• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.387-394
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• 2019

In this study, in order to evaluate the damage and deterioration of the track components of sleeper floating track (STEDEF), the field samples(specimens) were taken from the serviced line over 20 years old, and the track components were visually inspected, and investigated by laboratory tests and finite element analysis. As a result of visual inspection, the damage of the rail pad and fastener was slight, but the rubber boot was worn and torn at the edges of bottom. The resilience pads were clearly examined for thickness reduction and fatigue hardening layer. As a result of spring stiffness test of rail pad and resilience pad, the deterioration of rail pad was insignificant, but the deterioration of resilience pad exceeded design standard value. Therefore resilience pad was directly affected by train passing tonnage. As a result of comparing the deterioration state of the field sample and the numerical analysis result, the stress and displacement concentration position of the finite element model and the damage position of the field sample were coincident.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.562-570
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• 2019

The purpose of this study was to identify the factors influencing the quality of sleep in breast cancer patients receiving chemotherapy in the outpatient settings. The data were collected from 203 patients with breast cancer receiving chemotherapy in the outpatient settings at one tertiary hospital in B City. Stress, fatigue and depression were negatively correlated with quality of sleep (r=-.369, p=.001; r=-.565, p=.001; r=-.526, p=.001, respectively). Fatigue(${\beta}=-.387$, p<.001) was one of the biggest impact factors on quality of sleep which explained 31.6% of the variance of the sleep quality, followed by the experience of sleep disturbances prior to the diagnosis of breast cancer(${\beta}=-.178$, p<.002) and depression(${\beta}=-.231$, p<.004). In total, all of the antecedent variables explained significantly 37.4% of the variance of the sleep quality. Thus, in order to improve the quality of sleep, integrative nursing interventions need to be developed to reduce fatigue and depression among them, including an proactive system to screen out the patients with the experience of sleep disturbances prior to the diagnosis with breast cancer and to provide adequate pharmacological and/or non-pharmacological sleep interventions prior to the chemotherapy.

• 한국노년학
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• v.36 no.3
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• pp.727-749
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• 2016

This systematic review was performed to investigate relationship between sarcopenia and cognitive function among community-dwelling older adults. Studies which reported prevalence rates of sarcopenia in community-dwelling older adults, relationships between sarcopenia and cognitive dysfunction, or effective interventions in alleviated symptoms of sarcopenia were selected. Of 43 studies reviewed, prevalence rate of sarcopenia ranged from 2.5-42.4% in 25 studies, and 4 studies revealed a significantly positive correlation between sarcopenia and cognitive dysfunction. Among 12 randomized-control trials (RCTs), exercise intervention was used in 2 studies; nutrition intervention in 6; and 4 studies included both the exercise and nutrition interventions. All interventional studies reported positive effects on muscle mass, muscle strength, or physical function. However, only 6 studies met the high quality criteria of Risk of Bias, and there was no study which evaluated cognitive function as an outcome measure. Therefore, this study draws attention to the lack of high-quality RCTs and exclusion of cognitive function as an outcome measure in the research of sarcopenia. A comprehensive and sustained system including standardized sarcopenia screening, assessments of cognitive functioning, and evidence-based intervention programs is needed in order to prevent and manage sarcopenia amongst older adults in the community.

• Clean Technology
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• v.25 no.3
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• pp.179-188
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• 2019

