• Title/Summary/Keyword: $a^*/b^*$값

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국산개발 DCS의 발전소 적용

  • 김은기
    • 전기의세계
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    • v.41 no.9
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    • pp.5-11
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    • 1992
  • DCS가 정상이면 운전원의 설정값 조작치와 현장전송기의 측정값이 비교되어 오차가 비례 적분제어로 MV신호를 H/A에 보내고, ST신호의 GOOD(PUlLSE)에 의해서 A에 연결되어 제어 밸브를 열고 닫는다. 만일 DCS가 고장이면 ST신호의 BAD에 의해서 B에 열결되고 (H/A)가 A운전이면 PID 제어값이 M운전이면 운전원 조작 신호에 의해서 제어 밸브가 열리고 닫힌다. 상기와 같은 시스템 구성으로 DSC의 다양한 S/W를 적용하면 정밀, 제어 안정된 제어가 이루어져 발전소 안정 운전에 기여할 것이며, 기타 화학공장, 제철공장 등에 적용할 경우 기술의 파급효과가 큼은 물론 국내 자동제어 기술혁신의 디딤돌이 되리라 확신한다.

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Correlation of the Speed of Enhancement of Hepatic Hemangiomas with Intravoxel Incoherent Motion MR Imaging (간혈관종의 조영증강속도와 복셀내비결집운동 MR영상과의 상관관계)

  • Yang, Dal Mo;Jahng, Geon-Ho;Kim, Hyun Cheol;Kim, Sang Won;Kim, Hyug-Gi
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.3
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    • pp.208-218
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    • 2014
  • Purpose : To evaluate the relationship between the speed of enhancement of hepatic hemangiomas on gadolinium-enhanced MRI and ADC values by using various parameters, including the D, f, $D^*$ and $ADC_{fit}$ on intravoxel incoherent motion (IVIM) MR Imaging. Materials and Methods: The institutional review board approved this retrospective study. A total of 47 hepatic hemangiomas from 39 patients were included (20 men and 19 women). The hemangiomas were classified into three types according to the enhancement speed of the hepatic hemangiomas on gadolinium-enhanced dynamic T1-weighted images: rapid (Type A), intermediate (Type B), and slow (Type C) enhancement. The D, f, $D^*$ and $ADC_{fit}$ values were calculated using IVIM MR imaging. The diffusion/perfusion parameters and ADC values were compared among the three types of hemangiomas. Results: Both the $ADC_{fit}$ and D values of type C were significantly lower than those of type A (P = 0.0022, P = 0.0085). However, for the f and $D^*$, there were no significant differences among the three types. On DWI with all b values (50, 200, 500 and $800sec/mm^2$), the ADC values of type C were significantly lower than those of the type A (P < 0.012). For b values with $800sec/mm^2$, the $ADC_{800}$ values of the type C hemangiomas were significantly lower than those of type B (P = 0.0021). We found a negative correlation between hepatic hemangioma enhancement type and $ADC_{50}$ (${\rho}=-0.357$, P = 0.014), $ADC_{200}$ (${\rho}=-0.537$, P = 0.0001), $ADC_{500}$ (${\rho}=-0.614$, P = 0.0001), and $ADC_{800}$ (${\rho}=-0.607$, P = 0.0001). Therefore, four ADC values of $ADC_{50}$, $ADC_{200}$, $ADC_{500}$, and $ADC_{800}$ were decreased with decreasing enhancement speed. Conclusion: Hepatic hemangiomas had variable ADCs according to the type of enhancement, and the reduced ADCs in slowly enhancing hemangiomas may be related to the reduced pure molecular diffusion (D).

Performance Analysis of Block Turbo Coded OFDM System Using Channel State Information (채널상태정보를 이용하는 블록터보 부호화된 OFDM 시스템의 성능 분석)

  • Kim, Han-Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.2
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    • pp.872-877
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    • 2011
  • In this paper, the new decoding algorithm of Block Turbo Codes using Channel State Information(CSI), which is estimated to compensate for the distorted signal caused by multi-path fading, is proposed in order to improve error correction capacity during decoding procedure in OFDM system. The performance of the new decoding algorithm is compared to that of the conventional decoding algorithm without using channel state information under the Rayleigh fading channel. Experimental results showed that in case of only one iteration coding gains of up to 5.0dB~9.0dB can be obtained by applying the channel state information to the conventional decoding algorithm according to the modulation methods. In addition to that, the new decoding algorithm using channel state information at only one iteration shows a performance improvement of 3.5dB to 5.0dB when compared to the conventional decoding algorithm after four iterations. This leads to reduce the considerable amount of computation.

