• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.802-808
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• 2020

The IoT(Internet of Things) is based on the development of sensor technology and high-speed communication infrastructure, and the number of IoT connected to the network is increasing more than the number of people, and the increase is also very fast. In the field of defense, IoT is being deployed in various fields such as operations, military, base defense, and informatization, and the need is also increasing. Unlike the existing PC/server information protection system, cyber threats are also increasing as IoT sensors, which are vulnerable to information protection, are increasing in the network, so it is necessary to study the platform to protect the defense information and communication network. we investigated the case of connecting wired and wireless IoT to the defense network, and presented an efficient interlocking design method of the IoT integrated independent network with enhanced security by minimizing the contact point with the defense network.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.8
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• pp.619-627
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• 2017

MIMO(Multi-Input Multi-Output) radar is an emerging radar technology for its numerous advantages. However, in the electric warfare viewpoint, MIMO radar is a new developed radar technology for that existing parameter estimation cannot applied and a new radar parameter estimation based on the characteristics of MIMO radar is desired. In this paper, we propose a blind estimation scheme for the number of orthogonal waveforms of a uniform linear array(ULA) MIMO radar using minimum two electronic sensors.

• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.146-155
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• 2022

We proposed a simple process of creating electroconductive textiles by using PEDOT:PSS(Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate))/non-oxidized graphene to coat polyamide or polyurethane knitted fabric for smart healthcare purposes. Electroconductive textiles were obtained through a coating process that used different amounts of PEDOT:PSS/non-oxidized graphene solutions on polyamide/polyurethane knitted fabric. Subsequently, the surface, electrical, chemical, weight change, and elongation properties were evaluated according to the ratio of PEDOT:PSS/non-oxidized graphene composite(1.3 wt%:1.0 wt%; 1.3 wt%:0.6 wt%; 1.3 wt%:0.3 wt%) and the number of applications(once, twice, or thrice). The specimens' surface morphology was observed by FE-SEM. Further, their chemical structures were characterized using FTIR and Raman spectroscopy. The electrical properties measurement (sheet resistance) of the specimens, which was conducted by four-point contacts, shows the increase in conductivity with non-oxidized graphene and the number of applications in the composite system. Moreover, a test of the fabrics' mechanical properties shows that PEDOT:PSS/non-oxidized graphene-treated fabrics exhibited less elongation and better ability to recover their original length than untreated samples. Furthermore, the PEDOT:PSS/non-oxidized graphene polyamide/polyurethane knitted fabric was tested by performing tensile operations 1,000 times with a tensile strength of 20%; Consequently, sensors maintained a constant resistance without noticeable damage. This indicates that PEDOT:PSS/non-oxidized graphene strain sensors have sufficient durability and conductivity to be used as smart wearable devices.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.75-82
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• 2021

The number of traffic accidents is about 230,000, and due to non-recurring congestion and high driving speed, the number of deaths per traffic accident on freeways is more than twice compared to other roads. Currently, traffic information is provided based on nodes and links using the centerline of the road, but it does not provide detailed speed information. Recently, installing sensors for vehicles to monitor obstacles and measure location is becoming common not only for autonomous vehicles but also for ordinary vehicles as well. The analysis using large-capacity location-based data from such sensors enables real time service according to processing speed. This study presents an mapping method for individual vehicle data analysis based on space. The processing speed of large-capacity data was increased by using method which applied a quaternary notation basis partition method that splits into two directions of longitude and latitude respectively. As the space partition was processed, the average speed was similar, but the speed standard deviation gradually decreased, and decrease range became smaller after 9th partition.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.551-558
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• 2021

In this paper, we made the integrated intelligent air ventilation of the actuator module that can be remotely controlled based on IoT and sensors. we implemented a ventilation window system by configuring an algorithm design and a driving circuit to control the operation of the actuator to open and close the ventilation port based on a predetermined number of data that detects indoor gas/CO2/humidity temperature and outdoor fine dust related indoor/outdoor environment. It is difficult to store, manage, and analyze data due to the large number of sensors and conditions for the transmission data of indoor air circulation module. The remote monitoring and remote wireless control screens were constructed to automate the separation and operation conditions by extracting and managing the state. We apply MQTT to enhance big data transmission and construct the system using Rocket MQ to ensure safe transmission of operational big data against system errors.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.4
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• pp.403-410
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• 2010