Upon the combustion of coal particles in a coal-fired power plant, fly ash (80%) and bottom ash (20%) are unavoidably produced. Most of the ashes are, however, just dumped onto a landfill site. When the landfill site that takes the fly ash and bottom ash is saturated, further operation of the coal-fired power plant might be discontinued unless a new alternative landfill site is prepared. In this study, wet flotation separation system (floating process) was employed in order to recover unburned carbon (UC), ceramic microsphere (CM) and cleaned ash (CA), all of which serving as useful components within fly ash. The average recovered fractions of UC, CM, and CA from fly ash were 92.10, 75.75, and 69.71, respectively, while the recovered fractions of UC were higher than those of CM and CA by 16% and 22%, respectively. The combustible component (CC) within the recovered UC possessed a weight percentage as high as 52.54wt%, whereas the burning heat of UC was estimated to be $4,232kcal\;kg^{-1}$. As more carbon-containing UC is recovered from fly ash, UC is expected to be used successfully as an industrial fuel. Owing to the effects of pH, more efficient chemical separations of CM and CA, rather than UC, were obtained. The average $SiO_2$ contents within the separated CM and CA had a value of 53.55wt% and 78.66wt%, respectively, which is indicative of their plausible future application as industrial materials in many fields.

• Food Science and Industry
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• v.54 no.2
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• pp.93-101
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• 2021

Hazard Analysis Critical Control Point (HACCP) systems were developed to ensure a high level of food safety and reduced risk of foodborne illness. This paper focuses on significant issues associated with the implementation of HACCP; it provides an overview on recent literature. The structure of the paper follows six groupings of issues in the international literature of HACCP: (1) comparative studies and unification plan between HACCP and other food safety regulations; (2) verification of the HACCP system's effectiveness in improving food safety; (3) establishment of critical control point (CCP) for various foods HACCP model development; (4) expansion of HACCP application in the various fields and small businesses;(5) the impacts of HACCP on consumer's preferences and firms' financial performance in food industry; (6) HACCP and technological changes. The paper concludes with some suggestions for the future research in order to promote safe food supply chain for global customers.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.23-29
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• 2011

The oxidation slag has been widely used in civil engineering project, whereas the reduced slag from electric furnace has yet to be applied. Consequently in order to find out the recycling method in civil engineering field, the mineral compositions of the reduced slag were analyzed and some tests on water quality were performed to estimate the potential release of toxic compounds. Slag-soil mixtures of 0, 10, 20 and 30%(dry weight) soil were prepared in lysimeter columns and the effluents were collected with the period of one, two and four week options in closed system, respectively. The result from qualitative and quantitative analysis using X-ray Diffraction(XRD) and X-ray Fluorescence(XRF) indicates that the main mineral of the reduced slag is $Ca_2(SiO_4)$, a kind of calcium silicate. Also, the leaching medium analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy(ICP-OES) showed that main heavy metals such as Al, Fe and Mn are included in the reduced slag due to the effect of steel production process. It can be seen that the leachate does not violate the regulation guide line of waste material of heavy metal. Also the pH levels were increased from pH 6.9 for 0% soil to pH 10 for 30% soil. However the influence on leachate circulation period of one through four weeks was negligible.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.37-47
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• 2021

The purpose of this study was to identify relationship between resilience, social support, community resilience, and anxiety in nursing students. 252 participants were recruited from the university located in Gyeonggi-do and data were collected using self-reported questionnaires. Data were analyzed using the SPSS/WIN 25.0 program, with descriptive statistics x2-test, t-test, ANOVA, Pearson's correlation. The average score were resilience 3.10 out of 5, social support 4.22 out of 5, community resilience 3.21 out of 5, and anxiety 2.21 out of 4. In addition, social support(r=.32, p<.001) and community resilience(r=.18, p=.004) were positively correlated with resilience, but anxiety(r=-64, p<.001) was negatively correlated with resilience in university students. In conclusion, program and comprehensive support system are needed to strengthen social support and community resilience, to control and cope with anxiety in order to improve resilience of the university students.

