• Korean journal of aerospace and environmental medicine
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• v.29 no.2
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• pp.67-71
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• 2019

The health of licence holders (flight crew members and air traffic controllers) is recognized as an important element of aviation safety. The medical emergency symptoms that occur during the flight duty period without prior notice can interfere with human performance capabilities and threaten aviation safety. To prevent this, ICAO has been required to conduct a periodic medical assessment process of licence holders including routine analysis of in-flight incapacitation events and medical findings during medical to identify areas of increased medical risk and continuous reevaluation of the medical assessment process to concentrate on identified areas of increased medical risk. The supply and demand of licence holders have become a major issue due to the increase in air traffic around the world, and the pilot retirement age has been extended to 65 years. But, there is no significant change in the aviation medical assessments process. The follow up of the result of medical examination discovered through aviation medical examination is a very important part, but it has not been properly implemented, and the sick leaves and medical inflight incapacitation reporting system should be improved. The management of health risk factors for licence holders must be implemented to prevent aircraft accidents or aviation safety problems caused by health problems. In this paper, we propose the development plan and concrete improvement plan of the health risk management system of licence holders in Korea in terms of aviation safety.

• Journal of East-West Nursing Research
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• v.16 no.2
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• pp.138-146
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• 2010

Purpose: This study was conducted to compare depression and quality of life between the Tae Yin In and So Yin In groups of the Sasangin constitution in Korean elderly women. Methods: A total of 203 (Tae Yin In=103, So Yin In=100) women aged over 65 yr, who were living in Seoul or Gyung-gi province, participated in the study. Data were analyzed by descriptive statistics, $X^2$-test, independent t-test, ANOVA, and Scheffe test using SPSS PC+16 version. Results: Individuals in the So Yin In group had significantly worse depression than those in the Tae Yin In group. Those in the Tae Yin In group tended to have a better quality of life than those in the So Yin In group, but no significant difference was observed. Furthermore, individuals in the Tae Yin In and So Yin In groups all had low quality of life scores comparing with median value. Significant differences in depression and quality of life according to age and subjective health status were observed in the Tae Yin In group. In the So Yin In group, significant differences in quality of life according to education and subjective health status were observed. Conclusion: A concrete nursing intervention based on the Sasangin constitution for elderly women should be explored to decrease depression and improve quality of life. Additionally, the general characteristics of elderly women should be considered to develop an appropriate nursing intervention.

• Advances in materials Research
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• v.11 no.2
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• pp.121-146
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• 2022

In the recent years, the use of agricultural waste in green cement mortar and concrete production has attracted considerable attention because of potential saving in the large areas of landfills and potential enhancement on the performance of mortar. In this research, microparticles of palm oil fuel ash (POFA) obtained from a multistage thermal and mechanical treatment processes of raw POFA originating from palm oil mill was utilized as a pozzolanic material to produce high-performance cement mortar (HPCM). POFA was used as a partial replacement material to ordinary Portland cement (OPC) at replacement levels of 0, 5, 10, 15, 20, 25, 30, 35, 40% by volume. Sand with particle size smaller than 300 ㎛ was used to enhance the performance of the HPCM. The HPCM mixes were tested for workability, compressive strength, ultrasonic pulse velocity (UPV), porosity and absorption. The results portray that the incorporation of micro POFA in HPCMs led to a slight reduction in the compressive strength. At 40% replacement level, the compressive strength was 87.4 MPa at 28 days which is suitable for many high strength applications. Although adding POFA to the cement mixtures harmed the absorption and porosity, those properties were very low at 3.4% and 11.5% respectively at a 40% POFA replacement ratio and after 28 days of curing. The HPCM mixtures containing POFA exhibited greater increase in strength and UPV as well as greater reduction in absorption and porosity than the control OPC mortar from 7 to 28 days of curing age, as a result of the pozzolanic reaction of POFA. Micro POFA with finely graded sand resulted in a dense and high strength cement mortar due to the pozzolanic reaction and increased packing effect. Therefore, it is demonstrated that the POFA could be used with high replacement ratios as a pozzolanic material to produce HPCM.

