• KSBB Journal
• /
• v.9 no.4
• /
• pp.378-384
• /
• 1994

An improved method for the selective isolation of high-yielding mutant strains for the production of antifungal antibiotic KRF-001 was investigated. The mutant strain U. V 4, which produces high titer of KRF-001, was selected on the high potency agar plate after ultraviolet light irradiation. The U. V 4 strain produced 2-fold more KRF-001 than the mother strain in production media. Large scale fermentation was performed using the U. V 4 strain in 100$\ell$ fermenter. The antifungal antibiotic KRF-001 secreted into culture broth was detected by HPLC in 24hrs of fermentation.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.10a
• /
• pp.376-378
• /
• 2001

CBD(Component Based development)가 이미 완성된 소프트웨어 모듈인 컴포넌트들을 특정 목적을 위해 배치하고 조립함으로써 품질 보증된 고생산성의 재사용을 가능하게 됨에 따라, 최근 IT 비즈니스 솔루션 도출을 위한 핵심 적인 기술 전략으로 인식되고 있다. 따라서 영 역에 적절한 컴포넌트의 추출과 개발 및 응용 시스템으로의 전개를 위한 컴포넌트들의 배치와 조립 등을 포함하는 일련의 CBD 프로세스를 실제화 하기 위해서는 아키텍쳐 기반의 접근과 제어가 매우 중요하다. 하지만 대부분의 CBD 연구는 비즈니스 로직들의 기능성을 그룹화한 컴포넌트의 생산에 초점을 두고 있지 컴포넌트간의 상호작용을 명시하는 아키텍쳐 정보의 관리를 간과함으로써 컴포넌트의 조립과 통합을 통한 CBD 시스템으로의 전개는 극히 어려운 실정이다. 따라서, 본 논문에서는 CHD 프로세스 상에서 아키텍쳐 접근의 중요성과 전개 방법을 살펴보고, 컴포넌트 프레임워크(Component Framework)를 위한 아키텍쳐의 계층을 새롭게 재정의 하며 그 의미를 설명한다. 이를 위해 영역 분석 및 설계 정보를 선언적으로 명시하는 수단이며, 도메인 내에서 특정 서비스를 제공하는 컴포넌트간의 일반적 결합 방식의 규정하기 위한 수단으로서 설계 패턴을 이용하여 서비스 아키텍쳐 패턴을 정의하고 실 예로 적용한다.

• Proceedings of the Korea Contents Association Conference
• /
• 2019.05a
• /
• pp.371-372
• /
• 2019

금속 3D 프린팅의 응용분야는 자동차, 우주항공, 의료/헬스, 전자기기, 금형 등으로 분류할 수 있다. 최근 들어 선진국을 중심으로 아크 용접기반 금속 3D 프린팅 기술의 연구개발이 활발히 진행되고 있다. 3D 프린팅 기술은 CAD 설계 정보를 이용한 적층 제조방식이기 때문에 내부 형상이 아무리 복잡하여도 제작이 가능하고, 디자인이 변경되더라도 별도의 금형 제작 없이 제작이 가능하다는 장점이 있다. 와이어 아크기반 금속 3D 프린팅 기술은 차세대 생산제조 핵심기술로 발전할 전망이다. 금속 3D 프린터의 기술경쟁력 제고를 위해서 적층패턴, 와이어정밀 송급 및 적층품질 실시간 모니터링 등의 시스템 제어 기술과 대형 금속부품의 고생산성을 위한 적층가공 시스템 기술개발이 진행될 것으로 예상된다. 금속 와이어 아크를 이용한 대형 3D 프린팅 시스템의 지식재산권 확보 전략을 수립하기 위해 대형 3D 프린터 기술, 금속 와이어 3D 프린터 기술, 아크 3D 프린터 기술의 세 가지 분야에 대한 특허동향 분석을 수행하였다.

