• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.213-223
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• 2007

The aims of this study are to determine if the perceived risk of e commerce affect the Internet shopping mall users'decision to pre-purchase an item via e commerce, to find out if there are differences among the induced perceived risk according to gender, and to verify if the perceived risk according to gender have a correlation to a person's decision to pre-purchase an item via e commerce. It was found from the analysis of the collected data that there are five factors of perceived risk of e commerce: economic risk, the product performance risk, social risk, technology/time loss risk, and privacy risk. First, the collected data were analyzed to determine if the perceived risk of e commerce affect people's purchase intentions, and on the matter of whether there are differences among the pre-perceived risk according to sender, As regards the differences among the relationships between the pre-perceived risk of e commerce and the purchase intention of the Internet shopping mall users based on gender. It can thus be concluded that the pre-perceived risk of e commerce affect the Internet shopping mall users purchase intention. Different results were obtained, though, according to sender. This means e commerce purchasers can use these results to recognize the risk of e commerce.

• Food Science and Preservation
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• v.12 no.1
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• pp.8-16
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• 2005

To develop natural antimicrobial agents for extending the self-life of Kimchi, the effect of botanical antimicrobial agent-citrus products(BAAC) on microorganisms related to Kimchi spoilage was investigated. The inhibitory effect of BAAC on microorganisms related to Kimchi spoilage was increased according to the concentration of BAAC. Antimicrobial activities of BAAC against microoiganisms related to Kimchi spoilage were remarkably high. The effect of BAAC on the cellular membrane function of microorganisms showed the perturbation of cells in the presence of BAAC. Direct isualization of microbial cells by using both transmission md scanning electron microscope showed microbial cell membrane was destroyed by treating with BAAC. It could be confirmed that BAAC completely inhibit the growth of the test strains. The pH of BAAC-added Kimchi was a little higher than that of the control through the fermentation period. Titratable acidify, vitamin C and viable cells in BAAC-added Kimchi were changed more slowly than those in the control. Sensory evaluation did not show any significant difference between $0.01\%$ BAAC-added Kimchi and the control that showed the best palatabilities during fermentation.

• Food Science and Preservation
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• v.13 no.6
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• pp.740-748
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• 2006

The Chunma (Gastrodia elata Blume) requires a simple pre-treatment, due to inconvenience or preservation, toxicities, and pungencies in intact state. Various drying conditions were examined to establish the physicochemical properties of Chunma by the response surface methodology (RSM). Weter activity and total phenolic acid contents of Chunma dried extracts were optimal at $79.56^{\circ}C$ and $79.64^{\circ}C$ for 7.17 hr and 8.74 hr, respectively, for their characteristics. Electron-donating ability and nitrite-scavenging activity were optimal at 79.79 and $7.99^{\circ}C$ for 8.57 and 8.07 hr. We generated a regression equation for each variable and then superimposed the optimal condition in acquiring values for each frying process factor, physicochemical properties, resulting in that the optimal drying condition was at $75{\sim}80^{\circ}C$ for $8{\sim}9 hr$.

• Food Science and Preservation
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• v.9 no.1
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• pp.36-41
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• 2002

We examined the chemical properties of leek and dropwort and prepared the noodles with the dried powder of them, to develope functional processing floods which contain biological active compounds. The groups were divided by the drying methods as follows: hot air drying at 50$\^{C}$ (A), hot air drying after blanching for 30 sec (B), hot air drying after steaming for 2 min (C) and freeze drying (D). We had analyzed the content of vitamin C, total chlorophyll, and phenolic compounds and measured the hunter color values of dried powders individually. The contents of evaluated compounds were higher in A and D than in B and C groups and also the electron donating activity of A and D was stronger than B and C. The cooking properties of noodles prepared with leek and dropwort powder were examined. After cooking, the weight and volume of noodles prepared with powder were lower than those of control The turbidity of noodle soup were increased as the adding ratio was increased. The cutting strength of cooked leek noodles with A and B powder was similar to that of control, in case of dropwort, cooked noodles with D showed similar to that of control. The cutting strength of cooked noodles were decreased as the adding ratio were increased. The electron donating activity of noodles with vegetable powders showed high than that of control The sensory evaluation showed that significant difference between noodles with 2.5 ?/e addition groups and control was not recognized but was recognized between noodles with 5% addition groups and the control.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.110-110
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• 2016

