• Title/Summary/Keyword: Mixed sensitivity

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Fault Detection and Diagnosis Simulation for CAV AHU System (정풍량 공조시스템의 고장검출 및 진단 시뮬레이션)

  • Han, Dong-Won;Chang, Young-Soo;Kim, Seo-Young;Kim, Yong-Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.10
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    • pp.687-696
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    • 2010
  • In this study, FDD algorithm was developed using the normalized distance method and general pattern classifier method that can be applied to constant air volume air handling unit(CAV AHU) system. The simulation model using TRNSYS and EES was developed in order to obtain characteristic data of CAV AHU system under the normal and the faulty operation. Sensitivity analysis of fault detection was carried out with respect to fault progress. When differential pressure of mixed air filter increased by more than about 105 pascal, FDD algorithm was able to detect the fault. The return air temperature is very important measurement parameter controlling cooling capacity. Therefore, it is important to detect measurement error of the return air temperature. Measurement error of the return air temperature sensor can be detected at below $1.2^{\circ}C$ by FDD algorithm. FDD algorithm developed in this study was found to indicate each failure modes accurately.

A Study on Design Characteristic Shown in Movie Costume of Ishioka Eiko (이시오까 에이꼬 석강영자(石岡瑛子)의 영화 의상에 나타난 디자인 특성에 관한 고찰)

  • Kim, Hee-Jung
    • The Research Journal of the Costume Culture
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    • v.17 no.4
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    • pp.583-599
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    • 2009
  • The purpose of this study is to analyze movie costume of main character and find design characteristic and historical spirit focusing on the movie, in which Ishioka Eiko, Japanese movie costume designer constructing unique design world, participated. The study captured images of three movies such as , and with Digital Multimedia Converting System and analyzed them by focusing on the pictures showing designer's intention and design characteristic well among acquired 319 pictures. The costumes addressing movie costume designer's sense of values are recreated as future-oriented new works and are expressed as creative costumes by acquiring inspiration from past factors, dissolving them and applying up-to-date technology. Movie costume shall reflect historical spirit of our age as movie shows social cultural trend including fashion trend of manufactured age. Ishioka Eiko has searched for the design, which is proper for three principles such as 'be unique', 'be eternal' and 'be innovative' and from the result of analyzing movie costume, it is found that she showed characteristics of symbolism(transmission of the sensitivity), ornamentalism(effective representation as a decorative effect attention) and multiculturalism(harmony of time and culture) as well as uniqueness. The movie costume are different mutually and create new hybrid culture, in which different costume cultures are mixed with current costumes without the restriction to other culture. It is proper for the age of globalization and localization so it is expected that the multiculturalism will be enlarged more.

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Atmospheric Corrosion of 7B04 Aluminum Alloy in Marine Environments

  • Zhang, Xiaoyun;Liu, Ming;Lu, Feng;Liu, Minghui;Sun, Zhihua;Tang, Zhihui
    • Corrosion Science and Technology
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    • v.17 no.1
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    • pp.6-11
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    • 2018
  • Outdoor exposure tests using of 7B04 aluminium alloy samples including plate, tensile and various SCC samples were carried out in Tuandao station, Shandong province (East of China) and Wanning station, Hainan province (South of China). Corrosion characteristics including weight loss, microstructure, tensile strength and SCC susceptibility were investigated. The corrosion rates in Tuandao and Wanning showed high to low and the corrosion rates changed to the following equation of $w=at^b$ (b<1). The corrosion of 7B04 aluminium alloy in Wanning was more serious than that in Tuandao. Pitting appeared at early stage of expose test, and it can be changed to general corrosion with test time extension. The 7B04 aluminium alloy of which specimen shapes are forging and thick plate also showed SCC (Stress corrosion cracking) in the marine atmosphere. The higher SCC sensitivity was observed in Wanning station than in Tuandao station. The 7B04 aluminium alloy with a high stress level was more sensitive to SCC. Intergranular and transgranular or a mixed mode of cracking can be observed in different marine exposure.

