• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.405-410
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• 2007

We present a new global/local analysis with the aid of MLS(Moving Least Square)-based finite elements which can handle an arbitrary number of nodes on every element side. It give a great flexibility in constructing finite element meshes at the specified local regions without remeshing. Compared to other type global/local analysis, it does not require any superimposed mesh or need not solve the equilibrium equation twice as well as shows an excellent accuracy. To demonstrate the performance of proposed scheme, we will show several examples in relation to capturing highly local stress field.

• Journal of the Optical Society of Korea
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• v.16 no.3
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• pp.228-235
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• 2012

It is very important to analyze effectively the tolerance of an optical system with high resolution as the projection lens of photolithography or as the objective lens of a microscope. We would like to find an effective assembly structure and compensators to correct aberrations through global wavefront sensitivity analysis using Zernike polynomial expansion from the field and pupil coordinates rather than from only pupil coordinates. In this paper, we introduce global wavefront coefficients by small perturbations of the optical system, and analyze the optical performance with these coefficients. From this analysis, it is possible to see how we can enlarge the tolerance through the proper assembly structure and compensators.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1557-1566
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• 2006

We present a procedure for the application of global orthogonal polynomial into an atmospheric re-entry maneuvering problem. This trajectory optimization is imbedded in a family of canonically parameterized optimal control problem. The optimal control problem is transcribed to nonlinear programming via global orthogonal polynomial and is solved a sparse nonlinear optimization algorithm. We analyze the optimal trajectories with respect to the performance of re-entry maneuver.

• Journal of Korea Technology Innovation Society
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• v.19 no.3
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• pp.604-633
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• 2016

In this study, we attempt to identify factors that influence the performances of Korean firms regarding global R&D cooperation, and to derive policy implications for performance improvement. The hypothetic influential factors include firms' general characteristics, purposes and types of cooperation, technology, partners and their countries, and government support. We categorize the performances of global R&D cooperation into technological, economic, and strategic performance, and analyze the effects of those factors on each of the performances as well as the overall performance. We use a standard tobit model for the overall performance, while using a multivariate tobit model for the other performances to reflect the possible correlations among them. The survey data was collected from 162 Korean firms that had previously conducted or were currently conducting global R&D cooperation.

• Ocean Systems Engineering
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• v.13 no.3
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• pp.287-312
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• 2023

The global performance of a 15 MW floating offshore wind turbine, a newly designed semisubmersible floating foundation with multiple heave plates by CNOOC, is investigated with two independent turbine-floater-mooring coupled dynamic analysis programs CHARM3D-FAST and OrcaFlex. The semisubmersible platform hosts IEA 15 MW reference wind turbine modulated for VolturnUS-S and hybrid type (chain-wire-chain with clumps) 3×2 mooring lines targeting the water depth of 100 m. The numerical free-decay simulation results are compared with physical experiments with 1:64 scaled model in 3D wave basin, from which appropriate drag coefficients for heave plates were estimated. The tuned numerical simulation tools were then used for the feasibility and global performance analysis of the FOWT considering the 50-yr-storm condition and maximum operational condition. The effect of tower flexibility was investigated by comparing tower-base fore-aft bending moment and nacelle translational accelerations. It is found that the tower-base bending moment and nacelle accelerations can be appreciably increased due to the tower flexibility.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.2
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• pp.286-297
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• 2005

Recently, due to the gloalization of the industry environment and the consequent multi-national companies led by industrialized countries, fashion companies of newly industrialized countries are pursuing to globalize their businesses. This study conducted to review the global configuration of activities of the added value chain, the strategies to enhance global competitiveness, and global performance of value activities of Korean fashion companies. The data were collected from the survey by questionnaire on Korean fashion companies. The methods of analysis used in this study were regression, and descriptive statistics of the data. the results werw as follows. First, Korean fashion companies were undergoing diverse value activities through their foreign subsidiaries and overseas out-sourced companies in a wide spectrum of business activities ranging from design/planning o products to marketing/logistics. Second, the global competitive strategies that the Korean fashion companies were most focused on were the cost/productivity aspects. The efforts to differentiate the products from competitors, the efforts for innovation, an the efforts of growth were the next strategies. The strategy that was least emphasized was on seeking alliance with other business partners. Third, the result of the globalization efforts showed an overseas market growth of and average of 9%, and an average overseas market profit of 7.8%. The overall satisfaction on the result of the overseas market activities, and the rate of accomplishment of market targets were generally low.

• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.39-47
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• 2014

Solar applications analysis and building energy performance depend on the quality of the solar resource data available. Unfortunately, most of the weather stations do not measure solar radiation data in Korea, as a reason many researchers have studied different solar radiation estimation models and suggested to apply them to various locations in Korea. In addition, they also studied the impact of hourly global solar radiation on energy performance of an office building by comparing the simulated building energy consumptions using four different weather files, one using measured, and three estimated solar radiation from different models, which are Cloud-cover Radiation Model (CRM), Zhang and Huang Model (ZHM), and Meteorological Radiation Model (MRM), and concluded that there was some impact on energy performance of the building due to the using different solar radiation models. However, the result cannot be applied to all other buildings since the simulated office building for that study only used limited building characteristics such as using fixed values of solar heat gain coefficient (SHGC) and window-to-wall ratio (WWR), which are significant parameters related to solar radiation that affect to the building energy consumptions. Therefore, there is a need to identify how the building energy consumption will be changed by varying these building parameters. In this study, the impact of one measured and three estimated global solar radiation on energy performance of the office building was conducted taking account of SHGC and WWR. As a result, it was identified that the impact of four different solar radiation data on energy performance of the office building was evident regardless SHGC and WWR changes, and concluded that the most suitable solar models was changed from the CRM/ZHM to the MRM as SHGC and WWR increases.

• Steel and Composite Structures
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• v.46 no.6
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• pp.857-865
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• 2023

This study aimed to develop a seismic retrofit technique using a steel frame which can be easily transported and assembled on site. This enables the retrofit steel frame to be easily attached to an existing structure minimizing the unwanted gap between the structure and the steel frame assembly. A one-story one-bay RC frame was tested with and without seismic retrofit using the proposed steel frame to verify the seismic retrofit effect of the proposed system, and an analysis model was developed in Opensees for seismic performance evaluation of a case study soft first-story model structure retrofitted with the developed steel frame assembly. Seismic performance of the model structure was also evaluated considering soil structure interaction effect. The experimental study confirmed that the proposed seismic retrofit system can be applied effectively to improve the seismic performance of framed structures. Time history analysis results of the model structure showed that the proposed steel frame assembly was effective in increasing the seismic load resisting capacity of the soft first-story structure. However more steel frame assemblies were required to satisfy the given performance limit state of the model structure located on weak soil due to the negative soil-structure interaction effect.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.291-291
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• 2010

Emerging global economic growth and increasing demand for energy supply and demand imbalance and the excessive use of fossil fuels existing the rapidly increasing greenhouse gas emissions and resource depletion of global energy crisis is deepening. Accordingly, improvement of living conditions around and through the natural ecological preservation and the need for a comfortable life for the meeting the importance of energy management and consumption are emerging. Many in the field of architecture for energy-saving measures and conducts research and analysis from the early stages to verify the energy performance of BIM (Building Information Model) technology development and commercialization through the building's energy performance to an objective technology forecasts Analysis of the existing building energy performance in waste management also possible that "BIM-based green building process, the possibility of" suggested. In this study, BIM through the analysis of information using the structures for the management of waste, energy and physical data collected by Mapping it can effectively plan resources for recycling were analyzed.

• Journal of Information Technology Applications and Management
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• v.29 no.1
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• pp.83-95
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• 2022

Given the importance of SMEs in the Korean economy, research of the performance of SMEs is more necessary than ever. Therefore, this study aims to empirically analyze the factors influencing management performance for early-stage international startups in Korea. To do that, this study empirically analyzes the nine firm capabilities' (global mind, export infra, manpower internationality, funding, communicating, marketing, cooperating, competitiveness and reflecting) influence on the two business performances (fulfillment satisfaction and export). This study used SPSS of frequency, factor, reliability, correlation, and stepwise regression analysis with the GCL test data approved by the DSZ of Kdata. As results show, competitiveness, cooperating, and reflating capability positively influence fulfillment satisfaction. And manpower internationality and cooperating capability positively affect export. Based on this study result, implications for management and academic contribution and future study are suggested.