• Title/Summary/Keyword: on-state resistance

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Effect of Stress History on CPT-DMT Correlations in Granular Soil (응력이력이 사질토의 CPT-DMT 상관관계에 미치는 영향)

  • Lee, Moon-Joo;Choi, Sung-Kun;Kim, Min-Tae;Lee, Ju-Hyeong;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.730-739
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    • 2010
  • Stress history increases in penetration resistance due to the increase in residual horizontal stress of granular soil. This study analyzes the effect of stress history on the results of CPT and DMT from calibration chamber specimen in OC as well as NC state. Test results show that the normalized cone resistance by mean effective stress correlates well with the relative density and the state parameter, whereas the normalized cone resistance with regard to vertical effective stress is a little affected by stress history. The horizontal stress index($K_D$) in DMT more reflects the influence of stress history on granular soil than the dilatometer modulus($E_D$) and cone resistance($q_c$). The $K_D/K_0$, in which the effect of stress history on $K_D$ is compensated by the at-rest coefficient of earth pressure, $K_0$, is related to relative density, state parameter and the normalized cone resistance by mean effective stress. It is also observed that the normalized dilatometer modulus by mean effective stress($E_D/{\sigma_m}'$) is unique correlated with the state parameter, regardless of stress history.

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A Study of the Pre-Resistance Effects on the Optimization For Performance of the Ignition System with the Breaker Point Type (Breaker Point 型 점火裝置 性能 을 極大化하기 위한 Pre - Resistance 효果 에 對한 硏究)

  • 손병진;신영철
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.6 no.2
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    • pp.133-139
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    • 1982
  • One of factors that affect combustion in the cylinder of the engine is to keep a greater energy in the ignition system to minimize pollutant emissions and to increase its performance of the low temperature. This paper reviews theoretically the state and input variables of the ignition system from the state transition equation. Effects on characteristics of the system such as primary current, secondary available voltage and spark duration by reducing the pre-resistance from 3.5 to 0 ohm in 12V system is experimentally investigated when the ignition coil has a primary resistance of 1.5 ohms ad the dwell angle of the breaker point is 43.2 degrees (0.75 radian). Advantages and limitations for using the low resistance of the primary circuit are also presented to optimize the performance of the ignition system with the breaker point.

Determination of Design Parameters from Ground Investigation Results -Focus on geotechnical characteristic values- (지반조사결과에서 설계변수의 결정문제 -지반특성치 산정을 중심으로-)

  • Yoon, Gil-Lim;Yoon, Yeo-Won;Kim, Hong-Yeon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.126-133
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    • 2008
  • Geotechnical limit state design methods; LRFD of North America is an approach that estimates resistance using design model and then multiplies resistance factor by calculated resistance to reflect the uncertainty of geomaterials and design models; whereas, Eurocode of the Europe employs the partial resistance factor applied directly to each variable in the resistance equation that individual soil properties such as cohesion and angle of internal friction are applied. This discussion paper is a study on characteristic value which has globally been argued through processing of development of Eurocode 7 for geotechnical design even to the present. Estimating the characteristic value of soil properties affects not only determination of design value applied directly to design of geotechnical structures, but also economic feasibility and stability of the structures.

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On-state resistance secreasing effect of mim antifuse by re-programming method (재 프로그래밍 방법에 의한 MIM ANTIFUSE의 온저항 감소 효과)

  • 임원택;이상기;김용주;이창효;권오경
    • Journal of the Korean Vacuum Society
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    • v.6 no.3
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    • pp.194-199
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    • 1997
  • We fabricated MIM (Metal-Insulator-Metal) antifuses with Al/a-Si/Mo structure and then examined the I-V characteristics and on-state resistance distribution of antifuses. The leakage current of antifuses is below $1Pa/{\mu}m^2$, and programming voltage lies within 10 to 11 V. After programming, on-resistance of antifuses is mostly 10-20$\Omega$ and 20% of these have above 100$\Omega$. In order to reduce on-resistance and the deviation of this distribution, we tried to inject current again into already programed antifuses (we call this re-programming method). From this method, the resistance of antifuses with above 100Ω can be reduced to below 50$\Omega$. When antifuses are programmed by re-programming method, these antifuses have more uniform and lower on-resistance than programmed with one-pulse.

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Rotor Resistance Estimation of Induction Motor by ANN (ANN에 의한 유도전동기의 회전자 저항 추정)

  • Ko, Jae-Sub;Choi, Jung-Sik;Chung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.10
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    • pp.27-34
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    • 2006
  • This paper proposes a new method of on-line estimation for rotor resistance of the induction motor in the indirect vector controlled drive, using artificial neural network (ANN). The back propagation algorithm is used for training of the neural networks. The error between the desired state variable of an induction motor and actual state variable of a neural network model is back propagated to adjust the weight of a neural network model, so that the actual state variable tracks the desired value. The performance of rotor resistance estimator and torque and flux responses of drive, together with these estimators, are investigated variations rotor resistance from their nominal values. The rotor resistance are estimated analytically, using the proposed ANN in a vector controlled induction motor drive.

