This paper studies the asymptotic properties of moment estimators for the general shifting level process (SLP). A law of large numbers and a weak convergence theorem are obtained under conditions involving the unobservable processes which make up SLP. Specific conditions about those underlying processes are acided to give explicit results, applicable to a large class of moment estimators. Actua...

This paper studies outsourcing decisions for a two-level service process in which the first level serves as a gatekeeper for a second level of experts. The objective of the system operator (the client) is to minimize the sum of staffing costs, customer waiting costs, and mistreatment costs due to unsuccessful attempts by a gatekeeper to solve the customer’s problem. The client may outsource all...

Working at system level is attracting increasing interest, as it supports the exploration of several alternatives, before the hardware/software partitioning takes place. New issues must be taken into account, such as validation and verification at all steps. Within the framework of a system-level design methodology that supports verification, communication protocols among processes play a key r...

Current workflow languages for web services suffer from poor support for separation of concerns. Aspect-oriented software development is a well-known approach to improve this. In this paper, we present an aspect-oriented extension for the WS-BPEL language that improves on current state-of-the-art by introducing an explicit deployment construct, a richer joinpoint model, and a higher-level point...

The process oversubscription, which binds multiple parallel processes to one CPU core, can hide the communication latency and reduce CPU idle time. However, the lightweight OS kernels for Exascale systems may no longer support OS task scheduling. Without OS task scheduling, only one parallel process per CPU core is allowed, and then the process oversubscription is impossible. Even if the OS tas...

Control of process parameters are important in the chemical process industries. Proportional, integral and derivative controller is the most commonly used to form a closed loop system for the effective control of process parameter. In this paper, a liquid level in the cylindrical tank is to be controlled at setpoint value. At first, The model for such a real time process is identified and valid...

The ability to be changeable is inherent to software — in fact, this is what defines it as being “soft”. The long-term management of large software systems depends on the ability of a system to be “easy” to maintain and evolve. In contrast to commonly presented views, we define three ways to look at evolvability. First, it can be considered to be a quality property, and must therefore be subjec...