• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.241-244
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• 2001

스냅핏은 일종의 결속장치로서 흔히 플라스틱 부품들을 서로 체결하는데 이용되는데, 다른 결속장치에 비해 간편하고 생산품의 조립단가를 줄일 수 있고, 또한 분리력은 큰 반면에 결합력은 작게 만들 수 있는 장점을 가지고 있어 널리 사용된다. 스냅핏의 설계는 재료에 따른 물성(property) 및 구조적 강성(stiffness)이 설계 초기단계에서 고려되어야 하고, 또한 사출성형공정에서 스냅핏의 성형성도 예측되어야 한다. 그러나 스냅핏의 형상, 치수, 위치 등을 적절히 설계합성(synthesis)하고 적절한 재료를 선택하는 작업은 공정에 관한 종합적인 지식을 지원해 주는 합리적인 설계도구가 제공되지 못했던 이유로 사출 전문가의 오랜 기간 축적된 경험과 지식에만 전적으로 의존하여 왔다. 본 연구에서는 기존의 전문가에 의존해온 스냅핏 설계방법을 개선하기 위해 사출성형에 의해 제한되어지는 지식을 규칙베이스화하고 재료의 물성과 스냅핏의 형상 및 치수에 파라 스냅핏이 갖는 결합력, 분리력, 변형하중 및 허용언더컷 등을 출력하는 지적 설계 프로그램을 제안하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.1-5
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• 2001

One of the major advantages of using engineering plastics is ease of part assembly through a locking mechanism known as a snap fit. The typical snap fit involves a short cantilever beam with a projection at the free end. which slides over a one way ramp on the mating part to lock in place. The tightness of the mechanism is determined by the lateral interference of the two sliding members If too small they become loose and can't hold together. while if too large. excessive force can be generated. causing failure of the cantilever beam during the assembly operation. Therefore. the accurate determination of the force-deflection relationship for cantilever beams is a key element in snap fit design. And also. the process of injection molding should be considered when cantilever beam is designed. But it is not easy for novice designers to design them appropriately because of the profound knowledge related to injection molding. In this paper. an intelligent design program has been developed and proposed to improve a conventional empirical design method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.158-161
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• 2010

고중량, 부식 등의 문제를 안고 있는 목재/강재 리그매트를 대체할 수 있는 고강도 경량 고내구성 특성을 갖는 복합소재 리그매트를 전통 목재 연결방식의 결구시스템을 응용한 새로운 개념의 스냅핏 방식으로 개발하였다. 본 논문에서는 기존에 개발한 리그매트와 이를 개선한 개선형 리그매트의 스냅핏(snap-fit) 연결부의 안전성을 검증하기 위해 연결부 착탈 거동에 대한 해석 및 구조성능 시험을 실시하였고, 그 결과를 비교 분석하여 스냅핏 연결부의 긍정적인 효과를 입증하였다.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.3
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• pp.63-69
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• 2019

Soldering technology has been used in electronic industry for a long time. However, due to solder fatigue characteristics, automotive electronics are searching the semi-permanent interconnection technology such as press-fit method. Press fit interconnection is a joining technology that mechanically inserts a press fit metal terminal into a through hole in a board, and induces a strong bonding by closely contacting the inner surface joining of the through hole by plastic deformation of press-fit terminal. In this paper, the bonding properties of press-fit interconnection are investigated with PCB hole size and surface finishes. In order to compare interconnection reliability between the press fit and soldering, the change in resistance of the press-fit and soldering joints was observed during thermal shock test. After thermal cycling, the failure modes are investigated to reveal the degradation mechanism both press-fit and soldering technology.

