• Transactions of Materials Processing
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• v.20 no.6
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• pp.461-467
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• 2011

An artificial body force method is presented to accurately simulate drawing processes in which back pressing is exerted. A rigid-plastic finite element method is applied together with a numerical scheme to eliminate the numerically incurred plastic deformation in rigid or elastic region, which significantly influences simulation results because it eventually changes reduction of area in drawing. Back tension or compression is applied by body force at the rear part of material to obtain numerically stable solution. Two typical examples are shown, a drawing process with back tension applied and a tube drawing with a fixed plug and back pressing applied.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.338-343
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• 2007

We presented a special method of forging hollow shafts of hard-to-form material, which is composed of piercing with back pressing and hollow shaft extrusion. The presented method was applied to cold forging a bushing of an excavator. The finite element simulation technology was employed for developing the optimized process and the predictions were compared with the experiments. The method was also applied to an automotive part and was verified to be powerful for manufacturing the cold forged hollow shafts of the hard-to-form materials.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.470-473
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• 2009

In this paper, back pressure forging processes of which back pressures are exerted by mechanical forces including spring reaction are simulated by three-dimensional finite element method. The basic three-dimensional approach extended from two-dimensional approach is accounted for. An axisymmetric backward and forward extrusion process having a back pressing die, which is exposed to oscillation of forming load due to variation of reduction ratios with stroke and its related frequent variation of major deforming region, is simulated by both two and three dimensional approaches to justify the presented approach by their comparison. A three-dimensional forging process having a back pressing die attached to the punch by a mechanical spring is simulated and the results are investigated to reveal accuracy of the presented approach.

• Transactions of Materials Processing
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• v.19 no.5
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• pp.273-276
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• 2010

In this paper, back pressure forging processes of which back pressures are exerted by mechanical forces including spring reaction are simulated by three-dimensional finite element method. The basic three-dimensional approach extended from two-dimensional approach is accounted for. An axisymmetric backward and forward extrusion process having a back pressing die, which is exposed to oscillation of forming load due to variation of reduction ratios with stroke and its related frequent variation of major deforming region, is simulated by both two and three dimensional approaches to justify the presented approach by their comparison. A three-dimensional forging process having a back pressing die attached to the punch by a mechanical spring is simulated and the results are investigated to reveal accuracy of the presented approach.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.02a
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• pp.148-153
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• 2002

Spring back is the typical deformation of pressing process. This phenomenon much affects productivity and especially Incurs the unexpected result of assembling process. We have been searching for the various of the spring back to minimize spring back effect, because it is inevitable.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.6
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• pp.528-538
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• 2011

As a forming method for curved hull plates more efficient than the flame bending, mechanical bending using multi point press forming and die-less forming is discussed in this paper. the mechanical forming is a flexible manufacturing system for automatically forming of hull parts. It is especially suited to varied curved parts. This paper discusses a multiple point pressing machine composed of a pair of reconfigurable punches in order to achieve the rapid forming of curved hull plates using division forming and presents how forming information is obtained from the given design surface. Although the mechanical forming can be efficient in the metal forming, spring back after pressing is a phenomenon which must be carefully considered when quantifying the process variables. If the spring back is not accurately controlled, the fabricated shell plate cannot meet assembly tolerance. This paper describes the principles to calculate the proper stroke of each punch at the divided areas. the strokes are determined by an iterative process of sequential pressing and spring back compensation from an unfolded flat shape to its given design surface. FEA(finite element analysis) is used to simulate the spring back of the plate and the IDA(iterative displacement adjustment) method adjusts the offset of pressing punches from the deformation results and the design surface. The shape deviations of two surfaces due to spring back are compensated by integrated system using FEA and IDA method. For the practical application, It is aimed to develop an integrated system that can automatically perform the compensation process and calculate strokes of punches of the double sides' reconfigurable multiple-press machine and some experimental results obtained with mechanical bending are presented.

