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From Dynamic Linear Evaluation Rule to Dynamic CAPM in a Fractional Brownian Motion Environment  [PDF]
Qing Zhou, Chao Li
Journal of Mathematical Finance (JMF) , 2012, DOI: 10.4236/jmf.2012.24034
Abstract: In this paper, we present the fundamental framework of the evaluation problem under which the evaluation operator satisfying some axioms is linear. Based on the dynamic linear evaluation mechanism of contingent claims, studying this evaluation rule in the market driven by fractional Brownian motions has led to a dynamic capital asset pricing model. It is deduced here mainly with the fractional Girsanov theorem and the Clark-Haussmann-Ocone theorem.
SAR Imaging of Moving Target Based on Quadratic Phase Function  [PDF]
Chao Wang, Shaobin Li
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.43B003
Abstract:

In this paper, a novel signal processing technique hasbeen developed to refocus moving targets image from their smeared responses in the Synthetic Aperture Radar (SAR) image according to the characteristics of the received signals for moving targets. Quadratic Phase Function is introduced to the parameters estimation for moving target echo and SAR imaging. Our method is available even under a low SNR environment and acquiring an exact SAR image of moving targets. The simulated results demonstrated the validity of the algorithm proposed.

A Domain Extension Algorithm for Digital Error Correction of Pipeline ADCs  [PDF]
Ting Li, Chao You
Circuits and Systems (CS) , 2014, DOI: 10.4236/cs.2014.52006
Abstract:

A domain extension algorithm to correct the comparator offsets of pipeline analog-to-digital converters (ADCs) is presented, in which the 1.5-bit/stage ADC quantify domain is extended from a three-domain to a five-domain. This algorithm is designed for high speed and low comparator accuracy application. The comparator offset correction ability is improved. This new approach also promises significant improvements to the spurious-free dynamic range (SFDR), the total harmonic distortion (THD), the signal-to-noise ratio (SNR) and the minor analog and digital circuit modifications. Behavioral simulation results are presented to demonstrate the effectiveness of the algorithm, in which all absolute values of comparator offsets are set to |3Vref/8|. SFDR, THD and SNR are improved, from 34.62-dB, 34.63-dB and 30.33-dB to 60.23-dB, 61.14-dB and 59.35-dB, respectively, for a 10-bit pipeline ADC.

Progress in Antimonide Based III-V Compound Semiconductors and Devices  [PDF]
Chao Liu, Yanbo Li, Yiping Zeng
Engineering (ENG) , 2010, DOI: 10.4236/eng.2010.28079
Abstract: In recent years, the narrow bandgap antimonide based compound semiconductors (ABCS) are widely regarded as the first candidate materials for fabrication of the third generation infrared photon detectors and integrated circuits with ultra-high speed and ultra-low power consumption. Due to their unique bandgap structure and physical properties, it makes a vast space to develop various novel devices, and becomes a hot research area in many developed countries such as USA, Japan, Germany and Israel etc. Research progress in the preparation and application of ABCS materials, existing problems and some latest results are briefly introduced.
Principal Component Analyses in Anthropological Genetics  [PDF]
Xingdong Chen, Chao Chen, Li Jin
Advances in Anthropology (AA) , 2011, DOI: 10.4236/aa.2011.12002
Abstract: Principal component analyses (PCA) is a statistical method for exploring and making sense of datasets with a large number of measurements (which can be thought of as dimensions) by reducing the dimensions to the few principal components (PCs) that explain the main patterns. Thus, the first PC is the mathematical combination of measurements that accounts for the largest amount of variability in the data. Here, we gave an interpretation about the principle of PCA and its original mathematical algorithm, singular variable decomposition (SVD). PCA can be used in study of gene expression; also PCA has a population genetics interpretation and can be used to identify differences in ancestry among populations and samples, through there are some limitations due to the dynamics of microevolution and historical processes, with advent of molecular techniques, PCA on Y chromosome, mtDNA, and nuclear DNA gave us more accurate interpretations than on classical markers. Furthermore, we list some new extensions and limits of PCA.
Aerodynamic Model Analysis and Flight Simulation Research of UAV Based on Simulink  [PDF]
Chao Yun, Xiao-Min Li
Journal of Software Engineering and Applications (JSEA) , 2013, DOI: 10.4236/jsea.2013.62007
Abstract:

