• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.14-21
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• 2020

In order to provide confidential services between two communicating parties, block data encryption using a symmetric secret key is applied. A power analysis attack on a cryptosystem is a side channel-analysis method that can extract a secret key by measuring the power consumption traces of the crypto device. In this paper, we propose an attack model that can recover the secret key using a power analysis attack based on a deep learning convolutional neural network (CNN) algorithm. Considering that the CNN algorithm is suitable for image analysis, we particularly adopt the recurrence plot (RP) signal processing method, which transforms the one-dimensional power trace into two-dimensional data. As a result of executing the proposed CNN attack model on an XMEGA128 experimental board that implemented the AES-128 encryption algorithm, we recovered the secret key with 22.23% accuracy using raw power consumption traces, and obtained 97.93% accuracy using power traces on which we applied the RP processing method.

• Journal of Korea Multimedia Society
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• v.12 no.2
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• pp.200-208
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• 2009

JBIG2, as the next generation standard for binary image compression, must be designed in hardware modules for the JBIG2 FAX to be implemented in an embedded equipment. This paper proposes a hardware module of the high-speed Huffman coder for JBIG2. The Huffman coder of JBIG2 uses selectively 15 Huffman tables. As the Huffman coder is designed to use minimal data and have an efficient memory usage, high speed processing is possible. The designed Huffman coder is ported to Virtex-4 FPGA and co-operating with a software modules on the embedded development board using Microblaze core. The designed IP was successfully verified using the simulation function test and hardware-software co-operating test. Experimental results shows the processing time is 10 times faster than that of software only on embedded system, because of hardware design using an efficient memory usage.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.12
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• pp.48-54
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• 2010

This paper presents a high-performance architecture of integer-pel motion estimation circuit for H.264 video CODEC. Full search algorithm guarantees the best results by examining all candidate blocks. However, the full search algorithm requires a huge amount of computation and data. Many fast search algorithms have been proposed to reduce the computational efforts. The disadvantage of these algorithms is that data access from or to memory is very irregular and data reuse is difficult. In this paper, we propose an efficient integer-pixel motion estimation algorithm and the circuit architecture to improve the processing speed and reduce the external memory bandwidth. The proposed circuit supports seven kinds of variable block sizes and generates 41 motion vectors. We described the proposed high-performance motion estimation circuit at R1L and verified its operation on FPGA board. The circuit synthesized by using l30nm CMOS standard cell library processes 139.8 1080HD ($1,920{\times}1,088$) image frames per second and supports up to H.264 level 5.1.

• Journal of IKEEE
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• v.20 no.4
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• pp.398-411
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• 2016

SVM, a machine learning method, is widely used in image processing for it's excellent generalization performance. However, to add other data to the pre-trained data of the system, we need to train the entire system again. This procedure takes a lot of time, especially in embedded environment, and results in low performance of SVM. In this paper, we implemented an SVM trainer and classifier in an FPGA to solve this problem. We parlallelized the repeated operations inside SVM and modified the exponential operations of the kernel function to perform fixed point modelling. We implemented the proposed hardware on Xilinx ZC 706 evaluation board and used TSR algorithm to verify the FPGA result. It takes about 5 seconds for the proposed hardware to train 2,000 data samples and 16.54ms for classification for $1360{\times}800$ resolution in 100MHz frequency, respectively.

• Journal of IKEEE
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• v.20 no.4
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• pp.351-360
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• 2016

Recently, machine learning algorithms, especially deep learning-based algorithms, have been receiving attention due to its high classification performance. Among the algorithms, Convolutional Neural Network(CNN) is known to be efficient for image processing tasks used for Advanced Driver Assistance Systems(ADAS). However, it is difficult to achieve real-time processing for CNN in vehicle embedded software environment due to the repeated operations contained in each layer of CNN. In this paper, we propose a hardware accelerator which enhances the execution time of CNN by parallelizing the repeated operations such as convolution. Xilinx ZC706 evaluation board is used to verify the performance of the proposed accelerator. For $36{\times}36$ input images, the hardware execution time of CNN is 2.812ms in 100MHz clock frequency and shows that our hardware can be executed in real-time.

