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Vol.10 No.3

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Abstract

In this paper, we collect and analyze the status of mobile phone applications (hereafter apps) in the healthcare and fitness category of the Apple iTunes App Store and Google Play Store. We determine the number of apps and analyze statistical aspects such as classifications, age rating, fees, and user evaluation of the popular items. As of September 30, 2013, there were 236 popular apps available from iTunes. Google Play offered 720 apps. We discover that apps for healthcare and fitness are diverse. Apps for physical exercise have the greatest popularity. The proportions of apps that are suitable for all ages among the Google and iTunes popular apps are 55.8% and 89.4%, respectively. The user evaluation of apps in iTunes is relatively less positive. We determine that the proportion of paid apps to free apps in Google is higher than that of the apps in iTunes. We perform hypothesis tests and find statistically significant differences in age rating and perceived satisfaction between the apps of the Apple iTunes App Store and Google Play Store. However, we find no meaningful differences in the classification and price of the apps between the two app stores. We perform hypothesis tests to verify the differences in age rating and perceived satisfaction between the paid and free apps within and across the Google Play Store and iTunes App Store. There are statistically significant differences in the age rating between the paid and free apps in the Google play store, between the Google free and iTunes free apps, between the Google paid and iTunes paid apps, between the Google free and iTunes paid apps, and between the Google paid and iTunes free apps. There are statistically significant differences in the perceived satisfaction between the Google free and iTunes free apps, between the Google paid and iTunes paid apps, between the Google free and iTunes paid apps, and between the Google paid and iTunes free apps.

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Abstract

Depth-image-based rendering is generally used in real-time 2D-to-3D conversion for 3DTV. However, inaccurate depth maps cause flickering issues between image frames in a video sequence, resulting in eye fatigue while viewing 3DTV. To resolve this flickering issue, we propose a new 2D-to-3D conversion scheme based on fast and robust depth-map generation from a 2D video sequence. The proposed depth-map generation algorithm divides an input video sequence into several cuts using a color histogram. The initial depth of each cut is assigned based on a hypothesized depth-gradient model. The initial depth map of the current frame is refined using color and motion information. Thereafter, the depth map of the next frame is updated using the difference image to reduce depth flickering. The experimental results confirm that the proposed scheme performs real-time 2D-to-3D conversions effectively and reduces human eye fatigue.

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Abstract

In this paper, we describe an adaptive Markov chain Monte Carlo-based particle filter that effectively addresses real-time multi-face tracking on mobile platforms. Because traditional approaches based on a particle filter require an enormous number of particles, the processing time is high. This is a serious issue, especially on low performance devices such as mobile phones. To resolve this problem, we developed a tracker that includes a more sophisticated likelihood model to reduce the number of particles and maintain the identity of the tracked faces. In our proposed tracker, the number of particles is adjusted during the sampling process using an adaptive sampling scheme. The adaptive sampling scheme is designed based on the average acceptance ratio of sampled particles of each face. Moreover, a likelihood model based on color information is combined with corner features to improve the accuracy of the sample measurement. The proposed tracker applied on various videos confirmed a significant decrease in processing time compared to traditional approaches

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Abstract

Mobile learning is a practical learning method for busy adult learners because the mobility of digital devices can overcome the drawbacks of e-learning. However, research is strongly lacking in the theoretical exploration of mobile learning effects and functions and its empirical research. Moreover, the research of learning characteristics and learners' requirements must be considered before applying and disseminating mobile learning into the educational field. To address this shortcoming, this study conducted an online survey with 1,542 officers of the Ministry of Health and Welfare Affairs (MHWA) regarding learner recognition to mobile learning. The analysis of learners' attitudes toward mobile learning, based on age and position, indicated that subordinate workers appeared to place more value on mobile learning. Many participants preferred mobile learning because of its mobility and the effectiveness of anywhere and anytime. However, some participants continue to misunderstand mobile learning and its necessity. Therefore, consideration of learning effectiveness, the form of the content, and learner-centered learning must be reviewed in advance. This study could lead to practical implications of mobile learning.

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Text line segmentation is a critical task in handwritten document recognition. In this paper, we propose a novel text-line-segmentation method using baseline estimation and watershed. The baseline-detection algorithm estimates the baseline using Adaptive Head-Tail Connection (AHTC) on the document. Then, the watershed method segments the line region using the baseline-detection result. Finally, the text lines are separated by watershed result and a post-processing algorithm defines the lines more correctly. The scheme successfully segments text lines with 97% accuracy from the handwritten document images in the ICDAR database.

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A cause-effect graph considers only the desired external behavior of a system by identifying input-output parameter relationships in the specification. When testing a software system with cause-effect graphs, it is important to derive a moderate number of tests while avoiding loss in fault detection ability. Pairwise testing is known to be effective in determining errors while considering only a small portion of the input space. In this paper, we present a new testing technique that generates pairwise tests from a cause-effect graph. We use a Boolean Satisbiability (SAT) solver to generate pairwise tests from a cause-effect graph. The Alloy language is used for encoding the cause-effect graphs and its SAT solver is applied to generate the pairwise tests. Using a SAT solver allows us to effectively manage constraints over the input parameters and facilitates the generation of pairwise tests, even in the situations where other techniques fail to satisfy full pairwise coverage.

