• Title/Summary/Keyword: Evolutionary Process

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NEAR- TO MID-INFRARED SLIT SPECTROSCOPIC OBSERVATIONS OF THE UNIDENTIFIED INFRARED BANDS IN THE LARGE MAGELLANIC CLOUD

  • Mori, T.I.;Sakon, I.;Onaka, T.;Umehata, H.;Kaneda, H.;Ohsawa, R.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.209-212
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    • 2012
  • We present the results of the near-infrared (NIR) to mid-infrared (MIR) slit spectroscopic observations of the diffuse emission toward nine positions in the nearby irregular galaxy Large Magellanic Cloud (LMC) with the Infrared Camera (IRC) on board AKARI. The unique characteristic of AKARI/IRC provides a great opportunity to analyze variations in the unidentified infrared (UIR) bands based on continuous spectra from 2.5 to $13.4{\mu}m$ of the same slit area. The observed variation of $I_{3.3}/I_{11.3}$ suggests destruction of small-sized UIR band carriers, polycyclic aromatic hydrocarbons (PAHs) in harsh environments. This result demonstrates that the UIR $3.3{\mu}m$ band provides us powerful information on the excitation conditions and/or the size distribution of PAHs, which is of importance for understanding the evolutionary process of hydrocarbon grains in the Universe. It also suggests a new diagnostic diagram of two band ratios, such as $I_{3.3}/I_{11.3}$ versus $I_{7.7}/I_{11.3}$, for the interstellar radiation conditions. We discuss on the applicability of the diagnostic diagram to other astronomical objects, comparing the LMC results with those observed in other galaxies such as NGC 6946, NGC 1313, and M51.

Cryptic variation, molecular data, and the challenge of conserving plant diversity in oceanic archipelagos: the critical role of plant systematics

  • Crawford, Daniel J.;Stuessy, Tod F.
    • Korean Journal of Plant Taxonomy
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    • v.46 no.2
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    • pp.129-148
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    • 2016
  • Plant species on oceanic islands comprise nearly 25% of described vascular plants on only 5% of the Earth's land surface yet are among the most rare and endangered plants. Conservation of plant biodiversity on islands poses particular challenges because many species occur in a few and/or small populations, and their habitats on islands are often disturbed by the activity of humans or by natural processes such as landslides and volcanoes. In addition to described species, evidence is accumulating that there are likely significant numbers of "cryptic" species in oceanic archipelagos. Plant systematists, in collaboration with others in the botanical disciplines, are critical to the discovery of the subtle diversity in oceanic island floras. Molecular data will play an ever increasing role in revealing variation in island lineages. However, the input from plant systematists and other organismal biologists will continue to be important in calling attention to morphological and ecological variation in natural populations and in the discovery of "new" populations that can inform sampling for molecular analyses. Conversely, organismal biologists can provide basic information necessary for understanding the biology of the molecular variants, including diagnostic morphological characters, reproductive biology, habitat, etc. Such basic information is important when describing new species and arguing for their protection. Hybridization presents one of the most challenging problems in the conservation of insular plant diversity, with the process having the potential to decrease diversity in several ways including the merging of species into hybrid swarms or conversely hybridization may generate stable novel recombinants that merit recognition as new species. These processes are often operative in recent radiations in which intrinsic barriers to gene flow have not evolved. The knowledge and continued monitoring of plant populations in the dynamic landscapes on oceanic islands are critical to the preservation of their plant diversity.

Population Structure and Genetic Diversity of Garlic in Korea by ISSR Marker (산마늘의 지역적 변이와 종다양성 연구)

  • Huh Man-Kyu;Sung Jung-Sook;Choi Joo-Soo;Jeong Young-Kee;Rhu Eun-Ju;Chung Kyung-Tae
    • Journal of Life Science
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    • v.16 no.2 s.75
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    • pp.253-258
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    • 2006
  • Garlic is a perennial herb primarily distributed throughout the world. These plants are regarded as a medically and agricultural important crop in the world. The genetic relationships between cultivated and wild species were investigated at the population levels by constructing tree based on ISSR (inter-simple sequence repeats) markers. In addition, ISSR analysis was also conducted to estimate genetic diversity and population structure of these species. Three wild garlic populations in Korea were found to have more alleles per locus (mean 1.672 vs. 1.510) higher percent polymorphic locus (67.2 vs. 51.0), and higher diversity (0.250 vs. 0.198) than three cultivated populations. The cultivated and wild species in Korea are well separated from each other at phylogenetic trees. Although there is not direct evidence that A. victorialis is an ancestor of Korean A. sativum, there is a possibility that cultivated A. sativum in Korea has evolved from wild A. victorialis in Korea. Populations of A. victorialis may be useful in germ-plasm classification and evolutionary process.

