Showing papers by "Northeastern University (China) published in 2008"
TL;DR: Two new definitions, parameter important degree and decision partition, are proposed for analyzing the algorithm of normal parameter reduction in soft sets to overcome the problems of suboptimal choice and added parameter set.
Abstract: This paper is concerned with the reduction of soft sets and fuzzy soft sets. Firstly, the problems of suboptimal choice and added parameter set of soft sets are analyzed. Then, we introduce the definition of normal parameter reduction in soft sets to overcome these problems. In addition, a heuristic algorithm of normal parameter reduction is presented. Two new definitions, parameter important degree and decision partition, are proposed for analyzing the algorithm of normal parameter reduction. Furthermore, the normal parameter reduction is also investigated in fuzzy soft sets.
301 citations
TL;DR: In this letter, the global asymptotical stability analysis problem is considered for a class of Markovian jumping stochastic Cohen-Grossberg neural networks with mixed delays including discrete delays and distributed delays and an alternative delay-dependent stability analysis result is established based on the LMI technique.
Abstract: In this letter, the global asymptotical stability analysis problem is considered for a class of Markovian jumping stochastic Cohen-Grossberg neural networks (CGNNs) with mixed delays including discrete delays and distributed delays. An alternative delay-dependent stability analysis result is established based on the linear matrix inequality (LMI) technique, which can easily be checked by utilizing the numerically efficient Matlab LMI toolbox. Neither system transformation nor free-weight matrix via Newton-Leibniz formula is required. Two numerical examples are included to show the effectiveness of the result.
280 citations
01 Apr 2008
TL;DR: It is concluded that the stability result for linear switched systems still holds for such systems with time-varying delay under a certain delay bound, and the delay bound of guaranteeing system stability can be easily obtained based on linear matrix inequalities (LMIs).
Abstract: This correspondence considers the stability problem for a class of linear switched systems with time-varying delay in the sense of Hurwitz convex combination. The bound of derivative of the time-varying delay can be an unknown constant. It is concluded that the stability result for linear switched systems still holds for such systems with time-varying delay under a certain delay bound. Moreover, the delay bound of guaranteeing system stability can be easily obtained based on linear matrix inequalities (LMIs). As a special case, when the time-varying delay becomes constant, the criterion obtained in this correspondence is less conservative than existing ones. The reason for less conservativeness is also explicitly explained in this correspondence. Simulation examples illustrate the effectiveness of the proposed method.
263 citations
TL;DR: In this paper, ultrasonic surface rolling processing (USRP) was applied on quenched and tempered 40Cr. The results showed that the USRP can both get nano-structured layers, with grain size of 3-7nm and reduce the surface roughness to 0.05μm.
193 citations
TL;DR: A linear goal programming model is constructed to integrate the fuzzy assessment information and to directly compute the collective ranking values of alternatives without the need of information transformation to solve the group decision making (GDM) problems with multi-granularity linguistic assessment information.
184 citations
TL;DR: Results indicate that TNTA are indeed very attractive oxygen-sensing materials.
Abstract: [Lu, Hao Feng; Jiang, Zhou Hua] Northeastern Univ, Sch Met & Mat, Shenyang 110004, Peoples R China. [Lu, Hao Feng; Li, Feng; Liu, Gang; Chen, Zhi-Gang; Wang, Da-Wei; Cheng, Hui-Ming] Chinese Acad Sci, Shenyang Natl Lab Mat Sci, Inst Met Res, Shenyang 110016, Peoples R China. [Fang, Hai-Tao] Harbin Inst Technol, Sch Mat Sci & Engn, Harbin 150001, Peoples R China. [Lu, Gao Qing] Univ Queensland, Australian Inst Bioengn & Nanotechnol, Brisbane, Qld 4072, Australia. [Lu, Gao Qing] Univ Queensland, ARC Ctr Excellence Funct Nanomat, Sch Engn, Brisbane, Qld 4072, Australia.;Lu, HF (reprint author), Northeastern Univ, Sch Met & Mat, 11,Lane 3,WenHua Rd, Shenyang 110004, Peoples R China;jiangzh@smm.neu.edu.cn cheng@imr.ac.cn
182 citations
01 Feb 2008
TL;DR: By constructing a new stochastic Lyapunov-Krasovskii functional, sufficient conditions for delay-dependent guaranteed cost control are obtained which do not require system transformation or relaxation matrices.
