• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.4
• /
• pp.381-391
• /
• 2013

Wireless transmission of uncompressed video guarantees higher quality with lower latency than compressed video transmission. Although current wireless technologies cannot fully cover required data rates of about a few Gb/s for full high definition resolution, some wireless technologies such as ultra-wideband (UWB) provide 1 Gb/s data rate which is adequate for uncompressed video transmission in portable devices. In this paper, we propose an uncompressed video transmission system for wireless mirroring services in portable devices. We firstly simulated the performance of uncompressed video transmission using single or multiple 1 Gb/s UWB technology. Then we implemented hardware-based uncompressed video processing block and Gb/s wireless MAC accelerator. Finally, we show the implementation result and the demonstration of uncompressed HD video transmission using multiple 1 Gb/s UWB PHYs.

• Journal of Ocean Engineering and Technology
• /
• v.18 no.6 s.61
• /
• pp.79-83
• /
• 2004

The curved blocks which compose the bow and stem of a ship contain many skewed joints that are inclined horizontally and vertically. Most of these joints have a large fitness error and are continuously changing their form and are not easily accessible. The welding position and parameter values should be appropriately set in correspondence to the shape and the inclination of the joints. The welding parameters such as current, voltage, travel speed, and melting rate, are related to each other and their values must be in a specific limited range for the sound welding. These correlations and the ranges are dependent up on the kind and size of wire, shielding gas, joint shape and fitness. To determine these relationships, extensive welding experiments were performed. The experimental data were processed using several information processing technologies. The regression method was used to determine the relationship between current voltage, and deposition rate. When a joint is inclined, the weld bead should be confined to a the limited size, inorder to avoid undercut as well as overlap due to flowing down of molten metal by gravity. The dependency of the limited weld size which is defined as the critical deposited area on various factors such as the horizontally and vertically inclined angle of the joint, skewed angle of the joint, up or down welding direction and weaving was investigated through a number of welding experiments. On the basis of this result, an ANN system was developed to estimate the critical deposited area. The ANN system consists of a 4 layer structure and uses an error back propagation learning algorithm. The estimated values of the ANN were validated using experimental values.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.1C
• /
• pp.23-33
• /
• 2007

Video compression is essential technique for fast and efficient transmission of a large amount of video data maintaining high quality. Also, motion estimation and motion compensation is most important technique for efficient video compression. A proposed method is improved diamond search method which uses split diamond pattern and rotated diamond pattern. In particular, the proposed method shows superb result when it is used for the sequence with a direction of camera moving. Moreover when it is used for the sequence with little motion, complexity is reduced considerably by using fewer search points. Also, by varying the number of initial search points, the propose method can provide several options in terms of duality or speed. Simulation results shows that the proposed method sustains better visual quality compared with diamond search method and HEXBS even by using fewer search points. Besides, compared with existing methods, it is able to conduct a motion estimation more efficiently by changing the number of search points adaptively according to motion of video data.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.2
• /
• pp.83-92
• /
• 2013

RSA-CRT is a widely used algorithm that provides high performance implementation of the RSA-signature algorithm. Many previous studies on each operation step have been published to verify the physical leakages of RSA-CRT when used in smart devices. This paper proposes SAED (subtraction algorithm analysis on equidistant data), which extracts sensitive information using the event information of the subtraction operation in a reduction algorithm. SAED is an attack method that uses algorithm-dependent power signal changes. An adversary can extract a key using differential power analysis (DPA) of the subtraction operation. This paper indicates the theoretical rationality of SAED, and shows that its results are better than those of other methods. According to our experiments, only 256 power traces are sufficient to acquire one block of data. We verify that this method is more efficient than those proposed in previously published studies.

• The KIPS Transactions:PartB
• /
• v.10B no.3
• /
• pp.311-320
• /
• 2003

The Optimal filter yielding optimal texture feature separation is a most effective technique for extracting the texture objects from multiple textures images. But, most optimal filter design approaches are restricted to the issue of supervised problems. No full-unsupervised method is based on the recognition of texture objects in image. We propose a novel approach that uses unsupervised learning schemes for efficient texture image analysis, and the band-pass feature of Gabor-filter is used for the optimal filter design. In our approach, the self-organizing neural network for multiple texture image identification is based on block-based clustering. The optimal frequency of Gabor-filter is turned to the optimal frequency of the distinct texture in frequency domain by analyzing the spatial frequency. In order to show the performance of the designed filters, after we have attempted to build a various texture images. The texture objects extraction is achieved by using the designed Gabor-filter. Our experimental results show that the performance of the system is very successful.

