Jayant R. Kalagnanam

QoS-aware middleware for Web services composition

The paradigmatic shift from a Web of manual interactions to a Web of programmatic interactions driven by Web services is creating unprecedented opportunities for the formation of online business-to-business (B2B) collaborations. In particular, the creation of value-added services by composition of existing ones is gaining a significant momentum. Since many available Web services provide overlapping or identical functionality, albeit with different quality of service (QoS), a choice needs to be made to determine which services are to participate in a given composite service. This paper presents a middleware platform which addresses the issue of selecting Web services for the purpose of their composition in a way that maximizes user satisfaction expressed as utility functions over QoS attributes, while satisfying the constraints set by the user and by the structure of the composite service. Two selection approaches are described and compared: one based on local (task-level) selection of services and the other based on global allocation of tasks to services using integer programming.

Quality driven web services composition

The process-driven composition of Web services is emerging as a promising approach to integrate business applications within and across organizational boundaries. In this approach, individual Web services are federated into composite Web services whose business logic is expressed as a process model. The tasks of this process model are essentially invocations to functionalities offered by the underlying component services. Usually, several component services are able to execute a given task, although with different levels of pricing and quality. In this paper, we advocate that the selection of component services should be carried out during the execution of a composite service, rather than at design-time. In addition, this selection should consider multiple criteria (e.g., price, duration, reliability), and it should take into account global constraints and preferences set by the user (e.g., budget constraints). Accordingly, the paper proposes a global planning approach to optimally select component services during the execution of a composite service. Service selection is formulated as an optimization problem which can be solved using efficient linear programming methods. Experimental results show that this global planning approach outperforms approaches in which the component services are selected individually for each task in a composite service.

Foundations for smarter cities

This paper describes the information technology (IT) foundation and principles for Smarter Cities™. Smarter Cities are urban areas that exploit operational data, such as that arising from traffic congestion, power consumption statistics, and public safety events, to optimize the operation of city services. The foundational concepts are instrumented, interconnected, and intelligent. Instrumented refers to sources of near-real-time real-world data from both physical and virtual sensors. Interconnected means the integration of those data into an enterprise computing platform and the communication of such information among the various city services. Intelligent refers to the inclusion of complex analytics, modeling, optimization, and visualization in the operational business processes to make better operational decisions. This approach enables the adaptation of city services to the behavior of the inhabitants, which permits the optimal use of the available physical infrastructure and resources, for example, in sensing and controlling consumption of energy and water, managing waste processing and transportation systems, and applying optimization to achieve new efficiencies among these resources. Additional roles exist in intelligent interaction between the city and its inhabitants and further contribute to operational efficiency while maintaining or enhancing quality of life.

An efficient sampling technique for off-line quality control

The basic setting of this article is that of parameter-design studies using data from computer models. A general approach to parameter design is introduced by coupling an optimizer directly with the computer simulation model using stochastic descriptions of the noise factors. The computational burden of these approaches can be extreme, however, and depends on the sample size used for characterizing the parametric uncertainties. In this article, we present a new sampling technique that generates and inverts the Hammersley points (a low-discrepancy design for placing n points uniformly in a k-dimensional cube) to provide a representative sample for multivariate probability distributions. We compare the performance of this to a sample obtained from a Latin hypercube design by propagating it through a set of nonlinear functions. The number of samples required to converge to the mean and variance is used as a measure of performance. The sampling technique based on the Hammersley points requires far fewer sampl...

Configurable offers and winner determination in multi-attribute auctions

Abstract The theory of procurement auctions traditionally assumes that the offered quantity and quality is fixed prior to source selection. Multi-attribute reverse auctions allow negotiation over price and qualitative attributes such as color, weight, or delivery time. They promise higher market efficiency through a more effective information exchange of buyer’s preferences and supplier’s offerings. This paper focuses on a number of winner determination problems in multi-attribute auctions. Previous work assumes that multi-attribute bids are described as attribute value pairs and that the entire demand is purchased from a single supplier. Our contribution is twofold: First, we will analyze the winner determination problem in case of multiple sourcing. Second, we will extend the concept of multi-attribute auctions to allow for configurable offers. Configurable offers enable suppliers to specify multiple values and price markups for each attribute. In addition, suppliers can define configuration and discount rules in form of propositional logic statements. These extensions provide suppliers with more flexibility in the specification of their bids and allow for an efficient information exchange among market participants. We will present MIP formulations for the resulting allocation problems and an implementation.

