• Korean Journal of Digital Imaging in Medicine
• /
• v.13 no.2
• /
• pp.71-76
• /
• 2011

Because interventional procedure operates looking at premier as real time when perate intervention enemy, by patient is revealed during suitableness time in radiation, side effect such as radiation injury of skin is apt to happen. It established by purpose of study that measure exposure dose that patient receives about these problem, and find solution for radiation injury and repletion method. In this study, we used Rando phantom of identical structure with the human body which becomes accomplished with 4 branch ingredient of the attempt and system equivalent material them and absorbed dose were measured by TLD. According to the laboratory, it shows that operations such as TFCA procedure or uterine myoma embolization are more dangerous than TACE procedure. If both operations are inspected during a short time, it is not affected in being bombed. However, it can lead to palliative agenesis or depilate, definitive agenesis only if operations are repeated more than three times. Dose distibution based on experiment, to reduce radiation exposure to patients result from reduction of scatter ray as we control field size of radiation and protection of side organs except for tumor. also we knew that we can protect patients form radiation exposure, if we increas SOD and decrease SID.

• Journal of Korean Library and Information Science Society
• /
• v.25
• /
• pp.529-567
• /
• 1996

This paper surveyed the theoretical backgrounds of digital library. Its definition and function and case studies, and basic skills for system construction of digital library were suggested. The differences between the traditional library and the digital library were compared. And the conditions that should be take into consideration of digital library construction were suggested. Suggestions are summarized as follows : 1. For the construction of digital library, library collection should be digitalized by using CD-ROM and commercial online services. 2. The digitalization of library collection should be planned by subject sharing between the libraries. For the control of this cooperation, the orgnization to propel the digitalization should be established. And it is necessary to enact the standards for the digital library. 3. The connection between MARC formatted bibliographic database and full-text should be studied. 4. All the types of information about texts, pictures, sounds and if films should be also digitalized. 5. To satisfy the needs of many users, we have to establish the various users's interface which is fitted for several kinds of users. 6. When a digital library was constructed, the copyright and resources sharing must be guranteed depending on the cost of database's usage. 7. Because the digitalization of library will be related to the various kinds of libraries, the interface for resources sharing will be constantly concerned. 8. The sharing of information resources between the libraries will be enacted on the Internet. And we must be interested in various internet tools such as telecommunication softwares, media convert programs, etc. 9. By training staffs continously, all libraries must be ready to come the library in the future.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.9 no.1
• /
• pp.151-163
• /
• 2013

Recently the attention on digital hologram that is regarded as to be the final goal of the 3-dimensional video technology has been increased. Digital hologram is calculated by modeling the interference phenomenon between an object wave and a reference wave. The modeling for digital holograms is called by computer generated hologram (CGH) Generally, CGH requires a very large amount of calculation. So if holograms are generated in real time, high-speed method should be needed. In this paper, we analyzed CGH equation, optimized it for mapping general purpose graphic processing unit (GPGPU), and proposed a optimized CGH calculation technique for GPGPU by resource allocation and various experiments which include block size changing, memory selection, and hologram tiling. The implemented results showed that a digital hologram that has $1,024{\times}1,024$ resolution can be generated during approximately 24ms, using 1K point clouds. In the experiment, we used two GTX 580 GPGPU of nVidia Inc.

• Journal of Power Electronics
• /
• v.17 no.3
• /
• pp.686-694
• /
• 2017

Due to the wide use of electronic products, digitally controlled DC-DC converters are attracting more and more attention in recent years. However, digital control strategies may introduce undesirable Limit Cycle Oscillation (LCO) due to quantization effects in the Analog-to-Digital Converter (ADC) and Digital Pulse Width Modulator (DPWM). This results in decreases in the quality of the output voltage and the efficiency of the system. Meanwhile, even if the resolution of the DPWM is finer than that of the ADC, LCO may still exist due to improper parameters of the digital compensator. In order to discover how LCO is generated, the state space averaging model is applied to derive equilibrium equations of a digital PID controlled DC-DC converter in this paper. Furthermore, the influences of the parameters of the digital PID compensator, and the resolutions of the ADC and DPWM on LCO are studied in detail. The amplitude together with the period of LCO as well as the corresponding PID parameters are obtained. Finally, MATLAB/Simulink simulations and FPGA verifications are carried out and no-LCO conditions are obtained.

