• Journal of Microbiology
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• v.45 no.1
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• pp.15-20
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• 2007

The majority of soil microorganisms can derive ethylene from L-methionine (L-MET), while some rhizobacteria can hydrolyze 1-aminocyclopropane-1-carboxylate (ACC) due to their ACC-deaminase activity. In this study, three strains having either ACC-deaminase activity (Pseudomonas putida biotype A, $A_7$), or the ability to produce ethylene from L-MET (Acinetobacter calcoaceticus, $M_9$) or both (Pseudomonas fluorescens, $AM_3$) were used for inoculation. The highly ethylene specific bioassay of a classical 'triple' response in pea seedlings was used to investigate the effect of the inoculation with the rhizobacteria in the presence of 10 mM ACC or L-MET. The exogenous application of ACC had a concentration-dependent effect on the etiolated pea seedlings in creating the classical 'triple' response. The inoculation with P. putida diluted the effect of ACC, which was most likely due to its ACC-deaminase activity. Similarly, the application of $Co^{2+}$ reduced the ACC-imposed effect on etiolated pea seedlings. In contrast, the inoculation of A. calcoaceticus or P. fluorescens in the presence of L-MET caused a stronger classical 'triple' response in etiolated pea seedlings; most likely by producing ethylene from L-MET. This is the first study, to our knowledge, reporting on the comparative effect of rhizobacteria capable of utilizing ACC vs L-MET on etiolated pea seedlings.

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.603-608
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• 2006

As an important and relatively easy to implement technology for realizing Intelligent Transportation Systems(ITS), Adaptive Cruise Control(ACC) automatically adjusts vehicle speed and distance to a preceding vehicle, thus enhancing driver comfort and safety. One of the key issues associated with ACC development is usability and user acceptance. Control parameters in ACC should be optimized in such a way that the system does not conflict with driving behavior of the driver and further that the driver feels comfortable with ACC. A driving simulator is a comprehensive research tool that can be applied to various human factor studies and vehicle system development in a safe and controlled environment. This study investigated driving behavior with ACC for drivers with different driving styles using the driving simulator. The ACC simulation system was implemented on the simulator and its performance was evaluated first. The Driving Style Questionnaire(DSQ) was used to classify the driving styles of the drivers in the simulator experiment. The experiment results show that, when driving with ACC, preferred headway-time was 1.5 seconds regardless of the driving styles, implying consistency in driving speed and safe distance. However, the lane keeping ability reduced, showing the larger deviation in vehicle lateral position and larger head and eye movement. It is suggested that integration of ACC and lateral control can enhance driver safety and comfort even further.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.2
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• pp.81-93
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• 2007

Purpose: Adenoid cystic carcinoma (ACC) is a relatively rare tumor that arises in glandular tissues of the head and neck region and sometimes has a protracted clinical course with perineural invasion and delayed onset of distant lung metastasis. Treatment failure of salivary ACC is most often associated with perineural and hematogenous tumor spread. However, very little has been known about the cellular and molecular mechanisms of perineural invasion and hematogenous distant metastasis of parotid ACC. This study was designed to develop an orthotopic tumor model of parotid adenoid cystic carcinoma in athymic nude mice. Experimental Design: A melanoma cell line was injected into the parotid gland of athymic mice to determine whether such implantation was technically feasible. A parotid ACC cell line was then injected into the parotid gland or the subcutaneous tissue of athymic mice at various concentrations of tumor cells, and the mice were thereafter followed for development of tumor nodule. The tumors were examined histopathologically for perineural invasion or regional or distant lung metastasis. We used an oral squmous cell carcinoma cell line as control. Results: Implantation of tumor(melanoma) cell suspension into the parotid gland of nude mice was technically feasible and resulted in the formation of parotid tumors. A parotid ACC cell line, ACC3 showed no significantly higher tumorigenicity, but showed significantly higher lung metastatic potential in the parotid gland than in the subcutis. In contrast, mucosal squmous cell carcinoma cell line doesn’t show significantly higher lung metastatic potential in the parotid gland than in the subcutis. The ACC tumor established in the parotid gland seemed to demonstrate perineural invasion of facial nerve, needs further study. Conclusion: An orthotopic tumor model of salivary ACC in athymic nude mice was successfully developed that closely recapitulates the clinical situations of human salivary ACC. This model should facilitate the understanding of the cellular and molecular mechanisms of tumorigenisis and metastasis of salivary ACC and aid in the development of targeted molecular therapies of salivary ACC.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.61-65
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• 2003

This study was investigated to identify the regulatory mechanism of ACC gene expression by hormones and nutrition. The fragment of ACC promoter I (PI) -220 bp region was recombined to pGL3-Basic vector with luciferase as a reporter gene. The primary hepatocyte from the rat was used to investigate the regulation of ACC PI activity. ACC PI (-220 bp)/luciferase chimeric plasmid was transfected into primary rat hepatocyte by using lipofectin. ACC PI activity was shown by measuring luciferase activity. The addition of insulin, dexamethasone, and triiodothyronine to the culture medium increased the activity of ACC PI by 2.5-, 2.3- and 1.8-fold, respectively. In the presence of 1 $\mu$M dexamethasone, the effects of insulin was amplified about 1.2-fold showing the additional effects of dexamethasone. Moreover the activity of luciferase was increased by insulin, dexamethasone, and triiodothyronine treatment approximately 4-fold. These results indicated that insulin, dexamethasone and thyroid hormone coordinately regulate ACC gene expression via regulation of promoter I activity. On the -220 to ＋21 region of ACC PI, the addition of the glucose to the culture medium increased the activity of ACC PI. With 25 mM glucose, luciferase activity increased by 7-fold. On the other hand, on the -220 bp region, ACC PI activity was not changed by polyunsaturated fatty acids. Therefore, it can be postulated that there are response elements for insulin, triiodothyronine, dexamethasone, and glucose, but not PUFAs on the -220 bp region of ACC PI.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.457-467
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• 2020

