Risk Management of SMEs in Tourism Industry: A case study of a small domestic tourism agency in China

The research is focused on the risk management of SMEs in tourism industry. In estimation there are around 12,000 tourism agencies locate in 656 different cities in China. However, the current operations and regulations of small domestic tourism agencies are still immature and ready to trigger a major failure. In the mean time, these tourism agencies become quite vulnerable when facing the challenges bring about constantly changing external economic environment, natural catastrophes, and industry competition. The researcher aims to create a whole set of risk management process which is simple to use, especially for those business owners who are lack of previous risk management experiences and those businesses which are financially incapable of hiring a professional risk management officer. Even though the proposed risk management methods are primarily originated from a case tourism agency in China, it also can to be applied to other SMEs in tourism sector of similar kind. Risk identification has been recognized as the basic and indispensable stage in the risk management process. In the case tourism agency, risks are specific to each production process and each step in each process. By identifying the steps that need to be completed successfully, we can identify the specific risks. On the other hand, concerning case tourism agency’s risk assessment, both the probability and severity of potential losses has been tackled. The risk will be ranked in some way which enables risk management resources to be allocated in a more cost-effective manner. The probability and impact of future contingent losses were estimated by using a five point scale in each case, which is easy for the owner to understand and apply. In the mean time, a simple hypothetical approach of testing the correlation between risks has been proposed. This approach has not been widely covered in the literature and it provides another way of looking at and prioritizing the risk. More specifically, risk which possesses both a higher level of probability and size of contingent loss deserves more risk management attention as it indicates a non-ambiguous sign of risk. In terms of case tourism agency’s risk management, initial examination has been done to determine whether the risks are transferable or not. And an important conclusion has been drawn that the nature of the important identified risks meant that market insurance was not available, and so self-insurance and self-protection were considered as alternatives

Millicharged particles from proton bremsstrahlung in the atmosphere

Light millicharged particles can be copiously produced from meson decays in cosmic ray collisions with the atmosphere, leading to detectable signals in large underground neutrino detectors. In this paper we study a new channel to produce millicharged particles in the atmosphere, the proton bremsstrahlung process. We find that the proton bremsstrahlung channel can produce a much larger flux of millicharged particles than the previously studied meson decay channel, resulting in an improvement on the SuperK limit by nearly one order of magnitude. Consequently, SuperK can probe new parameter space beyond the current leading limits from ArgoNeuT. We further note that the study on the proton bremsstrahlung process can be extended to other atmospherically produced light particles, and to millicharged particle searches in proton accelerators.Comment: 11 pages, 8 figure

Shear thickening effects of drag-reducing nanofluids for low permeability reservoir

Drag-reducing nanofluids are complex non-Newtonian fluids. Their constitutive characteristics are the basis of flow mechanism analysis in porous media. However, the rheological effects of drag-reducing nanofluids have not been thoroughly studied. In the present work, rheological properties of several nanofluids were measured, and the shear thickening mechanism was investigated experimentally. The results show that all the nanofluids examined have complex characteristics and critical shear rates. The viscosity exhibits a slow linear increase with the shear rate below the critical shear rate, while the shear thickening power-law fluid behaviour appears above the critical shear rate. The critical shear rate increases with the increase of particle concentration, which indicates the injection rate needs to be controlled to avoid significant increase of nanofluids viscosity. The rheological curve of increasing shear rate nearly coincides with that of decreasing shear rate, which indicates that the shear thickening of nanofluids studied in this work is transient and reversible. A constant index constitutive equation with an exponent of 0.5 is obtained from test results by the fixed index method, and its coefficient k(c) is a linear function of the concentration, which can replace a set of conventional constitutive equations with different concentrations. The constant index constitutive equation also clarifies the coefficient dimension. Similar results have been obtained by analysing several other nanofluids using the fixed index method, which validates the new effective method for constructing the constitutive equations of non-Newtonian nanofluids.Cited as: Gu, C., Qiu, R., Liu, S., You, Z., Qin, R. Shear thickening effects of drag-reducing nanofluids for low permeability reservoir. Advances in Geo-Energy Research, 2020, 4(3): 317-325, doi: 10.46690/ager.2020.03.0

Role of Protein Charge Density on Hepatitis B Virus Capsid Formation

The role of electrostatic interactions in the viral capsid assembly process was studied by comparing the assembly process of a truncated hepatitis B virus capsid protein Cp149 with its mutant protein D2N/D4N, which has the same conformational structure but four fewer charges per dimer. The capsid protein self-assembly was investigated under a wide range of protein surface charge densities by changing the protein concentration, buffer pH, and solution ionic strength. Lowering the protein charge density favored the capsid formation. However, lowering charge beyond a certain point resulted in capsid aggregation and precipitation. Interestingly, both the wild-type and D2N/D4N mutant displayed identical assembly profiles when their charge densities matched each other. These results indicated that the charge density was optimized by nature to ensure an efficient and effective capsid proliferation under the physiological pH and ionic strength

