• Title/Summary/Keyword: Absolute delay

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Measurement of Autoignition Temperature of Ethylbenzene+n-hexanol and Ethylbenzene+n-propionic Acid Systems (Ethylbenzene+n-hexanol 계와 ethylbenzene+n-propionic acid계의 최소자연발화온도의 측정)

  • Ha, Dong-Myeong;Lee, Sung-Jin
    • Fire Science and Engineering
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    • v.21 no.3
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    • pp.33-40
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    • 2007
  • The values of the AITs(Autoignition temperatures) for fire and explosion protection are normally the lowest reported. This study measured the AITs of ethylbenzene+n-hexanol and ethylbenzene+n-propionic acid Systems from ignition delay time(time lag) by using ASTM E659-78 apparatus. The AITs of ethylbenzene, n-hexanol and n-propionic acid which constituted binary systems were $475^{\circ}C,\;275^{\circ}C\;and\;511^{\circ}C$, respectively. The experimental ignition delay time of ethylbenzene+n-hexanol and ethylbenzene+n-propionic acid systems were a good agreement with the calculated ignition delay time by the proposed equations with a few A.A.D.(average absolute deviation).

Identification of Discrete-Time Low-Order Model from Pulse Response (펄스응답에 의한 저차 이산시간 모델의 식별)

  • Hwang, Jiho;Cha, Seungpyo;Kim, Young Chol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.8
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    • pp.1062-1070
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    • 2018
  • This paper presents a simple identification method for discrete-time low-order model of unknown delay process from pulse response. The key idea is to find the parameters of the model such that the first N moments of the unknown process and the model are equal. We first show that the k-th moment of a process can be determined by the moments of the input and output. The parameters and delay are estimated separately. It is shown that for a given delay, the parameters of the low-order model can be determined by solving linear equations in a matrix form. Delay of the model is estimated such that the integral of the absolute errors (IAE) of the candidate models with possible delays minimizes. The illustrative example shows that the proposed method can directly identify low-order models without order reduction process from a single pulse response.

Measurement and Prediction of Autoignition Temperature (AIT) and Ignition Delay Time of n-Pentanol and p-Xylene Mixture (n-Pentanol p-Xylene 과 혼합물의 최소자연발화온도와 발화지연시간의 측정 및 예측)

  • Ha, Dong-Myeong
    • Fire Science and Engineering
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    • v.31 no.5
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    • pp.1-6
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    • 2017
  • The fire and explosion properties of combustible materials are necessary for the safe handling, storage, transportation and disposal. Typical combustion characteristics for process safety include auto ignition temperature(AIT). The AIT is an important index for the safe handling of combustible liquids. The AIT is the lowest temperature at which the material will spontaneously ignite. In this study, the AITs and ignition delay times of n-pentanol and p-xylene mixture were measured by using ASTM E659 apparatus. The AITs of n-pentanol and p-xylene which constituted binary system were $285^{\circ}C$ and $557^{\circ}C$, respectively. The experimental AITs and ignition delay times of n-pentanol and p-xylene mixture were a good agreement with the calculated AITs and ignition delay times by the proposed equations with a few A.A.D. (average absolute deviation). Therefore, it is possible to estimate the AITs and ignition delay times in other compositions of n-pentanol and p-xylene mixture by using the predictive equations which presented in this study.

The Minimum Autoignition Temperature Behavior(MAITB) of n-Decane and Acetic acid Mixture (n-Decane과 Acetic acid 혼합물의 최소자연발화온도 거동)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.28 no.2
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    • pp.49-54
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    • 2013
  • The autoignition temperature(AIT) is important index for the safe handling of flammable liquids which constitute the solvent mixtures. This study measured the AITs and ignition delay time for n-Decane and Acetic acid system by using ASTM E659 apparatus. The AITs of n-Decane and Acetic acid which constituted binary system were $212^{\circ}C$ and $512^{\circ}C$, respectively. The experimental AITs of n-Decane and Acetic acid system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D.(average absolute deviation). And n-Decane and Acetic acid system was shown the minimum autoignition temperature behavior(MAITB).