Detection of thin-layered soil using CRPT in soft soil (CRPT를 이용한 연약지반 협재층 탐지)

  • Yoon, Hyung-Koo;Kim, Joon-Han;Kim, Rae-Hyun;Choi, Yong-Kyu;Lee, Jong-Sub
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.117-125
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    • 2008
  • The detection of thin-layered soil is important in soft soils to evaluate the soil behavior. The smaller diameter cone penetrometer have been commonly used to detect the layer with increasing sensitivity. The objective of this study is to detect the thin-layered soil using cone resistance and electrical resistance. The cone resistivity penetration test (CRPT) is developed to evaluate the cone tip resistance and electrical resistance at the tip. The CRPT is a micro-cone which has a $0.78cm^2$ in projected area. The application test is conducted in a laboratory large-scale consolidometer (calibration chamber). The kaolinite, sand and water are mixed to make the specimen at the liquid limit of 46% using a slurry mixer. It takes two months for the consolidation of the specimen. After consolidation, the CRPT test is carried out. Furthermore the standard CPT results are compared with the electrical resistance measured at the tip in the field. This study suggests that the CRPT may be a useful tool for detecting thin-layers in soft soils.

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Genomic DNA Sequence of Mackerel Parvalbumin and a PCR Test for Rapid Detection of Allergenic Mackerel Ingredients in Food

  • Choi, Ka-Young;Hong, Kwang-Won
    • Food Science and Biotechnology
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    • v.16 no.1
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    • pp.67-70
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    • 2007
  • Mackerel (Scomber japonicus) often causes severe allergic reactions in sensitive people. Food containing undeclared mackerel may pose a risk to such people. The major allergenic protein in fish such as mackerel, codfish, and Alaska pollack has been found to be parvalbumin. In this study, we developed a polymerase chain reaction (PCR) method to detect mackerel DNA using primers corresponding to the parvalbumin gene. We cloned and sequenced 1.5 kb of parvalbumin gene by PCR using mackerel genomic DNA as a template. Nucleotide sequence analysis of genomic parvalbumin gene, composed of 4 exons and 3 introns, allowed the selection of two pairs of oligonucleotide primers specific for mackerel. These primers successfully enabled PCR amplification of specific regions of genomic parvalbumin DNA from mackerel, but no amplification from 8 other fish samples, surimi, and 6 boiled fish pastes. The sensitivity of this method was sufficient to detect 5 ng of purified mackerel DNA mixed with 50 ng of surimi DNA. This rapid and specific method for the detection of allergenic mackerel would be beneficial in reducing food allergy caused by the ingestion of hidden allergen in processed food.

Characteristics of Microfauna in Biological Treatment of Landfil Leachate with Reactor Including Porous Media (다공성 Media가 조여된 반응조를 이용한 매립지 침출수의 호기성 생물학적 처리시 미소생물상의 특성)

  • 홍성철;박연규
    • Journal of Environmental Science International
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    • v.5 no.1
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    • pp.61-69
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    • 1996
  • The combined wastewater of municipal landfill leachate and municipal sewage was treated using several sets of bench-scale aerated circulating system including porous media. Investigated items in this experiment were the dominant protozoa and metazoa in this system, the variation of microfauna relationship between operating condition and dominant genera. Also considered the factors determining dominant genera and their role. The outcome of this research is as follows; 1. Aspidisca, Vorticella, Truhellophyllum, Lecane, Philodina, Cyclops were mainly appeared prior to combinding leachate, while Trachelocerca, Bodo, Glaucoma were the dominant genera after combinding leachate. 2. As to metazoa, Nematode and Philodina were not influenced by 5oA leachate mixing ratio, meanwhile Crustacea has high sensitivity for increased leachate mixing ratio and it was not appeared in 5% leachate mixing ratio. 3. The appropriate treatability could'nt be expected at the above 10% leachate mixing ratio. Especially, in the condition of 20% leachate mixing ratio, all of the microfauna were affected damage seriously on their existence. Meanwhile hydraulic retention time, substrate loading rate and slut자e production rate didn't give notable influence on increasing the number of microfauna. 4. As to protozoa, saprozoic and holozoic species were appeared commonly and polysaprobic species were dominent. 5. Filamentous organsms were nearly not affected by leachate mixing. It seems that they could live without any trouble at the 10% leachate mixing ratio, if the substrate is sufficient. 6. Diversity of microfauna had a reducing trernd as the sewage was mixed with leachate.

