• 제목/요약/키워드: Time intervals

검색결과 2,136건 처리시간 0.024초

Optimizing Checkpoint Intervals for Real-Time Multi-Tasks with Arbitrary Periods (임의 주기를 가지는 실시간 멀티 태스크를 위한 체크포인트 구간 최적화)

  • Kwak, Seong-Woo;Yang, Jung-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • 제60권1호
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    • pp.193-200
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    • 2011
  • This paper presents an optimal checkpoint strategy for fault-tolerance in real-time systems. In our environment, multiple real-time tasks with arbitrary periods are scheduled in the system by Rate Monotonic (RM) algorithm, and checkpoints are inserted at a constant interval in each task while the width of interval is different with respect to the task. We propose a method to determine the optimal checkpoint interval for each task so that the probability of completing all the tasks is maximized. Whenever a fault occurs to a checkpoint interval of a task, the execution time of the task would be prolonged by rollback and re-execution of checkpoints. Our scheme includes the schedulability test to examine whether a task can be completed with an extended execution time. A numerical experiment is conducted to demonstrate the applicability of the proposed scheme.

Mining Information in Automated Relational Databases for Improving Reliability in Forest Products Manufacturing

  • Young, Timothy M.;Guess, Frank M.
    • International Journal of Reliability and Applications
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    • 제3권4호
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    • pp.155-164
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    • 2002
  • This paper focuses on how modem data mining can be integrated with real-time relational databases and commercial data warehouses to improve reliability in real-time. An important Issue for many manufacturers is the development of relational databases that link key product attributes with real-time process parameters. Helpful data for key product attributes in manufacturing may be derived from destructive reliability testing. Destructive samples are taken at periodic time intervals during manufacturing, which might create a long time-gap between key product attributes and real-time process data. A case study is briefly summarized for the medium density fiberboard (MDF) industry. MDF is a wood composite that is used extensively by the home building and furniture manufacturing industries around the world. The cost of unacceptable MDF was as large as 5% to 10% of total manufacturing costs. Prevention can result In millions of US dollars saved by using better Information systems.

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The Study of Driving Fatigue using HRV Analysis (HRV 분석을 이용한 운전피로도에 관한 연구)

  • 성홍모;차동익;김선웅;박세진;김철중;윤영로
    • Journal of Biomedical Engineering Research
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    • 제24권1호
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    • pp.1-8
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    • 2003
  • The job of long distance driving is likely to be fatiguing and requires long period alertness and attention, which make considerable demands of the driver. Driving fatigue contributes to driver related with accidents and fatalities. In this study, we investigated the relationship between the number of hours of driving and driving fatigue using heart rate variability(HRV) signal. With a more traditional measure of overall variability (standard deviation, mean, spectral values of heart rate). Nonlinear characteristics of HRV signal were analyzed using Approximate Entropy (ApEn) and Poincare plot. Five subjects drive the four passenger vehicle twice. All experiment number was 40. The test route was about 300Km continuous long highway circuit and driving time was about 3 hours. During the driving, measures of electrocardiogram(ECG) were performed at intervals of 30min. HRV signal, derived from the ECG, was analyzed using time, frequency domain parameters and nonlinear characteristic. The significance of differences on the response to driving fatigue was determined by Student's t-test. Differences were considered significant when a p value < 0.05 was observed. In the results, mean heart rate(HRmean) decreased consistently with driving time, standard deviation of RR intervals(SDRR), standard deviation of the successive difference of the RR intervals(SDSD) increased until 90min. Hereafter, they were almost unchanging until the end of the test. Normalized low frequency component $(LF_{norm})$, ratio of low to high frequency component (LF/HF) increased. We used the Approximate Entropy(ApEn), Poincare plot method to describe the nonlinear characteristics of HRV signal. Nonlinear characteristics of HRV signals decreased with driving time. Statistical significant is appeared after 60 min in all parameters.

