• 제목/요약/키워드: Sequential injection analysis

검색결과 23건 처리시간 0.025초

Optimization of filling process in RTM using genetic algorithm

  • Kim, Byoung-Yoon;Nam, Gi-Joon;Ryu, Ho-Sok;Lee, Jae-Wook
    • Korea-Australia Rheology Journal
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    • 제12권1호
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    • pp.83-92
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    • 2000
  • In resin transfer molding (RTM) process, preplaced fiber mat is set up in a mold and thermoset resin is injected into the mold. An important interest in RTM process is to minimize cycle time without sacrificing part quality or increasing cost. In this study, the numerical simulation and optimization process in filling stage were conducted in order to determine the optimum gate locations. Control volume finite element method (CVFEM) was used in this numerical analysis with the coordinate transformation method to analyze the complex 3-dimensional structure. Experiments were performed to monitor the flow front to validate simulation results. The results of numerical simulation predicted well the experimental results with every single, simultaneous and sequential injection procedure. We performed the optimization analysis for the sequential injection procedure to minimize fill time. The complex geometry of an automobile bumper core was chosen. Genetic algorithm was used in order to determine the optimum gate locations with regard to 3-step sequential injection case. These results could provide the information of the optimum gate locations in each injection step and could predict fill time and flow front.

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수치적 노이즈가 존재하는 사출 성형품 휨의 최적설계 (Design Optimization for Minimizing Warpage in Injection Molding Parts with Numerical Noise)

  • 박창현;김성룡;최동훈;표병기
    • 대한기계학회논문집A
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    • 제29권11호
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    • pp.1445-1454
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    • 2005
  • In order to minimize warping deformation which is an essential factor in the failure of injection molding parts, this study proposes an optimization design method fer determining design variables of injection molding parts. First, using a commercial package program for injection molding analysis, namely, Computer Aided Plastics Application(CAPA), we investigate the effects of parameters of injection molding process. Next, an optimum design process is established by interfacing CAPA to PQRSM embedded in EMD10S, a design framework developed by the conte. of innovative Design Optimization Technology(iDOT). PQRSM is a very efficient sequential approximate optimization algorithm. Optimum design results demonstrate the effectiveness of the design method suggested in this study by showing that the results of the optimum design is better than those of the initial design. It is believed that the proposed methodology can be applied to other injection molding design applications.

ANALYSIS OF IN-CYLINDER FUEL-AIR MIXTURE DISTRIBUTION IN A HEAVY DUTY CNG ENGINE

  • Lee, Seok-Y.;Huh, Kang-Y.;Kim, Y.M.;Lee, J.H.
    • International Journal of Automotive Technology
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    • 제2권3호
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    • pp.93-101
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    • 2001
  • Distribution of fuel-air mixture has a strong influence on performance and emissions of a compressed natural gas (CNG) engine. In this paper, parametric study is performed by KIVA-3V to investigate fuel-air mixture with respect to injection timing, cycle equivalence ratio and engine speed. With open-valve injection intensive mixing during intake and compression stroke results in relatively homogeneous mixture in the cylinder. Sequential induction of fuel-air mixture and fresh air results in stratification in the cylinder among the test cases at closed-valve injection. There is close similarity in the calculated distributions of the mixture in the cylinder with different cycle equivalence ratios and engine speeds. The results are compared against pressure traces and flame images obtained in a single cylinder engine converted from a 11L six-cylinder heavy duty diesel engine.

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사출금형의 균일 냉각을 위한 냉각회로의 다중목적함수 최적설계 (Multi-objective Optimization of an Injection Mold Cooling Circuit for Uniform Cooling)

  • 박창현;박정민;최재혁;이병옥;최동훈
    • 한국자동차공학회논문집
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    • 제20권1호
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    • pp.124-130
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    • 2012
  • An injection mold cooling circuit for an automotive front bumper was optimally designed in order to simultaneously minimize the average of the standard deviations of the temperature and the difference in mean temperatures of the upper and lower molds for uniform cooling. The temperature distribution for a specified design was evaluated by Moldflow Insight 2010, a commercial injection molding analysis tool. For efficient design, PIAnO (Process Integration, Automation and Optimization), a commercial PIDO tool, was used to integrate and automate injection molding analysis procedure. The weighted-sum method was used to handle the multi-objective optimization problem and PQRSM, a function-based sequential approximate optimizer equipped in PIAnO, to handle numerically noisy responses with respect to the variation of design variables. The optimal average of the standard deviations and difference in mean temperatures were found to be reduced by 9.2% and 56.52%, respectively, compared to the initial ones.

