• Transactions of Materials Processing
• /
• v.18 no.1
• /
• pp.39-44
• /
• 2009

This paper is concerned with forming technology of an automotive front side member part with ultra high strength steel sheet of DP980. The forming technology considered in this paper is the draw & form type, which installs the upper pad and lower pad to produce the complicated shape of ultra high strength steel sheet. In order to produce sound product, comparison between form type and draw & form type and between draw type and draw & form type are investigated by FE-analysis. FE-analysis is carried out with commercial sheet metal forming analysis S/W, DYNAFORM. It was shown from FE-analysis that the draw & form type satisfied the required specifications such as the dimensional accuracy and soundness of automotive front side member part. The effectiveness of the analytical result was verified by the experiment. From this investigation, the draw & form type is proved to be able to supply useful forming technology in forming ultra high strength steel.

• Communications of the Korean Mathematical Society
• /
• v.36 no.3
• /
• pp.423-445
• /
• 2021

In this paper, a new form of poly-Genocchi polynomials is defined by means of polylogarithm, namely, the Apostol-type poly-Genocchi polynomials of higher order with parameters a, b and c. Several properties of these polynomials are established including some recurrence relations and explicit formulas, which are used to express these higher order Apostol-type poly-Genocchi polynomials in terms of Stirling numbers of the second kind, Apostol-type Bernoulli and Frobenius polynomials of higher order. Moreover, certain differential identity is obtained that leads this new form of poly-Genocchi polynomials to be classified as Appell polynomials and, consequently, draw more properties using some theorems on Appell polynomials. Furthermore, a symmetrized generalization of this new form of poly-Genocchi polynomials that possesses a double generating function is introduced. Finally, the type 2 Apostolpoly-Genocchi polynomials with parameters a, b and c are defined using the concept of polyexponential function and several identities are derived, two of which show the connections of these polynomials with Stirling numbers of the first kind and the type 2 Apostol-type poly-Bernoulli polynomials.

• Journal of the Korean Society of Mechanical Technology
• /
• v.13 no.2
• /
• pp.155-163
• /
• 2011

The flat type automotive cross members with high strength steel have advantages in light weight and fewer parts compared to the hump type cross members. But the complex part shape of the flat type cross member and the poor formability of high strength steel make it difficult to form the parts without forming defects, such as splits and wrinkles. The purpose of this study is to develop the flat type automotive cross member with high strength steel. For that purpose, drawing processes are evaluated using PAM-$STAMP^{TM}$ and proper draw die and blank designs are proposed. Using the proposed die and blank design, the flat type upper and lower cross member could be formed successfully without forming defects.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.06a
• /
• pp.435-436
• /
• 2008

• Journal of the Korean Society for information Management
• /
• v.31 no.4
• /
• pp.49-68
• /
• 2014

The purpose of this study is to perform content analysis of research articles using the language network analysis method in Korea and catch the basic point of the language network analysis method. Six analytical categories are used for content analysis: types of language text, methods of keyword selection, methods of forming co-occurrence relation, methods of constructing network, network analytic tools and indexes. From the results of content analysis, this study found out various features as follows. The major types of language text are research articles and interview texts. The keywords were selected from words which are extracted from text content. To form co-occurrence relation between keywords, there use the co-occurrence count. The constructed networks are multiple-type networks rather than single-type ones. The network analytic tools such as NetMiner, UCINET/NetDraw, NodeXL, Pajek are used. The major analytic indexes are including density, centralities, sub-networks, etc. These features can be used to form the basis of the language network analysis method.

