• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.116-118
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• 2018

This paper introduces oneM2M global IoT standard middleware platform based smart city service data model support and FIWARENGSI interworking for Orion Broker. Also, service data models implementation using flexContainer resource types and FIWARENGSI interworking using the Interworking Framework (TS-0033) from oneM2M Release 3 are also illustrated. In this system, data model element level access (e.g. for subscription/notification feature) is enabled, which is enhancement compared to contentInstance resource type before, and service agnostic FIWARE NGSI interworking is provided over the Interworking Framework for smart city platform data interworking.

• Journal of the Korean Institute of Gas
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• v.24 no.3
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• pp.1-10
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• 2020

This paper describes the development of a smart advanced metering infrastructure(AMI) architecture and services for using smart metering in gas industry. A general gas AMI system is composed of a smart gas meter, IoT network, the AMI platform, and an operation management system with security functions. The proposed gas AMI platform supports two-way communication between smart metering devices and AMI services and is applied by oneM2M standard to support interoperability between various types of metering devices and heterogeneous IoT networks. To demonstrating AMI system with the proposed platform, we installed about 2,900 smart gas meters in real environments and operated AMI systems for one year. We verified that about 94% of gas meters are normally worked and AMI services are stably operated without error or malfunction.

• The Journal of Korea Robotics Society
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• v.17 no.2
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• pp.142-151
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• 2022

With the advent of the 4th industrial revolution, autonomous driving technology is being commercialized in various industries. However, research on autonomous driving so far has focused on platforms with wheel-type platform. Research on a tracked platform is at a relatively inadequate step. Since the tracked platform has a different driving and steering method from the wheel-type platform, the existing research cannot be applied as it is. Therefore, a path-tracking algorithm suitable for a tracked platform is required. In this paper, we studied a path-tracking algorithm for a tracked platform based on a GPS sensor. The existing Pure Pursuit algorithm was applied in consideration of the characteristics of the tracked platform. And to compensate for "Cutting Corner", which is a disadvantage of the existing Pure Pursuit algorithm, an algorithm that changes the LAD according to the curvature of the path was developed. In the existing pure pursuit algorithm that used a tracked platform to drive a path including a right-angle turn, the RMS path error in the straight section was 0.1034 m and the RMS error in the turning section was measured to be 0.2787 m. On the other hand, in the variable LAD algorithm, the RMS path error in the straight section was 0.0987 m, and the RMS path error in the turning section was measured to be 0.1396 m. In the turning section, the RMS path error was reduced by 48.8971%. The validity of the algorithm was verified by measuring the path error by tracking the path using a tracked robot platform.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.198-200
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• 2022

In this paper, we are going to explain the development of a platform that can integrate and manage various sensors and data by applying IoT standard technology to a smart city where various services exist. The structure was designed to integrate and manage various data through platform development and process the collected data according to the service. By designing a platform based on the LwM2M standard technology, it is possible to provide a function that can accommodate various devices.

• Journal of computational fluids engineering
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• v.18 no.3
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• pp.72-78
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• 2013

The turbulent flow behavior of air supply and exhaustion in the Shin-gum-ho subway station is analyzed for ordinary and emergency state. The depth of Shin-gum-ho station is 43.6m which consists of the island-type platform(8th floor in underground) and a two-story lobby (first & second floor in underground). An emergency stairway connects between the platform and the lobby. Ventilation operation mode for ordinary state is set up as a combination of air supply and exhaustion in the lobby and platform, while for emergency state it is set up as a full air supply in the lobby and a full exhaustion in the platform. The entire station is covered for simulation. The ventilation diffusers are modeled as 95 square shapes of $0.6m{\times}0.6m$ in the lobby and as 222 square shapes of $0.6m{\times}0.6m$ and 4 rectangular shapes of $1.2m{\times}0.8m$ in the platform. The total of 7.5million grids are generated and whole domain is divided to 22 blocks for MPI efficiency of calculation. Large eddy simulation(LES) is applied to solve the momentum equation and Smagorinsky model($C_s$=0.2) is used as SGS(subgrid scale) model. The time-averaged velocity fields are compared to experimental data and show a good agreement with it.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.356-367
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• 2021

