• Title/Summary/Keyword: evolution

Search Result 9,662, Processing Time 0.035 seconds

On the Origin of the Correlation between Hubble Residual and Mass of the Type Ia Supernova Host Galaxies

  • Kang, Yijung;Kim, Young-Lo;Lim, Dongwook;Chung, Chul;Lee, Young-Wook
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.39 no.1
    • /
    • pp.36.1-36.1
    • /
    • 2014
  • The correlation between mass of Type Ia Supernova (SN Ia) host galaxies and Hubble residual is now well-established. The origin of this relation, however, is yet to be understood. We have used low-resolution spectra of early-type hosts from YONSEI (YOnsei Nearby Supernovae Evolution Investigation) project to measure central velocity dispersion and Lick/IDS absorption indices. By using the Evolutionary Population Synthesis (EPS) models, luminosity-weighted mean age and metallicity of host galaxies were determined from $H{\beta}$ and absorption lines. Here we will discuss the correlation between the velocity dispersion, which indicates the mass of galaxies, and mean age of stellar population in our sample of early-type host galaxies.

  • PDF

The Atom of Evolution

  • Bhak, Jonghwa;Bolser, Dan;Park, Daeui;Cho, Yoobok;Yoo, Kiesuk;Lee, Semin;Gong, SungSam;Jang, Insoo;Park, Changbum;Huston, Maryana;Choi, Hwanho
    • Genomics & Informatics
    • /
    • v.2 no.4
    • /
    • pp.167-173
    • /
    • 2004
  • The main mechanism of evolution is that biological entities change, are selected, and reproduce. We propose a different concept in terms of the main agent or atom of evolution: in the biological world, not an individual object, but its interactive network is the fundamental unit of evolution. The interaction network is composed of interaction pairs of information objects that have order information. This indicates a paradigm shift from 3D biological objects to an abstract network of information entities as the primary agent of evolution. It forces us to change our views about how organisms evolve and therefore the methods we use to analyze evolution.

Framework for Innovative Mechanical Design Using Simulated Emergent Evolution (창발적 기계설계를 위한 컴퓨터기반 프레임워크)

  • Lee, In-Ho;Cha, Ju-Heon;Kim, Jae-Jeong
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.26 no.4
    • /
    • pp.701-710
    • /
    • 2002
  • The framework, described in this paper, involves artificial evolutionary systems that re -produce aimed solutions through a simulated Darwinian evolution process. Through this process the framework designs structures of machines innovatively and emergently especially in the stages of conceptual and basic design. Since the framework simulates the evolution of nature, it inevitably involves processes that converse the natural evolution to the artificial evolution. For the conversion, based on several methods as the building block modeling, Artificial Life, evolutionary computation and the law of natural selection, we propose a series of processes that consists of modeling, evaluation, selection, evolution etc. We have demonstrated the implementation of the framework with the design of multi-step gear systems.

ON ASYMPTOTIC BEHAVIOR OF A RANDOM EVOLUTION

  • Cho, Nhan-Sook
    • Bulletin of the Korean Mathematical Society
    • /
    • v.34 no.2
    • /
    • pp.233-245
    • /
    • 1997
  • In this paper, we study the asymptotic behavior of a random evolution. Some examples of random evolution can be found in Chapter 12 of [2].

  • PDF

Spatial and Temporal Features of PM10 Evolution Cycle in the Korean Peninsula (한반도내 미세먼지 발생주기의 시공간분포 특성)

  • Jang, Jae-Hoon;Lee, Hwa-Woon;Lee, Soon-Hwan
    • Journal of Environmental Science International
    • /
    • v.21 no.2
    • /
    • pp.189-202
    • /
    • 2012
  • Power spectral analysis for $PM_{10}$ observed at 10 cities in the Korean Peninsula from 2004 to 2010 was carried out to examine the spatial and temporal features of $PM_{10}$ evolution cycle. The power spectrum analysis proposed 9 typical cycles (0.5 day, 1day, 5.4day, 8~10day, 19~21day, 26day, 56day, 180day and 365day) for $PM_{10}$ evolution and the cycles are strongly associated with dilution and transportation due to the meterological influence. The spectrum intensity of 5.4day and 26day $PM_{10}$ evolution cycles mainly depend on the advection cycles of synoptic pressures system and long-term variation of climatological forcing, respectively. The intensity of $PM_{10}$ evolution with longer temporal cycles than one day tends to be stronger in La ni$\tilde{n}$a period in comparison with that in El ni$\tilde{n}$o period. Mean of typical intensity of $PM_{10}$ evolution in La ni$\tilde{n}$a period estimated to be 30% larger than El ni$\tilde{n}$o period. Thus the global scale meteorological phenomena such as El ni$\tilde{n}$o and La ni$\tilde{n}$a also can influence the variation of wind system in the Korean Peninsula and $PM_{10}$ evolution. but global scale forcing tends to influence different manner for $PM_{10}$ evolution in accordance with its temporal cycles.

