• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.578-581
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• 2001

A treatability study was conducted using a hydrocarbon-contaminated soil for the oPtimization of bioremediation strategy best fit to a given set of contamination. The applicability of nutrients, biosurfactant, and oil-degrading microorganisms were examined by monitoring $CO_2$ evolution and oil degradation The addition of inorganic nutrients in the form of slow released fertilizer accelerated the initial rate of $CO_2$ evolution by a factor of 3. The application of oil-degrading microorganisms did not significantly increased $CO_2$ evolution or biodegradation efficiency. Application of a commercial biosurfactant was most effect in terms of the total $CO_2$ evolution and the oil degradation rate. The results indicate that $CO_2$ evolution measurement was found to be a simple and reliable countermeasure of crude oil hydrocarbon mineralization for the rapid determination of the best-fit bioremediation strategy.

• 한국토양비료학회지
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• 제27권4호
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• pp.290-295
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• 1994

각기 다른 수종이 토양발생 이산화탄소량에 미치는 영향을 연구하기 위하여 광릉시험림내에서 비슷한 입지에 식재된 20년생 백합나무, 은수원사시나무, 루브라참나무 인공조림지를 대상으로 soda-lime 법으로 1994년 5월부터 10월까지의 임목생육기간동안 이산화탄소 발생량을 측정하였다. 이산화탄소 발생량은 수종에 따라 $0.21g/m^2/hr{\sim}0.33g/m^2/hr$로 차이가 있었다. 이산화탄소 발생량과 대기 및 토양온도간에는 정의 상관관계가 있음이 밝혀졌다. 이산화탄소 발생량은 7, 8월에 가장 높았고, 이산화탄소 발생량의 계절적 변화는 대기 및 토양온도와 반드시 일치하지는 않았다. 이산화탄소 발생에 영향을 미치는 제반 환경 및 삼림인자들에 대한 보다 상세한 연구가 필요한 것으로 사료된다.

• 한국대기환경학회지
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• 제12권3호
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• pp.307-314
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• 1996

The rate of evolution of ethylent by tomato plants was rapidly increased by ozone fumigation. In the present study, the mechanism of ethylent evolution by ozone was investigated in experiments with aminoethoxyvinylglycine (AVG) and tiron, which inhibit the formation of ethylene and peroxidation of lipids, respectively. Pretreatment with AVG significantly inhibited the ozone-induced ethylent evolution, but the treatment of plants with tiron did not inhibit. These results indicate that the induction of the evolution of ethylene by ozone involves the pathway via aminocyclopropane-1-carboxylate (ACC), while not released as a result of the peroxidation of lipids. Ozone-induced ethylent evolution was greater in dar- than light-incubated, intact tomato plants. The difference between dark- and light-ethylene evolution was examined with diuron, an inhibitor of photosynthetic electron transport. The inhibitor treatment promoted ethylent evolution. These results suggest that ethylent retention and metabolism in plants were regulated by internal $CO_2$ levels which, in turn, were controlled in large part by photosynthesis. Thus, ethylene was retained in illuminated leaf tissue under low intenal $CO_2$ concentration which may develop in a sealed container without exogenously supplied $CO_2$.

• 한국농림기상학회지
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• 제5권2호
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• pp.110-115
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• 2003

한계농지 토양 내의 탄소와 질소의 동태에 관한 연구는 적절한 연구 대상지의 부족으로 지금까지 폭 넓게 이루어지지 못했다. 본 연구에서는 서울 근처의 검단산 일대에서 지속적으로 산림이었던 지역, 과거 논으로 이용되었던 지역, 과거 밭으로 이용되었던 지역 등 세 곳의 연구 대상지를 선정하고 여기에서 2002년 7월 25일부터 2003년 1월 24일까지 토양 발생 $CO_2$와 무기태 질소의 유효도를 측정하였다. 현재 지속적으로 산림이었던 지역과 과거 논으로 이용되었던 지역은 낙엽활엽수림이고, 과거 밭으로 이용되었던 지역은 낙엽성 관목이 주 식생을 이루고 있다. 토양 발생 $CO_2$는 토양 온도의 계절적 변화에 따라 차이를 보였다. 본 연구 기간동안 토양 발생 $CO_2$량 (g $CO_2$/$m^2$/hr)의 평균은 각각 과거 논으로 이용되다. 산림으로 변한 지역이 0.42, 과거 밭으로 이용되다 관목으로 변한 지역이 0.50, 지속적으로 산림이었던 지역이 0.41로 나타났다. 토양 발생 $CO_2$와 토양 온도는 연구 지역간에 차이가 나타나지 않았으나 토양 습도는 주목할 만한 차이를 보였고, 토양 발생 $CO_2$에 대해 토양 습도는 매우 약한 상관관계를 나타냈다. 무기태 질소의 유효도는 세 곳의 연구 대상지에 따라 차이를 나타냈으며 이는 토양 수분과 관련이 있는 것으로 보인다.

