Policy models

Samarati, P. and S. De Capitani di Vimercati, Access control Policies, models, and mechanisms, in R. Focardi and R. Gorrieri, editors, Foundations of Security Analysis and Design, LNCS 2171. Springer-Verlag, 2001. 

There is at least one published analysis related to asthma based on a policy model. This model examined the relative clinical and economic impact of as-needed relievers (e.g. short-acting p-agonists) versus inhaled corticosteroid therapy in adults with a forced expiratory volume in 1 s >60% of predicted normal [49]. That model estimated that over a 10-year period, use of inhaled corticosteroids increased the costs, and improved clinical outcomes, at a cost of USD 7.50 per symptom-free day gained. Such a health policy model that focuses on primary prevention, rather than secondary control, might help guide economic and policy decisions for asthma prevention. 

Paltiel AD, Fuhlbrigge AL, Kitch BT, Liljas B, Weiss ST, Neumann PJ, Kuntz KM Cost-effectiveness of inhaled corticosteroids in adults with mild-to-moderate asthma Results from the asthma policy model. J Allergy Clin Immunol 2001 108 39-49. (NC)... 

Kaplan RM, Anderson JP. The general health policy model An integrated approach. In Spilker B, ed. Quality of Life and Pharmacoeconomics in Clinical Trials, 2d ed. Philadelphia, Lippincott-Raven, 1996 309-322. 

W. J. Song, M. K. Cho, I. S. Ha, and M. K. Choi. 2006. Healthcare System Architecture, Economic Value, and Policy Models in Large-Scale Wireless Sensor Networks in Computer Safety, Reliability, and Security. New York Springer. 

In this paper we propose a two-phase inspection policy for a single component preparedness system, in which the component itself may arise from a heterogeneous population. Criteria for the determination of optimal policy are presented. The work extends that of Vaurio (1999) who considered single phase polices for components from a homogeneous population. Reliability smdies of mixed failure distributions are well documented. Maintenance policy modelling when components in systems have mixed failure distributions is less well developed, and this paper makes a contribution to this area. 

A SC is modeled in this paper, determining the optimal ordering policy of one of the members in conditions in which the behavior of the other members is perfectly known and the demands are uncertain. A second case was considered where the demands are certain and the parameters of the order policy models of the other members are uncertain. It has been shown how financial risk can be managed. Extensions to the consideration of more uncertain parameters as well as decentralized control with sharing of Information or centralized control are work in progress. 

Wright Water Engineers, a small consulting engineering firm, developed a concise Business Ethics Policy modeled after the principles and canons of the ASCE Code of Ethics. www.wrightwater.com/documents/EthicsPolicy.pdf... 

Luss, H. (1983). An inspection policy model for production facilities. Management Science 29(9) 1102-1109. 

We read abstracts for aU articles that resulted from these searches, and then conducted a keyword search for nuclear within the article to determine its relevance to our topics and hypotheses and to look for repeating patterns, approaches, and attitudes toward nuclear. Articles that were irrelevant to our topic, or which only addressed climate change and nuclear power tangentially, were excluded. Policy modeling papers that explored nuclear power more thoroughly, particularly in relation to emissions targets, were included. 

The scientific basis of the "Orange Book" rests upon the reference monitor concept [Anderson 72] and the Bell-LaPadula security policy model [Bell 76], and indeed this basis has led to the development of commercially available (off-the-shelf) operating systems which can enforce the US DoD rules for processing classified information. 

The work of Bell and LaPadula is of fundamental importance to the development of computer security, not only because it precipitated the events that were then to follow, but because it demonstrates how some critical property of a computer system (in this case a security property) can be cast as an axiomatic model. If a computer system can be built which can be formally demonstrated to satisfy the axioms of such a model, referred to as a security policy model, then we have (probably) the greatest level of confidence ever achievable in that our security needs are met. 

Thus, notwithstanding the power of the policy modelling approach, care must be taken to model all the relevant aspects of the real world. However, if something important is missed, then it might be possible to counter it when the problem is viewed in the wider system context, described next. 

In conclusion, we note that the fault preventative approach provides high assurance in a single component. It is most effective when based on a formal security policy model and implemented using the reference monitor concept. Weaknesses in the security policy model can, however, be overcome by combining the fault preventative approach with a fault tolerant approach, indicating that the path to greater assurance requires a combination of the two methods. 

Safety engineers are now encouraged to use fault prevention techniques (e.g. through the publication of [MOD 91]), in particular the use of formal methods to the development of safety-critical software. To maximise the benefit of this approach the safety engineer would be wise to adopt the security principles of the "reference monitor concept" and security policy modelling. However, as in the case of security, the safety engineer would also be wise to utilise the more traditional safety engineering approach of fault tolerance in harmony with the new fault preventative approach. 

Tayur, Ganeshan MagSiZme/ QUANTITATIVE MODELS FOR SUPPLY CHAIN MANAGEMENT Weyant, J./ ENERGY AND ENVIRONMENTAL POLICY MODELING... 

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