Robust fixed‐order H2 controller for micro air vehicle—design and validation

Design and real‐time validation of a robust fixed‐order H₂ optimal controller for micro aerial vehicle, named Sarika‐2, is presented. Strengthened discrete optimal projection equations, which approximate the first‐order necessary optimality condition, are used for the controller design. Effect of low‐frequency gust disturbance and high‐frequency sensor noise is alleviated through the output sensitivity and control sensitivity minimization. The novelty of this paper is that a single robust H₂ controller, which is designed at the central operating point, ensures simultaneous stabilization of the radio‐controlled aircraft over the entire cruise speed range of 16–26 m/s. The controller is implemented on a digital‐signal‐processor‐based flight computer, and subsequently, it is validated through the real‐time hardware‐in‐loop‐simulation. The responses obtained from the hardware‐in‐loop‐simulation compares well with those obtained from the off‐line simulation. Copyright © 2006 John Wiley & Sons, Ltd.     

Association Between Waiting Times for Kidney Transplantation and Rates of Live Donation

A deceased donor (DD) allocation system incorporating net life survival benefit has been proposed. In this system, many kidneys will be shifted to younger recipients, thereby decreasing their waiting times. The goal of this study was to determine the potential effects of altering waiting times on the likelihood of live donor kidney transplantation (LDKT). We analyzed 93,727 waiting list candidates to determine the association of various patient factors with likelihood of LDKT. The proportion of patients receiving LDKT was compared by the median DD waiting time at that patient's transplant center for someone of that patient's age category and race. LDKT was consistently higher as waiting times became longer. After adjusting for all other factors associated with likelihood of LDKT, waiting time remained a significant, independent predictor. Patients with the longest DD waiting times had 2.3-fold higher odds of LDKT (95% CI 2.11-2.58, p < 0.001). In planning the new DD allocation policy, we must account for resulting alterations in LDKT. It is possible that shifting DD kidneys to younger recipients may decrease LDKT or shift it to older recipients, net effects not consistent with the goal of net life survival benefit.     

Changes in International Normalized Ratio (INR) and Model for Endstage Liver Disease (MELD) Based on Selection of Clinical Laboratory

Priority for liver transplantation is based on the Model for Endstage Liver Disease (MELD) score, a mathematical function which includes international normalized ratio (INR). We present an analysis to determine the lab-to-lab variation in INR at 14 clinical laboratories across the United States. We performed a survey to identify representative clinical laboratories across the United States, where INR was measured in the determination of MELD score. Five 'standard' samples for INR were formulated and were sent to the 14 clinical laboratories to determine variation in INR and MELD score. Among the 14 clinical laboratories, the range in INR for the five samples was: sample 1 (1.2-2.0), sample 2 (1.4-2.5), sample 3 (1.7-3.4), sample 4 (1.9-3.7) and sample 5 (2.4-5.1). The range in calculated MELD score was: sample 1 (8-14), sample 2 (10-17), sample 3 (12-20), sample 4 (14-21) and sample 5 (16-25). The selection of the clinical laboratory used to determine INR may result in substantial changes in MELD score independent of severity-of-illness. These data suggest that further review of interlaboratory variation in MELD should be undertaken because of the potential impact on prioritization for liver transplantation.     

云南省卫生资源配置标准的弹性系数研究

目的　在进行云南省区域分类基础上制定云南省区域卫生资源配置标准标志值后 ,根据云南省各个地区的特点增加不同弹性系数。方法　采用流行病学研究方法 ,收集和分析云南省不同地州市 1990～ 1999年有关人口、社会经济状况及卫生经费的投入、居民健康状况、居民文化、生活水平、少数民族状况、旅游地区、边境线长短及贫困状况等资料。结果　研究结果表明曲靖地区、玉溪市、保山地区增加弹性系数最少 ,分别为 0 67%、 1 5 8%和1 68% ,怒江州、迪庆州和西双版纳州增加弹性系数最多 ,分别为 11 15 %、 10 2 5 %和 9 84 %。其它地区的弹性系数分别为昆明市 5 88% ,昭通地区 2 3 1% ,楚雄州 2 3 0 % ,红河州 7 0 3 % ,文山州 5 5 3 % ,思茅地区 7 4 3 % ,大理州4 94 % ,德宏州 6 78% ,丽江地区 4 3 5 % ,临沧地区 6 13 %。结论　云南省区域卫生配置标准的弹性系数研究为云南省卫生资源区域分类配置标准提供了科学依据 ,不同弹性系数体现了云南省不同地区的卫生资源区域分类配置标准的公平性、合理性及实用性     

An optimal regulator for linear systems with multiple state and input delays

This paper presents an optimal regulator for a linear system with multiple state and input delays and a quadratic criterion. The optimal regulator equations are obtained reducing the original problem to the linear‐quadratic regulator design for a system without delays. Performance of the obtained optimal regulator is verified in the illustrative example against the best linear regulators available for the linear system without delays and for two rational approximations of the original time‐delay system. Simulation graphs demonstrating better performance of the obtained optimal regulator with respect to the criterion value are included. Copyright © 2006 John Wiley & Sons, Ltd.     

