Ryoso HAMANE

Approximation Algorithms for the Highway Problem under the Coupon Model
Ryoso HAMANE  Toshiya ITOH  Kouhei TOMITA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/08/01
Vol. E92-A  No. 8  pp. 1779-1786
Type of Manuscript: Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: Theory
Keyword: 
line highway problem,  cycle highway problem,  multi-valuations,  single-valuation, 
  Summary |  Full Text:PDF (428.1KB)
Approximation Preserving Reductions among Item Pricing Problems
Ryoso HAMANE  Toshiya ITOH  Kouhei TOMITA 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2009/02/01
Vol. E92-D  No. 2  pp. 149-157
Type of Manuscript: Special Section PAPER (Special Section on Foundations of Computer Science)
Category: 
Keyword: 
item pricing problem,  approximation preserving reductions,  price models,  selfloops, 
  Summary |  Full Text:PDF (487.9KB)
Improved Approximation Algorithms for Item Pricing with Bounded Degree and Valuation
Ryoso HAMANE  Toshiya ITOH 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2008/02/01
Vol. E91-D  No. 2  pp. 187-199
Type of Manuscript: Special Section PAPER (Special Section on Foundations of Computer Science)
Category: Approximation Algorithms
Keyword: 
item pricing,  approximation algorithm,  pseudodegree,  valuation ratio, 
  Summary |  Full Text:PDF (303.1KB)