A flexible layered control policy for resource allocation in a sensor grid

The paper proposes a flexible layered control policy for sensor resource allocation in a sensor grid. In order to allocate sensor resources in the system to maximize the sensor grid utility, different controllers are deployed at three levels: a job-level controller, an application group controller, and a sensor grid system controller. At the lowest levels, job-level controllers perform fast, frequent, local adaptation for optimizing a single sensor grid application at a time, while, at the highest levels, sensor grid system controllers perform less frequent control actions to optimize all applications. Sensor grid system control considers all sensor grid applications in response to large system changes at coarse time granularity. Sensor grid system control exploits the interlayer coupling of the resource layer and the application layer to achieve a system-wide optimization based on the sensor grid users’ preferences. Job-level control adapts a single application to small changes at fine granularity. The layered control system uses a set of utility functions to evaluate the performance of sensor grid applications and groups. The control system chooses control actions that would result in a higher level of utility. In the simulation, a performance evaluation of the algorithm is carried out.     

Applying rough set theory in the function group analysis for phenolic amide compounds

This research synthesized and assayed 15 phenolic amide compounds for antioxidant activity. The principle approach was based on the antioxidant activity (IC₅₀) values of various R₁-R₅ in the phenolic amide compound backbones for investigating the impact in functional groups. Through the analysis and calculation by rough set mathematics, it was determined that R₅ was responsible for the most significant impact on antioxidant activity. This finding indicated that the functional group at the para-position in the phenethylamine backbone was the most influential, followed by R₂ and R₄, indicating the critical role of the functional group at the meta-position. This result was consistent with the actual circumstance. In the future, functional groups at different positions should be synthesized to increase the number of compounds followed by integrating the mathematics model and computer toolbox to validate the accuracy and rationality.     

Spectral efficiency of cognitive radio networks under interference constraint and QoS guarantees

We study the problem of maximizing spectral efficiency of cognitive radio network deployments subject to an interference constraint and under specific quality of service (QoS) guarantees. The interference constraint corresponds to the upper limit of the received power that can be tolerated at the licensed users’ due to transmissions from unlicensed users. The QoS guarantees stem from the requirements imposed by the applications running at the users’ terminals. A cross-layer design is adopted that maps the user’s requirements into delay related QoS guarantees at the data link layer and error probability QoS guarantees at the physical layer. The obtained numerical results provide important insights regarding the impact of the considered constraint and guarantees on the achievable spectral efficiency of cognitive radio networks.     

An efficient scheduler of RTOS for multi/many-core system

Recently there is a trend to broaden the usage of lower-power embedded media processor core to build the future high-end computing machine or the supercomputer. However the embedded solution also faces the operating system (OS) design challenge which the thread invoking overhead is higher for fine-grained scientific workload, the message passing among threads is not managed efficiently enough and the OS does not provide convenient enough service for parallel programming. This paper presents a scheduler of master-slave real-time operating system (RTOS) to manage the thread running for the distributed multi/many-core system without shared memories. The proposed scheduler exploits the data-driven feature of scientific workloads to reduce the thread invoking overhead. And it also defines two protocols: (1) one is between the RTOS and application program, which is used to reduce the burden of parallel programming for the programmer; (2) another one is between the RTOS and networks-on-chip, which is used to manage the message passing among threads efficiently. The experimental results show that the proposed scheduler can manage the thread running with lower overhead and less storage requirement, thereby, improving the multi/many-core system performance.     

Receiving-peer-driven multi-video-source scheduling algorithms in mobile P2P overlay networks

This paper proposes two algorithms for multi-video-source in a new mobile P2P architecture for streaming media systems. One is serial, and the other is parallel. When the service peer set providing expected QoS is not empty, the former is called, otherwise the latter is called. The former triggers the video source change event, re-selects a video source, and synchronizes the multi-video-source by the time model of the streaming sequence when QoS is degraded. The latter allows the multiple video sources to concurrently send the data to the receiving peer according to the assigned transmission. Compared to the existing papers, the contribution of this paper is fourfold: (1) the serial and parallel scheduling algorithms, correctly switched according to the actual situation, are firstly proposed; (2) the mobile feature of peers are firstly considered and validated; (3) the client nodes have better and smoother video quality; (4) our algorithms have shorter run time, which is a crucial factor for an on-line system.     

Efficient and multi-level privacy-preserving communication protocol for VANET

In this paper, we introduce an efficient and multi-level conditional privacy preservation authentication protocol in vehicular ad hoc networks (VANETs) based on ring signature. The proposed protocol has three appealing characteristics: First, it offers conditional privacy preservation authentication: while every receiver can verify that a message issuer is an authorized participant in the system only a trusted authority can reveal the true identity of a message sender. Second, it is equipped with multi-level countermeasure: each vehicle can select the degree of privacy according to its own requirements. Third, it is efficient: our system outperforms previous proposals in message authentication and verification, cost-effective identity tracking in case of a dispute, and low storage requirements. We demonstrate the merits gained by the proposed protocol through extensive analysis.     

Design of decentralized controllers for MIMO processes

In this paper, the design of decentralized PID controller for interactive and delay time processes is proposed. Direct controller synthesis approach is used to obtain parameters of the multi-loop controllers. A detuning factor for each loop is specified based on the closed-loop time constant. Then appropriate controller settings are determined using the Maclaurin series expansion and the model of the process. The success of the proposed algorithm is based on the detuning parameter thus the selection of the desired closed-loop time constant is an important factor. The proposed method has no limitations regarding systems weak or strong interactions, multiple delays, and its operating behaviors such as monotonic or oscillatory. The proposed algorithm is simpler and improved performance of various processes are achieved as compared to some of the prevalent techniques. Simulation examples demonstrate the usefulness of the proposed method.