STUDY THE PROBLEMS OF OPTIMIZING THE CAPITAL STRUCTURE OF THE COMPANY

Directory of Open Access Journals (Sweden)

Olga Gaydarzhyyska

2016-11-01

Full Text Available The aim of this work is to study the problem of optimizing the capital structure of the company. Optimization of capital structure is a necessary condition of adaptation the enterprises regardless of the branch of economy to which a company belongs, to changes in the economy in its development. Methods and criteria of optimisation of the capital structure of the enterprise. The method of determining the optimal capital structure of the enterprise according to the criteria of maximizing financial profitability. Technique. The study is based on the theoretical analysis of scientific works and practical activity of enterprises. Results. It is proved that in the process of optimizing the capital structure necessary to take into account the predictable result of economic activity of the enterprise, that is, financial result from usual activity before taxation. The study of problems of optimization of capital structure aimed at opening opportunities for the effective organization of business enterprises, providing conditions for disclosure for businesses achieving the goals of any order, and the creation of opportunities for enterprise maximum level of profit. The principle of optimization is to select the solution that best would take into account internal possibilities and external terms of activity of the enterprise. Optimization is the choice of a certain economic indicator that would allow to compare the effectiveness of any solutions. Also it is advisable to pay attention to the use of different types of loan capital to business enterprises, to know that helps to speed up circulation of funds and increase returns on invested capital, increase the efficiency of financial activities of a business entity. Value. Today, the economic activities of enterprises has a significant impact on the development of trade and economy. The achievement of dynamic growth of the basic indicators of work of enterprises of any sector of the economy, is the basic

Optimism and Adaptation to Multiple Sclerosis: What Does Optimism Mean?

NARCIS (Netherlands)

Fournier, M.; Ridder, D.T.D. de; Bensing, J.

1999-01-01

The aim of the present study was to determine the meaning of optimism by explicating the dimensions underlying the notion and their links to adjusting to MS. Seventy-three patients responded to optimism questionnaire s (i.e., the LOT, Generalized Self-Efficacy Scale) and outcome questionnaires.

Optimism and adaptation to multiple sclerosis: what does optimism mean?

NARCIS (Netherlands)

Fournier, M.; Ridder, D. de; Bensing, J.

1999-01-01

The aim of the present study was to determine the meaning of optimism by explicating the dimensions underlying the notion and their links to adjusting to MS. Seventy-three patients responded to optimism questionnaires (i.e., the LOT, Generalized Self-Efficacy Scale) and outcome questionnaires. In

Positive psychological interventions aimed at enhancing psychological ownership

NARCIS (Netherlands)

van Zyl, Llewellyn; van der Vaart, Leoni; Stemmet, Lehan; Olckers, Chantal; van Zyl, Llewellyn; van der Vaart, Leoni

2017-01-01

Interventions aimed at the enhancement of positive organisational behaviours, within organisational contexts, are imperative for creating and sustaining a high-performance culture, where individual and organisational strengths are optimized and top-talent retained. Psychological ownership, one form

RF Gun Optimization Study

International Nuclear Information System (INIS)

Alicia Hofler; Pavel Evtushenko

2007-01-01

Injector gun design is an iterative process where the designer optimizes a few nonlinearly interdependent beam parameters to achieve the required beam quality for a particle accelerator. Few tools exist to automate the optimization process and thoroughly explore the parameter space. The challenging beam requirements of new accelerator applications such as light sources and electron cooling devices drive the development of RF and SRF photo injectors. A genetic algorithm (GA) has been successfully used to optimize DC photo injector designs at Cornell University [1] and Jefferson Lab [2]. We propose to apply GA techniques to the design of RF and SRF gun injectors. In this paper, we report on the initial phase of the study where we model and optimize a system that has been benchmarked with beam measurements and simulation

Development of the measure of ovarian symptoms and treatment concerns: aiming for optimal measurement of patient-reported symptom benefit with chemotherapy for symptomatic ovarian cancer.

Science.gov (United States)

King, Madeleine T; Stockler, Martin R; Butow, Phyllis; O'Connell, Rachel; Voysey, Merryn; Oza, Amit M; Gillies, Kim; Donovan, Heidi S; Mercieca-Bebber, Rebecca; Martyn, Julie; Sjoquist, Katrin; Friedlander, Michael L

2014-06-01

The aim of this study was to determine the optimal patient-reported outcome measure (PROM) for assessing symptom benefit in trials of palliative chemotherapy for women with symptomatic ovarian cancer. Candidate PROMs were EORTC QLQ-C30 plus ovarian-specific QLQ-OV28, Functional Assessment of Cancer Therapy-Ovarian (FACT-O), FACT Ovarian Symptom Index (FOSI), and gynecologic cancer-specific Symptom Representation Questionnaire. Predefined optimality criteria were inclusion of all symptoms necessary for the specified purpose, recall period covering typical length of palliative chemotherapy, numerical item rating scales, and all necessary symptoms included in a single symptom index. Qualitative and quantitative methods were applied to data from stage 1 of the Gynecologic Cancer Intergroup Symptom Benefit Study to determine the set of necessary symptoms and to objectively assess candidate PROMs against the optimality criteria. Ten necessary symptoms were identified: pain, fatigue, abdominal bloating/discomfort, sleep disturbance, bowel disturbance, nausea and vomiting, shortness of breath, poor appetite, urinary symptoms, and weight changes. Although QLQ-C30 and QLQ-OV28 together cover all these symptoms, they split them into numerous scales, dissipating potential symptom-benefit signal. Conversely, FACT-O does not cover all necessary symptoms and contains many other HRQoL-related items and treatment side effects, diluting potential symptom-benefit signal when summed into scales. Item response scales and composite scoring of all candidate PROMs were suboptimal to our specific purpose. We therefore developed a new PROM, the Measure of Ovarian Symptoms and Treatment (MOST) concerns, to provide optimal measurement for the specified purpose. This article documents the development of the MOST, a new PROM designed to assess patient-reported benefits and burden as end points in clinical trials of palliative chemotherapy for women with symptomatic ovarian cancer. The validity

Optimization study on the primary mirror lightweighting of a remote sensing instrument

Science.gov (United States)

Chan, Chia-Yen; Huang, Bo-Kai; You, Zhen-Ting; Chen, Yi-Cheng; Huang, Ting-Ming

2015-07-01

Remote sensing instrument (RSI) is used to take images for ground surface observation, which will be exposed to high vacuum, high temperature difference, gravity, 15 g-force and random vibration conditions and other harsh environments during operation. While designing a RSI optical system, not only the optical quality but also the strength of mechanical structure we should be considered. As a result, an optimization method is adopted to solve this engineering problem. In the study, a ZERODUR® mirror with a diameter of 466 mm has been chosen as the model and the optimization has been executed by combining the computer-aided design, finite element analysis, and parameter optimization software. The optimization is aimed to obtain the most lightweight mirror with maintaining structural rigidity and good optical quality. Finally, the optimum optical mirror with a lightweight ratio of 0.55 is attained successfully.

Compressed Biogas-Diesel Dual-Fuel Engine Optimization Study for Ultralow Emission

Directory of Open Access Journals (Sweden)

Hasan Koten

2014-06-01

Full Text Available The aim of this study is to find out the optimum operating conditions in a diesel engine fueled with compressed biogas (CBG and pilot diesel dual-fuel. One-dimensional (1D and three-dimensional (3D computational fluid dynamics (CFD code and multiobjective optimization code were employed to investigate the influence of CBG-diesel dual-fuel combustion performance and exhaust emissions on a diesel engine. In this paper, 1D engine code and multiobjective optimization code were coupled and evaluated about 15000 cases to define the proper boundary conditions. In addition, selected single diesel fuel (dodecane and dual-fuel (CBG-diesel combustion modes were modeled to compare the engine performances and exhaust emission characteristics by using CFD code under various operating conditions. In optimization study, start of pilot diesel fuel injection, CBG-diesel flow rate, and engine speed were optimized and selected cases were compared using CFD code. CBG and diesel fuels were defined as leading reactants using user defined code. The results showed that significantly lower NOx emissions were emitted under dual-fuel operation for all cases compared to single-fuel mode at all engine load conditions.

Optimal social insurance with linear income taxation

DEFF Research Database (Denmark)

Bovenberg, Lans; Sørensen, Peter Birch

2009-01-01

We study optimal social insurance aimed at insuring disability risk in the presence of linear income taxation. Optimal disability insurance benefits rise with previous earnings. Optimal insurance is incomplete even though disability risks are exogenous and verifiable so that moral hazard in disab...... in disability insurance is absent. Imperfect insurance is optimal because it encourages workers to insure themselves against disability by working and saving more, thereby alleviating the distortionary impact of the redistributive income tax on labor supply and savings.......We study optimal social insurance aimed at insuring disability risk in the presence of linear income taxation. Optimal disability insurance benefits rise with previous earnings. Optimal insurance is incomplete even though disability risks are exogenous and verifiable so that moral hazard...

CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

Energy Technology Data Exchange (ETDEWEB)

BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

2012-09-19

THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

SU-E-T-531: Large--Scale DVH Quality Study: Correlated Aims Lead Relaxations

Energy Technology Data Exchange (ETDEWEB)

Nohadani, O; Roy, A [Northwestern University, Evanston, IL (United States); Das, I [Indiana University- School of Medicine, Indianapolis, IN (United States)

2015-06-15

Purpose: Intensity modulated radiation therapy plans are designed to optimally target a tumor while sparing surrounding tissue. Desired dose distributions are iteratively approached via inverse planning. This leads to tradeoffs between clinical objectives for the planning target volume (PTV), organs at risk, and normal tissues. Dose volume histogram (DVHs) related aims are followed that are either institutional or internationally recommended. We analyze common goals and identify potential reasons that often lead to tradeoffs. Methods: 524 IMRT plans for various tumor sites were analyzed based on the main institutional DVH goal for PTV (D95) and the recommendations by ICRU-83 (D2, D50, and D98). Robust statistical tools are developed and applied to ensure that the results are immune to data uncertainties. The probability of violation was measured for each of the DVH goals based on the frequency of not meeting recommended doses. Conditional probabilities for satisfying and/or violating DVH aims were computed to test the hypothesized pair-wise relations between DVH aims. For example, for plans that satisfied D50, the probability of violating D98 was computed via P(D98 < 95% | 98% ≤ D50 ≤ 102%). The equality constraint D50 = 100% was relaxed to encompass the range [98,102]%. Results: A large majority of cases (88%) satisfied the institutional goal for PTV of D95 ≤ 95%. Similar consensus existed for D98. 51% of cases satisfied D2 ≥ 107%. However, only 18% of cases satisfied D50. The conditional probability showed correlations amongst the studied DVH goals. In fact, a negative correlation was revealed between D50 and D95 (and D98), suggesting that these competing goals cannot be satisfied concurrently. Conclusion: The majority of plans followed the institutional guidelines. The reason for their deviation from international recommendations seems to be that the latter goals are competing and cannot be satisfied concurrently in clinical practice.

Particle Swarm Optimization applied to combinatorial problem aiming the fuel recharge problem solution in a nuclear reactor; Particle swarm optimization aplicado ao problema combinatorio com vistas a solucao do problema de recarga em um reator nuclear

Energy Technology Data Exchange (ETDEWEB)

Meneses, Anderson Alvarenga de Moura; Schirru, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: ameneses@con.ufrj.br; schirru@lmp.ufrj.br

2005-07-01

This work focuses on the usage the Artificial Intelligence technique Particle Swarm Optimization (PSO) to optimize the fuel recharge at a nuclear reactor. This is a combinatorial problem, in which the search of the best feasible solution is done by minimizing a specific objective function. However, in this first moment it is possible to compare the fuel recharge problem with the Traveling Salesman Problem (TSP), since both of them are combinatorial, with one advantage: the evaluation of the TSP objective function is much more simple. Thus, the proposed methods have been applied to two TSPs: Oliver 30 and Rykel 48. In 1995, KENNEDY and EBERHART presented the PSO technique to optimize non-linear continued functions. Recently some PSO models for discrete search spaces have been developed for combinatorial optimization. Although all of them having different formulation from the ones presented here. In this paper, we use the PSO theory associated with to the Random Keys (RK)model, used in some optimizations with Genetic Algorithms. The Particle Swarm Optimization with Random Keys (PSORK) results from this association, which combines PSO and RK. The adaptations and changings in the PSO aim to allow the usage of the PSO at the nuclear fuel recharge. This work shows the PSORK being applied to the proposed combinatorial problem and the obtained results. (author)

Economic optimization of natural hazard protection - conceptual study of existing approaches

Science.gov (United States)

Spackova, Olga; Straub, Daniel

2013-04-01

Risk-based planning of protection measures against natural hazards has become a common practice in many countries. The selection procedure aims at identifying an economically efficient strategy with regard to the estimated costs and risk (i.e. expected damage). A correct setting of the evaluation methodology and decision criteria should ensure an optimal selection of the portfolio of risk protection measures under a limited state budget. To demonstrate the efficiency of investments, indicators such as Benefit-Cost Ratio (BCR), Marginal Costs (MC) or Net Present Value (NPV) are commonly used. However, the methodologies for efficiency evaluation differ amongst different countries and different hazard types (floods, earthquakes etc.). Additionally, several inconsistencies can be found in the applications of the indicators in practice. This is likely to lead to a suboptimal selection of the protection strategies. This study provides a general formulation for optimization of the natural hazard protection measures from a socio-economic perspective. It assumes that all costs and risks can be expressed in monetary values. The study regards the problem as a discrete hierarchical optimization, where the state level sets the criteria and constraints, while the actual optimization is made on the regional level (towns, catchments) when designing particular protection measures and selecting the optimal protection level. The study shows that in case of an unlimited budget, the task is quite trivial, as it is sufficient to optimize the protection measures in individual regions independently (by minimizing the sum of risk and cost). However, if the budget is limited, the need for an optimal allocation of resources amongst the regions arises. To ensure this, minimum values of BCR or MC can be required by the state, which must be achieved in each region. The study investigates the meaning of these indicators in the optimization task at the conceptual level and compares their

A Comparative Theoretical and Computational Study on Robust Counterpart Optimization: I. Robust Linear Optimization and Robust Mixed Integer Linear Optimization

Science.gov (United States)

Li, Zukui; Ding, Ran; Floudas, Christodoulos A.

2011-01-01

Robust counterpart optimization techniques for linear optimization and mixed integer linear optimization problems are studied in this paper. Different uncertainty sets, including those studied in literature (i.e., interval set; combined interval and ellipsoidal set; combined interval and polyhedral set) and new ones (i.e., adjustable box; pure ellipsoidal; pure polyhedral; combined interval, ellipsoidal, and polyhedral set) are studied in this work and their geometric relationship is discussed. For uncertainty in the left hand side, right hand side, and objective function of the optimization problems, robust counterpart optimization formulations induced by those different uncertainty sets are derived. Numerical studies are performed to compare the solutions of the robust counterpart optimization models and applications in refinery production planning and batch process scheduling problem are presented. PMID:21935263

Assessment Studies regarding the Optimal Sizing of Wind Integrated Hybrid Power Plants for Off-Grid Systems

DEFF Research Database (Denmark)

Petersen, Lennart; Iov, Florin; Tarnowski, German Claudio

2018-01-01

The paper focusses on the optimal sizing of off-grid hybrid power plants including wind power generation. A modular and scalable system topology as well as an optimal sizing algorithm for the HPP has been presented in a previous publication. In this paper, the sizing process is evaluated by means...... of assessment studies. The aim is to address the impact of renewable resource data, the required power supply availability and reactive power load demand on the optimal sizing of wind integrated off-grid HPPs....

Optimization of the carrot leaf dehydration aiming at the preservation of omega-3 fatty acids

Directory of Open Access Journals (Sweden)

Vanessa Vivian de Almeida

2009-01-01

Full Text Available The carrot leaf dehydration conditions in air circulation oven were optimized through response surface methodology (RSM for minimizing the degradation of polyunsaturated fatty acids, particularly alpha-linolenic (LNA, 18:3n-3. The optimized leaf drying time and temperature were 43 h and 70 ºC, respectively. The fatty acids (FA were investigated using gas chromatography equipped with a flame ionization detector and fused silica capillary column; FA were identified with standards and based on equivalent-chain-length. LNA and other FA were quantified against C21:0 internal standard. After dehydration, the amount of LNA, quantified in mg/100 g dry matter of dehydrated carrot leaves, were 984 mg.

A technical practice of affiliate marketing : case study: coLanguage and OptimalNachhilfe

OpenAIRE

Phan, Giang

2015-01-01

This study aims to introduce a new marketing method: Affiliate marketing. In addition, this study explains and explores many types of affiliate marketing. The study focuses on defining affiliate marketing methods and the technologies used to develop it. To clarify and study this new business and marketing model, the study introduces two case studies: coLanguage and OptimalNachhilfe. In addition, various online businesses such as Amazon, Udemy, and Google are discussed to give a broader v...

Retrospective study of thyroid cancer treatment: aims and data

International Nuclear Information System (INIS)

Vosmikova, K.; Hermanska, J.; Jirsa, L.; Karny, M.; Samal, M.

1998-01-01

Although opinions preferring individual administration of activity in the treatment of thyroid cancer with 131 I predominate, sufficient quantitative arguments in favor of this approach are unavailable as yet. Therefore, a retrospective study involving statistical processing was proposed with the aim to evaluate the relations between available data of the patients and success of treatment. Ideally, recommendations regarding activity to be administered in dependence on the biophysical status of the patient should emerge from the study

Experimental design: Case studies of diagnostics optimization for W7-X

International Nuclear Information System (INIS)

Dreier, H.; Dinklage, A.; Fischer, R.; Hartfuss, H.-J.; Hirsch, M.; Kornejew, P.; Pasch, E.; Turkin, Yu.

2005-01-01

The preparation of diagnostics for Wendelstein 7-X is accompanied by diagnostics simulations and optimization. Starting from the physical objectives, the design of diagnostics should incorporate predictive modelling (e.g. transport modelling) and simulations of respective measurements. Although technical constraints are governing design considerations, it appears that several design parameters of different diagnostics can be optimized. However, a general formulation for fusion diagnostics design in terms of optimization is lacking. In this paper, first case studies of Bayesian experimental design aiming at applications on W7-X diagnostics preparation are presented. The information gain of a measurement is formulated as a utility function which is expressed in terms of the Kullback-Leibler divergence. Then, the expected range of data is to be included and the resulting expected utility represents the objective for optimization. Bayesian probability theory gives a framework allowing us for an appropriate formulation of the design problem in terms of probability distribution functions. Results are obtained for the information gain from interferometry and for the design of polychromators for Thomson scattering. For interferometry, studies of the choice of line-of-sights for optimum signal and for the reproduction of gradient positions are presented for circular, elliptical and W7-X geometries. For Thomson scattering, the design of filter transmissions for density and temperature measurements are discussed. (author)

Coil Optimization for HTS Machines

DEFF Research Database (Denmark)

Mijatovic, Nenad; Jensen, Bogi Bech; Abrahamsen, Asger Bech

An optimization approach of HTS coils in HTS synchronous machines (SM) is presented. The optimization is aimed at high power SM suitable for direct driven wind turbines applications. The optimization process was applied to a general radial flux machine with a peak air gap flux density of ~3T...... is suitable for which coil segment is presented. Thus, the performed study gives valuable input for the coil design of HTS machines ensuring optimal usage of HTS tapes....

Optimality Conditions in Vector Optimization

CERN Document Server

Jiménez, Manuel Arana; Lizana, Antonio Rufián

2011-01-01

Vector optimization is continuously needed in several science fields, particularly in economy, business, engineering, physics and mathematics. The evolution of these fields depends, in part, on the improvements in vector optimization in mathematical programming. The aim of this Ebook is to present the latest developments in vector optimization. The contributions have been written by some of the most eminent researchers in this field of mathematical programming. The Ebook is considered essential for researchers and students in this field.

