• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.641-645
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• 2002

In case of aluminum-cased battery, The ratio of height and base of square is generally above the ten times, square-shaped and problem of non-axis symmetry. It is typical model to set up the analysis method of finite element. The reliable analysis of finite element method is suggested, which is used to investigate the possibility that multi-stage deep drawing and ironing used currently is replaced by backward impact extrusion favorable in the respect of cost production and productivity. The influence of parameter was analyzed and compared, which was considered to analyze the process of large deformation plasticity such as extrusion. Die and billet was made as the same shape of finite element model. The results of experiment show good forming without the rupture and wrinkles with the optimum velocity 100mm/sec obtained by analysis.

• Korean Journal of Veterinary Service
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• v.30 no.2
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• pp.283-286
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• 2007

Fungus generally doesn't produce toxic or harmful substances so it has low chances to cause food poisoning. However it leads to change appearance, odor and characteristics of the contaminated foods and result in sanitary risk problems. Therefore the contamination of fungi should be prevented since they are not proper for human consumption. Green fungi with white outline raised from the air cell of cooked eggs which were collected by Gyeongi Livestock Veterinary Service in August, 2006. The results came out after the cultivation using Sabouraud's Dextrose Agar(SDA). The conidium appeared white and monospore, the shape of colony was round and oval. Conidiophore was brown and granulated and wrinkles and formed. It was confirmed as Aspergillus nidulans based on the dying using Lactophenol cotton blue, the observation of septum and vesicle from the grown spores, and rDNA sequencing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.12
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• pp.940-949
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• 2013

In this paper, wrinkle reduction design was studied for triangular sail. Wrinkles in the solar sail membrane can change the load path and surface topology which may have an adverse effect on propulsion performance and controllability. In this study, wrinkle reduction strategies of adjusting cable angle, catenary and catenary-wire schemes were considered and the design parameters for wrinkle reduction were systematically investigated.

• Transactions of Materials Processing
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• v.9 no.2
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• pp.128-139
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• 2000

Wrinkling is one of the major defects in sheet metal products and may be also attributable to the wear of the tool. The initiation and growth of wrinkles are influenced by many factors such as stress state, mechanical properties of the sheet material, geometry of the body, and contact condition. It is difficult to analyze the wrinkling initiation and growth considering the factors because the effects of the factors are very complex and the wrinkling behavior may show a wide variation for small deviations of the factors. In this study, the bifurcation theory is introduced for the finite element analysis of wrinkling initiation and growth. All the above mentioned factors are conveniently considered by the finite element method. The finite element formulation is based on the incremental deformation theory and elastic-plastic elements considering the planar anisotropy of the sheet metal. The proposed method is verified by employing a column buckling problem. And then, the initiation and growth of wrinkling in deep drawing of cylindrical cup are analyzed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.242-245
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• 2007

In the present investigation, the multi-stage warm drawing process was applied to the magnesium alloy AZ31 sheet to examine the feasibility of multi-stage forming process as a high formability product making process. For that purpose, a multi-stage drawing die system with heating module was developed, and the AZ31 sheets of different sizes were consecutively drawn by the multi-stage drawing die. The obtained drawn cups of AZ31 showed that the multi-stage drawing provided the better formability than the single stage drawing in terms of drawing depth without cup defects such as wrinkles or fractures. The sheet formability improvement by using the multi-stage drawing die system against the single stage was also analyzed in terms of the finite element analysis of material state variables evolution.

• Journal of Industrial Technology
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• v.1
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• pp.9-16
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• 1981

In the steel Structural design, buckling is the main factor to determine size, particularly in compression member. Buckling may sometimes occur in the form of wrinkles in thin elements, such as webs, flanges, and other parts that make up a section. This phenomenon is called local buckling. The strength of the steel and the rigidity of the frame are considerably deteriorated by the local buckling. The specimens used for this experiments, H-Shape Steel beams composed by fillet-welding, are dessified classified into two groups, ie one for web test and another for flange fest. The aim of this study is to define the influences by the local bucking on the vesisting forces, deformation and the phenomena of the internal forces in the section, and to collect the basic data for design of steel beams.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.3
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• pp.117-122
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• 2004

In order to help understand the growth mechanisms of demetallization due to self healing on a metallized polypropylene film (MPPF), several types of defects affecting the breakdown of capacitor dielectrics were made. The breakdown voltages with dielectric thickness were measured at self healing and the demetallized area was evaluated for all of the self healing events. The shapes and growth processes of the demetallized spots on the dielectrics were investigated. As a result, self healing mainly occurred at pin tips, wrinkle sides, and junctions of the wrinkles, and the breakdown voltages strongly depended on the thickness of the dielectrics. In addition, the demetallized area due to self healing was governed by the breakdown voltage and it has been mainly grown by some factors; the applied voltage; the consequent self healing events taking place at the circumference of the original self healing spots; the conductive paths formed by two or more self healing spots and by the consequent self healing spots.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.06a
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• pp.102-109
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• 1998

In this study, the side panels were developed using the laser-welded Tailored Blanks (TB) with both the same thickness and the different thickness. At first, the formability of the same thickness T.B was investigated to be compared with one of the non welded panel with respect to weldline movements and strain distribution on blank during the stamping. Based on these results, we selected candidates of T.B with different thickness for stamping experiments. That is, we determined the weld line positions and the die step. Then we made some stamping tryouts with selected types of blank designs to investigate the formability of T.B with different thickness. During the tryouts, the wrinkles were found in the a-pillar lower region which is under the deformation mode of the shrink flange. In the b-pillar region, the fractures were found also, these defects have been reduced and corrected by controlling the blank design and the die faces and process pamameters.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2007.11a
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• pp.117-126
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• 2007

Cosmetics have mild activity on the human body, and intended to be used for cleaning, beautifying the human body, and also keeping healthy skin or hair, promoting attractiveness or altering the appearance. Functional cosmetics, in other words cosmeceuticals, are restricted for following functions: 1) Whiten the skin tone by preventing deposition of melanin pigmentation or lightening of the color of melanin of skin, 2) alleviate or improve wrinkles of the skin, and 3) protect the skin from the ultra violet rays from the sun. According to the functions of the functional cosmetics, skin whitening products, anti-wrinkle products, and suntan & sunscreen products are manufactured. In order to manufacture and import the functional cosmetics in Korea, the approval process in KFDA is necessary. The review process in KFDA is performed based on The Korea Food and Drug Administration Notification 2007-44, "The Regulation of Reviewing the Functional Cosmetics" (June 29, 2007). Only after the approval of KFDA, functional cosmetics are allowed to advertise to the consumers for their functionality.

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