New Stop Criterion for Reduce of Decoding Delay of Turbo Codes (터보부호의 복호지연 감소를 위한 새로운 반복중단 알고리즘)

  • Shim B. S.;Lee W. B.;Jeong D. H.;Lim S. J.;Kim T. H.;Kim H. Y.
    • Proceedings of the IEEK Conference
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    • 2004.06a
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    • pp.39-42
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    • 2004
  • Turbo codes, proposed by Berrou, that increase the interleaver size and the number of iteration have better than conventional convolutional codes, in case of BER performance. However, because turbo codes has been required much decoding delay to increase iteration number, it demands unnecessary iterative decoding. Therefore, in this paper, we propose iterative decoding stop criterion that uses the variance of absolute value of LLR. This algorithm can be reduced average iterative decoding number and had lossless performance of BER, because of decreasing unnecessary iterative decoding.

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Effect on Transient Performance of Driver's Acceleration Type in MPI Gasoline Engine (운전자의 가속타입이 MPI 가솔린엔진의 과도성능에 미치는 영향)

  • 곽지현;전충환;장영준
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.1
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    • pp.75-81
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    • 2000
  • To provide the appropriate direction for development of transient control in a gasoline engine, transient performance analysis and evalution under four accelerating types based on typical driver's acceleration type were implemented by experimental study. In order to evaluate the characteristics of transient performance quanititatively, the concept and method by transient response specifications were introduced. Several performance parameters in terms of engine speed(RPM), manifold absolute pressure(MAP), fuel injection duration($\DeltatI_{nj}$) and air excess ratio($\lambda$) were emasured simultaneously during the four types of the throttle valve opening with the step motor controlled by PC. The result showed that transient response specifications in terms of delay time, rising time and settling time characterized the transient performance for four acceleration types quantitatively. Intensified acceleration type was most economical and linear acceleration type revealed the best emission performance.

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Measurement and Prediction of Autoignition Temperature of n-Propanol+n-Decane Mixture (노말프로판올과 노말데칸 혼합물의 최소자연발화온도 측정 및 예측)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.29 no.6
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    • pp.55-61
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    • 2014
  • The autoignition temperature (AIT) of a material is the lowest temperature at which the substance will spontaneously ignite in the absence of an external ignition source such as a spark or flame. The AIT may be used as combustion property to specify operating, storage, and materials handling procedures for processs safety. This study measured the AITs of n-Propanol+n-Decane system from ignition delay time(time lag) by using ASTM E659 apparatus. The AITs of n-Propanol and n-Decane which constituted binary system were $435^{\circ}C$ and $212^{\circ}C$, respectively. The experimental AITs of n-Propanol+n-Decane system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D(average absolute deviation).

Correlation of Critical Air Temperature for Frost Delay on a Cold Plate (냉각면 평판에서 착상 지연을 위한 임계공기온도 상관식)

  • Kim, Jung-Soo;Kim, Yoo-Yil;Kim, Ook-Joong;Lee, Kwan-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.12 s.255
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    • pp.1188-1195
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    • 2006
  • This paper examines the critical air temperature at which frost formation does not occur on a cold plate in order to improve the efficiency of a heat pump. The critical air temperature on test points is obtained from numerical analysis and a correlation of the critical air temperature is derived as a function of frosting factors (air absolute humidity, air velocity, and cold plate temperature) by least square method. Experiments are carried out to verify the correlation proposed in this study, and the prediction obtained with the correlation agrees well with the experimental data. Based on the correlation, we propose the non-frosting regions according to frosting factors.

패턴분류와 임베딩 차원을 이용한 단기부하예측

  • Choe, Jae-Gyun;Jo, In-Ho;Park, Jong-Geun;Kim, Gwang-Ho
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1144-1148
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    • 1997
  • In this paper, a method for the daily maximum load forecasting which uses a chaotic time series in power system and artificial neural network. We find the characteristics of chaos in power load curve and then determine a optimal embedding dimension and delay time. For the load forecast of one day ahead daily maximum power, we use the time series load data obtained in previous year. By using of embedding dimension and delay time, we construct a strange attractor in pseudo phase plane and the artificial neural network model trained with the attractor mentioned above. The one day ahead forecast errors are about 1.4% for absolute percentage average error.

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Measurement and Prediction of Autoignition Temperature of n-Butanol + n-Decane System (n-Butanol과 n-Decane계의 최소자연발화온도 측정 및 예측)

  • Ha, Dong-Myeong;Hong, Soo-Kang
    • Fire Science and Engineering
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    • v.25 no.6
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    • pp.184-189
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    • 2011
  • This study measured the AITs of n-butanol + n-decane system from ignition delay time (time lag) by using ASTM E659 apparatus. The AITs of n-butanol and n-decane which constituted binary system were $340^{\circ}C$ and $212^{\circ}C$, respectively. The experimental AITs of n-butanol + n-decane system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D. (average absolute deviation).