• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.77-85
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• 2021

Glucosylceramides (GluCer) are known to play an important role in both water retention and epidermal permeability barrier function in the mammalian stratum corneum. In this study, we investigated the effects of pineapple fruit extract containing glucosylceramides (PFEG) on the maintenance and recovery of skin barrier function using atopic dermatitis-induced animal models. Five-week-old male Hos:HR-1 mice were divided into four groups fed on standard diet, unsaturated fatty acids-deficient (HR-AD) diet, and HR-AD diet supplemented with 0.01% or 0.1% pineapple-GluCer. Skin barrier function was evaluated by transepidermal water loss (TEWL), dermal moisture content, moisture content of the stratum corneum and wrinkle formation. The control group (HR-AD administration group) showed increased transepidermal water loss (TEWL), while the epidermal moisture content and the moisture content of the stratum corneum slowly decreased. However, in the PFEG groups (with 0.1% or 0.01% glucosylceramide), the TEWL levels were significantly reduced at 2 weeks. The PFEG also helped maintain skin moisturizing function by significantly suppressing the decrease of the epidermal moisture content and the moisture content of the stratum corneum. These results show that the PFEG is effective for maintaining and improving the function of the skin barrier. Therefore, this study suggests that PFEG is a potential candidate material for skin functional foods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.61-68
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• 2020

In this study, the international standard ISO TS 16774 Part 3 Test Method for Water (wash out) Resistance and KS F 4935 ｢Sealant Injection type for water leakage maintenance of adhesive flexible rubber asphalt series｣, which are standardized as a quality control method of injection type repair materials used for water leakage cracks in underground concrete structures, are currently used in Korea. As a result, considering the performance criteria of "mass change rate -0.1%" stipulated in KS F 4935, the remaining 13 types repair materials, excluding RG-2 of synthetic rubber and UG-1 of urethane, need to be reviewed for stabilization of the loss resistance due to the flow of ground water. The results of this study are determined to be available as a basic indicator for the selection of repair materials used for cracks in concrete structures. In addition, it is expected that the results of this study can be utilized as reference data that can be reflected in the improvement of the quality of repair materials that will be researched and developed later.

• The Journal of Information Systems
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• v.30 no.1
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• pp.151-177
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• 2021

Purpose This paper aims to improve management performance by effectively responding to production needs and reducing inventory through synchronizing production planning and procurement in the aviation industry. In this study, the differences in production planning and execution were first analyzed in terms of demand, supply, inventory, and process using the big data collected from a domestic aircraft manufacturers. This paper analyzed the problems in procurement and inventory management using legacy big data from ERP system in the company. Based on the analysis, we performed a simulation to derive an efficient procurement and inventory management plan. Through analysis and simulation of operational data, we were able to discover procurement and inventory policies to effectively respond to production needs. Design/methodology/approach This is an empirical study to analyze the cause of decrease in inventory turnover and increase in inventory cost due to dis-synchronize between production requirements and procurement. The actual operation data, a total of 21,306,611 transaction data which are 18 months data from January 2019 to June 2020, were extracted from the ERP system. All them are such as basic information on materials, material consumption and movement history, inventory/receipt/shipment status, and production orders. To perform data analysis, it went through three steps. At first, we identified the current states and problems of production process to grasp the situation of what happened, and secondly, analyzed the data to identify expected problems through cross-link analysis between transactions, and finally, defined what to do. Many analysis techniques such as correlation analysis, moving average analysis, and linear regression analysis were applied to predict the status of inventory. A simulation was performed to analyze the appropriate inventory level according to the control of fluctuations in the production planing. In the simulation, we tested four alternatives how to coordinate the synchronization between the procurement plan and the production plan. All the alternatives give us more plausible results than actual operation in the past. Findings Based on the big data extracted from the ERP system, the relationship between the level of delivery and the distribution of fluctuations was analyzed in terms of demand, supply, inventory, and process. As a result of analyzing the inventory turnover rate, the root cause of the inventory increase were identified. In addition, based on the data on delivery and receipt performance, it was possible to accurately analyze how much gap occurs between supply and demand, and to figure out how much this affects the inventory level. Moreover, we were able to obtain the more predictable and insightful results through simulation that organizational performance such as inventory cost and lead time can be improved by synchronizing the production planning and purchase procurement with supply and demand information. The results of big data analysis and simulation gave us more insights in production planning, procurement, and inventory management for smart manufacturing and performance improvement.

