Verifying security protocols by knowledge analysis

This paper describes a new interactive method to analyse knowledge of participants involved in security protocols and further to verify the correctness of the protocols. The method can detect attacks and flaws involving interleaving sessions besides normal attacks. The implementation of the method in a generic theorem proving environment, namely Isabelle, makes the verification of protocols mechanical and efficient; it can verify a medium-sized security protocol in less than ten seconds. As an example, the paper finds the flaw in the Needham-Schroeder public key authentication protocol and proves the secure properties and guarantees of the protocol with Lowe's fix to show the effectiveness of this method

The Impact of Bank and Non-Bank Financial Institutions on Local Economic Growth in China

This paper provides evidence on the relationship between finance and growth in a fast growing country, such as China.Employing data of 27 Chinese provinces over the period 1995-2003, we study whether the financial development of two different types of institutions - banks and non-bank financial institutions - have a (significantly different) impact on local economic growth.Our findings indicate that only banking development shows a statistically significant and economically relevant impact on local economic growth.growth;financial development;Chinese provinces;banks

Ballistic electron emission microscopy spectroscopy study of AlSb and InAs/AlSb superlattice barriers

Due to its large band gap, AlSb is often used as a barrier in antimonide heterostructure devices. However, its transport characteristics are not totally clear. We have employed ballistic electron emission microscopy (BEEM) to directly probe AlSb barriers as well as more complicated structures such as selectively doped n-type InAs/AlSb superlattices. The aforementioned structures were grown by molecular beam epitaxy on GaSb substrates. A 100 Å InAs or 50 Å GaSb capping layer was used to prevent surface oxidation from ex situ processing. Different substrate and capping layer combinations were explored to suppress background current and maximize transport of BEEM current. The samples were finished with a sputter deposited 100 Å metal layer so that the final BEEM structure was of the form of a metal/capping layer/semiconductor. Of note is that we have found that hole current contributed significantly to BEEM noise due to type II band alignment in the antimonide system. BEEM data revealed that the electron barrier height of Al/AlSb centered around 1.17 eV, which was attributed to transport through the conduction band minimum near the AlSb X point. Variation in the BEEM threshold indicated unevenness at the Al/AlSb interface. The metal on semiconductor barrier height was too low for the superlattice to allow consistent probing by BEEM spectroscopy. However, the superlattice BEEM signal was elevated above the background noise after repeated stressing of the metal surface. A BEEM threshold of 0.8 eV was observed for the Au/24 Å period superlattice system after the stress treatment

Design of a smart turning tool with application to in-process cutting force measurement in ultraprecision and micro cutting

In modern micromachining, there is a need to measure and monitor certain machining process parameters in process so as to detect tool wear in real time, to optimize the process parameters setup, and to render the machining process some level of smartness and intelligence. This paper presents the innovative design of a smart turning tool using two pieces of piezoelectric films to measure cutting and feed force in real time. The tool was tested on its performance through the calibration and cutting trials against the commercial dynamometer. The results show the smart turning tool has achieved the performance as designed

Modelling and simulation on the tool wear in nanometric cutting

Tool wear is a significant factor affecting the machined surface quality. In this paper, a Molecular Dynamics (MD) simulation approach is proposed to model the wear of the diamond tool in nanometric cutting. It includes the effects of the cutting heat on the workpiece property. MD simulation is carried out to simulate the nanometric cutting of a single crystal silicon plate with the diamond tip of an Atomic Force Microscope (AFM). The wear mechanism is investigated by the calculation of the temperature, the stress in the diamond tip, and the analysis of the relationship between the temperature and sublimation energy of the diamond atoms and silicon atoms. Microstrength is used to characterize the wear resistance of the diamond tool. The machining trials on an AFM are performed to validate the results of the MD simulation. The results of MD simulation and AFM experiments all show that the thermo-chemical wear is the basic wear mechanism of the diamond cutting tool

Design of generic modular reconfigurable platforms (GMRPS) for a product-oriented micro manufacturing system

With the proposition of the concept of product-service systems, many manufacturers are focusing on selling services or functionality rather than products. Industrial production is shifting production models from mass production to mass customization and highly personalized needs. As a result, there is a tendency for manufacturing system suppliers to develop product-oriented systems to responsively cope with the dynamic fast moving competitive market. The key features of such a manufacturing system are the reconfigurability and adaptability, which can enable the system respond to the changeable needs of customers quickly and adaptively. Therefore, one of the challenges for the micro manufacturing system provider has been the design of a reconfigurable machine platform which will provide the functionalities and flexibility required by the product-oriented systems. In this paper, a new micro manufacturing platform, i.e. a generic modular reconfigurable platform (GMRP) is proposed in order to provide an effective means for fabrication of high quality micro products at low cost in a responsive manner. The GMRP-based system aims to be a product-oriented reconfigurable, highly responsive manufacturing system particularly for high value nano/micro manufacturing purposes. To reuse components and decrease material consumption, GMRP is characterized by hybrid micro manufacturing processes, modularity of key components, and reconfigurability of machine platforms and key components. Furthermore, a practical methodology for the design of reconfigurable machine platforms is discussed against the requirements from product-driven micro manufacturing and its extension for adaptive production

From training to education. Lifelong learning in China

Lifelong learning was nothing unusual in the Chinese tradition. There was no age limit for education in ancient China, although education in those days was mainly for examinations, which were the testing ground for officials. A system of adult education was established in the 1950s, but that was to complement the formal education system as an instrument to implement state manpower planning. Lifelong education as a modern notion was introduced to China only at the end of the 1970s immediately after the Cultural Revolution. The notion did not gain much ground when education was closely associated with state manpower plans, and individuals did not have much room for personal development. The break away from strict manpower planning in the early 1980s has given rise to individual aspirations for education. Such aspirations have integrated with the long tradition of self-motivation in learning and have given rise to spectacular expansion in all kinds of adult education. While the motives for such learning are still very much related to jobs and incomes, alternative objectives for learning are fast developing outside the formal sectors of education. This article analyses the recent development of lifelong education in China, and uses Shanghai, the most developed city, as an illustration.postprin