• Journal of the Korea Society of Computer and Information
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• v.26 no.6
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• pp.97-105
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• 2021

In this paper, we propose BCON, a service that allows individuals to store personal contents safely, and reliably guarantee their ownership of contents, certifying their identities with DIDs(Decentralized identifiers). DID technology, which supports decentralized identification service based on a blockchain that cannot forgery or alter data, allows users to selectively provide their information, controlling personal information and reinforcing their sovereignty over their identity. BCON stores information about the content specified by a user on the blockchain and Authenticates the user's identity based on DID technology. It also provides functions for the user to safely upload and download the user's content to a distributed database. BCON consists of the content service verifier, the content storage service, the content management contract, and the user application, administrating rhe DID registry for Authority management.

• Korean Journal of Community Nutrition
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• v.28 no.5
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• pp.392-403
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• 2023

Objectives: This study was intended to investigate adults' health behaviors and eating habits according to their levels of social media use. Methods: From May 27 to July 11, 2022, an online survey was conducted of 452 male and female social media users in their 20s and 30s, and their eating habits and health behaviors were compared and analyzed according to their degree of social media use. For each of the three levels of food content use, the frequency of social media content use, and the total score range of average social media viewing time per day were divided into three parts, and a group with a score of less than 2 points was classified as low-use; a group with a score of 2 or more and less than 3 points was classified as middle-use; and a group with a score of 3 points or more was classified as high-use. Results: The use of food content was higher in women than in men (P < 0.001), and higher in those in their 20s than in those in their 30s (P < 0.001). The group with a high level of food content use showed a higher rate of post-use hunger than the group with a low level (P < 0.01). The experience of eating after using food content was also higher in the group with a high level of use than in the group with a low level of use (P < 0.001). The group with a normal or high level of food content use had more negative eating habits than the group with a low level. Conclusions: The study highlighted the need to provide desirable food content to people in their 20s and 30s with negative eating habits and to promote them so that they can use the right healthy nutrition-related content.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.791-794
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• 1999

Exact estimation of cement content in a hardened concrete can provide useful data to evaluate the quality and strength of the concrete and might be used to inspect the quality of precast concrete secondary products. Observation obtained in this research included : (1) the volume of coarse aggregate in the hardened concrete measured by the area comparison method has a high accuracy ; (2) the cement content in the mortar and the X-ray intensity of Ca-K$\alpha$ have a correlation factor of 0.96 ; (3) the cement content in the ready mixed concrete was estimated with high accuracy such as correlation factor of 0.99 and standard deviation of 0.64.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.391-394
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• 2003

Effects of the polymer-binder ratio and slag content on the properties of combined wet/dry-cured polymer-modified mortars using granulated blast-furnace slag are examined. Results shows that the flexural, compressive, tensile and adhesion in tension strengths of polymer-modified mortar using the slag tend to increase with increasing slag content, and is inclined to increase with increasing polymer-binder ratio. In particular, the polymer-modified mortars with slag content of 40% provide about 20% higher tensile strength than unmodified mortars. Such high strength development is attributed to the high tensile strength of polymer and the improved bond between cement hydrates and aggregates because of the addition of polymer.

• Journal of Korea Multimedia Society
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• v.20 no.6
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• pp.918-926
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• 2017

Various types of media services are emerging due to the development of Internet and digital media production and distribution technologies. Various DRM technologies are being developed to prevent illegal copying of media contents and to protect the rights of content creators. There is a problem that the DRM provider and the content service provider must provide services in a mutually dependent manner through individual contracts. In this paper, we propose a cloud-based DRM market system which can be used only by content service providers when necessary for various DRM. The DRM market system is expected to show the effect of service activation for related small and medium sized companies by providing an interface that satisfies the requirements of DRM providers and contents service providers by using multi DRM technology.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.645-650
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• 2003

The purpose of this study is to provide the optimum mix design of cold weather concrete to be placed at the foundation structures in substation. The basic performance tests including slump and slump flow, air content, compressive strength and freezing & thawing resistance were conducted for cold weather concrete by varying with W/C ratios such as 40%, 50% and 60% and air contents such as 3%, 4%, 5% and 6%. The effect on durability of concrete corresponding to the increasing amount of air content and W/C ratio was evaluated and the optimum mix design was recommended. From this study, the concrete mix design containing 6% of air content and 45% of W/C ratio is recommended for the foundation concrete of substation.

• Korean Journal of Child Studies
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• v.22 no.2
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• pp.219-235
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• 2001

The purpose of this study was to provide guidelines for the effective operation of Web-Based Training (WBT) for early childhood teachers. Based on content analysis and questionnaires administered to the 174 current trainees, this research analyzed (1) the educational effectiveness and learner satisfaction, (2) the operation and management, and (3) the system, interface, interaction and communication, motivation and content design of $WBT^{***}$. Results showed that most trainees were very satisfied with the WBT because the program provided plentiful professional information enabling them to pursue their educational objectives along with flexibility of time and space. On the other hand, system stability, communication, motivation, and content design need to be improved. Based on the research results, 8 strategies of effective management of web-based early childhood teacher training were proposed.

• Journal of Korean Library and Information Science Society
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• v.18
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• pp.269-300
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• 1991

Reviewing the outcomes of studies on contemporary information science during some periods and identifying the research area exposed in its studies are essential processes to develop the research and theories of information science and to establish the academic identity of information science. This study seeks to provide the some useful methodological approaches for establishing the research area of information science. The methodological approaches to research area of information science are as follows : (1) normative approach by concepts, definitions, and principles of information science, (2) content analysis of text books, (3) content analysis of curricula of graduate courses, (4) content analysis of graduate disserations or treatises, (5) IIS(Institute of Information Scientists)'s criteria for information science, (6) professors' need assessment, (7) interdisciplinary approach, etc. These are the representative types of methodological approach and have an enough validity and effectiveness in their own way. Therefore I think of that those should be integrately applied to establishing the academic identity of information science.

• Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.172-176
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• 2008

To develop a potent strain for the production of coenzyme $Q_{10}$, a photosynthetic bacterium was isolated from silt of the Nakdong River in Korea. Using l6S-rDNA sequence analysis, the isolated strain was identified as Rhodobacter sphaeroides. A stable improvement in its $CoQ_{10}$ content was achieved by chemical mutation, upon which the content of $CoQ_{10}$(2.94 mg/g dry cell) was increased by approximately 1.9-fold, comparable to that of R. sphaeroides reported in other studies. The isolate is a potentially valuable microorganism for mass production of $CoQ_{10}$, and may provide an appropriate model for further study of economical mass production.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.405-406
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• 2017

With the advance of ICT technology, E-Commerce is getting popular and used widely in daily life. Nowaday's commercial videos are also being used extensively to introduce commercial products to consumers. Most commercial companies are advertising their products on the internet with images and videos through online sharing sites. Putting pre-recorded videos online is easy, but it is difficult for sellers to interact with customers. Live Streaming is the transmission of digital content directly to the Internet in real time. Although there are many services available that provide live streaming on the internet, most are limited in the content they transmit. Building live streaming servers using open source projects will help users master the content which conveys to their customers. In this paper, we will consider implementation of Live Streaming Server for Video Commerce using Open Source.