(Tsinghua University) pp.47-54 https://doi.org/10.5392/IJoC.2014.10.3.047
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Abstract

Although the Korean Wave originated in China, its presence in this country had been faltering for some time. Recently, however, Korean Wave star centered K-drama via online video websites, Korean Wave TV programs with high ratings, and idol group centered K-pop with glocalization strategies are all popular in China once again. The purpose of this paper is to explore Chinese teens and twenty year olds as the main consumers of Korean popular culture and the how preferred genres, motives, and behaviors of Korean pop culture use and Korean image affect one another. According to the study results, media use via online video service was most common, and among the preferred genres, K-drama has the highest usage rates. In addition, it was discovered that motives and behaviors associated with the use of Korean pop culture had a considerable influence on a positive Korean image.

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Existing science education that excludes narrative thinking impedes the understanding of the context of workbook content. The object of this research is to develop a storytelling-learning program based on narrative thinking to elevate learners’ interest in science and expand their inventive problem-solving abilities. Following an analysis of the current Korean curriculum, eight types of storytelling materials that utilize local content were developed for grades 7–9. The learning program used quest storytelling and was designed such that learning activities such as investigation, discussion, and experimentation were included in the process of solving each quest. Learners experienced an interest in storytelling learning resulting from participation in this storytelling-learning program. Moreover, learners demonstrated inventive problem-solving abilities in the process of completing the stories. During the process of assembling the storytelling materials, the students interacted with enthusiasm and generated ideas. The teachers indicated a positive feedback to the storytelling program as a new attempt to stimulate learners’ interests. In the future, with continuous development and application, storytelling-science-learning programs that base science learning on narrative thinking are expected to be successful.

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This study explored the elements that affect team achievements in virtual environments. In this study, consideration was given to the role of group dynamics in facilitating productive interaction. We aspired to reveal the mechanisms of group dynamics and examined how group dynamics affected team achievements in virtual environments. The empirical study was performed with undergraduate students enrolled in an e-learning course. In collaboration with other majors, students executed team projects and managed project issues in forums or chat rooms. The results of the empirical study indicated that leadership, creative friction, and group cohesion (components of group dynamics) had positive relationships with team achievements. The findings confirmed that addressing creative conflict is a method to improve team performance and that leadership is a key factor in project teams.

(Ajou University) ; pp.73-83 https://doi.org/10.5392/IJoC.2014.10.3.073
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Abstract

Participants in Open Source Software (OSS) development projects usually contribute voluntarily without expecting direct compensation for their work. One of the central puzzles raised by the success of OSS is the motivation of the participants; why top-notch programmers choose to write software that is released for no fee. In order to respond to this peculiarity employing a meta-research method, we first identify and review theoretical perspectives from diverse disciplines including economics, sociology, political science, anthropology, psychology, and management. Then, we suggest a comprehensive framework that provides a holistic understanding of the puzzle in question. Reviewing key empirical studies based on the suggested framework, we also suggest a future research agenda.

Joseph Yoon(Pukyong National University) ; pp.84-89 https://doi.org/10.5392/IJoC.2014.10.3.084
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Abstract

The mass-spring model has been typically employed in physical-based simulators for clothes or patches. The mass-spring model frequently utilizes equal mass and the gravity factor. The model structure of masses supports a shape applicable to fishing nets. Therefore, to create a simulation model of a fishing net, we consider the mass-spring model and adopt the tidal-current and buoyancy effects in underwater environments. These additional factors lead to a more realistic visualization of fishing-net simulations. In this paper, we propose a new mass-spring model for a fishing-net and a method to simplify the calculation equations for a real-time simulation of a fishing-net model. Our 3D mass-spring model presents a mesh-structure similar to a typical mass-spring model except that each intersection point can have different masses. The motion of each mass is calculated periodically considering additional dynamics. To reduce the calculation time, we attempt to simplify the mathematical equations that include the effect of the tidal-current and buoyancy. Through this research, we expect to achieve a real-time and realistic simulation for the fishing net.

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The purpose of this study was to analyze the changes in muscle fatigue by using electromyography (EMG) measurements of the median frequency of shoulder muscles of patients who underwent rotator cuff repair, and to provide basic data for efficient exercise methods during rehabilitation after the repair. In the study, 24 male and 8 female patients who underwent rotator cuff repair performed continuous passive shoulder joint motion for 3 weeks and the median frequency of their shoulder muscles before and after the repair were compared using measurements by EMG. The infraspinatus, supraspinatus, and serratus anterior muscles showed significant differences in the changes in the median frequency before and after the repair. Significant differences were also found in the median frequency of the three muscles both before and after the repair. Additionally, the middle deltoid muscle had a lower median frequency than the supraspinatus muscle before the repair and the infraspinatus muscle had a lower median frequency than the middle deltoid muscle after the repair. It is expected that these results will serve as important data in developing rehabilitation exercise programs for the infraspinatus, supraspinatus, and serratus anterior muscles by compensating the middle deltoid muscle with the lowest muscle fatigue after the rotator cuff repair erase.

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