• The Korean Journal of Applied Statistics
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• v.23 no.3
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• pp.497-510
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• 2010

In medical practice and research, the problem of assessing reliability between two or more quantitative measures is quite common. Intraclass correlation coefficient(ICC) is commonly used to scale of reliability. Some methods were developed to calculate the required number of subjects, raters or replicates in one-way or two-way random ANOVA models. This paper, studies and compares the performance of four methods such as Walter et al. (1998), Giraudeau and Mary (2001), Saito et al. (2006) and Bonett (2002). In order to compare the efficiency of methods we compare the number of subjects, replicates and the width of confidence interval of ICC needed for some specific ICC values. In the case of subject size, Giraudeau's method is the best. In case of the number of replicates, Saito's method was superior to others. The width of confidence interval of ICC was narrower for Giraudeau's method than any others.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.141-147
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• 2015

The contrast of a display is generally evaluated by using the ratio of the minimum luminance to the maximum luminance of the display. However, this contrast ratio is not matched with perceived contrast because it uses only physical characteristic of display without considering human perceptual characteristics. In this paper, the proposed contrast measure that considers perceptually discriminable brightness within the range of display brightness is suggested. First, the range between the minimum and maximum brightness of display in CIECAM02 color space is calculated to measure the length of perceived brightness for the display. Next, brightness ranges which are perceptually same at each brightness level are determined by applying Weber-Fechner ratio and then, the number of brightness values within each brightness range is counted. Finally, perceptually discriminable brightness is defined as the sum of ratio between the number of brightness values in each brightness range and the perceptual contrast length of the display. In the experiments, preference test using various displays with random brightness patches is performed to evaluate perceived contrast. As a result, the proposed measure is more consistent with human perception than the previous contrast measures.

• Journal of The Korean Astronomical Society
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• v.46 no.3
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• pp.125-131
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• 2013

We present the relation between the genus in cosmology and the Betti numbers for excursion sets of three- and two-dimensional smooth Gaussian random fields, and numerically investigate the Betti numbers as a function of threshold level. Betti numbers are topological invariants of figures that can be used to distinguish topological spaces. In the case of the excursion sets of a three-dimensional field there are three possibly non-zero Betti numbers; ${\beta}_0$ is the number of connected regions, ${\beta}_1$ is the number of circular holes (i.e., complement of solid tori), and ${\beta}_2$ is the number of three-dimensional voids (i.e., complement of three-dimensional excursion regions). Their sum with alternating signs is the genus of the surface of excursion regions. It is found that each Betti number has a dominant contribution to the genus in a specific threshold range. ${\beta}_0$ dominates the high-threshold part of the genus curve measuring the abundance of high density regions (clusters). ${\beta}_1$ dominates the genus near the median thresholds which measures the topology of negatively curved iso-density surfaces, and ${\beta}_2$ corresponds to the low-threshold part measuring the void abundance. We average the Betti number curves (the Betti numbers as a function of the threshold level) over many realizations of Gaussian fields and find that both the amplitude and shape of the Betti number curves depend on the slope of the power spectrum n in such a way that their shape becomes broader and their amplitude drops less steeply than the genus as n decreases. This behaviour contrasts with the fact that the shape of the genus curve is fixed for all Gaussian fields regardless of the power spectrum. Even though the Gaussian Betti number curves should be calculated for each given power spectrum, we propose to use the Betti numbers for better specification of the topology of large scale structures in the universe.

• Journal of the Korean housing association
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• v.20 no.4
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• pp.121-129
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• 2009

Today, we are living while interchanging with various countries in multilateral measures and residential culture have been changed while interchanging in the same manner. In order to become an internationally recognized residential environment designer in this environment, we must understand the housing viewpoint of residents in that country first. Therefore, this study is intended to obtain the useful materials for residential environment design of Korea and China by comparing the housing viewpoint between Chinese students studying in Korea and Korean students. A survey using questionnaire was conducted on 205 Korean students and 193 Chinese students (Chinese race) from Y University on a random sampling basis. The result of survey is as follows. First, as both Korean and Chinese university students have a similar tendency on previous house type, current house type, and desired house type, it can be understood that they are similar each other in the experience and preference of house type. Second, Korean and Chinese university students consider and as the most important functions of residence, but Chinese university students consider more functions of residence than Korean students. And, both Korean and Chinese students consider a living room as the most important space among housing spaces, but Chinese consider a private room more importantly than Korean. Third, Chinese university students have stronger desire to possess houses, and desire to purchase houses with larger and more rooms at earlier time than Korean university students. Fourth, when selecting the house, Chinese university students give a higher consideration in terms such as , , , , and than Korean university students. Fifth, satisfaction level of Korean students on current houses was average as a whole, and most Chinese students were generally satisfied with their houses. Sixth, as both of Korean and Chinese university students have higher level of consideration in the items such as safety>, , , , , , , , , , and compared to the level of satisfaction, thoughtful consideration should be given to those items in housing planning.

