Web系统建模及其性能分析
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摘要
随着互联网的发展,Web-World Wide Web(WWW)的应用领域更加的广泛,技术发展更是多样化。对于迅速增长的网络用户,Web必须能够提供更加可靠和高质量的服务,才能应对当前的发展,所以对于Web系统的性能分析是一个重要的研究课题。在深入分析并掌握国内外研究现状的基础上,采用排队论和排队网络数学理论,对大型的Web集群系统建立模型,对常见的多层Web应用基础平台建立模型,对Web应用程序建立模型,得到系统的性能指标表达式。通过仿真和测试的手段进行比较分析,给出系统优化设计,对Web系统的性能规划和应用软件系统的设计提供了理论依据和分析方法。
     首先,采用基础的M/G/1排队模型,给出集群系统在考虑服务器性能和数量时的优化搭建方案;通过把复杂排队网络进行转换,基于M/M/c排队模型进行分析,给出集群系统中优化的服务器数量范围;采用异步休假的M/M/c排队模型,给出集群系统优化的能耗管理方案;采用仿真的方法对集群系统的负载均衡策略进行了性能分析。对相关模型进行了数值分析与验证。
     其次,基于多层的Web应用程序运行环境,分别对Web服务器、应用服务器和数据库服务器建立模型,通过排队网络的模型分析,与系统测试相结合,给出服务平台构建的优化配置方案。对于B/S模式下的Web基础网络平台建立了排队网络模型,采用排队网络模型MVA求解方法和扩散近似的方法给出了性能解析表达式,通过NS-2进行系统仿真对比,分析系统瓶颈并给出改进方案。
     再次,对集群环境下企业级的J2EE应用程序进行了排队网络模型的分析,对小型的共享主机平台的J2EE应用程序进行排队网络模型分析,通过测试验证了模型的正确性,给出系统的优化搭建方案。对于组合Web服务,按照并行组合关系建立马尔科夫链模型,对复杂的组合关系建立排队网络模型,分别进行求解并进行数值分析,给出系统优化的构建方案。对Web应用软件的UML设计方案进行模型的转换,采用分层排队网络模型进行分析,通过分层模型的MVA算法,得到系统相关的性能指标,对软件性能进行预测分析。
     最后,通过对实例Web应用中的AJAX技术进行响应时间和网络流量的分析,给出Web应用软件的实际性能优化方案,对其他影响性能的相关因素也进行了简要分析。
With the development of Internet, Web- World Wide Web(WWW) 's applicable field become more extensive, the progress of technology tends to be diversified. For the quickly increasable web users, Web must provide more reliable and high quality services, so it can keep up with the development. It is a very important research field for the web system performance evaluation. Based on deeply analyzing and mastering current research state at home and abroad, using the mathematic theory of queueing and queueing network, modeling the large web cluster system, modeling the basic platform of the multi tier web application, modeling the web application. The system's expressions of performance measures are obtained from simulation and tests. Through comparing and analyzing, the system's optimal results are presented, which provides theoretical basis and analysis methods for the web system performance planning and Web application designing.
     Firstly, by adopting the queue model of M/G/1, the optimal establishing policy of the cluster system are presented, considering the servers performance and server number simutaniously; Through the transition of complex queueing network model, by analyzing based on the M/M/c queue model, the range of optimal server number of the cluster are obtained; By adopting the M/M/c queue model with vacations, the optimal power management policy of the cluster are presented; from simulation, performance evaluation is done for the cluster's load balancing policies. Numerical analysis and validation is done for these models.
     Sencondly, based on the running enviroment of the multi tier web application, models are presented for web server, application server and database server respectively. Through queueing network analyzing, integrating the system tests, the optimal configuration policy of the sevice platform's establishment are presented. For web's basic network platform, queueing network model is given. By adopting the MVA algorithm and diffussion approxmimate algorithm of queueing network, the performance expressions are obtained. By comparision with simulation of NS-2, system's bottleneck is analyzed and improved policies are presented.
     Thirdly, queueing network analysis is done to the large scale J2EE application established in server clusters and small J2EE application on sharing hosts. Model's accuracy is validated from tests. The system optimal establishment policy is presented. For the composite web services, a marchov chain model is established according to the parelell relationship. A queueing network model is established according the complex composite relationship, Solving and numerical analysis are done respectively. System optimal establishment policy is presented. Through transition for web application's UML model, by analyzing from layered queueing network, according to the MVA algorithm of layered queueing network, some performace indices of the application are obtained, so performance prediction are done to the software.