VITATECS: A Diagnostic Dataset for Temporal Concept Understanding of Video-Language Models

The ability to perceive how objects change over time is a crucial ingredient in human intelligence. However, current benchmarks cannot faithfully reflect the temporal understanding abilities of video-language models (VidLMs) due to the existence of static visual shortcuts. To remedy this issue, we present VITATECS, a diagnostic VIdeo-Text dAtaset for the evaluation of TEmporal Concept underStanding. Specifically, we first introduce a fine-grained taxonomy of temporal concepts in natural language in order to diagnose the capability of VidLMs to comprehend different temporal aspects. Furthermore, to disentangle the correlation between static and temporal information, we generate counterfactual video descriptions that differ from the original one only in the specified temporal aspect. We employ a semi-automatic data collection framework using large language models and human-in-the-loop annotation to obtain high-quality counterfactual descriptions efficiently. Evaluation of representative video-language understanding models confirms their deficiency in temporal understanding, revealing the need for greater emphasis on the temporal elements in video-language research.Comment: 23 pages, 6 figures, 18 tables, data is available at https://github.com/lscpku/VITATEC

Joint Intrinsic and Extrinsic LiDAR-Camera Calibration in Targetless Environments Using Plane-Constrained Bundle Adjustment

This paper introduces a novel targetless method for joint intrinsic and extrinsic calibration of LiDAR-camera systems using plane-constrained bundle adjustment (BA). Our method leverages LiDAR point cloud measurements from planes in the scene, alongside visual points derived from those planes. The core novelty of our method lies in the integration of visual BA with the registration between visual points and LiDAR point cloud planes, which is formulated as a unified optimization problem. This formulation achieves concurrent intrinsic and extrinsic calibration, while also imparting depth constraints to the visual points to enhance the accuracy of intrinsic calibration. Experiments are conducted on both public data sequences and self-collected dataset. The results showcase that our approach not only surpasses other state-of-the-art (SOTA) methods but also maintains remarkable calibration accuracy even within challenging environments. For the benefits of the robotics community, we have open sourced our codes

Nucleotide differences in the mbf1 gene of the lichenized fungus Umbilicaria decussata collected in polar and non-polar regions

Multiprotein bridging factor 1 (MBF1) is a transcriptional co-activator related to stress tolerance in various organisms. We investigated the nucleotide differences in the mbf1 gene in the lichen-forming fungus Umbilicaria decussata collected from polar (i.e., Antarctica and the Arctic) and non-polar (i.e., Armenia) regions. The 552-bp Udmbf1 genes isolated from eight samples contained numerous sequence variations, including single nucleotide polymorphisms as well as insertions and deletions. The frequency of nucleotide changes was higher in the intron than in the coding sequence. The nucleotide polymorphism levels (π=0.01792, θ=0.01792) and haplotype diversity (Hd=1) in the Udmbf1 gene from Antarctic samples were relatively high. Additionally, of the 19 detected nucleotide sequence variation sites, 15 were observed only in Antarctic samples. The resulting amino acid changes occurred in the N-terminal, whose function remains unknown. Although these DNA polymorphisms and amino acid changes have been verified in Antarctic samples of U. decussata, there is still little evidence indicating that different environmental conditions affected the functional evolution of Udmbf1. Additional studies involving more U. decussata samples from representative ecotypes will be necessary to uncover the relationships among DNA polymorphisms, functional gene evolution, and lichen habitats

Long-distance propagation of high-velocity antiferromagnetic spin waves

We report on coherent propagation of antiferromagnetic (AFM) spin waves over a long distance ($\sim$10 $\mu$m) at room temperature in a canted AFM $\alpha$-Fe$_2$O$_3$ with the Dzyaloshinskii-Moriya interaction (DMI). Unprecedented high group velocities (up to 22.5 km/s) are characterized by microwave transmission using all-electrical spin wave spectroscopy. We derive analytically AFM spin-wave dispersion in the presence of the DMI which accounts for our experimental results. The AFM spin waves excited by nanometric coplanar waveguides with large wavevectors enter the exchange regime and follow a quasi-linear dispersion relation. Fitting of experimental data with our theoretical model yields an AFM exchange stiffness length of 1.7 angstrom. Our results provide key insights on AFM spin dynamics and demonstrate high-speed functionality for AFM magnonics