• Journal of Korean Society of Steel Construction
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• v.25 no.3
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• pp.267-278
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• 2013

In this study, stiffened plates with open ribs are analyzed to estimate and formulate the local displacement and local moments according to square loading sizes. For the local behaviors of plates stiffened with rectangular and reverse T ribs, the ratio functions according to the dimensions of stiffened plates are obtained at each square loading size. Analytical results show that values of the basic stiffened plates are different but the ratio functions of each square loading size are similar and the difference of the ratio functions between rectangular ribs and reverse T ribs are small, so the ratio functions can be unified by integrating the loading sizes regardless of the rib type. The application of the unioned ratio functions to L type ribs and rectangular loading shows good accuracies. Therefore, the local behaviors of plates stiffened with open ribs can easily be obtained by using the unioned ratio functions proposed in this study.

• KIISE Transactions on Computing Practices
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• v.22 no.6
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• pp.290-295
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• 2016

Recently, folksonomy-based image-sharing sites where users cooperatively make and utilize tags of image annotation have been gaining popularity. Typically, these sites retrieve images for a user request using simple text-based matching and display retrieved images in the form of photo stream. However, these tags are personal and subjective and images are not categorized, which results in poor retrieval accuracy and low user satisfaction. In this paper, we propose a categorization scheme for folksonomy images which can improve the retrieval accuracy in the tag-based image retrieval systems. Consequently, images are classified by the semantic similarity using text-information and image-information generated on the folksonomy. To evaluate the performance of our proposed scheme, we collect folksonomy images and categorize them using text features and image features. And then, we compare its retrieval accuracy with that of existing systems.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.6
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• pp.614-618
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• 2008

As the multimedia data increase a lot with the rapid development of the Internet, an efficient retrieval technique focusing on individual users is required based on the analyses of such data. However, user modeling services provided by recent web sites have the limitation of text-based page configurations and recommendation retrieval. In this paper, we construct the user preference model with a Bayesian network to apply the user modeling to video retrieval, and suggest a method which utilizes probability reasoning. To do this, context information is defined in a real office environment and the video scripts acquired from established cameras and annotated the context information manually are used. Personal information of the user, obtained from user input, is adopted for the evidence value of the constructed Bayesian Network, and user preference is inferred. The probability value, which is produced from the result of Bayesian Network reasoning, is used for retrieval, making the system return the retrieval result suitable for each user's preference. The usability test indicates that the satisfaction level of the selected results based on the proposed model is higher than general retrieval method.

• Journal of Korea Multimedia Society
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• v.12 no.10
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• pp.1466-1477
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• 2009

With development of 3D virtual space technology, diverse studies on 3D virtual space are being conducted because virtual space is being recognized as an appropriate technology for the field of urban and architectural design. However, while the process of urban and architectural design is done based on collaboration of various interested parties, there is lack of studies that support such collaboration. Communication within the virtual space must be provided for 3D virtual space to support collaboration, and a quick and direct technique of expressing one's intentions is required. sketch technique is effective. Ambiguous lines of sketch are extremely effective in that the range of thoughts in the idea stage can be broadened. However, such traditional sketch technique alone is difficult to support collaboration in 3D virtual space. That is because diverse shapes of 3D space require input of sketch. Accordingly in this study, sketch annotation that can effectively deliver intentions in 3D space was studied. Annotation technique using sketch-box was examined.

• Nuclear Engineering and Technology
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• v.28 no.2
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• pp.103-117
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• 1996

A mathematical model of vapor explosion propagation is presented. The model predict two-dimensional, transient flow fields and energies of the four fluid phases of melt drop, fragmented debris, liquid coolant and vapor coolant by solving a set of governing equations with the relevant constitutive relations. These relations include melt fragmentation, coolant-phase-change, and heat and momentum exchange models. To allow thermodynamic non-equilibrium between the coolant liquid and vapor, an equation of state for oater is uniquely formulated. A multiphase code, TRACER, has been developed based on this mathematical formulation. A set of base calculations for tin/water explosions show that the model predicts the explosion propagation speed and peak pressure in a reasonable degree although the quantitative agreement relies strongly on the parameters in the constitutive relations. A set of calculations for sensitivity studies on these parameters have identified the important initial conditions and relations. These are melt fragmentation rate, momentum exchange function, heat transfer function and coolant phase change model as well as local vapor fractions and fuel fractions.

