• 소성∙가공
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• 제15권1호
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• pp.42-46
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• 2006

For mass production, usually injection mold has multi-cavity which is filled through geometrical balanced runner system. Despite geometrical balanced runner system, filling imbalances between cavity to cavity have always been observed. These filling imbalances are one of the most significant factors to affect quality of plastic parts. Filling imbalances are results from non-symmetrical shear rate distribution within melt when it flows through tile runner system. It has been possible to decrease filling imbalance by optimizing processing conditions, but it has not completely eliminated this phenomenon during injection molding processing. This paper presents a solution for these filling imbalances by using Runner Core pin (RC pin). The Runner Core pin which is developed in this study creates a symmetrical shear distribution within runner. As a result of using Runner Core pin, a remarkable improvement in reducing filling imbalances was confirmed.

• 대한전자공학회논문지
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• 제27권5호
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• pp.737-746
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• 1990

Ga0.47In0.53As PIN photodiodes(PD) having various areas have been fabricated by liquid phase epitaxial techniques. Ternary melt has been baked out at 675\ulcorner in H2 atmosphere for 20 hours before growth, which resulted in reduction of background carrier concentration of grown epi-layer. Also, lattice mismatch has been controlled within 0.01%. The room temperature performance of 10**-4cm\ulcornerarea PIN PD at a bias voltage of -5V were` quantum efficiency(with no antireflection coating)=60% for 1.3\ulcorner light source, dark current\ulcorner5nA, and capacitance\ulcornerpE. Frequency response measurement of packaged PIN PD has shown that cut-off frequency (f-3dB) was 961MHz. This PD has shown a good eye pattern when it was incorporated in a 565Mbps optical receiver.

• 한국생산제조학회지
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• 제26권2호
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• pp.199-204
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• 2017

In this study, analytical methods for designing a torque arm pin and elastomeric bushings of a conventional-type three-point-suspension gearbox of a wind turbine are investigated. The design loads for the torque arm were derived by considering the effects of the transmitted torque and self-weight of the gearbox. Based on the design loads, design methods for the torque arm pin and elastomeric bushings were introduced in the terms of material and size selection. Finally, a small-scale conventional-type gearbox was designed by applying the derived design methods. This study is an elementary and analytical study for the design of the torque arm pin and elastomeric bushings. It is necessary to verify and supplement the results further through extensive experimentation.

• Nuclear Engineering and Technology
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• 제49권6호
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• pp.1339-1345
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• 2017

In the framework of the EU funded project NURESAFE, the subchannel code CTF and the neutronics code DYN3D were integrated and coupled on the NURESIM platform. The developments achieved during this 3-year project include assembly-level and pin-by-pin multiphysics thermal hydraulics/neutron kinetics coupling. In order to test this coupling, a PWR rod ejection transient was simulated on a MOX/UOX minicore. The transient is simulated using two different models of the minicore. In the first simulation, both codes model the core with an assembly-wise resolution. In the second simulation, a pin-by-pin fuel-centered model is used in CTF for the central assembly, and a pin power reconstruction method is applied in DYN3D. The analysis shows the influence of the different models on global parameters, such as the power and the average fuel temperature, but also on local parameters such as the maximum fuel temperature.

• Composites Research
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• 제31권6호
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• pp.323-331
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• 2018

스테인리스 강으로 제작된 요철핀의 보강이 복합재 모자형 체결부의 풀오프 강도에 미치는 영향을 시험으로 연구하였다. 요철핀에는 물리적, 화학적 표면처리를 수행하였고, 체결부의 외피와 보강재가 만나는 영역에 두께방향으로 핀을 삽입하였다. 모자형 체결부 시편은 요철핀을 포함하여 일체성형으로 제작하였다. 사용된 요철핀의 지름은 0.3, 0.5, 0.7 mm로 세 가지이다. 핀의 삽입밀도는 외피와 보강재가 만나는 면적 기준으로 0.5, 2.0% 두 가지이다. 요철핀과 일반핀의 효과를 비교하기 위하여 0.3 mm 일반핀을 2.0% 밀도로 삽입한 시편을 추가로 제작하여 시험을 수행하였다. 0.3, 0.5, 0.7 mm의 요철핀을 0.5%의 밀도로 삽입한 시편의 강도는 보강되지 않은 시편 대비 각각 45, 19, 9% 높게 나타났고, 2.0% 밀도의 경우 강도는 각각 127, 45, 11% 높게 나타났다. 시험 결과 지름이 동일할 경우 밀도가 높을수록, 밀도가 동일할 경우 지름이 작을수록 보강효과가 더 높게 나타나는 것을 알 수 있었다. 요철핀과 일반핀의 효과를 비교한 결과 2.0% 밀도로 0.3 mm 직경의 핀을 이용하여 보강할 경우, 요철핀 보강시편이 일반핀 보강 시편보다 64% 높은 강도를 보였다. 본 연구의 결과로부터 요철핀 보강이 복합재 모자형 체결부의 풀오프 강도 향상을 위한 효과적인 방법이 될 수 있음을 확인하였다.

