• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.173-181
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• 2017

This study was conducted to investigate the packaging characteristics including pack sources and pack components of processed foods in Korea. For the survey, 704 food package samples were selected based on the consumption of top 10 brackets in each food item. They were consisted of 1,245 packaging components. Seven specific items were firstly investigated including product name, capacity of the food, package component, package source, food contact area, food contact ratio, and package thickness. The processed foods in Korea can be classified into 16 pack sources and 21 pack components, respectively. By using this information, the data were analyzed specifically. The collected data were analyzed in 8 major categories: frequency of use by pack components and pack sources, pack components by the products, pack sources by the products and pack components, pack thickness/food contact ratio by the products, food contact ratio by pack components and pack sources. Consequently, this survey will provide various information of the packaging characteristics of processed foods in Korea.

• Journal of Mushroom
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• v.10 no.1
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• pp.15-20
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• 2012

Ventilation effects of bottles($1,100m{\ell}$) for culturing Flammulina velutipes on its mycelial growth and mushroom production were investigated. The degree of ventilation were controlled with hole positions, upper and under, and hole sizes in the bottle lids. The ventilation effects were measured with the contents of carbon dioxide, free sugars, chitin, moisture in the bottles and with the amount of produced mushrooms from the bottles. Carbon dioxide concentrations within the culturing bottles at exponential mycelial growth period vertex were relatively high in the bottles with lids without both a sponge and an aeration hole, and in those with a smaller hole. Free sugar contents in the mycelia were the highest in those with a 47mm hole on both sides, and in those with 26~33mm holes only underside. Chitin content was the highest in those with a 26mm hole only underside. On the other hand, the lids with 42mm~47mm holes on the both sides greatly lost water and decreased the mushroom production. In conclusion, the most efficient ventilation hole sizes on the lids for bottle($1,100m{\ell}$) cultivation of Flammulina velutipes using $1,100m{\ell}$ polypropylene bottle were 19mm on both sides of the lid and 26mm on only underside. They produced more mushrooms than the control by 6~9 %.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.143-156
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• 2010

Faced with an increase of malicious threats from the Internet as well as local area networks, many companies are considering deploying a security system. To help a decision maker select a suitable security tool, this paper proposed a three-step integrated framework using linear fuzzy regression (LFR) and physical programming (PP). First, based on the experts' estimations on security criteria, analytic hierarchy process (AHP) and quality function deployment (QFD) are employed to specify an intermediate score for each criterion and the relationship among these criteria. Next, evaluation value of each criterion is computed by using LFR. Finally, a goal programming (GP) method is customized to obtain the most appropriate security tool for an organization, considering a tradeoff among the multi-objectives associated with quality, credibility and costs, utilizing the relative weights calculated by the physical programming weights (PPW) algorithm. A numerical example provided illustrates the advantages and contributions of this approach. Proposed approach is anticipated to help a decision maker select a suitable security tool by taking advantage of experts' experience, with noises eliminated, as well as the accuracy of mathematical optimization methods.

• Korean journal of applied entomology
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• v.39 no.2
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• pp.123-129
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• 2000

This study was conducted to analyse the distribution of root-knot nematodes (Meloidogyne spp.) in fruit vegetable production areas in Korea. Soil samples were collected from greenhouses in Sungju (Kyungpook), Yeoju (Kyungki), Haman (Kyungnam), and Chungwon (Choongpook) provinces in 1997-1999. Plant parasitic nematodes were separated for density counting and some of the root-knot nematodes were identified using enzyme phenotypes of malate dehydrogenase (MDH) and esterase (EST). Among the 185 farms in Sungju province, Meloiciogyne spp. were detected from 99 farms (53.5%). Other plant parasitic nematodes detected were; Helic~otylmchuss pp. from 7 farms, Aphelenchus spp. from 43 farms, and Criconematids from 26 farms. Using the female enzyme phenotypes of MDH and EST. the four major root-knot nematodes in Korea, M. incognitc~(M I), M. uretznri~(M~ A), M. huplu (MH), and M. juvunica, could be identified. In the enzyme phenotype identification of 13 populations collected from Sunnam in Sungju province, 6 populations were identified as MA, 5 populations were identified as MI, and 2 populations were mixed with MI and MA. Among the 6 populations from Chojun in Sungju province. 4 populations were MA, one population was MI, and one population showed enzyme phenotypes of unknown species. Among the 14 populations of Yeoju province, l I populations were MH and 3 populations were MA.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.198-210
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• 2016

