SOA$$^\mathrm{}$$: a new way to design the decision in SOA—based on the new standard Decision Model and Notation (DMN)

In recent years, Service Oriented Architecture (SOA) technologies are emerging as a powerful vehicle for organizations that need to integrate their applications within and across organizational boundaries. In addition, organizations need to make better decisions more quickly. Moreover, they need to change those decisions immediately to adapt to this increasingly dynamic business environment. It is primarily a question in ensuring the decisional aspect by adopting the SOA as a support architecture. In this paper, we describe a new approach called SOA\(^\mathrm{+d}\) based on a certain number of standards. It is going to be studied on three dimensions: The first is related to the definition of the information system implied in the SOA based on the use case model. The second develops the business dimension which is based on the BPMN (Business Process Modeling Notation). The last dimension addresses the need of decision; we use the new standard decision model and notation (DMN) which is recently approved by Object Management Group (OMG) and considered as a simple notation to specify the decision. Finally, Service Oriented Architecture Modeling Language (SoaML) will be used for design of several services. We also present our meta-model Decisional Model of Service (DMS) to define a new set of concepts necessary for modeling the three levels. Some of them are already known, whereas others are new and are proposed as an element of this work. we illustrate our proposal with a real case study in the Pharmacy Inventory Management.     

Towards a formal study of automatic failure recovery in protocol-based web service composition

In the protocol-based Web service composition, the runtime unavailability of component services may result in a failed execution of the composite. In literature, multiple recovery heuristics have been proposed. This work provides a formal study and focuses on the complexity issues of the recovery problem in the protocol-based Web service composition. A recovery is a process responsible of migrating the failed execution into an alternative execution of the composite that still has the ability to reach a final state. The alternative execution is called a recovery execution. Following failure occurrence, several recovery executions may be available. The problem of finding the best recovery execution(s) is called the recovery problem. Several criteria may be used to determine the best recovery execution(s). In this work, we define the best recovery execution as the one which is attainable from the failed execution with a maximal number of invisible compensations with respect to the client. We assume that all transitions are compensatable. For a given recovery execution, we prove that the decision problem associated with computing the number of invisibly compensated transitions is NP-complete, and thus, we conclude that deciding of the best recovery execution is in \(\Sigma _2^P\).     

Top-<Emphasis Type="Italic">k</Emphasis> probabilistic prevalent co-location mining in spatially uncertain data sets

A co-location pattern is a set of spatial features whose instances frequently appear in a spatial neighborhood. This paper efficiently mines the top-k probabilistic prevalent co-locations over spatially uncertain data sets and makes the following contributions: 1) the concept of the top-k probabilistic prevalent co-locations based on a possible world model is defined; 2) a framework for discovering the top-k probabilistic prevalent co-locations is set up; 3) a matrix method is proposed to improve the computation of the prevalence probability of a top-k candidate, and two pruning rules of the matrix block are given to accelerate the search for exact solutions; 4) a polynomial matrix is developed to further speed up the top-k candidate refinement process; 5) an approximate algorithm with compensation factor is introduced so that relatively large quantity of data can be processed quickly. The efficiency of our proposed algorithms as well as the accuracy of the approximation algorithms is evaluated with an extensive set of experiments using both synthetic and real uncertain data sets.     

Distinct element method analysis of a retaining wall using a steel frame and fill materials

A technique is developed to clearly establish the shear resistance of a cellular structure, retaining wall composed of a steel frame and fill materials with both continuous and discontinuous characteristics. To overcome the limitation of the existing analysis approach based on continuum mechanics, in which the shear behavior and interaction between the frames and fill material of this type of structure are difficult to describe, this paper introduces displacement incremental analysis into the distinct element method. The results obtained by using the proposed approach are compared with experimental results to verify its accuracy. The results show an internal friction angle of fill materials and overburdening load are major factor determining the shear resistance of a retaining wall with a cellular structure type. From the results of the parametric study on the shear behavior of this type of structure, this paper also proposes a shear resistance moment-shear displacement formula for designing a retaining wall with a cellular structure type.     

Mesh-free canonical tensor products for six-dimensional density matrix: computation of kinetic energy

The computation of a six-dimensional density matrix is the crucial step for the evaluation of kinetic energy in electronic structure calculations. For molecules with heavy nuclei, one has to consider a very refined mesh in order to deal with the nuclear cusps. This leads to high computational time and needs huge memory for the computation of the density matrix. To reduce the computational complexity and avoid discretization errors in the approximation, we use mesh-free canonical tensor products in electronic structure calculations. In this paper, we approximate the six-dimensional density matrix in an efficient way and then compute the kinetic energy. Accuracy is examined by comparing our computed kinetic energy with the exact computation of the kinetic energy.     

Investigation of the potential of asymptotic homogenization for elastic composites via a three-dimensional computational study

Asymptotic homogenization is employed assuming a sharp length scale separation between the periodic structure (fine scale) and the whole composite (coarse scale). A classical approach yields the linear elastic-type coarse scale model, where the effective elastic coefficients are computed solving fine scale periodic cell problems. We generalize the existing results by considering an arbitrary number of subphases and general periodic cell shapes. We focus on the stress jump conditions arising in the cell problems and explicitly compute the corresponding interface loads. The latter represent a key driving force to obtain nontrivial cell problems solutions whenever discontinuities of the coefficients between the host medium (matrix) and the subphases occur. The numerical simulations illustrate the geometrically induced anisotropy and foster the comparison between asymptotic homogenization and well established Eshelby based techniques. We show that the method can be routinely implemented in three dimensions and should be applied to hierarchical hard tissues whenever the precise shape and arrangement of the subphases cannot be ignored. Our numerical results are benchmarked exploiting the semi-analytical solution which holds for cylindrical aligned fibers.     

Safe Autonomous Agent Formation Operations Via Obstacle Collision Avoidance

In this paper, we consider the problem of flocking and shape‐orientation control of multi‐agent systems with inter‐agent and obstacle collision avoidance. We first consider the problem of forcing a set of autonomous agents to form a desired formation shape and orientation while avoiding inter‐agent collision and collision with convex obstacles, and following a trajectory known to only one of the agents, namely the leader of the formation. Then we build upon the solution given to this problem and solve the problem of guaranteeing obstacle collision avoidance by changing the size and the orientation of the formation. Changing the size and the orientation of the formation is helpful when the agents want to go through a narrow passage while the existing size or orientation of the formation does not allow this. We also propose collision avoidance algorithms that temporarily change the shape of the formation to avoid collision with stationary or moving nonconvex obstacles. Simulation results are presented to show the performance of the proposed control laws.