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Standard Form 298 (Rev. 8-98)Prescribed by ANSI Std. Z39.18Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Complex mission plans may need to incorporate information from various sources and domains to achieve a task. This information is available through a variety of web services in the Service-Oriented Architecture (SOA), but the ability to automatically compose them into a single coherent task is not readily available. Traditional composition approaches require human-intensive involvement, making them time-consuming and error prone. Therefore, the ability to automatically or semi-automatically orchestrate web services in a short timeframe is highly desirable. SPONSOR / MONITOR'S ACRONYM(S) 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) SPONSOR / MONITOR'S REPORT NUMBER(S)Recent works in the area of automatic web service composition produced a plethora of automation approaches with different degrees of automation. Different situations call for different composition approaches. However, there is a lack of guidance regarding what approaches are appropriate for a particular situation. In this paper, we examine the various approaches and develop a general-purpose framework for automatic service composition. Within the framework, we outline the common steps in the various composition processes and review the options available at each step. We also provide guidelines for choosing a composition approach within the framework for the geospatial planning domain. 30-04-2009Memorandum Report 0602435NFebruary AbstractComplex mission plans may need to incorporate information from various sources and domains to achieve a task. This information is available through a variety of web services in the Service-Oriented Architecture (SOA), but the ability to automatically compose them into a single coherent task is not readily available. Traditional composition approaches require human-intensive involvement, making them time-consuming and error prone. Therefore, the ability to automatically or semi-automatically orchestrate web services in a short timeframe is highly desirable.Recent works in the area of automatic web service composition produced a plethora of automation approaches with different degrees of automation. Different situations call for different composition approaches. However, there is a lack of guidance regarding what approaches are appropriate for a particular situation. In this paper, we examine the various approaches and develop a general-purpose framework for automatic service composition. Within the framework, we outline the common s...

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Aggregate K Nearest Neighbor (AKNN) queries are problematic when performed within spatial networks. While simpler network queries may be solved by a single network traversal search, the AKNN requires a large number costly network distance computations to completely compute results. The M-Tree index, when used with Road Network Embedding, provides an efficient alternative which can return estimates of the AKNN results. The M-Tree index can then be used as a filter for AKNN results by quickly computing a superset of the query results. The final AKNN query results can be computed by sorting the results from the MTree. In comparison to Incremental Euclidean Restriction (IER), the M-Tree reduces the overall query processing time and the total number of necessary network distance computations required to complete a query. In addition, the M-Tree filtering method is tunable to allow increasing performance at the expense of accuracy, making it suitable for a wide variety of applications.