• Journal of Electrochemical Science and Technology
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• 제14권3호
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• pp.243-251
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• 2023

Developing oxygen evolution reaction (OER) electrocatalysts is essential to accomplish viable CO₂ and water electrolysis. Herein, we report the fabrication and OER performance of Ni-foam (NF)-immobilized Ni₆ nanoclusters (NCs) (Ni₆/NF) prepared by a dip-coating process. The Ni₆/NF electrode exhibited a high current density of 500 mA/cm² for the OER at an overpotential as low as 0.39 V. Ni₆/NF exhibited high durability in an alkaline solution without corrosion. Electrokinetic studies revealed that OER can be easily initiated on Ni6 NC with fast electron-transfer rates. Finally, we demonstrated stable CO₂-to-CO electroreduction using an NC-based zero-gap CO₂ electrolyzer operated at a current density of 100 mA/cm² and a full-cell potential of 2.0 V for 12 h.

• Genomics & Informatics
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• 제19권2호
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• pp.15.1-15.7
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• 2021

The direction of evolution can estimate based on the variation among nonsynonymous to synonymous substitution. The simulative study investigated the nucleotide sequence of closely related strains of respiratory syndrome viruses, codon-by-codon with maximum likelihood analysis, z selection, and the divergence time. The simulated results, dN/dS > 1 signify that an entire substitution model tends towards the hypothesis's positive evolution. The effect of transition/transversion proportion, Z-test of selection, and the evolution associated with these respiratory syndromes, are also analyzed. Z-test of selection for neutral and positive evolution indicates lower to positive values of dN-dS (0.012, 0.019) due to multiple substitutions in a short span. Modified Nei-Gojobori (P) statistical technique results also favor multiple substitutions with the transition/transversion rate from 1 to 7. The divergence time analysis also supports the result of dN/dS and imparts substantiating proof of evolution. Results conclude that a positive evolution model, higher dN-dS, and transition/transversion ratio significantly analyzes the evolution trend of severe acute respiratory syndrome coronavirus 2, severe acute respiratory syndrome coronavirus, and Middle East respiratory syndrome coronavirus.

• 경영과학
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• 제29권3호
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• pp.169-182
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• 2012

This study examines the co-evolutionary process between open innovation and firms' absorptive capacity. The effects of open innovation can be maximized through the capacity to absorb the knowledge from the external sources such as universities, government-support research institute, and private R&D centers. This study used data of STEPI technology innovation survey conducted at 2002, 2005, and 2008 (3 points measures). The data were analyzed through a structural equation model. Results suggest that open innovation at t0 point influences positively the absorptive capacity at t1 point, which subsequently enhances the intention of open innovation at t2 point. This result suggests the existence of co-evolutionary process between open innovation and firms' absorptive capacity. When knowledge comes from universities, the co-evolution has sustained; whereas when knowledge comes from private firms' R&D centers, the co-evolution has not effected. Theoretical and practical implications are discussed.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제2권1호
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• pp.95-110
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• 1998

Evolutionary Algorithms (EAs) are population-based optimization methods based on the principle of Darwinian natural selection. The representative methodology in EAs is genetic algorithm (GA) proposed by J. H. Holland, and the theoretical foundations of GA are the Schema Theorem and the Building Block Hypothesis. In the meaning of these foundational concepts, simple genetic algorithm (SGA) allocate more trials to the schemata whose average fitness remains above average. Although SGA does well in many applications as an optimization method, still it does not guarantee the convergence of a global optimum in GA-hard problems and deceptive problems. Therefore as an alternative scheme, there is a growing interest in a co-evolutionary system, where two populations constantly interact and co-evolve in contrast with traditional single population evolutionary algorithm. In this paper we show why the co-evolutionary algorithm works better than SGA in terms of an extended schema theorem. And predator-prey co-evolution and symbiotic co-evolution, typical approaching methods to co-evolution, are reviewed, and dynamic fitness landscape associated with co-evolution is explained. And the experimental results show a co-evolutionary algorithm works well in optimization problems even though in deceptive functions.

• Animal cells and systems
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• 제11권2호
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• pp.93-98
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• 2007

Gonadotropin-releasing hormone (GnRH), synthesized in the hypothalamus, plays a pivotal role in the regulation of vertebrate reproduction. Since molecular isoforms of GnRH and their receptors (GnRHR) have been isolated in a broad range of vertebrate species, GnRH and GnRHR provide an excellent model for understanding the molecular co-evolution of a peptide ligand-receptor pair. Vertebrate species possess multiple forms of GnRH, which have been created through evolutionary mechanisms such as gene/chromosome duplication, gene deletion and modification. Similar to GnRHs, GnRH receptors (GnRHR) have also been diversified evolutionarily. Comparative ligand-receptor interaction studies for non-mammalian and mammalian GnRHRs combined with mutational mapping studies of GnRHRs have aided the identification of domains or motifs responsible for ligand binding and receptor activation. Here we discuss the molecular basis of GnRH-GnRHR co-evolution, particularly the structure-function relationship regarding ligand selectivity and signal transduction of mammalian and non-mammalian GnRHRs.

• 천문학회지
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• 제13권1호
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• pp.9-14
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• 1980

The abundances of simple molecules are examined in terms of the time-dependent cloud evolution. The formation and destruction mechanisms of $H_2CO$ are reviewed. The average value of the fractional abundance of $H_2CO$ is derived to be in the range of $10^{-10}\;to\;5{\times}10^{-9}$. This is comparable to the observed values. The expected variations of the molecules formed from or destroyed by CO, CI, and $C^+$ whose abundances depend on the evolutionary state of the cloud are discussed.