• Title/Summary/Keyword: degenerated distribution

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Maximum likelihood estimation for a mixture distribution (이항-퇴화 혼합분포의 최우추정법)

  • Hwang, Seonyeong;Sohn, Seung Hye;Oh, Changhyuck
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.2
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    • pp.313-322
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    • 2015
  • A mixture distribution of a discrete uniform or degenerated distribution and two binomial distribution is proposed and a method of obtaining the maximum likelihood estimates of the parameters is provided. For the proposed model simulation studies were conducted to see performance of the maximum likelihood estimates and a mixture of a degenerated distribution and two binomial distributions was applied to fit a lecture evaluation data to show a good result.

The Effects of Heat-Affected Zone on Cold Forging Die Life (냉간단조용 금형의 열영향층 형성과 그 영향)

  • 이영선;이정환;정순철
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.06b
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    • pp.43-53
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    • 1998
  • Heat - affected zones degenerated in cold forging die have been investigated to improve the tool life. There are many cases of heat-affected zone which are degenerated in manufacturing die and using the cold forging process. In order to define amounts of grinding inmanufacturing the toolfor cold forging, we have investigated the hardness and microstructure of surface layer after EDM. Considering the results of T.R.S. and compression test, it is likely that mechanical properties of tool have been decreased sharply if the heat-affected zones degenerated by EDM were not machined properly. also analyzed the tool surfac which is fractured during the cold forging. According to the microstructures and hardness distribution, surface of many tools have been degenerated in cold forging and fractured due to the heat-affected zone.

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Moment Distribution in continuous Slabs of Simply Supported Bridges (단순 PC 빔교의 연속 바닥슬래브에 발생하는 모멘트 분포)

  • 최창근;송명관
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.398-405
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    • 1997
  • The finite element program is presented for the analysis of the moment distribution in continuous slabs of simply supported girders. The program includes the material nonlinearity of the continuous and steel reinforcements of the RC slabs, but assumes that the PC beam and cross beam behave linearly. In modeling the PC slabs and girders, the four node degenerated shell element formulated based on the assumed strain interpolation and the 3D beam element are used, respectively. Using the program, the influence of the existence of the cross bean, the filling of open joints on the continuous at supports, and perfect continuation of precast girder elements are examined.

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Temporal Change in Vertical Distribution of Woody Vegetation on the Flank of Sakurajima Volcano, Southern Kyushu, Japan

  • Teramoto, Yukiyoshi;Shimokawa, Etsuro;Ezaki, Tsugio;Lim, Young-Hyup;Kim, Suk-Woo;Chun, Kun-Woo
    • Journal of Forest and Environmental Science
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    • v.32 no.3
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    • pp.270-279
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    • 2016
  • This study explained vertical distributions and growth environments for woody vegetation. It had been degenerated by long-term volcanic activity of Sakurajima; vegetation and thicknesses of tephra layers and forest soils were investigated at 5 sites (250-700 m in altitude) with different altitudes localized at the northwestern-northern flanks of Sakurajima in Kagoshima Prefecture. The results in 2015 were compared with the vertical distribution of woody vegetation in 1963, when the volcanic activity of Sakurajima was relatively moderate. Thus, we investigated temporal changes in the vertical distribution of woody vegetation owing to volcanic activity over about 50 years (1963-2015). We indicated altitude decreased, the number of woody vegetation, number of species, sum of cross-sectional area of tree diameter at breast height, Fisher-Williams's diversity index ${\alpha}$, and forest soil thickness increased. However, these values were found to be degenerated when compared to climax forest values, and succession was incomplete. It seems that because the woody vegetation of the flank was affected by volcanic activity for a long time, exposing them to severe growth environments, areas with lower altitudes became distant from the craters of Sakurajima, thereby weakening the effect of volcanic activity in these areas at lower altitudes. a at the same altitudes over about 50 years (1963-2015) decreased by about 31-72%, and the sum of the cross-sectional area in tree diameter at breast heights decreased by about 14-62%. Thus, comparative growth environments for woody vegetation in 2015 were more severe than that of 1963, with respect to tephra layer thickness. In addition, for vegetation succession in the flank of Sakurajima, vegetation restoration should be promoted through the introduction of artificial woody plants covered by symbiotic microorganisms or organic materials.

Sexual Maturity and Spawning of Ocean Sunfish Mola mola in Korean Waters (한국 근해 개복치(Mola mola)의 성숙과 산란)

  • Kang, Min Joo;Baek, Hea Ja;Lee, Dong Woo;Choi, Jung Hwa
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.5
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    • pp.739-744
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    • 2015
  • The sexual maturation and spawning time of female ocean sunfish Mola mola in Korean waters were studied by observing the gonads histologically. Specimens were purchased in a fish market in October 2013 and May, June, and October 2014. Nine females (total length 100-250 cm, gonad weight 31-3,470 g) and one male (total length 131 cm, gonad weight 60 g) were studied. Histologically, the ovaries became active in May and spawning began in July and continued until October. In July, mature oocytes and yolk globule stage oocytes were observed; parts of the gonad showed traces of spawning, while others had degenerated and absorbed any oocytes. By October, many oocytes had degenerated and been absorbed. Therefore, the approximate spawning period of ocean sunfish is from July to October based on histological changes in the gonads. The asynchronous oocyte development suggests that the ocean sunfish is a multiple spawner, as reported previously. The catch distribution data suggest that the waters around Jeju Island are a sunfish spawning area.

