• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.74-82
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• 2019

The revolution of industry 4.0 is enabling us to build an intelligent connection society called smart cities. The use of renewable energy in particular solar energy is extremely important for modern society due to the growing power demand in smart cities, but its difficult to monitor and manage in each buildings since need to be deploy low energy sensors and information need to be transfer via wireless sensor network (WSN). The Internet of Things (IoT) / low-power wide-area (LPWA) is an emerging WSN technology, to collect and monitor data about environmental and physical electrical / electronics devices conditions in real time. However, providing power to IoT sensor end devices and other public electrical loads such as street lights, etc is an important challenging role because the sensor are usually battery powered and have a limited life time. In this paper, we proposes an efficient solar energy-based power management scheme for smart city based on IoT technology using LoRa wide-area network (LoRaWAN). This approach facilitates to maintain and prevent errors of solar panel based energy systems. The proposed solution maximizing output the power generated from solar panels system to distribute the power to the load and the grid. In this paper, we proved the efficiency of the proposed system with Simulink based system modeling and real-time emulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9B
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• pp.1381-1389
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• 2010

The smart grid technology is expected to significantly improve energy efficiency by dynamic power supply. One of its application is the Vehicle-to-Grid(V2G) that utilizes an electric vehicle's battery as a household storage battery. Meanwhile, a lot of researches are recently investigated in the area of wireless energy transfer technology because of its convenience and safety in charging a battery. With the wireless energy transfer infrastructure a wireless magnetic induction communication technique can help the dynamic power supply of the smart grid more efficient. In this paper, we propose a wireless magnetic induction communication sion cowhich includes data transmission and location-aware functions. We expect the sion cohelp the smart grid to control power supply more efficiently. We also developed its test-bed and evaluated the performance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.57-69
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• 2022

Even though demand to charge EV(electric vehicles) is increasing, there are some problems to construct EV charging stations and problems from deficient them. Typical problem of EV charging stations is discordance for EV charging station location with its demand. This study investigates methods to determine the optimized location for fast EV charging stations considering charging demand in Seoul. Firstly, variables influencing on determination of determine the optimized location for fast EV charging stations were decided, and then evaluation of weights of the variables and data collection were conducted. Using the weights, location potential scores for each area-cell were calculated and optimized locations for fast EV charging stations were resulted.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.5
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• pp.55-62
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• 2011

Recently, LBS(Location Based Service) is expanding its service areas with the spread of smart phones and the contents of the service are more individualized according to the customer's needs. Specially, LBSNS(Location Based Social Network Service) is emerging as the most promising service of LBS. This paper introduces a LBSNS model to form a community to share common contents dynamically centering around the place of user's smart phone. The methodology suitable for implementing the effective management and the automatic update of the community of social network is presented in this paper. In addition, we describe the significant future researches of LBSNS under the upcoming mobile environment.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.6
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• pp.395-402
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• 2013

We propose an accelerometer-based gesture recognition method for smartphone users. In our method, similarities between a new time series accelerometer data and each gesture exemplar are computed with DTW algorithm, and then the best matching gesture is determined based on k-NN algorithm. In order to investigate the performance of our method, we implemented a gesture recognition program working on an Android smartphone and a gesture-based teleoperating robot system. Through a set of user-mixed and user-independent experiments, we showed that the proposed method and implementation have high performance and scalability.

• Journal of the Korean Data and Information Science Society
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• v.20 no.1
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• pp.125-137
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• 2009

Smart card has a small sized micro computer chip. This chip contains processor, RAM, ROM, clock, bus system and crypto-co-processor. Hence it is more expensive, complicated and secure chip compared with RFID tag. The main application area of smart card is e-banking and secure communications. There are two kinds of smart card platforms; open platform and closed one. Java card is the most popular open platform because of its security, platform independency, fast developing cycle. However, the speed of Java card is slower than other ones, hence there have been hot research topics to improve the performance of Java card. In this paper, we propose an efficient transaction buffer management to improve the performance of Java card. The experimental result shows the advantage of our method.

• Journal of the Korea Convergence Society
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• v.6 no.5
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• pp.233-240
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• 2015

In this paper, we present an algorithm that estimates the speed of a moving object only using its sound information. In general, the speed gun projects the incident light onto a moving object and measures the frequency variation of the scattered light. Then the speed is measured by this frequency difference. In our study, instead of light information, we measure the speed by sound frequency difference when the object is coming and moving away. In our experiments on the speed measurement, on average the error of 6.08% was obtained. Utilizing this algorithm for smart device, we can measure the speed of a moving object without sensor that measures the frequency of the light.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.2064-2071
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• 2012

The generalization trend of smart phones have brought many smartphone games into daily lives. These games are mainly dependent on the interactions on the display of the phone using finger touches. On the other hand, functions for detecting the positions and actions of the phones such as gyro-sensors have been rapidly developed over the former orientation sensors and acceleration sensors. Though it has become technologically possible to detect the users' motion via the smartphone devices and to use the phone device directly as the game device, it is hard to find the actualized cases. This paper proposes a new paradigm including basic frameworks and algorithm for the games combining the motion recognitions and mutual communications on the smartphones and finally presents the details of its implementation and results.

• Smart Media Journal
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• v.2 no.3
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• pp.39-46
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• 2013

According to popularization of smart phones, we can easily see the QR code attached to products. Restaurants also provide customers with store information using QR code. Sixteen years have passed since QR code was developed. In Korea, QR code has been widely utilized in the field of marketing because of easiness of technique implementation and channel expansion to mobile. However, to recognize QR code, we should run the proper application and focus on it during loading time. To address this problem, this paper proposes the app to manage store information using NFC technology. The proposed app saves easily store information through the name card of a store and facilitates its management obtained by a smart phone.

• 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.