This work proposes an effective method of fighting spam by developing Inexpensive Email Addresses (IEA), a stateless system of Disposable Email Addresses (DEAs). IEA can cryptographically generate exclusive email addresses for each sender, with the ability to re-establish a new email address once the old one is compromised. IEA accomplishes proof-of-work by integrating a challenge-response mech...

The traditional approach in analysing IEA data has been to use single-level statistical models. This paper argues that multilevel modelling offers a wider spectrum in analysing IEA data because of multi-stage sampling, since students are nested within classes, classes within schools, and schools within countries. Two illustrative examples are used to provide support to this argument. In the fir...

Suggestions on international cooperation in climate policy beyond 2012 include substituting or complementing international environmental agreements (IEA) with technology oriented agreements (TOA). We look at the impact of TOA on environmental cooperation in the framework of coalition stability. Using a numerical model, we analyze the differences of several TOA and how they interact. We find tha...

In real-world scenarios, massive demands mi ght be simultaneously raised by massive customers. Mass customization (MC) of services is a cost-effective approach to deal with this scenario by offering a cus tomizabl e composite service that satisfies as many personalized requirements as possible. In this paper, Service Network (SN) is employed to repres ent a customizable composite service, so th...

Helium implantation at room temperature was performed to investigate irradiation hardening of ferritic/martensitic steels. Bulk hardness was extracted from Nix-Gao model using a Berkovich nano-indentor. The correlation between irradiation hardening and helium concentration ranging 500 2000 appm was examined. Nano-hardness increases as a function of helium concentration. The hardening of Fe is s...