• The Journal of the Society of Stroke on Korean Medicine
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• v.7 no.1
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• pp.59-64
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• 2006

Objective : This study was aimed to investigated the warning signs and its relationship with the other characteristics in acute stroke patients. Methods : Three-hundred sixty three acute stroke patients were recuited in the oriental medical hospitals of 3 universities located in metropolitan region from October in 2005 to October in 2006. We evaluated their stroke type with brain MRI, their waring signs, and general characteristics such as age, sex, past history, risk factor, etc. Result : Of the 363 patient, 138(38%) patients were experience of warning signs. The frequency of Stress were found more in experience of warning signs than none of them. Warning signs were more common in Large Artery Atherosclerosis than in the other etiology. Conclusion : Although a concrete conclusion can hardly be drawn from this study, it reminds physicians of the importance of warning signs which their patients appeal. For the further investigation, it seems to be necessary to construct fundamental databases for stroke by increasing the number of patients and by examination into the etiology and location.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1111-1117
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• 2023

Recently, South Korean newspapers began trying to charge for online news. This study attempts to shed light on the factors that influence payment for online news by analyzing Korea Press Foundation's 2022 Media Audience Survey (N = 58,936). The results of this study showed a steady increase in past payment and paying intent for online news since 2020. Predictors of past payment for online news included gender, age, and education, and interest in political and social issues. News use through specific media (i.e., newspapers, magazines, portals, messengers, social media, video sites, and podcasts), as well as mobile applications and e-mail newsletters, were found to contribute to paid subscriptions. Based on the findings of the study, news organizations should prepare to offer differentiated news content through their own news platforms and establish concrete plans to build trust in news.

• Human Ecology Research
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• v.62 no.2
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• pp.261-278
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• 2024

This study aims to enhance the life satisfaction of the elderly population in South Korea by exploring their satisfaction levels and identifying influencing factors. Utilizing data from the 17th Korean Welfare Panel, which includes 6,260 individuals aged 65 and older, this study employs independent sample t-tests, one-way ANOVA, and hierarchical regression analysis. The results showed that, in general, the life satisfaction of the elderly population was somewhat lower than that of the general adult population in all areas, except for job satisfaction and satisfaction with housing. Key factors influencing life satisfaction among the elderly population include demographic characteristics (gender, age, economic activity, residence, education level), subjective health status factors, financial factors (disposable income, monthly living expenses), and psychological factors (depression, self-esteem). Notably, psychological factors, particularly self-esteem and depression, profoundly affect all life satisfaction domains. Enhancing life satisfaction necessitates fostering positive self-perception and capabilities in the elderly population, suggesting the need for programs focused on positive emotional experiences. Moreover, depression significantly reduces life satisfaction, underscoring the importance of policy interventions to address negative emotions in this demographic. This study is expected to provide basic data for establishing concrete and effective policies for improving the quality of life for the elderly population. Additionally, by highlighting the importance of positive psychological factors, it is anticipated that the study will offer a new direction for improving the life satisfaction of the elderly population.

• Advances in concrete construction
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• v.16 no.3
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• pp.169-176
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• 2023

The aim of the study was to establish the influence of particle size, chemical and phase composition of fine microspherical high-calcium fly ash (HCFA), as well as superplasticizer content on the strength of cementless composite materials based on 100% HCFA and mixtures of HCFA with Portland cement (PC). For the initial HCFA fractions, the particle size distribution, chemical and quantitative phase composition were determined. The compressive strength of cured composite materials obtained at W/B 0.4 and 0.25 was determined at a curing time of 3-300 days. For cementless materials, it was found that a change in the particle size d90 from 30 ㎛ (fraction 3) to 10 ㎛ (fraction 4) leads to an increase in compressive strength by more than 2 times. Compressive strength increases by at least another 2.2 times with the addition of Melflux 5581F superplasticizer (0.12%) and at W/B 0.25. The HCFA-PC blends were investigated in the range of 60-90% HCFA and the maximum compressive strength was found at 80% HCFA. On the basis of 80% HCFA-20% PC blend, the samples of ultra-high strength (108 and 150 MPa at 28 and 100 days of hardening) were obtained with the addition of 0.3% Melflux 5581F and 5% silica fume. The quantitative phase composition was determined for composite materials with a curing age of 28 days. It has been established that in a sample with ultra-high strength, a more complete transformation of the initial phases of both HCFA and PC occurs as compared to their transformation separately.

