• Journal of Korean Society of Transportation
• /
• v.25 no.5
• /
• pp.23-32
• /
• 2007

Variable message sign (VMS), which is used for providing real-time information on traffic conditions and incidents, is one of the important components of intelligent transportation systems. VMS messages need to meet the requirements with the consideration of human factors that messages should be readable and understandable while driving. This study developed a legibility distance model for VMS messages using in-vehicle differential global positioning data (DGPS). Traffic conditions, highway geometric conditions, and VMS message characteristics were investigated for establishing the legibility model based on multiple linear regression analysis. The height of VMS characters, speed, and the number of lanes were identified as dominant factors affecting the variation of legibility distances. It is expected that the proposed model would play a significant role in designing VMS messages for providing more effective real-time traffic information.

• Journal of Korea Society of Industrial Information Systems
• /
• v.24 no.6
• /
• pp.43-53
• /
• 2019

In recent years, there have been many cases of damage to indoor air hazardous materials, and major damage due to the lack of quick action. In this regard, the system is intended to establish for sending push messages to the user's mobile when the concentration of hazardous substances is exceeded. This system extracts data with IoT system such as Arduino and Raspberry Pi and then constructs database through MongoDB and MySQL in cloud computing system. The database is imported through the application server using NodeJS and sent to the application for visualization. Also, when receiving signals about a dangerous situation in IoT system, push message is sent using Google FCM library. Mobile application is developed using Android Web view, and page to enter Web view is developed using HTML5 (HTML, Javascript CSS). The application of this system enables real-time monitoring of indoor air-dangerous substances. In addition, real-time information on indoor/outdoor detection location and concentration can be sent to the user's mobile in case of a risk situation, which can be expected to help the user respond quickly.

• Journal of Institute of Control, Robotics and Systems
• /
• v.8 no.6
• /
• pp.506-513
• /
• 2002

Distributed control systems(DCS) using fieldbus such as CAN have been applied to process systems but it is very difficult to design the DCS while guaranteeing the given end-to-end constraints such as precedence constraints, time constraints, and periods and priorities of tasks and messages. This paper presents a scheduling method to guarantee the given end-to-end constraints. The presented scheduling method is the integrated one considering both tasks executed in each node and messages transmitted via the network and is designed to be applied to a general DCS that has multiple loops with several types of constraints, where each loop consists of sensor nodes with multiple sensors, actuator nodes with multiple actuators and controller nodes with multiple tasks. An assignment method of the optimal period of each loop and a heuristic assignment rule of each message's priority are proposed and the integrated scheduling method is developed based on them.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.344-346
• /
• 2016

FHIR is a protocol that enables easy data exchange from the time the event occurred in health care settings as a standard for next-generation message exchange of HL7. Create a meaningful message from the ECG and medical equipment, and express the messages generated by standardized FHIR message it will be used in various medical institutions to ensure delivery to EMR, such as hospital information systems can query the results via a smartphone. In addition, it thought to be used in the future to expand SMART on FHIR, Cardiology, Cardiovascular Surgery ward in real-time remote monitoring.

• Journal of Korean Society of Transportation
• /
• v.17 no.1
• /
• pp.91-102
• /
• 1999

The objective of this study is to evaluate traffic management strategies using Variable Message Signs(MCS) on urban freeways. It is well known that real-time information on traffic conditions increases driver's comfort, and reduces the risks of accidents if drivers are aware of the traffic situation in advance, they decide whether to divert from the freeway or continue on the planned route. The experimental data collected on the Olympic highway we have shown the following results : 1. when the information on both the congested freeway and uncontested diversion route is displayed on the variable message sign. an additional 1.7 percent of traffic diverted, which results in a 3.7 percent reduction in total travel time. 2 Compared with one Proposed VMS message of 'reduce the speed', the other Proposed VMS message of 'keep speed 70km/h' is found to be much more effective in reducing mean speed.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.12
• /
• pp.3804-3814
• /
• 2000