Abstract: This paper studies the guaranteed cost control problem for a class of uncertain stochastic nonlinear systems with multiple time delays represented by the Takagi-Sugeno fuzzy model with uncertain parameters. By constructing a new stochastic Lyapunov-Krasovskii functional, sufficient conditions for delay-dependent guaranteed cost control are obtained which do not require system transformation or relaxation matrices. Conditions for the existence of an optimal guaranteed cost controller are presented in the linear matrix inequality format. Simulation examples are provided to demonstrate the effectiveness of the proposed approach in this paper.
172 citations
TL;DR: In this article, a new tuning method for fractional order proportional and integral (FO-PI) controller is presented, where the load disturbance rejection is optimized with a constraint on the maximum or peak sensitivity.
Abstract: This paper presents a new practical tuning method for fractional order proportional and integral (FO-PI) controller. The plant to be controlled is mainly first order plus delay time (FOPDT). The tuning is optimum in the sense that the load disturbance rejection is optimized yet with a constraint on the maximum or peak sensitivity. We generalized M s constrained integral (MIGO) based controller tuning method to handle the FO-PI case, called F-MIGO, given the fractional order a. The F-MIGO method is then used to develop tuning rules for the FOPDT class of dynamic systems. The final developed tuning rules only apply the relative dead time T of the FOPDT model to determine the best fractional order a and at the same time to determine the best FO-PI gains. Extensive simulation results are included to illustrate the simple yet practical nature of the developed new tuning rules. The tuning rule development procedure for FO-PI is not only valid for FOPDT but also applicable for other general class of plants.
162 citations
18 Aug 2008
TL;DR: A new selective sampling technique, sampling by uncertainty and density (SUD), is presented, in which a k-Nearest-Neighbor-based density measure is adopted to determine whether an unlabeled example is an outlier.
Abstract: This paper addresses two issues of active learning. Firstly, to solve a problem of uncertainty sampling that it often fails by selecting outliers, this paper presents a new selective sampling technique, sampling by uncertainty and density (SUD), in which a k-Nearest-Neighbor-based density measure is adopted to determine whether an unlabeled example is an outlier. Secondly, a technique of sampling by clustering (SBC) is applied to build a representative initial training data set for active learning. Finally, we implement a new algorithm of active learning with SUD and SBC techniques. The experimental results from three real-world data sets show that our method outperforms competing methods, particularly at the early stages of active learning.
162 citations
TL;DR: In this article, an anion exchange membrane for alkaline direct ethanol fuel cell (ADEFC) was prepared by doping KOH in polybenzimidazole (PBI) membrane.
160 citations
TL;DR: In this paper, a numerical code called RFPA was used to study the influence of different dip angle of layered joints and the lateral pressure coefficient on the stability of tunnel in jointed rock mass.
TL;DR: In this article, sediment co-deposition (SCD) technique from a Watt's type electrolyte containing nano-Al2O3 particles was used to improve the corrosion and high temperature oxidation resistance of composite coatings.
