• 접착 및 계면
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• 제3권1호
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• pp.37-42
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• 2002

Adhesives are becoming increasingly accepted for advanced engineering/boding tasks. Therefore the understanding of the basic principles and the benefits of elastic bonding and structural bonding respectively is of utmost importance. Structural bonding means adhesive performance in load-bearing environments. Furthermore. the time to achieve handling strength has an impact on the economics of an assembly line. The paper gives briefly a summary about the fundamentals of elastic bonding and discusses different adhesive systems in the context of handling strength. Hereby the focus lies on the Warm Melt Technology, and its potential is compared to standard adhesives (l-part, 2-part and Booster Technology, a special 2-C system). Examples illustrate their economical benefits. Main Points : ${\bullet}$ The basic principles and benefits of elastic bonding ${\bullet}$ Warm-melt Technology in comparison with standard adhesives ${\bullet}$ Handling strength an economic issue ${\bullet}$ Combination with Booster-Technology, a special 2-C PUR system ${\bullet}$ Presentation of real world applications Learning Objectives: ${\bullet}$ Fundamentals of elastic bonding ${\bullet}$ Warm-melt Technology: correlation between chain length and cristallinity ${\bullet}$ Handling strength and curing speed of various systems in comparison ${\bullet}$ Real world applications illustrate the potential of the Warm-melt Technology.

• 천문학회보
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• 제43권2호
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• pp.55.4-56
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• 2018

Linear Astigmatism Free - Three Mirror System (LAF-TMS) is the linear astigmatism free off-axis wide field telescope with D = 150 mm, F/3.3, and $FOV=5.51^{\circ}{\times}4.13^{\circ}$. We report the design and analysis results of its mirrors and optomechanical structures. Tolerance allowance has been analyzed to the minimum mechanical tolerance of ${\pm}0.05mm$ that is reasonable tolerance for fabrication and optical alignment. The aluminum mirrors are designed with mounting flexure features for the strain-free mounting. From Finite Element Analysis (FEA) results of mounting torque and self-weight, we expect 33 - 80 nm RMS mirror surface deformations. Shims and the L-bracket are mounted between mirrors and the mirror mount for optical alignment. The mirror mount is designed with four light-weighted mechanical parts. It can stably and accurately fix mirrors, and it also suppresses some of stray light.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권2호
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• pp.127-135
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• 2009

Objectives : The titanium fixation system has been used in orthognathic surgery for fixation of bone segments usually, but the biodegradable fixation system was developed and also being used. The strongest point in the biodegradable system is that no extra operation should be needed to remove fixation materials. In spite of this merit, oral & maxillofacial surgeons hesitate to use this system in fracture or orthognathic surgery. In this study, as we got some clinical experiences, we'd like to report the result of clinical study using the biodegradable fixation system in orthognathic surgery. Patients and Methods : A total of 35 patients composed of 17 males and 18 females with 25 osteotomies in maxilla and 34 osteotomies in mandible were fixated with the biodegradable fixation system(Inion $CPS^{(R)}$). We investigated methods of stabilization, fixation time, and complications on the basis of the method as above. Results : Four 2mm thick L shaped plates with 7 holes of which 1 hole was removed were fixed in maxilla with six $2.0{\times}7mm$ screws. Three $2.5{\times}16{\sim}18mm$ screws were used to fix superior ramus area and one mandibular angle area in mandible. It took about 27.4 minutes in maxilla, 25.3 minutes in mandible to perform the fixation which took longer time than the titanium system(9.5 minutes in maxilla, 8 minutes in mandible). Generally, there was no problem except 9 cases in which there were some complications. Conclusions : In most cases, the biodegradable fixation system can be used without problem in usual orthognathic surgery. But, this system is inferior to the titanium fixation one in some respects such as fixation time, size, and physical property. Some supplementations for such weak points as aforementioned should be needed for the universal use of biodegradable materials.

• 한국수학교육학회지시리즈A:수학교육
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• 제16권2호
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• pp.22-26
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• 1978

($\alpha$$_{x}$, $\alpha$X)와 ($\alpha$$_{Y}$ , $\alpha$Y)를 T$_2$ 공간 X와 Y의 Alexandroff base Compactification이라 할 때 $\alpha$fㆍ$\alpha$$_{x}$=$\alpha$$_{Y}$ f를 만족하는 open이고 연속인 함수 $\alpha$f:$\alpha$X$\longrightarrow$$\alpha$Y가 존재하는 연속함수 f:X$\longrightarrow$Y는 유일한 $\alpha$-extension $\alpha$f를 가지며 Category ABC를 T$_2$ 공간과 위와 같은 연속함수 f들의 Category라고 할 때 open이고 연속인 함수와 Compact space들의 Category는 Category ABC의 epireflective subcategory임을 밝혔다.