• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.175-183
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• 2014

This study investigates the response of structures to tunnelling-induced ground movements in clay ground, varying tunnel excavation condition (tunnel depth and diameter), tunnel construction condition (ground loss), and tunnel ground condition (soft clay and stiff clay). Four-story block-bearing structures have been used because the structures can easily be characterized of the extent of damages with crack size and distribution. Numerical parametric studies have been used to investigate of the response of structures to varying tunnelling conditions. Numerical analysis has been conducted using Discrete Element Method (DEM) to have real cracks when the shear and tensile stress exceed the maximum shear and tensile strength. The results of structure responses from various parametric studies have been integrated to consider tunnel excavation condition, tunnel construction condition, and tunnel ground condition and provide a relationship chart among them. Using the chart, the response of structures to tunnelling can easily be evaluated in practice in clay ground.

• The Korean Journal of Applied Statistics
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• v.33 no.4
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• pp.451-466
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• 2020

CCC-r chart is effective for high-quality processes with a very low fraction nonconforming. The values of process parameters should be estimated from the Phase I sample since they are often not known. However, if the Phase I sample size is not sufficiently large, an estimation error may occur when the parameter is estimated and the practitioner may not achieve the desired in-control performance. Therefore, we adjust the control limits of CCC-r charts using the bootstrap algorithm to improve the in-control performance of charts with smaller sample sizes. The simulation results show that the adjustment with the bootstrap algorithm improves the in-control performance of CCC-r charts by controlling the probability that the in-control average number of observations to signal (ANOS) has a value greater than the desired one.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1541-1549
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• 2013

This study investigates the response of structures to tunnelling-induced ground movements in sand ground, varying tunnel excavation condition (tunnel depth and diameter), tunnel construction condition (ground loss), ground condition (loose sand and dense sand). Four-story block-bearing structures have been used because the structueres can easily be characterized of the extent of dmages with crack size and distribution. Numerical parametric studies have been used to investigae of the response of structures to varying tunnelling conditions. Numerical analysis has been conducted using Discrete Element Method (DEM) to have real cracks when the shear and tensile stress exceed the maximum shear and tensile strength. The results of structure responses from various parametric studies have been integrated to consider tunnel excavation condition, tunnel construction condition, and ground condition and provided as a relationship chart. Using the chart, the response of structures to tunnelling can easily be evaluated in practice in sand ground.

• Journal of the Korean GEO-environmental Society
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• v.12 no.9
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• pp.79-87
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• 2011

This study conducted the research on the method of grouting quality management and the improvement effect by applying grouting construction's quality management technology to automatic injection management equipment through measure of liquefaction based on the case of reinforcement applying grouting at the region where liquefaction happened at section 12 site of highway construction. The pressure(p), speed(q), grouting penetration radius(R) value from injection pressure, injection speed, characteristics of grain size, and characteristics of viscosity through p-q-t chart analysis was applied to the automatic grouting system which could improve the quality management of grouting. Standard penetration test results after injection showed that N values represented 5-20 and the prevention of liquefaction became possible.

• Journal of Fashion Business
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• v.5 no.4
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• pp.144-157
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• 2001

The purpose of this study was to research on breast shape and size to suggest a brassiere sizing chart for elderly women. For this purpose 90 elderly women aged between 55 and 69 were sampled at random to review their breast types by age group, and thereby, suggest the basic measurements and production ratio of each brassiere size in reference to KS K 0070: 1999. The collected measurement data were processed statistically using the SPSS PC/WIN program for technical statistical analysis. The results of this study can be summarized as follows; 1. Analysis of Breast Measurements To find out difference among age groups, the 90 subjects were grouped into three(Group 1 ; aged 55 to 59, Group 2 ; aged 60 to 64, Group 3 ; aged 65 to 69). The results of the comparative analysis of anthropometric data from three groups show that getting older;- Various length measurements related to the drooping degree of breast were increased. It was found that the older group in their 65-69's had more drooping breasts than their 55-59's or 60-64's counterparts. Such findings suggests that older women's drooping can be corrected by a brassiere which serves to support the breasts. 2. Suggestions on a Brassiere Sizing For the basic measurements of brassiere parts for the elderly women, the correlation between underchest circumferences and cup sizes were analyzed. 3% or higher occurrences among the whole sample elderly women were included in the brassiere sizes. thus, the under-chest measurements were set at four intervals from 75 to 95, while the cup measurements were determined also at four intervals from "AAA" to "B" sizes. The resultant 6 sizes excluding the least frequent occurrences covered 73.2% of the sample elderly women actual breast sizes. As a consequence of reviewing the production ratio of each brassiere size for the women, it was found that the brassiere size of highest production ratio was "85A" (17.4%), followed by 80A (14.5%), 85AA 90A (10.1%) and 75A (8.7%) in their order.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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• pp.69-79
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• 1997

