Code OK1—Simulation of multi-beam irradiation on a spherical target in heavy ion fusion

Code OK1 is a fast and precise three-dimensional computer program designed for simulations of heavy ion beam (HIB) irradiation on a direct-driven spherical fuel pellet in heavy ion fusion (HIF). OK1 provides computational capabilities of a three-dimensional energy deposition profile on a spherical fuel pellet and the HIB irradiation non-uniformity evaluation, which are valuables for optimizations of the beam parameters and the fuel pellet structure, as well for further HIF experiment design. The code is open and complete, and can be easily modified or adapted for users' purposes in this field.

Program summary

Title of program: OK1Catalogue identifier: ADSTProgram summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSTProgram obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandComputer: PC (Pentium 4, ∼1 GHz or more recommended)Operating system: Windows or UNIXProgram language used: C++Memory required to execute with typical data: 911 MBNo. of bits in a word: 32No. of processors used: 1 CPUHas the code been vectorized or parallelized: NoNo. of bytes in distributed program, including test data: 16 557Distribution format: tar gzip fileKeywords: Heavy ion beam, inertial confinement fusion, energy deposition, fuel pelletNature of physical problem: Nuclear fusion energy may have attractive features as one of our human energy resources. In this paper we focus on heavy ion inertial confinement fusion (HIF). Due to a favorable energy deposition behavior of heavy ions in matter [J.J. Barnard et al., UCRL-LR-108095, 1991; C. Deutsch et al., J. Plasma Fusion Res. 77 (2001) 33; T. Someya et al., Fusion Sci. Tech. (2003), submitted] it is expected that heavy ion beam (HIB) would be one of energy driver candidates to operate a future inertial confinement fusion power plant. For a successful fuel ignition and fusion energy release, a stringent requirement is imposed on the HIB irradiation non-uniformity, which should be less than a few percent [T. Someya et al., Fusion Sci. Tech. (2003), submitted; M.H. Emery et al., Phys. Rev. Lett. 48 (1982) 253; S. Kawata et al., J. Phys. Soc. Jpn. 53 (1984) 3416]. In order to meet this requirement we need to evaluate the non-uniformity of a realistic HIB irradiation and energy deposition pattern. The HIB irradiation and non-uniformity evaluations are sophisticated and difficult to calculate analytically. Based on our code one can numerically obtain a three-dimensional profile of energy deposition and evaluate the HIB irradiation non-uniformity onto a spherical target for a specific HIB parameter value set in HIF.Method of solution: OK1 code is based on the stopping power of ions in matter [J.J. Barnard et al., UCRL-LR-108095, 1991; C. Deutsch et al., J. Plasma Fusion Res. 77 (2001) 33; T. Someya et al., Fusion Sci. Tech. (2003), submitted; M.H. Emery et al., Phys. Rev. Lett. 48 (1982) 253; S. Kawata et al., J. Phys. Soc. Jpn. 53 (1984) 3416; T. Mehlhorn, SAND80-0038, 1980; H.H. Andersen, J.F. Ziegler, Pergamon Press, 1977, p. 3]. The code simulates a multi-beam irradiation, obtains the 3D energy deposition profile of the fuel pellet and evaluates the deposition non-uniformity.Restrictions on the complexity of the problem: NoTypical running time: The execution time depends on the number of beams in the simulated irradiation and its characteristics (beam radius on the pellet surface, beam subdivision, projectile particle energy and so on). In almost of the practical running tests performed, the typical running time for one beam deposition is less than 2 s on a PC with a CPU of Pentium 4, 2.2 GHz (e.g., in Test 2 when the number of beams is 600, the running time is about 18 minutes).Unusual features of the program: No     

Multi-granularity and robust grooming in power- and port-cost-efficient IP over WDM networks

Previous studies on the power efficiency or port savings in IP over WDM networks have required explicit knowledge of the traffic between each network node pair and the resource assignment of each fiber link. However, it is difficult to estimate this information accurately in live networks, due to the inherent features of IP traffic, e.g., bursts, unpredictability, and variability. Furthermore, the granularity of the demands on an IP-level connection tends to be diverse, and the number of ports consumed in Optical Cross-Connects (OXCs) tends to grow due to the use of hybrid grooming (i.e., traffic grooming with an optical bypass) for power savings. Therefore, it is critical to achieve both power efficiency and port savings in realistic IP over WDM networks. In this paper, we investigate the problem of multi-granularity and robust grooming for power- and port-cost-efficient IP over WDM networks. First, a key parameter, the Multi-Granularity Power Ratio (MGPR), which is the sum of the different single-granularity power ratios, is proposed. Second, the MMPR (Minimizing Multi-granularity Power Ratio) method is used to compute the Traffic Distribution Vectors. Finally, we present the multi-granularity and robust grooming approach, called the Maximizing Hop First (MXHF) approach, where hybrid grooming is adopted to improve power efficiency and waveband merging is utilized to reduce the port cost. Simulation results demonstrate that the MXHF approach can achieve power efficiency and port savings comparing with state-of-the-art robust grooming methods.     