• Membrane Journal
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• v.31 no.6
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• pp.434-442
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• 2021

Poly(vinylidene fluoride) (PVDF) membrane has a good membrane durability because of its high mechanical resistance, thermal and chemical stability. However, the strong hydrophobic property of PVDF membrane can induce a low water permeability and easy fouling by proteins and organic matters. In order to improve the anti-fouling properties of PVDF membrane, the PVDF mixed matrix asymmetric membranes impregnated with biofunctional material 𝛽-cyclodextrin (𝛽-CD) in the membrane structure were prepared by phase inversion method. The membrane filtration experiments of pure water and BSA solution were performed using the PVDF/𝛽-CD mixed matrix asymmetric membranes prepared according to the 𝛽-CD contents. The experiments showed that the introduction of 𝛽-CD into the PVDF polymer matrix contributed to increase in the hydrophilic property of the PVDF membranes, and this led to the reduction of contact angles and improvement of anti-fouling properties. The PVDF/𝛽-CD membrane which was prepared using the dope solution with a 2 wt% 𝛽-CD content represented 64 L/m²·h of pure water flux, 95% of BSA rejection and maximum 80% of flux enhancements compared to flux results of the pristine PVDF membrane.

• The Korea Journal of Herbology
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• v.37 no.4
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• pp.49-57
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• 2022

Objective : This study was conducted to investigate antidiabetic effects of chunggugjang with medicinal herbal complex (CJ) in streptozotocin (STZ)-induced animal models. Method : STZ (65 mg/kg) was injected intraperitoneally to induce diabetes. Then rats were divided into 5 groups ; NG (normal diet + 0.9% saline), COS (STZ +saline 5 mL/kg), COB (STZ + fermented soybean(100 mg/kg), CJ 100/200 (STZ+CJ(100 and 200 mg/kg), CJ 300/600 (STZ+CJ(300 and 600 mg/kg). 4 weeks later, oral glucose tolerance test (OGTT) was performed. After sacrificing rats, serum levels of blood urea nitrogen (BUN), creatinine, aspartate amino transferase (AST), alanine amino transferase (ALT), total cholesterol (TC), and triglyceride (TG) were measured and histological changes were observed. Result : Body weight change and food efficiency ratio (FER) were decreased in the CJ 300/600 group than in the COS group. But, there was no change in water intake. Serum levels of glucose, AST, ALT and BUN were lower in the CJ 300/600 group than in the COS group. Also, TG, TC, and creatinine were decreased in the CJ 300/600 group than in the COS group. According to OGTT, 120 minutes postprandial glucose levels were lower in the CJ 300/600 group than in the COS group. In addition, administration of CJ extracts restored histopathological damage. Conclusion : The results suggest that CJ can be used as a functional material for diabetes treatment as it has the effect to improve pathological symptoms in STZ-induced diabetic rats.

• Composites Research
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• v.35 no.3
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• pp.147-152
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• 2022

Low-temperature characteristics according to internal temperature conditions during rotational molding of Type 4 pressure vessel liners were studied in this paper. Since rotational molding has a sensitive effect on the formability of the liner depending on the temperature conditions, the temperature conditions for the polyamide used should be accurately set. The structural changes of polyamide as the liner material was analyzed the surface by atomic force microscope (AFM), and the crystallinity measured with a differential scanning calorimeter (DSC) is used to evaluate the change of the mechanical strength value at low temperature. In addition, the formability of the liner was confirmed by observation of the yellow index inside the liner. As a result, as the melting range of the internal temperature becomes wider, the yellow index shows a lower value, and the elongation and impact characteristics at low temperatures are improved. It was also confirmed that the structure of the polyamide was uniform and the crystallinity was high by AFM and DSC. These experimental results contribute to the improvement of characteristics at low temperatures due to changes in temperature conditions during rotational molding.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.211-216
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• 2022