With the recent development of IoT and artificial intelligence technology, research and applications for optimization of real-world problems by collecting and analyzing data in real-time have increased in various fields such as manufacturing and smart city. Representatively, the digital twin platform that supports real-time synchronization in both directions with the virtual world digitized from the real world has been drawing attention. In this paper, we define a digital twin concept and propose a digital twin platform prototype that links real objects and predicted results from the virtual world in real-time by utilizing the oneM2M-based IoT platform. In addition, we implement an application that can predict accidents from object collisions in advance with the prototype. By performing predefined test cases, we present that the proposed digital twin platform could predict the crane's motion in advance, detect the collision risk, perform optimal controls, and that it can be applied in the real environment.

• Journal of Environmental Health Sciences
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• v.31 no.1
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• pp.39-46
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• 2005

This study was performed to investigate the concentration of $PM_{10}$ and $PM_{2.5}$ in inside train and platform of subway 1, 2, 4 and 5 in Seoul, KOREA. $PM_{10}$, $PM_{2.5}$, temperature, humidity and carbon dioxide were monitored using Portable Aerosol Spectrometer at afternoon (between 13:00 and 16:00). The concentrations of $PM_{10}$ and $PM_{2.5}$ in inside train were monitored to be higher than those measured in platform. In addition, $PM_{10}$ concentration in both platform and inside train were found to be greatly higher than range of from 35 ${\mu}g/m^3$ to 81${\mu}g/m^3$ in ambient air reported by Ministry of Environment. This study found that there were many inside train in subway 1, 2, 4 line where exceeded 150 ${\mu}g/m^3$ of Korean PM10 standard. The average percentage that exceeded PM10 standard was 83.3% in line 1, 37.9% in line 2 and 63.1% in line 4, respectively. In particular, most of inside train in subway line 1 were over PM10 limit. PM2.5 concentration ranged from 77.7 ${\mu}g/m^3$ to 158.2 ${\mu}g/m^3$, which were found to be greatly higher than ambient air PM2.5 standard promulgated by United States Environmental Protection Agency (US-EPA) (24 hours arithmatic mean : 65 ${\mu}g/m^3$, year average : 15 ${\mu}g/m^3$). The percentage of $PM_{2.5}$ in $PM_{10}$ was 86.2% in platform, 81.7% in inside train, 80.2% in underground and 90.2% in ground. These results indicated that fine particles ($PM_{2.5}$) accounted for most of $PM_{10}$.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.10
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• pp.989-994
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• 2016

This study was conducted the management of a water level through the water sensor, the waterline and the drain applied to the rice paddy. The gateway transfers the information to oneM2M(: Machine to Machine) platform of IoT(: Internet of Thing) standards to the height of the water level sensor information through the LoRa connection. Depending on the water level requested by the IoT platform, the gateway is to On or Off waterline or drain motor switch and send the information of the water level sensor. IoT platform performs the intelligent application function according to the condition of the water level.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.5
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• pp.809-816
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• 2023

The purpose of this study is to implement a device using the Raspberry Pi that can transmit and supervise data between devices and servers using the oneM2M standard platform, Mobius. Operating under the same concept as a Gateway or Router, this device performs the role of forwarding packets sent from end nodes to other networks. Theoretical functionality has been achieved to concurrently connect and supervise up to 65536 devices. The communication methods for end nodes connected to the Gateway include ZigBee and WiFi, and for long-distance communication, tests were conducted using LoRa modules.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1405-1414
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• 2014

The office management service platform configured with office's sensor devices, G/DSCL(Gateway/Device Service Capability Layer), NSCL(Network Service Capability Layer), and NA(Network Application). In this paper, we designed gateway resource tree and service scenario to fit the office management service and demonstrated appropriate operation of the office management service through intelligent functional modeling.