The AI&M procedure for learning from incomplete data

DEFF Research Database (Denmark)

Jaeger, Manfred

2006-01-01

We investigate methods for parameter learning from incomplete data that is not missing at random. Likelihood-based methods then require the optimization of a profile likelihood that takes all possible missingness mechanisms into account. Optimizing this profile likelihood poses two main difficult......We investigate methods for parameter learning from incomplete data that is not missing at random. Likelihood-based methods then require the optimization of a profile likelihood that takes all possible missingness mechanisms into account. Optimizing this profile likelihood poses two main...... by operations in the space of data completions, rather than directly in the parameter space of the profile likelihood. We apply the AI\\&M method to learning parameters for Bayesian networks. The method is compared against conservative inference, which takes into account each possible data completion......, and against EM. The results indicate that likelihood-based inference is still feasible in the case of unknown missingness mechanisms, and that conservative inference is unnecessarily weak. On the other hand, our results also provide evidence that the EM algorithm is still quite effective when the data...

The Economic Discourse of the Current Reform Aimed at Business Optimization in Ukraine

Directory of Open Access Journals (Sweden)

Purdenko Olena A.

2016-05-01

Full Text Available The aim of the article is to study the strengths and weaknesses of the current reforms and provide appropriate recommendations and proposals to improve the regulatory and economic business environment. The article analyzes the introduced reforms in the aspect of the regulatory field and the active current system of taxation with the detailing of the type and content of the basic implemented measures. There have been justified the advantages and disadvantages of the introduced system of taxation with respect to the main budget forming taxes, such as the enterprise income taxes, value added tax, individual income tax considering changes in the administering of unified social tax (UST and war tax, excise duty. On the basis of the results of the study it has been found that the introduced reforms only partially improved the tax administration system and in no way reduced the announced tax burden, the time spending of business for preparing the current report was not significantly reduced.

Educational Optimism among Parents: A Pilot Study

Science.gov (United States)

Räty, Hannu; Kasanen, Kati

2016-01-01

This study explored parents' (N = 351) educational optimism in terms of their trust in the possibilities of school to develop children's intelligence. It was found that educational optimism could be depicted as a bipolar factor with optimism and pessimism on the opposing ends of the same dimension. Optimistic parents indicated more satisfaction…

A review of intervention studies aimed at household energy conservation

NARCIS (Netherlands)

Abrahamse, W; Steg, L; Vlek, C; Rothengatter, T; Rothengatter, J.A.

This article reviews and evaluates the effectiveness of interventions aiming to encourage households to reduce energy consumption. Thirty-eight studies performed within the field of (applied) social and environmental psychology are reviewed, and categorized as involving either antecedent strategies

Construction of a device for optimal positioning of the patient in studies of breast gammagraphy

International Nuclear Information System (INIS)

González López, Dagoberto Eloy; Infante Ginarte, José R.; Paumier Valdés, Yonimiler; Corella San Nicolás, Migdalia; Suárez Rosales, Lisandra

2016-01-01

Breast tumors are the most common cause of cancer in women. The ideal way to detect breast cancer is by a mammography examination. But this test may either be questionable or provide inconclusive data on a significant number of cases, leading to invasive biopsy procedures. The aim of this study is to optimize the detection of breast cancer by gammagraphy to improve the complementary diagnosis provided by a mammography. Consequently and for that reason, a device allowing an optimal patient positioning was designed and built. The materials used for its construction had few gamma radiation absorption properties. The effectiveness of breast gammagraphy was evaluated using by the designed device in two study cases. In both, the definite diagnosis obtained through mammography from doubtful cases was conclusively confirmed. A diagnostic protocol mammogram/gammagraphy was recommended to optimize the selection of patients requiring biopsy. (author)

A study on optimal task decomposition of networked parallel computing using PVM

International Nuclear Information System (INIS)

Seong, Kwan Jae; Kim, Han Gyoo

1998-01-01

A numerical study is performed to investigate the effect of task decomposition on networked parallel processes using Parallel Virtual Machine (PVM). In our study, a PVM program distributed over a network of workstations is used in solving a finite difference version of a one dimensional heat equation, where natural choice of PVM programming structure would be the master-slave paradigm, with the aim of finding an optimal configuration resulting in least computing time including communication overhead among machines. Given a set of PVM tasks comprised of one master and five slave programs, it is found that there exists a pseudo-optimal number of machines, which does not necessarily coincide with the number of tasks, that yields the best performance when the network is under a light usage. Increasing the number of machines beyond this optimal one does not improve computing performance since increase in communication overhead among the excess number of machines offsets the decrease in CPU time obtained by distributing the PVM tasks among these machines. However, when the network traffic is heavy, the results exhibit a more random characteristic that is explained by the random nature of data transfer time

Optimization of Thermal Aspects of Friction Stir Welding – Initial Studies Using a Space Mapping Technique

DEFF Research Database (Denmark)

Larsen, Anders Astrup; Bendsøe, Martin P.; Schmidt, Henrik Nikolaj Blicher

2007-01-01

The aim of this paper is to optimize a thermal model of a friction stir welding process. The optimization is performed using a space mapping technique in which an analytical model is used along with the FEM model to be optimized. The results are compared to traditional gradient based optimization...

Optimizing Cardiac Out-Put to Increase Cerebral Penumbral Perfusion in Large Middle Cerebral Artery Ischemic Lesion—OPTIMAL Study

Directory of Open Access Journals (Sweden)

Hannah Fuhrer

2017-08-01

Full Text Available IntroductionIn unsuccessful vessel recanalization, clinical outcome of acute stroke patients depends on early improvement of penumbral perfusion. So far, mean arterial blood pressure (MAP is the target hemodynamic parameter. However, the correlations of MAP to cardiac output (CO and cerebral perfusion are volume state dependent. In severe subarachnoid hemorrhage, optimizing CO leads to a reduction of delayed ischemic neurological deficits and improvement of clinical outcome. This study aims to investigate the effect of standard versus advanced cardiac monitoring with optimization of CO on the clinical outcome in patients with large ischemic stroke.Methods and analysisThe OPTIMAL study is a prospective, multicenter, open, into two arms (1:1 randomized, controlled trial. Sample size estimate: sample sizes of 150 for each treatment group (300 in total ensure an 80% power to detect a difference of 16% of a dichotomized level of functional clinical outcome at 3 months at a significance level of 0.05. Study outcomes: the primary endpoint is the functional outcome at 3 months. The secondary endpoints include functional outcome at 6 months follow-up, and complications related to hemodynamic monitoring and therapies.DiscussionThe results of this trial will provide data on the safety and efficacy of advanced hemodynamic monitoring on clinical outcome.Ethics and disseminationThe trial was approved by the leading ethics committee of Freiburg University, Germany (438/14, 2015 and the local ethics committees of the participating centers. The study is performed in accordance with the Declaration of Helsinki and the guidelines of Good Clinical Practice. It is registered in the German Clinical Trial register (DRKS; DRKS00007805. Dissemination will include submission to peer-reviewed professional journals and presentation at congresses. Hemodynamic monitoring may be altered in a specific stroke patient cohort if the study shows that advanced monitoring is

An optimal generic model for multi-parameters and big data optimizing: a laboratory experimental study

Science.gov (United States)

Utama, D. N.; Ani, N.; Iqbal, M. M.

2018-03-01

Optimization is a process for finding parameter (parameters) that is (are) able to deliver an optimal value for an objective function. Seeking an optimal generic model for optimizing is a computer science study that has been being practically conducted by numerous researchers. Generic model is a model that can be technically operated to solve any varieties of optimization problem. By using an object-oriented method, the generic model for optimizing was constructed. Moreover, two types of optimization method, simulated-annealing and hill-climbing, were functioned in constructing the model and compared to find the most optimal one then. The result said that both methods gave the same result for a value of objective function and the hill-climbing based model consumed the shortest running time.

Acid activation of natural clays aiming their application in adsorption

International Nuclear Information System (INIS)

Silva, M.M. da; Sousa, A.K.F. de; Lima, W.S.; Vasconcelos, P.N.M. de; Rodrigues, M. G.F.

2012-01-01

Clays of smectite type have wide application in industrial, mainly due to their adsorption properties. However, it is necessary to subject them to chemical treatments to optimize their potential. This study aimed to analyze the effects of acid activation on the clay Brasgel fresh. In the acid activation was used concentrated hydrochloric acid at different concentrations (3M, 4.5 M and 6 M) at a temperature of 70 ° C for 30 minutes. The samples fresh and activated technique were characterized by X-ray Diffraction (XRD). The results show that the properties of clay after activation are improved, it could be used as adsorbents in the treatment of wastewater. (author)

Association between Optimism, Psychosocial Well Being and Oral Health: A Cross-Sectional Study.

Science.gov (United States)

Thiruvenkadam, G; Asokan, Sharath; Baby John, J; Geetha Priya, P R

The aim of the study was to assess the association of optimism and psychosocial well being of school going children on their oral health status. The study included 12- to 15-year-old school going children (N = 2014) from Tamilnadu, India. Optimism was measured using the revised version of the Life Orientation Test (LOT-R). A questionnaire was sent to the parents regarding their child's psychosocial behavior which included shyness, feeling inferiority, unhappiness and friendliness. Clinical examination for each child was done to assess the DMFT score and OHI-S score. The data obtained were statistically analyzed using Pearson Chi-Square test, Mann-Whitney test and Kruskal-Wallis test with the aid of SPSS software (version 17). Odds Ratio (OR) was calculated with 95% Confidence Interval (CI). The p value ≤ 0.05 was considered statistically significant. Boys with high optimism had significantly lesser DMFT score than the boys with low optimism (p=0.001). Girls with high optimism had significantly higher DMFT score (p=0.001). In psychosocial outcomes, inferiority (p=0.002) and friendliness (p=0.001) showed significant association with DMFT score. Among the boys, children who felt less inferior (p=0.001), less unhappy (p=0.029) and more friendly (p=0.001) had lesser DMFT score. Among the psychosocial outcomes assessed, inferiority and friendliness had significant association with oral health of the children and hence, can be used as a proxy measures oral health.

Pretreatments and enzymatic hydrolysis of sugarcane bagasse aiming at the enhancement of the yield of glucose and xylose

Directory of Open Access Journals (Sweden)

A. de A. Guilherme

Full Text Available ABSTRACT This work studied the enzymatic hydrolysis of sugarcane bagasse aiming at the production of glucose and xylose. The bagasse was subjected to two different pretreatments: combined acid and alkalinepretreatment and hydrogen peroxidepretreatment. The enzymatic hydrolysis was optimized and a kinetic study was carried out in a stirred tank reactor (STR in batch mode. Optimal conditions were obtained by subjecting the bagasse to the hydrogen peroxide pretreatment followed by enzymatic hydrolysis. The addition of xylanases to the enzymatic mixture improved the production of fermentable sugars by 48%.

Study of Research and Development Processes through Fuzzy Super FRM Model and Optimization Solutions

Directory of Open Access Journals (Sweden)

Flavius Aurelian Sârbu

2015-01-01

Full Text Available The aim of this study is to measure resources for R&D (research and development at the regional level in Romania and also obtain primary data that will be important in making the right decisions to increase competitiveness and development based on an economic knowledge. As our motivation, we would like to emphasize that by the use of Super Fuzzy FRM model we want to determine the state of R&D processes at regional level using a mean different from the statistical survey, while by the two optimization methods we mean to provide optimization solutions for the R&D actions of the enterprises. Therefore to fulfill the above mentioned aim in this application-oriented paper we decided to use a questionnaire and for the interpretation of the results the Super Fuzzy FRM model, representing the main novelty of our paper, as this theory provides a formalism based on matrix calculus, which allows processing of large volumes of information and also delivers results difficult or impossible to see, through statistical processing. Furthermore another novelty of the paper represents the optimization solutions submitted in this work, given for the situation when the sales price is variable, and the quantity sold is constant in time and for the reverse situation.

Optimization of friction stir welding using space mapping and manifold mapping-an initial study of thermal aspects

DEFF Research Database (Denmark)

Larsen, Anders Astrup; Bendsøe, Martin P.; Hattel, Jesper Henri

2009-01-01

The aim of this paper is to optimize a thermal model of a friction stir welding process by finding optimal welding parameters. The optimization is performed using space mapping and manifold mapping techniques in which a coarse model is used along with the fine model to be optimized. Different...

Control strategies for wind farm power optimization: LES study

Science.gov (United States)

Ciri, Umberto; Rotea, Mario; Leonardi, Stefano

2017-11-01

Turbines in wind farms operate in off-design conditions as wake interactions occur for particular wind directions. Advanced wind farm control strategies aim at coordinating and adjusting turbine operations to mitigate power losses in such conditions. Coordination is achieved by controlling on upstream turbines either the wake intensity, through the blade pitch angle or the generator torque, or the wake direction, through yaw misalignment. Downstream turbines can be adapted to work in waked conditions and limit power losses, using the blade pitch angle or the generator torque. As wind conditions in wind farm operations may change significantly, it is difficult to determine and parameterize the variations of the coordinated optimal settings. An alternative is model-free control and optimization of wind farms, which does not require any parameterization and can track the optimal settings as conditions vary. In this work, we employ a model-free optimization algorithm, extremum-seeking control, to find the optimal set-points of generator torque, blade pitch and yaw angle for a three-turbine configuration. Large-Eddy Simulations are used to provide a virtual environment to evaluate the performance of the control strategies under realistic, unsteady incoming wind. This work was supported by the National Science Foundation, Grants No. 1243482 (the WINDINSPIRE project) and IIP 1362033 (I/UCRC WindSTAR). TACC is acknowledged for providing computational time.

Optimal use of video for teaching the practical implications of studying business information systems

DEFF Research Database (Denmark)

Fog, Benedikte; Ulfkjær, Jacob Kanneworff Stigsen; Schlichter, Bjarne Rerup

that video should be introduced early during a course to prevent students’ misconceptions of working with business information systems, as well as to increase motivation and comprehension within the academic area. It is also considered of importance to have a trustworthy person explaining the practical......The study of business information systems has become increasingly important in the Digital Economy. However, it has been found that students have difficulties understanding the practical implications thereof and this leads to a motivational decreases. This study aims to investigate how to optimize...... not sufficiently reflect the theoretical recommendations of using video optimally in a management education. It did not comply with the video learning sequence as introduced by Marx and Frost (1998). However, it questions if the level of cognitive orientation activities can become too extensive. It finds...

Perhitungan Value at Risk Pada Portfolio Optimal: Studi Perbandingan Saham Syariah dan Saham Konvensional

Directory of Open Access Journals (Sweden)

Sri Astuti Heryanti

2017-05-01

Full Text Available The aim of this study was to obtain empirical evidence about the difference between the level of risk when investing stocks in the Islamic and conventional by using Value at Risk (VaR. The object of research including consistent stock in the Jakarta Islamic Index and LQ45. The analytical method used in this research is quantitative analysis consisting of the establishment of the optimal portfolio by Markowitz method, calculation of VaR and testing the differences with Independent sample t-test. This study indicated that the value every stock can be reduced by diversifying through the establishment of an optimal portfolio. Based on the calculation Independent sample t-test, it is known that there is no difference between VaR of Islamic stocks and conventional stocks.

Advanced commercial Tokamak optimization studies

International Nuclear Information System (INIS)

Whitley, R.H.; Berwald, D.H.; Gordon, J.D.

1985-01-01

Our recent studies have concentrated on developing optimal high beta (bean-shaped plasma) commercial tokamak configurations using TRW's Tokamak Reactor Systems Code (TRSC) with special emphasis on lower net electric power reactors that are more easily deployable. A wide range of issues were investigated in the search for the most economic configuration: fusion power, reactor size, wall load, magnet type, inboard blanket and shield thickness, plasma aspect ratio, and operational β value. The costs and configurations of both steady-state and pulsed reactors were also investigated. Optimal small and large reactor concepts were developed and compared by studying the cost of electricity from single units and from multiplexed units. Multiplexed units appear to have advantages because they share some plant equipment and have lower initial capital investment as compared to larger single units

Study on Feasibility of Applying Function Approximation Moment Method to Achieve Reliability-Based Design Optimization

International Nuclear Information System (INIS)

Huh, Jae Sung; Kwak, Byung Man

2011-01-01

Robust optimization or reliability-based design optimization are some of the methodologies that are employed to take into account the uncertainties of a system at the design stage. For applying such methodologies to solve industrial problems, accurate and efficient methods for estimating statistical moments and failure probability are required, and further, the results of sensitivity analysis, which is needed for searching direction during the optimization process, should also be accurate. The aim of this study is to employ the function approximation moment method into the sensitivity analysis formulation, which is expressed as an integral form, to verify the accuracy of the sensitivity results, and to solve a typical problem of reliability-based design optimization. These results are compared with those of other moment methods, and the feasibility of the function approximation moment method is verified. The sensitivity analysis formula with integral form is the efficient formulation for evaluating sensitivity because any additional function calculation is not needed provided the failure probability or statistical moments are calculated

Studies on multivariate autoregressive analysis using synthesized reactor noise-like data for optimal modelling

Energy Technology Data Exchange (ETDEWEB)

Ciftcioglu, O.; Hoogenboom, J.E.; Dam, H. van

1988-01-01

Studies on the multivariate autoregressive (MAR) analysis are carried out for the choice of the parameters for modelling the data obtained from various sensors optimally. Accordingly, the roles of the parameters on the analysis results are identified and the related ambiguities are reduced. Experimental investigations are carried out by means of synthesized reactor noise-like data obtained from a digital simulator providing simulated stochastic signals of an operating nuclear reactor so that the simulator constitutes a favourable tool for the present studies aimed. As the system is well defined with its known structure, precise comparison of the MAR analysis results with the true values is performed. With the help of the information gained through the studies carried out, conditions to be taken care of for optimal signal processing in MAR modelling are determined. Although the parameters involved are related among themselves and they have to be given different values suitable for the particular application in hand, some criteria, namely memory-time and sample length-time play an essential role in AR modelling and they are found to be applicable to each individual case commonly, for the establishment of the optimality.

Studies on multivariate autoregressive analysis using synthesized reactor noise-like data for optimal modelling

International Nuclear Information System (INIS)

Ciftcioglu, O.

1988-01-01

Studies on the multivariate autoregressive (MAR) analysis are carried out for the choice of the parameters for modelling the data obtained from various sensors optimally. Accordingly, the roles of the parameters on the analysis results are identified and the related ambiguities are reduced. Experimental investigations are carried out by means of synthesized reactor noise-like data obtained from a digital simulator providing simulated stochastic signals of an operating nuclear reactor so that the simulator constitutes a favourable tool for the present studies aimed. As the system is well defined with its known structure, precise comparison of the MAR analysis results with the true values is performed. With the help of the information gained through the studies carried out, conditions to be taken care of for optimal signal processing in MAR modelling are determined. Although the parameters involved are related among themselves and they have to be given different values suitable for the particular application in hand, some criteria, namely memory-time and sample length-time play an essential role in AR modelling and they are found to be applicable to each individual case commonly, for the establishment of the optimality. (author)

Engineering strategies aimed at control of acidification rate of lactic acid bacteria

DEFF Research Database (Denmark)

Martinussen, Jan; Solem, Christian; Holm, Anders Koefoed

2013-01-01

The ability of lactic acid bacteria to produce lactic acid from various sugars plays an important role in food fermentations. Lactic acid is derived from pyruvate, the end product of glycolysis and thus a fast lactic acid production rate requires a high glycolytic flux. In addition to lactic acid......, alternative end products - ethanol, acetic acid and formic acid - are formed by many species. The central role of glycolysis in lactic acid bacteria has provoked numerous studies aiming at identifying potential bottleneck(s) since knowledge about flux control could be important not only for optimizing food...

Aligning emergency care with the triple aim: Opportunities and future directions after healthcare reform.

Science.gov (United States)

Agrawal, Shantanu; Conway, Patrick H

2014-09-01

The Triple Aim of better health, better care, and lower costs has become a fundamental framework for understanding the need for broad health care reform and describing health care value. While the framework is not specific to any clinical setting, this article focuses on the alignment between the framework and Emergency Department (ED) care. The paper explores where emergency care is naturally aligned with each Aim, as well as current barriers which must be addressed to meet the full vision of the Triple Aim. We propose a vision of EDs serving as a nexus for care coordination optimally consistent with the Triple Aim and the requirements for such a role. These requirements include: (1) substantial integration in coordinated care models; (2) development of reliable and actionable data on ED quality, population health, and cost outcomes; (3) specific initiatives to control and optimize ED utilization; and (4) payment models which preserve surge and disaster response capacity. Published by Elsevier Inc.

