• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.177-184
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• 1987

The quantitative mechanics on the sideways walking of the crabs may provide a basic solution for entanglements of the walking legs in gillnets. The gaiting behaviour of the crabs on the flat board and the nettings 10, 16 and 23 mm in mesh size were experimented concerning about stepping positions and times in the laboratory using video set on July, 1984, It was found that the irregular movements of walking crabs in stepping positions and patterns were appeared on the nettings due to the absence of mechanical contact in spite of neural control of compensating, while on the flat surface evolved systematic leg movements. The mean stride length and walking velocity, which were increased with the carapace width on the flat board, as well as the step period and forward by backward stroke time were greater than those values on the netting, not associated with the carapace or the mesh size. Also, the step period and the Phase difference on the nettings revealed larger fluctuation than on the flat board. The joint angles of the walking legs, on the nettings in meropodite-carporodite and thorax-meropodite, which joint was varied especially up to below horizon because of the falling legs through the netting twine, were virtually wider than those on the flat substrate.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.275-280
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• 2013

With rapidly growing mobile wireless services, the existing copper-based mobile backhaul technologies suffer from reaching the capacity limits. PON technologies is drawing attention as a key solution to replace the existing mobile backhaul technologies due to not only providing innovative network capacity but also cost-effective maintenance caused by the bandwidth gain from optical fibers. With a PON-based mobile backhaul, broadband wireless multimedia services such as a video conference and IPTV can be seamlessly provided. In this paper, we first introduce overview of the PON-based mobile backhaul technology. For a example of practical integration, three types of EPON-WiMAX integrated architectures are proposed and comparatively analyzed in term of costs and network performance. Then, applicable plan and anticipated effects are presented when applying network coding on the PON-based mobile backhaul to improve the performance of delivering multicast traffic.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.6
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• pp.194-203
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• 2008

Though conventional video surveillance systems such as CCTV depended on operators, recently developed intelligent surveillance systems no longer needed operators. However, these new intelligent surveillance systems have their own problems such as Occlusion, changing scale of target object, and affine. This paper handled information damage caused by changing the scale of the target object among other objects. Due to the change of the scale, the inaccurate information of target can be obtained when we update the background information. To handle this problem, we introduce a solution for information damage caused by problem of changing scale of target object located among other objects. Specifically, we suggest multi-stage sampling particle filter based advanced MSER for object tracking system. Through this method, the problem caused by changing scale of target can be avoided.

• Journal of KIISE:Software and Applications
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• v.33 no.10
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• pp.823-835
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• 2006

Multimedia is a very popular service in the Internet. But, we cannot provide multimedia service at a uniform content, because networks and devices are various. Thus, an adaptive service is needed for multimedia transmission. Video Transcoding is the good solution that can service multimedia adaptively. This paper proposes the streaming system that is composed of encoder, transcoder, decoder The encoder enhanced time complexity and PSNR in case of transcoding using PP(Prediction Period). The decoder is almost same as the traditional media player. Transcoder reduced time complexity through combination of prediction period in encoder and skipping period to control frame rate in transcoder. In simulation results, the performances of proposed scheme outperform the system with traditional transcoder in time complexity and PSNR.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.471-476
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• 2016

Recently, important information related with smart work such as office and video conference are handled in smart device quite a lot compare with before. Also, execution environment of smart devices is getting developed as open software environment. It brought convenience to download and use any kind of application software. By that, security side of smart devices became vulnerable. This paper will discuss characteristics of smart device security technology based on virtualization that is a mobile device platform with isolated secure execution area based on TEE (Trusted Execution Environment). Also, this paper will suggest an implementation method about safe smart device security platform based on domain separation for application software which can be executed in smart devices. The domain separation based smart device security platform technology in this paper blocks unauthorized access and leakage of sensitive information in device. Also it will be the solution can block transmission and execution of malicious code in various area including variety of IoT devices in internet rather than just smart devices.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.1
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• pp.26-45
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• 2001

The Flash memory market: is an exciting market that has quickly over the last 10 years. Recently Flash memory provides a high-density. truly non-volatile, high performance read write memory solutions, also is characterized by low power consumption, extreme ruggedness and high reliability. Flash memory is an optimum solution for large nonvolitilc storage operations such as solid file storage, digital video recorder, digital still camera, The MP3 player and other portable multimedia communication applications requiring non-volatility. Regardless of the type of Flash memory, Flash media management software is always required to manage the larger Flash memory block partitions. This is true, since Flash memory cannot be erased on the byte level common to memory, but must be erased on a block granularity. The management of a Flash memory manager requires a keen understanding of a Flash technology and data management methods. Though Flash memory's write performance is relatively slow, the suggested algorithm offers a higher maximum write performance. Algorithms so far developed is not suitable for applications which is requiring more fast and frequent accesses. But, the proposed algorithm is focused on the justifiable operation even in the circumstance of fast and frequent accesses.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.2
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• pp.69-75
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• 2012

This paper presents a novel de-interlacing algorithm that can make up motion compensation errors by using maximum a posteriori (MAP) estimator. First, a proper registration is performed between a current field and its adjacent fields, and the progressive frame corresponding to the current field is found via MAP estimator based on the computed registration information. Here, in order to obtain a stable solution, well-known bilateral total variation (BTV)-based regularization is employed. Next, so-called feathering artifacts are detected on a block basis effectively. So, edge-directional interpolation is applied to the pixels where feathering artifact may happen, instead of the above-mentioned temporal de-interlacing. Experimental results show that the PSNR of the proposed algorithm is on average 4dB higher than that of previous studies and provides the better subjective quality than the previous works.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.3
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• pp.701-712
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• 2016

The number of subscriber of digital pay TV service such as Digital Cable TV and IPTV is increasing from various kind of service provider world widely. These services require personal information of users to provide VOD(Video on Demand) and customized contents. Therefore, massive amount of personal information collected by service provider can cause social confusion such as leakage of privacy and property damage. This paper investigates whether broadcasting stations are providing enough notification for privacy policy and methodology of collecting private information in proper way. Furthermore, we analyze actual network traffic of IPTV service between user and service provider to suggest solution of privacy protection along with current status analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8B
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• pp.613-619
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• 2012

The Long Term Evolution (LTE) system is already able to provide a background of variety services for mobile users with multimedia services such as audio, video, and data. In fact, the High Speed Packet Access plus (HSPA+) solution can greatly enhance bit rates on down-link. However, the supporting for multimedia applications with different QoS (Quality of Service) requirements is not devised yet. Hence, in this paper we propose an effective packet scheduling algorithm based on Proportional Fairness (PF) scheduling algorithms for the LTE. In this proposed packet scheduling scheme, we optimized instantaneous user data rates and the traffic class weight which prioritize user's packets. Finally, we evaluated and showed the performance of the proposed scheduling algorithm through simulations of multimedia traffics being transmitted to users over LTE links in a multi-cell environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5C
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• pp.505-513
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• 2009

This paper proposes a real-time foreground segmentation and background substitution method for protecting the privacy on visual communication. Previous works on this topic have some problems with the color and shape of foreground and the capture device such as stereo camera. we provide a solution which can segment the foreground in real-time using fixed mono camera. For improving the performance of a foreground extraction, we propose the Temporal Foreground Probability Model (TFPM) by modeling temporal information of a video. Also we provide an boundary processing method for natural and smooth synthesizing that using alpha matte and simple post-processing method.