• 한국식품저장유통학회지
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• 제6권1호
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• pp.23-28
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• 1999

Commercial red ginseng, which was manufactured for the past 6 years, showed a microbial level of 2.0${\times}$10\ulcorner to 7.2${\times}$10\ulcorner CFU/g of total aerobic bacteria and molds. The moisture content of commercial products was ranged from 13.54 to 17.26%, which were higher than that of the product standard, 14%. Irradiation of red ginseng at 2.5 kGy resulted in the reduction of microorganisms contaminated to below the detectable level. Irradiation prevented mold growth on red ginseng during storage at RH 90% and 25$^{\circ}C$; molds were found at the 72nd day after storage in 2.5 kGy-irradiated sample, while 41st day in the nonirradiated control. At this point of time, irradiated samples showed an increased level of moisture content required for mold growth, 22.2% in 2.5 kGy group and 21.5% in control group. Based on the above results, microbiological qualities of red ginseng could be effectively improved by the optimum dose of irradiation, which was expected to secure the quality stability of red ginseng during distribution under the high-moistured conditions.

• Preventive Nutrition and Food Science
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• 제17권1호
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• pp.53-63
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• 2012

This study was conducted to develop an optimal composite recipe for pan bread with ramie powder that has high sensory approval with all age groups and to estimate the DPPH radical scavenging activity and the pan bread shelf life after gamma irradiation. The sensory evaluation results showed significant differences in flavor (p<0.05), appearance (p<0.01), color (p<0.01), moistness (p<0.01), and overall quality (p<0.05) based on the amount of ramie powder added. As a result, the optimum formulations by numerical and graphical methods were calculated to be as follows: ramie powder 2.76 g (0.92%) and water 184.7 mL. Optimized pan bread with ramie powder and white pan bread were irradiated with gamma-rays at doses of 0, 10, 15, and 20 kGy. The total bacterial growth increased with the longer storage time and the least amount of ramie powder added. Consequently, these results suggest that the addition of ramie powder to pan bread provides added value to the bread in terms of increased shelf life.

• 대한기계학회논문집A
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• 제26권8호
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• pp.1545-1551
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• 2002

The optical storage device has recently experienced significant improvement, especially for the aspects of high capacity and fast transfer rate. However, it is necessary to study a new shape of air bearing surface for the rotary type actuator because the optical storage device has the lower access time than that of HDD (Hard Disk Drives). In this study, we proposed the air bearing shape by using SA (Simulated Annealing) algorithm which is very effective to achieve the global optimum instead of many local optimums. The objective of optimization is to minimize the deviation in flying height from a target value 100nm. In addition, the pitch and roll angle should be maintained within the operation limits.

• 한국농공학회논문집
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• 제47권3호
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• pp.3-13
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• 2005

The conceptual rainfall-runoff models are used to predict complex hydrological effects of a basin. However, to obtain reliable results, there are some difficulties and problems in choosing optimum model, calibrating, and verifying the chosen model suitable for hydrological characteristics of the basin. In this study, Genetic Algorithm and SCE-UA method as global optimization methods were applied to compare the each optimization technique and to analyze the application for the rainfall-runoff models. Modified TANK model that is used to calculate outflow for watershed management and reservoir operation etc. was optimized as a long term rainfall-runoff model. And storage-function model that is used to predict real-time flood using historical data was optimized as a short term rainfall-runoff model. The optimized models were applied to simulate runoff on Pyeongchang-river watershed and Bocheong-stream watershed in 2001 and 2002. In the historical data study, the Genetic Algorithm and the SCE-UA method showed consistently good results considering statistical values compared with observed data.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2003년도 제23차 추계총회 및 국제학술심포지움
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• pp.192.1-192
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• 2003

The aim of this study was to develop a model that could be used in the design of modified atmosphere packaging (MAP) for Mandarin oranges. Respiratory data at 5, 10, 20$^{\circ}C$ for mandarin oranges were gathered and altered for create useful respiration model. The maximum rate of oxygen uptake increased with increasing temperature. The packaging materials were conventional low density polyethylene and polypropylene with anti-fog, and anti-fungi treatments, and thickness was 30 $\mu\textrm{m}$ and 50 $\mu\textrm{m}$. Permeability tests were performed to find their oxygen, carbon dioxide, water vapor transmission rate as increases in temperature. Test results were then converted to logarithm format for MAP modeling. Optimum gas composition in the package system for fruits were set according to literature and upper or lower limits of oxygen and dioxide established. To predict gas composition at certain storage time, weight of fruits, film thickness, film type, and other variables, respiration rate was studied at various storage conditions. The validity of the model was tested experimentally by observing actual atmospheric changes inside packages. It is concluded that the strategy developed is of use in designing dynamic gas exchange MAP systems, and also has potential uses in similar agricultural products.

• 원예과학기술지
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• 제31권2호
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• pp.203-210
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• 2013

본 실험은 자두와 살구의 종간잡종인 플럼코트 '하모니' 과실의 수확 후 적정저장 온도를 구명하고 에틸렌작용 억제제인 1-MCP 처리효과를 알아보기 위하여 수행되었다. 과실은 숙기를 3가지로 구분하여 수확 후 각각 0, 5, 10 및 $20^{\circ}C$의 온도에 저장하였고, 1-MCP($1{\mu}L{\cdot}L^{-1}$) 처리는 $10^{\circ}C$에서 24시간 처리 후 $10^{\circ}C$에 저장하였다. 온도가 낮은 저장조건일수록 플럼코트 '하모니' 과실의 호흡량을 현저히 낮추었고 온도가 높을수록 호흡량의 증가와 함께 품질이 빨리 저하되었다. 저장온도 $20^{\circ}C$는 과실의 부패가 빠르게 촉진되어 유통조건으로 부적합하였다. 숙기에 따른 품질은 30-50% 정도의 붉은 착색 과실이 양호하였는데 특히, $10^{\circ}C$에 저장할 때, 식미가 가장 양호하였다. 1-MCP는 플럼코트 '하모니' 과실의 연화, 색도 변화, 산도 변화 등 전체적인 품질의 변화를 지연시키는데 효과적이었다.

