• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.9
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• pp.1-12
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• 1997

The performance of Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) protocol adopted as a draft standard of IEEE 802.11 wireless LAN, is analyzed by using mathematical method based on renewal theory. We introdude three kinds of CSMA/CA protocols basic, stop-and-wait and 4-Way handshake CSMA/CA with their mathematical analysis. First, a network of finite population is considered and then expand to infinite population. We model the CSMA/CA protocol as a hybrid protocol of 1-persistent CSMA and p-persistent CSMA protocol, and verify analaytical results by computer simulation. We have found that 4-Way Handshake CAMA/CA shows better performance than those of other two types of CSMA/CA in case of high traffic load.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.11a
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• pp.79-85
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• 1997

Virtual holography is a methodology of synthesizing apparent three-dimensional images from two-dimensional photographs. Since the input is photographic images of real objects, the degree of realism exceeds that offered by any computer-aided design software. The three-dimensional appearance is given in real-time by images from arbitrary viewing directions. If infinitely many photographs were taken and pasted together, virtual holography would have been trivial. But, the (infinite) storage requirement would prohibit such an attempt.

• KCI Concrete Journal
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• v.13 no.2
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• pp.10-18
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• 2001

The spectral analysis of surface waves (SASW) method, which is an in-situ seismic technique, has mainly been developed and used for many years to determine the stiffness profile of layered media (such as asphalt concrete and layered soils) in an infinite half-space. This paper presents a modified experimental technique for nondestructive evaluation of in-place cement mortar compressive strength in single-layer concrete slabs of rather a finite thickness through a correlation to surface wave velocity. This correlation can be used in the quality control of early age cement mortar structures and in evaluating the integrity of structural members where the infinite half space condition is not met. In the proposed SASW field test, the surface of the structural members is subjected to an impact, using a 12 mm steel ball, to generate surface wave energy at various frequencies. Two accelerometer receivers detect the energy transmitted through the medium. By digitizing the analog receiver outputs, and recording the signals for spectral analysis, surface wave velocities can be identified. Modifications to the SASW method includes the reduction of boundary reflections as adopted on the surface waves before the point where the reflected compression waves reach the receivers. In this study, the correlation between the surface wave velocity and the compressive strength of cement mortar is developed using one 36"x36"x4"(91.44$\times$91.44$\times$91.44 cm) cement mortar slab of 2,000 psi (140 kgf/$\textrm{cm}^2$) and two 36"x36"x4"(91.44$\times$91.44$\times$91.44 cm) cement mortar slabs of 3,000 psi (210 kgf/$\textrm{cm}^2$).

• Journal of Korea Game Society
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• v.9 no.3
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• pp.97-105
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• 2009

In this paper, we propose a new rendering scheme of cloth by measuring light-scattering pattern inside the cloth and reproducing using the pattern. To date, the BTF(Bidirectional Texture Function) has been one of the most appropriate method to realistically reconstruct cloth surface. However, the BTF has a couple of defects that it ultimately requires an infinite amount of data and all light effects should be used all together. We noted that internal scattering has a decisive contribution to the reality of cloth. Following this observation, we take an image of a ray of light scattering inside cloth for every position of the cloth sample and determine each pixel value by adding up all light influences arriving from its vicinity. Our method we propose in this paper provides a clue to more realistically represent cloth-like materials, which is one of the most challenging materials to express, by enabling each ray to be controlled individually.

• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.133-146
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• 2022

Despite the fact that Internet users around the world watch YouTube every day, very few users accurately recognize the recommendation algorithm for search results, and Google and YouTube are not disclosing it. Researchers tried to explore the undisclosed algorithm of YouTube in a reverse engineering design method, find key factors, and check the logical structure in which media platform operators recommend keyword search results and arrange them on the screen. Therefore, researchers studied the basic content priority factors through several months of discussion and data collection, and tried to reverse engineer the influencing factors based on the recommendation results according to male and female gender among the collected keyword search results. Although researchers' design only analyzed some of the almost infinite level of data uploaded and viewed for more than hundreds of hours every hour, these exploratory attempts will study media platform algorithms in the future, understand the intentions of operators, and protect users. thought it could be done.