     Finally, through analyzing of response time and traffic flow of AJAX of the instances of web application, actual optimal performance policies are presented for the web application, simple analysis for other performance indices are also presented.
引文
1 A Little History of the World Wide Web. http://www.w3.org/History.html. 2006
    2 W3C History. http://www.w3.org/Consortium/history. 2008
    3 Web Content Accessibility Guidelines 1.0. http://www.w3.org/tr/wai-webcontent. 2008
    4 D. Crane, E. Pascarello, D. James. Ajax in Action. Greenwich: Manning Publications, 2005:3-116
    5 Web Services Activity. http://www.w3.org/2002/ws. 2009
    6 W3C Semantic Web Activity. http://www.w3.org/2001/sw. 2009
    7 10 Future Web Trends. http://www.readwriteweb.com/archives/10_future_web_trends.php. 2007
    8杨建华,金笛等.集群虚拟服务器的仿真建模研究.电子技术应用, 2006,32(4):33-36
    9 Schroeder, T. Goddard, S. Ramamurthy. Scalable Web Server Clustering Technologies. IEEE Network, 2000,14(3): 38-45
    10张明胜,王艳华.集群负载均衡-CSM的实现.计算机工程, 2006,32(11):165-166
    11 L. Aversa, A. Bestavros. Load Balancing a Cluster of Web Servers using Distributed Packet Rewriting. Proceedings of the 2000 IEEE International Performance, Computing, and Communications, Phoenix, Arizona, 2000:24-29
    12 B. Urgaonkar, P. Shenoy, T. Roscoe. Resource Overbooking and Application Profiling in Shared Hosting Platforms. Proceedings of the 15th Symposium on Operating Systems Design and Implementation (OSDI), Boston, MA, 2002: 239-254
    13 G. Barish. Building Scalable and High-performance Java Web applications using J2EE Technology. USA:Addison Wesley Professional, 2001:23-321
    14林闯.计算机网络和计算机系统的性能评价.北京:清华大学出版社,2001:74-128
    15 R. Jain. The Art of Computer Systems Performance Analysis. New York: Wiley-Interscience,1991:1-171
    16盛友招.排队论及其在现代通信中的应用.北京:人民邮电出版社,2007:40-135
    17孙荣恒,李建平.排队论基础.北京:科学出版社,2002:23-56
    18田乃硕.休假随机服务系统.北京:北京大学出版社,2001:252-316
    19 N. S. Tian, Z. G. Zhang. Vaction Queueing Models-Theory and Applications. New York.:Springer Science,2006:193-295
    20田乃硕,岳德权.拟生灭过程与矩阵几何解.北京:科学出版社,2002:16-30
    21 G. Bolch, S. Greiner, H. de Meer, K.S. Trivedi, Queuing Networks and Markov Chains. John Wiley and Sons, 1998: 423–460
    22 A. M. Law, W. D. Kelton. Simulation Modeling and Analysis, third ed.. New York:McGraw-Hill Inc, 2000:12-230
    23 G. M. Marakas. Systems analysis and design. Beijing:China Machine Press, 2006:10-113
    24徐雷鸣. NS与网络模拟.北京:科学技术文献出版社,2003:30-230
    25陈绍英,刘建华,金成姬. LoadRunner性能测试实战.北京:电子工业出版社,2007:140-200
    26 D. A. Menasce, V. A. F. Almeida. Scaling for E-Business:Technologies, Models, Performance, and Capacity Planning. N.J.:Prentice Hall,2000:132-320
    27 A. Iyengar, J. Challenger, P. Dantzig. High-performance Web site design techniques. IEEE Internet Computing, 2000,4(2):17–26
    28 H. Bryhni, E. Klovning, O. Kure. A comparison of load balancing on Web-server systems. IEEE Network,2000,14(4):58–63
    29吴令云,潘纪明.一种WEB服务器集群系统实现方案.南京审计学院学报,2006,3(4):78-83
    30雷迎春,张松,李国杰. Web集群服务器的分离式调度策略.计算机研究与发展,2002,39(9):1093-1098
    31林闯. Web服务器集群请求分配和选择的性能分析,计算机学报, 2000,23(5):500-508
    32 Z. J. Zhang, W. G. Fan. Web server load balancing:A queueing analysis. European Journal of Operational Research, 2008,(186):681–693
    33于国防,王耀才,庄立运,贾栋清.集群服务器晌应延时预侧及其负载调度控制.计算机系统应用,2007,(7):26-29
    34 Z. Xiong, P.L. Y. Modeling and Performance Analysis of Dispatching Policies in Dispatcher-Based Web Server Cluster. Wuhan University Journal of Natural Sciences,2006,11(3):591-595