Models for Iterative Multiattribute Procurement Auctions

Multiattribute auctions extend traditional auction settings to allow negotiation over nonprice attributes such as weight, color, and terms of delivery, in addition to price and promise to improve market efficiency in markets with configurable goods. This paper provides an iterative auction design for an important special case of the multiattribute allocation problem with special (preferential independent) additive structure on the buyer value and seller costs. Auction Additive&Discrete provides a refined design for a price-based auction in which the price feedback decomposes to an additive part with a price for each attribute and an aggregate part that appears as a price discount for each supplier. In addition, this design also has excellent information revelation properties that are validated through computational experiments. The auction terminates with an outcome of a modified Vickrey-Clarke-Groves mechanism. This paper also develops Auction NonLinear&Discrete for the more general nonlinear case-a particularly simple design that solves the general multiattribute allocation problem, but requires that the auctioneer maintains prices on bundles of attribute levels.

Combinatorial and quantity-discount procurement auctions benefit Mars, incorporated and its suppliers

Simple auctions neglect the complex business constraints required by strategic sourcing. The Mars-IBM team created a procurement auction Web site that enables buyers to incorporate complex bid structures (such as bundled all-or-nothing bids and quantity-discounted bids) and business constraints into strategic-sourcing auctions. Outcomes in such auctions must lead to win-win solutions to sustain long-term relationships between procurer and suppliers. These factors are as important or more important than price. The Mars procurement auction Web site supports several alternatives to simple auctions that help match its needs as procurer and the capabilities of suppliers by incorporating optimal bid selection subject to constraints based on business rules in a dynamic environment. The ability to consider geographic, volume, and quality factors helps both parties. Feedback from participant suppliers has highlighted the benefits of time efficiency, transparency, and fairness. Although they reflect just one side of the benefits ledger, the monetary benefits to Mars (a

Auctions, Bidding and Exchange Design

14 billion company) and to its suppliers are significant.

Applications of flexible pricing in business-to-business electronic commerce

Auctions have found widespread use in the last few years as a technique for supporting and automating negotiations on the Internet. For example, eBay now serves as a new selling channel for individuals, and small and big enterprises. Another use for auctions is for industrial procurement. In both these settings traditional auction mechanisms such as the English, Dutch, First (or Second) price Sealed-Bid auctions are now commonplace. These auctions types are useful for settings where there is a single unit of an item being bought/sold. However, since procurement problems are business-to-business they tend to be more complex and have led to the development and application of advanced auction types that allow for negotiations over multiple units of multiple items, and the configuration of the attributes of items. At the heart of auctions is the problem of decentralized resource allocation.

Approximation algorithms for the multiple knapsack problem with assignment restrictions

The increasingly dynamic nature of business-to-business electronic commerce has produced a recent shift away from fixed pricing and toward flexible pricing. Flexible pricing, as defined here, includes both differential pricing, in which different buyers may receive different prices based on expected valuations, and dynamic-pricing mechanisms, such as auctions, where prices and conditions are based on bids by market participants. In this paper we survey ongoing work in flexible pricing in the context of the supply chain, including revenue management, procurement, and supply-chain coordination. We review negotiation mechanisms for procurement, including optimization approaches to the evaluation of complex, multidimensional bids. We also discuss several applications of flexible pricing on the sell side, including pricing strategies for response to requests for quotes, dynamic pricing in a reverse logistics application, and pricing in the emerging area of hosted applications services. We conclude with a discussion of future research directions in this rapidly growing area.