• Journal of Korean Neurosurgical Society
• /
• 제42권4호
• /
• pp.346-348
• /
• 2007

Surgical elevation of the depressed bone is known to be the conventional treatment usually recommended for a simple depressed skull fracture in the adult or pediatric age. The authors introduce, however, a case of depressed skull fracture in an infant which was elevated by means of a cup of breast pump and a suction generator without surgical elevation. In our case, without surgery, a 'cup-shaped' depressed skull fracture in an infant was safely elevated with no neurological signs. This method is considered a simple, effective, safe, and alternative procedure in an infant with simple depressed skull fracture.

• 소성∙가공
• /
• 제10권6호
• /
• pp.471-477
• /
• 2001

Milli-structure components are classified as a component group whose size is between macro and micro scales, that is, about smaller than 20mm and larger than 1mm. The forming of these components has a typical phenomenon of bulk deformation with thin sheets because of the forming size. In this study, milli-structure rectangular cup drawing is analyzed and measured using the finite element method and experiments. Special containers or cases of cellular phone vibrator to save installation space are produced by rectangular-shaped drawing. A systematic approach is established for the design and the experiment of the forming processes for rectangular milli-structure cases. To verify the simulation results, the experimental investigations were also carried out on a real industrial product. The numerical analysis by FEM shows good agreement with the experimental results in view of the deformation shape of the product.

• 소성∙가공
• /
• 제4권4호
• /
• pp.302-321
• /
• 1995

A method of determining an optimum blank shape for the non-circular deep drawing process is investigated. The rigid-plastic finite element method is introduced and the computer program code is developed. The ideal shape of a drawn cup with uniform wall height is assumed and metal flow is traced back-ward step by step to predict an initial blank shape of the ideal cup. For examples of the non-circular deep drawing products, three cases of drawn cup with quadrilateral punch shape are considered and optimum blank shapes for each case are proposed and compared with experimental results.

• 한국의류학회지
• /
• 제25권4호
• /
• pp.719-730
• /
• 2001

The purpose of this study is to develop the basic patterns of adult womens brassiere therewith, provide for some basic data useful to the brassiere manufacturing which are both functional and fitting. For this purpose, 220 adults women(aged between 20 and 59) were sampled to be measured for their body sizes and tested for their brassiere wearing. The collected data were statistically processed using the SAS 6.12 for Means, Standard Deviation, etc. The results of this study can be summarized as follows; 1. In order to develop the basic patterns of adult womens brassieres, 75A size was selected out of 12 size combination(3 women per 75A size) and then, their brassiere fitting was tested. As a result, the fronts of the basic patterns were found to have such problems as undone front center, poor levelling of upper cups bottom line or lower cups top line, poor shape of upper cups outside top line and shoulder strip position. On the other hand, n the rear side of the basic patterns, the central part of the wing was slightly lifted, while the wing width and straps interval did not befit the full-cup brassiere. The result of this first brassiere fitting test showed that the functionality and aesthetics of the basic pattern brassieres were more or less satisfactory, and thus, the problems were address for the second test. In the second test, the aesthetics, breast-shaping effect and functionality of the basic pattern brassieres were much improved. 2. The basic patterns of adult womens brassieres were characterized by a round cup wired as well as a full cup embracing the entire breasts. Each basic pattern which consisted of upper and lower cups was shaped \"straight(-)\". The basic sizes adopted at the first design stage (see fig. 1-2) was 75A of which was designed as upper foundation basic pattern. At the second stage, the upper body foundation pattern were used to design lower cup, upper cup, front panel and wing in their order.(see fig. 3-5, fig. 8)5, fig. 8)

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 추계학술대회논문집
• /
• pp.26-29
• /
• 1999

Process design for elliptically shaped deep drawing products is various according to size shape and specification of products. This study presents two approaches to design the preform that is a key process for elliptically shaped products, One of these is that cross-section of punch is circular. Another is that for the improvement of characteristics for final products the cross-section of the punch is similar to rectangular shape. After forming the preform process design of top-part drawing is the same. In the study blank shape and dimension are obtained by applying a numerical formula and surface area constancy.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 추계학술대회 논문집
• /
• pp.66-70
• /
• 2008

In this study, the formability of AZ31B magnesium alloy sheets was investigated by the analytical and experimental approaches. Tensile tests and limit dome height tests were rallied out at several temperatures between $25^{\circ}C$ and $300^{\circ}C$ to obtain the mechanical properties and forming limit diagram (FLD). The FLD-based criterion considering the strain-path and the blank temperature was used to predict the forming limit in a deep-drawing process of cross-shaped cup by finite element analysis. This criterion proved to be very useful in determining the optimal process conditions such as blank shape, punch velocity, minimum comer radius, fillet size, and so on, through the comparison between FEA and experimental data. In particular, the temperature of each tool that provided the best formability of the blank was determined by coupled temperature-deformation analyses. A practical method that can greatly reduce the forming time by increasing the punch speed during the forming process was suggested.