    35 M. T. Yong, R. Ayani, Comparison of load balancing strategies on cluster-based Web servers. Simulation ,2001,77 (5–6):185–195
    36郭静,祝永志,王延玲.基于RR-DNS的Web集群系统的可用性研究.计算机技术与发展,2008, 18(12):160-164
    37 Y. S. Hong, J. H. No, S. Y. Kim. DNS-based load balancing in distributed Web-server systems. International Workshop on Collaborative Computing, Integration, and Assurance. Gyeongju, Korea,2006:1-4
    38 Cherkasova, Ludmila, Karlsson, Magnus. Scalable Web Server Cluster Design with Workload-Aware Request Distribution Strategy WARD. HP TechnicalReport,2001, HPL-2001-2R1:1-20
    39 Z. G. Shan, C. Lin , D. C. Marinescu , Y. Yang. Modeling and performance analysis of QoS-aware load balancing of Web-server clusters. Computer Networks, 2002(40):235-256
    40 D. G. Down, M. E. Lewis. Dynamic load balancing in parallel queueing systems: Stability and optimal control. European Journal of Operational Research, 2006,168 (2):509-519
    41 W. Shi, M.H. MacGregor, P. Gburzynski. Load balancing for parallel forwarding. ACM Transactions on Networking , 2005,13 (4):790-801
    42熊忠阳,李光勇,张玉芳等. Web集群系统性能测试与优化.计算机应用研究,2008,25(3): 826-832
    43 E. Pinheiro, R. Bianchini, E. V. Carrera, T. Heath. Load Balancing and Unbalancing for power and performance in Cluster-Based Systems. In Workshop on Compilers and Operating Systems for Low Power,2001:1-18
    44 E. N. Elnozahy, M. Kistler, R. Rajamony. Energy-Efficent Server Clusters. Proceedings of the
    2nd Workshop on Power-Aware Computing Systems, Cambridge, MA, USA ,2002: 179-196
    45 J. S. Chase, D. C. Anderson, P. N. Thakar, A. M. Vahdat, R. P. Doyle. Managing Energy and Server Resources for Hosting Center. Proceedings of the 18th ACM symposium on Operating systems principles. Banff, Canada, 2001:103-116
    46 J. S. Chase, R. P. Doyle. Balance of power: Energy management for server clusters. Proceedings of the 8th Workshop on Hot Topics in Operating Systems (HotOS-8). Elmau, Germany, 2001:1-7
    47 Y. Y. Chen , A. Das , W. B. Qin , A. Sivasubramaniam , Q. Wang , N. Gautam. Managing server energy and operational costs in hosting centers, ACM SIGMETRICS Performance Evaluation Review, 2005,33(1):303-314
    48 M. Elnozahy, M. Kistler , R. Rajamony. Energy conservation policies for web servers. Proceedings of the 4th conference on USENIX Symposium on Internet Technologies and Systems, Seattle, WA, 2003:8-8
    49 W. Felter , K. Rajamani , T. Keller , C. Rusu. A performance-conserving approach for reducing peak power consumption in server systems. Proceedings of the 19th annual international conference on Supercomputing, Cambridge, Massachusetts,2005: 293-302
    50 T. Horvath , T. Abdelzaher , K. Skadron , X. Liu. Dynamic Voltage Scaling in Multi tier WebServers with End-to-End Delay Control, IEEE Transactions on Computers, 2007,56(4):444-458
    51 R. Nathuji , K. Schwan. VirtualPower: coordinated power management in virtualized enterprise systems. Proceedings of 21th ACM SIGOPS symposium on Operating systems principles, Stevenson, Washington,2007:265-278
    52 J. H. Cao, M. Andersson, C. Nyberg, M. Kihl. Web Server Performance Modeling Using an M/G/1/K*PS Queue. In 10th International Conference on Telecommunications (ICT’03), Tahiti, Papeete,2003: 1501-1506
    53 M. Andersson, J. H. Cao, M. Kihl, C. Nyberg. Performance modeling of an Apache web server with bursty arrival traffic. Proceedings of International Conference of Internet Computing. Las Vegas,USA, 2003:508-514
