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The group theory-based optimization algorithm (GTOA) is a discrete evolutionary algorithm designed by group theory methods, which is very suitable for solving combinatorial optimization problems with integer vectors as feasible solutions. In order to further improve the performance of GTOA for solving the discounted {0-1}knapsack problem (D{0-1}KP), firstly, this paper points out the deficiency of its random linear combination operator (RLCO) which fails to fully consider the current individual position information, and improves it based on the individual gene retention strategy. Then, the enhanced 0-component mutation strategy is introduced into the random inverse mutation operator (IRMO), which is used to deal with problems such as the decline in the quality of the solution and the decrease of population diversity caused by the failure of the individual 0-component to mutate in time. Based on the improvement of the two operators mentioned above, an enhanced GTOA (EGTOA) is proposed, and a new method for solving D{0-1}KP is proposed based on it. Subsequently, the improved strategies are applied to binary GTOA (GTOA-2), and an enhanced GTOA-2 (EGTOA-2) and a new method for solving D{0-1}KP are proposed. In order to verify the degree of performance improvement and superiority of EGTOA and EGTOA-2, they are used to solve four types of large-scale D{0-1}KP instances. The comparison with GTOA, GTOA-2, and 8 state-of-the-art algorithms of solving D{0-1}KP shows that the ability of EGTOA and EGTOA-2 to obtain optimal solutions is at least 1.14 times higher than that of GTOA and GTOA-2, and 5% to 60% higher than that of the existing 8 state-of-the-art algorithms. At the same time, their average performance is also better than GTOA, GTOA-2, and the 8 advanced algorithms. Therefore, EGTOA and EGTOA-2 are currently the best algorithms for solving D{0-1}KP.

The discounted {0-1} knapsack problem (D{0-1}KP) is a more complex variant of the classic 0-1 knap-sack problem (0-1KP). In order to efficiently solve the D{0-1}KP by using discrete differential evolution algorithm, firstly, a novel V-shape transfer function (NV) is proposed. The real vector of an individual is mapped into a binary vector by NV. Compared with the existing S-shaped and V-shaped transfer function, NV has lower computational complexity and higher efficiency. Then, a new discrete differential evolution algorithm (NDDE) is given based on the novel V-shape transfer function. A novel and efficient method for solving D{0-1}KP is proposed by NDDE. Finally, in order to verify the efficiency of NDDE in solving D{0-1}KP, it is used to solve four kinds of large-scale D{0-1}KP instances, and the results are compared with the existing algorithms such as group theory-based optimi-zation algorithm (GTOA), ring theory-based evolutionary algorithm (RTEA), hybrid teaching-learning-based optimi-zation algorithm (HTLBO) and whale optimization algorithm (WOA). The results show that NDDE not only has higher accuracy, but also has good stability, which is very suitable for solving large-scale D{0-1}KP instances.

AbstractThis article has investigated the friction behavior of a tribological system composed of a liquid crystal and polyimide. In this tribological system, ZrO2 and PMDA-ODA polyimide film used as a friction pair, and the liquid crystals used as lubricants including the single liquid crystal 5CB and the mixed liquid crystals LCs1 (5CB-5CEPO2), LCs2 (5CB-3CEPC3), LCs3 (5CB-2CEPPN), and conducted friction coefficient comparison experiments with n-hexadecane. It was found that the average friction coefficient of the LCs3 (90% 5CB + 10% 2CEPPN) is the smallest at the load of 5 N and the velocity of 200 rpm, which is 0.00113. Load and velocity selection experiments were investigated of LCs3, as well as polyimide film’s surface analysis including scanning electron microscope, white-light interference, polarization microscope, and surface-enhanced Raman scattering spectra. The results of the surface analysis indicated that some groups in the main chain and branch chain of the polyimide molecules are oriented parallel to the polyimide surface after rubbing. [ABSTRACT FROM AUTHOR]

Inhibition of the extracellular signal-regulated kinases 1/2 (ERK1/2) alone or in combination with other targets has emerged as a promising treatment strategy for a variety of human tumors. In addition to the development of inhibitors, the development of ERK1/2 degraders is an alternative approach to decrease its activity. We synthesized proteolysis-targeting chimeras (PROTACs) as effective ERK1/2 degraders, among which B1-10J showed high degradative activity, with DC50 of 102 nM and cytotoxic IC50 of 2.2 μM against HCT116 cells. Moreover, B1-10J dose-dependently inhibited tumor cell migration. Xenograft experiments in nude mice demonstrated that B1-10J inhibited HCT116 tumor cell growth and achieved significant regression of tumors at a daily dose of 25 mg/kg. [ABSTRACT FROM AUTHOR]