This study firstly aims to estimate a leading-price of Jeju flounders with various price-classes by fish weight and secondly plans to provide policy implications of flounder purchase projects by understanding dynamic changes and interactions among flounder producer price-classes caused by price impulses in the market. This study applies an unit root test for stability of data, uses a Granger causality test to estimate the leading-price among producer prices by fish weight, employs the vector autoregressive model to analyze statistical impacts among t-1 variables used in models, and finally utilizes impulse response analyses and forecast error variance decomposition analyses to understand dynamic changes and interactions among change rates of the producer prices caused by price impulses in the market. The results of the study are as follows. Firstly, KPSS, PP, and ADF tests show that the change rate of Jeju flounder monthly producer prices by fish weight differentiated by logarithm is stable. Secondly, the Granger causality test presents that the change rate of the 1kg flounder producer price strongly leads it of 500g, 700g, and 2kg flounder producer prices respectively. Thirdly, the vector autoregressive model indicates that the change rate of the 1kg producer price in t-1 period statistically, significantly influences it of own weight in t period and also slightly affects price change rates of other weights in t period. Fourthly, the impulse response analysis indicates that impulse responses of structural shocks for the change rate of the 1kg producer price are relatively more powerful in its own weight and in other weights than shocks emanating from price change rates of other weights. Fifthly, the variance decomposition analysis points out that the change rate of the 1kg producer price is relatively more influential than it of 500g, 700g, and 2kg producer prices respectively. In conclusion, the change rate of the 1kg Jeju flounder producer price leads the change rates of other ones and Jeju purchase projects need to be targeted to the 1kg Jeju flounder producer price as the purchase project implemented in 2014.

• Design & Manufacturing
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• v.14 no.1
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• pp.1-7
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• 2020

In this study, the variation of the shrinkage in the thickness direction of the molded parts according to the gate size of the polymer core fabricated through the 3D printer using the SLS method was studied. The polymer cores are laser sintered and the powder material is nylon base PA2200. The polymer cores have lower heat transfer rate and rigidity than the metal core due to the characteristics of the material. Therefore, the injection molding test conditions are set to minimize the deformation of the core during the injection process. The resin used in the injection molding test is a PP material. The packing condition was set to 80, 90 and 100% of the maximum injection pressure for each gate size. The runner diameter used was ∅3mm, and the gates were fabricated in semicircle shapes with cross sections 1, 2, and 3 ㎟, respectively. Thickness measurement was performed for 10 points at 2.5 mm intervals from the point 2.5 mm away from the gate, and the shrinkage to thickness was measured for each point. The shrinkage rate according to the gate size tends to decrease as the cross-sectional area decreases as the maximum injection pressure increases. The average thickness shrinkage rate was close to 0% when the packing pressure was 90% for the gate area of 1mm2. When the holding pressure was set to 100%, the shrinkage was found to decrease by 3% from the standard dimension due to the over-packing phenomenon. Therefore, the smaller the gate, the more closely the molded dimensions can be molded due to the high pressure generation. It was confirmed that precise packing process control is necessary because over-packing phenomenon may occur.

• Journal of the Korea Concrete Institute
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• v.24 no.5
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• pp.509-516
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• 2012

The aims of this research is to develop a fire resistant admixture to enhance high-pressured pumping of high-strength concrete (HSC) with a compressive strength of 60~80 MPa. Generally, the efficiency of HSC high-pressured pumping is dramatically reduced due to entanglement of short fibers added to prevent fire spalling. Therefore, the fire resistant admixture that can facilitate pumping of fire resistant HSC is urgently needed presently. The fire resistant HSC mix is comprised of Polypropylene fiber, Nylon fiber and Polymer powder. The test results showed that the slump-flow was improved by approximately 70% of the HSC without fire resistant admixture. However, the air void content was increased slightly due to the addition. The standard design compressive strength at 28-days was satisfied, while its flexural strength was similar to the concrete without the admixture. Since the flexural strength was 12~15% of its compressive strength, the general trend of flexural to compressive strength ratio in normal concrete was maintained. Even though its elastic modulus was decreased by adding the admixture, the study results showed that the concrete can be used for construction since all of the test results exceeded the code requirements.

