• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.657-662
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• 2017

Recently, according to the development of the smart home field, it provides a service to install and keep the smart home appliance in a user's residential environment pleasantly. However, the conventional system method has a problem in that it is not convenient because the user selects a device or manually operates the device. In this paper, we propose a system to set the priority of the devices selected by the user and proceed with the work. When a user selects a device, it recommends a device associated with the device. Compare and set the priority of each device. And it is a system that carries out work according to the set priority. Therefore the proposed system is expected to provide users with increased convenience and efficiency of work management.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.19-24
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• 2020

Recently, due to the rapid increase of pets, there is a need for an integrated pet-related personalized product recommendation service such as feed recommendation using a health status check of pets and various collected data. This paper implements a product recommendation system that can perform various personalized services such as collection, pre-processing, analysis, and management of pet-related data using big data. First, the sensor information worn by pets, customer purchase patterns, and SNS information are collected and stored in a database, and a platform capable of customized personalized recommendation services such as feed production and pet health management is implemented using statistical analysis. The platform can provide information to customers by outputting similarity product information about the product to be analyzed and information, and finally outputting the result of recommendation analysis.

• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.61-68
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• 2018

This paper propose the remote monitoring system using LoRa networks about storm overflow chamber, which is a device designed to discharge rainwater directly to a sewage treatment plant when it reaches a certain amount of rainfall during precipitation. In this system, when the information produced by the sensor is transmitted to the LoRa network server and updated, the application server can automatically receive data through the implemented communication interface. The application server carries out management functions of storm overflow chamber devices and subscription information, collects measured flow rate and opening-closing information, and provides statistical information using the collected data. The android app performs a firebase-based notification function to prompt the user of malfunctioning of the storm overflow chamber device.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.57-63
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• 2016

This paper describes implementation of the RF frequency synthesizer with $0.18{\mu}m$ silicon CMOS technology being used as an application of the IEEE802.15.4g SUN sensor node transceiver modules. Design of the each module like VCO, prescaler, 1/N divider, ${\Delta}-{\Sigma}$ modulator, and common circuits of the PLL has been optimized to obtain high speed and low noise performance. Especially, the VCO has been designed with NP core structure and 13 steps cap-bank to get high speed, low noise, and wide band tuning range. The output frequencies of the implemented synthesizer is 1483MHz~2017MHz, the phase noise of the synthesizer is -98.63dBc/Hz at 100KHz offset and -122.05dBc/Hz at 1MHz offset.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.2
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• pp.215-222
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• 2016

Research on gait recognition and its use is actively underway. This study suggests a method to recognize abnormal gaits of pedestrians. The purposes of the existing research to recognize normal steps are to measure physical activities and to validate people by their walks, but the purpose to recognize abnormal steps in this study is to insure the safe life of pedestrians. There are situations in which pedestrians are unaware of themselves vulnerable and can not ask for help. The purpose of this research is that even if pedestrians are unaware of themselves and there are no spontaneous requests for helps, it is intended for them to escape from dangers and difficulties by adopting the recent IOT technology. Hence, this study analyzes normal pace of pedestrians using the triaxial acceleration sensors, and takes ranges of their normal walking. And then, the steps of pedestrians are measured using the triaxial acceleration sensors, contrasted with their normal walking ranges, and determine whether their steps are normal or not. When it is out of the state for normal paces, a method to determine as abnormal paces is suggested.

• Journal of Korea Multimedia Society
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• v.17 no.12
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• pp.1473-1483
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• 2014

A public restroom is different from a household toilet in terms of location and a large number of sharing users. In addition, public restroom is usually messy and filthy. Recently, public toilet tends to be clearly managed than before, but it still has hygienic and clear problems. In this paper, we propose a machine-to-machine (M2M)-based public restroom management system to solve these problems, in which the system with a wireless communication device sends the status information of the toilet, such as blockage or trouble detected by a sensor, to the manager of the restroom at a remote location. In particular, we have developed a prototype management system for public restroom taking into account several system requirements, and verified the basic operations and performance of the management system. With the application of the system to public facilities, it will furnish users with more pleasant environments by restroom administrators who can respond effectively to the troubled toilet.

• Journal of Advanced Navigation Technology
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• v.19 no.1
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• pp.66-73
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• 2015

In this paper, an architecture of a perpetual smart video device and its energy control model for the internet of things (IoT) are proposed. The smart video device consists of a processor, an image sensor, a video codec, and a network controller. In the proposed energy control model, energy consumed by image sensing, video encoding, and transmission and energy harvested by solar panels are defined as an input and an output of a battery, an energy buffer. Frame rate, quantization parameter, and operating frequency of processor are defined as the energy control parameters, and these parameters control the input and the output energy of the energy buffer, finally control the energy left in the battery. The proposed energy control model is validated by the energy consumption measurement of the smart phone based platform for various combinations of energy control parameters, and can be used for the design of perpetual smart video device.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.413-416
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• 2017

The development of the internet, which is due to the advent of the fourth industrial revolution, has been slowly affecting our lives. Based on this trend, various products have recently emerged, and have yet to be developed in the context of identifying the dangers of infant babies. Increasingly, children are experiencing problems with detecting and responding to children's lives because of their daily living noise and housekeeping activities. This project attempts to develop a raspberry pie and an audiovisual sensor module to avoid the risk of preventing unwanted behavior from tripping the child's sudden behavior in everyday life. Further, it was designed to provide convenience to the guardian's convenience by implementing the smartphone app with the Wifi signal.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.6
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• pp.1307-1315
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• 2017

While the PSK mode of the DTLS is the most efficient in terms of the performance, it is not easy to pre-distribute and manage the symmetric key pairs as the number of sensor devices increases. On the other hand, both the RPK and certificate modes offer a convenient key management tool, but they do not guarantee a good computational performance. In this paper, the end-to-end security protocol suitable for the constrained devices is proposed, based on both the ECQV certificate and the PSK mode. Namely, the initial DTLS handshake is performed using the ECQV certificate, and the subsequent DTLS handshakes with the other CoAP servers in the same group are performed using the PSK mode for the purpose of reducing the overall computational load. Furthermore, a fine-grained access control for the CoAP client can be enforced to allow access to the limited number of CoAP servers.

• Journal of Convergence for Information Technology
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• v.8 no.4
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• pp.109-114
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• 2018

In general, the simple items we need to live in are purchased through retail stores such as supermarkets near our home. In the store, not only the items but also the management personnel and the payment instruments for the store management are located in one space called the store. Such a general store environment is gradually changing into an 'unmanned market' as a result of the development and fusion of information and communication technology (ICT). An unmanned market is an environment in which no one runs a market as the word has. An example of a typical change is Amazon's Unofficial Amazon Store. In addition, the usage and prospects of unmanned market in China are growing very meaningfully. In this study, the present situation of the unmanned market is examined in the US and China markets, and the development prospects are described. It also describes the key milestones necessary for the unmanned market.