• Title/Summary/Keyword: Noise level evaluation

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Optimization and Performance Evaluation for the Science Detector Systems of IGRINS

  • Jeong, Ueejeong;Chun, Moo-Young;Oh, Jae-Sok;Park, Chan;Yu, Young Sam;Oh, Heeyoung;Yuk, In-Soo;Kim, Kang-Min;Ko, Kyeong Yeon;Pavel, Michael;Jaffe, Daniel T.
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.91.1-91.1
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    • 2014
  • IGRINS (the Immersion GRating INfrared Spectrometer) is a high resolution wide-band infrared spectrograph developed by the Korea Astronomy and Space Science Institute (KASI) and the University of Texas at Austin (UT). This spectrograph has H-band and K-band science cameras, both of which use Teledyne's $2.5{\mu}m$ cutoff $2k{\times}2k$ HgCdTe HAWAII-2RG CMOS science grade detectors. Teledyne's cryogenic SIDECAR ASIC boards and JADE2 USB interface cards were installed to control these detectors. We performed lab experiments and test observations to optimize and evaluate the detector systems of science cameras. In this presentation, we describe a process to optimize bias voltages and way to reduce pattern noise with reference pixel subtraction schemes. We also present measurements of the following properties under optimized settings of bias voltages at cryogenic temperature (70K): read noise, Fowler noise, dark current, and reference-level stability, full well depth, linearity and conversion gain.

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Quality of Fresh Vegetable and Fruit Juice produced with Low-Speed and High-Speed Juicers (저속 압착 방식의 착즙기와 고속 파쇄 방식의 블랜더를 사용한 주스의 품질 변화에 대한 연구)

  • Kim, Youngsung
    • The Korean Journal of Food And Nutrition
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    • v.30 no.3
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    • pp.568-577
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    • 2017
  • Vegetables and fruits contain a great deal of vitamins, minerals, dietary fiber and phytochemicals. Therefore, healthconcious consumer prefer beverage made from fresh fruits and vegetables due to their health benefits. This study was conducted to investigate differences in nutritional composition and sensory characteristics of juices depending on the apparatus used: either a low-speed juicer or high-speed blender. All ingredients could be made into juice without addition of water using the low speed juicer. However, addition of water was necessary to produce juice with the high-speed blender. Phenol and flavonoid content, were higher in juice made with the low-speed juicer than that produced with the high-speed blender and were correlated with DPPH radical scavenging ability. Protease activity of pineapples juices was not significantly different for the two methods, but protease activity of kiwi juice was about 8 times higher in juice made with low-speed juicer than that made with the high-speed blender. SOD activity also tended to be higher in the juice made with low-speed juicer. The concentration of dissolved oxygen in the juice made with high-speed blender was higher than that of juice made with a low-speed juicer and was correlated with color change. In addition, the high-speed blender caused an increase juice temperature, but temperature was not changed during use of the low-speed juicer. The noise level of the low-speed juicer was low, but the high-speed blender had high noise intensity comparable to that of railway or aircraft noise. In the sensory evaluation of juice, juice made with the low-speed juicer was preferred over juice made with the high-speed blender. As a result, the overall quality of the juice produced using the low-speed juicer was superior.

$SF_6$ Gas Insulated Transformer ($SF_6$가스절연 변압기)

  • Cho, G.J.;Cho, K.D.;Ha, Y.S.;Cho, K.B.;Noh, C.W.
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.304-309
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    • 1991
  • We introduce the trend, of several countries, to the gas insulated transformer recently coming into the spot light by the advantages of less weight, GIS-lization, low noise level and easiness to decrease environmental pollutions, and the insulating gases. the cooling media and the insulating materials used for transformer. Hereinafter, additively the design of proto type $SF_6$ gas insulated transformer (insulation, cooling), which was developed by us(HICO) from 1987. 2 through 1990. 3, the manufacturing processes(leak protection, pressure, drying of main body), the accessories, the protective system, the cooling system, the method and the results of test and the evaluation of economics compared with conventional oil-filled transformer are represented.

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A Study on The Determination Method of Engineering Characteristic Values by QFD (품질기능전개를 통한 품질특성값 결정방법에 관한 연구)

  • 강지호;박명규
    • Journal of the Korea Safety Management & Science
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    • v.2 no.4
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    • pp.113-124
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    • 2000
  • First, in order to improve selecting method of quality characteristic level desired by customers, S/N(Signal-to-Noise) ratio of Taguchi in larger-the-better characteristics was applied. Second, the Matrix classification standard of ACE(Attribute Categorization Evaluation) is presented using KANO model on difference analysis of importance and satisfaction through questionnaire from customers. This is for reflecting the diverse EC which customers want in EC quality sufficiently. Also, establishing sales point will be helpful in business strategy through presenting types that are able to decide planning quality. Third, the important measure of EC about correlation among quality characteristics and a new weight of EC are calculated depending on importance of EC and the weight of customer attribute and materials of relationship matrix through correlation matrix analysis.

