• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.131-136
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• 1999

This paper proposes the robot inverse calibration method using a neural networks. A highorder networks called Pi-Sigma networks has been used. The Pi-Sigma networks uses linear summing units in the hidden layer and product unit in output layer. The inverse calibration model which compensates the difference of joint variables only between measuring value and analytic value about the desired pose(position, orientation) of a robot is proposed. The compensated values are determined by using the weights obtained from the learning process of the neural networks previously. To prove the reasonableness, the SCARA type direct drive robot(4-DOF) and anthropomorphic robot(6-DOF) are simulated. It shows that the proposed calibration method can reduce the errors of the joint variables from $\pm$2$^{\circ}$to $\pm$ 0.1$^{\circ}$.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.17-22
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• 2008

It is presented that sampling rates for behavioral modeling of quasi-memory less nonlinear devices can be far less than the Nyquist rate of the input signal. Although it has been believed that the sampling rate of nonlinear device modeling should be at least the Nyquist rate of the output signal, this paper suggests that far less than the Nyquist rate of the input signal can be applied to the modeling of quasi-memoryless nonlinear devices, such as frequency multipliers. To verify, a QPSK signal at 820 MHz were applied to a frequency tripler, whereby the device can be utilized as an up-converting mixer into 2.46 GHz with the aid of digital predistortion. AM-AM, AM-PM and PM-PM can be successfully measured regardless of sampling rates.

• Journal of dental hygiene science
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• v.15 no.1
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• pp.12-17
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• 2015

The purpose of this study was to evaluate the marginal and internal gap of metal coping fabricated using additive manufacturing (AM) group and subtractive manufacturing (SM) group by dental computer-aided design (CAD)/computer-aided manufacturing (CAM) systems. Twenty same cases of stone models of abutment teeth 16 by the universal numbering system were manufactured and scanned. Ten metal copings of control group were fabricated using SM and ten metal coping of experimental group were fabricated using AM. Marginal and internal gap of copings were measured using the silicone replica technique and digital microscope (${\times}140$). The data were analyzed using IBM SPSS 21.0 Statistical Software for independent samples t-test (${\alpha}=0.05$). Mean${\pm}$ standard deviation (SD) of marginal and internal gap total size of SM group was $101.00{\pm}40.33{\mu}m$ of AM group was $83.61{\pm}40.37{\mu}m$. Mean${\pm}$SD of marginal and internal gap total size of SM group was significantly greater than that of AM group (p<0.05). This study showed that AM metal copings had a better marginal and internal gap than SM metal copings.

• Journal of the Korea Society of Computer and Information
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• v.20 no.11
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• pp.47-54
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• 2015

In this paper, I examines the spatial representation of the change in the environment of the digital platform, and play the game with a focus on the spatial characteristics of a digital game. First, what is the Spatial characteristic of digital games? This section applies to a digital game "theory of Lefebvre", and the spatial representation of the practice space, divided into representational space were explored. Second, how to express dealing Is there space in the genre of adventure games? The spatial characteristics of the game medium through the Spatial characteristic of the adventure game genre that is most striking examples was analyzed whether the expression in any way. Consequently, the spatial characteristics of the digital game studies of the game as well as think a very large role in the development direction. In addition, this case analysis of the expression is the basis of this digital game that is utilized in many areas, and I am sure many possibilities to find a positive role in the game.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.135-141
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• 2011

Analog medias are converting to digital with the development of the digital communications. The Korean radio broadcasting services yet on analog and the research for the digital radio is progressing. The digital conversion of radio broadcasting has already progressed in foreign countries because of the technical limitation of analog broadcasting(The radio-frequency efficiency is poor). DAB is one of the digital radio mode, it doesn't use on AM/FM band and uses on T-DMB frequency band. So, it has an advantage of being able to broadcast with the existing radio without interference at once. On the other hand, it has the potential to cause interference to existing T-DMB broadcasting. In this paper, we propose an efficient DAB channel allocation method for digital radio on T-DMB frequency band. This paper allocates the DAB channel without interference to existing T-DMB broadcasting and proves the proposed method through simulations for the interference analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.4
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• pp.39-45
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• 2009

In this paper, designed and fabricated the microstrip antenna using parasitic plane. This active antenna for the use of AM/FM, DMB(Digital Multimedia Broadcasting), GPS(Global Positioning System) band in vehicle. Fabricated active antenna was compared to existing planar antenna represents more than 15% size reduction and equivalence performance compared to commercial helical antenna. And satisfy performance in DMB, GPS band. This active antenna composed of single input port and two output ports and entire size of antenna is $133{\times}31{\times}1.2mm$.

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.153-160
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• 2006

Recently, digital imaging is frequently used by crime scene investigators. However, the admissibility of digital photographic evidence in court is often raised because of the fact that digital photographs are more easily modified than film-based photographs. Therefore, in this article, the researcher reviewed some basic theories and legal considerations related with police crime scene investigations in Korea and The United States. This article is presented in the hope of clearing up some of the possibilities of falsifying photographic evidences and in the hope of setting the strict the rules of evidence regarding digital evidence in this county.

• Broadcasting and Media Magazine
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• v.1 no.3
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• pp.16-29
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• 1996

본 논문에서는 지상망 디지털 오디오방송(DAB) 시스템의 출현 배경과 미국 내에서 DAB 시스템의 개발과 성능시험 평가를 위한 NAB, NRSC, EIA, FCC, NASA, Lewis 연구소, 카나다 CRC의 활동상을 소개한다. 구체적으로는 미국에서 개발 중에 있는 USA Digital Radio사, Amati Communications사와 Kintel Technologies사의 FM In-Band On-Channel(IBOC)방식, AT＆T사의 FM In-Band Adjacent-Channel(IBAC)방식과 USA Digital Radio사의 AM IBOC 방식의 원리와 특성, 핵심기술, 개발현황, 성능시험 결과와 각 방식의 장단점을 비교 분석하며 또한 미국의 In-Band 방식과 유럽의 Eureka 147 New-Band 방식을 비교 분석한다.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1403-1406
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• 2003

This paper presents a user preference description for graphics contents that is developed in the process of the MPEG-21 DIA(Digital Item Adaptation) standard. The description scheme in this paper is proposed by the authors and adopted in the current AM (Adaptation Model) document of the MPEG-21 DIA. The goal of MPEG-21 standard is providing a multimedia framework that Provides augmented and transparent use of digital contents across various networks and terminals fur the life cycle of digital contents. DI (Digital Item) is a standardized basic unit of digital contents for transaction in the scope of MPEG-21. DIA contains both media resources and metadata including rights information.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.125-128
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• 2008

In this paper, the Transport Protocol Experts Group(TPEG) transmission and reception system based on Digital Radio Mondiale(DRM) is implemented for traffic information services. DRM stands for the European radio broadcasting standard to bring AM radio into digital radio, designed to work at frequencies below 30MHz. DRM can offer various data services such as text messages and a slide show service as well as audio services. In spite of low datarate, the TPEG system on DRM has an advantage that the traffic information service system for whole country can be established because DRM can offer wider service ranges than terrestrial-digital multimedia broadcasting(T-DMB) and simply archive a single frequency network.