• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.551-559
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• 2006

The purpose of this study was to find out morbidity rate and pattern of disease and affect of variables related disease and medical management of seafares'. The subjects this study were 1049 seafares' were took education in Korea Institute of Maritime and Fisheries Technology. This questionnaire was focused on finding the basic data for prevention of disease and promotion health for the seafares'. The collected data were analyzed by using descriptive statistics, Chi-square, cross tab, linear regression by SPSS 10.1 package. The result of this study are as follow. 1)The morbidity rate within recent 12 months was 69.0%. 2)there were significant differences qf occurred disease in age(p<0.05), income(p<0.01), career of ship on board(p<0.01), rank(p<.01), perceived health status(p<0.01), worry of health(p<0.01), fatigue symptoms(0.01), satisfy of job(p<0.05), rest time(p<0.05) 3) Considering disease unable to work more than 4 hour, the number of those who had oral disease 7.3%> tinea 6.6%> gastric ulcer 6.4, and musculoskeletal disease group were 20.9%, which revealed the highest rate oral disease 13.6%> skin disease> 12.4%, digestive disease> 12.1%. 4) As refer to medical management, The pain above 31days 35.7%, hospitalization and treatment below 7days were each 50.2%, 42.8%, medical service were doctor's office 27.9, which revealed the highest rate.

• Journal of Venture Innovation
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• v.3 no.1
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• pp.101-115
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• 2020

In the era of the 4th Industrial Revolution customers living began to come out, not inside the purchase funnel. Due to the diversity of product selection and the increase in digital channels, the way customers search for information and purchase it is changing innovatively. So, the customer journey in the digital age is much more complicated than the traditional funnel model suggests. Unlike many previous studies, this study was conducted for 1,200 customers in four product groups of fashion, automobile, cosmetics, and online shopping malls. As a result of the study, we investigated how digital self-efficacy plays a role in purchasing in a series of processes in which digital experience affects customer satisfaction and finally affects purchase. As a theoretical implication, as a result of introducing and testing digital self efficacy as moderated mediation effect. the digital self-efficacy between customer satisfaction and customer loyalty were determined to play a moderated mediation effect role. As a practical implication, it was necessary to actively utilize digital marketing for customers with high digital self-efficacy, but it was suggested that customers with low digital self-efficacy need to be careful about digital marketing fatigue.

• Composites Research
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• v.24 no.1
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• pp.45-50
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• 2011

Transparent and conductive carbon nanotube on polyethylene terephthalate (PET) were prepared by dip-coating method for self-sensing multi-functional nanocomposites. The changes in the electrical and optical properties of CNT coating mainly depended on the number of dip-coating, concentration of CNT solution. Consequently, the surface resistance and transmittance of CNT coating were sensitively controlled by the processing parameters. Surface resistance of CNT coating was measured using four-point method, and surface resistance of coated CNT could be better calculated by using the dual configuration method. Optical transmittance of PET film with CNT coating was evaluated using UV spectrum. Surface properties of coated CNT investigated by wettability test via static and dynamic contact angle measurement were consistent with each other. As dip-coating number increased, surface resistance of coated CNT decreased seriously, whereas the transmittance exhibited little lower due to the thicker CNT networks layer. Interfacial microfailure properties were investigated for CNT and indium tin oxide (ITO) coatings on PET substrates by electrical resistance measurement under cyclic loading fatigue test. CNT with high aspect ratio exhibited no change in surface resistance up to 2000 cyclic loading, whereas ITO with brittle nature showed a linear increase of surface resistance up to 1000 cyclic loading and then exhibited the level-off due to reduced electrical contact points based on occurrence of many micro-cracks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.421-432
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• 2020

This study was designed to determine the Internet game and smartphone usage status of senior elementary school students. Data were collected from 6 October 2018 to 30 September 2019, and 1618 subjects were analyzed using SPSS 18.0. As a result of the study, the I-GUESS rating was 6.1% in the high-risk group, and, the S-scale ratios were 10.1% for the potential-risk group and 0.8% for the high-risk group. Physical problems related to Internet games and using smartphones were experienced by 36.0% of the students, with eye fatigue being the highest at 20.4%. Emotional problems were found in 18.5% of the students, with anger being the highest at 6.8%. Social problems were experienced by 21.8% of the students, conflicts with parents being the highest at 10.3%. As a result of surveying the main content based on S-scale and I-GUESS, it was found that the higher the S-scale ratio and the I-GUESS rating, the more broadcast content was used. The correlation between I-GUESS rating and S-scale ratio showed that the higher the I-GUESS rating, the higher the S-scale ratio, and the higher the S-scale ratio, the higher the I-GUESS rating. Future research is necessary to develop an intervention program for elementary school students from a preventive perspective.

