Model checking temporal knowledge and commitments in multi-agent systems using reduction

Though modeling and verifying Multi-Agent Systems (MASs) have long been under study, there are still challenges when many different aspects need to be considered simultaneously. In fact, various frameworks have been carried out for modeling and verifying MASs with respect to knowledge and social commitments independently. However, considering them under the same framework still needs further investigation, particularly from the verification perspective. In this article, we present a new technique for model checking the logic of knowledge and commitments (CTLKC⁺). The proposed technique is fully-automatic and reduction-based in which we transform the problem of model checking CTLKC⁺ into the problem of model checking an existing logic of action called ARCTL. Concretely, we construct a set of transformation rules to formally reduce the CTLKC⁺ model into an ARCTL model and CTLKC⁺ formulae into ARCTL formulae to get benefit from the extended version of NuSMV symbolic model checker of ARCTL. Compared to a recent approach that reduces the problem of model checking CTLKC⁺ to another logic of action called GCTL¹, our technique has better scalability and efficiency. We also analyze the complexity of the proposed model checking technique. The results of this analysis reveal that the complexity of our reduction-based procedure is PSPACE-complete for local concurrent programs with respect to the size of these programs and the length of the formula being checked. From the time perspective, we prove that the complexity of the proposed approach is P-complete with regard to the size of the model and length of the formula, which makes it efficient. Finally, we implement our model checking approach on top of extended NuSMV and report verification results for the verification of the NetBill protocol, taken from business domain, against some desirable properties. The obtained results show the effectiveness of our model checking approach when the system scales up.     

Solid–liquid phase equilibria of binary indole mixtures with some aromatic compounds using a solid–liquid–vapor equation-of-state

The separation of useful chemicals, such as indole from coal tar, is an important subject of research in the field of fossil energy, renewable energy, and utilization of byproducts and waste materials. High-pressure crystallization is one of the proposed separation methods. To understand the process requires detailed knowledge of solid–liquid phase behaviors. Solid–liquid phase equilibrium data of various binary mixtures of indole have been reported in the literature. In the present report, we analyze some of the experimental data with our unified solid–liquid–vapor equation-of-state to see whether our model can be useful for the calculation of solid–liquid equilibria in these organic systems. Good correlations of the data and predictions of phase behavior, at very high pressures, are demonstrated.     

Membrane bioreactor with nonwoven fabrics as solid–liquid separation media for wastewater treatment

A nonwoven fabric module was utilized as a solid–liquid separation medium in a membrane bioreactor (MBR) for treating wastewater. The experimental results indicated that nonwoven fabrics had lower filtration resistance than microporous membranes in MBR applications. The optimal aeration intensity was approximately 0.01m³/m² s. The effect of mixed liquor suspended solid concentration on filtration resistance was not significant at an operating flux of under 0.8m³/m² d in the study range. The performance of nonwoven fabrics in a MBR application was further demonstrated in a pilot test. Chemical oxygen demand (COD) and suspended solids (SS) in the effluent were maintained under 60 and 10 mg/L, respectively, whereas influent COD varied from 800 to 1800mg/L. The transmembrane pressure was maintained below 5 kPa at a permeation flux of 0.18m³/m² d. The experimental results demonstrated that nonwoven fabrics maintained stable operation in MBR applications under appropriate operating conditions.     

Nonlinear multiobjective model-predictive control scheme for wastewater treatment process

A nonlinear multiobjective model-predictive control (NMMPC) scheme, consisting of self-organizing radial basis function (SORBF) neural network prediction and multiobjective gradient optimization, is proposed for wastewater treatment process (WWTP) in this paper. The proposed NMMPC comprises a SORBF neural network identifier and a multiple objectives controller via the multi-gradient method (MGM). The SORBF neural network with concurrent structure and parameter learning is developed as a model identifier for approximating on-line the states of WWTP. Then, this NMMPC optimizes the multiple objectives under different operating functions, where all the objectives are minimized simultaneously. The solution of optimal control is based on the MGM which can shorten the solution time. Moreover, the stability and control performance of the closed-loop control system are well studied. Numerical simulations reveal that the proposed control strategy gives satisfactory tracking and disturbance rejection performance for WWTP. Experimental results show the efficacy of the proposed method.     

