Optimization of Diphtheria Toxin Production by Corynebacterium diphtheriae Using a Casein-based Medium in a Fermenter

정용주,Jin-A Lee,Mi-Young Jung,Sang-Mi Lee,김태연,최용경,김익환 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.4

The Td-based combined vaccine contains only small amounts of the diphtheria toxoid antigen. However, a high level of purity is necessary for this antigen. The diphtheria toxin is produced by growing Corynebacterium diphtheriae in a semisynthetic, casein-based medium in a fermenter. In order to obtain a highly pure diphtheria toxoid, the optimal conditions to express the toxin at 300 Lf/mL in a fermenter culture were determined. When C. diphtheriae was cultivated in a fermenter and a high concentration of toxin was obtained, specific patterns for the pH and dissolved oxygen levels identified. Overall, the fermenter cultivation process was divided into four stages according to variations in the pH. A specific range of KLa in the fermenter (0.0092 ~ 0.0093/sec) was required to produce high level expression of diphtheria toxin. The amount of toxin expression varied significantly according to culture conditions. Agitation and aeration in the fermenter affected toxin expression, even when the optimal KLa value for toxin production was maintained. A previous study has reported that the amounts of agitation and aeration are important factors when cultivating fungus in the fermenter to produce chitinolytic enzyme. A mass production of diphtheria toxoid with a purity level greater than 2,500 Lf/ mgPN was obtained through purification and detoxification from this optimized toxin production.

Tetanus Toxin Production from Clostridium tetani, Using a Casein-based Medium in a Single-use Bioreactor

정용주,Mi-Young Jung,Jin-A Lee,김태연,최용경,김익환 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.4

Clostridium tetani, a spore-forming anaerobic bacterium, and a casein-based semisynthetic medium were used to produce tetanus toxin in this study. N-Z-Case TT (casein hydrolysate) solution and glucose stock media were mixed and autoclaved, which resulted in tetanus toxin expression. The toxin was expressed when the N-Z-Case TT solution reacted with the glucose stock at a high temperature, creating an adequate amount of Maillard reaction products (MRPs). After accumulating in C. tetani cells, tetanus toxin was secreted into the medium when cell lysis was induced by surface aeration. C. tetani was cultivated and tetanus toxin was expressed in a single-use bioreactor, which produced 80 Lf/mL of tetanus toxin in a medium with MRPs. While using the correct medium to induce tetanus toxin was important, other factors played a part in achieving the desired concentration of the toxin, including the medium processing and culture methods inside the bioreactor. Tetanus toxoid with a purity level greater than 2,500 Lf/mgPN was obtained by detoxifying and purifying the toxin recovered from the fermenter or single-use bioreactor. A single-use bioreactor could be used in a limited space without the need for constructing a large scale production facility, to produce the tetanus toxoid antigen for clinical trials.

외국인 유입에 따른 보건의료재정 변화 및 지속가능성 제고를 위한 대응방안 연구

정용주 ( Yongju Jung ) 한국병원경영학회 2020 병원경영학회지 Vol.25 No.4

Purposes: The problem in the recent immigration policy and social policy changes for foreigners is that the preliminary analysis or research on the actual impact of the influx of foreigners has not been done enough in Korea yet.. This study is to examine the impact of the Korean health insurance finances on the influx of foreigners. Approach: This study analyzed the health insurance statistics for foreigners and overseas Koreans of the Health Insurance Corporation from 2013 to 2017. The data is the “Status of Health Insurance Premiums for Nationals, Foreigners, and Overseas Koreans from 2013 to 2017” submitted by the National Health Insurance Service to the Health and Welfare Committee during the 2018 National Audit Period. Findings: To summarize the analysis, first, the proportion of foreigners was only 1% of all subscribers (1.7% at work, 1.9% in regions) until 2017. Second, employees at work have a lower pay-to-pay ratio, and local subscribers have a higher pay-to-pay rate, regardless of nationality. Third, as immigrants are mostly concentrated in younger ages, they are healthy and use of hospitals is relatively low. Fourth, in terms of gender distribution, there are many women of childbearing age due to marriage immigration among foreign local subscribers, and more men use hospitals than workers who have a high proportion of males due to childbirth. In conclusion, the impact of immigration on health insurance finances is not large, and has a positive effect on finances. Practical Implications: If we simply consider the financial aspect, encouraging foreigners to subscribe to health insurance has a positive effect on finances. In particular, the more foreign workers are enrolled, the greater the financial gain. In particular, increasing the employment of foreign women through language education, vocational training, and employment support will help finance health insurance. One of the reasons foreign subscribers have a positive impact on health insurance finance is the low medical utilization rate. It can be said that young and healthy foreigners use fewer hospitals and clinics, but another aspect means that foreigners have difficulty using health insurance for various reasons. Therefore, various supports must be accompanied so that foreign subscribers can use medical services when necessary.