Experience with the Wujciak-Opelz allocation system in a single center: an increase in HLA-DR mismatching and in early occurring acute rejection episodes

The present single-center, retrospective study was undertaken to assess the impact of the Wujciak-Opelz allocation system (XCOMB), currently used within Eurotransplant for renal allografts, on the incidence of early occurring rejection episodes (RE). Implementation of the system resulted in an increase of HLA-DR mismatches (MM), while the incidence of HLA-A + B + DR MM remained unchanged. During the 1st post-transplant month, the total number of RE, expressed per patient-months, increased by 64 % (0.326 vs 0.199, P = 0.007); when considering only severe and irreversible RE, the increase was 76 % (0.158 vs 0.090, P = 0.011). In contrast, from the 2nd to the 12th post-transplant month, the incidence of RE, regardless of severity, was similar before and after implementation of XCOMB. As early occurring RE have detrimental effects on long-term graft outcome, these observations, if confirmed on a larger scale, would justify changes in the allocation algorithm. Received: 13 February 1998 Received after revision: 29 April 1998 Accepted: 20 May 1998     

Role of ventricular assist devices in the German heart allocation system

The Eurotransplant (ET) allocation algorithm, newly implemented in 2000, gives priority for heart transplantation (HTx) to patients with high urgency (HU) status, but now this status is rescinded upon ventricular assist device (VAD) implantation and only regained if severe complications occur during mechanical circulatory support (MCS). We studied the effects of this change on the patients in our institute who were waiting for HTx with MCS. The median duration of MCS until HTx in adult patients gradually increased from 3.1 months in 1994, reaching a peak of 16.7 months in 2000, and then gradually decreased to 6.0 months in 2003. Among the patients with VAD implantation as a bridge to HTx, two patients were on MCS for more than 1 year (the longest duration of MCS being 1.6 years) at the end of 1999, and this figure increased to nine patients and a maximum MCS duration of 3.7 years at the end of 2003. These data imply that the patients in whom a complication occurred in the early phase of MCS and who had overcome this complication underwent HTx early with HU status, and those who were stable during MCS waited a long time for HTx. Furthermore, the number of patients in the latter group is increasing. The new allocation algorithm imposes on patients with MCS waiting for HTx who are relatively young and free from complications and serious coexisting disease, very long-term MCS without an end to VAD bridging, which is almost equivalent to destination therapy. Part of this paper was presented at the 42nd JSAO Conference (Tokyo, October 5–7, 2004)     

江苏省护理院卫生资源配置现状和效率研究

目的:分析江苏省护理院卫生资源配置现状与效率,并提出完善对策。方法:应用描述性统计方法分析2013~2019年护理院卫生资源配置和利用情况,采用数据包络分析法评价卫生资源投入产出效率,采取TOPSIS法综合评估床位利用效率。结果:2019年江苏省护理院为246家,其中71.95%集中在城市地区;2019年护理院床位数为38274张,床位医生比和床位护士比分别为1:0.06和1:0.18,床位使用率为72.32%,平均住院天数比2013年缩短20.5天。数据包络分析结果显示,2016~2018年综合技术效率值均为1.0,2019年为0.990。TOPSIS法评估结果显示,2013~2017年床位利用效率逐年上升,2018和2019年有所下降。结论:护理院城乡分布不均衡,人员配置不足,近年来投入产出效率为相对有效或弱有效,但床位总体利用率偏低。今后合理规划设置护理机构,增加人力资源配置,提升护理院服务质量,最大限度发挥护理院卫生资源的作用。     

基于熵权-TOPSIS结合RSR法的山东省卫生资源 配置地区性差异研究

目的 分析山东省卫生资源配置地区差异性,为优化区域卫生资源配置提供参考。方法 采用熵权-TOPSIS(Entropy weight TOPSIS)法与秩和比(RSR)法综合评价2015—2019年山东省卫生资源配置情况。结果 根据熵权-TOPSIS法可得2015—2019年鲁东、鲁中、鲁西南地区卫生资源配置综合评价平均水平分别为0.403、0.520、0.264;RSR法分档结果为好（ Ci >0.542）、中（0.092< Ci <0.542）、差（ Ci <0.092）三类,其中鲁东地区在三档中占比为2/3、4/12、0;鲁中地区占比为1/3、3/12、1/2;鲁西南地区占比为0、5/12、1/2。方差分析结果显示 F =18.755, P ＜0.001,说明分档结果具有统计学意义。结论 山东省卫生资源配置存在明显地区差异,鲁东、鲁中地区卫生资源配置情况较好,鲁西南地区较差。政府应发挥主导作用,完善人才激励机制,缩小卫生资源区域配置差异,提高人群健康水平。