• Advances in aircraft and spacecraft science
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• 제7권2호
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• pp.169-186
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• 2020

Based upon differential quadrature method (DQM) and nonlocal strain gradient theory (NSGT), mechanical-hygro-thermal vibrational analyzes of shear deformable porous functionally graded (FG) nanoplate on visco-elastic medium has been performed. The presented formulation incorporates two scale factors for examining vibrational behaviors of nano-dimension plates more accurately. The material properties for FG plate are porosity-dependent and defined employing a modified power-law form. It is supposed that the nano-size plate is exposed to hygro-thermal and variable compressive mechanical loadings. The governing equations achieved by Hamilton's principle are solved implementing DQM. Presented results indicate the prominence of moisture/temperature variation, damping factor, material gradient index, nonlocal coefficient, strain gradient coefficient and porosities on vibrational frequencies of FG nano-size plate.

• Coupled systems mechanics
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• 제8권3호
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• pp.247-257
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• 2019

Fee vibrational characteristics of porous steel double-coupled nanoplate system in thermo-elastic medium is studied via a refined plate model. Different pore dispersions called uniform, symmetric and asymmetric have been defined. Nonlocal strain gradient theory (NSGT) containing two scale parameters has been adopted to stablish size-dependent modeling of the system. Hamilton's principle has been adopted to stablish the governing equations. Obtained results from Galerkin's method are verified with those provided in the literature. The effects of nonlocal parameter, strain gradient, foundation parameters, porosity distributions and porosity coefficient on vibration frequencies of metal foam nanoscale plates have been examined.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.333.2-333.2
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• 2002

Kakkalide from Puerariae Flos expresses pharmacological actions after biotransformation to irisolidone by intestinal bacteria. B. breve K-110 was isolated as a bacterium metabolizing kakkalide. Therefore. we purified kakkalide-metabolizing p-Xylosidase from B. breve K-110. ${\beta}$-Xylosidase from B. breve K-110 (isolated from Korean intestinal microflora) was induced by kakkalide. We used defined medium contating 1mM kakkalide for the cultivationof B. breve K-110. (omitted)

• Asian Journal of Innovation and Policy
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• 제12권2호
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• pp.155-176
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• 2023

This paper employs datasets from the Enterprise Survey conducted by the World Bank to examine the relationship between four types of innovation defined by the Oslo Manual (OECD, 2005): product innovation, process innovation, marketing innovation, organization innovation, and the firm performance in the selected developing ASEAN economies. The main objective of this paper is to understand the characteristics of innovation activities at the firm level and how various innovation types affect firm performance. The empirical results from ASEAN manufacturing firms reveal that product innovation positively affects firms' performance, while non-technological innovations are negatively related to the performance of firms. The further employed quantile regression provides more insights into the roles of innovation types on different levels of firm performance: while product and process innovations actively contribute to the small and medium-size firms (below 25^th quantile and median), organizational and marketing innovations negatively affect them. Interestingly, the role of process innovation decreases when firm performance grows.

• International journal of advanced smart convergence
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• 제13권2호
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• pp.229-234
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• 2024

A smart factory is defined as a cutting-edge, intelligent factory that integrates all production processes from product planning to sales with information and communication technology. Through these factories, each company produces customized products with minimal cost and time. The smart factory promotion project in Korea has produced positive results even in difficult environments such as the COVID-19 situation. Through the transition to a smart manufacturing production system, the competitiveness of small and medium-sized businesses has been greatly strengthened, including increased productivity and reduced costs. This study was based on surveyed data conducted by organizations related to smart factory promotion in 2020. Significant contents and major characteristics that emerged from the surveyed data were inferred and described. Since the meaningful contents reflect the reality of the company, more efficient promotion of smart factories will be possible in the future.

• International Journal of Stem Cells
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• 제15권1호
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• pp.60-69
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• 2022

Organoids show great potential in clinical translational research owing to their intriguing properties to represent a near physiological model for native tissues. However, the dependency of organoid generation on the use of poorly defined matrices has hampered their clinical application. Current organoid culture systems mostly reply on biochemical signals provided by medium compositions and cell-cell interactions to control growth. Recent studies have highlighted the importance of the extracellular matrix (ECM) composition, cell-ECM interactions, and mechanical signals for organoid expansion and differentiation. Thus, several hydrogel systems prepared using natural or synthetic-based materials have been designed to recreate the stem cell niche in vitro, providing biochemical, biophysical, and mechanical signals. In this review, we discuss how recapitulating multiple aspects of the tissue-specific environment through designing and applying matrices could contribute to accelerating the translation of organoid technology from the laboratory to therapeutic and pharmaceutical applications.