Corporate Restructuring in the Face of the Korean Financial Crisis and Its Implications for Learning and Adaptation: An Evolutionary and Competence-based Perspective (경제위기 국면에서의 대기업 재구조화와 이의 학습 및 적응에 대한 함의: 진화론적 및 역량기반 관점)

  • Lee, Jong-Ho
    • Journal of the Korean Geographical Society
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    • v.37 no.5
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    • pp.480-497
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    • 2002
  • This paper is concerned with unveiling the responsiveness of large Korean firms to external shock by examining corporate restructuring in terms of production and organization. Throughout empirical research, I speculate on how corporate restructuring influences and relates to corporate teaming and adaptation. The main findings of this research are as follows. First, the restructuring of business structure was expected to strengthen core competencies and improve profitability and the restructuring of organizational structure to make it possible for responding more quickly to radical changes in its business environment. Second, both downsizing and employment adjustment have assisted the firm with unlearning obsolete practices, preconditions necessary for effectively accomplishing new teaming practices. Third, both the spatial reorganization of production activities and process innovation require and involve learning processes. In conclusion, it claims that corporate restructuring can be seen as a powerful loaming tool, particularly in the context of radical economic change.

A Study on Genetic Algorithm and Stereo Matching for Object Depth Recognition (물체의 위치 인식을 위한 유전 알고리즘과 스테레오 정합에 관한 연구)

  • Hong, Seok-Keun;Cho, Seok-Je
    • Journal of Navigation and Port Research
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    • v.32 no.5
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    • pp.355-361
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    • 2008
  • Stereo matching is one of the most active research areas in computer vision. In this paper, we propose a stereo matching scheme using genetic algorithm for object depth recognition. The proposed approach considers the matching environment as an optimization problem and finds the optimal solution by using an evolutionary strategy. Accordingly, genetic operators are adapted for the circumstances of stereo matching. An individual is a disparity set. Horizontal pixel line of image is considered as a chromosome. A cost function is composed of certain constraints which are commonly used in stereo matching. Since the cost function consists of intensity, similarity and disparity smoothness, the matching process is considered at the same time in each generation. The LoG(Laplacian of Gaussian) edge is extracted and used in the determination of the chromosome. We validate our approach with experimental results on stereo images.

Designing the Moving Pattern of Cleaning Robot based on Grammatical Evolution with Conditional Probability Table (문법적 진화기법과 조건부 확률을 이용한 청소 로봇의 이동 패턴 계획)

  • Gwon, Soon-Joe;Kim, Hyun-Tae;Ahn, Chang Wook
    • KIISE Transactions on Computing Practices
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    • v.22 no.4
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    • pp.184-188
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    • 2016
  • The cleaning robot is popularly used as a home appliance. The state-of-the-art cleaning robot can clean more efficiently by using information gathered from its sensor, which is difficult for low-price cleaning robots due to limitation in this aspect. In this paper, we suggested a method for the moving pattern of cleaning robot based on grammatical evolution. Optimized program is generated by using moving pattern grammar, which is defined by Backus-Naur form. In addition, conditional probability is used between each of the grammar elements during the program creation process. The proposed method is evaluated by robot simulation in order to verify its performance and further compare it with existing algorithms. The experiment results showed that the proposed method is better than the compared algorithms.

Future Agenda of the Four Major Rivers Restoration Project: Toward An Integrated Watershed Management System (4대강사업이 남긴 과제: 통합적 유역관리시스템의 구축)

  • Ahn, Hyung Ki
    • The Journal of the Korea Contents Association
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    • v.17 no.3
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    • pp.454-461
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    • 2017
  • The Four Major Rivers Restoration Project was the multi-purpose green growth project on the four major rivers in South Korea. However, the Four Major Rivers Project has attracted significant criticism from various social groups and wider international groups, e.g. Friends of the Earth. This study reviews the four river restoration project from the standpoint of an evolutionary process of water paradigms. It reveals that the project has achieved its intended purpose yet, suggesting to apply some valuable lessons in the consideration of the integrated watershed management system. Finally, it urges to introduce tentatively named "Basic law on Water Management" preceded by enacting ordinances at local level, because it'll help us find out ways ahead for the Integrated Water law.