We investigate both of central and dispersion tendencies of the observed test statistics in control charts in order to judge whether a production process is abnormal or not. In order to do it, first, we study about detection of changes of the population mean as a central tendency The $\bar{x}$ and x control charts are used for detecting the change of the population mean $\mu$. We shows the probability detecting the change of population mean using the $\bar{x}$ and x control charts. Secondly, we study about detection of changes of the population standard deviation as a dispersion tendency in the s control chart. In our studies, for the given several parameters the detection probabilities of changes of central and dispersion tendencies are calculated, the necessary sample size values n are suggested for detecting the changes, and their informations are given as various tables.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.41
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• pp.157-166
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• 1997

Classical SPC charting methods such as (equation omitted), R, S charts assume high volume manufacturing processes where at least 25 or 30 calibrate samples of size 4 or 5 each can be gathered to estimate the process parameters before on-line charting actually begines. However, for many processes, especially in a job-shop setting, production runs are not necessarily long and charting technique are required that do not that depend upon knowing the process parameters in advance of the run. In this paper, using modifying statistics, we give a method for constructing control charts for the process mean when the measurements are from a normal distribution. In this case, consider that smaller weight being assigned to the older data as time process and properties and taking method of exponential smoothing constant$(\lambda)$ are suggested.

• Journal of Korean Society for Quality Management
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• v.33 no.4
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• pp.117-122
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• 2005

Variable sampling rate(VSR) scheme varies the sampling rate for the current sample depending on the previous value of the control statistic. In this paper, we propose EWMA control charts with variable parameter(VP) scheme, which allows both the sample rate(the sample size or the sampling interval) and the weight to vary. We investigate the effectiveness of the VP scheme relative to the fixed parameter(FP) scheme and the VSR scheme in EWMA control charts. It is shown that using the VP scheme gives some improvements to the ability in detecting small and moderate shifts in the process normal mean.

• Communications for Statistical Applications and Methods
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• v.27 no.1
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• pp.65-77
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• 2020

Geometric charts are effective in monitoring the fraction nonconforming in high-quality processes. The in-control fraction nonconforming is unknown in most actual processes; therefore, it should be estimated using the Phase I sample. However, if the Phase I sample size is small the practitioner may not achieve the desired in-control performance because estimation errors can occur when the parameters are estimated. Therefore, in this paper, we adjust the control limits of geometric charts with the bootstrap algorithm to improve the in-control performance of charts with smaller sample sizes. The simulation results show that the adjustment with the bootstrap algorithm improves the in-control performance of geometric charts by controlling the probability that the in-control average run length has a value greater than the desired one. The out-of-control performance of geometric charts with adjusted limits is also discussed.

• Journal of Sericultural and Entomological Science
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• v.17 no.1
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• pp.69-74
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• 1975

This report was aimed to examine the status of raw silk quality and to come up with means of the good quality silk production by use of the statistical quality control method. The results obtained are as follow ： 1) The raw silk quality of size 20/22 denier was found to be 2A grade during the last five years. 2) In order to level up the silk grade, the better quality control is required especially in the average evenness and cleanness. 3) It was found that winding brakes and elongation of silk threads have been versed gradually through the period. 4) Larger variation was observed in cleanness control chart, but low evenness have stayed with in the desirable control range.