On selection of forwarding nodes for long opportunistic routes

Opportunistic routing is a promising routing paradigm which increases the network throughput. It forces the sender’s neighbors, who successfully overheard the transmitted packet, to participate in the packet forwarding process as intermediate forwarding nodes. As a seminal opportunistic routing protocol, MORE combines network coding idea with opportunistic routing to eliminate the need for strict coordination among active forwarding nodes. In this paper, we show that MORE performance does not scale well with the route length, especially when the route length goes beyond two hops. Also, we found that MORE fails to establish a working opportunistic route in sparse networks. Clearly, the network throughput is directly influenced by both the quantity and quality of forwarding nodes, and their cooperation order. In this paper, we propose a new forwarder selection mechanism which considers the route length, link qualities, the distance from the source, and nodes density. It eliminates the occasional route disconnectivity happening in MORE and improves the quality of the established opportunistic routes. The simulation result indicates that our proposal always outperforms MORE when dealing with long opportunistic routes.

     

Distributed Adaptive Dynamic Surface Control for Synchronization of Uncertain Nonlinear Multi-agent Systems

In this paper a distributed adaptive dynamic surface controller is proposed for multi-agent systems under fixed directed graph topologies. The agents have uncertain nonlinear dynamics and are influenced by bounded unknown disturbances. The controller should synchronize the states of all agents with the corresponding states of the nonautonomous leader. It is proved that, with the proposed controller, the synchronization error remains bounded; and the bounds can be arbitrarily decreased by increasing the controller gains. The control rules are designed such that each agent only requires the state information of its neighbors, rendering a distributed control. The effectiveness of the proposed method is demonstrated through two simulation examples.     

Perfect state transfer on spin-1 chains

We show that networks of spin-1 particles connected in a special geometry and subject to Affleck–Kennedy–Lieb–Tasaki (AKLT) interaction are capable of perfectly transferring states of particles (qubits and qutrits) if we also allow a global control of the network in predetermined time intervals. The geometry can be one, two, and three dimensional. The strengths of the couplings have the same modulus, and only their signs differ on various bonds. Any particle which is routed in the network acquires relative phase shifts which can be corrected after it is extracted from the network. An advantage of this protocol is that one can route more than one particle through the network simultaneously. We show that a uniform magnetic fields do not deteriorate the fidelity and only change the relative phases in a controllable way.     

A fuzzy reinforcement learning algorithm for inventory control in supply chains

In the real world, applications with very large state and action spaces and unknown state transition probability, classical reinforcement learning algorithms usually show poor performance. One way to address the performance problem is to approximate the policy or value function. Fuzzy rule-based systems are amongst the well-known function approximators. This paper presents a Flexible Fuzzy Reinforcement Learning algorithm, in which value function is approximated by a fuzzy rule-based system. The proposed algorithm has a separate module for tuning the structure of fuzzy rules. Moreover, the parameters of the system are tuned during the learning phase. Next, the proposed algorithm is applied to the problem of inventory control in supply chains. In this problem, a fuzzy agent (supplier) should determine the amount of orders for each retailer based on their utility for supplier, by considering its limited supply capacity. Finally, a simulation is performed to show the capability of the proposed algorithm.     

Highly efficient synthesis of coumarin derivatives in the presence of H14[NaP5W30O110] as a green and reusable catalyst

A variety of heteropolyanions including: Keggin, Dawson, Preyssler, mixed addenda and sandwich types, catalyzed the formation of 4-methylnaphtho-(1,2-b)-pyran-2-one (coumarin) from the condensation of α-naphthol and ethylacetoacetate in a solvent free system and under heating conditions. Our data vividly indicate that sodium30–tungsto pentaphosphate, [NaP₅W₃₀O₁₁₀]¹⁴⁻, which so-called Preyssler’s anion, with high hydrolytic (pH 0–12) and thermal stability is the catalyst of choice. This catalyst catalyzed the synthesis of other coumarin derivatives in high yields and good selectivity.     

Structural and Rheological Properties of Succinoglycan Biogums Made from Low-Quality Date Syrup or Sucrose Using Agrobacterium radiobacter Inoculation

This study examines and compares the structural and rheological properties of succinoglycan exopolysaccharide made by fermentation of sucrose or date syrup at identical temperature, pH, and total soluble solid. Using thin-layer chromatography (TLC), Fourier transform infrared (FTIR) spectroscopy, and rotational viscometery structural and rheological properties of prepared exopolysaccharides were assessed. The variables under studies were biogum concentrations (0.5%, 1.0%, 1.5%, and 2.0% w/w), temperature (5, 25 and 40°C), and pH (2.5, 4.0, 7.0, and 10.0). Results revealed that the quantity of exopolysaccharide produced in the date syrup (DSE) medium was three to five times greater than that of sucrose (SE) medium. The biogums exhibited non-Newtonian, shear-thinning behavior, and the viscosity of DSE was higher than SE at all tested concentrations. The TLC and FTIR spectroscopy assessments designated that the biogum is composed of glucose and galactose units, carrying a carboxylic group and indicated the presence of succinoglycan. The outcomes of this study could be useful to food industries seeking low cost biogum.     

A Proteomic Analysis of Human Follicular Fluid: Comparison between Younger and Older Women with Normal FSH Levels

The follicular fluid (FF) is produced during folliculogenesis and contains a variety of proteins that play important roles in follicle development and oocyte maturation. Age-related infertility is usually considered as a problem that can be solved by assisted reproduction technology. Therefore, the identification of novel biomarkers that are linked to reproductive aging is the subject of this study. FF was obtained from healthy younger (20–32 years old) and older (38–42 years old) women undergoing intracytoplasmic sperm injection (ICSI) due to male factor infertility. The FF was analyzed by two-dimensional gel electrophoresis (2-DE). The power of two-dimensional gel electrophoresis and the identification of proteins were exploited using matrix-assisted laser desorption-ionization time-of-flight/time-of-flight (MALDI-TOF-TOF) mass spectrometry. Twenty three protein spots showed reproducible and significant changes in the aged compared to the young group. Of these, 19 protein spots could be identified using MALDI-TOF-TOF-MS. As a result of MASCOT search, five unique downregulated proteins were identified in the older group. These were identified as serotransferrin, hemopexin precursor, complement C3, C4 and kininogen. A number of protein markers were found that may help develop diagnostic methods of infertility.