정압 스러스트 베어링의 유체-구조물 사이의 상호작용에 관한 연구 (A Study on Fluid-Structure Interaction of a Hydrostatic Thrust Bearing)

  • 김병탁
    • 한국기계가공학회지
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    • 제5권3호
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    • pp.92-98
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    • 2006
  • In this study, the behavior characteristics of a hydrostatic thrust bearing used in hydraulic equipment was analyzed using a commercial finite element program, ADINA. The solid domain was modeled with the fluid domain simultaneously to solve the fully coupled problem, because this is a problem where a fully coupled analysis is needed in order to model the fluid-structure interaction(FSI). The results such as bearing deformation, stress, film thickness and lifting bearing force were obtained through FSI analysis, and then they were compared with the results calculated from the classical method, a single step sequential analysis. It was found that the result difference between two analyses was increased according to the injection pressure. Therefore, in case of high pressure loading, it is desirable to conduct the FSI analysis to examine the deformation characteristics of a hydrostatic slipper bearing.

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고압 피스톤 펌프용 슬리퍼 베어링의 변형 특성에 관한 연구 (A Study on the Deformation Characteristics of a Slipper Bearing for High Pressure Piston Pump)

  • 고성위;김병탁
    • 한국해양공학회지
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    • 제23권5호
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    • pp.39-44
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    • 2009
  • The hydrostatic slipper bearing is generally used in high pressure axial piston pumps to support the load generated from two surfaces which are sliding relatively at low speed. The object of the bearing is to remove the possibility of direct contact by maintenance of an adequate oil film thickness between two metal surfaces. Because the bearing performance is influenced by the bearing deformation, it is highly dependent on the injection pressure, the bearing surface profile and so on. In this study, the deformation characteristics of a hydrostatic slipper bearing is investigated according to the injection pressure by the finite element analysis. In the analysis, the special boundary condition to take the fluid-structure interaction (FSI) into account is used on the interactive surface. The results, such as bearing deformation, stress and lifting force, obtained from the fully coupled analysis are compared with those from the single step sequential method.

Anesthetic efficacy of primary and supplemental buccal/lingual infiltration in patients with irreversible pulpitis in human mandibular molars: a systematic review and meta-analysis

  • Gupta, Alpa;Sahai, Aarushi;Aggarwal, Vivek;Mehta, Namrata;Abraham, Dax;Jala, Sucheta;Singh, Arundeep
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제21권4호
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    • pp.283-309
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    • 2021
  • Achieving profound anesthesia in mandibular molars with irreversible pulpitis is a tedious task. This review aimed at evaluating the success of buccal/lingual infiltrations administered with a primary inferior alveolar nerve block (IANB) injection or as a supplemental injection after the failure of the primary injection in symptomatic and asymptomatic patients with irreversible pulpitis in human mandibular molars. The review question was "What will be the success of primary and supplemental infiltration injection in the endodontic treatment of patients with irreversible pulpitis in human mandibular molars?" We searched electronic databases, including Pubmed, Scopus, and Ebsco host and we did a comprehensive manual search. The review protocol was framed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. We included clinical studies that evaluated and compared the anesthetic outcomes of primary IANB with primary and/or supplementary infiltration injections. Standard evaluation of the included studies was performed and suitable data and inferences were assessed. Twenty-six studies were included, of which 13 were selected for the meta-analysis. In the forest plot representation of the studies evaluating infiltrations, the combined risk ratio (RR) was 1.88 (95% CI: 1.49, 2.37), in favor of the secondary infiltrations with a statistical heterogeneity of 77%. The forest plot analysis for studies comparing primary IANB + infiltration versus primary IANB alone showed a low heterogeneity (0%). The included studies had similar RRs and the combined RR was 1.84 (95% CI: 1.44, 2.34). These findings suggest that supplemental infiltrations given along with a primary IANB provide a better success rate. L'Abbe plots were generated to measure the statistical heterogeneity among the studies. Trial sequential analysis suggested that the number of patients included in the analysis was adequate. Based on the qualitative and quantitative analyses, we concluded that the infiltration technique, either as a primary injection or as a supplementary injection, given after the failure of primary IANB, increases the overall anesthetic efficacy.

