• Title/Summary/Keyword: 14-face die

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Construction Method and Mathematics Educational Aspect of the Wooden Die for Drinking Game(14-face Die) (목제주령구(木製酒令具)의 제작기법 및 수학교육적 의미)

  • Lee Kang-Sup
    • Journal for History of Mathematics
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    • v.19 no.3
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    • pp.43-56
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    • 2006
  • This paper aims to introduce a construction method for the 'Wooden Die for Drinking Game' and to find some geometrical structures and mathematics educational viewpoints. As the results, we get two methods which are eventually same with Figure 5 and Figure 6-3. We proved the ground that classical probability of this Die's each side showing up is one out of fourteen and introduced few other empirical probabilities with Table 1 to Table 3. Also, some Chinese characters were corrected and re-interpreted. In fact, 象人打鼻 changed to 衆人打鼻, and 醜物 is interpreted as 'ugly animal' such as frog, toad, earthworm or pine caterpillar.

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Forming Characteristics of the Forward and Backward Tube Extrusion Using Pipe (중공축 소재를 이용한 전후방 복합압출의 성형 특성)

  • Kim S. H.;Lee H. Y.
    • Transactions of Materials Processing
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    • v.14 no.9 s.81
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    • pp.772-778
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    • 2005
  • This paper is concerned with the analysis of material flow characteristics of combined tube extrusion using pipe. The analysis in this paper concentrated on the evaluation of the design parameters for deformation patterns of tube forming, load characteristics, extruded length, and die pressure. The design factors such as punch nose radius, die corner radius, friction factor, and punch face angle are involved in the simulation. The combined tube extrusion is analyzed by using a commercial finite element code. This simulation makes use of pipe material and punch geometry on the basis of punch geometry recommended by International Cold Forging Group. Deformation patterns and its characteristics in combined forward and backward tube extrusion process were analyzed for forming loads with primary parameters, which are various punch nose radius relative to backward tube thickness. The results from the simulation show the flow modes of pipe workpiece and the die pressure at the contact surface between pipe workpiece and punch. The specific backward tube thickness and punch nose radius have an effect on extruded length in combined extrusion. The combined one step forward and backward extrusion is compared with the two step extrusion fer forming load and die pressure.

Kinetic Analysis of the Probability of Hexagonal Face in Juryeonggu (주령구에서 육각면이 나올 확률에 대한 운동역학적 해석)

  • Yoo, Wan Suk;Lee, Jeong Han
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.11
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    • pp.1085-1089
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    • 2017
  • Juryeonggu is a cuboctahedral die that was used during the Silla period in ancient Korea. This cuboctahedral die consists of two different penal servitudes of 14 sides; however, its equal probability distribution enables it to be used as a die. In this paper, a precise cuboctahedral die, Juryeonggu, was manufactured, and its probability was measured through experiments. Next, the probability was verified through Multibody-dynamics (MBD) modeling and analysis, and the effect of the coefficient of friction on the probability distribution was studied.

Process Design of Shaft Considering Effect of Preform and Eccentric Load on Cold Forging Product in Multistage Former of Horizontal Type (수평식 냉간 다단포머에서 예비성형체와 편심하중을 고려한 Shaft의 성형공정설계)

  • Park S. S.;Lee J. M.;Kim B. M.
    • Transactions of Materials Processing
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    • v.14 no.1 s.73
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    • pp.57-64
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    • 2005
  • This study deals with the cold forging process design for shaft in the main part of automobile motors with rectangular deep groove. In forging process, the accuracy and die lift is very important because it have influence on reduction of the production cost and the increase of the production rate. Therefore, it is necessary to develop the manufacturing process of shaft by cold forging., process variables are the cropped face angle of billet and the eccentric load of punch. The former is derived from cropping test, the latter is occurred by clearance between container and preform. Also, grooved preform select the process variable for decrease in punch deflection. We investigate that a deflection of punch and a deformation of preform to every process variables. Through this investigation, we suggest the optimal preform and process design, expect to be improved the tool life in forging process.

A study of frictional characteristics of galvanized sheet steels for automobiles (자동차용 표면처리강판의 마찰특성에 관한 연구)

  • 김영석;남재복;최원집
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.6
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    • pp.1474-1486
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    • 1990
  • The frictional characteristics of galvanized sheet steels(GA, EG, EGF, EGN) for automobiles were studied and compared with that of cold rolled sheet steel. A draw bead tester which simulates metal flow through a draw bead in stamping die face was used to measure coefficients of friction of galvanized sheet steels for four kinds of lubricants. Stamping formability of galvanized sheet steels for quarter outer panel was examined. The results show that stamping formability and friction characteristics were mainly influenced by the nature of zinc coating, surface roughness and micro hardness of coated layer, and proved to be very sensitive to the lubricant used.

A STUDY ON THE STRESS IN MOTHER OF AUTISTIC CHILDREN (자폐아동 어머니의 스트레스에 대한 연구)

  • Yoon, Soo-Young;Han, Kyung-Ja
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.4 no.1
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    • pp.54-67
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    • 1993
  • This study is to investigate the stress and stress degree in mothers of autistic children. In order to obtain data for planning nursing strategies for mothers of autistic children The assessment tool for the stress was constructed through reviewing literatures on the stress and gathering the stress items by nonstructed face to face interviewing 14 mothers of autistic children The stress tool consists of 74 items each with five point rating scale A data collection was made front 160 mothers of autistic children from 11 institutions for autistic children in Seoul and Kyung-Ki province. The reliability coefficients by Cronbach's a test was 0.94 for the stress scale. The results are as follows : 1) The mean of stress is 3.19, in the area of the etiology, prognosis and the treatment-education, with cause of the treatment the edeucatlon and the prognosis of child's handicap. The mean of stress is 2.85 In the area of the negative of mother's self image, 2.45 in the area of the mother's ordinary life. The mean of stress was 2.05, lowest in the family and social relationship 2) The mean score for the total was 2.62 points. The items with highest stress score were 'All autistic child has not been understood by the society', 'If we die, 1'm afraid that this child will not be cared by someone', 'There is no institution that the child get the schoolibg', etc The stress item with the lowest mean score were 'Keep away the child from husband', 'Being divorced by husband', etc. 3) An analysis of relationship of stress degree to general characteristic shows a statisically significants difference in the number of children in the family and the cognition of the seventy of the child problem

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