• Journal of Fashion Business
• /
• v.15 no.6
• /
• pp.148-162
• /
• 2011

The purpose of this study is to analyze lower body types of women and provide information of body improvement of Korean adult female clothing product to ready-made clothes companies. As for the method of this study, it was conducted to measure the parts of the lower body of adult women at the age from 19 to 24 years, to analyze their characteristics and to categorize body types. For study, it was measured 150 female women in Seoul. Data was analyzed by used SPSS/WIN 19.0 Program. The results of this study are as follows. The means of the subjects in their early 20s are 159.8cm in height, 67.0cm in waist circumference, 91.6cm in hip and 52.0kg in weight. As a result of comparison with the $5^{th}$ Korean's human body size on measurement data, 20 items out of 33 items showed significant difference. Factor analysis was executed for 66 body measure and calculation items to draw the body construction factors of the women's lower body in their early 20s and principal component analysis was performed by orthogonal varimax rotation to clarify the measurement of factors and to derive explanatory factors. As result of Cluster analysis, body types' characteristics divide into 3 types. Type1 has tall and fat body form, type2 has shortest and curvy body form and type3 has average height and the most skinny body form.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2003.11a
• /
• pp.301-306
• /
• 2003

The main gate of university is a symbolic role to grasp the its activities within a limited area. The form or shape is various at its circumstances such as activity type, region, etc. The study aimed at offering the information to grasp the fixed quantity to an university gate plan which analyzed a psychological judgment criteria according to form or shape characteristics of the university main gate. It selected ten universities through a classification of the types. The twenty adjective phrases were extracted by review of the further research. After then, it extracted to draw high adjective in observers visual image formation. This study analyzed the preference, symbolized representation of the university main gate. The results are summarized as follows : 1. The symbol and representation of form has a high correlation. In other words, the symbolic scale would be high positively when the representation scale be high. 2. Eight items among the twenty adjective items appeared to explain the university main gates. The twelve items of them wouldn't be related to grasp the main gate

• Journal of the Korean Society of Costume
• /
• v.57 no.4 s.113
• /
• pp.30-44
• /
• 2007

This research searched characteristic of expression of Surrealism in Fashion Art which is new genre as source of design origination and classified as type of Time, Instinct, Existence and analyzed these and after analyzed result, it tried to verify the value aesthetically and followed by compared characteristic of expression in Surrealism appeared in Art based on content of type of expression that deduced and discussed it. Also comparing common characteristic appeared in Fashion Art in surrealism of the east and the west, it suggested discussion that try to find out identity that draw more near to Fashion Art. Results of research are as following these; Surrealist deliver sentiment and emotion that impossible to happen in reality and primitive thought by combination of unrealistic image and this tendency concreted by expression of Time, Expression of Instinct, expression of Existence. It appeared that deconstruct function and purpose of Fashion Art and existing traditional beauty of form and it is in collusion with way of expression of modelling used in Art of Surrealism those are Irregularity, Disorder, Imperfection and Dissymmetry.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2009.10a
• /
• pp.301-306
• /
• 2009

High strength steels are widely used for lightweight automobile parts and the control of springback is very important in sheet metal forming. The object of this study is to develop the forming process for stair type side sill made of high strength steel, DP780. Stair type side sill with local formed area and geometry change area can improve stiffness and design freedom but there are a few studies for forming process. The forming technology considered in this paper is form type process, which have many advantages for farming of high strength steel compared with draw type process. Finite element analysis is carried out to predict formability and springback. It is shown that angle calibration of die is essential for reducing springback, and local forming involving bead is effective to control springback also. The effectiveness of local forming and angle calibration is verified by experimental.

• Transactions of Materials Processing
• /
• v.18 no.8
• /
• pp.601-606
• /
• 2009

High strength steels are widely used for lightweight automobile parts and the control of springback is very important in sheet metal forming. The object of this study is to develop the forming process for stair type side sill made of high strength steel, DP780. Stair type side sill with local formed area and geometry change area can improve stiffness and design freedom but there are few studies for forming process. The forming technology considered in this paper is form type process, which has many advantages for forming of high strength steel compared with draw type process. Finite element analysis is carried out to predict formability and springback. It is shown that angle calibration of die is essential for reducing springback, and local forming involving bead is effective to control springback also. The effectiveness of local forming and angle calibration is verified by experimental.