数学中国www, madio,net 114 The UMAP Journal 29.2(2008) to improve it. Then we build a model to investigate the influence of the changes In addition, we measure the historical change in the system. Gen erally, its effectiveness is increasing, but the growth rate is slower recently We also analyze the strengths and weaknesses of each model. Solution of task 1 Description and Analysis We put forward a method to measure a country s healthcare system. To simplify the problem, we first abstract the system as a simplified input- output system( Figure 1). Input: Health care Output: resource Figure 1 Healthcare as a simplified input-output system. Sufficient resources should be put in to guarantee that the system func- tions well. Viewed in isolation, the more resources the system gets, the betterit will be. However, linked to output, the better system is not the one with more resources but the one with a low input-output ratio. Later we discuss how to use the metric of resources to measure a healthcare system Output reflects the systems performance: The better the system is, the more output it will produce; we define performance later How the system operates cant be igored, since that affects the whole health situation of the country, such as the distribution of resources and the health level in different areas. These factors will be expressed by the metric of Inequities. Metrics Resources A good healthcare system needs adequate resources: human resources, material resources, and financial resources Human resources are the population engaged in medical careers, includ ing physicians, nurses, pharmacists, and other health workers Material resources are the hardware facilities in the medical system, such as hospitals and hospital beds数学中国 www.madio.net