Papers by Keyword: Concurrent

Abstract: In this paper, a two-stage optimization algorithm is proposed to simultaneously achieve the optimum structure and microstructure of lightweight cellular materials. Microstructure is assumed being uniform in macro-scale to meet manufacturing requirements. Furthermore, to reduce the computation cost, the design process is divided into two stages, which are concurrent design and material design. In the first stage, macro density and modulus matrix of cellular material are used both as design variables. Then, the optimum topology of macro-structure and modulus matrix of cellular materials will be obtained under this configuration. In the second stage, topology optimization technology is used to achieve a micro-structure of cellular material which is corresponded with the optimum modulus matrix in the earlier concurrent design stage. Moreover, the effectiveness of the present design methodology and optimization scheme is then demonstrated through numerical example.

Abstract: . The Temporal logic of actions TLA is a logic for specifying and reasoning about concurrent systems, which make systems and their properties are expressed in the same logic. In this paper, we introduce the concurrent programming languages and behavior semantics, mainly describe safety properties and liveness properties in TLA and take NeedhamSchroeder symmetric key protocol as an example to illustrate how to specify these properties in concurrent program by TLA.

Abstract: Cloud storage, which is composed of a large number storage devices and servers, provides large-scale flexible storage services through Internet. BCSS (Bupt-Cloud-Storage System) based on some cheap irresponsible PCs is designed as a mass storage platform to offer high reliable and available storage services. Meanwhile, it improves performance of data access by providing support of multi-user concurrent control. The experimental results verify efficiency of storage services and the performance of BCSS.

Abstract: Integration of the wireless LANs (WLAN) and 3G networks, such as Universal Mobile Telecommunication Service (UMTS), has been intensively studied recently due to their complementary characteristics. In this paper, we design and implement a flexible protocol stack architecture which can support concurrent transmission via multiple radio interfaces. Furthermore, the multiple services with various QoS requirements are differentiated and transported in the best wireless access network which is determined by the proposed network selection criterion-- Multi-Criteria Decision Making (MCDM), in the heterogeneous wireless network. Simulation results demonstrate that the proposed concurrent transmission scheme improves the network utility and provide the QoS services among the multiple wireless access networks more efficiently.

Abstract: In the concurrent and collaborative product development process, the realization of quantitative analysis and overall control of the development process management is the key and the difficulties in the current study. Through describes the concept and role of data maturity, a new methods to quantitative analysis and overall control of collaborative product development process based on the idea of data maturity was proposed in this paper. Base on the explanation of the theory of data maturity to control the process, the differences and relationship between data maturity and milestone was analyzed. The division method of data maturity level was discussed, and the corresponding relationship between each data maturity level and completion degree of the digital product model was illustrated also. In addition, the overall form of the product collaborative development process based on data maturity was provided. Finally, the detailed process between product structure design, process design and tooling design driven by each data maturity were explored, which realized the quantitative analysis and overall control of the product development process.

Abstract: A kinetic Monte Carlo (KMC) model for surface diffusion on a 2D lattice is proposed. An equivalent continuum cellular automaton (CA) model is derived from this. These models are shown to produce similar results at high temperatures. A hybrid KMC-CA model is derived which consistently allows material to transfer between a deterministic CA model and a stochastic KMC model concurrently embedded within it. The quality of the model is demonstrated by simulating the flattening of a sinusoidal surface profile and the evolution of an elliptical body into a circular one.