• Knowledge Management Research
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• v.21 no.3
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• pp.177-195
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• 2020

The social consciousness on fake reviews has triggered researchers to suggest ways to cope with them by analyzing contents of fake reviews or finding ways to discover them by means of structural characteristics of them. This research tried to collect data from blog posts in Naver and detect habitual patterns users use unconsciously by variables extracted from blogs and blog posts by a machine learning model and wanted to use the technique in predicting fake reviews. Data analysis showed that there was a very high relationship between the number of all the posts registered in the blog of the writer of the related writing and the date when it was registered. And, it was found that, as model to detect advertising reviews, Random Forest is the most suitable. If a review is predicted to be an advertising one by the model suggested in this research, it is very likely that it is fake review, and that it violates the guidelines on investigation into markings and advertising regarding recommendation and guarantee in the Law of Marking and Advertising. The fact that, instead of using analysis of morphemes in contents of writings, this research adopts behavior analysis of the writer, and, based on such an approach, collects characteristic data of blogs and blog posts not by manual works, but by automated system, and discerns whether a certain writing is advertising or not is expected to have positive effects on improving efficiency and effectiveness in detecting fake reviews.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.19-27
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• 2006

The purpose of this study was to find of morbidity rate and pattern of disease and affect of variables related disease and medical management of seafares' The subjects this study were 1049 seafares' who took education in Korea Institute of Maritime and Fisheries Technology. This questionnaire was focused on finding the basic data for prevention of disease and promotion health for the seafares' The collected data were analyzed by using descriptive statistics, Chi-square, cross tab, linear regression by SPSS 10.1 package. The result of this study are as follow. 1)The morbidity rate within recent 12 months was 69.0%. 2)there were significant differences of occurred disease in age(p<0.05), income(p<0.01), career of ship on board(p<0.01), rank(p<0.01), perceived health status(p<0.01), worry of health(p<0.01), fatigue symptoms(0.01), satisfy of job(p<0.05), rest time(p<0.05) 3) Considering disease unable to work more than 4 hour, the number of those who had oral disease 7.3%> tinea 6.6%> gastric ulcer 6.4, and musculoskeletal disease group were 20.9%, which revealed the highest rate oral disease 13.6%> skin disease> 12.4%, digestive disease> 12.1%. 4) As refer to medical management, The pain above 31days 35.7%, hospitalization and treatment below 7days were each 50.2%, 42.8%, medical service were doctor's office 27.9, which revealed the highest rate.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.335-341
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• 2019

Purpose: Chemically strong-acids (HF and $HCl/H_2SO_4$) dual etching implant surfaces have higher strengths of osseointegration than machined implant surfaces. However, the dual acid treatment deteriorates the physical properties of the titanium by weakening the fatigue resistance of the implant and causing microcracks. The removal torque comparison between the dual-acid etched (hydrochloric acid, sulfuric acid, HS) and single-acid etched implants (hydrochloric acid, H) could reveal the efficiency of implant surface acid treatment. Materials and methods: Nine $3.75{\times}4mm$ dual-acid etched SLA implants and nine single-acid etched SLA implants were inserted into New Zealand rabbit tibias. After 10 days, removal torque, roughness, and wetting angle were measured. Results: Mean removal torque values were as follows: Mean removal torque were 9.94 Ncm for HS group and 9.96 Ncm for H group (P=.995). Mean surface roughness value were $0.93{\mu}m$ for HS group and $0.84{\mu}m$ for H group (P=.170). Root mean square roughness (RSq) values were $1.21{\mu}m$ for HS group and $1.08{\mu}m$ for H group (P=.294), and mean wetting angle values were $99^{\circ}$ for HS group and $98^{\circ}$ for H group (P=.829). Statistical analysis showed no significant difference between the removal torques, roughness, or wetting angles of the two groups. Conclusion: In this experiment, we found no significant difference in removal torque, roughness, or wetting angle between dual-acid etched and single-acid etched implants.