• The Journal of Dong Guk Oriental Medicine
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• v.8 no.2
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• pp.155-173
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• 2000

The diagnosis in Oriental medicine is done by inspection, auscultation and olfaction, interrogation, four diagnostics of pulse feeling and palpation, and various system of identification like identification according to Qi(vital energy), Xue and body fluids, identification according to fair principles, identification according to principles of Wei, Qi, Ying and Xue, identification according to Sanjiao(the triple heater), identification according to four type physical constitution. Sometimes, symptoms and diagnosis techniques according to symptoms is selectively applied for the diagnosis. Among them the pulse feeling and palpation diagnosis technique using the sense of finger and palm of the hand is divided into feeling of pulse and palpation and pressing maneuver. Pressing maneuver is a diagnosis technique pressing and rubbing the affected part in order to attain data of identification including inside and outside condition of the body with regard to the nature, condition and relative seriousness of disease. There are palpation of the skin, palpation the hand and foot, palpation the chest and the abdomen, palpation shu points in pressing maneuver. The diagnosis of the Back Shu points is a technique to examine the change of disease condition from pressure ache, spontaneous ache, tension, relaxation, solidification revealed through channels and collaterals. I investigates starting disease and an attack of disease of twelve pulse and pulse condition through the study relative to the substance and technique of pressing maneuver, and adjusts diagnosis techniques of a region for acupuncture and matters to be attended. The conclusions are as follows. 1. The Shu or stream points in which pathogenic factors go are important to medical treatment of dormant diseases like bowels disease, cold symptom complex and insufficiency symptom complex. 2. Disease classified by system is diagnosed by the condition of process part like pro-trusion, cave-in, tension, relaxation, pressure ache through palpating the Shu or stream points, that is pressing upward or downward left and right sides of the backbone process by hands. 3. In real clinic pressing maneuver of one's back side is very important to patient's diagnosis treatment. Thus, pressing maneuver of one's back side have to be done without omission. 4. Diagnosis must be accomplished through the perception about the diversity of diagnosis technique of bowels disease, the exact knowledge about pressing maneuver of one's back side for enlargement of treatment range and rising of treatment rate, and pressing maneuver of the Shu or the stream points.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.804-807
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• 1997

Recently equal-channel angular pressing (ECAP) has been employed to produce ultra-fine grain size materials. In this paper pure-Zirconium is considered due to its applicability to nuclear reactors. Among many process parameters of ECAP frictional effect on the plastic deformation of die has been investigated. The back pressure effect due to friction increases the stress level of die especially at the crossing area of channels, which may result in plastic deformation of die. The finite element method has been employed to investigate this issue.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.112-114
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• 2010

Mainly through the pervasive emergence of portable devices (laptops, PDAs, now iPods), the screen arts, that is, the cinematic arts has suffered the loss of what constitutes the core of its existence: the theatre and theatre-audience. This paper discusses cinema's distinct place and significance in culture and its difference from television and other forms of mass media. The most pressing question at hand would be, "how do you bring back attention to the medium that is distinctly cinematic?" "How do you bring people back to the theatres?" This paper argues that cinema, and the film industry as a whole must push for a technological leap that is in conjunction with culture. With mentioning of the rapid development of 3D technologies in the moving images, this paper proposes that such technological novelties and innovation are necessary conditions for a new kind of film culture to emerge.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.538-543
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• 2008

A roller with a shaft and hot oil paths for pressing electrodes of polymer batteries were modeled and analyzed by FEM. There are many hot oil tubes in the roller and shaft, through which $72^{\circ}C$ hot oil flows for heating the surface of a roller and shaft. Thermal deformations and temperatures distributions of the roller and shaft were calculated and a convection boundary condition on surfaces was used. The influence of existence of a groove in the shaft on the flatness of a roller surface caused by thermal deformation was investigated. In addition, the amount of spring-back of electrodes under vacuum pressure and heating was calculated after the hot rolling process. It was shown from this study that the groove in one shaft had a favorable effect on the surface flatness.