• Annals of Occupational and Environmental Medicine
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• v.34
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• pp.24.1-24.13
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• 2022

Background: In modern society, depression is serious issue that causes socioeconomic and family burden. To decrease the incidence of depression, risk factors should be identified and managed. Among many risk factors for depression, this study examined socioeconomic risk factors for depression. Methods: We utilized first (2006), second (2008), and third (2010)-wave data from the Korean Longitudinal Study of Aging (KLoSA). Depressive symptom was measured with the 10-item Center for Epidemiological Studies Depression Scale, Short Form (CES-D-10) in the survey in 2008 and 2010. Three risk factors including job security, employment type and monthly income were measured in the survey in 2006. The association between risk factors and depressive symptom was analyzed by Cox proportional-hazard model. Results: We analyzed data from 1,105 workers and hazard ratios (HRs) for 3 risk factors were significant entirely. In addition, regular worker with high income group is the most vulnerable group of poor job insecurity on depression among male workers (HR: 1.73; 95% confidence interval [CI]: 1.07-2.81). Finally, HRs for 7 groups who had at least 1 risk factor had higher HRs compared to groups who had no risk factors after stratifying 3 risk factors. In the analysis, significantly vulnerable groups were total 5 groups and the group who had highest HR was temporary/daily workers with poor job security (HR: 2.51; 95% CI: 1.36-4.64). The results concerning women, regardless of job type, were non-significant. Conclusions: This study presented one or more risk factors among poor job security, low income, temporary/daily employment type increase hazard for depressive symptom in 2 or 4 years after the exposure. These results inform policy to screen for and protect against the risk of depression in vulnerable groups.

• Steel and Composite Structures
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• v.50 no.5
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• pp.563-581
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• 2024

This paper presents a novel finite element model for the free vibration analysis of variable-thickness functionally graded porous (FGP) microplates resting on Pasternak's medium in the hygro-thermal environment. The governing equations are established according to refined higher-order shear deformation plate theory (RPT) in construction with the modified couple stress theory. For the first time, three-node triangular elements with twelve degrees of freedom for each node are developed based on Hermitian interpolation functions to describe the in-plane displacements and transverse displacements of microplates. Two laws of variable thickness of FGP microplates, including the linear law and the nonlinear law in the x-direction are investigated. Effects of thermal and moisture changes on microplates are assumed to vary continuously from the bottom surface to the top surface and only cause tension loads in the plane, which does not change the material's mechanical properties. The numerical results of this work are compared with those of published data to verify the accuracy and reliability of the proposed method. In addition, the parameter study is conducted to explore the effects of geometrical and material properties such as the changing law of the thickness, length-scale parameter, and the parameters of the porosity, temperature, and humidity on the free vibration response of variable thickness FGP microplates. These results can be applied to design of microelectromechanical structures in practice.

• Advances in nano research
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• v.17 no.1
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• pp.33-49
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• 2024

Using the mechanical treatments for mechanical properties improvement was rarely in the development scope before. This research approves through analytical ways that surface impacts can improve the quality of the surface significantly. This fact is approved for deposited titanium on silicone substrate. The new algorithm called minimum resultant error method (MREM) which is a direct combination of nanoindentation, FEM and dimensional analysis through a reverse method is utilized to extract the mechanical characteristics of the coating surface before and after impact. This method is extended to the time dependent behavior of the material to obtain strain rate coefficient. To implement this new approach, a new analysis technic is developed to define the residual stress field caused by surface impact as initial condition for nanoindentation. Analyzing the model in micro and macro scale at the same time was one of the main resolved challenges in this study. The result was obtaining of the constants of Johnson-Cook constitutive equation. Comparing the characteristics of the coating surface before and after impact shows high improvement in yield stress (34%), Elastic modulus (7.75%) and strain hardening coefficient (2.8%). The main achievement is that the strength improvement in titanium thin layer is much higher than bulk titanium. The yield strength shows 41.7% improvement for coated titanium comparing with 24% for bulk material. The rate of enhancement is about 6 times when it comes to the Young's modulus.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.3
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• pp.131-142
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• 2024

