TAPInspector: Safety and Liveness Verification of Concurrent Trigger-Action IoT Systems

Trigger-action programming (TAP) is a popular end-user programming framework that can simplify the Internet of Things (IoT) automation with simple trigger-action rules. However, it also introduces new security and safety threats. A lot of advanced techniques have been proposed to address this problem. Rigorously reasoning about the security of a TAP-based IoT system requires a well-defined model and verification method both against rule semantics and physical-world states, e.g., concurrency, rule latency, and connection-based interactions, which has been missing until now. This paper presents TAPInspector, a novel system to detect vulnerabilities in concurrent TAP-based IoT systems using model checking. It automatically extracts TAP rules from IoT apps, translates them into a hybrid model with model slicing and state compression, and performs model checking with various safety and liveness properties. Our experiments corroborate that TAPInspector is effective: it identifies 533 violations with 9 new types of violations from 1108 real-world market IoT apps and is 60000 times faster than the baseline without optimization at least.Comment: 14 pages, 5 figure

Design and test of a pneumatic precision metering device for wheat

The objective of this study was to apply the precision metering on wheat seeding to overcome seed damage, seed loss and non-uniform distribution.  Accordingly, a prototype of the pneumatic precision metering device for wheat was developed.  The performance of the device, including quality of feed index (QFI), multiple index (MULI), miss index (MISI) and seed rate expressed in number of kernels per meter length (KPM), was investigated under laboratory conditions in Wuhan using a test stand with camera system.  The results revealed that the rotating speed (RS) and negative pressure (NP) and their interactions had a significant effect on these variables.  The maximum QFI (92.98%) was obtained at rotating speed of 19.0 rpm and negative pressures of 2.5 kPa with MULI and MISI of 2.01% and 5.09%, respectively.  However, the seed rate (KPM) was less than the recommended compared to previous hypothesis.  The best seed rate was 53 KPM producing QFI of 89.11% with MULI and MISI of 9.00% and 1.88%, respectively at rotating speed of 34 rpm and negative pressure of 4.5 kPa.  The recommended seed rates estimated at 40 KPM and 53 KPM for 12 cm and 15 cm row spacing respectively were achieved at a range of RS and NP with QFI ranging between 84.57 to 89.11%.  The study demonstrated that wheat could be seeding within an acceptable precisely range by pneumatic precision metering device. Keywords: wheat, experiments, performance indices, pneumatic precision metering device

Dynamic analysis for kernel picking up and transporting on a pneumatic precision metering device for wheat

The objective of this study was to theoretically investigate the factors affecting kernels during picking up and transporting stage using a pneumatic precision metering device designed especially for wheat precision seeding and correlates findings with the results from practical testing under laboratory conditions using a test stand with camera system.  The results from dynamic analysis were found to be corresponding with that of the laboratory testing.  The findings revealed that the performance indices, such as quality of feed index (QFI), multiple index (MULI) and miss index (MISI), were obviously influenced by changing the negative pressure force FQ and rotating speed ω.  The result from test stand highlighted that when the negative pressure increased the QFI increased, MULI increased and MISI decreased, however, the QFI decreased and MISI increased with increasing the rotating speed.  The dynamic analysis likewise revealed that increasing the friction index tanαg by choosing a suitable material with high friction angle αg for seed plate as well as enlarging the seed hole diameter could improve the efficiency of the negative pressure force FQ.   Keywords: wheat, kernel, picking up, transportation, dynamic model, precision metering devic

Go/No-Go Ratios Modulate Inhibition-Related Brain Activity: An Event-Related Potential Study

(1) Background: Response inhibition refers to the conscious ability to suppress behavioral responses, which is crucial for effective cognitive control. Currently, research on response inhibition remains controversial, and the neurobiological mechanisms associated with response inhibition are still being explored. The Go/No-Go task is a widely used paradigm that can be used to effectively assess response inhibition capability. While many studies have utilized equal numbers of Go and No-Go trials, how different ratios affect response inhibition remains unknown; (2) Methods: This study investigated the impact of different ratios of Go and No-Go conditions on response inhibition using the Go/No-Go task combined with event-related potential (ERP) techniques; (3) Results: The results showed that as the proportion of Go trials decreased, behavioral performance in Go trials significantly improved in terms of response time, while error rates in No-Go trials gradually decreased. Additionally, the NoGo-P3 component at the central average electrodes (Cz, C1, C2, FCz, FC1, FC2, PCz, PC1, and PC2) exhibited reduced amplitude and latency; (4) Conclusions: These findings indicate that different ratios in Go/No-Go tasks influence response inhibition, with the brain adjusting processing capabilities and rates for response inhibition. This effect may be related to the brain's predictive mechanism model

Wetting equilibrium in a rectangular channel

When a capillary channel with corners is wetted by a fluid, there are regions where the fluid fills the whole cross-section and regions where only the corners are filled by the fluid. The fluid fraction of the partially-filled region, $s^*$, is an important quantity related to the capillary pressure. We calculate the value of $s^*$ for channels with a cross-section slightly deviated from a rectangle: the height is larger in the center than those on the two short sides. We find that a small change in the cross-section geometry leads to a huge change of $s^*$. This result is consistent with experimental observations.Comment: 23 pages, 8 figures, submitted to Soft Matte

A Temporal-Pattern Backdoor Attack to Deep Reinforcement Learning

Deep reinforcement learning (DRL) has made significant achievements in many real-world applications. But these real-world applications typically can only provide partial observations for making decisions due to occlusions and noisy sensors. However, partial state observability can be used to hide malicious behaviors for backdoors. In this paper, we explore the sequential nature of DRL and propose a novel temporal-pattern backdoor attack to DRL, whose trigger is a set of temporal constraints on a sequence of observations rather than a single observation, and effect can be kept in a controllable duration rather than in the instant. We validate our proposed backdoor attack to a typical job scheduling task in cloud computing. Numerous experimental results show that our backdoor can achieve excellent effectiveness, stealthiness, and sustainability. Our backdoor's average clean data accuracy and attack success rate can reach 97.8% and 97.5%, respectively

Stroking hardness changes the perception of affective touch pleasantness across different skin sites

Human unmyelinated tactile afferents (CT afferents) in hairy skin are thought to be involved in the transmission of affective aspects of touch. How the perception of affective touch differs across human skin has made substantial progress; however, the majority of previous studies have mainly focused on the relationship between stroking velocities and pleasantness ratings. Here, we investigate how stroking hardness affects the perception of affective touch. Affective tactile stimulation was given with four different hardness of brushes a three different forces, which were presented to either palm or forearm. To quantify the physical factors of the stimuli (brush hardness), ten naive, healthy participants assessed brush hardness using a seven-point scale. Based on these ten participants, five more participants were added to rate the hedonic value of brush stroking using a visual analogue scale (VAS). We found that pleasantness ratings over the skin resulted in a preference for light, soft stroking, which was rated as more pleasant when compared to heavy, hard stroking. Our results show that the hairy skin of the forearm is more susceptible to stroking hardness than the glabrous of the palm in terms of the perception of pleasantness. These findings of the current study extend the growing literature related to the effect of stroking characteristics on pleasantness ratings