Chunked codes are efficient random linear network coding (RLNC) schemes with low computational cost, where the input packets are encoded into small chunks (i.e., subsets of the coded packets). During the network transmission, RLNC is performed within each chunk. In this paper, we first introduce a simple transfer matrix model to characterize the transmission of chunks and derive some basic prop...

In this lecture we give basic background about expander graphs. Expanders are graphs with strong connectivity properties: every two large subsets of vertices in an expander have many edges connecting them. Surprisingly, one can construct very sparse graphs that are expanders, and this is what makes them so useful. Expanders have a huge number of applications in theoretical computer science: in ...

BACKGROUND The Hyrax rapid palatal expander is useful for patients in mixed dentition with premature exfoliation of some deciduous teeth and maxillary hypoplasia. This appliance, which is provided of a vestibular arm for correcting maxillary asymmetric transverse discrepancies, represents an interceptive treatment able to reduce the duration of the orthodontic therapy with fixed appliances. C...

In dentistry, tissue expanders have been used to obtain sufficient soft tissue for alveolar bone augmentation in the severely atrophic ridge. Herein, we review two cases of soft tissue augmentation using a self-inflating tissue expander in patients in the Department of Oral and Maxillofacial Surgery at Ewha Womans University Mokdong Hospital for bone graft and implant operations. The results of...

It is known that the expansion property of a graph influences the performance of the corresponding code when decoded using iterative algorithms. Certain graph products may be used to obtain larger expander graphs from smaller ones. In particular, the zig-zag product and replacement product may be used to construct infinite families of constant degree expander graphs. This paper investigates the...

This paper shows how to compute O( √ logn)-approximations to the Sparsest Cut and Balanced Separator problems in Õ(n2) time, thus improving upon the recent algorithm of Arora, Rao, and Vazirani [Proceedings of the 36th Annual ACM Symposium on Theory of Computing, 2004, pp. 222–231]. Their algorithm uses semidefinite programming and requires Õ(n9.5) time. Our algorithm relies on efficiently find...

PurPoSe: Acellular dermal matrix (ADM) has gained popularity to enhance lower pole coverage in immediate implant or expander reconstruction. Advantages of ADM include improved rapid reconstruction, postoperative expander filling and lower capsular contracture. Potential trade-offs include higher seroma, infection and cost. Alternatives for implant coverage include local fascial flaps and inferi...

Novel compact beam expanders that could be useful for applications such as providing light to flat panel displays are presented. They are based on a planar configuration in which three spatially linear gratings are recorded on one transparent substrate, so as to expand a narrow incoming beam in two dimensions. We present the design and recording procedures along with results, showing a relative...