• 전기전자학회논문지
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• 제23권4호
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• pp.1430-1439
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• 2019

FMI를 기반으로 하는 co-simulation의 마스터 알고리즘(MA)에서 시뮬레이션 결과의 정확도를 높이는 방법으로 zero crossing 포인트를 찾기 위한 Bisectional algorithm을 사용할 수 있다. 그러나 이 알고리즘은 많은 Rollback을 야기한다. 따라서 본 논문에서는 제안하는 MA는 Bisection algorithm을 통해 zero crossing 포인트를 검출하면서도 반복되는 구간 그래프를 분석하여 그 값을 Markov chain을 적용하여 다음 구간을 예측하여 이를 step size에 적용한다. 시뮬레이션에서 실제 Rollback이 발생했을 때 그래프 형태별로 변화되는 step size를 배열로 저장하고, 이룰 다음 예측 구간에 적용함으로서 Rollback을 최소화하는 알고리즘을 제안한다. 시뮬레이션 결과를 통해 제안하는 알고리즘이 기존 알고리즘에 비해 최대 20% 이상의 시뮬레이션 시간이 감소되는 것을 확인하였다.

• Structural Engineering and Mechanics
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• 제82권3호
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• pp.271-282
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• 2022

The active learning surrogate model based on adaptive sampling strategy is increasingly popular in reliability analysis. However, most of the existing sampling strategies adopt the trial and error method to determine the size of the Monte Carlo (MC) candidate sample pool which satisfies the requirement of variation coefficient of failure probability. It will lead to a reduction in the calculation efficiency of reliability analysis. To avoid this defect, a new method for determining the optimal size of the MC candidate sample pool is proposed, and a new structural reliability analysis method combining polynomial chaos-based Kriging model (PC-Kriging) with adaptive sampling region is also proposed (PCK-ASR). Firstly, based on the lower limit of the confidence interval, a new method for estimating the optimal size of the MC candidate sample pool is proposed. Secondly, based on the upper limit of the confidence interval, an adaptive sampling region strategy similar to the radial centralized sampling method is developed. Then, the k-means++ clustering technique and the learning function LIF are used to complete the adaptive design of experiments (DoE). Finally, the effectiveness and accuracy of the PCK-ASR method are verified by three numerical examples and one practical engineering example.

• 대한원격탐사학회지
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• 제24권1호
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• pp.17-24
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• 2008

Rainfall data from three different types of rain gauge system have been collected for the summertime rain event at Mokpo in the Korean peninsula. The rain gauge system considered in this paper is composed of three tipping-bucket rain gauges with 0.1, 0.2, and 0.5 mm measuring resolutions, the Optical Rain Gauge (ORG), and the PARSIVEL (PARticle SIze and VELocity). The PARSIVEL rainfall rate has been considered as the reference for comparison since it gave good resolution and performance on this event. Comparison with the PARSIVEL rainfall rate gives the results that the error and temporal variation of rainfall rate are simultaneously reduced with increasing the averaging interval of rainfall rate or decreasing the size of tipping bucket. This suggests that the estimated rainfall rate must be optimized, differently for the type of tipping-bucket rain gages, by minimizing the averaging interval of rainfall rate under the condition satisfying the given performance of rainfall rate.

• 품질경영학회지
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• 제30권4호
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• pp.1-14
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• 2002

Traditional SPC techniques are looking out variation of process by fixed sampling interval and fixed sample size about every hour, the process of in-control or out-of-control couldn't be detected actually when the sample points are plotted near control limits, and it takes no notice of expense concerned with such sample points. In this paper, to overcome that, consider VSI(variable sampling interval) EWMA control charts which VSI method is applied. The VSI control charts use a short sampling internal if previous sample points are plotted near control limits, then the process has high probability of out-of-control. But it uses a long sampling interval if they are plotted near centerline of the control chart, since process has high possibility of in-control. And then a comparison and analysis between FSI(fixed sampling interval) and VSI EWMA in the statistical aspect and economic aspect is studied. Finally, we show that VSI EWMA control chart is more efficient than FSI EWMA control chart in the both aspects.

• 한국의류학회지
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• 제30권6호
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• pp.892-903
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• 2006

This study was to carry out interview and survey of currently marketed foundation garment, focusing on manufacturers, on the basis of data of Year 2004 SIZE KOREA in 2004, to re-establish suitable age range and standard size, to simplify size interval scale and size system and to revise the standard for consumers' easy understanding and availability; The findings of this study are as follows. 1. Considering the age, in which a bra is worn, has reduced socially, the applicable age range was expanded into $8{\sim}80$ years old, which was divided into for junior and for adult. 2. For bra size, the standard title changed into the foundation garments size standard, in which girdle and bodysuit were included. 3. Basic physical parts for establishing for bra size are underbust and bust. Interval scale of under bust and bust was 5cm and 2.5cm, respectively. And basic physical parts are waist and hip girth for girdle, and underbust, bust, and hip girth for bodysuit. 4. For bra size, underbust girth was applied together with bra-cup size without 'cm' unit. For bra-cup size, difference between underbust and bust was represented as English alphabet. In other words, AAA means that difference between under bust and bust is 5cm. AA, A, B, C and D means that the difference are 7.5cm, 10cm, 12.5cm, 15cm and 17.5cm. 5. For girdle size, waist girth was applied together with hip girth without 'cm' unit. And for bodysuit size, underbust girth was applied together with cup size like bra size, and English alphabet represented hip girth range.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1999년도 제36회 학술발표회논문집
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• pp.440-445
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• 1999

