• Journal of Microbiology and Biotechnology
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• 제30권6호
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• pp.793-803
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• 2020

Adaptive laboratory evolution (ALE) is an evolutionary engineering approach in artificial conditions that improves organisms through the imitation of natural evolution. Due to the development of multi-level omics technologies in recent decades, ALE can be performed for various purposes at the laboratory level. This review delineates the basics of the experimental design of ALE based on several ALE studies of industrial microbial strains and updates current strategies combined with progressed metabolic engineering, in silico modeling and automation to maximize the evolution efficiency. Moreover, the review sheds light on the applicability of ALE as a strain development approach that complies with non-recombinant preferences in various food industries. Overall, recent progress in the utilization of ALE for strain development leading to successful industrialization is discussed.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 1998년도 춘계정기학술대회
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• pp.22-22
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• 1998

This paper reviews the benefits of users participation in IMT-2000 standardization by the creation of users coalitions, focusing in particular on phased standards strategy necessary for the evolutionary approach from second generation to third generation systems. It first presents in detail the current status of IMT-2000 standardization progress occurring at each regional standard body including TIA of US, ETSI of Europe, TTA of Korea and ARIB of Japan. With this clear understanding of standardization situations worldwide, we may be able to come up with our standards strategies related to IPR issues and efficient standard-setting mechanism between manufacturers and service providers. In addition, this paper addresses the necessity for phased licensing of IMT-2000 service in order to avoid the high cost of new infrastructures and ensure an acceptable financial investment returns for existing cellular and PCS service providers. An author hopes that this paper can provide the adequate standardization directions of IMT-2000 to satisfy the varying regional and global market requirements.

• 천문학회보
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• 제42권2호
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• pp.38.1-38.1
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• 2017

Symbiotic stars are long-orbital-period interacting binaries characterized by extended emission over the whole electromagnetic range and by complex photometric and spectroscopic variability. In this contribution, I will present some high-cadence, long-term optical light curves of confirmed and candidate symbiotic stars in the Magellanic Clouds. By careful visual inspection and combined time series analysis techniques, we investigate for the first time in a systematic way the photometric properties of these astrophysical objects, trying in particular to distinguish the evolutionary status of the cool component, to provide its first-order pulsation ephemeris and to link all this information with the physical parameters of the binary system as a whole. Finally, I will discuss a new, promising photometric technique, potentially able to discover Symbiotic Stars in the Local Group of Galaxies without the recourse to costly spectroscopic follow-up.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.151-162
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• 2000

근접촉쌍성을 분광형에 따라 A형과 F형으로 분류하여 각각의 물리적 특성과 진화를 조사하였다. 그 결과, 근접촉쌍성이 TRO 이론에 따른 진화 경로를 겪는다고 가정하면, F형이 A형에 비하여 더 접촉에 가까운 즉, W UMa형에 근접한 상태에 있을 가능성이 있음을 알 수 있었다. NCBs의 질량-반경 관계, 질량-광도 관계 및 H-R도를 조사하였는데 그 결과 A형이 F형에 비하여 질량교환이 활발할 것으로 생각된다. 근접촉쌍성은 ZAMS와 평행하게 나타나며 접촉쌍성의 진화 위치와 거의 일치하고 있다.

• Journal of Astronomy and Space Sciences
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• 제21권2호
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• pp.83-92
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• 2004

질량비가 작은 접촉쌍성 GR Vir와 HV Aqr의 이미 발표된 분광 및 측광관측치를 WD프로그램에 적용하여 이 별들의 새로운 절대 물리량을 얻었다. GR Vir과 HV Aqr를 포함한 17개의 질량비가 작은 접촉쌍성들의 친화 상태를 조사하였다. 그 결과 질량비가 작은 접촉쌍성의 주성은 대부분 종년주계열상에 놓이며 반성은 영년주계열 아래 놓이고 있음을 확인하였다.