Purpose : This study explores the effects of dental hygiene students' ethical propensity and self-esteem on their awareness of protecting patient medical information and how these factors interact to influence their professional ethical consciousness. The aim of this study is to highlight the role of university education in shaping the ethical values of dental hygienists. Methods : Between June 1 and November 30, 2023, 210 dental hygiene students in Busan Metropolitan City participated in this study. After providing consent, the participants completed a self-administered questionnaire comprising 69 questions. The questions covered general characteristics (8 questions), ethical propensity (20 questions), self-esteem (10 questions), and awareness of patient medical information protection (31 questions), all measured on a five-point Likert scale. Results : Correlation analysis indicated that idealism had a significant positive correlation with relativism (r=0.35, p<.001), self-esteem (r=0.28, p<.001), and awareness of patient medical information protection (r=0.46, p<.001). Relativism had a significant positive correlation with self-esteem (r=0.17, p<0.05) and awareness of patient medical information protection (r=0.23, p<.01). Self-esteem had a significant positive correlation with awareness of patient medical information protection (r=0.34, p<.001). Multilinear regression analysis revealed that idealism (ß=0.38) and self-esteem (ß=0.22) significantly increased the level of awareness of patient medical information protection. However, relativism did not have a significant impact on the level of awareness of patient medical information protection. The model explained 26.0 % of the variance (24.9 % when corrected). Conclusion : Higher levels of idealism and self-esteem correlate with greater awareness of patient medical information protection. In addition to appropriate program development and strategies, university curricula for dental hygiene students should include systematic and continuous training to enhance the values of ethical awareness, idealism, and self-esteem.

• Journal of Oriental Neuropsychiatry
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• v.35 no.2
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• pp.153-162
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• 2024

Objectives: Among OECD countries, South Korea has been having the highest suicide rate since 2018, with 24.1 deaths per 100,000 people reported in 2020. The objectie of this study was to examine the use of generative artificial intellicence (AI) chatbots to train third-year Korean medicine (KM) students in conducting suicide risk assessments for patients with depressive disorders to train students for their clinical practice skills. Methods: The Claude 3 Sonnet model was utilized for chatbot simulations. Students performed mock consultations using standardized suicide risk assessment tools including Ask Suicide-Screening Questions (ASQ) tool and ASQ Brief Suicide Safety Assessment. Experiences and attitudes were collected through an anonymous online survey. Responses were rated on a 1~5 Likert scale. Results: Thirty-six students aged 22~30 years participated in this study. Their scores for interest and appropriateness (4.66±0.57), usefulness (4.60±0.61), and overall experience (4.63±0.60) were high. Their evaluation of the usability of artificial intelligence chatbot was also high at 4.58±0.70 points. However, their trust in chatbot responses (Q12) was lower (3.86±0.99). Common issues related to dissatisfaction included conversation disruptions due to token limits and inadequate chatbot responses. Conclusions: This is the first study investigating generative AI chatbots for suicide risk assessment training in KM education. Students reported high satisfaction, although their trust in chatbot accuracy was moderate. Technical limitations affected their experience. These preliminary findings suggest that generative AI chatbots hold promise for clinical training, particularly for education in psychiatry. However, improvements in response accuracy and conversation continuity are needed.

• The Journal of Korean Academic Society of Nursing Education
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• v.30 no.3
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• pp.280-289
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• 2024

Purpose: This study aimed to develop and evaluate the effectiveness of a preceptor educational program in a children's hospital. The program's impact was assessed by measuring improvements in clinical competency, communication competency, and leadership competency. Methods: Four day pediatric nurse preceptor education program was developed using the ADDIE (Analysis, Design, Development, Implementation, and Evaluation) model. A single-group pretest-posttest design was employed to assess the program's effects with seventeen participants who were newly trained preceptors. Additionally, participant satisfaction with the program was measured. Results: Following the implementation of the program, significant improvements were observed in clinical competency (Z=-3.62, p<.001), communication competency (Z=-2.77, p=.006), leadership competency (Z=-2.08, p=.038), other competence (Z=-2.64, p=.008), and total competency (Z=-3.52, p<.001) among participants. The overall satisfaction score was 4.41±0.62 on a 5-point scale. Conclusion: The pediatric nurse preceptor educational program significantly enhances the overall nursing competencies of preceptor nurses in a children's hospital. Further research is needed to evaluate the effects of this preceptorship on newly graduated nurses.

• Smart Structures and Systems
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• v.33 no.4
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• pp.291-300
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• 2024

Uncertainty of the model, system delay and drive dynamics can be considered as normal uncertainties, and the main source of uncertainty in the seismic control system is related to the nature of the simulated seismic error. In this case, optimizing the management strategy for one particular seismic record will not yield the best results for another. In this article, we propose a framework for online management of active structural management systems with seismic uncertainty. For this purpose, the concept of reinforcement learning is used for online optimization of active crowd management software. The controller consists of a differential controller, an unplanned gain ratio, the gain of which is enhanced using an online reinforcement learning algorithm. In addition, the proposed controller includes a dynamic status forecaster to solve the delay problem. To evaluate the performance of the proposed controllers, thousands of ground motion data sets were processed and grouped according to their spectrum using fuzzy clustering techniques with spatial hazard estimation. Finally, the controller is implemented in a laboratory scale configuration and its operation is simulated on a vibration table using cluster location and some actual seismic data. The test results show that the proposed controller effectively withstands strong seismic interference with delay. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings, sustainable human settlement planning and manage. Simulation results is believed to achieved in the near future by the ongoing development of AI and control theory.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.532-539
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• 2024