To the characteristics of decentralized deployment of the command, control, communications, computers, intelligence, surveillance and reconnaissance (C4ISR) services, limited computing/storage resources for combat platforms, and high requirements for evolutionary real-time performance, the overall architecture of distributed monitoring and evolution of system state is designed based on hierarchical structure, and a dynamic adjustment method of service deployment scheme hierarchy is proposed. By analyzing the implementation difficulties of the resource coordination module in the overall architecture, the distributed deployment model of the C4ISR service is demonstrated based on defining the evolution cost and information flow path length. To the characteristics that the service deployment location and information flow path are included in the evolution scheme, a pair of exchange ideas, shortest path planning method and m-best strategy are combined to propose a greedy solution algorithm to realize the rapid generation of evolution scheme. The experimental results show that the method can effectively control the evolution range while ensuring the efficiency of system information flow, and can be suitable for the agile adjustment of service deployment method in the process of task execution. [ABSTRACT FROM AUTHOR]

Based on the similarity of the community detection methods, the Givern-Newman (GN) algorithm is fast and accurate but has a higher running time. In order to improve the efficiency of GN Algorithm, this study presents a semi-supervised GN algorithm based on node similarity. By making full use of the constraint set of the prior knowledge must-link and cannot-link, the prior information is extended by the derived rules, and the extended information is verified by the method of distance measurement. Using new annealing maximisation algorithm to calculate node similarity iteratively, and validated using artificial and real networks. It proves that the proposed algorithm reduces the GN algorithm's running time and improves efficiency. [ABSTRACT FROM AUTHOR]

High-yield shale gas flow has been discovered in the Cambrian Shuijingtuo group shale (the Shuijingtuo shale) of the first shale gas well of Yichang, West Hubei, China. However, there are very few papers or reports involving high-performance water-based drilling fluid for the Shuijingtuo shale. X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) tests were conducted on the outcrop of the Shuijingtuo shale samples collected from Zigui County, West Hubei. Then, the screening experiments on mud-making materials, salt additives, nanoparticles, fluid loss additives, mixed metal hydroxides (MMH), and surfactants were carried out. A high-performance water-based drilling fluid for the Shuijingtuo shale (the SWDF drilling fluid) was proposed based on physical plugging by nanoparticles, electrical property inhibition, and wettability control theory. Finally, comprehensive appraisals on rheology, filtration, lubricity, temperature resistance, inhibition, anti-pollution capability, and expense of the SWDF drilling fluid were accomplished. XRD results showed that the Shuijingtuo shale samples had 55%~67% brittle minerals. Clay minerals were mainly illite (13%~27%), and no montmorillonite was observed, which indicated that the Shuijingtuo shale was a weak-expansive rock. SEM analysis results show that pore and micro-cracks on the surface of the Shuijingtuo shale could provide natural channels for the invasion of drilling fluid. Nanomaterials were found to reduce the fluid loss of drilling fluid and thermal stability of the nano-silica dispersion was better. As a whole, the SWDF drilling fluid had suitable viscosity and gel strength, a low API fluid loss of 7.2 mL, a lubricity coefficient of 0.21, temperature-resistance capability up to 120°C, and good inhibition to shale hydration. In addition, it had excellent resistance capability to inorganic salts (NaCl, MgCl2, and CaCl2) and low-yield mud-making materials (simulated cuttings). Also, the cost of the SWDF drilling fluid was competitive compared to common oil-based drilling fluids. As a consequence, the SWDF drilling fluid can meet the requirements of drilling horizontal wells in the Shuijingtuo shale of West Hubei, China. [ABSTRACT FROM AUTHOR]

Magnetorheological (MR) damper is one of the key technologies in the field of semi-active suspensions. However, the dynamic model and control strategy are not yet well established. A unified MR damper model and its inverse characterization are proposed to investigate MR damper dynamics. First, a novel unified model is proposed to describe the shear term of the MR damper force. This forward unified MR damper model uses one set of parameters to describe all MR force behavior under all currents and velocities, which agrees well with experimental data. Then, an inverse MR model based on the adaptive neuro-fuzzy inference system (ANFIS) technique has been established, where the precise training data are obtained from the proposed unified hysteretic model. A clear step-wise modeling process is proposed to decrease coupling degree of system which can be beneficial to improve inverse modeling efficiency. The inverse MR model is used for a semi-active suspension control, which can obtain the excitation current, exactly tracking the desired damping force computed by suspension control algorithm. Finally, validation of the proposed ANFIS inverse model has been conducted by comparison with three traditional empirical inverse approaches. The results reveal that the ANFIS inverse model could achieve much more tracking capability for the desired damping force and thus contributes to the development of semi-active suspension controllers. [ABSTRACT FROM AUTHOR]

A group test gives a positive (negative) outcome if it contains at least u (at most l) positive items, and an arbitrary outcome if the number of positive items is between thresholds l and u. This problem introduced by Damaschke is called threshold group testing. It is a generalization of classical group testing. Chen and Fu extended this problem to the error-tolerant version and first proposed efficient nonadaptive algorithms. In this article, we extend threshold group testing to the k-inhibitors model in which a test has a positive outcome if it contains at least u positives and at most k−1 inhibitors. By using ( d + k − l, u; 2 e + 1]-disjunct matrix we provide nonadaptive algorithms for the threshold group testing model with k-inhibitors and at most e-erroneous outcomes. The decoding complexity is O( nu+ k log n) for fixed parameters ( d, u, l, k, e). [ABSTRACT FROM AUTHOR]