In radiation therapy, accurate Quality Assurance (QA) is required to irradiate tumor tissue while minimizing damage to normal tissue. Therefore, a dosimeter that can accurately measure radiation is needed. The purpose of this study is to develop a highly efficient radiation dosimeter with high sensitivity by applying a particle in binder method that can reduce manufacturing costs and simplify processes to perovskite materials that are cheaper and simpler to manufacture. By evaluating the response characteristics to high-energy photon, the applicability of QA dosimeter to radiation therapy was evaluated. As a result of reproducibility evaluation, RSD at 6 MV energy was presented as 1.178% and 15 MV energy was presented as 1.141%. As a result of linearity evaluation according to linear regression analysis, R² values of 0.9999 were presented under each condition of 6 MV and 15 MV energy. It was found that the CsPbBr₃ dosimeter manufactured based on the results of reproducibility and linearity evaluation is highly applicable as a QA dosimeter in the field of therapeutic radiation. The CsPbBr₃ dosimeter manufactured in this study presented more than the standard performance in the evaluation of reproducibility and linearity, and it can be used as a radiotherapy QA dosimeter through improvement.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.20-29
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• 2022

In this study, in order to improve the durability of the cement composite printed with the ME type 3D printer, PDMS, sodium silicate, and a surface hardener were employed. Post-treatment was performed on 3D-printed cement composite by coating after immersion, and the degree of improvement in durability was evaluated. As a result, in all evaluations, the durability performances of the post-processed specimens were improved compared to those of the plain specimens. Water absorption resistance, chloride penetration resistance, and carbonation resistance of the PDMS treated specimens were improved by 36.3 %, 77.1 %, and 50.4 % when compared to plain specimens. Freeze-thaw resistance of the specimens treated with sodium silicate was found to be the most excellent, with an average enhancement of 47.5% compared to plain specimens. It was found that PDMS was the most efficient post-treatment materials for 3D-printed cement composite. However, as suggested in this study, the post-treatment method by coating after immersion may not be applicable to cement composite structures printed with a 3D printer in field. Therefore, a follow-up study needs to be preformed on the durability enhancing materials suitable for 3D printing.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.204-210
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• 2022

Cement is pointed out as the main cause of carbon dioxide emission in the construction industry. Many researchs are underway to use blast furnace slag, an industrial by-product, as a substitute for cement to reduce carbon dioxide emitted during the manufacturing the cement. When blast furnace slag is used as a substitute for cement, it has advantages such as long-term strength and chemical resistance improvement. However, blast furnace slag has a problem that makes initial strength low. This is due to the impermeable film on the surface created during the production of blast furnace slag. The created film is known to be destroyed in an alkaline environment, and based on this, previous studies have suggested a solution using various alkali activators. But, alkali activator is dangerous product since it is a strong alkaline material. And it has the disadvantage in price competitiveness. In this study, an experiment was conducted to improve the initial hydration reactivity of the blast furnace slag to secure the initial strength of the mortar substituted with the blast furnace slag and to check whether the carbonation resistance was increased. As a result of the experiment, it was confirmed that the mortar using alkaline water showed higher strength than the mortar using tap water, and there were more hydration products generated inside. In addition, it was confirmed that the mortar using alkaline water as a compounding water had high carbonation resistance.

• The Korea Journal of Herbology
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• v.33 no.2
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• pp.59-67
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• 2018

Objective : Plantago asiatica L. has been used for many years in Korea, China, and Japan for the treatment of many diseases such as anti-inflammatory, anti-asthma and diuretic. But the anti-obesity effect of Plantaginis asiaticae Folium has not been studied yet. Thus, this study aimed to demonstrate the anti-obesity efficacy of Plantaginis asiaticae Folium water extract (PAF) in high fat diet-induced obesity animal model. Method : Male, five-weeks old C57BL/6 mice were divided into 5 groups; ND (normal diet + 0.9% saline), HFD (high-fat diet + 0.9% saline), PC (high-fat diet + Garcinia cambogia 500 mg/kg), PAF 100, 300 (high-fat diet + PAF 100, 300 mg/kg. Treatments were performed daily for 6 weeks per os. We evaluated the changes of body weight, white adipose tissues weight, hepatic and fecal lipids level, pancreatic lipase activity and lipid profiles in plasma. Result : Body weights, adipose tissue weights and FER were significantly lower in mice fed the high-fat diet with PAF treatment than in mice fed the high-fat diet alone. In plasma, TG, TC, LDL-C, ATS and ALT levels significantly decreased in PAF groups compared with HFD group. Also, hepatic triglyceride (TG) levels decreased and fecal TG increased in PAF groups compared to HFD group. In addition, the activity of pancreatic lipase was decreased in the PAF groups compared to that of HFD group. Conclusion: These results suggest PAF extract is effective in preventing and improvement obesity, so it might be a potential and safe material for anti-obesity agent of weight control or functional supplements.