금속재료 중 철강은 기계적 성질이 우수하고 대량생산에 의한 뛰어난 경제성을 가지기 때문에 다양한 산업 분야에서 널리 사용되고 있다. 그러나 스테인리스강 등과 같은 일부 특수한 용도의 강을 제외하고는 부식 환경에 취약하기 때문에 그 용도에 따라 표면처리를 함으로서 내식특성을 부여하고 있다. 일반적으로 이러한 철강재료에 대한 부식문제를 해결하기 위한 방법으로는 습식프로세스 중 아연(Zn)도금이 사용되는데, 아연은 그 자체가 보유하고 있는 차폐(barrier)효과는 물론 상대적으로 이온화 경향이 크기 때문에 철에 대하여 전자를 공급하는 희생양극적(Sacrificial anode)역할을 하여 철을 방식하는 원리를 가지고 있다. 하지만 최근에 이르러 기존의 도금 프로세스 처리된 제품의 사용 및 적용분야가 확대되고 가혹해 짐에 따라서 내식성 향상을 위한 새로운 재료 및 신기술 개발이 요구되고 있는 실정이다. 본 연구에서는 친환경 프로세스 방법인 PVD법 중 하나인 스퍼터링(Sputtering)을 이용하여 0.8mm 두께의 냉연강판 (cold rolled steel) 상에 Al에 대한 Mg 함량을 10~30wt.%로 하여 약 $5{\mu}m$ 두께의 막을 제작하였다. 이때 20wt.% 막의 경우 공정압력조건을 증가시켜 증착 막의 결정배향성을 변화시켰다. 뿐만 아니라 제작된 막들에 대해서 $400^{\circ}C$온도에서 10분간 열처리함으로서 코팅막의 성분변화에 따른 영향을 살펴보기 위해 시편을 추가 제작하였다. 이와 같이 제작된 막들에 대한 형성메커니즘과 내식성의 상관관계 해명을 위해 막의 조성분포, 표면 및 단면의 모폴로지 관찰 및 결정구조 등 재료특성분석과 더불어 염수분무(Salt spray test), 침지시험 그리고 양극분극 시험 등을 통해 내식성 평가를 진행하였다. 이상의 종합적인 결과를 살펴보면 제작된 Al-Mg 막은 마그네슘 함량비 및 열처리 조건에 따라 조성분포와 막의 모폴로지 및 결정배향성이 변화한다는 것을 알 수 있었는데, 마그네슘 함량이 증가하고 열처리한 막의 내식성이 가장 양호한 것으로 나타났다. 이것은 Al-Mg 성분이 표면을 중심으로 균일 분산-분포하며, Al에 대한 Mg의 고용으로 인해 안정적으로 형성된 부식생성물과 금속화합물의 단계적 반응 효과에 의해 차폐효과와 희생양극적 특성이 동시에 향상되었기 때문으로 생각된다. 한편 공정 압력을 증가시켜 형성한 막은 결정학적 구조에서 보다 높은 표면 에너지와 증가한 격자 정수에 의해 Mg이 부식환경에서 빠르게 반응하여 안정적 피막을 형성하기 때문에 내식성이 향상된 것으로 보여 진다. 이상의 연구를 통해서 고내식성을 Al-Mg막의 유효성 확인하였으며, 설계에 대한 기초적인 응용지침을 제시할 수 있을 것으로 사료된다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.78-78
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• 2018

미역은 갈조식물인 미역과에 속하는 1년생 바닷말로서 주로 어린 줄기와 잎부분을 식용으로 한다. 폐기부로 분류되는 미역귀 부분 또한 가식부 이상으로 풍부한 미네랄과 알긴산을 함유하고 있으며 이를 이용한 건강 친화적인 슬라이스 잼의 개발을 목적으로 연구를 수행하였다. 제품 개발의 소재화를 위한 연구의 일환으로 미역귀 알긴산 추출, 알긴산의 항산화활성(DPPH, ABTS, SOD 유사활성, total polyphenol, 세포 독성, NO생성 억제능을 수행한 바는 아래와 같다. 미역귀 알긴산 추출물을 각각 10, 50, 100, $500{\mu}g/mL$의 농도로 처리한 시험구들의 전자공여능을 확인한 결과 각각 2.8, 27.5, 35.9, 43.4%로 나타났으며, ABTS 라디칼 소거능은 각각 4.2, 21.6, 33.4, 67.4%로 나타났다. 동일한 농도로 처리하였을 때 SOD 유사활성은 각각 9.2, 12.4, 23.2, 30.8%로 나타났다. 미역귀 알긴산 추출물의 total polyphenol은 $19.16{\pm}0.08mg%$로 확인되었다. 세포생존율은 10, 50, 100, $500{\mu}g/mL$의 농도로 처리하였을 때 118.8%, 120.7%, 121.1%, 124.9%로 나타났다. NO생성 억제능을 동일한 농도에서 확인한 결과 각각 3.1, 5.1, 7.9, 9.6%로 확인되었다. 본 연구결과 미역귀 알긴산 추출물은 항산화능이 탁월하게 나타나 건강 친화적인 기능성 소재로 활용도가 높을 것으로 기대된다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1158-1163
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• 2017

