منابع مشابه
On hard instances
Instance complexity was introduced by Orponen, Ko, Schh oning, and Watanabe 14] as a measure of the complexity of individual instances of a decision problem. Comparing instance complexity to Kolmogorov complexity, they introduced the notion of p-hard instances, and conjectured that every set not in P has p-hard instances. Whereas this conjecture is still unsettled, Fortnow and Kummer 6] proved ...
متن کاملHard Instances of Hard Problems
This paper investigates the instance complexities of problems that are hard or weakly hard for exponential time under polynomial time many one reductions It is shown that almost every instance of almost every problem in exponential time has essentially maximal instance complexity It follows that every weakly hard problem has a dense set of such maximally hard instances This extends the theorem ...
متن کاملEnsemble of Classifiers Based on Hard Instances
There are several classification problems, which are difficult to solve using a single classifier because of the complexity of the decision boundary. Whereas, a wide variety of multiple classifier systems have been built with the purpose of improving the recognition process. There is no universal method performing the best. The aim of this paper is to show another model of combining classifiers...
متن کاملKnapsack cryptosystems built on NP-hard instances
We construct three public key knapsack cryptosystems. Standard knapsack cryptosystems hide easy instances of the knapsack problem and have been broken. The systems considered in the article face this problem: They hide a random (possibly hard) instance of the knapsack problem. We provide both complexity results (size of the key, time needed to encypher/decypher...) and experimental results. Sec...
متن کاملGenerating Hard Satisfiable Scheduling Instances
We present a random generator of partially complete round robin timetables that produces exclusively satisfiable instances, and provide experimental evidence that there is an easy-hard-easy pattern in the computational difficulty of completing partially complete timetables as the ratio of the number of removed entries to the total number of entries of the timetable is varied. Timetables in the ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 2000
ISSN: 0304-3975
DOI: 10.1016/s0304-3975(98)00262-x