On optimal control policy for Probabilistic Boolean Network: a state reduction approach

BACKGROUND: Probabilistic Boolean Network (PBN) is a popular model for studying genetic regulatory networks. An important and practical problem is to find the optimal control policy for a PBN so as to avoid the network from entering into undesirable states. A number of research works have been done by using dynamic programming-based (DP) method. However, due to the high computational complexity of PBNs, DP method is computationally inefficient for a large size network. Therefore it is natural to seek for approximation methods. RESULTS: Inspired by the state reduction strategies, we consider using dynamic programming in conjunction with state reduction approach to reduce the computational cost of the DP method. Numerical examples are given to demonstrate both the effectiveness and the efficiency of our proposed method. CONCLUSIONS: Finding the optimal control policy for PBNs is meaningful. The proposed problem has been shown to be ∑ p 2 - hard . By taking state reduction approach into consideration, the proposed method can speed up the computational time in applying dynamic programming-based algorithm. In particular, the proposed method is effective for larger size networks.published_or_final_versio

Passive Scalar: Scaling Exponents and Realizability

An isotropic passive scalar field $T$ advected by a rapidly-varying velocity field is studied. The tail of the probability distribution $P(\theta,r)$ for the difference $\theta$ in $T$ across an inertial-range distance $r$ is found to be Gaussian. Scaling exponents of moments of $\theta$ increase as $\sqrt{n}$ or faster at large order $n$, if a mean dissipation conditioned on $\theta$ is a nondecreasing function of $|\theta|$. The $P(\theta,r)$ computed numerically under the so-called linear ansatz is found to be realizable. Some classes of gentle modifications of the linear ansatz are not realizable.Comment: Substantially revised to conform with published version. Revtex (4 pages) with 2 postscript figures. Send email to [email protected]

Physical Electronics and Surface Physics

Contains reports on one research project.Joint Services Electronics Program (Contract DAAB07-74-C-0630

Discovery of metabolite biomarkers: flux analysis and reaction-reaction network approach

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Using Positive Youth Development Constructs to Design a Drug Education Curriculum for Junior Secondary Students in Hong Kong

This paper outlines the design of a new curriculum for positive youth development (P.A.T.H.S. II) in Hong Kong. The paper discusses the conceptual base for designing a drug-education curriculum for junior-secondary students using four positive youth development constructs—cognitive competence, emotional competence, beliefs in the future, and self-efficacy. The program design is premised on the belief that adolescents do have developmental assets; therefore, the curriculum is designed to develop their psychosocial competencies. The goal of the curriculum is to develop the selfhood of these youths and ultimately achieve the goal of successful adolescent development

Towards a B2B E-Commerce Evaluation Management Model to Assess Organizational Drivers in Hospitals

Effective utilization of business-to-business (B2B) electronic commerce (e-commerce) in hospitals may lead to many benefits such as increased accessibility to healthcare providers, improved process efficiency, enhanced quality of healthcare services, increased responses to changes, decreased scheduling conflicts, and reduction in administrative costs. However, many hospitals have found that they have not yet fully reaped the expected benefits from their B2B e-commerce investments. Despite this, there has not been much discussion in the literature with respect to the relationship between the organizational drivers on B2B e-commerce benefits for hospitals. Hence, a mixed-method of case study and survey was conducted to examine the relationships between B2B e-commerce benefits, IT evaluation resources allocation, IT investment evaluation methodologies, IT maturity, and user information requirements determination process. A B2B e-commerce evaluation management model was developed to test these relationships. The results provided empirical evidence in support of our proposed model and revealed that hospitals’ IT evaluation resources allocation practices mediated the relationship of IT investment evaluation methodologies, IT maturity, and user information requirements determination process with B2B e-commerce benefits. The results also showed that the level of IT maturity had a significant impact on the adoption of IT investment evaluation methodologies