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Performance analysis of information propagation in DTN-like scale-free mobile social network
( Zhifei Wang ),( Su Deng ),( Hongbin Huang ),( Yahui Wu ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.11
Mobile social network can be seen as a specific application of the DTN (Delay Tolerant Network), in which the information propagation can be impacted by many social behaviors of the nodes. For a specific node, its social behaviors are various. For example, the node may not be interested in the information before receiving it and may also discard the information after getting it. On the other hand, people are more willing to forward the message to his friends. These interactive behaviors between nodes can be seen as social behaviors. It is easy to see that the impact of the social behaviors is related to the social ties, which can be manifested by the structure of the social network. State of the art works often simply assumes that the social networks can be divided into some communities. At present, some works find that the structure of some social networks is scale-free. To overcome this problem, this paper proposes a theoretical model to evaluate the impact of above social behaviors in the DTN-like scale-free network. Simulation shows the accuracy of the model. Numerical results show that both social behaviors and scale-free character have significant impact on information propagation. Moreover, the impact of social behaviors is related to the scale-free character of the networks.
Zhifei Liu,Liangyi Xue,Weiliang Shen,Jun Ying,Zhenhua Zhang 한국유전학회 2014 Genes & Genomics Vol.36 No.2
Follistatin is a multifunctional regulatory proteininvolved in numerous physiological activities. Tobetter understand its functions in Larimichthys crocea (L.crocea), the entire cDNA sequence of follistatin from L. crocea was cloned, the transcript abundance of follistatinwas measured at different development stages and in differentgender. A fasting-refeeding protocol was also performedto correlate follistatin tissue expression withnutritional status in the juvenile stage of L. crocea. Theresults showed that follistatin transcripts were weaklydetected before gastrula stage (9 h post-fertilization; hpf),and at the highest level at myogenesis stage (15 hpf) and 30days after hatching (30 dah). In adult fish, follistatin transcriptswere observed in all the ten tissues examined andmost abundant in eye, gill, muscle, brain and intestine. Moreover, the abundance of follistatin transcripts in mosttissues was influenced by the age and gender. Duringfasting and refeeding period, the regulatory response offollistatin in muscle, liver, gonad, spleen and brain of L. crocea varied greatly. Altogether, these findings supportthe evidence that follistatin plays a profound role in theteleost development and that it is an indispensable factorfor the survival of teleosts when challenged with environmentalstresses like fasting.
Unified solutions for piezoelectric bilayer cantilevers and solution modifications
Zhifei Shi,Xianfeng Wang 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.16 No.5
Based on the theory of piezoelasticity, the static performance of a piezoelectric bilayer cantilever fully covered with electrodes on the upper and lower surfaces is studied. Three models are considered, i.e., the sensor model, the driving displacement model and the blocking force model. By establishing suitable boundary conditions and proposing an appropriate Airy stress function, the exact solutions for piezoelectric bilayer cantilevers are obtained, and the effect of ambient thermal excitation is taken into account. Since the layer thicknesses and material parameters are distinguished in different layers, this paper gives unified solutions for composite piezoelectric bilayer cantilevers including piezoelectric bimorph and piezoelectric heterogeneous bimorph, etc. For some special cases, the simplifications of the present results are compared with other solutions given by other researches based on one-dimensional constitutive equations, and some amendments have been found. The present investigation shows: (1) for a PZT-4 piezoelectric bimorph, the amendments of tip deflections induced by an end shear force, an end moment or an external voltage are about 19.59%, 23.72% and 7.21%, respectively; (2) for a PZT-4-Al piezoelectric heterogeneous bimorph with constant layer thicknesses, the amendments of tip deflections induced by an end shear force, an end moment or an external voltage are 9.85%, 11.78% and 4.07%, respectively, and the amendments of the electrode charges induced by an end shear force or an end moment are both 1.04%; (3) for a PZT-4-Al piezoelectric heterogeneous bimorph with different layer thicknesses, the maximum amendment of tip deflection approaches 23.72%, and the maximum amendment of electrode charge approaches 31.09%. The present solutions can be used to optimize bilayer devices, and the Airy stress function can be used to study other piezoelectric cantilevers including multi-layered piezoelectric cantilevers under corresponding loads.
Zhifei Liu,Liangyi Xue,Sheng Sun,Zhen Xu,Hong Yu 한국유전학회 2014 Genes & Genomics Vol.36 No.5
The 3,110-bp myostatin-2 was obtained from amarine teleost, Larimichthys crocea (L. crocea), by PCRamplication coupled with 50- and 30-rapid amplification ofcDNA ends. Myostatin-2 contains a 71-bp 50-untranslatedregion, a 328-bp exon I, an 895-bp intron I, a 371-bp exonII, a 382-bp intron II, a 381-bp exon III, and a 682 bp 30-untranslated region, and it encodes a protein of 359 aminoacid residues. The deduced amino acid sequence has typicalcharacteristics of TGF-b family members with nineconserved cysteine residues and a RXXR proteolytic processingsite within the conserved C-terminal portion, andmore than 90 % similarity with other fish myostatin-2proteins. Quantitative assessment revealed that levels ofmyostatin-1 transcripts fluctuated markedly, whereas myostatin-2 expression remained very low during most stagesof embryonic development. In addition, both myostatin-1and -2 transcripts were detected in all 10 examined tissuesof juvenile and adult individuals, but they exhibited differentexpression patterns and responses to fasting. Expression of myostatin-1 was highest in skeletal muscle,which was higher than myostatin-2 by 2–3 orders ofmagnitude. Myostatin-2 transcripts were greatest in brain. Myostatin-1 expression increased significantly after 3 daysof fasting, whereas myostatin-2 expression was unaffected. Our results imply that myostatin-1 and -2 may have differentroles in skeletal muscle growth and development ofL. crocea.
Exact analyses for two kinds of piezoelectric hollow cylinders with graded properties
Taotao Zhang,Zhifei Shi 국제구조공학회 2010 Smart Structures and Systems, An International Jou Vol.6 No.8
Based on the theory of piezo-elasticity, the paper obtains the exact solutions of functionally graded piezoelectric hollow cylinders with different piezoelectric parameter g31. Two kinds of piezoelectric hollow cylinders are considered herein. One is a multi-layered cylinder with different parameter g31 in different layers; the other is a continuously graded cylinder with arbitrarily variable g31. By using the Airy stress function method with plane strain assumptions, the exact solutions of the mechanic and electrical components of both cylinders are obtained when they are subjected to external voltage (actuator) and pressure (sensor), simultaneously. Furthermore, good agreement is achieved between the theoretical and numerical results, and useful conclusions are given.