• Environmental Engineering Research
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• v.10 no.2
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• pp.71-78
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• 2005

A series of column experiments was conducted to develop a monitoring system for in-situ and realtime measurement of ozone transport in unsaturated porous media using a fiber optic sensor. The calibration of the fiber optic transflection dip probe (FOTDP) system was successfully carried out at various ozone concentrations using a column with length of 30 cm and diameter of 5 cm packed with glass beads, which don't react with gaseous ozone. The breakthrough curves (BTCs) of ozone were obtained by converting the normalized intensity into ozone concentration. The FOTDP system worked well for in-situ monitoring of gas phase ozone at various water saturations and in presence of soil organic matter (SOM). However, the FOTDP system did not measure the ozone concentration at more than 70% water saturation.

• Journal of Korea Multimedia Society
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• v.21 no.5
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• pp.599-608
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• 2018

As natural disasters are increasing due to the unusual weather and the modern society is getting complicated, the rapid change of the urban environment has increased human disasters. Thus, citizens are becoming more anxious about social safety. The importance of preparation for safety has been suggested by providing the disaster safety services such as regional safety index, life safety map, and disaster safety portal application. In this paper, we propose an application framework to predict the urban safety index based on user's location with realtime weather/atmosphere data after creating a predication model based on the machine learning using number of occurrence cases and weather/atmosphere history data. Also, we implement an application to provide traffic safety index with executing preprocessing occurrence cases of traffic and weather/atmosphere data. The existing regional safety index, which is displayed on the Si-gun-gu area, has been mainly utilized to establish safety plans for districts vulnerable to national policies on safety. The proposed system has an advantage to service useful information to citizens by providing urban safety index based on location of interests and current position with realtime related data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1314-1321
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• 1999

This paper presents a performance comparison of commercial realtime operating systems which is widely used and guarantees short response time for call processing in IMT-2000 base station. For this, we analyzed wireless call process and extracted primitives which have strong influence on the performance of the system are derived. Constructing and running a test-bed for call processing on the basis of the analysis, we tested if there's a bottleneck in the performance of the system and compared the performances among the commercial realtime operating systems.

• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.161-170
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• 2005

The Certificate Revocation List(CRL) or the Online Certificate Status Protocol(OCSP)has been used to validate certificates. However, the CRL cannot validate certificates in realtime because of the Time-Gap problem and the OCSP server overloads in a large scale secure system. In addition, the client cannot access a wired LAN until the client has been authenticated by the authentication server on the IEEE 802. 1x framework. Therefore, the client cannot validate the authentication server's certificate using a certificate validation server. Thus, the client cannot authenticate the authentication server in realtime. To solve these problems this paper designed a secure system that can protect the content of communications and authenticate users in realtime on a wireless LAN The designed certificate validation protocol was proved that the stability and efficiency of the system was very high, the result of the validation had the presence, the speed of the validation was not affected by the system scale, the number of authorities user must trust was reduced to one, and the overload of the validation server was Protected. And the designed user authentication and key exchange protocols were Proved that the mutual authentication was possible in realtime and the fact of the authentication could be authorized by the CA because of using the authorized certificates.

• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.77-85
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• 2014

Recently, several environment damage caused by malicious or suspicious code is increasing. We study comprehensive response system actively for malware detection. Suspicious code is installed on your PC without your consent, users are unaware of the damage. Also, there are need to technology for realtime processing of Big Data. We must develope advanced technology for malware detection. We must analyze the static, dynamic of executable file for fundamentally malware detection in recently and verified by a reputation for verification. It is need to judgment of similarity for realtime response with big data. In this paper, we proposed realtime detection and verification technology using multiple filter. Our malware study suggests a new direction of realtime malware detection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6A
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• pp.565-572
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• 2007

3G Long Term Evolution (3G LTE) is a next generation cellular networks system capable or providing various mobile multimedia services by using OFDMA and MIMO based radio access technology. Among many differences from existing WCDMA based systems, the facts that 3G LTE uses Physical Resource Block (PRB) as its radio resources and provides all services through the PS domain make the development of new resource management schemes necessary. This paper proposes an adaptive partitioning based downlink call admission control scheme. It separates realtime call requests from non-realtime ones, specifies maximum allowable resource amounts for each type, but if the maximum is exceeded, call requests are accepted with probability proportional to remaining resource amounts. Despite the fact that such adaptive concept has been already adopted by other call admission schemes, the contributions of our paper, which are that we are able to find an efficient way to apply the proposed scheme exploiting PRB characteristics and measure the resource usage of base stations by PRB utilization and payload ratio, are still valid. When judging from simulation results in comparison with others, our scheme is able to prioritize realtime call requests over non-realtime ones, and at the same time, overall system performance is superior.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.1016-1024
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• 2008

In this paper, we designed and implemented the ACE(ACtive Emergency call service system) system for emergency call service actively. ACE system has two physical components; E-Device(Emergency Mobile Device) and E-Server(Emergency Server). The role of E-Device is the mobile device in order to call emergency by using mild handi-capped, the elderly and children who are able to communicate theirs intention to another. E-Server is the server for management E-devices with realtime monitering. E-Device will be developed to the portable size for easily mild handi-capped, the elderly and children. When they need the service of emergency call, the button of E-device can be used and the call signal is transmitted to the emergency office and the guardian through Internet and CDMA. E-server should be developed the integrated control system for management of E-Devices basically. And it also supported to realtime monitoring of E-devices with respect to high quality of emergency call service for rise the efficiency.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.50-51
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• 2014

Although price of construction equipment affects overall cost of a construction projects, the cycle of updating them presented in the Poom-Saem in Korea is more than six years. Recently there is a demand of using the 'Standard Market Price of Construction Equipment', published by the ministry of Security and Public Administration, for estimating equipment operating and ownership cost. It is urgent to introduce an advanced system for updating the prices which can timely reflect market changes.

• Journal of information and communication convergence engineering
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• v.18 no.3
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• pp.147-154
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• 2020

In this study, we created a system that can determine the number of vehicles entering and departing a charging station in real time for solving waiting time problems during refueling. Accordingly, we use the You Only Look Once object detection algorithm to detect and count the number of vehicles in the charging station and send the data to the Firebase Realtime Database. The result is shown using an Android application that provides a map function with the Kakao Maps API at the user interface side. Our system has an accuracy of 91% and an average response time of 3.1 s. Therefore, this system can be used by drivers to determine the availability of a charging station and to identify the charging station with the least waiting time for charging their vehicle.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.751-755
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• 2004

This paper presents a simplified dynamics of railway vehicle for a tilting train simulator. The tilting train simulator has 6 electric-driven actuators and a visualization system with 1600mm-diameter dome screen. The each system shares the data by ethernet. In order to analyze the dynamics of railway vehicle and transfer the results of the analysis to the other system of the tilting train simulator in realtime base, We assumed the tilting train as a simplified rigid body model with primary and secondary suspensions. The simplified vehicle model has a 17-DOF. Through the running analysis on the tight curve with various radius, we verified the simplified vehicle model.