• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.393-408
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• 2004

There exists a clear need to monitor the performance of civil structures over their operational lives. Current commercial monitoring systems suffer from various technological and economic limitations that prevent their widespread adoption. The wires used to route measurements from system sensors to the centralized data server represent one of the greatest limitations since they are physically vulnerable and expensive from an installation and maintenance standpoint. In lieu of cables, the introduction of low-cost wireless communications is proposed. The result is the design of a prototype wireless sensing unit that can serve as the fundamental building block of wireless modular monitoring systems (WiMMS). An additional feature of the wireless sensing unit is the incorporation of computational power in the form of state-of-art microcontrollers. The prototype unit is validated with a series of laboratory and field tests. The Alamosa Canyon Bridge is employed to serve as a full-scale benchmark structure to validate the performance of the wireless sensing unit in the field. A traditional cable-based monitoring system is installed in parallel with the wireless sensing units for performance comparison.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.603-606
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• 2013

Mobile and wireless communication technologies to the development of a variety of next-generation mobile networks such as smart phones, tablet PC and mobile terminals will coexist various access networks. In a variety of network service continuity and quality of service degradation due to network conditions, and the EPC network traffic overload phenomenon still remains a problem. In this paper, the EPC network traffic overload in distributed cloud servers is proposed to select. Our proposed scheme using an efficient network handover can provide optimal service according to the network condition.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.127-134
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• 2013

While there are many services that can check current traffic condition and application program such as bus arrival alarm are developed, since it only provide simple alarm and check level of information, it is still insufficient in many senses. Therefore, the program that try to develop in this study is the system that predict arrival time to destination and inform the bus passengers by applying real time traffic information. The system developed related to this study is still very inadequate. In the system developed in this thesis, when the user input the current bus number and destination using smart-phone, relevant server acquire the bus route information from bus information DB, and analyze real time traffic information based on the information from traffic information DB, and inform customer of expected arrival time to destination. In this thesis, traffic congestion can be eased off and regular operation of public transportation can be improved with reliable destination arrival alarm. Also, it is considered that pattern of bus users can be analyzed by using these information, and analyzing average transport speed and time of public transportation, travel time depending on various situation can give a boost to study related to transportation information and its development.

• Korean Journal of Artificial Intelligence
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• v.9 no.2
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• pp.29-34
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• 2021

In this paper, for efficient parking control, in an Arduino environment, an intelligent parking control prototype was implemented to provide parking control and parking guidance information using HC-SR2O4 and RC522. The main elements of intelligent parking control are vehicle recognition sensors, parking control facilities, and integrated operating software. Whether the vehicle is parked on the parking surface may be confirmed through sensor or intelligent camera image analysis. Parking control equipment products include parking guidance and parking available display devices, vehicle number recognition cameras, and intelligent parking assistance systems. This paper applies and implements ultrasonic sensors and RFID concepts based on Arduino, recognizes registered vehicles, and displays empty spaces. When a vehicle enters a parking space to handle this function, the automatic parking management system distinguishes the registered vehicle from the external vehicle through the RC522 sensor. In addition, after checking whether the parking slot is empty, the HC-SR204 sensor is displayed through the LED so that the driver can visually check it. RFID is designed to check the parking status of the server in real time and provide the driver with optimal route service to the parking slot.

• Journal of KIISE:Databases
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• v.33 no.7
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• pp.655-667
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• 2006

Due to the rapid development in mobile communication technologies, the usage of mobile devices such as cellular phones and PDAs becomes increasingly popular. One of the best ways to maximize the usability of mobile devices is to make them aware of their current locations and the locations of other fixed and mobile objects. In this paper, we propose a cost-effective Bus Information System, ACE-BIS, which utilizes a mobile device to retrieve the bus routes to reach a destination from the current location. To accomplish this task, ACE-BIS maintains a small amount of information on bus stops and bus routes in a mobile device and runs a heuristic routing algorithm based on such information. When a user asks more accurate route information or calls for a 'leave later query', ACE-BIS entrusts the task to a server into which real-time traffic and bus location information is being collected. By separating the roles into a mobile device and a server, ACE-BIS is able to provide bus routes at the lowest cost for wireless communications, without imposing much burden to a server. The results of extensive experiments revealed that ACE-BIS is effective and scalable in most experimental settings.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.259-266
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• 2005

