• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.1
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• pp.88-93
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• 2020

Recently, SDN technology is applied to real communication business, users are getting bigger, and as the amount of data flowing in the network increases, interest in network data flow management is increasing. During this process, it must be ensured that the confidentiality, integrity, availability, and traceability of the data on the network being transmitted. In addition, it is necessary to develop an environment for observing the flow of data in real time on a network required in various fields and visually confirming the control. In this paper, first, Mininet is applied to construct a network topology and various environment attributes. Second, we added OpenDayLight in Mininet environment to develop a simulation environment to visually check and control network traffic flow in network topology.

• Journal of the Ergonomics Society of Korea
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• v.34 no.6
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• pp.563-581
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• 2015

Objective: This study was conducted to investigate the potential of sematic network analysis for design research. Background: As HCD (Human-Centered Design) was emphasized, lots of design research methodologies were developed and used in order to find user needs. However, it is still difficult to discover users' latent needs. This study suggests the semantic network analysis as a complementary means for design research, and proved its potential through the practical application, which compares multi-screen purchase and usage behaviors between America and China. Method: We conducted an in-depth interview with 32 consumers from USA and China, and analyzed interview texts through semantic network analysis. Cross cultural differences in purchase and usage behaviors were investigated, based on measuring centrality and community modularity of devices, functions, key buying factors and brands. Results: Americans use more services and functions in the multi-screen environment, compared to Chinese. As a device substitutes other devices, traditional boundaries of the devices are disappearing in the USA. Americans consider function to recall Apple, but Chinese consider function, design and brand to recall Apple, Sony and Samsung as an important brand at the time of their purchase. Conclusion: This study shows the potential of semantic network analysis for design research through the practical application. Semantic network analysis presents how the concepts regarding a theme are structured in the cognitive map of users with visual images and quantitative data. Therefore, it can complement the qualitative analysis of the existing design research. Application: As the design environment becomes more and more complicated like multi-screen environment, semantic network analysis, which is able to provide design insights in the intuitive and holistic perspective, will be acknowledged as an effective tool for further design research.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.666-674
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• 2013

This paper studied about the design and implementation of tactical communication network simulator in order to obtain tactical communication network parameter, such as link capacity and routing plan, and a number of exceptional cases that may occur during actual deployment by conducting simulation of a large-scale tactical communication networks. This tactical communication network simulator provides equipment models and link models of commercial OPNET simulator for tactical communication network. In addition, 6 types of simulation scenario writings convenience functions and traffic generation models that may occur in situations of tactical communication network environment were implemented in order to enhance user friendliness. By taking advantages of SITL(System-In-The-Loop) function of OPNET, the tactical communication network simulator allows users to perform interoperability test between M&S models and actual equipment in operating simulation of tactical communication network, which is run on software. In order to confirm the functions and performance of the simulator, small-scale of tactical communication network was configured to make sure interoperability between SITL-based equipment and a large-scale tactical communication network was simulated and checked how to cope with traffic generated for each network node. As the results, we were able to confirm that the simulator is operated properly.

• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.152-158
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• 1997

An analyzing method for pressure fluctuations in oil hydraulic pipe network was developed in this study. The object pipe network has multi-branch configuration, and the pipelines of it are composed of steel tubes, flexible hoses. Also, accumulators, orifices and lumped oil volume components are attached on it. Transfer matrix method, in other words impedance method, was used for the analysis. The reliability and usefulness of the analyzing method were confirmed by investigation computed results and experimental results got in this study.

• Nuclear Engineering and Technology
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• v.31 no.2
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• pp.192-201
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• 1999

This paper proposes an improved signal processing strategy for accurate feedwater flowrate estimation in nuclear power plants. It is generally known that ∼2% thermal power errors occur due to fouling Phenomena in feedwater flowmeters. In the strategy Proposed, the noises included in feedwater flowrate signal are classified into rapidly varying noises and gradually varying noises according to the characteristics in a frequency domain. The estimation precision is enhanced by introducing a low pass filter with the wavelet analysis against rapidly varying noises, and an autoassociative neural network which takes charge of the correction of only gradually varying noises. The modified multivariate stratification sampling using the concept of time stratification and MAXIMIN criteria is developed to overcome the shortcoming of a general random sampling. In addition the multi-stage robust training method is developed to increase the quality and reliability of training signals. Some validations using the simulated data from a micro-simulator were carried out. In the validation tests, the proposed methodology removed both rapidly varying noises and gradually varying noises respectively in each de-noising step, and 5.54% root mean square errors of initial noisy signals were decreased to 0.674% after de-noising. These results indicate that it is possible to estimate the reactor thermal power more elaborately by adopting this strategy.