• KSBB Journal
• /
• v.22 no.5
• /
• pp.305-312
• /
• 2007

It is crucial to develop a miniaturized cultivation method for large and rapid screening of high-yielding mutants of monacolin-K, a powerful anti-hypercholesterolemic secondary metabolite biosynthesized by the fungal cells of Monascus ruber. In order to investigate as many strains as possible in a short time, a miniaturized fermentation method especially suitable for the cultivation of the filamentous Monascus mutants was developed using $50m{\ell}$ culture-tube ($7m{\ell}$ of working volume) instead of the traditional $250m{\ell}$ flask ($50m{\ell}$ of working volume). Generally, in filamentous fungal cell fermentations, morphologies in growth and production cultures should be maintained as thick filamentous and compact-pelleted (usually less than 1 mm in diameter) forms, respectively, for enhanced production of secondary metabolites in final production cultures. In this study, we intended to induce the respective optimal morphologies in the miniaturized culture system for the purpose of rapid screening of overproducers. Miniaturized growth culture system was successfully developed due to the mass production of spores in the statistically optimized solid medium. When large amounts of spores were inoculated into the growth cultures, and brown rice flour (20 g/L) was also supplemented to the growth medium, dense filamentous morphologies were successfully induced in the growth cultures performed with the 50 ml culture tubes. It was implied that the amounts of spores inoculated into the growth tube-cultures and the growth medium components should be the key factors for the induction of the filamentous forms in the growth fermentations. Furthermore, in order to statistically optimize production medium, multiple experiments based on Plackett-Burman design and response surface method (RSM) were carried out, resulting in more than 2 fold enhanced production of monacolin-K in the final production cultures with the optimized production medium. Notably, under the production culture conditions with the statistically optimized medium, optimal pellet sizes below 1 mm in diameter were reproducibly induced, in contrast to the thick and viscous filamentous morphologies observed in the previous production cultures.

• Journal of the Economic Geographical Society of Korea
• /
• v.14 no.4
• /
• pp.453-466
• /
• 2011

The main aim of this paper is to explore the Korean development strategy in the context of trajectories of the economic development from 1961 to 2010. The fast and high growth in the period of 1961 and 2010 resulted from the 'export-oriented industrialization' through a combination of 'mass production-mass exports' and '(relatively) high productivity-low wages' up to the late 1980s, a mixture of 'mass production-mass exports' and '(relatively) high productivity-high wages' to the late 1990s, and a combination of the reformation of public and private sectors for overcoming the Korean financial crisis and the gradual improvement of the marketization and social safety net since 2000. With respect to this model of development, the global and national modes of regulation were established. Along with the formation of endogenous forces (as the national mode of regulation), that of exogenous forces (as the global mode of regulation) are the important rules of the game at the global level, which lead and stabilize the process of accumulation by the export-led industrialization in Korea. In this respect, the establishment of global modes of regulation is led by exogenous forces such as trade regulations, exchange rates, global-Korean industrial relations, and global regulations of loans to developing countries. On the other hand, the national modes of regulation are formed by endogenous forces such as the triangular relationship of the state, capital and labor.

• Microbiology and Biotechnology Letters
• /
• v.32 no.3
• /
• pp.243-248
• /
• 2004

Production of (R)-3-hydroxybutyric acid (R3HB) by fed-batch culture and continuous culture of metabolically engineered Escherichia coli harboring Ralstonia eutropha PHB biosynthesis and depolymerase genes was examined in a 30 1 pilot-scale fermentor. A new stable two-plasmid system, pBRRed containing the R. eutropha PHB depolymerase gene and pMCS 105 containing the R. eutropha PHB biosynthesis genes, was developed. Among a variety of E. coli strains harboring plasmids, recombinant E. coli XL-10 Gold (pBRRed, pMCS105) was able to produce R3HB with the highest efficiency in a batch culture. By the fed-batch culture of recombinant E. coli XL-10 Gold(pBRRed, pMCS 105) in a 30 1 fer-mentor, the final R3HB concentration was 22.4 g/l giving a productivity of 0.97 g/l-h. To produce R3HB to a high concentration with high productivity, a new strategy of fed-batch culture followed by a continuous culture was investigated. The maximum productivity and R3HB concentration were 5.06 g/l-h and 25.3 g/l, respectively. These results show that economical production of R3HB is possible by recombinant E. coli in large scale.

