非急诊挂号全面预约模式的探索与实践

为优化门诊流程,北京同仁医院开展非急诊挂号全面预约工作,拓展了多种预约途径,利用信息系统进行门诊流程的改造。改革实施6个月,每日利用各种途径预约挂号量显著提高,同时诊间复诊预约量持续增加。     

肝脏储备功能评估及应用研究

目前,肝脏外科已经进入了精准外科时代,术前准确评估肝脏的储备功能,对于选择合理的治疗方法,把握安全的肝切除范围,减少术后并发症,从而降低患者围手术期的肝功能衰竭的发生率均具有十分重要的意义。本文就综述了肝脏储备功能评估方法及其临床,以期促进精准肝脏外科手术的开展,提高肝脏疾病患者的生存率和生存质量。     

The “Reservation Effect”: Implications for Background Comparisons

A difficult challenge in ecological risk assessment can be determining what constitutes the “background” or ground-state condition for a site. This is because off-site conditions may not reflect to any relevant degree the history of the site itself and may therefore not be appropriate as benchmarks. One of the more important concerns is that underestimates may be made regarding contaminant-related impacts on-site because observations may indicate that community or population quality on-site equals or surpasses that observed off-site. In other cases, overestimates of the degree of contaminant impact may be made if environmental resources on-site are highly managed or devoid of natural communities. As such, management decisions may be confounded by artifacts of non-toxicant-related human influence and will not necessarily appropriately address the contaminant-related issues. Examples of these conditions are discussed herein.     

Energy and QoS Aware Routing in Wireless Sensor Networks

Many new routing protocols have been proposed for wireless sensor networks in recent years. Almost all of the routing protocols considered energy efficiency as the ultimate objective since energy is a very scarce resource for sensor nodes. However, the introduction imaging sensors has posed additional challenges. Transmission of imaging data requires both energy and QoS aware routing in order to ensure efficient usage of the sensors and effective access to the gathered measurements. In this paper, we propose an energy-aware QoS routing protocol for sensor networks which can also run efficiently with best-effort traffic. The protocol finds a least-cost, delay-constrained path for real-time data in terms of link cost that captures nodes energy reserve, transmission energy, error rate and other communication parameters. Moreover, the throughput for non-real-time data is maximized by adjusting the service rate for both real-time and non-real-time data at the sensor nodes. Such adjustment of service rate is done by using two different mechanisms. Simulation results have demonstrated the effectiveness of our approach for different metrics with respect to the baseline approach where same link cost function is used without any service differentiation mechanism.Kemal Akkaya received his B.S. degree in Computer Science from Bilkent University, Ankara, Turkey in 1997 and MS degree in Computer Science from Ortadogu Technical University (ODTU), Ankara, Turkey in 1999. He worked as a software developer at an automation project of Siemens and World Bank in Ankara, Turkey in 2000. He is currently a Ph.D. candidate at University of Maryland, Baltimore County (UMBC), Baltimore, MD. His research interests include energy aware routing, security and quality of service issues in ad hoc wireless networks.Mohamed F. Younis received B.S. degree in computer science and M.S. in engineering mathematics from Alexandria University in Egypt in 1987 and 1992, respectively. In 1996, he received his Ph.D. in computer science from New Jersey Institute of Technology. He is currently an assistant professor in the department of computer science and electrical engineering at the university of Maryland Baltimore County (UMBC). Before joining UMBC, he was with the Advanced Systems Technology Group, an Aerospace Electronic Systems R&D organization of Honeywell International Inc. While at Honeywell he led multiple projects for building integrated fault tolerant avionics, in which a novel architecture and an operating system were developed. This new technology has been incorporated by Honeywell in multiple products and has received worldwide recognition by both the research and the engineering communities. He also participated in the development the Redundancy Management System, which is a key component of the Vehicle and Mission Computer for NASAs X-33 space launch vehicle. Dr. Younis technical interest includes network architectures and protocols, embedded systems, fault tolerant computing and distributed real-time systems. Dr. Younis has four granted and three pending patents. He served on multiple technical committees and published over 40 technical papers in refereed conferences and journals.     

Object-Oriented Design of QoS Multicast Communications

Multicast (group) communications have been widely recognized by current research and industry. Multicast is very useful for various network applications such as distributed (replicated) database, video/audio conference, information distribution and server locations, etc. But design and implementation of such multicast communication systems in networks are complicated tasks, especially when quality of services (QoS) of applications such as real-time and reliability are desired. To quick design and implement multicast communication, good tools are crucial and must be facilitated. This paper presents a novel object-oriented (O-O) QoS driven approach for the quick design and prototyping of multicast communication systems under certain QoS requirements for multicast message transmission and receptions such as real-time, total ordering, atomicity and fault-tolerance, etc.     