Portfolio optimization with mean-variance model

Science.gov (United States)

Hoe, Lam Weng; Siew, Lam Weng

2016-06-01

Investors wish to achieve the target rate of return at the minimum level of risk in their investment. Portfolio optimization is an investment strategy that can be used to minimize the portfolio risk and can achieve the target rate of return. The mean-variance model has been proposed in portfolio optimization. The mean-variance model is an optimization model that aims to minimize the portfolio risk which is the portfolio variance. The objective of this study is to construct the optimal portfolio using the mean-variance model. The data of this study consists of weekly returns of 20 component stocks of FTSE Bursa Malaysia Kuala Lumpur Composite Index (FBMKLCI). The results of this study show that the portfolio composition of the stocks is different. Moreover, investors can get the return at minimum level of risk with the constructed optimal mean-variance portfolio.

An open-source optimization tool for solar home systems: A case study in Namibia

International Nuclear Information System (INIS)

Campana, Pietro Elia; Holmberg, Aksel; Pettersson, Oscar; Klintenberg, Patrik; Hangula, Abraham; Araoz, Fabian Benavente; Zhang, Yang; Stridh, Bengt; Yan, Jinyue

2016-01-01

Highlights: • An open-source optimization tool for solar home systems (SHSs) design is developed. • The optimization tool is written in MS Excel-VBA. • The optimization tool is validated with a commercial and open-source software. • The optimization tool has the potential of improving future SHS installations. - Abstract: Solar home systems (SHSs) represent a viable technical solution for providing electricity to households and improving standard of living conditions in areas not reached by the national grid or local grids. For this reason, several rural electrification programmes in developing countries, including Namibia, have been relying on SHSs to electrify rural off-grid communities. However, the limited technical know-how of service providers, often resulting in over- or under-sized SHSs, is an issue that has to be solved to avoid dissatisfaction of SHSs’ users. The solution presented here is to develop an open-source software that service providers can use to optimally design SHSs components based on the specific electricity requirements of the end-user. The aim of this study is to develop and validate an optimization model written in MS Excel-VBA which calculates the optimal SHSs components capacities guaranteeing the minimum costs and the maximum system reliability. The results obtained with the developed tool showed good agreement with a commercial software and a computational code used in research activities. When applying the developed optimization tool to existing systems, the results identified that several components were incorrectly sized. The tool has thus the potentials of improving future SHSs installations, contributing to increasing satisfaction of end-users.

Study of optimizing the process of Cadmium adsorption by synthesized silver nanoparticles using Chlorella vulgaris

Directory of Open Access Journals (Sweden)

Faezeh Sajadi

2016-05-01

Full Text Available Background and Aim: Cadmium (Cd is one of the most toxic heavy metals in water that mostly enters the water cycle through industrial waste water. Silver nanoparticles have the capacity to remove heavy metals from the water resources through the mechanism of adsorption. The present study aimed at producing  silver bio-nanoparticles and optimizing . Cd removal from aquatic solutions. Materials and Methods: Silver bio-nanoparticles were extracted via a micro-algae Chlorella vulgaris extract and silver nitrate synthesis. Then, the characteristics of the particles were  determined using FT-IR, XRD, SEM devices. In order to optimize Cadmium adsorption by means of silver nanoparticles, parameters including pH, reaction time, initial concentration of Cd and concentrations of nanoparticles were studied under different conditions. Results: The resulting nanoparticles were spherical, single and crystalline, whose sizes were 10-45 nm.  Under the condition of PH = 8, the initial concentration of cadmium 0.5 mg/L, adsorbent dosage of 0.5 mg, reaction time of 10 min, temperature of 300C and mixing speed of 200 rpm, 99% of cadmium was removed. Isotherm of Cadmium-ion adsorption followed Langmuir (R2> 0/96 (and Freundlich (R2> 0/94 models. Conclusion: Under optimal conditions, silver bio-nanoparticles had the capacity of quick and effective adsorption of cadmium. Thus, with a cheap, non-toxic and environmentally friendly method  can remove heavy metals in a short time.

Implementing the cost-optimal methodology in EU countries

DEFF Research Database (Denmark)

Atanasiu, Bogdan; Kouloumpi, Ilektra; Thomsen, Kirsten Engelund

This study presents three cost-optimal calculations. The overall aim is to provide a deeper analysis and to provide additional guidance on how to properly implement the cost-optimality methodology in Member States. Without proper guidance and lessons from exemplary case studies using realistic...... input data (reflecting the likely future development), there is a risk that the cost-optimal methodology may be implemented at sub-optimal levels. This could lead to a misalignment between the defined cost-optimal levels and the long-term goals, leaving a significant energy saving potential unexploited....... Therefore, this study provides more evidence on the implementation of the cost-optimal methodology and highlights the implications of choosing different values for key factors (e.g. discount rates, simulation variants/packages, costs, energy prices) at national levels. The study demonstrates how existing...

Causes of individual differences in adolescent optimism: a study in Dutch twins and their siblings.

Science.gov (United States)

Mavioğlu, Rezan Nehir; Boomsma, Dorret I; Bartels, Meike

2015-11-01

The aim of this study was to investigate the degree to which genetic and environmental influences affect variation in adolescent optimism. Optimism (3 items and 6 items approach) and pessimism were assessed by the Life Orientation Test-Revised (LOT-R) in 5,187 adolescent twins and 999 of their non-twin siblings from the Netherlands Twin Register (NTR). Males reported significantly higher optimism scores than females, while females score higher on pessimism. Genetic structural equation modeling revealed that about one-third of the variance in optimism and pessimism was due to additive genetic effects, with the remaining variance being explained by non-shared environmental effects. A bivariate correlated factor model revealed two dimensions with a genetic correlation of -.57 (CI -.67, -.47), while the non-shared environmental correlation was estimated to be -.21 (CI -.25, -.16). Neither an effect of shared environment, non-additive genetic influences, nor quantitative sex differences was found for both dimensions. This result indicates that individual differences in adolescent optimism are mainly accounted for by non-shared environmental factors. These environmental factors do not contribute to the similarity of family members, but to differences between them. Familial resemblance in optimism and pessimism assessed in adolescents is fully accounted for by genetic overlap between family members.

The Relationship between Optimism-Pessimism and Personality Traits among Students in the Hashemite University

Science.gov (United States)

Mahasneh, Ahmad M.; Al-Zoubi, Zohair H.; Batayeneh, Omar T.

2013-01-01

This study aimed to examine the correlation between optimism-pessimism and personality traits (extraversion, introversion, emotional stability and neuroticism), also aimed to identify the prevalence of optimism and pessimism in the study sample according to the variable sex, academic specialization, level of study, and grade point average. The…

OPTIMIZATION METHODS IN TRANSPORTATION OF FOREST PRODUCTS

Directory of Open Access Journals (Sweden)

Selçuk Gümüş

2008-04-01

Full Text Available Turkey has total of 21.2 million ha (27 % forest land. In this area, average 9 million m3 of logs and 5 million stere of fuel wood have been annually produced by the government forest enterprises. The total annual production is approximately 13million m3 Considering the fact that the costs of transporting forest products was about . 160 million TL in the year of 2006, the importance of optimizing the total costs in transportation can be better understood. Today, there is not common optimization method used at whole transportation problems. However, the decision makers select the most appropriate methods according to their aims.Comprehending of features and capacity of optimization methods is important for selecting of the most appropriate method. The evaluation of optimization methods that can be used at forest products transportation is aimed in this study.

Space engineering modeling and optimization with case studies

CERN Document Server

Pintér, János

2016-01-01

This book presents a selection of advanced case studies that cover a substantial range of issues and real-world challenges and applications in space engineering. Vital mathematical modeling, optimization methodologies and numerical solution aspects of each application case study are presented in detail, with discussions of a range of advanced model development and solution techniques and tools. Space engineering challenges are discussed in the following contexts: •Advanced Space Vehicle Design •Computation of Optimal Low Thrust Transfers •Indirect Optimization of Spacecraft Trajectories •Resource-Constrained Scheduling, •Packing Problems in Space •Design of Complex Interplanetary Trajectories •Satellite Constellation Image Acquisition •Re-entry Test Vehicle Configuration Selection •Collision Risk Assessment on Perturbed Orbits •Optimal Robust Design of Hybrid Rocket Engines •Nonlinear Regression Analysis in Space Engineering< •Regression-Based Sensitivity Analysis and Robust Design ...

Virtually optimized insoles for offloading the diabetic foot: A randomized crossover study.

Science.gov (United States)

Telfer, S; Woodburn, J; Collier, A; Cavanagh, P R

2017-07-26

Integration of objective biomechanical measures of foot function into the design process for insoles has been shown to provide enhanced plantar tissue protection for individuals at-risk of plantar ulceration. The use of virtual simulations utilizing numerical modeling techniques offers a potential approach to further optimize these devices. In a patient population at-risk of foot ulceration, we aimed to compare the pressure offloading performance of insoles that were optimized via numerical simulation techniques against shape-based devices. Twenty participants with diabetes and at-risk feet were enrolled in this study. Three pairs of personalized insoles: one based on shape data and subsequently manufactured via direct milling; and two were based on a design derived from shape, pressure, and ultrasound data which underwent a finite element analysis-based virtual optimization procedure. For the latter set of insole designs, one pair was manufactured via direct milling, and a second pair was manufactured through 3D printing. The offloading performance of the insoles was analyzed for forefoot regions identified as having elevated plantar pressures. In 88% of the regions of interest, the use of virtually optimized insoles resulted in lower peak plantar pressures compared to the shape-based devices. Overall, the virtually optimized insoles significantly reduced peak pressures by a mean of 41.3kPa (p<0.001, 95% CI [31.1, 51.5]) for milled and 40.5kPa (p<0.001, 95% CI [26.4, 54.5]) for printed devices compared to shape-based insoles. The integration of virtual optimization into the insole design process resulted in improved offloading performance compared to standard, shape-based devices. ISRCTN19805071, www.ISRCTN.org. Copyright © 2017 Elsevier Ltd. All rights reserved.

N-Springs pump and treat system optimization study

International Nuclear Information System (INIS)

1997-03-01

This letter report describes and presents the results of a system optimization study conducted to evaluate the N-Springs pump and treat system. The N-Springs pump and treat is designed to remove strontium-90 (90Sr) found in the groundwater in the 100-NR-2 Operable Unit near the Columbia River. The goal of the system optimization study was to assess and quantify what conditions and operating parameters could be employed to enhance the operating and cost effectiveness of the recently upgraded pump and treat system.This report provides the results of the system optimization study, reports the cost effectiveness of operating the pump and treat at various operating modes and 90Sr removal goals, and provides recommendations for operating the pump and treat

A study of optical design and optimization of laser optics

Science.gov (United States)

Tsai, C.-M.; Fang, Yi-Chin

2013-09-01

This paper propose a study of optical design of laser beam shaping optics with aspheric surface and application of genetic algorithm (GA) to find the optimal results. Nd: YAG 355 waveband laser flat-top optical system, this study employed the Light tools LDS (least damped square) and the GA of artificial intelligence optimization method to determine the optimal aspheric coefficient and obtain the optimal solution. This study applied the aspheric lens with GA for the flattening of laser beams using collimated laser beam light, aspheric lenses in order to achieve best results.

Optimization Studies for the H $\\rightarrow$ WW Boosted Decision Tree Analysis

CERN Document Server

Strickland, Jessica

2014-01-01

The aim of this project was to follow the ATLAS $H \\rightarrow WW$ BDT analysis and try to optimize training variables, pre-selection cuts, and training parameters such as the depth \\cite{orig, spin}. Machine learning was done with Monte Carlo samples of the $H \\rightarrow W^+ W^- \\rightarrow e \\mu \

Ecological radiation monotoring in NPP region, aims and tasks

International Nuclear Information System (INIS)

Egorov, Yu.A.

1986-01-01

Aims and tasks of ecological radiation monitoring in the NPP region are discussed. The aims of monitoring are: to determine possible sequences of NPP radioactive release effects on ecosystems, taking place on the background of chemical and thermal pollution to develop standard of radiation effect on ecosystems; the aims includes also obtaining of information for forecasting and evaluating long-term radiation effects, establishment of factors characterizing the ecosystem state, establishment of a combined effect of radioactive wastes with chemical and thermal ones. Finally, the aim of monitoring consists in providing the natural object conservation in the NPP region under optimal operation conditions. Thus it is necessary to solve the following problems: to observe systematically release, transport and transformation, when transporting radioactive and chemical contaminants in terrestial and aquatic biocenoses, as well as injection and transport in them of waste heat; to observe systematically the natural physico-chemical, chemico-biological processes affecting the injection and transport of contaminants in ecosystem components; to observe systematically the natural and, probably, antropogenic processes; to carry out systematically observations of the ecosystem state in the NPP region and eco-systems-monitors

Handbook of optimization in telecommunications

CERN Document Server

Pardalos, Panos M

2008-01-01

Covers the field of optimization in telecommunications, and the optimization developments that are frequently applied to telecommunications. This book aims to provide a reference tool for scientists and engineers in telecommunications who depend upon optimization.

A study on an optimal movement model

Energy Technology Data Exchange (ETDEWEB)

Feng Jianfeng [COGS, Sussex University, Brighton BN1 9QH, UK (United Kingdom); Zhang, Kewei [SMS, Sussex University, Brighton BN1 9QH (United Kingdom); Luo Yousong [Department of Mathematics and Statistics, RMIT University, GOP Box 2476V, Melbourne, Vic 3001 (Australia)

2003-07-11

We present an analytical and rigorous study on a TOPS (task optimization in the presence of signal-dependent noise) model with a hold-on or an end-point control. Optimal control signals are rigorously obtained, which enables us to investigate various issues about the model including its trajectories, velocities, control signals, variances and the dependence of these quantities on various model parameters. With the hold-on control, we find that the optimal control can be implemented with an almost 'nil' hold-on period. The optimal control signal is a linear combination of two sub-control signals. One of the sub-control signals is positive and the other is negative. With the end-point control, the end-point variance is dramatically reduced, in comparison with the hold-on control. However, the velocity is not symmetric (bell shape). Finally, we point out that the velocity with a hold-on control takes the bell shape only within a limited parameter region.

Optimism, Cynical Hostility, Falls, and Fractures: The Women's Health Initiative Observational Study (WHI-OS).

Science.gov (United States)

Cauley, Jane A; Smagula, Stephen F; Hovey, Kathleen M; Wactawski-Wende, Jean; Andrews, Christopher A; Crandall, Carolyn J; LeBoff, Meryl S; Li, Wenjun; Coday, Mace; Sattari, Maryam; Tindle, Hilary A

2017-02-01

Traits of optimism and cynical hostility are features of personality that could influence the risk of falls and fractures by influencing risk-taking behaviors, health behaviors, or inflammation. To test the hypothesis that personality influences falls and fracture risk, we studied 87,342 women enrolled in WHI-OS. Optimism was assessed by the Life Orientation Test-Revised and cynical hostility, the cynicism subscale of the Cook-Medley questionnaire. Higher scores indicate greater optimism and hostility. Optimism and hostility were correlated at r = -0. 31, p optimism and hostility with tests for trends; Q1 formed the referent group. The average follow-up for fractures was 11.4 years and for falls was 7.6 years. In multivariable (MV)-adjusted models, women with the highest optimism scores (Q4) were 11% less likely to report ≥2 falls in the past year (odds ratio [OR] = 0.89; 95% confidence intervals [CI] 0.85-0.90). Women in Q4 for hostility had a 12% higher risk of ≥2 falls (OR = 1.12; 95% CI 1.07-1.17). Higher optimism scores were also associated with a 10% lower risk of fractures, but this association was attenuated in MV models. Women with the greatest hostility (Q4) had a modest increased risk of any fracture (MV-adjusted hazard ratio = 1. 05; 95% CI 1.01-1.09), but there was no association with specific fracture sites. In conclusion, optimism was independently associated with a decreased risk of ≥2 falls, and hostility with an increased risk of ≥2 falls, independent of traditional risk factors. The magnitude of the association was similar to aging 5 years. Whether interventions aimed at attitudes could reduce fall risks remains to be determined. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

A study of optimization techniques in HDR brachytherapy for the prostate

Science.gov (United States)

Pokharel, Ghana Shyam

Several studies carried out thus far are in favor of dose escalation to the prostate gland to have better local control of the disease. But optimal way of delivery of higher doses of radiation therapy to the prostate without hurting neighboring critical structures is still debatable. In this study, we proposed that real time high dose rate (HDR) brachytherapy with highly efficient and effective optimization could be an alternative means of precise delivery of such higher doses. This approach of delivery eliminates the critical issues such as treatment setup uncertainties and target localization as in external beam radiation therapy. Likewise, dosimetry in HDR brachytherapy is not influenced by organ edema and potential source migration as in permanent interstitial implants. Moreover, the recent report of radiobiological parameters further strengthen the argument of using hypofractionated HDR brachytherapy for the management of prostate cancer. Firstly, we studied the essential features and requirements of real time HDR brachytherapy treatment planning system. Automating catheter reconstruction with fast editing tools, fast yet accurate dose engine, robust and fast optimization and evaluation engine are some of the essential requirements for such procedures. Moreover, in most of the cases we performed, treatment plan optimization took significant amount of time of overall procedure. So, making treatment plan optimization automatic or semi-automatic with sufficient speed and accuracy was the goal of the remaining part of the project. Secondly, we studied the role of optimization function and constraints in overall quality of optimized plan. We have studied the gradient based deterministic algorithm with dose volume histogram (DVH) and more conventional variance based objective functions for optimization. In this optimization strategy, the relative weight of particular objective in aggregate objective function signifies its importance with respect to other objectives

Core optimization studies at JEN-Spain

International Nuclear Information System (INIS)

Gomez Alonso, M.

1983-01-01

The JEN-1 is a 3-MW reactor which uses flat-plate fuel elements. It was originally fueled with 20%-enriched uranium but more recently with 90%-enriched fuel. It now appears that it will have to be converted back to using 20%- enriched fuel. Progress is presently being made in fuel fabrication. Plates with meat thicknesses of up to 1.5 mm have been fabricated. Plates are being tested with 40 wt % uranium in the fuel meat. Progress is also being made in reactor design in collaboration with atomic energy commissions of other countries for swimming pool reactors being designed or under construction in Chile, Ecuador, and Spain itself. The design studies address core optimization, safety analysis report updating, irradiation facilities, etc. Core optimization is specifically addressed in this paper. A common swimming-pool-type reactor such as the JEN-1 served as an example. The philosophy adopted in this study is not to try to match the high enrichment core, but rather to treat the design as new and try to optimize it using simplified neutronic/thermal hydraulic/economic models. This philosophy appears to be somewhat original. As many as possible of the fuel parameters are constrained to remain constant

Applications of combinatorial optimization

CERN Document Server

Paschos, Vangelis Th

2013-01-01

Combinatorial optimization is a multidisciplinary scientific area, lying in the interface of three major scientific domains: mathematics, theoretical computer science and management. The three volumes of the Combinatorial Optimization series aims to cover a wide range of topics in this area. These topics also deal with fundamental notions and approaches as with several classical applications of combinatorial optimization. "Applications of Combinatorial Optimization" is presenting a certain number among the most common and well-known applications of Combinatorial Optimization.

Graph-related optimization and decision support systems

CERN Document Server

Krichen, Saoussen

2014-01-01

Constrained optimization is a challenging branch of operations research that aims to create a model which has a wide range of applications in the supply chain, telecommunications and medical fields. As the problem structure is split into two main components, the objective is to accomplish the feasible set framed by the system constraints. The aim of this book is expose optimization problems that can be expressed as graphs, by detailing, for each studied problem, the set of nodes and the set of edges.  This graph modeling is an incentive for designing a platform that integrates all optimizatio

AN ADAPTIVE ACO-DRIVEN SCHEME FOR LEARNING AIM ORIENTED PERSONALIZED E-LEARNING

Directory of Open Access Journals (Sweden)

Sushma Hans

2014-10-01

Full Text Available The e-learning paradigm is now a well-established vehicle of modern education. It caters to a wide spectrum of students with diverse backgrounds who enroll with their own learning aims. A core challenge under this scenario is to generate personalized learning paths so that each student can achieve her learning aim most effectively. Prior works used static attributes such as prior knowledge level, learning ability, browsing preferences, learning style etc. to generate personalized learning paths. In this paper, we take an entirely new route by taking into account the continuous improvement of a learner in the light of her own learning aim, to redefine her learning path at each level of the course. We introduce the concept of personalized examination system that systematically evaluates the dynamic learning ability of every student according to her pre-set goals. The proposed intelligent e-learning system uses Ant Colony Optimization to iteratively optimize the forward learning paths. Experimental results reveal that the system is able to tap a student’s improved learning ability to choose more difficult paths that contribute highly towards her own aims. We demonstrate that the overall learning success of weaker students doubles as compared to statically generated paths while there is considerable improvement of 50% in the learning success for average students as well. This clearly indicates that our approach gives realistic benefits to initially weak students who gradually evolve as the course progresses.

