• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.119-124
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• 2009

Statement of problem: The increasing demand for esthetic restorations has been required developing new materials for tooth colored restoration. Ceromer(Ceramic Optimized Polymer) has some advantages over porcelain, and has gained increasing popularity in restorative dentistry. However, there is little information on the dimensional changes in a clinical restoration in moist conditions. Purpose: This study examined the dimensional changes in Ceromer restorations with a clinical crown shape that were fabricated in a clinical manner. Material and methods: The crowns for the maxillary central incisor were fabricated with two Ceromers($BelleGlass^{(R)}$ and $Targis^{(R)}$) using a similar clinical restoration manufacturing technique. A total of twenty specimens were prepared and immersed in distilled water at room temperature to allow for water absorption. The weight, height and width were measured at 24, 72 and 168 hours. The accumulated ratios of the changes were calculated and evaluated using a paired t-test and an independent independent t-test. Results: The dimensions and weight increased with increasing soaking time. $Targis^{(R)}$ showed significant differences in height and weight between 24 hours and the other times(P<.05). $BelleGlass^{(R)}$ showed significant differences in width and weight between 24 hours and the other times. The two materials showed different changing patterns of the dimensions but there were no statistically significant differences between them. Conclusion: The dimensions and weight of the Ceromer restorations were changed by water absorption. The clinical crown shaped specimen showed more complicated dimensional changes than the simplified specimens.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.991-1002
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• 2004

Online game business has emerged as the most lucrative entertainment industry, with over 20 million platers. The popularity of online games can be attributed to the presence of numerous PC Bangs around the country, which have pushed online games into the mainstream culture while broadband internet services facilitated online game play. The age distribution of online game players is expanding and a variety of new games are under development to target certain age groups. While the online game market continues to expand, with many new online game publishers entering the market, relatively little is known about which factors are strategically important for successful development of online games. A conceptual framework is proposed, and a structural equation modeling, for Identifying the factors affecting the market success of online games, is developed. The concept of online game community, idea generation, systematic development strategy, flexible development process, utilizing demo-version, outsourcing, etc, are ail introduced into the model, as the independent variables affecting the success level of online games directly and indirectly. Based on data collected from questionnaire survey, the validity of the model has been tested and interesting conclusions have been developed concerning the relationships between these variables. Statistical results show that utilizing online game community and system atic development strategy is the key for successful online game development. Other interesting results concerning game development strategy are also provided. It is hoped that this result might provide the useful guidelines for developing the successful online game contents. With a better understanding of key success factors, online game developers should be able to make adjustments in their development and marketing plans, providing them with a sustainable advantage over their competition.

• Informatization Policy
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• v.29 no.3
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• pp.82-104
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• 2022

One of the interesting social phenomena in short-form video platforms is the hashtag challenge wherein ordinary users are encouraged to create by imitating short viral videos on a particular theme. Despite the increasing popularity of hashtag challenges, theoretical discussion on related user behavior is still very insufficient. In this study, we attempted to examine the impact of micro-influencers in order to understand users' willingness to participate in hashtag challenges. For this purpose, the para-social interaction theory and imitation behavior literature were adopted as key theoretical basis. In an empirical investigation using 243 survey data from TikTok users, our study found that a user's illusion of intimacy with a micro-influencer (i.e., para-social interaction) had significant positive impact on the intention to participate in a hashtag challenge. This study also showed that the degree of para-social interaction in a short-form video platform was determined by both media content-related factors and media character-related factors (i.e., content attractiveness, physical attractiveness, and attitude homophily). Our work in this study provided significant theoretical and practical implications on how to leverage micro-influencers for the success of hashtag challenges in a short-form video platform.

• Journal of Internet Computing and Services
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• v.13 no.3
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• pp.115-126
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• 2012

Mashups have become very popular over the last few years, and their use also varies for IT convergency services. In spite of their popularity, there are several challenging issues when combining Open APIs into mashups, First, since portal sites may have a large number of APIs available for mashups, manually searching and finding compatible APIs can be a tedious and time-consuming task. Second, none of the existing portal sites provides a way to leverage semantic techniques that have been developed to assist users in locating and integrating APIs like those seen in traditional SOAP-based web services. Third, although suitable APIs have been discovered, the integration of these APIs is required for in-depth programming knowledge. To solve these issues, we first show that existing techniques and algorithms used for finding and matching SOAP-based web services can be reused, with only minor changes. Next, we show how the characteristics of APIs can be syntactically defined and semantically described, and how to use the syntactic and semantic descriptions to aid the easy discovery and composition of Open APIs. Finally, we propose a goal-directed interactive approach for the dynamic composition of APIs, where the final mashup is gradually generated by a forward chaining of APIs. At each step, a new API is added to the composition.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.4
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• pp.421-426
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• 2010

Due to the ease of deployment and the extended coverage, wireless mesh networks (WMNs) are gaining popularity and research focus. For example, the routing protocols that enhance the throughput on the WMNs and the link quality measurement schemes are among the popular research topics. However, most of these works assume that the locations of the mesh routers are predetermined. Since the operators in an Indoor mesh network can determine the locations of the mesh routers by themselves, it is essential to the WMN performance for the mesh routers to be initially placed by considering the performance issues. In this paper, we propose a mesh router placement scheme based on genetic algorithms by considering the characteristics of WMNs such as interference and topology. There have been many related works that solve similar problems such as base station placement in cellular networks and gateway node selection in WMNs. However, none of them actually considers the interference to the mesh clients from non-associated mesh routers in determining the locations of the mesh routers. By simulations, we show that the proposed scheme improves the performance by 30-40% compared to the random selection scheme.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.744-753
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• 2015

