• Geomechanics and Engineering
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• v.18 no.4
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• pp.449-457
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• 2019

Physical model tests were first performed to investigate the failure pattern of multiple pillar-roof support system. It was observed in the physical model tests, pillars were design with the same mechanical parameters in model #1, cracking occurred simultaneously in panel pillars and the roof above barrier pillars. When pillars 2 to 5 lost bearing capacity, collapse of the roof supported by those pillars occurred. Physical model #2 was design with a relatively weaker pillar (pillar 3) among six pillars. It was found that the whole pillar-roof system was divided into two independent systems by a roof crack, and two pillars collapse and roof subsidence events occurred during the loading process, the first failure event was induced by the pillars failure, and the second was caused by the roof crack. Then, for a multiple pillar-roof support system, three types of failure patterns were analysed based on the condition of pillar and roof. It can be concluded that any failure of a bearing component would cause a subsidence event. However, the barrier pillar could bear the transferred load during the stress redistribution process, mitigating the propagation of collapse or cutting the roof to insulate the collapse area. Importantly, some effective methods were suggested to decrease the risk of catastrophic collapse, and the deep-hole-blasting was employed to improve the stability of the pillar and roof support system in a room and pillar mine.

• Korean Journal of Medicinal Crop Science
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• v.26 no.6
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• pp.447-454
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• 2018

Background: The leaf temperature ($T_{LEAF}$) is one of the most important physical parameters governing water and carbon flux, including evapotranspiration, photosynthesis and respiration. Cnidium officinale is one of the important folk medicines for counteracting a variety of diseases, and is particularly used as a traditional medicinal crop in the treatment of female genital inflammatory diseases. In this study, we developed a model to estimate $T_{Leaf}$ of Cnidium officinale Makino based on black globe temperature ($T_{BGT}$). Methods and Results: This study was performed from April to July 2018 in field characterized by a valley and alluvial fan topography. Databases of $T_{LEAF}$ were curated by infrared thermometry, along with meteorological instruments, including a thermometer, a pyranometer, and an anemometer. Linear regression analysis and Student's t-test were performed to evaluate the performance of the model and significance of the parameters. The correlation coefficient between observed $T_{LEAF}$ and calculated $T_{BGT}$ obtained using an equation, developed to predict $T_{LEAF}$ based on $T_{BGT}$ was very high ($r^2=0.9500$, p < 0.0001). There was a positive relationship between $T_{BGT}$ and solar radiation ($r^2=0.8556$, p < 0.0001), but a negative relationship between $T_{BGT}$ and wind speed ($r^2=0.9707$, p < 0.0001). These results imply that heat exchange in leaves seems to be mainly controlled by solar radiation and wind speed. The correlation coefficient between actual and estimated $T_{BGT}$ was 0.9710 (p < 0.0001). Conclusions: The developed model can be used to accurately estimate the $T_{Leaf}$ of Cnidium officinale Makino and has the potential to become a practical alternative to assessing cold and heat stress.

• Journal of Oriental Neuropsychiatry
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• v.30 no.3
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• pp.237-249
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• 2019

Objectives: Interest in the use of complementary and alternative treatments to treat dementia. Meditation is used to treat various symptoms of physical and psychological diseases. Some studies suggest that meditation might have positive effects on cognitive functions, especially attention, in the elderly. However, how meditation affects Alzheimer's disease (AD) patients remains unclear. In this review, we assessed the effectiveness of practicing meditation in combination with standard care in AD. Methods: We searched the CCRCT, MEDLINE, EMBASE, AMED and CINAHL databases on 30 May 2017. We included randomized controlled trials (RCTs) that used meditation in adult patients diagnosed with AD. We allocated patients to a meditation combined with standard care or a standard care-only group. Results: The two RCTs met the inclusion criteria. A total of 98 patients were included in the meditation with standard care and standard care-only groups in this review. All meditation programs in the included trials were based on practicing mindfulness. The results of our meta-analysis indicatedthat adjunctive mindfulness meditation programs exerted favourable but non-significant effects on cognitive function on the Mini Mental State Examination (MMSE) (MD=4.68, 95% CI -0.11 to 9.46; Z=1.92, p=0.06). Only one study assessed depression, anxiety, quality of life and stress. No adverse events related to meditation were reported in the included studies. Conclusions: Insufficient data iscurrently available to determine the effectiveness of practicing meditation on patients diagnosed with AD. Hence, further RCTs with high methodological quality and larger sample sizes are needed to effectively estimate the effects of meditation on AD.

