• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.141-142
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• 2009

Due to recent extreme weather, the information of the reliability for the nation's major social overhead capital (SOC) is emerging as a major issue. So the real-time monitoring of the underground state has become a very important. This paper is about a open USN platform for the underground information collection. Various sensors to collect information for the underground is used. The interface and the power of each sensor may vary. In order to solve the interface and power problem, this paper refer to the open interface, the network required for an open platform and the energy problem.

• Journal of Internet Computing and Services
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• v.19 no.1
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• pp.123-130
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• 2018

With the emergence of a new paradigm called Open Science and Big Data, the need for data sharing and collaboration is also emerging in the computational science field. This paper, we analyzed data-driven research cases for computational science by field; material design, bioinformatics, high energy physics. We also studied the characteristics of the computational science data and the data management issues. To manage computational science data effectively it is required to have data quality management, increased data reliability, flexibility to support a variety of data types, and tools for analysis and linkage to the computing infrastructure. In addition, we analyzed trends of platform technology for efficient sharing and management of computational science data. The main contribution of this paper is to review the various computational science data repositories and related platform technologies to analyze the characteristics of computational science data and the problems of data management, and to present design considerations for building a future computational science data platform.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1278-1284
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• 2004

Platform screen dorr (PSD) is equipment composed of screens and doors on the platform of subways or light trains, separating the platform from the railroad. The equipment is opened and closed in connection to the doors of carriages. In order to operate the system safely, it is important to understand the characteristics of key parts. There are many parts and environmental factors such as voltage, current and temperature change but the present study measured the change rate of torque and energy changes according to the temperature of the driving motor and analyzed the characteristics of the changes and examined the features of a motor required for stable PDS and the conformability of control programs.

• Smart Structures and Systems
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• v.11 no.6
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• pp.589-604
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• 2013

Identification of damage has become an evolving area of research over the last few decades with increasing the need of online health monitoring of the large structures. The visual damage detection can be impractical, expensive and ineffective in case of large structures, e.g., offshore platforms, offshore pipelines, multi-storied buildings and bridges. Damage in a system causes a change in the dynamic properties of the system. The structural damage is typically a local phenomenon, which tends to be captured by higher frequency signals. Most of vibration-based damage detection methods require modal properties that are obtained from measured signals through the system identification techniques. However, the modal properties such as natural frequencies and mode shapes are not such good sensitive indication of structural damage. Identification of damaged jacket type offshore platform members, based on wavelet packet transform is presented in this paper. The jacket platform is excited by simple wave load. Response of actual jacket needs to be measured. Dynamic signals are measured by finite element analysis result. It is assumed that this is actual response of the platform measured in the field. The dynamic signals first decomposed into wavelet packet components. Then eliminating some of the component signals (eliminate approximation component of wavelet packet decomposition), component energies of remained signal (detail components) are calculated and used for damage assessment. This method is called Detail Signal Energy Rate Index (DSERI). The results show that reduced wavelet packet component energies are good candidate indices which are sensitive to structural damage. These component energies can be used for damage assessment including identifying damage occurrence and are applicable for finding damages' location.

• Journal of Platform Technology
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• v.12 no.1
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• pp.119-127
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• 2024

This paper utilized electromagnetic field energy as an external stimulus to enhance the germination rate of acacia(Robinia pseudoacacia) seeds. Electromagnetic field energy comprises three types: static magnetic field(SMF) energy, static electric field(SEF) energy, and microwave(MW) energy. When SMF energy was applied to seeds through a dry method for 90 minutes, the germination rate increased by more than 10% compared to the control group. Similarly, SEF energy applied through a dry method for 90 minutes resulted in an improvement of over 20% in the germination rate. Furthermore, when MW energy at 2.45 GHz was applied to the seeds through a wet method for 3 minutes, the germination rate increased by over 25%. Experimental results showed that seeds treated with MW energy exhibited the highest germination rate and the greatest sprout growth. Consequently, this paper confirms that treating seeds with MW energy through a wet method yields the most superior germination rate and seedling growth.