An adaptive dual control framework for QoS design

The widespread deployment of the advanced computer technology in business and industries has demanded the high standard on quality of service (QoS). For example, many Internet applications, i.e. online trading, e-commerce, and real-time databases, etc., execute in an unpredictable general-purpose environment but require performance guarantees. Failure to meet performance specifications may result in losing business or liability violations. As systems become distributed and complex, it has become a challenge for QoS design. The ability of on-line identification and auto-tuning of adaptive control systems has made the adaptive control theoretical design an attractive approach for QoS design. However, there is an inherent constraint in adaptive control systems, i.e. a conflict between asymptotically good control and asymptotically good on-line identification. This paper first identifies and analyzes the limitations of adaptive control for network QoS by extensive simulation studies. Secondly, as an approach to mitigate the limitations, we propose an adaptive dual control framework. By incorporating the existing uncertainty of on-line prediction into the control strategy and accelerating the parameter estimation process, the adaptive dual control framework optimizes the tradeoff between the control goal and the uncertainty, and demonstrates robust and cautious behavior. The experimental study shows that the adaptive dual control framework mitigate the limitations of the conventional adaptive control framework. Compared with the conventional adaptive control framework under the medium uncertainty, the adaptive dual control framework reduces the deviation from the desired hit-rate ratio from 40% to 13%.

分布式技术在生物信息资源建设中的应用

由于生命科学研究的复杂性,以及系统生物学的面向多个生物学水平进行研究的特点,对大规模、分布式应用资源进行整合是生命科学信息资源建设中面临的主要问题,分布式技术的应用使生物信息资源建设实现了高度的自动化,并行化。本文对分布式集成技术在生物学领域的应用和未来发展做了简要综述。并结合当今技术趋势给出了生物信息学项目进行分布式资源整合的解决方案。     

QoS Support by the HiperLAN/2 MAC Protocol: A Performance Evaluation

HiperLAN/2 (HIgh PErformance Radio Local Area Network) is a new standard from ETSI (European Telecommunications Standards Institute) for high-speed wireless LANs, interconnecting portable devices to each other and to broadband core networks, based on different networking technologies such as IP, ATM, IEEE 1394, and others. This paper introduces the basic features of the HiperLAN/2 MAC protocol. It presents performance evaluation results, specifically related to the mechanisms provided by HiperLAN/2 to manage bandwidth resource requests and granting. These results are assessed in terms of their flexibility and efficiency in supporting delay sensitive traffic, such as voice and Web data traffic, which are expected to be transported by broadband wireless LANs.     

A Framework for Automatic Adaptation of Tunable Distributed Applications

Increased platform heterogeneity and varying resource availability in distributed systems motivate the design of resource-aware applications, which ensure a desired performance level by continuously adapting their behavior to changing resource characteristics. In this paper, we describe an application-independent adaptation framework that simplifies the design of resource-aware applications. This framework eliminates the need for adaptation decisions to be explicitly programmed into the application by relying on two novel components: (1) a tunability interface, which exposes adaptation choices in the form of alternate application configurations while encapsulating core application functionality; and (2) a virtual execution environment, which emulates application execution under diverse resource availability enabling off-line collection of information about resulting behavior. Together, these components permit automatic run-time decisions on when to adapt by continuously monitoring resource conditions and application progress, and how to adapt by dynamically choosing an application configuration most appropriate for the prescribed user preference. We evaluate the framework using an interactive distributed image visualization application and a parallel image processing application. The framework permits automatic adaptation to changes in execution environment characteristics such as available network bandwidth or data arrival pattern by choosing a different application configuration that satisfies user preferences of output quality and timeliness.     

Resource Management for Ad-Hoc Wireless Networks with Cluster Organization

Boosted by technology advancements, government and commercial interest, ad-hoc wireless networks are emerging as a serious platform for distributed mission-critical applications. Guaranteeing QoS in this environment is a hard problem because several applications may share the same resources in the network, and mobile ad-hoc wireless networks (MANETs) typically exhibit high variability in network topology and communication quality. In this paper we introduce DYNAMIQUE, a resource management infrastructure for MANETs. We present a resource model for multi-application admission control that optimizes the application admission utility, defined as a combination of the QoS satisfaction ratio. A method based on external adaptation (shrinking QoS for existing applications and later QoS expansion) is introduced as a way to reduce computation complexity by reducing the search space. We designed an application admission protocol that uses a greedy heuristic to improve application utility. For this, the admission control considers network topology information from the routing layer. Specifically, the admission protocol takes benefit from a cluster network organization, as defined by ad-hoc routing protocols such as CBRP and LANMAR. Information on cluster membership and cluster head elections allows the admission protocol to minimize control signaling and to improve application quality by localizing task mapping.     