• Korean Journal of Materials Research
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• v.6 no.2
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• pp.138-144
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• 1996

탄소재료 결합모재의 전구체로 핏치류가 많이 이용된다. 본 연구에서는 탄화거동에서 차이를 보이고 있은 석유계와 석탄계 핏치의 첨가량을 10-70wt%까지 배합하여 400-50$0^{\circ}C$ 온도범위에서 열처리하는 동안에 나타나는 흐름거동, 용해도 정도 등을 관찰함으로서 모재로서의 가능성을 평가하였다. 질소분위기에서 열처리속도 2.5$^{\circ}C$/min로 43$0^{\circ}C$까지 승온하여 30분 동안 처리한 결과 석유계 핏치의 첨가량이 50%가 될 때 까지는 핏치의 유동성과 점결력을 좌우하는 것으로 알려질 $\beta$-resin의 양이 45wt%이상으로 나타났으며, 이렇게 혼합된 핏치는 탄화수율도 같은 조건으로 처리된 원료 핏치에 비해 73-100%까지 높은 값을 보임으로서 모재로서의 가능성이 있음을 보였다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.719-724
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• 2006

Owing to its special features of light weight, high durability, corrosion-resistant, composite material used in civil infrastructure can not only solve fundamental problems of deterioration and corrosion, but also reduce both construction and maintenance cost significantly. Composite deck panels of 스냅핏 type connection previously designed and fabricated have been redesigned herein. The sensitivity of gaps between snap-fits and tip angles was investigated. Stacking sequence of plies was scrutinized in order to facilitate pultrusion process. Deck panels of redesigned configuration due to bending has been analyzed. A comparison between the preliminary and modified deck design has been made.

• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.23-37
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• 2018

In recent years, it is very difficult to construct and expand new infrastructures in a city center because of long-term low growth and lack of space due to urban overcrowding. So, there is a need to study a variety of Retrofitting techniques and urban applications that can lead to sustainable development while efficiently utilizing existing facilities. 'Retrofit' means a sustainable urban retrofitting as a directed alteration of the structures, formations and systems of existing facilities to improve energy, water and waste efficiencies. In this study, we applied a hierarchical network design technique that can reflect the structural hierarchy of a city to study how to retrofit public transportation routes in Seoul. The hierarchical network design means dividing the hierarchy according to the functions of hubs and connecting different hierarchies to form a hierarchical network. As a result of comparing the application results of various retrofitting scenarios of public transport, the differences of daily PKT and PHT by about 2.6~3.2% less than before the improvement address that the convenience of passengers is increased. Therefore, it is expected that if the route planning is established according to the proposed method, it will increase the number of passengers and the operational efficiency by the improved convenience of public transit passengers.

• 월간 기계설비
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• s.58
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• pp.53-57
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• 1995

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.690-695
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• 1999

An experimental study for mesophase pitch prepared from coal tar pitch has been carried out to clarify the rheological behaviors in the molten state. The apparent viscosity, shear stress, shear rate, Qunoline insoluble(QI), and softening point(SP) change were investigated especially. The conditions to increase mesophase content during polymerization were heat treatment time of 5 hrs, catalyst concentration of 3% and reaction temperature of $420^{\circ}C$. Apparent viscosity change with increase in temperature of pitches was different according to the heat treatment conditions and apparent viscosity increased with increasing heat treatment temperature, heat treatment time, contents of mesophase, on the contrary, fluidity is decreased. Rheological behavior of molten mesophase pitches at about $270^{\circ}C$ showed Newtonian behavior below $375^{\circ}C$ and non-Newtonian behavior above $270^{\circ}C$, the flow behavior was analyzed with Casson model.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.6
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• pp.1027-1037
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• 2023

This paper presents an efficient method for generating informative apparel fit comments by analyzing 122 fit reviews found in 7 menswear patternmaking textbooks, which include both domestic and foreign sources. The fit reviews for menswear were categorized into top and bottoms, and the expressions varied based on body parts, causes, and fit issue appearances. The causes of fit issues could be attributed to size errors and structural errors in both top and bottoms. Both top and bottoms had fit reviews concerning unique body types, but it could cause trouble among learners as both were based on unclear criteria for body type classification and lacked relevant explanations. Common fit issue appearances included compound wrinkles, pulling wrinkles, sagging wrinkles, and garment being away from the body. No clear correlation was observed between the causes of fit issues and specific appearances. Limitations were identified in using textbooks as educational data, such as inconsistent solutions for different body types or fit issues, and the presence of ambiguous visual materials. As a result, strategies such as categorizing fit issue appearances, providing 3D visual examples with subcategorized causes, body types and parts could enhance quality of fit reviews and improve fit outcomes in clothing production systems.