Automating data exchange in process choreographies

Communication between organizations is formalized as process choreographies in daily business. While the correct ordering of exchanged messages can be modeled and enacted with current choreography techniques, no approach exists to describe and automate the exchange of data between processes in a choreography using messages. This paper describes an entirely model-driven approach for BPMN introducing a few concepts that suffice to model data retrieval, data transformation, message exchange, and correlation – four aspects of data exchange. For automation, this work utilizes a recent concept to enact data dependencies in internal processes. We present a modeling guideline to derive local process models from a given choreography; their operational semantics allows to correctly enact the entire choreography from the derived models only including the exchange of data. Targeting on successful interactions, we discuss means to ensure correct process choreography modeling. Finally, we implemented our approach by extending the camunda BPM platform with our approach and show its feasibility by realizing all service interaction patterns using only model-based concepts.     

Data entry in foreign exchange dealing

In the money dealing markets a computerized data entry system needs to be very easy to handle and very quick. One group of dealers found that a datapad used with an electronic pen proved efficient in recording transactions and keeping track of the day's trading.     

Optimal total exchange in Cayley graphs

Consider an interconnection network and the following situation: Every node needs to send a different message to every other node. This is the total exchange or all-to-all personalized communication problem, one of a number of information dissemination problems known as collective communications. Under the assumption that a node can send and receive only one message at each step (single-port model), it is seen that the minimum time required to solve the problem is governed by the status (or total distance) of the nodes in the network. We present a time-optimal solution for any Cayley network. Rings, hypercubes, cube-connected cycles, and butterflies are some well-known Cayley networks which can take advantage of our method. The solution is based on a class of algorithms which we call node-invariant algorithms and which behave uniformly across the network     

Reputation mechanisms in an exchange economy

We experimentally evaluate reputation mechanisms in an exchange market in which participants have the option of not fulfilling their contracts. These mechanisms vary in the information they provide on past behavior. Participants can choose who they trade with, allowing endogenous responses to low reputation through ostracizing or price discriminating behaviors. The participants responded strategically to the provided information. In particular, mechanisms revealing more information had a statistically significant increase in fulfillment rates and endogenous self-reporting of transaction outcomes was about the same as accurate exogenous reports. Our experimental design allowed us to identify the effect of reputation mechanism on endogenous market behavior. We found that decreasing fulfillment led to lower efficiency and increased market volume but did not affect the prices. We also find a large diversity of individual behavior within the experiments.     

Nonlinear dynamics in foreign exchange markets

Four types of nonlinear dynamics are empirically analysed here in respect of the current international foreign exchange markets, e.g. autoregressive heteroscedasticity model, Lorenz-type chaos, hysteresis and the positive feedback model. The estimated results provide strong support to the existence of significant nonlinearities in the exchange market dynamics in an international framework. Also, future expectations play an equal or more dominant role over past trends in influencing the current rates of market volatility.     

Bayesian rational exchange

The notion of rational exchange introduced by Syverson (Proceedings of the 11th IEEE Computer Society Foundations Workshop, pp. 2–13, 1998) is a particularly interesting alternative when an efficient scheme for fair exchange is required but the use of a trusted third party is not allowed. A rational exchange protocol cannot provide fairness, but it ensures that rational (i.e., self-interested) parties would have no reason to deviate from the protocol. Buttyán et al. (J. Comput. Security 12(3/4), 551–588, 2004) have recently pointed out how rationality in exchange protocols can be formalized and studied within the framework provided by Game Theory. In particular, Buttyan’s formal model was used to analyze Syverson’s rational exchange protocol. In this paper, we identify a series of drawbacks in Buttyan’s model which make it somewhat restrictive and unrealistic. We propose an extension to the model which enables us to consider different classes of protocol parties (e.g., honest and dishonest parties), as well as modeling attributes such as reputation or any other participant beliefs that could have an effect on the protocol outcome. The resulting new model enables us to reason rational exchange protocols from the point of view of Bayesian rationality, a notion that may be in some scenarios more appropriate than that defined in terms of Nash equilibrium.     

Temporal data exchange

Data exchange is the problem of transforming data that is structured under a source schema into data structured under another schema, called the target schema, so that both the source and target data satisfy the relationship between the schemas. Many applications such as planning, scheduling, medical and fraud detection systems, require data exchange in the context of temporal data. Even though the formal framework of data exchange for relational database systems is well-established, it does not immediately carry over to the settings of temporal data, which necessitates reasoning over unbounded periods of time.In this work, we study data exchange for temporal data. We first motivate the need for two views of temporal data: the concrete view, which depicts how temporal data is compactly represented and on which the implementations are based, and the abstract view, which defines the semantics of temporal data as a sequence of snapshots. We first extend the chase procedure for the abstract view to have a conceptual basis for the data exchange for temporal databases. Considering non-temporal source-to-target tuple generating dependencies and equality generating dependencies, the chase algorithm can be applied on each snapshot independently. Then we define a chase procedure (called c-chase) on concrete instances and show the result of c-chase on a concrete instance is semantically aligned with the result of chase on the corresponding abstract instance. In order to interpret intervals as constants while checking if a dependency or a query is satisfied by a concrete database, we will normalize the instance with respect to the dependency or the query. To obtain the semantic alignment, the nulls (which are introduced by data exchange and model incompleteness) in the concrete view are annotated with temporal information. Furthermore, we show that the result of the concrete chase provides a foundation for query answering. We define naïve evaluation on the result of the c-chase and show it produces certain answers.     