• The Journal of Korean Obstetrics and Gynecology
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• v.32 no.2
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• pp.87-99
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• 2019

Objectives: The aim of this study was to analyse the domestic trends of Chuna manual therapy on Obstetrics and Gynecological Diseases in Korean literature. Methods: We searched for papers which had Chuna manual therapy through 2 related journals and 5 Korean web databases. All relevant papers were selected and extracted to be analyzed according to their study designs, academic journals, and target disease. Results: Nine papers belonged to four types of study designs, systematic review, randomized or non-randomized controlled trial and case report. And they were published in four kinds of academic journals. There were four papers about postpartum pain, two low back pain during pregnancy, and a stress urinary incontinence. The exact Chuna techniques were explained in only seven papers. All of papers have been shown that Chuna manual therapy is useful for obstetrics and gynecological diseases. Conclusions: It has been identified that Chuna manual therapy could be a good treatment for obstetrics and gynecological diseases. However, more clinical and well-designed studies with Chuna manual therapy will be needed.

• Journal of Korean Academy of Nursing
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• v.49 no.2
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• pp.149-160
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• 2019

Purpose: The purpose of this study was to examine the effects of oral cryotherapy on oral mucositis, reactive oxygen series, inflammatory cytokines, and oral comfort in patients undergoing chemotherapy for gynecologic cancers. Methods: Participants were randomly assigned to the experimental group (n=25, receiving oral cryotherapy during chemotherapy) and the control group (n=25, receiving the usual care consisting of 0.9% normal saline gargles three times before meals). Oral mucositis was assessed using the oral assessment guide, while oral comfort was assessed using the oral perception guide. Reactive oxygen series was measured as total oxidant stress, and the level of two inflammatory markers, interleukin-6 (IL-6) and tumor necrosis factor-alpha ($TNF-{\alpha}$), were examined. The data were analyzed using t-test, chi-square test, Fisher's exact test, Mann-Whitney U-test, and repeated measures analysis of variance. Results: There was a significant difference in the oral mucositis score, reactive oxygen series score, $TNF-{\alpha}$ level, and oral comfort score between the two groups, and there were significant changes over time and in the group-by-time interactions. There was a significant difference in the IL-6 score between the two groups, but there were no significant changes over time or in the group-by-time interactions. Conclusion: The study results revealed that oral cryotherapy was more effective than the usual care regime of normal saline gargles for reducing oral mucositis, reactive oxygen series, and inflammatory cytokines and for improving oral comfort in gynecologic cancer patients undergoing chemotherapy.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.2
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• pp.51-57
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• 2021

The quality of the ceramic sintered coating on a metal surface through laser surface treatment is affected by the laser irradiation pattern. Depending on the laser irradiation pattern, the amount of residual stress and heat applied or accumulated on the surface increases or decreases, affecting the thickness attained in the ceramic sintering area. When the heat energy accumulated in the sintering area is high, the ceramic and the metal alloy melt and sufficiently mix to form a homogeneous and thick bonding interface. In this study, the thermal energy accumulation in the region sintered with zirconia was controlled using four types of laser processing patterns. The thickness of the diffusion region is analyzed by laser-induced breakdown spectroscopy of Mg-ZrO2 generated by laser sintering zirconia powder on the magnesium alloy surface. On the basis of the analysis of the Mg and Zr present in the sintered region through LIBS, the effect of the irradiation pattern on the sintering quality is confirmed by comparing and analyzing the heat and mass transfer tendency of the diffusion layer and the degree of diffusion according to the irradiation pattern. The derived diffusion coefficients differed by up to 9.8 times for each laser scanning pattern.

