• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.93-97
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• 1991

The enzymatic properties of purified CGTase from alkalophilic Bacillus sp. YC-335 have been examined. Apparent Vmax values of the enzyme in transferring glycosyl residues ${\alpha}-,\;{\beta}-and\;{\gamma}-cyclodextrin(CD)$ to sucrose were $16.13,\;21.8\;and\;9.8{\mu}moles/min/mg\;protein$, respectively and Km values of the corresponding CD were 1.68, 0.33 and 0.37 mM, respectively. A number of saccharides, specially starch hydrolyzates such as glucose and maltose, could activate the dextrinizing activity of the enzym. However, the dextrinizing activity was inhibited by ${\beta}-CD$. It was found from Lineweaver-Burk plot that the inhibition of CGTase by ${\beta}-CD$ was noncompetitive. High performance liquid chromatographic analysis showed that the enzyme has three kinds of activity ; transglycosylation and disproportionation as well as cyclization.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.125-133
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• 2007

Through open-sky policy, USA and European selected market principle of multiuser. However, in Asian case, major airlines monopolize airports. It is purpose that analyzes fare competition of Asian Hub Airport and the position of Incheon airport in Asia. Passengers required longer time and distance to go to the destination because direct flights decreases. But passengers increased in airport every year. Because of routes that decrease, airlines provide more services of flights. So airlines prefer to Hub Airports. As a result, both passengers and airlines are profitable by various routs and the increased frequency. On the assumption that distance and fare are related, the final formula is as following that defined the air fare from hub(H) to destination(Z) by logarithm. Analysis showed that log Rdist is not 1 but 0.08. As distance increases, fare doesn't increase. If distance from hub to destination airports is longer, Log dist_HZ is negative. It is that fare decreases from origin to destination via hub or that fare increases from hub to destination. HHI_HZ and HHI_AZ are negative. It means that if the degree of monopolization of hub and origin airports is lager, fare decreases from origin to destination via hub. Or fare increases from hub to destination. And it compares the Incheon airport with the other Asian hub airports and it examines the competitive fare by market division. As compared with the Incheon airport, Singapore, Beijing and Narita airports are higher fares. They compete with the other ones by Asian hub airports. But Hong Kong and Taipei airports must have more passengers through fare competition yet.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.142-148
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• 1997

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri possessing the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wastewaters polluted with various heavy metals. The effect of competing ions and metabolic inhibitors on heavy metal accumulation in the cells was investigated. Heavy metal accumulation into cells was drastically decreased in the presence of competing cation, $Al^{3+}$, and also decreased, at a lesser extent, in the presence of competing anions, $CO_3\;^{2-}$ and $PO_4\;^{2-}$. But heavy metal accumulation was not influenced generally in the presence of the other rations and anions. The accumulation of Cd, Zn or Cu by Cd-, Zn- or Cu-tolerant microorganism was remarkably decreased in the presence of metabolic inhibitors, but the accumulation of Pb by Pb-tolerant microorganism was little affected in the presence of metabolic inhibitors. These results suggested that the accumulation of Cd, Zn or Cu by Cd-, Zn- or Cu-tolerant microorganism was concerned with the biological activity depending on energy, and the accumulation of Pb by Pb-tolerant microorganism depended on not the biological activity but the physical adsorption on the cell surface. Each heavy metal-tolerant microorganism also exhibited some ability to accumulate the other heavy metals in solution containing equal concentrations of cadmium, lead, zinc and copper, when measured at 48 hours after inoculation of the microorganisms, but the accumulation rates were somewhat low as compared to the accumulation rates of heavy metal fitting to each tolerance. These results suggested that the accumulation of each heavy metal by each heavy metal-tolerant microorganism was a selective accumulation process.

