• International conference on construction engineering and project management
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• 2015.10a
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• pp.540-543
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• 2015

Solar energy is one of the most important alternative energy sources which have been shown to meet high levels of heating and cooling demands in buildings. However, the efficiencies to satisfy these demands using solar energy significantly vary based on the characteristics of individual building. Therefore, this paper is focused on developing the methodology which can help to design optimal solar system for heating and cooling to be in cooperated within the existing buildings according to their load profiles. This research has established the Solar Heating and Cooling (SHC) system which is composed of collectors, absorption chiller, boiler and heat storage tank. Each component of SHC system is analyzed and made by means of Modelica Language and Pistache tool is verified the results. Sequential approximate optimization (SAO) and meta-models determined to 15 design parameters to optimize SHC system. Finally, total coefficient of performance (COP) of the entire SHC system is improved approximately 7.3% points compared to total COP of the base model of the SHC system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.816-821
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• 2019

This study shows that it is reasonable for an R&D Information and Evaluation Center to have a building with the fifth floor above the ground and the second floor below the ground. A survey was conducted with 22,655 researchers who are registered in the NRF database. The researchers provided 883 responses. The results indicate that about 56% of the respondents positively support the construction of the NFR R&D Information and Evaluation Center. The survey results show that many respondents recognize that both evaluation and information integration functions among the NRF's roles are very important compared to other roles. The findings of the economic validity analysis support this statement. Based on the current demand for the construction of the R&D Information and Evaluation Center, this study investigates whether it is reasonable to build a new center in the available space while examining an environment focused on a physical work space and looking at significant results obtained through a cost-benefit analysis.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.571-576
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• 2002

Electromagnetic analysis has been made for the design of 3 MJ Compulsator (Compensated Pulsed Alternator, CPA) that will be used as the power supply system of the electrothermal-chemical launcher system. using finite element method with ANSYS/Emag. From the analysis results, it was possible to decide the excitation MMF and the rotor/stator size to obtain the desired output current. And using electromagnetic forces from the analysis results. the stresses on the components of 3 MJ CPA could be analyzed. The detailed design based on the analysis results has been made and the fabrication of 3 MJ CPA is in progress. Before assembling components into 3 MJ CPA. an experiment is being made to check the correspondence between analysis results and measurements.

• Journal of Technology Innovation
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• v.2 no.1
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• pp.170-190
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• 1994

The importantce of a development of competitiveness in domestic construction industry is growing as some of domestic construction markets is scheduled to open to foreign competing firms with higher level of construction technology and management. A national level of competitiveness in domestic construction industry and firms are partially, but significantly, affected by a technology level and a characteristics of production pattern. The purpose of the study is mainly to analyze and identify a technology level, production pattern and a development stage of R&D activities of domestic construction industry and firms. Based on these findings the study draws on a concluding remarks and derives technology policy implications. Results of analysis in the study impliy that (1) competitiveness of domestic construction firms(industry) in terms of technology level is relatively weak as compare to that of advanced foreign competing firms, (2) degrees of substitution of capital for labor are seemed to be relatively high, (3) R&D (investment) activities of domestic construction firms are generally spread out in forms of import, adjustment and betterment, and (4) only a small number of big domestic construction firms are seemed to afford to R&D investment for research facilities and equipments, but not enough for higher level of R&D man-power. The study suggests that technology policy for construction industry should be based on a fundamental policy directions. For example the increase in size and heightened quality level of R&D man-power should be placed in a top priority in policy agenda. Sound and specific policy items should be developed for planning and design, and maintenace and inspection technology in order to lead domestic industry to compete with foreign firms with full strength.

• Journal of Welding and Joining
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• v.31 no.1
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• pp.65-70
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• 2013

Finite element analysis and welding experiments were performed to evaluate deformation aspect for Flux Cored Arc Welding(FCAW) and Electro Gas Welding(EGW). Numerical researches of FCAW and EGW were performed considering the difference of number of welding pass and welding direction to arc flow. To perform the numerical study of FCAW and EGW, number of welding pass and welding direction to arc flow were considered in the finite element model. FCAW process requires multi pass and its welding direction is vertical to welding torch. On the other hand, EGW process requires single pass and its welding direction is parallel to welding torch. The difference of welding direction and heat input was considered in the finite element analysis. In FCAW process, Goldak's double ellipsoidal heat input model was adopted. In the EGW process, Hemi-spherical power density distribution was adopted. In the results of experiment and finite element analysis, angular deformation of FCAW process is larger than that of EGW process.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.58-67
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• 2014

