• Journal of Communications and Networks
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• v.6 no.1
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• pp.9-18
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• 2004

Self-encoded multiple access (SEMA) is a unique realization of random spread spectrum. As the term implies, the spreading code is obtained from the random digital information source instead of the traditional pseudo noise (PN) code generators. The time-varying random codes can provide additional security in wireless communications. Multi-rate transmissions or multi-level grade of services are also easily implementable in SEMA. In this paper, we analyze the performance of SEMA in additive white Gaussian noise (AWGN) channels and Rayleigh fading channels. Differential encoding eliminates the BER effect of error propagations due to receiver detection errors. The performance of SEMA approaches the random spread spectrum discussed in literature at high signal to noise ratios. For performance improvement, we employ multiuser detection and Turbo coding. We consider a downlink synchronous system such as base station to mobile communication though the analysis can be extended to uplink communications.

• The Journal of Information Technology
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• v.9 no.4
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• pp.49-55
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• 2006

In this paper, a new fragile watermarking algorithm for digital image is presented, which makes resolving the security and forgery problem of the digital image to be possible. The most suitable watermarking method that verifies the authentication and integrity of the digital image is the Wong's method, which invokes the hash function (MD5). The algorithm is safe because this method uses the hash function of the cryptology. The operations such as modulus, complement, shift, bitwise exclusive-or, bitwise inclusive-or are necessary for calculating the value of hash function. But, in this paper, an Arithmetic encoding method that only includes the multiplication operation is adopted. This technique prints out accumulative probability interval, which is obtained by multiplying the input symbol probability interval. In this paper, the initial probability interval is determined according to the value of the key, and the input sequence of the symbols is adjusted according to the key value so that the accumulative probability interval will depend on the key value. The integrity of the algorithm has been verified by experiment. The PSNR is above the 51.13db and the verifying time is $1/3{\sim}1/4$ of the verifying time of using the hash function (MD5), so, it can be used in the real-time system.

• Journal of the Society of Disaster Information
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• v.12 no.3
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• pp.249-260
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• 2016

This paper introduces the results of analysis of questionnaries for developing the effective responding method against social disasters by using ICT technologies. Over 200 peoples including 146 citizens and 55 officials and fireman responded on the questionnaries. In analytical results, approximately 87% citizens answered that the current disaster responding system has some problems, and also over 82% citizens is expecting that ICT is available to reduce the social disaster. For the question of necessity and efficiency of ICT implementation, many officials answered that the information of GIS and facilities would be mostly useful information to respond the social disaster.

• Journal of Korea Multimedia Society
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• v.10 no.5
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• pp.668-678
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• 2007

The development of a wire and wireless communication technologies might permit easily accessing on various information. But, the easiness of accessing information has basically the problem of an unintended information outflow. An executable file which has key algorithms, data and resources for itself has very weak point in the security. Because the various information such as algorithms, data and resources is included in an executable file on embedded systems or virtual machines, the information outflow problem may appear more seriously. In this paper, we propose a technique which can be protecting the executable file contents for resolving the outflow problem through the encryption. Experimentally, we applied the proposed technique to EVM-the virtual machine for embedded system and verified it. Also, we tried a benchmark test for the proposed technique and obtained reasonable performance overhead.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.227-228
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• 2014

In this paper, a license plate investigation which is one of parking usage is performed. We survey research that should be given time interval using the camera without the observer. We assigned the investigation time interval to each of to each of the parking car, average parking duration is determined. Parking turnover, the number of vehicles of parking per hour per parking surface, is examined.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.205-207
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• 2014

This paper uses $Color-x^2$ histogram that is composed of merits of color histogram and ones of histogram, in order to efficiently extract violent scenes in elevator. Also, we use a threshold so as to find out key frame, by use of existing $Color-x^2$ histogram. To increase the probability that discerns whether a real violent scene or not, we take advantage of statistical judgments with 20 sample visual images.

• Annual Conference of KIPS
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• 2013.05a
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• pp.695-697
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• 2013

Medical data sharing is increasing due to treatment duplication which increases the cost of medication. Medical healthcare system has been improved to combine with cloud computing. It reduces treatment delay and the medical data error. However, the concern about the privacy protection of medical information is also significant. Medical information is more sensitive than other information because involuntary disclosure can affect in both personal and social life. Privacy cloud brokerage has conquered great attention for solving these problems. Our method provides a security model in the cloud computing environment that facilitates the exchange of medical records between assigned custodians. It allows doctors to obtain a complete patient medical records which can help to avoid duplication, reduce the medical error and healthcare cost as well. In addition, our method offers a trustworthy solution against the privacy violence.

• Journal of Internet Computing and Services
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• v.6 no.6
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• pp.1-12
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• 2005

The number of web contents is enormous in the billions and rapidly growing, Most contents are state, but an increasing number are generated dynamically, Therefore, Internet-based client/server architecture of Contents Delivery Service System suffers from frequent disconnections and security threats casused by dependency of the server or overload. Idle computing resources in Internet are used for sloving these issues, In this paper, We implement and design the Content Delivery Service System for cyber education system using idle Computing Power in P2P computing to share computing resources, We implement not only internet infrastructure but also satellite infrastructure system. and designed to transfer real-time or non real-time contents.

• Journal of Digital Contents Society
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• v.14 no.4
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• pp.589-596
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• 2013

With the increase of social crime rate, the interest on the intelligent security system is also growing. This paper proposes a detection system of monitoring whether abnormal behavior is being carried in the images captured using CCTV. After detection of an object via subtraction from background image and morpholgy, this system extracts an abnormal behavior by each object's feature information and its trajectory. When an object is loitering for a while in CCTV images, this system considers the loitering as an abnormal behavior and sends the alarm signal to the control center to facilitate prevention in advance. Especially, this research aims at detecting a loitoring act among various abnormal behaviors and also extends to the detection whether an incoming object is identical to one of inactive objects out of image.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.5
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• pp.645-661
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• 2012

Recently, pirates are infesting on the sea and they have been hijacking the several vessels for example Samho Dream and Samho Jewelry of Korea. One of the items to reduce the risk is to adopt the invader detection system. If the pirates break in to the ship, the detection system can monitor the pirates and then call the security alarm. The crew can gain time to hide to the safe room and the report can be automatically sent to the control room to cope with the situation. For the invader detection, an unmanned observation system was proposed using the image detection algorithm that extracts the invader image from the recording image. To detect the motion area, the difference value was calculated between the current image and the prior image of the invader, and the 'AND' operator was used in calculated image and edge line. The image noise was reduced based on the morphology operation and then the image was transformed into morphological information. Finally, a neural network model was applied to recognize the invader. In the experimental results, it was confirmed that the proposed approach can improve the performance of the recognition in the invader monitoring system.