Home About us Contact
|
Home About us Contact | ||
|
|
||
Minimization Approach (minimization + approach)
Selected AbstractsA computerized harm minimization prevention program for alcohol misuse and related harms: randomized controlled trialADDICTION, Issue 4 2009Laura Vogl ABSTRACT Aims Hazardous alcohol use is a leading cause of death among adolescents and young adults world-wide, yet few effective prevention interventions exist. This study was the first to examine a computerized harm minimization intervention to reduce alcohol misuse and related harms in adolescents. Design Cluster randomized controlled trial of a six-session curriculum-integrated harm minimization prevention program. The intervention was delivered by computer in the form of a teenage drama, which provided education through alcohol-related scenarios to which young people could relate. Setting Schools in Australia. Participants A total of 1466 year 8 students (13 years) from 16 high schools in Australia were allocated randomly to a computerized prevention program (n = 611, eight schools) or usual classes (n = 855, eight schools). Measurements Change in knowledge, alcohol use, alcohol-related harms and alcohol expectancies. Findings A computerized prevention program was more effective than usual classes in increasing alcohol-related knowledge of facts that would inform safer drinking choices and decreasing the positive social expectations which students believed alcohol may afford. For females it was effective in decreasing average alcohol consumption, alcohol-related harms and the frequency of drinking to excess (more than four standard drinks; 10 g ethanol). For males the behavioural effects were not significant. Conclusions A harm minimization approach is effective in educating young people about alcohol-related risks and is effective in reducing risky drinking and harms among girls. Reduction of problems among boys remains a challenge. [source] Self-potential data interpretation using standard deviations of depths computed from moving-average residual anomaliesGEOPHYSICAL PROSPECTING, Issue 4 2006E.M. Abdelrahman ABSTRACT We have developed a least-squares minimization approach to determine simultaneously the shape (shape factor) and the depth of a buried structure from self-potential (SP) data. The method is based on computing the standard deviation of the depths determined from all moving-average residual anomalies obtained from SP data, using filters of successive window lengths for each shape factor. The standard deviation may generally be considered a criterion for determining the correct depth and shape factor of the buried structure. When the correct shape factor is used, the standard deviation of the depths is less than the standard deviations computed using incorrect shape factors. This method is applied to synthetic data with and without random errors, complicated regionals and interference from neighbouring sources, and is tested on a known field example from Turkey. In all cases, the shape and depth solutions obtained are in a good agreement with the actual values. [source] Multicriteria second-order neural networks approach to imaging through turbulenceINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 2 2003Yuanmei Wang Abstract Atmospheric turbulence can greatly limit the spatial resolution in optical images obtained of space objects when imaged with ground-based telescopes. Two widely used algorithms to remove atmospheric turbulence in this class of images are blind de-convolution and speckle imaging. Both algorithms are effective in removing atmospheric turbulence, but they use different types of prior knowledge and have different strengths and weaknesses. We have developed a multicriteria cross entropy minimization approach to imaging through atmospheric turbulence and a second-order neural network implementations. Our simulations illustrated the efficiency of our method. © 2003 Wiley Periodicals, Inc. Int J Imaging Syst Technol 13, 146,151, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.10037 [source] A nonlinear minimization approach to multiobjective and structured controls for discrete-time systemsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 16 2004Kwan Ho Lee Abstract In this paper, a nonlinear minimization approach is proposed for multiobjective and structured controls for discrete-time systems. The problem of finding multiobjective and structured controls for discrete-time systems is represented as a quadratic matrix inequality problem. It is shown that the problem is reduced to a nonlinear minimization problem that has a concave objective function and linear matrix inequality constraints. An algorithm for the nonlinear minimization problem is proposed, which is easily implemented with existing semidefinite programming algorithms. The validity of the proposed algorithm is illustrated by comparisons with existing methods. In addition, applications of this work are demonstrated via numerical examples. Copyright © 2004 John Wiley & Sons, Ltd. [source] Modeling of the bacterial luciferase-flavin mononucleotide complex combining flexible docking with structure-activity dataPROTEIN SCIENCE, Issue 8 2001Leo Yen-Cheng Lin FMN, flavin mononucleotide; FMNH2, reduced FMN Abstract Although the crystal structure of Vibrio harveyi luciferase has been elucidated, the binding sites for the flavin mononucleotide and fatty aldehyde substrates are still unknown. The determined location of the phosphate-binding site close to Arg 107 on the , subunit of luciferase is supported here by point mutagenesis. This information, together with previous structure-activity data for the length of the linker connecting the phosphate group to the isoalloxazine ring represent important characteristics of the luciferase-bound conformation of the flavin mononucleotide. A model of the luciferase,flavin complex is developed here using flexible docking supplemented by these structural constraints. The location of the phosphate moiety was used as the anchor in a flexible docking procedure performed by conformation search by using the Monte Carlo minimization approach. The resulting databases of energy-ranked feasible conformations of the luciferase complexes with flavin mononucleotide, ,-phosphopentylflavin, ,-phosphobutylflavin, and ,-phosphopropylflavin were filtered according to the structure-activity profile of these analogs. A unique model was sought not only on energetic criteria but also on the geometric requirement that the isoalloxazine ring of the active flavin analogs must assume a common orientation in the luciferase-binding site, an orientation that is also inaccessible to the inactive flavin analog. The resulting model of the bacterial luciferase,flavin mononucleotide complex is consistent with the experimental data available in the literature. Specifically, the isoalloxazine ring of the flavin mononucleotide interacts with the Ala 74,Ala 75 cis -peptide bond as well as with the Cys 106 side chain in the , subunit of luciferase. The model of the binary complex reveals a distinct cavity suitable for aldehyde binding adjacent to the isoalloxazine ring and flanked by other key residues (His 44 and Trp 250) implicated in the active site. [source] Reduced-order state estimation for linear time-varying systems,ASIAN JOURNAL OF CONTROL, Issue 6 2009In Sung Kim Abstract We consider reduced-order and subspace state estimators for linear discrete-time systems with possibly time-varying dynamics. The reduced-order and subspace estimators are obtained using a finite-horizon minimization approach, and thus do not require the solution of algebraic Lyapunov or Riccati equations. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] Incomplete sensitivities and cost function reformulation leading to multi-criteria investigation of inverse problemsOPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 2 2003A. Cabot Abstract This paper deals with the application of typical minimization methods based on dynamical systems to the solution of a characteristic inverse problem. The state equation is based on the Burgers equation. The control is meant to achieve a prescribed state distribution and a given shock location. We show how to use incomplete sensitivities during the minimization process. We also show through a redefinition of the cost function that a multi-criteria problem needs to be considered in inverse problems. This example shows that a correct definition of the minimization problem is crucial and needs to be studied before a direct application of brute force minimization approaches. Copyright © 2003 John Wiley & Sons, Ltd. [source] | |||||||||||||