The switched Ethernet has many features for real-time communications such as providing traffic isolation, large bandwidth, and full-duplex links, and so on. The switched Ethernet, however, cannot guarantee the timely delivery of a real-time message because message delay increases when collisions occurs at the output ports and message loss can even occur due to the overflow at the output buffer. Recently, many research efforts have been done to use the switched Ethernet as an industrial control network. In the industrial control network, sensors periodically sense the physical environment and transmit the sensed data to an actuator, and the periodic messages from sensors to actuators have typically real-time requirements such that those messages must be transmitted within their deadlines. This paper first suggests a feasible condition for EDF (Earliest Deadline First)-based scheduling of periodic messages on a synchronized switched Ethernet and a message scheduling algorithm which satisfies the proposed feasible condition. Pedreiras, et al. [10] suggested a feasible condition for message scheduling on the Ethernet (shared media Ethernet), but there has been no research result on the scheduling condition on the switched Ethernet until now. We compared the real-time message scheduling capacity between the Ethernet and the switched Ethernet by simulation. The simulation result shows that the message scheduling capacity of the Ethernet has almost remained constant as the number of nodes on the network increases, but, in the case of the switched Ethernet, the message scheduling capacity has increased linearly according to the number of nodes on the network.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.418-423
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• 2009

Unlike domestic railway transportation system in which majority of station are equipped with gate access controller and ticket office, it has been a very common practice in overseas railway transit or railway station that they use a pressure door mat, infrared-sensors or CCTV cameras so as to automatically determine the number of passenger onboard and alight and to reflect the information to their business (i.e., deployment of vehicles and human resources). The data collected by the automatic passenger counting (APC) system provides methods how to obtain the information about the number of passenger using the vehicles on the basis of date, time and stop(station) which enables large-scaled transit company to create profits through effective vehicle deployment and management of their employees. This paper addresses the basic features of the automatic passenger counting system using infrared sensor and describes those of the extended APC system in conjunction with wireless technologies such as GPS, WLAN or Cellular network.

• Journal of the Korea Society of Computer and Information
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• v.25 no.5
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• pp.73-79
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• 2020

As the number of earthquakes gradually increases on the Korean Peninsula, much research has been actively conducted to detect earthquakes quickly and accurately. Because traditional seismic stations are expensive to install and operate, recent research is currently being conducted to detect earthquakes using low-cost MEMS sensors. In this article, we evaluate how a low-cost MEMS acceleration sensor installed in a smartphone can be used to detect earthquakes. To this end, we installed about 280 smartphones at various locations in Korea to collect acceleration data and then assessed the installed sensors' noise floor through PSD calculation. The noise floor computed from PSD determines the magnitude of the earthquake that the installed MEMS acceleration sensors can detect. For the last few months of real operation, we collected acceleration data from 200 smartphones among 280 installed smartphones and then computed their PSDs. Based on our experiments, the MEMS acceleration sensor installed in the smartphone is capable of observing and detecting earthquakes with a magnitude 3.5 or more occurring within 10km from an epic center. During the last several months of operation, the smartphone acceleration sensor recorded an earthquake of magnitude 3.5 in Miryang on December 30, 2019, and it was confirmed as an earthquake using STA/LTA which is a simple earthquake detection algorithm. The earthquake detection system using MEMS acceleration sensors is expected to be able to detect increasing earthquakes more quickly and accurately.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.417-422
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• 2015

A service size of the IoT environment is determined by the number of sensors. The number of sensors increase means increases the amount of data generated by the IoT environment. There are studies to reliably operate a network for research and operational dynamic buffer for data when network congestion control congestion in the network environment. There are also studies of the stream data that has been processed in the connectionless network environment. In this study, we propose a sensor gateway for processing big data of the IoT environment. For this, review the RESTful for designing a sensor middleware, and apply the double-buffer algorithm to process the stream data efficiently. Finally, it generates a big data traffic using the MJpeg stream that is based on the HTTP protocol over TCP to evaluate the proposed system, with open source media player VLC using the image received and compare the throughput performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.119-125
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• 2018

Various techniques for indoor positioning using a smart phone have been studied. Among them, the positioning technology using the acceleration sensor and the gyro sensor built in the smartphone is widely used in conjunction with the WiFi fingerprint technology. The location tracking technology using sensors has been used for a long time, but the performance environment of the smartphone is poor and the user is moving with the smartphone in a certain posture. Therefore, in order to improve the accuracy of location tracking in a smartphone environment, it is necessary to study and develop appropriate algorithms in a mobile environment. In this paper, we analyze the performances of frequency analysis method, maximum sum of minimum acceleration method and adaptive threshold method, which are the user's moving step count detection algorithms, and determine the most accurate method.