• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.168-172
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• 2005

An autopilot system of a ship is very important for a safe and convenient navigation, which is realized with getting an azimuth data from a gyrocompass, a magnetic compass and a GPS(Global Positioning System) compass. Magnetic compass an azimuth error is generated by a vessel magnetism material such as steels. The magnetic pole is detected by the magnetic field sensor, it does not coincide with the true north, therefore, the detected azimuth data can not but accompany error. In this paper, in order to detect the minimum change of azimuth data which generates errors of azimuth information, a search algorithm using the Kalman Filtering method is utilized. The digital electronic compass is designed with the integration algorithm using the merits of an earth's magnetic field sensor and a GPS receiver.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2586-2594
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• 2009

A digital watermarking technique used as a protection and certifying mechanism of copyrighted creations including music, still images, and videos in terms of finding any loss in data, reproduction and pursuit. This study suggests using a selected geometric invariant point through the whole processing procedure of an image and inserting and extracting based on the invariant point so that it will be robust in a geometric transformation attack. The introduced algorithm here is based on a watershed splitting method in order to make medical images strong against RST(Rotation Scale, Translation) transformation and other processing. It also helps to maintain the watermark in images that are compressed and stored for a period of time. This algorithm also proved that is has robustness against not only JPEG compression attack, but also RST attack and filtering attack.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.1
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• pp.11-21
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• 2008

Recently, it has shown an increased interest in 3D stereoscopic contents due to the development of the digital image media. Therefore, many techniques in 3D stereoscopic image generation have being researched and developed. However, it is difficult to generate high immersion and natural 3D stereoscopic contents, because the lack of 3D geometric information imposes restrictions in 2D image. In addition, control of the camera interval and rendering of the both eyes must be repetitively accomplished for the stereo effect being high. Therefore, we propose integrated editing system for 3D stereoscopic contents production using a variety of images. Then we generate 3D model from projective geometric information in single 2D image using image-based modeling method. And we offer real-time interactive 3D stereoscopic preview function for determining high immersion 3D stereo view. And then we generate intuitively 3D stereoscopic contents of high-quality through a stereoscopic LCD monitor and a polarizing filter glasses.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8C
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• pp.689-696
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• 2010

The goal of this paper is to present a novel method for protecting digital image using 2-D cellular automata transform (CAT). A copyright and transform coefficients are used to generate a new content-based copyright and an original digital image is distributed without any hidden copyright. The parameter, which is called gateway value, for 2-D CAT is consisted of rule number, initial configuration, lattice length, number of neighbors, and etc. Since 2-D CAT has various gateway values, it is more secure than conventional methods. The proposed algorithm is verified using attacked images such as filtering, cropping, JPEG compression, and rotation for robustness.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.4
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• pp.431-437
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• 2019

PLC(Power Line Communication) is being used in various ways in smart grid system because of the advantages of low cost and high data throughput. However, power line channel has many problems due to impulse noise and various studies have been conducted to solve the problem. Recently, ACDL(Adaptive Cannonical Differential Limiter) which is based on an adaptive clipping with analog nonlinear filter, has been proposed and performs better than the others. In this paper, we show that ACDL is similar to the detection of slew rate with oversampled digital signal by simplification and analysis. Through the simulation under the PRIME standard it is shown that the proposed performs equal to or better than that of ACDL, but significantly reduce the complexity to implement. The BER performance is equal but the complexity is reduced to less than 10%.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.325-333
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• 2006

Recently, in the case of observing the global environment, satellite remote sensing technology has been important. It's because satellite remote sensing is valuable for assessing relatively large areas. But now, small scale remote sensing techniques are needed which can be applicable to the detail investigation of plant tree areas which afforest land after the large scale construction of roads, dams and airports. In this study, we tried to develop and propose a lower altitude sensing technique which can be used in ground remote sensing by using a CCD camera. As a result of this investigation the following can be concluded: We recognized the transference characteristics of filters which were used in comparative tests about the four ground remote sensing devices. We also found that the near-IR camera could be used for an imaging spectral radiometer in the extraction of the vegetation index. Furthermore, we found that the vegetation index has varied hour by hour during the day of the experiment. Finally, we brought about an increase phase of the NDVI in a forest fire, which caused considerable damage, by developing new ground remote sensing technology.

