• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.2
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• pp.1-7
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• 1993

In this paper, we show that Petri nets can be applied to design and reliability analysis of concurrent, parallel and embedded mode system such as a lift system that is familiar to our daily life. Modeling the behavioral characteristics of the lift system we extend the standard Petri nets by nadditionally constant timed transition, fault transition, stochastic imed ttransition and conditional transition concepts. Likewise, we present esults of rdesign and analysis of the system. This method can be applied to esign and danalysis of any other concurrent systems.

• Journal of Magnetics
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• v.16 no.4
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• pp.408-412
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• 2011

We investigated theoretically the magnetic field dependence of the quantum optical transition of qusi 2-Dimensional Landau splitting system, in GaN and ZnO. We apply the Quantum Transport theory (QTR) to the system in the confinement of electrons by square well confinement potential. We use the projected Liouville equation method with Equilibrium Average Projection Scheme (EAPS). Through the analysis of this work, we found the increasing properties of the optical Quantum Transition Line Shapes(QTLSs) which show the absorption power and the Quantum Transition Line Widths(QTLWs) with the magnetic-field in GaN and ZnO. We also found that QTLW, ${\gamma}(B)_{total}$ of GaN < ${\gamma}(B)_{total}$ of ZnO in the magnetic field region B < 25 Tesla.

• Proceedings of the KIEE Conference
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• summer
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• pp.342-344
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• 2004

In conventional small signal stability analysis, system is assumed to be invariant and the state space equations are used to calculate the eigenvalues of state matrix. However, when a system contains switching elements such as FACTS devices, it becomes non-continuous system. In this case, a mathematically rigorous approach to system small signal stability analysis is by means of eigenvalue analysis of the system periodic transition matrix based on discrete system analysis method. In this research, RCF(Resistive Companion Form) method is used to analyse small signal stability of a non-continuous system including switching elements'. Applying the RCF method to the differential and integral equations of power system, generator, controllers and FACTS devices including switching elements should be modeled in the form of state transition matrix. From this state transition matrix eigenvalues which are mapped to unit circle can be calculated.

• Journal of Plant Biology
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• v.34 no.4
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• pp.274-281
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• 1991

The relationship between elongation of hypocotyl and its vascular transition was studied with seedling of Glycine max. the hypocotyl elongation proceeded acropetally from the base of hypocotyl toward the cotyledonary node. The vascular transition did not occur in the basal region of the hypocotyl, which did not nearly elongate, with exarch radial vascular bundles. However, the vascular transition was almost completed at the middle part of the hypocoty, more or less elongated, with endarch collateral vascular bundles. Such bundles also appeared in the uppermost region of the hypocotyl, in which the elongation was the most striking. These results suggested that the vascular transition was related to the hypocotyl elongation and that the transition of primary vascular system in Glycine max seedling was established by rather rapid process. Our observations of the serial sections from root to hypocotyl revealed that the vascular system through the root-hypocotyl-cotyledon was a unit, to which one of the epicotyl that did not participate in transition was superimposed.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2981-2987
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• 2011

A comparative study of the photodynamic and antioxidant activities of methyl pheophorbide-a (MPa, 1) and its transition metal(II) complexes (2-5) is described. Four transition metal complexes (palladium(II): 2, zinc(II): 3, cobalt(II): 4 and copper(II): 5) of MPa were prepared by reaction between the corresponding transition metal and 1, respectively, and were characterized by $^1H$-NMR and UV-vis spectroscopic and mass spectrometric analyses. In vitro results show a photodynamic therapy (PDT) efficacy with A549 cells might be attributed to a heavy atom effect of the transition metal complexes of MPa. Among them, 4 and 5 showed higher photodynamic activity than that of 1 at the concentration of 5 ${\mu}M$ at 24 h incubation after photoirradiation. The images of morphological change for 2-5 show evidence for the PDT effect with A549 cells. And the all transition metal complexes of MPa showed higher antioxidant activity than that of MPa, in which 4 showed the highest antioxidant activity.

