• Asian-Australasian Journal of Animal Sciences
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• 제31권3호
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• pp.335-343
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• 2018

Objective: Remarkable difference in cellular activity was found between early and late subpassaged embryonic stem cell (ESCs) lines, which can be created by subtle changes in cell manipulation protocol. This study subsequently examined whether post-thaw subculture of early subpassaged ESC lines could further affect the activity of the ESCs. Methods: Fresh (as a control treatment) or cryopreserved F1 hybrid (B6CBAF1) early ESC lines (C57BL/6xCBA) of the 4 (P4) or the 19 passage (P19) were subcultured once, twice or six times under the same condition. The post-thaw survival of the ESCs was monitored after the post-treatment subculture and the ability of cell proliferation, reactive oxygen species (ROS) generation, apoptosis and mitochondrial ATP synthesis was subsequently examined. Results: Regardless of the subculture number, P19 ESCs showed better (p<0.05) doubling time and less ATP production than P4 ESCs and such difference was not influenced by fresh or cryopreservation. The difference between P4 and P19 ESC lines became decreased as the post-treatment subculture was increased and the six times subculture eliminated such difference. Similarly, transient but prominent difference in ROS production and apoptotic cell number was detected between P4 and P19 ESCs only at the 1st subculture after treatment, but no statistical differences between two ESC lines was detected in other observations. Conclusion: The results of this study suggest that post-thaw subculture of ESCs under the same environment is recommended for standardizing their cellular activity. The activity of cell proliferation ability and ATP synthesis can be used as parameters for quality control of ESCs.

• 한국축산식품학회지
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• 제23권4호
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• pp.342-349
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• 2003

Escherichia coli O157:H7, Staphylococcus aureus와 Salmonella enteritidis는 식품에 의해 전염되는 식품질환성 병원균으로서 세계적으로 알려진 식중독 미생물이다. 오미자 물 추출액 첨가 drink yoghurt에 오염된 식중독 유발균인 Esc. coli O157：H7, Sta. aureus와 Sal. enteritidis의 생존에 미치는 영향을 연구하였다. 오미자 물 추출액이 식중독 유발균에 대한생육 저해 활성을 검토하였고, 시험 균주의 최종 균체 농도가 $10^{5}$ CFU/mL 수준이 되도록 오미자 물 추출액 첨가 drink yoghurt에 Esc. coli O157：H7, Sta. aureus와 Sal. enteritidis를 각각 접종하여 37$^{\circ}C$에 배양하면서 시간별로 시험 균주들의 생존 균수를 측정하였다. 시험 결과 시험에 사용된 오미자 물 추출액의 첨가 농도가 증가할수록 모든 시험 균주에서 강한 증식 억제력이 나타났다. 대조구에 비해 오미자 물 추출액 0.4 ,0.6, 0.8과 1.0% 첨가구에서 Esc. coli O157：H7은 각각 0.13, 0.89, 1.99와 2.55의 log cycle 감소 현상을 보였고, Sta. aureus는 각각 0.45, 3.74, 4.13과 5.24의 log cycle이 감소되었으며, Sal. enteritidis는 각각 0.22, 3.44, 4.02와 4.07의 log cycle 감소가 나타나 모든 시험 균주에서 뚜렷한 성장 억제 효과가 관찰되었다. 오미자 물 추출액의 식중독 유발균에 대한 성장 저해 효과는 Sta. aureus, Sal. enteritidis, 그리고 Esc. coli O157：H7의 순으로 강하게 나타났다. 오미자 물 추출액을 0.4, 0.6, 0.8과 1.0% 첨가한 drink yoghurt 내에서 3.55${\times}$$10^{5}$ CFU/mL 수준으로 접종한 Esc. coli O157:H7은 24시간 배양시 1.00${\times}$$10^1$∼3.00${\times}$$10^1$ CFU/mL로 감소되었으며, 48시간 배양하였을 때에는 생육이 완전히 억제되었다. 그리고 1.24${\times}$$10^{5}$ CFU/mL 수준의 Sta. aureus를 접종한 경우 24시간 배양 후 아주 미약한 생존 균수의 감소를 보였으나 48시간 배양시 4.00${\times}$$10^2$∼8.50${\times}$$10^2$ CFU/mL 수준으로 감소하였고, Sal. enteritidis를 1.81${\times}$$10^{5}$ CFU/mL 수준으로 접종한 경우 24시간 배양 후부터 전연 증식을 나타내지 않았다. 이와 같이 오미자 물 추출액 첨가에 의해 drink yoghurt 내에서 식중독 유발균들의 증균 억제 효과를 확인할 수 있었다.할 수 있었다.

