• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2112-2118
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• 2017

Leuconostoc mesenteroides is used as a starter to produce high-quality kimchi products. In this study, an efficient and economical cabbage juice medium (CJM) was developed by process optimization of cabbage extraction and pasteurization and by compositional supplementation of various lacking nutrients. The pasteurized cabbage juice was determined to be a good medium candidate to cultivate L. mesenteroides, showing maximal cell numbers ($9.85{\times}10^8CFU/ml$) after 24 h. Addition of sucrose and yeast extract with soy peptone resulted in increment of bacterial cell counts in CJM, showing the supplementing effect of the lacking nutrients. Furthermore, addition of shell powder gave a protective effect on bacterial cells by preventing pH decline and organic acid accumulation in CJM, resulting in a 2-fold increase of bacterial counts. The optimized composition of CJM was 70% cabbage juice diluted with water, 0.5% (w/v) sucrose, 1% (w/v) yeast extract, 1% (w/v) soy peptone, and 1.5% (w/v) ark shell powder. The CJM developed in this study was able to yield a comparable level of bacterial counts with MRS medium and reduced the cost by almost 10-fold.

• Journal of Microbiology and Biotechnology
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• 제17권3호
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• pp.393-397
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• 2007

A Haematococcus pluvialis strain isolated from the ruins of Ephesus in Turkey was investigated as regards its adaptation to laboratory conditions and maximum growth rate. In the first stage of the experiment, the growth of H. pluvialis was compared in common culture media. Furthermore, in an effort to minimize the culture costs, the second stage of the experiment compared the growth rate in the culture medium selected in the first stage with that in commercial plant fertilizers. The results demonstrated that the maximum cell concentration of 0.90 g/l, corresponding to a growth rate of $0.150d^{-1}$, was found with an N-P-K 20:20:20 fertilizer under a light intensity of $75{\mu}mol$ photons $m^{-2}s{-1}$ on the $12^{th}$ day of cultivation.

• 정보통신설비학회논문지
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• 제10권4호
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• pp.115-120
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• 2011

Recently flash memory is widely used in various mobile devices as storage medium. Nonvolatile memory can be divided into two categories: NAND- and NOR-type flash memory. NOR flash memory is mainly used to store instruction codes for operation; while NAND for data storage. However, NAND does show more economical benefits, that is, it is approximately 30~40% cheaper than NOR flash. Therefore it can be useful to improve NAND flash performance by replacing NOR flash with NAND flash combining with various buffer systems.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.260-265
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• 2005

In the previous research about ethanol production, we confirmed that SFW(saccharified foodwastes) medium(0.56g-ethanol/g-glucose) is mere efficient than YM medium(0.538g-ethanol/g-glucose). Ethanol production using SFW needs large enzyme cost due to the enzymatic hydrolysis of foodwastes, although the enzymes was obtained from our economical enzyme production methods, using the intact whole culture broth of Trichoderma harzianum FJ1. Therefore, in this research we used synchronous saccharification and fermentationmethod to produce ethanol using foodwastes. Ethanol production yield was 0.45g-ethanol/g-reducing sugar in synchronous saccharification and for-mentation by a fed-batch mode.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.606-610
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• 1991

A relay is the one of small electrical components for automobiles and used for industry widely. We have developed the automation system for relay assembly and test to make it improve the productivity and decrease the man power. In order to determine the objective process of automation, we investigated 6 small and medium sized-enterprises and 1 greate sized-enterprise producing relays. And, we selected 2 model enterprises of them. One of the two is the system to develop. The scope of our study is the analyse of the conventional workcell, the determination of the system specification, the design of the system layout, the determination of the system cycle time, the design of the system mechanism, and the development of the controller for the system. We think that the developed system may be solve the technical and the economical problems interrupted efficiential automation of domastic small and medium sized-enterprises, and improve the international competitive power.

• Ocean and Polar Research
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• 제45권4호
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• pp.201-209
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• 2023

