• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.7-12
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• 2018

This study was conducted to determine effects of precooling and storage methods on asparagus spears' quality such as changes of fresh weight and color during simulated export distribution. Two types of precooling methods, air cooling and hydrocooling, were applied prior to packaging by comparing with no precooling as a control. Asparagus spears were packed with oxygen transmission rate (OTR) film for modified atmosphere packaging (MAP) and perforated (PF) film for a conventional packaging. All treatments were stored at $8^{\circ}C$ for 20 hours, and subsequently at $4^{\circ}C$ by final storage day, which is simulated distribution temperature condition from Yanggu, Korea to Shimonoseki, Japan. The half cooling time was 12 minutes for air cooling and 15 seconds for the hydrocooling, indicating precooling process of asparagus spears faster with the hydrocooling. Rates of respiration and ethylene production were lowest with hydrocooling. Fresh weight loss was higher, approximately 11%, at the control condition in conventional storage, compared with the MAP, less than 0.5%. Carbon dioxide and oxygen content in the MAP was in the permissible ranges for asparagus spears under recommended CA/MA conditions under both the air cooling and hydrocooling. Ethylene content in the film package was lower with the precooling treatment. Firmness of stems was lowest with the hydrocooling prior to the MAP. Visual quality, off-odor, and hue angle value were best with hydrocooling prior to the MAP. In conclusion, the combination of hydrocooling with the MAP is effective in preserving quality during the export distribution process.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.12 no.1
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• pp.41-44
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• 2006

To investigate the effect of functional MA film packaging on tomatoes produced in Egypt packed 7 kg corrugated paperboard box during 7 days of storage at room temperature, the weight loss, titratable acidity, soluble solid content(SSC, $^oBrix$), vitamin C and the rate of decay were measured. The weight loss in 0.06 mm functional MA film was 1.5%, but was 3% in non-packed tomatoes after 7 days of storage. The titratable acidity and SSC in functional MA film was kept higher than that of non-packed tomatoes and vitamin C and the rate of decay in functional MA film was changed lower than the others.

• Kyungpook Mathematical Journal
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• v.60 no.3
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• pp.599-627
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• 2020

In this paper, we characterize a class of biharmonic maps from and between doubly product manifolds in terms of theie warping function. Examples are constructed when all of the factors are Euclidean spaces.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.445-446
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• 2008

• Food Science and Preservation
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• v.24 no.6
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• pp.734-745
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• 2017

The effects of combination treatment with sulfur dioxide generating pad ($SO_2$ pad) and modified atmosphere packaging (MAP) on grape quality were examined under simulated exporting condition and actual export to Los Angeles, USA. The 'Campbell Early' grape harvested in Hwaseong, Gyeonggi was precooled at $0^{\circ}C$, selected and packaged at $10^{\circ}C$, and stored at $0^{\circ}C$ for 30 days. The treatment was as follows: general export packaging (control), only $SO_2$ pad, combination of $SO_2$ pad and MAP (perforated polyethylene film, $SO_2$ pad+MA). In case of control and only $SO_2$ pad under simulated exporting condition, the grape quality changes with storage time were decrease in hardness and brush length, increase in stem browning, and increased in shattering rate. The treatment of $SO_2$ pad+MA was the most effective in preserving the grape quality since $SO_2$ concentration inside the package remained around 2.9 ppm by MA film. Grape exports from harvest to local distribution of the USA took 30 days, and only $SO_2$ pad+MA package showed no fungus, maintained brush length and rachis color, and was lowest at 4.0% of shattering rate since the concentration of $SO_2$ in the package was about 4.0 ppm. As a result, it was considered that the combination of $SO_2$ pad and MA was the most effective way to maintain freshness of grape during long-term marine transportation and extend the shelf-life in exporting countries.