• International Journal of Precision Engineering and Manufacturing
• /
• 제4권3호
• /
• pp.48-54
• /
• 2003

This paper deals with mirror grinding of a small-sized aspherical lens by a resin bonded diamond spherical wheel. Up to now, a spherical lens has been used for the lens of the optical communication optical part. However, recently, aspherical optical parts are mainly used in order to attempt the improvement in image quality and miniaturization of the optical device. It is possible to manufacture the aspherical lens which is presently being used in optical instrument through ultra-precision machining technology. Also, to realize compactness, efforts are being made to produce a micro aspherical lens, fur which the development of a high-precision, micro molding die is inevitable. Therefore, extensive research is being done on methods of producing a micro aspherical surface by high-precision grinding. In this paper, the spherical wheel was trued by cup-shaped truer and tool path was calculated by the radius of curvature of the wheel after truing and dressing. Then in the aspherical grinding experiment, WC material which is used as a melding die for the small-sized aspherical lens was ground. The results showed that a form accuracy of 0.1918 $\mu\textrm{m}$ P-V and a surface roughness of 0.064 $\mu\textrm{m}$ Rmax could be achieved.

• Applied Microscopy
• /
• 제25권4호
• /
• pp.9-16
• /
• 1995

Ultrastructure of stemmata(larval eye) of 5th-instar larval in cabbage butterfly, Pieris rapae L, was morphologically investigated with light microscope, scanning electron microscope and transmission electron microscope Six stemmata are on each side of the head. Stemmata V and VI have a Y-shaped sulcus on the surface of their corneal lenses, the others have a columnar shaped process and smooth globular surface. The visual type of stemmata is resembled a single ommatidium of compound eye. The dioptric apparatus are a biconvex shaped cornea and crystalline cone. As a photoreceptor, each stemmata consists of 7 retinular cells arranged into 2 tiers. The first ceil tier of 3 distal retinular cells has formed a V-shaped cup rhabdome and the second cell tier of 4 basal retinular cells has formed a H-shaped fused rhabdome. Each retinular cell filled with pigment granules and contained multivesiclular bodies, coated vesicle and common organelles. The peripheral parts of retinular cells are enveloped by neuroglia cells and retinular cells are surrounded by 3 corneagenous cells. The distal portions of the 3 corneagenous cells contact each other, but the Y-shaped stemmata is separated from each other immediately under the cornea. The 7 axons from each stemma congregate into a bundle and each 7-axon group joins to form a stemmatal nerve, consisting of 42 retinular axons.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 춘계학술대회 논문집
• /
• pp.370-373
• /
• 2008

It is known that the temperatures of die, punch, holder and punch pad need to be kept different to get better formability in Mg sheet forming processes. Heating and cooling channels are usually equipped in each tool to assign different temperature. This study focused on the optimal design of the heating and cooling channels for a cross-shaped deep drawing die set. While the die and blankholder were heated to and kept at $250^{\circ}C$ by using heat cartridges, the punch and punch pad were kept at much lower temperature than that of the die and blankholder by water circulating through cooling channels. All the approaches were done by numerical analyses, aiming to maximize the cup height and to minimize the punch corner radius without any failure.

• Journal of Advanced Marine Engineering and Technology
• /
• 제39권7호
• /
• pp.729-734
• /
• 2015

본 연구는 내경부에 깊은 구멍이 있는 컵형상의 대형단조품을 형단조와 자유단조 공법을 복합하여 성형하기 위한 단조공법 개발에 관한 것이다. 제안된 단조공법은 형단조를 이용하여 예비성형체를 성형하고 코깅 공법을 이용하여 후방압출 형상을 성형하는 방법이다. 유한요소해석에서 제안된 공법이 후방압출공법에 비하여 낮은 성형하중으로 더 높은 유효변형율을 나타내었다. 제안된 공법으로 시제품을 제작하여 내부품질이 양호한 제품을 적은 용량을 프레스로 성형할 수 있음을 확인하여 제안 공법의 타당성을 검증하였다.