• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.29-41
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• 2017

In this study, we used individual trip data to estimate a macroscopic fundamental diagram (MFD) that relates flow (or production) to density (or state) in Daegu metropolitan city. The individual trip data were generated by processing data that were collected from DSRC-based (dedicated short range communication) traffic data collection system. Using the processed individual trip data, we first examined whether the assumptions for MFD are valid, and then the relation between outflow and accumulation was estimated in our study site. As a result, we found that i) the assumptions are valid to construct MFD; and ii) the reproducible and well-defined MFDs exist in the network level.

• Journal of the Korea Society of Computer and Information
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• v.25 no.2
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• pp.59-66
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• 2020

In this paper, we propose a pipe leak detection system through data collection using low-power wireless acoustic sensor modules and data analysis using deep auto-encoder. Based on the Fourier transform, we propose a low-power wireless acoustic sensor module that reduces data traffic by reducing the amount of acoustic sensor data to about 1/800, and we design the system that is robust to noise generated in the audible frequency band using only 20kHz~100kHz frequency signals. In addition, the proposed system is designed using a deep auto-encoder to accurately detect pipe leaks even with a reduced amount of data. Numerical experiments show that the proposed pipe leak detection system has a high accuracy of 99.94% and Type-II error of 0% even in the environment where high frequency band noise is mixed.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.159-169
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• 2016

The current railway control system in Korea is comprised of signaling, electric rail power, communication, and maintenance systems that are independent of each other. Further, these systems have different mediums and protocols for transmitting the field equipment data to the central control system. The Safety Supervision System has as its purpose the collecting of safety-related data from each system to predict and prevent accidents, this system utilizes standard protocol. Safety-related data need to be collected from field data transmission devices of the existing control system, the data should be collected without affecting the communication of the existing system. In this study, sniffing skill, which is typically used for network traffic monitoring or security, is used to collect data. The problems arising from the use of sniffing devices are noted, and the Packet Conversion Node is proposed as a solution to the problems. Further, functional and performance testing were completed for the prototype, and the software architecture and packet conversion process were verified.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.3
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• pp.169-179
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• 2014

For vehicle safety-related services using wireless communications, reliable collection of various driving informations transmitted periodically by neighbor vehicles is the most important. Every host vehicle analyses them to estimate a potential dangerous situation in a very short time and warns drivers to prevent an accident. However tremendous amount of periodic messages can cause the wireless communication in chaos and the services not in safe. In this paper, we propose a time-division broadcasting protocol to mitigate the communication congestion. It utilizes the received information of vehicle velocity and location, i.e. vehicle traffic density on a road to adjust the number of time slots in a given broadcasting period, and transmission power. The simulation results show that message reception ratio is changed to approximately 40% and channel access time also decreased from 10ms to 0.23ms.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.165-170
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• 2006

In the Civil Aviation field, the international trend (through ICAO, EUROCONTROL) is to adopt one positioning system that allows to follow more flight phases. This will allow to release themselves by ground installations and optimize the traffic flows following the aRea Navigation (RNAV) concept. In order to realize this goal the European Scientific Community are focusing on Augmentation Systems based on Satellite infrastructure (SBAS - Satellite Based Augmentation System) and on Ground based ones (GBAS - Ground Based Augmentation System). The goal of this work is to present some results on SBAS and GBAS performances. Regarding SBAS, the Department of Applied Sciences of Parthenope University, after the acquisition of a Novatel OEM4 SBAS receiver has created a monitoring station that reflect as much as possible a standardized measure environment for EGNOS Data Collection Network (EDCN), established by Eurocontrol. The Department of Applied Science has decided to carry out a own monitoring survey to verify the performance of EGNOS that can be achieved in South Europe region, a zone not very covered by official (EDCN) monitoring network. Regarding GBAS, we started from a data set of measurements carried out at the GBAS of Milan-Linate airport where we work on a ground installation (GMS - Ground Monitoring Station) that supervises the GBAS signal and that represent, for our purposes, the Aircraft subsystem. So the set of data collected is to be considered in RTK mode and after the measures session we processed them with the software PEGASUS v 4.11. Both experiences give us the possibility to evaluate the GNSS1 performance that can be achieved.

