• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.182-190
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• 2007

Statement of problem: Titanium has many advantages of high biocompatibility, physical properties, low-weight, low price and radiolucency, but it is incompatible with conventional dental porcelain due to titanium's oxidative nature. Many previous studies have shown that they used the method of sandblast for surface treatment prior to porcelain application, the researches are processing about the method of acid etching or surface coating. Purpose: The purpose of this research is to study the effect on bond strength of surface roughness between titanium and porcelain with the same surface topography. Material and method: In this study, we evaluated the bond strength by using 3-point bending test based on ISO 9693 after classified 8 groups - group P : polished with #1200 grit SiC paper, group S10 : $1.0{\mu}m$ surface roughness with sandblasting, group S15 : $1.5{\mu}m$ surface roughness with sandblasting, group S20 : $2.0{\mu}m$ surface roughness with sandblasting, group S25 : $2.5{\mu}m$ surface roughness with sandblasting, group S30 : $3.0{\mu}m$ surface roughness with sandblasting, group S35 : $3.5{\mu}m$ surface roughness with sandblasting, group E : $1.0{\mu}m$ surface roughness with HCl etching. Results: Within the confines of our research, the following results can be deduced. 1. In the results of 3-point bending test, the bond strength of sandblasting group showed significant differences from one of polishing group, acid etching group(P<.05). 2. The bond strength of sandblasting groups did not show significant differences. 3. After surface treatments, the group treated with sandblasting showed irregular aspect formed many undercuts, in the SEM photographs. The bond strength of sandblasting group was higher than 25 MPa, the requirement of ISO 9693. Conclusion: In above results, bond strength of titanium and low-fusing porcelain is influenced more to surface aspect than surface roughness. And titanium has clinically acceptable bond strength below surface roughness of $3.5{\mu}m$.

• Journal of the Korean Society of Costume
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• v.64 no.1
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• pp.136-151
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• 2014

This study systematically analyzed types of fashion brand application focusing on accounts created in Korea. While referring to 'Chanel' which has developed a fashion brand app for the first time in August of 2008, not only for App store by Apple Inc. of the greatest market share but also for Android market, the one and only competitor of App store, the study examined cases of fashion brand app in Korea and foreign countries which have been in service till August of 2013 since the year of 2008. To achieve the research goal, the study conducted a literature research and a case review, categorizing the app by their distinctive functions which were Basic Information, SNS, AR, LBS, Entertainment, Mobile Shopping and Live Streaming. As for the first function, Basic Information, it was considered to provide information on a brand such as prices, sizes and colors of products which should be the most fundamental function of a fashion brand. The function would include look book, catalogues, photographs and others of products, helping users of the app with their understanding on images and concepts of the brand. Second, SNS function was considered useful for its mobility and communication and with the help of theirs, the users share fashion information with each other. Third, AR function as in a filed of virtual reality would edit virtual objects to look real in an actual environment. This would eventually offer the users a chance to try for clothes virtually. The fourth function, LBS, would work with GPS to find a store closest from a present location. This would be a help when the users try to find stores holding promotion events or trails while hiking in mountains. The fifth Entertainment function would include all sorts of games and chances for the users to listen to music and keep fashion diaries. The sixth function, Mobile Shopping, would help the users purchase items online via the app as they would not visit a store in person. The seventh function, Live Streaming, would give the users chances to actually see fashion collections in real time, held all over the world in every season. Because of this function, not only fashion experts but also regular people have become able to enjoy the fashion shows. The distinctive characteristics of the fashion brand application discussed in the study will be a useful reference when any relevant fields try to design other new fashion brand application.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.119-123
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• 2010

