• ETRI Journal
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• v.41 no.6
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• pp.850-862
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• 2019

This work investigated three-dimensional (3D) focused microwave thermotherapy (FMT) at 925 MHz for a human tissue mimicking phantom using the time reversal (TR) principle for musculoskeletal disorders. We verified the proposed TR algorithm by evaluating the possibility of 3D beam focusing through simulations and experiments. The simulation, along with the electromagnetic and thermal analyses of the human tissue mimicking phantom model, was conducted by employing the Sim4Life commercial tool. Experimental validation was conducted on the developed FMT system using a fabricated human tissue mimicking phantom. A truncated threshold method was proposed to reduce the unwanted hot spots in a normal tissue region, wherein a beam was appropriately focused on a target position. The validation results of the simulation and experiments obtained by utilizing the proposed TR algorithm were shown to be acceptable. Effective beam focusing at the desired position of the phantom could be achieved.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.728-735
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• 2022

Roofers get exposed to increased risk of knee musculoskeletal disorders (MSDs) at different phases of a sloped shingle installation task. As different phases are associated with different risk levels, this study explored the application of machine learning for automated classification of seven phases in a shingle installation task using knee kinematics and roof slope information. An optical motion capture system was used to collect knee kinematics data from nine subjects who mimicked shingle installation on a slope-adjustable wooden platform. Four features were used in building a phase classification model. They were three knee joint rotation angles (i.e., flexion, abduction-adduction, and internal-external rotation) of the subjects, and the roof slope at which they operated. Three ensemble machine learning algorithms (i.e., random forests, decision trees, and k-nearest neighbors) were used for training and prediction. The simulations indicate that the k-nearest neighbor classifier provided the best performance, with an overall accuracy of 92.62%, demonstrating the considerable potential of machine learning methods in detecting shingle installation phases from workers knee joint rotation and roof slope information. This knowledge, with further investigation, may facilitate knee MSD risk identification among roofers and intervention development.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.12
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• pp.29-35
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• 2007

• Journal of the Korean Society for Precision Engineering
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• v.24 no.12
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• pp.20-28
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• 2007

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.57-67
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• 2009

The psychosocial stress and musculoskeletal disorders(MSDs) have been one of major health problems for hospital workers. This study tried to understand the relationship between symptoms associated with MSDs and risk factors such as working posture, job stress, psychosocial stress and fatigue. A total number of 655 hospital workers participated in this study. Specifically, REBA was applied for evaluating working posture and a checklist prepared by KOSHA(Korean Occupational Safety and Health Agency) was used for symptom survey. A questionnaire from KOSHA was also used for collecting data associated with job stress, psychosocial stress and fatigue. All these data were formulated and modeled by path analysis which was one of major statistical tools in this study. Specifically, path analysis for the data we collected came up with several major findings. As a result, as for body part(neck), (waist) and (arms) the degree of risk of work posture measured with the use of job stress(KOSS), psycho-social stress(PWI-SF) and REBA is significantly more affected by fatigue than muscular skeletal disease related consciousness symptom. However, regarding bod(wrist), the degree of risk of work posture measured with the use of job stress(KOSS) and REBA is directly affected by muscular skeletal disease related consciousness symptom. This study is meaningful in that the study clarified the causal relations of the degree of risk of work posture, degree of fatigue, and muscular skeletal disease related consciousness symptoms by each body part measured with the use of work stress(KOSS), psycho-social stress(PWI-SF) and REBA.

• Journal of Korean Academy of Nursing
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• v.48 no.6
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• pp.692-707
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• 2018

Purpose: We aimed to examine the effects of an integrated physical activity (PA) program developed for physically inactive workers on the theoretical basis of the PRECEDE-PROCEED model. Methods: Participants were 268 workers in three departments of L manufacturing unit in South Korea. The three departments were randomly allocated into integration (n=86) (INT), education (n=94) (ED), and control (n=88) (CT) groups. The INT group received self-regulation, support, and policy-environmental strategies of a 12-week integrated PA program, the ED group received self-regulation strategies only, and the CT group did not receive any strategies. After 12 weeks, process evaluation was conducted by using the measures of self-regulation (autonomous vs. controlled regulation), autonomy support, and resource availability; impact evaluation by using PA measures of sitting time, PA expenditure, and compliance; and outcome evaluation by using the measures of cardiometabolic/musculoskeletal health and presenteeism. Results: Among process measures, autonomous regulation did not differ by group, but significantly decreased in the CT group (p=.006). Among impact measures, PA compliance significantly increased in the INT group compared to the CT group (p=.003). Among outcome measures, the changes in cardiometabolic/musculoskeletal health and presenteeism did not differ by group; however, systolic blood pressure (p=.012) and a presenteeism variable (p=.041) significantly decreased only in the INT group. Conclusion: The integrated PA program may have a significant effect on increases in PA compliance and significant tendencies toward improvements in a part of cardiometabolic health and presenteeism for physically inactive workers. Therefore, occupational health nurses may modify and use it as a workplace PA program.