Mathematical simulation method can be adopted to check flight characteristic of UAV, also can be adopted to simulate hardware experiments of unmanned aerial vehicle (UAV), then related flight experiments can be performed. The simulation method can reduce the flight periods, cost and risk. UAV flight model research play an important role in simulation and modeling in initialize periods of the UAV producing. The study of the paper focuses on the aerodynamic force modeling work of UAV based on Simulink. The designed model not only can afford mathematics simulation experiment but also will do benefits to the research of flight control, navigation guidance of UAV.

Studies on the in Vitro Dissolution of Insoluble Volatile Drug from Su-Anxin Nasal Inhalant and Its Correlation on the Nose Steady Self-Controllable Expiration and Inspiration at Night  [PDF]
Xiaodong Li, Guoxiang Xie, Suyun Li, Chao Hou
Pharmacology & Pharmacy (PP) , 2011, DOI: 10.4236/pp.2011.22008
Abstract: In the paper, the in vitro dissolution of borneol in 12 hours from 6 batches of optimized inhalant samples were investigated. As a new dosage form, the in vitro release apparatus of nasal inhalant was invented and a pushing bump was used according to the simulation of the nose expiration and inspiration. Based on the data of r2 in the profile and similar factor f2 from 6 linear release tendencies, a good controlled release and a zero order tendency were observed. It can be suggested that there is a good correlation between the in vitro controlled release and the nose steady self-controllable expiration and inspiration, which will contribute to the trend of insoluble volatile drug controlled release and the effect of quick absorption in nasal pulmonary delivery to cure severe or acute cardiovascular or lung diseases at patients' sleeping, such as angina or breathing obstruction. Also, it was concluded that the prescription composed of insoluble volatile drugs can be prepared to be nasal inhalant from which drugs can be absorbed through nose steady self-controllable inspiration to the lung then into the blood and have a great effectiveness improvement of bioavailability at night timing drug delivery system.
Investigation of airborne fungi at different altitudes in Shenzhen University  [PDF]
Li Li, Chao Lei, Zhi-Gang Liu
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.25063
Abstract: Aim: To investigate the richness of species or genera of airborne fungi, the amount of airborne fungi, and its seasonal variation at different al-titudes in Shenzhen University. The effect of meteorological factors on airborne fungi was also analyzed. Methods: Slide-exposure me- thod and open-plate method were used. Results: There were 27 genera or species of fungus spores identified. Among the identified fungal genus, Cladosporium, Ustilago, Alternaria, Helminth-sporium and Uredinales were more prevalent. There were 18 genera of fungi colonies identified. Among which Penicillium, non-sporulating fungi, Aspergillus, Saccharomyces and Cladosporium were more common. The airborne fungal spores were present in the atmosphere of Shenzhen University all year round. The peaks of airborne spores appeared during April and October, while the lowest numbers were observed during January, July and December from March 2005-Febrary 2006. The highest volumes of fungi colonies were observed during April, October and September, while the lowest numbers were de-tected during in January, July and December or May from March 2005-Febrary 2006. The meteoro-logical factors had no relationship between the total monthly spore count at 10 and 30 meter height. At 70 meter, the total spores count was negatively correlated with solar radiation. Conclusions: Most of the fungi spores decreased along with the increase of altitudes.
Uniformly Almost Periodic Functions and Almost Periodic Solutions to Dynamic Equations on Time Scales
Yongkun Li,Chao Wang
Abstract and Applied Analysis , 2011, DOI: 10.1155/2011/341520
Abstract: Firstly, we propose a concept of uniformly almost periodic functions on almost periodic time scales and investigate some basic properties of them. When time scale or , our definition of the uniformly almost periodic functions is equivalent to the classical definitions of uniformly almost periodic functions and the uniformly almost periodic sequences, respectively. Then, based on these, we study the existence and uniqueness of almost periodic solutions and derive some fundamental conditions of admitting an exponential dichotomy to linear dynamic equations. Finally, as an application of our results, we study the existence of almost periodic solutions for an almost periodic nonlinear dynamic equations on time scales. 