• Journal of Periodontal and Implant Science
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• v.46 no.6
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• pp.382-395
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• 2016

Purpose: Alendronate has been proposed as a local and systemic drug treatment used as an adjunct to scaling and root planing (SRP) for the treatment of periodontitis. However, its effectiveness has yet to be conclusively established. The purpose of the present meta-analysis was to assess the effectiveness of SRP with alendronate on periodontitis compared to SRP alone. Methods: Five electronic databases were used by 2 independent reviewers to identify relevant articles from the earliest records up to September 2016. Randomized controlled trials (RCTs) comparing SRP with alendronate to SRP with placebo in the treatment of periodontitis were included. The outcome measures were changes in bone defect fill, probing depth (PD), and clinical attachment level (CAL) from baseline to 6 months. A fixed-effect or random-effect model was used to pool the extracted data, as appropriate. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the Cochrane ${\chi}^2$ and $I^2$ tests. Results: After the selection process, 8 articles were included in the meta-analysis. Compared with SRP alone, the adjunctive mean benefits of locally delivered alendronate were 38.25% for bone defect fill increase (95% CI=33.05%-43.45%; P<0.001; $I^2=94.0%$), 2.29 mm for PD reduction (95% CI=2.07-2.52 mm; P<0.001; $I^2=0.0%$) and 1.92 mm for CAL gain (95% CI=1.55-2.30 mm; P<0.001; $I^2=66.0%$). In addition, systemically administered alendronate with SRP significantly reduced PD by 0.36 mm (95% CI=0.18-0.55 mm; P<0.001; $I^2=0.0%$) and increased CAL by 0.39 mm (95% CI=0.11-0.68 mm; P=0.006; $I^2=6.0%$). Conclusions: The collective evidence regarding the adjunctive use of alendronate locally and systemically with SRP indicates that the combined treatment can improve the efficacy of non-surgical periodontal therapy on increasing CAL and bone defect fill and reducing PD. However, precautions must be exercised in interpreting these results, and multicenter studies evaluating this specific application should be carried out.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.209-214
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• 2017

The purpose of this study is to identify the factors that led greenhouse grape farms to delay their heating periods after the coming into force of the Korea-Chile Free Trade Agreement (FTA). Panel data on the cropping (system) changes from 2004 through 2016 were used for the analysis. According to the panel logistic model, the estimated coefficient of the cultivation area was 0.0002, which was statistically significant at the 10% significance level, the estimated coefficient of grape imports was 1.4258, which was statistically significant at the 1% significance level, and the estimated coefficient of the regional dummy was 0.808, which was statistically significant at the 5% significance level. The results indicated that the use of wider cultivation areas, increase in grape imports, and colder climate(in the mid-northern part of Korea) increased the likelihood of delayed heating. The Korean government is offering direct payment programs and business closure support to the greenhouse grape farmers. While these actions can relieve the damage caused by the increase in grape imports, they will not provide the ultimate solution. Various support measures are needed, such as renewing the varieties to meet the changing demand of grape consumers, providing agricultural materials to reduce the heating expenses, and modernizing greenhouse facilities to improve the energy efficiency and reduce the costs.

• Smart Media Journal
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• v.2 no.4
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• pp.60-65
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• 2013

In this paper, we propose a high-resolution disparity map generation method using a low-resolution time-of-flight (TOF) depth camera and color camera. The TOF depth camera is efficient since it measures the range information of objects using the infra-red (IR) signal in real-time. It also quantizes the range information and provides the depth image. However, there are some problems of the TOF depth camera, such as noise and lens distortion. Moreover, the output resolution of the TOF depth camera is too small for 3D applications. Therefore, it is essential to not only reduce the noise and distortion but also enlarge the output resolution of the TOF depth image. Our proposed method generates a depth map for a color image using the TOF camera and the color camera simultaneously. We warp the depth value at each pixel to the color image position. The color image is segmented using the mean-shift segmentation method. We define a cost function that consists of color values and segmented color values. We apply a weighted average filter whose weighting factor is defined by the random walk probability using the defined cost function of the block. Experimental results show that the proposed method generates the depth map efficiently and we can reconstruct good virtual view images.