• Progress in Medical Physics
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• v.14 no.3
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• pp.196-202
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• 2003

In 3-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT), many studies on reducing setup error have been conducted in order to focus the irradiation on the tumors while sparing normal tissues as much as possible. As one of these efforts, we developed an image enhancement and registration tool for simulators and portal images that analyze setup errors in a quantitative manner. For setup verification, we used simulator (films and EC-L films (Kodak, USA) as portal images. In addition, digital-captured images during simulation, and digitally-reconstructed radiographs (DRR) can be used as reference images in the software, which is coded using IDL5.4 (Research Systems Inc., USA). To improve the poor contrast of portal images, histogram-equalization, and adaptive histogram equalization, CLAHE (contrast limited adaptive histogram equalization) was implemented in the software. For image registration between simulator and portal images, contours drawn on the simulator image were transferred into the portal image, and then aligned onto the same anatomical structures on the portal image. In conclusion, applying CLAHE considerably improved the contrast of portal images and also enabled the analysis of setup errors in a quantitative manner.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.1
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• pp.51-58
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• 2013

As it is changing into aging society, rehabilitation, welfare and sports industry markets are being expanded fast. Especially, the field of vital signals interface to control welfare instruments like wheelchair, rehabilitation ones like an artificial arm and leg and general electronic ones is a new technology field in the future. Also, this technology can help not only the handicapped, the old and the weak and the rehabilitation patients but also the general public in various application field. The commercial bio-signal measurement instruments and interface systems are complicated, expensive and large-scaled. So, there are a lot of limitations for using in real life with ease. this thesis proposes a wireless transmission interface system that uses EMG(electromyogram) signals and a control module to manipulate hardware systems with portable size. We have designed a hardware module that receives the EMG signals occurring at the time of wrist movement and eliminated noises with filter and amplified the signals effectively. DSP(Digital Signal Processor) chip of TMS320F2808 which was supplied from TI company was used for converting into digital signals from measured EMG signals and digital filtering. We also have used PCA(Principal Component Analysis) technique and classified into four motions which have right, left, up and down direction. This data was transmitted by wireless module in order to display at PC monitor. As a result, the developed system obtains recognition success ratio above 85% for four different motions. If the recognition ratio will be increased with more experiments. this implemented system using EMG wrist direction signals could be used to control various hardware systems.

• Journal of KIISE:Software and Applications
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• v.27 no.5
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• pp.529-542
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• 2000

Recent years, the use of multimedia information is rapidly increasing, and the video media is the most rising one than any others, and this field Integrates all the media into a single data stream. Though the availability of digital video is raised largely, it is very difficult for users to make the effective video access, due to its length and unstructured video format. Thus, the minimal interaction of users and the explicit definition of video structure is a key requirement in the lately developing image and video management systems. This paper defines the terms and hierarchical video structure, and presents the system, which construct the clustering-based video hierarchy, which facilitate users by browsing the summary and do a random access to the video content. Instead of using a single feature and domain-specific thresholds, we use multiple features that have complementary relationship for each other and clustering-based methods that use normalization so as to interact with users minimally. The stage of shot boundary detection extracts multiple features, performs the adaptive filtering process for each features to enhance the performance by eliminating the false factors, and does k-means clustering with two classes. The shot list of a result after the proposed procedure is represented as the video hierarchy by the intelligent unsupervised clustering technique. We experimented the static and the dynamic movie videos that represent characteristics of various video types. In the result of shot boundary detection, we had almost more than 95% good performance, and had also rood result in the video hierarchy.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.1
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• pp.47-55
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• 2005

This work describes an 8b 240 MS/s CMOS ADC as one of embedded core cells for high-performance displays requiring low power and small size at high speed. The proposed ADC uses externally connected pins only for analog inputs, digital outputs, and supplies. The ADC employs (1) a two-step pipelined architecture to optimize power and chip size at the target sampling frequency of 240 MHz, (2) advanced bootstrapping techniques to achieve high signal bandwidth in the input SHA, and (3) RC filter-based on-chip I/V references to improve noise performance with a power-off function added for portable applications. The prototype ADC is implemented in a 0.18 um CMOS and simultaneously integrated in a DVD system with dual-mode inputs. The measured DNL and INL are within 0.49 LSB and 0.69 LSB, respectively. The prototype ADC shows the SFDR of 53 dB for a 10 MHz input sinewave at 240 MS/s while maintaining the SNDR exceeding 38 dB and the SFDR exceeding 50 dB for input frequencies up to the Nyquist frequency at 240 MS/s. The ADC consumes, 104 mW at 240 MS/s and the active die area is 1.36 ㎟.