In this research work, an advanced wireless communication-based crank slider mechanism for multiparameter friction techniques is analyzed. The earlier models are unable to find exact friction; ...therefore, a correct crank function cannot be identified. The dynamic crank sliding mechanism is required for advanced mechanical applications. The available models are not suitable for future mechanical exhibiting. In this work, an SVM-based crank slider with a dynamic friction model is implemented. The SVM mathematical technique continually balances dynamic modeling with friction balancing. Finally, the controller/observer methods showed effective numerical outcomes. The variables of the system are analyzed, noting the mistakes and the estimations that are made. The performance measures accuracy of 98.45%, sensitivity of 97.34%, crank slider of 96.34%, and recall at 97.34%.
Existing knowledge on remote working can be questioned in an extraordinary pandemic context. We conducted a mixed‐methods investigation to explore the challenges experienced by remote workers at this ...time, as well as what virtual work characteristics and individual differences affect these challenges. In Study 1, from semi‐structured interviews with Chinese employees working from home in the early days of the pandemic, we identified four key remote work challenges (work‐home interference, ineffective communication, procrastination, and loneliness), as well as four virtual work characteristics that affected the experience of these challenges (social support, job autonomy, monitoring, and workload) and one key individual difference factor (workers’ self‐discipline). In Study 2, using survey data from 522 employees working at home during the pandemic, we found that virtual work characteristics linked to worker's performance and well‐being via the experienced challenges. Specifically, social support was positively correlated with lower levels of all remote working challenges; job autonomy negatively related to loneliness; workload and monitoring both linked to higher work‐home interference; and workload additionally linked to lower procrastination. Self‐discipline was a significant moderator of several of these relationships. We discuss the implications of our research for the pandemic and beyond.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Ambient backscatter, an emerging communication mechanism where battery-free devices communicate with each other via backscattering ambient radio frequency (RF) signals, has achieved much attention ...recently because of its desirable application prospects in the Internet of Things. In this paper, we formulate a practical transmission model for an ambient backscatter system, where a tag wishes to send some low-rate messages to a reader with the help of an ambient RF signal source, and then provide fundamental studies of noncoherent symbol detection when all channel state information of the system is unknown. For the first time, a maximum likelihood detector is derived based on the joint probability density function of received signal vectors. In order to ease availability of prior knowledge of the ambient RF signal and reduce computational complexity of the algorithm, we design a joint-energy detector and derive its corresponding detection threshold. The analytical bit error rate (BER) and BER-based outage probability are also obtained in a closed form, which helps with designing system parameters. An estimation method to obtain detection-required parameters and comparison of computational complexity of the detectors are presented as complementary discussions. Simulation results are provided to corroborate theoretical studies.
The digital economy has become a driving force in the rapid development of the global economy and the promotion of export trade. Pivotal in its advent, the digital transformation of enterprises ...utilizes cloud computing, big data, artificial intelligence, and other digital technologies to provide an impetus for evolution and transformation in various industries and fields. in enhancing quality and efficiency. This has been critical for enhancing both quality and efficiency in enterprises based in the People's Republic of China. Through the available data on its listed enterprises, this paper measures their digital transformation through a textual analysis and examines how this transformation influences their export product quality. We then explore the possible mechanisms at work in this influence from the perspective of enterprise heterogeneity. The results find that: (1) Digital transformation significantly enhances the export product quality in an enterprises, and the empirical findings still hold after a series of robustness tests; (2) Further mechanism analysis reveals that the digital transformation can positively affect export product quality through the two mechanisms of process productivity (phi), the ability to produce output using fewer variable inputs, and product productivity (xi), the ability to produce quality with fewer fixed outlays; (3) In terms of enterprise heterogeneity, the impact of digital transformation on export product quality is significant for enterprises engaged in general trade or high-tech industries and those with strong corporate governance. In terms of heterogeneity in digital transformation of enterprise and the regional digital infrastructure level, the higher the level of digital transformation and regional digital infrastructure, the greater the impact of digital transformation on export product quality. This paper has practical implications for public policies that offer vital aid to enterprises as they seek digital transformation to remain sync with the digital economy, upgrade their product quality, and drive the sustainable, high-quality, and healthy development of their nation's economy.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Dielectric capacitors have attracted increasing attention for their fast charge–discharge speeds as well as high power density, and they have been widely used in advanced electronics and electric ...power systems. Here, dopamine-modified TiO
2
(TiO
2
@PDA) nanosheets were synthesized via hydrothermal reaction and in situ polymerization. Then the synthesized TiO
2
@PDA nanosheets were introduced into the poly(vinylidene fluoride) (PVDF) matrix via solution blending. Our results reveal that loading a small amount of TiO
2
@PDA nanosheets can effectively enhance the energy storage performance of the nanocomposites. For example, a superior discharge energy density with 10.53 J/cm
3
is obtained for the 9 wt.% TiO
2
@PDA/PVDF nanocomposite at 195 MV/m, which is 1.75 times as large as discharge energy density of pure PVDF (6.01 J/cm
3
at 170 MV/m). Such significant improvement is due to the large aspect ratio as well as dopamine modification of the TiO
2
nanosheets. The study provides a feasible way to prepare the nanocomposites with excellent energy storage performance.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
With the emergence of drug-resistant strains, the treatment of tuberculosis (TB) is becoming more difficult and there is an urgent need to find new anti-TB drugs.
