• Current Optics and Photonics
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• v.1 no.4
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• pp.289-294
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• 2017

A high-performance time-division multiplexing (TDM) -based multiuser (MU) multiple-input multipleoutput (MIMO) system for efficient indoor visible-light communication (VLC) is presented. In this work, a MIMO technique based on RGB light-emitting diodes (LEDs) with selection combining (SC) is utilized for data transmission. That is, the proposed scheme employs RGB LEDs for parallel transmission of user data and transmits MU data in predefined slots of a time frame with a simple and efficient design, to schedule the transmission times for multiple users. Simulation results demonstrate that the proposed scheme offers an approximately 6 dB gain in signal-to-noise ratio (SNR) at a bit error rate (BER) of $3{\times}10^{-5}$, as compared to conventional MU single-input single-output (SISO) systems. Moreover, a data rate of 66.7 Mbps/user at a BER of $10^{-3}$ is achieved for 10 users in indoor VLC environments.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.143-145
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• 2005

This paper describes the transmission method of an information using communication networks between RTU(Remote Terminal Unit) and PCU(Protection and Control System) of the DC switchgear for Light Railway Vehicle. Also the test result carried out in the laboratory was represented. In this test, transmission signal waveform, polling time, response time and request/response frame between RTU and PCU were measured. The field test including the measurements of analog signal and status of the digital logic operation of PCU was conducted in Gyeongsan Test Track.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.38-41
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• 2010

Compared to conventional molding technology, the color uniformity of light direction emitted from LED is improved with PCB type lead frame technology in which metal thin film is used and transfer molding technology which makes the density of phosphor uniform by manufacturing high density LED lamp. The light efficiency and the color uniformity of the LED are improved by molding the phosphor layer outside of chip and controlling the thickness of the phosphor layer. CIE x,y difference of LED in major axis is also improved uniformly from 0 to 90 degrees.

• Journal of Welding and Joining
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• v.9 no.2
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• pp.20-28
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• 1991

The main subject of this study is the construction of an automatic welding system that has the capability to trace the weld seam in GMA welding of lap joints. The system was composed of a vision sensor, moving torch, and personal computer(IBM-PC). In the developed vision sensor, an image was captured by the frame grabber at the time of short circuit during welding. The threshold method was adopted for determining the structured light and the central difference method for detecting the weld joint. And the seam tracing of the torch was performed by using the data regeneration algorithm. In this system using the image at the time of short circuit, weld seam tracking was performed without any relations to arc light and spatters.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.152-153
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• 2021

Various types of panels can be designed using acrylic rods, which are materials that allow light to pass through existing concrete. After designing using people, animals and objects, a prototype was produced by mixing ultra-high-strength concrete, and taking care not to damage the fixed acrylic rod during pouring and demolding. Yun Dong-ju's free design of a figure and a researcher were inserted into the wall inside the interior space, and then the installation was completed on-site. For installation, a metal frame was installed on the temporary wall, which is a non-structural wall, and then a relatively heavy concrete panel was fixed using a structural sealant and then applied to the field.

• Honam Mathematical Journal
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• v.37 no.2
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• pp.253-264
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• 2015

In the present paper, we consider a position vector of an arbitrary curve in the three-dimensional Galilean space $G_3$. Furthermore, we give some conditions on the curvatures of this arbitrary curve to study special curves and their Smarandache curves. Finally, in the light of this study, some related examples of these curves are provided and plotted.

• Journal of the Korean Wood Science and Technology
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• v.20 no.1
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• pp.46-50
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• 1992

본 연구는 잣나무 간벌재를 이용한 plywood gusset plate 접합과 toothed metal plate 접합에 대하여 인장력을 가해 조사하였다. plywood gusset plate 접합에 있어서는 합판과 부재 사이를 상온 경화제(초산 비닐 수지)로 접착한 후 6d 못으로 접합한 형태와 단지 합판만을 사용한 형태의 plywood gusset plate 접합 사이의 기계적 특성 차이를 조사했다. toothed metal plate 접합은 plywood gusset plate 접합보다 인장력에서 좋은 behavior를 보였다. 또한 접착제를 가한 plywood gusset plate 접합은 접합제를 가하지 않은 형태보다 큰 하중 지지력을 보였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.288-291
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• 2003

The technology and performance of the world-largest 54-inch LCD TV using PVA mode have been introduced from two points of view: one is to manufacture large-size panels, the other is to improve electro-optical performance required for multimedia applications. Current ongoing research activities that have been explored include new stitching design, one drop filling with column spacer, response time less than one frame rate, color performance and light efficiency enhancement.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.247-249
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• 2005

UTM-02 모델의 초기형상을 기반으로 차체 프레임 구조물에 대한 경량화 설계를 수행하였다. 전체 프레임을 14개의 부재로 나누었으며, 부재 두께를 설계변수로 정하였다. 효율적인 설계최적화를 수행하기 위하여 반응면기법을 이용하였다. 반응면기법을 통해 근사된 목적함수와 제한조건을 이용하여 최적화를 수행하였으며 각 설계변수들에 대한 감도도 산출하였다.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.10a
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• pp.155-160
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• 2005

This study is focused on the indeterminancy of the contemporary social structure based on the philosophical concept of relationship. The indeterminate relationship is one of the prominent characteristics of contemporary architecture. This study aims to clarity the indeterminate programs of the contemporary urban spatial structures. By tracing this new characteristics of new architectural trend, the spatial situations of could be understood in light of new conceptual frame as well as some relevant architectural project cases.