• East Asian mathematical journal
• /
• v.34 no.1
• /
• pp.59-67
• /
• 2018

We present new recurrence formulas for the raw and central moments of a compound binomial random variable. Our approach involves relating two compound binomial random variables that have parameters with a difference of 1 for the number of trials, but which have the same parameters for the success probability for each trial. As a consequence of our recursions, the raw and central moments of a binomial random variable are obtained in a recursive manner without the use of Stirling numbers.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.40 no.1
• /
• pp.139-154
• /
• 2015

This paper uses the Heckman model to evaluate the income difference between the public sector and the private sector based on the CHNS data. The research finds that the difference of the public sector versus the private sector between the west area and the east area is about 10% from 1989 to 2000, the transition of the income difference is smooth, that data has made sharp increase to 32% from 2000 to 2011. Considering the income difference between the west area and the central area, the central area and the east area from 1989 to 1997, the data is about 10~15%, from 2000 to 2011 is rocketing time, the data reaches 20%. This paper is very revealing about the income difference ofthe public sector versus the private sector is increasing year after year, and the economy is developing rapidly but with imbalance among different areas in China. It would provides the reference for adjust the income distribution system in future.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.7
• /
• pp.533-541
• /
• 1999

Multi-discharge type ozonizer(MDO) using superposed silent discharge has been designed and manufactured. It consists of three electrodes( central electrode, internal electrode, and external electrode ) and double gaps( gap between central electrode and internal electrode, gap between internal electrode and external electrode ). Therefore, ozone is generated by superposing silent discharges generated between the gaps respectively. And the MDO consists of three types of superposed discharge ozonizers according to voltage appling method for each electrode ; A.C. high voltages are applied two of three electrodes with phase difference of 180[˚], the other electrode is a ground. This paper describes that discharge and ozone generation characteristics of MDO which comprising central electrode and internal electrode applied A.C. high voltages with phase difference of 180[˚] respectively, and the grounded external electrode. As a result, the maximum ozone concentration, generation, and yield can be obtained 10208[ppm], 6.4[g/h], and 280[g/kwh] respectively.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.12 no.1
• /
• pp.34-40
• /
• 2012

We have developed a highly sensitive inspection technique based on an electron beam inspection for detecting the contact failure of a poly-Si plugged layer. It was difficult to distinguish the contact failure from normal landing plugs with high impedance. Normally, the thermal annealing method has been used to decrease the impedance of poly-Si plugs and this method increases the difference of charged characteristics and voltage contrast. However, the additional process made the loss of time and broke down the device characteristics. Here, the interval scanning method without thermal annealing was effectively applied to enhance the difference of surface voltage between well-contacted poly-Si plugs and incomplete contact plugs. It is extremely useful to detect the contact failures of non-annealed plug contacts with high impedance.

• Journal of Ecology and Environment
• /
• v.46 no.1
• /
• pp.8-17
• /
• 2022

Background: Parthenium hysterophorus L. (Asteraceae; hereafter Parthenium) is an invasive alien species of global significance because of its' negative ecological and socioeconomic impacts. This species is spreading rapidly from lowland Tarai to Middle Mountain regions in Nepal. In the present study, we analyzed the impacts of Parthenium on plant community composition including their soil seedbank in subtropical grasslands located in central Nepal. Data was collected in a 10 m long transects passing through areas of high (> 90% cover), medium (40%-60%) and low (< 10%) levels of Parthenium cover using a plot of 1 m². Altogether, we sampled 90 plots in 30 transects. Seedling emergence method was used to estimate soil seedbank density in the soil samples (0-10 cm depth) collected from the plots with high Parthenium cover. Results: There was no significant difference in the plant species richness at different levels of Parthenium invasion whereas there was a significant change in the species composition of above ground flora due to Parthenium invasion. There was also a significant difference in species composition between soil seedbank and aboveground flora in the highly invaded plots. Parthenium was the most dominant in soil seedbank, contributing 65% to the total soil seedbank. Conclusions: Our study suggests that Parthenium has considerable negative impact on the native grassland flora, and the dominance of Parthenium in the soil seedbank means there is a challenge for its management. It also suggests the need of monitoring the soil seedbank dynamics while managing Parthenium weed.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.28 no.1
• /
• pp.47-58
• /
• 1998

The purpose of this study was to investigate an influence of the change of central panoramic curves on the image reconstruction in the dental implant CT. The author designed three experimental groups according to the location of central panoramic curve. In group A, central panoramic curve was determined as the curve connecting the center of roots from the first premolar to the first molar. In group B, central panoramic curve was determined as the line connecting the lingual cortical plate at the level of the mesial aspect of the first premolar with the buccal cortical plate at the level of the mesial aspect of the first molar. In Group C, central panoramic curve was determined as the line connecting the buccal cortical plate at the level of the mesial aspect of the first premolar with the lingual cortical plate at the level of the mesial aspect of the first molar. Twenty four reformatted CT images was acquired from four mandibles embedded in the resin block and twenty four contact radiographs of dog specimens were acquired. Each Image was processed under Adobe Photoshop program analysed by MSPA(mandible/maxilla shape pattern analysis) variables such as MXVD, MXHD, UHD, MHD, and LHD. The obtained results were as follows ; 1. The mean of MXVD variable was 19.9, 20.2, and 20.0 in group A, B, and C, respectively, which were smaller than actual value 20.5. But, there was no significant difference among 3 groups (p>0.05). 2. The mean of MXHD, UHD, MHD, and LHD variables in group A, B, and C was 11.9, 12.2, and 12.3; 9.3, 9.5, and 9.6; 10.0, 10.3, and 10.3; 9.2, 9.3, and 9.4 respectively which were equal to or greater than the actual value 11.8, 9.3, 10.0, and 9.2. But, there was no significant difference among 3 groups (p>0.05). 3. The number of noneffective observations with difference over or under 1 mm with comparison to the actual value was 24(20％), 58(48.3％), and 52(43.3％), respectively, in group A, B, and C. 4. In group A, the number of observations over 1 mm and under 1 mm was 9 and 15, respectively, but in group Band C, the number of observations over 1 mm was more than under 1 mm.

