Vocabulary Size Tests of Different Modality and Their Relationships with L2 Reading and Listening Comprehension by Korean EFL Learners in Middle School

The present research intends to compare the orthographic and phonological vocabulary sizes of Korean EFL students in middle school and to address the relationship between the two different types of vocabulary size tests and L2 reading and listening comprehension. The participants were found to have greater orthographic vocabulary knowledge than phonological knowledge. Specifically, their vocabulary knowledge, regardless of its modality, drastically decreased in frequency level from 1,000 to 2,000 and from 3,000 to 4,000. Although both types of vocabulary knowledge exhibit a correlation with each other, as well as with reading and listening comprehension, orthographic vocabulary size was shown to be the most predictive in terms of the variance found in both reading and listening. The findings of the study contribute to existing research on L2 vocabulary acquisition by providing further evidence of the non-parallel development of phonological and orthographic vocabulary knowledge by EFL students, and by suggesting the significant predictive value that orthographic vocabulary knowledge has on the performance of students in reading and listening comprehension tests employed in Korea

Mediating effect of life satisfaction and depression on the relationship between cognition and activities of daily living in Korean male older adults

This study investigated the mediating effects of life satisfaction and depression on the relationship between cognition and activities of daily living (ADL) among male older adults. A secondary analysis was conducted utilizing data from the 2020 Elderly Survey. The participant pool consisted of 4035 Korean male older adults aged 65 years and above, selected from the total survey population of 10,097. The study focused on four variables: cognition, Korean Activities of Daily Living (K-ADL), life satisfaction and depression. The main analysis employed Hayes’s PROCESS Macro for SPSS v.4.0, and Model 6 was applied to determine the mediating effect of life satisfaction and depression on the relationship between cognition and ADL. The analysis revealed a negative correlation between ADL and cognition scores. ADL scores exhibited positive correlations with both life satisfaction and depression scores. A positive correlation emerged between life satisfaction and depression scores. The examination unveiled an indirect mediating effect between life satisfaction and depression scores. It is necessary to establish an intervention strategy that considers life satisfaction and the degree of depression when establishing a strategy to predict and prevent the decline in daily living ability in older adults with cognitive decline

Friction force measurement and analysis of the rotating liner engine

textAs emissions regulations become more stringent and fuel prices increase at a significant rate, the fuel efficiency of piston engines becomes more important than ever. Since most of the engine’s friction losses are from the piston/ring assembly, it is indispensable to reduce the piston/ring assembly friction for better fuel economy. The Rotating Liner Engine (RLE) was developed to remove the boundary lubrication of the piston/ring assembly friction through cylinder liner rotation. Even though the RLE was initially developed mainly by Dr. Dardalis several years ago, the friction reduction effect of the RLE was not confirmed except via preliminary motoring tests using a crude dynamometer. The main purpose of this dissertation is to confirm the RLE effect on piston assembly friction reduction using sophisticated measurement methods. Three different friction measurement methods were applied in measuring the friction force difference between a baseline engine and a prototype RLE. Through the use of three different friction measurement methods, the friction reduction of the RLE has been confirmed via this dissertation research and each of the friction measurement methods is also compared based on its measurement results. The analysis of the friction mechanism of the baseline engine was performed using the instantaneous IMEP method and a commercial simulation program called RINGPAK. Through the use of experimental methods and the simulation, the friction mechanism of the piston/ring assembly is analyzed. The limitation of the experimental and the calculation methods is also discussed.Mechanical Engineerin

Factors Influencing the Health-Related Quality of Life of Workers According to the Type of Work

This paper describes a descriptive cross-sectional study that was conducted to identify and compare the factors affecting health-related quality of life (HRQoL) according to the type of work. The method involved a secondary analysis of 4131 workers who participated in the first year of the 8th Korea National Health and Nutrition Examination Survey (2019). In this study, a complex sample plan file was created and then weighted and analyzed. For the analyses, frequency, χ2-test, t-test, and linear regression analyses were used for complex sample analysis. Factors that significantly affected the HRQoL of daytime workers were educational background, living with a spouse, regular work, depression for two consecutive weeks, and suicidal thoughts. The explanatory power was 18.9% (p < 0.001). The factor that significantly affected the HRQoL of shift workers was whether they took dietary supplements for 2 weeks or more during the past year, and the explanatory power was 17.6% (p = 0.007). This study confirmed that the factors affecting HRQoL differ according to the type of work. Based on the results of this study, when developing a program to improve the HRQoL of workers, it is necessary to establish a differentiated strategy according to the type of work

Do Adults Who Practice Aerobic Physical Activities Have Different Influencing Factors for Depression: A Secondary Data Analysis

