• Journal of the Korean Statistical Society
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• v.23 no.2
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• pp.403-420
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• 1994

An economic design of the $\bar{X}-R$ chart using variable sample size (VSS) scheme is proposed in this paper. In this design the sample size at each sampling time changes according to the values of the previous two sample statistics, sample mean and range. The VSS scheme uses large sample if the sample statistics appear near inside the control limits and smaller sample otherwise. The set of process parameters, such as the sampling interval, control limits and the sample sizes, are chosen to minimize the expected cost per hour. The efficiency of the VSS scheme is compared to the fixed sample size one for cases where there is multiple of assignable causes. Percent reductions of the expected cost in the VSS design are calculated for some given sets of cost parameters. It is shown that the VSS scheme improves the confidence of the procedure and performs statistically better in terms of the number of false alarms and the average time to signal, respectively.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.183-191
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• 2023

This study was conducted experimentally to investigate the surface temperature of the heat sink, the air temperature in the flow channel and the sample temperature by changing the channel number of channel type heat sink and the air flow rate when heating and cooling the bio sample. The target temperature of the sample was 15℃ or less as the minimum value and 82℃ or more as the maximum value. In this study, the channel number of the heat sink(N = 1, 2, 4, 5, 10) and the air flow rate(Q=25, 42, 54m³/min) were varied. The bio sample was replaced with water, and the volume of water is 4mL. The size of the heat sink is 80x73x150mm and the material is aluminum. When cooling the sample, the surface temperature, the air temperature and the sample temperature were highly dependent on the number of channels and the flow rate. However, when the sample is heated, the surface temperature, air temperature and sample temperature do not depend on the number of channels and the flow rate. It was found that the conditions for satisfying the minimum temperature of 15℃ or less when cooling the sample were the number of channels N≥5 and the flow rate Q≥42m³/min. When heating the sample, the conditions to satisfy the maximum temperature of 82℃ or more are the number of channels N≤5 and the air flow rate Q≤42m³/min.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.565-571
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• 2018

This paper designed the main blade in V-shape and tried to identify the design conditions by changing the main blade number and sub-blade number. Power output and power coefficient increased as main blade number increased. Sample 2 shows a 50% increase in power output compared to sample1. Sample 3 and sample4 increased by 92.8% and 114.7%, respectively. Sample 2 shows a 38.4% increase in power coefficient compared to sample1. Sample 3 and sample4 increased by 92.3% and 107.7%, respectively. Power output and power coefficient increased as sub-blade number increased. Sample 6 shows a 33.3% increase in power output compared to sample 5 and Sample 7 increased by 42.1%. Compared to sample5, efficiency increased by 35.3% for sample 5 and 47.1% for sample 7. The highest power output and power coefficient were measured when main blade and sub-blade were each 30 number. Sample 8 increased power output by 5.6% and power efficiency by 3.7% compared to sample 4. Compared to sample 7, sample 8 increased power efficiency by 12% and power output by 17.3%.

• Asia-Pacific Journal of Business
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• v.13 no.3
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• pp.329-341
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• 2022

Purpose - The purpose of this study was to investigate consistency in estimating the number of vacant jobs using the two business labor force survey with two different time points of survey. Design/methodology/approach - We studied the cause of the differences in estimating the number of vacant jobs between the monthly sample and the new sample in business labor force survey. Findings - To summarize our findings, As the size of the company increases, the number of vacant jobs in the company also increases, and the probability that the number of vacant jobs in the company is zero decreases. The monthly sample was assessed to have a higher likelihood that the number of vacant jobs in the company was zero and the number of vacant jobs was considerable compared to the local sample. Research implications or Originality - Because local survey sample companies tend to minimize the number of vacant jobs even when they reply under the same conditions, the estimation result of the number of vacant jobs in the current monthly survey differs significantly from the estimation result of the local survey. Divergent "degrees of knowledge of question items," survey methodologies, or investigators could be the causes of the various response trends.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.10 no.1
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• pp.1-38
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• 1997

This study was performed to investigate the effects of Kamigyemyoungsan and each compositive herbs on the intravascular coagulation and subcutaneous hematoma. The intravascular coagulation was induced by the injection of endotoxin into the caudal vein of the rats. These rats were treated with endotoxin after administering orally extracts of Kamigyemyoungsan and each compositive herbs. Then the number of platelet, prothrombin time, the concentration of fibrinogen and FDP(fibrinogen degration product), hematocrit and RBC and WBC were measured. The subcutaneous hematoma was induced by the subcutaneous injection of the autologous whole blood to produce clotting in situ in rats. Then the extracts of Kamigyemyoungsan and each compositive herbs were administered orally. The lesions were then dissected and observed. The results were obtained as follows ; 1. The number of platelets of the trial groups was increased as compared with the control group, and revealed significance in sample Ⅰ. 2. The concentration of fibrinogen of the trial groups was increased as compared with the control group, and revealed significance in sample Ⅰ, sampleⅡ and sample Ⅴ. 3. The prothrombin time was shortened significantly in the trial groups, except sampleⅡ and sampleⅣ as compared with the control group. 4. The concentration of FDP decreased in the trial groups, and revealed significance in sample Ⅰ and sample Ⅵ as compared with the control group. 5. The hematocrit significantly increased in sample Ⅰ, sampleⅢ and sample Ⅵ as compared with the control group. 6. The number of RBC significantly increased in sample Ⅵ only as compared with the control group. 7. The number of WBC significantly increased in the trial groups, except sampleⅣ and sample Ⅵ as compared with the control group. 8. Histologically, the lesions in the trial groups showed significantly thinner fibroblastic neomembrane than the control group, except sampleⅢ. According to the above results, it is considered that Kamigyemyoungsan and each compositive herbs have inhibitive effects on the thrombosis and the fibroblastic neomembrane development. Therefore, it seems to be applicable to the diseases related to thrombosis and hematoma.