• 천문학회지
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• 제37권4호
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• pp.273-279
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• 2004

Chemical compositions of planetary nebulae are of interest for a study of the late stage of stellar evolution and for elemental contributions to the interstellar medium of reprocessed elements since possibly a large fraction of stars in 0.8 - 8 $M_{\bigodot}$ range go through this stage. One of the methods for getting chemical composition is a construction of theoretical photoionization models, which involves geometrical complexities and a variety of physical processes. With modelling effort, one can analyze the high dispersion and find the elemental abundances for a number of planetary nebulae. The model also gives the physical parameter of planetary nebula and its central star physical parameter along with the knowledge of its evolutionary status. Two planetary nebulae, NGC 7026 and Hu 1-2, which could have evolved from about one solar mass progenitor stars, showed radically different chemical abundances: the former has high chemical abundances in most elements, while the latter has extremely low abundances. We discuss their significance in the light of the evolution of our Galaxy.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.1-9
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• 1999

Plant biotechnology including plant tissue culture is the most important science to rescue human beings from the crisis of biosphere of the earth which they will face in the 21st century. Global area other than Asia of trangenic crops increased more than 16 times from 1996 to 1998. In Asian countries, micropropagation using tissue culture techniques has been well developed and has contributed to agricultural production. Although researches on levels of laboratory and test field trial of transgenic crops have been performed actively in some Asian countries, areas of growing transgenic crops are still small in Asia countries except in China. In this paper, the status of plant biotechnology in global and Asian countries are reviewed and the future prospect of plant biotechnology in Asia and roles of Korean and Japanese plant scientists in it are discussed.

• 천문학회보
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• 제43권2호
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• pp.60-60
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• 2018

It has been known that XZ CMi is a near-contact binary composed of a hotter and more massive main-sequence primary star close to its Roche-lobe and a Roche-lobe filling giant/subgiant secondary star. There still exist, however, many discordant matters among the previous investigators: diverse mass ratios and temperatures ranging from 0.38 to 0.83 and from 7,000 K to 8,876 K, respectively. In order to make a contribution to the two confusions we conducted spectroscopic and photometric observations. A total of 34 high-resolution spectra were obtained during 4 nights from 2010 and 2018 with the Bohyunsan Optical Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). In parallel, BVRI multi-band photometric observations were carried out 5 nights in 2010 at Sobaeksan Optical Astronomy Observatory (SOAO). In this presentation, we present physical parameters of XZ CMi through the simultaneous analyses of new double-lined radial velocity curves and new light curves. We will also briefly discuss the evolutionary status of the system.

• 천문학회보
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• 제44권2호
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• pp.51.4-51.4
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• 2019

We started a systematic observational study of the 22 GHz water and 44 GHz class I methanol masers in 87 high-mass young stellar objects (HM-YSOs) as a KaVA large program (LP). The primary goal is to understand dynamical evolution of HM-YSOs and their circumstellar structures by measuring spatial distributions and 3-dimensional velocity fields of multiple maser species. In the first-year observations (2016-2017), we made snap-shot imaging surveys of 25 water and 19 methanol maser sources. In the second-year observations (2018-2019), we have carried out monitoring observations of 19 water and 3 methanol maser sources that were selected on the basis of the first-year survey results. By combining follow-up observations with VERA (distances), JVN/EAVN (6.7 GHz methanol masers), and ALMA cycles 3 and 6 (thermal lines/continuum), we will provide novel information on physical properties (density, temperature, size, mass), 3D dynamical structures of disk/jet/outflow/infalling envelope, and relationship between evolutionary of HM-YSOs. In this presentation, we will report the current status and future plans of our KaVA large program.

• 천문학회보
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• 제45권1호
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• pp.57.4-58
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• 2020

The B-fields in Star-forming Region Observations (BISTRO) is a large program of the James Clerk Maxwell Telescope (JCMT) to study the roles of magnetic fields in molecular clouds on intermediate scales (a few thousands au or larger scales), in which a large number of researchers over the world are involved. This project was initiated in 2016 with polarimetric observations of nearby star-forming regions and has been extended toward massive and farther regions (BISTRO-2) and various evolutionary stages and environmental conditions (BISTRO-3). The current status of the BISTRO projects is reported. In addition, we discuss magnetic fields in the Serpens Main molecular cloud, which is one of the BISTRO star-forming regions. Utilizing the Histogram of Relative Orientations method, which compares polarization directions with density gradients, we show that magnetic fields are parallel to filaments in less dense filamentary structures but perpendicular to dense ones. Furthermore, the magnetic field directions with respect to density gradients vary again with density in denser core regions, which is understood by core formation and pinched fields. Note: (PI) D. Ward-Thompson, (co-PIs) P. Bastien, T. Hasegawa, W. Kwon, S. Lai, and K. Qiu