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The purpose of this paper is to add expanded perlite (EP) immobilized microorganisms that replace part of the standard sand in mortar to improve the self-healing ability of mortar cracks and reduce the water absorption of mortar after healing.

Bacillus pseudofirmus spores were immobilized with EP particles as self-healing agents. The effects of adding self-healing agents on the compressive strength of mortar specimens were observed. The ability of mortar specimens to heal cracks was evaluated using crack microscopic observation and water absorption experiments. The filler at the cracks was microscopically analyzed by scanning electron microscope and X-ray diffraction experiments.

First, the internal curing effect of EP promotes the hydration of cement in mortar, which generates more amount and denser crystal structure of Ca(OH)2 at mortar cracks and improves the self-healing ability of mortar. Second, the self-healing ability of mortar improves with the increase of self-healing agent admixture. Adding a self-healing agent of high admixture makes the planar undulation of calcite crystal accumulation at mortar cracks more significant. Finally, the initial crack widths that can be completely healed by adding EP and self-healing agents to the mortar are 200 µm and 600 µm, respectively.

The innovation points of this study are as follows. (1) The mechanism of the internal curing effect of EP particles on the self-healing ability of mortar cracks was revealed by crack microscopic observation tests and microscopic experiments. (2) The effect of different self-healing agent amounts on the self-healing ability of mortar cracks has been studied. (3) The effects of EP particles and self-healing agents on healing different initial widths were elucidated by crack microscopic observation tests.

This paper aims to study the establishment of cooperative supply game model considering transportation hub location, and design the profit allocation rule of the cooperative supply coalition.

Based on the economic lost-sizing (ELS) game model and considering the location of transportation hub and the topology design of basic traffic network, we build a supply game model to maximize the profit of cooperative supply coalition. Based on the principle of proportion and the method of process allocation, we suppose the procedural proportional solution of the supplier cooperative supply game.

Through numerical examples, the validity and applicability of the proposed model and the procedural proportional solution were verified by comparing the procedural proportional solution with the weighted Shapley value, the equal division solution and the proportional rule.

This paper constructs a feasible mixed integer programming model for cooperative supply game. We also provide the algorithm of the allocation rule of cooperative supply game and the property analysis of the allocation rule.

Student in-class participation is a crucial aspect in the learning process, including in synchronous learning process. Several variables may hinder students from actively participating in synchronous learning including communication anxiety. As behavior, student in-class participation can be modeled using theory of planned behavior (TPB) with communication anxiety as barrier variable. The current study aims to investigate student decision-making process to actively participate in synchronous online learning using TPB frameworks and examine the effect of communication anxiety as part of extended TPB.

This was quantitative nonexperimental research conducted by gathering cross-sectional data through electronic survey. A total of 1,009 Indonesian college students voluntarily participate in the survey. Structural equation modeling was used to analyze the data and test the hypothesis.

The results indicate that there was significant and positive effect between TPB-related variables: (1) attitude, (2) subjective norms, (3) behavioral control, (4) intention and (5) behavior. Communication anxiety, as an additional variable in the extended model, shows significant and negative effects on behavioral control and active participation behavior. However, the communication anxiety indicates insignificant effect on students’ intention to participate in online synchronous learning. The findings support the evidence that students’ intention to actively participate in synchronous learning can be described using TPB and communication anxiety hinders student to actively participate in synchronous learning.

The paper extends TPB on student active participation. Prior research limited to original theory of planned behavior (TPB) on student in-class and massive open online course (MOOC) participations, whereas the current research includes communication anxiety as additional variable on extended TPB to understand students’ intention to actively participate in synchronous online learning.

The purpose of this paper is to evaluate the application of an acoustic micro‐imaging (AMI) inspection technique in monitoring solder joints through lifetime performance and demonstrate the robustness of the monitoring through analysis of AMI data.

Accelerated thermal cycling (ATC) test data on a flip chip test board were collected through AMI imaging. Subsequently, informative features and parameters of solder joints in acoustic images were measured and analysed. Through analysing histogram distance, mean intensity and grey area of the solder joints in acoustic images, cracks between the solder bump and chip interface were tracked and monitored. The results are in accord with associated Finite Element (FE) prediction.

At defective bumps, the formation of a crack causes a larger acoustic impedance mismatch which provides a stronger ultrasound reflection. The intensity of solder joints in the acoustic image increase according to the level of damage during the ATC tests. By analysing the variation of intensity and area, solder joint fatigue failure was monitored. A failure distribution plot shows a normal distribution pattern, where corner joints have the lowest reliability and are more likely to fail first. A strong agreement between AMI monitoring test data and FE prediction was observed, demonstrating the feasibility of through lifetime monitoring of solder joints using AMI.

The paper indicates the feasibility of the novel application of AMI inspection to monitor solder joint through lifetime performance non‐destructively. Solder joints' real life conditions can be tracked by an AMI technique, hence solder joint fatigue failure cycles during the ATC tests can be monitored and analysed non‐destructively.

This paper discusses the implementation method of open router based on active network, and describes the measure to assure the security of network. The active network can supply the clients with the new services by loading new code on the router in active network, but not changing the hardware.

The purpose of this paper is to provide a solution to investigate the deception effects of the radar equipped with decoys.

Since the attacking process of the anti‐radiation missile (ARM) is very complicated, numerical simulations are used here to analyze the effects of the operating parameters and the layout parameters of the radar and the decoys on the survival probabilities.

The survival probabilities of all the radar and the decoys can be over 99.5 percent when three decoys distribute near the radar in an appropriate way and the decoy level is set to some appropriate values.

The movement model of the ARM is simple and should be improved further.

The numerical results may be applied directly in practice and the dynamic simulation algorithms may be as a reference of the radar‐decoy technique in the future works.

Some coordinate systems are built. Based on it, the models of the radar and decoys against an ARM are introduced, including the fields radiated by the radar and the decoys, the guidance signal and the movement of the ARM. Numerical simulations have been performed here. Some conclusions have been given.

A modified hybrid ARQ type‐II retransmission technique is presented. In this scheme, only the originally punctured bits are transmitted instead of full retransmission, if necessary. Compared to Narayanan's retransmission scheme, the structure of the modified turbo encoder and decoder is simpler. Simulation results demonstrated that a frame error rate reduction can be obtained. At the same time, the effective code rate remained relatively high.