A flight scheduling model for Taiwan airlines under market competitions

In this research, we develop a short-term flight scheduling model with variable market shares in order to help a Taiwan airline to solve for better fleet routes and flight schedules in today's competitive markets. The model is formulated as a non-linear mixed integer program, characterized as an NP-hard problem, which is more difficult to solve than the traditional fixed market share flight scheduling problems, often formulated as integer/mixed integer linear programs. We develop a heuristic method to efficiently solve the model. The test results, mainly using the data from a major Taiwan airline's operations, show the good performance of the model and the solution algorithm.     

Robust portfolio planning in the presence of market anomalies

In this study, a short-term portfolio modeling formulation is developed using existing anomalies as a single determinant for daily Istanbul Stock Exchange National 100 Composite Index (ISE) and US dollars (USD) returns in a Robust optimization (RO) framework. Using anomalies in planning within an RO framework establishes a balance between risk seeking and risk averse behaviors, as generating profit from anomalies is risky and RO enables to settle down the extreme risk seeking behavior. Applications of the model using various data sets result in real profit generation such that terminal wealth figures increase considerably more than Wholesale Price Index (WPI). This study demonstrates that RO is a viable approach to make use of anomaly information for short-term profits.     

Minimizing the makespan on single-machine scheduling with aging effect and variable maintenance activities

This paper considers a single-machine scheduling with a position-dependent aging effect described by a power function under maintenance activities and variable maintenance duration considerations simultaneously. We examine two models of the maintenance duration in this study. The objective is to find jointly the optimal maintenance frequency, the optimal maintenance positions, and the optimal job sequences to minimize the makespan of all jobs. We provided polynomial time solution algorithms for all the studied problems.     

探索性创新的资源和常规刚性对市场份额影响

企业内部存在资源刚性和常规刚性。文章采用基于主体建模方法,分析企业探索性创新活动中两种刚性对企业竞争地位的影响。研究发现,资源刚性的减小或创新资源配置灵活性的增加,并不一定使得企业市场份额增加,但常规刚性的增加会对企业市场份额产生消极影响;资源刚性的减弱能够缓和常规刚性的增强对企业市场份额产生的不利影响,而当常规具有灵活性时,会破坏资源刚性的减弱对企业市场份额产生的积极影响。总体上,探索性创新的资源刚性与常规刚性在对企业市场份额影响上,不存在完全的协同效应。