How to improve snap-stabilizing point-to-point communication space complexity?

A snap-stabilizing protocol, starting from any configuration, always behaves according to its specification. In this paper, we are interested in the message forwarding problem in a message-switched network in which the system resources must be managed in order to deliver messages to any processor of the network. To this end, we use the information provided by a routing algorithm. In the context of an arbitrary initialization (due to stabilization), this information may be corrupted. In Cournier et al. (2009) [1], we show that there exist snap-stabilizing algorithms for this problem (in the state model). This implies that we can request the system to begin forwarding messages without losses even if routing information is initially corrupted.In this paper, we propose another snap-stabilizing algorithm for this problem which improves the space complexity of the one in Cournier et al. (2009) [1].     

Examining the effectiveness of technology use in classrooms: A tertiary meta-analysis

Identifying effective literacy instruction programs has been a focal point for governments, educators and parents over the last few decades (Ontario Ministry of Education, 2004, 2006; Council of Ontario Directors of Education, 2011). Given the increasing use of computer technologies in the classroom and in the home, a variety of information communication technology (ICT) interventions for learning have been introduced. Meta-analyses comparing the impact of these programs on learning, however, have yielded inconsistent findings (Andrews et al., 2007, Torgerson and Zhu, 2003, Slavin et al., 2008, Slavin et al., 2009). The present tertiary meta-analytic review re-assesses outcomes presented in three previous meta-analyses. Four moderator variables assessed the impact of the systematic review from which they were retrieved, training and support, implementation fidelity and who delivered the intervention (teacher versus researcher). Significant results were found when training and support was entered as a moderator variable with the small overall effectiveness of the ICTs (ES = 0.18), similar to those found in previous research, increasing significantly (ES = 0.57). These findings indicate the importance of including implementation factors such as training and support, when considering the relative effectiveness of ICT interventions.     

Online assessment of strategic reading literacy skills

This study investigates the possibility of assessing strategic reading literacy skills with computers. The critical value of this assessment is the recording of online indices of the reader's behavior that can be interpreted in terms of strategies. The study uses materials of a standardized paper-and-pencil reading literacy test called CompLEC (Llorens et al., 2011) and a technology called Read&Answer (Vidal-Abarca et al., 2011) that presents texts and questions with a masking procedure that allows the recording of reading time and readers' actions to develop a computer-based version called e-CompLEC. We found that reliability and validity of the two versions are largely equivalent, and that e-CompLEC provides self-regulation and reading behavior indices predictive of performance. The study also shows how self-regulation is an important component of reading literacy processes.     

On the small cycle transversal of planar graphs

We consider the problem of finding a k-edge transversal set that intersects all (simple) cycles of length at most s in a planar graph, where s≥3 is a constant. This problem, referred to as Small Cycle Transversal, is known to be NP-complete. We present a polynomial-time algorithm that computes a kernel of size 36s³k for Small Cycle Transversal. In order to achieve this kernel, we extend the region decomposition technique of Alber et al. (2004) [1] by considering a unique region decomposition that is defined by shortest paths. Our kernel size is a significant improvement in terms of s over the kernel size obtained under the meta-kernelization framework by Bodlaender et al. (2009) [7].     

Some optimization problems on weak-bisplit graphs

A new decomposition scheme for bipartite graphs namely canonical decomposition was introduced by Fouquet et al. [Internat. J. Found. Comput. Sci. 10 (1999) 513-533]. The so-called weak-bisplit graphs are totally decomposable following this decomposition. We present here some optimization problems for general bipartite graphs which have efficient solutions when dealing with weak-bisplit graphs.     

Multiobjective mixed symmetric duality involving cones

A pair of multiobjective mixed symmetric dual programs is formulated over arbitrary cones. Weak, strong, converse and self-duality theorems are proved for these programs under K-preinvexity and K-pseudoinvexity assumptions. This mixed symmetric dual formulation unifies the symmetric dual formulations of Suneja et al. (2002) [14] and Khurana (2005) [15].