• Journal of Science and Technology Studies
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• v.12 no.2
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• pp.81-116
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• 2012

Transition toward sustainablity being in progress in a variety of areas including climate, energy, household, transportation. This study analyzed system transition and backcasting of its management with case of sustainable transportation, foods, household system transition in the Netherlands. Backcasting has become a popular approach for sustainability taking a more reflexive perspective and looking back to the participatory experiments. In the Netherlands, participatory backcasting utilized as s innovative approach for long-term strategy for sustainability, based on stakeholder involvement, construction of normative sustainable futures, stakeholder leaning. In this study, we can be understood that transition management requires the participation and contribution of business, government, research and the public & public interest groups and backcating is tool leading to a sustainable future vision, stakeholder involvement. To create a new path toward sustainablity, it requires integrated consideration of related policy perspectives and participatory backcasting aiming at system innovations for influencing transitions.

• Journal of Technology Innovation
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• v.22 no.4
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• pp.89-116
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• 2014

Socially-oriented R&D programs aimed at solving societal problem rather than scientific and industrial fruits have started recently. Societal problem is recognized as dilemma since this problem related to various stakeholders. And this is not solved with single program and needed long-term process. So the perspective of socio-technical system transition including technological and institutional change is needed. This paper suggests policy implication of Socially-oriented R&D programs from socio-technical system transition perspective. 'Transitioning of Socially-oriented R&D program' is the key concept of restructuring the program for the system transition. The establishment of multi-layer transition governance and the transition vision-making and transition experiment planning are the key process of transitioning the R&D program. This paper suggests the ways and issues of implementing this process in Socially-oriented R&D program.

• Journal of Science and Technology Studies
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• v.16 no.1
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• pp.63-89
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• 2016

The purpose of this article is to re-interpretate 'Post Catch-up Studies' on the Korean innovation system with the framework of 'Transition Studies'. The viewpoints of the vision, research area and system innovation process of Post Catch-up studies are reviewed and reconfigurated. The Transition Studies concepts of Sustainability, Coevolution of industry and society, and transition management are introduced into the Post-catch up Studies and discussed. It is suggested that Post catch-up studies should support sustainability system transition and make use of transition management tools for the sustainable post catch-up innovation and policy.

• Journal of Science and Technology Studies
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• v.11 no.1
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• pp.61-88
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• 2011

This paper presents theoretical discussions on socio-techical system transition, by shedding light on the STS context. With a rising attention paid by STI policy researchers, the socio-technical system perspective seems particularly promising in applying to the pursuit for the sustainable development. The normative strand in STI policy research has been strongly influenced by the STS tradition that emphasizes active and participatory roles not only of academian but also of science and technology. Throughout reviewing the development of the socio-technical system perspective, its theoretical components of environment, drivers and dynamics are discussed, often being linked to older perspectives. STI policy involves in socio-technical transition in a manner of transition management and governance, which is the final part of this paper.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.941-950
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• 2001

A study of counter-current two-phase flow in narrow rectangular channels has been performed. Two-phase flow regimes were experimentally investigated in a 760mm long and 100mm wide test section with 2.0 and 5.0mm gap widths. The resulting flow regime maps were compared with the existing transition criteria. The experimental data and the transition criteria of the models showed relatively good agreement. However, the discrepancies between the experimental data and the model predictions of the flow regime transition become pronounced as the gap width increased. As the gap width increased the transition gas superficial velocities increased. The critical void fraction for the bubbly-to-slug transition was observed to be about 0.25. The two-phase distribution parameter for the slug flow was larger for the narrower channel. The uncertainties in the distribution parameter could lead to a disagreement in slug-to-churn transition between the experimental findings and the transition criteria. For the transition from churn to annular flow the effect of liquid superficial velocity was found to be insignificant.