• Title/Summary/Keyword: Technology evolution

Search Result 2,189, Processing Time 0.027 seconds

Evolution of the Mir-155 Family and Possible Targets in Cancers and the Immune System

  • Xie, Guang-Bing;Liu, Wei-Jia;Pan, Zhi-Jun;Cheng, Tian-Yin;Luo, Chao
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.18
    • /
    • pp.7547-7552
    • /
    • 2014
  • The mir-155 family is not only involved in a diversity of cancers, but also as a regulator of the immune system. However, the evolutionary history of this family is still unclear. The present study indicates that mir-155 evolved independently with lineage-specific gain of miRNAs. In addition, arm switching has occurred in the mir-155 family, and alternative splicing could produce two different lengths of ancestral sequences, implying the alternative splicing can also drive evolution for intragenic miRNAs. Here we screened validated target genes and immunity-related proteins, followed by analyzation of the mir-155 family function by high-throughput methods like the gene ontology (GO) and Kyoto Eneyclopedin of Genes and Genemes (KEGG) pathway enrichment analysis. The high-throughput analysis showed that the CCND1 and EGFR genes were outstanding in being significantly enriched, and the target genes cebpb and VCAM1 and the protein SMAD2 were also vital in mir-155-related immune reponse activities. Therefore, we conclude that the mir-155 family is highly conserved in evolution, and CCND1 and EGFR genes might be potential targets of mir-155 with regard to progress of cancers, while the cebpb and VCAM1 genes and the protein SMAD2 might be key factors in the mir-155 regulated immune activities.

SE-CAC: A Novel Call Admission Control Scheme for Multi-service IDMA Systems

  • Ge, Xin;Liu, Gongliang;Mao, Xingpeng;Zhang, Naitong
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.5 no.5
    • /
    • pp.1049-1068
    • /
    • 2011
  • In this paper a simple and effective call admission control (CAC) scheme is proposed for the emerging interleave-division multiple-access (IDMA) systems, supporting a variety of traffic types and offering different quality of service (QoS) requirements and priority levels. The proposed scheme is signal-to-interference-plus-noise ratio (SINR) evolution based CAC (SE-CAC). The key idea behind the scheme is to take advantage of the SINR evolution technique in the process of making admission decisions, which is developed from the effective chip-by-chip (CBC) multi-user detection (MUD) process in IDMA systems. By virtue of this semi-analytical technique, the MUD efficiency can be estimated accurately. Additionally, the computational complexity can be considerably reduced. These features make the scheme highly suitable for IDMA systems, which can combat intra-cell interference efficiently with simple CBC MUD. Analysis and simulation results show that compared to the traditional CAC scheme considering MUD efficiency as a constant, the proposed SE-CAC scheme can guarantee high power efficiency and throughput for multimedia traffic even in heavy load conditions, illustrating the high efficiency of CBC MUD. Furthermore, based on the SINR evolution, the SE-CAC can make accurate estimation of available resource considering the effect of MUD, leading to low outage probability as well as low blocking and dropping probability.

Incompatible deformation and damage evolution of mixed strata specimens containing a circular hole

  • Yang, Shuo;Li, Yuanhai;Chen, Miao;Liu, Jinshan
    • Geomechanics and Engineering
    • /
    • v.20 no.5
    • /
    • pp.461-474
    • /
    • 2020
  • Analysing the incompatible deformation and damage evolution around the tunnels in mixed strata is significant for evaluating the tunnel stability, as well as the interaction between the support system and the surrounding rock mass. To investigate this issue, confined compression tests were conducted on upper-soft and lower-hard strata specimens containing a circular hole using a rock testing system, the physical mechanical properties were then investigated. Then, the incompatible deformation and failure modes of the specimens were analysed based on the digital speckle correlation method (DSCM) and Acoustic Emission (AE) data. Finally, numerical simulations were conducted to explore the damage evolution of the mixed strata. The results indicate that at low inclination angles, the deformation and v-shaped notches inside the hole are controlled by the structure plane. Progressive spalling failure occurs at the sidewalls along the structure plane in soft rock. But the transmission of the loading force between the soft rock and hard rock are different in local. At high inclination angles, v-shaped notches are approximately perpendicular to the structure plane, and the soft and hard rock bear common loads. Incompatible deformation between the soft rock and hard rock controls the failure process. At inclination angles of 0°, 30° and 90°, incompatible deformations are closely related to rock damage. At 60°, incompatible deformations and rock damage are discordant due that the soft rock and hard rock alternately bears the major loads during the failure process. The failure trend and modes of the numerical results agree very well with those observed in the experimental results. As the inclination angles increase, the proportion of the shear or tensile damage exhibits a nonlinear increase or decrease, suggesting that the inclination angle of mixed strata may promote shear damage and restrain tensile damage.

A hybrid identification method on butterfly optimization and differential evolution algorithm

  • Zhou, Hongyuan;Zhang, Guangcai;Wang, Xiaojuan;Ni, Pinghe;Zhang, Jian
    • Smart Structures and Systems
    • /
    • v.26 no.3
    • /
    • pp.345-360
    • /
    • 2020
  • Modern swarm intelligence heuristic search methods are widely applied in the field of structural health monitoring due to their advantages of excellent global search capacity, loose requirement of initial guess and ease of computational implementation etc. To this end, a hybrid strategy is proposed based on butterfly optimization algorithm (BOA) and differential evolution (DE) with purpose of effective combination of their merits. In the proposed identification strategy, two improvements including mutation and crossover operations of DE, and dynamic adaptive operators are introduced into original BOA to reduce the risk to be trapped in local optimum and increase global search capability. The performance of the proposed algorithm, hybrid butterfly optimization and differential evolution algorithm (HBODEA) is evaluated by two numerical examples of a simply supported beam and a 37-bar truss structure, as well as an experimental test of 8-story shear-type steel frame structure in the laboratory. Compared with BOA and DE, the numerical and experimental results show that the proposed HBODEA is more robust to detect the reduction of stiffness with limited sensors and contaminated measurements. In addition, the effect of search space, two dynamic operators, population size on identification accuracy and efficiency of the proposed identification strategy are further investigated.

