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The post-entry operation sustainability of airline routes directly affects their profitability. This paper investigates factors influencing the operating duration of airline routes based on a survival analysis modeling method. Key factors are selected from five aspects representing characteristics in terms of cost and supply, route and airport, market structure, airline cooperation type, and time heterogeneity. The transatlantic market between Europe and the US is chosen as the empirical study due to its high degree of liberalization. The research period ranges 19 years from 2003 to 2021. First, the single factor analysis is conducted by utilizing the Kaplan-Meier method. Second, a Weibull parameter survival model is constructed to quantitatively analyze the relationship between the chosen factors and the operating duration of airline routes. The results show that：(1) The average operating duration of the EU-US routes is five years, among which routes that were continuously operated for more than 10 years account for 16%；(2) the operating duration of airline routes is significantly influenced by distance, airline’s total capacity, route structure, endpoint airports type, route competition, airline type, and region as well as alliance；(3) both independent and interaction variables representing alliance and code-share characteristics have significant impacts on route operating duration. Routes operated by Star and SkyTeam members have a longer operating duration. For airlines in the same alliance, the route-exit risks between operating carriers and marketing carriers in code-sharing cooperation are significantly different. [ABSTRACT FROM AUTHOR]

BDS precise orbit and precise clock products provided by IGS analysis centers may differ due to the use of different antenna phase center models, which has a great impact on the comparison between precise products and the use of precise products to evaluate the accuracy of the BDS signal-inspace user range error. In this paper, the influence of different antenna phase center correction models on the precise orbit and clock products is analyzed in depth by using the measured observation data. Based on this, the BDS signal-in-space user range error evaluation method is proposed considering different antenna phase center correction models. With the precise orbit and clock products provided by the Center for Orbit Determination in Europe (CODE) , Deutsches GeoForschungs Zentrum(GFZ) and Wuhan University (WHU),we evaluate the broadcast orbit,broadcast clock and signal-in-space user range error. The results show that after considering the difference of the satellite antenna phase center correction model? the accuracy of the signal-in-space user range error evaluated by the BDS precise orbit and precise clock products provided by different analysis centers is basically the same. Geostationary orbit is better than 1. 68 m, inclined geosynchronous orbit is better than 0. 78 m, medium earth orbit is better than 0. 66 m, which verifies the correctness of the evaluation method proposed in this paper [ABSTRACT FROM AUTHOR]

The co-occurrence of mental illness and substance abuse is among the most prevalent mental disorders worldwide. It has become more significant in the United States, Europe, and Hong Kong, and it presents complex issues for both mental health and substance abuse practitioners. This paper explores the historical and conceptual issues on dual diagnosis. In addition, different perspectives on dual diagnosis are crucial for developing public policies and programs to address client needs on the road to recovery. The dominant view on dual diagnosis has been the medical perspective. This paper describes three more perspectives: moralistic, psychosocial risk, and phenomenological. This broader view on dual diagnosis will benefit both policy and service development for this population. [ABSTRACT FROM AUTHOR]

LNG has been steadily increasing its share of the global gas trade. The United States and European countries have studied the interchangeability of natural gas according to specific situations and provided results of the relevant studies. In China, the import of LNG is steadily increasing, but the problems regarding quality and interchangeability were not fully understood and resolved. In this paper, a study on applicability of Weaver indices has been completed. The experiments were conducted for 17 typical gas appliances and 11 natural gas sources with 187 test conditions. Comparing the experimental results with the results predicted by Weaver indices, it suggested that the limits of Lifting JJ need to change to ≥0. 95, Incomplete Combustion JI need to change to ≤0.04 and the limit of AGA index Lifting IL change to ≤1.05. [ABSTRACT FROM AUTHOR]

In this paper the triangular intuitionistic fuzzy numbers are used to express the change factors of the underlying assets of the option in order to describe the uncertainty of the estimated value of the European option price and the hesitation degree of the investors, the intuitionistic fuzzy binomial tree pricing model is made, and the risk neutral pricing method is used to research the single period European call option pricing problem. The findings of the study are that the European option price expressed by a triangular intuitionistic fuzzy number, which can reflect the certainty degree, negation degree and hesitation degree of the investor on the estimated value of the option price, and then the interval value of European option price is obtained by using the cuts sets operation of the triangular intuitionistic fuzzy numbers. Some numerical examples show that European call option price obtained by the triangular intuitionistic fuzzy number can express more the hesitation degree of the investors than the one obtained by the fuzzy number. [ABSTRACT FROM AUTHOR]