• 한국지능시스템학회논문지
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• 제24권4호
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• pp.349-354
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• 2014

지금까지 스마트 카드의 사용자 인증은 단말기에서 PIN(Personal Information Number)을 대조하는 MOT(Match On Terminal)방식으로 이루어져 왔다. 이러한 기존의 방법은 사용자의 망각이나 분실로 인해 PIN정보가 유출될 위험이 있으며, 단말기에서 사용자 정보를 대조하기 때문에 사용자 정보에 대한 불법적인 접근 가능성이 높다. 따라서, 본 논문은 PIN방식과 비교하여 현저히 분실과 망각 위험이 낮은 생체정보를 이용하는 MOC(Match On Card)방식 사용자 인증 방법을 제안한다. 이를 위해, 제한적인 저장 공간을 가지고 있는 스마트 카드에도 저장 할 수 있는 저용량의 얼굴 생체벡터를 구성하고 낮은 연산속도를 가진 스마트 카드에서 실시간으로 매칭 결과를 알아 낼 수 있는 단순한 매칭 알고리즘을 제안한다.

• 마이크로전자및패키징학회지
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• 제18권2호
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• pp.29-33
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• 2011

솔더와 PCB Cu 패드와 솔더 경계면에서 발생하는 수직응력과 수평응력을 분석하여 PGA 패키지의 신뢰성 향상을 위한 리드핀의 형상설계에 대한 연구를 수행하였다. 이와 같은 연구를 위해 리드핀의 $20^{\circ}$ 각도 굽힘 변형과 50 ${\mu}m$ 인장조건에서 4인자 3수준의 다구찌 최적설계와 유한요소해석을 수행하였다. 해석결과에 의하면 리드핀의 헤드곡면과 PCB Cu 패드가 접촉하는 폭(d2)이 솔더에서 발생하는 응력감소에 가장 큰 영향을 미치는 인자로 계산되었다. 또한, 다 구찌법의 파라메타 설계에 의해 기존 리드핀 형상모델에 비해 약 18.7%의 등가 von Mises 응력이 감소하는 형상을 도출하였다. 한편, 최대 수직응력이 발생하는 위치가 PCB의 Cu 패드와 솔더의 외곽이 접촉하는 위치이고 최대 수평응력이 발생하는 위치가 SR 층과 솔더의 외곽표면이 접촉하는 위치임을 파악하여, PGA 패키지의 박리 불량은 솔더의 외곽부터 발생하여 내부로 진행될 것으로 예측되었다.

• 임산에너지
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• 제18권2호
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• pp.84-91
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• 1999

The objective of this study was to present creep and the effects of mechano-sorptive deflection of drift pin moment resisting joint between LVL members under changing relative humidity (RH) conditions. The LVL members with steel gusset were jointed by a square pattern of eight injected drift pin. Three diameter drift pins were used to test specimens (6mm, 10mm, and 16mm). The creep test was conducted under two constant loading conditions : one at 30 kgf(840 kgf-cm) and the other at 60 kgf(1680 kgf-cm). The experiment was conducted in an open shed outside. (1)The total rotation creep model of moment resisting joing can be expressed as the sum of the creep of controlled environment (3-parameter model), dimensional change and mechano-sorptive deflection resulting from the variable environment. (2)Mechanosorptive rotation creep is recoverable as moisture content increases during adsorption. Least squares method for linear regression analysis was performed using mechano-sorptive rotation creep as the dependent variable and moisture content as the independent variable. The slope of low moment specimens are compared with those of high moment. This means that low moment condition is more easily affected by changes in humidity than high moment conditions. (3)Although creep deflection is higher for small diameter drift pin than for large diameter drift pin, the shape of creep deflection curves for all specimens is similar.

• Tribology and Lubricants
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• 제25권6호
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• pp.409-413
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• 2009

This paper presents the hardness and friction characteristics of pb-free pin-bush bearing metal, which is manufactured by a centrifugal casting technology. A bronze metal with a high hardness and low friction properties is usually used for Diesel engine pin-bush bearing and high pressure cylinder. Pb-free metal for pin-bush bearings shows a little high hardness of 120 Hv compared with that of a conventional Pb bearing metal of 100~110 Hv. In general, the friction coefficient of pin-bush bearings is affected by a rotating speed and a load for various rubbing contact modes. But a contact load is more influential parameter when the contact rubbing mode transits from a mixed lubrication to a dry friction contact. The experimental result shows that the friction coefficient is more unstable at the dry contact mode compared with that of other two rubbing modes such as oil film contact and mixed friction conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.96-98
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• 2002

This paper proposes the digital pin line checker which can extremely improve the efficiency of the pine line checking using a micro processor. The line checker is designed which can check efficiently up to maximum 2048 pin. Alarm busser is designed ringing real-timely the case that the pin line is connected differently with real node number. Accordingly the comparing and identifying work visually the node number showing on the displaying board with real node number is avoided after the electronic stimulus enforce to the pin of the fixture by the test engineer. The digital line checker is designed based on the 8051. And the effectiveness and accuracy of the proposed line checking strategy is tested by simulating the several error connections for pin lines on the small scale board.