The proportion of investment in national R&D projects in construction and transportation has been increasing continuously; in terms of the size of R&D projects, there are many medium- to large-sized projects of over KRW 10 billion. However, in spite of such continuous increase in R&D investments, there are many technologies developed but not commercialized, i.e., the quiescence of technology. Accordingly, it is necessary to link the R&D results to commercialization by expanding the scope of R&D projects. In this context, this study presented objective reference prices to be used in contracting/transacting technology and implementing commercialization strategy by conducting technology valuations against on-going research projects with earnings approach, and by estimating value of patented technology. Sum of free cash flow (business value) that can be generated during the life of the technology was estimated as KRW 512 million by reflecting a discount rate of 16.34% to convert it into the present value. In addition, the technology value was computed as KRW 227million by applying a technology factor of 44.39% to the above value. Based on the technology value estimated in this way, it is necessary to establish industrialization and commercialization strategy of the technology.

• Journal of Drive and Control
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• v.19 no.4
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• pp.77-84
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• 2022

The aims of this study was to estimate transfer force delivered to cone crusher housing and contribution of force transmission. The rock crushing condition caused vibrations in the cone crusher housing, which were experimentally measured, and frequency response functions (FRF) were also found through modal impact tests. Vibration data and frequency response functions were applied to the transfer path analysis (TPA) model. Next, transfer forces delivered to the cone crusher housing were quantified via the TPA method. Contribution of force transfer was also analyzed based on force estimation results. Finally, this study describes basic concepts and components of the TPA method and reviews its applicability to rotating machinery that experiences impact vibrations and forces.

• Journal of the Korea Convergence Society
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• v.13 no.1
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• pp.31-42
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• 2022

The purpose of this study is to analyze the reference data of the National R&D Report database built by the Korea Institute of Science and Technology Information(KISTI) to derive problems and to find complementary points for the construction technical items in the system. To this end, we investigated the descriptions of references in the National R&D Report constructed in the KISTI DB and analyzed the construction process, guidelines, types, items, etc. Based on this, the appropriateness and accuracy of the classification results of the reference types constructed with the DB were checked. As a result, the problems of the items built into the system and corrections to the construction guidelines were derived. Through this, database construction can proceed efficiently and data quality is expected to improve. In addition, a follow-up study was proposed on the convergence service plan that can be provided in the future through standardization of technical regulations.

• Journal of Information Technology Applications and Management
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• v.21 no.3
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• pp.1-17
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• 2014

In this study, various characteristics of R&D related economic variables were studied to analyze complexity of science and technology activities in Korea, as reliance of R&D activities of the private sector is growing by the day. In comparison to other countries, this means that it is likely to be fluctuated by economic conditions. This complexity characteristic signifies that the result of science and technology activities can be greatly different from the anticipated results - depending on the influences from economic conditions and the results of science and technology activities which may be unpredictable. After reviewing the results of 17 variables related to science and technology characteristics of complex systems intended for time-series data - in the total R&D expenditure, and private R&D expenditure, numbers of SCI papers, the existence of chaotic characteristics were. using Lyapunov Exponent, Hurst Exponent, BDS test. This result reveals science and technology activity of the three most important components in Korea which are; heavy dependence on initial condition, the long term memory of time series, and non-linear structure. As stable R&D investment and result are needed in order to maintain steady development of Korea economy, the R&D structure should be less influenced by business cycles and more effective technology development policy for improving human resource development must be set in motion. And to minimize the risk of new technology, the construction of sophisticated technology forecasting system should take into account, for development of R&D system.

• Tunnel and Underground Space
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• v.22 no.4
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• pp.257-265
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• 2012

In this study, a series of CFD (Computational Fluid Dynamics) simulations carried out to evaluate the optimum design model of the internal flow path of drill bit. The Star-CCM+ code was adopted to simulate the multi-phase discharge flow of rock particles and flushing air during a drilling process. The input parameters for the flow simulation of rock particles and air were obtained from the in-situ drilling test results. After the three design factors were determined, the experimental design method (Taguchi method) was utilized to evaluate the optimum value of each factor.