Melosira nummuloides (KNU-HAPCC-101), which is a biological resource for fucoxanthin extraction, was separated from single cells, and optimal growth conditions were derived according to temperature, salinity, light intensity, light emitting diode, N:P ratio of culture medium, and dilution ratio of culture medium. These parameters were assessed to ascertain the best culture conditions for the most economical and efficient indoor mass production. The specific growth rate was the highest at 25℃ in temperature, but there was no significant difference between 15℃ and 20℃. M. nummuloides died at 0 psu in salinity, and the specific growth rate was the highest at 30 psu in respect to salinity. The light intensity was similar in all experimental groups except for 5 µmol photons m^-2 s^-2. The maximum biomass and specific growth rate in the light-emitting diode experiment were revealed at the red wavelength, but the concentration of chlorophyll-a was the lowest at the red wavelength whereas the white wavelength produced the highest chlorophyll-a concentration. In the experiment according to the ratio of nitrogen and phosphorus (N:P) based on the f/2 culture medium, the growth rate was significantly higher in the 15:1 to 50:1 ratio range. The growth rate according to the dilution concentration of the f/2 culture medium was the highest in the f/2 culture medium, but did not show a significant difference from the f/4 culture medium. M. nummuloides can be mass-cultured under conditions of a temperature of 15-25℃, a salinity of 15-35 psu, light intensity of 25-150 µmol photons m^-2 s^-2, and f/4 media concentration level with an N:P ratio 15:1 or more. Based on the data of this study, it is expected that fucoxanthin can be produced in a highly efficient manner through the development of a mass culture system.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.620-623
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• 2004

Conventionally injection molds & dies are manufactured through an order-oriented manner. This brings unexpected orders into the shop floor such as hot order, re-work, and new types of mold & dies. Thus, there needs appropriate resource assignment plans considering the available times of machines and workers. Further, a scheduling system is required that can create work schedules periodically or by customers' requests. Yet, in small & medium sized mold & die makers, production schedules usually depend on the shop floor workers' experience and their manual preparation. Hence, developed in this study is a scheduling management system (SMS) based on order release and review (ORR) in small and medium sized mold & die companies. The proposed SMS considers delivery dates as well as flexible work schedules, so as to meet frequent changes of customers' order. The system can provide effective resource assigning and work scheduling plans, securing standard data associated with shop floors. Furthermore, the system pursues economical schedules for companies' needs, equipped with an available to promise (ATP) function that can effectively accommodate the changes of production plans.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.301-304
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• 2005

Most of the small and medium industries rather focus on immediate problems and how to properly maintain organizational matters and existing system than the strategic and operational use of Information Technology when they deal with applications and operation of Information System. This study found out that there were few studies on IT outsourcing for small and medium companies in Korea compared to large enterprises' IT outsourcing. Most preceding studies researched the problems of partnership and technical, managerial, and economical success factors for big companies. Small and medium companies have the problems of financial difficulty, organizational scale (40.3%), shortage of manpower for system operation (24.1%), and lack of practical use of managers (8.9%). SMB firms have required support of government for their Informationalization but, we found out amount of companies (41%) not be informed or don't account on government's supporting IT of SMB programs. In addition, Range and Contents of outsourcing, Reputation of Outsourcing vendor, Reliability of maintaining were selected as CSFs of SMB IT outsourcing. While large corporation staff more considered CEO's willing and inner facts of their companies.

• 생명과학회지
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• 제12권5호
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• pp.566-569
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• 2002

Acetobacter strains는 포도당을 함유한 복합배지에서 셀룰로오스를 합성할 수 있는 세균이다. 본 연구에서는 Acetobacter sp. A9에 의한 셀룰로오스 생산에 영향을 미치는 몇 가지 배양 환경요인을 진탕배양을 통하여 조사하였다. 배지에 3-(N-morpholino) propanesulfonir acid (MOPS)와 CaCO$_3$ 등과 같은 완충성분의 첨가는 hcetobacter sp. A9에 의한 셀룰로오스 생산량을 증가시켰다. 따라서 배양시간 경과에 따른 배양액의 수소이온농도 조절이 경제적인 셀룰로오스 대량생산에 중요한 요인임을 알 수 있었다. 배지에 직경 10 mm의 bead를 첨가함으로써 다양한 기능을 가진 'disintegrated bacterial cellulose'가 생산되었다.

• Composites Research
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• 제26권3호
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• pp.160-164
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• 2013

In this study, the effect of phosphoric acid (PA) as a fiber spinning aid on the strength increase of polyacrylonitrile (PAN) nano-fibers by using modified mechano-electrospinning technologies has been analyzed. The medium carbonization temperature of $800^{\circ}C$ has been selected for the future economic production of these new materials. The concentration of PAN in dimethyl sulfoxide (DMSO) was fixed as 5 wt%. The weight fraction of PA was selected as being 2%, 4%, 6%, and 8% in comparison to PAN. These solutions have been used to make the nanofibers. The mechano-electrospinning apparatus installed in KRICT was made by our own design. By using this apparatus the continous and highly aligned precursor nano-fibers have been obtained. The bundle of 50 well aligned nano diameter continuous fibers with the diametr of 10 microns with 6 wt% phosphoric acid for addition showed maximum mechanical properties of 1.6 GPa as tensile strength and 300 GPa as Young's modulus. The weight of final product can be increased 19%, which can improve the economical benefits for the application of these new materials.