• Title/Summary/Keyword: Cascade system

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Effects of Green Tea Catechin on Microsomal Phospholipase A2 Activity and Arachidonic Acid Cascade in Rat Lung Exposed to Microwave (마이크로웨이브를 조사한 흰쥐 폐조직의 Phospholipae A2 활성과 Arachidonic Acid Cascade계에 미치는 녹차 Catechin의 영향)

  • Kim, Mi-Ji
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.7
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    • pp.936-942
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    • 2012
  • In the present study, the effects of green tea catechin on microsomal phospholipase $A_2$ ($PLA_2$) activity and the arachidonic acid (AA) cascade in the lungs of microwave exposed rats were investigated. One Sprague-Dawley male rats weighting $100{\pm}10$ g was randomly assigned to the normal group and three were assigned to the microwave exposed groups. The microwave exposed groups were subdivided into three groups according to the levels of dietary catechin supplementation: catechin free diet (MW) group, 0.25% catechin (MW-0.25C) group and 0.5% catechin (MW-0.5C) group. Rats were sacrificed on the 6th day after microwave irradiation (2.45 GHz, 15 min). The lung microsomal $PLA_2$ activity in the MW and MW-0.25C groups was 30% and 15% greater than that of the normal group, respectively, whereas no significant difference between the normal group and MW-0.5C group was observed. The percentage of phosphatidylethanolamine (PE) hydrolyzed in the lung microsome in the MW, MW-0.25C and MW-0.5C group increased by 47%, 18% and 20%, respectively, due to microwave irradiation. The formation of thromboxane $A_2$ ($TXA_2$) in the lung microsome was 50% greater in the MW group than in the normal group. However, the levels of $TXA_2$ in the MW-0.25C and MW-0.5C group were normal. The formation of prostacyclin ($PGI_2$) in the lung microsome was 31% lower in the MW group than in the normal group, while the levels of $PGI_2$ in the MW-0.25C and MW-0.5C group were similar to the normal group. The lung microsomal thiobarbituric acid reactive substances (TBARS) concentration, which can be used as an index of lipid peroxide was 34% greater in the MW group, when compared with the normal group. However, there was no difference between the MW-0.25C, MW-0.5C and normal groups. In conclusion, lung function appeared to be improved by green tea catechin supplementation due to its antithrombus action, which in turn controls the AA cascade system.

Region-Based Facial Expression Recognition in Still Images

  • Nagi, Gawed M.;Rahmat, Rahmita O.K.;Khalid, Fatimah;Taufik, Muhamad
    • Journal of Information Processing Systems
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    • v.9 no.1
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    • pp.173-188
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    • 2013
  • In Facial Expression Recognition Systems (FERS), only particular regions of the face are utilized for discrimination. The areas of the eyes, eyebrows, nose, and mouth are the most important features in any FERS. Applying facial features descriptors such as the local binary pattern (LBP) on such areas results in an effective and efficient FERS. In this paper, we propose an automatic facial expression recognition system. Unlike other systems, it detects and extracts the informative and discriminant regions of the face (i.e., eyes, nose, and mouth areas) using Haar-feature based cascade classifiers and these region-based features are stored into separate image files as a preprocessing step. Then, LBP is applied to these image files for facial texture representation and a feature-vector per subject is obtained by concatenating the resulting LBP histograms of the decomposed region-based features. The one-vs.-rest SVM, which is a popular multi-classification method, is employed with the Radial Basis Function (RBF) for facial expression classification. Experimental results show that this approach yields good performance for both frontal and near-frontal facial images in terms of accuracy and time complexity. Cohn-Kanade and JAFFE, which are benchmark facial expression datasets, are used to evaluate this approach.

A Study on The Characteristics of The Inlet Boundary Condition of a Supersonic Turbine Cascade (초음속 터빈 캐스케이드 입구 경계조건의 특성에 관한 연구)

  • 신봉근;성영식;정수인;김귀순;이은석
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.10a
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    • pp.99-103
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    • 2003
  • An analysis of the flow within supersonic turbine cascades is necessary to design and manufacture turbo-pump system. Because of the differences between the specified inlet boundary value and the computed inlet value caused by the far field inlet boundary condition, the computations at desired inlet conditions can not be achieved. So, this paper studied the problem occurred when far field inlet conditions were specified as inlet boundary conditions. And the numerical analyses using Fine Turbo, CFD Program, has been performed and compared with those of experiments when a converging-diverging nozzle or a linear nozzle was located in front of cascades instead of the far field inlet condition.

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Velocity Control of Permanent Magnet Synchronous Motors using Model Predictive and Sliding Mode Cascade Controller (슬라이딩 모드 및 모델 예측 직렬형 제어기를 이용한 영구자석형 동기전동기의 속도제어)

  • Lee, Ilro;Lee, Youngwoo;Shin, Donghoon;Chung, Chung Choo
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.9
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    • pp.801-806
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    • 2015
  • In this paper, we propose cascade-form velocity controller for a permanent magnet synchronous motor (PMSM). The proposed controller consists of a sliding-mode controller (SMC) for the inner current control loop and a model-predictive controller (MPC) for the outer velocity control loop. With SMC, we can ensure that the current tracking error always converges to zero in finite time. The SMC is designed to track the desired currents. Additionally, with MPC, we can obtain the optimal velocity control input which minimizes the cost function. Constraint conditions for input and input variation are included in the MPC design. The simulation results are included to validate the performance of the proposed controller.

