• Title/Summary/Keyword: final closing

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Finite Element Simulation of Material Flow and Weld Line Formation in SMC Compression Molding (SMC 압축성형의 소재유동과 겹침선 형성에 관한 유한요소 해석)

  • Hahn, Young-Won;Im, Yong-Taek
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.1
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    • pp.79-87
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    • 1996
  • SMC(Sheet Molding Compound) is made of unsaturated polyester resin and other additives reinforced with randomly distributed chopped fiberglass strands. Because of its higher stiffness per unit mass, SMC was used as a substitute for steel for automotive steel outer panels. Thus, understanding of flow characteristics during fabrication of SMC is of importance since the formation of weld line depends on material flow. In the present study, SMC compression molding simulations in the flat and T-shape molds were accomplished. During simulations, the preferential the preferential flow occurred at the low mold closing speed while plug flow was observed for the higher mold closing speed. When the preferential flow was observed, the weld line was seen at the final stage. For simulations, rigid-viscoplastic finite element method was applied. Self-contact algorithm was also applied in order to predict the formation of the weld line. Simulation results were compared to the experimental results available in the literature.

Effects of Proprioceptive Neuromuscular Facilitation Program Combined with Dynamic Neuromuscular Stabilization Approach on Balance in Patient with Cerebellum Atrophy -Case Report- (동적 신경근 안정화 접근법과 결합한 PNF 중재 프로그램이 소뇌 위축 환자의 균형에 미치는 영향 -사례보고-)

  • Na, Eun-Jin;Moon, Sang-Hyun;Kim, Eun-Kyung;Park, Du-Jin
    • PNF and Movement
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    • v.14 no.3
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    • pp.237-244
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    • 2016
  • Purpose: This case report examines the influence of proprioceptive neuromuscular facilitation (PNF) combined with a dynamic neuromuscular stabilization approach on balance in patients with cerebellar atrophy. Methods: The target subject of this case report was a 34-year-old woman who was informed of the purpose of this research and voluntarily agreed to participate in it. The case report conformed to research ethics based on the Helsinki Declaration. The target subject was confirmed to have cerebellar atrophy from an unknown cause in 2009 and was diagnosed with slight ataxia. At that time, she could carry out daily activities without physical therapy. On May 19, 2015, she suffered both a subdural hemorrhage (SDH) and subarachnoid hemorrhage (SAH) in a traffic accident. She was urgently moved to the emergency room and managed by nonsurgical treatment, and then, the cerebellar atrophy and ataxia gradually deteriorated. To evaluate the patient's balance capacity before and after intervention, the trunk impairment scale (TIS), trunk impairment scale (OLST) during eye-closing/opening, timed up and go test (TUG), and visual analogue scale (VAS) were conducted. The PNF intervention program was executed for 30 min, four times a week, for three weeks. Results: The TIS and OLST during eye-closing/opening were improved by as much as a point, by 8.15 s and 6.21 s, respectively, after applying the PNF program. TUG and VAS decreased by 1.33 s and 3 points, respectively, after intervention. According to the result, the OLST during eye-closing/opening and VAS improved remarkably in comparison with those before intervention. Conclusion: As the final result of the case report, PNF intervention combined with DNSA more effectively improved the static balance capacity, such as the OLST during eye-closing/opening and VAS, compared to the dynamic balance capacity. In addition, the intervention duration and period of the exercise program are recommended to be more than 1 h a day for four weeks considering the learning ability of a patient with cerebellar atrophy.

A Study on the selection and noise test of elelctronic sensor for Vacuum Circuit Breaker (진공차단기용 전자식 센서의 선정 및 노이즈 시험에 관한 연구)

  • Lee, Ki Seon;Park, Jung Cheul;Chu, Soon Nam
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.10
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    • pp.2503-2508
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    • 2014
  • This study is about the selection and noise test of electronic sensor which is preceded by electric Operating Cell(EOC) development using electronic sensor technology to solve the structural weakness of Mechanism Operated Cell(MOC) in VCB, and has a final target in product development minimizing contact malfunction of the chattering or rebounce states caused by existing MOC. In this test results, when opening and closing VCB, rising velocity of surge voltage in opening time was measured 4.2 times faster than closing time and noise decibel value was measured respectively 120dB and 110dB. When supplying 60kV power frequency overvoltage, we found that sensor output graph in VCB opening and closing times operated stably without distortion. When supplying 150kV $1.2{\times}50{\mu}s$ impulse frequency voltage, we found that voltage graph of output contact in sensor opening and closing sides maintained a normal condition without distortion, and when supplying 2500A current, we found that tested result of electric field noise operated stably without distortion.

