Kathy
Notarianni, The Role of Uncertainty in Improving Fire
Protection Regulation
Committee: Paul Fischbeck - chair (SDS/EPP), Ardeshir
Mahdavi (Architecture), Granger Morgan (EPP/ECE/Heinz),
and Bill Grosshandler (NIST)
Traditional
fire codes use design standards (e.g., place a sprinkler
head every 20 feet). Performance-based standards (e.g.,
design the building so everyone can get out in three minutes)
hold great appeal but because of the many uncertainties
they have been difficult to implement. Using advanced
analytical methods, this thesis demonstrates a strategy
that can make design standards more defensible, and make
performance standards feasible.
Seven
barriers to determining and documenting a level of fire
safety for a given project are identified and the potential
for switchover in the acceptability of a design is demonstrated.
A taxonomy is created to help understand, identify, and
investigate uncertainties as a function of the steps in
a fire safety-engineering calculation.
An
iterative methodology for the treatment of uncertainty
in fire-safety engineering calculations is developed.
This methodology structures and quantifies many aspects
of good engineering and policy analysis as applied to
fire-safety engineering and shows where effort should
be made to treat complexity and where best-guess or average
numbers can be used. Modifications to the current performance-based
design process are suggested to provide for integration
of uncertainty analysis.
A
case study shows the importance of a model that properly
incorporates uncertainty over a traditional deterministic
model. Results of the case study provide insights useful
for selecting design criteria, improving code language,
and establishing research programs to support performance-based
fire safety designs that ensure fire-safe buildings.
In
an evaluation of the cost-effectiveness of mandating residential
fire sprinklers, this dissertation also demonstrates the
value of properly incorporating variability and uncertainty
in a cost-effectiveness and benefit-cost decision-making
context. Mandating residential fire sprinklers in new
mobile homes is shown to be cost-effective when compared
to other residential life-saving options.
Work
supported by the Building and Fire Research Laboratory
(BFRL) at the National Institute of Standards and Technology
(NIST).
| SOME
POLICY RELEVANT WEB SITES:
A
Resources for the Future site provides roughly 100
links to 50 organizations on the clean-up of the
US nuclear weapons complex: www.rff.org/nuclearcleanup.
Columbia
University's Center for Science Policy and Outcomes
has a site at www.cspo.org.
AAAS
compares science and technology policy academic
programs at www.aaas.org/SPP/DSPP/SEPP/
index.htm.
Two
Carnegie Mellon sites: The Green Design Initiative
offers a tool for free web-based life-cycle assessment
of goods and services produced in the US at: www.eiolca.net/;
The Center for the Study and Improvement of Regulation
has a site at www.epp.cmu.edu/csir. |
|
|
John
Shultz, The Risk of Accidents and Spills at Offshore Production
Platforms: A Statistical Analysis of Risk Factors and the
Development of Predictive Models
Committee: Paul Fischbeck _ chair (SDS/EPP), Mike DeKay
(Heinz/EPP), Jim Garrett (CEE) and Mitchell Small (CEE/EPP)
How
should scarce inspection resources be allocated to assure
the safety of offshore oil production platforms? This dissertation
develops two models (expert and logistics regression) to
predict the likelihood of accidents and spills and rank
the platforms in terms of risk. The models are based on
databases maintained by the Minerals Management Service
and a 1998 survey of platforms inspectors.
A
few platforms (<20%) account for the majority of accidents
and spills (>80%). Every platform that had an accident
during the ten-year period also had a spill during that
period. However, not every platform that had a spill also
had an accident. Major complexes were over 12 times as likely
as non-major complexes to experience either an accident
or a spill.
A
rank ordering of platforms based on a logistic regression
model predicts 50% of the accidents or spills that will
occur in the top 10% of ranked platforms. In this model,
platform complexity is the most important risk factor, inspection
history is second, accident history is third and age of
the platform, or experience of the operating company ranks
fourth. The model shows that the relative merit of risk
factors varies somewhat over time, but there is no trend
in model accuracy over time.
The
expert models also routinely predict 50% of the accidents
or spills in the top 10% of ranked platforms. The experts
consider platform complexity as the most important risk
factor, age of the platform or experience of the operating
company is second, inspection history is third, and accident
history is fourth (out of four ranked risk factors).
Both
models are consistently good at ranking platforms. The logistic
regression model is significantly better (95% confidence
level) than the expert model at predicting accidents but
it is not significantly better than the expert model at
predicting spills. Overall, a ranking based on an expert
model risk index is much easier to calculate, and is only
slightly less accurate than a ranking based on the logistics
model.
Work
supported by the Offshore Operations and Safety Management
Office, Minerals Management Service, and the US Department
of Interior.
Peha - continued
from pg. 4
homes that could
not receive a terrestrial broadcast. The satellite carriers
did not obey this restriction, until 1999 when a judge ordered
them to discontinue service to over two-million households,
many of whom called their congressman to complain. As a
result, this issue was of tremendous concern throughout
Congress.
The
long-term concern is that there should be competition for
cable television. To make this possible, satellite carriers
must be able to offer the popular programs that are only
available from network stations. This can be done without
threatening local broadcasters by allowing "local into
local service," e.g. allowing a satellite carrier to
beam the Atlanta NBC affiliate back to households that are
in Atlanta. This was not legal under the old law. A comprehensive
bill to address both short-term and long-term issues was
co-authored by the republican and democratic leadership
of the House Commerce Committee. |
