Now showing items 33-52 of 56

    • On the Intellectual Terrain Around NP 

      Hartmanis, Juris; Chari, Suresh (Cornell University, 1993-12)
      In this paper, we view $P \stackrel{?}{=} NP$ as the problem which symbolizes the attempt to understand what is and what is not feasibly computable. The paper shortly reviews the history of the developments from Godel's ...
    • On the Power of Multiplication in Random Access Machines 

      Hartmanis, Juris; Simon, Janos (Cornell University, 1974-09)
      We consider random access machines with a multiplication operation, having the added capability of computing logical operations on bit vectors in parallel. The contents of a register are considered both as an integer and ...
    • On the Problem of Finding Natural Computational Complexity Measures 

      Hartmanis, Juris (Cornell University, 1973-06)
      To develop an abstract theory which deals with the quantitative aspects of computing we need a deeper understanding of how to define "natural" computational complexity measures axiomatically. To this end, this paper ...
    • On the Recognition of Primes by Automata 

      Hartmanis, Juris; Shank, H. (Cornell University, 1968-02)
      A study of the problem of recognizing the set of primes by automata is presented. A simple algebraic condition is derived which shows that neither the set of primes nor any infinite subset of primes can be accepted by a ...
    • On the Structure of Feasible Computations 

      Hartmanis, Juris; Simon, Janos (Cornell University, 1974-08)
      During the last four years research on the lower level computational complexity has yielded a rich set of interesting results which have revealed deep and unexpected connections between various problems and thus brought ...
    • On the Structure of Feasible Computations 

      Hartmanis, Juris (Cornell University, 1982-03)
      This paper discusses the study of computational complexity of feasible computations and surveys some recent insights and results about the structure of NP complete languages and the attempts to separate the classic ...
    • On the Succintness of Different Representations of Languages 

      Hartmanis, Juris (Cornell University, 1978-06)
      The purpose of this paper is to give simple new proofs of some interesting recent results about the relative succintness of different representations of regular, deterministic and unambiguous context-free languages and ...
    • One-Way Functions, Robustness, and the Non-Isomorphism of NP-Complete Sets 

      Hartmanis, Juris; Hemachandra, Lane A. (Cornell University, 1986-01)
      This paper 1. gives a relativized counterexample to the conjectured connection between the existence of one-way functions and the existence of non-isomorphic NP-complete sets. 2. establishes that in relativized worlds ...
    • One-Way Log-Tape Reductions 

      Hartmanis, Juris; Immerman, Neil; Mahaney, Stephen R. (Cornell University, 1978-07)
      One-way log-tape (1-L) reductions are mappings defined by log-tape Turing machines whose read head on the input can only move to the right. The 1-L reductions provide a more refined tool for studying the feasible complexity ...
    • An Overview of the Theory of Computational Complexity 

      Hartmanis, Juris; Hopcroft, John E. (Cornell University, 1970-04)
      The purpose of this paper is to outline the theory of computational complexity which has emerged as a comprehensive theory during the last decade. This theory is concerned with the quantitative aspects of computations and ...
    • Refinement of Hierarchies of Time Bounded Computations 

      Hartmanis, Juris; Hopcroft, John E. (Cornell University, 1968-06)
      It is shown that for any "slowly growing" time function $T(n)$ and any $\epsilon > 0$ there exists a computation which can be performed by a multitape Turing machine in time $T(n)\log^{\epsilon}T(n)$ and cannot be performed ...
    • Relations Between Diagonalization, Proof Systems, and Complexity Gaps 

      Hartmanis, Juris (Cornell University, 1977-06)
      In this paper we study diagonal processes over time-bounded computations of one-tape Turing machines by diagonalizing only over those machines for which there exist formal proofs that they operate in the given time bound. ...
    • Relations Between Diagonalization, Proof Systems, and Complexity Gaps 

      Hartmanis, Juris (Cornell University, 1977-03)
      In this paper we study diagonal processes over time-bounded computations of one-tape Turing machines by diagonalizing only over those machines for which there exist formal proofs that they operate in the given time bound. ...
    • Relative Succinctness of Representations of Languages and Separation of Complexity Classes 

      Hartmanis, Juris (Cornell University, 1978-08)
      In this paper we study the relative succinctness of different representations of polymomial time languages and investigate what can and cannot be formally verified about these representations. We also show that the ...
    • Size Arguments in the Study of Computation Speeds 

      Hartmanis, Juris (Cornell University, 1970-08)
      In this paper we use arguments about the size of the computed functions to investigate the computation speed of Turing machines. It turns out that the size arguments yield several new results which we have not been able ...
    • Some Observations About NP Complete Sets 

      Hartmanis, Juris (Cornell University, 1987-03)
      In this paper we summarize and extend some recent results about the properties of NP complete sets and related results about the structure of feasible computations.
    • Space Bounded Computations: Review And New Separation Results 

      Hartmanis, Juris; Ranjan, Desh (Cornell University, 1989-05)
      In this paper, we review the key results about space bounded complexity classes, discuss the central open problems and outline the relevant proof techniques. We show that, for a slightly modified Turing machine model, ...
    • Sparse Sets in NP-P: EXPTIME Versus NEXPTIME 

      Hartmanis, Juris; Sewelson, Vivian; Immerman, Neil (Cornell University, 1983-02)
      This paper investigates the structural properties of sets in NP-P and shows that the computational difficulty of lower density sets in NP depends explicitly on the relations between higher deterministic and nondeterministic ...
    • Structural Complexity Column for the Bulletin of the European Association for Theoretical Computer Science 

      Hartmanis, Juris (Cornell University, 1987-06)
      Abstract not Available
    • Structural Complexity Column: Some Observations About Relativization of Space Bounded Computations 

      Hartmanis, Juris (Cornell University, 1988-05)
      NO ABSTRACT AVAILABLE