Aleksandar Jurisic

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Objective. Our objective was to estimate degree and rate of discordant growth and its impact on perinatal outcome in dichorionic twin pregnancies conceived by in vitro fertilization (IVF) compared to those conceived spontaneously. Study Design. Growth discordance was defined as 90th percentiles for the study population. Adverse perinatal outcome was defined(More)
Let Γ be a distance-regular graph with diameter d. For vertices x and y of Γ at distance i, 1 ≤ i ≤ d, we define the sets Ci(x, y) = Γi−1(x) ∩ Γ(y), Ai(x, y) = Γi(x) ∩ Γ(y) and Bi(x, y) = Γi+1(x) ∩ Γ(y). Then we say Γ has the CABj property, if the partition CABi(x, y) = {Ci(x, y), Ai(x, y), Bi(x, y)} of the local graph of y is equitable for each pair of(More)
Antipodal covers of strongly regular graphs which are not necessarily distance-regular are studied. The structure of short cycles in an antipodal cover is considered. In most cases, this provides a tool to determine if a strongly regular graph has an antipodal cover. In these cases, covers cannot be distance-regular except when they cover a complete(More)
We classify triangleand pentagon-free distance-regular graphs with diameter d ≥ 2, valency k, and an eigenvalue multiplicity k. In particular, we prove that such a graph is isomorphic to a cycle, a k-cube, a complete bipartite graph minus a matching, a Hadamard graph, a distance-regular graph with intersection array {k, k − 1, k − c, c, 1; 1, c, k − c, k −(More)
Let be a distance-regular graph of diameter d ≥ 2 and a1 = 0. Let θ be a real number. A pseudo cosine sequence for θ is a sequence of real numbers σ0, . . . , σd such that σ0 = 1 and ciσi−1 + aiσi + biσi+1 = θσi for all i ∈ {0, . . . , d−1}. Furthermore, a pseudo primitive idempotent for θ is Eθ = s ∑di=0 σiAi , where s is any nonzero scalar. Let v̂ be the(More)