• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.1
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• pp.20-24
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• 2019

Ferroelectric material properties are strongly governed by domain structures and their evolution processes, but the evolution processes of complex domain patterns during a macroscopic electrical poling process are still elusive. In the present work, domain-evolution processes in a PZT ceramic near the morphotropic phase-boundary composition were studied during a step-wise electrical poling using piezoresponse force microscopy (PFM). Electron backscatter diffraction was used with the PFM data to identify the grain boundaries in the region of interest. In response to an externally the applied electric field, growth and retreat of non-$180^{\circ}$ domain boundaries wasere observed. The results indicate that ferroelectric polarization-switching nucleates and evolves in concordance with the pattern of the pre-existing domains.

• Korean Journal of Materials Research
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• v.27 no.9
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• pp.484-488
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• 2017

In the present study, domain evolution processes of a near-morphotropic PZT ceramic during poling was studied using vertical piezoresponse force microscopy (PFM). To perform macroscopic poling in bulk polycrystalline PZT, poling was carried out in a stepwise fashion, and PFM scan was performed after unloading the electric field. To identify the crystallographic orientation and planes for the observed non-$180^{\circ}$ domain walls in the PFM images, compatibility theory and electron backscatter diffraction (EBSD) were used in conjunction with PFM. Accurate registration between PFM and the EBSD image quality map was carried out by mapping several grains on the sample surface. A herringbone-like domain pattern consisting of two sets of lamellae was observed; this structure evolved into a single set of lamellae during the stepwise poling process. The mechanism underlying the observed domain evolution process was interpreted as showing that the growth of lamellae is determined by the potential energy associated with polarization and an externally applied electric field.

• International Journal of CAD/CAM
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• v.11 no.1
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• pp.1-10
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• 2011

Product lifecycle management (PLM) is a new business strategy for enterprise's product R&D. A PLM system holds and maintaining the integrity of the product data produced throughout its entire lifecycle. There is, therefore, a need to build a safe and effective product data model to support PLM system. The paper proposes a domain-based product data model for PLM. The domain modeling method is introduced, including the domain concept and its defining standard along the product evolution process. The product data model in every domain is explained, and the mapping rules among these models are discussed. Mapped successively among these models, product data can be successfully realized the dynamic evolution and the historical traceability in PLM system.

• Proceedings of the Technology Innovation Conference
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• 1998.06a
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• pp.57-90
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• 1998

This study attempts to explore the evolution paths of Korean SMEs'strategies and their technological teaming processes. Several different evolution paths are identified based on a dynamic strategic group analysis of 115 SMEs'strategy in the Korean electronic component industry for the period of 1990-1995. Further, inadept case analyses on technological learning processes in 5 firms are undertaken. Major findings of this study can be summarized as follows : 1) There are three dominant evolution paths in SMEs'strategy. First path indicates the evolution from a subcontractor or petty imitator group(a strategic group with the narrow product/market domain and the low level of accumulated resource/capabilities) into an innovator group(a strategic group with the narrow domain but high level of technological capability) by accumulating technological capabilities. Second, some firms move from a subcontractor group into a generalizer group(a strategic group with broad product/market domain but relatively low level of technological capability) by simply adding product lines. Third path involves firms which evolve from a subcontractor group into a production focus group(a strategic group with high level of production capability) by investing in production capabilities. 2) An in-depth case analysis shows those who succeeded in technological learning are managed by CEOs, who have technological expertise and strategic vision, and have made an effort to establish management practices to support innovation, such employee educational program, performance-based reward system, etc. The successful firms also aggressively pursue diverse external linkages with outside technology sources to learn product and process technologies. Fiendly, this study discusses several implications of the findings for the theoretical development and strategic management of small firms in Korea.

• Journal of Science Education
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• v.40 no.1
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• pp.1-16
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• 2016