• Korean Journal of Metals and Materials
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• v.48 no.5
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• pp.394-400
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• 2010

The effects of oxidation behavior on the hot ductility of plain carbon steels were investigated at various temperatures in order to simulate the continuous casting process more precisely, in which the process undergoes in air atmosphere rather than Ar atmosphere. The high temperature oxidation behavior and scale morphology of the carbon steels exposed to the air and Ar atmosphere at various temperatures were also investigated in order to assess the mechanism of the RA value decreasing in an air atmosphere. The RA values obtained from the air atmosphere were marked below 45% by the test temperature, except for over 1000${^{\circ}C}$, with the RA values remaining in low values in both the low and high temperature region, at which the RA values generally recovered in the Ar atmosphere. The surface roughness of the specimen was developed by external and internal oxidation when the specimen was deformed in an air atmosphere at high temperature, with the result being the stress concentrated at the roughness of the specimen surface, resulting in low RA values. The hot ductility in the air atmosphere was found to be likely controlled by the oxidation rate instead of the microstructures corresponding to test temperatures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.4
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• pp.257-268
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• 2021

Objectives: Cleft lip and palate is a common congenital anomaly that impairs the aesthetics, speech, hearing, and psychological and social life of an individual. To achieve good aesthetic outcomes, presurgical nasoalveolar molding (NAM) has become important. Currently, the intraoral NAM technique is widely practiced. Numerous modifications have been made to intraoral NAM techniques, but the original problem of compliance leading to discontinuation of treatment remains unsolved. Therefore, the present study compared an extraoral NAM technique with the intraoral NAM technique. Materials and Methods: Twenty infants with complete unilateral cleft lip and palate were included and divided into two equal groups. Group A received the intraoral NAM technique, and Group B received the extraoral NAM technique. Pre- and postoperative extraoral and intraoral measurements were recorded. Results: Groups A and B did not differ significantly in any extraoral or intraoral parameter. Conclusion: The extraoral NAM technique is as effective as the intraoral NAM technique in achieving significant nasal and alveolar changes in complete unilateral cleft lip and palate patients. Additionally, it reduces the need for frequent hospital visits for activation and the stress associated with the insertion and removal of the intraoral NAM plate, thereby improving compliance.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.1-9
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• 2022

The causes of accidents occurring in chemical plants vary, but 96% of industrial accidents occurring worldwide are caused by workers' unsafe behavior. The International Labour Organization (ILO) has announced 20 elements of workers' anxiety-warning behaviors that occur on multiple occasions at industrial sites in order to warn them of the risk of accidents caused by workers' anxiety-driven behavior, and to prevent industrial accidents, workers' anxiety-driven behavior should be controlled under stress In this study, major types of unsafe behavior were analyzed on the basis of information on the accident investigation history of domestic workspaces in order to find out how workers can manage their unsafe behavior. Based on the results of the analysis of the major anxiety war behavior, the root cause of causing anxiety war behavior was analyzed using the Swiss Cheese Model, and each root cause management method was proposed.

• Advances in nano research
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• v.13 no.1
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• pp.87-96
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• 2022

Drug self-delivery systems can easily realize combination drug therapy and avoid carrier-induced toxicity and immunogenicity because they do not need non-therapeutic carrier materials. So, designing appropriate drug self-delivery systems for specific diseases can settle most of the problems existing in traditional drug delivery systems. Retinal pigment epithelium is very important for the homeostasis of retina. However, it is vulnerable to oxidative damage and difficult to repair. Worse still, the antioxidants can hardly reach the retina by non-invasive administration routes due to the ocular barriers. Herein, the targeted group (folic acid) and antioxidant (melatonin) have been grafted on the surface of ZnO quantum dots to fabricate a new kind of drug self-delivery systems as a protectant via eyedrops. In this study, the negative nanoparticles with size ranging in 4~6 nm were successfully synthesized. They could easily and precisely deliver drugs to retinal pigment epithelium via eyedrops. And they realized acid degradation to controlled release of melatonin and zinc in retinal pigment epithelium cells. Consequently, the structure of retinal pigment epithelium cells were stabilized according to the expression of ZO-1 and β-catenin. Moreover, the antioxidant capacity of retinal pigment epithelium were enhanced both in health mice and photic injury mice. Therefore, such new drug self-delivery systems have great potential both in prevention and treatment of oxidative damage induced retinal diseases.