• The Journal of Advanced Prosthodontics
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• v.10 no.4
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• pp.300-307
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• 2018

PURPOSE. To investigate the fatigue and fracture resistance of computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic molar crowns on dental implants and human teeth. MATERIALS AND METHODS. Molar crowns (n=48; n=8/group) were fabricated of a lithium-disilicate-strengthened lithium aluminosilicate glass ceramic (N). Surfaces were polished (P) or glazed (G). Crowns were tested on human teeth (T) and implant-abutment analogues (I) simulating a chairside (C, crown bonded to abutment) or labside (L, screw channel) procedure for implant groups. Polished/glazed lithium disilicate (E) crowns (n=16) served as reference. Combined thermal cycling and mechanical loading (TC: $3000{\times}5^{\circ}C/3000{\times}55^{\circ}C$; ML: $1.2{\time}10^6$ cycles, 50 N) with antagonistic human molars (groups T) and steatite spheres (groups I) was performed under a chewing simulator. TCML crowns were then analyzed for failures (optical microscopy, SEM) and fracture force was determined. Data were statistically analyzed (Kolmogorow-Smirnov, one-way-ANOVA, post-hoc Bonferroni, ${\alpha}=.05$). RESULTS. All crowns survived TCML and showed small traces of wear. In human teeth groups, fracture forces of N crowns varied between $1214{\pm}293N$ (NPT) and $1324{\pm}498N$ (NGT), differing significantly ($P{\leq}.003$) from the polished reference EPT ($2044{\pm}302N$). Fracture forces in implant groups varied between $934{\pm}154N$ (NGI_L) and $1782{\pm}153N$ (NPI_C), providing higher values for the respective chairside crowns. Differences between polishing and glazing were not significant ($P{\geq}.066$) between crowns of identical materials and abutment support. CONCLUSION. Fracture resistance was influenced by the ceramic material, and partly by the tooth or implant situation and the clinical procedure (chairside/labside). Type of surface finish (polishing/glazing) had no significant influence. Clinical survival of the new glass ceramic may be comparable to lithium disilicate.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1892-1897
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• 2003

A new thermal inkjet printer head on SOI wafer with virtual valve was proposed. It was composed of two rectangular heaters with same size. So we could call it T-jet(Twin jet). T-jet has a lot of merits. It has the advantage of being fabricated with one wafer and is easy to change the size of chamber, nozzle, restrictor and so on. However, above all, It is the best point that T-jet has a virtual valve. And it was manufactured on SOI wafer. The chamber was formed in its upper silicon whose thickness was 40um. The chamber's bottom layer was silicon dioxide of SOI wafer and two heaters were located underneath the chamber's ceiling. And the restirctor was made beside the chamber. Nozzle was molded by process of Ni plating. Ni was 30um thick. Nozzle ejection test was performed by printer head having 56 nozzles in 2 columns with 600NPI(nozzle per inch) and black ink. It measured a drop velocity of 12m/s, a drop volume of 30pl, and a maximum firing frequency of 12KHz for single nozzle ejection. Throwing out the ink drop in whole nozzles at the same time, it was observed that the uniformity of the drop velocity and volume was less than 4%.

• Journal of the Korean Geographical Society
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• v.39 no.6 s.105
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• pp.819-832
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• 2004

Daily rainfall data from 14 stations during 1941 to 2000 were analyzed in order to examine the characteristics of the variation of summer rainfall and the identify relationship between the variation of summer rainfall and the variation of SOI(Southern Oscillation Index) and NPI(North Pacific Index), global temperature. For further investigation, study period is divided into two 30 year intervals, 1941-1970 and 1971-2000. There are the trend of increase in August and decrease in September in the later period compared with the earlier one. It was Mid-west in August where there is the largest variation. It is related to the increase of the frequency of heavy rainfall. The second period of extreme rainfall by ten days is absent, or it change from early in September to late in August. According to the result, the dry spell in August disappears and Changma is continued to early in September. Gradually, there is change from negative (or positive) to positive (or negative) to the rainfall anomaly of the mid of August and the mid of September (or July). The correlation between the variation of rainfall and oceanic variation and global temperature is statistically significant.