A Comparison between Korean and American College Students' Evolution Concepts based on the History of Evolutionary Ideas (진화개념의 역사에 근거한 한국과 미국 대학생의 진화개념 수준 비교)

  • Ha, Minsu
    • Journal of The Korean Association For Science Education
    • /
    • v.37 no.4
    • /
    • pp.659-668
    • /
    • 2017
  • This study was conducted to identify whether there is a significant difference in the developmental stages of the evolution concept depending on the major and the country. For this study, college students (both biology major and non-biology major) in Korea and the United States answered evolution concept assessment developed by Ha (2007). The data were analyzed based on the method of developed by Ha (2016). As a result of this study, Cronbach alpha for internal consistency reliability and MNSQ indices for item response fitness of the ordered multiple choice method providing 0 to 4 point scores to creationism, teleology, intentionality, use/disuse, and natural selection respectively, satisfied the benchmark. The level of Korean college students' evolution concepts was located in use/disuse and the level of USA college students' evolution concepts was located in teleology. No interaction effect was found between the difference of conceptual progressions of evolution concept by major and country and evolution contexts (human, animal, and plant). There was a significant relationship between developmental stages of evolution concept and their religiosity. Based on the results of this study, we discuss developmental characteristics of evolutionary concepts.

Analysis of Elementary School Children's Concepts in Evolution Based on Science History (과학사적 진화개념 발달 단계에 기초한 초등학생들의 진화 개념 분석)

  • Lee Mi-Sook;Oh Se-Pyoung;Lee Kil-Jae
    • Journal of Korean Elementary Science Education
    • /
    • v.24 no.2
    • /
    • pp.145-159
    • /
    • 2005
  • Students' alternative concepts of evolution are similar to misconcepts and disputes which scientists had in science history. The aims of this study are to analyze the elementary children's concept in evolution based on science history. Lee (2004)'s two tests were applied to 6th grade to investigate the children's evolution concepts and genetic concepts related to the historical development of the evolution concepts. The test results were analyzed in accordance with 4 stages of science history based on Lee (2004)'s method. These stages are divided to stage 1 (Before Lamarck), stage 2 (Lamarck), stage 3 (Darwin), stage 4 (After Darwin). The major results are as follows. Most of elementary school children are fixed to the stage 2. They usually do not show the consistency of evolution concepts in the three dimensional aspects such as mechanism, time, and subjects. Many children do not have concrete meaning of gene, inheritance, sexual reproduction, mutation and could not connect these concetps and process of evolution. Also, they believe the inheritance of acquired traits and spontaneous generation. Therefore it is confirmed that they still have similar misconcepts and disputes which scientists had in transition time between stage 2 and 3 and most of children already have strong Lamarckian thought acquired from daily life experience before learning about natural selection and evolution.

  • PDF

Differential Evolution Algorithm based on Random Key Representation for Traveling Salesman Problems (외판원 문제를 위한 난수 키 표현법 기반 차분 진화 알고리즘)

  • Lee, Sangwook
    • The Journal of the Korea Contents Association
    • /
    • v.20 no.11
    • /
    • pp.636-643
    • /
    • 2020
  • The differential evolution algorithm is one of the meta-heuristic techniques developed to solve the real optimization problem, which is a continuous problem space. In this study, in order to use the differential evolution algorithm to solve the traveling salesman problem, which is a discontinuous problem space, a random key representation method is applied to the differential evolution algorithm. The differential evolution algorithm searches for a real space and uses the order of the indexes of the solutions sorted in ascending order as the order of city visits to find the fitness. As a result of experimentation by applying it to the benchmark traveling salesman problems which are provided in TSPLIB, it was confirmed that the proposed differential evolution algorithm based on the random key representation method has the potential to solve the traveling salesman problems.

Globular clusters with multiple red giant branches as remaining nuclei of primeval dwarf galaxies

  • Lee, Young-Wook;Han, Sang-Il;Joo, Seok-Joo;Lim, Dongwook;Jang, Sohee;Na, Chongsam;Roh, Dong-Goo
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.38 no.2
    • /
    • pp.73.2-73.2
    • /
    • 2013
  • In the current ${\Lambda}CDM$ hierarchical merging paradigm, a galaxy like the Milky Way formed by numerous mergers of ancient subsystems. Most of the relics of these building blocks, however, are yet to be discovered or identified. Recent progress in the Milky Way globular cluster research is throwing new light on this perspective. The discoveries of multiple stellar populations having different heavy element abundances in some massive globular clusters are suggesting that they are most likely the remaining cores or relics of disrupted dwarf galaxies. In this talk, we will report our progress in the (1) narrow-band photometry, (2) low-resolution spectroscopy, and (3) population modeling for this growing group of peculiar globular clusters.

  • PDF

Development of an Effective Strategy to Teach Evolution

  • Ha, Min-Su;Cha, Hee-Young
    • Journal of The Korean Association For Science Education
    • /
    • v.31 no.3
    • /
    • pp.440-454
    • /
    • 2011
  • This study proposes a new instructional strategy and corresponding materials designed from various alternative frameworks to help students understand evolution as a biologically acceptable theory. Biology teachers have normally taught the evolutionary mechanism by means of comparing Lamarckism with natural selection. In this study, a new instructional strategy in which the Lamarckian explanation is first excluded because Lamarckism is known to be subsumed in a learner's cognitive structure as a strong preconception of evolution is suggested for teaching evolution. After mutation theory is introduced, Darwinism including natural selection is explained separately during the next class hour. Corresponding instructional materials that aid student understanding of the evolutionary mechanism were developed using recently published articles on human genetic traits as scientific evolutionary evidence instead of the traditional evolutionary subject matter, giraffe neck. Evolutionary evidence from human genetic traits allows students to exclude anthropocentric thoughts effectively and raise concern for the phenomenon of evolution positively. The administered instructional strategy and materials in this research improved student conception, concern, and belief of evolution and it is believed that they helped students understand the evolutionary mechanism effectively.