Using an optimization approach to design an insole for lowering plantar fascia stress--a finite element study.

Science.gov (United States)

Hsu, Yu-Chun; Gung, Yih-Wen; Shih, Shih-Liang; Feng, Chi-Kuang; Wei, Shun-Hwa; Yu, Chung-Huang; Chen, Chen-Sheng

2008-08-01

Plantar heel pain is a commonly encountered orthopedic problem and is most often caused by plantar fasciitis. In recent years, different shapes of insole have been used to treat plantar fasciitis. However, little research has been focused on the junction stress between the plantar fascia and the calcaneus when wearing different shapes of insole. Therefore, this study aimed to employ a finite element (FE) method to investigate the relationship between different shapes of insole and the junction stress, and accordingly design an optimal insole to lower fascia stress.A detailed 3D foot FE model was created using ANSYS 9.0 software. The FE model calculation was compared to the Pedar device measurements to validate the FE model. After the FE model validation, this study conducted parametric analysis of six different insoles and used optimization analysis to determine the optimal insole which minimized the junction stress between plantar fascia and calcaneus. This FE analysis found that the plantar fascia stress and peak pressure when using the optimal insole were lower by 14% and 38.9%, respectively, than those when using the flat insole. In addition, the stress variation in plantar fascia was associated with the different shapes of insole.

Effect of surface area of substrates aiming the optimization of carbon nanotube production from ferrocene

International Nuclear Information System (INIS)

Osorio, A.G.; Bergmann, C.P.

2013-01-01

Highlights: ► An optimized synthesis of CNTs by ferrocene is proposed. ► The surface area of substrates influences the nucleation of CNTs. ► The higher the surface area of substrates the lower the temperature of synthesis. ► Chemical composition of substrates has no influence on the growth of CNTs. - Abstract: Ferrocene is widely used for the synthesis of carbon nanotubes due to its ability to act as catalyst and precursor of the synthesis. This paper proposes an optimization of the synthesis of carbon nanotubes from ferrocene, using a substrate with high surface area for their nucleation. Four different surface areas of silica powder were tested: 0.5, 50, 200 and 300 m 2 /g. Raman spectroscopy and microscopy were used to characterize the product obtained and X-ray diffraction and thermal analysis were also performed to evaluate the phases of the material. It was observed that the silica powder with the highest surface area allowed the synthesis of carbon nanotubes to occur at a lower temperature (600 °C), whereas substrates with a surface area lower than 50 m 2 /g will only form carbon nanotubes at temperatures higher than 750 °C. In order to evaluate the influence of chemical composition of the substrate, three different ceramic powders were analyzed: alumina, silica and zirconia. carbon black and previously synthesized carbon nanotubes were also used as substrate for the synthesis and the results showed that the chemical composition of the substrate does not play a relevant role in the synthesis of carbon nanotubes, only the surface area showed an influence.

Optimal river monitoring network using optimal partition analysis: a case study of Hun River, Northeast China.

Science.gov (United States)

Wang, Hui; Liu, Chunyue; Rong, Luge; Wang, Xiaoxu; Sun, Lina; Luo, Qing; Wu, Hao

2018-01-09

River monitoring networks play an important role in water environmental management and assessment, and it is critical to develop an appropriate method to optimize the monitoring network. In this study, an effective method was proposed based on the attainment rate of National Grade III water quality, optimal partition analysis and Euclidean distance, and Hun River was taken as a method validation case. There were 7 sampling sites in the monitoring network of the Hun River, and 17 monitoring items were analyzed once a month during January 2009 to December 2010. The results showed that the main monitoring items in the surface water of Hun River were ammonia nitrogen (NH 4 + -N), chemical oxygen demand, and biochemical oxygen demand. After optimization, the required number of monitoring sites was reduced from seven to three, and 57% of the cost was saved. In addition, there were no significant differences between non-optimized and optimized monitoring networks, and the optimized monitoring networks could correctly represent the original monitoring network. The duplicate setting degree of monitoring sites decreased after optimization, and the rationality of the monitoring network was improved. Therefore, the optimal method was identified as feasible, efficient, and economic.

Concepts of combinatorial optimization

CERN Document Server

Paschos, Vangelis Th

2014-01-01

Combinatorial optimization is a multidisciplinary scientific area, lying in the interface of three major scientific domains: mathematics, theoretical computer science and management.  The three volumes of the Combinatorial Optimization series aim to cover a wide range  of topics in this area. These topics also deal with fundamental notions and approaches as with several classical applications of combinatorial optimization.Concepts of Combinatorial Optimization, is divided into three parts:- On the complexity of combinatorial optimization problems, presenting basics about worst-case and randomi

Interpretive Research Aiming at Theory Building: Adopting and Adapting the Case Study Design

Science.gov (United States)

Diaz Andrade, Antonio

2009-01-01

Although the advantages of case study design are widely recognised, its original positivist underlying assumptions may mislead interpretive researchers aiming at theory building. The paper discusses the limitations of the case study design for theory building and explains how grounded theory systemic process adds to the case study design. The…

Asymptotically Optimal Agents

OpenAIRE

Lattimore, Tor; Hutter, Marcus

2011-01-01

Artificial general intelligence aims to create agents capable of learning to solve arbitrary interesting problems. We define two versions of asymptotic optimality and prove that no agent can satisfy the strong version while in some cases, depending on discounting, there does exist a non-computable weak asymptotically optimal agent.

Systematization of Accurate Discrete Optimization Methods

Directory of Open Access Journals (Sweden)

V. A. Ovchinnikov

2015-01-01

Full Text Available The object of study of this paper is to define accurate methods for solving combinatorial optimization problems of structural synthesis. The aim of the work is to systemize the exact methods of discrete optimization and define their applicability to solve practical problems.The article presents the analysis, generalization and systematization of classical methods and algorithms described in the educational and scientific literature.As a result of research a systematic presentation of combinatorial methods for discrete optimization described in various sources is given, their capabilities are described and properties of the tasks to be solved using the appropriate methods are specified.

Optimal database combinations for literature searches in systematic reviews : a prospective exploratory study

NARCIS (Netherlands)

Bramer, W. M.; Rethlefsen, Melissa L.; Kleijnen, Jos; Franco, Oscar H.

2017-01-01

Background: Within systematic reviews, when searching for relevant references, it is advisable to use multiple databases. However, searching databases is laborious and time-consuming, as syntax of search strategies are database specific. We aimed to determine the optimal combination of databases

ESFR core optimization and uncertainty studies

International Nuclear Information System (INIS)

Rineiski, A.; Vezzoni, B.; Zhang, D.; Marchetti, M.; Gabrielli, F.; Maschek, W.; Chen, X.-N.; Buiron, L.; Krepel, J.; Sun, K.; Mikityuk, K.; Polidoro, F.; Rochman, D.; Koning, A.J.; DaCruz, D.F.; Tsige-Tamirat, H.; Sunderland, R.

2015-01-01

In the European Sodium Fast Reactor (ESFR) project supported by EURATOM in 2008-2012, a concept for a large 3600 MWth sodium-cooled fast reactor design was investigated. In particular, reference core designs with oxide and carbide fuel were optimized to improve their safety parameters. Uncertainties in these parameters were evaluated for the oxide option. Core modifications were performed first to reduce the sodium void reactivity effect. Introduction of a large sodium plenum with an absorber layer above the core and a lower axial fertile blanket improve the total sodium void effect appreciably, bringing it close to zero for a core with fresh fuel, in line with results obtained worldwide, while not influencing substantially other core physics parameters. Therefore an optimized configuration, CONF2, with a sodium plenum and a lower blanket was established first and used as a basis for further studies in view of deterioration of safety parameters during reactor operation. Further options to study were an inner fertile blanket, introduction of moderator pins, a smaller core height, special designs for pins, such as 'empty' pins, and subassemblies. These special designs were proposed to facilitate melted fuel relocation in order to avoid core re-criticality under severe accident conditions. In the paper further CONF2 modifications are compared in terms of safety and fuel balance. They may bring further improvements in safety, but their accurate assessment requires additional studies, including transient analyses. Uncertainty studies were performed by employing a so-called Total Monte-Carlo method, for which a large number of nuclear data files is produced for single isotopes and then used in Monte-Carlo calculations. The uncertainties for the criticality, sodium void and Doppler effects, effective delayed neutron fraction due to uncertainties in basic nuclear data were assessed for an ESFR core. They prove applicability of the available nuclear data for ESFR

Thermodynamic optimization of power plants

NARCIS (Netherlands)

Haseli, Y.

2011-01-01

Thermodynamic Optimization of Power Plants aims to establish and illustrate comparative multi-criteria optimization of various models and configurations of power plants. It intends to show what optimization objectives one may define on the basis of the thermodynamic laws, and how they can be applied

A short numerical study on the optimization methods influence on topology optimization

DEFF Research Database (Denmark)

Rojas Labanda, Susana; Sigmund, Ole; Stolpe, Mathias

2017-01-01

Structural topology optimization problems are commonly defined using continuous design variables combined with material interpolation schemes. One of the challenges for density based topology optimization observed in the review article (Sigmund and Maute Struct Multidiscip Optim 48(6):1031–1055...... 2013) is the slow convergence that is often encountered in practice, when an almost solid-and-void design is found. The purpose of this forum article is to present some preliminary observations on how designs evolves during the optimization process for different choices of optimization methods...

Optimization of multi-objective micro-grid based on improved particle swarm optimization algorithm

Science.gov (United States)

Zhang, Jian; Gan, Yang

2018-04-01

The paper presents a multi-objective optimal configuration model for independent micro-grid with the aim of economy and environmental protection. The Pareto solution set can be obtained by solving the multi-objective optimization configuration model of micro-grid with the improved particle swarm algorithm. The feasibility of the improved particle swarm optimization algorithm for multi-objective model is verified, which provides an important reference for multi-objective optimization of independent micro-grid.

Optimism and Cause-Specific Mortality: A Prospective Cohort Study.

Science.gov (United States)

Kim, Eric S; Hagan, Kaitlin A; Grodstein, Francine; DeMeo, Dawn L; De Vivo, Immaculata; Kubzansky, Laura D

2017-01-01

Growing evidence has linked positive psychological attributes like optimism to a lower risk of poor health outcomes, especially cardiovascular disease. It has been demonstrated in randomized trials that optimism can be learned. If associations between optimism and broader health outcomes are established, it may lead to novel interventions that improve public health and longevity. In the present study, we evaluated the association between optimism and cause-specific mortality in women after considering the role of potential confounding (sociodemographic characteristics, depression) and intermediary (health behaviors, health conditions) variables. We used prospective data from the Nurses' Health Study (n = 70,021). Dispositional optimism was measured in 2004; all-cause and cause-specific mortality rates were assessed from 2006 to 2012. Using Cox proportional hazard models, we found that a higher degree of optimism was associated with a lower mortality risk. After adjustment for sociodemographic confounders, compared with women in the lowest quartile of optimism, women in the highest quartile had a hazard ratio of 0.71 (95% confidence interval: 0.66, 0.76) for all-cause mortality. Adding health behaviors, health conditions, and depression attenuated but did not eliminate the associations (hazard ratio = 0.91, 95% confidence interval: 0.85, 0.97). Associations were maintained for various causes of death, including cancer, heart disease, stroke, respiratory disease, and infection. Given that optimism was associated with numerous causes of mortality, it may provide a valuable target for new research on strategies to improve health. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Design Optimization of Piles for Offshore Wind Turbine Jacket Foundations

DEFF Research Database (Denmark)

Sandal, Kasper; Zania, Varvara

Numerical methods can optimize the pile design. The aim of this study is to automatically design optimal piles for offshore wind turbine jacket foundations (Figure 1). Pile mass is minimized with constraints on axial and lateral capacity. Results indicate that accurate knowledge about soil...

Bidirectional relationship between sleep and optimism with depressive mood as a mediator: A longitudinal study of Chinese working adults.

Science.gov (United States)

Lau, Esther Yuet Ying; Harry Hui, C; Cheung, Shu-Fai; Lam, Jasmine

2015-11-01

Sleep and optimism are important psycho-biological and personality constructs, respectively. However, very little work has examined the causal relationship between them, and none has examined the potential mechanisms operating in the relationship. This study aimed to understand whether sleep quality was a cause or an effect of optimism, and whether depressive mood could explain the relationship. Internet survey data were collected from 987 Chinese working adults (63.4% female, 92.4% full-time workers, 27.0% married, 90.2% Hong Kong residents, mean age=32.59 at three time-points, spanning about 19 months). Measures included a Chinese attributional style questionnaire, the Pittsburgh Sleep Quality Index, and the Depression Anxiety Stress Scale. Cross-sectional analyses revealed moderate correlations among sleep quality, depressive mood, and optimism. Cross-lagged analyses showed a bidirectional causality between optimism and sleep. Path analysis demonstrated that depressive mood fully mediated the influence of optimism on sleep quality, and it partially mediated the influence of sleep quality on optimism. Optimism improves sleep. Poor sleep makes a pessimist. The effects of sleep quality on optimism could not be fully explained by depressive mood, highlighting the unique role of sleep on optimism. Understanding the mechanisms of the feedback loop of sleep quality, mood, and optimism may provide insights for clinical interventions for individuals presented with mood-related problems. Copyright © 2015 Elsevier Inc. All rights reserved.

Does high optimism protect against the inter-generational transmission of high BMI? The Cardiovascular Risk in Young Finns Study.

Science.gov (United States)

Serlachius, Anna; Pulkki-Råback, Laura; Juonala, Markus; Sabin, Matthew; Lehtimäki, Terho; Raitakari, Olli; Elovainio, Marko

2017-09-01

The transmission of overweight from one generation to the next is well established, however little is known about what psychosocial factors may protect against this familial risk. The aim of this study was to examine whether optimism plays a role in the intergenerational transmission of obesity. Our sample included 1043 participants from the prospective Cardiovascular Risk in Young FINNS Study. Optimism was measured in early adulthood (2001) when the cohort was aged 24-39years. BMI was measured in 2001 (baseline) and 2012 when they were aged 35-50years. Parental BMI was measured in 1980. Hierarchical linear regression and logistic regression were used to examine the association between optimism and future BMI/obesity, and whether an interaction existed between optimism and parental BMI when predicting BMI/obesity 11years later. High optimism in young adulthood demonstrated a negative relationship with high BMI in mid-adulthood, but only in women (β=-0.127, p=0.001). The optimism×maternal BMI interaction term was a significant predictor of future BMI in women (β=-0.588, p=0.036). The logistic regression results confirmed that high optimism predicted reduced obesity in women (OR=0.68, 95% CI, 0.55-0.86), however the optimism × maternal obesity interaction term was not a significant predictor (OR=0.50, 95% CI, 0.10-2.48). Our findings supported our hypothesis that high optimism mitigated the intergenerational transmission of high BMI, but only in women. These findings also provided evidence that positive psychosocial factors such as optimism are associated with long-term protective effects on BMI in women. Copyright © 2017 Elsevier Inc. All rights reserved.

PLA and two components silicon rubber blends aiming for frozen foods packaging applications

Science.gov (United States)

Meekum, Utai; Khiansanoi, Apichart

2018-03-01

Designing of PLA and two components silicone rubber blends was studies. Frozen food packaging application is the main ultimate aim. The statistical method using 23 DOE was conducted. The standard testing methods, in particular impact testing at sub-zero temperature, were performed. The preliminary blend formula comprised 1.0 phr of silane and polyester polyols, respectively, was initially resolved. Then, the optimize the silicone portion in the blends was determined. Blending formula using 8.0 phr of silicone with respect to PLA matrix gave rise to the overall satisfactory properties. 3. TETA was used as the silicone curing agent and reactively blended onto the ingredients. TETA at 0.4 phr, with respect to the silicone, enhanced the mechanical properties, especially flexibility and toughness, of the PLA/silicone blend. Exceeding the optimal TETA loading would cause the chain scission and also the dilution effects. Hence, marginal inferior properties of the blends were be experienced. The preliminary biodegradability investigation found that the PLA/silicone blend initially triggered at the second week. Its degradation rate was likely to be faster than neat PLA.

Bi-objective optimization for multi-modal transportation routing planning problem based on Pareto optimality

Directory of Open Access Journals (Sweden)

Yan Sun

2015-09-01

Full Text Available Purpose: The purpose of study is to solve the multi-modal transportation routing planning problem that aims to select an optimal route to move a consignment of goods from its origin to its destination through the multi-modal transportation network. And the optimization is from two viewpoints including cost and time. Design/methodology/approach: In this study, a bi-objective mixed integer linear programming model is proposed to optimize the multi-modal transportation routing planning problem. Minimizing the total transportation cost and the total transportation time are set as the optimization objectives of the model. In order to balance the benefit between the two objectives, Pareto optimality is utilized to solve the model by gaining its Pareto frontier. The Pareto frontier of the model can provide the multi-modal transportation operator (MTO and customers with better decision support and it is gained by the normalized normal constraint method. Then, an experimental case study is designed to verify the feasibility of the model and Pareto optimality by using the mathematical programming software Lingo. Finally, the sensitivity analysis of the demand and supply in the multi-modal transportation organization is performed based on the designed case. Findings: The calculation results indicate that the proposed model and Pareto optimality have good performance in dealing with the bi-objective optimization. The sensitivity analysis also shows the influence of the variation of the demand and supply on the multi-modal transportation organization clearly. Therefore, this method can be further promoted to the practice. Originality/value: A bi-objective mixed integer linear programming model is proposed to optimize the multi-modal transportation routing planning problem. The Pareto frontier based sensitivity analysis of the demand and supply in the multi-modal transportation organization is performed based on the designed case.

Cross-cultural exchange: How students can frustrate the aims of study abroad programmes

Science.gov (United States)

Barnes, Leslie R.

1982-09-01

Readily accepting that study abroad programmes may have as many differing forms and aims as there are participating institutions, and that by no means all programmes include academic content in their goals, I would nevertheless maintain: 1. that a sociological perspective is as necessary as the hitherto predominantly psychological approach in obtaining a balanced assessment of study abroad programmes;

Optimal control for Malaria disease through vaccination

Science.gov (United States)

Munzir, Said; Nasir, Muhammad; Ramli, Marwan

2018-01-01

Malaria is a disease caused by an amoeba (single-celled animal) type of plasmodium where anopheles mosquito serves as the carrier. This study examines the optimal control problem of malaria disease spread based on Aron and May (1982) SIR type models and seeks the optimal solution by minimizing the prevention of the spreading of malaria by vaccine. The aim is to investigate optimal control strategies on preventing the spread of malaria by vaccination. The problem in this research is solved using analytical approach. The analytical method uses the Pontryagin Minimum Principle with the symbolic help of MATLAB software to obtain optimal control result and to analyse the spread of malaria with vaccination control.

Dispositional optimism and coping with pain.

Science.gov (United States)

Bargiel-Matusiewicz, K; Krzyszkowska, A

2009-12-07

The aim of this article is to analyze the relation between dispositional optimism and coping with chronic pain. The study seeks to define the relation between life orientation (optimism vs. pessimism) and coping with pain (believes about pain control and the choice of coping strategy). The following questionnaires were used: LOT-R - Life Orientation Test, BPCQ - The Beliefs about Pain Control Questionnaire and CSQ - The Pain Coping Strategies Questionnaire. The results show that dispositional optimism correlates positively with: internal locus of pain control r=0.6, Pr=0.38, Pr = 0.93, Pr = 0.82, Pr = -0.28, P<0.05. We conclude that dispositional optimism plays a key role in forming the mechanisms of coping with chronic pain and thereby in improving the psychophysical comfort of patients.