• 한국가축번식학회지
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• 제26권1호
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• pp.17-23
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• 2002

본 연구는 지금까지 돼지 난포란 성숙을 위해서 많이 사용하고 있는 mTCM-199, mWaymouth MB 752/1 그리고 NCSU-23 성숙배지를 비교하고 액상정액을 이용한 체외수정 방법을 개발하고자 실시하였다. 미성숙 난포란은 0.5 $m\ell$의 성숙배지에 각 well 당 30~40개씩 적하하였고, 38.5$^{\circ}C$, 5% CO2, 95% 공기로 조절된 CO2 배양기에서 44시간 성숙 시켰다. 미성숙 난포란을 mTCM-199, mWaymouth MB 752/l 그리고 NCSU-23 성숙배지에서 44시간 배양한 결과 CVBD 발생율은 각각 95.6, 94.1 그리고 94.9%였으며, MH단계까지의 성숙율은 각각 92.5, 90.1 그리고 91.1%였다. 성숙배지별, GVBD 발생율과 MH까지의 성숙율간에 유의성은 인정되지 않았다. 액상정액의 제조용 정액은 90% 이상의 운동성을 가진 농후정자부분을 사용하였으며 정액 채취 후 2시간 동안에 22~24$^{\circ}C$의 실온까지 냉각시켰다.실온까지 냉각한 정액은 BTS 희석액으로 2$\times$$10^{8}$ $m\ell$ 정자농도로 조정하여 100 $m\ell$ 플라스틱병에 30 $m\ell$씩 주입하여 17$^{\circ}C$에서 5일간 보관하였다. 5일 보관 후 운동성이 70% 이상인 정자를 체외수정에 이용하였다. 성숙 후 cumulus cell들이 제거된 성숙난포란은 0.5 $m\ell$의 mTCM-199 또는mTBM 수정배지에 30~40개씩 적하하고, 최종정자농도를 2$\times$$10^{6}$$m\ell$되도록하여 6시간 동안 수정시켰다. 체외수정시킨 수정란들은 0.5 $m\ell$의 NCSU-23 배양배지에서 수정 후 6시간 배양하여 정자침입율, 다정자침입율 그리고 웅성전핵형성율을 조사하였고, 수정 후 45시간 배양하여 난할율을 조사하였다. NC-SU-23 성숙배지와 mTBM 수정배지를 이용하였을때 웅성전핵형성율이 48.0%로써 mTCM-199 성숙배지와 수정배지 또는 mWaymouth MB 752/1 성숙배지와 mTCM-199 수정배지를 이용하였을 때보다 웅성 전핵 형성율이 높았다. 2~4세포기까지의 난할율은 mTCM-199 성숙, 수정 및 배양배지에서 24.1%, mWaymouth 752/1 성숙배지, mTCM-199 수정 및 배양배지에서 43.6%, 그리고 NCSU-23 성숙배지, mTBM 수정배지 및 WCSU-23 배양배지를 이용한 것이 71.2%였다. 이상의 결과를 종합하면 BTS 희석액으로 17$^{\circ}C$에서 5일 보존한 액상정액으로 체외수정이 가능함을 입증하였고, NCSU-23 성숙배지, mTBM 수정배지 및 NCSU-223 배지가 미성숙 난포란의 성숙, 수정 및 배양에 우수한 배지임을 입증하였다.

• Applied Biological Chemistry
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• 제30권1호
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• pp.77-87
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• 1987