• BMB Reports
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• 제39권4호
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• pp.426-431
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• 2006

Embryonic stem cells (ESCs), representing a population of undifferentiated pluripotent cells with both self-renewal and multilineage differentiation characteristics, are capable of spontaneous differentiation into cardiomyocytes. The present study sought to define the kinetic characterization of lactate dehydrogenase (LDH) and creatine kinase (CK) of ESC- and neonatal-derived cardiomyocytes. Spontaneously differentiated cardiomyocytes from embryoid bodies (EBs) derived from mouse ESC line (Royan B1) and neonatal cardiomyocytes were dispersed in a buffer solution. Enzymes were extracted by sonication and centrifugation for kinetic evaluation of LDH and CK with spectrophotometric methods. While a comparison between the kinetic properties of the LDH and CK of both groups revealed not only different Michaelis constants and optimum temperatures for LDH but also different Michaelis constants and optimum pH for CK, the pH profile of LDH and optimum temperature of CK were similar. In defining some kinetic properties of cardiac metabolic enzymes of ESC-derived cardiomyocytes, our results are expected to further facilitate the use of ESCs as an experimental model.

• International Journal of Concrete Structures and Materials
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• 제10권3호
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• pp.257-269
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• 2016

Early-strength-concrete (ESC) made of Type I cement with a high Blaine value of $500m^2/kg$ reaches approximately 60 % of its compressive strength in 1 day at ambient temperature. Based on the 210 compressive test results, a generalized rateconstant material model was presented to predict the development of compressive strengths of ESC at different equivalent ages (9, 12, 18, 24, 36, 100 and 168 h) and maximum temperatures (20, 30, 40, 50 and $60^{\circ}C$) for design compressive strengths of 30, 40 and 50 MPa. The developed material model was used to find optimum curing regimes for precast prestressed members with ESC. The results indicated that depending on design compressive strength, conservatively 25-40 % savings could be realized for a total curing duration of 18 h with the maximum temperature of $60^{\circ}C$, compared with those observed in a typical curing regime for concrete with Type I cement.

• 대한기계학회논문집A
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• 제41권2호
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• pp.111-119
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• 2017

본 논문은 자세 제어 장치(ESC)와 후륜 조향 장치(RWS)를 장착한 통합 섀시 제어기의 성능을 향상시키기 위해 후륜 조향각을 결정하는 방법을 제안한다. 차량을 안정화시키기 위해 필요한 제어 요 모멘트는 자세 제어 장치와 후륜 조향 장치를 이용하여 만들어진다. 각 장치의 타이어 힘을 결정하기 위해 의사역행렬 제어할당 방법을 적용한다. 제어기의 성능을 향상시키기 위해 후륜 조향 장치의 조향각을 결정하는 데에 네 가지 방법을 적용한다. 차량 시뮬레이션 패키지인 CarSim에서 시뮬레이션을 수행하여 제안된 방법들이 통합 섀시 제어기의 성능을 향상시킬 수 있음을 검증한다.

• Molecules and Cells
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• 제25권4호
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• pp.487-493
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• 2008

HoxB4 has been shown to enhance hematopoietic engraftment by hematopoietic stem cells (HSC) from differentiating mouse embryonic stem cell (mESC) cultures. Here we examined the effect of ectopic expression of HoxB4 in differentiated human embryonic stem cells (hESCs). Stable HoxB4-expressing hESCs were established by lentiviral transduction, and the forced expression of HoxB4 did not affect stem cell features. HoxB4-expressing hESC-derived CD34+ cells generated higher numbers of erythroid and blast-like colonies than controls. The number of CD34+ cells increased but CD45+ and KDR+ cell numbers were not significantly affected. When the hESC derived CD34+ cells were transplanted into $NOD/SCID{\beta}2m-/-$ mice, the ectopic expression of HoxB4 did not alter their repopulating capacity. Our findings show that overexpression of HoxB4 in differentiating hESCs increases hematopoietic colony formation and hematopoietic cell formation in vitro, but does not affect in vivo repopulation in adult mice hosts.