This paper presents an efficient implementation of a run-time monitor which checks the satisfaction of the timing constraints of real-time object-oriented programs based on a real-time object model called TMO(Time-triggered Messagedtriggered Object). An execution environment of TMO programs on Windows as, WTMOS(Windows TMO System) has been utilized for the implementation and an experimental application for thermostatic control has been developed to analyze the performance of the run-time monitor. We suggest a methodology for application programmers to specify the target methods with the monitoring conditions and an implementation technique which incurs the small cost by effectively distributing the functions of the monitor into the WTMOS and a TMO object.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.10
• /
• pp.1018-1023
• /
• 2010

The CAN (Controller Area Network) system is the most dominant protocol for in-vehicle networking system because it provides bounded transmission delay among ECUs (Electronic Control Units) at data rates between 125Kbps and 1Mbps. And, many automotive companies have chosen the CAN protocol for their in-vehicle networking system such as chassis network system because of its excellent communication characteristics. However, the increasing number of ECUs and the need for more intelligent functions such as ADASs (Advanced Driver Assistance Systems) or IVISs (In-Vehicle Information Systems) require a network with more network capacity and the real-time QoS (Quality-of-Service). As one approach to enhancing the network capacity of a CAN system, this paper introduces a CAN system with dual communication channel. And, this paper presents a distributed message allocation method that allocates messages to the more appropriate channel using forecast traffic of each channel. Finally, an experimental testbed using commercial off-the-shelf microcontrollers with two CAN protocol controllers was used to demonstrate the feasibility of the CAN system with dual communication channel using the distributed message allocation method.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.27 no.1
• /
• pp.65-71
• /
• 2017

Since existing Internet of Things(IoT) is vulnerable, it may cause property damage due to the information leakage. Especially, the smart door lock system built on the IoT can cause more damage. To solve these problems, this paper classify the data generated by the sensor according to the condition and send an alarm message to the user's smartphone through Google Cloud Message (GCM). We made it possible to check the images in real time through the smartphone application and control the door lock using the TCP / IP protocol. Also, we applied OTP-Based Matrix SEED algorithm to door lock system to improve security.

• Journal of Korea Multimedia Society
• /
• v.11 no.7
• /
• pp.1007-1015
• /
• 2008

In order to provide real-time data from sensors and instruments at manufacturing processes on web, we proposed a communication service model based on XML(eXtensible Markup Language). HTML(Hyper Text Markup Language) is inadequate for describing real-time data from manufacturing plants while it is suitable for display of non-real-time multimedia data on web. For applying XML-based web service of process data in Intranet environment, real-time performance of communication services was evaluated to provide the system design criteria. XML schema for the data presentation was proposed and its communication performance was evaluated by simulation in terms of transmission delay due to increased message length and processing delay for transformation of raw data into defined format. For transformation of raw data into XML format, we proposed two structures: one is the scheme where transformation is done at an SCC(Supervisory Control Computer) after receiving real-time data from instruments. the other is the scheme where transformation is carried out at instruments before the data are transmitted to the SCC. Performances of two structures were evaluated on a testbed under various conditions such as six packet sizes and offered loads of 20%, 50% and 80%, respectively. Test results show that proposed schemes are applicable to the systems in Ethernet 100BaseT network if total message traffic is less than 7 Mbps.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.3
• /
• pp.361-369
• /
• 2018

This paper proposes a design of asymmetric time division multiple access method for tactical radio communication. Typical tactical radio communication has a limited execution of transmission, because uplink message requires more extended response time than downlink message. In order to solve this problem, this paper analyzes operational environment of Korean tactical radio communication and proposes an asymmetric TDMA based on it for performance of tactical communication. The simulation model is used to investigate constraints of real experiments for proving effectiveness of the proposed approach. Simulations results show that the proposed scheme outperforms the conventional scheme in terms of throughput, response time, and delay.