tailieunhanh - Handbook of Wireless Networks and Mobile Computing phần 3

nhưng duy trì tính toàn vẹn của lưu trữ đọc-ghi dữ liệu trên một cluster là khó khăn. Nếu bản sao giữa các lưu trữ cần thiết, nó là khá rõ ràng rằng chúng ta không nên thực hiện các cơ sở hạ tầng đó như là một phần của ứng dụng của chúng tôi, Thử nghiệm tính năng và Điều chỉnh một ứng dụng | LOWER BOUNDS 103 mum is achieved by one of the vertices of the polytope TC G representing the feasible dual solutions and defined as follows TC G X E t v x v c t for all tEĩỉ I ver J A classification of the vertices of this polytope will therefore lead to a comprehensive set of lower bounds that can be obtained from fractional tile covers. Foranyspecific constrained graph such a classification can be obtained by using vertex enumeration software . the peckdgeOrs developcdbyAvis 2 In 18 l-cln uaiini raiphe fti constraints Co Cj were considered. In this case the channel assignment was found to be equivalent to the tile cover problem. Moreover the tile eoverprt blcn. is oqmvalem to the ttcteẹml the lover problem for 1-eltques leading to a family op bwn bounds that can always be aHemed. None of the bounds was new. Two bounds were clique bounds of the type mentioned earlier. The third bound was liistgiimiS I ync tn l2 andces bcitaeideplolloivs Gp umaxỊciiiisO teiC - Ck rn k-lộa k0 Cailique efld vElC where 1 issuchthal co- lIat coh neỏi Tletili coverapyroachledla anumbee olnew bound for oraahs with coyllramtsco Si eThe eki A edfri tb soiiollad zel ílaaictideeitar 1-clibue idatcomeins a e2idlique esa kubvea a2 ill ft ir cliaracIarleedby aoodspaitition g rao where íillrecaeimeiaieVea. Al iiiile thee onsloamCs HwClbMoCaaando k ciZ n alles ed elique. Note that in a nested clique with node partition 2 R with constraints k u a every pair of nodes from Q has a constraint of at le est M wife the conslaaint between any yai r of nodetie tSe nested flique i 5 6t least a. The followingia o lower tonne for a nested clique Q R with parameters k a liy. s Gs ewoA w101 to 2 Q ven attolde oian ia sffret ilemed inl O using adihoo melhodii Thesaaoa bounOcanalsebe Oe voyuomgedyo aovertl. a ill runs tile aovers onomderoOnaw IkmiorioiTKaleacI vm iwith e I ieiia l and MOseiie osoOtodenola k