中国陆地生态系统生态资产测量及其动态变化分析

利用遥感技术,结合生态学方法,在对生态参数测量的基础上,通过建立生态资产计算模型,对中国陆地生态系统1992、1995和2000年的生态资产进行测量,并据此绘制中国陆地生态系统多年的生态资产空间分布图.结果表明,中国陆地生态系统1992、1995及2000年的生态资产分别为8.148×10¹²元、1.086×10¹³元和1.244×10¹³元人民币.从单位面积价值来看,森林的平均单位面积价值最高,为24 673元·hm^-2;其次为湿地(21 353元·hm^-2),说明森林和湿地对生态资产的贡献最大.从生态资产的空间分布来看,中国陆地生态系统的生态资产总体空间分布由东向西递减,由中部向东北和南部递增,这与植被的地带性分布梯度基本一致.受气候变化和人类活动的影响,20世纪90年代以来中国陆地生态系统的生态资产呈上升趋势,其最大值的空间分布也明显向南移动,总体变化率在20%左右,但生态资产与GDP的比值则显著下降.     

地表水资源供给服务供需关系对节水政策的响应——以大清河流域为例

水资源是基础性自然资源和战略资源,科学量化水资源供给服务的供需关系、识别供需矛盾的突出区域是进行流域水资源管理的重要前提。以大清河流域为例,利用InVEST模型,建立了水资源供给服务空间流动量化方法,预测了用水效率提升、节水灌溉两种节水政策情景对水资源供给服务供需关系的影响。结果表明：(1)流域水资源供给服务和水资源需求量均呈现出上游低、下游高的空间分布格局,农业用水为流域主要用水类型,2010—2015年,流域水资源供给服务增长0.97%,水资源需求量出现了9.6%的下降;(2)2010—2015年,流域整体水资源供给服务的供需比由0.78提升至0.88,服务的空间流动使得上游盈余的水量缓解了中下游的用水压力,但中下游水资源需求大于供给的问题仍普遍存在;(3)提升用水效率、推行节水灌溉这两种节水政策均能够有效改善大清河流域的水资源供需关系,分别可将流域水资源供需比提升至0.97和0.96,基本达到供需平衡。研究可为北方资源型缺水流域水资源供需匹配度的提高、节水政策潜力的评估提供借鉴。     

Bumble bee pollen use and preference across spatial scales in human‐altered landscapes

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泰山森林生态系统服务功能及其价值评估

森林在给人类带来经济效益的同时,也带来了巨大的生态效益。随着经济社会的发展,人们越来越多地关注森林的生态效益。以泰山森林生态系统为研究对象,依据林业行业标准《森林生态系统服务功能评估规范》,从涵养水源、保育土壤、林木营养物质积累、固碳制氧、保护生物多样性、净化大气环境及森林防护7个方面对泰山森林生态系统的生态服务功能进行了定量评估,得出泰山森林生态系统每年的生态服务价值量为18214.97万元,以涵养水源(10376.84万元/a)、生物多样性保护(3796万元/a)和固碳制氧(2736.38万元/a)价值为主;泰山森林生态系统中松栎林的生态服务价值相对高于其他林种的,尤其是以侧柏林为最高;从不同林龄的角度进行评估,泰山森林生态服务价值以中龄林为主,占到生态服务价值总量的35%,过熟林的生态价值总量虽然排在最后,但其单位面积的价值量最高。     

建立门诊医患互动诊疗新模式的探讨

为进一步提高医疗技术资源的应用效能,提高门诊诊疗效率和患者就诊效率,有效缓解门诊“三长一短”的现状,在门诊传统诊治模式的基础上,建立门诊医患互动诊疗新模式,实现科学分诊和交替诊治,开辟患者就诊新流程。就医患者因此避免了相互间的影响,缩短了滞留门诊的时间。医生因此减少了大量的“非技术性”工作,诊疗科室改变了工作中时闲、时忙效率低下的状况。有限的医疗资源,得到更加有效的运用。     

The use of steel in the United Kingdom's transport sector: A stock–flow–service nexus case study