• 품질경영학회지
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• 제32권1호
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• pp.92-101
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• 2004

Tris paper present an economic statistical design which have statistically constraints for the optimal design of an EWMA control charts with variable sampling interval. Cost function use that proposed by Lorenzen and Vance, and the optimal design parameters include the sample size, control limit width, sampling interval, EWMA weight value. Comparisons between VSI EWMA control charts optimal economic design and optimal economic statistical designs show the following fact. Although have demerits which are more costly than economic design, have merits which to detect shifts more efficiently and to improve statistical performance.

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5901-5908
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• 2014

Background: Data from BreastScreen Australia Screening and Assessment Services (SAS) for 2002-2010 were analysed to determine whether some SAS characteristics were more conducive that others to high screening performance, as indicated by high priority performance indicators and standards. Materials And Methods: Indicators investigated related to: numbers of benign open biopsies, screen-detected invasive cancers, and interval cancers, and wait times between screening and assessment. Multivariate Poisson regression was undertaken using as candidate predictors of performance, SAS size (screening volume), urban or rural location, year of screening, accreditation status, and percentages of clients from culturally and linguistically diverse backgrounds, rural and remote areas, and socio-economically disadvantaged areas. Results: Performance standards for benign biopsies and invasive cancer detection were uniformly met irrespective of SAS location and size. The interval cancer standard was also met, except in 2003 when the 95% confidence interval of the rate still incorporated the national standard. Performance indicators improved over time for: benign open biopsy for second or subsequent screening rounds; rates of invasive breast cancer detection for second or subsequent screening rounds; and rates of small cancer detection. No differences were found over time in interval cancer rates. Interval cancer rates did not differ between non-metropolitan and metropolitan SAS, although state-wide SAS had lower rates. The standard for wait time between screening and assessment (being assessed ${\leq}28$ days) was mostly unmet and this applied in particular to SAS with high percentages of culturally and linguistically diverse women in their screening populations. Conclusions: Gains in performance were observed, and all performance standards were met irrespective of SAS characteristics, except wait times to assessment. Additional descriptive data should be collected on SAS characteristics, and their associations with favourable screening performance, as these may be important when deciding on SAS design

• 복식문화연구
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• 제13권4호
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• pp.526-539
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• 2005

Recently in the apparel industry, early adolescent girls are emerging as a new consumer group. In response to this, companies are developing clothes, cosmetics, underwear, etc. This study proposed a new size range and size interval for early adolescent girls and presented reference measurements for body parts necessary in designing clothes. For this purpose, a total of 529 girls aged between 10 and 14 were measured and data were collected from 42 anthropometric measurements and 41 photographic measurements per a person. SAS 8.1 was used in data analysis including means, standard deviations, frequency analysis. Based on the results, this study proposed: for Type A - 7 sizes (140A-67, 145A-65, 145A-69, 150A-69, 150A-73, 155A-73, 155A-76): for Type X - 7 sizes (150x-72, 155x-72, 155x-77, 160x-77, 160x-80, 165x-77, 165x-80); and for Type H - 8 sizes (145H-74, 145H-82, 150H-78, 150H-82, 155H-82, 155H-86, 160H-86, 160H-88). Reference measurements suggested for upper garments were 9 items. The outcome of this study may be used as a basic material for adolescent apparel manufacturers to set their apparel sizing system and to supply their consumers, namely, adolescent girls with products fitting their somatotype.

• 콘크리트학회논문집
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• 제11권3호
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• pp.59-67
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• 1999

The mass concrete structures are generally constructed in an incremental manner by deviding the whole structures by a series of many blocks. The temperature and stress distributions of any specific block are continuously affected by the blocks placed before and after the specific block. For an accurate analysis of mass concrete structures, the sequence of all the blocks must be accordingly considered including the change of material properties with time for those blocks considered. The purpose of this study is to propose a realistic analysis method which can take into account not only the influence of the sequence, time interval and size of concrete block placement on the temperatures and stresses, but also the change of material properties with time. It is seen from this study that the conventional simplified analysis, which neglects material property changes of some blocks with time and does not consider the effect of adjacent blocks in the analysis, may yield large discrepancies in the temperature and stress distributions of mass concrete structures. This study gives a method to choose the minimum number of blocks required to obtain reasonably accurate results in analysis. The study provides a realistic method which can determine the appropriate size and time interval of block placement, and can be efficiently used in the design and construction of mass concrete structures.