This experiment was conducted at Sinheung series (fine loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts) in 2007 to 2008 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. Three kinds of green manure crops (hairy vetch, barley, rye) incorporated in soil for rice cultivation. 6.3 kg N $10a^{-1}$, and3.2 kg $P_2O_5$ $10a^{-1}$ were applied to rye and barley plot before rice transplanting. Chemical fertilizers had not been applied to hairy vetch plot. Glomalin concentration, soil bulk density, and porosity were measured in soil from different green manure crops incorporation after rice harvesting in paddy. Soil bulk density and porosity after rice harvesting improved at surface soil of hairy vetch incorporation plot. Degree of water stable aggregates increased all green manure incorporation plots. Glomalin concentrations significantly increased at hairy vetch incorporation treatment. In barley plot, the concentration of glomalin increased at 10-20 soil depth. There were no differences relationship between soil carbon, and glomalin concentration, but relationship between soil aggregate stability, and glomalin concentration significantly positive under green manure crop-rice cropping system. Rice yield decreased at hairy vetch incorporation plot because of field lodging. We suggested that hairy vetch incorporation should be considered about application amount, and water management using rice cultivation because of soil properties changes.

• Korean Journal of Cognitive Science
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• v.21 no.2
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• pp.283-307
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• 2010

In this study, a new open-ended format math testing system for elementary school students has been proposed. This system is an application of the recently proposed Constructive Multiple-choice Testing (CMT) system on math testing. The CMT system is a testing system in which the examinee has to respond to an item twice, first in an open ended format, and then in the multiple choice format. The advantages of this system is that process information can easily be obtained and that the examinee can receive feedback immediately after the test, based on his/her multiple choice responses. This open-ended format math testing system includes the manager mode, which allows the generation of the test items and student account management, and the testing mode, which allows the students to input their solution process using the menu bar and the keyboard. When two groups, one tested using the CMT system and the other tested using the paper and pencil test, were compared, there was no significant difference in average scores between the two groups although the testing time was longer for the group tested using the CMT system. This result suggests that the open-ended format math testing system proposed in this study can be used effectively in the actual classroom setting.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.523-529
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• 2017

This study analyzed the financial information between 2011 and 2014 comparing management performance and utilization of capital and human resources between private non-profit general hospitals and regional public hospitals operated as general hospitals. The purpose of this study was to enhance the productivity for financial independence of regional public hospitals. Comparison analysis variables were value added to the total assets, value added to the productive activity tangible fixed assets, value added to personnel expenses, ratio of value added, and operating margin to revenues. According to the analysis results, regional public hospitals showed lower investment efficiency indicator and higher ratio of value added, as well as significantly lower operating margin-to-revenues compared with private non-profit general hospitals. Moreover, the effect of investment efficiency indicators on operating margin-to-revenues was value added to the productive activity of tangible fixed assets and value added to personnel expenses in regional public hospitals; the value added to personnel expenses in private non-profit general hospitals had a significant effect on the operating margin-to-revenues, the effect of value added to personnel expenses was the greatest. Therefore, it is necessary to asset utilization to the revenue and propriety of human resources to personnel expenses in regional public hospitals.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.391-406
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• 2015

As the individual participation in online news sites proliferates, the importance of online news comments has been increasing. Social comment services which help people leave comments on news articles using their own SNS (social networking site) accounts have gained popularity recently. Using data gathered from an online news site, this study, therefore, (1) identifies factors differentiating social comments from general comments, (2) examines how social comments are significantly different from general comments in terms of each factor, (3) and further validates how the social comments' characteristics vary among different type of SNS. Then, we investigated this study by applying t-test, ANOVA, and Duncan test of SPSS Statistics. Our results provide insights on the significant differences in all the factors between general and social comments. We also found that there is a significant difference between Facebook and Twitter groups among three types of SNS. The findings of this study would help assess the actual benefit of social comment services as they may provide us with several valuable leads to solve the malicious comments issue. Moreover, they would suggest the need to apply this service to other areas, such as online environments in private and public sectors.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.208-223
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• 2020