Recently data centric routing or application dependent routing protocols are emerged in mobile ad hoc networks. In this paper, we propose a routing method for query processing in MANET(Mobile Ad hoc NETwork) environment, called road-based query routing, with consideration on real time traffic information of large number of vehicles. In particular, we focus on the method that process arrival time dependent shortest path query in MANET without a central server on the road networks. The main idea of our approach lies in a routing message that includes query predicates based on the road connectivity and on data gathering method in real time from vehicles on the road by ad-hoc network. We unify route discovery phase and data delivery(query processing) phase in our mechanism and reduce unnecessary flooding messages by pruning mobile nodes which are not on the same or neighboring road segments. In order to evaluate the performances of the proposed method, we established a model of road networks and mobile nodes which travel along the roads. The measurement factor is the number of nodes to whom route request is propagated according to each pruning strategy. Simulation result shows that road information is a dominant factor to reduce the number of messages.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.291-298
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• 2015

It is pretty hard to sell the kids' furniture online because of the characteristics of the consumers that they will like to make purchases after looking at the actual objects and then considering purchasing them. In this paper, we made the scheme to boost the on-line malls of the kids' furniture market by collecting the consumers' intention to buy before purchasing with questionnaire survey, comparing it with the real data of purchasing, and analyzing the differences. We analyzed the visit number of shopping mall, the page number of views, page duration time per visit, and customer's shopping path by using log data from the children's furniture online shopping mall server. In addition, we analyzed where the customer's influx route is among online advertising. We found that there are requirements for the designs, prices, brand names, and practicalities by the consumers purchasing the kids' furniture online. To strengthen competitiveness of the online kids' furniture malls, we proposed that reinforcing the on-line experiences of furniture, the differential strategies for the products, ensuring the fixed customers are needed.

• Journal of KIISE:Information Networking
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• v.35 no.2
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• pp.120-129
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• 2008

The purpose of sensor network is gathering the information from sensor nodes. If there are selfish node that deliberately avoid packet forwarding to save their own energy, the sensor network has trouble to collect information smoothly. To solve this problem we suggest a mechanism which uses credit payment schema according to the amount of forwarding packets. Sensor nodes use credits to send their own message and they forward packets of other sensor nodes to get credits. To offer authenticity we combined the roles of sink node and server, also we used piggybacking not to send additional report message. The packet trace route is almost fixed because sensor node doesn't have mobility. In this case, it happens that some sensor nodes which don't receive forwarding packets therefore they can't get credit. So, we suggested the way to give more credits to these sensor nodes. Finally, we simulated the suggested mechanism to evaluate performance with ns2(network simulator). As a result, packet transmission rate was kept on a high rate and the number of arrival packets to sink node was increased. Also, we could verify that more sensor nodes live longer due to deceasing the energy consumption of sensor nodes.

• Journal of Digital Contents Society
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• v.18 no.7
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• pp.1403-1409
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• 2017

As the Internet evolves, security becomes more important. Especially, e-mail has become one of the most important services that companies and ordinary users use on the Internet. However, security vulnerabilities such as sniffing attacks, IDs, and password spoofs are causing many problems. This paper introduces an example of implementation of encrypted mailing program with which the secured mail is encrypted by symmetric key methode and the encrypted message can not be read without proper decryption. In order to use the current mailing systems, we keep the rules related to SMTP and POP3, and only the encrypted message is stored in the mail server system and the message can be decrypted only at the terminals of the senders and the receivers with the key which is shared in advanced by independent route between them. This implementation scheme can provide an efficiency that it does not request any change of current mailing system, which can be an additional security protection.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.263-266
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• 2017

Numerous maritime safety technologies and systems are being developed to support safe navigation at Sea. e-Navigation is a representative system for maritime safety. It is being developed to maximize the ships safety by applying most maritime safety technologies. The e-Navigation system is being developed by the International Maritime Organization (IMO) with the aim of introducing it by 2019. South Korea has already recognized the importance of maritime safety support technology and is actively introducing e-Navigation. Korean e-Navigation is being designed to provide diverse functions for maritime safety, such as providing an optimal safe route, risk analysis, and weather information. Service modules that provide e-Navigation's each function use different types of data that are difficult to configure as a single database. In this paper, we analyze the data needed for Korean e-Navigation, the data service system structure and types that can effectively support it.