are at the onset of a major revolution in education, a revolution unparalleled since the invention of the printing press. The computer will be the instrument of this revolution. Computers and computer application are everywhere these days. Everyone can't avoid the influence of the computer in today's world. The computer is no longer a magical, unfamiliar tool that is used only by researchers or scholars or scientists. The computer helps us do our jobs and even routine tasks more effectively and efficiently. More importantly, it gives us power never before available to solve complex problems. Mathematics instruction in secondary schools is frequently perceived to be more a amendable to the use of computers than are other areas of the school curriculum. This is based on the perception of mathematics as a subject with clearly defined objectives and outcomes that can be reliably measured by devices readily at hand or easily constructed by teachers or researchers. Because of this reason, the first large-scale computerized curriculum projects were in mathematics, and the first educational computer games were mathematics games. And now, the entire mathematics curriculum appears to be the first of the traditional school curriculum areas to be undergoing substantial trasformation because of computers. Recently, many research-Institutes of our country are going to study on computers in orders to use it in mathematics education, but the study is still start ing-step. In order to keep abreast of this trend necessity, and to enhance mathematics teaching/learning which is instructed lecture-based teaching/learning at the present time, this study aims to develop/present practical method of computer-using. This is devided into three methods. 1. Programming teaching/learning method This part is presented the following five types which can teach/learn the mathematical concepts and principle through concise program. (Type 1) Complete a program. (Type 2) Know the given program's content and predict the output. (Type 3) Write a program of the given flow-chart and solve the problem. (Type 4) Make an inference from an error message, find errors and correct them. (Type 5) Investigate complex mathematical fact through program and annotate a program. 2. Problem-solving teaching/learning method solving This part is illustrated how a computer can be used as a tool to help students solve realistic mathematical problems while simultaneously reinforcing their understanding of problem-solving processes. Here, four different problems are presented. For each problem, a four-stage problem-solving model of polya is given: Problem statement, Problem analysis, Computer program, and Looking back/Looking ahead. 3. CAI program teaching/learning method This part is developed/presented courseware of sine theorem section (Mathematics I for high school) in order to avail individualized learning or interactive learning with teacher. (Appendix I, II)

• The Journal of the Korea Contents Association
• /
• v.16 no.12
• /
• pp.446-457
• /
• 2016

The purpose of the study was to understand the various aspects of learning experiences of Korean university students on K-MOOC. Analyses on the major motivation of the enrollment in a certain MOOC class, the actual learning experiences in the class and the perception of the achievement of the class were the three main foci of the current study. The study employed inductive content analysis as a major analysis tool. Reflective journals from 94 students who enrolled in K-MOOC classes were collected and analyzed at the end of the semester. The result of this study indicated that most of students selected the specific K-MOOC classes based on their general interests on the topics the class offered. Other factors such as intellectual curiosity, practical reasons for their study or work and popularity were also influential on the selection of MOOC classes. Watching videos, taking quizzes and taking tests were the three major sources of the students' satisfaction. Most students felt that K-MOOC is technically satisfactory. However, some students reported on simple errors and absence of advanced functions in the platform. Students perceived positively on their academic achievements of obtaining knowledge(remembering and understanding), attitudes (receiving), and skills through K-MOOC. This study ultimately showed a new awareness of learning experiences around K-MOOC from the perspective of the students. Future research is needed to understand the relationships between the students' learning experience and the students' performance in MOOC classes.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.4
• /
• pp.43-48
• /
• 2018

This study was conducted to reproduce digital colour based on the lightness of the background and size of the colour stimulus so that colour can be similarly perceived under different conditions. With the evolution of display technologies, display devices of various sizes can now reproduce more accurate colour and enhanced images, thus affecting the overall quality of display images. This study reproduced digital colour by considering the visual characteristics of the digital media environment. To accomplish this, we developed a colour appearance model which distinguishes the properties of foveal and peripheral vision. The proposed model is based on existing research on the lightness of the background and size of the colour stimulus. Based on experimental results, an analysis of variance was performed in order to develop the colour appearance model. The algorithm and modelling were verified based on the proposed model. In addition, to apply this model to display technologies, a practical colour control system and a method for handling complex input images were developed. Through this research, colour conversion errors which might occur when the input image is converted to fit a specific display size are resolved from the perspective of the human visual system. As a result, more accurate colour can be displayed and enhanced images can be reproduced.

• School Mathematics
• /
• v.16 no.4
• /
• pp.803-825
• /
• 2014

From the early stages of learning algebra, literal symbols are used to represent algebraic objects such as variables and parameters. The concept of parameters contains both indeterminacy and fixity resulting in confusion and errors in understanding. The purpose of this research is to compare the beginners of algebra and pre-service teachers who completed secondary mathematics education in terms of understanding this paradoxical nature of parameters. We recruited 35 middle school students in eight grade and 73 pre-service teachers enrolled in a undergraduate course at one university. Using them we conducted a survey on the perception of the nature of parameters asking if one considers parameters suggested in a problem as variables or constants. We analyzed the collected data using the mixed method of qualitative and quantitative approaches. From the analysis results, we identified several difficulties in understanding of parameters from both groups. Especially, our statistical analysis revealed that the proportions of subjects with limited understanding of the concept of parameters do not differ much in two groups. This suggests that learning algebra in secondary mathematics education does not improve the understanding of the nature of parameters significantly.

• Journal of the Korea Convergence Society
• /
• v.12 no.12
• /
• pp.19-29
• /
• 2021

Although several industrial revolutions and technological developments have provided time for modern people, more than 75% of modern people are currently suffering from the problem of "lack of time". Therefore, in this paper, it was judged that it was necessary to improve the mobile APP service for efficient time management of modern people, and a study was conducted on the development of usability evaluation tools. First, the current status was analyzed through case studies of six time management apps with different purposes, and then usability studies were conducted to establish a total of five evaluation principles with operability, cognition, user suitability, minimization of work errors, and sharing. Based on this, a draft of the time management mobile app usability evaluation item was prepared, and a total of 44 usability evaluation tool items were derived through three Delphi surveys of design experts over 5 years and less than 10 years. As a result, intuitive screen and menu composition and user's perception of content were evaluated as the most important factors, and conclusions such as the need to improve the structure and function of the main content screen for user error prevention and usability were drawn. This study will not only contribute to improving the usability of existing time management mobile apps, but will also be used as a material for designing an integrated time management platform for efficient time management and purpose promotion in the future, and is expected to be used as an academic reference.

• Journal of the Korean Society for information Management
• /
• v.40 no.3
• /
• pp.245-271
• /
• 2023

The purpose of this study was to assess the perception of e-book subscription services among the digitally native generation in their twenties, who have a high e-book usage rate. This study employed a mixed-methods approach, combining survey responses and usability testing. It aimed to assess the awareness and usage of e-book subscription services among university students in their twenties, a demographic known for their high utilization of electronic devices and e-books. The survey was conducted among 202 university students, and the responses were categorized and examined based on whether they were users or non-users. As a result of the survey, I found there is different awareness of e-book between users and non-users, on the other hand, convenience and portability are the strong point of e-books for users and non-users commonly also. Usability testing was performed on a group of 10 university students in their twenties who had not previously used the 'Millies Library' application, which is renowned as the most widely-used e-book platform. Following the experiment, participants expressed positive feedback regarding various optional features, convenience, design, and cost-effectiveness. However, they also had negative reactions concerning touch errors, malfunctions, functional practicality, a lack of interest, system issues, and the absence of a library.