• Title/Summary/Keyword: 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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    • v.27 no.5
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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.

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

  • Woo, Taemin;Park, Buhm Soon
    • Journal of Science and Technology Studies
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    • v.16 no.2
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    • pp.33-63
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    • 2016
  • This paper compares and contrasts the concept of nature and the theory of evolution held by leading synthetic biologists and transhumanists in the post-genomic era. Synthetic biology, which emerged in the early 2000s, aims to design biological systems that perform specific functions with the two key concepts of "rational design" and "directed evolution". However, synthetic biology has also raised serious concerns about the creation of man-made biological materials and the manipulation of the direction and speed of evolution. It is no wonder that transhumanists, who dream of creating new, enhanced human species, have welcomed the arrival of synthetic biology. How, then, can we deal with the nature reinvented by synthetic biology? By what means can one justify research that may affect the process of evolution? What intellectual resources do synthetic biology and transhumanism share in common? What influence would the new trend of commercialization of science and technology exert upon the development of synthetic biology? Addressing those questions, this paper argues that the moral authority of nature can be restored in this post-genomic era.

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

  • Kim, Seung-Beom;Kim, Ji-Hui;Yu, Yeon-U
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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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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    • 2003.10a
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    • pp.499-503
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    • 2003
  • In the study, we have obtained modified cellulase with higher cellulose degradation activity by molecular evolution method. Cellobiohydrolase(CBH I ) gene of Trichorderma reerri has been used. Cellulase mutant 228-G2 was selected and the activity of cellulase mutant 228-G2 was increased by 300% compared to original CBH I The 17 among 1542bases were found to be modified with mutant 228-G2.

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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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    • v.38 no.1
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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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    • v.24 no.7
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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

  • Choe, Gi-Seop;Kim, Ji-Hui;Kim, Geun-Jung;Yu, Yeon-U
    • 한국생물공학회:학술대회논문집
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    • 2003.10a
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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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The TRIZ Theory and it′s Application (TRIB이론과 응용)

  • 이장용
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.2 no.2
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    • pp.25-31
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    • 2001
  • The TRIZ theory which was invented by Russian scientist Genrich Altshuller provides a systematic methodology for innovative engineering design in place of brainstorming. synectics, analogical thinking, which seeming1y high efficiency are still variations of the trials and errors method. TRIZ theory gives designer the ability to explore design solutions in fields other than his (her) own experience. Among several TRIZ theories, most widely used techniques in engineering field are contradiction theory. Su-Field analysis, physical phenomenon and effect and directed production evolution. which are described in this thesis and its application to conceptual design of high-speed train is performed as a case study of TRIZ theory.

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

  • Park, Sang-Young
    • Bulletin of the Korean Space Science Society
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    • 2003.10a
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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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    • v.26 no.3
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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.