• Journal of Korean Academy of Nursing
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• v.25 no.3
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• pp.431-440
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• 1995

The purpose of this study was to compare Korean and American women as to the perception of their newborns, and to assess factors contributing to a positive mother-infant relationships. American mothers were with their own newborns in the same rooms and could feed and take care of them if they wanted, but Korean mothers were separated from their babies. The subjects of this study were 86 Korean and 86 American primiparas within two-three days after delivery. Data were collected from May to August 1993, using the Neonatal Perception Inventory (NPI) devised by Broussard(1963) with additions by Lee, Ja Hyung(1986). The results of this study are as follows : 1. There was a significant difference in the mothers' perceptions of their babies according to mothers' age(P<0.05, P0.01). Mothers of 20 years and downward had negative perceptions of their babies. 2. There was no difference in the methers' perceptions of their babies according to whether they had a job or not. 3. There was a significant difference in the mothers' perceptions of their newborns according to mothers' education level(P<0.01). Mothers graduated from a junior high school had negative perceptions of their babies. 4. There was no difference in the mothers' perceptions according to their feeding pattern. 5. There was a significant difference between Korean mothers' perceptions and American mothers' perceptions of their babies(P<0.01). 69.7% of Korean mothers and 44. l％ of American mothers had positive perceptions. But Korean mothers perceived that it would be more difficult for them to take care of their babies. As seen above, Korean primiparas evaluated their babies higher than Americans. But they perceived that it would be more difficult for them to take care of their babies. The results suggest that there needs a rooming-in system and systematic prenatal educations for the primiparas in Korea.

• Journal of Oriental Neuropsychiatry
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• v.31 no.4
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• pp.301-314
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• 2020

Objectives: The purpose of this study was to provide clinical evidence to support the use of herbal medicine combined with western medicine for BPSD. Methods: Studies were identified by searching CNKI, Pubmed, EMBASE, Cochrane Library, SCIENCEON, RISS, KMbase, KISS, OASIS. Literature searches of Chinese, English, and Korean databases were performed. Two authors independently extracted the data and evaluated the quality of each study. Results: The literature search identified 203 articles. Of these, 7 were selected for the analysis. The risk of bias in most studies was unclear. The most frequently used diagnostic tools were the NINCDS-ADRDA and DSM-IV. The most commonly used results indicator was NPI. In 6 of the 7 papers, combination treatment (herbal & Western medicine) was statistically significantly more effective than single treatment (Western medicine alone) for BPSD. No significant adverse events were reported. Conclusions: Herbal medicine in combination with Western medicine is more effective for treating BPSD than Western medicine alone. However, the quality of the studies used in this study was uncertain and the sample size was too small. Based on the findings of this study, more high-quality clinical trials are needed to confirm the efficacy of combination treatment.

• Journal of Preventive Medicine and Public Health
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• v.55 no.6
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• pp.568-577
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• 2022

Objectives: Many studies have shown that social distancing, as a non-pharmaceutical intervention (NPI) that is one of the various measures against coronavirus disease 2019 (COVID-19), is an effective preventive measure to suppress the spread of infectious diseases. This study explored the relationships between traditional health-related behaviors in Korea and social distancing practices during the COVID-19 pandemic. Methods: Data were obtained from the 2020 Community Health Survey conducted by the Korea Disease Control and Prevention Agency (n=98 149). The dependent variable was the degree of social distancing practice to cope with the COVID-19 epidemic. Independent variables included health-risk behaviors and health-promoting behaviors. The moderators were vaccination and unmet medical needs. Predictors affecting the practice of social distancing were identified through hierarchical multiple logistic regression analysis. Results: Smokers (adjusted odds ratio [aOR], 0.924) and frequent drinkers (aOR, 0.933) were more likely not to practice social distancing. A greater degree of physical activity was associated with a higher likelihood of practicing social distancing (aOR, 1.029). People who were vaccinated against influenza were more likely to practice social distancing than those who were not (aOR, 1.150). However, people with unmet medical needs were less likely to practice social distancing than those who did not experience unmet medical needs (aOR, 0.757). Conclusions: Social distancing practices were related to traditional health behaviors such as smoking, drinking, and physical activity. Their patterns showed a clustering effect of health inequality. Therefore, when establishing a strategy to strengthen social distancing, a strategy to protect the vulnerable should be considered concomitantly.

• Journal of Preventive Medicine and Public Health
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• v.56 no.4
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• pp.377-383
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• 2023

Objectives: Korea and Japan have managed the spread of coronavirus disease 2019 (COVID-19) using markedly different policies, referred to as the "3T" and "3C" strategies, respectively. This study examined these differences to assess the roles of active testing and contact tracing as non-pharmaceutical interventions (NPIs). We compared the proportion of unlinked cases (UCs) and test positivity rate (TPR) as indicators of tracing and testing capacities. Methods: We outlined the evolution of NPI policies and investigated temporal trends in their correlations with UCs, confirmed cases, and TPR prior to the Omicron peak. Spearman correlation coefficients were reported between the proportion of UCs, confirmed cases, and TPR. The Fisher r-to-z transformation was employed to examine the significance of differences between correlation coefficients. Results: The proportion of UCs was significantly correlated with confirmed cases (r=0.995, p<0.001) and TPR (r=0.659, p<0.001) in Korea and with confirmed cases (r=0.437, p<0.001) and TPR (r=0.429, p<0.001) in Japan. The Fisher r-to-z test revealed significant differences in correlation coefficients between the proportion of UCs and confirmed cases (z=16.07, p<0.001) and between the proportion of UCs and TPR (z=2.12, p=0.034) in Korea and Japan. Conclusions: Higher UCs were associated with increases in confirmed cases and TPR, indicating the importance of combining testing and contact tracing in controlling COVID-19. The implementation of stricter policies led to stronger correlations between these indicators. The proportion of UCs and TPR effectively indicated the effectiveness of NPIs. If the proportion of UCs shows an upward trend, more testing and contact tracing may be required.

