• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.4
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• pp.216-221
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• 2024

Objectives: This study aimed to develop and validate a model to predict the need for intensive care unit (ICU) admission in patients with dental infections using an automated machine learning (ML) program called H2O-AutoML. Materials and Methods: Two models were created using only the information available at the initial examination. Model 1 was parameterized with only clinical symptoms and blood tests, excluding contrast-enhanced multi-detector computed tomography (MDCT) images available at the initial visit, whereas model 2 was created with the addition of the MDCT information to the model 1 parameters. Although model 2 was expected to be superior to model 1, we wanted to independently determine this conclusion. A total of 210 patients who visited the Department of Oral and Maxillofacial Surgery at the Dankook University Dental Hospital from March 2013 to August 2023 was included in this study. The patients' demographic characteristics (sex, age, and place of residence), systemic factors (hypertension, diabetes mellitus [DM], kidney disease, liver disease, heart disease, anticoagulation therapy, and osteoporosis), local factors (smoking status, site of infection, postoperative wound infection, dysphagia, odynophagia, and trismus), and factors known from initial blood tests were obtained from their medical charts and retrospectively reviewed. Results: The generalized linear model algorithm provided the best diagnostic accuracy, with an area under the receiver operating characteristic values of 0.8289 in model 1 and 0.8415 in model 2. In both models, the C-reactive protein level was the most important variable, followed by DM. Conclusion: This study provides unprecedented data on the use of ML for successful prediction of ICU admission based on initial examination results. These findings will considerably contribute to the development of the field of dentistry, especially oral and maxillofacial surgery.

• Journal of Periodontal and Implant Science
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• v.54 no.3
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• pp.161-176
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• 2024

Purpose: Peri-implant mucositis (PIM) and peri-implantitis (PI) are multicausal conditions with several risk factors contributing to their pathogenesis. In this study, we retrospectively investigated risk variables potentially associated with these peri-implant diseases (PIDs) over a follow-up period of 1 to 18 years. Methods: The study sample consisted of 379 implants placed in 155 patients. Single-visit clinical and radiographic evaluations were employed to determine the presence or absence of PIDs. Parameters related to the patient, site, surgery, implant, and prosthetic restoration were documented. The relationships between risk variables and the occurrence of PIDs were individually examined and adjusted for confounders using multivariate binary logistic regression models. Results: The prevalence rates of PIM and PI were 28.4% and 36.8% at the patient level and 33.5% and 24.5% at the implant level, respectively. Poor oral hygiene, active gingivitis/periodontitis, preoperative alveolar ridge deficiency, early or delayed implant placement, implant length of 11.0 mm or less, and poor restoration quality were strong and independent risk indicators for both PIDs. Furthermore, a follow-up period of more than 5 years and a loading time of more than 4 years were important indicators for PI. Simultaneously, age and smoking status acted as modifiers of the effect of mesiodistal (MD) and buccolingual (BL) widths of restoration on PI. Conclusions: In this study population, oral hygiene, periodontal status, preoperative alveolar ridge status, implant placement protocol, implant length, and the quality of coronal restoration appear to be robust risk indicators for both PIM and PI. Additionally, the length of follow-up and functional loading time are robust indicators of PI. Furthermore, the potential modifying relationships of age and smoking status with the MD and BL widths of restoration may be crucial for the development of PI.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.4
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• pp.14-22
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• 2012

The position, size and landscape of the former Donam SeoWon as well as the physical organization of the old site, are studied to extract data for the enhancement of the authenticity of Donam SeoWon since its registration as a world heritage site. The results are as follows. The 'Donam(豚巖)' encaved rock, the tombstone of teacher Sagye(沙溪), Kimjipsadang(金集祠堂), the head of the Gwangsan Kim family, the Sagye stream in front of them, and the Gyeryong and Daedun mountains in the distance are united in the former Donam SeoWon as landscape elements that clearly show the characteristics of the former site, which was called 'Donam-Wollim(豚巖園林).' Moreover Yangseongdangsipyoung(養性堂十詠), adds the garden elements of a medical herb field, twins pond, a bamboo forest, a school, and a peach field. On this site, one can also engage in activities that are related to the land and are closely related to Neo-Confucianism such as fish watching, conferencing, visit in seclusion(訪隱), looking for monks, and overseeing farming. The former site facing east is assumed to have Sau(祠宇) - Eungdodang(凝道堂) - Ipdeokmum(入德門) - Sanangru(山仰樓: estimated). Jeonsacheong seems to have been located to the left of the Sau area, Yangseongdang, which contained upper and lower twin lotus ponds, on the right and was surrounded by various plants. As it has been used as a lecture hall for the past 250 years, the former Donam SeoWon, located 1.8km away from the current area, must be preserved, and the landscape should be formed to establish the authenticity of Donam SeoWon.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.3
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• pp.80-91
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• 2017

