• Title/Summary/Keyword: One-Step

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A Study On the Combined One Body Stamping Using F.E.A. (유한요소해석을 이용한 일체복합성형성에 대한 연구)

  • Kwon S. Y.;Lee J. K.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.05a
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    • pp.171-175
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    • 2005
  • Automotive parts manufacturers are doing their best to strengthen the competitiveness. They are developing a large variety of new manufacturing technologies to reduce the manufacturing cost. Combined One Body Stamping(C.O.B.S) is one of the remarkable technologies to reduce production cost. C.O.B.S makes possible to form several parts together in a process using only one die set while conventional stamping demands the same number of die sets to the number of parts. But the deformation mechanism in C.O.B.S is more complicated because the interactions between blanks. So the interaction effects should be considered in the stage of initial blank shape design. In the study, a blank design method to consider the interactions between blanks was proposed and verified through the simulations and experiments. A commercial incremental FE code, LS-Dyna, was used to simulate the C.O.B.S Process. And a reverse one step FE code, Hyper Form, was used to predict initial blank shape. The boundary conditions of the reverse one step FE analysis were determined by the proposed method.

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The evaluation of surface roughness and polishing time between polishing systems (연마시스템에 따른 복합레진의 표면거칠기와 연마시간에 대한 평가)

  • Kim, Ye-Mi;Shin, Su-Jung;Song, Min-Ju;Park, Jeong-Won
    • Restorative Dentistry and Endodontics
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    • v.36 no.2
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    • pp.119-124
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    • 2011
  • Objectives: The purpose of this experiment was to evaluate four different polishing systems of their polishability and polishing time. Materials and Methods: 4 mm diameter and 2 mm thickness Teflon mold was made. Z-250 (3M ESPE) hybrid composite resin was slightly overfilled and pressed with slide glass and cured with Optilux 501 for 40 sec each side. Then the surface roughness (glass pressed: control group) was measured with profilometer. One surface of the specimen was roughened by #320 grit sand paper and polished with one of the following polishing systems; Sof-Lex (3M ESPE), Jiffy (Ultradent), Enhance (Dentsply/Caulk), or Pogo (Dentsply/Caulk). The surface roughness and the total polishing time were measured. The results were analyzed with one-way ANOVA and Duncan's multiple range test. Results: The surface roughness was lowest in Pogo, and highest in Sof-Lex. Polishing times were shortest with Pogo, and followed by the Sof-Lex, Enhance and Jiffy. Conclusions: One-step polishing system (Pogo) is very effective to get the smooth surface in a short time, therefore it can be recommended for final polishing system of the restoration.

The Interlimb Coordination During Movement Initiation From a Quiet Stance: Manipulation of Swing Limb Kinetics and Kinematics -A Preliminary Study

  • Kim, Hyeong-Dong;Yoon, Bum-Chull
    • Physical Therapy Korea
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    • v.13 no.4
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    • pp.79-86
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    • 2006
  • The purpose of the current experiment was to describe interlimb coordination when swing limb conditions are being manipulated by constraining step length or by adding a 5 or 10 pound weight to the swing limb distally. Subjects were asked to begin walking with the right limb to land on the primary target (normal step length) that is 10 cm in diameter. However, if, during movement, the light was illuminated, then the subject had to step on one of the secondary targets (long and short step length). These three step length conditions were repeated while wearing a 5 pound ankle weight and then when wearing a 10 pound ankle weight. Ground reaction force (GRF) data indicated that there were changes in the forces and slopes of the swing and stance Fx GRFs. Long stepping subjects had to increase the propulsive force required to increase step length. Consequently, swing and stance toe-off greatly increased in the long step length condition. Short step length subjects had to adequately adjust step length, which decreased the speed of gait initiation. Loading the swing limb decreased the force and slope of the swing limb. Swing and stance toe-off was longest for the long step length condition, but there was a small difference of temporal events between no weight and weight condition. It appears that subjects modulated GRFs and temporal events differently to achieve the peak acceleration force of the swing and stance limb in response to different tasks. The findings from the current study provide preliminary data, which can be used to further investigate how we modulate forces during voluntary movement from a quiet stance. This information may be important if we are to use this or a similar task to evaluate gait patterns of the elderly and patient populations.

