7673006
A Clocked DNA-Based Replicator
A stepped replicator is described that uses the energy of hybridization to pry the product from the template in order to prevent product inhibition of replication. Toehold-mediated strand displacement is used to reset the system to its initial state after a round of replication. It is argued that the formation of dimers between structures in the process of replicating should not be able to form and, consequently, the system should exhibit exponential growth.
205667500
FFT-based algorithms for the string matching with mismatches problem
The string matching with mismatches problem requires finding the Hamming distance between a pattern P of length m and every length m substring of text T with length n. Fischer and Paterson's FFT-based algorithm solves the problem without error in O(@snlogm), where @s is the size of the alphabet @S [SIAM-AMS Proc. 7 (1973) 113-125]. However, this in the worst case reduces to O(nmlogm). Atallah, Chyzak and Dumas used the idea of randomly mapping the letters of the alphabet to complex roots of unity to estimate the score vector in time O(nlogm) [Algorithmica 29 (2001) 468-486]. We show that the algorithm's score variance can be substantially lowered by using a bijective mapping, and specifically to zero in the case of binary and ternary alphabets. This result is extended via alphabet remappings to deterministically solve the string matching with mismatches problem with a constant factor of 2 improvement over Fischer-Paterson's method.
5070409
Index based processing of semi-restrictive temporal joins
Temporal joins are important but very costly operations. While a temporal join can involve the whole time (and/or key) domain, we consider the more general case where the join is defined by some time-key rectangle from the whole space (i.e., when the user is interested in joining portions of the-usually large-temporal data). In the most restrictive join, objects (within this rectangle) are joined together based on key equality and interval intersection. This paper concentrates on semi-restrictive joins, i.e., when either the key equality (equi-join) or the interval intersection (time-join) predicates are used. Given the large relations created by the ever increasing time dimension, we assume that each temporal relation is indexed and examine efficient ways to process semi-restrictive temporal joins. Utilizing an index is helpful since it directs the join towards the objects that are within the time-key rectangle. A straightforward approach is to perform an unsynchronized join. An index selection query on each relation identifies all objects within the time-key rectangle which are then joined. Although simple, this approach ignores the data distribution in the other relation. Instead, in a synchronized join, both indices are concurrently traversed as the join is computed. Synchronized semi-restrictive join algorithms can be performed utilizing traditional indices like B+-trees or R-trees. The drawback of this approach is that traditional indices do not achieve good temporal data clustering. Better clustering is achieved by temporal indices through record copying. Nevertheless, record copies can greatly affect the correctness and effectiveness of join performance.
1978214
A Language Modeling Approach to Passage Question Answering
This paper reports our efforts on developing a language modeling approach to passage question answering. In particular, we address the following two problems: (i) generalized language modeling for question classification; (ii) constrained language modeling for passage retrieval.
8536303
Web Based Question Answering with Aggregation Strategy
The Web is apparently an ideal source of answers to a large variety of questions, due to the tremendous amount of information available online. This paper describes a question answering system LAMP, which can instantly find answers from the Web. LAMP is publicly accessible on the Web, and its performance is comparable to the state-of-the-art question answering systems. One novel characteristic of this system is that its answer selection method is based on aggregation, which is shown to be more effective than the common methods based on individual or redundancy.
8809044
Adaptive Vision for Playing Table Soccer
For real time object recognition and tracking often color-based methods are used. While these methods are very efficient, they usually dependent heavily on lighting conditions. In this paper we present a robust and efficient vision system for the table soccer robot KiRo. By exploiting knowledge about invariant characteristics of the table soccer game, the system is able to adapt to changing lighting conditions dynamically and to detect relevant objects on the table within a few milliseconds. We give experimental evidence for the robustness and efficiency of our approach.
11522705
A supply chain network equilibrium model with random demands
Abstract In this paper, we develop a supply chain network model consisting of manufacturers and retailers in which the demands associated with the retail outlets are random. We model the optimizing behavior of the various decision-makers, derive the equilibrium conditions, and establish the finite-dimensional variational inequality formulation. We provide qualitative properties of the equilibrium pattern in terms of existence and uniqueness results and also establish conditions under which the proposed computational procedure is guaranteed to converge. Finally, we illustrate the model through several numerical examples for which the equilibrium prices and product shipments are computed. This is the first supply chain network equilibrium model with random demands for which modeling, qualitative analysis, and computational results have been obtained.