A data-driven path replanning algorithm based on Pythagorean-hodograph (PH) curve is proposed for unpowered gliding vehicles considering the terminal velocity constraint in uncertain windy ...environments. Based on the characteristics of the PH curve, the terminal velocity constraint is satisfied by adjusting path parameters including the arc length in path replanning. For the path replanning, a tailored PH curve regeneration algorithm is proposed to resolve the inconsistent path replanning issue of the existing PH curve generation method. An artificial-neural-network-based path replanner is trained to provide the path parameters corresponding to the terminal velocity constraint. Unlike most model-based methods, the proposed method can deal with the external disturbance by replanning the flight path. Compared with other data-driven studies, the proposed method does not require a computationally expensive trajectory optimization process to collect training data. Performance evaluation and comprehensive comparison are performed via numerical simulation considering various types of modeled and unmodeled wind uncertainties using several network configurations.
Here, we demonstrate that the peptidyl-prolyl cis/trans isomerase Pin1 interacts noncovalently with the hepatitis B virus (HBV) core particle through phosphorylated serine/threonine-proline (pS/TP) ...motifs in the carboxyl-terminal domain (CTD) but not with particle-defective, dimer-positive mutants of HBc. This suggests that neither dimers nor monomers of HBc are Pin1-binding partners. The
TP,
SP, and
SP motifs within the HBc CTD are important for the Pin1/core particle interaction. Although Pin1 dissociated from core particle upon heat treatment, it was detected as an opened-up core particle, demonstrating that Pin1 binds both to the outside and the inside of the core particle. Although the amino-terminal domain S/TP motifs of HBc are not involved in the interaction,
SP contributes to core particle stability, and
TP might be involved in core particle assembly, as shown by the decreased core particle level of S49A mutant through repeated freeze and thaw and low-level assembly of the T128A mutant, respectively. Overexpression of Pin1 increased core particle stability through their interactions, HBV DNA synthesis, and virion secretion without concomitant increases in HBV RNA levels, indicating that Pin1 may be involved in core particle assembly and maturation, thereby promoting the later stages of the HBV life cycle. By contrast, parvulin inhibitors and
knockdown reduced HBV replication. Since more Pin1 proteins bound to immature core particles than to mature core particles, the interaction appears to depend on the stage of virus replication. Taken together, the data suggest that physical association between Pin1 and phosphorylated core particles may induce structural alterations through isomerization by Pin1, induce dephosphorylation by unidentified host phosphatases, and promote completion of virus life cycle.
Today, more hotel companies attempt to use hotel apps to provide useful content about hotel facilities, events or promotions, and directions. By using experiential values in the context of hotel app ...experience, this study explores how hotel guests perceive hotel apps and what affects their satisfaction with those apps and their re-use intentions through Partial Least Squares Structural Equation Modeling (PLS-SEM). A total of 212 usable responses were collected for data analysis through an online survey. The results of structural analysis revealed that while service excellence and esthetic values from hotel app experiences influence guest satisfaction, the playfulness value does not. Theoretical and managerial implications are discussed.
In longitudinal electroencephalography (EEG) studies, repeatable electrode positioning is essential for reliable EEG assessment. Conventional methods use anatomical landmarks as fiducial locations ...for the electrode placement. Since the landmarks are manually identified, the EEG assessment is inevitably unreliable because of individual variations among the subjects and the examiners. To overcome this unreliability, an augmented reality (AR) visualization-based electrode guidance system was proposed.
The proposed electrode guidance system is based on AR visualization to replace the manual electrode positioning. After scanning and registration of the facial surface of a subject by an RGB-D camera, the AR of the initial electrode positions as reference positions is overlapped with the current electrode positions in real time. Thus, it can guide the position of the subsequently placed electrodes with high repeatability.
The experimental results with the phantom show that the repeatability of the electrode positioning was improved compared to that of the conventional 10-20 positioning system.
The proposed AR guidance system improves the electrode positioning performance with a cost-effective system, which uses only RGB-D camera. This system can be used as an alternative to the international 10-20 system.
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•Carbon nanotube-polyethylenimine coatings on PCM heat sinks are developed.•Layer-by-Layer (LbL) solution processing enables nanocoatings of charged precursors.•LbL processes lead to ...optimal porous thermal interfaces between PCM and heat sinks.•PCM-LbL heat sinks enhance cooling performances for transient thermal loads.•LbL coatings improve active sites-contact interfaces for liquid–solid phase change.