• Geomechanics and Engineering
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• v.23 no.1
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• pp.51-59
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• 2020

In this paper, the WEKA platform was used to mine and analyze measured data of floor failure depth and a prediction system of floor failure depth was developed with Java. Based on the standardization and discretization of 35-set measured data of floor failure depth in China, the grey correlation degree analysis on five factors affecting the floor failure depth was carried out. The correlation order from big to small is: mining depth, working face length, floor failure resistance, mining thickness, dip angle of coal seams. Naive Bayes model, neural network model and decision tree model were used for learning and training, and the accuracy of the confusion matrix, detailed accuracy and node error rate were analyzed. Finally, artificial neural network was concluded to be the optimal model. Based on Java language, a prediction system of floor failure depth was developed. With the easy operation in the system, the prediction from measured data and error analyses were performed for nine sets of data. The results show that the WEKA prediction formula has the smallest relative error and the best prediction effect. Besides, the applicability of WEKA prediction formula was analyzed. The results show that WEKA prediction has a better applicability under the coal seam mining depth of 110 m~550 m, dip angle of coal seams of 0°~15° and working face length of 30 m~135 m.

• Journal of the Korean Solar Energy Society
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• v.37 no.1
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• pp.1-14
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• 2017

A series of coupled time domain simulations considering stochastic waves and wind based on five 1-h time-domain analyses are performed in normal operating conditions. Power performance and tower base Fore-Aft bending moment and pitching motion response of the floating spar-buoy wind turbine with 2 MW direct-drive PMSG have been analyzed by using HAWC2 that account for aero-hydro-servo-elastic time domain simulations. When the floating spar-buoy wind turbine is tilted in the wind direction, maximum of platform pitching motion is close to $4^{\circ}$. Statistical characteristics of tower base Fore-Aft bending moment of floating spar-buoy wind turbine are compared to that of land-based wind turbine. Maximum of tower base Fore-Aft bending moment of floating spar-buoy wind turbine and land-based wind is 94,448 kNm, 40,560 kNm respectively. This results is due to changes in blade pitch angle resulting from relative motion between wave and movement of the floating spar-buoy wind turbine.

• Journal of Advanced Research in Ocean Engineering
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• v.2 no.4
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• pp.179-191
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• 2016

As the demand for renewable energy has increased following the worldwide agreement to act against global climate change and disaster, large-scale floating offshore wind systems have become a more viable solution. However, the cost of the whole system is still too high for practical realization. To make the cost of a floating wind system be more economical, a new concept of tension leg platform (TLP) type ocean floating wind system has been developed. To verify the performance of a 5-MW TLP type ocean floating wind power system designed by the Korea Advanced Institute of Science and Technology, the FAST simulation developed by the National Renewable Energy Laboratory is used. Further, 1/50 scale model tests have been carried out in the ocean engineering tank of the Research Institute of Medium and Small Shipbuilding, Korea. This paper compares the simulation and ocean engineering tank test results on motion prediction and tension assessment of the TLP anchor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.846-847
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• 2016

LED lighting is energy in lighting control based on had developed into a human-centered / multi-functional lighting systems from simple one trillion people thereby using environmental change by combining IT technology and software, including a variety of sensor functions and communication functions, depending on the evolution of the IT Convergence Era the reduction, and the strength and the color tone customized illumination of the user-section of light has been desired. For this intelligent lighting system is applied to the sensor and the control center of the user should be possible, and it is necessary for this artist platform of the communication module. In this paper, we propose a communication platform that utilizes Bluetooth BLE module for LED lighting control.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2395-2406
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• 2023

To study the influence of parameter uncertainty in small pressurized water reactor (SPWR) once-through steam generator (OTSG), the nonlinear mathematical model of the SPWR is firstly established. Including the reactor core model, the OTSG model and the pressurizer model. Secondly, a control strategy that both the reactor core coolant average temperature and the secondary-side outlet pressure of the OTSG are constant is adopted. Then, the uncertainty quantification method is established based on Latin hypercube sampling and statistical method. On this basis, the quantitative platform for parameter uncertainty of the OTSG is developed. Finally, taking the uncertainty in primary-side flowrate of the OTSG as an example, the platform application work is carried out under the variable load in SPWR and step disturbance of secondary-side flowrate of the OTSG. The results show that the maximum uncertainty in the critical output parameters is acceptable for SPWR.