• Title/Summary/Keyword: internal stability

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Stability Analysis of Sheet Pile Reinforced with Strut (버팀대로 보강된 널말뚝의 안정해석)

  • Kim, Ji Hoon;Kang, Yea Mook;Chee, In Taeg
    • Korean Journal of Agricultural Science
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    • v.24 no.2
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    • pp.226-236
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    • 1997
  • The results obtained by elasto-plastic analysis method about the displacement, deformation and stability on the soft ground excavation using sheet pile were summarized as follows ; 1. In the case of strut 1 step, the maximum wall displacement value in the first and the second excavation was small, but it increase remarkably after the third excavation and when the excavation depth was 8m, the point of maximum wall displacement was shown 0.75H~0.8H. 2. The value of safety factor(Fs) was increased with increasing of the penetration depth of sheet pile, cohesion and internal friction angle of ground. Safety factor was mostly effected by penetration depth of sheet pile and more effected by cohesion than internal friction angle of ground. 3. Since the deformation of sheet pile of this ground from the results of analysis and measurement increased remarkabaly after 6m excavation depth, it was desirable that the point of strut installation was GL-6m. 4. Safe excavation depth on ground by analysis considered penetration depth, cohesion and internal friction was shown at the table 3.

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Stability of Retroviral Vectors Against Ultracentrifugation Is Determined by the Viral Internal Core and Envelope Proteins Used for Pseudotyping

  • Kim, Soo-hyun;Lim, Kwang-il
    • Molecules and Cells
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    • v.40 no.5
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    • pp.339-345
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    • 2017
  • Retroviral and lentiviral vectors are mostly pseudotyped and often purified and concentrated via ultracentrifugation. In this study, we quantified and compared the stabilities of retroviral [murine leukemia virus (MLV)-based] and lentiviral [human immunodeficiency virus (HIV)-1-based] vectors pseudotyped with relatively mechanically stable envelope proteins, vesicular stomatitis virus glycoproteins (VSVGs), and the influenza virus WSN strain envelope proteins against ultracentrifugation. Lentiviral genomic and functional particles were more stable than the corresponding retroviral particles against ultracentrifugation when pseudotyped with VSVGs. However, both retroviral and lentiviral particles were unstable when pseudotyped with the influenza virus WSN strain envelope proteins. Therefore, the stabilities of pseudotyped retroviral and lentiviral vectors against ultracentrifugation process are a function of not only the type of envelope proteins, but also the type of viral internal core (MLV or HIV-1 core). In addition, the fraction of functional viral particles among genomic viral particles greatly varied at times during packaging, depending on the type of envelope proteins used for pseudotyping and the viral internal core.

Dynamic Stability Analysis of Floating Transport Wind-Turbine Foundation Considering Internal Fluid Sloshing Effect (내부 유체 슬로싱 효과를 고려한 부유이송 해상풍력 기초의 동적 안정성 해석)

  • Hong, Seokjin;Kim, Donghyun;Kang, Sinwook;Kang, Keumseok
    • KEPCO Journal on Electric Power and Energy
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    • v.2 no.3
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    • pp.461-467
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    • 2016
  • In order to install the floating transport type wind-turbine foundation, water pumping is used to sink the foundation. During this process, its mass and center of gravity, and buoyancy center become continuously changed so that the dynamic stability of the floating foundation become unstable. Dynamic stability analysis of the floating foundation is a complex problem since it should take into account not only the environmental wave, wind, and current loads but also its weight change effect simultaneously considering six-degree-of-freedom motion. In this study, advanced numerical method based on the coupled computational fluid dynamics (CFD) and multi-body dynamics (MBD) approach has been applied to the dynamic stability analysis of the floating foundation. The sloshing effect of foundation internal water is also considered and the floating dynamic characteristics are numerically investigated in detail.