Rationally designed hybrids of heat sinks (HSs) and phase change materials (PCMs) can mutually complement their fundamental limitations. However, integrating PCMs into HSs inevitably incurs additional thermal resistances and degradation during solid–liquid phase transitions owing to unstable contact interfaces. Herein, we report layer-by-layer (LbL)-assembled multiwalled carbon nanotube (MWCNT)–polyethyleneimine (PEI) functional interfaces between the PCM and HS surfaces to enhance thermal management capabilities. The LbL process used in this study involves direct fabrication of electrostatically adhered nanocoatings of multiple materials via a solution process, which resulted in facile formation of MWCNT-PEI percolation networks on an aluminum HS. The PCM-HS was completed by filling the HS channels with a PCM (n-eicosane). The functional interface increased the active surface areas for thermal transport and optimized the porous structures for the stabilization of the PCM–HS boundary under repetitive solid–liquid phase changes. Comparison of the fabricated specimens (bare and PCM-filled HSs without LbL interfaces) elucidated the enhanced thermal performances in transient-static operating conditions. This was confirmed by experimentally measuring the real-time temperature responses at various levels of heating power and the time delays to reach the set point temperatures, indicating a more than 10% improvement in effectiveness using the LbL interface. Furthermore, the LbL interfaces efficiently alleviated thermal shock or overload under intermittent thermal loads. The developed LbL interface offers a tunable–scalable method to fabricate PCM-filled HSs with advanced thermal properties that cannot be achieved using a conventional HS.
A vector field-based guidance law is proposed for the speed and impact angle control of an unpowered, glide-capable air-to-ground munition. An artificial 3-D space is designed for the glider vehicle ...to satisfy the terminal constraints. The glider vehicle is guided to the target position by the proposed vector field-based guidance law while satisfying the desired impact angle and final speed constraints. In the numerical simulations, various wind conditions are considered to demonstrate the performance of the proposed guidance law.
Passive cooling using phase change materials (PCMs) is a promising solution to address thermal challenges for modern electronics, electric vehicles, and energy storage systems. The high latent heat ...of PCMs can significantly decrease overheating or thermal shock; however, their low thermal conductivity and unstable shape limit their practical application. Herein, we report a multiscale rational design strategy for tuning the thermal properties of PCM (octadecane), enabled by 3D-printed structural materials and multiwalled carbon nanotubes (MWCNTs)/graphene nanoplatelets (GNPs), serving as PCM reservoirs and thermally functional additives. Octadecane, used as the PCM, was thermally reinforced with MWCNT/GNP functional additives using one- and two-dimensional thermal transport at the micro-/nanoscale, and the developed nanocomposite PCM was incorporated into the 3D-printed grid structures serving two purposes: thermal transport at the macroscale and mechanical support during the liquid–solid phase change. Thus, the fabricated 3D-printed structures with incorporated thermal energy management composites (3DS-TEMCs), with different infill density/MWCNT/GNP parameters, exhibited tunable latent heat/thermophysical properties and outstanding thermal conductivity (~0.45–0.79 W/(m K)) higher than that of pure octadecane (~0.15 W/(m K)). In passive cooling tests implemented in a local heating configuration, the 3DS-TEMCs inhibited overheating and thermal shock under transient thermal loads in the operating temperature ranges of electronic devices and batteries. The proposed 3DS-TEMC offers a tunable and scalable strategy to impart PCMs with advanced thermophysical characteristics compared to conventional PCMs.
Artificial structures for controlling ultrasonic‐waves are attractive for developing superb functions in sensing‐imaging techniques. However, the complicated fabrication and fixed design associated ...with the particular wave limit the scalability. Herein, a versatile‐reversible ultrasonic‐wave engineering using programmable heating of local areas on thermoresponsive polymers is presented. As an abrupt shift of the elastic modulus occurs at selectively heated zones over the glass transition temperature, the drastic modulus change alters the S0 phase velocity of the Lamb wave within ultrasonic waves passing through the heated regimes. The modified wave propagation results in an active wavelength shift and wave refraction, which enables multifunctional programming of wave propagation pathways and wavefront shapes. Multiple functions such as reduced wavelength, wave steering, energy focusing and bifurcation are implemented in one nylon 6 thermoresponsive polymer, according to predesigned heating shapes. This work demonstrates the capability of temperature‐responsive wave engineering in bulk solid media with only a heating configuration.
Programmable heating of local areas on thermoresponsive polymers offers versatile‐reversible ultrasonic‐wave engineering. The drastic modulus change at the glass transition temperature activated by selective heating configuration inside the media conducts a pre‐designed wavelength shift and wave refraction, which enable multiple functions, such as reduced wavelength, wave steering, energy focusing, and bifurcation.
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