AGRICULTURE AND RURAL DEVELOPMENT: LESSONS FOR CHRISTIAN GROUPS COMBATING PERSISTENT POVERTY

Persistent poverty is one of the core challenges faced by Christians and by development scholars and practitioners alike. There is no question that Jesus was concerned about the poor - both materially and spiritually. From his first public address in the Synagogue in Nazareth, His home town, where He concluded by saying that He had come to "preach good news to the poor" (Luke 4:18), Jesus lived the gospel in word and deed. We, as Christian men and women, whether researchers or practitioners, are called to do no less. When Jesus made His parting remarks to His disciples, He said (John 20:21) "As the Father has sent me, I am sending you." emphasizing that we are to do likewise. This concern permeates the Old and New Testament, another example being the words of the prophet Micah (6:8): "He has showed you, O man, what is good. And what does the LORD require of you? To act justly and to love mercy and to walk humbly with your God." We are here to think through together some of the implications of this mandate for ourselves as researchers and practitioners. More specifically, to consider how the work we do as researchers can inform our work in the field as practitioners in such a way as to more effectively help those who are materially poor.Community/Rural/Urban Development, O1, Q12, Q18,

Test of shell-model interactions for nuclear structure calculations

The binding energy and excitation spectra of 6Li are calculated in a no-core shell-model space giving encouraging results. The results of this calculation are then treated as a theoretical experiment, against which different effective-interaction approximations are compared. In this way insight into the perturbation expansion for the effective interaction is obtained

Improving Performance of Iterative Methods by Lossy Checkponting

Iterative methods are commonly used approaches to solve large, sparse linear systems, which are fundamental operations for many modern scientific simulations. When the large-scale iterative methods are running with a large number of ranks in parallel, they have to checkpoint the dynamic variables periodically in case of unavoidable fail-stop errors, requiring fast I/O systems and large storage space. To this end, significantly reducing the checkpointing overhead is critical to improving the overall performance of iterative methods. Our contribution is fourfold. (1) We propose a novel lossy checkpointing scheme that can significantly improve the checkpointing performance of iterative methods by leveraging lossy compressors. (2) We formulate a lossy checkpointing performance model and derive theoretically an upper bound for the extra number of iterations caused by the distortion of data in lossy checkpoints, in order to guarantee the performance improvement under the lossy checkpointing scheme. (3) We analyze the impact of lossy checkpointing (i.e., extra number of iterations caused by lossy checkpointing files) for multiple types of iterative methods. (4)We evaluate the lossy checkpointing scheme with optimal checkpointing intervals on a high-performance computing environment with 2,048 cores, using a well-known scientific computation package PETSc and a state-of-the-art checkpoint/restart toolkit. Experiments show that our optimized lossy checkpointing scheme can significantly reduce the fault tolerance overhead for iterative methods by 23%~70% compared with traditional checkpointing and 20%~58% compared with lossless-compressed checkpointing, in the presence of system failures.Comment: 14 pages, 10 figures, HPDC'1

Universality of Decay out of Superdeformed Bands in the 190 Mass Region

Superdeformed nuclei in the 190 mass region exhibit a striking universality in their decay-out profiles. We show that this universality can be explained in the two-level model of superdeformed decay as related to a strong separation of energy scales: a higher scale related to the nuclear interactions, and a lower scale caused by electromagnetic decay. Furthermore, we present the results of the two-level model for all decays for which sufficient data are known, including statistical extraction of the matrix element for tunneling through the potential barrier.Comment: 7 pages, 3 figures. v2: some minor clarifications, minor correction to Fig.

Extrapolation Method for the No-Core Shell Model

Nuclear many-body calculations are computationally demanding. An estimate of their accuracy is often hampered by the limited amount of computational resources even on present-day supercomputers. We provide an extrapolation method based on perturbation theory, so that the binding energy of a large basis-space calculation can be estimated without diagonalizing the Hamiltonian in this space. The extrapolation method is tested for 3H and 6Li nuclei. It will extend our computational abilities significantly and allow for reliable error estimates.Comment: 8 pages, 7 figures, PRC accepte

Existence of a Density Functional for an Intrinsic State

A generalization of the Hohenberg-Kohn theorem proves the existence of a density functional for an intrinsic state, symmetry violating, out of which a physical state with good quantum numbers can be projected.Comment: 6 page