• Title/Summary/Keyword: Evolutionary change

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A Study on the Formation and the Change of the CDM(Clean Development Mechanism) Industry in the Republic of Korea from the Change in Industrial Networks (한국 청정개발체제 네트워크 변화에 따른 산업 형성과 변화 연구)

  • Lee, Jin-Hyung
    • Journal of the Economic Geographical Society of Korea
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    • v.20 no.4
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    • pp.486-502
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    • 2017
  • This study investigated the formation process and networks of Korean Clean Development Mechanism(CDM) industry. It aimed to reveal the factors and the drivers for the formation processes of this industry in the specific place. Based on the analysis of the Project Design Documents(PDDs) of the CDM projects and the collected project data by international institutions, surveys, and interviews were done. On the basis of these data, the analysis on the industrial change as complex emergent effects by the network evolution caused by adaptive activity of firms is conducted. In the time of the genesis, a kind of serendipity that the industrial activities of Korean firms meet to new system, CDM, In the changing process of the Korean CDM industry, the role of policies fo Korean Government was important to promote the new and renewable energy projects of the power companies. In the time of restructuring, Korean government policies formed new initial conditions for the new domestic GHGs reduction industry. In this processes, the localization of knowledge acted as a key driver for the formation of the Korean CDM industry.

Identification of Dynamic property of Squeeze Film Damper Using Magnetic Fluid (자성유체를 이용한 스퀴즈 필름 댐퍼의 동특성 동정)

  • Ahn, Young Kong;Ha, Jong-Yong;Kim, Yong-Han;Ahn, Kyoung Kwan;Yang, Bo-Suk;Morishita, Shin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.227-230
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    • 2005
  • The paper presents the identification of dynamic property of a rotor system with a squeeze film damper (SFD) using magnetic fluid. An electromagnet is installed in the inner damper of the SFD. The magnetic fluid is well known as a functional fluid. Its rheological property can be changed by controlling the applied current to the fluid and the fluid can be used as lubricant. Basically, the proposed SFD has the characteristics of a conventional SFD without an applied current, while the damping and stiffness properties change according to the variation of the applied electric current. Therefore, when the applied current is changed, the whirling vibration of the rotor system can be effectively reduced. The clustering-based hybrid evolutionary algorithm (CHEA) is used to identify linear stiffness and damping coefficients of the SFD based on measured unbalance responses.

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Reliability-based Shape Optimization Using Growth Strain Method (성장-변형률법을 이용한 신뢰성 기반 형상 최적화)

  • Oh, Young-Kyu;Park, Jae-Yong;Im, Min-Gyu;Park, Jae-Yong;Han, Seog-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.5
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    • pp.637-644
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    • 2010
  • This paper presents a reliability-based shape optimization (RBSO) using the growth-strain method. An actual design involves uncertain conditions such as material property, operational load, Poisson's ratio and dimensional variation. The purpose of the RBSO is to consider the variations of probabilistic constraint and performances caused by uncertainties. In this study, the growth-strain method was applied to shape optimization of reliability analysis. Even though many papers for reliability-based shape optimization in mathematical programming method and ESO (Evolutionary Structural Optimization) were published, the paper for the reliability-based shape optimization using the growth-strain method has not been applied yet. Growth-strain method is applied to performance measure approach (PMA), which has probabilistic constraints that are formulated in terms of the reliability index, is adopted to evaluate the probabilistic constraints in the change of average mises stress. Numerical examples are presented to compare the DO with the RBSO. The results of design example show that the RBSO model is more reliable than deterministic optimization. It was verified that the reliability-based shape optimization using growth-strain method are very effective for general structure. The purpose of this study is to improve structure's safety considering probabilistic variable.

