• The Korean Journal of Applied Statistics
• /
• v.34 no.4
• /
• pp.579-588
• /
• 2021

Wald, Agresti-Coull, Jeffreys, and Bayes-Laplace methods are commonly used for confidence interval of binomial proportion are applied for prediction intervals. We used coverage probability, mean coverage probability, root mean squared error, and mean expected width for numerical comparisons. From the comparisons, we found that Wald is not proper as for confidence interval and Agresti-Coull is too conservative to differ from confidence interval. However, Jeffrey and Bayes-Laplace are good for prediction interval and Jeffrey is especially desirable as for confidence interval.

• Archives of Plastic Surgery
• /
• v.35 no.5
• /
• pp.514-520
• /
• 2008

Purpose: Many attempts have been made to describe ideal facial proportions for over two thousands year and constantly lasted till now. Dr. Marquardt has derived supposedly ideal facial proportions from the facial golden mask using golden ratio of 1 : 1.618. On the other hand, facial reducing surgeries such as mandible angle reduction are popularized in Asia because the width of mid and lower face of Korean is recognized to be wider. The purpose is to analyze characters of Korean university students' faces in horizontal plane and establish the objective data for facial width distributions and clinical applications. Methods: We applied the facial golden mask to the photographs in 1000 cases, compared the width of mid and lower face between the facial golden mask and Korean university students' faces. And we first calculated the horizontal ratio(HR) of middle and lower face each for using comparative scale of width, facial golden mask. We divided 1,000 cases into 3 groups by degrees of HR and analyzed data of HR on each groups. Using calculated horizontal ratio, we newly invented the cumulative frequency of distribution graphs in Korean university students' faces. Results: Mean data of HR were over 1.0 in all groups, which means that Korean university students' faces are typically wider than facial golden mask in horizontal planes. And this study was statistically significant(p- value < 0.05). Clinically using the cumulative frequency distributions of Korean university students' face width, we can easily explain changes of facial width to patient after facial reducing surgery and describe the changes into objective data. Conclusion: This study concludes thatKorean university students' faces are wider than facial golden mask is significantly true and the cumulative frequency of distribution graphs are expected to be widely used for comparison of results in facial reducing surgery.

• Tribology and Lubricants
• /
• v.29 no.1
• /
• pp.13-18
• /
• 2013

Slider bearing is a widely used load-carrying element in the industry. While a large number of studies have investigated the effect of overall surface curvature, very few have considered sinusoidal surface. Recently, consideration of surface roughness/waviness or intentional wave design has been identified as an important issue in the manufacture of hard disk driver, mechanical seal, hydraulic machine, and etc. This study investigated the load-carrying capacity of a finite-width slider bearing with a wavy surface. Film thickness ratios, length-width ratio, ambient pressure, amplitude, and partial distribution were selected as the simulation parameters. The calculation results showed that the load-carrying capacity rapidly varied at small film thickness ratio, but the waviness near the area of minimum film thickness made much more influence with an increase in film thickness ratio. As the length-width ratio of bearing was increased, ambient pressure became more influential at small film thickness ratios. Furthermore a particular partial distribution of the wavy area led to higher load-carrying capacity than did the whole distribution. Consequently, the results of this study are expected to be of use in surface micro-machining of finite-width slider bearings.

• The korean journal of orthodontics
• /
• v.46 no.6
• /
• pp.379-385
• /
• 2016

Objective: Forced eruption has been proposed for the reconstruction of deficient bone and soft tissue. The aim of this study was to examine the changes in the alveolar ridge width and the vertical levels of the interproximal bone and papilla following forced eruption. Methods: Patients whose hopeless maxillary anterior teeth were expected to undergo severe bone resorption and soft tissue recession upon extraction were recruited. In addition, patients whose maxillary anterior teeth required forced eruption for restoration due to tooth fracture or dental caries were included. Before and after forced eruption, the interproximal bone height was measured by radiographic analysis, and changes in the alveolar ridge width and the interproximal papilla height were measured with an acrylic stent. Results: This prospective study demonstrated that the levels of the interproximal alveolar bone and papilla were significantly increased by 1.36 mm and 1.09 mm, respectively, in the vertical direction. However, the alveolar ridge width was significantly reduced by an average of 0.67 mm in the buccolingual direction. The changes in the level of the interproximal alveolar bone and papilla were positively correlated. Conclusions: Although the levels of the interproximal bone and papilla were significantly increased, the alveolar ridge width was significantly decreased following forced eruption. There was a modest positive and significant correlation between the changes in the height of the interproximal alveolar bone and the papilla. Based on our findings, modification of vertical forced eruption should be considered when augmentation of the alveolar ridge width is required.