Abstract: Ni–Al2O3 composite coatings were prepared by using sediment co-deposition (SCD) technique from a Watt's type electrolyte containing nano-Al2O3 particles. The corrosion resistance and high temperature oxidation resistance of resulting composite coatings were investigated. It was found that the incorporation of nano-Al2O3 particles in Ni matrix refined the Ni crystal and changed the preferential orientation of composite coatings. Meanwhile, the corrosion and oxidation resistance were improved after the incorporation of nano-Al2O3 particles into Ni matrix. The nano-Al2O3 content in deposits plays an important role for improving the corrosion and oxidation protection. The corrosion and oxidation resistance of Ni-Al2O3 nano-composite coatings produced via SCD technique are superior to that of CEP technique. Compared to pure Ni and Ni-Al2O3 composite coatings fabricated using CEP technique, the Ni–7.58 wt.% Al2O3 composite coating obtained by SCD technique exhibits better corrosion resistance and enhanced high temperature oxidation resistance. Moreover, the mechanism of corrosion and high temperature oxidation resistance of Ni–Al2O3 nano-composite coatings are discussed.
TL;DR: Experiments conducted on the real data sets CB513 and RS126 demonstrate that the proposed ELM based protein secondary structure prediction framework can achieve as good prediction accuracy as other popular methods; however, at very fast learning speed.
TL;DR: In this article, an anion exchange membrane for alkaline direct methanol fuel cell (ADMFC) was prepared by doping polybenzimidazole (PBI) membrane with KOH.
TL;DR: The growth responses and possible phytoremediation ability of three ornamental plants selected from the previous preliminary experiments were further examined and showed that these tested plants had higher tolerance to Cd and Pb contamination and could effectively accumulate the metals.
TL;DR: Wang et al. as discussed by the authors investigated how C. microphylla plantations affected the physical, chemical and microbiological properties of a sandy soil and found that shrub growth altered microclimate, increased litter input, and hence, improved soil water holding capacity, contents of total carbon, total N and microbial biomass C and N.
TL;DR: A fault detection observer is designed by employing two performance indesxes which are used to increase the fault sensitivity in finite frequency domain and attenuate the effects of disturbances in full frequency domain.
Abstract: This paper deals with the fault detection (FD) problem in the finite frequency domain for linear time-invariant discrete-time systems with bounded disturbances. A fault detection observer is designed by employing two performance indesxes which are used to increase the fault sensitivity in finite frequency domain and attenuate the effects of disturbances in full frequency domain. With the aid of the generalized Kalman–Yakubovich–Popov (GKYP) Lemma, the design methods are presented in terms of solutions to a set of linear matrix inequalities (LMIs). Numerical examples are given to illustrate the effectiveness of the proposed method.
TL;DR: In this article, a nano-sized titanium carbide (TiC) was employed as the support material for an iridium (Ir) electrocatalyst in a proton exchange membrane water electrolyser (PEMWE).
TL;DR: The present system was applied for selective isolation of heme-protein, i.e., hemoglobin from human whole blood without any pretreatment, giving rise to satisfactory results.
18 Nov 2008
TL;DR: This paper proposes a security solution for LEACH, a protocol in which the clusters are formed dynamically and periodically, and uses improved random pair-wise keys (RPK) scheme, an optimized security scheme that relies on symmetric-key methods; is lightweight and preserves the core of the original LEACH.
Abstract: Wireless sensor networks routing protocols always neglect security problem at the designing step, while plenty of solutions of this problem exist, one of which is using key management. Researchers have proposed many key management schemes, but most of them were designed for flat wireless sensor networks, which is not fit for cluster-based wireless sensor networks (e.g. LEACH). In this paper, we investigate adding security to cluster-based routing protocols for wireless sensor networks which consisted of sensor nodes with severely limited resources, and propose a security solution for LEACH, a protocol in which the clusters are formed dynamically and periodically. Our solution uses improved random pair-wise keys (RPK) scheme, an optimized security scheme that relys on symmetric-key methods; is lightweight and preserves the core of the original LEACH. Simulations show that security of RLEACH has been improved, with less energy consumption and lighter overhead.
TL;DR: In this article, a chrome-free conversion coating on magnesium-lithium alloy was obtained from a phosphate-permanganate solution, and the morphology, the composition and the corrosion resistance of this coating were examined.