• KSBB Journal
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• v.16 no.6
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• pp.527-532
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• 2001

Trichlooethylene (TCE) has become a widespread contaminant in air, soil, and underground water due to extensive industrial used and improper disposals. Since TCE is a suspected carcinogen and constitutes public health concerns, many treatment systems have been investigated to remove this hazardous waste. One of the most premising reactor systems for the treatment of TCE is trickling biofilter (TBF), in which monooxygenase (MO), the corresponding enzyme for initiating primary substrate oxidation, fortuitously degrades TCE via cometabolism. TCE, however, is not easily treated by simple TBF. This is mainly due to the toxicities of TCE and its degradation products to microbial film in TBF. In this paper, recent progresses on the development of bioreactor system for the treatment of TCE, especially gas-phase TCE, are reviewed. The potentials of novel biofilm reactor systems were also discussed for the long-term continuous treatment of TCE.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.131-137
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• 1993

Human neutrophil elastase (HNE, EC 3,4,21, 11), a mediator of tissue breakdown, was inhibited by tetracycline, oxytetracycline and demeclocycline. Among them, oxytetracycline showed the most potent inhibitory effect on the activity of HNE. IC50 of this drug at our specific condition was less than 1 mM. Tetracycline inhibited human neutrophil elastase non-competitively, and oxytetracycline inhibited competitively. Ki values of tetracycline and oxytetracycline were 4.9 mM and 0.39 mM, respectively. Structural modified tetracycline, de-dimethylaminotetracycline, which showed no antibiotic activity since the active dimethylamino radical was removed from the position #4 of the tetracycline, showed similar inhibition effect on the activity of human neutrophil elastase to that of tetracycline. Thus, we speculated that inhibition of human neutrophil elastase by tetracyclines was not depended on the dimethylamino radical which is a critical active site for antibiotic effect, rather it was depended on the hydoxyl radical of tetracyclines. Therefore, the property of inhibiting elastase may be an additional molecular biochemical mechanism of action of these drugs at the inflammatory sites.

• Journal of Korean Port Research
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• v.13 no.1
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• pp.65-78
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• 1999

운송에 필요한 각종 서류와 정보의 효율적 교환은 국제물류시스템의 중요한 일부분이 되었다. 또한 EDI(전자문서교환)는 수출입에 필요한 각종 상거래 서식을 컴퓨터가 읽을 수 있는 표준화된 전자문서의 형태로 바꾸어 교환함으로써 무역절차의 간소화와 운송서류의 신속한 교환을 가능하게 하여 물류 효율성을 증대시키는 것으로 알려져있다. 이러한 맥락에서 세계각국의 항만당국은 자국의 물류혁신을 도모하기 위하여 경쟁력으로 EDI의 도입을 추진해왔다. 그러나 90년대에 들어 EDI의 발전은 처음의 기대와는 달리 저조한 것으로 나타났다. 이는 크게 두가지로 설명된다. 첫째는 EDI 문서의 국제표준을 제정하는 UN/ECE 산하 WP4의 표준제정 미 공표의 비효율성으로 인해 실제 상거래에서 필요한 문서들의 EDI 표준화가 제때에 이루어지지 않았다는 점이다. 두 번째 이유는 대부분의 EDI 사용자가 전자문서의 교환통로로 이용해 왔던 부가가치통신망(VAN)서비스의 고비용적인 구조로 인하여 비용에 민감한 중소규모 화주들의 폭넓은 이용을 저해왔다는 점이다. 따라서 본고에서는 EDI의 확산을 저해했던 두가지 문제점에 입각하여 먼저 효율적 EDI 표준 제공을 위한 국제적 노력의 산물인 CEFACT(Center for Facilitation of Procedures and practices for Administration Commerce and Transport))와 보다 안전하고 신뢰성 있는 전자상거래 솔류션의 마련을 위해 이루어진 각종 국제기구들의 활동 및 결과물들을 소개하고 다음으로 인터넷의 급속한 확산으로 새롭게 개발되고 있는 Web-based EDI, XML/EDI, Simpl-EDI, Form-based EDI 그리고 Lite-EDI의 저비용적 구조 측면을 분석하여 중소규모화주들의 EDI에 대한 인식을 제고시킴으로써 EDI의 전반적인 확산을 도모하고 있다.