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Comparisons of Different Step-drawdown Test Analysis Methods; Implication for Improrvced Analysis for Step-drawdown Test Data (단계양수시험 해석 방법에 따른 우물 및 수리 상수 변동 분석)

  • An, Hyowon;Ha, Kyoochul;Lee, Eunhee;Do, Byung Hee
    • Journal of Soil and Groundwater Environment
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    • v.25 no.4
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    • pp.35-47
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    • 2020
  • Step-drawdown test is one of the widely-used aquifer test methods to evaluate aquifer and well losses. Various approaches have been suggested to estimate well losses using the step-drawdown test data but the uncertainties associated with data interpretation and analysis still exist. In this study, we applied three different step-drawdown test analysis methods -Jacob (1947), Labadie and Helweg (1975), Gupta (1989)- to the step-drawdown test data in Seobu-myeon, Hongseong-gun, South Korea and estimated aquifer and well losses. Comparisons of different step-drawdown test analysis methods revealed that the estimated well losses showed different values depending on the applied methods and these variations are likely to be related to the limitation of the assumptions for each analysis method. Based on the detailed analysis of time-drawdown data, we performed step-drawdown test analysis after removing outlier data during the initial stage of step drawdown test. The results showed that the application of the revised time-drawdown data could substantially decrease the error of the analysis as well as the variations in the estimated well losses from different analysis methods.

Program Development of Scientists' Episode: Focusing on Scientists' Joy, Anger, Sorrow, and Pleasure (과학자의 희로애락(喜怒哀樂)이 담긴 과학사 에피소드 활용 교육 프로그램 개발)

  • Lee, Yun-Kyung;Shin, Dong-Hee
    • Journal of The Korean Association For Science Education
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    • v.34 no.5
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    • pp.469-478
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    • 2014
  • To provide students an alternative image of science and scientist, we developed five lesson plans that include scientists' joy, anger, sorrow, and pleasure in their life. Through the 10 hour lessons with the five topics, we investigated the effect of our program on students' image change toward scientists, their science learning, and their career development in science field. Twenty high school students participated in our program and five of them were analyzed. The qualitative data included opinionnaire survey before and after the program, field note, video recording, students' worksheets, and interview. The science episode lessons that reflect the human side of scientists were designed in five steps. The first step is the one about imaging of scientists, the second step is the one about reading scientists' episode in their life, the third step is the one about investigating human side of scientists, the fourth step is the one about feeling sympathy in scientists' context, and the last step is the one about judging human side of scientists. Students participated in this program got to feel familiarity in scientists as well as confidence in science. By obtaining the alternative image of scientists after the class, it is expected that students will play roles of well-prepared supporters with scientific literacy.

Comparison of Methods for Stable Simultaneous Expression of Various Heterologous Genes in Saccharomyces cerevisiae (출아효모에서 다양한 이종 유전자의 안정적 동시발현을 위한 방법의 비교)

  • Jung, Heo-Myung;Kim, Yeon-Hee
    • Microbiology and Biotechnology Letters
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    • v.47 no.4
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    • pp.667-672
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    • 2019
  • We compared two integration systems for stable expression of heterologous genes in Saccharomyces cerevisiae. A Candida glabrata-derived gene was used as the selective marker for the Cre/loxP system, and XYLP, XYLB, GRE3, and XYL2 genes were used as model heterologous genes and ligated into the universal pRS-CMT vector. The resulting pRS-XylP, pRS-XylB, pRS-Gre3, and pRS-Xyl2 plasmids were sequentially integrated into yeast chromosome VII by four integration processes (marker rescue and gene integration). The four introduced genes were successfully expressed. Further, the pRS-PBG2 plasmid harboring expression cassettes for the four genes was constructed for one-step integration. The four genes that were introduced were stably maintained as a gene cluster and were simultaneously expressed. The one-step integration was more effective for the simultaneous integration and expression of the four genes related to xylan/xylose metabolism. This method will enable the generation of a useful biosystem through appropriate use of gene integration methods.