재택근무 제도강화와 테크노스트레스가 업무생산성에 미치는 영향에 관한 연구 : 행동통제와 기술준비도의 조절효과를 중심으로

정용주(Yong Ju Jung),김진수(Jin Soo Kim) 한국데이타베이스학회 2020 Journal of information technology applications & m Vol.27 No.4

Corna Virus is being widely spreaded across the world and accelerating working environments to home-based telecommuting environments rapidly. Many companies, however, are afraid of decrease in productivities due to insufficient technology readiness by new technology environments. Therefore, finding out the influencing factors which improve the productivities in home-based telecommuting environments is a very important research issue. This study suggests several influencing factors such as technology readiness, technostress, and control behavior and a research model by literature review. To verify the model a total of 204 questionnaires are collected from office workers who are currently utilizing home-based telecommuting. The statistical analysis show that technostress influences negatively to productivities. In addition, moderating effect analysis show that control behavior affects negatively and technostress positively to alleviate the technostress. The result is expected to provide a theocratical framework for further related research and practical guidelines for improving productivities in home-based telecommuting environments.

의미적 개념 기반 비디오 트랜스코딩 방법 및 시스템

정용주(Yong Ju Jung),김영석(Young Suk Kim),Troung Cong Thang,노용만(Yong Man Ro),김태희(Tae-hee Kim),김재곤(Jae-Gon Kim) 한국방송·미디어공학회 2004 한국방송공학회 학술발표대회 논문집 Vol.2004 No.-

본 논문에서는 다양한 사용자 환경에서 비디오의 범용적인 서비스를 위한 다차원 비디오 트랜스코딩의 판단에 관하여 논한다. 효율적인 판단을 위해 여러 영화 비디오 클림들을 비슷한 의미적 개념을 가지는 비디오들과 비슷한 장면 복잡도를 가지는 비디오들로 분류하고, 각 종류별로 주관적인 테스트(subjective test)를 실시하여 비디오 트랜스코딩에 있어서 사용자 인지(perception)의 특성을 분석한다. 이렇게 분석된 인간의 시각 특성들을 이용해 비디오 트랜스코딩 판단 궤적(trajectory)을 만들고 이를 다차원 비디오 트랜스코딩 판단 시에 적용하기 위한 방법을 제안한다.

최고경영자 교체요인과 경영성과에 대한 패널자료분석

정용주(Yong Joo Jung),이의택(Eui Taek Lee),김정일(Jeong Il Kim) 한국자료분석학회 2020 Journal of the Korean Data Analysis Society Vol.22 No.1

