Screws are the closest and most familiar mechanical elements of everyday life, and are generally used so widely that there is no machine without screws. Screws are used to make it easier to combine objects with objects, and are also used to transfer large forces from machines. The most influential factor in the coupling of these screws is the effective diameter. If the effective diameter is not accurate, the support cannot be finished or endured, leading to a major accident. The importance of these screws cannot be ignored, so in this study, the effective diameter was measured using the three-wire method, the screw micrometer method, and the projector method, and the one-way factor design method was applied to determine the exact method compared to the KS standard.

The study presents two measurement split-plot models with a restricted randomization to save cost and time Split-plot models are used to handle HTCM (Hard To Control Measurement) factors such as high temperature and long-time catalyst control The models d

The paper presents the measurement split split-plot models for saving the time and cost. The split split-plot designs developed are efficiently used to estimating the gauge R&R(Reproducibility & Repeatability) when the completely randomized design of all factors(such as high pressure and temperature) is expensive and time consuming. The models studied include three split split-plots considering the type of experimental units.

The research develops measurement processes for estimating and evaluating the gauge R&R(Reproducibility & Repeatability) using ANOVA(Analysis of Variance) of experimental design tools. The ten-step processes developed include experimental goal setting, the selection of characteristics(factors, levels), data model, ANOVA, EMS(Expected Mean Square), estimation of gauge precisions, and evaluation indexes. The three-factor combined measurement models are presented to show the processes developed in this paper.

The purpose of this study is to quantitatively analyze the corresponding residents' benefit to get in the future from the district unit plan of the settlement zone by Cheongju local government. The target districts were selected as Gumdeong-gol district, Juseong district, and Shinmok-gol district, and Hyeonam district which had recently set their district unit plans. Specific targets to be analyzed were some infrastructure including roads, parking lots, parks and others. Using the analysis methods of the Logit model and non-parametric test approach, this study estimated to the average amounts to be willingly paid(WTP) by the residents in targeting settlement zones and tested the reliability of the average amounts of WTP. The results of analysis were as follows. First, it was found that the WTPs for infrastructure under 1st influence area in target districts were estimated as 5,233won for road, 2,826won for parking lot, and 3,705won for park respectively. For the WTPs for infrastructure under 1nd area were estimated as 4,910 won for road, 2,242won for parking lot, and 3,620won for park respectively. Second, as the result of calculating the non-parametric WTP which built the 95% confidence interval, it was found that the all WTPs except the WTP for parking lot were fell into the 95% confidence interval. Third, as the result of calculating yearly total sum of benefits that the residents would get from the 1st influence area and the 2nd influence area, it was found that Gumdeong-gol district were expected to get 62,376,472won-amounted benefits, and Juseong district, and Shinmok-gol district, and Hyeonam district would get 35,0778,016won, 26,886,560won, and 22,252,032won respectively.