Red supergiant stars in NGC 4449, NGC 5055, and NGC 5457

  • Chun, Sang-Hyun;Sohn, Young-Jong;Asplund, Martin;Casagrande, Luca
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.44.2-45
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    • 2016
  • We present near-infrared photometric properties of red supergiant stars (RSGs) in three galaxies NGC 4449, NGC 5055 and NGC 5457. The near-infrared imaging data of WFCAM UKIRT were used and combined with optical archive data to identify the RSGs in the galaxies. We found that the RSGs can be identified from the foreground Galactic stars in (i-K, ri) colour-colour diagram. The effective temperatures and luminosities of the identified RSGs are estimated from JHK photometry using MARCS model. In the H-R diagram, the majority of RSGs in the galaxies are distributed between $logL/L{\odot}=4.8$ and 5.7, and their effective temperature and luminosities agree with the current evolutionary tracks with masses in the range $9-30M{\odot}$. We also compared the spatial distribution of RSGs with the HII regions. A tight spatial correlation between RSGs and HII region was found in NGC 4449 and NGC 5457. We do not find a clear metallicity dependance on the RSG effective temperature in the three galaxies, but the maximum luminosity of the three galaxies is constant at $logL/L{\odot}{\sim}5.6$. Additional spectroscopy data, including photometry are essential to examine whether the physical properties of RSGs change with metallicity.

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Silhouette differences among cats do not suggest a general selection for paedomorphosis

  • Pares-Casanova, Pere M.
    • Korean Journal of Veterinary Research
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    • v.53 no.3
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    • pp.155-158
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    • 2013
  • Paedomorphosis is the retention of juvenile morphology at maturity and is important in generating evolutionary change in domestic species and species in the wild. This preliminary study compared morphological characteristics of seven domestic cat pure breeds and felid species from around the world. An original procedure based on elliptical Fourier (EF) methods was applied to head lateral views of specimens and were assessed in order to analyse head profile. For comparative purposes three domestic kittens of different ages and three species of genus Lynx were also used. EF descriptors, allowed for the quantification of the head profile. Using the Fourier transform, reconstruction of the mean head profile revealed that there was a general shape difference between wild cats, domestic cats and kittens. Results suggested that variability in head profile differentiate quite well between adult cats and kittens, but domestic and wild cats appeared grouped into a similar cluster. The similarity between breeds can thus be attributed more to the general head profile than to flatness, i.e. to the general conformation rather than facial profile. Therefore, no effect of paedomorphism on the studied breeds can be undertaken. The present approach opens interesting ethnological perspectives for the aloidic characterisation for domestic breeds.

Identification and Phylogeny of the Human Endogenous Retrovirus HERV-W LTR Family in Cancer Cells

  • Yi, Joo-Mi;Kim, Hwan-Mook;Kim, Heui-Soo
    • Animal cells and systems
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    • v.6 no.2
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    • pp.167-170
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    • 2002
  • The long terminal repeats (LTRs) of human endogenous retrovirus (HERV) have been found to be coexpressed with sequences of closely located genes. It has been suggested that the LTR elements have contributed to the structural change or genetic variation of human genome connected to various diseases and evolution. We examined the HERV-W LTR elements in various cancer cells (2F7, A43l , A549, HepG2, MIA-PaCa-2, PC-3, RT4, SiHa, U-937, and UO-31). Using genomic DNA from the cancer cells, we performed PCR amplification and identified twelve new HERV-W LTR elements. Those LTR elements showed a high degree of sequence similarity (88-99%) with HERV-W LTR (AF072500). A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-W LTR elements could be mainly divided into two groups through evolutionary divergence. Three HERV-W LTR elements (RT4-2, A43l-1, and UO3l-2) belonged to Group 1, whereas nine LTR elements (2F7-2, A549-1, A549-3, HepG2-3, MP2-2, PC3-1, SiHa-8, SiHa-10, and U937-1) belonged to Group 11. Taken together, our new sequence data of the HERV-W LTR elements may contribute to an understanding of tissue-specific cancer by genomic instability of LTR integration.

Hardware Implementation of Genetic Algorithm and Its Analysis (유전알고리즘의 하드웨어 구현 및 실험과 분석)

  • Dong, Sung-Soo;Lee, Chong-Ho
    • 전자공학회논문지 IE
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    • v.46 no.2
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    • pp.7-10
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    • 2009
  • This paper presents the implementation of libraries of hardware modules for genetic algorithm using VHDL. Evolvable hardware refers to hardware that can change its architecture and behavior dynamically and autonomously by interacting with its environment. So, it is especially suited to applications where no hardware specifications can be given in advance. Evolvable hardware is based on the idea of combining reconfigurable hardware device with evolutionary computation, such as genetic algorithm. Because of parallel, no function call overhead and pipelining, a hardware genetic algorithm give speedup over a software genetic algorithm. This paper suggests the hardware genetic algorithm for evolvable embedded system chip. That includes simulation results and analysis for several fitness functions. It can be seen that our design works well for the three examples.

