• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.31 no.5
• /
• pp.278-293
• /
• 2019

The joint distribution of wave height and period has been maltreated despite of its great engineering value due to the absence of any analytical model for wave period, and as a result, no consensus has been reached about the effect of nonlinearity on these joint distribution. On the other hand, there was a great deal of efforts to study the effects of non-linearity on the wave height distribution over the last decades, and big strides has been made. However, these achievements has not been extended to the joint distribution of wave height and period. In this rationale, we first express the joint distribution of wave height and period as the product of the marginal distribution of wave heights with the conditional distribution of associated periods, and proceed to derive the joint distribution of wave heights and periods utilizing the models of Longuet-Higgins (1975, 1983), and Cavanie et al. (1976) for conditional distribution of wave periods, and height distribution derived in this study. The verification was carried out using numerically simulated data based on the Wallops spectrum, and the nonlinear wave data obtained via the numerical simulation of random waves approaching toward the uniform beach of 1:15 slope. It turns out that the joint distribution based on the height distribution for finite banded nonlinear waves, and Cavanie et al.'s model (1976) is most promising.

• Phonetics and Speech Sciences
• /
• v.13 no.3
• /
• pp.53-64
• /
• 2021

It is known that the voicing contrast for Japanese word-initial stops is primarily realized as differences in the voice onset time (VOT). However, recent studies have reported that voiced stops are more often produced with a positive VOT than with a negative VOT among the younger generation nationwide. It is also known that post-stop F0 is associated with the stop contrast, but the degree of F0 use differs from region to region. This study explores whether the difference in post-stop F0 functions as a perceptual cue to the stop contrast along with VOT. Fifty-five college students who are native listeners from four different regions participated in two or three perception tests. The results show that VOT is a primary cue to the voiced-voiceless distinction of word-initial stops, but that the effect of post-stop F0 on the stop contrast is marginal. The post-stop F0 is involved in perception only when VOT is ambiguous, such that a sound with high F0 is more often perceived as a voiceless stop, but not vice versa. The results of this study indicate that the acoustic parameters associated with the stop contrast are not the same in production and perception, and suggest that other factors such as context, which is not an acoustic characteristic, may also be involved in the stop contrast.

• Food Engineering Progress
• /
• v.15 no.1
• /
• pp.1-5
• /
• 2011

Codonopsis lanceolata L. (Campanulaceae) has long been used in traditional Korean medicine to treat bronchitis, cough, and inflammatory diseases, however, the efficacy of anti-tumor activities remains to be defined. In this study the effects of Codonopsis lanceolata (C. lanceolata) on proliferation, migration and adhesion in lung (A549, H1299) and ovarian cancer (SKOV-3) cells were investigated. To assess and compare the pharmacological effects and production places of C. lanceolata, the ethanolic extracts of C. lanceolata from different places in Korea (Hongseong, Yecheon, Yeongwol, Yanggu, Gangjin, and Hoengseong) were prepared. The extract from Hoengseong county did have only marginal anti-proliferative activity in all the cell lines tested, however, other extracts had little or no effect on cell proliferation. The extracts from Hongseong, Gangjin or Hoengseong county had partial anti-migratory activity in lung cancer cells, but not in ovarian cancer cells. In addition, the extract from Hoengseong county had partial anti-adhesive activity in ovarian cancer cells, however, other extracts did not affect cell adhesion in both lung and ovarian cancer cells. Taken together, these findings provide the first description of anti-tumor efficacy of C. lanceolata from different production places in Korea, and suggest that C. lanceolata from Hoengseong county may have therapeutic potential in lung and ovarian cancers.

• The Journal of the Korea Contents Association
• /
• v.19 no.1
• /
• pp.293-303
• /
• 2019

The purpose of this research is to investigate the psychological factors affecting job performance of public enterprise employee. Based on the literature review, three types of job performance are identified, which are behavioral responses to the demands from job environment. They are named as task performance, contextual performance, and adaptive performance. As independent variables, four factors were selected form positive psychological concepts, which are self-efficacy, hope, optimism, and resilience. These are the factors which compose of the concept of psychological capital. All the factors are hypothesized to positively affect job performances. From the regression analysis results, all the psychological factors in the model were turned out to have statistically significant impacts on the job performances. The importance of variable 'resilience' were dominant all three models, which might be interpreted as a behavioral response to the demands from uncertain organizational enviornments. From the marginal effect analysis, contextual performance decreases first five years, then reach peak at 20th. year. These results demonstrates that mid-level employees in the organizational hierarchy are more concerned with the overall performance of organization.

• Journal of Korean Academy of Oral Health
• /
• v.42 no.4
• /
• pp.136-144
• /
• 2018

