57 research outputs found
Replication Data for The influence of Chinese college students' collectivism spirit on work engagement: a mediating model of organizational identity
No full textThe dataset used for this stud
Replication Data for The examination of the relationship between learning motivation and learning effectiveness: a mediation model of learning engagement
No full textThe datasets were used in the study of the examination of the relationship between learning motivation and learning effectiveness: a mediation model of learning engagemen
Replication Data for The study of the relationship between college students' entrepreneurial motivation and entrepreneurial intention: a mediation model of satisfaction with innovation and entrepreneurship curriculums
No full textThe datasets were used for the study of the relationship between college students' entrepreneurial motivation and entrepreneurial intention: a mediation model of satisfaction with innovation and entrepreneurship curriculum
Airline scheduling and air traffic control : incorporating uncertainty and passenger and airline preferences
No full textThesis: Ph. D., Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 193-201).The global airline industry is a multi-stakeholder stochastic system whose performance is the outcome of complex interactions between its multiple decisions-makers under a high degree of uncertainty. Inadequate understanding of uncertainty and stakeholder preferences leads to adverse effects including airline losses, delays and disruptions. This thesis studies a set of topics in airline scheduling and air traffic control to mitigate some of these issues. The first part of the thesis focuses on building aircraft schedules that are robust against delays. We develop a robust optimization approach for building aircraft routes. The goal is to mitigate propagated delays, which are defined as the delays caused by the late arrival of aircraft from earlier flights and are the top cause of flight delays in the United States air transportation system. The key feature of our model is that it allows us to handle correlation in flight delays explicitly that existing approaches cannot handle efficiently. We propose an efficient decomposition algorithm to solve the robust model and present the results of numerical experiments, based on data from a major U.S. airline, to demonstrate its effectiveness compared to existing approaches. The second part of the thesis focuses on improving the planning of air traffic flow management (ATFM) programs by incorporating airline preferences into the decision-making process. We develop a voting mechanism to gather airline preferences of candidate ATFM designs. A unique feature of this mechanism is that the candidates are drawn from a domain with infinite cardinality described by polyhedral sets. We conduct a detailed case study based on actual schedule data at San Francisco International Airport to assess its benefits in planning of ground delay programs. Finally, we study an integrated airline network planning model which incorporates passenger choice behavior. We model passenger demand using a multinomial logit choice model and integrate it into a fleet assignment and schedule design model. To tackle the formidable computational challenge associated with solving this model, we develop a reformulation, decomposition and approximation scheme. Using data from a major U.S. airline, we prove that the proposed approach brings significant profit improvements over existing methods.by Chiwei Yan.Ph. D
Fabulas Antiguas de China
No full text121 fables from various eras. As I have read the first thirty, I am surprised at the large amount of overlap with, for example, 100 Ancient Chinese Fables (1985/89). The best new fable in my sampling comes in El Arte on 12: A fellow spent three years and his whole fortune on learning how to slay dragons, but then found that there are so few dragons that he could not practice his dear art! I have now found an English translation of this book, listed under 1981/83. See my comment on El Arte there.Original language: chiWei Jinzh
The examination of job separation tendency of nursing staff in the first public–private joint-venture hospital in Taiwan: a multiple mediation model of job satisfaction and job performance
No full textAbstract Nursing staff are the largest number of employees in hospitals and the high turnover rate is a global problem, which is also a critical issue faced by many hospitals in Taiwan. Therefore, the purpose of this study is to explore the factors affecting the job turnover of nursing staff and to propose suggestions to reduce job turnover. The results showed that among demographic variables, all variables except the affiliated unit were significantly positively or negatively related to job turnover intention. In the job characteristic analysis, it was found that job structure, repetitiveness of the job, the participation of nursing staff in job decisions, and compassionate leadership style were the antecedent variables affecting the intention to leave. Among organizational factors, colleague rapport was an antecedent variable to the intention to leave. Fairness of distribution, opportunity of in-service education, and colleague rapport added to job satisfaction to decrease the intention to leave. When using job performance as a mediation variable, this study found that promotion opportunity, fairness of distribution, and opportunity of in-service education could not affect the intention to leave through job performance. This study also found that the external job opportunities variable could be through a mediation variable, job satisfaction or job performance, which in turn affected the intention to leave. Several suggestions were proposed for top hospital management personnel, such as management by participation, planning a clear job structure, job rotation and job enrichment, and establishing a good working atmosphere and working environment to reduce job turnover
