This paper presents a new O(nlog(n)) algorithm for computing the convex hull of a set of 3 dimensional points. The algorithm first sorts the point in (x,y,z) then incrementally adds sorted points to the convex hull using the constraint that each new point added to the hull can 'see' at least one facet touching the last point added. The reduces the search time for adding new points. The algorith...

In the present study, the overall economic impact of hull fouling on a mid-sized naval surface ship (Arleigh Burke-class destroyer DDG-51) has been analyzed. A range of costs associated with hull fouling was examined, including expenditures for fuel, hull coatings, hull coating application and removal, and hull cleaning. The results indicate that the primary cost associated with fouling is due ...

We show that for every integer k ≥ 2 and every k graphs G1, G2, . . . , Gk, there exists a hull graph with k hull vertices v1, v2, . . . , vk such that link L(vi) = Gi for 1 ≤ i ≤ k. Moreover, every pair a, b of integers with 2 ≤ a ≤ b is realizable as the hull number and geodetic number (or upper geodetic number) of a hull graph. We also show that every pair a, b of integers with a ≥ 2 and b ≥...

Pipelines provide an economic mode of fluid transportation for petroleum systems, specially when large amounts of these products have to be pumped for large distances. The system discussed in this paper is composed of a petroleum refinery, a multiproduct pipeline connected to several depots and the corresponding consumer markets that receive large amounts of gasoline, diesel, LPG and aviation f...

Six strain of Trichoderma (T. viride, T. harzianum, T. reesei, T. longibrachiatum, T. koningii, T. virens) were isolated and used for extracellular enzyme production. Species of Trichoderma are collected from the surrounding soil of suger beet root fields in East Iran, and held in vitro cultured PDA. TCM and TFM are used for the growth of spores and induceing the production of Cellulase. Finall...

We give an explicit formula for the probability that the convex hull of an n-step random walk in R does not contain the origin, under the assumption that the distribution of increments of the walk is centrally symmetric and puts no mass on affine hyperplanes. This extends the formula by Sparre Andersen (Skand Aktuarietidskr 32:27–36, 1949) for the probability that such random walk in dimension ...

With Generation Z's increasing awareness of environmental problems, the rise eco-friendly products is in high demand. Regarding skincare products, Z newest consumer who enters market with a decent knowledge problems—using Theory Planned Behaviour (TPB), product knowledge, price consciousness, and knowledge. This paper aims to understand how far affects their purchase intention toward green skin...

We provide an explicit description of the convex hull of the set of matrices of bounded rank, restricted to balls for the spectral norm. As applications, we deduce two relaxed forms of the rank function restricted to balls for the spectral norm: one is the quasiconvex hull of this rank function, another one is the convex hull of the rank function, thus retrieving Fazel's theorem (2002). Key-wor...

We study the complexity of computing the mixed-integer hull conv(P ∩ Z ×R) of a polyhedron P . Given an inequality description, with one integer variable, the mixed-integer hull can have exponentially many vertices and facets in d. For n, d fixed, we give an algorithm to find the mixed integer hull in polynomial time. Given P = conv(V ) and n fixed, we compute a vertex description of the mixed-...