• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.110-112
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• 2000

Recently, the interest and the importance of the signal monitoring and recording during sleep is increasing. Conventional paper based recording systems are being replaced by digital type and polysomnographic system. We developed special digital signal processor system for the polysomnographic recording. This system consists of digital signal processing part and PC interface part for user's convenience. This system includes two digital filters, one fur low pass filtering of high frequency noise and the other for notch filtering of 60Hz AC noise. This system can be used for the efficient and convenient measurement of polysomnographic signals and also can be developed for the portable use.

• The KIPS Transactions:PartB
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• v.16B no.1
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• pp.25-34
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• 2009

DVR(Digital Video Recorder) system stores video inputs in compressed digital formats and retrieve them. DVR system has several advantages over traditional analog tape recorder system which are (1) improved real-time monitoring, recording and searching capability, and (2) other capabilities such as watermarking and remote monitoring through network. AVI format is the most popular format used for DVR systems. However, AVI format has drawbacks in recording and searching due to structural problem. Some vendors develop and use their own format, do not open the format to the public. In this paper, ESP format is proposed. ESP format solves the drawbacks of AVI format, and the advantages of AVI format apply to ESP format. Moreover, ESP format provides multistream recording/replay and event-recording. In result, ESP format enchances functionality of recording and searching in DVR system.

• Korean Journal of Optics and Photonics
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• v.17 no.4
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• pp.335-341
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• 2006

A modified Michelson interferometer type digital holography microscopy system is developed. There is a problem about recording and numerical reconstruction area at the microscopy application of Michelson type interferometer structure in the digital holography field. In this paper, to overcome this problem, we developed a new reflection type digital holography microscope system and increased recording and numerical reconstruction area of target object.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.11
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• pp.2439-2450
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• 1997

As recording densities increase in digital magnetic recording channels, the performances of digital detection techniques such as PRML and DFE degrade significantly due to nonlinear distortion in recording channels. The primary impediments for hgih-density recording are generally classified as nonlinear transition shift, which can be reduced substantially by the precompensation technique, and partial erasure which usually requires sophisticated nonlinear equalization techniques. In order to acheieve the highest density recording, accurate estimation of the parameters associated with these two noninear distortions is crucial. In this paper, a new estimation technique to distinguish these two different nonlinear effect using a proposed adaptive algorithm in time domain is presented. The effectiveness of the proposed adaptive approach to identify uniquely the nonlinear parameter with bias is demonstrated by computer simulation.

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.460-469
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• 2022

Increasing interest in the metaverse world these days, interest in realistic content such as 3D displays is growing. In particular, hologram images seen in movies provide viewers with an immersive display that cannot be seen in conventional 2D images. Since the first discovery of holography by Dennis Gabor in 1948, this technology has developed rapidly. Spatially, this beginning of technology like Optical hologram called analog hologram and Digital hologram such as computer-generated hologram (CGH). In analog and digital holograms, a recording angle and a recording wavelength are having important role when reproducing and display hologram. In the hologram, diffraction of light causes by unexpected formed by the synthesis from interference with object and reference light. When recording, the incident light information and mismatched reproduction light reconstruct the hologram in an undesirable direction. Reproduction light that is out of sync with incident light information with initial condition of recording will cause reconstructed image in an undesirable direction. Therefore, we analyze the holographic interference pattern generated by hologram recording in volume holograms using photopolymer and analyze the characteristics that vary depending on the angle of the reproduced light. This is expected to be used as a basic research on various holographic application that may cause as holograms are applied to industries in the future.

• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.303-309
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• 2004

Many system devices for fluoroscopic and general X-ray studies in diagnostic radiographic system have been being changed from analog mode to digital mode. In addition, among diagnostic imaging and radiologic examinations, fluoroscopic studies that requires functional diagnosis is being widely used. The video recording method of fluoroscopic studies has been useful in functional image diagnosis and dynamic image observation, but the utility of its image quality is being reduced because of limitation in setting play segments of the video player, inconvenience of play, difficulties in preserving reproduced images, the change of image quality, etc. In order to complement these shortages, it is necessary to facilitate access to patient diagnosis information such as storing, editing and sharing functional diagnosis images in response to the trend of the digitalization of digital radiographic & fluoroscopic system(DRF). Thus this study designed and implemented a device of storing functional dynamic images real time using a computer rather than existing video recording, aiming at contribution to functional image diagnosis.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.545-551
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• 2023

As digital information is readily available to everyone today, the adoption of digital evidence is increasing. However, it is virtually impossible to determine the authenticity of forgery in the case of a voice recording file that has gone through a sophisticated editing process along with the spread of various voice file editing tools. This study aims to prove that forgery, which is difficult to distinguish from the original file, is possible by using insertion, deletion, linking, and synthetic editing technologies in voice recording files. This study presents the difficulty of detecting forgery by encoding a forged voice file with the same extension as the original. In addition, it was shown that forgery detection is impossible if additional transition band deletion and secondary encoding are performed only for experiments in which features occurred. Through this, this study is expected to contribute to the establishment of more stringent evidence admissibility criteria for adopting voice recording files as digital evidence.

• 한국가시화정보학회:학술대회논문집
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• 2005.12a
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• pp.1-5
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• 2005

The digital HPTV velocity field measurement consists of four steps: recording, numerical reconstruction, particle extraction and velocity extraction. In the velocity extraction process, we improved PTV algorithm to extract the displacement of particle each placed in 3D space. Because a digital recording device was used, some factors such as a spatial resolution, numerical aperture, and particle concentration can affect the performance of the digital HPTV. Especially, a particle concentration ($C_{o}$) affected tile reconstruction efficiency in numerical reconstruction and particle extraction process. In this paper, the reconstruction efficiency was analyzed experimentally with different particle concentration. Optimal reconstruction efficiency was shown in the range of $C_{o}$=$13\∼15$ particles/$mm^{3}$.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.307-314
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• 2014

Digital broadcasting areas are leading information technology and having been strengthen the competitiveness of industries. In this paper, we developed HSS(Home Stream Station) for recording and transmitting digital broadcasting on digital TV without additional devices, which is based on cable TV network at home. The HSS can record a broadcasting program selected by user while digital TV shows the other channel. User can watch the program stored on the HSS at any time and any digital TV in the home. LAN interface of the HSS was also developed for supplying high quality digital broadcasting-contents through home network using IP-STB(Set Top Box).

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.133-141
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• 1996

As the recording density of digital magnetic recording channels increased, the nonlinear distortion caused by inadequate rise-times, demagnetizing field, and overwrite effect during the recording process becomes significant, resulting in limitation on the recording rate. In this paper, a new method for identifying the nonlinear distortion in hihg-density magnetic recording channel using and i.i.d. (independent, identically distributed) inut is described. The proposed method does not require the operatin of large-size matrix inversion which are necessary for the conventional method, and it enables us to estimate nonlinear parameters transition shifts, which can be used to compensate the nonlinear distortion, is demonstrated by computer simulations.