Experimental Study of Dam-Break-Like Tsunami Bore Impact Mechanism on a Container Model
No full textTsunami disasters have frequently occurred in recent years. More and more researchers are focusing on this topic. To investi-gate the tsunami bore impact mechanism on a container model, a multi-functional slope-changing tsunami flume is built in this study. To simulate a tsunami bore, a dam-break wave was generated by a free-falling gate in a reservoir. A needle water level gauge and a high-speed camera were used to measure the tsunami wave heights and velocities for different storage water levels in the test flume, and the corresponding Froude numbers of tsunami waves were also calculated. The factors af-fecting the movement distance of the tsunami wave impacting the container model are explored in this experiment, and the results show that the movement distance is positively correlated with the storage water level, and negatively correlated with the container density and the coast slope
Weathering assessment approach for building sandstone using hyperspectral imaging technique
No full textAbstract Weathering is one of the most common causes of building sandstone damage. The evolution of building sandstone in various weathering behaviors is critical for research. An intelligent assessment approach for classifying weathering degree of building sandstone in a humid environment is presented in this study. This synthesis method relates to three parts: microscopic observation of weathering characteristics, hyperspectral acquisition of weathered samples, and machine learning technology for a classification model. At first, weathering process is divided into initial weathered stage, accelerated weathered stage, and stable weathered stage according to the causes and mechanisms of weathering. Secondly, a novel classification method of weathering degree is proposed based on the weathering stage. Then, the mapping relationship between microscopic characteristics and hyperspectral image of shedding samples can be established in the visible and near-infrared spectral ranges (400–1000 nm) according to the change law of spectral absorption feature. Next, the spectral data of building sandstone with different weathering degrees are classified using Random Forest model. Furthermore, the hyperparameters of Random Forest model are optimized by Gray Wolf Optimizer algorithm for better performance. The trained model is finally applied to evaluate the weathering degree of large-scale sandstone walls quantitatively. The whole weathering assessment process is worth recommending for diagnosing and monitoring the building sandstone
Author response: Oxidative stress induces stem cell proliferation via TRPA1/RyR-mediated Ca2+ signaling in the Drosophila midgut
No full textInvestigating the Dynamic Change and Driving Force of Vegetation Carbon Sink in Taihang Mountain, China
No full textVegetation plays an important role in absorbing carbon dioxide and accelerating the achievement of carbon neutrality. As the ecological barrier of North China, the Taihang Mountains are pivotal to the ecological construction project of China. Nevertheless, the dynamic development of the vegetation carbon sink in the region and the impact factors on the sink have not been systematically evaluated. This study employed a comprehensive approach, utilising remote sensing technology and meteorological and topographic data, in conjunction with the net ecosystem productivity (NEP) estimation model to reveal the characteristics of vegetation carbon sinks in the Taihang Mountain, and then revealed the dynamics evolution of the NEP and the inter-annual trend by using Theil–Sen Median slope estimation, the Mann–Kendall test, and the coefficient of dissociation and analysed the driving roles of the influencing factors by using the parameter optimal geographic detector. Our findings suggest that the NEP in the Taihang Mountain area has a clear growth trend in time, the average value of NEP in the Taihang Mountain area is 289 gC-m−2-a−1 from 2000 to 2022, and the spatial distribution shows the characteristics of high in the northeast and low in the middle and west, with a gradual increase from the northeast to the southwest; the areas with high fluctuation of NEP are mainly distributed in the areas around some cities that are susceptible to the interference of natural or anthropogenic factors. The vegetation carbon sinks in the Taihang Mountains are influenced by a variety of natural factors, among which the explanatory power of each natural factor is as follows: DEM (0.174) > temperature (0.148) > precipitation (0.026) > slope (0.017) > slope direction (0.003). The natural factor DEM had the strongest explanatory power for NEP changes, and the two-by-two effects of the natural factors on vegetation carbon sinks were all significantly stronger than the effects of a single factor, in which the interaction between DEM and precipitation had the strongest explanatory power; distinguishing from climate change factors, the contribution of anthropogenic activities to NEP changes in more than 90% of the area of the Taihang Mountainous Region was more than 60%, and the driving force of anthropogenic factors on NEP changes in the Taihang Mountainous Region was significantly stronger than that of natural climate change. The contribution of anthropogenic factors to NEP changes in the Taihang Mountains was significantly stronger than that of natural climate change. The results of this study can not only provide a reference for carbon reduction and sink increase and ecological restoration projects in the Taihang Mountains but also benefit the research paradigm of vegetation carbon sequestration in other regions
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