    54 J. J. Lu, S. S. Gokhale. Web Server Performance Analysis. Proceedings of the Sixth International Conference on Web Engineering. Palo Alto,California,USA,2006:111-112
    55 D. A. Wu, H. Takagi. Processor-sharing and random-service queues with semi-Markovian arrivals. Journal of Applied Probability,2005,42(2): 478-490
    56 T. V. Do1, U. R. Krieger, R. Chakka. Performance modeling of an Apache Web server with a dynamic pool of service processes. Telecommunication Systems, 2008,39(2):117-129
    57 K. M. Elleithy, A. Komaralingam. Using a Queuing Model to Analyze the Performance of Web Servers. International Conference on Advances in Infrastructure for e-Business, e-Education, e-Science, and e-Medicine on the Internet. L’Aquila, Italy,2002:1-7
    58 D. F. Kassa, A. E. Krzesinski. A queueing network model of TCP performance. ACM International Conference Proceeding Series. 2005,(150):56-65
    59 D. Miorandi, A.A. Kherani, E. Altman. A queueing model for HTTP traffic over IEEE 802.11 WLANs. Proceedings of 16th ITC Specialist Seminar on Performance Evaluation of Wireless and Mobile Systems. Antwerp, Belgium,2004:63-79
    60 J. Choi, J. Yoo. A novel performance analysis model for an IEEE 802.11 wireless LAN. IEEE Communications Letters, 2006,10(5):335-337
    61 N. Gautam. Performance analysis and optimization of web proxy servers and mirror sites. European Journal of Operational Research, 2002,(142):396-418
    62 M. Bramson, J. G. Dai. Heavy traffic limits for some queueing networks. Annals of Applied Probability, 2001,(11):49-88
    63 A. Ratkowski. Method for performance analysis of applications servers software by the use of queueing networks. [Warsaw University of Technology Master Disertation], 2005:43-85
    64 D. Menasce. Web server software architectures. IEEE Internet Computing. 2003,7(6): 78-81
    65姚磊,戴冠中,张慧翔,潘文平. Web服务器性能测量系统的研究进展.计算机科学,2007,34(4):86-88
    66席静,褚兴军,徐志伟.一种提高Web服务器性能的方法.计算机研究与发展, 2002,39(4):415-422
    67 L. Wells, S. Christensen, L. M. Kristensen, K. H. Mortensen. Simulation Based Performance Analysis of Web Servers. Proceedings of the 9th International Workshop on Petri Nets and Performance Models. Aachen, Germany,2001: 59-68
    68胡萍,陈志鹏.基于线程池的高性能服务器软件的设计和实现.计算机技术与发, 2006,16(8):49-51
    69 I. Haddad, G. Butler. Experimental Studies of Scalability in Clustered Web Systems. Proceedings of the 18th International Parallel and Distributed Processing Symposium (IPDPS’04).Santa Fe, New Mexico,2004:185-190
    70 A. Chandra, W. Gong, P. Shenoy. Dynamic resource allocation for shared data centers using online measurements. Proceedings of the 11th International Workshop on Quality of Service (IWQoS’03). Monterey, CA,2003: 300-301
    71 R. Doyle, J. Chase, O. Asad, W. JIN, A. Vahdat, A. Model-based resource provisioning in a Web service utility. Proceedings of the 4th conference on USENIX Symposium on Internet Technologies and Systems. Seattle, WA, 2003:1-5
    72 D. Villela, P. Pradhan, D. Rubenstein. Provisioning servers in the application tier for e-commerce systems. Proceedings of the 12th International Workshop on Quality of Service. Montreal, Canada,2004: 57-66
    73 S. Ranjan, J. Rolia, H. Fu, E. Knightly, QoS-driven server migration for internet data centers. Proceedings of the 10th International Workshop on Quality of Service, Miami, FL.,2002:3-12
    74 A. Chandra, P. Goyal, P. Shenoy. Quantifying the benefits of resource multiplexing in on-demand data centers. In 1st Workshop on Algorithms and Architectures for Self-Managing Systems. San Diego, California, USA,2003:1-6