This study investigated the antioxidative activity and whitening efficacy of Crataegus pinnatifida Bunge fruit 70% ethanol extract (CFE). The total polyphenol contents of CFE was 61.31 mg/g, and the total flavonoid contents was 25.42 mg/g. The electron donating ability of CFE at a concentration of $1,000{\mu}g/mL$ was 85.80%. The ABTS radical scavenging activity, and reducing power of CFE at a concentration of $1,000{\mu}g/mL$ were 17.3% and 0.31, relatively. The maximum permissible levels of CFE in melanoma cells were $100{\mu}g/mL$. CFE at $50{\mu}g/mL$ reduced melanin contents by 8.5%. CFE at $1,000{\mu}g/mL$ reduced intracellular tyrosinase activity by 46.83%. Collectively, the results of this study suggest that CFE effectively inhibited tyrosinase activity, whereas melanin synthesis was weak. These results suggest that Crataegus pinnatifida Bunge fruit could be used as a whitening agent and antioxidant resources for functional foodstuffs, cosmetics, and beauty industrial materials.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1073-1078
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• 2011

Changes of antioxidative components and activity of fermented tea manufactured by Bacillus subtilis, Saccharomyces cerevisiae, and Lactobacillus bulgaricus were evaluated during the fermentation period. The ascorbic acid content in the fermented tea was relatively lower (43.62~62.84 mg%) than that of green tea (66.74 mg%) during the entire fermentation period. The tea fermented by L. bulgaricus, which had the least contact with air, showed less change in ascorbic acid content. The polyphenol content of green tea was 14.88%, whereas that of fermented tea was 11.54~14.12% and it decreased during the fermentation period. The amount of flavonoids in green tea was 7.78 mg%, whereas that of fermented tea was 4.33~7.88 mg%. DPPH radical scavenging activity and ABTS reducing activity of green tea were 87.47% and 203.22 AEAC mg% (ascorbic acid equivalent antioxidant capacity), respectively, whereas those of fermented tea were lower than green tea. Results indicated that the antioxidative components and activity of fermented tea were lower than those of green tea during the fermentation period. But, when the sensory and hygienic quality are considered, fermented tea can be one of the higher quality tea products on the market.

• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.237-247
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• 2015

The project management information system (PMIS) has recently been developed by using the information technology(IT) in order to implement advanced information management technology to construction industry in Korea. The PMIS has been applied not only to domestic construction projects, but also to some overseas projects executed by Korean construction companies. This study was performed to develop the PMIS that is tailored to the US construction IT market. It has been monopolized by the US-based IT companies, but other companies are recently emerging with competitive technology and market strategy. As a preceding study, existing commercially available systems were analyzed, and the required features of the PMIS were identified by analyzing the core elements of contract, process and cost management about construction projects in the US. Then, the PMIS was developed based on the aforementioned analysis results. The system includes the document management module with an internal electronic approval system, the cost-plus-based automatic labor cost calculation module, and the progress management module to support the integrated project cost management. In addition, the functionality of the developed system was verified by experts about construction management in the US via questionnaire survey. The developed PMIS, in this study, is expected to be applied not only to the US construction IT market as a system specialized for the US construction industry, but also to other oversea markets in the future.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.1
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• pp.51-58
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• 2013

As it is changing into aging society, rehabilitation, welfare and sports industry markets are being expanded fast. Especially, the field of vital signals interface to control welfare instruments like wheelchair, rehabilitation ones like an artificial arm and leg and general electronic ones is a new technology field in the future. Also, this technology can help not only the handicapped, the old and the weak and the rehabilitation patients but also the general public in various application field. The commercial bio-signal measurement instruments and interface systems are complicated, expensive and large-scaled. So, there are a lot of limitations for using in real life with ease. this thesis proposes a wireless transmission interface system that uses EMG(electromyogram) signals and a control module to manipulate hardware systems with portable size. We have designed a hardware module that receives the EMG signals occurring at the time of wrist movement and eliminated noises with filter and amplified the signals effectively. DSP(Digital Signal Processor) chip of TMS320F2808 which was supplied from TI company was used for converting into digital signals from measured EMG signals and digital filtering. We also have used PCA(Principal Component Analysis) technique and classified into four motions which have right, left, up and down direction. This data was transmitted by wireless module in order to display at PC monitor. As a result, the developed system obtains recognition success ratio above 85% for four different motions. If the recognition ratio will be increased with more experiments. this implemented system using EMG wrist direction signals could be used to control various hardware systems.