• 제목/요약/키워드: directed evolution

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FDI and the Evolution of Directed Technological Progress Bias: New Evidence from Korean Outward Investment

  • Boye Li;Xiang Li;Yaokun Wu
    • Journal of Korea Trade
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    • 제27권5호
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    • pp.1-22
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    • 2023
  • Purpose - Southeast Asia has been the focus of Korea's foreign investment. Korea has been helping developing countries in Southeast Asia achieve economic growth and win-win cooperation through capital exports. FDI is an important channel for technology diffusion. However, the impact of FDI on the bias of technological progress in the host country is dependent on the host country's own endowment structure and capital-labor factor substitution elasticity. Therefore, the central issue of this paper is to accurately evaluate the impact of Korea's FDI to the four Southeast Asian countries in various industries on their bias of technological progress. Design/methodology - The paper uses macroeconomic data for Korea and four East Asian countries to estimate capital-labor factor elasticities of substitution using nonlinear, seemingly uncorrelated regressions (NLSUR). Then, the biased technological change index (BTCI) is calculated for each country. Finally, panel data analysis is used to explore the impact of Korean FDI in various industries in the four Southeast Asian countries on their own directed technological progress, and a robustness test is conducted. Findings - There is a substitution relationship between capital and labor factors based on their elasticity in Korea, Singapore and the Philippines. There is a complementary relationship between capital and labor factors in Indonesia and Malaysia. According to the BTCI, there is a trend toward labor-biased technological progress in all countries. Korean investments in manufacturing, wholesale and retail trade in the host country trigger capital-biased technological change in the host country; investments in the finance, insurance and information and communication sectors trigger labor-biased technological change. In addition, this paper also confirms that directed technological progress can enable cross-country transmission. Originality/value - The innovation of this paper lies in three aspects. First, we estimate the BTCI for five countries and explore the trend and situation of directed technological progress in each country from each country's own perspective. Second, we explore the impact of Korean FDI in the host country on the bias to its technological progress at the industry level. Second, we explore the impact of Korean FDI in various industries in the four Southeast Asian countries on the four countries' own directed technological progress from a national perspective. Finally, we propose corresponding countermeasures for technological progress from the perspective of inverse factor endowment. These innovative points not only expand the understanding of technological progress and cross-country technology transfer in East Asia but also provide practical references for policy-makers and business operators.

인공적인, 너무나 자연적인: 포스트 게놈 시대 합성생물학과 트랜스휴머니즘 (Artificial, All Too Natural: Synthetic Biology and Transhumanism in the Post-Genomic Era)

  • 우태민;박범순
    • 과학기술학연구
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    • 제16권2호
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    • pp.33-63
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    • 2016
  • 이 논문은 포스트 게놈 시대에 합성생물학 연구자들과 트랜스휴머니스트들의 자연관과 진화개념을 비교분석하는 것을 목적으로 하고 있다. 2000년대 새롭게 등장한 합성생물학은 "합리적 설계"와 "방향적 진화"라는 두 가지 핵심적인 개념을 통해 생명 시스템을 디자인하는 것을 가능케 했다. 인간이 생명체를 설계해 만들어내고 진화과정을 가속화시킬 뿐만 아니라 특정 방향으로 유도한다는 점에서, 자연적인 것과 인공적인 것 사이의 경계가 무너지는 것 아닌가 하는 우려가 제기되었다. 이렇게 합성생물학으로 재구성된 자연을 어떻게 받아들여야 할 것인가? 진화의 속도와 방향에 영향을 주는 연구를 어떻게 정당화할 수 있는가? 합성생물학과 트랜스휴머니즘은 어떤 지적 자산을 공유하고 있나? 과학기술의 상업화와 같은 사회경제적 요소가 분야의 흐름에 영향을 주지는 않은지? 자연의 도덕적 권위는 사라졌는가? 본 논문은 합성생물학을 선도하고 있는 세 명의 과학자와 최근 대표적 트랜스휴머니스트로 떠오르고 있는 옥스퍼드 대학의 철학자들을 관점을 소개하고 비교분석하여 이 질문들에 답하려고 한다.

