• ALGAE
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• 제34권2호
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• pp.153-162
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• 2019

Anthropogenic disturbances, including coastal habitat modification and climate change are threatening the stability of kelp beds, one of the most diverse and productive marine ecosystems. To test the effect of temperature and irradiance on the microscopic gametophyte and juvenile sporophyte stages of the rare kelp, Saccharina angustissima, from Casco Bay, Maine, USA, we carried out two sets of experiments using a temperature gradient table. The first set of experiments combined temperatures between $7-18^{\circ}C$ with irradiance at 20, 40, and $80{\mu}mol\;photons\;m^{-2}\;s^{-1}$. The second set combined temperatures of $3-13^{\circ}C$ with irradiance of 10, 100, and $200{\mu}mol\;photons\;m^{-2}\;s^{-1}$. Over two separate 4-week trials, in 2014 and again in 2015, we monitored gametogenesis, the early growth stages of the gametophytes, and early sporophyte development of this kelp. Gametophytes grew best at temperatures of $8-13^{\circ}C$ at the lowest irradiance of $10-{\mu}mol\;photons\;m^{-2}\;s^{-1}$. Light had a significant effect on both male and female gametophyte growth only at the higher temperatures. Temperatures of $8-15^{\circ}C$ and irradiance levels of $10-100{\mu}mol\;photons\;m^{-2}\;s^{-1}$ were conditions for the highest sporophyte growth. Sporophyte and male gametophyte growth was reduced at both temperature extremes-the hottest and coldest temperatures tested. S. angustissima is a unique kelp species known only from a very narrow geographic region along the coast of Maine, USA. The coupling of global warming with high light intensity effects might pose stress on the early life-history stages of this kelp, although, as an intertidal species, it could also be better adapted to temperature and light extremes than its subtidal counterpart, Saccharina latissima.

• 한국융합학회논문지
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• 제13권3호
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• pp.301-307
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• 2022

현대인의 네일숍 방문과 시술 빈도 증가에 따른 지나친 업무강도와 네일숍 방문고객으로부터 받는 스트레스는 네일 미용인의 직무 심리에 부정적 영향을 미치고 있다. 이에 네일 미용인의 네일 시술기법을 통한 직무 효능감과 직무 만족도를 상승시킬 현실적이고 구체적인 방안 마련 필요성에 따라 네일 케어, 젤 매니큐어, 프렌치 스컬프쳐, 네일 그라데이션 등의 네일기법 시술 시 지각하게 되는 직무 효능감과 직무 만족도에 대한 연구모형과 가설을 바탕으로 연구하였다. 연구 결과 네일 그라데이션기법이 네일 미용인의 직무 효능감을 가장 높게 유발하는 것으로 나타났으며, 젤 매니큐어기법을 시술할수록 네일 미용인의 직무 만족도가 증가하는데 유의적 영향을 미치는 것으로 나타났다. 본 연구를 통해 다양한 네일기법 간 복합적인 응용이 가능해지고 네일 미용인의 직무 심리 양상에 대한 좌표를 제시함과 동시에 직무환경 개선과 새로운 네일 시술기법 개발을 위한 기초자료로 작용하리라 사료한다.

• International Journal of Computer Science & Network Security
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• 제22권3호
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• pp.276-284
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• 2022

The research aims to study the dynamics of academic procrastination and its impact on the mental health of students during the transition to distance learning during the COVID-19 pandemic. At the beginning of the COVID-19 pandemic, it was identified a declining tendency of overall rates of academic procrastination and at the same time increase in the number of carriers of mid and high levels of academic procrastination. The decline in the general rates of academic procrastination at the beginning of 2021 testifies to the adaptation processes experienced by students to the conditions of distance learning. It was documented that students' academic procrastination is accompanied by a steady negative emotional tension. During the transition to distance learning, the intensity of students' learning activity has increased, which altogether causes stress as one of the main reasons for the academic procrastination among future psychologists. The study identified a risk of academic procrastination manifestation among students for their mental health, which provides a basis for developing and testing a program to prevent the phenomenon of academic procrastination among degree-seeking students.

• Current Optics and Photonics
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• 제6권3호
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• pp.227-235
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• 2022