A Video based Traffic Light Recognition System for Intelligent Vehicles (지능형 자동차를 위한 비디오 기반의 교통 신호등 인식 시스템)

  • Chu, Yeon Ho;Lee, Bok Joo;Choi, Young Kyu
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.2
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    • pp.29-34
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    • 2015
  • Traffic lights are common in cities and are important cues for the path planning of intelligent vehicles. In this paper, we propose a robust and efficient algorithm for recognizing traffic lights from video sequences captured by a low cost off-the-shelf camera. Instead of using color information for recognizing traffic lights, a shape based approach is adopted. In learning and detection phase, Histogram of Oriented Gradients (HOG) feature is used and a cascade classifier based on Adaboost algorithm is adopted as the main classifier for locating traffic lights. To decide the color of the traffic light, a technique based on histogram analysis in HSV color space is utilized. Experimental results on several video sequences from typical urban environment prove the effectiveness of the proposed algorithm.

Study on the Cooling Performance of Single and Cascade Refrigeration Systems Using Thermoelectric Modules (열전소자를 이용한 싱글 및 캐스케이드 냉동시스템의 냉각 성능에 관한 연구)

  • Lim, Changhak;Kim, Dongwoo;Kim, Yongchan;Seo, Kookjeong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.12
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    • pp.641-646
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    • 2013
  • The purpose of this study is to improve the cooling performance of single and cascade refrigeration systems using thermoelectric modules. The system consists of a heat sink, fan, and thermoelectric module. The operating parameters considered in this study include power distribution between the first- and second-stage thermoelectric modules, air flow, and variable condensing unit. The cooling capacity increased with decreases in the temperature difference between hot and cold surfaces, but decreased with increases in the condensing temperature. The COP decreased with increasing electric power of the thermoelectric module because of the increased Joule heat. The cooling performance improvement using the thermoelectric module is represented by the freezer temperature.

In-vivo Measurements of Blood Flow Characteristics in the Arterial Bifurcation Cascade Networks of Chicken Embryo (유정란 태아외부혈관의 단계적으로 분기되는 동맥 분지관 내부 혈액 유동특성의 in-vivo 계측)

  • Lee, Jung-Yeop;Lee, Sang-Joon
    • 한국가시화정보학회:학술대회논문집
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    • 2006.12a
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    • pp.121-124
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    • 2006
  • The arteries are very important in cardiovascular system and easily adapt to varying flow and pressure conditions by enlarging or shrinking to meet the given hemodynamic demands. The blood flow in arteries is dominated by unsteady flow phenomena due to heart beating. In certain circumstances, however, unusual hemodynamic conditions cause an abnormal biological response and often induce circulatory diseases such as atherosclerosis, thrombosis and inflammation. Therefore quantitative analysis of the unsteady pulsatile flow characteristics in the arterial blood vessels plays important roles in diagnosing these circulatory diseases. In order to verify the hemodynamic characteristics, in-vivo measurements of blood flow inside the extraembryonic arterial bifurcation cascade of chicken embryo were carried out using a micro-PIV technique. To analyze the unsteady pulsatile flow temporally, the (low images of RBCs were obtained using a high-speed CMOS camera at 250fps with a spatial resolution of $30{\mu}m\times30{\mu}m$ in the whole blood vessels. In this study, the unusual flow conditions such as flow separation or secondary flow were not observed in the arterial bifurcations. However, the vorticity has large values in the inner side of curvature of vessels. In addition, the mean velocity in the arterial blood vessel was decreased and pulsating frequency obtained by FFT analysis of velocity data extracted in front of the each bifurcation was also decreased as the bifurcation cascaded.

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An Expert System for the Fault Diagnosis of Hard Disk Drive Test System

  • Moon, Un-Chul;Kim, Woo-Kuen;Lee, Seung-Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2418-2423
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    • 2005
  • Hard Disk Drive (HDD) test system is the equipment for the final test of HDD product by iterative read/write/seek test. This paper proposes an expert system for the fault diagnosis of HDD test systems. The purposed expert system is composed with two cascade inference, fuzzy logic and conventional binary logic. The fuzzy logic determines the possibility of the system fault using the test history data, then, the binary logic inferences the fault location of the test system. The proposed expert system is tested in SAMSUNG HDD product line, KUMI, KOREA, and shows satisfactory results.

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An Expert System for the Fault Diagnosis of Hard Disk Drive Test System

  • Moon, Un-Chul;Kim, Woo-Kuen;Lee, Seung-Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2424-2429
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    • 2005
  • Hard Disk Drive (HDD) test system is the equipment for the final test of HDD product by iterative read/write/seek test. This paper proposes an expert system for the fault diagnosis of HDD test systems. The purposed expert system is composed with two cascade inference, fuzzy logic and conventional binary logic. The fuzzy logic determines the possibility of the system fault using the test history data, then, the binary logic inferences the fault location of the test system. The proposed expert system is tested in SAMSUNG HDD product line, KUMI, KOREA, and shows satisfactory results.

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An Expert System using Fuzzy and Binary logic for the Fault Diagnosis of Hard Disk Drive Test System (Hard Disk Drive 검사시스템의 고장 진단을 위한 퍼지-이진 논리 결합형 전문가 시스템에 관한 연구)

  • 문운철;이승철;남창우
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.6
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    • pp.457-464
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    • 2004
  • Hard Disk Drive (HDD) test system is an equipment for the final test of HDD product by iterative read/write/seek test. This paper proposes an expert system for the fault diagnosis of HDD test systems. The purposed expert system is composed with two cascade inference, fuzzy logic and conventional binary logic. The fuzzy logic determines the possibility of the system fault using the test history data, then, the binary logic inferences the fault location of the test system. The proposed expert system is tested in SAMSUNG HDD production line, KUMI, KOREA, and shows satisfactory results.