MD simulation of structural change of polyethylene induced by high energy ion bombardment

  • Kim, Chan-Soo;Ahmed, Sk. Faruque;Moon, Myoung-Woon;Lee, Kwang-Ryeol
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.02a
    • /
    • pp.358-358
    • /
    • 2010
  • Ion beam bombardment at low energy forms nanosize patterns such as ripples, dots or wrinkles on the surface of polymers in ambient temperature and pressure. It has been known that the ion beam can alter the polymer surface that induces skins stiffer or the density higher by higher compressive stress or strain energies associated with chain scissions and crosslinks of the polymer. Atomic scale structure evolution in polymers is essential to understand a stress generation mechanism during the ion beam bombardment, which governs the nanoscale surface structure evolution. In this work, Molecular Dynamics (MD) simulations are employed to characterize the phenomenon occurred in bombardment between the ion beam and polymers that forms nanosize patterns. We investigate the structure evolution of Low Density Polyethylene (LDPE) at 300 K as the polymer is bombarded with Argon ions having various kinetic energies ranging from 100 eV to 1 KeV with 50 eV intervals having the fluence of $1.45\;{\times}\;1014 #/cm2$. These simulations use the Reactive Force Field (ReaxFF), which can mimic chemical covalent bonds and includes van der Waals potentials for describing the intermolecular interactions. The results show the details of the structural evolution of LDPE by the low energy Ar ion bombardment. Analyses through kinetic and potential energy, number of crosslinks and chain scissions, level of local densification and motions of atoms support that the residual strain energies on the surface is strongly associated with the number of crosslinks or scissored chains. Also, we could find an optimal Ar ion beam energy to make crosslinks well.

  • PDF

Research and Development Trends in Seawater Electrolysis Systems and Catalysts (해수 수전해 시스템 및 촉매 연구 개발 동향)

  • Yoonseong Jung;Tuan Linh Doan;Ta Nam Nguyen;Taekeun Kim
    • Applied Chemistry for Engineering
    • /
    • v.34 no.6
    • /
    • pp.567-575
    • /
    • 2023
  • Water electrolysis is undergoing active research as one of the promising technologies for producing effective green hydrogen. Using seawater directly as a raw material for a water electrolysis system can solve the problem of the limitations of existing freshwater raw materials, as seawater accounts for approximately 97% of the water on Earth. At the same time, abundant by-product materials can be obtained, representative examples of which are Cl2, ClO-, Br2, and Mg(OH)2 produced during electrolysis, depending on their composition and pH environment. In order to develop a successful seawater electrolysis system and oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalysts, it is necessary to understand the causes and consequences of reactions that occur in the seawater environment. Therefore, in this paper, we will investigate the reaction mechanism and characteristics of the seawater electrolysis system as well as the research and development trends of electrochemical catalysts used in anode and cathode electrodes.

Evolution of Inter-firm Technology Transfer and Technological Capability Formation of Local Parts Firms in the Thai Automobile Industry

  • Techakanont, K.;Terdudomtham, T.
    • Journal of Technology Innovation
    • /
    • v.12 no.2
    • /
    • pp.151-183
    • /
    • 2004
  • This paper investigates the evolution of 'inter-firm' technology transfer in the Thai automobile industry, which has gradually been integrated into global production network of some specific automotive models(one-ton pickups). This paper discusses the linkage between the role of automobile assemblers in transferring technology and the way their strategic changes bring about heightened demands on the technological capacity of suppliers and the contents of technology transfer. With higher competition at the global level, local suppliers are required to improve their technical and managerial skills, especially in the area of 'product engineering' capability. The authors examine the ways local firms have adapted to these changes in their environments, as well as the ways they utilize inter-firm relationship with automobile assemblers as a means to improve their own technological capabilities. The dynamic process of capability formation in local parts firms, through intensive efforts and learning inducements brought about by inter-firm relationships, are also discussed.

  • PDF

Hydrogen Evolution Ability of Selected Pure Metals and Galvanic Corrosion Behavior between the Metals and Magnesium

  • Luo, Zhen;Song, Kaili;Li, Guijuan;Yang, Lei
    • Journal of Electrochemical Science and Technology
    • /
    • v.11 no.4
    • /
    • pp.323-329
    • /
    • 2020
  • The cathodic hydrogen evolution ability of different pure metals and their long term galvanic corrosion behavior with pure Mg were investigated. The hydrogen evolution ability of pure Ti, Al, Sn and Zr is weak, while that of Fe, W, Cr, and Co is very strong. Initial polarization test could not completely reveal the cathodic behavior of the tested metals during long term corrosion. The cathodic hydrogen evolution ability may vary significantly in the long term galvanic tests for different metals, especially for Al whose cathodic current density reduced to 1/50 of the initial value. The anodic polarization shows that Al and Sn as alloying elements are supposed to provide relatively good passive effect for Mg alloy, while Ag can provide a slight passive effect and Zn has little passive effect.