    75 B. Urgaonkar, P. Shenoy. Cataclysm: Handling extreme overloads in internet services.Proceedings of the 23rd Annual ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing (PODC’04). Newfoundland, Canada,2004:740-749
    76 R. Levy, J. Nagarajarao, G. Pacifici, M. Spreitzer, A. Tantawi, A. Youssef. Performance management for cluster based web services. Proceedings of 8th International Symposium on Integrated Network Management. Colorado Springs, Colo,2003: 247-261
    77 A. Kamra, V. Misra, E. Nahum. Yaksha: A Self-Tuning Controller for Managing the Performance of 3-Tiered Web Sites. Proceedings of the 12th International Workshop on Quality of Service(IWQoS). Montreal, Canada,2004: 47-56
    78 B. Urgaonkar, G. Pacifici, P. Shenoy, M. Spreitzer, A. Tantawi. Analytic modeling of multitier Internet applications. ACM Transactions on the Web ,2007,1(1):1-35
    79 Y. W. Bai, C. Y. Cheng. The Performance Estimation by Queuing Network Models for a Web-based Medical Information System. Proceedings of 17th IEEE Symposium on Computer-Based Medical Systems. Bethesda, MD, USA ,2004: 191-196
    80 Y. Mustafa , U. Z. Ukirmizi. Performance Evaluation of Closed Queueing Networks with Limited Capacities. Turkish Journal of Engineering & Environmental Sciences, 2006,(30):269-283
    81 M. Benani, D. Menasc. Resource allocation for autonomic data centers using analytic performance models. Proceedings of IEEE International Conference on Autonomic Computing(ICAC’05). Seattle, WA,2005:229-240
    82 X. Y. Zheng, D. R. Chen. Using multi-class queueing network to solve performance models of e-business sites. Journal of Zhejiang University Science,2004,5(1):31-39
    83 A. Kamra, V. Misra, E. Nahum. Controlling the Performance of 3-Tiered Web sites:Modeling, Design and Implementation. Proceedings of the joint international conference on Measurement and modeling of computer systems. New York, USA,2004:414-415
    84 M. Arlitt, D. Krishnamurthy, J. Rolia. Characterizing the capability of a large Web-based shopping system. ACM Trans. on Internet Technology, 2001,1(1):44-69
    85 K. Kant, P. Mohapatra. Scalable Internet servers: Issues and challenges. ACM SIGMETRICS Performance Evaluation Review, 2000, 28(2):5-8
    86 T. Abdelzaher, K. G. Shin, N. Bhatti. Performance guarantees for Web server endsystems:A control-theoretical approach. IEEE Transactions on Parallel and Distributed Systems,2002, 13(1): 80-96
    87 T. K. Liu, S. Kumaran, Z. W. Luo. Layered queueing models for enterprise JavaBean applications. Proceedings of 15th IEEE International Conference of Enterprise Distributed Object Computing. Seattle, Washington 2001: 174-178
    88 J. Xu, A. Oufimtsev, M.Woodside, L. Andmurphy. Performance modeling and prediction of enterprise java beans with layered queuing network templates. ACM SIGSOFT Software Engineering Notes,2006,31(2): 163-184
    89 Cortellessa, Vittorio, H. Singh, B. Cukic. Early reliability assessment of UML based software models. Proceedings of the third international workshop on Software and performance. Rome, Italy,2002:302-309
    90 Fernandes, M. Joao, J. R. Machado,S. D. Henrique. Modeling industrial embedded systems with UML. Proceedings of the eighth international workshop on Hardware/software codesign. Estes Park, Colorado,2000:18-22
    91 Alsaadi, Ahmad. A performance analysis approach based on the UML class diagram. Proceedings of the fourth international workshop on Software and performance. California, USA,2004:254-260
