• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.4
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• pp.233-242
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• 2023

The unscented Kalman filter (UKF), which is widely used to estimate the states of nonlinear dynamic systems, can be improved to realize robust system identification by using multiple sigma-point sets. When using Kalman filter methods for system identification, artificial noises must be appropriately selected to achieve optimal estimation performance. Additionally, an appropriate scaling factor for the sigma-points must be selected to capture the nonlinearity of the state-space model. This study entailed the use of Bouc-Wen hysteresis model to examine the nonlinear behavior of a single-degree-of-freedom oscillator. On the basis of the effects of the selected artificial noises and scaling factor, a new UKF method using multiple sigma-point sets was devised for improved robustness of the estimation over various signal-to-noise-ratio values. The results demonstrate that the proposed method can accurately track nonlinear system states even when the measurement noise levels are high, while being robust to the selection of artificial noise levels.

• The Journal of Korean Physical Therapy
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• v.35 no.3
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• pp.71-76
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• 2023

Purpose: This study investigated effect of the scapular retraction exercise on the subacromial and costoclavicular space using different thera-band intensities. Methods: Thirty-six healthy adults participated in this study, and the subjects were randomly divided into three groups (low, moderate, and high-intensity groups). The exercise was conducted twice a week for three weeks. The subacromial and costoclavicular space were measured before and after the intervention via ultrasonography. Data analysis was performed using the two-way Analysis of Variance with repeated measures and the paired t-test. Results: The effect of the scapular retraction exercise on the subacromial and costoclavicular space using a thera-band after a 60° shoulder abduction has significant difference in all groups (p<0.05). However, there was no significant difference between the groups, and the values in the groups before the exercise did not differ significantly from those after the exercise (p>0.05). Conclusion: Our results indicate that the scapular retraction exercise after a 60° shoulder abduction can be used to widen the subacromial and costoclavicular spaces.

• Journal of Korean Critical Care Nursing
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• v.16 no.1
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• pp.71-86
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• 2023

Purpose : This study aims to investigate the status of delirium intervention in adult intensive care unit (ICU) patients and the perception of this delirium by medical staff. Methods : This retrospective study involves 185 patients, whereas, a descriptive survey is conducted with 197 medical staff members. Results : The delirium group includes 100 patients (54.1%). The incidence of delirium is 64.9% in the medical ICU, 65.9% in the surgical ICU, 42.4% in the neuro ICU, and 46.5% in the cardiac ICU. The percentages of delirium prevention intervention differs between the two groups: 65.0% in the delirium group and 95.3% in the non-delirium group. The medical staff recognize that delirium is a common problem in the ICU (100.0%) and requires active medical intervention (98.5%). Conclusion : The length of stay at the ICU is longer in the delirium group than in the non-delirium group. It is necessary to standardize delirium prevention and treatment protocols to be equally applicable to all ICU patients.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1076-1083
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• 2023

Poly(3-hydroxybutyrate) (PHB) is a biodegradable and biocompatible bioplastic. Effective PHB degradation in nutrient-poor environments is required for industrial and practical applications of PHB. To screen for PHB-degrading strains, PHB double-layer plates were prepared and three new Bacillus infantis species with PHB-degrading ability were isolated from the soil. In addition, phaZ and bdhA of all isolated B. infantis were confirmed using a Bacillus sp. universal primer set and established polymerase chain reaction conditions. To evaluate the effective PHB degradation ability under nutrient-deficient conditions, PHB film degradation was performed in mineral medium, resulting in a PHB degradation rate of 98.71% for B. infantis PD3, which was confirmed in 5 d. Physical changes in the degraded PHB films were analyzed. The decrease in molecular weight due to biodegradation was confirmed using gel permeation chromatography and surface erosion of the PHB film was observed using scanning electron microscopy. To the best of our knowledge, this is the first study on B. infantis showing its excellent PHB degradation ability and is expected to contribute to PHB commercialization and industrial composting.

