当地取向下的商业中心——芬兰Easton商业中心

正LAHDELMA MAHLAM?KI ARCHITECTS公司成立于1997,是由长期合作伙伴Ilmari Lahdelma和Rainer Mahlam?KI共同成立的。目前,该办公室由来自芬兰和海外的37位建筑师、设计师和传播者组成。他们的作品展示了芬兰固有的设计:注重可持续性、材料和高质量的细节。这些设计特点结合尖端的技术,将芬兰建筑推向国际舞台。     

The shape of the utility or value function in stochastic multicriteria acceptability analysis

Stochastic multicriteria acceptability analysis (SMAA) is a decision support method that allows representing uncertain, imprecise, and partially missing criteria measurements and preference information as probability distributions. In this paper, we test how the assumed shape of the utility or value function affects the results of SMAA in two different problem settings: identifying the most preferred alternative and ranking all the alternatives. A linear value function has been most frequently applied, because more precise shape information can be difficult to obtain in real-life applications. In this paper, we analyse one past real-life problem and a large number of randomly generated test problems of different size using additive functions of different shape. The shape varies from linear to increasingly concave and convex exponential utility or value functions corresponding to different attitudes on marginal value or risk. The results indicate that in most cases slight non-linearity does not significantly affect the results. The proposed method can be used for evaluating how robust a particular real-life decision problem is with respect to the shape of the function. Based on this information, it is possible to determine how accurately the DMs’ preferences need to be assessed in a particular problem, and if it is possible to assume a simple linear shape.     

Techno-economic analysis of a coal-fired CHP based combined heating system with gas-fired boilers for peak load compensation

Combined heat and power (CHP) plants dominate the heating market in China. With the ongoing energy structure reformation and increasing environmental concerns, we propose gas-fired boilers to be deployed in underperforming heating substations of heating networks for peak load compensation, in order to improve both energy efficiency and environmental sustainability. However, due to the relatively high price of gas, techno-economic analysis is required for evaluating different combined heating scenarios, characterized by basic heat load ratio (β). Therefore, we employ the dynamic economics and annual cost method to develop a techno-economic model for computing the net heating cost of the system, considering the current state of the art of cogeneration systems in China. The net heating cost is defined as the investment costs and operations costs of the system subtracted by revenues from power generation. We demonstrate the model in a real-life combined heating system of Daqing, China. The results show that the minimum net heating cost can be realized at β=0.75 with a cost reduction of 16.8% compared to coal heating alone. Since fuel cost is the dominating factor, sensitivity analyses on coal and gas prices are discussed subsequently.     

Modeling the machine configuration and line-balancing problem of a PCB assembly line with modular placement machines

This paper studies the combined task of determining a favorable machine configuration and line balancing (MCLB) for an assembly line where a single type of printed circuit board is assembled by a set of interconnected, reconfigurable machine modules. The MCLB problem has been solved previously by heuristic methods. In the present work, we give a mathematical formulation for it and transform the model into a linear integer programming model that can be solved using a standard solver for problems of moderate size. The model determines the best machine configuration and allocation of components to the machine modules with the objective of minimizing the cycle time. Because the solutions found in this way are globally optimal, they can be used to evaluate the efficiency of previous heuristics designed for the MCLB problem. In our experiments, an evolutionary algorithm gave near optimal results.