• Korean Journal of Artificial Intelligence
• /
• v.9 no.2
• /
• pp.7-14
• /
• 2021

Purpose: To solve urban problems, empirical research is being actively conducted to implement a smart city based on various ICT technologies, and digital twin technology is needed to effectively implement a smart city. A digital twin is essential for the realization of a smart city. A digital twin is a virtual environment that intuitively visualizes multidimensional data in the real world based on 3D. Digital twin is implemented on the premise of the convergence of GIS and BIM, and in particular, a lot of time is invested in data pre-processing and labeling in the data construction process. In digital twin, data quality is prioritized for consistency with reality, but there is a limit to data inspection with the naked eye. Therefore, in order to improve the required time and quality of digital twin construction, it was attempted to detect a building using Mask R-CNN, a deep learning-based masking algorithm for aerial images. If the results of this study are advanced and used to build digital twin data, it is thought that a high-quality smart city can be realized.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.6B
• /
• pp.1156-1164
• /
• 1999

In this paper, we have studied the 8 YSB (8 Vestigial Side Band) method which is decided as the standard of modulators for next generation digital TV System. In developing digital TV System, one of the difficult problems is how digital signal can be transmitted to the receiver without any phase distortion. But, phase error is liable to occur by imperfect design, circumstance variation and device degradation. These characteristics result in distortion of 1,0 signal of modulator and interference in adjacent channels. In particular, the interference in modulator of a high power amplifier result in serious problems in adjacent channels. Here we analyzed problems of phase error which are occurred when 8 levels digital signals are modulated to If signal. And we suggested phase error compensation algorithm and discussed the results for adaptation of the algorithm

• The KIPS Transactions:PartB
• /
• v.10B no.4
• /
• pp.367-372
• /
• 2003

The existing watermarking techniques for copyright protection of a digital image are fragile in geometric distortion and it is hard to detect whether it was manipulated artificially. In this paper, we proposed the new copyright protection system that can authorize a digital mage and :an embed or extract a robust watermark in a artificial manipulation in order to solve these problems. In a watermarking part, the proposed a watermarking technique embeds a watermark in a phase component after a Complex Wavelet Transform (CWT) with an original image, and a watermark is extracted from an watermarked image by stages. A copyright about an image can be insisted on than a threshold after comparing a correlation of an original watermark with an extracted watermark if large. In an authentication part of a digital image, EZW (Embedded Zerotree Wavelet) is used, and an authentication cord of an watermarked image is generated. An authentication code of an image to have been distribute to is compared with a generated authentication cord, and artificial operation isn´t than a threshold if large. The proposed copyright protection system through performance evaluation display that it was robust in geometric distortion and a artificial operation was able to be detected.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.9
• /
• pp.1150-1157
• /
• 2020

It is expected that if a viewer feels the higher realism, it will increase efficiency at 3D hologram. Therefore, the purpose of this study is to analyze the effects of the evaluation factors on realism for digital signage using 3D holograms. For empirical analysis, the evaluation factors were derived and built up hypothesis(The evaluation factors of digital signage using 3D holograms will affect the realism). As a result of the experiment, Hypothesis 1 (Social presence) and 3 (Harmony with the space) were adopted while Hypothesis 2 (Graphic's elaboration) was rejected. Finally, research has shown that in order to improve the realism of digital signage using 3D holograms, the contents should be produced in consideration of presence so that the viewers could feel as if they were actually inside of contents rather than expressed extremely well made higher image resolution. Hence, the 3D hologram contents should be installed in a place where it would fit well with the space around it.

• Journal of Digital Contents Society
• /
• v.16 no.1
• /
• pp.113-121
• /
• 2015

Artifact pattern representation of a method using the digital technology is largely are two digital rubbing technique and digital contrast technique. Digital rubbing technique is clearly with the naked eye to see the original prestigious and difficult to build a digital rubbing data patterns by scanning a prestigious and patterns carved into the artifacts in three dimensions without compromising the circle to represent the three-dimensional effect by contrast it to the objective value refers to a technique that can be represented in digital. Digital contrast technique can not be calculated if the depth information of the object due to the glassy film of artefacts in a three-dimensional surface scanning and the application of this technique refers to a realistic image mapped digital technique for generating digital image contrast. Digital rubbing technique is mainly useful to express the most prestigious and patterns expressed in pottery or tile and stone monument, etc. engraved or embossed, digital contrast techniques can be used effectively to artifacts such as magnetic or glass can not be applied to the digital rubbing technique.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.8A
• /
• pp.1252-1258
• /
• 1999

This paper describes a COMS IF transceiver IC for 10-MHz bandwidth wireless local loops. It interfaces between the RF section and the digital MODEM section and performs the IF-to-baseband (Rx) and baseband-to-IF (Tx) frequency conversions. The chip incorporates variable gain amplifiers, phase-locked loops, low pass filters, analog-to-digital and digital-to-analog converters. It has been implemented in a 0.6 -${\mu}{\textrm}{m}$ 2-poly 3-metal CMOS process. The phase-locked loops include voltage-controlled oscillators, dividers, phase detectors, and charge pumps on chip. The only external complonents are the filter and the varactor-tuned LC tank circuit. The chip size is 4 mm $\times$ 4 mm and the total supply current is about 57 mA at 3.3 V.