Research for Computer Models

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An Examination of the Ship Material Condition Metrics (SMCM) Methodlogy
February 1, 2002
There is a perceived need for a single metric that represents the operational mechanical and electrical (M&E) readiness of ships. Such a number could be useful in maintenance planning, programming, and execution; in evaluating whether the fleet is ready for contingency; and in spotting systematic readiness deficiencies and making associated resource decisions. One effort to develop such a metric is the Ship Material Condition Metrics (SMCM) initiative developed at the Naval Warfare Assessment Station (NWAS) at Corona, California. As a pilot project, the formulas for the metric have been applied to the evaluation of the USS Lake Champlain (CG-57). OpNav N81 asked CNA to evaluate the way the metric was constructed. The NWAS model aims to roll up "readiness" evaluations of small pieces of equipment into a single number for the entire ship M&E. We assessed the model on two levels. In the first, we evaluated the NWAS model parameters and model structure for a significant subset of the ship systems. As a result of our investigations, we can suggest modifications to the formulas which should permit better handling of redundant systems and should better represent the criticality of particular subsystems. In the other part of our evaluation, we took a step back and critically reviewed the fundamental structure of the calculations, formulas, and numerical scales. Our aim was to evaluate whether the SMCM methodologies would give measures that are meaningful, consistent, and useful.
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A Survey of Enlisted Retention: Models and Findings
November 1, 2001
This survey represents a survey of enlisted retention models and findings. It includes discussion of: the Annualized Cost of Leaving (ACOL) model; panel prohibit models; conditional logit models; multinomial logit models; reverse causation between bonuses and the reenlistment rate; joint models of attrition and retention; elasticity computation; elasticity estimates; estimation of discount rates; and, effects of variables other than pay.
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TACAIR Material Readiness in Operation Allied Force
June 1, 2001
This work was done as part of a larger study conducted for N814. The purpose of the larger study was to examine the link between mission performance and readiness drivers using data from CVN-71's combat operations during Operation Allied Force (OAF). In this part of the project, we looked specifically at material readiness of the embarked airwing (CVW-8). Our original intent was to estimate the parameters for a complete Markov model of aircraft material condition. We were unable to implement a complete realization of this model because of problems that included missing data and resource constraints. However, we were able to make substantial progress on two components of the process, and present these results.
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Behavioral Health Care Delivery Models and Examples: Contractual to Functional Integration
November 1, 2000
Navy Medicine has identified mental and behavioral health as one of the major product line areas for which it wants to develop a strategy for providing these specialty services. To inform this strategy development process, we provide a review of the mental health care delivery models that dominate the U.S. health care delivery system, assess where the Navy stands in comparison to current delivery trends, and outline salient issues regarding potential changes that the Navy should consider as part of its managed care evolution. This report focuses on three types of delivery models: contractual, functional and educational.
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A Concise User's Guide to ISAAC-FL: ISAAC's Mission-Fitness Landscape Mapper Program
September 1, 1997
ISAAC (Irreducible Semi-Autonomous Adaptive Combat) is a simple multiagent-based 'toy model' of land combat design to illustrate how certain aspects of land combat can be viewed as emergent phenomena resulting from the collective, nonlinear, decentralized interactions among notional combatants. ISAAC takes a bottom-up, synthesist approach to the modeling of combat, vice the more traditional top-down, reductionist approach, and represents a first step toward developing a complex systems theoretic analyst's toolbox for identifying, exploring, and possibly exploiting emergent collective patterns of behavior on the battlefield. This model was developed as part of a recently completed project, sponsored by the Marine Corps Combat Development Command, that assessed the general applicability of 'complex systems theory.' The focus of this brief is a stand-alone Mission-Fitness Landscape Mapper that uses the core engine to 'map-out' the behavior over a user-defined d-dimensional slice of ISAAC's total N-dimensional phase-space.
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Implementing Readiness-Based Sparing in the Marine Aviation Logistics Support Program: Readiness Implications
December 1, 1995
The Marine Aviation Logistics Support Program (MALSP) was developed to ensure that all logistics support required for major regional contingency can be deployed quickly and efficiently when needed. The foundation for the MALSP is a set of standardized logistics support packages containing all the elements (spare parts, people, support equipment, and mobile facilities) required to support any contingency plan the Marine Corps may be tasked to execute. This study focuses on how the Marine should determine spare parts requirements for the MALSP. Specifically, we were asked by the Deputy Chief of Staff for Aviation, Headquarters Marine Corps to help them answer two questions: What are the potentia
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Procedures and Software for Assessing Uncertainty in Cost Estimates
June 1, 1995
With extensive literature on the treatment of uncertainty in cost estimates, and because several uncertainty software packages are now available, the Naval Center for Cost Analysis asked the Center for Naval Analyses to conduct a study with the objective of evaluating the procedures and software that it now employs. This report begins with a discussion of introductory analytical issues and then focuses on the software packages that were evaluated. Additional analytical questions are addressed in connection with those evaluations.
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The GIFT Model: Implications for Women's Bunks and Accession Policy
May 1, 1995
This report poses the question of how many women's bunks are needed in the larger context of enlisted personnel management policies. The relevant aspects of personnel policy are the number of female accession, their occupational distribution, and women's continuation behavior. In addition, the decision on the number of women's bunks is connected to possible policy goals in the areas of gender-neutral recruiting, female leadership afloat, equal access to assignments, and the related issue of gender differences in shipboard duty.
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Review of the Integrated Theater Engagement Model (ITEM)
July 1, 1994
The Assessment Division (N81) asked CNA to review the Integrated Theater Engagement Model (ITEM), version 5.2.3--a computer model built by SAIC. CNA agreed to conduct a review of ITEM to support a level-2 validation, verification, and accreditation (VV&A) as defined by the draft OPNAV instruction. ITEM is an interactive computer simulation providing integrated air, land, and naval warfare engagement modules for the analysis of joint force operations in theater-level campaigns.
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Comparison of Three Procedures for Smoothing Score Distributions
June 1, 1991
Distributions of test scores need to be smoothed in equating and/or norming. Popular parametric smoothing procedures are based on beta-binomial and log-linear models. A new approach has been developed using polynomials of the beta-binomial cumulative distribution function. The same approach was also applied to extend the beta-binomial family to more than four parameters. These methods were compared using cross-validation in two examinee samples who took the Armed Services Vocational Aptitude Battery. Results show that the log-linear and extended beta-binomial families fit the data about equally well.
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