• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.347-352
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• 2011

When concrete is worked in cold weather, the methods of using hot air, water and aggregate heating, accelerators are used to prevent early frosting and to improve early strength. But these methods raise problems such as implementation difficulty, high cost, and energy losses. Among the available cold weathering methods, accelerator method is the most economical but with the drawbacks of rapid setting and insufficient workability in the initial hydration stage. Therefore, the tablet method usually used for pharmaceutical field was applied to the accelerator method to compare the controlled reaction time of the new and old accelerator method. Based on the test results, physical and mechanical properties of concrete were tested and the possibility of delaying initial reactions to increase the total reaction time was evaluated. The results showed that when both accelerators and tablet were used, setting-time decreased. Physical properties of concrete were optimal for tablet 0.5% and 1.0%. Also, accelerator 0.5%, tablet 0.5% and 1.0% showed good early strengths.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.78-85
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• 2019

Membrane proteins are involved in many common diseases, including heart disease and cancer. In various disease states, such as cancer, abnormal signaling pathways that are related to the membrane proteins cause the cells to divide out of control and the expression of membrane proteins can be altered. Membrane proteins have the hydrophobic environment of a lipid bilayer, which makes an analysis of the membrane proteins notoriously difficult. Therefore, this study evaluated the efficacy of two different methods for optimal membrane protein extraction. High-speed centrifuge and reagent-based method with a -/+ filter aided sample preparation (FASP) were compared. As a result, the high-speed centrifuge method is quite effective in analyzing the mitochondrial inner membranes, while the reagent-based method is useful for endoplasmic reticulum membrane analysis. In addition, the function of the membrane proteins extracted from the two methods were analyzed using GeneGo software. GO processes showed that the endoplasmic reticulum-related responses had higher significance in the reagent-based method. An analysis of the process networks showed that one cluster in the high-speed centrifuge method and four clusters in the reagent-based method were visualized. In conclusion, the two methods are useful for the analysis of different subcellular membrane proteins, and are expected to assist in selecting the membrane protein extraction method by considering the target subcellular membrane proteins for study.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.26-35
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• 2013

Outbreak of animal infectious diseases such as foot-and-mouth disease, avian influenza are becoming prevalent worldwide. For prevent the further infection, tremendous numbers of the infected or culled stocks are buried around farm. This burial method can generate a wide range of detrimental components such as leachate, nutrient, salt, and pathogenic bacteria, consequently. In this study, for the stabilization of livestock carcasses leachate, advanced oxidation processes utilizing the Fenton reaction was investigated in lab-scale experiments for the treatment for $COD_{Cr}$ of livestock carcass leachate. $COD_{Cr}$ reduction by the Fenton oxidation was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of pH ($x_1$), dosage of $FeCl_2{\cdot}4H_2O$ ($x_2$) and dosage of $H_2O_2$ ($x_3$) on the dependent variables $COD_{Cr}$ concentration ($y_1$). A 1 M NaOH and $H_2SO_4$ was using for pH control, $FeCl_2{\cdot}4H_2O$ was used as iron catalyst and NaOH was used for Fenton reaction. The optimal conditions for Fenton oxidation process were determined: pH, dosage of $FeCl_2{\cdot}4H_2O$ and dosage of $H_2O_2$ were 3, 0.6 g (0.0151 M) and 7 mL(0.259 M), respectively. Statistical results showed the order of significance of the independent variables to be pH > initial concentration of ferrous ion > initial concentration of hydrogen peroxide.

• Journal of the Korean GEO-environmental Society
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• v.18 no.4
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• pp.23-29
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• 2017

As the Enforcement Ordinance of Environmental Policy Act was revised in 2013, Total Organic Carbon (TOC) was added as an indicative parameter for organic matter in Water and Aquatic Ecosystem Environmental Criteria. Under these imminent circumstances, a regulatory standard is needed to achieve the proposed TOC limitation control water quality from the STP (Sewage Treatment Plant). In this study, a electrolysis utilizing the electrochemical reaction was investigated in lab-scale experiments for the treatment of TOC in sewage effluent. TOC reduction by a electrolysis was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of electrode space ($x_1$), current density ($x_2$) and electrolyte concentration ($x_3$) on the dependent variables removal efficiency of TOC (y). The optimal conditions for electrolysis were determined: electrode space, current density and electrolyte concentration were 50 mm, $10.3mA/cm^2$ and 0.1M, respectively. Statistical results showed the order of significance of the independent variables to be electrode space > current density > electrolyte concentration.