FORECASTING OF FINANCIAL TIME SERIES BY A DIGITAL FILTER AND A NEURAL NETWORK

  • Saito, Susumu;Kanda, Shintaro
    • Proceedings of the Korea Society for Simulation Conference
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    • 2001.10a
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    • pp.313-317
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    • 2001
  • The approach to predict time series without neglecting the fluctuation in a short period is tried by using a digital FIR filter and a neural network. The differential waveform of the Nikkei average closing price is filtered by the FIR band-pass filter of 101 length. It is filtered into the five frequency bands of 0-1Hz, 1-2Hz, 2-3Hz, 3-4Hz and 4-5Hz by setting the sampling frequency 10Hz. The each filtered waveform is learned and forecasted by the neural network. The neural network of the back propagation method is adopted in the learning the waveform. By inputting the data of 20 days in the past, the prediction of 10 days ahead is carried out. After learning the time series of each frequency band by the neural network, the predicted data far each frequency band are obtained. The predicted waveforms of each frequency band are synthesized to obtain a final forecast. The waveform can be forecasted well as a whole.

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Modeling of the filling process during resin injection/compression molding

  • Chang, Chih-Yuan
    • Advanced Composite Materials
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    • v.16 no.3
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    • pp.207-221
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    • 2007
  • The filling process of resin injection/compression molding (I/CM) can be divided into injection and compression phases. During the resin injection the mold is kept only partially closed and thus a gap is present between the reinforcements and the upper mold. The gap results in preferential flow path. After the gap is filled with the resin, the compression action initiates and forces the resin to penetrate into the fiber preform. In the present study, the resin flow in the gap is simplified by using the Stokes approximation, while Darcy's law is used to calculate the flow field in the fiber mats. Results show that most of the injected resins enter into the gap during the injection phase. The resin injection time is extremely short so the duration of the filling process is determined by the final closing action of the mold cavity. Compared with resin transfer molding (RTM), I/CM process can reduce the mold filling time or injection pressure significantly.

The Study of void Closing Behavior in Upset Forging of Large Ingot (대형 잉곳의 업셋 단조에서의 기공 압착 거동에 관한 연구)

  • Lee K. J.;Bae W. B.;Cho J. R.;Kim D. K.;Kim J. T.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.406-409
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    • 2005
  • In the forging operation of large ingot two break-down process are upsetting and cogging. The first purpose of upsetting is to ensure sufficient forging ratio for subsequent cogging operations and consolidate the voids along the centerline. The second purpose is related to improve the physical properties for a final product. Voids which are generated during the casting process can be one of the decisive defects of materials. So it is necessary to know the standard of Judgment for void-closure in upsetting operation. In practical conditions, FEM analysis(DEFORM 2D 8.1) was carried out to decide how much effective strain has influence on void-closure. It is finally suggested that the function consists of the effective strain of analysis data and the area rate of void.

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Hydraulic Characteristic Analysis of Final Closing considering non-Darcy Flow (Non-Darcy 흐름을 고려한 최종체절 수리특성분석)

