Prediction of acute and chronic complications by a new computer simulation model for type 1 and type 2 diabetes: the Diabetes Mel l it us Model (DMM)

Summary

An epidemiological simulation model for patients with type 1 and type 2 diabetes (the Diabetes Mellitus Model (DMM)) was developed based on published clinical and observational data and expert estimations, for prediction of short- and long-term outcomes in defined patient cohorts. A computer program was developed with an interface for definition of patient cohorts and for results display. Patient cohorts can be user-defined by gender, age, duration and type of diabetes, glycosylated haemoglobin, blood pressure, albumin excretion and therapy. Based on risk

equations and current risk variable levels, the DMM simulates complications over 10 years (hypoglycaemia; retinopathy; blindness; microalbuminuria and macroalbuminuria; end-stage renal disease; neuropathy; amputation; diabetic foot syndrome; myocardial infarction; stroke; angina pectoris; heart failure; and death). The DMM is suitable for simulation of complications and for estimation of clinical implications of various diabetes care strategies, and may be particularly valuable in lieu of long-term clinical trial data.     

电子商务实训课程教学改革与探索

高职院校电子商务实训课程教学应增加实战训练环节,通过Internet网上电子商务的交易开展实战训练,使学生真正掌握电子商务交易的流程,培养其成为电子商务行业的职业操手。     

How effective are heuristic solutions for electricity planning in developing countries

Heuristic algorithms have been widely used to provide computationally feasible means of exploring the cost effective balance between grid versus off grid sources for universal electrification in developing countries. By definition in such algorithms however, global optimality is not guaranteed. We present a computationally intensive but globally optimal mixed integer non-linear programming (MINLP) model for electricity planning and use it in a Monte Carlo simulation procedure to test the relative performance of a widely used heuristic algorithm due to [28]. We show that the overall difference in cost is typically small suggesting that the heuristic algorithm is generally cost effective in many situations. However we find that the relative performance of the heuristic algorithm deteriorates with increasing degree of spatial dispersion of unelectrified settlements, as well as increasing spatial remoteness of the settlements from the grid network, suggesting that the effectiveness of the heuristic algorithm is context specific. Further, we find that allocation of off grid sources in the heuristic algorithm solution is often significantly greater than in the MINLP model suggesting that heuristic methods can overstate the role of off-grid solutions in certain situations.     

抽样定理的System View仿真与实现

通过分析SystemView仿真软件的优势及主要的功能模块库和应用领域,重点通过通信系统中的抽样定理实例介绍了该软件的使用方法及注意事项。最后,总结该软件的教学应用效果及对相关课程教学的借鉴作用,特别适合通信系统的仿真与设计。     

大空间飞机修理厂房分层空调的可行性分析

本文以某大空间飞机修理厂房为研究对象,采用Airpak软件对其原始分层空调设计方案气流组织进行模拟,并对方案可行性进行评价。     

Making Good Decisions with Minimal Information: Simultaneous and Sequential Choice

The adaptive pressures facing humans and other animals to make decisions quickly can be met both by increasing internal information-processing speed and by minimizing the amount of information to be used. Here we focus on the latter effect and ask how, and how well, agents can make good decisions with a minimal amount of information, using two specific tasks as examples. When a choice must be made between simultaneously-available options, minimal information in the form of binary recognition (whether or not each item is recognized) can be used in the recognition heuristic to choose effectively. When options are encountered sequentially one at a time, minimal information as to whether or not each option is the best encountered so far is sufficient to guide agents using a simple search-cutoff rule to high performance along several choice criteria. Both of these examples have important economic as well as biological applications, and show the power of simple fast and frugal heuristics to produce good decisions with little information. This revised version was published online in August 2006 with corrections to the Cover Date.     

On the performance of the Chow-Lin procedure for quarterly interpolation of annual data: Some Monte-Carlo analysis

Most of the countries of the OECD offer quarterly estimates of their national growth or of their Gross National Product. Official Statistical Agencies in western countries have to deal with the problem of estimating Quarterly National Accounts series congruently with Annual National Accounts. In Spain, the Instituto Nacional de Estadística uses the Chow-Lin disaggregation method, which is based on information provided by a group of high-frequency related variables, to estimate the quarterly components of National Accounts from annual components. In this paper, we analyse the relative quality of the estimates obtained through the Chow-Lin procedure, under different sets of hypotheses.JEL Classification: C15, C43, M40We are grateful to Maria Amparo Ripoll for her assistance. The authors also wish to thank three anonymous referees and an editor for their constructive suggestions and comments. This research was partially made during the stay of the first author at the Universidad Carlos III de Madrid. It has been partially supported by the research project DGCYT PB98-1460.     

Futures beyond dystopia

The speculative imagination is an higher-order human capacity that can productively explore the not-here and the not-yet. To some extent it is already doing so. But these explorations are limited by prevailing cultural assumptions. The purpose of this paper is to suggest that there are other arenas to explore that, were they taken seriously, could exert sufficient symbolic ‘pull' to qualify as desirable images of futures. They could then begin to act as ‘magnets' for the realisation of possibilities that are presently obscured.     

Investment planning under uncertainty and flexibility: the case of a purchasable sales contract*

Investment decisions are not only characterised by irreversibility and uncertainty but also by flexibility with regard to the timing of the investment. This paper describes how stochastic simulation can be successfully integrated into a backward recursive programming approach in the context of flexible investment planning. We apply this hybrid approach to a marketing question from primary production which can be viewed as an investment problem: should grain farmers purchase sales contracts which guarantee fixed product prices over the next 10 years? The model results support the conclusion from dynamic investment theory that it is essential to take simultaneously account of uncertainty and flexibility.     

悬索桥空缆状态数值分析

本文主要介绍悬索桥空缆状态数值分析方法。主要包括:基于无应力状态分析法和悬链线理论求解悬索桥空缆线形的数值迭代方法;等高、不等高悬链线求解方法及利用matlab编制相应程序实现空缆线形数据的求解。