Water-induced changes in mechanical parameters of soil-rock mixture and their effect on talus slope stability

  • Xing, Haofeng;Liu, Liangliang;Luo, Yong
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.353-362
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    • 2019
  • Soil-rock mixture (S-RM) is an inhomogeneous geomaterial that is widely encountered in nature. The mechanical and physical properties of S-RM are important factors contributing towards different deformation characteristics and unstable modes of the talus slope. In this paper, the equivalent substitution method was employed for the preparation of S-RM test samples, and large-scale triaxial laboratory tests were conducted to investigate their mechanical parameters by varying the water content and confining pressure. Additionally, a simplified geological model based on the finite element method was established to compare the stability of talus slopes with different strength parameters and in different excavation and support processes. The results showed that the S-RM samples exhibit slight strain softening and strain hardening under low and high water content, respectively. The water content of S-RM also had an effect on decreasing strength parameters, with the decrease in magnitude of the cohesive force and internal friction angle being mainly influenced by the low and high water content, respectively. The stability of talus slope decreased with a decrease in the cohesion force and internal friction angle, thereby creating a new shallow slip surface. Since the excavation of toe of the slope for road construction can easily cause a landslide, anti-slide piles can be used to effectively improve the slope stability, especially for shallow excavations. But the efficacy of anti-slide piles gradually decreases with increasing water content. This paper can act as a reference for the selection of strength parameters of S-RM and provide an analysis of the instability of the talus slope.

Effect of Microporous Structure of Al2O3/PVdF_HFP Ceramic Coating Layers on Thermal Stability and Electrochemical Performance of Composite Separators for Lithium-Ion Batteries (Al2O3/PVdF_HFP 세라믹코팅층의 미세기공구조가 리튬이차전지용 복합분리막의 열 안정성 및 전기화학특성에 미치는 영향)

  • Jeong, Hyun-Seok;Kim, Kyu-Chul;Lee, Sang-Young
    • Journal of the Korean Electrochemical Society
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    • v.12 no.4
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    • pp.324-328
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    • 2009
  • The internal short-circuit between cathodes and anodes has been known to be a critical concern for the safety failures of lithium-ion batteries, which is strongly influenced by the thermal stability of separators. In this study, to effectively suppress the internal short-circuit failures, we developed a new composite separator with the improved thermal stability compared to conventional polyolefin-based separators. The composite separators were prepared by introducing a ceramic coating layer ($Al_2O_3$/PVdF-HFP) onto both sides of a polyethylene (PE) separator. The microporous structure of ceramic coating layers is determined by controlling the phase inversion of coating solutions and becomes more developed with the increase of nonsolvent (water) content. This structural change of ceramic coating layers was observed to greatly affect the thermal stability as well as the electrochemical performance of composite separators, which was systematically discussed in terms of phase inversion.

Influence of moisture content on main mechanical properties of expansive soil and deformation of non-equal-length double-row piles: A case study

  • Wei, Meng;Liao, Fengfan;Zhou, Kerui;Yan, Shichun;Liu, Jianguo;Wang, Peng
    • Geomechanics and Engineering
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    • v.30 no.2
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    • pp.139-151
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    • 2022
  • The mechanical properties of expansive soil are very unstable, highly sensitive to water, and thus easy to cause major engineering accidents. In this paper, the expansive soil foundation pit project of the East Huada Square in the eastern suburb of Chengdu was studied, the moisture content of the expansive soil was considered as an important factor that affecting the mechanics properties of expansive soil and the stability of the non-equal-length double-row piles in the foundation pit support. Three groups of direct shear tests were carried out and the quantitative relationships between the moisture content and shear strength τ, cohesion c, internal friction angle φ were obtained. The effect of cohesion and internal friction angle on the maximum displacement and the maximum bending moment of piles were analyzed by the finite element software MIDAS/GTS (Geotechnical and Tunnel Analysis System). Results show that the higher the moisture content, the smaller the matrix suction, and the smaller the shear strength; the cohesion and the internal friction angle are exponentially related to the moisture content, and both are negatively correlated. The maximum displacement and the maximum bending moment of the non-equal length double-row piles decrease with the increase of the cohesion and the internal friction angle. When the cohesion is greater than 33 kPa or the internal friction angle is greater than 25.5°, the maximum displacement and maximum bending moment of the piles are relatively small, however, once crossing the points (the corresponding moisture content value is 24.4%), the maximum displacement and the maximum bending moment will increase significantly. Therefore, in order to ensure the stability and safety of the foundation pit support structure of the East Huada Square, the moisture content of the expansive soil should not exceed 24.4%.