• The Korean Journal of Woman Psychology
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• v.15 no.3
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• pp.447-468
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• 2010

This study examined whether aggression mediates the effects of seven sub-types of narcissistic personality on psychopathy. It hypothesized that some of narcissistic personality could affect aggression that, in turn, contributes to psychopathy. The sample of this study consisted of 864 college students (451 males and 413 females). The participants completed an assessment battery consisting of Narcissistic Personality Inventory(NPI), Aggression Questionnaire(AQ), and Self-Reported Psychopathy Scale(SRPS). According to the results, narcissistic personality and aggression variables affected psychopathy, and aggression predicted students' psychopathy. The effects of students' narcissistic personality on psychopathy were partly mediated by aggression. The research findings partly supported the hypothesis, and were discussed on gender differences in relation among sub-types of narcissistic personality, aggression, and psychopathy. The implications and limitations of this study were suggested.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2505-2510
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• 2014

Background: The standard radiotherapy (RT) fractionation practiced in India and worldwide is 50Gy in 25 fractions over 5 weeks to the chest wall or whole breast followed by tumour bed boost in case of breast conservation (BCS). A body of validated data exists regarding hypofractionation in breast cancer. We here report initial results for 135 patients treated at our center with the START-B type of fractionation. Materials and Methods: From May 2011 till July 2012, women with all stages of breast cancer (excluding metastatic), who had undergone BCS or mastectomy were planned for 40Gy in 15 fractions over 3weeks to chest wall/whole breast and supraclavicular fossa (where indicated) followed by tumour bed boost in BCS patients. Planning was done using Casebow's technique. The primary end point was to assess the acute toxicity and the cosmetic outcomes. Using cosmetic scales; patients were assessed during radiotherapy and at subsequent follow up visits with the radiation oncologist. Results: Of the 135 patients, 62 had undergone BCS and 73 mastectomy. Median age of the population was 52 years. Some 80% were T1&T2 tumours in BCS whereas most patients in mastectomy group were T3&T4 tumours (60%). 45% were node negative in BCS group whilst it was 23% in the mastectomy group. Average NPI scores were 3.9 and 4.9, respectively. Most frequently reported histopathology report was infiltrating ductal carcinoma (87%), grade III being most common (58%), and 69% were ER positive tumours, and 30% were Her 2 Neu positive. Triple negative tumours accounted for 13% and their mean age was young (43 yrs.) The maximum acute skin toxicity at the end of treatment was Grade 1 in 94% of the mastectomy grouppatients and 71% in BCS patients. Grade 2 toxicity was 6% in mast group and 23% in BCS group. Grade 3 was 6% in BCS group, no grade 3 toxicity in mastectomy patients and there was no grade 4 skin toxicity in any case. Post RT at 1 month; 39% of BCS patients had persisting Grade I skin reaction which was only 2% in mastectomy patients. At 3 months post RT, 18% patients had persisting hyperpigmentation. At 6 months 8% patients had persisting erythema in the BCS group only. Some 3% BCS and 8% mastectomy patients had lymph edema till the date of evaluation. Cosmetic outcome in BCS patients remained good to excellent 6 months post surgery and radiotherapy. 1 patient of BCS and 3 patients of mast had developed metastatic disease at the time of evaluation. Conclusions: Hypofractionated RT is well tolerated in Indian population with reduced acute skin toxicity and good cosmetic outcome. Regimens such as these should be encouraged in other centers to increase machine output time. The study is on-going to assess long term results.

• Journal of Information Management
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• v.42 no.3
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• pp.1-26
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• 2011

The domain of LED is analyzed for describing the current status of Korea's R&D in the domain comparing with those of others quantitatively. Fourteen sub-domains of LED manufacturing technology are selected and the time span for analysis is ten-year: 2001-2010. Bibiliometric analysis is performed by the unit of publication, core researcher, institution and country. Strategical diagram is also produced with devised two indicators: NGI and NPI. As a result, Korea is competitive in the area of Chip Scale Package, but R&D supports in another promising areas, such as large-caliber sapphire wafer, are necessary. It is also revealed that research activities are expanded dominantly in academia, but practical technologies are developed in industrial circle. It is suggested that to support core corporate and to encourage industrial-academic collaboration is essential for systematical technology development and high achievement in prominent areas.