• The Transactions of the Korea Information Processing Society
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• v.6 no.3
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• pp.699-709
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• 1999

This paper is aimed at defining items of analysis using SNMP MIB-II for the purpose of managing the Internet based network running on TCP/IP protocol, and then utilize these items, in conjunction with various Web technology and JAVA to design and implement a Web based interface of a management system to analyze the performance and status of the Internet. Among the required items in order to accomplish this task are utilization, interface packet transmission rate, I/O traffic ratio, and so on. Based on these items, the actual analysis is carried out by the Web interface according to the type of analysis. For instance, the interface executes the function of real-time analysis, collection processing, elementary analysis and detailed analysis. The demand of the user is fed into the Web interface which carried out a real-time analysis with the client system which in turn will eventually produce the results of the analysis. In order words, the interface acts as a mediator server for the analysis system. Furthermore, a protocol for exchange of data and messages between the server and the analysis system, the MATP protocol, was also designed. Finally, the results obtained through the system presented in this paper were displayed on screen according to the type of analysis. The system realized in this paper uses We technology and is independent of platform and allows the user to determine the performance of Internet at his/her own host according to the selected items of analysis.

• Analytical Science and Technology
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• v.13 no.1
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• pp.101-107
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• 2000

The automotive paints could be generally differentiated by color, layer sequence and chemistry of the paint layers comprising each of the topcoat and the primer system. The successful identification of hit-andrun a and traffic accidental vehicles from evidential paint fiagments is greatly facilitated with a comprehensive laboratory collection of reference paint samples and the technique for direct analysis without sample preparation. The Pyrolysis-Gas Chromatography(PGC) is a precise and reliable method for performing both quantitative and qualitative analysis of polymeric materials and forensic samples. Our Forensic Laboratory is conducting the examination and identification of 73 reference paint samples; 4 colors of each domestic automotive make that is popular in Korea, by Curie Point Pyrolyzer(JHP-3) and GC with capillary column(ultra alloy-5). This method can be used not only to compare paint traces with their suspected sources, but also to identify the type, make and model of the automotive car.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.125-134
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• 2009

Recently, as IT technology and the ubiquitous environment have diffused, the application of these techniques are being attempted in the field of traffic operations and management. Therefore, it is necessary to develop data collection systems and signal control strategies that are suitable in the ubiquitous environment and that will improve efficiency and safety of signalized intersections. The authors conducted a study on the Wireless Sensor Network (WSN) signal control strategy using a wireless communication network between individual vehicles and a signal-control system and full actuated signal control technique to propose a new signal control strategy in the ubiquitous environment. The WSN was defined to evaluate the algorithm used with PARAMICS API simulation. The simulation produced results that the WSN signal control is more effective than other signal control methods. The WSN signal control could reduce vehicle delay time to a maximum of 64% in comparison with other signal control methods in low and near saturation flow conditions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.4
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• pp.30-37
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• 2014

The Electronic Toll Collection System based on Free-Flow Multi-Lane is needed to solve some yearly problems such as traffic congestion, safety accident, maintenance by hold-up of one way hi-pass system. The hi-pass communication system is first-in, first-out method in one way environment so, it can't handle various running patterns such as vehicle platoon, switching lane and passing in multi-lane environment. In this thesis we compared and analyzed the communication system of foreign countries ETCS operating system and domestic hi-pass communication system, then studied communication system which can run in multiple-way accepting existing hi-pass OBU. And we formed the communication system of Free-Flow Multi-Lane environment as a plan using incoherent of IR antenna and coherent of RF antenna. The communication system in Free-Flow Multi-Lane environment can be used not alone in parking garages but in expressways of ETCS and toll roads from now on.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.1-8
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• 2021

With the rapid increase in the use of IoT and mobile devices, cyber criminals targeting IoT devices are also on the rise. Among IoT devices, when using a wireless access point (AP), problems such as packets being exposed to the outside due to their own security vulnerabilities or easily infected with malicious codes such as bots, causing DDoS attack traffic, are being discovered. Therefore, in this study, in order to actively respond to cyber attacks targeting IoT devices that are rapidly increasing in recent years, we proposed a method to collect traces of intrusion incidents artifacts from IoT devices, and to improve the validity of intrusion analysis data. Specifically, we presented a method to acquire and analyze digital forensics artifacts in the compromised system after identifying the causes of vulnerabilities by reproducing the behavior of the sample IoT malware. Accordingly, it is expected that it will be possible to establish a system that can efficiently detect intrusion incidents on targeting large-scale IoT devices.