• Journal of Korea Water Resources Association
• /
• v.31 no.6
• /
• pp.675-684
• /
• 1998

This paper presents the empirical formulas for determining the design-width for medium rivers in the Han river basin. The design flood, the watershed ares, and the channel slope of 216 medium rivers in the Han river basin are collected. the design width formulas are then determined by 1) the least squares (LS) method, 2)the least median squares (LMS) method, and 3) the reweighted least squares method based on the LMS (RLS). The six types of formulas are considered to determine the acceptable type for medium streams in the Han river basin. The root mean squared errors (RMSE), the absolute mean (AME) errors, and the mean errors (ME) are computed to test the formulas derived by three regression methods. It si found that the equation related stream width to the watershed area and the channel slope is acceptable for determining the design width for medium streams in the Han river basin. It is expected that the equations proposed by this study be used an index for determining the design-width for medium streams in the Han river basin.

• Communications for Statistical Applications and Methods
• /
• v.24 no.1
• /
• pp.29-41
• /
• 2017

The estimation problem of expected time to failure of units is studied in a discrete set up. A simple step-stress accelerated life testing is considered with a Type-I censored sample from geometric distribution that is a commonly used distribution to model the lifetime of a device in discrete case. Maximum likelihood estimators as well as the associated distributions are derived. Exact, approximate and bootstrap approaches construct confidence intervals that are compared via a simulation study. Optimal confidence intervals are suggested in view of the expected width and coverage probability criteria. An illustrative example is also presented to explain the results of the paper. Finally, some conclusions are stated.

• The Research Journal of the Costume Culture
• /
• v.19 no.2
• /
• pp.245-254
• /
• 2011

The purpose of this study was to develop uniform pattern of obese junior-high school girls by using the virtual twin and 3D virtual garment simulation system. The results were as follows; first, by using 3D virtual garment simulation, new uniform pattern considered obese junior-high school girls was development. The basic numerical formula were as follows; bust girth=B/2+2.5, armhole depth=B/4, front waist girth=W/4+1.8, back waist girth=W/4+1, front hip girth=H/4+1, back hip girth=H/4+1, chest width=chest width+1.5, back width=back width+1 and back neck width 8cm. Second, according to the results of the new uniform pattern's appearance evaluation, it estimated more highly than existing pattern in silhouette and ease amount, confirming that new uniform pattern is appropriate for the obese junior-high school girls. Also, new uniform pattern was evaluated to allow proper space length of bust, waist, abdomen and hip. Virtual models production through 3D body scan data, pattern draft and virtual garment digital program were applied to prototypic design method so as to enhance the fitness of ready-made garments. This study is expected to serve as one of important basic data for ensuing studies that may utilize 3D virtual garment simulation system with 2D patterns, and also for future 3D pattern production program development.

• The Research Journal of the Costume Culture
• /
• v.12 no.2
• /
• pp.290-299
• /
• 2004

The purpose of this study is to testify the pattern making method to develop the men's basic bodice pattern using 3-dimensional body scan data. The experimental patterns were made by adding wearing ease on flattened body scan data and tracing the outlines of it. The experimental bodice pattern were composed of front, back, and side panels. To compare the difference between the experimental pattern and traditional pattern, two pattern making methods were compared. Two sets of basic bodice patterns were made for each of the 10 male subjects: a set of pattern was made by experimental method and the other set was made by Bunka pattern making method. The experimental and traditional patterns were measured at 13 dimensions. The results show that there was a difference between the experimental patterns and traditional patterns at the front length, back length, front width, front neck width, back neck width, and back neck depth. The fit was also compared for both patterns. The results of the fit test show that the experimental patterns were superior to the traditional patterns at the fit of neck, shoulder, and armhole. The experimental pattern making method was expected to be useful for mass customization.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.12
• /
• pp.776-781
• /
• 2017

In this study, we investigated the effect of electrode pattern design on the thermal shock resistance and temperature uniformity of a ceramic heater. A cordierite substrate with a low thermal expansion coefficient was fabricated by tape casting, and a tungsten electrode was printed and used as a heating element. The temperature distribution of the ceramic heater was calculated by a finite-element method (FEM) by considering various electrode patterns, and the tensile stress distribution due to the thermal stress was calculated. In the electrode pattern with a single-line width, the central part of the ceramic heater was heated to the maximum temperature, and the position of the ceramic heater having a double-line width was changed to the maximum temperature, depending on the position of the minimum line width pattern. The highest tensile stress was found along the edges of the ceramic heater. The temperature gradient at the edge determined the tensile stress intensity. The smallest tensile stress was observed for electrode pattern D, which was expected to be advantageous in resisting thermal shock failures in ceramic heaters.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.10
• /
• pp.1123-1130
• /
• 2011

The pattern shape engraved on the gravure printing roll is one of the most important factors influencing ink transfer. This study focuses on the relations between dot geometry engraved on gravure printing roll and the ink transfer during the gravure printing process. The influence of dot width on printed patterns will be demonstrated. Results reveal that as the width of a dot on the printing roll increases, the ink transfer rate also increases. But over a certain size of width, surface uniformity began to recede. Therefore, proper dot geometry on the printing roll should be decided to guarantee good printing quality according to printing conditions and expected performance of the electronic devices.