• Journal of Hospice and Palliative Care
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• v.26 no.2
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• pp.60-68
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• 2023

Purpose: For the dignity of patients nearing the end of their lives, it is essential to provide end-of-life (EoL) care in a separate, dedicated space. This study investigated the utilization of specialized rooms for dying patients within a hospice unit. Methods: This retrospective study examined patients who died in a single hospice unit between January 1, 2017, and December 31, 2021. Utilizing medical records, we analyzed the circumstances surrounding death, the employment of specialized rooms for terminally ill patients, and the characteristics of those who received EoL care in a shared room. Results: During the 1,825-day survey period, deaths occurred on 632 days, and 799 patients died. Of these patients, 496 (62.1%) received EoL care in a dedicated room. The average duration of using this dedicated space was 1.08 days. Meanwhile, 188 patients (23.5%) died in a shared room. Logistic regression analysis revealed that a longer stay in the hospice unit was associated with a lower risk of receiving EoL care in a shared room (odds ratio [OR]=0.98, 95% confidence interval [CI] 0.97~0.99; P=0.002). Furthermore, a higher number of deaths on the day a patient died was associated with a greater risk of receiving EoL care in a shared room (OR=1.66, 95% CI 1.33~2.08; P<0.001). Conclusion: To ensure that more patients receive EoL care for an adequate duration in a private setting, additional research is necessary to increase the number of dedicated rooms and incorporate them into the hospice unit at an early stage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1695-1700
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• 2014

Oriental herbal liquor (Yakju) is a type of Korean traditional alcoholic beverage that uses Nuruk and oriental herbs for fermentation. The purpose of this study was to develop cosmetic ingredients using Jubak, which is a by-product of alcoholic fermentation of oriental herbal liquor. To investigate antioxidant, whitening, and anti-aging effects of Jubak, we prepared extract of Jubak and its solvent fractions. Ethyl acetate fraction (KSD E4-3) showed the most prominent free radical [1,1-diphenyl-2-picrylhydrazyl (DPPH)] scavenging activity ($SC_{50}$: 0.75 mg/mL). KSD E4-3 significantly inhibited in vitro mushroom tyrosinase activity ($IC_{50}$: 0.82 mg/mL) and reduced the melanin contents in mouse melanoma melanocyte, B16F10 cells. KSD E4-3 down-regulated protein expression of tyrosinase related proteins (TRP)-1, -2, which play key roles in melanogenesis. For anti-aging effects, inhibition of matrix metalloproteinase (MMPs) expression was evaluated using human keratinocyte, HaCaT cells. Treatment of HaCaT cells with KSD E4-3 reduced expression of MMP-1, -2, -9 and inhibited proteolytic activities of MMP-2, -9. These results suggest that KSD E4-3 induces down-regulation of cellular melanogenesis and protects against photoaging induced by UVB-induced damage. Thus KSD E4-3 could potentially be a valuable cosmetic ingredient.

• Composites Research
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• v.25 no.4
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• pp.93-97
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• 2012

Carbon nano fibers (CNFs) reinforced magnesium alloy (AZ91) matrix composites have been fabricated by liquid pressing process. In order to improve the dispersibility of CNFs and the wettability with magnesium alloy melt, CNFs were mixed with submicron sized SiC particles ($SiC_p$). Also, the mixture of CNFs and $SiC_p$ were coated with Ni by electroless plating. In liquid pressing process, AZ91 melts have been pressed hydrostatically and infiltrated into three reinforcement preforms of only CNFs, the mixture of CNFs and $SiC_p$ (CNF+$SiC_p$), and Ni coated CNFs and $SiC_p$ ((CNF+$SiC_p$)/Ni). Some CNFs agglomerates were observed in only CNFs reinforced composite. In cases of the composites reinforce with CNF+$SiC_p$ and (CNF+$SiC_p$)/Ni, CNFs were dispersed homogeneously in the matrix, which resulted in the improvement of mechanical properties. The compressive strengths of CNF+$SiC_p$ and (CNF+$SiC_p$)/Ni reinforced composites were 38% and 28% higher than that of only CNFs composite.

• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.107-113
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• 2013

The major tributaries in Sapgyo-reservoir watershed at Chungcheongnam-do were monitored for flowrate and water quality in order to analyze the characteristics of watershed and to prepare for implementation of total maximum daily load (TMDL). According to the analytical results of flowrate and water quality monitoring data of sixteen tributaries, the tributaries with the value of flowrate over $0.5m^3/s$ were 62.5% among the monitored tributaries and the value of flowrate in the Cheonancheon, Namwoncheon, Shinyangcheon except Gokgyocheon, Muhancheon, Sapgyocheon was relatively greater than the other tributaries. However, 37.5% of the tributaries were exceeded the water quality standards of Sapgyocheon sub-basin ($BOD_5$ 5 mg/L and/or below) and the concentration of water pollutants regardless of water quality parameters in Cheonancheon, Maegokcheon, Oncheoncheon including Gokgyocheon located in Gokgyocheon catchment were relatively higher than the other tributaries. The tributaries for improving the water quality, according to stream grouping method based on the results of flowrate and water quality monitoring data, were selected. In the Sapgyo-reservoir watershed, the tributaries for improving water quality, which has a large flowrate and a high concentration of water pollutants, were selected at Cheonancheon, Gokgyocheon, Maegokcheon, Namwoncheon, Oncheoncheon. The various water quality improving plans for those tributaries, in accordance with the reduction of point source pollution by population and livestock, should be established and implemented.

• Journal of Life Science
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• v.24 no.7
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• pp.750-756
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• 2014

Citrus, yield of which is the highest among fruits produced in Korea, is extensively consumed for processed food items. The amount of by-products of citrus produced from the processing within a short period after the harvest is tremendous. These by-products are mostly dumped into land or neglected because of cost involved in processing them. The aim of the present study was to explore the usefulness of the by-products as a new material by examining the anti-inflammatory activity of fermented extracts of citrus peels. The peels of 'unshu' (Citrus unshiu) was fermented with Aspergillus niger and their extracts before or after fermentation were analyzed using HPLC. The analysis showed that neohesperidin level considerably increased and the two new compounds were synthesized after fermentation. The anti-inflammatory activity of the fermented extracts was examined on RAW 264.7 murine macrophage cells stimulated with lipopolysaccharide. Fermented unshu extracts significantly enhanced the decrease of nitric oxide (NO) production, iNOS and COX-2 expression, comparing with those of unfermented extracts. Also TNF-${\alpha}$ and IL-6 production, both of which are pro-inflammatory cytokine, were more inhibited in fermented extracts. These results showed that the fermentation and promotion of the function of the by-products of citrus peels will help find a new application.

• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.189-197
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• 2005

Cellulose-digesting bacteria were isolated from hindgut of Allomyrina dichotoma (Coleoptera: Dynastidae). The bacterial isolates were identified as Yersinia sp. and Bacillus sp. The addition of the identified bacteria to diet increased growth rate of the cetoniid beetle, Protaetia brevitarsis senlensis (Coleoptera: Cetoniidae), probably by digesting cellulose nutrient contained in the oak tree sawdust diet. An additive of wheat flour at more than 10% to the sawdust diet significantly enhanced growth of P. brevitarsis senlensis. Trimmed branches of apple trees have been disposed in the apple farms and could be used for a diet component of the cetoniid beetle when the cellulose-digesting bacteria were mixed with the derived-sawdust. Resulting manure from mass rearing of P. brevitarsis senlensis contained high organic matters and trace amounts of toxic metals. When the manure were splayed on soil, it was effective as a natural compost and significantly stimulated lettuce growth. This research suggests a model technology to use cellulose-digesting bacteria to use for culturing grub, which results in natural recycles of trimmed branches in apple farms as grub diet, and to use grub manure as a natural compost.