• The KIPS Transactions:PartD
• /
• v.13D no.3 s.106
• /
• pp.437-444
• /
• 2006

A chaos cipher system that focuses on the stream cipher system has a demerit that the longer the text is, the slower the speed of the encryption and description and the transmission and reception. On this study, we designed the cipher web mail system showing much better capabilities than the existing web mail system as the text is longer. In the embodiment of the cipher web mail system, we developed the key stream, the encryption and description of the text and the inside and outside mail viewer and so on. After the efficiency test, it was valued high in the respect of the speed of the encryption and description and the transmission and reception. And it made up for the defect of the stream cipher system. We expect that we can use it through the persistent applied study in the server system security, the file security, the security of the internet information, the protection of the e-commerce system information and other fields based on the cipher technique as the wide use cipher system that can replace the block cipher system.

• The KIPS Transactions:PartD
• /
• v.8D no.6
• /
• pp.771-780
• /
• 2001

EJB(Enterprise JavaBeans) is the server-side component model and its purpose is to reduce the complexity of software development and to increase software reusability. Many concerns for development of EJB components have recently been raised. However, it is difficult to compose EJB components provided by third parties through the plug-and-play method. Therefore, the composition method by lego block styles is needed for EJB components. In this paper, we propose an approach to composition of EJB components using the C2 architectural style. In order to support EJB composition, we modified the general C2 architecture framework. We propose how to create EJB wrappers that can compose EJB components according to the C2 framework. Our approach also enables developers to create a new composite EJB that uses a C2 architecture which is composed of EJB components. To do this, we propose how to create a new composite EJB.

• The KIPS Transactions:PartC
• /
• v.13C no.7 s.110
• /
• pp.843-850
• /
• 2006

This is devoted to first, to propose a hash chain algorithm that generates more secure key than conventional encryption method. Secondly, we proposes encryption method that is more secure than conventional system using a encryption method that encrypts each block with each key generated by a hash chain algorithm. Thirdly, After identifying the user via wired and wireless network using a user authentication method. We propose a divided session key method so that Although a client key is disclosed, Attackers cannot catch a complete key and method to safely transfer the key using a divided key method. We make an experiment using various size of digital contents files for performance analysis after performing the design and implementation of system. Proposed system can distribute key securely than conventional system and encrypt data to prevent attacker from decrypting complete data although key may be disclosed. The encryption and decryption time that client system takes to replay video data fie is analogous to the conventional method.

• Journal of Broadcast Engineering
• /
• v.9 no.4 s.25
• /
• pp.434-445
• /
• 2004

Motion Estimation is an essential module in video encoders based on international standards such as H.263 and MPEG. Many fast motion estimation algorithms have been proposed in order to reduce the computational complexity of a well-known full search algorithms(FS). However, these fast algorithms can not work efficiently in DSP processors recently developed for video processing. To solve for this. we propose an efficient motion estimation scheme optimized in the DSP processor like Philips TM1300. A motion vector predictor is pre-estimated and a small search range is chosen in the proposed scheme using strong motion vector correlation between a current macro block (MB) and its neighboring MB's to reduce computation time. An MPEG-4 SP@L3(Simple Profile at Level 3) encoding system is implemented in Philips TM1300 to verify the effectiveness of the proposed method. In that processor, we can achieve better performance using our method than other conventional ones while keeping visual quality as good as that of the FS.

• The KIPS Transactions:PartB
• /
• v.12B no.2 s.98
• /
• pp.123-130
• /
• 2005

In this paper, fingerprint identification algorithm using pixel direction factor in blocks is proposed to minimize false acceptance ratio and to apply security system. The proposed algorithm is that a fingerprint image is divided by 16 blocks, then feature parameters which have direct factors of $0^{\circ},\;45^{\circ},\;90^{\circ}\;and\;135^{\circ}$ is extracted for each block. Membership function of a reference fingerprint and an input fingerprint for the extracted parameters is calculated, then identification of two fingerprint is distinguished using fuzzy inference. False acceptance ratio is evaluated about different fingerprints of In kinds regardless of sex and shape which are obtained from adults, and false rejection ratio is evaluated about fingerprints which are obtained by adding fingerprints of 10 kinds on different fingerprints of 100 kinds. The experiment results is that false acceptance ratio is average $0.34\%$ about experiment of 4,950 times, and false rejection ratio is average $3.7\%$ about experiment of 1,000 times. The proposed algerian is excellent for recognition rate and security.