Nodes in wireless sensor networks (WSNs) have the potential to be selfish without transmitting packets in routing. This study mainly focuses on the problem of reliable delivery mechanism in WSNs, and the authors' objective is to ensure stable cooperation among nodes for packets delivery and minimum routing cost at the same time. Based on the performance metrics in terms of the rate of packets forwarding, correctly reporting event, and energy remain, the authors present a coalitional game model with a characteristic function to be shared among coalition members. Then an efficient and fast convergence coalition formation algorithm is proposed to obtain the stable coalition partition in the game. Finally, on the basis of the coalitional game model, the authors design a reliable coalition formation routing (RCFR) protocol, which selects route according to the principle of lowest cost. Simulation experiments are conducted to analyse the performance of RCFR, compared with original ad hoc on-demand distance vector routing and the method proposed by Kazemeyni. The results show that RCFR effectively enhances packet delivery ratio, decreases routing establishing time, balances energy consumption, and reduces average signalling overhead.
Background Coprinus comatus is a novel cultivated edible fungus, hailed as a new preeminent breed of mushroom. However, C. comatus is difficult to keep fresh at room temperature after harvest due to high respiration, browning, self-dissolve and lack of physical protection. Methods In order to extend the shelf life of C. comatus and reduce its loss in storage, changes in quality, biochemical content, cell wall metabolism and ultrastructure of C. comatus (C.c77) under 4 °C and 90% RH storage regimes were investigated in this study. Results The results showed that: (1) After 10 days of storage, mushrooms appeared acutely browning, cap opening and flowing black juice, rendering the mushrooms commercially unacceptable. (2) The activity of SOD, CAT, POD gradually increased, peaked at the day 10, up to 31.62 U g−1 FW, 16.51 U g−1 FW, 0.33 U g−1 FW, respectively. High SOD, CAT, POD activity could be beneficial in protecting cells from ROS-induced injuries, alleviating lipid peroxidation and stabilizing membrane integrity. (3) The activities of chitinase, β-1,3-glucanase were significantly increased. Higher degrees of cell wall degradation observed during storage might be due to those enzymes’ high activities. (4) The fresh C. comatus had dense tissue and every single cell had the number of intracellular organelles which structure can be observed clearly. After 10 d storage, the number of intracellular organelles was declined and the structure was fuzzy, the nucleus disappeared. After 20 d storage, C. comatus’s organization was completely lost, many cells were stacked together and the cell wall was badly damaged.
Abstract:This paper presents a new genetic algorithm for the resource-constrained project scheduling problem (RCPSP). The algorithm employs a standardized random key (SRK) vector representation with an additional gene that determines whether the serial or parallel schedule generation scheme (SGS) is to be used as the decoding procedure. The iterative forward-backward improvement as the local search procedure is applied upon all generated solutions to schedule the project three times and obtain an SRK vector, which is reserved into population. Several evolutionary strategies are implemented including the elitist selection (the high quality solution set), and the selection of parents used in crossover operator. The computational experiments on 1 560 standard instances show that the proposed algorithm outperforms the current state-of-the-art heuristic algorithms for J30 and J60, and ranks the third for J120 with 50 000 schedules; it ranks the second for J30 and J60, and ranks the fifth for J120 with 5 000 schedules; it ranks the third, second, and fifth for J30, J60 and J120 with 1 000 schedules, respectively. It is demonstrated that the proposed algorithm is competitive for RCPSP, especially for larger number of schedules.The resource-constrained project scheduling problem (RCPSP) can be stated as follows. A single project consists of a set of activities, where each activity has to be processed in order to complete the project. The activities are interrelated by two kinds of constraints. First, precedence constraints force activity j is not to be started before all its immediate predecessors have been finished. Second, performing the activities requires resources with limited capacities. Altogether there are K renewable resource types. While being processed, activity j requires jk r units of resourceduring each period of its nonpreemptive duration j d . The availability of each resource type k in each time period is k R units. For the start activity 1 and end activity N , we have 1The parameters j d , jk r , k R are assumed to be non-negative and deterministic. The objective of RCPSP is to determine a schedule with minimal makespan such that both the precedence and resource constraints are fulfilled.RCPSP is an important and challenging problem, which has been widely studied over the past few decades. There are some surveys given in Refs. [1][2][3]. The suggested algorithms can be classified into two categories: exact and heuristic algorithms. Blazewicz et al proved that RCPSP as a generalization of the job shop scheduling problem is strongly NP-hard [4] such that the computation time for obtaining the optimal solution using exact algorithms can be extremely long for more than 60 activities. This has motivated researchers to develop heuristic algorithms for dealing with large and highly resourceconstrained projects. Hartmann and Kolisch [1,2] presented a classification and performance evaluation of different heuristic algorithms. Most of the heuristic algorithms are grouped into X-pass methods (single-pass method...
A simple HPLC method using UV detection was developed and validated for the determination of levodropropizine (LDP) in dog plasma. The sample was prepared for injection using a liquid-liquid extraction method with 1-phenypiperazine as the internal standard. The mobile phase was methanol-diethylamine solution (0.05 M) (20:80, v/v, pH adjusted to 3.0 with H3PO4) with a detection wavelength of 240 nm. The limit of quantitation (LOQ) of LDP in a biological matrix was determined to be 25.25 ng/mL. The calibration curve was linear across the concentration range of 25.25 to 2020 ng/mL. The intra-day and inter-day precision values (CV %) were within 7% and accuracy (R.E. %) was within 6% of the nominal values for medium (252.5 ng/mL) and high (2020 ng/mL) LDP concentrations. For the LDP concentration at the LOQ, the intra-day and inter-day precision and accuracy were within 20% and 10%, respectively. The average absolute recovery for LDP was 70.28%. This method was successfully used to analyze plasma samples in a steady-state bioavailability study of a newly developed sustained-release LDP tablets (SR) using immediate-release tablets (IR) as the reference. The relative bioavailability of the SR was determined to be 106.3 +/- 12.8% (n=6). The Cmax of the SR was significantly lower (P<0.05), and the tmax was significantly longer than that of the IR (P<0.05). The results of ANOVA and two one-sided tests indicated that the SR exhibited acceptable sustained release properties and was bioequivalent to the IR.
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