This study identifies factors of Hanbok-trippers - a term for people who dress in Hanbok(Korean traditional costume) while going on a trip - who converge on Gyeongbokgung Palace by determining the characteristics of class, places to visit and preferred places. This study interprets the voluntary hobby activities of Hanbok-trippers from a viewpoint of a landscape prosumer and the meaning of the urban landscape. As a result of in-depth interviews, on-site survey, and observation surveys focused on Hanbok-trippers, there were various levels of participants. They are classified into three groups - leading group, entry group, temporary-experience group - according to their cognitions, types of Hanbok use, activities, etc. The leading group and entry group are a voluntary hobbyist class due to the ongoing tendencies of their participation. There are differences in the purpose and factors of visiting Gyeongbokgung Palace as a place for a Hanbok-trip. The leading group visited Gyeongbokgung Palace for cultural activities, regular get-together, public relations, and as a gathering place to go neighboring destinations. In this case, the main factors of the visit are the traditional landscape, convenient transportation, chances for traditional culture exhibitions and events in Gyeongbokgung Palace and its neighborhood. The entry group visits Gyeongbokgung Palace because of its traditional landscape and cultural activities nearby. The traditional landscape and many Hanbok-trippers are main factors of visiting Gyeongbokgung Palace for the Temporary-experience group. This study found that Gyeongbokgung Palace has a new sense of place of 'Introductory course of Hanbok-trip', 'Hanbok Playground' because temporary-experience group visits there to experience a Hanbok-trip for the first time. Hanbok-trippers consume places and landscape in actual places offline, producing a new landscape at the same time, and has the characteristics of a 'landscape prosumer' by producing landscape images online through their own personal or social media. Their colorful and voluntary movements contribute to the dynamism of the urban landscape and can become a new cultural asset for the city. The voluntary hobbyist class can be considered a new type of participants in bottom-up planning such as urban regeneration and place marketing. This study has significance in that it conceptualized the 'landscape prosumer' through the voluntary hobbyist class of Hanbok-trippers with the concept of the 'prosumer' that has been studied only in the consumer studies and marketing fields, and has identified the significance of the urban landscape.

• Asia pacific journal of information systems
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• v.18 no.2
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• pp.41-72
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• 2008

The purpose of this study is the investigation of the effects of user participation, network effect, social influence, and usefulness on stickiness and continued use on Internet communities. In this research, stickiness refers to repeat visit and visit duration to an Internet community. Continued use means the willingness to continue to use an Internet community in the future. Internet community-based companies can earn money through selling the digital contents such as game, music, and avatar, advertizing on internet site, or offering an affiliate marketing. For such money making, stickiness and continued use of Internet users is much more important than the number of Internet users. We tried to answer following three questions. Fist, what is the effects of user participation on stickiness and continued use on Internet communities? Second, by what is user participation formed? Third, are network effect, social influence, and usefulness that was significant at prior research about technology acceptance model(TAM) still significant on internet communities? In this study, user participation, network effect, social influence, and usefulness are independent variables, stickiness is mediating variable, and continued use is dependent variable. Among independent variables, we are focused on user participation. User participation means that Internet user participates in the development of Internet community site (called mini-hompy or blog in Korea). User participation was studied from 1970 to 1997 at the research area of information system. But since 1997 when Internet started to spread to the public, user participation has hardly been studied. Given the importance of user participation at the success of Internet-based companies, it is very meaningful to study the research topic of user participation. To test the proposed model, we used a data set generated from the survey. The survey instrument was designed on the basis of a comprehensive literature review and interviews of experts, and was refined through several rounds of pretests, revisions, and pilot tests. The respondents of survey were the undergraduates and the graduate students who mainly used Internet communities. Data analysis was conducted using 217 respondents(response rate, 97.7 percent). We used structural equation modeling(SEM) implemented in partial least square(PLS). We chose PLS for two reason. First, our model has formative constructs. PLS uses components-based algorithm and can estimated formative constructs. Second, PLS is more appropriate when the research model is in an early stage of development. A review of the literature suggests that empirical tests of user participation is still sparse. The test of model was executed in the order of three research questions. First user participation had the direct effects on stickiness(${\beta}$=0.150, p<0.01) and continued use (${\beta}$=0.119, p<0.05). And user participation, as a partial mediation model, had a indirect effect on continued use mediated through stickiness (${\beta}$=0.007, p<0.05). Second, optional participation and prosuming participation significantly formed user participation. Optional participation, with a path magnitude as high as 0.986 (p<0.001), is a key determinant for the strength of user participation. Third, Network effect (${\beta}$=0.236, p<0.001). social influence (${\beta}$=0.135, p<0.05), and usefulness (${\beta}$=0.343, p<0.001) had directly significant impacts on stickiness. But network effect and social influence, as a full mediation model, had both indirectly significant impacts on continued use mediated through stickiness (${\beta}$=0.11, p<0.001, and ${\beta}$=0.063, p<0.05, respectively). Compared with this result, usefulness, as a partial mediation model, had a direct impact on continued use and a indirect impact on continued use mediated through stickiness. This study has three contributions. First this is the first empirical study showing that user participation is the significant driver of continued use. The researchers of information system have hardly studies user participation since late 1990s. And the researchers of marketing have studied a few lately. Second, this study enhanced the understanding of user participation. Up to recently, user participation has been studied from the bipolar viewpoint of participation v.s non-participation. Also, even the study on participation has been studied from the point of limited optional participation. But, this study proved the existence of prosuming participation to design and produce products or services, besides optional participation. And this study empirically proved that optional participation and prosuming participation were the key determinant for user participation. Third, our study compliments traditional studies of TAM. According prior literature about of TAM, the constructs of network effect, social influence, and usefulness had effects on the technology adoption. This study proved that these constructs still are significant on Internet communities.

• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.625-631
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• 2008

We used the visitation aspect of dabbling ducks(Anas spp.) to investigate the estuarine ecosystem of Nakdong River and to compare the data collected during two periods: trom May, 1989 to April 1993 and from May, 2002 to April 2006. Over for the 8 years of field surveys, 356,110 individuals from 11 species of dabbling ducks(Anas spp.) were observed in the Nakdong estuary. In the early 1990s, the average number of species gradually increased from October through November, whereas the highest numbers of species were recorded in October during the second survey period. The average number of individuals recorded during the second period was 2-3 times higher than that observed in the 1990s. Statistical analysis using a t-test indicated that the number of individuals showed significant difference at 5% level between November and February in both the early 1990s and the mid-2000s. During the winter, dabbling ducks select both estuarine wetlands as resting sites and rice paddy as feeding sites. More wintering migrants including ducks would visit to Nakdong river if we provide with enough rice paddy near the estuary. The farmland around Nakdong estuary is used by dabbling ducks as a habitat, we hope it must be conserved thoroughly. CRP(crop reserve program), implemented by the local government of Kangseo-gu, Busan City is effective in conserving rice paddy; therefore, the CRP program need to be continuously applied in the Nakdong river basin.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.887-892
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• 2019

Many researchers have developed a series of vision-based technologies to monitor construction sites automatically. To achieve high performance of vision-based technologies, it is essential to build a large amount and high quality of training image database (DB). To do that, researchers usually visit construction sites, install cameras at the jobsites, and collect images for training DB. However, such human and site-dependent approach requires a huge amount of time and costs, and it would be difficult to represent a range of characteristics of different construction sites and resources. To address these problems, this paper proposes a framework that automatically constructs a training image DB using web crawling techniques. For the validation, the authors conducted two different experiments with the automatically generated DB: construction work type classification and equipment classification. The results showed that the method could successfully build the training image DB for the two classification problems, and the findings of this study can be used to reduce the time and efforts for developing a vision-based technology on construction sites.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.1-11
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• 2017

Interest in all kinds of renewable energies has been highly increased while the micro-small-hydro power(MSHP) development has shown relatively slowly growth because of the negative public recognition about dam site development. It is, however, announced that the micro-SHP shows higher energy conversion efficiency compared to other renewable energies and does not emit any carbon dioxide. Thus, it is concerned about the development and application of micro-SHP as an alternative energy. In this study, the application for Android was exploited with Eclipse to visualize readily the potential realizable amount of hydropower by micro-SHP. With this application, we can select the region from the map, obtain the design discharge of the selected site was calculated with HEC-HMS, presented by U.S. Army of Corp. and perform the simply economic analysis in sequence. Yeongwol in Gangwon-do Province, Korea was chosen as the target area since historically abundant precipitation was found and it is possible to obtain fundamental data from WAMIS. Results from this study could be expanded the whole region of Korea. Also, the initial investment cost would be reduced if the location for micro-SHP would be determined properly, because this application can help us easily select and examine the potential micro-SHP sites without on-the-spot visit.