Optimization for PET imaging based on phantom study and NECdensity

International Nuclear Information System (INIS)

Daisaki, Hiromitsu; Shimada, Naoki; Shinohara, Hiroyuki

2012-01-01

In consideration of the requirement for global standardization and quality control of PET imaging, the present studies gave an outline of phantom study to decide both scan and reconstruction parameters based on FDG-PET/CT procedure guideline in Japan, and optimization of scan duration based on NEC density was performed continuously. In the phantom study, scan and reconstruction parameters were decided by visual assessment and physical indexes (N 10mm , NEC phantom , Q H,10mm /N 10mm ) to visualize hot spot of 10 mm diameter with standardized uptake value (SUV)=4 explicitly. Simultaneously, Recovery Coefficient (RC) was evaluated to recognize that PET images had enough quantifiably. Scan durations were optimized by Body Mass Index (BMI) based on retrospective analysis of NEC density . Correlation between visual score in clinical FDG-PET images and NEC density fell after the optimization of scan duration. Both Inter-institution and inter-patient variability were decreased by performing the phantom study based on the procedure guideline and the optimization of scan duration based on NEC density which seem finally useful to practice highly precise examination and promote high-quality controlled study. (author)

Complementary coordination strategies in a joint Fitts’ reciprocal aiming task

DEFF Research Database (Denmark)

Konvalinka, Ivana; Skewes, Lea; Michael, J.

How do dyads coordinate their actions to achieve a common goal when one person has the more difficult task? In the present study, dyads were instructed to engage in a Fitts’s reciprocal aiming task as accurately as possible, and at a given tempo sent through their headphones. They were in conditi...... a joint goal, by taking on leader-follower roles....... was assigned to either the target’s role – with varying target width, and hence task difficulty – or the reference role – with the widest (easiest) target. Results show that when the task was performed interactively with the other person, they were most synchronized, and also used the target most similarly......, while compromising rhythmic accuracy. In addition, as task difficulty increased for the member with the target’s role, the participant with the reference role became more adaptive to her tempo. This suggests that interacting members of a dyad optimally negotiate coordination strategies to achieve...

A study for optimal transmutation system

International Nuclear Information System (INIS)

Park, W.S.; Song, T.Y.; Shin, H.S.; Park, C.K.

1996-01-01

Couple of transmutation systems are being under investigation to design the optimal transmutation device. Several basic studies were performed for that objectives: (1) select the radioactive nuclides to be transmuted: (2) investigate the physical characteristics of each nuclide; (3) study the most favorable neutron energy environment for the transmutation. The existing LWR and LMFBR cores were found to be not a satisfiable ones in terms of transmutation rate itself. (author). 5 refs, 2 figs, 3 tabs

Enhanced index tracking modelling in portfolio optimization

Science.gov (United States)

Lam, W. S.; Hj. Jaaman, Saiful Hafizah; Ismail, Hamizun bin

2013-09-01

Enhanced index tracking is a popular form of passive fund management in stock market. It is a dual-objective optimization problem, a trade-off between maximizing the mean return and minimizing the risk. Enhanced index tracking aims to generate excess return over the return achieved by the index without purchasing all of the stocks that make up the index by establishing an optimal portfolio. The objective of this study is to determine the optimal portfolio composition and performance by using weighted model in enhanced index tracking. Weighted model focuses on the trade-off between the excess return and the risk. The results of this study show that the optimal portfolio for the weighted model is able to outperform the Malaysia market index which is Kuala Lumpur Composite Index because of higher mean return and lower risk without purchasing all the stocks in the market index.

NUMERICAL SIMULATION AND OPTIMIZATION OF ...

African Journals Online (AJOL)

30 juin 2011 ... This article has as an aim the study and the simulation of the photovoltaic cells containing CdTe materials, contributing to the development of renewable energies, and able to feed from the houses, the shelters as well as ... and the output energy of conversion is 18.26%.Optimization is made according to the.

Nonparametric variational optimization of reaction coordinates

Energy Technology Data Exchange (ETDEWEB)

Banushkina, Polina V.; Krivov, Sergei V., E-mail: s.krivov@leeds.ac.uk [Astbury Center for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT (United Kingdom)

2015-11-14

State of the art realistic simulations of complex atomic processes commonly produce trajectories of large size, making the development of automated analysis tools very important. A popular approach aimed at extracting dynamical information consists of projecting these trajectories into optimally selected reaction coordinates or collective variables. For equilibrium dynamics between any two boundary states, the committor function also known as the folding probability in protein folding studies is often considered as the optimal coordinate. To determine it, one selects a functional form with many parameters and trains it on the trajectories using various criteria. A major problem with such an approach is that a poor initial choice of the functional form may lead to sub-optimal results. Here, we describe an approach which allows one to optimize the reaction coordinate without selecting its functional form and thus avoiding this source of error.

A Multi-level hierarchic Markov process with Bayesian updating for herd optimization and simulation in dairy cattle

NARCIS (Netherlands)

Demeter, R.M.; Kristensen, A.R.; Dijkstra, J.; Oude Lansink, A.G.J.M.; Meuwissen, M.P.M.; Arendonk, van J.A.M.

2011-01-01

Herd optimization models that determine economically optimal insemination and replacement decisions are valuable research tools to study various aspects of farming systems. The aim of this study was to develop a herd optimization and simulation model for dairy cattle. The model determines

PLA and two components silicon rubber blends aiming for frozen foods packaging applications

Directory of Open Access Journals (Sweden)

Utai Meekum

2018-03-01

Full Text Available Designing of PLA and two components silicone rubber blends was studies. Frozen food packaging application is the main ultimate aim. The statistical method using 23 DOE was conducted. The standard testing methods, in particular impact testing at sub-zero temperature, were performed. The preliminary blend formula comprised 1.0 phr of silane and polyester polyols, respectively, was initially resolved. Then, the optimize the silicone portion in the blends was determined. Blending formula using 8.0 phr of silicone with respect to PLA matrix gave rise to the overall satisfactory properties. 3. TETA was used as the silicone curing agent and reactively blended onto the ingredients. TETA at 0.4 phr, with respect to the silicone, enhanced the mechanical properties, especially flexibility and toughness, of the PLA/silicone blend. Exceeding the optimal TETA loading would cause the chain scission and also the dilution effects. Hence, marginal inferior properties of the blends were be experienced. The preliminary biodegradability investigation found that the PLA/silicone blend initially triggered at the second week. Its degradation rate was likely to be faster than neat PLA. Keywords: PLA/silicone blends, Mechanical properties, Sub-zero impact strength

A new hybrid optimization algorithm CRO-DE for optimal coordination of overcurrent relays in complex power systems

Directory of Open Access Journals (Sweden)

Mohamed Zellagui

2017-09-01

Full Text Available The paper presents a new hybrid global optimization algorithm based on Chemical Reaction based Optimization (CRO and Di¤erential evolution (DE algorithm for nonlinear constrained optimization problems. This approach proposed for the optimal coordination and setting relays of directional overcurrent relays in complex power systems. In protection coordination problem, the objective function to be minimized is the sum of the operating time of all main relays. The optimization problem is subject to a number of constraints which are mainly focused on the operation of the backup relay, which should operate if a primary relay fails to respond to the fault near to it, Time Dial Setting (TDS, Plug Setting (PS and the minimum operating time of a relay. The hybrid global proposed optimization algorithm aims to minimize the total operating time of each protection relay. Two systems are used as case study to check the effeciency of the optimization algorithm which are IEEE 4-bus and IEEE 6-bus models. Results are obtained and presented for CRO and DE and hybrid CRO-DE algorithms. The obtained results for the studied cases are compared with those results obtained when using other optimization algorithms which are Teaching Learning-Based Optimization (TLBO, Chaotic Differential Evolution Algorithm (CDEA and Modiffied Differential Evolution Algorithm (MDEA, and Hybrid optimization algorithms (PSO-DE, IA-PSO, and BFOA-PSO. From analysing the obtained results, it has been concluded that hybrid CRO-DO algorithm provides the most optimum solution with the best convergence rate.

Optimization of External Envelope Insulation Thickness: A Parametric Study

Directory of Open Access Journals (Sweden)

Eleftheria Touloupaki

2017-02-01

Full Text Available Almost four years after the implementation deadline of the energy performance of buildings Directive recast (2010/31/EU and after being referred to the Court of Justice of the EU by the European Commission, Greece has not yet proceeded with the necessary calculations and legislative measures on the minimum, cost-optimal energy performance requirements for buildings. This paper aims to identify the optimal thickness of insulation that is cost-effective to apply in urban multi-family domestic buildings in the four climate zones of Greece. A reference building is selected in order to perform calculations over ten scenarios of external insulation thickness for each climate zone on a basic and three sensitivity analysis calculations according to the EU comparative methodology framework. The resulting energy savings for each insulation scenario are calculated, and then the cost-effectiveness of the measure is examined in financial and macroeconomic perspective for an economic lifecycle of 30 years. The results demonstrate the inadequacy of the national regulation’s current insulation limits and the externalities (funding gaps that need to be addressed in order to achieve the effective improvement of energy efficiency in Greek homes.

An Optimization Study on Syngas Production and Economic Evaluation

Directory of Open Access Journals (Sweden)

Qasim Faraz

2016-01-01

Full Text Available Syngas production in Gas-to-liquid (GTL process is focused in past by several researchers to increase the production with minimal capital and operating costs. In this study, syngas production process is simulated and optimized to increase its production and the economic analysis is studied for the proposed optimized process. Aspen HYSYS v8.4 is used for all process simulation work in this article. A new configuration is rigorously simulated while using auto-thermal reforming. Results exhibit a tremendous rise in production of syngas.

Stochastic optimization-based study of dimerization kinetics

Indian Academy of Sciences (India)

To this end, we study dimerization kinetics of protein as a model system. We follow the dimerization kinetics using a stochastic simulation algorithm and ... optimization; dimerization kinetics; sensitivity analysis; stochastic simulation ... tion in large molecules and clusters, or the design ..... An unbiased strategy of allocating.

Isostatic lines’ study to optimize steel space grid envelope structures for tall buildings according to their solicitations

OpenAIRE

Señís López, Roger

2013-01-01

Based on the first study completed with wind tunnel tests, the aim of this paper is to define a second methodology for the optimization of steel space grid envelope structures for tall buildings according to their isostatic lines according to their solicitations. It is by means of the comparison NatHaz online database and numerical simulation research of wind flow repercussion in buildings, through Computational Fluid Dynamics (CDF), that we can understand and analyse the grid ...

Optimal partial mass transportation and obstacle Monge-Kantorovich equation

Science.gov (United States)

Igbida, Noureddine; Nguyen, Van Thanh

2018-05-01

Optimal partial mass transport, which is a variant of the optimal transport problem, consists in transporting effectively a prescribed amount of mass from a source to a target. The problem was first studied by Caffarelli and McCann (2010) [6] and Figalli (2010) [12] with a particular attention to the quadratic cost. Our aim here is to study the optimal partial mass transport problem with Finsler distance costs including the Monge cost given by the Euclidian distance. Our approach is different and our results do not follow from previous works. Among our results, we introduce a PDE of Monge-Kantorovich type with a double obstacle to characterize active submeasures, Kantorovich potential and optimal flow for the optimal partial transport problem. This new PDE enables us to study the uniqueness and monotonicity results for the active submeasures. Another interesting issue of our approach is its convenience for numerical analysis and computations that we develop in a separate paper [14] (Igbida and Nguyen, 2018).

Portfolio optimization for index tracking modelling in Malaysia stock market

Science.gov (United States)

Siew, Lam Weng; Jaaman, Saiful Hafizah; Ismail, Hamizun

2016-06-01

Index tracking is an investment strategy in portfolio management which aims to construct an optimal portfolio to generate similar mean return with the stock market index mean return without purchasing all of the stocks that make up the index. The objective of this paper is to construct an optimal portfolio using the optimization model which adopts regression approach in tracking the benchmark stock market index return. In this study, the data consists of weekly price of stocks in Malaysia market index which is FTSE Bursa Malaysia Kuala Lumpur Composite Index from January 2010 until December 2013. The results of this study show that the optimal portfolio is able to track FBMKLCI Index at minimum tracking error of 1.0027% with 0.0290% excess mean return over the mean return of FBMKLCI Index. The significance of this study is to construct the optimal portfolio using optimization model which adopts regression approach in tracking the stock market index without purchasing all index components.

Topology optimization of turbulent flows

DEFF Research Database (Denmark)

Dilgen, Cetin B.; Dilgen, Sumer B.; Fuhrman, David R.

2018-01-01

The aim of this work is to present a fast and viable approach for taking into account turbulence in topology optimization of complex fluid flow systems, without resorting to any simplifying assumptions in the derivation of discrete adjoints. Topology optimization is an iterative gradient...

Deterministic mean-variance-optimal consumption and investment

DEFF Research Database (Denmark)

Christiansen, Marcus; Steffensen, Mogens

2013-01-01

In dynamic optimal consumption–investment problems one typically aims to find an optimal control from the set of adapted processes. This is also the natural starting point in case of a mean-variance objective. In contrast, we solve the optimization problem with the special feature that the consum......In dynamic optimal consumption–investment problems one typically aims to find an optimal control from the set of adapted processes. This is also the natural starting point in case of a mean-variance objective. In contrast, we solve the optimization problem with the special feature...... that the consumption rate and the investment proportion are constrained to be deterministic processes. As a result we get rid of a series of unwanted features of the stochastic solution including diffusive consumption, satisfaction points and consistency problems. Deterministic strategies typically appear in unit......-linked life insurance contracts, where the life-cycle investment strategy is age dependent but wealth independent. We explain how optimal deterministic strategies can be found numerically and present an example from life insurance where we compare the optimal solution with suboptimal deterministic strategies...

Unconstrained Optimization

DEFF Research Database (Denmark)

Frandsen, P. E.; Jonasson, K.; Nielsen, Hans Bruun

1999-01-01

This lecture note is intended for use in the course 04212 Optimization and Data Fitting at the Technincal University of Denmark. It covers about 25% of the curriculum. Hopefully, the note may be useful also to interested persons not participating in that course. The aim of the note is to give...... an introduction to algorithms for unconstrained optimization. We present Conjugate Gradient, Damped Newton and Quasi Newton methods together with the relevant theoretical background. The reader is assumed to be familiar with algorithms for solving linear and nonlinear system of equations, at a level corresponding...

Study on the Optimal Charging Strategy for Lithium-Ion Batteries Used in Electric Vehicles

Directory of Open Access Journals (Sweden)

Shuo Zhang

2014-10-01

Full Text Available The charging method of lithium-ion batteries used in electric vehicles (EVs significantly affects its commercial application. This paper aims to make three contributions to the existing literature. (1 In order to achieve an efficient charging strategy for lithium-ion batteries with shorter charging time and lower charring loss, the trade-off problem between charging loss and charging time has been analyzed in details through the dynamic programing (DP optimization algorithm; (2 To reduce the computation time consumed during the optimization process, we have proposed a database based optimization approach. After off-line calculation, the simulation results can be applied to on-line charge; (3 The novel database-based DP method is proposed and the simulation results illustrate that this method can effectively find the suboptimal charging strategies under a certain balance between the charging loss and charging time.

The importance of personality and parental styles on optimism in adolescents.

Science.gov (United States)

Zanon, Cristian; Bastianello, Micheline Roat; Pacico, Juliana Cerentini; Hutz, Claudio Simon

2014-01-01

Some studies have suggested that personality factors are important to optimism development. Others have emphasized that family relations are relevant variables to optimism. This study aimed to evaluate the importance of parenting styles to optimism controlling for the variance accounted for by personality factors. Participants were 344 Brazilian high school students (44% male) with mean age of 16.2 years (SD = 1) who answered personality, optimism, responsiveness and demandingness scales. Hierarchical regression analyses were conducted having personality factors (in the first step) and maternal and paternal parenting styles, and demandingness and responsiveness (in the second step) as predictive variables and optimism as the criterion. Personality factors, especially neuroticism (β = -.34, p parental styles (1%). These findings suggest that personality is more important to optimism development than parental styles.

The relationship between traits optimism and anxiety and health-related quality of life in patients hospitalized for chronic diseases: data from the SATISQOL study

Science.gov (United States)

2013-01-01

Background The impact of psychological factors is often taken into account in the evaluation of quality of life. However, the effect of optimism and trait anxiety remains controversial and they are rarely studied simultaneously. We aimed to study the effect of this factor on health-related quality of life (HRQOL) of patients after a hospitalization in relation with their chronic disease. Methods Using cross-sectional data from the SATISQOL cohort, we conducted a multicentric study, including patients hospitalized for an intervention in connection with their chronic disease. Six months after hospitalization, patients completed a generic HRQOL questionnaire (SF-36), and the STAI and LOT-R questionnaires to evaluate optimism and trait anxiety. We studied the effect of each trait on HRQOL separately, and simultaneously, taking account of their interaction in 3 models, using an ANOVA. Results In this study, 1529 patients were included in three participating hospitals and there existed wide diversity in the chronic diseases in our population. The HRQOL score increased for all dimensions of SF36 between 15,8 and 44,5 when the level of anxiety decreased (p optimism (optimism on HRQOL. In the model 3, assessing the effect of both anxiety and optimism on HRQOL, and their interaction, the HRQOL score for all dimensions of the SF36 increased when the level of anxiety decreased (p optimism (p optimism was significant for the Social Functioning dimension (p = 0.0021). Conclusions Optimism and trait anxiety appeared to be significantly correlated with HRQOL. Furthermore, an interaction existed between the trait anxiety and optimism for some dimensions of SF36. Contrary to optimism, it seems essential to evaluate trait anxiety in future studies about HRQOL, since it could represent a confounding factor. PMID:23914779

Numerical study and ex vivo assessment of HIFU treatment time reduction through optimization of focal point trajectory

Science.gov (United States)

Grisey, A.; Yon, S.; Pechoux, T.; Letort, V.; Lafitte, P.

2017-03-01

Treatment time reduction is a key issue to expand the use of high intensity focused ultrasound (HIFU) surgery, especially for benign pathologies. This study aims at quantitatively assessing the potential reduction of the treatment time arising from moving the focal point during long pulses. In this context, the optimization of the focal point trajectory is crucial to achieve a uniform thermal dose repartition and avoid boiling. At first, a numerical optimization algorithm was used to generate efficient trajectories. Thermal conduction was simulated in 3D with a finite difference code and damages to the tissue were modeled using the thermal dose formula. Given an initial trajectory, the thermal dose field was first computed, then, making use of Pontryagin's maximum principle, the trajectory was iteratively refined. Several initial trajectories were tested. Then, an ex vivo study was conducted in order to validate the efficicency of the resulting optimized strategies. Single pulses were performed at 3MHz on fresh veal liver samples with an Echopulse and the size of each unitary lesion was assessed by cutting each sample along three orthogonal planes and measuring the dimension of the whitened area based on photographs. We propose a promising approach to significantly shorten HIFU treatment time: the numerical optimization algorithm was shown to provide a reliable insight on trajectories that can improve treatment strategies. The model must now be improved in order to take in vivo conditions into account and extensively validated.

The Czech longitudinal study of optimal development

Czech Academy of Sciences Publication Activity Database

Kebza, V.; Šolcová, Iva; Kodl, M.; Kernová, V.

2012-01-01

Roč. 47, Suppl. 1 (2012), s. 266-266 ISSN 0020-7594. [International Congress of Psychology /30./. 22.07.2012-27.07.2012, Cape Town] R&D Projects: GA ČR GAP407/10/2410 Institutional support: RVO:68081740 Keywords : optimal development * Prague longitudinal study Subject RIV: AN - Psychology

A method optimization study for atomic absorption ...

African Journals Online (AJOL)

A sensitive, reliable and relative fast method has been developed for the determination of total zinc in insulin by atomic absorption spectrophotometer. This designed study was used to optimize the procedures for the existing methods. Spectrograms of both standard and sample solutions of zinc were recorded by measuring ...

