• Korean Journal of Materials Research
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• v.31 no.6
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• pp.345-352
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• 2021

In this study, Ni nanoparticle supported by graphene oxide (GO) (Ni-GO) is successfully synthesized through hydrothermal synthesis and calcination, and Cr(VI) is extracted from aqueous solution. The morphology and structure of Ni-GO composites are characterized by scanning electron microscopy (SEM), trans mission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). High-resolution transmission electron microscopy (HRTEM) and XRD confirms the high dispersion of Ni nanoparticle after support by GO. Loading Ni on GO can obviously enhance the stability of Ni-GO composites. It can be calculated from TGA that the mass percentage of Ni is about 60.67 %. The effects of initial pH and reaction time on Cr(VI) removal ability of Ni-GO are investigated. The results indicate that the removal efficiency of Cr(VI) is greater than that of bared GO. Ni-GO shows fast removal capacity for Cr(VI) (<25 min) with high removal efficiency. Dynamic experiments show that the removal process conforms to the quasi-second order model of adsorption, which indicates that the rate control step of the removal process is chemical adsorption. The removal capacity increases with the increase of temperature, indicating that the reaction of Cr(VI) on Ni-GO composites is endothermic and spontaneous. Combined with tests and characterization, the mechanism of Cr(VI) removal by rapidly adsorption on the surface of Ni-GO and reduction by Ni nanoparticle is investigated. The above results show that Ni-GO can be used as a potential remediation agent for Cr(VI)-contaminated groundwater.

• The Journal of Economics, Marketing and Management
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• v.10 no.4
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• pp.25-34
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• 2022

Purpose: Technology and innovation drive new mobile application for ojek online. Using the theory of technology acceptance model and perceived risk theory, the researcher wants to find how these factors affect user's intention to use GO-FOOD that leads to technology adoption. Research design, data and methodology: The researcher uses GO-FOOD users that located in East Java, Indonesia for the object of study. Results: The findings of the research discovered that perceive usefulness and perceive ease of use do not significantly affect user's behavioral intention while perceive risk is significantly affecting the user's behavioral intention. Conclusions: The findings suggested that GO-FOOD or similar application should focus more on reducing or eliminating user's perception of risk towards the mobile application

• Proceedings of the Korea Water Resources Association Conference
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• 1991.07a
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• pp.76-87
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• 1991

• The Journal of the Convergence on Culture Technology
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• v.2 no.4
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• pp.49-54
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• 2016

Development of AR/VR has expanded computer games from indoor static contents to outdoor dynamic contents. The syndrome of 'Pokemon Go' which is a representative AR game was born, and Nintendo's stock price shot up a massive 120%. Although some people gained profits, new damages are emerging including illegal intrusion or road accidents because it is a type of game to visit real locations. There are reported about 114 thousand road accidents related to the game. This study aims to examine the trends of AR game in 2016 and analyze damages and positive cases to suggest a method for preventing accidents due to the AR game, and a business model.

• Journal of Platform Technology
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• v.11 no.5
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• pp.110-125
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• 2023

In this paper, we utilize time-series aircraft location data measured based on 2019 domestic airports to analyze Go-Around and UOC_D situations during the approach phase of domestic airports. Various clustering-based machine learning techniques are applied to determine the most appropriate analysis method for domestic aviation data through experimentation. The ADS-B sensor is solely employed to measure aircraft positions. We designed a model using clustering algorithms such as K-Means, GMM, and DBSCAN to classify abnormal situations. Among them, the RF model showed the best performance overseas, but through experiments, it was confirmed that the GMM showed the highest classification performance for domestic aviation data by reflecting the aspects specialized in domestic terrain.

• Advances in aircraft and spacecraft science
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• v.9 no.1
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• pp.69-93
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• 2022

Reduced graphene oxide (rGO) is one of the derivatives of graphene, which has drawn some experimental research interests in recent years however, numerical research studying the mechanical behaviors of composites made of rGO has not been taken into consideration yet. The objective of this research is to investigate the buckling, and free vibration of functionally graded reduced graphene oxide reinforced nanocomposite (FG rGORC) plates employing isogeometric analysis (IGA). The effective Young's modulus of rGORC is determined based onthe Halpin-Tsai model. Four different FG distribution types of rGO are considered varying across plate thickness. Besides, the refined plate theory is used based on Reddy's third-order function. To capture the size effect, modified couple stress theory (MCST) is employed. A comprehensive study is provided examining the effect of various parameters including rGO weight fraction, FG distribution types, boundary conditions, material length scale parameter, etc. Our obtained results show that the addition of only 1% of uniformly distributed rGO into epoxy plates leads to the fundamental frequency and critical buckling load 18% and 39% higher than those of pure epoxy plates, respectively.

