• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.138-143
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• 1996

The 3-dimensional complex parts which construct automobile and aerospace parts are very difficult to polish by traditional polishing method. Abrasive flow machining is useful to polish an internal or external surface of the 3-dimensional shape part. In this paper media flow between workpiece and tooling part has been simulated and the charateristics of abrasive flow machining process have been analyzed according to various machining conditions by calculating the material removal and surface roughness.

• Lingua Humanitatis
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• v.2 no.1
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• pp.303-314
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• 2002

The main purpose of this paper is to show how Jespersen analyzed the date of English compound related with reduplication. Especially dealing with the compound words he classified the examples related with reduplication as a separate part and attempted to account for the patters based on the structure of the first syllable constituting the initial part of the second element in a compound word. 1 tried to explain the peculiar shape of the reduplicational pattern in English based on the Optimality Theory, especially the method of 'melodic overwriting' of McCarthy(1997). According to the analysis the initial part of the second element of a compound has to be stipulated before reduplication occurs. When the reduplicant has to be decided at the first syllable of the second element, the form which is stipulated to take the position comes to appear at the post instead of repeating the morphemic shape of the first syllable at the first element of the word.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.159-163
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• 2004

The KNR(Korean National Railroad) has a speed limit regulation(130km/h) for the train passing the turnout to guarantee a safety. Since that speed is set as below the maximum commercial speed(140km/h), it has been regarded as a major factor to obstacle the total efficiency. The crossing rail part of the turnout system is formed into a antisymmetric, furthermore, there are several discontinuous part. Thus, measuring the strain signals of this part is impossible actually and it must be in the most difficult work related the turnout research. In this research, the program that can anticipate the signals at the various conditions with considering its own shape was developed and the preciousness of its results had been examined by comparing analyzed and measured ones at the other parts. The simulation was performed with varying the factors such as train speed and contact depth. As a results, it was proved that the regulation was not useless and very important guide at least up to now.

• Transactions of Materials Processing
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• v.26 no.6
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• pp.372-377
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• 2017

In this paper, an effective design procedure was proposed to design the rib of die structure for auto-body member with ultra-high strength steel (UHSS) having ultimate tensile strength (UTS) of 1.5 GPa. From analysis results of the die structure, structural safety of the die was evaluated with information such as displacement and von-Mises stress. It was concluded that the casting part could be designed in order to reduce tool deformation. A design guideline of the die structure was proposed, especially for the rib structure in the casting part with an optimization scheme and local reinforcement concept. Simulation result following the design guideline fully explained that stability of the tool structure could be obtained simultaneously with weight minimization.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.182-186
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• 1996

In this work, a method is described to investigate the progressive and compound process in the coining and piercing operation for given conditions and parameters, using the FEM simulation and model experiment. The effect of the die shape on the compound process is established, and the die shape depends on the position of coining die and the width of the part coined. It is found that Progressive process is better than compound process, since material's filling into the die is not completed and the higher stress acts on the edge of the punch according to width being increased.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.320-323
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• 2002

This paper discusses process design of cold forging for inner tooth part, drum clutch. In respect to high productivity, low material consumption and low piece production costs, Metal forming has more merits than machining process. Net shape forming is huh technology which satisfies merits of metal forming and achieves high accuracy. Recently, net shape forming method widely applied because of high productivity, low material consumption and low piece production costs using press. In this study, the method which accuracy of drum clutch, automatic transmission pin, can be improved is discussed. First, process variables for process design of drum clutch are selected, and then process design is accomplished using forming analysis method. from forming analysis, forming load, stress, unfiling part is obtained. and comparing these results, optimal process design can be determined.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.54-60
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• 2014

In industry, several casting process are widely used to manufacture complex and accurate blank part of hard materials such as aluminum, casting steels, bronze and magnesium alloys which are difficult to manufacture in a blank shape. Even if the casting process does not high accuracy superior surface characteristics other machining process, the casting process is widely used in manufacturing blank part. Furthermore, it is difficult to select appropriate casting process a part among several casting process. for effective selection different process, a careful decision given casting application is necessary. An appropriate casting for a given material and shape condition must be selected for novice engineers in industry. In this paper, an expert system based on an analytic network process(ANP) is suggested for best selection of casting considering a prior interdependency effect among various factors such as material, geometry, process capability, economy and equipment.

• 연구논문집
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• s.31
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• pp.101-112
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• 2001

A Twisting machine is to twist yarns for improving yarn stiffness. After twisting yarns, the twisting machine is winding yarn at a bobbin. Traverse cam is main part of winding yarn part. In other to improve twisting machine performance and stability, improve traverse cam part. Original displacement curves of traverse cam has two problems. One is that displacement curve has a vertex point the other is that velocity curve is discontinue point. So that, in this paper proposes a modified displacement curves of traverse cam and new shape design method of the traverse cam using the relative velocity method[1]. The relative velocity method calculates the relative velocity of the follower versus the cam at a center of roller, and then determines a contact point by using the geometric relationship and the kinematical constraints. Finally, we present to compare two designed cam. One is designed using original displacement curves the other is using modified displacement curve.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.241-244
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• 2009

We studied the optimization method of sensing part for measuring heart rate in wrist. In order to know optimum structure of sensing part, we measured the heart rate signal by changing the shape and size of sensor pad structure and the thickness of silicon. The shapes of structure using in experiment are Empty, Rectangle, Embossing, Length, Width. We were compared the amplitude of output signal about each shape when thickness of silicon pad is increasing from 0 to 7 mm by 1 mm.

• Journal of Korean Society of Forest Science
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• v.73 no.1
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• pp.21-32
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• 1986

This study was done to classify 15 species in the genus Acer through tracking of the changing shape of the vascular branch from the base part to the terminal part of petiole by the anatomical method. The basic vascular branches were 3 ea, except A. mandshuricum 3-4 ea. The vascular bundle was separated, moved and connected from the base part to the terminal part of petiol, the number of separated vascular branch was 11-32 ea., the number of connected vascular branch was 0-17 ea., and the ratio of the separated vascular branch to the connected was 0.00-8.00. The maximum number of vascular branch in No, 39 of cross section part was observed in 12 species; A. ginnala and A. buergerianum were No. 11, A. truncatum and A. platanoides were No. 13, A. saccharium was No. 26. The number of the connected vascular branches with the main vascular branch were 0-6, while the number of the separated vascular branch were 0-7. On the ratio of separation to connection of the base vascular branch; "A", "B" and "C", the symmetrical shapes on the basis of "B" were A>BC, AB>C shape. The classical groups by the development of main vascular branch formation were obtained 7 groups of "a" through "g" shape. Especially, A. negundo and A. saccharinum were shown to have central vascular branches with unique changing patterns.