《风流寡妇》：爱情与外交

来自音乐之乡奥地利的维也纳轻歌剧团12月8、9、10日将携世界经典名剧《风流寡妇》翩翩登上北京展览馆剧场的舞台。

Grammar Consciousness-Raising Tasks and Intermediate Learners＇ Achievement and Perceptions

While there is lots of empirical evidence showing that grammar consciousness raising tasks （GCRTs） have an edge over the traditional modes of grammar instruction, there is very little qualitative evidence reflecting learners＇ perceptions of externally imposed educational changes including GCRTs. To extrapolate the previous findings and fill in this gap, this study aims to： （I） test the alleged superiority of GCRTs in grammar instruction and （2） explore learners＇ perceptions of learning grammar through GCRTs. To this end, this study used a mixed-method design including a quantitative and a qualitative dimension. The former dimension aimed at testing the superiority of GCRTs on a random sample of intermediate learners from Simin language school in Karaj, Iran through the robust Solomon-four-group design and the latter dimension aimed at collecting and analyzing qualitative interview data on learners＇ perceptions of GCRTs. The quantitative results clearly showed that learners being taught through GCRTs significantly outperformed those instructed through the traditional mode of grammar instruction and the qualitative analysis of learners＇ perspectives showed that the participants had a positive perception of GCRTs and this positive perception was rooted in GCRTs＇ potential to： （1） facilitate the internalization of grammar and （2） involve learners in discovery learning. The findings have clear implications for syllabus designers and practitioners.

A Survey on Device-Independent Quantum Communications

Quantum communications helps us to enhance the security and efficiency of communications and to deepen our understanding of quantum physics. Its rapid development in recent years has attracted the interest of researchers from diverse fields such as physics, mathematics, and computer science. We review the background and current state of quantum communications technology, with an emphasis on quantum key distribution, quantum random number generation, and a relatively hot topic: device independent protocols.

The Perception of Small- and Medium-Sized Enterprises （SMEs） on the Importance of a Proper Accounting System： Malaysian Evidence

This paper examines the relationship between small- and medium-sized enterprises＇ （SMEs） entrepreneurs＇ perceptions towards a proper accounting system with the level of accounting staff recruited, preparation of final accounts, meetings with accounting staff, and entrepreneurs＇ ranking of accounting according to their priority. The methodology used to gather the data is survey questionnaire. It has been distributed to SMEs based on simple random sampling method. Three hundred businesses were selected from the total of 3,390 businesses listed in Kuala Lumpur, Malaysia area obtained from Small and Medium Industries Development Corporation （SMIDEC） website and a few random selected from Ampang and Cheras areas. Regression analysis has been used to analyze the data. The results of the study reveal that there was a significant relation between SMEs entrepreneurs＇ perceptions on the importance of a good accounting system and the level of professional accounting staff recruited. Furthermore, findings of this study also found that there was an insignificant relationship between SMEs entrepreneurs＇ perceptions on the importance of a good accounting system and preparation of final accounts of the company and frequency of meetings with accounting staff.

Optimal reduction of anthropogenic emissions for air pollution control and the retrieval of emission source from observed pollutants Ⅰ. Application of incomplete adjoint operator

The ultimate solution to anthropogenic air pollution depends on an adjustment and upgrade of industrial and energy structures. Before this process can be completed, reducing the anthropogenic pollutant emissions is an effective measure. This is a problem belonging to "Natural Cybernetics", i.e., the problem of air pollution control should be solved together with the weather prediction; however, this is very complicated. Considering that heavy air pollution usually occurs in stable weather conditions and that the feedbacks between air pollutants and meteorological changes are insufficient, we propose a simplified natural cybernetics method. Here, an off-line air pollution evolution equation is first solved with data from a given anthropogenic emission inventory under the predicted weather conditions, and then, a related "incomplete adjoint problem" is solved to obtain the optimal reduction of anthropogenic emissions. Usually, such solution is sufficient for satisfying the air quality and economical/social requirements. However, a better solution can be obtained by iteration after updating the emission inventory with the reduced anthropogenic emissions. Then, this paper discusses the retrieval of the pollutant emission source with a known spatio-temporal distribution of the pollutant concentrations, and a feasible mathematical method to achieve this is proposed. The retrieval of emission source would also help control air pollution.