• Spatial Information Research
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• v.23 no.3
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• pp.91-100
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• 2015

We developed a micro UAV based rapid mapping system that provides geospatial information of target areas in a rapid and automatic way. Users can operate the system easily although they are inexperienced in UAV operation and photogrammetric processes. For the aerial data acquisition, we constructed a micro UAV system mounted with a digital camera, a GPS/IMU, and a control board for the sensor integration and synchronization. We also developed a flight planning software and data processing software for the generation of geo-spatial information. The processing software operates automatically with a high speed to perform data quality control, image matching, georeferencing, and orthoimage generation. With the system, we have generated individual ortho-images within 30 minutes from 57 images of 3cm resolution acquired from a target area of $400m{\times}300m$.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.71-81
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• 2011

In order to easily create video tutorials, the algorithm is needed that video camera recording, white board images, video attachments, and document data are combined in real-time. In this study, we implemented the video lecture content creation system using wavelet-based lossless compression to composite multimedia objects in real-time and reproduce the images. Using commercially available PC can be useful when lecturers want to make video institutional contents, it can be operated easily and fastly. Therefore, it can be very efficient system for e-Learning and m-Learning. In addition, the proposed system including multimedia synthesis technology and real-time lossless compression technology can be applied to various fields, different kinds of multimedia creation, remote conferencing, and e-commerce so there are highly significant.

• Korean Institute of Interior Design Journal
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• v.24 no.2
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• pp.171-179
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• 2015

The aim of this study is to figure out the preference features on design components of shop facade on the basis of the questionnaire survey on short-term memory and sensory memory of human right after an image experiment. As for a preceding research, this study examined the design features of facade into tangible elements and intangible elements, and also classified them into physical, aesthetical, marketing and symbolic components in detail. And, it extracted 5 representative elements in preceding studies including shape, material, pattern, color and sign, which is the standard of a questionnaire survey and preference analysis. The subjects of the experiment were 30 men and women who were over 20 years old majoring interior design. They were exposed to 20 images with 10 seconds respectively through a video, and were asked to respond the questionnaire promptly. The findings of preference analysis of design components of facade including shape, material, pattern, color and sign are as follows. Firstly, shape was the most interesting and attracting component, and designs applied with shape of objects such as 'web', 'drawer', 'wheel' and 'button' obtained high preference. Secondly, as for material, block, steel, exposed concrete board attracted higher preference as memorable materials than other materials. Material was affected by shape, pattern and color. Thirdly, pattern was the most lasting element. Designed pattern had higher preference than simple pattern. Fourthly, as for color, red and green with strong stimulation and attention attained priority having long lasting memory. Fifthly, when visiting a shop, sign out of 5 elements of shape, material, pattern, color and sign drew attention the most. As for the preference of location of sign, 'center top' was the most noticeable. The findings of this study could be utilized for facade design, and also could be used for commercialization considering highly preferred components, and top preference aspects of such elements. advised that to give an impression to customers is important to make a successful design for sales marketing, which, in turn, would lead customers to revisit the shop.

• Journal of Korean Neurosurgical Society
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• v.51 no.1
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• pp.8-13
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• 2012

Objective : This is prospective study of clinical outcomes of percutaneous plasma disc coagulation Therapy (PDCT) in patients with herniated lumbar disc disease (HLD) to evaluate the safety and efficacy in its clinical application and usefulness as a reliable alternative to microscopic discectomy. Methods : Forty-six patients were enrolled in this study from April 2006 to June 2010. All patients had one-level HLD. Disc degeneration was graded on routine T2-weighted magnetic resonance Image (MRI) using the Pfirrmann's grading system and all index levels were grade 3 and grade 4. Indications for surgery were radiculopathy caused by disc protrusion with soft consistency. MRI was done at one month after the procedure in all patients to check post-PDCT change. The clinical outcomes were evaluated using Visual Analog Scales (VAS) score and MacNab's criteria. Results : This study was approved by the Institutional Review Board of our institution. The age of the study population ranged from 16 to 59 years with a mean age of 37.2 years. There were 29 males and 17 females in this study. The mean period of clinical follow-up was 21 months. The average preoperative VAS score for radiculopathy was $7.4{\pm}1.4$, while the final follow-up VAS score was $1.4{\pm}0.7$ (p<0.001). In MacNab's criteria, 41 patients (89.1%) had achieved favorable improvement (excellent and good) until later follow-up. There were one patient from infection and two patients who needed to convert to open discectomy. Conclusion : PDCT is a safe and efficient treatment modality in a selective patient with HLD.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.677-680
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• 2008

Miniaturization of equipments which have wireless network function and sensor have changed utilization method of computer in daily life, and have contributed to development for ubiquitous computing environment. In this paper, we design camera control system based wireless mobile and web-environmental through which nurse, doctor and family of patient can share and observe the information on condition of patient in hospital. Besides, this camera control system makes it possible to integrate diverse equipments of hospital into one system, and to conduct remote control function which can be applied to the patient control system. It is impossible to control shooting direction of camera apparatus in a remote area for observing patient in a hospital room through general web camera. So in this paper, we showed new design; we attached step motor which can rotate 360 degrees to web camera, and the step motor can operate through control board. Besides, we developed application for two environments, mobile and web-based environment, which enables us to offer proper efficiency in accordance with condition of observer through observation of control and collected image data.