• 한국식품조리과학회지
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• 제21권4호
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• pp.545-555
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• 2005

The physicochemical and microbial characteristics of Oiji prepared with dry salting method, which has been used industrially for industry, were investigated. Low salting and low storage temperature were employed:extremely low salting extremely low temperature; ESET $(5\%,\;0^{\circ}C)$, very low salting extremely low temperature;VSET $(10\%,\;0^{\circ}C)$, extremely low salting very low temperature; ESVT$(5\%,\;5^{\circ}C)$, low salting very low temperature; VSVT$(10\%,\;5^{\circ}C)$ and high salting low temperature;HSLT$(30\%,\;10^{\circ}C)$ for control. Acidity was lower, and pH was higher in VSET, in of which the fermentation pattern was similar with that of HSLT The time required to reach the optimum acidity ($0.3\%$ lactic acid) was longer delayed for VSET (168 days), than for compared to ESVT (51 days). During storage of Oiji, greenness (-a) as measured with of the Hunter color system wasshowed the highest in VSET, and the lowest while in ESVT, the lowest. Total microbial and lactic acid bacteria counts number were the lowest in HSLT and VSET and were the lowest than in other groups, while the highest in ESVT. Yeast was not detected in HSLT, but was the highest while in VSVT. E coli coliform and listeria were detected in the $5\%$ salting groups, although Salmonella was not detected in any of the all groups. Texture profile analysis demonstrated exhibited that fracturability and hardness were highest in HSLT and VSET, compared to the other groups. Scores of over-all preference for ESVT and HSLT were higher atwith 6.3 and 6.2, respectively, compared to the other products. Based on these results, lower saltiness less than $10\%$ and lower storage temperature (less than $5^{\circ}C$) condition was optimum for maximizing the better for good quality of industrial Oiji preparation in industry.

• KSBB Journal
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• 제23권2호
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• pp.169-176
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• 2008

The concentration of fresh gel from Aloe vera L. by using ulfrafiltration (UF) process was investigated and analyzed. The two membranes (organic and ceramic) with different molecular weight cut-off (MWCO) and modules (flat sheet and tubular) was used. Under optimum operation conditions, ceramic (zirconium dioxide) tubular membrane with MWCO of 50 kDa resulted in higher flux, less fouling, more turbid, higher total solid, higher polysaccharide and less aloin content. Optimum operation conditions were transmembrane pressure of 1.0 bar, feed velocity of 240 L/hr and temperature of $23^{\circ}C$. Volume concentration factor of aloe gel was 3.13 at permeate flux of $51.1\;L/m^2{\cdot}hr$ after processing time of 1.66 hr. Aloin in fresh aloe gel by UF process was effectively removed as permeate and bioactive polysaccharide content was 2.1 times higher than that of fresh aloe gel. These results allowed a very good level of concentration degree and polysaccharide content. Thus, ultrafiltration process of this study was suitable for the concentration of fresh aloe gel though the aloe concentrate showed both the viscosity decrease and partially separation of liquid layer during storage at $4^{\circ}C$.

• 동력기계공학회지
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• 제15권4호
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• pp.5-10
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• 2011

In case of using rapid vacuum-freeze drying for high quality dry flower of flowering plant, the morphological and physiological characteristics of dry rose showed as the following. The dry ratio of about 82% presented after 1 day in case of using rapid vacuum-freeze drying and it was reached that the optimum storage water content of general dry products was 18%. The dry ratio of about 89% presented after 4 days. This result indicates very short dry time comparing with natural dry time of 12 days. Also, the morphological characteristics of flowering plant in case of vacuum-freeze drying showed similar shape with real flower. The contraction decreased about 9% comparing with real flower under dry time of 72 hours. But the contraction in case of natural dry decreased 36% and showed noticeable difference. The brightness which affects physiological characteristics of dry flowering plant showed lower values according to the dry process and chromaticity was thick. After 4 days, natural dry was thick with about 2 times comparing with vacuum-freeze drying. In case of vacuum-freeze drying, the quantity of anthocyanin and chlorophyl which affect discoloration and bleaching of dry flowering plant showed the clear difference comparing with natural dry method due to the sublimation by vacuum after rapid freeze with short initial time.

• 원예과학기술지
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• 제18권3호
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• pp.395-398
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• 2000

본 연구는 떫은감 "청도반시"를 조기착색과는 9월 21일, 적숙과는 10월 11일에 수확하여 수확시기에 따른 연화정도를 조사하고, 연시제조의 적정온도를 설정하고자 10, 15, $20^{\circ}C$에서의 품질변화를 조사하였다. 경도는 처리온도 15, $20^{\circ}C$에서 처리 2일만에 전체 경도 감소량에 70% 정도 감소되었으며, 6일 이후에는 경도의 감소가 완만하게 되었다. 처리온도 $10^{\circ}C$는 다른 처리온도에 비하여 높은 경도를 나타내어 연시제조에는 효과가 없었다. 가용성탄닌은 수확시기에 관계없이 15, $20^{\circ}C$의 처리구에서 6일째에 급격히 감소하였으나, 무처리구는 가용성탄닌이 약간 감소되었다. 조기수확과의 Hunter 'L', 'b' value는 모든 처리온도에서 2일째까지 증가한 후 감소하였고, 적숙과는 초기부터 감소하기 시작하여 8일째부터는 비교적 일정한 경향을 보였다.