Directed evolution을 이용한 (S)-Ketoprofen ethlyester의 광학분활용 Esterase의 특성 개량

  • 김승범;김지희;유연우
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XII)
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    • pp.445-449
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    • 2003
  • As for the purpose, we first introduce an random mutation into wild-type gene to expand a mutation space, and then further recombine the mutant genes by staggered extension process PCR. As a result, we obtained the best clones 6-52 that showed a high activity and stability, from a round of error prone and staggered extension process PCR. The purified enzyme showed a similar pH stability to the wild-type enzyme and reveal a slightly high optimum pH at 12. In the optimum temperature, an identical dependency was also showed and a quite high stability in the thermal stability was obtained. Along with this, the enzyme was also stable at a reaction that supplement with a 15 % of ethanol as an additive. The addition of other solvents and surfactants did not improve the reaction and thus resulted in a similar profile to those of wild-type enzyme. The specific activity on the target compound rac-ketoprofen ethyl ester was calculated to be about 85, 000 unit, and the kinetic constants Km and Vmax were determined to be 0.2 mM and 90 mM/mg-protein/min respectively. The deduced amino acid alignment with the wild type enzyme revealed five mutations at L120P, I208V, T249A, D287H and T357A. Based on these observations, the site directed mutagenesis to delineate the mutagenic effect is under progress.

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The development of modified cellulase with higher activity by directed evolution

  • Kang, Whan-Koo;Son, Jeong-Il;Hwang, Sun-Duk;Kim, Bum-Chang;Kim, Hyoung-Sik;Lee, Byung-Ryul;Lee, Chul-Woo
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XIII)
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    • pp.499-503
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    • 2003
  • 본 연구에서는 Trichorderma reerri의 cellobiohydrolase (CBH1) gene을 이용하여 분자진화 방법을 이용한 cellulose분해 활성이 증가된 cellulase 변이체를 선별하고자 하였다. 재조합된 벡터가 도입된 균주의 발현을 SDS-PAGE로 확인한 후, 분자 진화에 의한 cellulase 변이체를 trypan blue staining법으로 cellulase 변이체 228-G2를 선별하였으며, cellulose분해 활성을 DNS법으로도 다시 확인 할 수 있었다. Cellulase 변이체 228-G2의 분해활성 증가율은 original CBH I에 비해 약 300%증가 된 것을 확인하였고, DNA sequence를 확인할 결과 1542bp 중 17개의 염기서열이 바뀐 것을 알 수 있었다.

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Geostationary Satellite Station Keeping Robustness to Loss of Ground Control

  • Woo, Hyung Je;Buckwalter, Bjorn
    • Journal of Astronomy and Space Sciences
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    • 제38권1호
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    • pp.65-82
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    • 2021
  • For the vast majority of geostationary satellites currently in orbit, station keeping activities including orbit determination and maneuver planning and execution are ground-directed and dependent on the availability of ground-based satellite control personnel and facilities. However, a requirement linked to satellite autonomy and survivability in cases of interrupted ground support is often one of the stipulated provisions on the satellite platform design. It is especially important for a geostationary military-purposed satellite to remain within its designated orbital window, in order to provide reliable uninterrupted telecommunications services, in the absence of ground-based resources due to warfare or other disasters. In this paper we investigate factors affecting the robustness of a geostationary satellite's orbit in terms of the maximum duration the satellite's station keeping window can be maintained without ground intervention. By comparing simulations of orbit evolution, given different initial conditions and operations strategies, a variation of parameters study has been performed and we have analyzed which factors the duration is most sensitive to. This also provides valuable insights into which factors may be worth controlling by a military or civilian geostationary satellite operator. Our simulations show that the most beneficial factor for maximizing the time a satellite will remain in the station keeping window is the operational practice of pre-emptively loading East-West station keeping maneuvers for automatic execution on board the satellite should ground control capability be lost. The second most beneficial factor is using short station keeping maneuver cycle durations.

A Highly Active Alpha Amylase from Bacillus licheniformis: Directed Evolution, Enzyme Characterization and Structural Analysis

  • Liu, Yihan;Fan, Shuai;Liu, Xiaoguang;Zhang, Zhimeng;Wang, Jianling;Wang, Zhengxiang;Lu, Fuping
    • Journal of Microbiology and Biotechnology
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    • 제24권7호
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    • pp.898-904
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    • 2014
  • The stability of Bacillus licheniformis alpha-amylase (BLA) under acid condition was enhanced through direct evolution using the error-prone polymerase chain reaction. One beneficial mutation site, H281I, was obtained in BLA. The specific activity of H281I was 161/352 U/mg, which was 62.6/27.5% higher than that of the wild-type (WT) (99/276 U/mg) at pH 4.5/6.5 and $95^{\circ}C$. The pH optimum for H281I was decreased about 1 unit, whereas no significant changes of optimum temperature and thermostability were observed compared with the wild type (WT). The $k_{cat}/K_m$ value of H281I was 1.7-/1.4-fold higher at pH 4.5/6.5, respectively, than that of WT. The structure model analysis indicated that the H281I mutation altered the predicted interaction between the amino acid residues at 281 and 273, thus creating a conducive local environment for substrate binding, as reflected by its decreased $K_m$, and consequently increased the specific activity.