A Study on Buckling Load Characteristic of Songdo Convention Center with Initial Imperfection and Joint Rigidity (송도 컨벤션 센터의 초기형상불완전 및 절점강성에 따른 좌굴하중 특성에 관한 연구)

  • Moon, Hye-Su;An, Sang-Gil;Shon, Su-Deok;Lee, Dong-Woo;Kim, Seung-Deog
    • Proceeding of KASS Symposium
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    • 2006.05a
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    • pp.191-204
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    • 2006
  • This paper investigate the optimum thickness distribution of plate structure with different essential boundary conditions in the fundamental natural frequency maximization problem. In this study, the fundamental natural frequency is considered as the objective function to be maximized and the initial volume of structures is used as the constraint function. The computer-aided geometric design (CAGD) such as Coon's patch representation is used to represent the thickness distribution of plates. A reliable degenerated shell finite element is adopted calculate the accurate fundamental natural frequency of the plates. Robust optimization algorithms implemented in the optimizer DoT are adopted to search optimum thickness values during the optimization iteration. Finally, the optimum thickness distribution with respect to different boundary condition

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Optimum Thickness Distributions of Plate Structure with Different Essential Boundary Conditions in the Fundamental Frequency Maximization Problem (기본고유진동수 최대화 문제에 있어서 경계조건에 따른 판구조물의 최적두께 분포)

  • Lee, Sang-Jin;Kim, Ha-Ryong
    • Proceeding of KASS Symposium
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    • 2006.05a
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    • pp.227-232
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    • 2006
  • This paper investigate the optimum thickness distribution of plate structure with different essential boundary conditions in the fundamental natural frequency maximization problem. In this study, the fundamental natural frequency is considered as the objective function to be maximized and the initial volume of structures is used as the constraint function. The computer-aided geometric design (CAGD) such as Coon's patch representation is used to represent the thickness distribution of plates. A reliable degenerated shell finite element is adopted calculate the accurate fundamental natural frequency of the plates. Robust optimization algorithms implemented in the optimizer DoT are adopted to search optimum thickness values during the optimization iteration. Finally, the optimum thickness distribution with respect to different boundary condition

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Model-based Clustering of DOA Data Using von Mises Mixture Model for Sound Source Localization

  • Dinh, Quang Nguyen;Lee, Chang-Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.1
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    • pp.59-66
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    • 2013
  • In this paper, we propose a probabilistic framework for model-based clustering of direction of arrival (DOA) data to obtain stable sound source localization (SSL) estimates. Model-based clustering has been shown capable of handling highly overlapped and noisy datasets, such as those involved in DOA detection. Although the Gaussian mixture model is commonly used for model-based clustering, we propose use of the von Mises mixture model as more befitting circular DOA data than a Gaussian distribution. The EM framework for the von Mises mixture model in a unit hyper sphere is degenerated for the 2D case and used as such in the proposed method. We also use a histogram of the dataset to initialize the number of clusters and the initial values of parameters, thereby saving calculation time and improving the efficiency. Experiments using simulated and real-world datasets demonstrate the performance of the proposed method.

A Study on Body Fat Distribution in Obese Human - Specially Related to Risk Factors in Degenerated Diseases - (비만자의 체지방량 및 분포에 관한 기초연구-성인병의 발생 위험 요인과 관련하여-)

  • 이기열;장미라;김은경;허갑범
    • Journal of Nutrition and Health
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    • v.24 no.3
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    • pp.157-165
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    • 1991
  • The purpose of this study was to investigate differences in body fat distribution between normal and obese subjects and the relationship between risk factors(fasting blood sugar, blood pressure. fasting serum lipids) and obesity. Measurements of height. weight, skinfold thickness. body circumference. percent body fat. blood pressure, fasting blood sugar and serum lipids were made and a dietary survey was performed on 120(Males 61. Females 59) adult subjects. 1) Among the female subjects, the obese group appeared to have significantly higher centrality of body fat than the normal group. Obese groups of both sexes appeared with higher blood pressure than normal groups. No differences in daily average nutrient intake, fasting blood sugar and fasting serum lipids concentrations were observed between obese and normal groups. 2) In males. the serum triglyceride concentration was observed to have a significantly positive correlation to body weight, body mass index and body circumference, additionally concentrations of total cholesterol and LDL-cholesterol were observed to have significantly positive correlations to the skinfold thickness. but the ratio of HDL-cholesterol/total cholesterol was observed to be significantly negatively correlated to the skinfold thickness. 3) In females. the obese group consumed about 47% of total energy intake at lunch. whereas the normal group consumed about 29% . The food habit score of males appeared to be negatively related to body weight, percent ideal body weight. But the food habit score of females appeared to be negatively related to percent body fat(r=-0.32, p<0.05) .

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A Study on the Optimum Thickness Distributions of Plate Structures with Different Essential Boundary Conditions (경계조건에 따른 판 구조물의 최적두께분포에 대한 연구)

  • Lee, Sang-Jin;Kim, Ha-Ryong
    • Journal of Korean Association for Spatial Structures
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    • v.5 no.4 s.18
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    • pp.53-59
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    • 2005
  • This paper provides the results of the investigation on the optimum thickness distribution of plate structures with different essential boundary conditions. In this study, the strain energy to be minimized is considered as the objective function and the initial volume of structures is used as the constraint function. The computer-aided geometric design (CAGD) such as Coon's patch representation is used to represent the thickness distribution of plates. A reliable degenerated shell finite element is adopted to calculate the accurate strain energy level of the plates. Robust optimization algorithms provided in the optimizer DOT are adopted to search the optimum thickness values during the optimization iteration. Finally, the square plate is used to find out the optimum thickness distribution of plates according to different essential boundary condition.

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