Exergetic optimization of turbofan engine with genetic algorithm method

Energy Technology Data Exchange (ETDEWEB)

Turan, Onder [Anadolu University, School of Civil Aviation (Turkey)], e-mail: onderturan@anadolu.edu.tr

2011-07-01

With the growth of passenger numbers, emissions from the aeronautics sector are increasing and the industry is now working on improving engine efficiency to reduce fuel consumption. The aim of this study is to present the use of genetic algorithms, an optimization method based on biological principles, to optimize the exergetic performance of turbofan engines. The optimization was carried out using exergy efficiency, overall efficiency and specific thrust of the engine as evaluation criteria and playing on pressure and bypass ratio, turbine inlet temperature and flight altitude. Results showed exergy efficiency can be maximized with higher altitudes, fan pressure ratio and turbine inlet temperature; the turbine inlet temperature is the most important parameter for increased exergy efficiency. This study demonstrated that genetic algorithms are effective in optimizing complex systems in a short time.

A hybrid algorithm for instant optimization of beam weights in anatomy-based intensity modulated radiotherapy: a performance evaluation study

International Nuclear Information System (INIS)

Vaitheeswaran, Ranganathan; Sathiya Narayanan, V.K.; Bhangle, Janhavi R.; Nirhali, Amit; Kumar, Namita; Basu, Sumit; Maiya, Vikram

2011-01-01

The study aims to introduce a hybrid optimization algorithm for anatomy-based intensity modulated radiotherapy (AB-IMRT). Our proposal is that by integrating an exact optimization algorithm with a heuristic optimization algorithm, the advantages of both the algorithms can be combined, which will lead to an efficient global optimizer solving the problem at a very fast rate. Our hybrid approach combines Gaussian elimination algorithm (exact optimizer) with fast simulated annealing algorithm (a heuristic global optimizer) for the optimization of beam weights in AB-IMRT. The algorithm has been implemented using MATLAB software. The optimization efficiency of the hybrid algorithm is clarified by (i) analysis of the numerical characteristics of the algorithm and (ii) analysis of the clinical capabilities of the algorithm. The numerical and clinical characteristics of the hybrid algorithm are compared with Gaussian elimination method (GEM) and fast simulated annealing (FSA). The numerical characteristics include convergence, consistency, number of iterations and overall optimization speed, which were analyzed for the respective cases of 8 patients. The clinical capabilities of the hybrid algorithm are demonstrated in cases of (a) prostate and (b) brain. The analyses reveal that (i) the convergence speed of the hybrid algorithm is approximately three times higher than that of FSA algorithm (ii) the convergence (percentage reduction in the cost function) in hybrid algorithm is about 20% improved as compared to that in GEM algorithm (iii) the hybrid algorithm is capable of producing relatively better treatment plans in terms of Conformity Index (CI) (∼ 2% - 5% improvement) and Homogeneity Index (HI) (∼ 4% - 10% improvement) as compared to GEM and FSA algorithms (iv) the sparing of organs at risk in hybrid algorithm-based plans is better than that in GEM-based plans and comparable to that in FSA-based plans; and (v) the beam weights resulting from the hybrid algorithm are

Optimization of physical rehabilitation in congenital clubfoot

Directory of Open Access Journals (Sweden)

M.L. Golovakha

2013-09-01

Full Text Available The aim of the study was to improve the results of treatment of children with typical form of congenital clubfoot by optimizing of physical rehabilitation. The study included the following objectives: to make the algorithm work with the child, to justify the basis of physical rehabilitation, to study its effects, to develop a framework of implementation and optimization of the physical rehabilitation of children with congenital clubfoot. In the course of the study were 62 children involved with the typical form of congenital clubfoot: the main group (n = 42 and control group (n = 42. Age children from 4 years to 7 years. Physical rehabilitation was a logical continuation of treatment. Optimization analysis was performed by clinical examination, radiometric data and indicators of functional methods of research. Comparative analysis of the results of the physical rehabilitation of children with congenital clubfoot in both groups showed a trend more pronounced positive changes in children the main group in all respects.

Modelling and Optimizing Mathematics Learning in Children

Science.gov (United States)

Käser, Tanja; Busetto, Alberto Giovanni; Solenthaler, Barbara; Baschera, Gian-Marco; Kohn, Juliane; Kucian, Karin; von Aster, Michael; Gross, Markus

2013-01-01

This study introduces a student model and control algorithm, optimizing mathematics learning in children. The adaptive system is integrated into a computer-based training system for enhancing numerical cognition aimed at children with developmental dyscalculia or difficulties in learning mathematics. The student model consists of a dynamic…

Optimization of surface maintenance

International Nuclear Information System (INIS)

Oeverland, E.

1990-01-01

The present conference paper deals with methods of optimizing the surface maintenance of steel-made offshore installations. The paper aims at identifying important approaches to the problems regarding the long-range planning of an economical and cost effective maintenance program. The methods of optimization are based on the obtained experiences from the maintenance of installations on the Norwegian continental shelf. 3 figs

A Pilot Study Assessing ECG versus ECHO Ventriculoventricular Optimization in Pediatric Resynchronization Patients.

Science.gov (United States)

Punn, Rajesh; Hanisch, Debra; Motonaga, Kara S; Rosenthal, David N; Ceresnak, Scott R; Dubin, Anne M

2016-02-01

Cardiac resynchronization therapy indications and management are well described in adults. Echocardiography (ECHO) has been used to optimize mechanical synchrony in these patients; however, there are issues with reproducibility and time intensity. Pediatric patients add challenges, with diverse substrates and limited capacity for cooperation. Electrocardiographic (ECG) methods to assess electrical synchrony are expeditious but have not been extensively studied in children. We sought to compare ECHO and ECG CRT optimization in children. Prospective, pediatric, single-center cross-over trial comparing ECHO and ECG optimization with CRT. Patients were assigned to undergo either ECHO or ECG optimization, followed for 6 months, and crossed-over to the other assignment for another 6 months. ECHO pulsed-wave tissue Doppler and 12-lead ECG were obtained for 5 VV delays. ECG optimization was defined as the shortest QRSD and ECHO optimization as the lowest dyssynchrony index. ECHOs/ECGs were interpreted by readers blinded to optimization technique. After each 6 month period, these data were collected: ejection fraction, velocimetry-derived cardiac index, quality of life, ECHO-derived stroke distance, M-mode dyssynchrony, study cost, and time. Outcomes for each optimization method were compared. From June 2012 to December 2013, 19 patients enrolled. Mean age was 9.1 ± 4.3 years; 14 (74%) had structural heart disease. The mean time for optimization was shorter using ECG than ECHO (9 ± 1 min vs. 68 ± 13 min, P cost for charges was $4,400 ± 700 less for ECG. No other outcome differed between groups. ECHO optimization of synchrony was not superior to ECG optimization in this pilot study. ECG optimization required less time and cost than ECHO optimization. © 2015 Wiley Periodicals, Inc.

Peran Layanan Jasa Search Engine Optimization untuk Meningkatkan Daya Saing pada Bisnis Startup (Studi pada Kaldera Trail and Jeep Adventure Malang)

OpenAIRE

Wira Bharata

2016-01-01

This study aimed to investigate the role of SEO as a strategic competitive advantage. This study uses a qualitative approach with case studies are used as a research design. Researchers in the interviews to the owner Caldera Trail & Jeep Adventure. The results of this study indicate that the role of SEO to optimize the website proved successful in the company’s competitive advantage strategy Caldera Trail & Jeep Adventure. The results showed online marketing is done through Facebook, ...

Multiobjective optimization model of intersection signal timing considering emissions based on field data: A case study of Beijing.

Science.gov (United States)

Kou, Weibin; Chen, Xumei; Yu, Lei; Gong, Huibo

2018-04-18

Most existing signal timing models are aimed to minimize the total delay and stops at intersections, without considering environmental factors. This paper analyzes the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. First, considering the different operating modes of cruising, acceleration, deceleration, and idling, field data of emissions and Global Positioning System (GPS) are collected to estimate emission rates for heavy-duty and light-duty vehicles. Second, multiobjective signal timing optimization model is established based on a genetic algorithm to minimize delay, stops, and emissions. Finally, a case study is conducted in Beijing. Nine scenarios are designed considering different weights of emission and traffic efficiency. The results compared with those using Highway Capacity Manual (HCM) 2010 show that signal timing optimized by the model proposed in this paper can decrease vehicles delay and emissions more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development. Vehicle emissions are heavily at signal intersections in urban area. The multiobjective signal timing optimization model is proposed considering the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. The results indicate that signal timing optimized by the model proposed in this paper can decrease vehicle emissions and delays more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development.

Multi-Objective Optimization for Energy Performance Improvement of Residential Buildings: A Comparative Study

Directory of Open Access Journals (Sweden)

Kangji Li

2017-02-01

Full Text Available Numerous conflicting criteria exist in building design optimization, such as energy consumption, greenhouse gas emission and indoor thermal performance. Different simulation-based optimization strategies and various optimization algorithms have been developed. A few of them are analyzed and compared in solving building design problems. This paper presents an efficient optimization framework to facilitate optimization designs with the aid of commercial simulation software and MATLAB. The performances of three optimization strategies, including the proposed approach, GenOpt method and artificial neural network (ANN method, are investigated using a case study of a simple building energy model. Results show that the proposed optimization framework has competitive performances compared with the GenOpt method. Further, in another practical case, four popular multi-objective algorithms, e.g., the non-dominated sorting genetic algorithm (NSGA-II, multi-objective particle swarm optimization (MOPSO, the multi-objective genetic algorithm (MOGA and multi-objective differential evolution (MODE, are realized using the propose optimization framework and compared with three criteria. Results indicate that MODE achieves close-to-optimal solutions with the best diversity and execution time. An uncompetitive result is achieved by the MOPSO in this case study.

Optimization of ejector design and operation

Directory of Open Access Journals (Sweden)

Kuzmenko Konstantin

2016-01-01

Full Text Available The investigation aims at optimization of gas ejector operation. The goal consists in the improvement of the inflator design so that to enable 50 liters of gas inflation within ~30 milliseconds. For that, an experimental facility was developed and fabricated together with the measurement system to study pressure patterns in the inflator path.

Topology optimization under stochastic stiffness

Science.gov (United States)

Asadpoure, Alireza

Topology optimization is a systematic computational tool for optimizing the layout of materials within a domain for engineering design problems. It allows variation of structural boundaries and connectivities. This freedom in the design space often enables discovery of new, high performance designs. However, solutions obtained by performing the optimization in a deterministic setting may be impractical or suboptimal when considering real-world engineering conditions with inherent variabilities including (for example) variabilities in fabrication processes and operating conditions. The aim of this work is to provide a computational methodology for topology optimization in the presence of uncertainties associated with structural stiffness, such as uncertain material properties and/or structural geometry. Existing methods for topology optimization under deterministic conditions are first reviewed. Modifications are then proposed to improve the numerical performance of the so-called Heaviside Projection Method (HPM) in continuum domains. Next, two approaches, perturbation and Polynomial Chaos Expansion (PCE), are proposed to account for uncertainties in the optimization procedure. These approaches are intrusive, allowing tight and efficient coupling of the uncertainty quantification with the optimization sensitivity analysis. The work herein develops a robust topology optimization framework aimed at reducing the sensitivity of optimized solutions to uncertainties. The perturbation-based approach combines deterministic topology optimization with a perturbation method for the quantification of uncertainties. The use of perturbation transforms the problem of topology optimization under uncertainty to an augmented deterministic topology optimization problem. The PCE approach combines the spectral stochastic approach for the representation and propagation of uncertainties with an existing deterministic topology optimization technique. The resulting compact representations

optimization of water resources allocation in semi-arid region

African Journals Online (AJOL)

Eng Obi Ibeje

This study is aimed at achieving optimal water resources allocation .... (2005) points out, in his discussions of non- cooperative games model ... the linear and dynamic programming model which many ... e.g. Institute of Water and Hydropower.

Preliminary study for a nuclear multi-cycle reload optimization system

International Nuclear Information System (INIS)

Baptista, Rafael Pereira; Lima, Alan Miranda M. de; Medeiros, Jose Antonio Carlos Canedo; Schirru, Roberto

2007-01-01

Fuel assemblies in a reactor are discharged normally after several fuel cycles. This happens because of the concentration of fissile material existing in the fuel assemblies in the core decreases to values such that it is not more possible to keep the reactor operating producing energy at normal rated power. Therefore, the refueling optimization for a nuclear power plant is in fact a multi-cycle problem. A typical multi-cycle reload optimization depends on several kinds of relationships: one is the relationship between the locations where the fuel assemblies are placed for a specified fuel cycle; another is the relationship between fuel loading patterns for the subsequent fuel cycles. This makes the problem very complex and difficult to solve. Until the moment, all the presented proposals for solution are far from solving the multi-cycle optimization problems in reactor fuel management. In this work, we will show preliminary studies of possible solutions for a typical multi-cycle reload optimization problem trying to consider most important restrictions of a real model. In the initial comparisons, the optimization results will be compared with those obtained by the successive single cycle optimizations. (author)

Optimization of C4.5 algorithm-based particle swarm optimization for breast cancer diagnosis

Science.gov (United States)

Muslim, M. A.; Rukmana, S. H.; Sugiharti, E.; Prasetiyo, B.; Alimah, S.

2018-03-01

Data mining has become a basic methodology for computational applications in the field of medical domains. Data mining can be applied in the health field such as for diagnosis of breast cancer, heart disease, diabetes and others. Breast cancer is most common in women, with more than one million cases and nearly 600,000 deaths occurring worldwide each year. The most effective way to reduce breast cancer deaths was by early diagnosis. This study aims to determine the level of breast cancer diagnosis. This research data uses Wisconsin Breast Cancer dataset (WBC) from UCI machine learning. The method used in this research is the algorithm C4.5 and Particle Swarm Optimization (PSO) as a feature option and to optimize the algorithm. C4.5. Ten-fold cross-validation is used as a validation method and a confusion matrix. The result of this research is C4.5 algorithm. The particle swarm optimization C4.5 algorithm has increased by 0.88%.

Crashworthiness design of transient frame structures using topology optimization

DEFF Research Database (Denmark)

Pedersen, Claus B. Wittendorf

2004-01-01

The aim of this paper is to present topology optimization as a method to obtain conceptual designs for crash-worthiness. The topology optimization formulation uses rigorously computed sensitivities. The large displacements and plasticity of the 2D beam elements are modelled with the co-rotational......The aim of this paper is to present topology optimization as a method to obtain conceptual designs for crash-worthiness. The topology optimization formulation uses rigorously computed sensitivities. The large displacements and plasticity of the 2D beam elements are modelled with the co...

DYNAMIC OPTIMAL BUDGET ALLOCATION FOR INTEGRATED MARKETING CONSIDERING PERSISTENCE

OpenAIRE

SHIZHONG AI; RONG DU; QIYING HU

2010-01-01

Aiming at forming dynamic optimal integrated marketing policies, we build a budget allocation model considering both current effects and sustained ones. The model includes multiple time periods and multiple marketing tools which interact through a common resource pool as well as through delayed cross influences on each other's sales, reflecting the nature of "integrated marketing" and its dynamics. In our study, marginal analysis is used to illuminate the structure of optimal policy. We deriv...

Device Optimization and Transient Electroluminescence Studies of Organic light Emitting Devices

Energy Technology Data Exchange (ETDEWEB)

Lijuan Zou

2003-08-05

Organic light emitting devices (OLEDs) are among the most promising for flat panel display technologies. They are light, bright, flexible, and cost effective. And while they are emerging in commercial product, their low power efficiency and long-term degradation are still challenging. The aim of this work was to investigate their device physics and improve their performance. Violet and blue OLEDs were studied. The devices were prepared by thermal vapor deposition in high vacuum. The combinatorial method was employed in device preparation. Both continuous wave and transient electroluminescence (EL) were studied. A new efficient and intense UV-violet light emitting device was developed. At a current density of 10 mA/cm{sup 2}, the optimal radiance R could reach 0.38 mW/cm{sup 2}, and the quantum efficiency was 1.25%. using the delayed EL technique, electron mobilities in DPVBi and CBP were determined to be {approx} 10{sup -5} cm{sup 2}/Vs and {approx} 10{sup -4} cm{sup 2}/Vs, respectively. Overshoot effects in the transient El of blue light emitting devices were also observed and studied. This effect was attributed to the charge accumulation at the organic/organic and organic/cathode interfaces.

Device Optimization and Transient Electroluminescence Studies of Organic light Emitting Devices

International Nuclear Information System (INIS)

Lijuan Zou

2003-01-01

Organic light emitting devices (OLEDs) are among the most promising for flat panel display technologies. They are light, bright, flexible, and cost effective. And while they are emerging in commercial product, their low power efficiency and long-term degradation are still challenging. The aim of this work was to investigate their device physics and improve their performance. Violet and blue OLEDs were studied. The devices were prepared by thermal vapor deposition in high vacuum. The combinatorial method was employed in device preparation. Both continuous wave and transient electroluminescence (EL) were studied. A new efficient and intense UV-violet light emitting device was developed. At a current density of 10 mA/cm 2 , the optimal radiance R could reach 0.38 mW/cm 2 , and the quantum efficiency was 1.25%. using the delayed EL technique, electron mobilities in DPVBi and CBP were determined to be ∼ 10 -5 cm 2 /Vs and ∼ 10 -4 cm 2 /Vs, respectively. Overshoot effects in the transient El of blue light emitting devices were also observed and studied. This effect was attributed to the charge accumulation at the organic/organic and organic/cathode interfaces

Computational study of smoke flow control in garage fires and optimization of the ventilation system

Directory of Open Access Journals (Sweden)

Banjac Miloš J.

2009-01-01

Full Text Available With the aim of evaluating capabilities of a ventilation system to control the spread of smoke in the emergency operating mode, thereby providing conditions for safe evacuation of people from a fire-struck area, computational fluid dynamics simulation of a fire in a semi-bedded garage was conducted. Using the experimental results of combustion dynamics of a passenger car on fire, optimal positions of ventilation openings were determined. According to recommendations by DIN EN 12101 standard, the operating modes of a ventilation system were verified and optimal start time of the smoke extraction system was defined.

Development and Optimization of controlled drug release ...

African Journals Online (AJOL)

The aim of this study is to develop and optimize an osmotically controlled drug delivery system of diclofenac sodium. Osmotically controlled oral drug delivery systems utilize osmotic pressure for controlled delivery of active drugs. Drug delivery from these systems, to a large extent, is independent of the physiological factors ...

Optimized Management of Groundwater Resources in Kish Island: A Sensitivity Analysis of Optimal Strategies in Response to Environmental Changes

Directory of Open Access Journals (Sweden)

Davood Mahmoodzadeh

2016-05-01

Full Text Available Groundwater in coastal areas is an essential source of freshwater that warrants protection from seawater intrusion as a priority based on an optimal management plan. Proper optimal management strategies can be developed using a variety of decision-making models. The present study aims to investigate the impacts of environmental changes on groundwater resources. For this purpose, a combined simulation-optimization model is employed that incorporates the SUTRA numerical model and the evolutionaty method of ant colony optimization. The fresh groundwater lens in Kish Island is used as a case study and different scenarios are considered for the likely enviromental changes. Results indicate that while variations in recharge rate form an important factor in the fresh groundwater lens, land-surface inundation due to rises in seawater level, especially in low-lying lands, is the major factor affecting the lens. Furthermore, impacts of environmental changes when effected into the Kish Island aquifer optimization management plan have led to a reduction of more than 20% in the allowable water extraction, indicating the high sensitivity of groundwater resources management plans in small islands to such variations.

Evaluation and cultural adaptation of a German version of the AIMS2-SF questionnaire (German AIMS2-SF).

NARCIS (Netherlands)

Rosemann, T.J.; Korner, T.; Wensing, M.J.P.; Schneider, A.; Szecsenyi, J.

2005-01-01

OBJECTIVES: The aim of the study was to examine the validity of a translated and culturally adapted version of the Arthritis Impact Measurement Scales 2, Short Form (AIMS2-SF) in patients suffering from osteoarthritis (OA) in primary care. METHODS: A structured procedure was used for the translation

HSTLBO: A hybrid algorithm based on Harmony Search and Teaching-Learning-Based Optimization for complex high-dimensional optimization problems.