• Journal of Korea Multimedia Society
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• v.1 no.1
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• pp.1-17
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• 1998

Video information is an important component of multimedia systems such as Digital Library, World-Wide Web (WWW), and Video-On-Demand (VOD) service system. Video information has hierarchical document structure inherently, so it is named "structure video document" in this paper. This paper proposes a data model, a query language, and an indexing scheme for structured video documents in order to store, retrieve, and share video documents efficiently. In representing structured video documents, the object-oriented data modeling technique is used since the hierarchical structure information can be modeled as complex objects. We also define object types for the structure information. Our query language supports not only content-based retrieval, which means the queries based on the structure of video documents, and spatial/temporal relation for video documents. In order to perform structure queries efficiently, as well as to reduce the storage overhead of indices, an optimized inverted index structure is proposed.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2008-2019
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• 1999

As computing technologies are rapidly progressed and widely used, the needs of high quality information have been increased. To satisfy these needs, it is essential to develop a system which can provide an efficient storing, managing and retrieving mechanism of complex multimedia data, esp. video data. In this paper, we propose a metadata model which can support content-based retrieval of video data. And we design and implement an integrated user interface for querying and browser for content-based retrieval in video database which can efficiently access and browse the video clip that user want to see. Proposed query processor and browser can support various user queries by integrating image feature, spatial temporal feature and annotation. Our system supports structure browsing of retrieved result, so users can more exactly and efficiently access relevant video clip. Without browsing the whole video clip, users can know the contents of video by seeing the storyboard. This storyboard facility makes users know more quickly the content of video clip.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1213-1219
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• 2012

A remote $CO_2$ laser system can rapidly change both the distance and the direction of the laser beam by moving a lens and rotating mirrors. It is then easy to weld complex patterns of weld lines. A conventional spot weld joint specimen and a remote $CO_2$ laser weld joint specimen with complex weld line patterns were prepared and tested both statically and dynamically. The relationships between the fatigue strength, i. e. the maximum cyclic force, and the fatigue life were obtained. The fatigue strength of the tested welded joints at two million cycles was found to be approximately 10% of the static strength. Furthermore, it was observed that the fatigue fracture mode changed with the level of the applied cyclic force. The fatigue crack origins were confirmed as the highest stress points found in the structural analysis. The maximum cyclic stress for different weld patterns converges as the fatigue life approaches two million cycles.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.209-219
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• 2011

Most of the computer-based distance learning systems are asynchronous ones that allow students to download from the server the lecture previously given by a lecturer. While these asynchronous systems has the advantage that enable students to view the lecture with no time restriction, the study may not be effective due to the lack of support for real-time interaction between students and lecturers. Based on the student-lecturer-collaboration session model, this paper presents a collaboration session-centric synchronous distance learning system that supports real-time interaction between students and teachers, awareness information during lecture, and feedback from students. Basic feature of the proposed system include audio and video conferencing, text-based chat, and shared slide with annotation support.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.345-353
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• 2020

As part of the mushroom surveys in the unexplored areas of Korea in 2019 and 2020, a phalloid fungus was found in a saline sand beach. The specimen was mainly characterized by its reticulate pileus and violet volva with well-developed rhizomorphs. Based on ribosomal DNA internal transcribed spacer (ITS) sequencing and morphological characteristics, the specimen was identified as Phallus hadriani. Additionally, a morphological comparison of closely related species was performed. This study describes for the first time the presence of P. hadriani in Korea.