• 천문학회보
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• 제42권1호
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• pp.53.1-53.1
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• 2017

The YONSEI (YOnsei Nearby Supernova Evolution Investigation) project is to investigate the luminosity evolution of Type Ia supernovae (SNe Ia) by using their early-type host galaxies. As a part of this project, we have constructed our own SN catalogue. SALT2 and MLCS2k2 light-curve fitters implemented in SNANA package are employed to analyze the light-curve data. The catalogue provides a rest-frame peak magnitude in B-band or distance modulus, a light-curve shape parameter, and a color or an extinction value of each SN in the redshift range from 0.01 to 1.4. In this poster, we will present our progress in the detailed systematic tests for this catalogue.

• Animal Systematics, Evolution and Diversity
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• 제33권4호
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• pp.284-284
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• 2017

• Animal Systematics, Evolution and Diversity
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• 제35권1호
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• pp.40-40
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• 2019

• 한국지능시스템학회논문지
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• 제17권3호
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• pp.417-422
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• 2007

A new evolution method termed queen-bee and mutant-bee evolution is based on the previous queen-bee evolution [1]. Even though the queen-bee evolution has shown very good performances, two parameters for strong mutation are added to the genetic algorithms. This makes the application of genetic algorithms with queen-bee evolution difficult because the values of the two parameters are empirically decided by a trial-and-error method without a systematic method. The queen- bee and mutant-bee evolution has no this problem because it does not need additional parameters for strong mutation. Experimental results with typical problems showed that the queen-bee and mutant-bee evolution produced nearly similar results to the best ones of queen-bee evolution even though it didn't need to select proper values of additional parameters.

• Bulletin of the Korean Chemical Society
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• 제16권9호
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• pp.845-850
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• 1995

A systematic method is presented to analyze the bandgaps of conjugated polymers in terms of geometrical relaxations and electronic effect of moieties using the equation of Eg=ΔEδr + ΔE1-4 + ΔEel. The relationship between ΔEδr and δr is derived from trans-PA and is transferred to other conjugated polymeric systems. By applying this method to heterocyclic polymers, very useful information is obtained to understand the evolution of bandgaps of PT, PPy and PF in connection with the chemical structures and electronic effect of the heteroatoms. We believe that this method is very helpful to understand the evolution of bandgaps of various conjugated polymers in connection with the chemical structures and electronic effect of moieties. Also, the method is expected to provide valuable information to design a small bandgap polymers.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
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• pp.233-236
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• 2007

A new evolution method for strong exploration and strong exploitation termed queen-bee and mutant-bee evolution is proposed based on the previous queen-bee evolution [1]. Even though the queen-bee evolution has shown very good performances, two parameters for strong mutation are added to the genetic algorithms. This makes the application of genetic algorithms with queen-bee evolution difficult because the values of the two parameters are empirically decided by a trial-and-error method without a systematic method. The queen-bee and mutant-bee evolution has no this problem because it does not need additional parameters for strong mutation. Experimental results with typical problems showed that the queen-bee and mutant-bee evolution produced nearly similar results to the best ones of queen-bee evolution even though it didn't need to select proper values of additional parameters.

• 소프트웨어공학소사이어티 논문지
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• 제26권1호
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• pp.17-29
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• 2013

소프트웨어 시스템 진화는 소프트웨어 시스템의 유지보수의 일종으로 계획적이고 체계적인 유지보수 프로세스이다. 소프트웨어 진화 연구는 기존 시스템의 비용편익 분석을 통해 시스템의 유지가치에 대한 판단 근거를 제공하며, 아키텍처를 기반으로 하는 진화는 반복적인 진화 작업의 자동화를 가능케 하여 유지보수 비용 감소를 가능하게 해주는 연구이다. 본 논문에서는 아키텍처 변환패턴을 이용한 소프트웨어 시스템 진화 프레임워크를 제안한다.

• 천문학회보
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• 제36권2호
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• pp.69.2-69.2
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• 2011

The discovery of dark energy from Type Ia supernovae (SN Ia) is based on the implicit assumption that the look-back time evolution of SN Ia luminosity, after light-curve corrections, would be negligible. A strong support for this assumption was the apparent insensitivity of SN Ia distances across the host galaxy morphologies. However, Hicken et al. 2009 (H09) shows a systematic difference in the Hubble residual (HR) of $0.144{\pm}0.070$ mag between the E-S0 and Scd/Sd/Irr galaxies, after light-curve corrections. If true, this indicates that the light-curve fitters used by the SN Ia community can not correct for the population age (and therefore the evolution) effect. In order to confirm this, we have combined nearby SN Ia samples and the first-year SDSS-II SN Survey. The SNANA package was used for analyzing SN Ia light-curve, both for the MLCS2k2 and SALT2 fitters. We find a systematic difference in the HR of $0.10-0.13{\pm}0.030$ mag between E-S0 and Scd/Sd/Irr galaxies, which is in agreement with the result of H09, but now at the 3-5 ${\sigma}$ level. Considering the significant difference in the mean age of stellar population between these morphological types, the difference in the HR reported here suggests that the evolution effect of SN Ia luminosity should be considered in the cosmological application of SN Ia data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.4191-4211
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• 2019

Software product lines (SPLs) are complex software systems by nature due to their common reference architecture and interdependencies. Therefore, any form of evolution can lead to a more complex situation than a single system. On the other hand, software product lines are developed keeping long-term perspectives in mind, which are expected to have a considerable lifespan and a long-term investment. SPL development organizations need to consider software evolution in a systematic way due to their complexity and size. Addressing new user requirements over time is one of the most crucial factors in the successful implementation SPL. Thus, the addition of new requirements or the rapid context change is common in SPL products. To cope with rapid change several researchers have discussed the evolution of software product lines. However, for the evolution of an SPL, the literature did not present a systematic process that would define activities in such a way that would lead to the rapid evolution of software. Our study aims to provide a requirements-driven process that speeds up the requirements engineering process using social network sites in order to achieve rapid software evolution. We used classification, topic modeling, and sentiment extraction to elicit user requirements. Lastly, we conducted a case study on the smartwatch domain to validate our proposed approach. Our results show that users' opinions can contain useful information which can be used by software SPL organizations to evolve their products. Furthermore, our investigation results demonstrate that machine learning algorithms have the capacity to identify relevant information automatically.

• 경영과학
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• 제13권2호
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• pp.193-203
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• 1996

There is no generally accepted definition of information technology (IT) although this is an important issue in the management information systems (MIS) area. In an effort to address this issue, the evolution of IT is reviewed from a historical perspective. A historical review on IT suggests that its evolution be broken down into three stages in a systematic way. Further, the identification of mainstream research interests at each stage makes a contribution in part to defining IT. Two approaches to defining IT are identified, and limitations of each approach are discussed. Finally, a better way to address these limitations is suggested.