• 전기전자학회논문지
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• 제27권3호
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• pp.327-332
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• 2023

전통적인 실리콘 기반 반도체 소자 보다 높은 성능과 다양한 활용성으로 차세대 반도체 후보로 높은 관심 받고 있는 CNTFET은 CNT 배치와 같은 CNTFET만의 고유한 공정 편차가 아직 성숙되지 않아 상용화에 어려움을 겪고 있다. 이러한 어려움을 극복하고자 반복적인 회로 구성으로 공정 편차의 영향을 적게 받는 회로를 MOSFET-CNTFET 기반 하이브리드 회로로 구현하여 CNTFET 의 장점을 취하고 단점을 보완하고자 하는 수많은 연구들이 지속적으로 수행되어 왔다. 본 논문에서는 하이브리드 SRAM의 성능이 기존의 MOSFET SRAM 또는 CNTFET SRAM에 존재하는 반도체 공정 변화에 의해 얼마나 변화될 수 있는지를 비교하였다. 시뮬레이션 결과, CNT 밀도를 32nm 당 7개에서 9개 사이로 유지할 수 있다면, hybrid SRAM은 기존 MOSFET SRAM보다 읽기 동작에서 그리고 쓰기 동작에서 공정 편차에 대한 강건성이 각각 약 2.6배 그리고 약 1.1배 있음을 보여준다.

• 분석과학
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• 제18권6호
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• pp.535-541
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• 2005

본 연구에서는 오존/활성탄 혼합공정에서 부식산의 초기 pH(pH 3~pH 11)와 반응온도 ($0^{\circ}C$, $20^{\circ}C$, $40^{\circ}C$)를 변화시켰을 때 생성되는 알데히드류의 생성을 조사하였으며, 오존/활성탄 혼합공정 외에 활성탄 흡착과 오존 단독공정을 실험하여 공정에 따른 차이를 비교하였다. 오존 주입농도는 0.08g $O_3/g$ DOC, 활성탄 충진율은 16.5 v/v%였으며, 생성되는 알데히드류는 PFBOA법으로 전처리하여 GC/PDECD로 분석하였다. 오존/활성탄 혼합공정에서 생성되는 알데히드류를 분석한 결과, 포름알데히드와 글리옥살만이 검출되었으며, 그 생성량은 오존단독 공정에 비하여 오존/활성탄 혼합공정에서 더 적게 생성되었다. 오존/활성탄 혼합공정에서 부식산의 초기 pH를 변화시켰을 때, pH 11과 pH 7 에서 반응초기에 포름알데히드가 높은 농도(약 400 ppb)로 생성되었으며, 반응이 진행됨에 따라 포름알데히드와 글리옥살 농도는 모두 감소하는 경향을 나타냈다. 반응온도에 따른 실험에서는 온도가 가장 높은 $40^{\circ}C$에서 포름알데히드와 글리옥살이 가장 많이 생성되었으며, 이때 반응초기의 최고 농도는 각각 약 520 ppb, 120 ppb이었다.

• 대한환경공학회지
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• 제27권9호
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• pp.989-994
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• 2005

본 연구에서는 활성탄 흡착, 오존 단독, 오존/활성탄 혼합공정을 이용하여 부식산을 처리하고 부식산의 처리효율을 $UV_{254}$와 DOC를 통해 살펴보았으며, 부식산의 분해특성은 분자량 크기분포의 변화와 활성탄 표면변화를 통해 관찰하였다. 각 공정에서의 DOC 제거효율을 살펴본 결과, 활성탄 흡착공정은 약 19%, 오존 단독공정은 38%이었으나, 오존/활성탄 혼합공정에서는 약 80%로 활성탄 흡착공정과 오존 단독공정의 DOC 처리효율을 합한 것보다 훨씬 높아, 혼합공정을 도입함으로써 시너지 효과를 얻을 수 있는 것으로 나타났다. 기리고 $UV_{254}$ 감소율 역시 오존/활성탄 혼합공정에서 가장 크게 나타났다. 오존/활성탄 혼합공정에서 활성탄은 고유의 흡착제 역할뿐만 아니라 흡착된 유기물과 오존의 접촉을 촉진시키는 반응자리를 제공하는 역할을 하는 것으로 사료된다. 각 공정에서의 분자량크기분포 변화를 살펴본 결과, 활성탄 흡착공정에의 분자량 크기분포는 반응 전후에 큰 차이가 없었으며, 오존 단독공정에서는 30 kDa 이상의 분자량이 반응시간 10분 이후에는 거의 감소하지 않고 일정하였으나, 0.5 kDa 이하의 저분자량은 초기 4.8%에서 120분 처리시 12.3%로 증가하였다. 한편 오존/활성탄 혼합공정에서는 120분 처리시 30 kDa 이상 분자량이 초기 36.3%에서 3.9%로 뚜렷하게 감소하였으며, 0.5 kDa 이하의 저분자량은 초기 4.8%에서 40.1%로 크게 증가하였다.