Directory of Open Access Journals (Sweden)

Shouheng Tuo

Full Text Available Harmony Search (HS and Teaching-Learning-Based Optimization (TLBO as new swarm intelligent optimization algorithms have received much attention in recent years. Both of them have shown outstanding performance for solving NP-Hard optimization problems. However, they also suffer dramatic performance degradation for some complex high-dimensional optimization problems. Through a lot of experiments, we find that the HS and TLBO have strong complementarity each other. The HS has strong global exploration power but low convergence speed. Reversely, the TLBO has much fast convergence speed but it is easily trapped into local search. In this work, we propose a hybrid search algorithm named HSTLBO that merges the two algorithms together for synergistically solving complex optimization problems using a self-adaptive selection strategy. In the HSTLBO, both HS and TLBO are modified with the aim of balancing the global exploration and exploitation abilities, where the HS aims mainly to explore the unknown regions and the TLBO aims to rapidly exploit high-precision solutions in the known regions. Our experimental results demonstrate better performance and faster speed than five state-of-the-art HS variants and show better exploration power than five good TLBO variants with similar run time, which illustrates that our method is promising in solving complex high-dimensional optimization problems. The experiment on portfolio optimization problems also demonstrate that the HSTLBO is effective in solving complex read-world application.

Equipment cost optimization

International Nuclear Information System (INIS)

Ribeiro, E.M.; Farias, M.A.; Dreyer, S.R.B.

1995-01-01

Considering the importance of the cost of material and equipment in the overall cost profile of an oil company, which in the case of Petrobras, represents approximately 23% of the total operational cost or 10% of the sales, an organization for the optimization of such costs has been established within Petrobras. Programs are developed aiming at: optimization of life-cycle cost of material and equipment; optimization of industrial processes costs through material development. This paper describes the methodology used in the management of the development programs and presents some examples of concluded and ongoing programs, which are conducted in permanent cooperation with suppliers, technical laboratories and research institutions and have been showing relevant results

Administered activity optimization of the MDP labeled with Tc-99 m in bone tip studies

International Nuclear Information System (INIS)

Perez Diaz, Marlen; Esteves Aparicio, Eric; Dopico Hernandez, Rolando; Gorrin, Orlando Cabrera

2003-01-01

The aim of the present study was to determine the optimum activity of the Cuban MDP labeled with Tc-99 m, for establishing a compromise relation between image quality and patient radiological protection in Nuclear Medicine studies. The used statistical technique was the discriminant analysis to arrive at the optimization criterion. Three samples of 18 patients each were selected. Each sample was undergone to a different acquisition protocol. Each sample was divided into three groups of 6 patients each. The administered activities were: 293 MBq, 430 MBq or 598 MBq. Images of hands and femurs were graded for each study. The ratios Signal /Background and Signal/ Noise were processed. The value of 430 MBq was enough to obtain good image quality using a protocol of 10 minutes of acquisition for the used technical conditions. (author)

Optimization of Approximate Inhibitory Rules Relative to Number of Misclassifications

KAUST Repository

Alsolami, Fawaz

2013-10-04

In this work, we consider so-called nonredundant inhibitory rules, containing an expression “attribute:F value” on the right- hand side, for which the number of misclassifications is at most a threshold γ. We study a dynamic programming approach for description of the considered set of rules. This approach allows also the optimization of nonredundant inhibitory rules relative to the length and coverage. The aim of this paper is to investigate an additional possibility of optimization relative to the number of misclassifications. The results of experiments with decision tables from the UCI Machine Learning Repository show this additional optimization achieves a fewer misclassifications. Thus, the proposed optimization procedure is promising.

Essays and surveys in global optimization

CERN Document Server

Audet, Charles; Savard, Giles

2005-01-01

Global optimization aims at solving the most general problems of deterministic mathematical programming. In addition, once the solutions are found, this methodology is also expected to prove their optimality. With these difficulties in mind, global optimization is becoming an increasingly powerful and important methodology. This book is the most recent examination of its mathematical capability, power, and wide ranging solutions to many fields in the applied sciences.

Optimal perturbations for nonlinear systems using graph-based optimal transport

Science.gov (United States)

Grover, Piyush; Elamvazhuthi, Karthik

2018-06-01

We formulate and solve a class of finite-time transport and mixing problems in the set-oriented framework. The aim is to obtain optimal discrete-time perturbations in nonlinear dynamical systems to transport a specified initial measure on the phase space to a final measure in finite time. The measure is propagated under system dynamics in between the perturbations via the associated transfer operator. Each perturbation is described by a deterministic map in the measure space that implements a version of Monge-Kantorovich optimal transport with quadratic cost. Hence, the optimal solution minimizes a sum of quadratic costs on phase space transport due to the perturbations applied at specified times. The action of the transport map is approximated by a continuous pseudo-time flow on a graph, resulting in a tractable convex optimization problem. This problem is solved via state-of-the-art solvers to global optimality. We apply this algorithm to a problem of transport between measures supported on two disjoint almost-invariant sets in a chaotic fluid system, and to a finite-time optimal mixing problem by choosing the final measure to be uniform. In both cases, the optimal perturbations are found to exploit the phase space structures, such as lobe dynamics, leading to efficient global transport. As the time-horizon of the problem is increased, the optimal perturbations become increasingly localized. Hence, by combining the transfer operator approach with ideas from the theory of optimal mass transportation, we obtain a discrete-time graph-based algorithm for optimal transport and mixing in nonlinear systems.

AFRICAN BUFFALO OPTIMIZATION ico-pdf

Directory of Open Access Journals (Sweden)

Julius Beneoluchi Odili

2016-02-01

Full Text Available This is an introductory paper to the newly-designed African Buffalo Optimization (ABO algorithm for solving combinatorial and other optimization problems. The algorithm is inspired by the behavior of African buffalos, a species of wild cows known for their extensive migrant lifestyle. This paper presents an overview of major metaheuristic algorithms with the aim of providing a basis for the development of the African Buffalo Optimization algorithm which is a nature-inspired, population-based metaheuristic algorithm. Experimental results obtained from applying the novel ABO to solve a number of benchmark global optimization test functions as well as some symmetric and asymmetric Traveling Salesman’s Problems when compared to the results obtained from using other popular optimization methods show that the African Buffalo Optimization is a worthy addition to the growing number of swarm intelligence optimization techniques.

Optimal design of a hybridization scheme with a fuel cell using genetic optimization

Science.gov (United States)

Rodriguez, Marco A.

Fuel cell is one of the most dependable "green power" technologies, readily available for immediate application. It enables direct conversion of hydrogen and other gases into electric energy without any pollution of the environment. However, the efficient power generation is strictly stationary process that cannot operate under dynamic environment. Consequently, fuel cell becomes practical only within a specially designed hybridization scheme, capable of power storage and power management functions. The resultant technology could be utilized to its full potential only when both the fuel cell element and the entire hybridization scheme are optimally designed. The design optimization in engineering is among the most complex computational tasks due to its multidimensionality, nonlinearity, discontinuity and presence of constraints in the underlying optimization problem. this research aims at the optimal utilization of the fuel cell technology through the use of genetic optimization, and advance computing. This study implements genetic optimization in the definition of optimum hybridization rules for a PEM fuel cell/supercapacitor power system. PEM fuel cells exhibit high energy density but they are not intended for pulsating power draw applications. They work better in steady state operation and thus, are often hybridized. In a hybrid system, the fuel cell provides power during steady state operation while capacitors or batteries augment the power of the fuel cell during power surges. Capacitors and batteries can also be recharged when the motor is acting as a generator. Making analogies to driving cycles, three hybrid system operating modes are investigated: 'Flat' mode, 'Uphill' mode, and 'Downhill' mode. In the process of discovering the switching rules for these three modes, we also generate a model of a 30W PEM fuel cell. This study also proposes the optimum design of a 30W PEM fuel cell. The PEM fuel cell model and hybridization's switching rules are postulated

Parameter Optimization of MIMO Fuzzy Optimal Model Predictive Control By APSO

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Adel Taieb

2017-01-01

Full Text Available This paper introduces a new development for designing a Multi-Input Multi-Output (MIMO Fuzzy Optimal Model Predictive Control (FOMPC using the Adaptive Particle Swarm Optimization (APSO algorithm. The aim of this proposed control, called FOMPC-APSO, is to develop an efficient algorithm that is able to have good performance by guaranteeing a minimal control. This is done by determining the optimal weights of the objective function. Our method is considered an optimization problem based on the APSO algorithm. The MIMO system to be controlled is modeled by a Takagi-Sugeno (TS fuzzy system whose parameters are identified using weighted recursive least squares method. The utility of the proposed controller is demonstrated by applying it to two nonlinear processes, Continuous Stirred Tank Reactor (CSTR and Tank system, where the proposed approach provides better performances compared with other methods.

Intersection signal control multi-objective optimization based on genetic algorithm

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Zhanhong Zhou

2014-04-01

Full Text Available A signal control intersection increases not only vehicle delay, but also vehicle emissions and fuel consumption in that area. Because more and more fuel and air pollution problems arise recently, an intersection signal control optimization method which aims at reducing vehicle emissions, fuel consumption and vehicle delay is required heavily. This paper proposed a signal control multi-object optimization method to reduce vehicle emissions, fuel consumption and vehicle delay simultaneously at an intersection. The optimization method combined the Paramics microscopic traffic simulation software, Comprehensive Modal Emissions Model (CMEM, and genetic algorithm. An intersection in Haizhu District, Guangzhou, was taken for a case study. The result of the case study shows the optimal timing scheme obtained from this method is better than the Webster timing scheme.

Instant PageSpeed optimization

CERN Document Server

Jaiswal, Sanjeev

2013-01-01

Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. Instant PageSpeed Optimization is a hands-on guide that provides a number of clear, step-by-step exercises for optimizing your websites for better performance and improving their efficiency.Instant PageSpeed Optimization is aimed at website developers and administrators who wish to make their websites load faster without any errors and consume less bandwidth. It's assumed that you will have some experience in basic web technologies like HTML, CSS3, JavaScript, and the basics of netw

Optimization Route of Food Logistics Distribution Based on Genetic and Graph Cluster Scheme Algorithm

OpenAIRE

Jing Chen

2015-01-01

This study takes the concept of food logistics distribution as the breakthrough point, by means of the aim of optimization of food logistics distribution routes and analysis of the optimization model of food logistics route, as well as the interpretation of the genetic algorithm, it discusses the optimization of food logistics distribution route based on genetic and cluster scheme algorithm.

Studies on generalized kinetic model and Pareto optimization of a product-driven self-cycling bioprocess.

Science.gov (United States)

Sun, Kaibiao; Kasperski, Andrzej; Tian, Yuan

2014-10-01

The aim of this study is the optimization of a product-driven self-cycling bioprocess and presentation of a way to determine the best possible decision variables out of a set of alternatives based on the designed model. Initially, a product-driven generalized kinetic model, which allows a flexible choice of the most appropriate kinetics is designed and analysed. The optimization problem is given as the bi-objective one, where maximization of biomass productivity and minimization of unproductive loss of substrate are the objective functions. Then, the Pareto fronts are calculated for exemplary kinetics. It is found that in the designed bioprocess, a decrease of emptying/refilling fraction and an increase of substrate feeding concentration cause an increase of the biomass productivity. An increase of emptying/refilling fraction and a decrease of substrate feeding concentration cause a decrease of unproductive loss of substrate. The preferred solutions are calculated using the minimum distance from an ideal solution method, while giving proposals of their modifications derived from a decision maker's reactions to the generated solutions.

Developing a dashboard to help measure and achieve the triple aim: a population-based cohort study.

Science.gov (United States)

Seow, Hsien-Yeang; Sibley, Lyn M

2014-08-30

Health system planners aim to pursue the three goals of Triple Aim: 1) reduce health care costs; 2) improve population health; and 3) improve the care experience. Moreover, they also need measures that can reliably predict future health care needs in order to manage effectively the health system performance. Yet few measures exist to assess Triple Aim and predict future needs at a health system level. The purpose of this study is to explore the novel application of a case-mix adjustment method in order to measure and help improve the Triple Aim of health system performance. We applied a case-mix adjustment method to a population-based analysis to assess its usefulness as a measure of health system performance and Triple Aim. The study design was a retrospective, cohort study of adults from Ontario, Canada using administrative databases: individuals were assigned a predicted illness burden score using a case-mix adjustment system from diagnoses and health utilization data in 2008, and then followed forward to assess the actual health care utilization and costs in the following year (2009). We applied the Johns Hopkins Adjusted Clinical Group (ACG) Case-Mix System to categorize individuals into 60 levels of healthcare need, called ACGs. The outcomes were: 1) Number of individuals per ACG; 2) Total system costs per ACG; and 3) Mean cost per person per ACG, which together formed a health system "dashboard". We identified 11.4 million adults. 16.1% were aged 65 or older, 3.2 million (28%) did not use health care services that year, and 45,000 (0.4%) were in the highest acuity ACG category using 12 times more than an average adult. The sickest 1%, 5% and 15% of the population use about 10%, 30% and 50% of total health system costs respectively. The dashboard measures 2 dimensions of Triple Aim: 1) reduced costs: when total system costs per ACG or when average costs per person is reduced; and 2) improved population health: when more people move into healthier rather than

Nisin Production Utilizing Skimmed Milk Aiming to Reduce Process Cost

Science.gov (United States)

Jozala, Angela Faustino; de Andrade, Maura Sayuri; de Arauz, Luciana Juncioni; Pessoa, Adalberto; Penna, Thereza Christina Vessoni

Nisin is a natural additive for conservation of food, pharmaceutical, and dental products and can be used as a therapeutic agent. Nisin inhibits the outgrowth of spores, the growth of a variety of Gram-positive and Gram-negative bacteria. This study was performed to optimize large-scale nisin production in skimmed milk and subproducts aiming at low-costs process and stimulating its utilization. Lactococcus lactis American Type Culture Collection (ATCC) 11454 was developed in a rotary shaker (30°C/36 h/100 rpm) in diluted skimmed milk and nisin activity, growth parameters, and media components were also studied. Nisin activity in growth media was expressed in arbitrary units (AU/mL) and converted to standard nisin concentration (Nisaplin®, 25 mg of pure nisin is 1.0×106 AU/mL). Nisin activity in skimmed milk 2.27 gtotal solids was up to threefold higher than transfers in skimmed milk 4.54 gtotal solids and was up to 85-fold higher than transfers in skimmed milk 1.14 gtotal solids. L. lactis was assayed in a New Brunswick fermentor with 1.5 L of diluted skimmed milk (2.27 gtotal solids) and airflow of 1.5 mL/min (30°C/36/200 rpm), without pH control. In this condition nisin activity was observed after 4 h (45.07 AU/mL) and in the end of 36 h process (3312.07 AU/mL). This work shows the utilization of a low-cost growth medium (diluted skimmed milk) to nisin production with wide applications. Furthermore, milk subproducts (milk whey) can be exploited in nisin production, because in Brazil 50% of milk whey is disposed with no treatment in rivers and because of high organic matter concentrations it is considered an important pollutant. In this particular case an optimized production of an antimicrobial would be lined up with industrial disposal recycling.

Study on Parameter Optimization Design of Drum Brake Based on Hybrid Cellular Multiobjective Genetic Algorithm

Directory of Open Access Journals (Sweden)

Yi Zhang

2012-01-01

Full Text Available In consideration of the significant role the brake plays in ensuring the fast and safe running of vehicles, and since the present parameter optimization design models of brake are far from the practical application, this paper proposes a multiobjective optimization model of drum brake, aiming at maximizing the braking efficiency and minimizing the volume and temperature rise of drum brake. As the commonly used optimization algorithms are of some deficiency, we present a differential evolution cellular multiobjective genetic algorithm (DECell by introducing differential evolution strategy into the canonical cellular genetic algorithm for tackling this problem. For DECell, the gained Pareto front could be as close as possible to the exact Pareto front, and also the diversity of nondominated individuals could be better maintained. The experiments on the test functions reveal that DECell is of good performance in solving high-dimension nonlinear multiobjective problems. And the results of optimizing the new brake model indicate that DECell obviously outperforms the compared popular algorithm NSGA-II concerning the number of obtained brake design parameter sets, the speed, and stability for finding them.

Optimization of PV/Wind/Battery stand-alone system, using hybrid FPA/SA algorithm and CFD simulation, case study: Tehran

International Nuclear Information System (INIS)

Tahani, Mojtaba; Babayan, Narek; Pouyaei, Arman

2015-01-01

Highlights: • The utilization of an optimized Hybrid PV/Wind/Battery system has been studied. • The proposed system has been studied for a building in Tehran. • A novel hybrid optimization method, namely FPA/SA has been proposed. • The impact of inclined part of the roof on wind velocity is studied by CFD. • LPSP and Payback time were considered as objective functions in this study. - Abstract: Renewable energy hybrid systems are a promising technology toward sustainable and clean development. Due to stochastic behavior of renewable energy sources, optimization of their convertors has great importance for increasing system’s reliability and efficiency and also in order to decrease the costs. In this research study, it was aimed to study the utilization of an optimized hybrid PV/Wind/Battery system for a three story building, with an inclined surface on the edge of its roof, located in Tehran, capital of Iran. For this purpose, a new evolutionary based optimization technique, namely hybrid FPA/SA algorithm was developed, in order to maximize system’s reliability and minimize system’s costs. The new algorithm combines the approaches which are utilized in Flower Pollination Algorithm (FPA) and Simulated Annealing (SA) algorithm. The developed algorithm was validated using popular benchmark functions. Moreover the influence of PV panels tilt angle (which is equal to the slope of inclined part of the roof) is studied on the wind speed by using computational fluid dynamics (CFD) simulation. The outputs of CFD simulations are utilized as inputs for modeling wind turbine performance. The Loss of Power Supply Probability (LPSP) and Payback time are considered as objective functions, and PV panel tilt angle, number of PV panels and number of batteries are selected as decision variables. The results showed that if the tilt angle for PV panels is set equal to 30° and the number of PV panels is selected equal to 11 the fastest payback time which is 12 years and

Bulbous Bow Shape Optimization

OpenAIRE

Blanchard , Louis; Berrini , Elisa; Duvigneau , Régis; Roux , Yann; Mourrain , Bernard; Jean , Eric

2013-01-01

International audience; The aim of this study is to prove the usefulness of a bulbous bow for a fishing vessel, in terms of drag reduction, using an automated shape optimization procedure including hydrodynamic simulations. A bulbous bow is an appendage that is known to reduce the drag, thanks to its influence on the bow wave system. However, the definition of the geometrical parameters of the bulb, such as its length and thickness, is not intuitive, as both parameters are coupled with regard...

Anger and health in dementia caregivers: exploring the mediation effect of optimism.

Science.gov (United States)

López, J; Romero-Moreno, R; Márquez-González, M; Losada, A

2015-04-01

Although previous studies indicate a negative association between caregivers' anger and health, the potential mechanisms linking this relationship are not yet fully understood. The aim of this study was to explore the potential mediating role of optimism in the relationship between anger and caregivers' physical health. Dementia caregivers (n = 108) were interviewed and filled out instruments assessing their anger (reaction), optimism and health (vitality). A mediational model was tested to determine whether optimism partially mediated the relationship between anger and vitality. Angry reaction was negatively associated with optimism and vitality; optimism was positively associated with vitality. Finally, the relationship between angry reaction and vitality decreased when optimism was entered simultaneously. A non-parametric bootstrap approach confirmed that optimism significantly mediated some of the relationship between angry reaction and vitality. These findings suggest that low optimism may help explain the association between caregivers' anger and reduced sense of vitality. The results provide a specific target for intervention with caregivers. Copyright © 2013 John Wiley & Sons, Ltd.

The Improvement of Particle Swarm Optimization: a Case Study of Optimal Operation in Goupitan Reservoir

Science.gov (United States)

Li, Haichen; Qin, Tao; Wang, Weiping; Lei, Xiaohui; Wu, Wenhui

2018-02-01

Due to the weakness in holding diversity and reaching global optimum, the standard particle swarm optimization has not performed well in reservoir optimal operation. To solve this problem, this paper introduces downhill simplex method to work together with the standard particle swarm optimization. The application of this approach in Goupitan reservoir optimal operation proves that the improved method had better accuracy and higher reliability with small investment.