• Journal of Life Science
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• v.19 no.2
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• pp.179-184
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• 2009

Zinc is an essential trace element for human and plays an important biological role in antioxidant properties. We have been reported that zinc-enriched S. cerevisiae FF-10 contained 392 mg% in the YM basal and 3,193 mg% in the YM optimal medium. Antioxidative activity of FF-10 was tested in vitro models by DPPH (${\alpha},{\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl) radical scavenging activity and lipid peroxidation using linoleic acid (LA) and rat liver homogenate. DPPH radical scavenging activity was higher in the cell-free extract of FF-10 cultured in the YM optimal medium (YMOM) than that in the YM basal medium (YMBM). The inhibition activity of lipid peroxidation using rat liver homogenate was shown in the following order: BHT > YMOM > YMBM and these values were dose dependently. The lipid peroxidation of the control mixture by ferric thiocyanate and TBA methods using LA was increased rapidly as typical peroxidation curve of LA from one day and the antioxidation activity of the cell free extracts by cultivating FF-10 in the YMOM were higher than that of the YMBM. Result of this study indicate that the cell-free extracts containing a high intercellular zinc of S. cerevisiae FF-10 cultured in YMOM showed strong antioxidation capacities in DPPH radical scavenging activity and lipid peroxidation using LA and rat liver homogenate.

• Journal of Korean Society of Steel Construction
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• v.24 no.6
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• pp.693-700
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• 2012

In this study, the Charpy impact test along with metallurgical observation was conducted to evaluate low temperature impact toughness of structural steel welds with different welding processes to find out the optimal welding process to guarantee the required impact toughness at low temperatures. The welding processes employed are shield metal arc welding (SMAW) and flux cored arc welding(FCAW), which are commonly used welding methods in construction. The Charpy impact test is a commercial quality control test for steels and other alloys used in the construction of metallic structures. The test allows the material properties for service conditions to be determined experimentally in a simple manner with a very low cost. To investigate the impact toughness at low temperatures of the steel welds, specimens were extracted from the weld metal and the heat affected zone. Standard V-notch Charpy specimens were prepared and tested under dynamic loading condition. The low temperature impact performance was evaluated based on the correlation between the absorbed energy and the microstructure. Analysis of the results showed that the optimal welding process to ensure the higher low temperature impact toughness of the HAZ and the weld metal is SMAW process using the welding consumable for steels targeted to low temperature use.

• Korean Journal of Acupuncture
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• v.30 no.2
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• pp.88-96
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• 2013

Objectives : In the acupuncture treatment of Korean Medicine, the Tonifying or Purging depending on how many times the needle is rotated has been used widely. However, there is little evidence about the optimal number of rotation. This study, therefore, was aimed to investigate the optimal number of rotation. Methods : Heart rate variation was measured before and after exercise in 20 healthy adults. Acupuncture was performed at PC6 immediately after exercise according to the protocol of each group without remaining. Pre-exercise and post-exercise measurements were compared and the rotation number that produced statistically significant difference was investigated. Results : Significant differences were found in the heart rate variation and R-R interval Average, between non-rotation group (control) and both of 15 times rotation group of tonifying and 6 times rotation group of purging. Conclusions : Significantly effective number of rotation in the effect of PC6 on the HR and RRAv was 15 times in the tonifying and 6 in the purging respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.4
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• pp.231-244
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• 2015

The accuracy of reference point of VLBI antenna is mandatory to perform collocation of different space geodetic techniques. In this study, we evaluated the optimal methods for the 3D circle fitting to enhance the accuracy of the reference point of VLBI antenna. Two kinds of methodologies for the orthonormal coordinate system with translation of planar observation point and the unitary coordinate transforamation were suggested and their fitting accuracies were evaluated where the orthogonal distance was calculated by residual between observation point and fitting model and the recursive calculation was performed to improve the accuracy of 3D circle fitting. Finally, we found that the methodology for the unitary coordinate transformation is highly appropriate to determine the optimal equation for azimuth-axis and elevation-axis of VLBI antenna. Therefore, the reference point of VLBI antenna with high accuracy can be determined by the intersection of the above two axises (azimuth-axis and elevation-axis). This result is expected to be utilized for a variety of researches for connection between VLBI observation results and the national control point.