• Knowledge Management Research
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• v.5 no.1
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• pp.1-17
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• 2004

Based on the diffusion of innovation paradigm, this study conceptualizes the constituent components (3P) and the growth stages (6C) for knowledge management. It is critical for knowledge management efforts to identify 'where we are' and decide 'where to go' and then to manage 'how to go'. As a framework for the success of knowledge management, the 3P6C model is intended to systematically guide these efforts toward knowledge asset management and implementation, for knowledge productivity. This model is illustratively applied to such success stories as in Skandia, Buchman Lab and Hall Mark Cards. Such applications of this model show that they have been through such prior activities required in the earlier stages, and thattechnological platform is just one of the 3 key components working as an enabler, implying together the existence of growth path in KM success. Provided in the appendix are a set of exemplary scenarios in knowledge management practice for growth stage assessment.

• The Korea Journal of Herbology
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• v.31 no.2
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• pp.39-45
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• 2016

Objectives : Abnormal regulation of glucose and impaired lipid metabolism that result from a defective or deficient insulin are the key etiological factor in type 2 diabetes mellitus. The our study investigated the effects of Gamioknyeo-jeon (GO) on blood glucose and lipid metabolism improved by it in db/db mice (a murine model of type 2 diabetes mellitus).Methods : The animals were divided into 3 groups: Normal groups were not-treated C57BL/6 mice; Control groups were treated orally with DW in db/db mice; GO groups were treated orally with GO (200 ㎎/㎏/day) in db/db mice. After mice were treated with GO for 5 weeks, we measured AST, ALT, creatinine, BUN, body weight, food intake, blood glucose, insulin and lipid levels (total cholesterol, HDL cholesterol, and LDL cholesterol and atherogenic index(AI) and cardiac risk factor(CRF).Results : Serum AST, ALT, creatinine, BUN levels were not changed by GO do not show any toxic effects. GO groups were decreased in body weight, food intake and blood glucose level among compared to Control groups. Also, GO groups were found to have atherogenic Index and cardiac risk factor as well as lipid metabolism improvement (total cholesterol and LDL cholesterol decrease). Finally, GO groups were increased the insulin compared to Normal and control groups.Conclusions : We suggest that GO may have the control effects of diabetes mellitus by improving blood glucose control and lipid metabolism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.351-354
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• 2016

The competition of Go between AlphaGo and Lee Sedol attracted global interest leading AlphaGo to victory. The core function of AlphaGo is deep-learning system, studying by computer itself. Afterwards, the utilization of deep-learning system using artificial intelligence is said to be verified. Recently, the government passed the loT Act and developing its business model to promote loT. This study is on analyzing IoT business environment using deep-learning AI and constructing specialized business models.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.468-476
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• 2001

The ROK TRANSCOM is trying to establish a concrete wartime sealift operation plan. But there are many problems to be solved for setting up the plan. The most serious problem is to procure war materiel to be shipped in U.S.A and next one is to determine the number of sealift assets and to allocate them. The process of sealift operation can be described as follows. Before the order of vessel mobilization, all vessels appointed for activation would be scattered in worldwide in the state of Beaded or unloaded. After the order of vessel mobilization, vessels would go to SPGE(seaport of embarkation) to load war materiel. Some loaded ships should offload the commercial cargo to the near port as soon as they are activated, before they would go to SPOE. All vessels would load procured materiel in SPOE and then go to SPOD(seaport of debarkation). They would offload war materiel in SPOD and then go back to SPOE to load war materiel again. We will simulate this process using ARENA(1), evaluate the sealift capability of ROK and find omit problems of the sealift plan. This model ultimately evaluates the sealift capability and provides planners with critical information far establishing and correcting the plan. This study can also provide military planners with a flexible and accessible decision support tool to provide advance planning under a variety of conditions on the sealift capability. The military planner is expected to make use of this model as a standard for establishing effective and concrete sealift operation in the near future. We can conclude how procurement capability significantly affects the result of sealift operation through this model. We could decide the appropriate levee of sealift asset such as the number of vessels and the number of available berth. So we could allocate effectively the resources for completing the sealift operation within the TGT(Target) time.