1. Introduction In recent years, researches in many fields on time scales have received much attention. The theory of calculus on time scales (see [1, 2] and references cited therein) was initiated by Hilger in his Ph.D. thesis in 1988 [3] in order to unify continuous and discrete analysis, and it has a tremendous potential for applications and has recently received much attention since his fundamental work. It has been created in order to unify the study of differential and difference equations. Many papers have been published on the theory of dynamic equations on time scales [4–10]. Also, the existence of almost periodic, asymptotically almost periodic, and pseudo-almost periodic solutions is among the most attractive topics in qualitative theory of differential equations and difference equations due to their applications, especially in biology, economics and physics [11–29]. However, there are no concepts of almost periodic functions on time scales so that it is impossible for us to study almost periodic solutions for dynamic equations on time scales. Motivated by the above, our main purpose of this paper is firstly to propose a concept of uniformly almost periodic functions on time scales and investigate some basic properties of them. Then we study the existence and uniqueness of almost periodic solutions to linear dynamic equations on almost time scales. Finally, as an application of our results, we study the existence of almost periodic solutions for almost periodic nonlinear dynamic equations on time scales. The organization of this paper is as follows. In Section 2, we introduce some notations and definitions and state some preliminary results needed in the later sections. In Section 3, we propose the concept of uniformly almost periodic functions on almost periodic time scales and investigate the basic properties of uniformly almost
Almost Periodic Functions on Time Scales and Applications
Yongkun Li,Chao Wang
Discrete Dynamics in Nature and Society , 2011, DOI: 10.1155/2011/727068
Abstract: We first propose the concept of almost periodic time scales and then give the definition of almost periodic functions on almost periodic time scales, then by using the theory of calculus on time scales and some mathematical methods, some basic results about almost periodic differential equations on almost periodic time scales are established. Based on these results, a class of high-order Hopfield neural networks with variable delays are studied on almost periodic time scales, and some sufficient conditions are established for the existence and global asymptotic stability of the almost periodic solution. Finally, two examples and numerical simulations are presented to illustrate the feasibility and effectiveness of the results. 1. Introduction It is well known that in celestial mechanics, almost periodic solutions and stable solutions to differential equations or difference equations are intimately related. In the same way, stable electronic circuits, ecological systems, neural networks, and so forth exhibit almost periodic behavior. A vast amount of researches have been directed toward studying these phenomena (see [1–6]). Also, the theory of calculus on time scales (see [7] and references cited therein) was initiated by Stefan Hilger in his Ph.D. thesis in 1988 [8] in order to unify continuous and discrete analysis, and it has a tremendous potential for applications and has recently received much attention since his foundational work. Therefore, it is meaningful to study that on time scales which can unify the continuous and discrete situations. However, there are no concepts of almost periodic time scales and almost periodic functions on time scales, so that it is impossible for us to study almost periodic solutions to differential equations on time scales. Motivated by the above, the main purpose of this paper is to propose the concept of almost periodic time scales and then give the definition of almost periodic functions on almost periodic time scales, then establish some basic results about almost periodic differential equations on almost periodic time scales by using the theory of calculus on time scales and some mathematical methods. Furthermore, based on these results, as an application, we consider the following high-order Hopfield neural networks with variable delays on time scales: where corresponds to the number of units in a neural network, corresponds to the state vector of the th unit at the time , represents the rate with which the th unit will reset its potential to the resting state in isolation when disconnected from the network and
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