Abstract: The scenario of bypass transition is generally described
as follows: the low-frequency disturbances in the free-stream may
generate long stream-wise streaks in the boundary layer, which later
may trigger secondary instability, leading to rapid increase of
high-frequency disturbances. Then possibly turbulent spots emerge,
and through their merging, lead to fully developed turbulence. This
description, however, is insufficient in the sense that it does not
provide the inherent mechanism of transition that during the transition,
a large number of waves with different frequencies and wave numbers
appear almost simultaneously, producing sufficiently large Reynolds
stress, so the mean flow profile can change rapidly from laminar to
turbulent. In this paper, such a mechanism will be figured out from
analyzing DNS data of transition.
Abstract: This paper proposes a low-cost reconfigurable
architecture for AES algorithm. The proposed architecture separates
SubBytes and MixColumns into two parallel data path, and supports
different bit-width operation for this two data path. As a result, different number of S-box can be supported in this architecture. The
throughput and power consumption can be adjusted by changing the
number of S-box running in this design. Using the TSMC 0.18μm CMOS standard cell library, a very low-cost implementation of 7K
Gates is obtained under 182MHz frequency. The maximum throughput is 360Mbps while using 4 S-Box simultaneously, and the
minimum throughput is 114Mbps while only using 1 S-Box
Abstract: As business environments are rapidly changing,
the manufacturing system must be reconfigured to adapt to
various customer needs. In order to cope with this challenge, it
is quintessential to test industrial control logic rapidly and
easily in the design time, and monitor operational behavior in
the run time of automated manufacturing system. Proposed
integrated model for virtual prototyping and operational
monitoring of industrial control logic is to improve limitations
of current ladder programming practices and general discrete
event simulation method. Each plant layout model using HMI
package and object-oriented control logic model is designed
independently and is executed simultaneously in integrated
manner to reflect design practices of automation system in the
design time. Control logic is designed and executed using UML
activity diagram without considering complicated control
behavior to deal with current trend of reconfigurable
manufacturing. After the physical installation, layout model of
virtual prototype constructed in the design time is reused for
operational monitoring of system behavior during run time.
Abstract: A novel path planning approach is presented to solve
optimal path in stochastic, time-varying networks under priori traffic
information. Most existing studies make use of dynamic programming
to find optimal path. However, those methods are proved to
be unable to obtain global optimal value, moreover, how to design
efficient algorithms is also another challenge.
This paper employs a decision theoretic framework for defining
optimal path: for a given source S and destination D in urban transit
network, we seek an S - D path of lowest expected travel time
where its link travel times are discrete random variables. To solve
deficiency caused by the methods of dynamic programming, such as
curse of dimensionality and violation of optimal principle, an integer
programming model is built to realize assignment of discrete travel
time variables to arcs. Simultaneously, pruning techniques are also
applied to reduce computation complexity in the algorithm. The final
experiments show the feasibility of the novel approach.
Abstract: Some meta-schedulers query the information system of individual supercomputers in order to submit jobs to the least busy supercomputer on a computational Grid. However, this information can become outdated by the time a job starts due to changes in scheduling priorities. The MSR scheme is based on Multiple Simultaneous Requests and can take advantage of opportunities resulting from these priorities changes. This paper presents the SWARM meta-scheduler, which can speed up the execution of large sets of tasks by minimizing the job queuing time through the submission of multiple requests. Performance tests have shown that this new meta-scheduler is faster than an implementation of the MSR scheme and the gLite meta-scheduler. SWARM has been used through the GridQTL project beta-testing portal during the past year. Statistics are provided for this usage and demonstrate its capacity to achieve reliably a substantial reduction of the execution time in production conditions.
Abstract: Although lots of experiments have been done in enhanced oil recovery, the number of experiments which consider the effects of local and global heterogeneity on efficiency of enhanced oil recovery based on the polymer-surfactant flooding is low and rarely done. In this research, we have done numerous experiments of water flooding and polymer-surfactant flooding on a five spot glass micromodel in different conditions such as different positions of layers. In these experiments, five different micromodels with three different pore structures are designed. Three models with different layer orientation, one homogenous model and one heterogeneous model are designed. In order to import the effect of heterogeneity of porous media, three types of pore structures are distributed accidentally and with equal ratio throughout heterogeneous micromodel network according to random normal distribution. The results show that maximum EOR recovery factor will happen in a situation where the layers are orthogonal to the path of mainstream and the minimum EOR recovery factor will happen in a situation where the model is heterogeneous. This experiments show that in polymer-surfactant flooding, with increase of angles of layers the EOR recovery factor will increase and this recovery factor is strongly affected by local heterogeneity around the injection zone.