Bahnasawy, N. A., F. Omara, M. A. Koutb, and M. Mosa,
"A New Algorithm for Static Task Scheduling for Heterogeneous Distributed Computing Systems",
International Journal of Information and Communication Technology Research, vol. 4, issue 6, pp. 221-234, 2011.
AbstractEffective task scheduling is essential for obtaining high performance in Heterogeneous Distributed Computing Systems (HeDCSs). However, finding an effective task scheduling in HeDCSs should take into consideration the heterogeneity of processors and inter-processor communication over head, which results from non-trivial data movement between tasks scheduled on different processors. In this paper, a new high performance task scheduling algorithm called Sorted Nodes in Leveled DAG Division (SNLDD) is presented for HeDCSs with considering a bounded number of processors. The main concept of the proposed algorithm is to divide the Directed Acyclic Graph DAG into levels and tasks in each level are sorted in descending order according to their computation size. A new attribute has been introduced and used to efficiently select tasks for scheduling in HeDCSs. This selection of tasks enables the proposed SNLDD algorithm to generate high-quality task schedule in a heterogeneous computing environment. To evaluate the performance of the proposed SNLDD algorithm, a comparison study has been done between it and the Longest Dynamic Critical Path (LDCP) algorithm which is considered the most efficient algorithm. According the comparative results, it is found that the performance of the proposed algorithm provides better performance than the LDCP algorithm in terms of speedup, efficiency, complexity, and quality.
Barakat, N. A. M., M. F. Abadir, K. T. Nam, A. M. Hamza, S. S. Al-Deyab, W. -il Baek, and H. Y. Kim,
"Synthesis and film formation of iron–cobalt nanofibers encapsulated in graphite shell: magnetic, electric and optical properties study",
Hak Yong Kim, vol. 21, pp. 10957-10964, 2011.
AbstractNovel characteristics for the FexCoy alloys have been obtained when these compounds were synthesized in the form of nanofibers encapsulated in a graphite shell. The prepared nanofibers reveal good semiconducting features as a thin film from the prepared nanofibers supported on a graphite disk and could be utilized as a diode with good rectifying behaviour. Magnetic properties study showed that the introduced nanofibers are magnetically clean as very low remanent magnetizations were detected; moreover the saturation magnetization is a temperature-independent property. Optical properties study indicated that these nanofibers have band gap energies of 4.73 and 5.43 eV. FexCoy bimetallic alloys could be produced in the form of nanofibers encapsulated in a graphite shell by calcination of electrospun nanofiber mats composed of poly(vinyl alcohol), ferrous acetate and cobalt acetate tetrahydrate in an argon atmosphere at 750 °C. The composition of the nanofibers could be adjusted by controlling the concentration of the original electrospun solution; two formulations have been prepared: FeCo and FeCo2.7. Transmission electron microscopy indicated that the thickness of the graphite shell enveloping the obtained nanofibers is 10 nm. A graphite disk possessing on its surface a well attached thin film from the introduced nanofibers could be successfully prepared when a diskette made of poly(acrylonitrile) was used as a collector during the electrospinning process. The introduced methodology is effective, simple and can be exploited to produce different metallic alloys nanofibers.