• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.333-333
• /
• 2010

크라이오 펌프는 크기에 비해 상대적으로 큰 배기속도를 가지고 있고 자체 기체 방출이 적어 비교적 쉽고 빠르게 도달압력을 낮출 수 있다. 또 초고진공 펌프로서 경쟁 상대인 터보분자 펌프보다 기체 돌입에 대한 기계적 사고 가능성이 낮다. 그러나 흡착 패널의 온도에 민감하게 반응하는 배기 성능 측면에서 볼 때 크라이오 펌프의 대유량 및 펄스 기체 부하에 대한 성능 유지 및 회복능력은 의문의 여지가 있다. 크라이오 펌프의 기체부하에 대한 공식적인 성능지표로는 최대배기량(max. throughput)과 교차(crossover)값이 있다. 전자는 연속적인 유량[$Pa{\cdot}m^3/s$]에 대해, 또 후자는 일정 기체량[$Pa{\cdot}m^3$]에 대해 흡착 패널이 20 K를 넘지 않는 가동범위를 구하는 것이다. 교차값은 넓은 의미에서 펄스 기체부하에 대한 성능으로 볼 수도 있지만 원래 목적은 진공용기를 저진공 상태에서 고진공 상태로 전환하는 시점을 정하려는 데 있다. 펌프회사에서 제공하는 사양에는 대부분 아르곤 회복시간(Ar recovery time)이라는 지표가 있는데 이는 아르곤을 상당한 유량으로 흘리다 멈췄을 때 얼마나 빨리 기저 상태로 회복되는가를 나타낸다. 보통 사양서에 제시하지는 않지만 주로 크라이오 펌프의 재생상태를 알아보기 위해 사용하는 걸프(gulp) 시험이 있는데 일정량의 기체를 펄스로 도입한 후 압력변화를 기록하여 재생후 배기성능 회복 능력을 보는 것이다. 이들은 겉보기에 서로 다르지만 한편으로는 서로 중복되거나 연관성을 가지고 있어서 실용적인 면에서 절차들을 비교, 검토 및 개선하고 때에 따라서는 적절히 결합할 수 있는 방안을 모색할 필요성이 있다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.12
• /
• pp.1618-1624
• /
• 2018

The undergraduate structure based on flipped learning should be a necessary course to cultivate value creation capability based on students' problem solving capability through the change of university education in the fourth industrial revolution era. Flipped learning stimulated the learner's high order thinking and activates communication between the faculty-student and the students through the use of activity oriented teaching strategy. Introduction and spread of Flipping Learning combining project-based learning with MOOC is required. The professor should be able to apply net teaching and learning methods using flipping learning and active learning, and develop class contents reflecting new knowledge, information and technology. As the introduction and spread of AI-based(E-Advisor, chat bot et al) learning consulting, Which is becoming increasingly advanced, the transition to "personalized education" that meets the 4th Industrial Revolution should be made.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.16 no.2
• /
• pp.3-12
• /
• 2006

The spread of mobile devices, PDAs and sensors has enabled the construction of ubiquitous computing environments, transforming regular physical spaces into 'smart space' augmented with intelligence and enhanced with services. However, unless privacy concerns are taken into account early in the design process of various ubiquitous devices(e.g. mobile devices, PDAs, sensors, etc.). we will end up crating ubiquitous surveillance infrastructure. Also, it may inappropriate to use public key techniques for computational constrained devices in ubiquitous computing environment. In this paper, we propose efficient user authentication and ky agreement protocol not only to preserve anonymity for protecting personal privacy but also to be suitable for computational constrained devices in ubiquitous computing environments.

• Journal of Plant Biotechnology
• /
• v.40 no.4
• /
• pp.217-223
• /
• 2013

Pueraria lobata, a medicinally important leguminous plant produces various isoflavones including puerarin, daidzin and daidzein which are metabolized to equol via dihydrodaidzein and tetrahydrodaidzein by the bacterial fermentation of natural isoflavone sources in human intestines. In this study, we described callus proliferation and isoflavone production in callus of Korean wild arrowroot and dihydrodaidzein biosynthesis in callus extract fermented with Pediococcus pentosaceus. Proliferation was the best at callus cultured in the medium containing 1.0 mg/L TDZ and 1.0 mg/L NAA at light condition for 12 days. Puerarin was significantly more produced at callus cultured in the medium containing 2.0 mg/L kinetin and 1.0 mg/L NAA at dark condition for 16 days, but daidzin and daidzein were not significant. Callus extract was successfully fermented with P. pentosaceus and dihydrodaidzein, which is one of equol precursors formed by biotransformation, was confirmed to be produced. These results will facilitate mass production of callus and isoflavones as equol precursors from Korean wild arrowroot and can be applied for the production of equol by biotransformation in vitro.

