• Interaction and multiscale mechanics
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• v.7 no.1
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• pp.543-561
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• 2014

We present a full energy and force formulation of the quasicontinuum method with non-local and local transition elements. Non-local transition elements are developed to transmit inhomogeneity from the atomistic to the continuum regions. Local transition elements are developed to resolve the mathematical mismatch between non-local atoms and the local continuum. The rationale behind these transition elements is provided by analyzing the energy and force transitions between atoms and continuum under the Cauchy-Born rule. We show that breakdown of the Cauchy-Born rule occurs for slaved atoms of local elements within the cutoff of non-local atoms. The inadequacy of the Cauchy-Born rule at the transition region naturally leads to the need of atomistic treatment of transition slaved and transition representative atoms. Such an atomistic treatment together with a full or cutoff sampling allows non-local transition elements containing these transition entities to transmit inhomogeneity. Different force formulations for transition representative atoms and pure local representative atoms allow the local transition elements to resolve non-local and local mismatches. The method presented herein is validated by force calculations in an unstressed perfect crystal as well as an unrelaxed grain boundary model. A nanoindentation simulation in 3D is conducted to demonstrate the accuracy and efficiency of the proposed method.

• Asia-Pacific Journal of Business
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• v.10 no.1
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• pp.87-103
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• 2019

In December 2017, the Moon Jae-in administration announced a major policy shift away from nuclear and coal, committing itself to the vision of creating a society where renewable sources account for 20% of its electricity generation by 2030. This energy transition involves not just a technical transition from conventional energy sources to renewable energy but also active participation of multiple stakeholders in the energy governance. While energy policy making has long been dominated by the central government in Korea with the aim of managing the supply for rapid industrialization and economic growth, the Moon administration aims to diffuse the central government's authority across various actors in society. Among those actors, this study focuses on the roles that local governments play in energy transition. Despite deepening local autonomy since 1995, Korean local governments have remained policy targets or recipients in the energy policy domain. This article discusses how such a traditional role has evolved under the new administration's energy transition policy and examines what challenges and limitations local governments face in creating a more decentralized energy governance system.

• Journal of Contemporary Eastern Asia
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• v.18 no.1
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• pp.153-174
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• 2019

South Korea's energy policy has been historically established through an energy production structure that relies on thermal and nuclear power generation in relation to a centralized 'Hard Energy System'. However, climate change issues are forcing the transition to renewable energy, and it is crucial for local governments to enable this. This study analyses Seoul city's local energy governance, which is known as One Less Nuclear Power Plant Initiative, by applying the collaborative governance framework inspired by Ansell and Gash (2008) and the Reflexivity framework of Confucianism. It is considered that the local energy governance model of Seoul city can be used as a model by other local governments, and it will eventually lead to a decentralized energy system in this era of energy transition.

• Asian Journal of Innovation and Policy
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• v.11 no.3
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• pp.293-319
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• 2022

By analyzing the adaptive capacity, market formation and policy direction as functional areas of Technological Innovation System (TIS), the article evaluates the progress of renewable energy transition in the Maldives, with the inclusion of ideas from Mauritius and Cabo Verde. On the policy direction in the Maldives, technology roadmaps produced with assistance from International Renewable Energy Agency (IRENA) and Asian Development Bank (ADB) are evaluated. Although there are inducing factors such as the Solar Risk Management Initiative, the progress of energy transition is hindered by the lack of technical capacity and local value chain. The findings indicate the importance of facilitating and establishing industry and knowledge networks, incorporating innovation policies, greater involvement of the local private sector along with international investors, and taking water-energy nexus to achieve complementary targets. The study adds value to knowledge by offering a simplified TIS framework, with a current insight of the energy transition in Small Island Developing States with a focus on the Maldives.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.10
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• pp.795-803
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• 2015

The boundary layer developing over the suction surface of a first-stage turbine blade for power generation has been investigated in this study. For three locations selected in the region where local thermal load changes dramatically, mean velocity, turbulence intensity, and one-dimensional energy spectrum are measured with a hot-wire anemometer. The results show that the suction-surface boundary layer suffers a transition from a laminar flow to a turbulent one. This transition is confirmed to be a "separated-flow transition", which usually occurs in the shear layer over a separation bubble. The local minimum thermal load on the suction surface is found at the initiation point of the transition, whereas the local maximum thermal load is observed at the location of very high near-wall turbulence intensity after the transition process. Frequency characteristics of turbulent kinetic energy before and after the transition are understood clearly from the energy spectrum data.