Differential Embryo Development among Tibetan Chicken, DRW and Shouguang Chicken Exposed to Chronic Hypoxia

  • Li, Mei;Zhao, Chun-Jiang;Wu, Chang-Xin
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.3
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    • pp.336-342
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    • 2009
  • Avian embryos at high altitude are independent of maternal protection against hypoxia, which is contrary to mammals. It is well known that chronic hypoxic exposure at key points can significantly impact on avian development. Tibetan Chicken, a Chinese indigenous breed, living in Tibetan areas with an altitude of 2.2 to 4.1 thousand meters, has an adaptive mechanism to hypoxia. In the present study, fertilized eggs of Tibetan Chicken were incubated under 13% and 21% oxygen concentration. Two lowland chicken breeds, Shouguang Chicken, an indigenous chicken breed in Shandong Province of China, and Dwarf Recessive White Chicken, an imported breed in Beijing, were used as control groups. The embryo mass and some organs such as brain, heart, liver, stomach and eye weight in the three species were measured at Hamburger-Hamilton stage 39, 41, 43 and 45 under hypoxic and normal conditions. The results showed that in hypoxia Tibetan Chicken significantly differed from the two lowland chicken breeds in embryo mass at Hamburger-Hamilton stage 41, 43 and 45 (p<0.01). In particular, Dwarf Recessive White Chicken and Shouguang Chicken showed retarded growth in hypoxic incubation (p<0.01), whereas Tibetan Chicken showed no significant difference between hypoxic and normal conditions (p>0.05). In addition, heart and the other organs showed different susceptibility to hypoxia at the studied stages. In conclusion, chronic hypoxia induced a change in the embryo development of the three different species and Tibetan Chicken showed adaptation to hypoxia. Of note, the embryo developmental physiology of Tibetan Chicken in response to hypoxia will shed light on the process of physiological acclimation or evolutionary adaptation as well as the study of clinical disease.

The Palaeoenvironmental Changes and Macromammal Evolution during the Pleistocene in East Asia (동아시아의 제4기 자연환경의 변화와 젖먹이근동물의 제4기적 진화)

  • Sun Joo, Park
    • The Korean Journal of Quaternary Research
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    • v.2 no.1
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    • pp.51-85
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    • 1988
  • The understanding of the faunal sequence and palaeoenvironment of East Asia since the Late Tertiary depends mainly on the knowledge of Chinese fauna and its environmental changes. The recent Chinese researches including geology, geomorphology, climats fluctuation and loess distribution of this area have provided that the rapid uplifting of Himalayas and Qinghai/Xizang Plateau since the Lower Pleistocene was a main selective factor for the process of environmental changes in this vast territory. Although different concepts of the Plio-Pleistocene boundary have been provided, its boundary can not exceed over 2 mya. Instead of the traditional zoogeographical dicthomy in China, faunal compositions of Pleistocene are divided into three faunal zones. The knowledge of macrofaunal evolution in China are useful to understand the palaeoecology of East Asia. Palaeoenvironment of Korea during the Pleistocene Period can be reconstructed by using the analogy of the current Chinese studies.

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Evolution of Product Architecture and Competitive Strategy: A Study of Commercial Vehicles Industry in Korea and China (제품 아키텍처의 진화와 경쟁전략: 한.중 상용차 산업을 중심으로)

  • Lee, Seung-Gyu;Park, Tae-Hun;Kim, Gyeong-Tae
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2008.10a
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    • pp.24-36
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    • 2008
  • Architecture-based competition has become a very important issue in many industries. As companies seek lower cost, fast development, and more customizability at the same time, modular architecture of products and processes seem to be an inevitable choice. Existing literature, however, has only focused on the basic contents of architecture-based competition. Different competitive environments and technological competencies of incumbent companies influence the evolutionary dynamics of dominant architecture of industries. In this paper we suggest a new theoretical framework to deal with the complex co-adaptation process of architecture-based competition. We first explore the emerging modular architecture in Chinese commercial vehicle industry, and then compare it with the architecture strategies of Korean companies. Based on the explorative case study, we propose new hypotheses relating the market demand, technological competencies of major players and dominant architecture in an indus-try.

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