• Journal of Digital Convergence
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• v.9 no.5
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• pp.225-233
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• 2011

Internet telephony is an Internet service which supports voice telephone using VoIP technology on the IP-based Internet. It has some advantages in that voice telephone services can be accompanied with multimedia services such as video communication and messaging services. Recently, the introduction of smart phones has led to a growth in social networking services and thus, the research and development of Internet telephony has been actively progressed and has the potential to become a replacement for the telephone service that is currently being used. In this paper we designed and implemented a recording system which records voice data of SIP-based Internet telephone's voice calls. It is developed on the linux system and has some features such as audio mixing of two in/out voice channels, live packet sniffing, and the ability to transfer mixed audio files to the log file server. These functions are implemented using various open source softwares. Afterwards, this VoIP recording system will be applied as a base technology to advanced services like a VoIP-based call center system.

• Korean Journal of Optics and Photonics
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• v.12 no.4
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• pp.339-344
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• 2001

We propose a method to represent binary data by modulating both the intensity and the phase of uniform plane waves with a twisted-nematic liquid crystal display for holographic digital data storage especially in a disk-shaped recording medium. As far as intensity modulation is concerned, our method is not different from the conventional method, because binary bit values 0 and 1 are represented by the dark (off) and lit (on) states of the liquid crystal display pixels, respectively (or vice versa). With our method, however, the on pixels are also controlled so that the beams passing through them can have one of two different phase delays. If the difference of the two phase delays is close to 180 degrees, we can reduce the dc component of the data image and thus improve the beam intensity uniformity at the holographic recording plane when Fourier plane holograms are recorded. The feasibility of our method is experimentally demonstrated. rated.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.2
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• pp.13-25
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• 2017

Recently, the high performance of tactical situation display console and tactical data links are used to integrate the operational situations in accordance with information age and NCW (Network Centric Warfare). The tendency to maximize the efficiency of task execution has been developed by sharing information and the state of the battle quickly through complex and diverse information exchange. Tactical data link is a communication system that shares the platform with core components of weapons systems and battlefield situation between the command and control systems to perform a Network Centric Warfare and provides a wide range of tactical data required for decision-making and implementation.It provides the tactical information such as tactical information such as operational information, the identification of the peer, and the target location in real time or near real time in the battlefield situation, and it is operated for the exchange of mass tactical information between the intellectuals by providing common situation recognition and cooperation with joint operations. In this study, still image management, audio file management, tactical screen recording and playback using the storage and playback, NITF (National Imagery Transmission Format) message received from the displayer integrates the tactical situation in three dimensions according to multiple data link operation to suggest ways to ensure data integrity between the data link processor during the entire operation time.

• The Journal of the Acoustical Society of Korea
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• v.18 no.3
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• pp.17-26
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• 1999

We present the first speech coarticulation database of Korean, English and Konglish/sup 3)/ named "SORIDA"/sup 4)/, which is designed to cover the maximum number of representations of coarticulation in these languages [1]. SORIDA features a compact database which is designed to contain a maximum number of triphones in a minimum number of prompts. SORIDA contains all consonantal triphones and vowel allophones in 682 Korean prompts of word length and in 717 English prompt words, spoken five times by speakers of balanced genders, dialects and ages. Korean prompts are synthesized lexicons which maximize their coarticulation variation disregarding any stress phenomena, while English prompts are natural words that fully reflect their stress effects with respect to the coarticulation variation. The prompts are designed differently because English phonology has stress while Korean does not. An intermediate language, Konglish has also been modeled by two Korean speakers reading 717 English prompt words. Recording was done in a controlled laboratory environment with an AKG Model C-100 microphone and a Fostex D-5 digital-audio-tape (DAT) recorder. The total recording time lasted four hours. SORIDA CD-ROM is available in one disk of 22.05 kHz sampling rate with a 16 bit sample size. SORIDA digital audio-tapes are available in four 124-minute-tapes of 48 kHz sampling rate. SORIDA′s list of phonetically-rich-words is also available in English and Korean.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1260-1263
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• 2005

Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time. Today any data storage system cannot satisfy these conditions, however holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System can be constructed without mechanical actuating part therefore fast data transfer rate and high storage capacity about 1Tb/cm3 can be realized. In this research, to reduce errors of binary data stored in holographic data storage system, a new method for bit error reduction is suggested. First, find fuzzy rule using experimental system for Element of Holographic Digital Data System. Second, make fuzzy rule table using Genetic algorithm. Third, reduce prior error element and recording Digital Data. Recording ratio and reconstruction ratio will be very good performance

• Journal of Digital Contents Society
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• v.16 no.5
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• pp.835-847
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• 2015

Photo scanning can create point cloud and polygon models like 3D scanners bringing an object into the 3 dimensional world by combining several sheets of photographic information. The created data give us information about planes and sectional forms required for a 2 dimensional survey as well as 3 dimensional figures of buried cultural property. It requires a lot of time to record buried cultural property in the field, however, the photo scanning technique does not need additional equipment and manpower so the work may begin immediately while the property is protected. Moreover, it reduces financial burdens as it creates 3 dimensional data using images acquired by photography but provides the optimal condition to check 3 dimensional information quickly and easily.

• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.1
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• pp.115-124
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• 2022

This study analyzed the intention of continuous use of the electronic attendance-absence system. Perceived ease of use, acceptance attitude, and user satisfaction variables were selected to analyze the factors affecting the intention of continuous use. To achieve the purpose of this study, a survey was conducted targeting students who had experience in using the electronic attendance-absence system at K University located in Chungcheongbuk-do. The use environment of the electronic attendance-absence system was non-face-to-face, and the questionnaires answered by 921 students were analyzed. The study results are as follows. First, perceived ease of use and acceptance of the electronic attendance-absence system were found to have a positive effect on user satisfaction. Second, it was found that the learner's perceptual ease, acceptance attitude, and user satisfaction for the electronic attendance-absence system had a positive effect on the intention of continuous use. This study is meaningful in that it identified the intention of continuous use based on the experience of the electronic attendance-absence system in a non-face-to-face environment.

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.496-502
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• 2016

In this paper, we proposed and implemented a GUI-based system to recognize and record measured values of digital instruments in the industrial site through image processing. Unlike the existing vehicle license plate recognition system, the measured values of the measuring instrument are displayed on the LCD screen as digital numbers. So, the proposed system considers the decimal point, a negative sign, light reflected by LCD protective glass, and various disturbance factors. We used blob-labeling technique to recognize the numbers displayed on the LCD screen, the recognized number images were determined as certain numbers through the template matching, and recognized values were recorded in the storage device with measurement time. Therefore, the proposed system in this paper would reduce the burden of writing when recording the measured values of the inside/outside diameter or height of the product in the industrial site, so effective and errorless process management in production process is possible by preventing errors in recording measurements when written by hand.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.536-542
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• 2016

Freight and passenger transport operators must converts the operation records of digital operation recording device (Digital Tachograph) that is mounted on their vehicle in a certain format, and report them to governmental agencies. However, for most of the individual carrier who cannot access a computer environment easily and are not familiar with the use of computer, it has given a big inconvenience to them because the procedures for entering the data obtained from the operation are so complicate. Therefore, in this study, a mobile system for converting the operation record file to request form of a government agency is designed and developed, so that the converted file can be submitted to the government agency in a simple way through the personal mobile device. By entering the data obtained from an actual operation recording device into the system, converting the data in the proposed algorithms, and checking the contents of the converted file in data viewer, it was confirmed that the proposed functions is working properly in the system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.1 s.232
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• pp.123-130
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• 2005

A digital in-line holographic particle image velocimetry (HPIV) which can be applied to measure three-dimensional velocity fields of turbulent flows was developed. There are three different implementation methods of HPIV: traditional film-based HPIV, intermediate HPIV and digital HPIV. The traditional film-based HPIV and intermediate HPIV method is rather troublesome to do experiments and takes long calculation time, compared with the digital HPIV, Configuration of the digital in-line HPIV is simple and the data processing routine is similar to conventional 2D PIV methods. The digital HPIV 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. The developed digital in-line HPIV system was applied to a vertical jet flow. The 3D velocity vectors measured by the digital HPIV method in the near field are in a good agreement with 2D PIV results.