• 제목/요약/키워드: results

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입자 강화 복합재의 등가 열전도 계수에 대한 연구 (A Study on Effective Thermal Conductivity of Particulate Reinforced Composite)

  • 이재곤
    • 동력기계공학회지
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    • 제10권4호
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    • pp.133-138
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    • 2006
  • Effective thermal conductivity of particulate reinforced composite has been predicted by Eshelby's equivalent inclusion method modified with Mori-Tanaka's mean field theory. The predicted results are compared with the experimental results from the literature. The model composite is polymer matrix filled with ceramic particles such as silica, alumina, and aluminum nitride. The preliminary examination by Eshelby type model shows that the predicted results are in good agreements with the experimental results for the composite with perfect spherical filler. As the shape of filler deviates from the perfect sphere, the predicted error increases. By using the aspect ratio of the filler deduced from the fixed filler volume fraction of 30%, the predicted results coincide well with the experimental results for filler volume fraction of 40% or less. Beyond this fraction, the predicted error increases rapidly. It can be finally concluded from the study that Eshelby type model can be applied to predict the thermal conductivity of the particulate composite with filler volume fraction less than 40%.

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Ratcheting behavior of 90° elbow piping under seismic loading

  • Chen, Xiaohui;Huang, Kaicheng;Ye, Sheng;Fan, Yuchen;Li, Zifeng
    • Earthquakes and Structures
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    • 제17권5호
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    • pp.489-499
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    • 2019
  • Elastic-plastic behavior of nuclear power plant elbow piping under seismic loads has been conducted in this study. Finite element analyses are performed using classical Bilinear kinematic hardening model (BKIN) and Multilinear kinematic hardening model (MKIN) as well as a nonlinear kinematic hardening model (Chaboche model). The influence of internal pressure and seismic loading on ratcheting strain of elbow pipe is studied by means of the three models. The results found that the predicted results of Chaboche model is maximum, closely followed by the predicted results of MKIN model, and the minimum is the predicted results of BKIN model. Moreover, comparisons of analysis results for each plasticity model against predicted results for a equivalent cyclic loading elbow component and for a simplified piping system seismic test are presented in the paper.

The Impact of the Competitiveness of Intermediate Software on Enterprise Results: a Case Study of Chinese Intermediate Software

  • Liu, Zi-Yang
    • 한국컴퓨터정보학회논문지
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    • 제23권12호
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    • pp.123-129
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    • 2018
  • The purpose of this paper is to draw a conclusion on the impact of intermediate software on enterprise results. In this paper, product innovation and product reliability are especially used as analytical factors. An exploratory analytical study is conducted on the competitiveness of intermediate software, in the hope of gaining a new understanding of the competitiveness of intermediate software. Data are analyzed using such quantitative analytical tools as SPSS and AMOS. Using reliability analysis, validity analysis and structural equation model analysis, the final results are achieved. According to the analysis results, we can draw the following conclusions: the competitiveness of intermediate software has a positive impact on the innovation of software products. The competitiveness of intermediate software doesn't have a positive impact on the reliability of software products. Product innovation has a positive impact on enterprise results. Product reliability also has a positive impact on enterprise results. By analyzing the conclusions, we can make certain suggestions and draw implications on the competitiveness of China's software industry.

SOME FIXED POINT RESULTS FOR TAC-SUZUKI CONTRACTIVE MAPPINGS

  • Mebawondu, Akindele A.;Mewomo, Oluwatosin T.
    • 대한수학회논문집
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    • 제34권4호
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    • pp.1201-1222
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    • 2019
  • In this paper, we introduce the notion of modified TAC-Suzuki-Berinde type F-contraction and modified TAC-(${\psi}$, ${\phi}$)-Suzuki type rational mappings in the frame work of complete metric spaces, we also establish some fixed point results regarding this class of mappings and we present some examples to support our main results. The results obtained in this work extend and generalize the results of Dutta et al. [9], Rhoades [18], Doric, [8], Khan et al. [13], Wardowski [25], Piri et al. [17], Sing et al. [23] and many more results in this direction.

액중 방전 성형과 인공신경망 기법을 활용한 Cowper-Symonds 구성 방정식의 변형률 속도 파라메터 역추정 (Estimating Strain Rate Dependent Parameters of Cowper-Symonds Model Using Electrohydraulic Forming and Artificial Neural Network)

  • 변한비;김정
    • 소성∙가공
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    • 제31권2호
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    • pp.81-88
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    • 2022
  • Numerical analysis and dynamic material properties are required to analyze the behavior of workpiece during an electrohydraulic forming (EHF) process. In this study, EHF experiments were conducted under three conditions (6, 7, 8 kV). Dynamic material properties of Al 5052-H34 were inversely estimated through an ANN (Artificial Neural Network) model constructed based on LS-Dyna analysis results. Parameters of Cowper-Symonds constitutive equation, C and p, were used to implement dynamic material properties. By comparing experimental results of three conditions with ANN model results, optimized parameters were obtained. To determine the reliability of the derived parameters, experimental results, LS-Dyna analysis results, and ANN results of three conditions were compared using MSE and SMAPE. Valid parameters were obtained because values of indicators were within confidence intervals.