Abstract: A chrome-free conversion coating on magnesium–lithium alloy was obtained from a phosphate–permanganate solution. The morphology, the composition and the corrosion resistance of this coating were examined. The thin and non-penetrating cracked morphology with some deposits existed on the phosphate–permanganate conversion coating. The main elements of the conversion coating were Mg, O, K, P and Mn. The results of the electrochemical measurements and the immersion tests demonstrated that the corrosion resistance of the magnesium–lithium alloy has been improved by the phosphate–permanganate conversion treatment.
TL;DR: Sufficient conditions for robust static output feedback stabilizing controller designs are given in terms of solutions to a set of linear matrix inequalities, and the results are extended to H2 and H∞static output feedback controller designs.
09 Jun 2008
TL;DR: This study proposes a dynamic programming algorithm for computing a tight lower bound on the number of common grams shared by two similar strings in order to improve query performance and proposes an algorithm for automatically computing a dictionary of high-quality grams for a workload of queries.
Abstract: Approximate queries on a collection of strings are important in many applications such as record linkage, spell checking, and Web search, where inconsistencies and errors exist in data as well as queries. Several existing algorithms use the concept of "grams," which are substrings of strings used as signatures for the strings to build index structures. A recently proposed technique, called VGRAM, improves the performance of these algorithms by using a carefully chosen dictionary of variable-length grams based on their requencies in the string collection. Since an index structure using fixed-length grams can be viewed as a special case of VGRAM, a fundamental problem arises naturally: what is the relationship between the gram dictionary and the performance of queries? We study this problem in this paper. We propose a dynamic programming algorithm for computing a tight lower bound on the number of common grams shared by two similar strings in order to improve query performance. We analyze how a gram dictionary affects the index structure of the string collection and ultimately the performance of queries. We also propose an algorithm for automatically computing a dictionary of high-quality grams for a workload of queries. Our experiments on real data sets show the improvement on query performance achieved by these techniques. To our best knowledge, this study is the first cost-based quantitative approach to deciding good grams for approximate string queries.
TL;DR: Hybrid films of polyaniline (PANI) and manganese oxide (MnOx) were obtained through potentiodynamic deposition from solutions of aniline and MnSO4 at pH 56 as mentioned in this paper.
TL;DR: In this article, a horn crucible was designed specially for this experiment and the horn was part of ultrasonic horn, and the molten alloy was treated direct in this crucible.
TL;DR: In this article, a novel ionic liquid of trifluoroacetic propylamine, i.e., [CH 3 CH 2 CH 2 NH 3 + ] [CF 3 COO − ] (TFAPA), was synthesized.
TL;DR: In this article, a nano-sized γ-alumina powder was prepared via sol-gel precipitation in ethanol followed by a washing-drying treatment and calcination, where the reactant concentration, the molar ratio of reactants and the calcination temperature were inspected by homogenous design.
TL;DR: In this paper, the fault detection observer design problem in finite frequency domain for linear time-invariant continuous-time systems with bounded disturbances is considered and two finite frequency performance indexes are introduced to measure the fault sensitivity and the disturbance robustness.
Abstract: This paper deals with the fault detection observer design problem in finite frequency domain for linear time-invariant continuous-time systems with bounded disturbances. Two finite frequency performance indexes are introduced to measure the fault sensitivity and the disturbance robustness. Faults are considered in the low frequency domain while disturbances are considered in certain finite frequency domain. With the aid of the Generalized Kalman-Yakubovich-Popov lemma, the design methods are presented in terms of solutions to a set of linear matrix inequalities. An example of the VTOL aircraft is studied to illustrate the effectiveness of the proposed method.
TL;DR: In this article, a robust H"2 state-feedback controller for continuous-time Markov jump linear systems subject to polytopic-type parameter uncertainty is proposed based on the parameter-dependent Lyapunov function approach.