Bal khadka - Academia.edu (original) (raw)
Papers by Bal khadka
The credit on {\it reduction theory} goes back to the work of Lagrange, Gauss, Hermite, Korkin, Z... more The credit on {\it reduction theory} goes back to the work of Lagrange, Gauss, Hermite, Korkin, Zolotarev, and Minkowski. Modern reduction theory is voluminous and includes the work of A. Lenstra, H. Lenstra and L. Lovasz who created the well known LLL algorithm, and many other researchers such as L. Babai and C. P. Schnorr who created significant new variants of basis reduction algorithms. In this paper, we propose and investigate the efficacy of new optimization techniques to be used along with LLL algorithm. The techniques we have proposed are: i) {\it hill climbing (HC)}, ii) {\it lattice diffusion-sub lattice fusion (LDSF)}, and iii) {\it multistage hybrid LDSF-HC}. The first technique relies on the sensitivity of LLL to permutations of the input basis BBB, and optimization ideas over the symmetric group SmS_mSm viewed as a metric space. The second technique relies on partitioning the lattice into sublattices, performing basis reduction in the partition sublattice blocks, fusing ...
Journal of Algebra Combinatorics Discrete Structures and Applications, 2016
Let V be an n-dimensional vector space over Fq. By a geometric t-[q n , k, λ] design we mean a co... more Let V be an n-dimensional vector space over Fq. By a geometric t-[q n , k, λ] design we mean a collection D of k-dimensional subspaces of V , called blocks, such that every t-dimensional subspace T of V appears in exactly λ blocks in D. A large set, LS[N][t, k, q n ], of geometric designs, is a collection of N t-[q n , k, λ] designs which partitions the collection V k of all k-dimensional subspaces of V. Prior to recent article [4] only large sets of geometric 1-designs were known to exist. However in [4] M. Braun, A. Kohnert, P. Östergard, and A. Wasserman constructed the world's first large set of geometric 2-designs, namely an LS[3][2,3,2 8 ], invariant under a Singer subgroup in GL8(2). In this work we construct an additional 9 distinct, large sets LS[3][2,3,2 8 ], with the help of lattice basis-reduction.
The credit on {\it reduction theory} goes back to the work of Lagrange, Gauss, Hermite, Korkin, Z... more The credit on {\it reduction theory} goes back to the work of Lagrange, Gauss, Hermite, Korkin, Zolotarev, and Minkowski. Modern reduction theory is voluminous and includes the work of A. Lenstra, H. Lenstra and L. Lovasz who created the well known LLL algorithm, and many other researchers such as L. Babai and C. P. Schnorr who created significant new variants of basis reduction algorithms. In this paper, we propose and investigate the efficacy of new optimization techniques to be used along with LLL algorithm. The techniques we have proposed are: i) {\it hill climbing (HC)}, ii) {\it lattice diffusion-sub lattice fusion (LDSF)}, and iii) {\it multistage hybrid LDSF-HC}. The first technique relies on the sensitivity of LLL to permutations of the input basis BBB, and optimization ideas over the symmetric group SmS_mSm viewed as a metric space. The second technique relies on partitioning the lattice into sublattices, performing basis reduction in the partition sublattice blocks, fusing ...
Journal of Algebra Combinatorics Discrete Structures and Applications, 2016
Let V be an n-dimensional vector space over Fq. By a geometric t-[q n , k, λ] design we mean a co... more Let V be an n-dimensional vector space over Fq. By a geometric t-[q n , k, λ] design we mean a collection D of k-dimensional subspaces of V , called blocks, such that every t-dimensional subspace T of V appears in exactly λ blocks in D. A large set, LS[N][t, k, q n ], of geometric designs, is a collection of N t-[q n , k, λ] designs which partitions the collection V k of all k-dimensional subspaces of V. Prior to recent article [4] only large sets of geometric 1-designs were known to exist. However in [4] M. Braun, A. Kohnert, P. Östergard, and A. Wasserman constructed the world's first large set of geometric 2-designs, namely an LS[3][2,3,2 8 ], invariant under a Singer subgroup in GL8(2). In this work we construct an additional 9 distinct, large sets LS[3][2,3,2 8 ], with the help of lattice basis-reduction.