A Vector Matroid-Theoretic Approach in the Study of Structural Controllability Over F(z)

In this paper, the structural controllability of the systems over F(z) is studied using a new mathematical method-matroids. Firstly, a vector matroid is defined over F(z). Secondly, the full rank conditions of [sI-A|B] are derived in terms of the concept related to matroid theory, such as rank, base and union. Then the sufficient condition for the linear system and composite system over F(z) to be structurally controllable is obtained. Finally, this paper gives several examples to demonstrate that the married-theoretic approach is simpler than other existing approaches

The state of the market and the contrarian strategy: Evidence from China’s stock market

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 The Chinese Economic Association.Using the most comprehensive weekly dataset of ‘A’ shares listed on the Chinese stock market, this paper examines short-term contrarian strategies under different market states from 1995–2010. We find statistically significant profits from contrarian strategies, especially during the period after 2007, when China (along with other countries) experienced an economic downturn following the worldwide financial crisis. Our empirical evidence suggests that: (1) no significant profit is generated from either momentum or contrarian strategies in the intermediate horizon; (2) after microstructure effects are adjusted for, contrarian strategies with only four to eight weeks holding periods based on the stocks’ previous four to eight week's performance generate statistically significant profits of around 0.2% per week; (3) the contrarian strategy following a ‘down’ market generates higher profit than those following an ‘up’ market, suggesting that a contrarian strategy could be used as a shelter when the market is in decline. The profits following a ‘down’ market are robust after risk adjustment

On the turbulent flow models in modelling of omni-flow wind turbine

Yong Chen, Pei Ying, Yigeng Xu, Yuan Tian, 'On the turbulent flow models in modelling of omni-flow wind turbine', paper presented at The International Conference on Next Generation Wind Energy (ICNGWE2014), the Universidad Europa de Madrid, Madrid, Spain, 7th-10th October 2014.The computational fluid dynamics (CFD) has a wide application in the wind energy industry. In CFD simulations, a turbulence model plays a significantly important role in accuracy and resource cost. In this paper, a novel wind turbine, omni-flow wind turbine, was investigated with different turbulence models. Four turbulence models, standard k-ε, realizable k-ε, standard k-ω and SST k-ω models, were employed for this wind turbine in order to assess the best numerical configuration. The performance of these four turbulence models was validated with wind tunnel tests. It is evident that the realizable k-ε turbulence model is most suitable to simulate this novel wind turbine

Assessing the safety and efficacy of switching to brinzolamide/timolol fixed combination as a replacement therapy in patients with uncontrolled intraocular pressure in Taiwan

AbstractPurposeThe objective of this study is to assess the safety and efficacy of switching to brinzolamide 1% and timolol 0.5% fixed combination (BTFC) from prior pharmacotherapy in patients with open-angle glaucoma (OAG) or ocular hypertension (OH) in Taiwan.MethodsThis was a multicenter, open-labeled, interventional prospective study. The 8-week study involved patients with OAG or OH with uncontrolled intraocular pressure (IOP) and consisted of three study visits to the clinical site. Patients were instructed to discontinue their prior medications at the first visit, prior to starting the study medication. Enrolled patients were dosed with BTFC twice daily in both eyes for 8 weeks. IOP measurements and safety evaluations were conducted at both Week 4 and Week 8.ResultsA total of 74 patients were enrolled. The overall mean IOP reductions from baseline after Week 8 of BTFC was 3.45 mmHg (15.42%); when subgrouped by prior medication class (β-blockers vs. non-β-blockers), the reduction in mean IOP after transitioning to BTFC at Week 8 was as follows: subgroup β-blockers were 3.23 mmHg (14.9 %) and non-β-blockers were 3.58 mmHg (15.25%). All mean IOP changes from baseline were statistically significant (p < 0.001). Of the 69 patients (per protocol population) who were switched to BTFC regardless of prior therapy, 37 (53.6%) patients at Week 4 and 38 (55.1%) patients at Week 8 had IOP ≤ 18 mmHg. No treatment-related serious adverse events were reported in this study.ConclusionThe results of this study demonstrated the potential benefit of using BTFC as a replacement therapy in order to ensure adequate IOP control. BTFC administered twice daily was safe and effective in patients with uncontrolled IOP in Taiwan

Computational and Experimental Investigations of an Omni-Flow Wind Turbine

This document is the Accepted Manuscript version, made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License CC BY NC-ND 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/ ). The final, definitive version of this paper is available online at doi: https://doi.org/10.1016/j.apenergy.2015.01.067.Both numerical and experimental studies were conducted to evaluate the performance of an omni-flow wind turbine designed to provide renewable electricity on the top of urban buildings like skyscrapers. The numerical approach was based on Finite Volume Method (FVM) and the turbulence flow was studied with several commonly used Reynolds-averaged Navier–Stokes turbulence models. The results of the study were evaluated with the wind tunnel test results over a range of tip speed ratios. The numerical results showed the effect of blade number on both power output and starting capability. Although both the power and torque coefficient were improved significantly by the optimisation of the blade number, there was only a slight change when the blade number was greater than twenty. The results from wind tunnel testing also showed excellent starting capability with a starting wind velocity as low as 1.6 m/s. A numerical simulation was also conducted for the wind turbine working under non-uniform flow conditions. The numerical results have shown that the peak power coefficient of such a wind turbine under non-uniform flow, was lower than that under the uniform flow. Additionally, the applied thrust on a blade was subject to frequent and periodical changes. However, the effect of the change of thrust in magnitude and frequency was not significant. Therefore the omni-flow wind turbine has the potential to meet the challenge of unpredictable wind velocity and direction as a consequence of the urban environment.Peer reviewedFinal Accepted Versio

Tetra­aqua­tetra­kis­(4,4′-bipyridine dioxide-κO)terbium(III) octa­cyanidotungstate(V)

In the title compound, [Tb(C10H8N2O2)4(H2O)4][W(CN)8], both metal atoms are eight-coordinated. The TbIII ion displays a dodeca­hedral geometry, while the Wv ion exhibits a distorted square-anti­prismatic geometry. The Tb atoms are located on a special position of site symmetry -4, whereas the W atoms are located on a twofold rotation axis. The cations are linked by O—H⋯O hydrogen bonds. The title compound is isotypic with the corresponding and previously described Mo compound [Qian & Yuan (2011 ▶). Acta Cryst. E67, m845]