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Time synchronization is the basis of coordination and cooperation in underwater acoustic networks. However, because of the propagation delay, node mobility, and Doppler shift, it is impossible to balance the accuracy and energy consumption simply in water. As a promising technology, partial clustering has high convergence and makes breakthroughs in time synchronization. This paper proposes PCDE-Sync, a novel synchronization mechanism with partial clustering and the Doppler effect. Firstly, a clustering method built on the artificial fish swarm algorithm is presented. It models the cluster construction according to fish's preying, swarming, and following behaviors. Secondly, we design a synchronization mechanism to conduct clock correction and compensation by the Doppler effect. Finally, we compare the performance of PCDE-Sync with the most advanced protocols, namely MU-Sync, MM-Sync, and DE-Sync, in terms of the cumulative error after synchronization, the mean square error under different clock skew and that under distinctive node mobility, and energy consumption. The experimental results show that PCDE-Sync makes a trade-off between accuracy and complexity, which does well in solving synchronization issues.

In order to solve the problems of high surface roughness and low dimensional accuracy of titanium alloy metal-wire fuse additive manufacturing, this paper proposes a high surface quality and dimensional accuracy of titanium alloy additive manufacturing with composite heat source process. On the basis of orthogonal experiments, titanium alloy wires with diameter of 0.3 mm Ti-6Al-4V were deposited in a small molten pool by laser and Joule heat source. Thin-walled titanium alloy parts with high surface quality and dimensional accuracy were obtained, and the quality, microstructure, and mechanical properties were tested. The measurement areas are shown that the average roughness Ra is 1.65 μm in the direction deposition, and the dimensional accuracy error is less than 0.28 mm. On this basis, the microstructure and mechanical properties of titanium alloy thin-walled were analyzed. The microstructures are net-like, with microhardness of about 330HV. The ultimate tensile strength of titanium alloy thin-walled parts is 917.56 MPa, and the elongation can reach 20.68%, which is comparable to the strength of casting and forging fracture. The results show that the proposed additive manufacturing process of metal-wire with composite heat source has the potential of further metal AM in high surface quality parts.

A uric acid (UA) electrochemical biosensor was constructed using ferrocene (Fc) decorated cuprous oxide (Cu2O) enhanced electro-active characteristics and covalently immobilized with uricase (UOx) on glassy carbon electrode (GCE). The electrochemical characteristics of the fabricated electrode was analysed by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry (DPV). DPV studies revealed rapid response of fabricated electrode UOx/Fc/Cu2O/GCE towards UA in a wide concentration range of 0.1–1,000 μM with a sensitivity of 1.900 μA mM−1 cm−2 and very low detection limit of 0.0596 μM. A very low magnitude Michaelis–Menten constant (Km) value was evaluated as 34.7351 μM which indicated the chemical attraction of the enzyme towards the UA was much higher. The developed biosensor was successfully applied to detect UA in human urine samples. Moreover, reproducibility and stability studies demonstrated the fabricated UOx/Fc/Cu2O/GCE biosensor had high reproducibility with a RSD of 2.8% and good reusability with a RSD of 3.2%. Specificity studies results showed the fabricated biosensor had strong anti-interference ability. The improved sensor performance was attributed to the synergistic electronic properties of Cu2O and Fc that provided enhances delectrocatalytic activity and electron transfer. The present biosensor can be extended for use in clinical settings.

In the original article, Fengzhang Ren’s and Jingjing Ma’s first names are spelled wrong. They are correct as shown here.

According to the traditional control methods of batching-material system exists defects low precision and bad real-time, this paper has proposed the combined control algorithm. This paper has designed a Fuzzy-PID control Glass batching-material system by using of combining the traditional PID and the Fuzzy control algorithm. The system uses expert system of online learning and adjusts automatically the control parameters, realize the best combination controlling precision and speed. The actual operation result of the system has proved the feasibility and validity of the Fuzzy-PID combined control. DOI: http://dx.doi.org/10.11591/telkomnika.v11i6.2689 Full Text: PDF

In this paper, a deterministic global optimization algorithm is proposed for solving min-max and max-min linear fractional programming problem (P) which have broad applications in engineering, management science, nonlinear system, economics and so on. By utilizing equivalent problem (Q) of the (P) and two-phase linear relaxation technique, the relaxation linear programming (RLP) about the (P) is established. The proposed algorithm is convergent to the global minimum of (P) through the successive refinement of the feasible region and solutions of a series of RLP. And finally the numerical examples are given to illustrate the feasibility of the presented algorithm.

In this paper a global optimization algorithm is proposed for solving minimax linear fractional programming problem (P). By utilizing equivalent problem �ƒ Q�≈ and linearization technique, the relaxation linear programming (RLP) about the (Q) is established. The proposed branch and bound algorithm is convergent to the global minimum of (Q) through the successive refinement linear relaxation of the feasible region of objective function and solutions of a series of (RLP). And finally the numerical experiment is given to illustrate the feasibility of the presented algorithm.

In this paper a branch and bound algorithm is proposed for polynomial programming problems (P) that arise in various practical problems. By utilizing an exponential variable transformation and the mean value theorem a linear relaxation of the (P) is then obtained. Through the successive refinement of a linear relaxation of feasible region of the objective function and the solutions of a series of linear programming problems the proposed algorithm is convergent to the global minimum of the (P). At finally numerical results indicate the feasibility of the proposed algorithm. Recently, Shen and Jiao (7) give a branch-and-pruning approach for solving problem (P). The purpose of the paper is to develop a global optimization algorithm for problems (P), which is based on using the exponential transformation and mean value theorem along with linear approximation each nonlinear term in order to generate linear relaxation. In this method, (1) a new linear relaxation for the problem (P) is proposed, which is more convenient in the computation than the convex relaxation (6), thus any effective linear programming algorithm can be used to solve P problem. (2) the generated relaxed linear programming problems are embedded within a branch-and-bound algorithm without increasing new variables and constraints.

A global optimization algorithm is proposed for solving sum of general linear ratios problem (P) using new pruning technique. Firstly, an equivalent problem (P1) of the (P) is derived by exploiting the characteristics of linear constraints. Then, by utilizing linearization method the relaxation linear programming (RLP) of the (P1) can be constructed and the proposed algorithm is convergent to the global minimum of the (P) through the successive refinement of the linear relaxation of feasible region and solutions of a series of (RLP). Then, a new pruning technique is proposed, this technique offers a possibility to cut away a large part of the current investigated feasible region by the optimization algorithm, which can be utilized as an accelerating device for global optimization of problem (P). Finally, the numerical experiments are given to illustrate the feasibility of the proposed algorithm.

A new method for discriminating reconstructed milk in raw milk is proposed by combining NIRS (Near Infrared Spectroscopy) with the theory model BPR (Biomimetic Pattern Recognition). In order to compare its discrimination performance, we also carry out experiments by using a traditional method combining near infrared spectroscopy with DA (Discrimination Analysis). The results indicate that the accuracy of detection is 98.3% using the new method; while 87.5% using the traditional method. Comparison results show that the proposed new method is superior to the traditional method and the combination of NIRS with BPR has good potential to detect adulteration of raw milk with reconstructed milk.