, as a model organism of
, can be ...used for the rapid and efficient screening of bioactive compounds. The 14-membered resorcylic acid lactones (RALs) have a wide range of bioactivities such as antibacterial, antifouling and antimalarial activity. In order to further study their bioactivities, we initially constructed a 14-membered RALs library, which contains 16 new derivatives. The anti-
activity was evaluated in vitro. Derivatives
,
,
and
exhibited promising activity with MIC
values of 80, 90, 80 and 80 μM, respectively. The preliminary structure-activity relationships showed that the presence of a chlorine atom at C-5 was a key factor to improve activity. Further studies showed that
markedly inhibited the survival of
and significantly reduced the dosage of positive drugs isoniazid and rifampicin when combined with them. These results suggest that
is a bioactive compound capable of enhancing the potency of existing positive drugs, and its effective properties make it a very useful leads for future drug development in combating TB resistance.
Resuspension of particles indoors increases the risk of consequent exposure through inhalation and non-dietary ingestion. Studies have been conducted to characterize indoor particle resuspension but ...results do not always agree, and there are still many open questions in this field. This paper reviews the recent research of indoor resuspension and summarizes findings to answer six critical questions: 1) How does the resuspension sources compared to other indoor sources; 2) How is resuspension determined and how does the resuspension measure change as a function of particle size; 3) What are the primary resuspension mechanisms; 4) What are the factors affecting resuspension; 5) What are the knowledge gaps and future research directions in this area; and 6) How can what we know about resuspension guide better exposure mitigation strategies? From synthesized results, we conclude that resuspension is an important source for indoor particulate matter, compared with other indoor sources. Among all existing quantification terms of resuspension, resuspension fraction has the least variation in its estimates by explicitly defining surface loading and walking frequency, and thus is recommended to be adopted in future research over other terms. Resuspension increases with particle size in the range of 0.7–10 μm, although differences exist in resuspension estimates by orders of magnitude. The primary mechanism of particle resuspension involves rolling detachment, and the adhesive forces can be greatly reduced by microscopic surface roughness. Particle resuspension is by nature complicated, affected by various factors and their interactions. There are still many open questions to be answered to achieve an understanding of resuspension fundamentals. Given the complex and multidisciplinary nature of resuspension, understanding indoor particle resuspension behavior requires cross-disciplinary participation from experts in aerosol science, textile science, surface chemistry, electrostatics, and fluid mechanics.
•Studies on the resuspension of particles via human activities indoors are reviewed.•Resuspension is compared with other indoor sources in terms of source strength.•Resuspension estimates increase with particle size in the range of 0.7–10 μm.•Fundamental mechanisms and factors of resuspension are reviewed.•Future research directions are suggested under the framework of open questions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
We propose a theoretical scheme for creating a two-dimensional Electromagnetically Induced Grating in a three-level
$$\Lambda $$
Λ
-type atomic system interacting with a weak probe field and ...two simultaneous position-dependent coupling fields—a two dimensional standing wave and an optical vortex beam. Upon derivation of the Maxwell wave equation, describing the dynamic response of the probe light in the atomic medium, we perform numerical calculations of the amplitude, phase modulations and Fraunhofer diffraction pattern of the probe field under different system parameters. We show that due to the azimuthal modulation of the Laguerre–Gaussian field, a two-dimensional asymmetric grating is observed, giving an increase of the zeroth and high orders of diffraction, thus transferring the probe energy to the high orders of direction. The asymmetry is especially seen in the case of combining a resonant probe with an off-resonant standing wave coupling and optical vortex fields. Unlike in previously reported asymmetric diffraction gratings for PT symmetric structures, the parity time symmetric structure is not necessary for the asymmetric diffraction grating presented here. The asymmetry is due to the constructive and destructive interference between the amplitude and phase modulations of the grating system, resulting in complete blocking of the diffracted photons at negative or positive angles, due to the coupling of the vortex beam. A detailed analysis of the probe field energy transfer to different orders of diffraction in the case of off-resonant standing wave coupling field proves the possibility of direct control over the performance of the grating.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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