• 한국기계가공학회지
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• 제19권9호
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• pp.33-39
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• 2020

Self-piercing rivets are often used in the automotive industry, among other industries, as mechanical components to join multiple materials such as aluminum alloys. Self-piercing rivets have a strong sealing property, although there is considerable scope for their performance improvement. In this study, to enhance the performance of self-piercing rivets, the hybrid self-piercing riveting (SPR) technique, using the existing SPR and structural adhesive, was proposed. Moreover, heterogeneous material specimens subjected to the hybrid SPR technique were manufactured and tested. The joint strength of the test pieces of different materials was evaluated through finite element analyses.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.757-760
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• 2005

The technology of rapid prototyping (RP) is used for design verification, function test and fabrication of prototype. The current issues in RP are improvement in accuracy and application of various materials. In this paper, a hybrid rapid prototyping system is introduced which can fabricate nano composites using various materials. This hybrid system adopts RP and machining process, so material deposition and removal is performed at the same time in a single station. As examples, micro gears and a composite scaffold were fabricated using photo cured polymer with nano powders such as carbon black and hydroxyapatite. From the micro gear samples the hybrid RP technology showed higher precision than those made by casting or deposition process.

• 한국기계가공학회지
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• 제9권2호
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• pp.1-5
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• 2010

According to the high demand of hybrid components, the hybrid materials development and processing technology were increased in the industry field. Although hybrid materials have various machining technologies, the research about them has rarely been proceed. This study is to carry out results about design technology of miniaturized high-speed air spindle and machining characteristics of hybrid materials using that. We studied machining characteristics in Nickel-Chrome alloy(Ni-Cr) according to change rotating speed using miniaturized high-speed air spindle. As the following results, the change of surface shape and roughness was investigated as the processing conditions such as rotating speed of miniaturized high-speed air spindle.

• 상하수도학회지
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• 제30권4호
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• pp.459-469
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• 2016

Gas hydrate desalination process is based on a liquid to solid (Gas Hydrate, GH) phase change followed by a physical process to separate the GH from the remaining salty water. The GH based desalination process show 60.5-90% of salt rejection, post treatment like reverse osmosis (RO) process is needed to finally meet the product water quality. In this study, the energy consumption of the GH and RO hybrid system was investigated. The energy consumption of the GH process is based on the cooling and heating of seawater and the heat of GH formation reaction while RO energy consumption is calculated using the product of pressure and flow rate of high pressure pumps used in the process. The relation between minimum energy consumption of RO process and RO recovery depending on GH salt rejection, and (2) energy consumption of electric based GH process can be calculated from the simulation. As a result, energy consumption of GH-RO hybrid system and conventional seawater RO process (with/without enregy recovery device) is compared. Since the energy consumption of GH process is too high, other solution used seawater heat and heat exchanger instead of electric energy is suggested.

• 한국전기전자재료학회논문지
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• 제20권1호
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• pp.35-40
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• 2007

The new PEI(poly(epoxy-imide))-nano Silica film has been synthesized via in situ CS sol process, and the chemical bonding and microstructure of nano silica dispersed in resin were examined by FT-IR, TAG and SEM. The dielectric properties of these hybrid films over a given temperature and frequency ranges have been studied in a point of view of stable chemical bonding of nano Silica filler. The results from IR spectra and SEM photograph indicated that PEI-Silica hybrid film prepared with nano CS sol process has been synthesized in uniform and chemical bonding. The decrease property of dielectric constant with CS content, tangent loss consistent of given frequency and temperature has been explained in terms of the chain movement of polymer through chemical bonging and size effect of nano silica. The new PEI-CS sol hybrid film with such stable chemical and dielectric properties was expected to be used as a high functional coating application in ET, IT and electric power products.

• 소성∙가공
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• 제20권2호
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• pp.160-166
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• 2011

Weight reduction while maintaining functional requirements is one of the major goals in the automotive industry. The use of lightweight magnesium alloys offers great potential for reducing weight because of the low density of these alloys. However, the formability and the surface quality of the final magnesium alloy product for auto-body structures are not acceptable without a careful optimization of the design parameters. In order to overcome some of the main formability limitations in the stamping of magnesium alloys, a new approach, the so-called "hybrid technology", has been recently proposed for body-in-white structural components. Within this approach, necessary level of mechanical joining can be obtained through the use of lightweight material-steel adhesion promoters. This paper presents the development process of an automotive hybrid hood assembly using magnesium alloy sheets. In the first set of material pairs, the selected materials are magnesium alloy AZ31B alloy and steel(SGCEN) as inner and outer panels, respectively. In order to optimize the design of the inner panel, the stamping process was analyzed with the finite element method (FEM). Laser welding by CW Nd:YAG were used to join the magnesium alloy sheets. Based on the simulation results and mechanical test results of the joints, the determination of die design variables and their influence on formability were discussed. Furthermore, a prototype based on the proposed design was manufactured and the static stiffness test was carried out. The results demonstrate the feasibility of the proposed hybrid hood with a weight reduction of 25.7%.

• 한국경영과학회지
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• 제21권3호
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• pp.47-61
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• 1996

An ATM switch must deal with various kinds of input sources having different traffic characteristics and it must guarantee very small value of cel loss probability, about 10$^{8}$ -10$^{12}$ , to deal with loss-sensitive traffics. In order to estimate such a rate event probability with simulation procedure, a variance reduction technique is essential for obtaining an appropriate level of precision with reduced cost. In this paper, we propose a hybrid simulation technique to achieve reduction of variance of cell loss probability estimator, where hybrid means the combination of analytical method and simulation procedure. A discrete time queueing model with multiple input sources and a finite shared buffer is considered, where the arrival process at an input source and a finite shared buffer is considered, where the arrival process at an input source is governed by an Interrupted Bernoulli Process and the service rate is constant. We deal with heterogeneous input sources as well as homogeneous case. The performance of the proposed hybrid simulation estimator is compared with those of the raw simulation estimator and the importance sampling estimator in terms of variance reduction ratios.