Effects of CRM Success Factors on Job & Customer Performance in Banking Sectors: Focused on the Mediating Effect of Internal Member Satisfaction

  • Byun, Yoon-Sang;Park, Cheong-Yeul
    • Journal of Distribution Science
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    • v.15 no.1
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    • pp.57-70
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    • 2017
  • Purpose - This study examined the effects of CRM success factors on business performance and customer performance, and the effects on job performance and customer performance through internal member satisfaction by considering of technology, organizational environment and customer relationship factors in CRM success factors from banking sectors. Research design, data, and methodology - An online questionnaire was conducted to 251 employees in banking sectors. The data were analyzed by SPSS 22.0 and Amos 21.0. CRM success factors, internal member satisfaction, job performance, and customer performance were analyzed by descriptive statistics and Pearson's correlation analysis. The bootstrapping in structural equations was conducted to verify the mediating effect of internal member satisfaction. Results - Internal members' satisfaction had a positive effect on job and customer performance. It mediated the relationship between organizational environment, customer relationship factors and job performance. It also mediated the relationship between organizational environment and customer performance. Conclusions - If internal members' relationship with customers is improved by the members' satisfaction, customer retention, customer satisfaction, and work performance will be achieved. The stability and usability in CRM system support jobs effectively, but the internal members did not feel their job satisfaction. Thus, they did not show a positive effect on job and customer performance.

Physical and Mechanical Properties of Panels Fabricated with Particle and Fiber by Composition Types (구성형태(構成形態)에 따른 파티클과 파이버로 제조(製造)한 패널의 물리적 및 기계적 성질)

  • Yoon, Hyoung-Un;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.20 no.2
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    • pp.9-22
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    • 1992
  • The aim of this research was to investigate physical and mechanical properties of various composition panels, each fabricated with a ratio of fiber to particle of 2 to 10. Type A consisted of fiber-faces and particle-core in layered-mat system. Type B consisted of fiberboard-faces on particleboard-core. Type C consisted of fibers and particles in mixed-mat system. The results obtained from tests of bending strength, internal bond, screw holding strength and stability were as follows: 1. The bending strength and internal bonding of both the Type A panel and the Type B panel were higher than those of the Type C panel and three-layered particle board. 2. The mechanical properties of the Type C panel showed the lowest values of all composition methods. It seems that the different compression ratios of the particle and fiber interrupted the densification of the fibers when hot pressed. 3. The dimensional stability of layered-mat system panels consising of fiber-faces and particle-core was better the than control particleboard. 4. In composition methods of particle and fiber, layered-composition method was more resonable than mixed-composition. The Type B panel had the highest mechanical properties of all the composition types. 5. The Type A panel was considered the ideal composition method because of its resistance to delamination between the particle-layer and the fiber-layer and because of its lower adhesive content and more effective manufa cturing process.

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Comparison of clustering methods of microarray gene expression data (마이크로어레이 유전자 발현 자료에 대한 군집 방법 비교)

  • Lim, Jin-Soo;Lim, Dong-Hoon
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.1
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    • pp.39-51
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    • 2012
  • Cluster analysis has proven to be a useful tool for investigating the association structure among genes and samples in a microarray data set. We applied several cluster validation measures to evaluate the performance of clustering algorithms for analyzing microarray gene expression data, including hierarchical clustering, K-means, PAM, SOM and model-based clustering. The available validation measures fall into the three general categories of internal, stability and biological. The performance of clustering algorithms is evaluated using simulated and SRBCT microarray data. Our results from simulated data show that nearly every methods have good results with same result as the number of classes in the original data. For the SRBCT data the best choice for the number of clusters is less clear than the simulated data. It appeared that PAM, SOM, model-based method showed similar results to simulated data under Silhouette with of internal measure as well as PAM and model-based method under biological measure, while model-based clustering has the best value of stability measure.