• Journal of The Korean Astronomical Society
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• v.51 no.6
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• pp.207-214
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• 2018

A coelostat is often used for solar observations, because it corrects the image rotation automatically by guiding sunlight into a fixed telescope with two plane mirrors. For the purposes of education and spectroscopic observation, the solar group at Seoul National University (SNU) plans to develop the SNU coelostat (SNUC) and install it in the SNU Astronomical Observatory (SAO). Requirements of the SNUC are < 1" positioning accuracy with 30 cm beam size on the entrance pupil in the compact dome. To allow for installation in the small dome, we design a compact slope type coelostat with a 45 cm primary plane mirror and a 39 cm secondary plane mirror. The motion of the SNUC is minimized by fixing the position of the slope frame. Numerical simulations of the available observational time of the designed coelostat shows that the sun can be observed ay all times from June to early August and at least three hours in other months. Since the high accuracy driving motors installed in the SNUC can be affected by external environment factors such as humidity and temperature variations, we design a prototype to test the significance of these effects. The prototype consists of a 20 cm primary plane mirror, a 1 m slope rail, a direct drive motor, a ballscrew, a linear motion guide, an AC servo motor, a reduction gear and a linear encoder. We plan to control and test the accuracy of the prototype with varying atmospheric conditions in early 2019. After testing the prototype, the SNUC will be manufactured and installed in SAO by 2020.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.185-190
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• 2019

This study aims to apply the mathematical method of fractional order derivatives to the controller that controls the system response. In general, the Laplace transform of the PID controller has an exponent of the integer order of s. The derivative of the fractional order has a fractional exponent of s when it is transformed by Laplace transform. Therefore, this controller proposes a design method with the result of discrete time conversion. Because controllers with fractional exponents of s are not easy to design. This controller is applied to a standard secondary system and its performance is examined. Then, it applies to solenoid valve which is widely used in industrial field. A Luenberger's observer was designed to estimate the disturbance state and the observed state was applied to the fractional order controller. As a result, uniform and precise control performance was obtained. It was confirmed that the position error of the steady state is within 0.1 [%] and the rising time is within about 0.03 [s].

• The Plant Pathology Journal
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• v.35 no.5
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• pp.508-520
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• 2019

Interplay between Cymbidium mosaic virus (CymMV)/Odontoglossum ringspot virus (ORSV) and its host plant Phalaenopsis equestris remain largely unknown, which led to deficiency of effective measures to control disease of P. equestris caused by infecting viruses. In this study, for the first time, we characterized viral small interfering RNAs (vsiRNAs) profiles in P. equestris co-infected with CymMV and ORSV through small RNA sequencing technology. CymMV and ORSV small interfering RNAs (siRNAs) demonstrated several general and specific/new characteristics. vsiRNAs, with A/U bias at the first nucleotide, were predominantly 21-nt long and they were derived predominantly (90%) from viral positive-strand RNA. 21-nt siRNA duplexes with 0-nt overhangs were the most abundant 21-nt duplexes, followed by 2-nt overhangs and then 1-nt overhangs 21-nt duplexes in infected P. equestris. Continuous but heterogeneous distribution and secondary structures prediction implied that vsiRNAs originate predominantly by direct Dicer-like enzymes cleavage of imperfect duplexes in the most folded regions of the positive strand of both viruses RNA molecular. Furthermore, we totally predicted 54 target genes by vsiRNAs with psRNATarget server, including disease/stress response-related genes, RNA interference core components, cytoskeleton-related genes, photosynthesis or energy supply related genes. Gene Ontology classification showed that a majority of the predicted targets were related to cellular components and cellular processes and performed a certain function. All target genes were down-regulated with different degree by vsiRNAs as shown by real-time reverse transcription polymerase chain reaction. Taken together, CymMV and ORSV siRNAs played important roles in interplay with P. equestris by down modulating the expression levels of endogenous genes in host plant.

• Korea Journal of Hospital Management
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• v.24 no.3
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• pp.27-37
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• 2019

Purpose: The Purpose of this study is to provide basic data for solving mental health problems of people with disabilities by analyzing the relationship between leisure activities and the mental health. Methods: We used the chi-square test and the logistic regression model to analyze the data of the National Survey of People with Disabilities in 2017. 6,437 responses of secondary processed data were used in the analysis, Socio-economic, health behaviors and risk variables that affect the mental health of people with Disabilities were used as control variables. Result: As a result of the analysis, People with disabilities who are satisfied with their leisure activities have less depression for two weeks and less suicidal impulses (Depression: [OR]=1.80 p-value<.0001, Suicide Impulse: [OR]=2.26 p-value<.0001). In the case of the experience of leisure activities, some significance was relevant to depression for two weeks (Depression: [OR]=1.65 p-value=0.0052). Conclusion: In order to improve mental health of people with disabilities, it is necessary to provide opportunities for participation in leisure activities by improving the socioeconomic status of them. In addition, a high quality leisure program should be provided that meets the individual's needs to increase the satisfaction of leisure activities for people with disabilities.