• Management & Information Systems Review
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• v.38 no.2
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• pp.165-182
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• 2019

This study investigated the consumer acceptance process of the fourth industrial revolution new product to be introduced into the market in the future. The 4th Industrial Revolution new products are technological advances compared to the existing ones. The technology acceptance model that was used in the past has been modified to reflect variables like the social effects of the 4th Industrial Revolution, expected experience, and perceived risk. Modified models were proposed and verified. Six representative new products of the 4th Industrial Revolution were selected and examined by 40 respondents, and the hypotheses were verified using programs such as SPSS and AMOS. And conclusions and implications are as follows. First, the innovativeness of the fourth industrial revolution new products influences positive evaluation factors such as expected experience and perceived usefulness and it also affect positively to the perceived risk. In addition, the expected experience of the fourth industrial revolution new products has a great effect on the perceived usefulness and social influence, but it didn't affect to the perceived risk. Like the results of the TAM model, purchase intention of the fourth industrial revolution new products are strongly influenced by perceived usefulness. Finally, the perceived risk of the new product of the 4th Industrial Revolution had no statistically significant effect on the purchase intention, and the social influence of the 4th Industrial Revolution had a significant effect on the purchase intention. In general, respondents are highly aware of the social impact of the Fourth Industrial Revolution and seem to be very positive in this respect.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.3
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• pp.147-153
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• 2013

There exist various types of the WEC (Wave Energy Converter), and among them, the point absorber is the most popularly investigated type. However, it is difficult to find examples of systematically measured data analysis for the design of the point absorber type of power buoy in the world. The study investigates the wave load acting on the point absorber type resonance power buoy wave energy extraction system proposed by Kweon et al. (2010). This study analyzes the time series spectra with respect to the three-year wave data (2002.05.01~2005.03.29) measured using the pressure type wave gage at the seaside of north breakwater of Hupo harbor located in the east coast of the Korean peninsula. From the analysis results, it could be deduced that monthly wave period and wave height variations were apparent and that monthly wave powers were unevenly distributed annually. The average wave steepness of the usual wave was 0.01, lower than that of the wind wave range of 0.02-0.04. The mode of the average wave period has the value of 5.31 sec, while mode of the wave height of the applicable period has the value of 0.29 m. The occurrence probability of the peak period is a bi-modal type, with a mode value between 4.47 sec and 6.78 sec. The design wave period can be selected from the above four values of 0.01, 5.31, 4.47, 6.78. About 95% of measured wave heights are below 1 m. Through this study, it was found that a resonance power buoy system is necessary in coastal areas with low wave energy and that the optimal design for overcoming the uneven monthly distribution of wave power is a major task in the development of a WEF (Wave Energy Farm). Finding it impossible to express the average spectrum of the usual wave in terms of the standard spectrum equation, this study proposes a new spectrum equation with three parameters, with which basic data for the prediction of the power production using wave power buoy and the fatigue analysis of the system can be given.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.4
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• pp.599-604
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• 1998

We have investigated Pt and $RuO_2$ as a bottom electrode for ferroelectric capacitor applications. The bottom electrodes were prepared by using an RF magnetron sputtering method. Some of the investigated parameters were a substrate temperature, gas flow rate, RF power for the film growth, and post annealing effect. The substrate temperature strongly influenced the surface morphology and resistivity of the bottom electrodes as well as the film crystallographic structure. XRD results on Pt films showed a mixed phase of (111) and (200) peak for the substrate temperature ranged from RT to $200^{\circ}C$, and a preferred (111) orientation for $300^{\circ}C$. From the XRD and AFM results, we recommend the substrate temperature of $300^{\circ}C$ and RF power 80W for the Pt bottom electrode growth. With the variation of an oxygen partial pressure from 0 to 50%, we learned that only Ru metal was grown with 0~5% of $O_2$ gas, mixed phase of Ru and $RuO_2$ for $O_ 2$ partial pressure between 10~40%, and a pure $RuO_2$ phase with $O_2$ partial pressure of 50%. This result indicates that a double layer of $RuO_2/Ru$ can be grown in a process with the modulation of gas flow rate. Double layer structure is expected to reduce the fatigue problem while keeping a low electrical resistivity. As post anneal temperature was increased from RT to $700^{\circ}C$, the resistivity of Pt and $RuO_2$ was decreased linearly. This paper presents the optimized process conditions of the bottom electrodes for memory device applications.