2D to 3D Anaglyph Image Conversion using Quadratic & Cubic Bézier Curve in HTML5 (HTML5에서 Quadratic & Cubic Bézier 곡선을 이용한 2D to 3D 입체 이미지 변환)

  • Park, Young Soo
    • Journal of Digital Convergence
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    • v.12 no.12
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    • pp.553-560
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    • 2014
  • In this paper, we propose a method to convert 2D image to 3D anaglyph using quadratic & cubic B$\acute{e}$zier Curves in HTML5. In order to convert 2D image to 3D anaglyph image, we filter the original image to extract the RGB color values and create two images for the left and right eyes. Users are to set up the depth values of the image through the control point using the quadratic and cubic B$\acute{e}$zier curves. We have processed the depth values of 2D image based on this control point to create the 3D image conversion reflecting the value of the control point which the users select. All of this work has been designed and implemented in Web environment in HTML5. So we have made it for anyone who wants to create their 3D images and it is very easy and convenient to use.

Presentation of Target Color with Extraction Variables in Natural Dyes Extraction (천연색소 추출공정에서 추출특성에 따른 목표색의 재현)

  • Tak, Eun-Soo;Bae, Min-Woo;Kang, Seung-Hyeon;Bae, You-Jin;Kang, Su-Yeon;Jung, Soo-Kyung;Hong, In-Kwon
    • Applied Chemistry for Engineering
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    • v.21 no.5
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    • pp.559-563
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    • 2010
  • The representation of color with natural dyes is closely related with the modern well-being life. This study is focused on the representation of target color of the blue, yellow, and red color system, these color sources were originated from the green tea, gardenia, and black rice respectively. The quantitative numerical value of brightness (L), color coordinates (a, b) were designated for the target color, the optimum color nearest to the target value was extracted with the solvent pH, temperature, and extraction time. The longer the extraction time had more thickening color in case of the gardenia. The L-a-b coordinate of extracted color were analyzed with the color difference meter and compared with the target color. The experimental variables were optimized to extract the color of the smallest ${\Delta}E$ with the target color. As a result, the CIE standard value was proposed and the color was represented.

Quality Characteristics of High and Low Grade Hanwoo Beef During Storage at $1^{\circ}C$ (고급 및 저급 한우육의 저장중 품질 특성)

  • Jeong, Geun-Gi;Park, Na-Young;Lee, Shin-Ho
    • Korean Journal of Food Science and Technology
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    • v.38 no.1
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    • pp.10-15
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    • 2006
  • Quality changes of first grade Hanwoo beef were compared with those of third grade Hanwoo beef to investigate effect of initial raw meat quality on maintenance of meat quality during storage for 28 days at $1\;{\pm}\;1^{\circ}C$. Crude fat content of first grade meat was higher, whereas water content was lower, than those of third grade meat. Total bacterial counts of first and third grade beef packaged with polyethylene for 21 days storage at $1\;{\pm}\;1^{\circ}C$ were 106 and $108\;CFU/cm^2$, respectively. Volatile basic nitrogen (VBN) value of first grade meats was lower than that of third grade meat during storage for 28 days at $1\;{\pm}\;1^{\circ}C$. Drip loss percents of first and third grade meats were 4.19 and 6.06% during 14 days storage at $1^{\circ}C$, respectively. L, a, and b values decreased gradually during storage regardless of meat grade, with a value of first grade meat being higher than that of third grade meat at early stage of storage at $1^{\circ}C$.