• Journal of Environmental Health Sciences
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• v.38 no.6
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• pp.561-567
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• 2012

Objectives: Parabens are widely used as antimicrobial agents in pharmaceuticals and cosmetics as well as by the food industry. Parabens have been reported to show weak estrogenic activity and be related to health effects such as allergic reactions and skin and breast cancer. We evaluated an online solid phase extraction (SPE) method coupled with LC-MS/MS technique using free and conjugated parent parabens in human urine for assessing human exposure to parabens. Methods: We employed LC/MS/MS through online solid phase extraction and column-switching techniques and analyzed free and conjugated parabens as biomarkers of human exposure. Four major parabens, methyl-paraben (MP), ethyl-paraben (EP), propyl-paraben (PP) and butyl-paraben (BP), were analyzed. Method validation was performed by sensitivity, accuracy, precision and comparison of the results of online SPE with offline SPE. Results: The limits of detection (LOD) were in the range of 0.2-2 ng/mL, and actual limits of quantification (LOQ) were in the range of 0.7-6 ng/mL urine, depending upon the compound. Accuracy was in the range of 98.3-106.4%, and precision was in the range of 1.3-8.7% (CV) depending upon the compound. We found a good correlation between the results of analysis by online SPE method and that by off-line SPE method. Conclusions: The online SPE method showed proper LOD and validated accuracy, precision and good correlation with the offline method for analyzing parabens in urine.

• Journal of the Korean Geotechnical Society
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• v.33 no.4
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• pp.35-46
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• 2017

Most of high carbon fly ashes (HCFA) are discarded in landfills with high costs due to low recycling rate. This study aims to explore the geotechnical behaviors of HCFA mixtures reinforced with fiber and sand. A series of compaction test, unconfined compressive strength test and modified 1D consolidation test with bender element were performed. Specimens were prepared at their optimal moisture contents based on the results of compaction tests. The results of this study demonstrate that the inclusion of fibers to the matrix of HCFA increases unconfined compressive strength (UCS), strain at UCS, and maximum shear modulus ($G_{max}$) at a given void ratio. Reinforcement with sand increases UCS of HCFA; while the strain at UCS is irrelevant with sand fractions. Sand particles may disrupt the direct contacts between HCFA particles at low sand content, resulting in a decrease in $G_{max}$. However, it can be expected that the mixtures with sand content larger than 20% are in dense state; thus, $G_{max}$ of HCFA reinforced with sand shows greater value than that of unreinforced HCFA compacted with the same energy. Regardless of types of reinforcement, the compression index ($C_c$) of both fiber and sand reinforced HCFA is mainly determined by initial void ratio.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5835-5842
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• 2015

Background: Melatonin, which is mainly produced by the pineal gland, has a good inhibitory effect on cell growth of multiple cancer types. However, the underlying molecular mechanisms of anti-tumor activity for colon cancer have not been fully elucidated. In this study, we investigated the effects of melatonin on migration in human colon cancer RKO cells and the potential molecular mechanisms. Materials and Methods: The viability of RKO cells was investigated by MTT assay after treatment with melatonin, SB203580 (p38 inhibitor) and phorbol 12-myristate 13-acetate (PMA, MAPK activator) alone or in combination for 48h. The effects of melatonin, and ML-7, a selective inhibitor of myosin light chain kinase (MLCK), and SB203580, and PMA on the migration of RKO cells were analyzed by in vitro scratch-wound assay. The relative mRNA levels of MLCK was assessed by real-time quantitative RT-PCR. Western blotting analysis was performed to examine the expression of MLCK, phosphorylation of myosin light chain (pMLC) and p38 (pp38). Results: The proliferation and migration of human colon cancer RKO cells were inhibited significantly after treatment with melatonin. The expression levels of MLCK and phosphorylation of MLC of RKO cells were reduced, and real-time quantitative RT-PCR showed that melatonin had significant effects on suppressing the expression of MLCK. Furthermore, the phosphorylation level of p38, which showed the same trend, was also reduced when cells were treated by melatonin. In addition, ML-7 (25umol/l) could down-regulate the phosphorylation of p38. Conclusions: Melatonin could inhibit the proliferation and migration of RKO cells, and further experiments confirmed that p38 MAPK plays an important role in regulating melatonin-induced migration inhibition through down-regulating the expression and activity of MLCK.