• KDI Journal of Economic Policy
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• v.19 no.1
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• pp.151-194
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• 1997

본고는 다음과 같은 문제를 제기한다. 해외직접투자와 관련한 우려 중의 하나가 수출이 잘되고 있는 부문에서 해외투자가 증가하여 국내의 수출기반을 약화시킬 수 있다는 것인데, 이를 어떻게 해석할 수 있을 것인가? 이 문제에 대한 접근을 위해 본 논문에서는 우리나라 수출입(輸出入) 및 해외직접투자(海外直接投資)의 구조변화(構造變化)에 관한 분석을 시도하고 해외직접투자의 요인(要因)을 추론하였다. 근년에 해외직접투자가 급증하면서 해외직접투자의 경제적 효과에 대한 관심이 높아지고 산업공동화를 우려하는 견해도 대두되고 있다. 특히 우리 기업의 해외진출을 진출(進出)이 아닌 탈출(脫出)로 인식하기도 한다. 고임금, 고금리, 고지가, 고물류비 등 국내의 고비용 구조가 우리 기업을 해외로 몰아내고 있다는 것이다. 본고는 해외투자에 관한 이러한 시각이 우리 기업의 해외투자가 기업고유(企業固有)의 자산(資産) 또는 경쟁우위(競爭優位)를 활용 강화하기 위해 이루어지는 측면을 간과하고 있음을 지적한다. 본고는 다음과 같은 점을 강조한다. 우선 해외투자는 경쟁우위가 증가하는 부문(본고에서는 수출비중이 커지는 부문)에서 오히려 더 자주 이루어지는 경향이 있다는 것이다. 이는 절충적 패러다임에서의 소유권우위적 요소가 해외투자의 요인 및 양상을 설명하는 데 중요함을 의미한다. 우리나라의 최대 수출업종인 조립금속 기계장비부문에서의 해외투자 증가도 이러한 맥락에서 보면 아주 당연하다고 할 수 있다. 그리고 조립금속 기계장비부문의 해외투자 내용을 살펴보면 주로 보급률이 높은 중저급 성숙기제품 중심으로 해외투자가 이루어지고 고급제품은 주로 국내에서 생산되거나 선진기술습득을 위해 선진국에서 생산되고 있는 것으로 판단된다. 결과적으로 주요수출업종(主要輸出業種)에서의 해외투자(海外投資)는 오히려 당연하고 내용면에서도 국내경제(國內經濟)의 구조고도화(構造高度化)를 저해하지는 않는 것으로 판단된다. 본고는 향후 정책이 해외직접투자가 국내산업구조(國內産業構造)의 질적(質的) 고도화(高度化)에 효과적(效果的)으로 기여하는 방향으로 마련되어야 함을 강조하고 이를 위해 국내(國內) 기술기반(技術基盤)의 강화(强化), 고급인력(高級人力) 개발(開發) 등을 제안한다. 해외직접투자의 증가가 국내 고부가 직종의 증가로 이어지고 이것이 저부가 직종의 감소를 상회하도록 해야 하고, 이러한 정책이 실패하면 국내의 고용감소는 불가피하며 고용감소를 우려하여 해외직접투자를 인위적으로 규제하는 것은 고용사정을 더욱 악화시킬 뿐임을 강조한다.