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A Study on The Determination Method of Engineering Characteristic Values by QFD (품질기능개선을 통한 품질특성값 결정방법에 관한 연구)

  • 강지호;박명규
    • Proceedings of the Safety Management and Science Conference
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    • 2000.05a
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    • pp.481-490
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    • 2000
  • First, in order to improve selecting method of quality characteristic level desired by customers, S/H(Signal-to-Noise) ratio of Taguchi in larger-the-better characteristics was applied. Second, the Matrix classification standard of ACE(Attribute Categorization Evaluation) is presented using KANO model on difference analysis of importance and satisfaction through questionnaire from customers. This is for reflecting the diverse EC which customers want in EC quality sufficiently. Also, establishing sales point will be helpful in business strategy through presenting types that are able to decide planning quality. Third, the important measure of EC about correlation among quality characteristics and a new weight o( EC are calculated depending on importance of EC and the weight of customer attribute and materials of relationship matrix through correlation matrix analysis.

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Precise response time measurement and analysis of liquid crystal displays

  • Glinel, David;Boher, Pierre;Leroux, Thierry
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.723-728
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    • 2006
  • In this paper, we present a new system, OPTISCOPE SA, especially designed for precise measurement of temporal behavior of LCD displays. We show that gray to gray level response time measurement requires a very sensitive and precise instrument and also that the capacity to measure luminance levels and gamma curve can be useful. Quite often, precise evaluation of LCD response time needs also use of low pass and stop band filters to suppress noise and flicker. Low pass filters affect the results but can be corrected for simple temporal behaviors. For complex temporal behaviors like those observed for overdriven LCDs, we show that direct adjustment of theoretical responses is much more efficient to get a complete picture of the temporal behavior of such displays.

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Overview of Environmental Impact Assessment and Environmental Protection Technology in Tunnel Construction (터널 건설에 따른 환경영향 평가 및 대응기술 개발 방향)

  • Bae Gyu-Jin
    • 한국터널공학회:학술대회논문집
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    • 2005.04a
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    • pp.63-74
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    • 2005
  • The environmental influence in tunnel construction is the drying of the ground water, the drop of the ground water level, and noise and vibration by tunnel excavation. The environmental influence can cause the change of natural ecosystem and the source of popular complaints. In case of popular complaints, the tunnel construction can be stopped or the construction period can be extended. Also, the financial loss may be reached to hundreds of billions won. The technology development to minimize the environmental influence in the tunnel construction is very important in order to control popular complaints and to preserve ecosystem. It should be required the investigation, the evaluation, and the assessment of environmental impact to reduce environmental influence in the tunnel construction. The objective of this research is to review the environmental impact assessment in Korea and to introduce the environmental protection technology which minimizes the environmental influence generated in the tunnel construction.

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The Operation Characteristics of Domestic Stirling Engine Cogeneration System (가정용 스털링엔진 열병합발전시스템 운전특성에 관한 연구)

  • Choi, Jae-Joon;Park, Byung-Sik;Jung, Dae-Heon
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.309-314
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    • 2009
  • The unpredicted worldwide oil price makes the energy efficiency technology be more importance than any other period. The small cogeneration system is one of the most representative technology among the energy efficiency technologies, and the Stirling engine cogeneration system has been concerned and investigated due to the preferable characteristics - low toxic emission, low noise and vibration level, and the various form of fuel. A tiny, 1kW of electrical output, gas fueled Stirling engine cogeneration system was investigated. The electrical efficiency and thermal efficiency of the system were measured. The experiment was executed at an independent Stirling engine mode, independent secondary burner mode, and the combined mode. Part load characteristics of the Stirling engine cogeneration system were investigated also. With the efficiency characteristics, the $O_2$ and NOx emission characteristics were measured.

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Femtocell Subband Selection Method for Managing Cross- and Co-tier Interference in a Femtocell Overlaid Cellular Network

  • Kwon, Young Min;Choo, Hyunseung;Lee, Tae-Jin;Chung, Min Young;Kim, Mihui
    • Journal of Information Processing Systems
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    • v.10 no.3
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    • pp.384-394
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    • 2014
  • The femtocell overlaid cellular network (FOCN) has been used to enhance the capacity of existing cellular systems. To obtain the desired system performance, both cross-tier interference and co-tier interference in an FOCN need to be managed. This paper proposes an interference management scheme that adaptively constructs a femtocell cluster, which is a group of femtocell base stations that share the same frequency band. The performance evaluation shows that the proposed scheme can enhance the performance of the macrocell-tier and maintain a greater signal to interference-plus-noise ratio than the outage level can for about 99% of femtocell users.

A Development of Waveform Composition Program and Evaluation of Application on Site (파형합성 프로그램 개발 및 현장 적용성 평가)

  • Yoon, Ji-Sun;Woo, Taek-Gyu;Bae, Sang-Hoon
    • Explosives and Blasting
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    • v.27 no.1
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    • pp.38-46
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    • 2009
  • Recently, as a reduction method of vibration and noise, an electronic detonation which has an accuracy of time and a freedom of input delay time was introduced. A waveform composition program can determine a delay time and accomplish simulation under environment similar to real blast using a delay time. In this study, optimum delay time which controls vibration is obtained and real measurement vibration level is estimated by a waveform composition program.