• Journal of the Korea Safety Management & Science
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• v.25 no.1
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• pp.51-58
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• 2023

Determination of explosion reference pressure is important in designing and testing flameproof enclosures (Ex d). Although relative humidity affects to explosion pressure, its effect is not well investigated for the gas group IIB, IIA, and I. This study tested explosion pressure for Ethylene (8 vol.%), Propane (4.6 vol.%), and Methane (9.8 vol.%), which are the representative gas of the gas group IIB, IIA, and I, at ambient temperature and atmospheric pressure (1 atm) under different relative humidity (0% ~ 80%). Ethylene- and Propane-air mixed gases generally tended to decrease as the relative humidity increased; however, explosion pressure was largely dropped at 20% of relative humidity compared to 0% and 10% of relative humidity. On the other hand, Methane-air mixture gas showed similar pressures at 0% and 10% of relative humidity; but no explosion occurred at more than 20%. The results of this study can be used in setting a testing protocol of explosion reference pressure for designing and testing a flameproof enclosure.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.1
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• pp.55-59
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• 2004

This study developed a fully automated test system for pressure vessels, containing such as oxygen, nitrogen, which is widely used in many industries. The pressure vessel test has three major parts including weight measurement test, water-hydraulic test and leakage test followed by cleaning and drying. The control system for these tests consists of three parts: a PLC, a monitoring system and a database management system. The PLC oversees overall control of test machines, while the monitoring system measures and displays weight, pressure, flow etc. for every situations, and the database management system stores test data. These three modules are designed to communicate with one another at 1 Hz frequency alerting problematic situations to the operator. The system has gone through actual field tests for verification of performances.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.694-701
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• 2022

This paper introduces a study of concrete structures with a broken tire and a flat tire as a complete overhaul. The materials used to make concrete in this study are solid aggregate, cement, sand, flat tire, broken wheel, drinking water, and Ordinary Portland Cement. A total of 6 main compounds were thrown into solid cylinders and replaced by 0% as a controller followed by 5% and 10%. The cylinder pressure test of the concrete is done by applying the same pressure to the cylinders until a failure occurs. The results of the pressure test show that by applying 5% aggregation the pressure decreases. In Crumb wheel joints, the compression force decreases constantly as the percentage change increases. Therefore, the crumb wheel is not recommended for use as a complete replacement due to its compressive church power.

• Journal of Korean Clinical Nursing Research
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• v.16 no.3
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• pp.5-23
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• 2010

Purpose: This study was conducted to determine the validity and reliability of performance measurement tools based on the nursing process for prevention and management of pressure ulcers, falls and pain. Methods: The performance measurement tools were reviewed by a panel of experts and refined on the basis of the panel's suggestions. The validity of the performance measurement tools was measured by surveying hospital nurses. The reliability of these tools was tested by having nursing experts use the tools in five nursing units to assess nursing performance in prevention and management of pressure ulcers, falls and pain. Results: The performance measurement tools in this study were found to be acceptable as tools to evaluate quality of nursing care in pressure ulcers, falls and pain. The reliability of the performance measurement tools was acceptable. Conclusion: These results indicate that the performance measurement tools developed in this study are valid and reliable instruments to monitor and improve quality of nursing care in prevention and management of pressure ulcers, falls and pain.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.6
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• pp.834-840
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• 2021

The management and installation methods of pressure gauges in water supply pipeline are not efficiently regulated and their installations are different in each site. In this paper, various domestic and overseas documents are examined about the pressure gauge. In order to improve the efficiency of operation management such as pipeline network and pump operation, water pressure needs to be measured as accurate as possible, by which decision making for optimal pipe network can be achieved. To get the goal, the installation of pressure gauge should be reviewed about where and how to install. In this study, an optimal horizontal distance test is conducted, in which pressure value variation is monitored and analyzed according to up and down stream distances and valve flow control, and a optimal vertical position test is also analyzed by installing the pressure gauges vertically from the up(180°) to the bottom (0°) of the pipeline.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.236-249
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• 2015

The master plan of forest land management proposes forest watershed management that considers regional characteristics in order to overcome the problem of uniform forest land management. In order to manage the forest watersheds in Gyeonggi-do, this study classified 1,823 forest watersheds in Gyeonggi-do and attempted to understand their characteristics. It conducted a factor analysis and cluster analysis from the perspective of conservation value and development pressure using forest land indicators. In terms of conservation value, three factors were drawn: the topography factor, vegetation factor and public service factor, while in terms of development pressure, three factors were drawn: the easiness of development factor, economic benefits factor and development activity factor. Using these factors, forest watersheds were divided into three clusters in terms of conservation value while they were divided into three clusters in terms of development pressure. Using the results of the cluster analysis from a conservation-development perspective, the forest watersheds were classified into nine different types, and the characteristics were identified by each type. It is judged that the factors and clusters drawn as a result of the research accurately reflect the present conditions of Gyeonggi-do, and the nine types of forest watersheds have clear characteristics according to each type, which are judged to be utilized in forest management in the future.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.90-97
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• 2008