• Journal of agricultural medicine and community health
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• v.44 no.4
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• pp.209-219
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• 2019

Objectives: This study investigated musculoskeletal symptoms in upper limbs according to the working environment (job stress) of dental hygienists and examine their relationship with upper limb functions. Methods: The subjects include 198 dental hygienists in dental hospitals and dental clinics in Pusan and Gyeongnam. The questionnaire was consisted of general characteristics of the subjects, job stress, musculoskeletal symptoms in upper limbs and function (Disability Measurement Tool for Upper Extremity Disorders-11, DASH-11). Results: The study was analyzed their musculoskeletal symptoms in upper limbs according to their general characteristics and found that the symptoms occurred in the neck (39.4%), the shoulders (54.6%), elbows (14.7%), and the hands (50.0%). Job stress was associated with upper limb functions (DASH-11) (model 3, B=5.210, p=0.012) and repeated elbow bending and spreading posture was associated with DASH-11 (model 3, B=6.561, p=0.029). Elbow symptoms were associated with DASH-11 in the upper limbs (B=10.679, p=0.003). Conclusion: Dental hygienists are experiencing limitations of upper limb function due to job stress. In particular, even if the correction of their uncomfortable posture is significantly related to the job stress and upper limb function, in order to improve the upper limb function of the dental hygienist, efforts to reduce the job stress as well as the uncomfortable posture are necessary.

• Journal of the Ergonomics Society of Korea
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• v.36 no.3
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• pp.221-230
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• 2017

Objective: The purpose of this study is to draw the accident prevention model using the signal detection theory, and to implement accident prevention program, based on a health promotion and support activities in a shipbuilding company. Background: Workers' health management is perceived important from the human resource management perspective, as well as from the personal perspective. Method: This study developed an accident prevention model by analyzing the correlation between 704 workers' health examination variables, and reviewed the verification of the model through a follow-up survey on the control variables and status of hazards targeting 650 workers for four years from 2007 to 2010. Also, a health promotion program was implemented targeting a production division to improve alcohol habits, smoking, musculoskeletal pain complaints and hearing control indices, which are the control variables of the model. Results: As a result of four years' implementation, the following effects were obtained: the days away from work fell 87.5%, and accident rate dropped 71.5% in 2010, respectively, compared to 2006, before the activity was implemented. Conclusion: This study shows that the accident prevention activities based on workers' health promotion activities are effective to prevent industrial accidents and injuries. Application: The research findings will serve as a practical guideline for establishing preventive measures in the shipbuilding company.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.18 no.2
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• pp.31-39
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• 2012

Background: The purpose of this study was to develop a problem-based learning model for orthopedic manual physical therapy. A problem-based learning (PBL) model for orthopedic manual physical therapy developed from PBL module of Jeju C university (Halla-Newcastle PBL Center). A summary of this study is as follows: 1) PBL model is comprised of a class of 30 students, operated small group as of 4~5 students. 2) PBL is suggested a scenario of clinical case, induced variety reaction through group discussion and presentation. 3) PBL is occurred wide variety learning through group work activity and self-directed learning. 4) The tutor as a facilitator is played a guide for group discussion, work activity and team learning. 5) The evaluation for PBL is performed such as student self-evaluation, group activity evaluation, individual presentation, and practice. This model is considered wide variety learning through team learning and self-directed learning by clinical reasoning and problem solving for musculoskeletal clinical case. We suggest problem based learning for the education of orthopedic manual physical therapy in which the learners are very interested in and has the effective outcome.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1237-1242
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• 2011

The A detailed 3D finite-element analysis model of a human foot has been developed by converting CT scan images to 3D CAD models in order to analyze the distribution of plantar pressure. The 3D foot model includes all muscles, bones, and skin. On the basis of this model and the pressure distribution results, shoes for diabetes patients, which can make the plantar pressure distribution uniform, may be designed through finite-element contact analysis.