Design of a microstripe line ceramic dielectric filter (마이크로스트립라인 세라믹 유전체필터 설계)

  • Ko, Hee-Youl;Kim, Chung-Hoi;Kang, Byung-Don;Koo, Bon-Keup
    • Proceedings of the KAIS Fall Conference
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    • 2012.05b
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    • pp.712-715
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    • 2012
  • 본 논문에서는 EM 시뮬레이터를 이용하여 LTE2300 대역의 마이크로스트립 라인 대역여파기를 설계하고 시편을 제작하였다. 중심주파수 2300MHz, 대역폭 350MHz, 삽입손실 1.5dB, 감쇄는 1930MHz와 2690MHz에서 15dB 이상, 1000MHz에서 60dB 이상으로 설계하였다. 또한 반사손실은 15dB로 설계하였다. 구현은 유전율 9.8인 알루미나 유전체에서 하였으며, 전송선로와 접지는 silver paste를 사용하였다. EM 시뮬레이션을 통해 얻은 결과값과 이를 통해 실제 제작된 시편의 보정값을 얻어 data base화 하였으며, 좋은 재현성을 얻을 수 있음을 확인하였다. 특히 일반적으로 마이크로스트립 라인 필터의 제작에 적용되는 에칭 또는 포토리소그라피 대신 레이저를 이용하여 패턴을 구현하였으며, 이 또한 우수한 특성과 재현성을 보여주었다.

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Effect of Changes on Color Characteristics by Microstructural Transformations of Cu-Sn Bronzes (Cu-Sn 청동기의 미세조직 변화 양상이 색도 변화에 미치는 영향)

  • Lee, Jae-Sung;Park, Jang-Sik
    • Journal of Conservation Science
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    • v.30 no.4
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    • pp.417-425
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    • 2014
  • Color characteristics of the Cu-Sn alloys (bronze) in as-cast conditions were determined by reference to the $L^*$, $a^*$, $b^*$ color space. Results show that the values of $a^*$ and $b^*$ decrease with the increase in Sn levels, indicating that the colors of bronze alloys are increasingly away from red and yellow with the increase in the fraction of the ${\delta}$ phase while the opposite is true with the ${\alpha}$ phase. It has also been found in similar experiments with the Cu-22% Sn alloys that heat treatments in varying conditions produce subtle differences in their color characteristics as observed in the $L^*$, $a^*$, $b^*$ color space, due likely to the formation of various phases in different fractions.

A Setting of Initial Cluster Centers and Color Image Segmentation Using Superpixels and Fuzzy C-means(FCM) Algorithm (슈퍼픽셀과 FCM을 이용한 클러스터 초기값 설정 및 칼라영상분할)

  • Lee, Jeong-Hwan
    • Journal of Korea Multimedia Society
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    • v.15 no.6
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    • pp.761-769
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    • 2012
  • In this paper, a setting method of initial cluster centers and color image segmentation using superpixels and Fuzzy C-means(FCM) algorithm is proposed. Generally, the FCM can be widely used to segment color images, and an element is assigned to any cluster with each membership values in the FCM. However the algorithm has a problem of local convergence by determining the initial cluster centers. So the selection of initial cluster centers is very important, we proposed an effective method to determine the initial cluster centers using superpixels. The superpixels can be obtained by grouping of some pixels having similar characteristics from original image, and it is projected $La^*b^*$ feature space to obtain the initial cluster centers. The proposed method can be speeded up because number of superpixels are extremely smaller than pixels of original image. To evaluate the proposed method, several color images are used for computer simulation, and we know that the proposed method is superior to the conventional algorithm by the experimental results.

A Handover Mechanism for IEEE 802.11 Wireless Networks using GPS and SNR (IEEE 802.11 무선 네트워크에서 GPS와 SNR을 이용한 핸드오버 메커니즘)

  • Yoon, In-Su;Chung, Sang-Hwa;Kim, Jeong-Soo
    • Journal of KIISE:Information Networking
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    • v.36 no.3
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    • pp.256-262
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    • 2009
  • In this paper, we propose a mechanism for increasing the handover performance of the IEEE 802.11 link layer. The mechanism reduces the number of scanning channels by referencing an AP map based on GPS. Also, by monitoring the SNRs of the mobile node and neighbor APs, it enables the handover to maintain a higher SNR than a given threshold. The experimental results establish that it has a disconnection ratio of 6.7% and an average SNR of 16.8 dB. It is 4.1% lower disconnection ratio and 26% higher SNR than the mechanism used by MadWifi.