Nilpotent operators similar to irreducible operators

We give a necessary and sufficient condition for the nilpotent operators to be similiar to irreducible operators, and give an answer to D.A.Herrero Conjectures for nilpotent operators.

Positive Observer Design for Positive Markovian Jump Systems with Partly Known Transition Rates

The paper is concerned with positive observer design for positive Markovian jump systems with partly known transition rates. By applying a linear co-positive type Lyapunov-Krasovskii function,a sufficient condition is proposed to ensure the stochastic stability of the error positive system and the existence of the positive observer, which is computed in linear programming. Finally, an example is given to demonstrate the validity of the main results.

A Stochastic Evolutionary Game Perspective on the Stability of Strategic Alliances Against External Opportunism

This paper applies stochastic evolutionary game theory to analyzing the stability of cooperation among members against external opportunism in a multi-firm alliance.The authors first review the pros and cons of pertinent traditional models,and then a stochastic game model on decisions is proposed,where a coordination parameter,a time variable,a punishment effect and bounded rationality are considered.The Gauss white noise is introduced to reflect the random disturbance in the process.Several sufficient criteria on stability are developed,which enable us to investigate"if-then"type scenarios and project the impact of different strategies.

Observer-Based Controller Design for Singular Stochastic Markov Jump Systems with State Dependent Noise

This paper is concerned with the problem of observer-based controller design for singular stochastic Markov jump systems with state-dependent noise. Two concepts called "non-impulsiveness"and "mean square admissibility" are introduced, which are different from previous ones. Sufficient conditions for the open-and closed-loop singular stochastic Markov jump systems with state-dependent noise to be mean square admissible are provided in terms of strict LMIs. The controller gain and the observer gain which guarantee the resulting closed-loop error system to be mean square admissible are obtained in turn by solving the strict LMIs. A numerical example is presented to show the efficiency of the design approach.

Laplacians and Spectrum for Singular Foliations

The author surveys Connes' results on the longitudinal Laplace operator along a(regular) foliation and its spectrum, and discusses their generalization to any singular foliation on a compact manifold. Namely, it is proved that the Laplacian of a singular foliation is an essentially self-adjoint operator(unbounded) and has the same spectrum in every(faithful) representation, in particular, in L2 of the manifold and L2 of a leaf.The author also discusses briefly the relation of the Baum-Connes assembly map with the calculation of the spectrum.

A New Algorithm of Energy Suppression for Satellite Navigation

The satellite navigation anti-interference technique, especially space anti-interference technique, is subjected to many restrictions, such as cost, energy depletion, and so on, and the satellite signal strength is limited by the International Radio Advisory Committee, the International Telecommunication Union (ITU) and satellite companies. This paper focuses on satellite navigation systems, especially satellite navigation systems adopting direct sequence spread spectrum (DSSS). The notch filter is used to remove some frequencies from the pseudorandom code frequency spectrum making use of its cyclostationarity first, then the filtered pseudorandom code is modulated by the carrier to attain energy suppression, but the pseudorandom code autocorrelation characteristic stays unchanged. The feasibility of this algorithm is verified by simulation results.

Random Sampling Scattered Data with Multivariate Bernstein Polynomials

In this paper, the multivariate Bernstein polynomials defined on a simplex are viewed as sampling operators, and a generalization by allowing the sampling operators to take place at scattered sites is studied. Both stochastic and deterministic aspects are applied in the study. On the stochastic aspect, a Chebyshev type estimate for the sampling operators is established. On the deterministic aspect, combining the theory of uniform distribution and the discrepancy method, the rate of approximating continuous fimction and Lp convergence for these operators are studied, respectively.