• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1340-1345
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• 2018

Mo-10 at.% Cu nanocomposite powders were fabricated by using planetary ball-milling (PBM), a mechanical alloying technique for preparing nanocomposite alloy powders of metals with mutual insolubility, and the variations in the physical and the chemical characteristics with the process conditions were investigated. We observed that Mo-10 at.% Cu was an appropriate composition to ensure a good alloying grade and minimal welding between particles. The influences of the temperature and the milling conditions on the mechanical alloying process and the phase change of Mo-10 at.% Cu composite powders were investigated, and the particle and the grain sizes of the powders after mechanical alloying were confirmed. The Mo-10 at.% Cu powders showed homogeneous elemental distributions and no phase changes up to $1200^{\circ}C$; their compositions were retained after the mechanical alloying process. The finest grain size obtained was about 5 nm for powders processed using optimum PBM processing conditions: ball-to-powder weight ratio of 5 : 1, ambient air atmosphere, a milling time of 20 h, a rotation speed of 200 rpm, and a stearic acid content of 4 wt.% produced superfine-grained Mo-10 at.% Cu nanocomposite powders with an average grain size of 5 nm (which is smaller than that of other similar materials reported in the literature). The analytical results confirmed that the PBM technique presented here is a promising method for preparing superfine-grained Mo-10 at.% Cu powders with improved properties.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.3
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• pp.49-56
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• 2023

The allowable mean overtopping discharge is used as a design parameter for coastal structures. The crest elevation of coastal structures should ensure the wave overtopping discharge within acceptable limits for structural safety and the safety of pedestrians, vehicles, operations, and so on. In this study, two-dimensional physical model tests on typical rubble-mound structure geometries were performed and the the mean wave overtopping discharges under various water depth and wave conditions were measrued. The various test conditions were applied to the tests with the change of the wave steepness, relative freeboard and relative wave height. An empirical formula from the experimental data was proposed to predict the mean wave overtopping volumes.

• Journal of the Korean Magnetics Society
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• v.6 no.1
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• pp.21-27
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• 1996

The effects of various manufacturing conditions on the characteristics of metal particle tape using ultra-fine metal powder were investigated. As functions of kneading conditions and milling solid contents. coating thickness, orientation, calender and curing conditions. various properties of the tapes were studied. By the consideration of physical and eletromagnetic properties of the tapes, optimum process conditions were determined. As a result of above investigations, we concluded that manufacturing processes were very important factor in addition to dispersion behavior of particles for achieving maximum properties of the metal particle tape.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.333-338
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• 2003

Polymeric composite structures used in ground transportation applications such as the carbody of tilting train may be exposed to a ground environmental conditions during long-term missions. In this study, the degradation of mechanical and physical properties of graphite/epoxy composite and glass fabric/phenol composite under ground environmental conditions was investigated. Accelerated environmental conditions of ultraviolet radiation, temperature, and moisture were considered. Several types of specimens were used to investigate the effects of environmental conditions on mechanical properties of the composites. Also, storage shear modulus, loss shear modulus, and tan 8 were measured as a function of exposure times through a dynamic mechanical analyzer. Finally, composite surfaces exposed to environmental conditions were examined using a scanning electron microscope.

• Journal of Hospice and Palliative Care
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• v.18 no.1
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• pp.25-34
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• 2015

Purpose: This study is to find relationship between cancer patient's spiritual health and the level of their anxiety and pain. Methods: From April 27 through May 11, 2012, a survey was conducted with 167 cancer patients hospitalized at a university hospital in Busan. Spiritual health was measured by the Spiritual Health Inventory developed by Highfield (1992). The instrument for anxiety measurement was the State-Trait Anxiety Inventory by Spielberger (1975) and that for pain was the Visual Analogue Scale (2009). The association between patients' characteristics and spiritual health, anxiety or pain degree were analyzed using the ANOVA test. The interrelationship between spiritual health, anxiety and pain was analyzed using Pearson's correlation coefficients. Results: The patients exhibited a moderate degree of spiritual health and anxiety and a mild level of pain. Patients' spiritual health significantly differed by their religion, education, monthly income of the family, illness conditions, physical conditions, metastasis, daily living and support. Their anxiety level was significantly different according to age, religion, education, illness conditions, physical conditions, metastasis, daily living, family/friends' support and use of analgesics. Significant differences were also found in the level of pain according to illness conditions, physical conditions, metastasis, daily living, family/friends' support and use of analgesics. We found a moderately negative correlation between spiritual health and anxiety. Anxiety and pain showed a positive correlation, and spiritual health and pain exhibited a negative correlation. Conclusion: To help cancer patients to manage their spiritual health, anxiety and pain, a program should be developed considering the primary factors discussed in this study.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.3
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• pp.276-291
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• 2020

As social distancing is implemented to prevent the spread of COVID-19, there is an increasing number of workers participating in telework. This study aims to classify the feasibility of working at home for occupations and industries based on physical working conditions, and to analyze regional distribution of the teleworkable jobs. And the raw data of the Korea Working Conditions Survey is used to examine working environment and characteristics of jobs. The main findings show that 35% of jobs in South Korea can be done at home, and the occupations that are less amenable to work at home are closely related to the economically vulnerable workers who earn low wages. Furthermore, the regions that are heavily dependent on manufacturing for employment are likely to have a lower share of jobs that can be done at home due to the industrial structure and working conditions.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.3
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• pp.34-42
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• 1997

