Jonathan Turner is a Senior Professor in the Department of Computer
Science and Engineering, at Washington University.
While no longer a fulltime faculty member, he continues to
work on selected projects.
His interests include
the design of instruments for
automated longterm monitoring of marine environments,
hyperspectral analysis of seawater,
design and analysis of algorithms and data structures.
He is a Fellow of the IEEE, a Fellow of the ACM and a
member of the National Academy of Engineering.
He now lives in Sarasota, Florida where he sails his 28'
sailboat TurnerLoose whenever he can.
Current/Recent Projects
 Graph Algorithms and Data
Structures is an online reference, which covers a variety
of different algorithms and data structures.
Javascript implementations
of all the algorithms are provided. In addition, there is a web application
that can be used to examine the code and run it within the browser.
This is a workinprogress and will likely remain so for sometime.
Comments welcome.
 The Programmable Hyperspectral Seawater Scanner (PHySS)
is a second generation marine spectrophotometer, designed to detect
and discriminate among marine organisms in seawater samples.
The PHySS is designed to be deployed for long periods either at fixed
locations (pilings or buoys) or on autonomous vehicles. It is
userprogrammable, giving users complete control over the details
of the sampling process. Raw data from PHySS units is uploaded
in near realtime to a cloud data server, where it can be accessed
through an extensible analysis console that allows users to
modify provided analysis libraries or develop their own.
See these reports for details of
PHySS
operations and
data
analysis.
 Bounded
edge coloring is a generalization of the classical
edge coloring problem in which each edge has a specified minimum
color. We show that the problem is NPcomplete and
study several approximation algorithms for it.
Bounded edge coloring is an abstraction of an offline crossbar
scheduling problem and has implications for the minimum speedup
required to achieve ideal performance.
 Multicast switch scheduling. Packet scheduling in
crossbar switches
is an interesting and challenging problem. While the unicast case
is fairly wellunderstood, relatively little is known about
the multicast case. One version of this problem can
be formulated as an
edge group coloring
problem in bipartite graphs.
In this problem, each vertex in the input subset divides
its incident edges into groups. Edges belonging to
different groups at a given vertex are required to have different
colors. Edges in the same group may share a color.
The objective of the problem is to color all the edges using as
few colors as possible. Such a coloring corresponds to a crossbar
switch schedule that transfers multicast packets from inputs to
outputs in the fewest steps.
The problem is NPcomplete and the best approximation
algorithm known has a performance bound of
O(log n/log log n).
Attention Prospective Graduate Students: I am no longer accepting new students
Favorite Quotes

In theory, there's no difference between theory and practice.
In practice, there is. Jan L. A. van de Snepscheut

Don't worry about other people stealing your ideas.
If your ideas are any good, you'll have to ram them down peoples' throats.
Howard Aiken

A design is complete not when there is nothing more to add,
but when there is nothing more that can be taken away.
Antoine de SaintExupery

A scientific theory should be as simple as possible.
But no simpler.
Albert Einstein

I apologize for writing such a long letter. I did not have time
to write a shorter one. Blaise Pascal

Omit needless words. Theodore Strunk

Asking if computers can think is like asking if submarines can swim.
Edsger Dijkstra

The real question is not whether computers think, but whether people do.
B. F. Skinner

I think, therefore I am. Rene Descartes