Wedged insoles are frequently used to reduce the pains caused by the knee arthritis or the foot overuse syndrome. The present study analyzed the effect of wedged rear-foot insoles on the foot pressure in walking. Three medially wedged insoles with three angles (5, 8 and 15") and three laterally wedged insoles with the same angles were made, and a flat insole were prepared. Ten healthy males in twenties walked in a specified line with each insole. Center of pressure (COP), relative vertical force and maximum force on anatomical areas were analyzed from the measured foot pressure data. At heel contact, medially wedged insoles significantly increased the pressure of the medial foot side (COP moved medially by 2-5 mm and maximum pressure of 1st metatarsal head increased by 110-120% relative to the flat insole), In contrast, laterally wedged insoles significantly increased the lateral side pressure (COP moved laterally by 1-5 mm and the ratio of $2^{nd}$ metatarsal head pressure to $1^{st}$ metatarsal head increased by 0.5-2.0 relative to the flat insole). At toe off, both wedged insoles significantly increased the pressure of the medial foot side (COP moved medially by 0.5-10 mm and the ratio of $1^{st}$ metatarsal head pressure to $5^{th}$ metatarsal head increased by 2.0 relative to the flat insole). Especially, the laterally wedged insoles significantly increased the relative vertical force (6-12%) of the rear-foot more than the flat insole.

• Journal of Families and Better Life
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• v.24 no.5 s.83
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• pp.161-174
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• 2006

This study examined different individual and parental factors that affect children's achievement motivation. For an analysis, perceived competence, intrinsic locus of control were included in individual variables. For parental variables, parental support and achievement pressure and marital conflict were examined. The sample consisted of 561 fifth and sixth grade children. Statistics and methods used for the data analysis were Cronbach's alpha, Factor analysis, frequency, percentage, Pearson's correlation, and Hierarchical Regression. Several major results were found from the analysis. First, girl's achievement motivation was higher than boys. No age difference was found between fifth and sixth grade. Second, boy's and girl's achievement motivation had a positive correlation with perceived competence, intrinsic locus of control, parental support and achievement pressure but a negative correlation with parental marital conflict. Third, important variables predicting boy's and girl's achievement motivation were perceived academic competence, parental achievement pressure and perceived social competence. Important variables predicting boy's individual and social oriented achievement motivation were perceived academic competence and parental achievement pressure. On the other hand, important variables predicting girl's individual oriented achievement motivation were perceived social competence, perceived academic competence, intrinsic locus of control and parental achievement pressure. Important variables predicting girl's social oriented achievement motivation were parental achievement pressure, perceived academic competence and mother's support.

• International journal of advanced smart convergence
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• v.7 no.3
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• pp.44-60
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• 2018

This study is to identify the effects of hypertension management program at a community health center on the disease-related knowledge, self-efficacy, anthropometric measurements and blood pressure of a hypertensive patient in local community. This study is a quasi-experimental study using nonequivalence control group no-synchronized design in order to verify the effects of the hypertension management program at a community health center on the hypertension-related knowledge, self-efficacy, anthropometric measurements and blood pressure of a hypertensive patient in local community. The result indicated a significant difference between the experimental group and control group in the scores of hypertension-related knowledge (t=-4.25, p<.001), self-efficacy (t=-4.20, p<.001), systolic blood pressure (t=7.70, p<.001) and diastolic blood(t=5.91, p<.001), body weight(t=2.32, p=.026) and abdominal circumference(t=2.17, p=.036). The hypertensive patients' knowledge and self-efficacy were improved, and their weight and abdominal circumference as well as systolic blood pressure and diastolic blood pressure were reduced. Therefore, it was confirmed that multilateral approaches in terms of physical and psychosocial aspects only targeting hypertensive patients were required for managing hypertensive patients in local community.

• Journal of the Korea Safety Management & Science
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• v.24 no.4
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• pp.101-107
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• 2022

To test a flameproof enclosure for the safety certificate, a reference pressure of explosion needs to be determined. However, the explosion pressure may be changed according to relative humidity of explosive gases. Therefore, the guideline on relative humidity should be recommended for measuring the explosion pressure for accurate and reproducible testings. This study examined the relationship of explosion pressure with relative humidity of hydrogen (31 vol %)-air and acetylene (14 vol %)-air mixture gases. The explosion pressures were measured by increasing the relative humidity of the gases by 10 % from dry state to 80 % in a cylindrical explosion enclosure of 2.3 L. on ambient temperature and atmospheric pressure (1 atm). The maximum explosive pressures were remained almost constant until the relative humidity reached 10 % for the hydrogen-air mixture and 20 % for the acetylene-air mixture. However, the maximum explosive pressures linearly decreased as the relative humidity increased. Based on the results of the study, it would be recommended to use 10 % relative humidity for the hydrogen-air mixture and 20 % for the acetylene-air mixture as the critical value in testing a flameproof enclosure.