  • Choi, Hung Sik;Park, Jung Soo;Shin, Heung Keun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.1469-1473
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    • 2004
  • Non-Darcy흐름에 따른 호안제체의 흐름과 배수갑문을 통한 유출입 특성을 고려한 체절구간의 수리특성분석 도형에 의한 해석결과는 실측자료와 비교적 잘 일치하여 개발된 모형의 적용성이 있음을 보여주었다. 실측치와 비교한 계산결과는 본간(1958) 식에 의한 계산이 나(1987)에 의한 방법보다 비교적 정확하게 계산할 수 있음을 보여주었다. 아울러 완전 또는 불완전 월류의 구분이 없이 잠수도에 의한 계산을 통해서 하나의 유량계수 관계곡선을 사용하여 간편하게 사용할 수 있는 나 식의 사용성을 보여 주었다. 본간 식과 나 식에 의한 계산 값이 실측치보다는 유출입 특성이 크게 나타나고 있는 것으로 나타났다. 따라서 현장에서의 체절구간의 불규칙적인 단면 양상을 감안한 유량계수의 조정이 필요할 것으로 판단된다. 일반적으로 체절구간의 수리특성의 분석을 위해서 제체구간 유량의 고려는 Darcy 흐름에 기초하여 분석한 것이 지금까지의 분석이다. 제체를 통과는 유량과 개방구간을 통과하는 유량의 비가 체절구간이 좁을수록 크게 나타나 제체의 정확한 유출임 특성을 고려한 체절구간의 수리특성을 분석해야할 필요가 있음을 확인하였다.

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Flow Through Rubble Mound Dike (사석제를 투과하는 흐름)

  • 김채수;남선우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.4
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    • pp.109-116
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    • 1988
  • This study was aimed at determining a regime of flow through rubble mound dike consisted of all sized quarrystons, and deriving a relationship between hydraulic gradient (I) and mean flow velocity (V) through the dike. The analysis was carried out with the data observed after final gap closing of the Haenam Sea dike from May, 6 to May, 14, 1987. The resu]ts are summarized as follows: 1. The regime of flow would be defined as the turbulent flow. 2. As to the relationships, two kinds of formula that are exponential and binomial were obtained. Exponential formula: I=2.099V 1.2888 Binomial formula: I=0.6113V+5.5235V$^2$ 3. Correlation coefficient of the former was 0.824 and that of the latter was 0.821, and the deviations between observed data and estimated were 0.0070 and 0.0064 respectively. 4. Comparing the correlation coefficient, both the equations have the same correlation coefficients, but in case of the deviation the binomial equation was better than the exponential equation. Therefore, the binomial equation is proposed for analyzing the flow through rubble mound dike.

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An Improved Convergent Approach for Synthesis of Erlotinib, a Tyrosine Kinase Inhibitor, via a Ring Closure Reaction of Phenyl Benzamidine Intermediate

  • Asgari, Davoud;Aghanejad, Ayuob;Mojarrad, Javid Shahbazi
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.909-914
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    • 2011
  • An improved convergent and economical method has been developed for the synthesis of erlotinib, a 4-anilinoquinazoline and an EGFR-tyrosine kinase inhibitor for treatment of non-small-cell lung cancer. The final two steps for the formation of this 4-anilinoquinazoline from suitable 2-aminobenzonitrile intermediate and 3-ethynylaniline were modified and were performed in a simple one-pot reaction. The ring-closing mechanism for the formation of erlotinib from the suitable formamidine intermediate and 3-ethynylaniline was investigated and determined to proceed via the formation of phenyl benzamidine intermediate rather than involving Dimroth rearrangement reported earlier. The new benzamidine intermediate was isolated for the first time and characterized.

Interim palatal lift prosthesis as a constituent of multidisciplinary approach in the treatment of velopharyngeal incompetence

  • Raj, Neerja;Raj, Vineet;Aeran, Himanshu
    • The Journal of Advanced Prosthodontics
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    • v.4 no.4
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    • pp.243-247
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    • 2012
  • The velopharynx is a tridimensional muscular valve located between the oral and nasal cavities, consisting of the lateral and posterior pharyngeal walls and the soft palate, and controls the passage of air. Velopharyngeal insufficiency may take place when the velopharyngeal valve is unable to perform its own closing, due to a lack of tissue or lack of proper movement. Treatment options include surgical correction, prosthetic rehabilitation, and speech therapy; though optimal results often require a multidisciplinary approach for the restoration of both anatomical and physiological defect. We report a case of 56 year old male patient presenting with hypernasal speech pattern and velopharyngeal insufficiency secondary to cleft palate which had been surgically corrected 18 years ago. The patient was treated with a combination of speech therapy and palatal lift prosthesis employing interim prostheses in various phases before the insertion of definitive appliance. This phase-wise treatment plan helped to improve patient's compliance and final outcome.