oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 1 )

2019 ( 173 )

2018 ( 1217 )

2017 ( 1084 )

Custom range...

Search Results: 1 - 10 of 78568 matches for " Zhiping Chen "
All listed articles are free for downloading (OA Articles)
Page 1 /78568
Display every page Item
A New Class of Time-Consistent Dynamic Risk Measures and its Application  [PDF]
Rui Gao, Zhiping Chen
Technology and Investment (TI) , 2013, DOI: 10.4236/ti.2013.41B008
Abstract: We construct a new time consistent dynamic convex cash-subadditive risk measure in this paper. Different from exist-ing measures, both potential loss and volatility of risky objects are considered. Based on a one-period measure that dis-torts financial values, punishes downside risk yet rewards upside potential, a dynamic time consistent version is con-structed recursively through a modified translation property. We then establish a portfolio selection model and give its optimal condition.
A New LFM-Signal Detector Based on Fractional Fourier Transform
Zhiping Yin,Weidong Chen
EURASIP Journal on Advances in Signal Processing , 2010, DOI: 10.1155/2010/876282
Abstract: A new LFM-signal detector formulated by the integration of the 4th-power modulus of the fractional Fourier transform is proposed. It has similar performance to the modulus square detector of Radon-ambiguity transform because of the equivalence relationship between them. But the new detector has much lower computational complexity in the case that the number of the searching angles is far less than the length of the signal. Moreover, it is proved that the new detector can be generalized to the integration of the nth-power (2
A New LFM-Signal Detector Based on Fractional Fourier Transform
Yin Zhiping,Chen Weidong
EURASIP Journal on Advances in Signal Processing , 2010,
Abstract: A new LFM-signal detector formulated by the integration of the 4th-power modulus of the fractional Fourier transform is proposed. It has similar performance to the modulus square detector of Radon-ambiguity transform because of the equivalence relationship between them. But the new detector has much lower computational complexity in the case that the number of the searching angles is far less than the length of the signal. Moreover, it is proved that the new detector can be generalized to the integration of the nth-power ( ) modulus of the fractional Fourier transform via mathematical derivation. Computer simulation results have confirmed the effectiveness of the proposed detector in LFM-signal detection.
Screening of Microalgae for Biodiesel Feedstock  [PDF]
Xi Chen, Guoqiang He, Zhiping Deng, Nan Wang, Wei Jiang, Sanfeng Chen
Advances in Microbiology (AiM) , 2014, DOI: 10.4236/aim.2014.47044
Abstract:

Three heterotrophic microalgae identified as Scenedesmus sp. Y5, Scenedesmus sp. Y7 and Chorellasp. Y9 were isolated and screened from natural water based on biomass yield and lipid productivity. Fatty acids’ composition analysis showed that both Y5 and Y7 mainly contained C16:0, C18:1 (n - 9), C18:2 (n - 6) and C18:3 (n - 3) and Y9 mainly contained C16:0, C18:0 and C18:2 (n - 6), suggesting that these microalgae can be ideal feedstock for biodiesel. Considering the specific growth rate and lipid productivity, the culture conditions were optimized for Scenedesmus sp. Y5, Scenedesmus sp. Y7 and Chorellasp. Y9. Based on the optimization of cultural conditions, all of these three microalgae were tested in fed-batch fermentation, and their biomass productivities were 4.960 g·L-1·d-1, 5.907 g·L-1·d-1 and 4.038 g·L-1