• Journal of Korean society of Dental Hygiene
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• v.11 no.5
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• pp.659-670
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• 2011

Objectives : The purpose of this study was to examine the state of oral health care among special school personnels in an attempt to provide some information on the improvement of the oral health care of students with disabilities who would be under the first hand influence of school personnels. Methods : The subjects in this study were personnels who were selected by random selection in five different special schools located in the city of Jeonju, North Jeolla Province. A self-administered survey was conducted in person from July 5 to 14 after the purpose of this study was explained. Results : 1. Concerning their general characteristics, the level of oral health knowledge was high in the personnel whose career is 5 years more, and the younger personnels had a better oral health knowledge, and the men were more knowledgeable than the women. 2. As to oral health education experience, the rate of the respondents who ever received oral health education stood at 35.3 percent. In relation to the frequency of oral health education, the biggest group that accounted for 58.2 percent received that education once. As for the route of education, the largest group that represented 52.7 percent received that education at dental hospitals or clinics. In relation to satisfaction with oral health education, the greatest group that accounted for 38.5 percent were dissatisfied with that education. 3. As for an intention of receiving oral health education in the future, the biggest group that accounted for 60.9 percent intended to receive that education if they would have free time, and the largest group that represented 47.7 percent believed that oral health education should be conducted by dental hygienists. 4. Concerning their general characteristics, the level of oral health promotion behavior according to age in both bushing and supplies of oral health care was high in forties-1.89 point and 3.33 point, and that in regular visit to a dental clinic was the highest in twenties for 2.58 point, and that in dietary control was the highest in twenties for 2.59 point. 5. Their oral health knowledge had a significant positive correlation to their toothbrushing, regular dental clinic visit and dietary control that were the subfactors of oral health promotion behavior. 6. As for the impact of oral health promotion behavior on oral health knowledge, toothbrushing exerted the greatest influence on that(${\beta}$=0.306, p<0.001). Conclusions : Appropriate institutional measures should be taken to let dental hygienists who are expert in oral health care provide incremental oral health care for students and adults with disabilities in educational institutions and facilities for the disabled, and the development of oral health education programs is urgently required to offer systematic oral health education for not only students with disabilities but their teachers and guardians.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.4
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• pp.33-43
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• 2020

In order to reduce damage from farmland inundation caused by recent climate change, it is necessary to predict the risk of farmland inundation accurately. Inundation modeling should be performed by considering multiple time distributions of possible rainfalls, as digital forecasts of Korea Meteorological Administration is provided on a six-hour basis. As building multiple inputs and creating inundation models take a lot of time, it is necessary to shorten the forecast time by building a data base (DB) of farmland inundation probability. Therefore, the objective of this study is to establish a DB of farmland inundation probability in accordance with forecasted rainfalls. In this study, historical data of the digital forecasts was collected and used for time division. Inundation modeling was performed 100 times for each rainfall event. Time disaggregation of forecasted rainfall was performed by applying the Multiplicative Random Cascade (MRC) model, which uses consistency of fractal characteristics to six-hour rainfall data. To analyze the inundation of farmland, the river level was simulated using the Hydrologic Engineering Center - River Analysis System (HEC-RAS). The level of farmland was calculated by applying a simulation technique based on the water balance equation. The inundation probability was calculated by extracting the number of inundation occurrences out of the total number of simulations, and the results were stored in the DB of farmland inundation probability. The results of this study can be used to quickly predict the risk of farmland inundation, and to prepare measures to reduce damage from inundation.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.791-796
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• 2007

As large-scale buildings, skyscrapers, and multi-purpose buildings recently increase in numbers dramatically, the internal space of such buildings becomes more and more large and complicated accordingly. Since such structures usually accommodate a number of random people, the potential possibilities of disastrous tragedies are high, and the rates of injury and physical damage caused by the complicated system of the building also increase as well. However, most of the shelter designs of the existing buildings are based on the specifications according to the assigned laws and involved regulations. In this case, only general criteria are referred to regardless of the characteristics of each structure while other disaster-related features are not taken into consideration sufficiently. Since any actual fire may cause a terrible calamity, in such plans, shelter inducement can be neither safe nor effective. Thus, this study examines and analyzes currently run disaster prevention systems and shelter inducement facilities with COEX Mall as its subject, and analyzes the responding system to each situation based on the fire scenarios by means of As-Is Model. Through this analysis, presented are the measures to solve the problems of current disaster prevention systems and to improve shelter inducement methods effectively.