• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.21-33
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• 2014

Background: Significant technological development and changes happened in the tractor industries. Contrariwise, the test procedures of the major standard development organizations (SDO's) remained unchanged or with a little modification over the years, demanding new tractor test standards or improvement of existing ones for tractor performance, safety, and comfort. Purpose: This study focuses on reviewing the research trends regarding performance, safety and comfort evaluation of agricultural tractors. Based on this review, few recommendations were proposed to revise or improve the current test standards. Review: Tractor power take-off power test using the DC electric dynamometer reduced human error in the testing process and increased the accuracy of the test results. GPS signals were used to determine acceleration and converted into torque. High capacity double extended octagonal ring dynamometer has been designed to measure drawbar forces. Numerical optimization methodology has been used to design three-point hitch. Numerous technologies, driving strategies, and transmission characteristics are being considered for reducing emissions of gaseous and particulate pollutants. Engine emission control technology standards need to be revised to meet the exhaust regulations for agricultural tractors. Finite Element Analysis (FEA) program has been used to design Roll-Over Protective Structures (ROPS). Program and methodology has been presented for testing tractor brake systems. Whole-body vibration emission levels have been found to be very dependent upon the nature of field operation performed, and the test track techniques required development/adaptation to improve their suitability during standardized assessment. Emphasizes should be given to improve visibility and thermal environment inside the cab for tractor operator. Tractors need to be evaluated under electromagnetic compatibility test conditions due to large growing of electronic devices. Research trends reviewed in this paper can be considered for possible revision or improvement of tractor performance, safety, and comfort test standards.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.221-225
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• 2009

The purpose of this study was to investigate the biomechanical effects of an application of whole body vibration during strengthening exercise. Every participant performed four weeks exercise program using general leg-press versus vibrating leg-press. Participants did legpress exercise three sets of 25 repetitions with the load of 25 percent of 1RM during first week, three sets of 20 repetitions with 40 percent of 1RM during second week, three sets of 15 repetitions with 60 percents of 1RM during third week, and three sets of 15 repetitions with 80 percent of 1RM during last fourth week. The vibration(25Hz, 5mm) was applied only to the vibration exercise group. A three dimensional virtual lower extremity model for one of subject and virtual leg-press model were generated. The knee extensor muscle forces were analyzed using the virtual model and the knee joint torque(maximum extension torque) was measured using an isokinetic device. Calculated muscle forces were smaller in vibrating leg-press exercise than in general leg-press exercise. An increase of the maximum knee extension joint torque was 2.14 times larger approximately after the four week vibration leg-press exercise program was performed.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.199-205
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• 2020

The purpose of this study was to identify the factor Disaster Nursing Core Competencies in nursing college students. A descriptive correlation study design was used. The subjects were 144 university students of a university located in D and K city. The study used a Educational Needs on Disaster Nursing, Disaster Nursing Knowledge, Disaster Preparedness, Self-efficacy and Disaster Nursing Core Competencies. Data were collected from February 25 to March 15, 2019 and analyzed with t-test, pearson's correlation coefficient and multiple response analysis, stepwise multiple regression by using SPSS IBM 22.0 Program. The findings are follows: First, among the disaster nursing education methods, simulation based practice were the highest. Second, Disaster Nursing Core Competencies was positively correlated with Disaster Preparedness, self-efficacy and Disaster Knowledge. Third, the influencing factors in Disaster Nursing Core Competencies were Grade(β=0.343), Self-efficacy(β=0.329), Disaster Preparedness(β=0.282), Experience of practice in ER(β=0.159), adjusted R²=.532. Therefore, it is necessary to develop an Customized Disaster Program that can improve the Disaster Nursing Core Competencies of nursing college students based on the factors affecting the Disaster Nursing Core Competencies and Educational needs.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.2
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• pp.67-74
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• 2016

Explosive bolt is one of separation device that uses high explosive charge, and is separated by pressure formed by an explosion and the resulting shock waves. Explosive bolt having such a mechanism would have to be designed to minimize shock and debris formation generated during separation. In this study, separation tests were carried out with distance as variable for restraining the explosive bolt (Air Gap). Bolt release and its separating shape with variation of air gap is observed, and we used accelerometer to measure the shock wave transmitted through a bound object. In addition, separation behavior of explosive bolt is analyzed using ANSYS AUOTODYN program. By comparing the results of previously performed experiments and analysis, we could confirm the effects of air gap to the release behavior of explosive bolt, and decide optimum constraining environment for specific separation bolts.

