• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.13-21
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• 2016

In this paper we are trying to explain the effect of temperature on polymer membrane exchange water electrolysis (PEMWE) and polymer membrane exchange fuel cell (PEMFC) simultaneously. A comprehensive studying approach is proposed and applied to a 50Watt PEM fuel cell system in the laboratory. The monitoring process is carried out through wireless LoRa node and gateway network concept. In this experiment, temperature sensor measure the temperature level of electrolyzer, fuel cell stack and $H_2$ storage tank and transmitted the measured value of data to the management control unit (MCU) through the individual node and gateway of each PEMWE and PEMFC. In MCU we can monitor the temperature and its effect on the performance of the fuel cell system and control it to keep the lower heating value to increase the efficiency of the fuel cell system. And we also proposed a mathematical model and operation algorithm for PEMWE and PEMFC. In this model, PEMWE gives higher efficiency at lower heating level where as PEMFC gives higher efficiency at higher heating value. In order to increase the performance of the fuel cell system, we are going to monitor, communicate and control the temperature and pressure of PEMWE and PEMFC by installing these systems in a building of university which is located in the southern part of Korea.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.295-304
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• 2019

This paper introduces a customized Smart Fire and Crime system for one person households. Recently, the number of one person household has skyrocketed due to the increasing number of one person household and the aging population. As a result, the demand for private security companies for one person household is increasing and smart security systems that are applied with rapidly evolving IoT and sensor technologies are also becoming a major issue. However, despite the increasing trend of one person households, the existing system focuses on multiple households, so that there are disadvantages of the one person households to operate in such a big system which operate separately. Therefore, in this paper, we design and implement a system that provides a personalized safety service for one person household that integrates a security system and a fire monitoring system. This will help prevent criminal activity in places where the police can not reach at a lower cost than using existing private companies, and help monitor the situation of the houses in real time.

• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.27-33
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• 2022

Sleep is an essential factor for living a healthy life, but most modern people complain of poor sleep. For these people, as the need for a means to simply evaluate and manage the quality of sleep increases, devices that can check the sleep state at home without monitoring by an examiner are being developed. The smart sleep mask, which is the subject of this usability test, provides bio-signal monitoring while sleeping so that you can conveniently measure and manage your sleep state for yourself. The purpose of this study is to evaluate the usability and safety of the smart sleep mask, to find and prevent potential factors related to errors in use that may occur, and to develop the comfort and safety of this product. As a result of the formative evaluation of the sleep mask prototype, it was reported that it was difficult to turn on the power and check the results, and that the sleep mask was not comfortable to wear. Different opinions were presented on the size and weight of the sleeping mask by people in different age groups.

• 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 Bio-Environment Control
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• v.25 no.1
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• pp.30-41
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• 2016

Korean government has planned to increase the productivity of horticultural crops and to expand supply smart greenhouse for energy saving by modernization of horticultural facilities based on ICT in policy. However, the diversity and linkages of monitoring and control are significantly insufficient in the agricultural sector in the current situation. Therefore, development of a service system with smart-farm based on the internet of things(IoT) for intelligent systemization of all the process of agricultural production through remote control using complex algorithm for diverse monitoring and control is required. In this study, domestic and international research trend related to ICT-based horticultural facilities was briefly introduced and limits were analyzed in the domestic application of the advanced technology. Finally, future core technologies feasible to graft in agricultural field were reviewed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.9
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• pp.1132-1140
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• 2016

According to global trend, despite the overall scale of agricultural industry has been downsized, agriculture accommodating cutting-edge ICT technologies has been proliferated, and various timely-issued relevant researches have been on progress to deploy the future food cultivation. In this paper, we propose an effective nutrient management system with web-based monitoring with functionality of controlling temperature, humidity, pH (hydrogen ion), EC (Electric Conductivity), LED and cooling fan to maintain the hydroponic nurturing environment being optimal. In this paper, in order the arduino hardware and java software are employed to control the nurturing environment automatically in optimal fashion. In proposed system, due to the usage of WiFi router with the socket communication and DB-assisted Web server with proper interfaces, it allows to facilitate the management to keep monitoring and controling overall hydroponic nurturing environment. Since the proposed Web-based management system provides the superior reliability, the short nurturing period and the robustness to the pest by controlling LED emitting color rather than conventional system, so it can be applied and appropriate for in-house vegetable factory overcoming limitation of time and location.