• Food Science and Preservation
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• v.21 no.1
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• pp.129-139
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• 2014

This study was conducted in order to investigate the optimal fermentation periods of the Smilax china L. leaves as a fermented tea via Aspergillus oryzae for 0 (non-fermented), and 10, 20, and 30 days (NF, F10, F20, F30). It was also observed for its quality characteristics. In the color and spectrum (400~700nm) of 1% tea water extract, NF was light yellow, whereas fermented tea (F10~F30) was light red color, and the F10 among F10~F30 has the clearest color and spectrum. Furthermore, acceptabilities of aroma and brightness were insignificantly different between NF and F10~30, while the mouth feel and overall acceptabilities were insignificantly distinct among all of the fermented teas. Therefore, these results suggest that the appropriate fermentation period for tea fermentation is 10 days. On the other hand, the total polyphenol and flavonoid content in the NF was the highest among all of the fermented teas. In the antioxidant parameters, EDA (electron donating ability), FRAP (ferric reducing antioxidant power), and LPOIA (lipid peroxidation inhibitory activity) in the NF were the highest among all fermented teas. Meanwhile, the XOI (xanthine oxidase inhibitory activity) was low, as well as insignificantly different from NF and F10~F30, whereas the AOI (aldehyde oxidase inhibitory activity) was markedly higher (38.09~41.70%) by the hot water tea extract (with or without fermentation), particularly the AOI that has increased via fermentation. In conclusion, the overall antioxidant activity tended to be reduced by fermentation; however, the EDA, FRAP and LPOIA in the fermented tea for 10 days was higher than the activities during 20~30 days of fermentation. There was a similar result in the color and acceptability of fermented tea for 10 days, which was remarkably better than those of 20-30 days. Therefore, fermented tea from the leaves of Smilax china L. could be expected to be used as a functional tea without the loss of inhibitory activity of both the XO and AO via fermentation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.163-186
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• 2000

We have previously screened 150 medicinal plants on the inhibition of elastase and found a significant inhibitory effects of the extracts of Areca catechu L. on the aging and inflammation against the skin tissues. To isolate and identify the compounds having biological activity, we was further purified by each of the solvent fractions, silica gel column chromatography, preparative TLC and reversed-Phase HPLC. Peak in HPLC, which coincided with the inhibitory activity against elastase, was identified as Phenolic substance using various colorimetric methods, UV, and IR. $IC_{50}$/ values of phenolic substance purified from Areca catechu were 26.9 $\mu\textrm{g}$/$m\ell$ for porcine pancreatic elastase (PPE) and 60.8 $\mu\textrm{g}$/$m\ell$ for human neutrophil elastase (HNE). This Phenolic substance showed more potent activity than those of reference compounds, oleanolic acid (76.5 $\mu\textrm{g}$/$m\ell$ for PPE, 219.2 $\mu\textrm{g}$/$m\ell$ for HNE) and ursolic acid (31.0 $\mu\textrm{g}$/$m\ell$ for PPE, 118.6 $\mu\textrm{g}$/$m\ell$ for HNE). According to the Lineweaver-Burk Plots, the inhibition against both PPE and HNE by this phenolic substance was competitive with substrate. Phenolic substance from Areca catechu exhibited high free radical scavenging effect ($SC_{50}$/ : 6 $\mu\textrm{g}$/$m\ell$) and inhibited effectively hyaluronidase activity ($IC_{50}$/: 210 $\mu\textrm{g}$/$m\ell$). These results suggest that the Phenolic substance Purified from Areca catechu showed anti-aging effect by protecting connective tissue proteins.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.369-380
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• 2023

The incorporation of innovative technology systems into domestic construction practices has catalyzed an organic evolution of the industry, significantly enhancing the level of domestic construction technology and intensifying competitiveness. In particular, the on-site implementation of these groundbreaking construction technologies has proven effective in diminishing construction costs and accelerating project timelines. Nevertheless, despite a period of 33 years since the inception of this new construction technology system, both the volume of designated construction technologies and their practical application on construction sites remain static. As a consequence, this study introduces a strategic plan to dissect and overcome the barriers faced in the adoption of new construction technology across a multitude of sectors. The chief outcomes encompass the inception of a new construction technology utilization surveillance system, an assessment of distinct technologies, refinement of the post-evaluation system, and the creation of a new technology market system. This systematic enhancement is anticipated to foster the practical application of new construction technologies within the industry.