Enhanced thermostability and substrate susceptibility of esteraseusing directed evolution

  • 최기섭;김지희;김근중;유연우
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XIII)
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    • pp.480-484
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    • 2003
  • A stereoselective-hydrolysing enzyme was cloned from Pseudomonas fluorescens KCTC1767 which had high enantiomeric activity toward (S)-ketoprofen ethyl ester. Analyses of typical properties resulted in low thermostability and substrate specificity. A round error-prone PCR and StEP(STaggered Extension Process) was adopted to evolute this character. As a result, the best clone 6-52 was selected which was represented to increased thermostability(40 fold) compared to wild type enzyme in $50^{\circ}C$. Additionally, specific activity toward (S)-ketoprofen ethyl ester and p-nitrophenyl derivatives improved 3 fold and 1.5 fold, respectively. DNA sequence analyses was showed some exchanged amino acid residue that was L120p, 1208v, T249A, D287H and T357A. Which the 120th's leucine substituted for proline was presumed structurally important residue concerning with catalytic activity.

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TRIB이론과 응용 (The TRIZ Theory and it′s Application)

  • 이장용
    • 한국산학기술학회논문지
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    • 제2권2호
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    • pp.25-31
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    • 2001
  • 제품의 개념설계 단계에서 효과적으로 사용될 수 있는 TRIZ 이론이 소개 되었으며, 그것의 몇가지 응용 예를 기술하였다. 제품의 개념설계 단계에서는 지금까지 비정형화된 방법 기존의 설계결과물 및 설계자의 경험과 직관에 상당부분 의존하여 작업이 수행되 었는데, TRIZ이론에서는 이것을 체계적인 방법으로 수행할 수 있는 기법들을 제공한다. 본 논문에서는 이런 기법들 중 공학 설계 부분에 많이 이용되는 것들을 중심으로 설명하였으며, 이것을 고속철도 개념설계 단계에 적용하여 기존의 설계결과를 TRIZ 이론을 통하여도 얻어낼 수 있음을 보여주었다.

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An Analytical Method for Low-Thrust and High-Thrust Orbital Transfers

  • Park, Sang-Young
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2003년도 한국우주과학회보 제12권2호
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    • pp.47-47
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    • 2003
  • Analytical formulae are presented to approximate the evolution of the semi major axis, the maneuver time, and the final mass fraction for low thrust orbital transfers with circular initial orbit, circular target orbit, and constant thrust directed either always along or always opposite the velocity vector. For comparison, the associated results for high-thrust transfers, i.e. the two-impulse Hohmann transfer, are summarized. All results are implemented in a computer code designed to analyze planar planetary and interplanetary space missions. This implementation yields fast and reasonably accurate approximations to trajectory performance boundaries. Consequently, the approach can provide trajectory analysis for each spacecraft configuration during the conceptual space mission design phase. As an example, a mission from Low-Earth Orbit (LEO) to Jupiter's moon Europa is analyzed.

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First Record of Scyllarine Lobster Chelarctus cultrifer (Crustacea: Decapoda: Scyllaridae) from Korea

  • Lee, Seok-Hyun;Ko, Hyun-Sook
    • Animal Systematics, Evolution and Diversity
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    • 제26권3호
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    • pp.333-335
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    • 2010
  • The scyllarine lobster Chelarctus cultrifer is described as the first species of the genus Chelarctus known from Korean waters. C. cultrifer is very similar to the Galearctus kitanoviriosus but it is different in the pleura of the abdominal somites 2 to 4 are broader and ending in sharp posteriorly directed points and having the propodi of pereiopods 3 and 4 are forming subchelates with the dactyli. The record of the species represents an extension of its previously known range from Somalia to Hawaiian Islands and brings the number of known species of the scyllarine lobsters in Korea to three.