This paper presents the results of research on developing marine unified communications to provide VoIP service based on marine satellites. With the recent popularity of smart-phones and other mobile devices, the demand for Internet-based wired and wireless unified technology has been growing in marine environments, and increasing interest is being directed to VoIP products and service models with high price competitiveness and the ability to deliver a variety of services. In this regard, this research designed three instruments, developed their unit modules, and verified their performances. These three instruments included the following: (1) a marine VoIP module equipped with an analogue gateway that can be linked to the existing devices used in vessels, which is more than 80% smaller than that of a land system; (2) a text/voice/video engine for marine satellite communications that runs on technology that minimizes communication data usage, which is a core technology for a marine VoIP service; and (3) a unified communication service that can support multilateral cloud-based message conversations, telephone number-based call functions, and voice/video calling between a private space in a ship and shore.

• Food Science and Industry
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• v.52 no.1
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• pp.40-51
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• 2019

For better understanding the relationship between consumers' perception and sensory characteristics of products, diverse types of rapid sensory profiling technique have been suggested as alternatives to conventional descriptive analysis. Among these, check-all-that-apply (CATA) method has gained popularity for studying consumers' perception and intuitive responses to products due to their simplicity, speed, and ease of use. CATA method has been used to gather consumers' perception derived from sensory characteristics of products as well as consumers' emotion responses to products in recent years. Moreover, many researchers reported that CATA method can be used to provide valuable information for product optimization by applying a penalty analysis and collecting responses to ideal product. Thus, this article reviews recent research using CATA in the field of sensory and consumer science and introduces practical applications to achieve various business objectives in food industry.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.180-190
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• 2022

This study reviews the current status of Korean traditional creative music groups that have entered the North American World Music market. It also explores some success factors and strategies behind the artists' sustainable activities in the region as well as improvements needed for the Korean government's support. For the purpose of realistic suggestions, music groups that have entered the North American World Music market and experts in artists' global activities have been interviewed for analysis. The interview questionnaire consisted of the following items: 1. how the music groups reached the North American market, 2. what made them successful, 3. what strategies they used to perform in the region, 4. what challenges they faced, and 5. how the government support could be improved. The study found the following success factors: the groups' participation in Korean and international music markets, existence of a local agency, uniqueness and popularity of Korean music, and possibility to organize workshops. It also identified the following challenges: absence of lucrative touring plans, complicated visa issuance, and limitations of networking. It is hoped that this research will provide useful information for music groups planning to enter the North American World Music market and that it will make some meaningful policy suggestions to relevant organizations.

• Journal of the Korean association of regional geographers
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• v.1 no.1
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• pp.81-91
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• 1995

Modern geography in France since the end of 19th century was begun with regional geography. France after losing the Franco-Prussian war in 1871 had tried to regain the deteriorated national proudness through the colonial expansion. The social and historical contexts in France had encouraged French geographers to engage in detailed small area studies. In particular, after Blache became a faculty at Sorbonne University his idea on integrative rather than selective description on area studies had gained paradigmatic popularity not only in geography but in other disciplines. The regional geography tradition was then firmly established as a science and as an art by Vidalian school until the beginning of Second World War. However, when industrialization and urbanization were the dominant science since the 1950s spatial analytic geography has become popular research tradition replacing the previledged regional geography. Nevertheless, geography in France is still acknowledged as an interesting and valuable discipline since regional geography tradition had accumulated rich knowledges on various regions. As regional geography provides valuable information and helps to understand various world regions, it should be regenerated as a research tradition which are able to fulfill societal needs accruing nowadays. By doing this, geography can rectify its disciplinary identity which has been disintegrated internally by giving too much emphasis on specialties, and melding into nearby disciplines. Our geography education for the chorography in particular focuses mainly on the listings of simple geographic facts, in this regard. Rather than attracting students' concern and motivation, geography is considered as a subject oriented toward simply memorizing geographic facts. To overcome these problems, regional geography should be discussed openly and popularized in research. Regional geographic methods available and results produced in other countries should be introduced, and critical assessments should be made for selective acknowledgment for nurturing our regional geography.

• The KIPS Transactions:PartD
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• v.18D no.3
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• pp.157-168
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• 2011

Recently flash memory has been being utilized as a main storage device in mobile devices, and flashSSDs are getting popularity as a major storage device in laptop and desktop computers, and even in enterprise-level server machines. Unlike HDDs, on flash memory, the overwrite operation is not able to be performed unless it is preceded by the erase operation to the same block. To address this, FTL(Flash memory Translation Layer) is employed on flash memory. Even though the modified data block is overwritten to the same logical address, FTL writes the updated data block to the different physical address from the previous one, mapping the logical address to the new physical address. This enables flash memory to avoid the high block-erase cost. A flashSSD has an array of NAND flash memory packages so it can access one or more flash memory packages in parallel at once. To take advantage of the internal parallelism of flashSSDs, it is beneficial for DBMSs to request I/O operations on sequential logical addresses. However, the B-tree structure, which is a representative index scheme of current relational DBMSs, produces excessive I/O operations in random order when its node structures are updated. Therefore, the original b-tree is not favorable to SSD. In this paper, we propose AS(Always Sequential) B-tree that writes the updated node contiguously to the previously written node in the logical address for every update operation. In the experiments, AS B-tree enhanced 21% of B-tree's insertion performance.