• 마이크로전자및패키징학회지
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• 제9권1호
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• pp.49-52
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• 2002

본 연구를 통하여 저온 반도체 공정용 정전퍽(ESC)을 테이프캐스팅 공정에 의하여 스테인레스스틸에 소다붕규산염유리가 도포된 형태로 제작할 수 있음을 입증하였다. 스테인레스스틸 기판위의 유리 도포층은 125 $\mu\textrm{m}$의 두께로 제작되었다. 유리 도포층의 접합력은 매우 우수하여 $300^{\circ}C$이상의 온도변화에서도 균열이나 층간갈라짐 현상이 발생하지 않았다. 정전 고착압력은 전반적으로 이론적 관계인 전압의 제곱에 비례하는 경향을 보였으나, 고온과 고인가전압에서는 이 관계에서 벗어나는 것으로 나타났다. 이러한 이탈현상은 고온과 고인가전압에서 전기비저항의 감소에 따른 누설전류의 증가에 기인한다.

• 대한안전경영과학회지
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• 제13권3호
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• pp.63-69
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• 2011

As environmental protection is becoming more and more important, green production has become a key issue for almost every manufacturer and will determine a manufacturer can be sustainable in the long term. Therefore a performance evaluation system for green suppliers is necessary to determine the suitability of suppliers to cooperate with the company. While the works on the evaluation and/or selection of suppliers are abundant, those that concern environmental issues are rather limited. The objective of this study is to construct a combined model based on fuzzy analytic hierarchy process (FAHP) and balanced scorecard (ESC) for evaluating green suppliers in the manufacturing industry. The ESC concept is applied to define the hierarchy with four major perspectives (i.e. financial, customer, internal business process, and learning and growth), and performance indicators are selected for each perspective. FAHP is then proposed in order to tolerate vagueness and ambiguity of information. Finally, FAHP is finally constructed to facilitate the solving process. With the proposed model, manufacturers can have a better understanding of the capabilities that a green supplier must possess and can evaluate and select the most suitable green supplier for cooperation.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.152-155
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• 2014

ABS/ESC 기능 통합 SoC에 사용되는 자동차 제동 솔레노이드 밸브 구동용 디지털 PWM 컨트롤러를 설계하였다. 직접 제어와 PI 제어 방식을 지원하도록 설계된 PWM 컨트롤러는 총 12채널로 구성된다. 직접 제어 방식의 6개 채널은 설정된 PWM 듀티값에 따라 일정한 PWM을 출력하며, PI 제어 방식의 6개의 채널은 설정된 전류값을 기준으로 드라이버의 전류 값에 따라 변화하는 PWM을 출력하여 일정한 전류를 갖도록 설계되었다. 또한 솔레노이드 밸브 열림 감지, Dither, PWM 위상 시프트 기능 등을 갖는다. 설계된 PWM 컨트롤러는 44,779 게이트로 구현되었으며, 0.18um CMOS 공정으로 제작된 칩의 측정 결과로부터 기능이 정상적으로 동작하는 것을 확인하였다.

• 반도체디스플레이기술학회지
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• 제19권4호
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• pp.46-50
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• 2020

In this research, the attractive force of Coulomb type electrostatic chuck(ESC), which consisted of alumina dielectric, on glass substrate was studied by using the finite element analysis. The attractive force is caused by the high electrical resistance which occurs in contact region between glass substrate and dielectric layer. This research tries the simple geometrical modeling of ESC and glass substrate with air gap. The influences of the applied voltage, and air gap are investigated. When alumina dielectric with 1014 Ω·cm, 1.5 kV voltage, and 0.01 mm air gap were applied, electrostatic force in this work reached to 4 gf/㎠. This results show that the modeling of air gap is essential to derive the attractive force of the ESC.