• Journal of Biosystems Engineering
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• v.38 no.1
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• pp.1-8
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• 2013

Purpose: Path planning and tracking algorithms applicable to various agricultural operations, such as tillage, planting, and spraying, are needed to generate steering angles for auto-guidance tractors to track a point ahead on the path. An optimal coverage path algorithm can enable a vehicle to effectively travel across a field by following a sequence of parallel paths with fixed spacing. This study proposes a path generation and tracking algorithm for an auto-guided Korean tractor with a tillage implement that generates a path with C-type turns and follows the generated path in a paddy field. A mathematical model was developed to generate a waypoint path for a tractor in a field. This waypoint path generation model was based on minimum tractor turning radius, waypoint intervals and LBOs (Limit of Boundary Offsets). At each location, the steering angle was calculated by comparing the waypoint angle and heading angle of the tractor. A path following program was developed with Labview-CVI to automatically read the waypoints and generate steering angles for the tractor to proceed to the next waypoint. A feasibility test of the developed program for real-time path tracking was performed with a mobile platform traveling on flat ground. The test results showed that the developed algorithm generated the desired path and steering angles with acceptable accuracy.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.150-157
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• 2008

The purpose of this study was to investigate the effect of short-tenn stretching type of muscular strength gymnastics on health-related fitness and rating of perceived pain for automotive industry workers. The subjects selected were 27, who were divided into 3 groups(A group=10, B group=9, C group=8). Group A performed a short-term stretching Type of Muscular Strength Gymnastics only one time. Group B continuously performed the exercise program two times. Group C was a control group. The exercise program was a stretching Type of Muscular Strength Gymnastics, which was performed 3 times per week for 4 weeks. Its intensity was RPE 11-15. Data analysis was conducted by using SPSS ver 14.0. The test was conducted with two-way repeated ANOVA, post-hoc Ducan and paired t-test (a<.05). This study showed the following results. Muscular strength, muscular endurance and flexibility increased in all intra and between groups. Ratio of %fat decreased for group B but the control group presented conversely. Rating of perceived pain of group A decreased at arm and hands. Rating of perceived pain of group A decreased at back and leg.

• Journal of radiological science and technology
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• v.28 no.2
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• pp.79-89
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• 2005

This paper presents the overall attributes of the current IAEA programs and their future prospects in the arena of applications of radioisotopes and ionizing radiation, thus dealing with the demand to achieve a condensed understanding of the Agency's programs for an effective and efficient deployment of the respective national R&D projects in Korea. The considerable and beneficial advantages of a participation in the IAEA programs have been reviewed and their immediate relevance has been emphasized. A strategic approach for the enhancement of an active participation in the program and its efficient implementation has also been established. It is anticipated that the proposed recommendations such as the long term strategy and the applicable guidelines will be useful in formulating a nuclear policy for the further development of the international cooperative projects in the future.

• Journal of Korean Biological Nursing Science
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• v.25 no.3
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• pp.215-227
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• 2023

Purpose: The aim of this study was to develop a mobile app-based musculoskeletal exercise program (AMSEP) for operating room (OR) nurses and evaluate its effects on self-efficacy, the flexibility of the shoulders, lower back, and legs, and musculoskeletal symptoms and fatigue. Methods: The AMSEP was developed based on the information-motivation-behavioral skill model. In total, 48 OR nurses were recruited at a university hospital in Korea and divided into an experimental group (n=24) and a control group (n=24), matched for career experience in the OR. The experimental group participated in the AMSEP, while the control group received a booklet regarding musculoskeletal exercise. Results: The experimental group showed significant increases in self-efficacy (t = -2.77, p = .008) and flexibility of the right shoulder (t = -4.08, p < .001), left shoulder (t = -3.28, p = .002), lower back (t = -3.75, p < .001), and legs (t = -3.96, p < .001) compared to the control group. Musculoskeletal symptoms (t = 2.75, p = .008), and fatigue (Z = -1.98, p = .048) significantly decreased in the experimental group compared to the control group. Conclusion: Our findings indicate that the AMSEP for OR nurses provided information on the prevention of musculoskeletal disorders and methods of exercise, as well as an opportunity for continued exercise performance through self-management. The AMSEP was easily accessible and effective in increasing self-efficacy and flexibility and reducing musculoskeletal symptoms and fatigue.