Objectives: The aim of this study is to analyze the differences in factors related to the incidence of dental caries between children in fluoridated and non-fluoridated areas and compared the DMFT and DMFS scores to confirm the effect of water fluoridation program (WFP) in Geoje and Changwon. Methods: The oral health examination and questionnaire survey were conducted in fluoridated and non-fluoridated areas. The number of surveyed children aged 8, 10, and 12 years in the fluoridated and non-fluoridated area of two cities was 1,524 and 1,383, respectively. Self-recorded questionnaires included self-perception of their own dental health, daily toothbrushing frequency, intake frequency of cariogenic sweet snacks and beverages, experience of gingival bleeding, experience of unmet dental treatment, and use of oral hygiene device except for toothbrush and toothpaste. The prevalence of caries and fissure-sealant status were surveyed. The logistic regression analysis was used to analyze the difference in children's self-rated oral health status between the fluoridated and non-fluoridated area. The mean number of sealed teeth and surfaces, marginal means of the DMFT and DMFS scores adjusted for the difference in the samples' sex distribution, and region were compared between the fluoridated and non-fluoridated areas. Results: In the fluoridated area, the experience rate of unmet dental treatments was higher among children aged 10 years, intake frequency of cariogenic sweet snacks and beverages were higher among the whole sample, and experience rate of professional fluoride application were lower than in the non-fluoridated area. The DMFT score for permanent dentition adjusted for differences in sex, region, and mean number of fissure-sealed teeth in the fluoridated area was significantly lower among whole samples and 8-, 10-, and 12-year-olds alone than in the non-fluoridated area. Conclusions: WFP can alleviate oral health inequality because it is effective in reducing the incidence of caries among children is disadvantaged demographic, socioeconomic, and cultural contexts.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.1
• /
• pp.11-17
• /
• 2021

Purpose: This study was to find out whether the rendering screen difference affect to measuring distance in a CAD program according to three types of CAD programs. Materials and methods: The model presented in ISO 12836 for dental scanner evaluation was reduced by 70%. This model was repeatedly scanned 15 times using Trios II (3Shape, Denmark). Using the output STL file, 3Shape CAD, inLab 15, and ExoCAD programs were used to measure the horizontal distance (H) and vertical distance (V) between adjacent point angle, and for each experiment, three groups were set according to the CAD program type. Statistical analysis was performed using One-way ANOVA test and post hoc was performed using Dunnett T3 test. Results: In the horizontal and vertical distance measurement, there was no difference in the average of the measured values between the three groups according to the CAD program (P>.05). Conclusion: There were no effect of the difference in the rendering screen in the horizontal and vertical linear distance measurements of the inlay model on the dental CAD program.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.1
• /
• pp.89-94
• /
• 2023

Recently, credit risk in the Chinese corporate bond market has increased significantly, and there is a possibility that banks that have invested in corporate bonds may become insolvent. The purpose of this study is to empirically analyze the effect of Chinese commercial banks' investment in securities on financial performance. The analysis results are as follows. First, it is estimated that as the share of securities investment by Chinese commercial banks increases, the bank's profitability decreases. It was found that investment in securities did not have a positive impact on profitability due to the increase in credit risk in the corporate bond market and the increase in marginal companies. Second, it is estimated that as the proportion of securities investment by Chinese commercial banks increases, the bank's soundness deteriorates. As credit risk in China's capital market is increasing, continuous management of non-performing assets is required. Chinese commercial banks need portfolio management through securities investment in addition to loan assets to improve profitability. However, volatility should be managed by adjusting the scale of securities management to an appropriate level.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.4D
• /
• pp.323-330
• /
• 2010

The time in port for vessels is one of the important factors for analyzing the operation status and the capacity of ports. In addition, the time in port for vessels can be directly used for estimating the greenhouse gas emissions resulted from vessels in port. However, it is unclear which variables can affect the time in port for vessels and what the marginal effect of each variable is. With these challenges in mind, the study analyzes the time in port for vessels arriving and departing port of Busan by using a parametric survival model. The results show that the log-logistic accelerated failure time model is appropriate to explain the time in port for 19,167 vessels arriving and departing port of Busan in 2008, in which the time in port is significantly affected by gross tonnage of vessels, service capacity of terminal, and vessel type. This study also shows that the greenhouse gas emission resulted from full-container vessels, which accounted for about 61% of all vessels with loading/unloading purpose arriving and departing port of Busan in 2008, is about "17 ton/vessel" in the boundary of port of Busan. However, the hotelling greenhouse gas emissions resulted from non-container vessels (3,774 vessels; 20%) are greater than those from the full-container vessels. Hence, it is necessary to take into account more efficient port management polices and technologies to reduce the service time of non-container vessels in port of Busan.

• Korean Journal of Culture and Social Issue
• /
• v.19 no.2
• /
• pp.109-131
• /
• 2013

It is expected that expanded use of smartphone and enhanced information technology will enable smartwork to change individuals and organizations. Smartwork is expected to allow people to perform their roles without barriers of time and space. However, people tend not to accept and actively utilize smartwork. The present study is to examine how important flexibility-willingness is for performance outcome in the context of smartwork. It was hypothesized that flexibility-willingness mediates between perceived smartwork usefulness and work-family conflict. It was also hypothesized based on technology acceptance model that task interdependence and process control moderates the relationship between flexibility-willingness and work-family conflict because the relationship is not consistent. The results show that the mediation effect of the flexibility-willingness is statistically significant. The moderator effects of task interdependence was marginal proved but process control wasn't. From these results, we discussed the theoretical implications of findings, limitations, suggestions for future research in discussion.

• Journal of Life Science
• /
• v.33 no.12
• /
• pp.1046-1051
• /
• 2023

Cigarette smoking is one of the major causes of preventable diseases, disability, and death in Korea and worldwide. It has been clearly linked to the most common causes of death among the elderly and contributes to morbidity and disability associated with many chronic illnesses that are common in this age group. The health benefits of smoking cessation for the elderly have been clearly demonstrated. However, few studies have analyzed the relationship between health and smoking by considering the following many factors, especially among disabled people. In this study, we discuss the impacts of many factors on smoking among disabled people. Adults with disabilities are more likely to smoke than their peers. Public health agencies and practitioners should consider what reasonable adjustments may need to be made to policies and interventions to ensure that they are effective for adults with disabilities.