• Journal of Space Technology and Applications
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• v.1 no.1
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• pp.23-32
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• 2021

The high-level Space Situational Awareness (SSA) objective is to provide to the users dependable, accurate and timely information in order to support risk management on orbit and during re-entry and support safe and secure operation of space assets and related services. Therefore the risk assessment for the re-entry of space objects should be managed nationally. In this research, the Software for Re-Entry Prediction of space objects (SREP) was developed for national SSA system. In particular, the rate of change of the drag coefficient is estimated through a newly proposed Drag Scale Factor Estimation (DSFE), and is used for high-precision orbit propagator (HPOP) up to an altitude of 100 km to predict the re-entry time and position of the space object. The effectiveness of this re-entry prediction is shown through the re-entry time window and ground track of space objects falling in real events, Grace-1, Grace-2, Tiangong-1, and Chang Zheng-5B Rocket body. As a result, through analysis 12 hours before the final re-entry time, it is shown that the re-entry time window and crash time can be accurately predicted with an error of less than 20 minutes.

• Korean journal of aerospace and environmental medicine
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• v.31 no.1
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• pp.24-30
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• 2021

Purpose: The purpose of this study is to consider ways to strengthen it through comparison and curriculum while recognizing the importance of global competencies in liberal arts education in universities. Methods: In order to explore ways to reinforce the sub-competence of global competencies, this study was conducted at a four-year university in Chungcheong-do for one year in 2019, such as 'Global Culture Talk', 'Global Travel', 'Global Nanta', and 'Making Global Friends'. Cases of comparison and application of educational programs were analyzed. The program was attended by the Department of Business Administration, Department of Aviation Service, Department of Design, Department of Manga Animation, Department of Broadcasting and Film, and foreign exchange students. The competency-centered curriculum not only has clear educational goals, but is also very advantageous in establishing a feedback system by measuring its performance. This study will assess the effectiveness of the education plan by diagnosing the change in competencies before and after the comparison and curriculum is operated. Results: The overall global competency has increased by 0.2 points compared to 2017. By subsector, it was found that the flexibility increased by 1.4 points. In the field of cross-cultural understanding, it rose 0.6 points, and in the field of global understanding, it rose 2.2 points, showing the largest increase in the sub-fields. Nevertheless, the field of global interest remains at a low level. This is considerably low compared to flexibility and ability to understand other cultures, and it is expected that measures for improvement should be continuously sought. Since the understanding of other cultures has already exceeded 60 points, it is expected that the global competency of the university will be strengthened if the level is consistently maintained and the emphasis is placed on enhancing flexibility and improving global understanding. Conclusion: The importance of strengthening global capabilities is steadily rising. Universities are also reorganizing the curriculum by analyzing the needs and satisfaction of education consumers to respond to this. The programs operated and analyzed in this study were also made as part of this effort. However, since there are various factors that affect global competency, it cannot be but admitted that it is not easy to gauge the change in competency with only a few programs and short-term efforts. However, if the efforts pursued by this study are accumulated and supplemented through feedback from a long-term perspective, it can be expected that there are not a lot of contributions to strengthening global competencies in liberal arts education.

• Resources Recycling
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• v.31 no.6
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• pp.81-91
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• 2022

The use of lithium-ion batteries increases significantly with the rapid spread of electronic devices and electric vehicle and thereby an increase in the amount of waste batteries is expected in the near future. Therefore, studies are continuously being conducted to recover various resources of cathode active material (Ni, Co, Mn, Li) from waste battery. In order to recover the cathode active material, black mass is generally recovered from waste battery. The general process of recovering black mass is a waste battery collection - discharge - dismantling - crushing - classification process. This study focus on the crushing/classification process among the processes. Specifically, the particle size distribution of various samples at each crushing/classification step were evaluated, and the particle shape of each particle fraction was analyzed with a microscope and SEM (Scanning Electron Microscopy)-EDS(Energy Dispersive Spectrometer). As a result, among the black mass particle, fine particle less than 74 ㎛ was the mixture of cathode and anode active material which are properly liberated from the current metals. However, coarse particle larger than 100 ㎛ was present in a form in which the current metal and active material were combined. In addition, this study developed a PBM(Population Balance Model) system that can simulate two-species mixture sample with two different crushing properties. Using developed model, the breakage parameters of two species was derived and predictive performance of breakage distribution was verified.