• Journal of Platform Technology
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• v.8 no.4
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• pp.59-69
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• 2020

Recently, the seriousness of ultrafine dust and fine dust has emerged as a national disaster, but small and medium-sized cities in provincial areas lack fine dust monitoring stations compared to their area, making it difficult to manage fine dust. Although the computing resources for collecting and processing fine dust data are not large, it is necessary to utilize cloud and private and public data to share data. In this paper, we proposed a small edge computing system that can measure fine dust, ultrafine dust and temperature and humidity and process it to provide real-time control of fine dust and service to the public. Collecting fine dust data and using public and private data to service fine dust ratings is efficient to handle with edge computing using raspberry pie because the amount of data is not large and the processing load is not large. For the experiment, the experiment system was constructed using three sensors, raspberry pie and Thinkspeak, and the fine dust measurement was conducted in northern part of kyongbuk region. The results of the experiment confirmed the measured fine dust measurement results over time based on the GIS data of the private sector.

• Journal of IKEEE
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• v.25 no.1
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• pp.193-200
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• 2021

In order to prevent illegal fishing and reduce lost fishing gear, it is necessary to develop a constant and continuous fishing gear monitoring system in the marine environment. In this paper, we design a long-term operational, reliable system model with communication coverage of more than 25Km considering the reality of gradually expanding fishing activity due to the depletion of fishery resources and marine environments. The design results are implemented to verify the operability of the system by separating the communication success rate of SKT and private LoRa networks and verifying the control function of each control system through the collected location information, respectively.

• Smart Structures and Systems
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• v.29 no.1
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• pp.251-266
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• 2022

Structural Health Monitoring (SHM) of critical infrastructure comprises a major pillar of maintenance management, shielding public safety and economic sustainability. Although SHM is usually associated with data-driven metrics and thresholds, expert judgement is essential, especially in cases where erroneous predictions can bear casualties or substantial economic loss. Considering that visual inspections are time consuming and potentially subjective, artificial-intelligence tools may be leveraged in order to minimize the inspection effort and provide objective outcomes. In this context, timely detection of sensor malfunctioning is crucial in preventing inaccurate assessment and false alarms. The present work introduces a sensor-fault detection and interpretation framework, based on the well-established support-vector machine scheme for anomaly detection, combined with a coalitional game-theory approach. The proposed framework is implemented in two datasets, provided along the 1st International Project Competition for Structural Health Monitoring (IPC-SHM 2020), comprising acceleration and cable-load measurements from two real cable-stayed bridges. The results demonstrate good predictive performance and highlight the potential for seamless adaption of the algorithm to intrinsically different data domains. For the first time, the term "decision trajectories", originating from the field of cognitive sciences, is introduced and applied in the context of SHM. This provides an intuitive and comprehensive illustration of the impact of individual features, along with an elaboration on feature dependencies that drive individual model predictions. Overall, the proposed framework provides an easy-to-train, application-agnostic and interpretable anomaly detector, which can be integrated into the preprocessing part of various SHM and condition-monitoring applications, offering a first screening of the sensor health prior to further analysis.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.459-464
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• 2023

The mobile house of this article is provided with stand-alone power system that uses photovoltaic energy and enables sensing and environmental monitoring. Excess power generated is stored in lithium batteries, which enable smooth operation of the mobile house even in environment in which solar energy cannot be used. The house has been designed that its systems can be operated continuously by diesel power generation even when photovoltaic energy cannot be generated due to long rainy season or heavy snow. BMS (batter management system) has been constructed for photovoltaic and power management, and monitors the charge/discharge and usage amount of photovoltaic energy. Various sensing data are recorded and transmitted automatically, and the design allows for wireless monitoring by means of computer and smartphone app. The container house proposed in this study enables efficient energy management by performing optimal energy operation in remote areas, parks, event venues, and construction sites where there is no system power source.