• Advances in aircraft and spacecraft science
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• v.4 no.5
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• pp.555-571
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• 2017

The description of transitional flows by means of RANS equations is sometimes based on non-local approaches which require the computation of some boundary layer properties. In this work a non-local Laminar Kinetic Energy model is used to predict transitional and separated flows. Usually the non-local term of this model is evaluated along the grid lines of a structured mesh. An alternative approach, which does not rely on grid lines, is introduced in the present work. This new approach allows the use of fully unstructured meshes. Furthermore, it reduces the grid-dependence of the predicted results. The approach is employed to study the transitional flows in the T106c turbine cascade and around a NACA0021 airfoil by means of a discontinuous Galerkin method. The local nature of the discontinuous Galerkin reconstruction is exploited to implement an adaptive algorithm which automatically refines the mesh in the most significant regions.

• Proceedings of the KIEE Conference
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• summer
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• pp.120-122
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• 2004

This paper analyse impacts of Community Energy System (CES) on the grid during transition periods for integrating of the CES and the grid. In the near future, CES might be one of major energy supply structures. The basic concept of CES is that it supplies electrical and thermal energy to the local customer loads through the islanded power network separated from the grid. Therefore, the interconnection with the grid occurs only when the energy supply from the CES generators does not meet the demand of the local load. For avoiding impacting the grid during the transition operation modes of CES, it is necessary to thoroughly analyse the influences on the grid during those periods. In order to show them, in this paper, we model the CES with 2.34 WVA DG and simulate the impacts on the grid due to interconnection of CES The simulation results show that, in order to reduce bad influences of CES on the grid, CES need the efficient load management and generation control schemes during the transition periods.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.980-986
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• 2012

In this paper we develop a minimalist model of single molecule spectroscopy in a dynamic environment. Our model is based upon a lattice system consisting of a probe molecule embedded in an Ising-model like environment. We assume that the probe molecule interacts with the Ising spins via a dipole-dipole potential, and calculate free energy curves and lineshapes of the system. To investigate fluctuation behavior of the system we exploit the metadynamics sampling method. In particular, using the method, we calculate the free energy curve of magnetization of the lattice and that of the transition energy of the probe molecule. Furthermore, we compare efficiencies of three different sampling methods used; unbiased, umbrella, and metadynamics sampling methods. Finally, we explore the lineshape behavior of the probe molecule as the system undergoes a phase transition from a sub-critical and to a super-critical temperature. We show that the transition energy of a probe molecule is broadly distributed due to the heterogeneous, local environments.

• Journal of Welding and Joining
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• v.10 no.1
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• pp.43-51
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• 1992

The plastic zone formed around a notch tip is important in analyzing the fracture toughness of structures and particularly weld cracks existed in the weld HAZ (heat affected zone) which produces local plastic deformation at the crack tip. Therefore, in order to analyze the fracture toughness in weld HAZ, it is necessary to investigate the new fracture toughness parameter $K_{c}$ $^{*}$ and critical plastic strain energy $W_{p}$ $^{c}$ according to the shape and size of the plastic zone. 1) If the temperature corresponding to $K_{c}$ $^{*}$=130kg-m $m^{-3}$ 2/ is determined, transition temperature $T_{tr}$ the magnitude of plastic zone size, and heat input change depending on the fracture toughness. The blunted amounts of the parent and weld HAZ show mild linear variation until .delta.=0.4mm and then increase very steeply there after. 2) The relation between the plastic strain energy( $W^{p}$ ) and transition temperature( $T_{*}$tr) in parent metal is more sensitive than that of weld HAZ. However, the plastic strain energy depends on the transition temperature, and thus the yield stress, .sigma.$_{ys}$ becomes an important parameter for plastic strain energy. 3) The critical plastic strain energy( $W_{p}$ $^{c}$ ) absorbed by the plastic zone at the notch tip indicated in case of parent metal: 60J/mm, in case of heat input(20KJ/cm): 75J/mm, in case of heat input(30KJ/cm); 50J/mmJ/mm.

• Journal of Science and Technology Studies
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• v.19 no.3
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• pp.291-333
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• 2019

The regional innovation policies so far have been separated from the social problems facing the local communities. The regional innovation policies, regarding the region as the location of the business, have focused on the invigoration of business innovation activities. However, as the recent emergence of the new paradigm of innovation policy aiming the sustainability, 'transformative innovation policy,' has led to a search for regional innovation policies that begin with solving the local social problems. This research paper deals with regional innovation theory that starts from searching for solutions and system transformation for social problems such as climate crisis and energy problems. The objective is to present a new framework called 'transformative regional innovation policy' and to improve its content through case studies by combining the results of the transformative innovation policy and the regional innovation policy studies. In particular, the contribution of this paper is to analyze and discuss the concept of the transition platform, which aims to solve the local social problems, through the case studies of Gussing, Austria and Esbjerg, Denmark. Lastly, it discusses the derived implications of the cases applied in Korean society.