Xanthan gum의 생산력(生産力)이 있는 Xanthomonas SNUF-560 균주(菌株)에서 자외선(紫外線) 조사방법(照射方法)으로 생산능(生産能)이 우수(優秀)한 변이주(變異株)를 선택(選擇)해서 동결건조법으로 보존(保存)했으며 PDA배지(培地)에서 2주(週)마다 이식(移植)하여 생산실험(生産實驗)에 사용(使用)하였다. 최적발효배지(最適醱酵培地)의 검토(檢討)에서 탄소원(炭素源)으로 sucrose 40g/l, 질소원(窒素源)으로 glutamic acid 10mM, 유기산(有機酸)으로 succinic acid 10g/l, $PO_4\;^{-3}\;65mM$일때 각각 좋은 결과(結果)를 얻었으며, 최종적(最終的)으로 배지(培地) 1과 배지(培地) 2에서 각각 1,050cp(12g/l), 900cp(10.5g/l)를 얻었으며 조성(組成)은 다음과 같다. 배지(培地) 1 = sucrose 40g/l, glutamate 10mM, $PO_4\;^{-3}\;65mM(KH_2PO_4\;12.65g/l)$, citrate 2g/l, $MgSO_4{\cdot}7H_2O\;0.2g/l$, $H_3BO_3\;0.006g/l$, ZnO 0.006g/l $FeCl_2{\cdot}6H_2O\;0.0024g/l$ $CaCO_3\;0.02g/l$ 배지(培地) 2 : sucrose 40g/l, $(NH_4)_2SO_4\;2g/l\;PO_4\;^{-3}\;65mM\;(KH_2PO_4\;12.65g/l)$ succinate 10g/l, $MgSO_4{\cdot}7H_2O\;0.02g/l$ $H_3BO_3\;0.006g/l$ $FeCl_2{\cdot}6H_2O\;0.0024g/l$ $CaCO_3\;0.02g/l$.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.789-796
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• 2000

In order to analyze the effects of tktA, $aroF^{FBR}$, and aroL expression in a tryptophan-producing Escherichia coli, a series of plasmids carrying the genes were constructed. Introduction of tktA, $aroF^{FBR}$, and aroL into the E. coli strain resulted in approximately 10-20 fold increase in the activities of transketolase, the feedback inhibition-resistant 3-deoxy-D-arabinoheptulsonate-7-phosphate synthase, and shikimate kinase. Expression of $aroF^{FBR}$ in the aroB mutant strain of E. coli resulted in the accumulation of 10 mM of 3-deoxy-D-arabinoheptulsonate-7-phosphate (DAHP) in the medium. Simultaneous expression of tktA and $aroF^{FBR}$ in the strain further increased the amount of excreted DAHP to 20 mM. In contrast, the mutant strain which has no gene introduced accumulated 0.5 mM of DAHP. However, the expression of tktA and $aroF^{FBR}$ in a tryptophan-producing E. coli strain did not lead to the increased production of tryptophan, but instead, a significant amount of shikimate, which is an intermediate in the tryptophan biosynthetic pathway, was excreted to the growth medium. Despite the fact that additional expression of shikimate kinase in the strain could possibly remove 90% of excreted shikimate to 0.1 mM, the amount of tryptophan produced was still unchanged. Removing shikimate using a cloned aroL gene caused the excretion of glutamate, which suggests disturbed central carbon metabolism. However, when cultivated in a complex medium, the strain expressing tktA, $aroF^{FBR}$, and aroL produced more tryptophan than the parental strain. These data indicate that additional rate-limiting steps are present in the tryptophan biosynthetic pathway, and the carbon flow to the terminal pathway is strictly regulated. Expressing tktA in E. coli cells appeared to impose a great metabolic burden to the cells as evidenced by retarded cell growth in the defined medium. Recombinant E. coli strains harboring plasmids which carry the tktA gene showed a tendency to segregate their plasmids almost completely within 24h.

• 한국정보통신학회논문지
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• 제21권1호
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• pp.115-122
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• 2017

최근에는 선박에 탑재되는 장비들이 다양화/ 첨단화되고 있는 추세이며, 이러한 변화와 함께 선박 네트워크는 데이터의 통합 관리를 위한 경량화 이더넷 기반의 구조로 전환되고 있다. 이러한 요구에 따라 본 논문에서는 추진/발전 계통의 각 장비로부터 데이터를 수집하여 각 장비가 발생하는 아날로그 혹은 NMEA 형식의 상태 데이터를 처리한 후, 경량화 이더넷 기반의 IEC 61162-450 메시지 형식으로 변환하기 위한 게이트웨이 시스템의 개발에 관한 내용을 다룬다. 이를 위해, 선박 장비의 표준화 요구 및 관련 연구를 분석하고, 필요성을 도출하였다. 또한, 기존의 문제를 해결하기 위해 추가적인 데이터 형식을 정의하고, 게이트웨이 시스템을 개발한 후, 그 유용성을 검증하였다. 이를 통해 기존 선박 탑재 장비들이 발생하는 데이터를 이더넷 기반으로 통합적으로 관리하고 활용하기 위한 밑거름이 될 수 있을 것으로 판단된다.