The purpose of this study is to explore the variables of knowledge, acceptance of theory of evolution and epistemology that could be keys for teaching and learning the theory of evolution within school contexts, and to suggest instructional tips for teaching evolution in relation to the grade levels of education. This cross-sectional study examined the grade level differences (8th, 11th, and preservice teachers) of four variables: evolutionary knowledge; acceptance of theory of evolution; and both domain-specific epistemology (nature of science in relation to evolution) and context-specific epistemology (scientific epistemological views) and their relationships. This study, then, built conceptual models of each grade level students' acceptance of theory of evolution among the factors of evolutionary knowledge and epistemology (both domain-specific and context-specific). The results showed that the scores of evolutionary knowledge, evolution in relation to NOS, and scientific epistemology increased as the grade levels of education go up(p<.05) except the scores of acceptance of theory of evolution(p>.05). In addition, the 8th graders' and the 11th graders' acceptance of evolutionary theory was most explained by 'evolution in relation to NOS', while the preservice teachers' acceptance of evolutionary theory was most explained by evolutionary knowledge. Interestingly, 'scientific epistemological views' were only included for the 8th graders, while evolutionary knowledge and 'evolution in relation to NOS' (context-specific epistemology) were included in explaining all the level of students' acceptance of evolutionary theory. This study implicated that when teaching and learning of the theory of evolution in school contexts, knowledge, acceptance of evolutionary theory and epistemology could be considered appropriately for the different grade levels of students.

• International Journal of Advanced Culture Technology
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• v.4 no.1
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• pp.31-36
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• 2016

Morphology evolution of the active layer in bulk hetero-junction organic photovoltaic is modeled and visualized. The width of the phase domain can be predicted using the relationship of characteristics length and evolution time of the process. The 3D numerical simulation of the PCBM/P3HT blend morphology evolution with respect to time is presented. It is observed that the domain width of composition phase can be predicted by using the relationship between value of characteristic length R(t) and evolution time t.

• Genomics & Informatics
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• v.7 no.2
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• pp.131-135
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• 2009

Domains are the building blocks of proteins. Exon shuffling is an important mechanism accounting for combination of a limited repertoire of protein domains in the evolution of multicellular species. A relative excess of domains encoded by symmetric exons in metazoan phyla has been presented as evidence of exon shuffling, and symmetric domains can be divided into old and new domains by determining the ages of the domains. In this report, we compare the spread, versatility, and subcellular localization of old and new domains by analyzing eight metazoan genomes and their respective annotated proteomes. We found that new domains have been expanding as multicellular organisms evolved, and this expansion was principally because of increases in class 1-1 domains amongst several classes of domain families. We also found that younger domains have been expanding in membranes and secreted proteins along with multi-cellular organism evolution. In contrast, old domains are located mainly in nuclear and cytoplasmic proteins. We conclude that the increasing mobility and versatility of new domains, in contrast to old domains, plays a significant role in metazoan evolution, facilitating the creation of secreted and transmembrane multidomain proteins unique to metazoa.

• Journal of Life Science
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• v.14 no.4
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• pp.716-725
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• 2004

Sox protein family, a transcription factor, has been found in whole animal kingdom, and contains a sequence-specific DNA binding domain called high mobility group domain (HMG). The Sox protein family based on the amino acid sequence of HMG domain was classified into 10 groups. Each group of Sox family shows significant conservation from nematode to human. The HMG domain affect to various developmental cell differentiation through binding to enhancer and regulating other transcription factors. Recently, many molecular biologists focus their research on the illustration of Sox-related disease, evolution and phylogeny. Especially, stem cell research with Sox gene family is indispensable field for understanding of their biological functions. The understanding of Sox genes may contribute to understand their role in human genetic disease and whole animal evolution.

• Bulletin of the Korean Chemical Society
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• v.7 no.3
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• pp.204-210
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• 1986

It is shown that the linear stability coincides with the thermodynamic stability in the case of stress tensor evolution for simple dense fluids even if the constitutive (evolution) equation for the stress tensor is nolinear. The domain of coincidence can be defined in the space of parameters appearing in the constitutive equation and we find the domain is confined in an elliptical cone in a three-dimensional parameter space. The corresponding state theory in rheology of simple dense fluids is also further examined. The validity of the idea is strengthened by the examination.

• Microbiology and Biotechnology Letters
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• v.36 no.2
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• pp.149-157
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• 2008

Many proteins consist of distinctive domains that can act independently or cooperatively to achieve a unique function. As these domains evolve from a naturally existing repertoire of functional domains, this implies that domain organization is an intrinsic element involved in building the complex structure and function of proteins. Thus, identifying functional domains would appear to be critical to the elucidation of questions related to protein evolution, folding, and the engineering of hybrid proteins for tai- lored applications. However, the simple application of "Lego-like assembly" to the engineering of hybrid proteins is an oversimplification, as many hybrid constructs lack structural stability, usually due to unfavorable domain contacts. Thus, directed evolution, along with computational studies, may help to engineer hybrid proteins with improved physico-chemical properties. Accordingly, this paper introduces several approaches to functional hybrid protein engineering that potentially can be used to create modulators of gene transcription and cell signaling, and novel biosensors to analyze biological functions in vivo.