Reflection on Nursing Methodology (간호학 방법론에 대한 성찰)

  • 이은주;박영숙
    • Journal of Korean Academy of Nursing
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    • v.23 no.3
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    • pp.453-466
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    • 1993
  • Quantitative methodology has been the predominent methodology utilized in research in nursing. However since the 1970s qualitative methodology has also emerged as a useful methodology and has been utilized by many researchers. But in the use of this methodology, the philosophical, epistemelogical, and theoretical backgrounds have been neglected by many researchers. This paper reports a review of the literature on methodologies, quanitative and qualitative, used in nursing, and makes suggestions for future research directions. It explains why qualitative methodology has emerged as as effective methodology in nursing and discusses how the qualitative methodology differs from the quanitative one. A comparison of the two is made based on perspectives of humane being and human behavior as well as the development of nursing science. This paper also presents several views on change in nursing science, since viewpoint not only influences the determination of the current stage of nursing science but also the shaping of the future directions of nursing science and research. Scientific revolution by Kuhn, the evolutionary perspective by Toulmin, the transition of research tradition by Laudan. and convolutionary processes are presented. However, this paper indicates that it is too early to adopt these points of view, because the history of nursing science is too short. It suggests that nursing needs pluralism in philosophy, paradigms and theory, as well as in methodology. Although we experience paradoxes in adopting different perspectives in nursing, it is wise for us to continue to include a variety of viewpoints including those to which we are not accustomed, such as qualitative methodology, since we are not yet able to decide what is best for the development of nursing science.

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SUSSING MERGER TREES : THE IMPACT OF HALO MERGER TREES ON GALAXY PROPERTIES IN A SEMI-ANALYTIC MODEL

  • Lee, Jaehyun;Yi, Sukyoung K.
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.33.2-33.2
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    • 2014
  • Halo merger trees are essential backbones of semi-analytic models for galaxy formation and evolution. Recent studies have pointed out that extracting merger trees from numerical simulations of structure formation is non-trivial; different algorithm can give differing merger histories. Thus they should be carefully understood before being used as input for models of galaxy formation. As one of the projects proposed in the SUSSING MERGER TREES Workshop, we investigate the impact of different halo merger trees on a semi-analytic model. We find that the z = 0 global galaxy properties in our model show differences between trees when using a common parameter set, but that these differences are not very significant. However, the star formation history of the Universe and the properties of satellite galaxies can show marked differences between trees with different methods for constructing a tree. Calibrating the SAM for each tree individually to the empirical data can reduce the discrepancies between the z = 0 global galaxy properties, however this is at cost of increasing the differences in evolutionary histories of galaxies. Furthermore, the underlying physics implied can vary, resulting in key quantities such as the supernova feedback efficiency differing by factors of 2. Such a change alters the regimes where star formation is primarily suppressed by supernovae. Therefore, halo merger trees extracted from a common halo catalogue using different, but reliable, algorithms can result in a difference in the semi-analytic model, however, given the enormous uncertainties in galaxy formation physics, these are not necessarily significant.

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An Evolution of Software Reliability in a Large Scale Switching System: using the software

  • Lee, Jae-Ki;Nam, Sang-Sik;Kim, Chang-Bong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.4A
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    • pp.399-414
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    • 2004
  • In this paper, an evolution of software reliability engineering in a large-scale software project is summarized. The considered software consists of many components, called functional blocks in software of switching system. These functional blocks are served as the unit of coding and test, and the software is continuously updated by adding new functional blocks. We are mainly concerned with the analysis of the effects of these software components in software reliability and reliability evolution. We analyze the static characteristics of the software related to software reliability using collected failure data during system test. We also discussed a pattern which represents a local and global growth of the software reliability as version evolves. To find the pattern of system software, we apply the S-shaped model to a collection of failure data sets of each evolutionary version and the Goel-Okumoto(G-O) model to a grouped overall failure data set. We expect this pattern analysis will be helpful to plan and manage necessary human/resources fur a new similar software project which is developed under the same developing circumstances by estimating the total software failures with respect to its size and time.