The Super Database Computer (SDC) is a highperformance relational database server for a joinintensive environment under development at University of Tokyo. SDC is designed to execute a join in a highly parallel way. Compared to other join algorithms, a hash-based algorithm is quite efficient and easily parallelieed, and has been employed by many database machines. However, in the presence of da...

In this paper, we study the transient behavior of a finite server (representing an ATM switch) which derives its input from a token leaky bucket with renewal cell arrival and deterministic token arrival distributions. We derive expressions for the transient and time averaged state probabilities, and transient and time averaged blocking probabilities for both the leaky bucket and server. We also...

1. The following example shows that in some physical situations, non-uniqueness is natural and obvious, not pathological. Consider a water bucket with a hole in the bottom. If you see an empty bucket with a puddle beneath it, can you figure out when the bucket was full? No, of course not! It could have finished emptying a minute ago, ten minutes ago, or whatever. The solution to the correspondi...

Robotic regolith excavation on the Moon and Mars enables outposts, fuel depots, and sustained space exploration. In any space mission, mass is always at a premium because it is the main driver behind launch costs. Low mass and reduced gravity (1/6 of Earth gravity on the Moon, 1/3 on Mars) results in machines with limited weight available to produce traction or plunge tools into regolith. Bucke...

Probabilistic inference algorithms for belief updating, nding the most probable explanation, the maximum a posteriori hypothesis, and the maximum expected utility are reformulated within the bucket elimination framework. This emphasizes the principles common to many of the algorithms appearing in the probabilistic inference literature and clariies the relationship of such algorithms to nonseria...

We address the problem of lot splitting for various time bucket lengths in MRP systems. Two approaches for lot splitting can be applied: either use the same (equal) or a variable number of subbatches. Equal subbatching strategies have logistical and computational advantages. Literature states that variable batching strategies are only marginal better. However, these results do not take into acc...

“Bucket brigades” are a way of sharing work on a flow line that results in the spontaneous emergence of balance and consequent high throughput. All this happens without a work-content model or traditional assembly line balancing technology. Here we show that bucket brigades can be effective even in the presence of variability in the work content. In addition, we report confirmation at the natio...

Previous work on the dynamics of bucket brigades has focused on systems in which workers can be ordered with respect to their speeds and where this ordering does not change throughout the line. While this assumption is valid in most environments, it may not be satisfied in some. We consider such environments and explore the conditions under which bucket brigades continue to be effective (compar...

This paper deals with the dimensioning of token buckets. Two related problems are formulated and solved. The first is the token bucket allocation problem (TBAP) which is finding the cost-minimal token bucket for the transmission of a given VBR traffic stream, e.g. an MPEG movie, from the user's point of view. This problem has been treated in literature before but as we will show not completely....