Given an undirected graph, one can assign directions to each of the edges of the graph, thus orienting the graph. To be as egalitarian as possible, one may wish to find an orientation such that no vertex is unfairly hit with too many arcs directed into it. We discuss how this objective arises in problems resulting from telecommunications. We give optimal, polynomial-time algorithms for: finding...

This paper presents a computationally efficient yet powerful binary framework for robust facial representation based on image gradients. It is termed as binary gradient correlation patterns (BGCP). To discover underlying local structures in the gradient domain, BGCP computes image gradients from multiple directions and simplifies them into a set of binary strings. Certain types of these binary ...

We develop a new framework for investigating linear equivalence of divisors on graphs using a generalization of Gioan’s cycle-cocycle reversal system for partial orientations. An oriented version of Dhar’s burning algorithm is introduced and employed in the study of acyclicity for partial orientations. We then show that the Baker-Norine rank of a partially orientable divisor is one less than th...

Digital Gabor filters are indispensable tools of local time-frequency analysis in signal processing. With strong orientation selectivity, discrete (tight) Gabor frames generated by 2D Gabor filters also see their wide applications in image processing and volume data processing. However, owing to the lack of multi-scale structures, discrete Gabor frames are less effective than multiresolution an...

An orientation-dependent displacement sensor based on grating inscription over a fiber core and inner cladding has been demonstrated. The device comprises a short piece of multi-cladding fiber sandwiched between two standard single-mode fibers (SMFs). The grating structure is fabricated by a femtosecond laser side-illumination technique. Two well-defined resonances are achieved by the downstrea...

We study graph orientations that minimize the entropy of the in-degree sequence. The problem of finding such an orientation is an interesting special case of the minimum entropy set cover problem previously studied by Halperin and Karp (Theoret. Comput. Sci., 2005) and by the current authors (Algorithmica, to appear). We prove that the minimum entropy orientation problem is NP-hard even if the ...

Poljak and Turzík (Discrete Math. 1986) introduced the notion of λ-extendible properties of graphs as a generalization of the property of being bipartite. They showed that for any 0 < λ < 1 and λ-extendible property Π, any connected graph G on n vertices and m edges contains a spanning subgraph H ∈ Π with at least λm+ 1−λ 2 (n−1) edges. The property of being bipartite is λ-extendible for λ = 1/...

E-services will change the future of business as well as private relationships. The rearrangement of value chains, new competitive arenas and the growing necessity and interest in overtaking public responsibility by citizens and private enterprises will lead us to new challenges in creating learning organisations and knowledge infrastructures. Precondition for a sustainable model of learning ad...

Anisotropy in material structure leads to distinct anisotropy in mechanical and thermal properties for polymer materials. In this work, poly(3-hexylthiophene) (P3HT) thin films are fabricated using the spin coating technique for investigation of anisotropic thermal transport. Raman spectroscopy study of spincoated P3HT films confirms the partially aligned molecular structure. Based on the main ...

Organic Computing has emerged recently as a challenging vision for future information processing systems. Organic Computing is based on the insight that we will soon be surrounded by large collections of autonomous systems, which are equipped with sensors and actuators, aware of their environment, communicating freely, and organizing themselves in order to perform the actions and services that ...