In the 21st general election held in April 15, 2020, the importance of social media as an election campaigning tool became more prominent when engaged with Corona 19. Therefore, in this study, various studies were conducted to establish SNS strategy as an election campaign tool. This study analyzed the contents of SNS (Facebook, Twitter, YouTube) activities as an election campaign tool to analyze messages on social media messages of candidates Lee Nak-yeon and candidate Hwang Kyo-an of Jongno-gu, Seoul during the 2020 21st National Assembly election. Data collection mainly analyzed posts from each candidate's official account, and the research method used text analysis using the R program. Word cloud, comparative analysis, q-graph analysis, LDA, and STM analysis were used during text analysis. In addition, the analysis result was confirmed to be statistically significant through correlation analysis. As a result of research, candidate Lee Nak-yeon's election includes corona, people, problems, crisis, suffering, and wisdom, which indicates that the crisis caused by corona must be overcome through any means possible. On the other hand, candidate Hwang Kyo-an's election includes Moon Jae-in, the regime, save, the fatherland, the judge, and the economy. And from the perspective of political publicity, candidate Lee Nak-yeon made a lot of acclaims, while candidate Hwang Kyo-an made a lot of attacks, and both themes emphasized the policy rather than the image.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.93-101
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• 2017

This study investigate the effect of each type of search volume on the number of Facebook fans and the number of tourists. According to the hierarchy effect model, the effect of communication appears to be the sequentiality of cognition-attitude-behavior. Applying this theory, this study predicted that when consumers who have higher involvement and knowledge on specific cities through search behavior, they will be more active in information search through Facebook fan page subscription and will lead to direct tourism behavior. To verify the prediction, we examined the influences among search volume of Seoul shown in Google Trend, the number of fans of official facebook page named 'Seoul Korea', and the number of foreign tourists. As a result, the type of search keyword was divided into four categories: tourism attraction keyword, natural environment keyword, symbolic keyword, and accessibility keyword. The regression analysis showed that tourism attraction keyword and symbolic keyword have influence on Facebook fanpage 'Like'. In addition, facebook fanpage fan size have mediation effect between search volume and number of tourists. All in all, it would be useful to appeal to foreign tourists with a message that emphasizes tourism attraction and Korea-related contents.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.791-801
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• 2010

Forest soil carbon model is a useful tool for understanding complex soil carbon cycle in forests and estimating dynamics of soil carbon to climate change. However, studies on development and application of the model are insufficient in Korea. The need for development of Korean model is now growing, because there are notable problems and limitations for adapting overseas models in Korea to meet the requirements of the international organizations such as IPCC, which demands highly reliable data for national reports. Therefore, we have studied 7 overseas forest soil carbon models (CBM-CFS3, CENTURY, Forest-DNDC, ROMUL, RothC, Sim-CYCLE, YASSO), analyzed and compared their structure, decomposition mechanism, initializing process and, input and output data. Then we evaluated applicability of these models in Korea with three criteria; availability of input data, performance of model, and possibility of regional modification. Finally, a systematic process for applying a new model was suggested based on these analyses.

• Journal of the Korean Society of Radiology
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• v.1 no.2
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• pp.13-22
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• 2007

The purpose of this study was to survey a development of the wireless transmission system of medical images for ubiquitous medicine. There have been many changes in medical equipments and medical record medical treatment and medical record within hospital and PACS(Picture Archiving Communication System) which is picture management system for patients can be typical cases. It is difficult to use these automated medical systems unless they are within hospital and in case of rapid image reading in the emergency cases or in absence of doctor, it is difficult to perform it immediately. The present study implemented an image transmission system using CDMA connection so that images in the server can be viewed at any time and in any place. Remote wireless diagnosis based on medical images using PDA is applicable to medical areas that require mobility, and the use of PDA can be an ideal alternative for point of care. The use of PDA enables prompt and accurate access to digital medical images, which in turn reduces medical accidents and improves the quality of medical services through high productivity and efficiency of medical practitioners' works. It also enables quick response to patients' demands and high-quality medical services and, consequently, patients' high satisfaction.