542 research outputs found
Exploring How Tourism Majorsâ Perceived Professional Competence Influences Their Choice of Tourism Careers in China
With the rapid development of tourism in China, various economic sectors such as agriculture, sports, food and beverages, cultural heritage, and outdoor adventure have become integrated into the tourism industry. China\u27s tourism industry has changed and these changes now require tourism practitioners to adapt. Chinese universities must also adapt their tourism curriculum and educational practices to reflect changes in the tourism sector. Research suggests that university training programs should increase their emphasis on developing studentsâ professional competency and expand the range of competencies they address in their curriculum. At the same time, tourism enterprises in China are unable to recruit enough competent employees, resulting in a shortage of qualified workers. To improve the professional competence of tourism students in China, tourism education departments must respond to the needs of, and changes in, the tourism industry.
The purpose of this two-phase, mixed-method exploratory design study is to identify the professional competencies that tourism experts in China believe tourism students must acquire, and examine the relationship between these competencies, tourism studentsâ perceptions of professional competence, and their intent to pursue a career in the tourism sector. The present study began with basic qualitative research in the form of interviews with Chinese tourism experts in China to identify the professional competencies that Chinese tourism students need. During the second stage of research, these results were incorporated into a written questionnaire that was distributed to approximately 800 tourism majors in China. Through the analysis of survey data, we examined the relationship between student demographics, their perceived professional competence, and their intent to pursue a career in the tourism sector.
The study results indicate that the causal relationship between students\u27 perceived professional competence and students\u27 intention for a career in tourism is valid. These findings provide theoretical support for improving tourism students\u27 perceived professional competency. The results also suggest strategies to increase the percentage of tourism students who will choose to work in the tourism sector upon graduation
Research on Wellbore Quality Control Technology for Coalbed Methane Deviated Wells
AbstractDeviated well is one of the main well types to develop coalbed methane in China. It's been widely used by various coalbed methane companies in recent years. Compared with traditional oil and gas wells, coalbed methane wells are characterized by shallow depth and strict well spacing, which means higher wellbore quality control technology. Furthermore, coalbed methane wells are apt to produce coal dust during dewatering and coal dust causes serious abrasion of pipe and rod. It's required to improve wellbore quality. This paper analyzes the weakness of current wellbore quality control standard and technology for coalbed methane wells on the basis of the characterization of coaled methane wells and finds out the key factors that control wellbore quality of coalbed methane deviated wells. The technology is developed to improve wellbore quality of coalbed methane wells from trajectory design and real-time control. Through the on-site test in Baode block, Shanxi Province, the technology is further improved and it's confirmed by the test result that this technology can improve the wellbore quality of coalbed methane deviated wells. In addition, this paper also presents some good suggestions for compiling standard about wellbore quality control for coalbed methane deviated wells
Evaluating the Perceived Safety of Urban City via Maximum Entropy Deep Inverse Reinforcement Learning
Inspired by expert evaluation policy for urban perception, we proposed a
novel inverse reinforcement learning (IRL) based framework for predicting urban
safety and recovering the corresponding reward function. We also presented a
scalable state representation method to model the prediction problem as a
Markov decision process (MDP) and use reinforcement learning (RL) to solve the
problem. Additionally, we built a dataset called SmallCity based on the
crowdsourcing method to conduct the research. As far as we know, this is the
first time the IRL approach has been introduced to the urban safety perception
and planning field to help experts quantitatively analyze perceptual features.
Our results showed that IRL has promising prospects in this field. We will
later open-source the crowdsourcing data collection site and the model proposed
in this paper.Comment: ACML2022 Camera-ready Versio
Project Evaluation and Selection with Task Failures
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154433/1/poms13107_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154433/2/poms13107.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154433/3/poms13107-sup-0001-Appendix.pd
Understanding the in vivo Uptake Kinetics of a Phosphatidylethanolamine-binding Agent \u3csup\u3e99m\u3c/sup\u3eTc-Duramycin
Introduction 99mTc-Duramycin is a peptide-based molecular probe that binds specifically to phosphatidylethanolamine (PE). The goal was to characterize the kinetics of molecular interactions between 99mTc-Duramycin and the target tissue. Methods High level of accessible PE is induced in cardiac tissues by myocardial ischemia (30 min) and reperfusion (120 min) in SpragueâDawley rats. Target binding and biodistribution of 99mTc-duramycin were captured using SPECT/CT. To quantify the binding kinetics, the presence of radioactivity in ischemic versus normal cardiac tissues was measured by gamma counting at 3, 10, 20, 60 and 180 min after injection. A partially inactivated form of 99mTc-Duramycin was analyzed in the same fashion. A compartment model was developed to quantify the uptake kinetics of 99mTc-Duramycin in normal and ischemic myocardial tissue. Results 99mTc-duramycin binds avidly to the damaged tissue with a high target-to-background radio. Compartment modeling shows that accessibility of binding sites in myocardial tissue to 99mTc-Duramycin is not a limiting factor and the rate constant of target binding in the target tissue is at 2.2 ml/nmol/min/g. The number of available binding sites for 99mTc-Duramycin in ischemic myocardium was estimated at 0.14 nmol/g. Covalent modification of D15 resulted in a 9-fold reduction in binding affinity. Conclusion 99mTc-Duramycin accumulates avidly in target tissues in a PE-dependent fashion. Model results reflect an efficient uptake mechanism, consistent with the low molecular weight of the radiopharmaceutical and the relatively high density of available binding sites. These data help better define the imaging utilities of 99mTc-Duramycin as a novel PE-binding agent