Increasing environmental concerns have prompted countries around the world to tighten regulations on greenhouse gases and fuel efficiency. Research is being done using advanced driver assistance systems to improve fuel economy and for the convenience of drivers. Research on systems such as adaptive cruise control (ACC), LKAS, and AEB is active. The purpose of ACC is to control the longitudinal speed and distance of the vehicle and minimize the driver's load, which is considered useful for accident prevention. From this point of view, research has used a mathematical method of safety evaluation as a function of distances and scenarios while considering domestic road environments. A vehicle is tested with a simulation in a proposed scenario. The purpose of the analysis is to verify the functional safety of ACC by comparing the theoretical calculations using theoretical equations, the relative distances in the simulation, and an actual vehicle test. These methods are expected to enable many companies to use scenarios, formulas, and simulations as safety verification methods in the development of ACC.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.62.2-62.2
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• 2008

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1364_1366
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• 2009

고출력 펄스 전원으로 PFN Marx 펄스 전원공급장치를 설계 및 제작하였다. PFN Marx는 커패시터와 인덕터 그리고 스파크 갭과 전원을 공급하는 전원공급장치와 전류 인덕터로 구성하여 제작을 하였다. 여기에 사용하는 스파크 갭 스위치는 개스를 채우는 방식으로 개스의 압력을 조정하여 스위치의 스위칭 전압을 조정하여 준다. PFN Marx는 커패시터와 인덕터가 직병렬로 구성이 되며 펄스폭과 PFN의 임피던스를 결정하는 중요한 요소이다. PFN marx는 33단으로 구성을 하였으며 부하를 $100{\Omega}$으로 설계 및 시뮬레이션을 통하여 제작하였다. PFN Marx 펄스전원공급장치를 약 500 kV, 수백 ns까지 시험을 하였다. 본 논문에서는 PFN Marx 펄스전원장치의 설계 제작 및 시험에 대하여 고찰하고자 한다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1367_1369
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• 2009

선형가속기의 에너지를 3.0 GeV로 증강시키기 위하여 마이크로웨이브 증폭기의 펄스 전원를 설계하였다. 현재 클라이스트론-모듈레이터를 12set에서 2set를 추가로 증설할 예정이며 기존의 마이크로웨이브 모듈은 1개의 모듈이 4개의 가속관에 마이크로웨이브를 공급하고 있다. 현재 운전중인 12개의 가속 모듈중에 1개의 모듈을 각각 2개의 가속관으로 나누어서 2개에 모듈로 마이크로웨이브를 공급하고 나머지 9개의 모듈은 4개의 가속관에 마이크로웨이브를 공급할 예정이다. 선형가속기의 에너지 증강사업에서 200 MW의 펄스 모듈레이터와 80 MW의 클라이스트론 2set 새로운 방식으로 설치할 계획이며 기존의 모듈레이터 또한 성능향상을 할 예정이다. 본 논문에서는 마이크로웨이브 증강 방안 및 새로운 방식의 모듈레이터에 대한 설계에 대하여 발표하고자 한다.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.13-19
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• 1985

Acc I endonuclease has been isolated from 300g (wet weight) cells of Acinetobacter calcoaceticus. The cells were broken by using French press at 20, 000p.s.i. After ammonium sulfate fractionation, the enzyme was further purified by heparin agarose, DEAE-sephades, Affi.-gel Blue, phosphocellulose, and hydroxylapatite column chromatography. The purified Acc I endonudlease has a single polypeptide species and its subunit molecular weight was 45,000 ${\pm}$ 1,000 daltons as judged by 10% SDS-polyacrylamide gel electrophoresis. The isolated enzyme was essentially free of contaminating nucleases as judged by homochromatography by using a $^{32}P-labeled$ oligonucleotide. The enzyme showed maximum activity at pH values between 8.0 and 11.0 and in the presence of $MgCl_2$. Acc I endonuclease was maximally active in the absence of NaCl and was completely inhibited at 200 mM NaCl.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1447-1448
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• 2007

고출력 펄스 전원으로 PFN Marx 펄스 전원공급장치를 설계 및 제작하였다. PFN Marx는 커패시터와 인덕터 그리고 스파크 갭과 전원을 공급하는 전원공급장치와 전류 인덕터로 구성하여 제작을 하였다. 여기에 사용하는 스파크 갭 스위치는 개스를 채우는 방식으로 개스의 압력을 조정하여 스위치의 스위칭 전압을 조정하여 준다. PFN Marx는 커패시터와 인덕터가 직병렬로 구성이 되며 펄스폭과 PFN의 임피던스를 결정하는 중요한 요소이다. PFN Marx 펄스 전원공급장치를 시뮬레이션 및 제작하여 시험을 하였다. 요구되는 사양은 전압 수십 kV, 펄스 폭수백 ns이다. 본 논문에서는 PFN Marx 펄스전원장치의 설계 및 시험에 대하여 고찰하고자 한다.