Unsaturated Hydraulic Conductivity Functions of van Genuchten's and Campbell's models Tested by One-step Outflow Method through Tempe Pressure Cell (empe 압력셀에서 1-단계 유출법을 이용한 van Genchten모형과 Campbell모형의 불포화수리전도도 추정 검증)

  • Han, Kyung-Hwa;Ro, Hee-Myong;Cho, Hyun-Jun;Kim, Lee-Yul;Hwang, Seon-Woong;Cho, Hee-Rae;Song, Kwan-Cheol
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.4
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    • pp.273-278
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    • 2008
  • This study was carried out in order to test unsaturated hydraulic conductivity estimation of van Genuchten's and Campbell's models using one-step outflow method through Tempe pressure cell. The undisturbed soil cores (columns) were taken from Ap1, B1 and C horizons of Songjeong series (the fine loamy, mesic family of Typic Hapludults). After the saturated hydraulic conductivity Ks of the cores was determined by constant head method, water outflow rate and retentivity of cores were measured in Tempe pressure cell. Fitted curves by models accorded to measured data except for both end of pressure range. In near-saturated condition, measured water retention characteristics showed a relatively better fitness with Campbell's model than van Genuchten's. The soil unsaturated conductivity estimated by Campbell's model was higher than by van Genuchten's. In Ap1 and B1 horizon, the soil unsaturated conductivities obtained by one-step outflow method went between van Genuchten's and Campbell's hydraulic functions, slightly closer to van Genuchten's. In C horizon, van Genuchten's model had better fitness with the one-step outflow data. Consequently, van Genuchten's model generally had better fitness with measured hydraulic conductivity than Campbell's model at the soil water potential range of -10~-75 kPa, especially in C1 horizon. In near-saturated condition, Campbell's model could be thought as relatively accurate hydraulic model, because of the better fitness of Campbell's model with soil water retention data than van Genuchten's model.

One step multiplex RT-PCR preventing DNA carryover contamination for differential diagnosis of swine influenza viruses (DNA 교차 오염 방지 기능을 가진 돼지 인플루엔자바이러스 감별진단용 one-step multiplex RT-PCR 진단법)

  • Kim, Hee-Jung;Kim, Eun-Mi;Shin, Yeun-Kyung;Song, Jae-Young;Kim, Seong-Hee;Lee, Kyoung-Ki;Lee, Myoung-Heon;Kim, Young-Hwa;Park, Jun-Cheol;Yeo, Sang-Geon;Park, Choi-Kyu
    • Korean Journal of Veterinary Service
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    • v.37 no.4
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    • pp.263-271
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    • 2014
  • In this study, we developed a cost and time saving one-step multiplex RT-PCR for the simultaneous detection and differentiation of swine influenza viruses (SIV) and 2009 pandemic influenza H1N1 virus (pH1N1). The one-step multiplex RT-PCR using four sets of primer was confirmed to be capable of detection of all SIV subtypes and differential diagnosis of major SIV subtype H1, H3 and pH1N1 on individual or mixed viral culture samples. The sensitivity of the multiplex RT-PCR was determined to be at least $2^{-6}$ $HA/25{\mu}L$ of the presented SIVs, providing sufficient efficacy for a routine SIV monitoring in diagnostic laboratories. In addition, compared with the conventional RT-PCR methods that cannot avoid the carryover DNA contamination, the developed RT-PCR applied with the uracil DNA glycosylase (UNG) system was proven to prevent a false positive reaction by carryover contamination of the pre-amplified DNA. In conclusion, the one-step RT-PCR with UNG system could be applicable to detect and differentiate of SIV from the viral cultures without worry of carryover DNA contamination in clinical laboratories.