The K-band properties of Seyfert 2 galaxies
It is well known that the [O {\sc iii}]5007 emission line and hard
X-ray(2-10keV) luminosities are good indicators of AGN activities and that the
near and mid-infrared emission of AGN originates from re-radiation of dusty
clouds heated by the UV/optical radiation from the accretion disk. In this
paper we present a study of the near-infrared K-band (2.2m) properties for
a sample of 65 Seyfert 2 galaxies. By using the AGN/Bulge/Disk decomposition
technique, we analyzed the 2MASS K-band images for Seyfert 2 galaxies
in order to derive the K- band magnitudes for the central engine,
bulge, and disk components. We find that the K-band magnitudes of the
central AGN component in Seyfert 2 galaxies are tightly correlated with the [O
{\sc iii}]5007 and the hard X-ray luminosities, which suggests that
the AGN K-band emission is also an excellent indicator of the nuclear
activities at least for Seyfert 2 galaxies. We also confirm the good relation
between the central black hole masses and bulge's K-band magnitudes for Seyfert
2s.Comment: 7 pages, 4 figures, accepted for publication in A&
The performance of a heat pump using nanofluid (R22+TiO2) as the working fluid â an experimental study
It has been well known that the nano-particles, including metals, oxides, carbides, or carbon nanotubes, can increase the conduction and convection coefficients and consequently, enhance the heat transfer. Using nanofluids as working fluids in the refrigeration, air-conditioning and heat pump systems has attracted much attention. This work set-up a test rig to experimentally study the system performance of a heat pump with nanofluid as refrigerant, which was prepared by mixing 5wt% TiO2 with R22. Results show that adding the nano particle TiO2 didnât changed the heat absorbed in the evaporator clearly but increase the heat released in the condenser. As a results, compared to using pure R22, when using R22 + TiO2, the COP of the cooling cycle was decreased slightly, however, the COP of the heating cycle was increased significantly increased power consumption of compression.publishedVersio
Chaotic Phase-Coded Waveforms with Space-Time Complementary Coding for MIMO Radar Applications
A framework for designing orthogonal chaotic phase-coded waveforms with space-time complementary coding (STCC) is proposed for multiple-input multiple-output (MIMO) radar applications. The phase-coded waveform set to be transmitted is generated with an arbitrary family size and an arbitrary code length by using chaotic sequences. Due to the properties of chaos, this chaotic waveform set has many advantages in performance, such as anti-interference and low probability of intercept. However, it cannot be directly exploited due to the high range sidelobes, mutual interferences, and Doppler intolerance. In order to widely implement it in practice, we optimize the chaotic phase-coded waveform set from two aspects. Firstly, the autocorrelation property of the waveform is improved by transmitting complementary chaotic phase-coded waveforms, and an adaptive clonal selection algorithm is utilized to optimize a pair of complementary chaotic phase-coded pulses. Secondly, the crosscorrelation among different waveforms is eliminated by implementing space-time coding into the complementary pulses. Moreover, to enhance the detection ability for moving targets in MIMO radars, a method of weighting different pulses by a null space vector is utilized at the receiver to compensate the interpulse Doppler phase shift and accumulate different pulses coherently. Simulation results demonstrate the efficiency of our proposed method
Chaotic Phase-Coded Waveforms with Space-Time Complementary Coding for MIMO Radar Applications
A framework for designing orthogonal chaotic phase-coded waveforms with space-time complementary coding (STCC) is proposed for multiple-input multiple-output (MIMO) radar applications. The phase-coded waveform set to be transmitted is generated with an arbitrary family size and an arbitrary code length by using chaotic sequences. Due to the properties of chaos, this chaotic waveform set has many advantages in performance, such as anti-interference and low probability of intercept. However, it cannot be directly exploited due to the high range sidelobes, mutual interferences, and Doppler intolerance. In order to widely implement it in practice, we optimize the chaotic phase-coded waveform set from two aspects. Firstly, the autocorrelation property of the waveform is improved by transmitting complementary chaotic phase-coded waveforms, and an adaptive clonal selection algorithm is utilized to optimize a pair of complementary chaotic phase-coded pulses. Secondly, the crosscorrelation among different waveforms is eliminated by implementing space-time coding into the complementary pulses. Moreover, to enhance the detection ability for moving targets in MIMO radars, a method of weighting different pulses by a null space vector is utilized at the receiver to compensate the interpulse Doppler phase shift and accumulate different pulses coherently. Simulation results demonstrate the efficiency of our proposed method
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