Optimal all-to-all personalized exchange in self-routablemultistage networks

All-to-all personalized exchange is one of the most dense collective communication patterns and occurs in many important applications in parallel computing. Previous all-to-all personalized exchange algorithms were mainly developed for hypercube and mesh/torus networks. Although the algorithms for a hypercube may achieve optimal time complexity, the network suffers from unbounded node degrees and thus has poor scalability in terms of I/O port limitation in a processor. On the other hand, a mesh/torus has a constant node degree and better scalability in this aspect, but the all-to-all personalized exchange algorithms have higher time complexity. In this paper, we propose an alternative approach to efficient all-to-all personalized exchange by considering another important type of networks, multistage networks, for parallel computing systems. We present a new all-to-all personalized exchange algorithm for a class of unique-path, self-routable multistage networks. We first develop a generic method for decomposing all-to-all personalized exchange patterns into some permutations which are realizable in these networks, and then present a new all-to-all personalized exchange algorithm based on this method. The newly proposed algorithm has O(n) time complexity for an n×n network, which is optimal for all-to-all personalized exchange. By taking advantage of fast switch setting of self-routable switches and the property of a single input/output port per processor in a multistage network, we believe that a multistage network could be a better choice for implementing all-to-all personalized exchange due to its shorter communication latency and better scalability     

Coordination in information exchange between organizationaldecision units

The information technology (IT) infrastructure of today's organization is often one of distributed networked computing, with a flexible architecture to incorporate diverse software and hardware components to meet the needs of different user groups. One problem that may be encountered in this environment is the lack of information exchange across user groups or teams because of incompatible data definitions, diversity of formats, and differences in information processing capabilities and IT resource allocation across the organization. Successful information flows involve a user group providing information attribute levels (e.g., levels of precision or detail, timeliness, etc.), data definitions, formats and presentation styles required by the recipient group(s). When information exchange occurs without a fit between the attribute required and that provided, we have the problem of “information coordination.” It is thus critical to design and implement a set of organizational mechanisms which will encourage units within an organization to share relevant information in a coordinated manner. We develop a stylized model of coordination based information exchange between two decision units, and show that structured communication regarding the units' intended information sharing choices can partly mitigate the problem of coordination. When there is uniformity in information management capability and IT resources across the organization, the positive impact of such communication is reinforced, These results imply an emerging role of MIS, where the latter functions as a coordinator of communication and understanding between interdependent derision units, and a facilitator of equity in information processing capability across the units     

Knowledge-intensive genetic discovery in foreign exchange markets

This paper considers the discovery of trading decision models from high-frequency foreign exchange (FX) markets data using genetic programming (GP). It presents a domain-related structuring of the representation and incorporation of semantic restrictions for GP-based searching of trading decision models. A defined symmetry property provides a basis for the semantics of FX trading models. The symmetry properties of basic indicator types useful in formulating trading models are defined, together with semantic restrictions governing their use in trading model specification. The semantics for trading model specification have been defined with respect to regular arithmetic, comparison and logical operators. This study also explores the use of two fitness criteria for optimization, showing more robust performance with a risk-adjusted measure of returns     

模型驱动构架中模型信息交换研究

模型是OMG提出的模型驱动构架中的核心。探讨怎样利用XMI标准为不同模型之间搭起信息交换的桥梁是该文的重点。介绍了模型驱动构架,讨论了模型信息交换的必要性。接着探讨了怎样利用XMI标准描述遵从MOF规范的模型,提出了模型差异的概念,并给出了基于XMI标准的实现。     

All-port total exchange in cartesian product networks

We present a general solution to the total exchange (TE) communication problem for any homogeneous multidimensional network under the all-port assumption. More specifically, we consider cartesian product networks where every dimension is the same graph (e.g. hypercubes, square meshes, n-ary d-cubes) and where each node is able to communicate simultaneously with all its neighbors. We show that if we are given an algorithm for a single n-node dimension which requires T steps, we can construct an algorithm for d-dimensions and running time of n^d−1T steps, which is provably optimal for many popular topologies. Our scheme, in effect, generalizes the TE algorithm given by Bertsekas et al. (J. Parallel Distrib. Comput. 11 (1991) 263–275) for the hypercubes and complements our theory (IEEE Trans. Parallel Distrib. Systems 9(7) (1998) 639) for the single-port model.     

Usable optimistic fair exchange

Fairly exchanging digital content is an everyday problem. It has been shown that fair exchange cannot be achieved without a trusted third party (called the Arbiter). Yet, even with a trusted party, it is still non-trivial to come up with an efficient solution, especially one that can be used in a p2p file sharing system with a high volume of data exchanged.We provide an efficient optimistic fair exchange mechanism for bartering digital files, where receiving a payment in return for a file (buying) is also considered fair. The exchange is optimistic, removing the need for the Arbiter’s involvement unless a dispute occurs. While the previous solutions employ costly cryptographic primitives for every file or block exchanged, our protocol employs them only once per peer, therefore achieving an O(n) efficiency improvement when n blocks are exchanged between two peers. Our protocol uses very efficient cryptography, making it perfectly suitable for a p-2-p file sharing system where tens of peers exchange thousands of blocks and they do not know beforehand which ones they will end up exchanging. Therefore, our system yields up to one-to-two orders of magnitude improvement in terms of both computation and communication (40 s vs. 42 min, 1.6 MB vs. 200 MB). Thus, for the first time, a provably secure (and privacy-respecting when payments are made using e-cash) fair exchange protocol can be used in real bartering applications (e.g., BitTorrent) [14] without sacrificing performance.