• Journal of Korean Academy of Nursing
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• v.30 no.3
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• pp.549-559
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• 2000

The purpose of this study was to investigate the correlation between the knowledge and educational needs related to recurrent in coronary artery bypass graft patients as a basis to provide an individual nursing education for the population. The subjects consisted of 110 patients who had coronary artery bypass graft(CABG) at Asan Medical Center in Seoul and Sechong hospital in Buchon. Data was obtained from a knowledge questionnaire and a learning needs questionnaire between November 1998 and February 1999. Data were analyzed using SAS program for Wilcoxon rank sum test and Spearman correlation coefficient. The results were as follows : 1. With regard to the 18 items to measure knowledge, the mean (median) of items 'don't know' was 4.9(4) items. The mean (median) of items answered wrong was 3.2(3) items. The number of items answered 'don't know' tend to show higher in those who had less education, blue color jobs and myocardiac infarction history than in their counter parts. There were higher frequency of items answered 'don't know' in those who had no hypertension 2. With regard to the level of knowledge by questionnaire about CABG, The most "I dont know" (59.1%) highly response was 'He has to be treated with anticoagulant drug to prevent revasculized vessel from obstructing.' The seond highest response (56.4%) was 'If you were hypotensive, the coronary attack would collapse. 'During the hospitalized day, the patient has complete bedrest.' The highest error probability was cholesterol has not to intake.', 'After surgery, the sexual life is need controlled for 1 year. 3. The mean of educational needs was 3.38. With regard to the level of learning needs by sentence about CABG, 'Food that benefit heart disease', 'Recurrence possibility of heart disease', 'Management method of operation site', 'Risk symptom that visit hospital or report immediately' were higher than other sentenses. With regard to the level of learning needs by factor 'food(5 items)', 'disease(9 items)' and 'exercise(3 items)' showed the highest than other factors. The educational needs by patients characteristics tend to show higher in males, under the age of 49, middle or high school degree, previous experience of admission with coronary artery disease, history of myocardial infarction, expierience of PTCA, history of cerebro-vascular accident, previous expierience of smoking than in their counter parts. 4. The number of items answered 'don't know', wrong and correct weren't correlated with the level educational needs. As the results, the number of items answered 'don't know' tend to show higher in those who had less educated, blue color jobs and myocardiac infarction history than in their counter parts. There were higher frequency of items answered 'don't know' in those who had no hypertension .There were higher frequency of items answered 'don't know' on anti-thrombolitic theraphy, hypotension and pain relief. Also there were higher frequency of items answered wrong on bed rest period, cholesterol intake, and sexual life. Educational needs were higher in young age group, had previous experience of procesure and history of other disease. And when we educate CABG patients, education for diet, recurrence possibility of disease, management methods of operation site and risk symptom should be emphasized.

• The Korean Journal of Pain
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• v.29 no.2
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• pp.96-102
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• 2016

Background: It is widely accepted that cervical interlaminar steroid injection (CIESI) is more effective in treating radicular pain than axial neck pain, but without direct comparison. And the differences of effect after CIESI according to MRI findings are inconsistent. In this retrospective study, we evaluated the therapeutic response of CIESI according to pain sites, durations, MRI findings, and other predictive factors altogether, unlike previous studies, which evaluated them separately. Methods: The medical records of 128 patients who received fluoroscopy guided CIESI were analyzed. We evaluated the therapeutic response (more than a 50% reduction on the visual analog scale [VAS] by their second visit) after CIESI by (1) pain site; neck pain without radicular pain/radicular pain with or without neck pain, (2) pain duration; acute/chronic (more than 6 month), and (3) findings of MRI; herniated intervertebral disc (HIVD)/spinal stenosis, respectively and altogether. Results: Eighty-eight patients (68%) responded to CIESI, and there were no significant differences in demographic data, initial VAS score, or laboratory findings. And there were no significant differences in the response rate relating to pain site, pain duration, or MRI findings, respectively. In additional analysis, acute radicular pain with HIVD patients showed significantly better response than chronic neck pain with spinal stenosis (P = 0.04). Conclusions: We cannot find any sole predictive factor of therapeutic response to the CIESI. But the patients having acute radicular pain with HIVD showed the best response, and those having other chronic neck pain showed the worst response to CIESI.