Bioequivalence of GLUNATE® Tablet to PASTIC® Tablet (nateglinide 90 mg) (파스틱 정®(나테글리니드 90 mg)에 대한 글루나테 정®의 생물학적 동등성)

  • Tak, Sung-Kwon;Lee, Jin-Sung;Choi, Sang-Joon;Seo, Ji-Hyung;Lee, Myung-Jae;Kang, Jong-Min;Ryu, Ju-Hee;Hong, Seung-Jae;Yim, Sung-Vin;Lee, Kyung-Tae
    • Journal of Pharmaceutical Investigation
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    • 제39권2호
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    • pp.141-147
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    • 2009
  • The purpose of this study was to evaluate the bioequivalence of two nateglinide tablets, $PASTIC^{(R)}$ tablet (ILDONG Pharm. Co., Ltd., Seoul, Korea, reference drug) and $GLUNATE^{(R)}$ tablet (ILHWA. Co., Ltd., Seoul, Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Thirty-five healthy male volunteers, $23.1{\pm}2.3$ years in age and $69.2{\pm}8.8\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a tablet containing 90 mg of nateglinide was orally administrated, blood was taken at predetermined time intervals over a period of 8 hr and concentrations of nateglinide in plasma were monitored using LC-MS/MS. Pharmacokinetic parameters such as AUCt (the area under the plasma concentration-time curve from time 0 to 8 hr), $C_{max}$ (maximum plasma drug concentration) and $TC_{max}$ (time to reach $CC_{max}$) were calculated and analysis of variance (ANOVA) test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and $C_{max}$ and untransformed $T_{max}$. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $GLUNATE^{(R)}/PASTIC^{(R)}$ were ${\log}1.0782{\sim}{\log}1.1626$ and ${\log}0.9621{\sim}{\log}1.1679$, respectively. Since these values were within the acceptable bioequivalence intervals of ${\log}0.80{\sim}{\log}1.25$, recommended by KFDA, it was concluded that $GLUNATER^{(R)}$ tablet was bioequivalent to $PASTIC^{(R)}$ tablet, in terms of both rate and extent of absorption.

Studies on Artificial Contorl of Parturition in Korean Native Goats III. The Effects of Prostaglandin $F_2\alpha$ and Estradiol-Benezoate (한국 재래산양 분만의 인위적 조절에 관한 연구 III. Prostaglandin $F_2\alpha$와 Estradiol-Benzoate 병용투여에 의한 분만수기 효과)

  • 윤창현;민관식;장규태;오석두
    • Korean Journal of Animal Reproduction
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    • 제16권2호
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    • pp.109-116
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    • 1992
  • The present study was carried out to establish a practical regimen for artificial parturition induction using prostaglandin F2$\alpha$(PGF2$\alpha$) and estradiol-benezoate in Korean native goats. The effect of parturition induction and the time intervals to induced parturition after injection were investigated. The birth weight and body weight of kids at 15 days of age were measured. A total of 24 pluriparous goats were offered for this experiment. The animals were divided into 4 goats per treatment by the injection time(142, 145 or 148 day of pregnancy) and dosage(5.0$\times$10 or 7.5$\times$7.5mg). The results obtained were summarized as follows : A total of 24 pregnant goats were intramusculary treated with 5.0$\times$10 or 7.5$\times$7.5mg of PGF2$\alpha$ and estradiol-benzoate for parturition induction of Day 142, 145 or 148 of gestation. Parturition was induced in all of the goats(100%) treated. The kids produced from induced parturition were all healthy. The time intervals to induced parturition after PGF2$\alpha$ and estradiol-benezoate injection of 5.0$\times$10 or 7.5$\times$7.5mg to pregnant goats on Day 148(23.22$\pm$0.51~23.40$\pm$1.26hrs) were significantly(P<.01) shorter than those of the 142 days of the gestation(26.34$\pm$2.22~28.39$\pm$3.02hrs). No significant difference was found in the time intervals between the doses(5.0$\times$10 or 7.5$\times$7.5mg) treated for parturition induction. The birth weight of kids from induced parturition was no significant difference between on Day 148 and on Day 142 of gestation. However, the birth weight of kids from parturition induced on Day 148 was found significantly(P<.01) heavier than that of the 142 days of gestation. The body weight of kids at 15 days old was also significantly(P<.01) lighter in the parturition induced on day 142 than those on Day 142. The birth weight and body weight of kids at 15 days old were not affected by 5.0$\times$10 or 7.5$\times$7.5mg injection of PGF2$\alpha$ and estradiol-benzoate for inducing parturition. From the above results, it was concluded that the parturition induction by PGF2$\alpha$ and estradiol-benezoate injection of 5.0$\times$10 or 7.5$\times$7.5mg on Day 142 of gestation, which was correspondent to 8 days before expected spontaneous parturition, was available without any significant troubles.

