Integrated Optimization Model of Production Planning and Scheduling for Batch Production

An integrated optimization model of production plan and scheduling is introduced. Function objective is to minimize sum of total setup cost (initial setup cost and related setup cost), stock cost, production cost and overtime cost. Restraint functions include equilibrium stock, production capacity, as while as scheduling restraints (procedure restriction and machine capacity restriction). Feasible plan can be set down with considering scheduling restraints

Local martingale difference approach for service selection with dynamic QoS

AbstractUsers in Service-oriented architecture (SOA) seek the best Quality of service (QoS) by service selection from the candidates responding in succession. In case the QoS changes dynamically, choosing one service and stop the searching is problematic for a service user who makes the choice online. Lack of accurate knowledge of service distribution, the user is unable to make a good decision. The Local Martingale Difference (LMD) approach is developed in this paper to help users to achieve optimal results, in the sense of probability. The stopping time is proved to be bounded to ensure the existence of an optimal solution first. Then, a global estimation over the time horizon is transformed to a local determination based on current martingale difference to make the algorithm feasible. Independent of any predetermined threshold or manual intervention, LMD enables users to stop around the optimal time, based on the information collected during the stochastic process. Verified to be efficient by comparison with three traditional methods, LMD is adaptable in vast applications with dynamic QoS

Reconciling Semantic Heterogeneity in Web Services Composition

Service Oriented Computing (SOC) is a popular computing paradigm for the development of distributed Web applications. Service composition, a key element of SOC, is severely hampered by various types of semantic heterogeneity among the services. In this paper, we address the various semantic differences from the context perspective and use a lightweight ontology to describe the concepts and their specializations. Atomic conversions between the contexts are implemented using XPath functions and external services. The correspondences between the syntactic service descriptions and the semantic concepts are established using a flexible, standard-compliant mechanism. Given the naive BPEL composition ignoring semantic differences, our reconciliation approach can automatically determine and reconcile the semantic differences. The mediated BPEL composition incorporates necessary conversions to convert the data exchanged between different services. Our solution has the desirable properties (e.g., adaptability, extensibility and scalability) and can significantly alleviate the reconciliation efforts for Web services composition.This work was partially supported by the MIT Sloan China Management Education Project and grants from the National Natural Science Foundation of China (No. 60674080 and No. 60704027) and the National High-Tech R&D (863) Plan of China (No. 2007AA04Z150)

Reconciling Protocol Mismatches of Web Services by Using Mediators

In the era of Global Services, Service Oriented Architecture (SOA) has been gaining momentum for building Web-based information systems. Service composition is one of the key objectives for adopting SOA. Unfortunately, Web services are not always exactly compatible and it is a non-trivial task to address the mismatches between them. To this end, an approach based on mediator patterns is proposed to develop mediators for reconciling protocol mismatches of partially compatible services and mediating them together. A heuristic technique is developed for identifying protocol mismatches and selecting appropriate patterns. The main steps of the reconciliation approach are presented.The work is partially supported by the MIT Sloan China Management Education Project

Rule-Based Automatic Generation of Mediator Patterns for Service Composition Mismatches

To perform service composition, mismatches are challenging obstacles due to the decentralization and independent development of services. Mediation, as a promising solution, attracts most attentions. And pattern based mediation proposed a modularly constructive thoughtway: Basic mediator patterns were created and sufficient for advanced mediators against all possible mismatches. The pattern structure is illustrated in this paper. And construction rules for each pattern are presented. Executable codes such as BPEL codes can be automatically generated from these rules. As a systematic engineering solution, its feasibility is validated through a case study in the end

Mechanism of Beraprost Effects on Pulmonary Hypertension: Contribution of Cross-Binding to PGE2 Receptor 4 and Modulation of O2 Sensitive Voltage-Gated K+ Channels

Background: The purpose of this study is to elucidate mechanism(s) by which the orally active PGI2 analog, Beraprost (BPS), ameliorates pulmonary hypertension (PH). Prostaglandins are an important treatment for PH. Mechanisms of their action are not fully elucidated in relation to receptor subtype and effects on O2 sensitive Kv channels.Methods: Distal (3rd order and beyond) pulmonary arteries from chronically hypoxic rats and from humans with established PH were studied. Measurements included pulmonary haemodynamics and histology, vascular reactivity, prostanoid receptor expression and activity of the O2 sensitive Kv channels.Results: Prostacyclin receptor (IP), prostaglandin receptor E3 (EP3) and prostaglandin receptor E4 (EP4) are the main pulmonary artery receptor subtypes in both rat and human pulmonary arteries. Circulating levels of PGI2 and PGE2 were reduced in PH. PH was also associated with reduced receptor expression of IP but not of EP4. The effects on IP expression were overcome with BPS. Dilatory responses in PH to BPS were reduced in the presence of EP4 blockade. Expression and activity of oxygen sensitive Kv channels were reduced in pulmonary artery smooth muscle cell from rats with PH and humans with PAH and were also overcome by administration of BPS. Effects of BPS on oxygen sensitive Kv channels were reduced in the presence of EP4 blockade implicating the EP4 receptor, as well as the IP receptor, in mediating BPS effects.Conclusion: Reduced expression of pulmonary IP receptors and reduced activity of O2 sensitive Kv channels are found in PH in both humans and rats. The orally active prostacyclin analogue, BPS, is able to reverse these changes, partly through binding to the EP4 receptor

Workflow Model Performance Analysis Concerning Instance Dwelling Times Distribution

Abstract Instances dwelling times (IDT) which consist of waiting times and handle times in a workflow model is a key performance analysis goal. In a workflow model the instances which act as customers and the resources which act as servers form a queuing network. Multidimensional workflow net (MWF-net) includes multiple timing workflow nets (TWF-nets) and the organization and resource information. This paper uses queuing theory and MWF-net to discuss mean value and probability distribution density function (PDDF) of IDT. An example is used t