• Title/Summary/Keyword: High Efficiency LED

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Coordinates Determination of tow Level Control Point by Aerial Triangulation (사진기준점측량을 이용한 저등급 기준점의 좌표결정)

  • 최재화;이석배;최윤수
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.6 no.2
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    • pp.34-41
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    • 1988
  • Nowadays the considerable improvements, not only in photogrammetric equipment but also in adjustment methods have led to a high accuracy of Aerial Triangulation and reach the step to obtain A.T. technique that uses Global Position System without ground control survery. The enterance of analytical plotter have made considerable development both in accuracy and in efficiency and improved working environment of A.T. by the combination of On-Line Analytical Plotting System. In this paper, in A.T., with using of analytical polotter, aims to improve the acccuracy in coordinates determination of low level control point. The result shows that in case of A.T. with analytical plotter AVIOLYT BC2, the accuracy of control points improves to 7% in planimetry and to 40% in height compared to A.T. with precision plotter Autograph A-8.

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Design Optimization for High Efficiency Distributed Bragg Reflectors through Simulation Methodology (시뮬레이션을 이용한 고효율 분산 브래그 반사경 최적화 설계 및 특성)

  • Kim, Kwan-Do
    • Journal of IKEEE
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    • v.22 no.1
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    • pp.189-192
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    • 2018
  • This study focused on the development of simulation methodology and design optimization for the DBR(Distributed Bragg Reflectors) structures, which are commonly used in manufacturing optical films and the key components of LED chip and LCD inspection equipments. From the multi-layer simulation, the following results are obtained. First, the wavelength(nm) vs. reflectance(%) can be calculated in the DBR structures that $TiO_2$ and $SiO_2$ thin films are stacked alternately. As a results, it is suggested that highly efficient DBR structures can be designed and manufactured using simulation methodology.

A Study on Remote Control of Inverter Based on VLC for SMART FEMS (스마트 FEMS를 위한 VLC기반 인버터 원격제어 연구)

  • Lee, Jung-Hoon;Lee, Seung-Youn;Choi, Sang-Yule;Lee, Jong-Joo;Kim, Hyung-O
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.10
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    • pp.1382-1387
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    • 2018
  • There is a high demand for energy efficiency improvement of factories that make up a large part of national electric energy. Therefore, research on smart FEMS technology for monitoring, analyzing and controlling energy consumption patterns is under way, but there is still a lack of research on detailed element technology for communication and control inside the factory. In this paper, we proposed OFDM VLC system based on MODBUS protocol for communication between gateways, sensors, and devices to implement smart FEMS in indoor factory environment. Assuming a conveyor belt load control, we validated the proposed system by simulating the inverter motor control and checking the performance.

A Study on Realization of Visible Light Communication System for Power Line Communication Using 8-bit Microcontroller

  • Yun, Ji-Hun;Hong, Geun-Bin;Kim, Yong-Kab
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.5
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    • pp.238-241
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    • 2010
  • The purpose of this study is to solve the problems of radio frequency bandwidth frequency depletion, confusion possibilities, and security that are in current wireless communications systems, and to confirm the possibility of applying those solutions for the next generation network. To solve the problems of the current wireless communications system, a visible light communications system for power line communication (PLC) via 8-bit microcontroller is created and the capacity is analyzed. The exclusive PLC chip APLC-485MA, an 8-bit ATmega16 microcontroller, high brightness 5pi light emitting diodes (LEDs), and the LLS08-A1 visible light-receiving sensor were used for the transmitter and receiver. The performance was analyzed using a designed program and an oscilloscope. The voltage change was measured as a function of distance from 10-50 cm. Blue LEDs showed the best performance among the measured LED types, with 0.47 V of voltage loss, but for a distance over 50 cm, precise data was not easy to obtain due to the weak light. To overcome these types of problems, specific values such as the changing conditions and efficiency value relevant to the light emitting parts and the visible light-receiving sensor should be calculated, and continuous study and improvements should also be realized for better communication conditions.

Design and Performance Evaluation of a Diode Type Corona Charger for Real-Time Measurement of the Submicron Aerosol (실시간 미세입자 측정을 위한 다이오드형 코로나 하전기의 설계 및 성능평가)

  • Cho, Myung-Hoon;Ji, Jun-Ho;Park, Dong-Ho;Bae, Gwi-Nam;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.9
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    • pp.1066-1074
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    • 2004
  • With a diode corona charger, which is a component of ELPI(Electrical Low Pressure Impactor), aerosol particles are charged to make electrical detection possible before they are collected by the impactor. We designed and evaluated two cylindrical corona chargers, each of which had a central corona needle electrode. For the performance evaluation of each corona charger the polydisperse dioctyl sebacate(DOS) particles, with diameters of 0.1∼0.8 $\mu$m and NaCl particles, smaller than 0.1$\mu$m, were used. The particles were then led through an electrostatic classifier (TSI model 3081) to classify monodisperse aerosol with minimal size deviation. After evaluating the wall loss of the particles in the corona charger, we measured the product of penetration and number of charges, Pㆍn, to evaluate the corona charger efficiency at high positive voltages of 4, 5, 6 kV.