• Journal of Gastric Cancer
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• v.19 no.2
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• pp.157-164
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• 2019

Purpose: Although standard radical gastrectomy is recommended after noncurative resection of endoscopic submucosal dissection (ESD) for early gastric cancer in most cases, residual tumor and lymph node metastasis have not been identified after surgery. The aim of this study is to evaluate the feasibility of sentinel node navigation surgery after noncurative ESD. Materials and Methods: This trial is an investigator-initiated, multicenter prospective phase II trial. Patients who underwent ESD for clinical stage T1N0M0 gastric cancer with noncurative resections were eligible. Qualified investigators who completed the prior phase III trial (SENORITA 1) are exclusively allowed to participate. In this study, 2 detection methods will be used: 1) intraoperative endoscopic submucosal injection of dual tracer, including radioisotope and indocyanine green (ICG) with sentinel basins detected using gamma-probe; 2) endoscopic injection of ICG, with sentinel basins detected using a fluorescence imaging system. Standard laparoscopic gastrectomy with lymphadenectomy will be performed. Sample size is calculated based on the inferior confidence interval of the detection rate of 95%, and the calculated accrual is 237 patients. The primary endpoint is detection rate, and the secondary endpoints are sensitivity and postoperative complications. Conclusions: This study is expected to clarify the feasibility of laparoscopic sentinel basin dissection after noncurative ESD. If the feasibility is demonstrated, a multicenter phase III trial will be initiated to compare laparoscopic sentinel node navigation surgery versus laparoscopic standard gastrectomy in early gastric cancer after endoscopic resection.

• Research in Community and Public Health Nursing
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• v.30 no.2
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• pp.217-225
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• 2019

Purpose: The purpose of this study is to assess socio-demographic, disaster-related, physical health-related, psychological, and social factors that may adversely affect disaster victims' QoL (Quality of Life). Methods: A cross sectional study was designed by using the secondary data. From the 3rd Disaster Victims Panel Survey (2012~2017), a total of 1,659 data were analyzed by using descriptive statistics including frequency, percentage, t-test, ANOVA, and multivariate linear regression. Results: Older people with lower health status lacking financial resources prior to a disaster were more at risk of low levels of QoL. Lower levels of perceived health status, resilience, and QoL were reported by disaster exposed individuals, while their depression was higher than the depression in the control group of disaster unexposed ones. Resilience, social and material supports were positively associated with QoL whereas depression and PTSD (Post-Traumatic Stress Disorders) were negatively associated. Conclusion: These findings suggest that psychological symptoms and loss due to disasters can have adverse impacts on the QoL of disaster victims in accordance with their prior socio-demographic background. They also indicate that targeted post-disaster community nursing intervention should be considered a means of increased social support as well as physical and mental health care for disaster victims.

• Archives of Plastic Surgery
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• v.46 no.2
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• pp.108-113
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• 2019

Background The aim of this study was to assess the safety of one-per-mil tumescent injections into viable skin flaps that had survived an ischemic insult, in order to assess the potential suitability of one-per-mil tumescent injections in future secondary reconstructive procedures such as flap revision and refinements after replantation. Methods Forty groin flaps harvested from 20 healthy Wistar rats weighing 220 to 270 g were subjected to acute ischemia by clamping the pedicle for 15 minutes. All flaps showing total survival on the 7th postoperative day were randomly divided into group A (one-per-mil tumescent infiltration; n=14), group B (normal saline infiltration; n=13), and group C (control, with no infiltration; n=13) before being re-elevated. Transcutaneous oxygen tension ($TcPO_2$) was measured before and after infiltration, and changes in $TcPO_2$ were statistically analyzed using analysis of variance, the paired t-test, and the independent t-test. The viability of flaps was also assessed using the Analyzing Digital Images software at 7 days after the second elevation. Results Thirty-nine flaps survived to the final assessment, with the sole exception of a flap from group A that did not survive the first elevation. $TcPO_2$ readings showed significant decreases (P<0.05) following both one-per-mil tumescent ($99.9{\pm}5.7mmHg$ vs. $37.2{\pm}6.3mmHg$) and normal saline ($103{\pm}8.5mmHg$ vs. $48.7{\pm}5.9mmHg$) infiltration. Moreover, all groin flaps survived with no signs of tissue necrosis. Conclusions One-per-mil tumescent infiltration into groin flap tissue that had survived ischemia did not result in tissue necrosis, although the flaps experienced a significant decrease of cutaneous oxygenation.