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Development of Methane Gas Sensor by Various Powder Preparation Methods

  • Min, Bong-Ki;Park, Soon-Don;Lee, Sang-Ki
    • The Korean Journal of Ceramics
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    • v.5 no.2
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    • pp.125-130
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    • 1999
  • After $SnO_2$ fine powder by precipitation method, Ca as crystallization inhibitor and Pd as catalyst were added to $SnO_2$ raw material by various methods. Thick film device was fabricated on the alumina substrate by mixing ethylene glycol and such mixed powders. The sensing characteristics of the device for methane gas were investigated. The most excellent gas sensing property was shown by the thick film device fabricated by Method 3 in which Ca and Pd doped $SnO_2$ powder is prepared by mixing $SnO_2$ powder, 0.1 wt% Ca acetate and 1 wt% $PdCl_2$ in deionized water and by calcining the mixture, after $Sn(OH)_4$ is dried at $110^{\circ}C$ for 36h. The sensitivity of the sensor fabricated with $SnO_2$-0.1 wt%Ca acetate-1wt%$PdCl_2$ powder heat-treated at $700^{\circ}C$ for 1h was about 86% for 5,000 ppm methane in air at $350^{\circ}C$ of the operating temperature. Response time and recovery were also excellent.

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Implementation of the robust speed control system for DC servo motor using TDF compensator method (2자유도 보상법에 의한 직류서보전동기의 강인한 속도제어시스템 구현)

  • Kim, Dong-Wan
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.52 no.2
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    • pp.74-80
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    • 2003
  • In this paper, a robust two-degree-of-freedom(TDF) the speed control system using $H_{\infty}$ optimization method and real genetic algorithm is proposed for the robust stability and the robust performance in dc servo motor system. This control system composed of feedback and feedforward controller. The feedback(FB) controller with $H_{\infty}$ optimization method is designed for real genetic algorithm that is model matching problem using mixed sensitivity function. The feedforward(FF) controller with $H_{\infty}$optimization method is minimized the error between transfer function of the optimal model and the overall transfer function. The proposed robust two-degree-of-freedom speed control system is simulated to the dc servo motor. By the simulation, feedback controller can obtain the robust stability property and feedforward controller can obtain the robust performance property under modelling error. The performance of the dc servo motor is analyzed by the experiment setting. The validity of the proposed method is verified through being compared with pid(proportional integrated differential)control system design method for the dc servo motor.

Characteristic comparison of sensing materials in mixed potential type NH3 gas sensors for urea-SCR DeNOx system in diesel engine (디젤 엔진 Urea-SCR DeNOx 시스템용 혼합전위 방식 암모니아 가스 센서의 감지물질 특성 비교)

  • Choi, An-Gi;Yang, Young-Chang;Koo, Bon-Chul;Park, C.O.
    • Journal of Sensor Science and Technology
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    • v.19 no.3
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    • pp.176-183
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    • 2010
  • It is considered that the urea injection DeNOx SCR(selective catalytic reduction) system is the only promising method to satisfy the worldwide NOx emission standards. As for the theoretical aspect, reactants of NO and $NO_2$ with $NH_3$ produce $H_2O$, $N_2$ and $O_2$ which do not harm human beings and environmental as well. The realization of maximum NOx conversion (without using a post oxidation catalyst) is only possible with closed loop controlled urea dosing. It means built-in $NH_3$ gas sensor have to be developed for detecting accurate $NH_3$ concentration for the feedback system. Using YSZ(yttria-stabilized zirconia) as a solid state electrolyte and $In_2O_3$ as a sensing material, this paper aims to study dependable $NH_3$ gas sensor for the promising solution of DeNOx technology, which have a reproducible electric output signal, a high sensitivity and fast response.

Multi-Point Aerodynamic Design Optimization of DLR F-6 Wing-Body-Nacelle-Pylon Configuration

  • Saitoh, Takashi;Kim, Hyoungjin;Takenaka, Keizo;Nakahashi, Kazuhiro
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.3
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    • pp.403-413
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    • 2017
  • Dual-point aerodynamic design optimization is conducted for DLR-F6 wing-body-nacelle-pylon configuration adopting an efficient surface mesh movement method for complex junction geometries. A three-dimensional unstructured Euler solver and its discrete adjoint code are utilized for flow and sensitivity analysis, respectively. Considered design conditions are a low-lift condition and a cruise condition in a transonic regime. Design objective is to minimize drag and reduce shock strength at both flow conditions. Shape deformation is made by variation of the section shapes of inboard wing and pylon, nacelle vertical location and nacelle pitch angle. Hicks-Henne shape functions are employed for deformation of the section shapes of wing and pylon. By the design optimization, drag coefficients were remarkably reduced at both design conditions retaining specified lift coefficient and satisfying other constraints. Two-point design results show mixed features of the one-point design results at low-lift condition and cruise conditions.