• Korean Journal of Animal Reproduction
• /
• v.23 no.1
• /
• pp.13-18
• /
• 1999

The totipotential spermatogonial stem cells of adult testis which give rise to mature sperm cells is well-known to incorporate foreign DNA as well as those of somatic cells. Also, the integration rates of foreign DNA after haploid stages are generally known to decrease and /or is simply bound foreign DNA into the sperm plasma membrane. To overcome these problems, liposome and DNA complexes were used to determine how direct injection of these complexes into testis were integrated into sperm genome and resulted in transgenic offspring. To study this purpose, cation liposome was gently mixed with WAF/hGH DNA (1 : 2) and the complexes were injected into testis. At 10, 20, 40, 60, and 80 days after direct injection into testis, mature sperm cells were recovered by using artificial virgin method from two goats and each semen except a part of semen used for DNA analysis such as PCR or Southern blotting was cryopreserved for the artificial insemination. The results obtained in this study are summarized as follows. 1. By PCR, the presence of exogenous DNA was confirmed up to 80 days after injection with liposome/DNA complexes. The highest integration rates were obtained at day 40 after direct injection. This results suggested that spermatogonial stem cells were integrated exogenous DNA into their genome. 2. Among 23 Korean Native Goats which were artificially inseminated, 4 goats resulted in pregnancy and produced 7 young goats. 3. Two young goats were confirmed as a transgenic by PCR and Southern blot analysis. Therefore, our results suggested that testis-mediated gene transfer can be used as a feasible tools for the production of transgenic livestock.

• Korean Journal of Weed Science
• /
• v.30 no.2
• /
• pp.122-134
• /
• 2010

We investigated the levels of resistance and accumulation of terapyrroles, reactive oxygen species, lipid peroxidation, and antioxidative enzymes for reasons of growth reduction in herbicide-transgenic rice overexpressing Myxococcus xanthus, Arabidopsis thaliana, and human protoporphyrinogen oxidase (Protox) genes. The transgenic rice overexpressing M. xanthus (MX, MX1, PX), A. thaliana (AP31, AP36, AP37), and human (H45, H48, H49) Protox genes showed 43~65, 41~72 and 17~70-fold more resistance to oxyfluorfen, respectively, than the wild type. Among transgenic rice lines overexpressing Protox genes, several lines showed normal growth compared with the wild type, but several lines showed in reduction of plant height and shoot fresh weight under different light conditions. However, reduction of plant height of AP37 was much higher than other lines for the experimental period. On the other hand, the reduction of plant height and shoot fresh weight in the transgenic rice was higher in high light condition than in low light condition. Enhanced levels of Proto IX were observed in transgenic lines AP31, AP37, and H48 at 7 days after seeding (DAS) and transgenic lines PX, AP37, and H48 at 14 DAS relative to wild type. There were no differences in Mg-Proto IX of transgenic lines except for H41 and H48 and Mg-Proto IX monomethyl ester of transgenic lines except for MX, MX1, and PX. Although accumulation of tetrapyrrole intermediates was observed in transgenic lines, their tetrapyrrole accumulation levels were not enough to inhibit growth of transgenic rice. There were no differences in reactive oxygen species, MDA, ALA synthesizing capacity, and chlorophyll between transgenic lines and wild type indicating that accumulated tetrapyrrole intermediate were apparently not high enough to inhibit growth of transgenic rice. Therefore, the growth reduction in certain transgenic lines may not be caused by a single factor such as Proto IX, but by interaction of many other factors.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.57-66
• /
• 2021

The purpose of this study was to verify whether the Interactive Cinematherapy Course developed based on discussion is still effective for emotional intelligence and empathic ability, even in a college lecture environment where courses are given online due to COVID-19. The subjects were enrolled in the Interactive Cinematherapy Course and experienced either an online (N=139) or offline (N=212) course before and after COVID-19. To the offline course, students were given structural questions and conducted discussions, whereas the online course students were given feedback via e-mail to substitute discussion. The results were as follows. Compared to the offline courses, students in both online/offline courses commonly showed an increase in "Other's emotion appraisal", "Cognitive Empathy", "Perspective taking", "Fantasy", and "Emphatic Concern". The online course students showed an increase in the "Use of emotion", while offline course students showed an increase in "Self emotion appraisal". This shows that online and offline courses do not have a significant difference in effects. In qualitative research, the lecturer's communication ability and concern helped enhance the effectiveness of the Interactive Cinematherapy Course given online. This implies that communication between the lecturer and students and role of the lecturer are more important than the online environment.

• Journal of the Society of Disaster Information
• /
• v.18 no.3
• /
• pp.622-635
• /
• 2022

Purpose: Due to the change of demography, the ratio of senior drivers has increased and the transition to a super-aged society is expected to make more seniors drive in the future. Method: In this research, we analyzed medical characteristics of the driver's age-specific decline in body function and saw that both the function of the physical as well as mental capacities deteriorates as people age. Among them, various functions are precipitously weakened after reaching 70, implying that those over the age of 70 are classified as seniors in a medical sense. In this context, we also could identify that based on such age criteria, various safety policies for senior drivers should be developed and set up in Korea. Result: We could find a steep fall in the physical function of body after reaching 70 from the chronological change of cognitive function and judgment ability. In particular, it is revealed that the driving license institution and aptitude test for drivers over 70 should be thoroughly examined, as physical functions necessary for driving such as eyesight and hearing ability is not strong enough in many drivers over 70. Conclusion: Focusing on the physical capacity to drive, we tried to find the hazardous age bracket of senior drivers which might influence driving behaviors. Going forward, we expect this work would help to understand the policies for senior drivers and drivers' physical differences.