Electrochemical insertion of lithium into a doped diamond film grown on carbon felt substrates

This paper summarizes the preliminary results obtained from lithium electrochemical intercalation into boron-doped diamond films grown on carbon felt (BDD/CF electrode). BDD films have been grown by Hot Filaments Chemical Vapor Deposition (HFCVD) and have been characterized by Scanning Electron Microscopy (SEM) and Raman Scattering spectroscopy. BDD/CF composite electrodes, which contain a diamond layer, lead to higher conductivity and smaller grain sizes. In turn, they are richer in boundary or sp² sites, and present a reversible specific capacity that is much larger than that of the substrate alone, indicating that the diamond layer effectively participates in lithium storage. Diamond layers displaying boron doping levels of 10¹⁹ and 10²¹ part cm^− 3 provide a specific capacity of 160 and 370 mA h g^− 1, respectively, which is associated with lithium storage.     

Predictive control of an activated sludge process: An application to the Viikinmäki wastewater treatment plant

In this work, we discuss the application of multivariable predictive control for the activated sludge process in a full-scale municipal wastewater treatment plant. Emphasis is given to the selection of a control configuration that contributes to minimising the economic costs while improving the removal efficiency of the nitrogen compounds. For this task, a simple dynamic matrix control algorithm is favoured for controlling the nitrogen concentrations at the end of the biological process. The behaviour of the activated sludge process is reproduced in a commercial simulator that acts as a real-time testing platform and that is also used for identifying the multivariable input–output models for the predictive controller. For demonstrating the effectiveness of the proposed approach, different control configurations are considered and compared against the aeration control strategies currently used at the plant. Based on the simulation results, this work shows the potentiality of the dynamic matrix control which is able to decrease the energy consumption costs and, at the same time, reduce the ammonia peaks and nitrate concentration in the effluent.     

Identification of relationship between sunspots and natural runoff in the Yellow River based on discrete wavelet analysis

Annual natural runoff is an important index of a river, which may be affected by solar activities. In this study, 304 years of annual natural runoff at the Sanmenxia station located in the Yellow River and the sunspot relative number are decomposed with the application of a Complex Morlet. According to the results of real part, modulus and second power of modulus, the annual runoff series at the Sanmenxia station has an obvious periodic oscillation on 90–100, 50–80, 35–50, 15–35, about 10, and less than 10-year scales. Also, there are obvious periodic variability with 60–90 years, 30–50 years and about 10 years. There are two centers of energy: one is about 1840–1850 on 7–11-year scale and the other is about 1825–1925 on 60–70-year scale. From the wavelet variance, 3, 26, 46, 68 year periods are detected within a 100-year scale, and the 68-year period is the most significant. Similar analyses are conducted for the sunspot relative number within the same period 1700–2003. The sunspot series shows 11- and 60-year period variation, as well as eight energy centers. Then, the correlation analyses for 11- and 60-year serial scales are computed. From a long-term period (1700–2003) view, there is no notable correlation between the natural runoff and the sunspot relative number; however, it is evident that the correlations exist within a short-term period. The results also indicate that the relationships between solar activities and the natural runoff in the Yellow River are complicated.     

Denitrifying phosphorous removal in anaerobic/anoxic SBR system with different startup operation mode

To achieve stable and efficient nitrogen and phosphorus removal and to investigate the characteristics of the A/A SBR enriched with denitrifying phosphorus removal bacteria(DPB),the whole course of startup was studied with two reactors operated in different mode.The reactor I was operated under anaerobic/settling/anoxic/settling mode,and the reactor II was operated under anaerobic/anoxic/settling mode.Differences between the two reactors in removal efficiency of COD,nitrogen and phosphorus were examined.The results indicated that efficient performance could be achieved in both reactors with different startup operation mode,while the phosphorus removal efficiency was improved sooner in reactor I than in reactor II,which suggested that reactor I would supply a more favorable condition for DPB proliferation.Meanwhile,it was observed that the amount of organic substrates consumption had a linear correlation to that of phosphorus release in anaerobic phase when DPB was accumulated in the A/A SBR denitrifying phosphorus removal system.     

新型喜树碱缓释微胶囊的制备

为了降低喜树碱药物的毒性,提高人体服药后的顺应性.以生物相容性良好的壳聚糖和海藻酸钠为囊壁材料,喜树碱药物微粒为囊芯,采用静电吸引层层纳米自组装技术(LbL法)制备了喜树碱微胶囊.实验结果表明:LbL法制备的微胶囊用激光共聚焦显微镜观察具有明显的核-壳结构;提高了喜树碱在水中的分散性;释放速度可控,不同包裹层数的微胶囊在模拟人体体液环境下(pH7.4)释放速度不同,随着高分子层数增加,药物释放速度降低.这种具有缓控释效果的微胶囊能大大降低病人服药后的不良反应,具有很好的应用前景.