• Journal of Digital Contents Society
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• v.18 no.2
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• pp.239-247
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• 2017

In the past, delivering knowledge mainly, education focused on the development of left brain. However, as the importance of right brain is widely accepted, various approaches on education in creativity have been tried. With the advance in the research on the brain, it has been known that the left brain and the right brain are closely linked to work effectively while they are specialized to some functionalities differently. We developed an educational content exploiting Chinese characters to facilitate the balanced development of both brain. Making categorizations from Yin-yang and five elements of the universe, it consists of four stages. The first stage is to stimulate the brain with visual scandal. The second one, third one, and the fourth one are to develop the right brain, left brain, and both brain respectively. Through expert interview, the potential of the developed content as an efficacious method for brain development was verified.

• Convergence Security Journal
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• v.15 no.5
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• pp.23-28
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• 2015

This study was carried out the exercise monitoring utilizing mobile device which is easily accessible and personalized exercise prescription based on it. For this, a variety of exercise monitoring and status of those were investigated and suggested the potential of personalized exercise prescription. If individual users send their body and vital informations using a mobile device, all informations are collected in u-Fitness center. After then exercise expert provide a customized prescription based on the collected information and feed data into database of u-Fitness center. System of U-Fitness center will provide the best personalized exercise prescription by automatically connecting to the content providers. In the future, a variety of mobile devices and services will work together and it can be evolved as an open platform that can be used for multiple services according to the needs of individual users on a single platform.

• Smart Structures and Systems
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• v.12 no.2
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• pp.97-119
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• 2013

This paper presents numerical and experimental results on the use of guided waves for structural health monitoring (SHM) of crack growth during a fatigue test in a thick steel plate used for civil engineering application. Numerical simulation, analytical modeling, and experimental tests are used to prove that piezoelectric wafer active sensor (PWAS) can perform active SHM using guided wave pitch-catch method and passive SHM using acoustic emission (AE). AE simulation was performed with the multi-physic FEM (MP-FEM) approach. The MP-FEM approach permits that the output variables to be expressed directly in electric terms while the two-ways electromechanical conversion is done internally in the MP-FEM formulation. The AE event was simulated as a pulse of defined duration and amplitude. The electrical signal measured at a PWAS receiver was simulated. Experimental tests were performed with PWAS transducers acting as passive receivers of AE signals. An AE source was simulated using 0.5-mm pencil lead breaks. The PWAS transducers were able to pick up AE signal with good strength. Subsequently, PWAS transducers and traditional AE transducer were applied to a 12.7-mm CT specimen subjected to accelerated fatigue testing. Active sensing in pitch catch mode on the CT specimen was applied between the PWAS transducers pairs. Damage indexes were calculated and correlated with actual crack growth. The paper finishes with conclusions and suggestions for further work.

• Smart Structures and Systems
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• v.21 no.3
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• pp.279-286
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• 2018

The free longitudinal vibration of a circular truncated nanocone is investigated based on the nonlocal elasticity theory. Exact analytical formulations for tapered nanostructures are derived and the nonlinear differential governing equation of motion is developed. The nonlocal small scale effect unavailable in classical continuum theory is addressed to reveal the long-range interaction of atoms implicated in nonlocal constitutive relation. Unlike most previous studies applying the truncation method to the infinite higher-order differential equation, this paper aims to consider all higher-order terms to show the overall nonlocality. The explicit solution of nonlocal stress for longitudinal deformation is determined and it is an infinite series incorporating the classical stress derived in classical mechanics of materials and the infinite higher-order derivative of longitudinal displacement. Subsequently, the first three modes natural frequencies are calculated numerically and the significant effects of nonlocal small scale and vertex angle on natural frequencies are examined. The coupling phenomenon of natural frequency is observed and it is induced by the combined effects of nonlocal small scale and vertex angle. The critical value of nonlocal small scale is defined, and after that a new proposal for determining the range of nonlocal small scale is put forward since the principle of choosing the nonlocal small scale is still unclear at present. Additionally, two different types of nonlocal effects, namely the nonlocal stiffness weakening and strengthening, reversed phenomena existing in nanostructures are observed and verified. Hence the opposite nonlocal effects are resolved again clearly. The nano-engineers dealing with a circular truncated nanocone-based sensors and oscillators may benefit from the present work.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.12
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• pp.1222-1229
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• 2012

For the reduction of electric energy consumption and its efficient use at homes or buildings, a new work item proposal for new architecture and functional requirements of Energy Saving System (ESS) was proposed to IEC TC 100 and accepted as a new project, IEC PT 62654 in 2009. Recently, the final ballot for publication passed without negative votes and IEC TS 62654 was finally published in August 2012. For the verification of this standard, Prototype of ESS system composed of an ESS server, ESS clients, and portable ESS terminal were especially implemented in parallel with the standardization. Electric Power Control and Management (EPCM) protocol for the communication between ESS server and clients was also implemented, which supports self-configuration of ESS network, power consumption monitoring, remote power control, and additional functions for intelligent energy saving services.