Energy and material flows and material stocks are key requirements for the supply of goods and services, which in turn support societal development. However, most resource accounting methods restrict the analysis to resource flows, which fails to acknowledge the increasing role of in‐use stocks in service provision. Using the UK transport sector as a case study, we undertook a material flow analysis through the lens of the stock–flow–service (SFS) nexus. We used the latter to identify how steel consumption and accumulation in vehicles contributed to passenger mobility between 1960 and 2015. Our results show that the efficiency of the steel stock contained in cars and motorcycles decreased from 37.5 to 28.0 passenger‐km (pkm)/kg‐year. The steel service for buses decreased from 63.6 to 32.1 pkm/kg‐year, while that of the national railway increased from 23.8 to 70.3 pkm/kg‐year steel. London Underground steel stock–service efficiency improved from 31.5 to 57.0 pkm/kg‐year steel. The annual fraction of flows that maintained the steel stock varied according to vehicle category and was between 3.4% and 8.2%. In terms of the stock expansion rate, the greatest change (on average, an annual increase of 3%) was that of “cars and motorcycles.” This reflects the demographic transitions and the growing consumer demand for car‐based mobility. We discussed how the SFS nexus contributes to a more comprehensive form of resource accounting and reflect upon some of its limitations and how they might be addressed.     

黄河流域资源型城市土地利用转型及其对生态系统服务价值的影响

分析快速城镇化背景下黄河流域资源型城市土地利用转型趋势,探讨该区域土地利用转型对生态系统服务价值的影响,为资源型城市实现绿色转型发展提供科学依据。运用ArcGIS空间分析方法探索研究区土地利用结构与时空转型格局,构建黄河流域资源型城市生态系统服务价值评估方法,分析不同类型和不同区域资源型城市生态系统服务价值变化情况,并进一步探究不同土地利用转型类型对生态系统服务价值的影响程度。研究结果表明：（1）20年来,伴随着快速的城镇化过程,黄河流域资源型城市发生了明显的土地利用转型,草地、耕地和林地相互转换规模较大,建设用地不断扩张,耕地则持续减少;（2）2020年,研究区生态系统服务价值总量为1.222万亿元,呈增长趋势,且形成"中部高-东西低"的空间格局;（3）各资源型城市生态系统服务价值量表现出北高南低、中高东低的空间格局,成熟型和再生型资源型城市以及中游地区资源型城市的单位面积生态系统服务价值较大;（4）草地、耕地和林地之间的相互转换是导致生态系统服务价值变化的主要转型类型。为提升黄河流域资源型城市生态系统服务价值,有效发挥生态系统功能,构建区域生态安全体系,首先,应严格落实国土空间用途管制制度,保持林地、草地和耕地的稳定性;其次,从严控制建设用地扩张趋势,减缓因建设占用耕地或生态用地导致生态系统服务价值损失;再次,稳步提高对未利用地的生态化利用效率;最后,积极探索提升资源型城市生态系统服务价值的差异化管理方案。     

钾细菌诱变选育和发酵的研究

通过钾细菌的诱变选育和发酵工艺探索 ,来提高发酵菌量和芽孢量 ,确保钾细菌肥的质量的研究。试验选用钾细菌P1为出发菌株 ,经紫外线、硫酸二乙酯交替处理 ,筛选出一株产菌量和芽孢量较高的突变株PE -R。用该菌株进行了发酵各因素的试验确定了最佳发酵条件 :接种量 2 0 %、淀粉浓度 1.2 %、氮源浓度 0 .3%、发酵初始pH7.0 - 7.2、发酵后期温度 37℃、发酵后期风量 1:1.2。试验结果表明 ,采用该工艺进行工业化生产 ,发酵菌量从 2 0× 10 10 个 /ml增加到 4 5× 10 10 个 /ml,芽孢生成量从 4 5 %增加到 95 % ,发酵时间从 2 4h缩短到 15h ,制成菌肥 1年后检测活菌保留率仍在 93 6 %。     

生态系统服务流研究方法最新进展

生态系统服务流是生态系统服务研究的重点和难点,处于发展的起步阶段,并向着定量化和空间化的趋势发展.目前,学术界关于生态系统服务流的概念含糊不清.本文首先对生态系统服务流的两种理解及其代表性的理论和方法进行了阐述:一是生态系统服务从生态系统到人的传递过程,其代表性方法是分布式生态系统模型,二是生态系统服务实际上为人们所使用的那部分,其代表性方法论是黑/灰箱理论.在此基础上分别列举了这两种理解的最新研究方法,论述了不同的理解以及方法对于研究生态系统服务流的特点以及存在问题.最后,总结了未来生态系统服务流研究的发展机遇,特别强调最新的空间技术与信息技术(如大数据),以及对生态系统服务的全面认识(如重视城市生态系统服务流的研究、重视非生物流的整合等)在未来研究中的重要性.