This study was carried out to investigate the proper cooking conditions of soda-anthraquinone and alkaline sulfite-anthraquinone pulping of rice-straw, and get basic data f9r the use of rice-straw chemical pulp through the test of characteristics and physical properties of pulps made in the various cooking conditions From the experimental results , we can conclude as follows. In the soda-anthraquinone pulping of rice-straw, the optimum cooking conditions were 60 min. at $150^{\circ}C$ in the amount of caustic soda of 20% with the addition of anthraquinone(0.05%). And total yield, Kappa No. and brightness of pulp made in the condition above mentioned were 41.9%, 7.7 and 51.1 respectively. In the alkaline sulfite-anthraquinone pulping of rice-straw, the proper mixing ratio of cooking chemical(caustic soda : sodium sulfite) was 50:50. And the optimum cooking conditions were 60 min. at $150^{\circ}C$ in the amount of cooking chemical of 20% with the addition of anthraquinone(0.05%). At that time, the total yield, Kappa No, and brightness of pulp were 50.1%, 9.1 and 40.2 respectively. As a result, the alkaline sulfite-anthraquinone pulping was superior to the soda-anthraquinone pulping in the aspect of yield, but inferior in the viewpoints of Kappa No. and brightness. For the comparison of qualities of pulps made in the various cooking methods and conditions, the physical properties of four sorts of pulps were tested. As a result, soda-anthraquinone pulps were superior to alkaline sulfite-anthraquinone pulps in the various strengths excluding tear strength and brightness. On the other hand, pulps made in the condition of addition of cooking chemical of 20% were superior to pulps in the dosage of 15% in the aspects of all the strengths and brightness.

• PNF and Movement
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• v.19 no.3
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• pp.375-382
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• 2021

Purpose: The objectives of the present study were to investigate the disadvantages of tire pressure asymmetry of a wheelchair tire and recommend the criterion for appropriate tire pressure without generating negative changes in the musculoskeletal system in asymptomatic participants. Methods: Fourteen asymptomatic participants were asked to sit in pressure-controlled wheelchairs and perform desk work for 20 minutes in each tire condition. The asymmetry of the tire conditions was set as 0% difference, 25% difference, and 50% difference from the recommended pressure. The pelvic alignment and muscular recruitment represented as a flexion-relaxation ratio (FRR) were measured at pre-test, and after each condition of desk work. The displacement of the center of pressure (COP) was measured during the desk work. Results: The tire air pressure condition significantly affected the FRR and COP (P < 0.05). Both sides of the FRR values were significantly higher under the symmetrical tire conditions (0% difference) and pre-test, compared with the asymmetrical tire condition of 50% difference (P < 0.05). The mediolateral COP displacement of the asymmetrical tire conditions (25% and 50% difference) was significantly higher than that of the symmetrical tire conditions (0%) (P < 0.05). Conclusion: Asymmetrical tire conditions could cause changes in the muscle recruitment pattern of the erector spine and mediolateral COP displacement. Tire pressure asymmetry higher than 50% could be a risk factor for prevalence of back pain, so this level of asymmetry in tire pressures should be cautioned against for wheelchair users.

• Korean Journal of Health Education and Promotion
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• v.19 no.1
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• pp.133-147
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• 2002

This study conducted an analysis of the correlations among menopausal symptoms of middle-aged women, their exercise performance and subjective health conditions on those 417 middle-aged women aged 40-59 years, residing in Seoul and the Kyongki Province area, from December 6, 2000 through Jun. 20, 2001, using the SPSS 10.00 program. Resultant findings were revealed, as follows: 1. A difference was represented in general characteristics between menopausal symptoms of middled-aged women and variables such as satisfaction with life, sexual life, diseases, the presence or absence of surgical operations; a difference between exercise performance and variables such as age, the presence or absence of vocations, weight control, satisfaction with life, and sleep; and also a difference between subjective health conditions and variables such as weight control, satisfaction with life, diseases, and the presence or absence of surgical operations. 2. Furthermore, a difference was revealed between the levels of menopausal symptoms by exercise performance and variables such as mental and physical symptoms and psychological symptoms. 3. The group of good exercise performance showed higher subjective health conditions as to subjective health conditions by the levels of exercise performance. 4. The better their subjective health conditions, the lower their menopausal symptoms as to menopausal symptoms by subjective health conditions. 5. A negative relationship was disclosed between menopausal symptoms and exercise performance; a positive relationship between exercise performance and subjective health conditions; and a negative relationship between subjective health conditions and menopausal symptoms.

• Safety and Health at Work
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• v.8 no.4
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• pp.378-385
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• 2017

Background: The present rapid shift of industrialization from developed to developing countries requires developing countries to understand issues related to work organization, management, and working conditions. There are many factors slackening production, of which working conditions is part. A complete inquiry into the workers' working conditions can enable managements to reduce risks in the workplaces and improve productivity. Understanding and awareness of the benefits of workplace research and a probe into the working conditions in the Ugandan apparel assembly plants are urgently required. Methods: A total of 103 (70 women and 33 men) workers from five different plants were interviewed. Together with the top management of various plants, questionnaires about the workers' opinions of their physical working conditions were prepared. Data was collected using two methods: (1) questionnaire; and (2) observation of the workers during their work. Results: The results indicated that poor plant working conditions were mainly contributed by the workers' social factors and the management policies. Conclusion: The government, together with the management, should work to improve the working conditions in the apparel assembly plants, as it greatly affects both.