• Journal of the Korea Safety Management & Science
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• v.9 no.3
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• pp.165-171
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• 2007

Dependent models in quality statistics are classified as serially autocorrelated model, multivariate model and dependent sample model. Dependent sample model is most efficient in time and cost to obtain samples among the above models. This paper proposes to implement parametric and nonparametric models into production system depended on demand pattern. Nonparametric models have distribution free and asymptotic distribution free techniques. Quality statistical models are classified into two categories ; the number of dependent sample and the type of data. The type of data consists of nominal, ordinal, interval and ratio data. The number of dependent sample divides into 2 samples and more than 3 samples.

• The Journal of Korean Medicine
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• v.23 no.3
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• pp.11-25
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• 2002

Objectives: This study was undertaken to investigate the effects of Yijin-tang and GamiYijin-tang on the gastrointestinal functions of rats Methods: Sprague-Dawley rats were used as experimental animals, and were administered Yijin-tang (Sample I group, 47.5 mg/ml) and GamiYijin-tang(Sample II group, 38.37 mg/ml, Sample ill group, 85.3 mg/ml) water extract once a day. Changes of gastric juice volume and intestinal mobility index were measured. The effects on colitis induced by dextran sulfate sodium in the rats were also observed. Results: 1. Gastric juice volume was decreased significantly in the sample I group (P<0.05) compared to the control group; there was not significant effect in the sample II and sample III groups. 2. The moving distance of carbon bolus was increased significantly in the sample n (p<0.05) and sample II (p<0.05) groups compared to the control group; there was not significant effect in the sample I group. 3. The intestinal mobility index was increased significantly only in the sample II group (P<0.05) compared to the control group. 4. The feces consistency was increased significantly on the 3rd and 5th day of the sample I group (P<0.05), on 3rd, 4th, and 5th day of the sample II (p<0.05) and the sample III (p<0.05) groups compared to the control group. 5. The feces property index was increased significantly only on the 5th day of the sample III group (p<0.05) compared to the control group. 6. The number of WBC and RBC, levels of hemoglobin and hematocrit were not changed in all sample groups compared to the control group. 7. The number of the type B Goblet cells were increased significantly in the sample II (p<0.05) and the sample III (P<0.05) groups, but the number of the type C Goblet cells were decreased significantly only in the sample ill group (P<0.05) compared to the control group. Conclusions: According to the above results, GamiYijin-tang compared to the Yijin-tang were decreased hight significantly in gastrointestinal mucose and histological antidiarrheal function with protection of the goblet cell more excellently were observed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.2139-2151
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• 2014

Embedded system testing, especially long-term reliability testing, of flash memory solutions such as embedded multi-media card, secure digital card and solid-state drive involves strategic decision making related to test sample size to achieve high test coverage. The test sample size is the number of flash memory devices used in a test. Earlier, there were physical limitations on the testing period and the number of test devices that could be used. Hence, decisions regarding the sample size depended on the experience of human testers owing to the absence of well-defined standards. Moreover, a lack of understanding of the importance of the sample size resulted in field defects due to unexpected user scenarios. In worst cases, users finally detected these defects after several years. In this paper, we propose that a large number of potential field defects can be detected if an adequately large test sample size is used to target weak features during long-term reliability testing of flash memory solutions. In general, a larger test sample size yields better results. However, owing to the limited availability of physical resources, there is a limit on the test sample size that can be used. In this paper, we address this problem by proposing a self-adaptive reliability testing scheme to decide the sample size for effective long-term reliability testing.

• Korean Journal of Environmental Biology
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• v.32 no.3
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• pp.211-215
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• 2014

In order to accurately estimate the litter mass, we evaluated the required sample sizes across 13 chronosequence stands for five years (1994~1996, 2003~2004) in northern hardwood forests in New Hampshire, USA. It was found that the number of required litter traps in our stands (0.25~0.5 ha) within ${\pm}10%$ of the sample mean was appeared to be similar or higher than the 15 litter traps installed in this study. Notably, in 1994 and 1995, the number of required litter trap was twice higher than the 15 litter traps. Further, within ${\pm}20%$ of the sample mean, the number of required litter traps was less than 10 across all 13 stands for five years, which indicates that we can reduce the sample size. Precisely, the number of sample size had increased in stands with steep and high elevation, but no relations with stand age across 13 stands were observed. Based on these results, we suggest that it is important to sample litter mass for several years, in order to determine the number of appropriate sample size, and stands with steep and high elevation may need more litter traps.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.182-184
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• 1998

PCR was used for quantitative counting of Bifidobacterium spp. in a sample mixed with Lactobacillus acidophilus using two primer sets; one set for universal priming and the other set for Bifidobacterium specific priming. DNA products from two independent PCRs with DNA extracted from the mixed sample were found to be easily distinguishable from each other by agarose gel electrophoresis. The concentrations of PCR products correlated with the total number of bacteria and with the number of Bifidobacterium spp. present in the sample.