• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.5
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• pp.72-78
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• 2011

Currently, for the damper case, the material produced by cast/forge welding is mechanically processed and then the final product is mass-produced. By cutting the cast/forge welded material, the issues of excessive cutting time, multiple process production, and a large amount of chips (40% loss from the original material) arise, causing increased production cost and reduced profitability. Thus, in this study, the incremental forming technology which generates no chips was applied in production. Analysis was excuted for 1st and 2nd works by change of tool diameter and working tool. For this, 3D molding and analysis were executed, which was applied to the processing the result, successful processing could be achieved through a few trials of molding processing according to tool forming and rotation counts.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.95-98
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• 2005

Shafts having asymmetry or odd number of symmetry in the cross-section can not be simply manufactured by conventional incremental radial forging. In order to manufacture such shafts, the new concept of incremental forging with one punch and a flexible fixture is developed by suggesting a flexible fixture, instead of two opposed punches used in radial forging, so that the flexible fixture only supports the workpiece while the punch is moving during forming. A new flexible fixture is designed using the steel shots and vacuum technology. An equilateral triangular cross-section is selected as the sample shape to be manufactured by the proposed manufacturing method. The desired triangular cross-sectional shaft is manufactured with the errors of $3.0\%$.

• Structural Engineering and Mechanics
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• v.49 no.5
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• pp.645-660
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• 2014

This paper presents the design and project of an innovative concept for a Single Point Incremental Forming (SPIF) Machine. Nowadays, equipment currently available for conducting SPIF result mostly from the adaptation of conventional CNC machine tools that results in a limited range of applications in terms of materials and geometries. There is also a limited market supply of equipment dedicated to Incremental Sheet Forming (ISF), that are costly considering low batches, making it unattractive for industry. Other factors impairing a quicker spread of SPIF are large forming times and poor geometrical accuracy of parts. The following sections will depict the development of a new equipment, designed to overcome some of the limitations of machines currently used, allowing the development of a sounding basis for further studies on the particular features of this process. The equipment here described possesses six-degrees-of freedom for the tool, for the sake of improved flexibility in terms of achievable tool-paths and an extra stiffness provided by a parallel kinematics scheme. A brief state of the art about the existing SPIF machines is provided to support the project's guidelines.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.84-93
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• 2020

This study had two aims (1) to explore the trajectory of family functioning (flexibility and cohesion) in the mothers' perspective and classify it according to the development of their child, and (2) to examine the differences in children's self-esteem as well the internal and external behavioral problems based on the latent groups. A total of 1,348 mothers and their children who participated in the survey in 2013 through to 2017 were analyzed. The group was subdivided into low incremental, average incremental, average-above incremental, and high unchanged groups according to the flexibility, and into low incremental, average incremental, decremental, high incremental, and above-high unchanged groups in terms of cohesion. From 2015 to 2017, the self-esteem of elementary school-age children showed differences depending on the flexibility and cohesion of family functioning; children in the high-unchanged group of flexibility and the above-high unchanged group of cohesion showed high self-esteem. Behavior problems of early childhood and elementary school-age children varied according to the latent classes of flexibility and the cohesion of family functioning. Children in low incremental and average incremental groups of flexibility and low incremental, average incremental, and decremental groups of cohesion showed more internal and external behavioral problems. These findings suggest that family functioning has significant effects on the psychological aspects of children.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3378-3393
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• 2014

We have witnessed the rapid development of information technology in recent years. One of the key phenomena is the fast, near-exponential increase of data. Consequently, most of the traditional data classification methods fail to meet the dynamic and real-time demands of today's data processing and analyzing needs--especially for continuous data streams. This paper proposes an improved incremental learning algorithm for a large-scale data stream, which is based on SVM (Support Vector Machine) and is named DS-IILS. The DS-IILS takes the load condition of the entire system and the node performance into consideration to improve efficiency. The threshold of the distance to the optimal separating hyperplane is given in the DS-IILS algorithm. The samples of the history sample set and the incremental sample set that are within the scope of the threshold are all reserved. These reserved samples are treated as the training sample set. To design a more accurate classifier, the effects of the data volumes of the history sample set and the incremental sample set are handled by weighted processing. Finally, the algorithm is implemented in a cloud computing system and is applied to study user behaviors. The results of the experiment are provided and compared with other incremental learning algorithms. The results show that the DS-IILS can improve training efficiency and guarantee relatively high classification accuracy at the same time, which is consistent with the theoretical analysis.

• Journal of the Korean Professional Engineers Association
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• v.20 no.4
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• pp.42-44
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• 1987

• Journal of the Korean Society for Precision Engineering
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• v.34 no.3
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• pp.217-224
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• 2017

Structural pipe frames are usually manufactured by complex processes, in which a straight pipe with an arbitrary cross-section is prepared via a roll-forming process and then fabricated into three-dimensional shapes by a secondary process. These conventional processes have low productivity. Recently, the inefficiency of the conventional processes has created the need to develop new forming technologies. In this study, a new incremental roll-forming process is proposed. The study is aimed at verifying the feasibility of the proposed process and investigating the fundamental process parameters using finite-element simulations. The result of the simulation demonstrates that the proposed process can be used effectively for cold fabrication of various shapes of structural pipes. In addition, the result of the investigation of parameters shows that the forming amount, number of roll sets, and distance between roll sets are significant factors to be considered in resolving dimensional errors of the product and improving its quality.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1685-1696
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• 1994

In this paper, a new forming process of the large-size forgings within the limit of forming loads is developed by introducing the incremental forging method and combined forming method. For the development of the forming process, various related processes are proposed and modelling experiments of plasticine and corresponding numerical simulation ate carried out. Thus, an optimal process considering the productivity and economical efficiency is recommended from the study of formability and forming loads, etc. The selected process is subjected to a modelling experiment of lead and 1/7 scale prototype experiment of the real material so as to verify the effectiveness of a selected process as well as to determine the design parameters. The developed process is then applied the forging product of dome shape. Dome-shaped forgings can be produced by the developed process within the limit loads and with the simple tools.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.11
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• pp.1931-1942
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• 1997

A new load/displacement parameter method is developed for the cases that loads are applied to one or more points, and displacements of a structure are controlled at one or more points sinultaneously. The procedure exploits a generalized Riks method, which utilizes load/displacement parameters as scaling factors in order to analyze the post-buckling phenomena including snap-through or snap-back. A convergence characteristic is improved by employing new relaxation factors in incremental displacement parameter, particularly at the region where exhibits severe numerical instability. The improved performance is illustrated by means of numerical example.

• Journal of Internet Computing and Services
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• v.5 no.5
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• pp.119-127
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• 2004

As, the development of language-based programming environment, a study on incremental parsing has become an essential part. The purpose of this paper is to show the more efficient incremental parsing algorithm than earlier one that demands parsing speed and memorizing space too much. This paper suggests the threaded tree construction algorithm not using stack. In addition, to remove the reparsing process, it proposes the algorithm for creation node and construction incremental threaded tree not using stack.