• Journal of Environmental Science International
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• v.33 no.3
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• pp.193-203
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• 2024

This study aims to determine the factors affecting the level of satisfaction with the Cell Broadcast Service (CBS) among citizens in Incheon. Partial least squares (PLS) regression, instead of multiple regression, was used for the analysis because it can solve multicollinearity and sample size issues. The analysis results are as follows: The factor with the greatest effect on satisfaction with CBS among Incheon citizens, was the elimination of redundancies (VIP=1.185). Therefore, local governments, government agencies, and public organizations must coordinate their ideas and collectively create guidelines to eliminate redundancies. The second most influential factor was the expansion in the broadcast medium from legal, institutional, and policy aspects (VIP=1.087). This is because differences in generation, age, gender, and personal characteristics were not considered. Therefore, it is necessary to devise a customized messaging tool through the expansion of broadcast media. The broadcast criteria of the legal, institutional, and policy perspectives comprised the third most influential factor, with a high VIP value of 1.053. Consequently, it is essential to devise a plan to avoid distributing unnecessary cell broadcast services, by establishing criteria for areas and sections, time, and the direct and indirect impact zones of a disaster. In the future, this study could be used as base data to develop policies, guidelines, and response measures for Incheon CBS. Given the lack of research on the diverse characteristics of each social class and the city traits of each region, and a lack of concrete empirical research on each factor, continuous and in-depth studies are required in the future.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.1
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• pp.8-16
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• 2013

Currently, global warming has advanced by the usage of fossil fuels such as coal and petroleum. and the atmosphere temperature in the world of 100 years(1906~2005) has been risen $0.74^{\circ}C{\pm}0.18^{\circ}C$, IPCC announced that the global warming effect of last decade was nearly doubled compared to the changes($0.07^{\circ}C{\pm}0.02^{\circ}C$/10year) in the past 100 years. Moreover, due to the global warming, heat wave, heavy snow, heavy rain, super typhoon, were caused and are increasing to happen in the world continuously causing damages and destruction of social infrastructures, where concrete structures are suffering deterioration by long-term extreme climate changes. to solve these problems, the new construction technology and codes are necessary. In this study, to solve these problems, experiments on a variety of cases considering the temperature and humidity, the main factors of climate factors, were performed, and the cases are decided by temperature and humidity. The specimens were tested in compressive strength test and split tensile test by the curing age(3,7,28 days) morever, performance based design(PBD) method was applied by using the satisfaction curve developed from the experiment date. PBD is the design method that gathers the current experimental analysis and past experimental analysis and develops the material properties required for the structure, and carries out the design of concrete mix, and it is recently studied actively worldwide. Also, it is the ultimate goal of PBD to design and perform on structures have sufficient performance during usage and to provide the problem solving for various situations, Also, it can achieve maximum effect in terms of functionality and economy.

• Journal of the Korea Concrete Institute
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• v.27 no.2
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• pp.127-136
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• 2015

To evaluate the effects of limestone powder and silica fume on the properties of high-strength high-volume ground granulated blast-furnace slag (GGBFS) blended cement concrete, this study investigated the rheology, strength development, hydration and pozzolanic reaction characteristics, porosity and pore size distribution of high-strength mortars with the water-to-binder ratio of 20, 50 to 80% GGBFS, up to 20% limestone powder, and up to 10% silica fume. According to test results, compared with the Portland cement mixture, the high-volume GGBFS mixture had much higher flow due to the low surface friction of GGBFS particles and higher strength in the early age due to the accelerated cement hydration by increase of free water; however, because of too low water-to-binder ratio and cement content, and lack of calcium hydroxide content, the pozzolanic reactio cannot be activated and the long-term strength development was limited. Limestone powder did not affect the flowability, and also accelerate the early cement hydration. However, because its effect on the acceleration of cement hydration is not greater than that of GGBFS, and it does not have hydraulic reactivity unlikely to GGBFS, compressive strength was reduced proportional to the replacement ratio of limestone powder. Also, silica fume and very fine GGBFS lowered flow and strength by absorbing more free water required for cement hydration. Capillary porosities of GGBFS blended mortars were smaller than that of OPC mortar, but the effect of limestone powder on porosity was not noticeable, and silica fume increased porosity due to low degree of hydration. Nevertheless, it is confirmed that the addition of GGBFS and silica fume increases fine pores.