• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.108-111
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• 2003

The Objective of this work was to design Surface Antenna Structure (SAS) and investigate fatigue behavior of SAS that was asymmetric sandwich structure. This term, SAS, indicates that structural surface becomes antenna. Constituent materials were selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, SSFIP elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.5 GHz and final demonstration article was $16\;{\times}\;8$ array antenna. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue life curve of SAS was obtained. The fatigue load was determined experimentally at a 0.75(1.875kN) load level. SAS concept is the first serious attempt at integration for both antenna and composite engineers and promises innovative future communication technology.

• Laser Solutions
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• v.2 no.2
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• pp.18-26
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• 1999

An innovative real-time weld monitoring technique using chromatic filtering of the thermal radiation from a weld pool is developed. The thermal radiation from the weld pool is focused on an aperture and the transmitted thermal radiation is monitored at two wavelengths with high-speed single-element detectors. Due to the chromatic aberration introduced in the focusing optics, the transmittance curve of thermal radiation varies by the wavelength. Owing to this difference in the transmittance, the local variation of thermal radiation from the weld pool can be monitored by processing the two spectroscopic signals from two detectors. In this paper, the algorithms to monitor the laser power on the weld specimen and the focus shift we investigated and the performances of laser power and focus monitoring are shown for a pulsed Nd:YAG laser welding. The monitoring of the weld pool size variation is also discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.114-117
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• 2005

Air cleaners in all of the automotive engines have been used for decades. In the early 1920's the oil bath type was the popular shape of air cleaners. The air cleaners of the oil wetted bath type were introduced in 1940's. The shape of the dry pleated paper type media was introduced in the 1950's. This trend still continues with new and innovative media being introduced. Engine air cleaners should have effectively removed and reduced harmful contaminants being ingested into engines. This studies show that both, the ingested contaminant size and concentration need to be controlled. This paper com pare and analyze the characteristics over the economics, engine performances and reduction of noises of power-plus air filters with wet paper which were sticked to heavy duty diesel engine.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.12
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• pp.18-29
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• 2014

This paper proposes the integration of photovoltaic (PV) and energy storage systems for sustained power generation. In this proposed system, whenever the PV system cannot completely meet load demands, the super capacitor provides power to meet the remaining load. A power management strategy is designed for the proposed system to manage power flows between PV array systems and supercapacitors (SC). The main task of this study was to design PV systems with storage strategies including MPPT with direct control and an advanced DC-link controller and to analyze dynamic model proposed for a PV-SC hybrid power generation system. In this paper, the simulation models for the hybrid energy system are developed using Matlab/Simulink, SimPowerSystems and Matlab/Stateflow tool. This is the key innovative contribution of the research paper. The system performances are verified by carrying out simulation studies using practical load demand profile and real weather data.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.332-335
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• 2007

Electron injection improvement in OLED organic layers can be obtained by their doping or using alkaline-earth or alkali metals as electron injection layers (EIL). Common handling problems can be solved by an innovative metal dispensing technology to ensure controlled and reliable metal layers for OLED. Thickness and deposition rate of EIL during the process have been explored to optimize device performances.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.235-242
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• 2008

An innovative Panel ExTension SATellite(PETSAT) and propulsion system for PETSAT, are presented in this paper. First, we outline what PETSAT is. Next, based on PETSAT ethos, design policy of the propulsion system is provided. According to the policy, we designed propulsion system and concretely estimated and assembled mono-propellant and bi-propellant systems, and it indicated that mono-propellant propulsion with 50-60 seconds of specific impulse and 1 N of thrust is probable. In the case of bi-propellant, 120-150 seconds of specific impulse is valid even based on the design policy. We conducted captive tests of mono-propellant and bi-propellant propulsions with a breadboard model of propulsion system for PETSAT, and obtained good operations and performances. Based on the test results, we designed and manufactured flight model propulsion system for PETSAT. We are planning to demonstrate it in SOHLA-2L project progressed by the Space Oriented Higashiosaka Leading Association(SOHLA). SOHLA-2L will be the first on-orbit demonstrator of PETSAT in 2008.