흐름주입분석법에 의한 환경시료 중$N(NO_2^-),\;N(NO_3^-)$$N(NH_4^+)$의 정량분석에 관한 연구 (A Study on the Determination of$N(NO_2^-),\;N(NO_3^-)$and$N(NH_4^+)$in Environmental Samples by Flow Injection Analysis)

  • 이재성;김영상;정윤희;이희정
    • 대한화학회지
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    • 제41권5호
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    • pp.256-265
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    • 1997
  • 토양과 수질시료 중에서 nitrite, nitrate 그리고 ammonia성 질소를 빠르고 연속적으로 정량할 수 있는 방법에 관하여 연구하였다. 실제시료를 측정하기전에 각 성분의 표준시료를 사용하여 FIA의 구조적 인자(주입 양, 반응코일 길이 그리고 흐름속도)를 결정하였다. Nitrite는 Griess reaction에 의해 sulfanilamide와 반응 후 N-(1-naphthylenediamine dihydrochloride)과 결합하여 azo 색소를 형성시킨 후 540 nm에서 측정하였고, nitrate는 hydrazine을 사용하여 nitride로 환원시킨 후 측정하였다. Ammonia는 Nessler법을 사용하여 440 nm에서 측정하였다. 최적 조건에서 $N(NO_2^-),\;N(NO_3^-)와\;N(NH_4^+)$의 검출한계(S/N=3)는 0.1 ㎍/ML, 0.4 ㎍/mL 그리고 0.3 ㎍/ML이었다. 실제시료를 비색법, ion chromatography 및 FIA로 측정하여 비교한 결과 상호 일치성이 80~125%로 나타내어 만족스러웠다. 시료의 주입횟수는 30회/시간 이상으로 조절할 수 있었다.

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흰쥐의 일주기조절중추내 바이러스 감염에 대한 매개변수 분석 (Parametric Analysis on the Viral Infection in The Rat Circardian Control Center)

  • 김진상
    • The Journal of Korean Physical Therapy
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    • 제10권2호
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    • pp.113-125
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    • 1998
  • The neurotropic psudorabies virus(PRV) to replicate within neurons is very useful pathogen for neuronal tracing. I carried out this study to investigate the parametric analysis on the viral infection in the rat circadian control center with two genetically engineered strains out of PRV. The two strains are isogenic with the attenuated Bartha strain of PRV ; in one strain a lacZ reporter gene was inserted into the gC locus (PRV-BaBlu ; $4.75\times10^8pfu/ml$) and the other strain contained a PRV envelope glycoprotein gene(PRV-D ; $2.5\times10^8pfu/ml$) theat is absent in PRV-BaBlu. simultaneous or temporally separated sequential injection of$2{\mu}l$ of each strain into the vetreous body of eye produced a course of transsynaptic infection of retinohypothalamic circuitry. The results were as follows; 1. PRV-BaBlu and PRV-D infected the suprachiasmatic nucleus in hypothalamus and intergeniculate leaflet in lateral geniculate nucleus of thalamus. 2. The rate of PRV infection was dependent upon PRV strain. 3. Pre-infected neurons by PRV-D were interfered with the replication of PRV-BaBlu. 4. Dual injection of PRV-D and PRV-BaBlu showed more virulent than the parental strain.

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