The Cooling System for Head up Display (Head up Display용 냉각시스템)

  • Ji, Youg-Seok;Kim, Young-Seop;An, Byeong-Man;Lim, Sang-Min
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.1
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    • pp.67-71
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    • 2010
  • Head up display’s cooling system is auto-diagnosed resulting from the external environment. The quantity of heat depending on this Head up display’s cooling system layout determines the speed of FAN for system cooling. In other words, a system’s heat quantity is planned through the air density depending on altitude, the amount of wind in air depending on FAN control condition, and the algorithm that is proportional to delta temperature. To detect the altitude, we use the criteria of delta T, which is determined by the subtracted value of LED junction temperature, and atmospheric temperature that is recorded on the Head up display system. Depending on the classification of delta T value, the altitude section is determined. While we can use GPS as the tool to detect the altitude, we should predict the change of the air density as the altitude alters, and should not just measure the altitude. And the value of delta T is used as the criterion of detecting the altitude for increasing the cooling efficiency of the car’s inner Head up display system with reflecting the speed of the FAN dependent upon the air density. In our theory, altitude is depending on the value of delta T and stabilizing or maintaining the system’s temperature by changing FAN’s rpm depending on determined value of altitude.

The study on the Efficient methodology to apply the GPU for military information system improvement (국방정보시스템 성능향상을 위한 효율적인 GPU적용방안 연구)

  • Kauh, Janghyuk;Lee, Dongho
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.11 no.1
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    • pp.27-35
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    • 2015
  • Increasing the number of GPU (Graphic Processor Unit) cores, the studies on High Performance Computing Platform using GPU have actively been made in recent. This trend has led to the development of GPGPU (General Purpose GPU) and CUDA (Compute Unified Device Architecture) Framework. In this paper, we explain the many benefits of the GPU based system, and propose the ICIDF(Identify Compute-Intensive Data set and Function) methodology to apply GPU technology to legacy military information system for performance improvement. To demonstrate the efficiency of this methodology, we applied this method to AES CPU based program obtained from the Internet web site. Simply changing the data structure made improved the performance of AES program. As a result, the performance of AES based GPU program is improved gradually up to 10 times. Depending on the developer's ability, additional performance improvement can be expected. The problem to be solved is heat issue, but this problem has been much improved by the development of the cooling technology.

ON THE ORIGIN OF THE HII REGIONS ASSOCIATED WITH MASSIVE AND COMPACT SUPERSTAR CLUSTERS

  • Silich, Sergiy;Tenorio-Tagle, Guillermo;Munoz-Tunon, Casiana
    • Journal of The Korean Astronomical Society
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    • v.40 no.4
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    • pp.187-188
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    • 2007
  • This contribution to the IV Korea-Mexico meeting deals with the hydrodynamics of the matter reinserted within super star clusters (SSCs) by both stellar winds and supernova explosions, results recently printed in The Astrophysical Journal (Silich et al. 2007). The motivation of such a project arose from the persistent presence of the small mass and compact HII regions that sit right on top of many massive and compact SSCs, from which one expects a large mechanical energy power. The data used for our calculations appear only recently (see Smith et al. 2006) for the massive and compact SSC M82-A1. We presented in our paper the calculated flow, derived through analytical and semi-analytical methods, which led to almost identical results. We have found out that the only way of accommodating a compact HII region (4.5 pc in radius, in the case of M82-A1) on top of a 6.3 Myr old and massive (> $10^6M_{\bigodot}$) SSC with a half light radius of 3 pc, requires of two assumptions: a very low heating efficiency (< 10%) within the cluster, what leads to a bimodal solution (see Tenorio-Tagle et al. 2007) and a high pressure in the surrounding medium.

SILAGE FERMENTATION AND SILAGE ADDITIVES - Review -

  • Bolsen, K.K.;Ashbell, G.;Weinberg, Z.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.5
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    • pp.483-493
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    • 1996
  • Advances in silage technology, including precision chop forage harvesters, improved silos, polyethylene sheeting, shear cutting silo unloaders, and the introduction of total mixed rations, have made silage the principal method of forage preservation. A better understanding of the biochemistry and microbiology of the four phases of the ensiling process has also led to the development of numerous silage additives. Although acids and acid salts still are used to ensile low-DM forages in wet climates, bacterial inoculants have become the most widely used silage additives in the past decade. Commercial inoculants can assure a rapid and efficient fermentation phase; however, in the future, these products also must contribute to other areas of silage management, including the inhibition of enterobacteria, clostridia, and yeasts and molds. Nonprotein nitrogen additives have the problems of handling, application, and reduced preservation efficiency, which have limited their wide spread use. Aerobic deterioration in the feedout phase continues to be a serious problem, especially in high-DM silages. The introduction of competitive strains of propionic acid-producing bacteria, which could assure aerobically stable silages, would improve most commercial additives. New technologies are needed that would allow the farmer to assess the chemical and microbial status of the silage crop on a given day and then use the appropriate additive(s).

Nanomedicine: Drug Delivery Systems and Nanoparticle Targeting (나노의학: 나노물질을 이용한 약물전달시스템과 나노입자의 표적화)

  • Youn, Hye-Won;Kang, Keon-Wook;Chung, June-Key;Lee, Dong-Soo
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.5
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    • pp.337-346
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    • 2008
  • Applications of nanotechnology in the medical field have provided the fundamentals of tremendous improvement in precise diagnosis and customized therapy. Recent advances in nanomedicine have led to establish a new concept of theragnosis, which utilizes nanomedicines as a therapeutic and diagnostic tool at the same time. The development of high affinity nanoparticles with large surface area and functional groups multiplies diagnostic and therapeutic capacities. Considering the specific conditions related to the disease of individual patient, customized therapy requires the identification of disease target at the cellular and molecular level for reducing side effects and enhancing therapeutic efficiency. Well-designed nanoparticles can minimize unnecessary exposure of cytotoxic drugs and maximize targeted localization of administrated drugs. This review will focus on major pharmaceutical nanomaterials and nanoparticles as key components of designing and surface engineering for targeted theragnostic drug development.