• Ocean Systems Engineering
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• v.12 no.4
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• pp.413-437
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• 2022

An innovative concept for wet-transportation and stepwise installation of mono-bucket foundation for 15 MW offshore wind turbine is proposed. Case studies for two different mono-bucket and wrap-buoy dimensions are conducted and their hydrostatic and hydrodynamic performances are compared for both wet-towing and lowering operations. The intact stability and transient responses are analyzed in detail for various stages of lowering operation. Wave-induced motion statistics during wet tow in sea state 4 (highest operational window) are checked. The proposed concept is found to be feasible and can be an alternative cost-effective solution without using heavy-lift crane vessel in practice.

• Journal of Internet Computing and Services
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• v.23 no.2
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• pp.97-105
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• 2022

Web services show a rapid evolution and integration to meet the increased users' requirements. Thus, web services undergo updates and may have performance degradation due to undetected faults in the updated versions. Due to these faults, many performances and regression anomalies in web services may occur in real-world scenarios. This paper proposed applying the deep learning model and innovative explainable framework to detect performance and regression anomalies in web services. This study indicated that upper bound and lower bound values in performance metrics provide us with the simple means to detect the performance and regression anomalies in updated versions of web services. The explainable deep learning method enabled us to decide the precise use of deep learning to detect performance and anomalies in web services. The evaluation results of the proposed approach showed us the detection of unusual behavior of web service. The proposed approach is efficient and straightforward in detecting regression anomalies in web services compared with the existing approaches.

• Journal of Service Research and Studies
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• v.7 no.3
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• pp.71-91
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• 2017

The purpose of this study is to suggest directions for enhancing competitiveness of corporate management by examining how individual creativity and organizational members' value innovation culture perception affect innovation behavior and knowledge sharing, and how innovation behavior and knowledge sharing affect organizational innovation performance and management outcomes In order to achieve these research objectives, the measurement variables of each variable were extracted through previous research and 423 valid samples were analyzed using SPSS 22.0 statistical package program and LISREL 9.1 to verify a hypothesis. As a result of this study, it was found that the creative thinking skills of the individual creativity, the meaningful tasks of the value innovation culture recognition, and the risk - taking culture have a significant influence on the innovation behavior. Only the meaningful tasks of organizational members' value innovation culture perception affect knowledge sharing. Innovation behavior has a significant effect on knowledge sharing and innovation performance, but not on business outcome. In addition, knowledge sharing has no significant effect on innovation performance but has a significant effect on business performance. Finally, we confirmed that innovation performance has a significant effect on management outcome.

• Journal of Energy Engineering
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• v.29 no.1
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• pp.85-99
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• 2020

This article analyzes the influence of sectoral system of innovation(i.e. technological regime, market demand, networks, and institution) on innovative performances(i.e. product-, process-, organizational-, marketing-, and environmental- innovation) in Korean environmental industry, conducting a multiple regression analysis based on survey data from 201 Korean environmental companies. As the results, product innovation is positively influenced by internal technology accumulation and market demand response, while not affected by external knowledge utilization, market competition, networks among market and non-market agents, government support and regulation. Process innovation is positively influenced by internal technology accumulation, networks among non-market agents and regulation, but not by external knowledge utilization, market demand response, market competition, networks among market agents, and government support. While organizational innovation is positively influenced by internal technology accumulation, external knowledge utilization and regulation, it is not affected by market demand response, market competition, networks among market and non-market agents, and government support. While marketing innovation is positively influenced by internal technology accumulation, networks among non-market agents, and government support, it is not affected by external knowledge utilization, market demand response, market competition, networks among market agents, and regulation. Environmental innovation is positively influenced by external knowledge utilization and regulation, but negatively influenced by market competition. It is not affected by internal technology accumulation, market demand response, networks among market and non-market agents, and government support. Such results suggests the following policy implications. First, it is necessary to expand the sphere of relating markets through the application of convergence technology, new regulations, and overseas markets. Second, reinforcing ecosystems among environmental market agents through demand-linked joint R&D should be revitalized. Third, it is needed to strengthen more supporting policies rather than regulation. This article has the limitation of using the survey data. And further researches on the environmental sectoral system of innovation structure itself will be tried.