• Journal of Korean Public Health Nursing
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• v.33 no.1
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• pp.73-84
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• 2019

Purpose: This study was conducted to differentiate the factors associated with the BMI group of adolescents between rural and urban areas, and provide baseline data in the development of health education programs considering their personal and environmental characteristics. Methods: Secondary data analysis was performed using the data from an on-line survey of the 9th adolescence behavioral health in 2013. The instruments included general, behavioral, and psychosocial characteristics. This study was a cross-sectional survey conducted with 26,513 adolescents. The data were analyzed using a t-test, two-way ANOVA, and multinomial logistic regression analysis. Results: Significant differences in the prevalence of obesity between urban and rural areas were nated and rural areas exhibited a higher prevalence of obese adolescents (p<0.05). The factors associated with the BMI group were the mothers' education level (low) and lower age of adolescents (middle school) in rural areas, wherase those for urban areas were gender (boys) and the fathers' education level (low) (p<0.05). Conclusion: Because there was a significant difference in the prevalence of obesity between rural and urban areas, it is necessary to develop a tailored education program considering the regional and environmental characteristics that the adolescents belonged to in order to prevent and control adolescent obesity.

• Safety and Health at Work
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• v.10 no.1
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• pp.80-86
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• 2019

Background: Emigration of health-care workers is a problem within global health systems which affects many countries, including Peru. Several factors have caused health-care workers to emigrate, including burnout syndrome (BS). This study aims to identify the association between BS and its dimensions with the intention of physicians and nurses to emigrate from Peru in 2014. Methods: A cross-sectional study, based on a secondary analysis of the National Survey of Health Users (ENSUSALUD - 2014) was conducted. Sampling was probabilistic, considering the 24 departments of Peru. We include the questionnaire for physicians and nurses, accounting for 5062 workers. BS was measured by the Maslach Burnout Inventory-Human Services Survey. Adjusted odds ratio (OR) was calculated using multiple logistic regression. Results: Of the study population, 44.1% were physicians, 37.7% males, and 23.1% were working in Lima. It was found that 2.8% [95% confidence interval (CI): 2.19-3.45] of health-care workers had BS. The overall prevalence of intention to emigrate among health-care workers was 7.4% (95% CI: 6.36-8.40). Association was found between BS and intention to emigrate in Peruvian health-care workers (OR = 2.15; 95% CI: 1.05-4.40). Emotional exhaustion was the BS dimension most associated with intention to emigrate (OR = 1.80; 95% CI: 1.16-2.78). Conclusion: Physicians and nurses from Peru who suffered from BS were more likely to have intention to emigrate. Policies should be established to reduce BS as a strategy to control "brain drain" from health-care workers of Peru.

• Animal Bioscience
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• v.34 no.11
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• pp.1776-1783
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• 2021

Objective: This project aimed to evaluate the effects of both different additives and filling methods on nutritive quality, fermentation profile, and in situ digestibility of whole plant corn silage. Methods: Whole plant corn forage harvested at 26.72% dry matter (DM) was chopped and treated with two filling methods, i) fill silos at one time (F1), ii) fill silos at three times (F3), packing samples into one/three silo capacity at the first day, another one/three capacity at the second day, then one/three at the third day, three replicates. For each replicate, samples were treated with three additives, i) control (CTRL, no additive), ii) Sila-Max (MAX, Ralco Nutrition Inc., Marshall, MN, USA), and iii) Sila-Mix (MIX, Ralco Nutrition Inc., USA). With three replicates of each secondary treatment, there were nine silos, 54 silos in total. Each silo had a packing density of 137.61 kg of DM/m3. All silos were weighed and stored in lab at ambient temperature. Results: After 60 d of ensiling, all items showed good silage fermentation under MAX filled one time or three times (p<0.01). Higher silage quality for all additives was obtained at filling one time than that filled three times (p<0.01). The highest DM and lowest DM loss rate (DMLR) occurred to MAX treatment at two filling methods (p<0.01); Digestibility of acid detergent fiber, neutral detergent fiber (NDF), and curde protein had the same results as silage quality (p<0.01). Yield of digestible DM and digestible NDF also showed higher value under MAX especially for filling one time (p<0.05). Conclusion: All corn silages showed good fermentation attributes (pH<4.0). The forage filled one time had higher silage quality than that filled three times (p<0.01). MAX with homofermentative lactic acid bacteria enhanced the lactic acid fermentation, silage quality and nutrient digestibility, and so improved the digestible nutrient yield.