Effects of monochromatic lights on the growth performance, carcass characteristics, eyeball development, oxidation resistance, and cecal bacteria of Pekin ducks

  • Hua, Dengke;Xue, Fuguang;Xin, Hairui;Zhao, Yiguang;Wang, Yue;Xiong, Benhai
    • Animal Bioscience
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    • v.34 no.5
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    • pp.931-940
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    • 2021
  • Objective: Light is a significant component of housing environment in commercial poultry industry. This study was conducted to investigate whether Pekin ducks perform better under monochromatic lights than under white light with respect to their growth performance, carcass quality, eyeball development, oxidation resistance, and cecal bacterial communities. Methods: A total of 320 one-day-old male Pekin ducklings were randomly distributed into five rooms with different light treatments, white, red, yellow, green, and blue light. Each room consisted of 4 replicated pens with 16 ducklings per pen. Results: Blue light significantly decreased fat deposition by decreasing abdominal fat. Long wavelength light, such as red, green, and yellow light, considerably increased the back-to-front eyeball diameter and the red light potentially enlarged the side-to-side eyeball diameter. Besides, the blue light had adverse effects on the oxidation resistance status in terms of increasing the product malonaldehyde of lipid oxidation and decreasing the plasma concentration of total superoxide dismutase. The phyla of Firmicutes had the greatest abundance in the green and blue treatments, while Bacteroidetes in blue treatment was the least. The genus of Faecalibacterium was significantly lower under the red light. Conclusion: The high risk of cecal health status and decreased anti-oxidation activity were observed under blue light. Red, yellow, and green light might increase the risk of oversized eyeball and cecal illness. Therefore, monochromatic lights compared to white light did not show advantages on the performance of housing ducks, it turns out that the white light is the best light condition for grow-out ducks.

Lower Antibody Response in Chickens Homozygous for the Mx Resistant Allele to Avian Influenza

  • Qu, L.J.;Li, X.Y.;Xu, G.Y.;Ning, Z.H.;Yang, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.4
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    • pp.465-470
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    • 2009
  • The chicken Mx gene has been regarded as a candidate gene for resistance to avian influenza virus (AIV). In this study, three groups of chickens with homozygotes (AA, GG) and heterozygotes (AG) of the resistant (A) and susceptible alleles (G) to AIV of the Mx gene were constructed from a line of dwarf egg-type chickens. These chickens were not examined for their resistant activities to AIV because the differential resistance had only been detected in vitro. The birds of the three groups were vaccinated with inactivated H5N2 AIV vaccine and the level of hemagglutination inhibition (HI) antibody to AIV was detected. The association between disease resistant activity to AIV and antibody response to AIV vaccination in the three groups was analyzed. The chickens with homozygous resistant allele A showed the lowest antibody levels, whereas the heterozygous chickens (AG) presented the highest antibody level after the boosting vaccination, which indicates that the efficiency of artificial selection on the resistant allele of Mx gene will be compromised since the homozygotes of the allele presented the weakest antibody response to the corresponding vaccine.

Experimental study on the estimating effective horse power of a bottom trawl ship (저층 트롤선의 유효마력 산정에 관한 실험적 연구)

  • Wang, Woo-Kyung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.3
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    • pp.227-233
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    • 2005
  • In order to estimate the effective horse power(EHP) in towing net of a bottom trawl ship, the ship's resistance was calculated by using a series data of Yamagata and Wigley formula. Also the effective horse power for a ship(EHPs) was estimated versus the ship speed in sailing and the propulsive efficiency was calculated with the brake horse power and the effective horse power. Then the effective horse power for a ship and a trawl net were estimated in the application of the propulsive efficiency in towing net. The total effective horse power($EHP_T$) was average 187.6kW and the effective horse power for a 1.awl net($EHP_n$) was average 176.7kW at a smooth sea state in towing net. The ratio of $EHP_n$ to $EHP_T$ was about 94.0% and the value was higher slightly than was already informed at a smooth sea state. The power for keeping up a townet speed was required more about 20% of a maximum continuous power at a rather rough sea state than a smooth sea state. In the future, if the residual resistance is considered with a sea state, $EHP_n$ will be estimated more correctly Also the data of EHP estimated by this method will be used as the basic data to design a trawl net.

A Review of Studies on Antibiotic Course and Antibiotic Resistance in Nasopharyngeal Pathogens in Primary Care Setting (일차진료 항생제 치료기간과 비인두 항생제 내성률에 대한 연구 고찰)

  • Shin, Hyang Hwa;Lee, Sun Haeng;Yun, Sung Joong;Chang, Gyu Tae
    • The Journal of Pediatrics of Korean Medicine
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    • v.32 no.2
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    • pp.64-71
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    • 2018
  • Objectives The purpose of this study is to examine the correlation of antibiotics administration duration and antimicrobial resistance by reviewing domestic and foreign literatures. Methods We searched literatures dated up to 23 February, 2018 in PubMed and Cochrane Library using terms of "Anti-Bacterial Agents", "Carrier State", "Nasopharynx", "Drug Administration Schedule", and also searched via RISS (Research Information Service System), KISS (Koreanstudies Information Service System), DBpia (DataBase Periodical Information Academic) using terms of antibiotics, resistance, and dose. Results In comparison with shortened and standard antibiotic course, longer treatment duration is associated with greater antimicrobial resistance or non-significant difference, but we cannot find literature that shortened antibiotic course increases antimicrobial resistance on human nasopharyngeal flora. Conclusions Currently, there is no evidence that completing the standard antibiotic course reduces antimicrobial resistance. It can be a strategy for reducing antibiotic use to apply Korean medicine treatment, as well as short-course antibiotic therapy or delayed antibiotic prescription. Additional well-designed trials should be conducted in domestic and foreign settings about the appropriate duration of antibiotic therapy.