Robust surgery loading

We consider the robust surgery loading problem for a hospital’s operating theatre department, which concerns assigning surgeries and sufficient planned slack to operating room days. The objective is to maximize capacity utilization and minimize the risk of overtime, and thus cancelled patients. This research was performed in collaboration with the Erasmus MC, a large academic hospital in the Netherlands, which has also provided historical data for the experiments. We propose various constructive heuristics and local search methods that use statistical information on surgery durations to exploit the portfolio effect, and thereby to minimize the required slack. We demonstrate that our approach frees a lot of operating room capacity, which may be used to perform additional surgeries. Furthermore, we show that by combining advanced optimization techniques with extensive historical statistical records on surgery durations can significantly improve the operating room department utilization.     

利用最小调整法求解特殊的二维0-1规划

具有特殊约束的二维0-1规划的实际应用广泛,在解法中多是应用传统算法,或是在它基础上进行改进,但是此类解法计算繁琐不易推广.针对这种情形,本文引入最小调整法处理此类问题,并将其与传统算法进行对比,充分展示了该方法的优越性,呈现出灵活、方便、简单、易行的特点.通过举例验证了方法的有效性.     

Dynamic evolution of economically preferred facilities

In a sustained development scenario, it is often the case that an investment is to be made over time in facilities that generate benefits. The benefits result from joint synergies between the facilities expressed as positive utilities specific to some subsets of facilities. As incremental budgets to finance fixed facility costs become available over time, additional facilities can be opened. The question is which facilities should be opened in order to guarantee that the overall benefit return over time is on the highest possible trajectory. This problem is common in situations such as ramping up a communication or transportation network where the facilities are hubs or service stations, or when introducing new technologies such as alternative fuels for cars and the facilities are fueling stations, or when expanding the production capacity with new machines, or when facilities are functions in a developing organization that is forced to make choices of where to invest limited funding.     

On Mutual Transform Between Number-Difference State and Phase State Corresponding to Operational Phase Operator

In the mutual transform between the number-difference state and the phase state corresponding to the operational phase operator we find that there exists an end-point ambiguousness. This problem can be avoided by Lighthill＇s method.     

城市交通管理中的出租车规划模型

最佳数量的确定和价格的制定是城市出租车规划中的两个核心问题.对影响出行强度的市区人口和建成区面积分析建立了出行总量预测模型,再通过分析出租车最佳数量与出租车运营里程的关系,得出出租车最佳数量的预测模型.在出租车最佳数量模型的基础上,分析出租车数量的差异和差异产生的原因,给出了出租车定价判断模型,为出租车定价机制的调整指明了方向.最后以长沙市为例进行了实证分析.     

Profile‐based push models in manpower planning

A methodology is presented to deal with heterogeneity due to observable variables in modeling personnel systems. For a manpower system, a model based on personnel profiles is introduced. The proposed algorithm concerns an analysis of the evolution of personnel profiles under time‐discrete Markov assumptions. In this way, based on an historical personnel database, the estimation of transition probabilities of profiles as well as the computation of forecasts on the evolution of the manpower system can be found. Based on the presented procedure, a policy supporting software package has been developed for the Belgian Federal Government (research project financed by Federaal Wetenschapsbeleid). Copyright © 2007 John Wiley & Sons, Ltd.     

On the noniterative multiproduct multiperiod production planning method

Bahl and Zionts [H.C. Bahl, S. Zionts, A noniterative multiproduct multiperiod production planning method, Operations Research Letters 1 (1982) 219-221] formulated a problem for planning multiproduct multiperiod production on a single facility. They developed a column-minima noniterative method and claimed that it gave an optimal solution. We show that the claim is incorrect.     

Spectrum planning and performance evaluation between heterogeneous satellite networks

A new network has been recently proposed for the provision of fixed broadband services via high altitude platform stations (HAPS) in the 48/47 GHz band. One of the critical issues of this technology is spectrum sharing with the fixed satellite service. This paper examines the effect of Earth-to-stratosphere co-channel interference produced by ground stations of HAPS network to geostationary orbit (GEO) satellite receivers and proposes an interference-to-noise (I/N) calculation model for the evaluation of the current HAPS ground stations power characteristics set by ITU-R. Analytical and simulation results for archetypal systems in realistic scenarios indicate that efficient use of the spectrum shared between heterogeneous HAPS and Fixed Satellite Networks is feasible. Certain consideration is needed prior to the HAPS network development in suburban areas for latitudes from 55° to 65°, and in rural areas for latitudes from 60° to 75°.