• Food Science and Preservation
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• v.24 no.3
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• pp.351-360
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• 2017

We have studied the technology to extend the storage period of 'Seolhyang' strawberries using modified atmosphere package (MAP) and ethyl pyruvate (EP) treatment for domestic distribution and export. The selected ripe strawberries harvested on December 28, 2016 at the Sancheong farmhouse were transported to the laboratory for 2 h and tested. After a day's precooling at $4^{\circ}C$, the strawberries were divided into seven experimental groups. These groups were control, active MAP using low density polyethylene (LDPE), active MAP using polyamide (PA), active MAP using PA with EP treatment, passive MAP using LDPE, passive MAP using PA and passive MAP using PA with EP treatment. Quality analysis was carried out every 4 days during the storage period of 16 days. During the storage period of 16 days, MAP decreased from 3.5% to less than 1.1% in weight loss ratio compared with control, and decreased from 36% to less than 7% in fungal incidence. In the case of fungi in the EP treatment group, hyphae did not grow on the outside of the strawberry but grew to the inside. This tendency was similar to that in the low oxygen and high carbon dioxide environment of the MAP, the mycelium of the fungus did not grow outside of the strawberry. Fungi are the biggest problem in the distribution and export of strawberries, and these results suggest that MAP alone could inhibit mold and increase shelf life.

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.239-244
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• 2020

Effect of 6kg large unit with the carton box (20% open ratio) and MA box (10,000cc·m^-2·day^-1·atm^-1 oxygen transmission rates modified atmosphere package), and the 100g small unit with MA film on asparagus sensory quality were evaluated. The CO₂ concentration depended largely on the packing unit and maintained at around 3% in small MA packages, whereas in the MA box increased to 12%. Ethylene concentration rapidly increased until after 3 days of storage in MA packages and then decreased to maintain 5μL·L^-1. Unrelated to the unit size, the lower weight loss was obtained in MA packages. A significant difference in visual quality was shown since the 15th day, the best and worst were the MA box and small MA package on the finish day. Off-odor was the highest in small MA packages and the lowest in the carton box (< 3.0). Although there was no significant difference in firmness among all treatments, the packages showed the highest firmness in tips and stems, respectively. The sugar content and hue angle decreased during storage, but there was no statistical difference in all treatments. EL was lowest and highest in small MA package and carton box, respectively. On the 10th day, the total aerobic bacteria was lowest in small MA packages, but no significant difference on the 20th day. E. coli was not found in all treatments on the 10th day, while it was the lowest in the MA box on the 20th day. The mold and yeast were not observed during the whole storage. Based on the above results, the carton box packaged with 10,000cc OTR film was more effective in maintaining the quality of green asparagus with the suitable CO₂ concentration for asparagus cold storage.

• Journal of the Korean Mathematical Society
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• v.37 no.6
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• pp.885-899
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• 2000

We obtain generalized versions of the Fan-Browder fixed point theorem for G-convex spaces. We define the class B of better admissible multimaps on G-convex spaces and show that any closed compact map in b fro ma locally G-convex uniform space into itself has a fixed point.

• Journal of Korea Water Resources Association
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• v.32 no.3
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• pp.291-300
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• 1999

The Snyder's synthetic unit hydrograph method is selected to apply the concept of the fractal dimension by stream order for the practicable rainfall-runoff generation, and fourth types of the Snyder's relation are derived from topographic and observed unit hydrograph data of twenty-nine basins. As a result of the analysis of twenty-nine basins and the verification of two basins, the Snyder's relation which considers the fractal dimension of the stream length and uses calculated unit hydrograph data shows the best result. The concept of the fractal dimension by stream order is applied to the Snyder's synthetic unit hydrograph method. The topographic factors, used in the Snyder's synthetic unit hydrograph method, which have a property of the stream length like $L_{ma}$ (mainstream length) and $L_{ca}$ (length along the mainstream to a point nearest the watershed centroid) were considered. In order to simplify the fractal property of stream length, it is supposed that $L_{ma}$ has not the fractal dimension and the stream length between $L_{ma}$ and ($L_{ma}\;-\;L_{ca}$) has the fractal dimension of 1.027. From the utilization of this supposition, a new Snyder's relation which consider the fractal dimension of the stream length occurred by the map scale used was finally suggested.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.273-279
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• 2003

버섯은 수확 후 이산화탄소 발생량이 2$0^{\circ}C$에서 200-500mg$CO_2$/kgㆍhr로 호흡속도가 아주 높은 편으로 저장이나 유통 중에 호흡속도를 낮추는 것이 버섯의 품질유지에 효과적이다. 따라서 저장고 또는 포장내의 기체조성을 변화시켜 신선 농산물의 호흡속도를 조절하여 저장하는 CA(Controlled Atmosphere)저장법이나, MAP(Modified Atmosphere Packaging)저장법을 버섯 저장에 이용하는 연구들이 보고되고 있으며 환경기체조성이 저장중인 버섯의 생리적인 현상에 미치는 영향에 관한 연구도 보고되고 있다. (중략)