• Cartoon and Animation Studies
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• s.33
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• pp.363-382
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• 2013

Up until about ten years ago, the use of typography played only an auxiliary role on broadcast television programs, primarily by transmitting information in order to facilitate a basic understanding of content. Recently, however, kinetic typography has become an important component in broadcast production. In fact, kinetic typography has developed into a visual language and a means of artistic expression, one that is increasingly used in the production of entertainment programs on television. This paper analyzes six aspects of kinetic typography: manner of development, location, intent, expressive techniques, color and font selection. Particular attention is placed on their use in three highly rated television entertainment programs: "2 Days & 1 Night", "Running Man", and "Infinite Challenge". The development way consists of the technique : starts off with cut and ends with cut. While, other techniques show conversation and situation representation using Z axis : zoom-in, zoom-out in , X axis : pan in <2 Days & 1 Night>. and Y axis : tilt in . Typographic design elements, expression technique, color, font are shown up according to the feature of each program. The resulting analysis suggests new ways for motion arts designers and the broadcast media to use kinetic typography in the development of television programs.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.134-144
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• 2011

Crossmedia Storytelling is receiving attention as a new style of description in the age of limitless competition and infinite fusion among media. Crossmedia Storytelling specifies a form of storytelling carried out through mixed usage of plural media, such as televisions, movies, and web services. It is different from OSMU strategy in that plays one source of contents according to the characteristics of various media while Crossmedia Storytelling demands users' active participation. Moreover, it is also slightly different from Transmedia Storytelling in the point that narratives of each media are not complete themselves and only through effectively combining plural media can the whole story fully enjoyed. This research aims to analyze how users move among media in terms of Crossmedia contents by examining cases of Swedish interactive drama series , from Australia, and from the United States. To do so, first, the paper looks into the principles of Crossmedia communication and examines that it is based on online word-of-mouth communication, such as viral marketing. As a result, the following was found in the cases of Crossmedia Storytelling: negative stories that arouse users' emotional reactions & users' participation are effective, and the set-up of Sneezer, which causes the knowledge gap, is very important. It was also found that users' participation was actively taking place through online WOM communication in Crossmedia Storytelling.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.1-10
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• 2014

Recently, the value and the status of the digital archives that are built individually in the crossroads of oblivion and memory are due to big data has attracted attention globally is confusing. Video data that contains the cultural memory of the digital archive, such as culture, art, life, society, and social conditions of the time, it is a cultural heritage of national common expressed. Also, it remains a trace of history from the various media just like magazines, books, painting, photography, and film. Digital archive system is one of the best research results of media convergence and it has also a good opportunity to take full advantage of the new opportunities and cultural assets. The collection of infinite information of big data in perspective transient that exist at the same time compatibility of big data, it is trying to dismantle the cultural memory of us. It was asserted that must meet the criteria which can correspond to via the new digital era, will be applied to preserve the traditional media. The current image archive is necessary to accommodate proper two different directions.

• Tunnel and Underground Space
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• v.16 no.6 s.65
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• pp.495-505
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• 2006

Calculating the distribution of stresses and displacements around a circular tunnel excavated in infinite isotropic rock mass subjected to hydrostatic stress condition is one of the basic problems in rock engineering. While closed-form solutions for the distribution are known if rock masses are considered as elastic, perfectly plastic, or brittle-plastic media, a few numerically approximated solutions based on various simplifying assumptions have been reported for strain-softening rock mass. In this study, a simple numerical method is introduced for the analysis of strain-softening behavior of the circular tunnel in Mohr-Coulomb rock mass. The method can also applied to the analysis of the tunnel in brittle-plastic or perfectly plastic media. For the brittle-plastic case where closed-formsolution exists, the performance of the present method is verified by showing an excellent agreement between two solutions. In order to demonstrate the strain-softening behaviors predicted by the proposed method. a parameter study for a softening index is given and the construction of ground reaction curves is carried out. The importance of defining the characteristics of dilation in plastic analysis is discussed through analyzing the displacements near the surface of tunnel.

• Journal of the Korea Computer Graphics Society
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• v.23 no.3
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• pp.115-122
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• 2017

As the era of the fourth industrial revolution began, augmented reality showed infinite possibilities throughout society. However, current augmented reality systems such as head-mount display and hand-held display systems suffer from various problems such as weariness and nausea, and thus space-augmented reality, which is a projector-based augmented reality technology, is attracting attention. Spacial augmented reality requires precise tracking of dynamic objects to project virtual images in order to increase realism of augmented reality and induce user 's immersion. The infrared sensor-based precision tracking algorithm developed in this paper demonstrates very robust tracking performance with an average error rate of less than 1.5% and technically opens the way towards advanced augmented reality technologies such as tracking for arbitrary objects, and Socially, by easy-to-use tracking algorithms for non-specialists, it allows designers, students, and children to easily create and enjoy their own augmented reality content.