Among various risk factors that need managing in large scale complex infrastructure projects, geotechnical risk is one of the most prominent factor particularly for underground works like tunnels. Uncertainties in soil conditions cannot be avoided 100% even after extensive geotechnical investigations. Therefore, underground works face large delays and cost overrun especially for hydropower projects in developing countries. Its uncertainty ex ante and ex post directly cause increased transaction cost in terms of contract administration, claims, variation orders and disputes. It also reduces trust and increases opportunistic behaviors due to asymmetric information between the parties. Subsequently, parties are spending more time on claim management rather than handling the project execution. Traditional project management tools are becoming less effective under these conditions. FIDIC published the Conditions of Contract for Underground Works wherein a Geotechnical Baseline Report (GBR) sets out the allocation of risks between the parties for subsurface physical conditions determining the foreseeable and unforeseeable conditions. At the same time, Building Information Modeling (BIM) is being adopted for efficient design, quality control and cost management. In this study, soil classification along the tunnel alignment for on-going hydropower projects is modelled in the virtual environment of Autodesk Revit (2024). The actual soil encountered along the tunnel during construction stage can be compared with the baseline conditions. In addition, BIM serves as a central source providing symmetric information to the Parties to develop an environment of trust and coordination. It is anticipated that these tools will improve the project management skills for underground works through minimizing the opportunistic behavior and transaction cost.

• Journal of Climate Change Research
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• v.34 no.22
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• pp.9093-9113
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• 2021

This study examines the role of the relative wind (RW) effect (wind relative to ocean current) in the regional ocean circulation and extratropical storm track in the south Indian Ocean. Comparison of two high-resolution regional coupled model simulations with and without the RW effect reveals that the most conspicuous ocean circulation response is the significant weakening of the overly energetic anticyclonic standing eddy off Port Elizabeth, South Africa, a biased feature ascribed to upstream retroflection of the Agulhas Current (AC). This opens a pathway through which the AC transports the warm and salty water mass from the subtropics, yielding marked increases in sea surface temperature (SST), upward turbulent heat flux (THF), and meridional SST gradient in the Agulhas retroflection region. These thermodynamic and dynamic changes are accompanied by the robust strengthening of the local low-tropospheric baroclinicity and the baroclinic wave activity in the atmosphere. Examination of the composite life cycle of synoptic-scale storms subjected to the high-THF events indicates a robust strengthening of the extratropical storms far downstream. Energetics calculations for the atmosphere suggest that the baroclinic energy conversion from the basic flow is the chief source of increased eddy available potential energy, which is subsequently converted to eddy kinetic energy, providing for the growth of transient baroclinic waves. Overall, the results suggest that the mechanical and thermal air-sea interactions are inherently and inextricably linked together to substantially influence the extratropical storm tracks in the south Indian Ocean.

• Journal of Climate Change Research
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• v.34 no.12
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• pp.5081-5092
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• 2021

Paleoproxy records indicate that abrupt changes in thermohaline circulation (THC) were induced by rapid meltwater discharge from retreating ice sheets. Such abrupt changes in the THC have been understood as a hysteresis behavior of a nonlinear system. Previous studies, however, primarily focused on a near-static hysteresis under fixed or slowly varying freshwater forcing (FWF), reflecting the equilibrated response of the THC. This study aims to improve the current understanding of transient THC responses under rapidly varying forcing and their dependency on forcing time scales. The results simulated by an Earth system model suggest that the bifurcation is delayed as the forcing time scale is shorter, causing the Atlantic meridional overturning circulation collapse and recovery to occur at higher and lower FWF values, respectively. The delayed shutdown/recovery occurs because bifurcation is determined not by the FWF value at the time but by the total amount of freshwater remaining over the THC convection region. The remaining freshwater amount is primarily determined by the forcing accumulation (i.e., time-integrated FWF), which is modulated by the freshwater/salt advection by ocean circulations and freshwater flux by the atmospheric hydrological cycle. In general, the latter is overwhelmed by the former. When the forced freshwater amount is the same, the modulation effect is stronger under slowly varying forcing because more time is provided for the feedback processes.