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추상 시간 기계를 기반으로 한 실시간 시스템의 시간 명세와 분석

  • 노경주;이문근
    • Journal of Software Engineering Society
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    • 제13권3호
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    • pp.45-54
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    • 2000
  • 실시간 시스템은 특정 시간 내에 요구하는 정보를 제공해주는 시스템이다. 즉 실시간 시스템에서 요구되는 시간을 충족하지 못할 경우 시스템의 신뢰도는 급격히 감소하며, 요구되는 시간의 범위를 넘어서서 제공되는 정보는 활용도와 가치에 있어서 거의 무의미하게 된다. 이러한 실시간 시스템의 성공적인 동작을 보장하기 위해서는 보다 정확한 시스템 설계가 중요하다. 특히 실시간 시스템에서 필요로 하는 여러 종류의 시간제약에 대한 풍부한 표현력과 명세 된 시간에 대한 검증이 중요하다. 본 논문은 특정 시점(time points)과 시간 간격(time intervals), 주기(period), 이산 시간(discrete time)으로 연속적인 시간(continuous time) 표현, 다수의 타이머에 의한 지역 시간과 전역시간 등의 시간 관련 동작을 ATM(Abstract Time Machine)을 기반으로 명세하고 명세하고 명세 된 시간에 대한 분석 방법을 살펴본다.

FINANCIAL TIME SERIES FORECASTING USING FUZZY REARRANGED INTERVALS

  • Jung, Hye-Young;Yoon, Jin-Hee;Choi, Seung-Hoe
    • The Pure and Applied Mathematics
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    • 제19권1호
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    • pp.7-21
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    • 2012
  • The fuzzy time series is introduced by Song and Chissom([8]) to construct a pattern for time series with vague or linguistic value. Many methods using the interval and fuzzy logical relationship related with historical data have been suggested to enhance the forecasting accuracy. But they do not fully reflect the fluctuation of historical data. Therefore, we propose the interval rearranged method to reflect the fluctuation of historical data and to improve the forecasting accuracy of fuzzy time series. Using the well-known enrollment, the proposed method is discussed and the forecasting accuracy is evaluated. Empirical studies show that the proposed method in forecasting accuracy is superior to existing methods and it fully reflects the fluctuation of historical data.

Wavelet Transforms: Practical Applications in Power Systems

  • Akorede, Mudathir Funsho;Hizam, Hashim
    • Journal of Electrical Engineering and Technology
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    • 제4권2호
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    • pp.168-174
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    • 2009
  • An application of wavelet analysis to power system transient generated signals is presented in this paper. With the time-frequency localisation characteristics embedded in wavelets, the time and frequency information of a waveform can be presented as a visualised scheme. This feature is very important for non-stationary signals analysis such as the ones generated from power system disturbances. Unlike the Fourier transform, the wavelet transform approach is more efficient in monitoring fault signals as time varies. For time intervals where the function changes rapidly, this method can zoom in on the area of interest for better visualisation of signal characteristics.

An analysis of the gyro random process (자이로 랜덤 프로세스의 분석)

  • 고영웅;김경주;이재철;권태무
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.210-212
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    • 1996
  • Random drift rate (i.e., random drift in angle rate) of a gyro represents the major error source of inertial navigation systems that are required to operate over long time intervals. It is uncorrectable and leads to an increase in the error with the passage of time. In this paper a technique is presented for analyzing random process from experimental data and the results are presented. The problem of estimating the a priori statistics of a random process is considered using time averages of experimental data. Time averages are calculated and used in the optimal data-processing techniques to determine the statistics of the random process. Therefore the contribution each component to the gyro drift process can be quantitatively measured by its statistics. The above techniques will be applied to actual gyro drift rate data with satisfactory results.

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Effect of Chinese Milk Vetch (Astragalus sinicus L.) Cultivation dring Winter on Rice Yield and Soil Properties

  • Cho, Young Son;Choe, Zhin Ryong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • 제44권1호
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    • pp.49-54
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    • 1999
  • An experiment was carried out using pots to investigate the effects of Chinese milk vetch on the seedling establishment and growth in rice. Four irrigations with five-day intervals and three different levels of vetch straw were investigated. Significantly higher panicle numbers were obtained in vetch-treated pots. Vetch levels were non-treatment as checks, vetch with top removed, root plus shoot 7.5 ton/ha, and root plus shoot 3.0 ton/ha. The time for complete degradation of vetch straws was reduced from 10 days to 5 days as submerged time was delayed, and was affected by the amount of mulched vetch straws. As the mulched vetch amount increased, the time for a complete degradation was extended from 4 days to 12 days. Grain yield and its components were significantly affected by irrigation time and mulched vetch amount. Effectively controlled, lowered reduction damage from the degrading vetch straw, irrigation date and vetch amount were the most important factors for the improving of seedling establishment in direct-sown rice.

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