• Design & Manufacturing
• /
• 제12권3호
• /
• pp.13-18
• /
• 2018

Flexible display tends to grow every year, It tends to be larger, slimmer, and higher in image quality. Therefore, accuracy is required in the manufacturing process of each part. In the curved monitor, the bottom chassis has a structure to which other parts can be attached. The accuracy of the curvature which the bottom chassis of the curve monitor monitors has is important. If the curvature error is large, serious defects such as cracks, warpage, twisting and the like occur. Curvature was analyzed using 3D scanner. In the Forming process and Restriking process steps, spring go occurred, and spring back occurred in the Notching process and Bending process steps. Even in the same process, it was confirmed that the curvature value varied depending on the formed shape.

• 한국방재학회 논문집
• /
• 제4권4호
• /
• pp.13-19
• /
• 2004

본 연구에서는 만곡부 피해지점을 조사함에 있어 피해가 극심하게 발생한 유역을 선택하여, 만곡부의 피해 관련 인자들로 추정되는 인자들에 대하여 2002년 강릉시 남대천 유역을 대상으로 조사하였다. 선정 조사 된 하천은 9개이며 채택된 피해지점은 23개 지점이다. 제시된 회귀직선식에서는 사행파장과 하천연장, 사행대와 하천연장의 상관계수가 가장 높은 것으로 나타났다. 또한 분석된 특성인자들 중에 하상경사와 사행대, 곡률비와 하폭의 관계를 포락곡선으로 제시하고자 하였다. 이것은 만곡부의 수해복구설계 및 하천 정비시 재해예방에 도움이 될 것이다.

• 한국해양공학회지
• /
• 제29권4호
• /
• pp.322-330
• /
• 2015

As a new technical approach, a hydraulic and magnetic clamp device was developed to realize a magnetic clamp crane system by simultaneously actuating eight individual hydraulic cylinders. In this approach, an Sr-type of ferritic permanent magnet (SrO· 6Fe₂O₃), rather than the previous electromagnet, was utilized for the purpose of lifting and transporting the large curved steel plates used for manufacturing ships. This study had the goal of developing and manufacturing a hydraulic, magnetic clamp prototype composed of three main parts, including the base frame, cylinder joint, and magnet joint, in order to safely transport curved steel plates. Furthermore, this research included a performance evaluation of the manufactured prototype and acquired the purposed quantity value in the performance test. The most significant item, the magnetic adhesive force (G), was evaluated in a performance test, which utilized a ferritic permanent magnet (Sr type) with 3700~4000 G of residual induction (Br) and 2640/2770 Oe of coercive force (Hc). In particular, relevant items such as the hoist tension (kN), transportation time (s), and applied load (Kgf) on the hydraulic cylinders were also evaluated in order to determine the optimum values.

• 대한조선학회논문집
• /
• 제48권6호
• /
• pp.528-538
• /
• 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.

• 대한기계학회논문집A
• /
• 제20권6호
• /
• pp.1743-1752
• /
• 1996

In this paper, a precision inspection technique using CAD/CAI integration is proposed for the parts having very thin and sharp 3 dimensional curve features. The technique begings with feature reconstruction of turbine blades which have 3 dimensional combined feometry, such as splines, and thin circles. The alifnment procedures consistsb of two phases-rough and fine phases : rough phase alignment is based on the conventional 6 point5s probing on the clear cut surfacef, and fine phase alignment is based on the intial measurement on the 3 dimensional curved parts using an lterative measurement feed-back least sequares technique for alignment. Forf the analysis of profile tolerance of parts, the actual measured points are obtained by finding the closet points on the CAD geometry by the developed subdivision technique and the Tschebycheff norm is applied based on iterative fashion, giving accurate profile tolerance value. The developed inspection technique is applied to practical procedures of blade manufacturing and demonstrated high performance.

• 대한수학회보
• /
• 제35권3호
• /
• pp.533-545
• /
• 1998

In this paper, we prove the existence of solutions of the heat equation for harmonic map on a compact manifold with a boundary when the target manifold is allowed to have positively curved parts.

• 소성∙가공
• /
• 제9권5호
• /
• pp.504-511
• /
• 2000

Hydroforming is a forming process enabling circular metal tubes to be produced in complex cross sections along curved axial paths. This forming process is widely used to manufacture parts in automotive industry. This paper presents bending and forming results to following angle of weld line positions. These compare to good bending, bad bending and without weld line model case. And then this result of after forming compare to each forming cases. The purpose of this paper is found that adaptive weld line position for bended final shape.

• 대한가정학회지
• /
• 제25권2호
• /
• pp.13-23
• /
• 1987

The present study is undertaken to utilize the computer in pattern making of Jeugo-ris for women. The results are as follow: 1. Basic points which can be connected to depict basic pattern are represented with the numerical expreession and the curved lines consist of three types of arc. 2. The patterns of Jeugo-ris were automatically depicted by inputting the standard size(large, medium and small) and body measurements for bodice(bust girth, center back length, sleeve length). 3. This program includes the function of expressing the specific parts of patterns and of extending the patterns with or without standard lines.

• 소성∙가공
• /
• 제20권1호
• /
• pp.60-63
• /
• 2011

BLU(back light unit) is one of kernel parts of LCD(liquid crystal display) unit. New 3-D micro-lens pattern for LGP(light guide plate), one of the most important parts of LCD-BLU, had been researched. Instead of dot pattern made by chemical etching or laser ablation, SCS(slanted curved surface) micro-lens pattern was designed with optical CAE simulation. This study introduce the method of design using optical CAE simulation for SCS micro-lens, the new fabrication method of micro-mold with SCS micro-lens pattern.

• 복식
• /
• 제50권6호
• /
• pp.127-142
• /
• 2000

The names of Chinese Po corresponding to Korean Jikryung are Yesal and Jikshin. Thus the purpose of this paper is to review of the shapes and usage of Yesal and Jikshin and then make a comparative review between the twos and Jikryung having side Moo. Results of the study are described as follows : 1. The Chinese costume, Yesal is translated literally into Korean, Euisal or Euisal Jikryung and called Euisal Diknyung or Uisakot in Korean while Jikshin is translated into Korean, Jikryung and called Diknyung. 2. Yesal is a new type of clothing as created during the Ming period. The costume is the remnant type of Yosunoja and Byunsunoja in the periods of Sung and Yuan. Types of Yesal are classified into two, or one whose rear part's upper and lower areas are connected with each other and whose front part's upper and lower areas are net, the other in which those upper and lower areas are disconnected both in front and rear parts. 3. Types of Jikshin are classified into two, one having Pa and the other having loot. The latter is re-classified into two, one whose sleeve is large and wide, the whole length of which is long and which was usually worn by Sain, and the other whose sleeve is small and narrow, the whole length of which is short and which was by the grass root. 4. Yesal and Jikryung both having Pa have the almost same shapes except their front parts. Baerae of the former is more curved than that of the latter. Also the both were used as official uniforms worn by civil and military officials from higher to lower levels. 5. Jikshin and Jikryung both having Pa have the same shapes. Baerae of the former is more curved than that of the latter. The both were used as official uniforms worn by civil and military officials under a King and as casual costumes by Sadaeboo. In terms of color, Jikshin and Jikryung both employed red, blue and green, Especially the red color was favorably used both in China and Chosen at that time.