• Cement
• /
• s.54
• /
• pp.59-74
• /
• 1974

AIS 지역 국가들의 시멘트 소비는 1970년에 14.1백만톤에 달했으며 1985년에는 44.2백만톤에 달할 것으로 예측된다. 1970년의 생산 능력은 18.4백만톤으로 이것은 수요를 훨씬 상회하는 것이다. 이같은 과잉 생산 능력 상태는 1981년 후부터는 과잉 수요 현상으로 전환하게 될 것으로 예상 된다. 1985년 AIS지역 전체로 볼 때 공급 부족량이 약 11.5백만톤에 이를 것인 바 그 대부분은 한국 $\cdot$ 베트남 $\cdot$ 인도네시아에서 부족하게 될 것이다. 한국의 시멘트 산업은 AIS지역 국가들 중에서 생산 기술면이나 생산 효율면에서 가장 앞서 가고 있다. 그러나 한국에서의 생산 시설 확장은 이 지역의 공급 부족량 해결에 기여는 하지 못할 것이며 오직 자국내 공급난 해결을 하는데 그칠 것이다. 이 보고서에서는 두 개의 상이한 계획안이 검토되었는데 이것은 지역내 협력효과와 같은 경제적인면에 초점을 두었다. 비교적 지역 협력에 기여할 것으로 보이는 두 개의 안은 AIS지역내의 2개 국가에 시멘트 공장을 건설하는 것으로서 인도네시아에 세우는 년산 1백만톤 규모의 단일공장과 타이에 세우는 년산 1백만톤 규모의 3개 공장이 바로 그것이다. 인도네시아에 세우는 공장은 인도네시아 시장의 수요 및 나아가 1985년에 Sri Lanka에서 일어날 과잉 수요를 메우게 될 것이다. 타이에 세우게 될 공장은 자국의 시멘트를 조달하고 메콩강과 연해 있는 3개국 수요를 충당하게 될 것이다. 이것은 1개의 공장을 건설하고 후에 그 생산 능력을 3배가하는 방법으로 이 3개의 공장이 완성된다면 이것은 또한 몇가지 경제성을 얻게 될 것이다. 인도네시아와 타이의 이 계획은 1985년에야 완성될 것인데 건설 기간은 약 28내지 30개월이 소요될 것으로 추산된다. 한편 이 지역의 시멘트 판매가격을 톤당 22달러로 볼 때 생산비에 포함된 총회수율, 즉 추정소득과 총투자 사이의 관계에서 산출한 이상 2개 사업의 총회수율은 12.1 $\%$로 추산된다. 총부가가치는 인도네시아가 10.7백만달러, 타이가 23.9백만달러로서 합계 34.6백만달러로 추산된다. 이것은 총투자액인 166.0백만달러에 대하여 4.8의 총자본투자효율을 나타내는 것이다. 이 사업은 이 지역외에서의 시멘트 수입시와 비교하면 73.8백만달러의 외화를 절약하는 셈이 되며 이 외에도 약 1,740명의 고용 증대를 가져 올 수 있을 것이다. 시멘트 운송비는 생산원가와 세계시장 가격과의 사이에서 생기는 마진보다 더 비싸다. 이와 같은 사실은 시멘트가 지역 협력에 적합한 품목이 못된다는 것을 의미한다. 이것을 해결하기 위해서는 현재 세계 시멘트 시장가격을 상회하는 선에서 가격협정을 맺는 것이 이 지역 시멘트 공업 육성책의 하나로 필요 불가결한 실정이다.

• Knowledge Management Research
• /
• v.23 no.4
• /
• pp.1-19
• /
• 2022

As the untact culture spreads, the digital divide, which is a problem of access to digital information for the vulnerable, can appear as information inequality in various fields, including the social and cultural field. This study identified the digital divide level for the vulnerable population and analyzed the effects of information accessibility, demographic and social characteristics, and physical and mental health characteristics on the information level. As a result, the higher the accessibility of information, the smaller the digital divide and the greater the digital utilization, so it is necessary to increase the accessibility of information devices and increase the ability to utilize them. In addition, the higher the age, the more women than men, and the lower the income level, the greater the digital divide, so it is necessary to increase digital capabilities through detailed class-specific programs for the vulnerable. Finally, it was found that the digital divide and the level of digital literacy had a significant effect on the life satisfaction and daily life satisfaction of the vulnerable. The expansion of competency-building education programs to enhance information utilization capabilities by changing the paradigm to a digital inclusion policy should be continuously operated.