• Bulletin of the Korean Mathematical Society
• /
• v.51 no.2
• /
• pp.317-328
• /
• 2014

In Bae et al. [2], we have considered the uniform CLT for the martingale difference arrays under the uniformly integrable entropy. In this paper, we prove the same problem under the bracketing entropy condition. The proofs are based on Freedman inequality combined with a chaining argument that utilizes majorizing measures. The results of present paper generalize those for a sequence of stationary martingale differences. The results also generalize independent problems.

• Journal of Welding and Joining
• /
• v.22 no.6
• /
• pp.43-49
• /
• 2004

In this study, a visual sensor system which can detect I-butt weld joint with height variation and includes a seam tracking algorithm was investigated. Three-dimensional position of an object can be acquired by using the method of distance measurement, i.e., an optical trigonometry which results from the spatial relations between the camera, the object and the structured light by a visible laser. Effects of laser intensity and iris number for the image quality as well as object material were investigated for the optical system design. For the image processing, a region of interest is defined from the whole image and a line image of laser is drew by using the gray level difference in the image. From the drew laser line, the weld joint can be recognized in searching the biggest point position calculated from the central difference method. Through a series of welding experiments, a good tracking performance was confirmed under GMA welding.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.18 no.1
• /
• pp.81-136
• /
• 1988

The aim of this study was to determine whether T.M.J. tomographic examination yielded significant differences in condyle positions among asymptomatic, myalgia, derangement, and arthrosis groups of T.M.J. disorders. The author obtained sagittal linear tomograms of right and left T.M.Js. of 36 asymptomatic, 22 myalgia, 54 derangement, and 31 arthrosis patients taken at serial lateral, central, and medial sections in the intercuspal position after submentovertex radiographs analyzed. With the dual linear measurements of the posterior and anterior interarticular space, condyle positions were mathematically expressed as proportion. All data from these analysis was recorded and processed statistically. The results were obtained as follows. 1. In asymptomatic group, radiographically concentric condyle position was found in 50.0% to 65.4% of subjects, with a substantial range of variability. No significant differences existed between men and women and also between right and left T.M.Js. for condyle position. 2. In women, significant difference for mean condyle position of left lateral section of each diagnostic category existed between derangement and myalgia groups (P<.05). Also that of left central section existed between derangement and myalgia groups, and that of left medial section existed between derangement and myalgia groups (P<.05). 3. In main-symptom side, condyle position in myalgia group was more concentric, and condyle position in derangement group was more posterior. This showed significant differences between derangement and myalgia groups in lateral, central, and medial sections of main- symptom sides, and only between derangement and myalgia groups in central section of contra-lateral sides (P<.05). Condyle position in arthrosis group was broadly distributed among all positions. 4. In contra-lateral side, significant difference for mean condyle position of central section of each symptomatic group existed between derangement and myalgia groups (P<.05). Condyle position in derangement group was more posterior. The distribution of the condyle position of contra-lateral side in patients with unilateral symptoms was similar to that of main-symptom side in each symptomatic group. No significant difference existed between main-symptom and contra-lateral sides. 5. For internal derangement subgroups, condyle position in reducible disc displacement group was more posterior than non-reciprocal and locking groups, but there was no significant difference. 6. From 16 to 25 years, significant difference for mean condyle position of medial section of main-symptom side of each symptomatic group existed between myalgia and derangement groups (P<.05).

• Journal of Periodontal and Implant Science
• /
• v.34 no.1
• /
• pp.19-28
• /
• 2004

Tooth is the most important element in esthetic consideration on facial area. Tooth alignment which is in harmony with gingiva, lips, and face is also key element. The purpose of this study was to give a clinical discipline for restoration of gingival contour, which contains a ratio of maxillary 6 anterior teeth, research for gingival contour etc., in case of rehabilitation of maxillary anterior teeth. 300 Dankook university dental school students ,who is their twenties and free from periodontitis, participate in this study. The result was from each 70 males and females who had normal occlusion and tooth alignment. Length, width and length/width ratio of maxillary 6 anterior teeth were 0.74-0.81 in male, 0.81-0.84 in female. There was significant difference between male and female. The most deepest position of gingiva in maxillary central incisor and canine was located in distal part of teeth and maxillary lateral incisor was middle portion. In maxillary central incisors, gingival line of the most deepest point appeared significant difference between male and female (p<0.01) whereas there was no difference in lateral incisors and canines. Distance between interdental papilla apex and the most deepest portion appeared significant difference between male and female. Distance of the deepest position of gingiva is statistically significant except maxillary central incisors and lateral incisors. Standard deviation and mean of the width of labio-lingual were measured in cervical area and there was a significant difference both male and female.(p<0.01) From this result, we could get the mean of maxillary anterior gingival line and these results have great value in clinical guidance in studying maxillary anterior teeth.