• Journal of Communications and Networks
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• v.15 no.3
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• pp.292-300
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• 2013

Nowadays, energy saving has become a hot topic and information and communication technology has become a major power consumer. In long term evolution advanced (LTE-A) networks, heterogeneous deployments of low-power nodes and conventional macrocells provide some new features, such as coverage extension, throughput enhancement, and load balancing. However, a large-scale deployment of low-power nodes brings substantial energy consumption and interference problems. In this paper, we propose a novel switching strategy (NS), which adaptively switches on or off some low-power nodes based on the instantaneous load of the system. It is compatible with the microcells' load balancing feature and can be easily implemented on the basis of existing LTE-A specifications. Moreover, we develop an analytical model for analyzing the performance of system energy consumption, block rate, throughput, and energy efficiency. The performance of NS is evaluated by comparison with existing strategies. Theoretical analysis and simulation results show that NS not only has a low block rate, but also achieves a high energy efficiency.

• International Journal of Advanced Culture Technology
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• v.11 no.4
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• pp.223-232
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• 2023

The purpose of this study is to determine the impact of social network sports community consciousness on loyalty and sports attitude. In order to achieve this research purpose, the population of the study was selected as adult men and women over the age of 20 who are active in the social network sports community in 2022. The sampling method used cluster random sampling to select a total of 300 people, 150 men and 150 women, as research subjects. The survey tool used was the questionnaire method, and the questionnaire whose reliability and validity had been verified in previous studies at home and abroad was used by requoting, modifying, or supplementing it to suit the purpose of this study. It was also structured on a 5-point scale. Frequency analysis, factor analysis, reliability analysis, simple regression analysis, and multiple regression analysis were performed on the collected data using the statistical program SPSS Windows 20.0 Version. The results obtained through this process are as follows. First, social network sports community consciousness was found to have a partial effect on loyalty. Second, social network sports community consciousness was found to have a partial effect on sports attitudes. Third, social network sports community loyalty was found to have a partial effect on sports attitudes. Considering these results, various activities such as decision-making process, relationship formation, and opinion expression of modern people are carried out by the O-line community. In addition, while in the past it was a format that led from offline activities to online activities, currently, there are more and more formats that lead from online activities to offline activities. Therefore, modern people's SNS sports community activities provide many experiences, which creates a sense of community and sports attitudes are formed based on this. This can be said to lead to loyal activities.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.2
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• pp.172-184
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• 2017

Nanotechnology is a leading branch of technology and is expected to improve national industrial competitiveness. For maintaining a sustainable growth in nanotechnology, Korean government has set up specific plans from a long-term perspective. One of these plans is tracking and promoting certain potential technologies called Future 30 Nanotechnologies. This study aims to develop an analysis framework for comprehending the Future 30 Nanotechnologies. We applied this framework to the carbon nanomaterials field. Through co-authorship and keyword network analysis, we identified the research trends of three countries (i.e., Korea, US, and China.). This research framework could be utilized in the development of a nanotechnology policy.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.55-64
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• 2019

This study identified key patents on U.S. underground water technology through patent network analysis. As a result, there were many technologies that used the technology to remove heavy metals to prevent contamination of groundwater. While patents between groundwater technology patents were in charge of intermediaries, the connectivity between groundwater technologies is not high. The patented technologies related to groundwater were largely distinguishable by pumping, monitoring, and decontamination. Monitoring includes techniques that enable identification of physical and biological properties, such as the type of contaminants, as well as geographic characteristics for analysis of groundwater flow, flow or water quality. Pollution purification technology refers to the process of physiochemical and biological purification for soil and groundwater. U.S. technology cases showed that the U.S. had high technology in water treatment area. And patent protection were also needed to cope with water shortages caused by climate change.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.3
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• pp.75-83
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• 2001

This study selected Yangpyung as a target site because Yangpyung is a area of high value blessed with well preserved natural resources and beautiful natural scene and where thoughtless development and malformed use of land are in progress under the mask of hotel, accommodations and sales facility which fits the interests of land owner. As for the method used for this study, I inquired into domestic/international instances and the concept of existing environmental indicators and assessment of suitability with a view to establish assessment indicators and pose the concept through theoretical investigation of green-network and to establish green-network. 17 articles of environmental indicators such as aspect analysis, contour, greenbelt, DEM, NDVI, nature conservation area, reservoir and area for the promotion of agriculture were chosen as a actual analysing n data for setting up assessment indicators. From the result of analysis, as anticipated, green zone in Yongmusan areas within Youngmun and Seojong areas were the center of green-network in the wide area green-network in Yangpyung and the restricted area by basin system, road and legal regulation was selected as spot area and finally arable land and reservoir were selected as base which connects core with spot.