• Safety and Health at Work
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• v.15 no.2
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• pp.181-186
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• 2024

Background: This study aimed to analyze the trend of occupational noise-induced hearing loss (ONIHL) in Brazilian workers at a metallurgical plant with a hearing conservation program (HCP), which has been addressed in a previous study. Methods: All 152 workers in this time series (20032018) participated in the HCP and used personal protective equipment. All annual audiometry records in the company's software were collected from the electronic database. The trend of ONIHL was analyzed with the joinpoint regression model. The hearing thresholds of ONIHL cases at the end of the series were compared with those found in a national reference study. Results: The binaural mean hearing thresholds at 3, 4, and 6 kHz at the end of the series were higher for ages ≥50 years, exposures ≥85 dB (A), time since admission >20 years, and maintenance workers. Significance was found only in the group divided by age. There was an increasing time trend of ONIHL, though with a low percentage variation for the period (AAPC = 3.5%; p = 0.01). Hearing thresholds in this study differed from the reference one. Conclusion: Despite the unmet expectation of a stationary trend in the study period, the time pace of ONIHL evolution did not follow what was expected for a population exposed to noise. These findings signal to the scientific community and public authorities that good ONIHL control is possible when HCP is well implemented.

• Journal of Korean Academy of Nursing
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• v.20 no.2
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• pp.185-194
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• 1990

The purpose of this study was to investigate the correlation of discomfort. self - esteem. personality and life - satisfaction in persons with rheumatoid arthritis and to provide basic data to help them attain a better quality of life. From Jan. 27 to Feb. 24, 1988, 53 patients, registered at a rheumatic clinic at one general hospital in Seoul, were accepted as subjects for this study. The instruments used for this study were a discomfort scale and life- satisfaction scale developed by the researcher, Rosenberg's Self - esteem Scale and Wallston and Wallston's Multidimensional Health Locus of Control (MEILC) Scale. The reliability of the scales were tested by Cronsbach's alpha. The collected data were analyzed by the SAS program using unpaired t-test, ANOVA, and Pearson's Correlation Coefficients. The results were as follows : 1. There was a significant difference in the subjects perceived discomfort level(t＝-3.49, p＝ .0010) between the onset of the disease(14.87$\pm$9.02) and the present(19.87$\pm$8.44). 2. There was a significant correlation between the MHLC - internal score and the MHLC -chance score (r＝-.4366, p＝ .0011). 3. The findings related to the demographic variables regarding the MHLC scores were as follows : 1) Regarding sex, there was a significant difference for the MHLC -internal score(t＝4.2572, df＝15.2, p＝ .0007) between male(32.13$\pm$2.47) and female(27.56$\pm$4.17). But the MHLC-chance score for male(15.13$\pm$2.85) was lower(t＝3.1539, df＝21.8, p$\pm$ .0047) than for female(19.47$\pm$6.29). 2) Regarding educational background, the MHLC - chance score for the below - high school group(20.52$\pm$5.81) was higher(t＝2.5450, df＝51.0, p＝ .0140) than the college graduate group(16.41$\pm$5.76). 4. The average Self - esteem score was 26.87 (S.D.＝5.29) and there was a significant correlation between the Self- esteem score and the MHLC - chance score (r＝ .3122, p＝ .0026). 5. It was found that the subjects' Discomfort score was correlated with the Self -esteem score(r＝-.3788, p＝ .0051) and the Life - satisfaction score(r＝-3570, p＝ .0087). It was also found that subjects' Self - esteem score was correlated with the Life-satisfaction score(r＝ .4474, p＝ .0008).