• ETRI Journal
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• 제30권6호
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• pp.757-764
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• 2008

In this paper, we present a design evaluation system with visualization and interaction of mobile devices using virtual-reality-based prototypes which can be used to easily change design parameters and simulate embedded software. To evaluate and predict affective-engineering-based design preferences for mobile devices under a virtual environment, we have developed a high quality visualization platform which creates images that look similar to real mobile devices in addition to real-time simulation of realistic motions and functions of mobile devices. To support a quantitative usability test scenario for external design shape, we also have built a system which consists of a mixed-reality-based testing platform for measuring hand load.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권4호
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• pp.784-799
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• 2013

This paper presents an adaptive rate control scheme for streaming-based content sharing service. This scheme delivers multimedia contents from a user device to another device or seamlessly redirects streaming service across heterogeneous user devices. In the proposed scheme, a streaming server adjusts video quality level according to the network and client status. Our scheme is different from other rate control schemes, because the video quality at the server is decided not only based on the available bandwidth, but also based on the device characteristics and bandwidth requirement at the access network. We also propose a bandwidth estimation method to achieve more equitable bandwidth allocations among streaming flows competing for the same narrow link with different Round Trip Times (RTTs). Through the simulation, we prove that our scheme improves the network stability and the quality of streaming service by appropriately adjusting the quality of the video stream. The simulation results also demonstrate the ability of the proposed scheme in ensuring RTT-fairness while remaining throughput efficient.

• 공학논문집
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• 제3권1호
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• pp.47-56
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• 1998

본 논문은 내용기반 문서분류 전문가시스템 개발을 위한 온톨로지 개념 도입과 구축에 관한 연구이다. 전문가시스템 개발에 있어서 온톨로지가 미치는 영향에 대해 알아보고, 온톨로지 개념을 정립하고자 한다. 정립된 온톨로지의 개념에 입각하여 특정 영역인 미술 분야에 있어서 내용기반 문서분류 전문가시스템 개발 시 필요한 개념소를 추출하며 온톨로지 계통도를 제시한다.

• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.473-482
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• 2008

In this paper we propose an expert system for content-based image retrieval with object database. The proposed system finds keyword by using knowledge-base and feature of extracted object, and retrieves image by using keyword based image retrieval method. The system can decrease error of image retrieval and save running time. The system also checks whether similar objects exist or not. If not, user can store information of object in object database. Proposed system is flexible and extensible, enabling experts to incrementally add more knowledge and information. Experimental results show that the proposed system is more effective than existing content-based image retrieval method in running time and precision.

• 반도체디스플레이기술학회지
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• 제10권3호
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• pp.75-81
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• 2011

This paper presents a novel method for image classification based on a hybrid genetic algorithm (GA) and support vector machine (SVM) approach which can significantly improve the classification performance for content-based image retrieval (CBIR). Though SVM has been widely applied to CBIR, it has some problems such as the kernel parameters setting and feature subset selection of SVM which impact the classification accuracy in the learning process. This study aims at simultaneously optimizing the parameters of SVM and feature subset without degrading the classification accuracy of SVM using GA for CBIR. Using the hybrid GA and SVM model, we can classify more images in the database effectively. Experiments were carried out on a large-size database of images and experiment results show that the classification accuracy of conventional SVM may be improved significantly by using the proposed model. We also found that the proposed model outperformed all the other models such as neural network and typical SVM models.

• Journal of Information Processing Systems
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• 제16권4호
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• pp.991-1000
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• 2020

We propose a content-based image retrieval system that uses a combination of completed local binary pattern (CLBP) and color autocorrelogram. CLBP features are extracted on a multi-resolution multi-direction filtered domain of value component. Color autocorrelogram features are extracted in two dimensions of hue and saturation components. Experiment results revealed that the proposed method yields a lot of improvement when compared with the methods that use partial features employed in the proposed method. It is also superior to the conventional CLBP, the color autocorrelogram using R, G, and B components, and the multichannel decoded local binary pattern which is one of the latest methods.

• 한국멀티미디어학회논문지
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• 제24권8호
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• pp.1090-1100
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• 2021

Recently, as indoor activities increase due to the spread of infectious diseases, the metaverse is attracting attention. Metaverse refers to content in which the virtual world and the real world are closely related, and its representative platform technology is VR(Virtual Reality). However, since VR hardware is difficult to access in terms of cost, the concept of streaming-based cloud VR has emerged. This study proposes a server configuration and deployment method in an edge network when metaverse content involving multiple users operates based on cloud VR. The proposed algorithm deploys the edge server in consideration of the network and computing resources and client location for cloud VR, which requires a high level of computing resources while at the same time is very sensitive to latency. Based on simulation, it is confirmed that the proposed algorithm can effectively reduce the total network traffic load regardless of the number of applications or the number of users through comparison with the existing deployment method.

• International Journal of Knowledge Content Development & Technology
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• 제12권1호
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• pp.85-104
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• 2022

In this study, in line with the era of the fourth industrial revolution, general concepts, technologies, trends, and examples of virtual reality and augmented reality were examined, and based on this, a plan that could be applied to libraries in the future was proposed. As a result of the study, first, it is necessary to construct a smart space as an experiential play space that can satisfy cultural desires transcending time and space by providing immersive contents using 4th technology such as VR and AR. Second, it is necessary to expand experiential cultural support services through VR, AR and MR. Third, to develop educational contents based on augmented reality technology. In order to apply and activate virtual reality and augmented reality in libraries in the future, based on a survey of librarians and users of public libraries, a survey on the application status, satisfaction, and demand of current public libraries should be conducted.

• Educational Technology International
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• 제9권2호
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• pp.123-142
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• 2008

The purpose of this study was to examine how computer conferencing might facilitate collaborative learning for students to engage in meaningful discussion. The participants in this study consisted of the instructor and the students in a graduate level course. Different sources of evidence were used to triangulate the data: in-depth interviews, content analysis of transcripts of discussion, and other archival data including course syllabus, presentation materials, and lecture notes. Participants perceived web-based learning as collaborative process, providing opportunities to share the idea, respect and evaluate different perspectives, and co-construct new insights. Analysis of the data revealed several challenges related collaboration in a web-based learning environment: absence of a sense of community, technical problems, adaptability to different types of learner, and managing the discussion. The data also indicated that a variety of strategies were used to facilitate learning: building a sense of community, technical support, developing instructional methodologies, class size, and design of the content.

• International Journal of Contents
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• 제8권2호
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• pp.36-42
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• 2012

This study was conducted to develop Web-based multimedia content that assists undergraduate students in a clinical practicum on adult nursing. The study examined whether students in the intervention group could obtain clinical knowledge and perform more effectively when encouraged to learn Web content as compared with students in the conventional group. Web-based multimedia content consisting of 13 learning modules was developed based on real patients' scenarios through collaboration among college professors. A total of 120 nursing students (74 for the intervention and 46 for the conventional groups) from two universities in G-city, who engaged in a 3-week long clinical practicum in the digestive and respiratory units of a university hospital, participated in the study. Students' knowledge, self-directed learning, and clinical performance ability were measured using self-administered questionnaires. Data for pre- and posttests were collected over a 2-month period, between May and June of 2009. Clinical knowledge and self-reported clinical performance scores were significantly higher in students using the Web-enhanced clinical practicum than in those in the conventional group. However, there was no significant difference in self-directed learning ability between the 2 groups. These results demonstrate that Web-based multimedia content can be an effective educational tool for enhancing students' clinical knowledge and performance.