• The Journal of Internal Korean Medicine
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• v.40 no.3
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• pp.390-408
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• 2019

Objectives: Several pattern diagnosis questionnaires have been developed to objectify the process of pattern diagnosis in Korean medicine. In this context, this study aimed to develop a food retention questionnaire for functional dyspepsia (FRQ-FD) by modifying the previously developed food retention questionnaire (FRQ) and to verify its reliability and validity. Furthermore, this study aimed to identify the optimal cut-off value of the FRQ-FD for standardization and use in clinical situations. Methods: To develop the FRQ-FD, we extracted the major symptoms of food retention pattern for functional dyspepsia from Chinese/Korean medicine textbooks and requested an importance survey from experts using the Delphi method. The first draft of the FRQ-FD was composed of 25 questions comprising 8 questions from the textbooks and the Delphi method and 17 questions from the FRQ already developed in 2013. To analyze its reliability, validity, and optimal cut-off value, 60 subjects were enrolled in this study from June 25 to August 13, 2018. Thirty patients were diagnosed as both functional dyspepsia and food retention pattern, and 30 healthy participants were not. All participants were requested to fill up the FRQ-FD, Stomach Qi Deficiency Questionnaire (SQDQ), Scale for Stomach Qi Deficiency pattern (SSQD), visual analog scale (VAS) for dyspepsia, Nepean Dyspepsia Index-Korean version (NDI-K), and functional dyspepsia-related quality of life (FD-QoL). Results: No statistically significant differences were found in sex distribution, age, and body mass index between the patient group and the control group. As five questions affected the reliability negatively and three questions affected the clinical validity negatively, we decided to exclude the eight questions upon further investigation. The Cronbach's ${\alpha}$ coefficient of the revised FRQ-FD (17 items) was 0.899, and its clinical validity was verified. Construct validity was analyzed by factor analysis and produced five factors. Statistically significant positive correlations were found between the revised FRQ-FD and the other dyspepsia scales, namely, SQDQ, SSQD, VAS, NDI-K, and FD-QoL. VAS and NDI-K especially had strong positive correlations with FRQ-FD. Conclusions: The FRQ-FD developed in this study can provide fundamental reliability and validity for a pattern diagnosis questionnaire. FRQ-FD can help to diagnose food retention pattern in functional dyspepsia patients. Further studies are required to inspect several statistical factors.

• Asian Spine Journal
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• v.12 no.6
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• pp.1085-1091
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• 2018

Study Design: Case-control. Purpose: To determine optimal cut-off value for body mass index (BMI) in predicting surgical success in patients with lumbar spinal canal stenosis (LSCS). Overview of Literature: BMI is an essential variable in the assessment of patients with LSCS. Methods: We conducted a prospective study with obese and non-obese LSCS surgical patients and analyzed data on age, sex, duration of symptoms, walking distance, morphologic grade of stenosis, BMI, postoperative complications, and functional disability. Obesity was defined as BMI of ${\geq}30kg/m^2$. Patients completed the Oswestry Disability Index (ODI) questionnaire before surgery and 2 years after surgery. Surgical success was defined as ${\geq}30%$ improvement from the baseline ODI score. Receiver operating characteristic (ROC) analysis was used to estimate the optimal cut-off values of BMI to predict surgical success. In addition, correlation was assessed between BMI and stenosis grade based on morphology as defined by Schizas and colleague in total, 189 patients were eligible to enter the study. Results: Mean age of patients was $61.5{\pm}9.6years$. Mean follow-up was $36{\pm}12months$. Most patients (88.4%) were classified with grades C (severe stenosis) and D (extreme stenosis). Post-surgical success was 85.7% at the 2-year follow-up. A weak correlation was observed between morphologic grade of stenosis and BMI. Rates of postoperative complications were similar between patients who were obese and those who were non-obese. Both cohorts had similar degree of improvement in the ODI at the 2-year followup. However, patients who were non-obese presented significantly higher surgical success than those who were obese. In ROC curve analysis, a cut-off value of ${\leq}29.1kg/m^2$ for BMI in patients with LSCS was suggestive of surgical success, with 81.1% sensitivity and 82.2% specificity (area under the curve, 0.857; 95% confidence interval, 0.788-0.927). Conclusion: This study showed that the BMI can be considered a parameter for predicting surgical success in patients with LSCS and can be useful in clinical practice.