Practice in aerobic activities can positively impact depression. This study aimed to identify differences between adults who do and do not practice aerobic activities in terms of general, physical, and psychological factors that influence depression. This study comprised a secondary analysis of data from the 6th (year 2) and 7th (years 1, 3) editions of the Korea National Health and Nutrition Examination Survey. Data from 12,891 adults were analyzed, of whom 7148 reported no practice in aerobic physical activities and 5743 reported practicing such activities. Data were analyzed using SPSS 25. Among those who did not perform aerobic activities, gender, family income, marital status, obesity, frequency of drinking, subjective health, subjective body weight, and stress were found to influence the level of depression. For those who practiced aerobic activities, gender, age, family income, education level, marital status, blood pressure, hypercholesterolemia status, frequency of drinking, subjective health, subjective body weight, and stress influenced the level of depression. This study found that the factors affecting depressive symptoms differ depending on whether individuals practice aerobic activities. Thus, to reduce depressive symptoms among adults, it is necessary to consider their level of physical activity and target the influencing factors associated with this level

Factors Associated with Adolescents’ Internet Use Duration by Suicidal Ideation

Purpose: This study aimed to identify the factors associated with Internet use duration by distinguishing between individuals with suicidal ideation and those without. Methods: Data were obtained from the 14th Korea Youth Risk Behavior Web-Based Survey (2018), which is a nationwide survey. Respondents aged 12–18 years (N = 60,040) who answered “yes” or “no” to the question about having suicidal ideation were included in the analysis. Study variables were general characteristics, physical and psychological factors, and Internet use duration. A complex sample logistic regression was performed to determine the influential factors. Results: Significant factors associated with weekend Internet use among those with suicidal ideation were sex, economic status, residence type, physical activity, sedentary duration, recovery after sleep deprivation, and stress, with an explanatory power of 20.0% (p < 0.001). Significant factors associated with weekday Internet use among those with suicidal ideation were sex, frequency of eating breakfast per week, sedentary duration, and weight control efforts, with an explanatory power of 15.9% (p < 0.001). Significant factors associated with weekend Internet use among those with no suicidal ideation were breakfast frequency and frequency of alcohol consumption per month, with an explanatory power of 10.9% (p < 0.001). Significant factors associated with weekday Internet use among those with no suicidal ideation were frequency of eating breakfast per week, frequency of eating fast food per week, sedentary duration, and suicide attempt, with an explanatory power of 13.6% (p < 0.001). Conclusions: The findings indicated significant differences in Internet use duration between adolescents with suicidal ideation and those without, suggesting the need for customized prevention programs focusing on adolescents’ psychological state

Examining the health-related quality of life of middle-aged men with metabolic syndrome based on their stress level

Background: This study was conducted to identify the factors that affect the health-related quality of life (HRQoL) of middle-aged men with metabolic syndrome (MetS) based on their stress level using data from the Korea National Health and Nutrition Examination Survey (KNHANES). Methods: The participants of this study were men aged between 40–64 with MetS who were included in the KNHANES. The main variables of this study were HRQoL, which was measured using the EuroQol-5 Dimension (EQ-5D); general characteristics, health-related characteristics, and dietary behaviors. Results: The subjective health of the group with less stress was significantly better. Compared to the unhealthy group, the groups perceived as healthy and normal had a higher HRQoL. The economic level, suicidal ideation, and dinner arrangement (presence of family) of the stressed group were significantly associated with their HRQoL. Compared to a low economic level, the high and middle economic levels were more associated with the subjects’ HRQoL. Compared to the group without suicidal ideation, the group that experienced suicidal association had a lower HRQoL. Compared to the group that did not dine with their family, the group that dined with family had a higher HRQoL. Conclusions: The results of this study expand the scientific understanding of HRQoL based on stress among middle-aged men with metabolic syndrome. Since differences in the influence of the factors that affect HRQoL were identified based on the level of stress experienced, the stress level of middle-aged men should be considered when devising an intervention strategy to improve their HRQoL

Factors Influencing Depressive Symptoms in Middle-Aged South Korean Workers by Job Type: A Population-Based Study

Depressive symptoms can be influenced by different factors, including job types. In this study, we identified factors that affect depressive symptoms among South Korean workers by job type using data from the Korea National Health and Nutrition Examination Survey. Examined respondents were between 40 and 69 years (N = 9375). A complex sample linear regression analysis revealed various significant factors based on job type. For office workers, the number of household members, health-related quality of life, diabetes, sitting time, subjective health, and stress were significant influencing factors for depressive symptoms (explanatory power of 23.2%) (p < 0.001). For service workers, gender, health-related quality of life, food intake, aerobic exercise, sitting time, subjective health, and stress were significant influencing factors for depressive symptoms (explanatory power of 49.6%) (p < 0.001). For labor workers, gender, type of living, health-related quality of life, BMI, weight change, weight control, aerobic exercise, diabetes, subjective health, and stress were significant influencing factors for depressive symptoms (explanatory power of 35.8%) (p < 0.001). These differences highlight the need for customized programs targeted at each job type to maintain and promote mental health among workers