    92 Hoeben, Fried. Using UML models for performance calculation. Proceedings of the second international workshop on Software and performance. Rome, Italy,2000:77-82
    93 Lindemann, Christoph. Performance analysis of time-enhanced UML diagrams based on stochastic processes. Proceedings of the third international workshop on Software and performance. Rome, Italy,2002:25-34
    94 Balsamo, Simonetta, M. Marzolla. A simulation-based approach to software performance modeling. Proceedings of 11th ACM SIGSOFT international symposium on Foundations of software engineering. Helsinki, Finland,2003:363-366
    95 Bernardi, Simona, S. Donatelli, J. Merseguer. From UML sequence diagrams and statecharts to analysable petri net models. Proceedings of the third international workshop on Software and performance table of contents. Rome, Italy,2002:35-45
    96 V. Cortellessa, R. Mirandola, Deriving a Queueing Network Based Performance Model from UML Diagrams. Proceedings of International Workshop Software and Performance. Ottawa, Canada,2000:58-70
    97 S. Balsamo, M. Marzolla. Performance evaluation of UML software architectures with multiclassQueueing Network models. WOSP 2005,Palma de Mallorca, Illes Balears,2005:37-42
    98徐忠富,陈永光,杨建华,彭珲. USDP分析设计中基于排队网络模型的软件性能预测方法.计算机科学, 2007, 34(10):272-277
    99边学工,胡瑞敏,陈军,李德仁.基于分层排队网络模型的MCU性能预测及优化研究.计算机学报,2004,27(2):209-215
    100 O. Das, C. M. Woodside. Layered Dependability Modeling of an Air Traffic Control System. International Workshop on Software Architectures for Dependable Systems. Ottawa, Ontario,2003:1-6
    101 O. Das, C. M. Woodside. Dependability Modeling of Self-healing Client-Server Applications. Lecture Notes in Computer Science, 2004,(3069): 266-285
    102田乃硕,高作峰,夏茂辉.同步休假M/M/c排队系统的条件随机分解方法.复杂系统控制问题研究论文集.北京.1998:91-99
    103田乃硕.多级适应性到达间隔的GI/M/n排队系统.应用数学学报, 1990, 13:421-430
    104田乃硕.多服务台休假排队系统的一个综述.排队论通讯, 1996, 1:3-6
    105 N. Tian, Q. Li. The M/M/c Queue with PH-synchronous Vacations. Sys. Sci. & Math. Sci., 2000, 13:7-16
    106 Y. Sakai, Y. Takahachi, T. Hasegawa. A Composite Queue with Vacation/Set-up/Close-down Time for SVCC in NP Qver ATM Networks. J. Opns. Res. Soc. of Japan, 1998, 41:68-80
    107 N. Tian, Q. Li, J. Cao. Conditional Stochastic Decompositions in the M/M/c Queue with Server Vacations. Stoc. Mod., 1999, 15(2):367-377
    108田乃硕,徐秀丽等.部分服务台同步多重休假的M/M/c排队.运筹学学报, 2001, 5(3):85-94
    109田乃硕,张忠军.异步休假M/M/c排队系统的稳态理论.应用数学学报, 2001, 24(2):185-194
    110田乃硕.同步休假GI/M/c排队的稳态理论.运筹学学报, 2001, 5(1):70-80
    111 N. Tian, G. Zhang. Stationary Distribution of GI/M/c Queue with PH Type Vacations. Queueing Systems, 2003, 44(2):183-202
    112 X. Chao, Y. Zhao. Analysis of Multiple-server Queue with Station and Server Vacation. Eur. J. Opns. Res., 1998, 110:392-406
    113 K. Madan, W. Abu-Dayyeh, F. Taiyyan. A Two Server Queue with Bernoulli Schedules adn A Sigle Vacation Policy. Appl. Math. Compu., 2003, 145:59-71
    114 Zhang, N. Tian. Analysis of Queueing Systems with Synchronous Single Vacation for SomeServers. Queueing Systems, 2003, 45(2):161-174
    115 G. Zhang, N. Tian. Analysis of Queueing Systems with Synchronous Vacations of Partial Servers. Performance Evaluation, 2003, 52:269-282
    116 G. Zhang, N. Tian. The Two Threshold Vacation Policy in Multiserver Queueing System. European Journal of Operations Research, 2004, 156:375-389
    117 L. Xu, G. Zhang. The Analysis of Multi-server Queue with Single Vacation and a (e, d) Policy. Performance Evaluation, 2006, 63(8):825-838

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