• Journal of Power Electronics
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• v.11 no.5
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• pp.759-766
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• 2011

This paper focuses on monitoring and predicting the short circuit faults of the rotor windings of large turbo-generator systems. For the purpose of increasing efficiency and decreasing maintenance cost, a method that combines the HHT (Hilbert Huang Transform) with a wavelet has been studied. This method is based on analyzing a classical Albright detecting coil. Due to the Empirical Mode Decomposition (EMD) and the Intrinsic Mode Functions (IMF) of the HHT the exact location of a short circuit of rotor windings may be given. However, a part of the useful information is eliminated by the unreasonable decomposing scale of the wavelet. Based on the thermodynamics modeling method, this study was illustrated with a 50MW turbo-generator system that is installed in Northern China. The analysis results, which have very good agreement with those of a previous study, show that the method of combining the HHT with a wavelet is an effective way to analyze and predict the short circuit faults of the rotor windings of large generators, such as supercritical turbo-generator systems and wind turbo-generator systems. This work can offer a useful reference for analyzing smart grids by improving the power quality of a distribution network that is supplied by a turbo-generator system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.725-726
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• 2017

Recently, IoT (Internet of Things) has been applied to various fields, not limited to places, through continuous research. However, the existing IoT system is based on the surrounding environment rather than the user-oriented operation of the device. therefore, there is a problem in that the efficiency and accuracy of the work are low. In this paper, we propose a user remote control analysis algorithm to solve these problems. When the user performs the remote control, the command is collected and the data is sorted according to the device and time. Analyze time-dependent behavior of devices based on sorted data. based on the results of the analysis, the environment is controlled by operating the device inside the home. Therefore, it is expected that the accuracy and convenience of device operation will be increased by providing customized service to users.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.569-570
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• 2017

Bitcoin-based blockchain technology provides an infrastructure that enables anonymous smart contracts, low-cost remittances, and online payments. However, the block-chain technology that implements the bitcoin has scalability constraints in tradeoffs between throughput and latency. To solve these problems, the Byzantine fault tolerant block-chain technique has been proposed. This technique improves throughput without increasing latency by selecting a leader and constructing many microblocks that do not contain proofs of work within the existing block by the leader. However, this technique may be less secure than existing techniques in selecting the reader. In this paper, we propose a technique for scalability of the blockchain technology by using microblock technology and parallel execution technique. Within one microblock there is information about several transactions. In the proposed scheme, the throughput of the microblocks can be increased by performing concurrently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.54-60
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• 2016

Building information modeling (BIM) has the advantage of having been utilized for various scenarios through a single model. Although extracting 2D drawings from BIM is one of the advantages, there are many difficulties when utilized in practical work. Architectural detail drawings are an important factor for expressing interior finishing materials and complicated construction methods, as well as for cost estimations. However, creating detail drawings does not have a standard, and each design company establishes its own detail drawings, so it is hard to share or exchange information in the construction industry. Therefore, this study suggests a systemized method for making detail drawings, and explains how it can be utilized as back data for quantity take-off and construction expenses linked with BIM libraries.

• Journal of Advanced Navigation Technology
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• v.17 no.6
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• pp.633-637
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• 2013

By using geolocation and maps, we need to trace the path of ourselves, others, or the objects. Until now, we used a native apps development mehod to develop path tracking systems in mobile devices such as smart phones and tablet computers. A disadvantage of this method is that we have to work again to provide the same service on different platforms. Web Apps and Hybrid Apps are developed to recover this disadvantage. Since Hybrid Apps look like Native Apps apparently, users prefer Hybrid Apps to Web Apps. In this paper, we develop a hybrid app which can trace the path on mobile devices. The recently suggested next generation markup language, HTML5, has geolocation features. By using them, we implemented a hybrid app for a path tracking system. First, we create a web app using HTML5, CSS, and JavaScript, Then, PhoneGap, a mobile development framework, is used to convert it to the hybrid app. By implementing hybrid app, various apps which need path tracking can be developed rapidly and effectively, regardless of the mobile devices.