Igniter and Thickness Effects on Upward Flame Spread

  • J.Q. Quintiere;Lee, C.H.
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.154-161
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    • 1997
  • Several studies have developed upward flame spread models which use somewhat different features. However, the models have not considered the transient effects of the igniter and the burning rate. Thus, the objective of this study is to examine a generalized upward flame spread model which includes these effects. We shall compare the results with results from simpler models used in the past in order to examine the importance of the simplifying assumptions. We compare these results using PMMA, and we also include experimental results for comparison. The results of the comparison indicate that flame velocity depends on the thermal properties of a material, the specific model for flame length and transient burning rate, as well as other variables including the heat flux by igniter and flame itself. The results from the generalized upward flame spread model can provide a prediction of flame velocity, flame and pyrolysis height, burnout time and position, and rate of energy output as a function of time.

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Puzzles of Astronomical Spectroscopic Results

  • 이상각
    • 천문학회보
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    • 제38권1호
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    • pp.25-25
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    • 2013
  • Review briefly results of the solar and stellar chemical abundances from the high resolution spectroscopy and discuss the solar composition problem and puzzles of the astronomical spectroscopic results.

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초등학생들의 학교구강검진결과에 대한 학부모의 이행수준과 관련요인 (Implementation Level and Factors of Parents about Dental Examination in Elementary School Children)

  • 최성미;사공준;장은진
    • 보건의료산업학회지
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    • 제7권2호
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    • pp.179-190
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    • 2013
  • This study evaluated the interest of parents of elementary school children on the examination with their memory of results, their consistency and their compliance with results sheets to improve effects of School dental health management project. This study recruited 1,334 second-, third-, fifth- and sixth-grade students at two elementary schools located in Daegu metropolitan city performing School Dental Examination Project in 2008 and investigated whether the students visited dental hospitals following results of the examination, how the parents remembered the results and how their memory was same with real results based on results of the examination, the parents' memory of results. The parents of second- and third-grade students showed good memory of malocclusion and number of Caries and higher consistency for dental caries. The parents of fifth- and sixth-grade students showed good memory of dental caries. Visiting rates of dental hospitals accordance with grade were 75.7% due to dental caries in second- and third-grade students and 60.5% due to malocclusion in fifth- and sixth-grade students. Among students with abnormal results of the examination, 77.1% of the children with dental caries of parents having same memory with real results visited the hospitals while 52.7% of those of parents having different memory with them did.

관절 내 종골 골절의 골절양상에 따른 수술적 치료 (Operative Treatment of Intraarticular Calcaneal Fracture According to the Fracture Type)

  • 라종득;박현수;임창석;장영수;박상원;정태원;전용수
    • 대한족부족관절학회지
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    • 제8권2호
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    • pp.176-181
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    • 2004
  • Purpose: We evaluated the clinical results of operative treatment of the intraarticular calcaneal fracture according to fracture classification. Materials and Methods: There were 25 cases (24 patients) which had at least one year follow up, 17 men and 7 women who were treated from June 1997 to March 2003. We have analysed the Bohler's angle, cruciate angle, width and posttraumatic osteoarthritis in radiological evaluation, and evaluated clinical results according to the Creighton-Nebraska health foundation score. Results: Excellent results were noted in 7 cases, good results in 6 cases, fair results in 4 cases and poor results in 8 cases. Radiological changes showed as follows: Bohler angle $17^{\circ}$, Crucial angle $0.1^{\circ}$, Width 6mm. Conclusion: Type II showed satisfactory results and type IV showed unsatisfactory results in Sanders classification. Proper evaluation of the intraarticular calcaneal fracture by X-ray and CT scan is necessory to predict prognosis and decise method of operative treatment.

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Whole-Blood Gene-Expression Profiles of Cows Infected with Mycobacterium avium subsp. paratuberculosis Reveal Changes in Immune Response and Lipid Metabolism

  • Shin, Min-Kyoung;Park, Hong-Tae;Shin, Seung Won;Jung, Myunghwan;Im, Young Bin;Park, Hyun-Eui;Cho, Yong-Il;Yoo, Han Sang
    • Journal of Microbiology and Biotechnology
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    • 제25권2호
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    • pp.255-267
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    • 2015
  • Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease, a chronic debilitating disease affecting ruminants worldwide. In the present study, we aimed to determine the major gene networks and pathways underlying the immune response to MAP infection using whole-blood cells, as well as provide the potential transcriptional markers for identifying the status of MAP infection. We analyzed the transcriptional profiles of whole-blood cells of cattle identified and grouped according to the presence of MAP-specific antibodies and the MAP shed by them. The grouping was based on the results obtained by ELISA and PCR analyses as follows: i) Test1 group: MAP-negative results obtained by ELISA and positive results obtained by PCR; ii) Test2 group: MAP-positive results obtained by ELISA and negative results obtained by PCR; iii) Test3 group: MAP-positive results obtained by ELISA and positive results obtained by PCR; iv) uninfected control: MAP-negative results obtained both by ELISA and PCR analysis. The results showed down-regulated production and metabolism of reactive oxygen species in the Test1 group, activation of pathways related to the host-defense response against MAP (LXR/RXR activation and complement system) in the Test2 and Test3 groups, and anti-inflammatory response (activation of IL-10 signaling pathway) only in the Test3 group. Our data indicate a balanced response that serves the immune-limiting mechanism while the host-defense responses are progressing.