본 연구에서는 한국거래소 유가증권시장에서 2010년부터 2018년까지 금융업종을 제외한 균형패널자료를 가지고 있는 기업 495개 기업을 선정하여 최고경영자 교체가 어떤 요인으로부터 기인하고 있는지, 그리고 교체이후 경영성과에 어떤 변화가 있는지를 패널자료분석, 패널로짓분석, 패널프로빗분석, 그리고 공분산분석으로 연구하였다. 연구결과, 시장성과를 나타내는 Tobin’s Q와 주가순자산이익률(PBR)은 최고경영자 교체기업과 비교체기업이 차이가 없었으며, 회계성과를 나타내는 총자산순이익률(ROA)인 경우는 최고경영자가 교체된 기업의 총자산순이익률이 더 낮게 나타났다. 최고경영자 교체에 영향을 주는 변수를 선정한 결과 시장성과 변수인 Tobin’s Q와 주가순자산비율(PBR)은 영향을 주지 않고 있으며, 회계성과인 총자산순이익률은 음으로 매우 유의하여 이 값이 작을수록 최고경영자 교체가 일어나는 것으로 분석되었다. 최고경영자 교체 이후에 시장성과와 회계성과에 변화를 줄 것이라는 가설을 분석한 결과, Tobin s Q와 주가순자산이익률은 모두 유의하지 않아 유임과 교체집단에 차이가 없다는 것을 의미하였으며, 회계성과를 나타내는 총자산순이익률과 자기자본이익률(ROE)는 모두 유의하고 평균값도 교체 집단이 높아 회계성과는 교체된 집단이 더 좋아졌다는 것을 알 수 있었다. 결과적으로, 최고경영자 교체는 시장성과보다 회계적 성과에 기인하는 것으로 보이며, 교체 이후에는 시장성과보다는 회계성과가 매우 호전되고 있다. The research examined what factors contributed to CEO turnover, and what changes occurred to management performance after CEO turnover through panel data analysis, panel logit analysis, panel probit analysis, and ANCOVA (analysis of covariance). The Korea composite stock price index (KOSPI) market of the Korea exchange selected companies from 2010 to 2018 with the exclusion of financial companies. The results showed that there was no significant difference between companies with CEO turnover and those without for Tobin’s Q and PBR (price book-value ratio). However, ROA (return on assets) was lower for companies that replaced their CEO than that did not. After selection of factors affecting CEO turnover, Tobin’s Q and PBR did not affect the replacement. For account performance, negative values of ROA was substantially significant and smaller values of ROA led to the replacement. After CEO turnover, both Tobin s Q and PBR were not significant which indicates the two groups showed no difference. Yet, both ROA and ROE (return on equity) were significant and the averages were higher among CEO turnover companies. As a result, CEO turnover was caused by account performance more than market performance, and account performance improved more than market performance after CEO turnover.

국내설계기준의 해외진출을 위한 지진하중 특성 검토

정용주(Jung, Yong Joo),고성혁(Ko, Sung Hyuk) 한국콘크리트학회 2019 한국콘크리트학회 학술대회 논문집 Vol.31 No.2

최고경영자의 리더십 특성이 내부고객만족과 경영성과에 미치는 영향

정용주(Jung, Yong Ju),전희준(Jeon, Hea June) 한국서비스경영학회 2018 서비스경영학회지 Vol.19 No.1

In this study, we looked at what healthcare institutions need to achieve effective performance in rapidly changing environments. We analyzed the impact that factors’ relationship such as leadership, internal customer satisfaction, and managerial performance, and how reputation and size of hospitals can affect these relationships. Research shows that transformational leadership and servant leadership have a causal relationship in internal customer satisfaction. Internal customer satisfaction was also confirmed to have a significant influence on hospital managerial performance. It was confirmed that the hospital"s reputation and size (number of beds) have a significant influence on the relationship between internal customer satisfaction and hospital performance. The lower level of the reputation and the smaller the hospital size was, the greater the impact of causal effect of internal customer satisfaction to managerial performance.

항공영상에서 그림자 경계 탐색 및 복원 기법 연구

정용주(Jung, Yong Ju),장영운(Jang, Young Woon),최연웅(Choi, Yun Woong),조기성(Cho, Gi Sung) 한국측량학회 2006 한국측량학회지 Vol.24 No.4

조직의 공정성, 조직문화 개선 그리고 서비스 접점이 병원 경영성과에 미치는 영향

정용주 ( Yongju Jung ) 한국병원경영학회 2019 병원경영학회지 Vol.24 No.2

The purpose of this study was to investigate the effect of fairness, culture, and service points on organizational management to maximize the ability of organizational members. The subjects of the survey were selected from major hospitals, small and medium hospitals. A total of 500 questionnaires were distributed, but 404 (80.8%) were used for the final analysis. The SPSS WIN 20 program was used to analyze the collected data. The following conclusions were obtained. First, in this study, organizational fairness did not show any general difference, and fairness was obtained with relatively high scores. In terms of improving organizational culture, size of hospital there is a statistically significant difference. the larger the organization, the more the organizational culture needs to be improved. Organizational fairness were significant differences in service encounter points and size of hospital. Second, the correlation between fairness, organizational culture improvement, service contact point and management performance showed a very positive correlation. Third, fairness has no effect on business performance. However, in this study, organizational culture improvement and service contact points are statistically significant and positive (+) influence on dependent variable management performance. Therefore, in order to improve the organizational culture of the hospital, it is necessary for the CEO to the vision, core, to discuss and make a reasonable plan. In order to actively cope with rapidly changing hospital environment, it will be necessary to positively support the of new medical market and the increase of market share.