• Journal of Labour Economics
• /
• v.40 no.4
• /
• pp.1-31
• /
• 2017

Recent empirical studies highlight the importance of between-firm or between-establishment factors in rising wage inequality. Examining the establishment-level data from the Mining and Manufacturing Survey of 2000-14, this paper finds that overall between-establishment wage dispersion has increased in Korea. However, unlike other OECD countries, the divergence occured in the lower tail of the wage distribution. Dispersion in labor productivity exhibits a similar movement, therefore explains the widening wage dispersion. In contrast, the link between wages and total factor productivity is much weaker, which appears to be associated with inefficient capital reallocation. I also find much heterogeneity in the productivity-wage relationship across productivity distribution. The most productive establishments turn the smallest portion of productivity gains into wage increases.

• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.534-537
• /
• 2002

An agarase gene from Bacillus cereus ASK202 was expressed in high levels by E. coli BL21(DE3)/pEBA1 using pET28a(+) vector system with the inducible T7 promoter in the presence of isopropyl- ${\beta}$ -thiogalactopyranoside. The open reading frame encodes 761 amino acid residues with a calculated molecular weight of 83,300 daltons and a potential signal peptide about 36 amino acid residues at the N-terminus. E. coli BL21(DE3)/pEBA1 produce 1280 unit/ ${\ell}$ of agarase. The optimum physical condition for the agarase activity was pH 5.6, and $40^{\circ}C$, respectively. The agarase activity was stable up pH $4.0{\sim}9.0$ and $4{\sim}40^{\circ}C$. The km and maximum rate of metabolism for agar were 0.068mg/$m{\ell}$ and 0.094mg/$m{\ell}{\cdot}min$, respectively.

• Microbiology and Biotechnology Letters
• /
• v.15 no.6
• /
• pp.396-401
• /
• 1987

Protein productivities of a cloned gene ($\beta$-galactosidase) and the cultural performances of two recombinant Escherichia coli strains, which use different host-vector systems, were studied. E. coli JM109/pTBG10 strain which carries Tac promoter had higher protein productivity than E. coli MH3000 (pRKc1857)/pASI(lacZ) strain which carries pL promoter. Induction of protein syn-thesis was optimum at the initial-and mid-logarithmic growth phases for both strains. Oxygen demand was observed to be very high during the cloned gene expression, and could be alleviated to some extent through pH control. The ratio of specific growth rates of plasmid-harboring to plasmidfree cell, $\mu$+ /$\mu$-, of the high productivity strain was observed to be lower than that of the low productivity one. Plasmid stability was analyzed for 20-30 generations, and it was found that the traction of plasmid-harboring cells dropped to l0% level in about 25 generations for both strains when the cloned gene expression was induced.

• 한국생물공학회:학술대회논문집
• /
• 2003.04a
• /
• pp.228-232
• /
• 2003

Lovastatin produced by Aspergillus terreus via polyketide pathway is a secondary metabolite with high anti-hypercholesterolemic activity. In this paper we are going to present effective strain development strategies for lovastatin production by comparing the productivity of the mutants obtained through traditional rational screening process and protoplast fusion method. Mutants resistant against various antibiotics and/or antimetabolites showed significantly higher lovastatin productivity than the corresponding mother strains, demonstrating that rational screening method was very efficient in selecting high yielding producers. Recombinant fusants obtained using protoplast fusion between high producers were observed to have very different morphology and physiology as represented by the production and secretion of lovastatin, as well as cell growth pattern. In parallel with the strain development, optimization process for the production medium was carried out in order to find optimal concentrations of the medium components using such a powerful statistical method as response surface method (RSM). It was concluded that not only the optimum production medium but also good morphological characteristics of the high-yielding producers led to higher lovastatin production.