• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.324-330
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• 2015

Energy Saving Methods in existing railway vehicle are considered by active approach such as regenerative energy storage and utilization, eco driving, etc. On the other hands, energy saving measures in railway station are operated by passive method such as reduction of operating time in ventilation system, cooing system and power equipment. To reduce energy and for independence in railway system, it requires an active energy saving measures. It needs to its own power source besides the power source of electric supply company such as renewable energy and regenerative energy and take the advantage of power storage system and stored power are used in optimum time. This paper deal with 3-level NPC inverter and T-type NPC inverter that used in various multi-level topology applicable to the railway system.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.7-18
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• 2016

Several authentication methods have been developed to make use of tokens in the mobile networks and smart payment systems. Token used in smart payment system is genearated in place of Primary Account Number. The use of token in each payment transaction is advantageous because the token authentication prevents enemy from intercepting credit card number over the network. Existing token authentication methods work together with the cryptogram, which is computed using the shared key that is provisioned by the token service provider. Long lifetime and repeated use of shared key cause potential brawback related to its vulnerability against the brute-force attack. This paper proposes a per-transaction shared key mechanism, where the per-transaction key is agreed between the mobile device and token service provider for each smart payment transaction. From server viewpoint, per-transaction key list is easy to handle because the per-transaction key has short lifetime below a couple of seconds and the server does not need to maintain the state for the mobile device. We analyze the optimum size of the per-transaction shared key which satisfy the requirements for transaction latency and security strength for secure payment transactions.

• Journal of the Korea Convergence Society
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• v.3 no.2
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• pp.7-12
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• 2012

An advanced and proactive response mechanism against diverse attacks should be proposed for enhance its security and reliability on android based commercial smart work device. In this study, we propose a user-oriented vulnerability analysis and response system on commercial smart work device based on android when diverse attacks are activated. Proposed mechanism uses simplified and optimized memory for monitoring and detecting the abnormal behavior on commercial smart work device, with which we can find and determine the attacker's attempts. Additionally, proposed mechanism provides advanced vulnerability analysis and monitoring/control module.

• Textile Coloration and Finishing
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• v.23 no.1
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• pp.43-50
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• 2011

Electrically conductive yarn coated with silver particles are widely used to make smart wear but recent studies on smart fabrics are focused on measuring method of electrical characteristics and improving technologies of its electric properties. Also durability of conductive yarn with environmental change was also important work to make smart fabric. We compared resistance changes of silver coated conductive yarns under various physical and chemical conditions such as repeated strain, heat exposure and pH for basic informations on smart wear manufacturing process. And we deduct that repeated strain among the physical conditions was most effective factors on yarn resistance change and the low resistance change was observed with increasing the number of filaments in identical yarn fineness.

• Journal of Korea Game Society
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• v.13 no.4
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• pp.35-46
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• 2013

In this paper, we show a real-time lightning simulation for smart device game. Our proposed method uses physically based Dielectric Breakdown Model to similar real world lightning path and we simplify the algorithm for real-time simulation in smart device. In addition, the rendering process can render multiple lightning and can real-time render in smart device. Finally, our lightning can support interactive with user. The simulation method will be effectively useful for a game that needs a real-time simulation as its game element in smart device environment.

• Proceedings of the IEEK Conference
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• summer
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• pp.237-243
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• 2004

A multichannel smart sound sensor capable to detect and identify sound events in noisy conditions is presented in this paper. Sound information extraction is a complex task and the main difficulty consists is the extraction of high­level information from an one-dimensional signal. The input of smart sound sensor is composed of data collected by 5 microphones and its output data is sent through a network. For a real time working purpose, the sound analysis is divided in three steps: sound event detection for each sound channel, fusion between simultaneously events and sound identification. The event detection module find impulsive signals in the noise and extracts them from the signal flow. Our smart sensor must be capable to identify impulsive signals but also speech presence too, in a noisy environment. The classification module is launched in a parallel task on the channel chosen by data fusion process. It looks to identify the event sound between seven predefined sound classes and uses a Gaussian Mixture Model (GMM) method. Mel Frequency Cepstral Coefficients are used in combination with new ones like zero crossing rate, centroid and roll-off point. This smart sound sensor is a part of a medical telemonitoring project with the aim of detecting serious accidents.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.361-366
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• 2017

The abnormal state of the main equipment across the industry is accompanied by abnormal rise of temperature, change in the vibration and noise. In this study, we developed a smart sensing module equipped with BLE, and developed a smart sensing device that can detect abnormal vibration due to its own flaws of the equipment by interfacing with an MEMS-based acceleration sensor. The smart sensing device developed in this study can be easily installed in a small space and can monitor the vibration status of the equipment in real time, and can easily inform the user of the steady state and the problem occurrence status with array LED display.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.2
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• pp.110-119
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• 2020

In order to provide priorities of the factors affecting the introduction of Smart Factory, This study reconstructed the factors and calculated the priorities through AHP (Analytic Hierarchy Process). The first layer of the hierarchy have 4 factors; productivity increase, brand image improve, marketing improve, cost reduction. The second layer of the hierarchy have 3 factors belong to the first layer, so the total number of second layer is 12. We divided the characteristics of enterprises into type of manager and age. The C.R. (consistency ratio) values of the respondents were found to be less than 0.1 and were judged to be a 'reasonable test'. As a result, the weights of the higher layer and the lower layer were obtained respectively, and then the weights of the higher layer and the weights of the lower layer were multiplied to obtain the total weights. Unlike previous studies that only surveyed factors that companies consider when introducing smart factory, (1) weighing and prioritizing factors were achieved. There are differences in priorities, (2) smart factory can be studied with the type of manager and firm age. When establishing policies, it is a practical implication (3) to assess its strategy not only for government officials but also for executives.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.11-19
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• 2018

With the development of smart grid technology, it has become a hotspot to increase benefits of both residential users and electric power companies through demand response technology and interactive technology. In this paper, the game theory is introduced to the interaction between residential users and an electric company, making a mutually beneficial situation for the two. This paper solves the problem of electricity pricing and load shifting in the interactive behavior by building the game-theoretic process, proposing the interaction strategy and doing the optimization. In the simulation results, the residential users decrease their cost by 11% mainly through shifting the thermal loads and the electric company improves its benefits by 5.6% though electricity pricing. Simulation analysis verifies the validity of the proposed method and shows great revenue for the economy of both sides.

• Journal of Satellite, Information and Communications
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• v.7 no.2
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• pp.1-7
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• 2012

In recent years, importance of environmental protection and energy resources has increased. Therefore, eco - friendly consumption patterns is rapidly increased. Accordingly, efficient energy consumption technology is noted in a variety of industries. Smart grid technology can improve energy efficiency by using IT technology. Among them, the demand response is an critical factor in the smart grid. In this paper, we present basic concept of smart grid and demand response. In addition, we present demand response technology and its application examples.