To investigate the aging-related physiological functions of organic light-emitting diodes (OLEDs), we examined mRNA expression changes in aging-related genes due to oxidative stress inhibition by 630-nm red light OLEDs. As a result of irradiating 630-nm OLED with an intensity of 5 mW/cm² for 15 min, the viability of dermal fibroblasts significantly increased by 1.3-fold. In addition, reactive oxygen species generated by H₂O₂ were significantly reduced about 4.9-fold by irradiation with 630-nm OLED. Quantitative reverse-transcription polymerase chain reaction results showed that 630-nm OLEDs altered aging-related gene mRNA expression levels through antioxidant activity. The mRNA expression levels of matrix metalloproteinase1 (MMP1) and MMP9 decreased significantly, by about 2.2- and 2.5-fold, compared to the control group, whereas those of collagen, type I, and alpha 1 increased significantly, by 4.9-fold. The mRNA expression levels of cancer suppression genes p16 and p53 in dermal fibroblasts were also significantly reduced by 630-nm OLED irradiation, by about 1.4- and three-fold, respectively, compared to the control. Overall, it was confirmed that 630-nm OLED irradiation lowered the level of ROS formation induced by H₂O₂ in dermal fibroblasts, and that this antioxidant effect could regulate the mRNA expression levels of aging- and tumor suppression-related genes. This study shows a link between 630-nm OLED irradiation and anti-aging physiological functions such as antioxidant function, and suggests the potential of OLEDs as a useful light source for skin care.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3361-3379
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• 2022

A nuclear power plant (NPP) piping is designed against low-frequency earthquakes. However, earthquakes that can occur at NPP sites in the eastern part of the United States, northern Europe, and Korea are high-frequency earthquakes. Therefore, this study conducts bi-directional shaking table tests on actual-scale NPP piping and studies the response characteristics of low- and high-frequency earthquake motions. Such response characteristics are analyzed by comparing several responses that occur in the piping. Also, based on the test results, a piping numerical analysis model is developed and validated. The piping seismic performance under high-frequency earthquakes is derived. Consequently, the high-frequency excitation caused a large amplification in the measured peak acceleration responses compared to the low-frequency excitation. Conversely, concerning relative displacements, strains, and normal stresses, low-frequency excitation responses were larger than high-frequency excitation responses. Main peak relative displacements and peak normal stresses were 60%-69% and 24%-49% smaller in the high-frequency earthquake response than the low-frequency earthquake response. This phenomenon was noticeable when the earthquake motion intensity was large. The piping numerical model simulated the main natural frequencies and relative displacement responses well. Finally, for the stress limit state, the seismic performance for high-frequency earthquakes was about 2.7 times greater than for low-frequency earthquakes.

• Safety and Health at Work
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• 제11권4호
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• pp.543-549
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• 2020

Background: The working conditions of bus drivers are difficult; they lead to occupational diseases and require careful study, particularly in Ukraine. The objective of the article is the description of occupational health risks of passenger bus drivers that lead to deteriorating health. Methods: The risk assessment was performed using a modified Risk Score method, which allowed determining the generalized level of danger to the driver's health. The hygienic hazards level was assessed as based on Stevenson's law, which was generalized later. Results: Based on the modification of the Risk Score method, it was possible to depart from expert assessments method of the risk level and calculate the general indicator based on the degree of dependence of the impact on the human body on its intensity, proposed by V. Minko. This allows objective determining of the impact of hygiene hazards on the health of the driver and to predict the occurrence of occupational diseases associated with the cardiovascular system, musculoskeletal system, and partial or complete disability due to the accumulation of emotional fatigue. The hazard assessment was carried out for three brands of passenger buses common in Ukraine, in which the driver is exposed to the dangers of fever, vibration, noise, harmful impurities in the bus cabin, and emotional load. Conclusion: The health of drivers in the cabins of passenger buses is most affected by hygiene hazards: fever, vibration, and emotional stress. The generalized level of risk is calculated by the modified method of Risk Score is 0.83; -0.99, -0.92 respectively.

• 인간식물환경학회지
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• 제24권5호
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• pp.545-550
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• 2021

Background and objective: With increasing land use intensity in urban areas, apartment buildings have been recognized as a typical type of urban residence. In this study, the impacts of different views through a window on health-related responses were investigated using psychological and physiological parameters. Methods: Photos of three different types of views taken on low (2-12 m), middle (28-35 m), and high (over 54 m) floors of dense apartment building areas were used as visual stimuli. Twenty-two healthy adults participated in the indoor experiment. Semantic differential methods and profile of mood states were used as psychological tools. Autonomic nervous activity was evaluated using blood pressures, pulse rate and heart rate variability (HRV). Results: Analytic data showed different characteristics of psychological and physiological outcomes in three different apartment views. In the analysis of psychological parameters, significantly negative responses to the views on middle floors were found in the subscales of tension-anxiety and anger-hostility, compared to low floors. Significantly positive scores in the subscale of vigor were found on low floors with abundance of vegetation and high floors with a view of the sky. A significantly increased value of HF was found on low floors (2,294.96 ± 169.79), compared to the middle(1,553.45 ± 84.66) and high (1,523.02 ± 70.49) floors. Despite the high scores in openness and vigor, high floor views showed significantly higher LF/HF values (1.83 ± 0.09), the indicator of the sympathetic nervous system, than low (1.30 ± 0.07) and middle floor views (1.34 ± 0.06), which might be related to the unconscious fear of heights. Conclusion: Views from different heights in an apartment building can affect the psychological states of residents. Green space through the window may have a positive health outcome by reducing physiological stress.