An Expectation Maximization Algorithm to Model Failure Times by Continuous-Time Markov Chains
Qihong Duan,Zhiping Chen,Dengfu Zhao
Mathematical Problems in Engineering , 2010, DOI: 10.1155/2010/242567
Abstract: In many applications, the failure rate function may present a bathtub shape curve. In this paper, an expectation maximization algorithm is proposed to construct a suitable continuous-time Markov chain which models the failure time data by the first time reaching the absorbing state. Assume that a system is described by methods of supplementary variables, the device of stage, and so on. Given a data set, the maximum likelihood estimators of the initial distribution and the infinitesimal transition rates of the Markov chain can be obtained by our novel algorithm. Suppose that there are transient states in the system and that there are failure time data. The devised algorithm only needs to compute the exponential of upper triangular matrices for times in each iteration. Finally, the algorithm is applied to two real data sets, which indicates the practicality and efficiency of our algorithm. 1. Introduction Among many quantitative analysis methods of system reliability, the state space representation has often been employed by reliability engineers, for example, [1–5]. The state space representation has been recognized by industrial IEC61511 standards [6]. This method assumes that the structure of the system is modelled with a continuous-time Markov chain (CTMC). In the state space representation, nodes represent states of the system and arcs represent the transitions between nodes. This method is well adapted to study the reliability of various systems and allows an exact analysis of their probability of failure. In the state space representation method, the time interval between two consecutive transitions is a random variable of an exponential distribution. However, many studies have presented counterexamples. For some mechanical and electronic components, the failure rate function of time to failure (TTF) has a bathtub curve: a monotonically decreasing function initially, eventually becoming a constant, and finally changing to a monotonically increasing function after sufficient time elapses [7]. Because existing approaches do not provide a perfect solution to deal with this class of systems, several researchers have explored models with nonexponential distributions (see [8–10] and references therein). Among many approaches treating TTF with nonexponential distributions, the extended Markov-model [11] is recommendable. In the extended Markov-model, an operation state is divided into substates with different levels of failure rates, which result in a nonconstant failure rate of the operation state. That is, in these models, the bug of failure rate
Fiber Sensor Systems Based on Fiber Laser and Microwave Photonic Technologies
Hongyan Fu,Daru Chen,Zhiping Cai
Sensors , 2012, DOI: 10.3390/s120505395
Abstract: Fiber-optic sensors, especially fiber Bragg grating (FBG) sensors are very attractive due to their numerous advantages over traditional sensors, such as light weight, high sensitivity, cost-effectiveness, immunity to electromagnetic interference, ease of multiplexing and so on. Therefore, fiber-optic sensors have been intensively studied during the last several decades. Nowadays, with the development of novel fiber technology, more and more newly invented fiber technologies bring better and superior performance to fiber-optic sensing networks. In this paper, the applications of some advanced photonic technologies including fiber lasers and microwave photonic technologies for fiber sensing applications are reviewed. FBG interrogations based on several kinds of fiber lasers, especially the novel Fourier domain mode locking fiber laser, have been introduced; for the application of microwave photonic technology, examples of microwave photonic filtering utilized as a FBG sensing interrogator and microwave signal generation acting as a transversal loading sensor have been given. Both theoretical analysis and experimental demonstrations have been carried out. The comparison of these advanced photonic technologies for the applications of fiber sensing is carried out and important issues related to the applications have been addressed and the suitable and potential application examples have also been discussed in this paper.
Spectral properties of LH2 exhibit very similar even when heterologously express LH2 with β-subunit fusion protein in Rhodobacter sphaeroides  [PDF]
Zhiping Zhao, Xin Nie, Zongli Hu, Guoping Chen, Zaixin Li, Zhi Zhang
Advances in Biological Chemistry (ABC) , 2013, DOI: 10.4236/abc.2013.31013
Abstract:

Interactions between the light-harvesting subunits and the non-covalently bound photopigments attribute considerably to the spectral properties of photosynthetic bacteria light-harvesting complexes. In our previous studies, we have constructed a novel Rhodobacter sphaeroides expression system. In the present study, we focus on the spectral properties of LH2 when heterologously express LH2 with β-subunit- GFP fusion protein in Rb. sphaeroides. Near infra-red spectrum of LH2 remained nearly unchanged as measured by spectroscopy. Fluorescence spectrum suggested that the LH2 with β-subunit-GFP fusion protein complexes still possessed normal activity in energy transfer. However, photopigments contents were significantly decreased to a very low level in the LH2 with β-subunit-GFP fusion protein complexes compared to that of LH2. FT-IR spectra indicated that interactions between photopigments and LH2 α/β- subunits appeared not to be changed. It was concluded that the LH2 spectral properties exhibited very similar even when heterologously expressed LH2 b-subunit fusion protein in Rb. sphaeroides. Our present study may supply a new insight into better understand the interactions between light-harvesting subunits and photopigments and bacterial photosynthesis and promote the development of the novel Rb. sphaeroides expression system.

Contribution of South China Sea Tropical Cyclones to an Increase in Southern China Summer Rainfall Around 1993

CHEN Jiepeng,WU Renguang,WEN Zhiping,

大气科学进展 , 2012,
Abstract: The increase in southern China summer rainfall around 1993 was accompanied by an increase in tropical cyclones that formed in the South China Sea. This study documents the connection of these two features. Our analysis shows that the contribution of tropical cyclones that formed in the South China Sea to southern China summer rainfall experienced a significant increase around 1993, in particular, along the coast and in the heavy rain category. The number of tropical cyclones that formed in the western North Pacific and entered the South China Sea decreased, and their contribution to summer rainfall was reduced in eastern part of southern China (but statistically insignificant). The increase in tropical cyclone-induced rainfall contributed up to ~30% of the total rainfall increase along the coastal regions. The increase of tropical cyclones in the South China Sea appears to be related to an increase in local sea surface temperature.
A NEW BRANCH-AND-BOUND ALGORITHM FOR SOLVING LARGE COMPLEX INTEGER CONVEX QUADRATIC PROGRAMS
求解中大规模复杂凸二次整数规划问题的新型分枝定界算法

Chen Zhiping Xi Feng,
陈志平
,郤峰

计算数学 , 2004,
Abstract: In view of disadvantages of usual branch-and-bound algorithms when they are used to solve high-dimensional complex integer quadratic programs, new methods for selecting the branching variable and node are devised by sufficiently utilizing Structural properties of integer quadratic programs. By combining the HNF algorithm and the solution of the original problem's continuous relaxation problem, a new technique for finding a good initial integer feasible solution is developed. These improvements result in a new branch-and-bound algorithm, which can be used to efficiently solve large-scale complex integer quadratic programs. Numerical results show that our new algorithm is not only a great enhancement on the existing branch-and-bound algorithms, but robust, efficient and suitable for different complex integer quadratic programming problems.
Formulation of Macroscopic TransportModels for Numerical Simulationof Semiconductor Devices
Edwin C. Kan,Zhiping Yu,Robert W. Dutton,Datong Chen
VLSI Design , 1995, DOI: 10.1155/1995/12686
Abstract:
Page 1 /78568
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.