• 운동영양학회지
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• 제24권3호
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• pp.7-12
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• 2020

[Purpose] This study was performed to investigate the acid-base and ion balance at rest and after exercise in healthy males under normoxia, moderate hypoxia, and severe hypoxia. [Methods] Ten healthy Korean males completed three different trials on different days, comprising exercise under normoxia (F_iO₂ = 20.9%, N trial), moderate hypoxia (F_iO₂ = 16.5%, MH trial), and severe hypoxia (F_iO₂ = 12.8%, SH trial). They undertook endurance exercise for 30 min on a cycle ergometer at the same relative exercise intensity equivalent to 80% maximal heart rate under all conditions. Capillary blood samples were obtained to determine acid-base and ion balance at rest and after exercise. [Results] Exercise-induced blood lactate elevations were significantly increased as hypoxic conditions became more severe; SH > MH > N trials (P = 0.003). After exercise, blood glucose levels were significantly higher in the SH trial than in the N and MH trials (P = 0.001). Capillary oxygen saturation (S_CO₂) levels were significantly lowered as hypoxic conditions became more severe; SH > MH > N trials (P < 0.001). The pH levels were significantly lower in the MH trial than that in the N trial (P = 0.010). Moreover, H_CO_3^- levels were significantly lower in the SH trial than in the N trial, with significant interaction (P = 0.003). There were no significant differences in blood Na⁺, K⁺, and Ca²⁺ levels between the trials. [Conclusion] MH and SH trials induced greater differences in glucose, lactate, S_CO₂, pH, and HCO_3^- levels in capillary blood compared to the N trial. Additionally, lactate, S_CO₂, and HCO_3^- levels showed greater changes in the SH trial than in the MH trial. However, there were no significant differences in Na⁺, K⁺, and Ca²⁺ levels in MH and SH trials compared to the N trial.

• Geomechanics and Engineering
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• 제28권6호
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• pp.613-624
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• 2022

A study of the evolution of overburden fractures under the solid-fluid coupling state was conducted based on the geological and mining characteristics of the coal seam depth, weak strata cementation, and high-intensity mining in the mining areas of West China. These mining characteristics are key to achieving water conservation during mining or establishing groundwater reservoirs in coal mines. Based on the engineering background of the Daliuta Coal Mine, a non-hydrophilic simulation material suitable for simulating the weakly cemented rock masses in this area was developed, and a physical simulation test was carried out using a water-sand gushing test system. The study explored the spatial distribution and dynamic evolution of the fractured zone in the mining overburden under the coupling of stress and seepage. The experimental results show that the mining overburden can be vertically divided into the overall migration zone, the fracture extension zone and the collapse zone; additionally, in the horizontal direction, the mining overburden can be divided into the primary fracture zone, periodic fracture zone, and stop-fracture zone. The scope of groundwater flow in the overburden gradually expands with the mining of coal seams. When a stable water inrush channel is formed, other areas no longer generate new channels, and the unstable water inrush channels gradually close. Finally, the primary fracture area becomes the main water inrush channel for coal mines. The numerical simulation results indicate that the overlying rock breaking above the middle of the mined-out area allows the formation of the water-conducting channel. The water body will flow into the fracture extension zone with the shortest path, resulting in the occurrence of water bursting accidents in the mining face. The experimental research results provide a theoretical basis for the implementation of water conservation mining or the establishment of groundwater reservoirs in western mining areas, and this theoretical basis has considerable application and promotion value.

• 스마트미디어저널
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• 제12권3호
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• pp.9-18
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• 2023

코로나19의 심화로 인해 고강도 사회적 거리두기가 장기화되고 많은 사회적 문제를 나았다. 특히 비대면 체계로 인해 물리적, 심리적 고립이 발생하였고 많은 피해가 발생하였다. 코로나로 인한 여러 사회적 문제들은 코로나19로 피해를 입은 모든 사람들에게 심한 스트레스로 작용하여 결국엔 우울증 등의 정신건강을 위협하는 요소로 작용되었다. 정신질환을 겪는 사람들은 늘어나는 반면 실제로 정신건강 서비스 이용률은 저조한 상황이기 때문에 정신건강 문제를 겪고 있는 사람들을 위한 시스템 구축이 필요한 상황이다. 이에 본 연구에서는 우울증 대상자와 일반인 대상자로부터 스마트폰을 이용한 센서 정보를 바탕으로 우울증 탐지 및 위급상황 탐지모델을 구축하였다. 우울증 탐지와 위급상황 탐지를 위해 VAE, DAGMM, ECOD, COPOD, LGBM 알고리즘을 이용하였다. 연구 결과로 우울증 탐지 모델은 F1 score 0.93, 위급상황 탐지 모델은 F1 score 0.99의 성능의 모델을 구축하였다.