Some Studies on Forming Optimization with Genetic Algorithm

Directory of Open Access Journals (Sweden)

Ganesh Marotrao KAKANDIKAR

2012-07-01

Full Text Available Forming is a compression-tension process involving wide spectrum of operations andflow conditions. The result of the process depends on the large number of parameters and theirinterdependence. The selection of various parameters is still based on trial and error methods. In thispaper the authors present a new approach to optimize the geometry parameters of circularcomponents, process parameters such as blank holder pressure and coefficient of friction etc. Theoptimization problem has been formulated with the objective of optimizing the maximum formingload required in Forming. Genetic algorithm is used as a tool for the optimization: to optimize thedrawing load and to optimize the process parameters. A finite element analysis simulation softwareFast Form Advanced is used for the validations of the results after optimization with prior results.

Sparse Learning with Stochastic Composite Optimization.

Science.gov (United States)

Zhang, Weizhong; Zhang, Lijun; Jin, Zhongming; Jin, Rong; Cai, Deng; Li, Xuelong; Liang, Ronghua; He, Xiaofei

2017-06-01

In this paper, we study Stochastic Composite Optimization (SCO) for sparse learning that aims to learn a sparse solution from a composite function. Most of the recent SCO algorithms have already reached the optimal expected convergence rate O(1/λT), but they often fail to deliver sparse solutions at the end either due to the limited sparsity regularization during stochastic optimization (SO) or due to the limitation in online-to-batch conversion. Even when the objective function is strongly convex, their high probability bounds can only attain O(√{log(1/δ)/T}) with δ is the failure probability, which is much worse than the expected convergence rate. To address these limitations, we propose a simple yet effective two-phase Stochastic Composite Optimization scheme by adding a novel powerful sparse online-to-batch conversion to the general Stochastic Optimization algorithms. We further develop three concrete algorithms, OptimalSL, LastSL and AverageSL, directly under our scheme to prove the effectiveness of the proposed scheme. Both the theoretical analysis and the experiment results show that our methods can really outperform the existing methods at the ability of sparse learning and at the meantime we can improve the high probability bound to approximately O(log(log(T)/δ)/λT).

Neutronic performance optimization study of Indian fusion demo reactor first wall and breeding blanket

International Nuclear Information System (INIS)

Swami, H.L.; Danani, C.

2015-01-01

In frame of design studies of Indian Nuclear Fusion DEMO Reactor, neutronic performance optimization of first wall and breeding blanket are carried out. The study mainly focuses on tritium breeding ratio (TBR) and power density responses estimation of breeding blanket. Apart from neutronic efficiency of existing breeding blanket concepts for Indian DEMO i.e. lead lithium ceramic breeder and helium cooled solid breeder concept other concepts like helium cooled lead lithium and helium-cooled Li_8PbO_6 with reflector are also explored. The aim of study is to establish a neutronically efficient breeding blanket concept for DEMO. Effect of first wall materials and thickness on breeding blanket neutronic performance is also evaluated. For this study 1 D cylindrical neutronic model of DEMO has been constructed according to the preliminary radial build up of Indian DEMO. The assessment is being done using Monte Carlo based radiation transport code and nuclear cross section data file ENDF/B- VII. (author)

Faculty Sense of Academic Optimism and Its Relationship to Students' Achievement in Well Performing High Schools

Science.gov (United States)

Cromartie, Michael Tyrone

2013-01-01

The aim of this study was to determine the organizational characteristics and behaviors that contribute to sustaining a culture of academic optimism as a mechanism of student achievement. While there is a developing research base identifying both the individual elements of academic optimism as well as the academic optimism construct itself as…

A Correlational and Descriptive Study of Student Writing in Three Aims of Discourse.

Science.gov (United States)

1981-12-01

than the old abondend house does now. As it stands it is the perfect target and meeting place for criminals and drug addicts . If the house were C... Whale and Robinson (1978) discovered that, in a free-writing situation, students most often chose to write transactional (referential and persuasive...discourse.27 (Perhaps in the transactional aim they used the narrative mode more than any other, as Pianko’s study suggested, but Whale and Robinson did

SCADA System for the Modeling and Optimization of Oil Collecting Pipeline Network: A Case Study of Hassi Messaoud Oilfield

OpenAIRE

M. Aouadj; F. Naceri; M. Touileb; D. Sellami; M. Boukhatem

2015-01-01

This study aims are data acquisition, control and online modeling of an oil collection pipeline network using a SCADA «Supervisory Control and Data Acquisition» system, allowing the optimization of this network in real time by creating more exact models of onsite facilities. Indeed, fast development of computing systems makes obsolete usage of old systems for which maintenance became more and more expensive and their performances don’t comply any more with modern company operations. SCADA sys...

Advanced backend optimization

CERN Document Server

Touati, Sid

2014-01-01

This book is a summary of more than a decade of research in the area of backend optimization. It contains the latest fundamental research results in this field. While existing books are often more oriented toward Masters students, this book is aimed more towards professors and researchers as it contains more advanced subjects.It is unique in the sense that it contains information that has not previously been covered by other books in the field, with chapters on phase ordering in optimizing compilation; register saturation in instruction level parallelism; code size reduction for software pipe

Characterization and optimization of the RA-3 experimental dosimetry for normal sheep lung radio-tolerance study

International Nuclear Information System (INIS)

Soto, M.S.; Gonzalez, S.J.; Thorp, Silvia I.; Pozzi, Emiliano; Gadan, M.; Miller, Marcelo; Farias, R.

2009-01-01

In the spirit of the novel technique proposed by the University of Pavia group (Italy) to irradiate an isolated organ using BNCT, the Comision Nacional de Energia Atomica (CNEA) in collaboration with the Fundacion Favaloro has initiated a project that aims to investigate the feasibility of BNCT for ex-situ treatment of diffuse metastatic disease in the lungs. The present work was carried out in the framework of the undergoing experimental study of the radio tolerance of normal sheep lung. With the purpose of characterizing and optimizing the resulting experimental dosimetry in normal lung subjected to neutron irradiation in the BNCT facility of the RA-3 reactor (CNEA), we have performed a series of experiments to find the optimum configuration of the container-lung system deriving a dose distribution preferentially uniform throughout the organ. Once the optimal set-up was established, we measured the total gamma dose rate and estimated the irradiation time compatible with the maximum tolerable dose of normal lung resulting from previous studies in rats. This estimation was performed using RBE, CBE and tolerance dose values derived from radiobiological studies with BNCT. In parallel with the experimental characterization, we built two different computational models of the container-lung system to perform Monte Carlo simulation with MCNP and Treatment Planning System NCTPlan. (author)

Identifying and prioritizing indicators and effective solutions to optimization the use of wood in construction classical furniture by using AHP (Case study of Qom

Directory of Open Access Journals (Sweden)

Mohammad Ghofrani

2017-02-01

Full Text Available AbstractThe aim of this study was to identify and prioritize the indicators and provide effective solutions to optimize the use of wood in construction classical furniture using the analytic hierarchy process (case study in Qom. For this purpose, studies and results of other researchers and interviews with experts, the factors affecting the optimization of wood consumption were divided into 4 main categories and 23 sub-indicators. The importance of the sub after getting feedback furniture producers were determined by AHP. The results show that the original surface design and human resources are of great importance. In addition, among 23 sub-effective optimization of the use of wood in construction classical furniture, ergonomics, style, skill training and inlaid in classical furniture industry in order to weight the value of 0/247, 0/181, 0/124 and 0/087 are of paramount importance and the method of use of force specialist solutions were a priority.

Using the multiphase optimization strategy (MOST to optimize an HIV care continuum intervention for vulnerable populations: a study protocol

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Marya Viorst Gwadz

2017-05-01

efficacy in a preliminary study. Methods/design Study aims are: 1 using a highly efficient fractional factorial experimental design, identify which of five intervention components contribute meaningfully to improvement in HIV viral suppression, and secondary outcomes of ART adherence and engagement in HIV primary care; 2 identify mediators and moderators of intervention component efficacy; and 3 using a mathematical modeling approach, build the most cost-effective and efficient intervention package from the efficacious components. A heterogeneous sample of African American/Black and Hispanic PLWH (with respect to age, substance use, and sexual minority status will be recruited with a proven hybrid sampling method using targeted sampling in community settings and peer recruitment (N = 512. Discussion This is the first study to apply the MOST framework in the field of HIV prevention and treatment. This innovative study will produce a culturally based HIV care continuum intervention for the nation’s most vulnerable PLWH, optimized for cost-effectiveness, and with exceptional levels of efficacy, efficiency, and scalability. Trial registration ClinicalTrials.gov, NCT02801747 , Registered June 8, 2016.

Comparative study for the design of optimal composite pressure vessels

International Nuclear Information System (INIS)

Butt, A.M.; Haq, S.W.U.

2009-01-01

Composite pressure vessels require special design attention to the dome region because of the varying wind angles generated using the filament winding process. Geometric variations in the dome region cause the fiber to change angels and thickness and hence offer difficulty to acquire a constant stress profile (isotensoid). Therefore a dome contour which allows an isotensoid behavior is the required structure. Two design methods to generate dome profiles for similar dome openings were investigated namely Netting Analysis and Optimal Design method. Both methods assume that loads are carried by the fiber alone (monotropic) ignoring the complete composite behavior. Former method produced a lower dome internal volume and a higher fiber thickness as compared to the later optimal design method when studied against different normalized dome opening radiuses. The optimal dome contour was studied in ANSYS with a trial design. The dome was considered to have transversely isotropic property with a dome contour based on monotropic model. While investigating the dome with non linear large displacement finite element analysis, the dome still exhibited isotensoid behavior with transverse isotropic material assignment. Elliptic integrals were used to generate the optimal dome contours and hence elliptic dome contours were formed which were isotensoid in nature with complete composite representation. (author)

A study on optimization of the nuclear safety system

International Nuclear Information System (INIS)

Lee, Sang Hoon; Koh, Byung Joon; Kim, Jin Soo; Kim, Byoung Do; Cho, Seong Won; Kwon, Seog Kwon; Choi, Kwang Sik

1986-12-01

The number of nuclear facilities (nuclear power plants, research reactors, nuclear fuel facilities) under construction or in operation in Korea continues to increase and this has brought about increased importance and concerns toward nuclear safety in Korea. Also, domestic nuclear related organizations are increasingly carrying out the design/construction of nuclear power plants and the development /supply of nuclear fuels. In order to flexibly respond to these changes and to suggest direction to take, it is necessary to re-examine the current nuclear safety regulation system. This study is carried out in two stages and this report describes the results of the analysis and the assessment of the nuclear licencing system of such foreign countries as sweden and German, as the first of the two. In this regard, this study includes the analysis on the backgrounds on the choice of nuclear licensing system, the analysis on the licensing procedures, the analysis on the safety inspection system and the enforcement laws, the analysis on the structure and function of the regulatory, business and research organizations as well as the analysis on the relationship between the safety research and the regulatory duties. In this study, the German safety inspection system and the enforcement procedures and the Swedish nuclear licensing system are analyzed in detail. By comparing and assessing the finding with the current Korea Nuclear Licensing System, this study points out some reform measures of the Korean system that needs to improved. With the changing situations in mind, this study aims to develop the nuclear safety regulation system optimized for Korean situation by re-examining the current regulation system. (Author)

Solving Optimization Problems via Vortex Optimization Algorithm and Cognitive Development Optimization Algorithm

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Ahmet Demir

2017-01-01

Full Text Available In the fields which require finding the most appropriate value, optimization became a vital approach to employ effective solutions. With the use of optimization techniques, many different fields in the modern life have found solutions to their real-world based problems. In this context, classical optimization techniques have had an important popularity. But after a while, more advanced optimization problems required the use of more effective techniques. At this point, Computer Science took an important role on providing software related techniques to improve the associated literature. Today, intelligent optimization techniques based on Artificial Intelligence are widely used for optimization problems. The objective of this paper is to provide a comparative study on the employment of classical optimization solutions and Artificial Intelligence solutions for enabling readers to have idea about the potential of intelligent optimization techniques. At this point, two recently developed intelligent optimization algorithms, Vortex Optimization Algorithm (VOA and Cognitive Development Optimization Algorithm (CoDOA, have been used to solve some multidisciplinary optimization problems provided in the source book Thomas' Calculus 11th Edition and the obtained results have compared with classical optimization solutions. 

Optimal study of a solar air heating system with pebble bed energy storage

International Nuclear Information System (INIS)

Zhao, D.L.; Li, Y.; Dai, Y.J.; Wang, R.Z.

2011-01-01

Highlights: → Use two kinds of circulation media in the solar collector. → Air heating and pebble bed heat storage are applied with different operating modes. → Design parameters of the system are optimized by simulation program. → It is found that the system can meet 32.8% of the thermal energy demand in heating season. → Annual solar fraction aims to be 53.04%. -- Abstract: The application of solar air collectors for space heating has attracted extensive attention due to its unique advantages. In this study, a solar air heating system was modeled through TRNSYS for a 3319 m 2 building area. This air heating system, which has the potential to be applied for space heating in the heating season (from November to March) and hot water supply all year around in North China, uses pebble bed and water storage tank as heat storage. Five different working modes were designed based on different working conditions: (1) heat storage mode, (2) heating by solar collector, (3) heating by storage bed, (4) heating at night and (5) heating by an auxiliary source. These modes can be operated through the on/off control of fan and auxiliary heater, and through the operation of air dampers manually. The design, optimization and modification of this system are described in this paper. The solar fraction of the system was used as the optimization parameter. Design parameters of the system were optimized by using the TRNSYS program, which include the solar collector area, installation angle of solar collector, mass flow rate through the system, volume of pebble bed, heat transfer coefficient of the insulation layer of the pebble bed and water storage tank, height and volume of the water storage tank. The TRNSYS model has been verified by data from the literature. Results showed that the designed solar system can meet 32.8% of the thermal energy demand in the heating season and 84.6% of the energy consumption in non-heating season, with a yearly average solar fraction of 53.04%.

The methods and applications of optimization of radiation protection

International Nuclear Information System (INIS)

Liu Hua

2007-01-01

Optimization is the most important principle in radiation protection. The present article briefs the concept and up-to-date progress of optimization of protection, introduces some methods used in current optimization analysis, and presents various applications of optimization of protection. The author emphasizes that optimization of protection is a forward-looking iterative process aimed at preventing exposures before they occur. (author)

Maximum production rate optimization for sulphuric acid decomposition process in tubular plug-flow reactor

International Nuclear Information System (INIS)

Wang, Chao; Chen, Lingen; Xia, Shaojun; Sun, Fengrui

2016-01-01

A sulphuric acid decomposition process in a tubular plug-flow reactor with fixed inlet flow rate and completely controllable exterior wall temperature profile and reactants pressure profile is studied in this paper by using finite-time thermodynamics. The maximum production rate of the aimed product SO 2 and the optimal exterior wall temperature profile and reactants pressure profile are obtained by using nonlinear programming method. Then the optimal reactor with the maximum production rate is compared with the reference reactor with linear exterior wall temperature profile and the optimal reactor with minimum entropy generation rate. The result shows that the production rate of SO 2 of optimal reactor with the maximum production rate has an increase of more than 7%. The optimization of temperature profile has little influence on the production rate while the optimization of reactants pressure profile can significantly increase the production rate. The results obtained may provide some guidelines for the design of real tubular reactors. - Highlights: • Sulphuric acid decomposition process in tubular plug-flow reactor is studied. • Fixed inlet flow rate and controllable temperature and pressure profiles are set. • Maximum production rate of aimed product SO 2 is obtained. • Corresponding optimal temperature and pressure profiles are derived. • Production rate of SO 2 of optimal reactor increases by 7%.

The Effect of Anxiety, Depression, and Optimism on Postoperative Satisfaction and Clinical Outcomes in Lumbar Spinal Stenosis and Degenerative Spondylolisthesis Patients: Cohort Study.

Science.gov (United States)

Lee, Jaewon; Kim, Hong-Sik; Shim, Kyu-Dong; Park, Ye-Soo

2017-06-01

The aim of this study is to evaluate the effect of depression, anxiety, and optimism on postoperative satisfaction and clinical outcomes in patients who underwent less than two-level posterior instrumented fusions for lumbar spinal stenosis and degenerative spondylolisthesis. Preoperative psychological status of subjects, such as depression, anxiety, and optimism, was evaluated using the Hospital Anxiety and Depression Scale (HADS) and the Revised Life Orientation Test (LOT-R). Clinical evaluation was determined by measuring changes in a visual analogue scale (VAS) and the Oswestry Disability Index (ODI) before and after surgery. Postoperative satisfaction of subjects assessed using the North American Spine Society lumbar spine questionnaire was comparatively analyzed against the preoperative psychological status. The correlation between patient's preoperative psychological status (depression, anxiety, and optimism) and clinical outcomes (VAS and ODI) was evaluated. VAS and ODI scores significantly decreased after surgery ( p optimism) was not related to the degree of improvement in clinical outcomes (VAS and ODI) after surgery. However, postoperative satisfaction was moderately correlated with optimism. Anxiety and optimism were more correlated with patient satisfaction than clinical outcomes. Accordingly, the surgeon can predict postoperative satisfaction of patients based on careful evaluation of psychological status before surgery.

Case study on implementation of the dose constraint concept in optimization in working environment

Energy Technology Data Exchange (ETDEWEB)

Krajewska, Grazyna; Krajewski, Pawel [Central Laboratory for Radiological Protection, PL-03194, Warsaw (Poland)

2014-07-01

A case study of already fixed dose constrain values in nuclear medicine sector, indicated that, the practical implementation of ICRP principle of optimization ( Publication 103, ICRP, 2007) still hit on methodology problems due to lack of adequate numerous monitoring data of internal contamination and complicated mathematical formalism. In practice, to ensure that 'the likelihood of incurring exposure, the number of people exposed, and the magnitude of their individual doses are kept as low as reasonably achievable', the baseline of effective doses together with statistical distribution is required. Furthermore, as it has revealed in this study, doses PHP's generated with MC methods had un-regularly shapes, depending on random operations rather than routine procedures. The role of dose constraints for occupational exposures, was further elaborated in Publication 101 (ICRP, 2006) as 'the dose constraint is a value of individual dose used to limit the range of options considered in the process of optimization'. The revisions of the International Basic Safety Standards as well as the Euratom Basic Safety Standard Directive both aim to implement new ICRP recommendations and have requirements to use dose constraints, defined broadly along the lines provided by the ICRP, and suggest that values be selected from the bands recommended by the ICRP. These will be obligatory adopted in the national regulations by regulatory authorities of EU countries. However, due to accidental characteristics of monitoring data, the 95% confidence tail of the doses for the most highly exposed individuals is near the limit of 20 mSv per year. This is apparently observed in the particular endocrinology units dealing with I-131 therapy. One might concluded that dose limitation and optimization are viewed as sufficient for the management of occupational exposures and reasonably be achieved. (authors)

Computational study of formamide-water complexes using the SAPT and AIM methods

International Nuclear Information System (INIS)

Parreira, Renato L.T.; Valdes, Haydee; Galembeck, Sergio E.

2006-01-01

In this work, the complexes formed between formamide and water were studied by means of the SAPT and AIM methods. Complexation leads to significant alterations in the geometries and electronic structure of formamide. Intermolecular interactions in the complexes are intense, especially in the cases where the solvent interacts with the carbonyl and amide groups simultaneously. In the transition states, the interaction between the water molecule and the lone pair on the amide nitrogen is also important. In all the complexes studied herein, the electrostatic interactions between formamide and water are the main attractive force, and their contribution may be five times as large as the corresponding contribution from dispersion, and twice as large as the contribution from induction. However, an increase in the resonance of planar formamide with the successive addition of water molecules may suggest that the hydrogen bonds taking place between formamide and water have some covalent character

Topology Optimization for Convection Problems

DEFF Research Database (Denmark)

Alexandersen, Joe

2011-01-01

This report deals with the topology optimization of convection problems.That is, the aim of the project is to develop, implement and examine topology optimization of purely thermal and coupled thermomechanical problems,when the design-dependent eects of convection are taken into consideration.......This is done by the use of a self-programmed FORTRAN-code, which builds on an existing 2D-plane thermomechanical nite element code implementing during the course `41525 FEM-Heavy'. The topology optimizationfeatures have been implemented from scratch, and allows the program to optimize elastostatic mechanical...

Optimizing the construction of devices to control inaccesible surfaces - case study

Science.gov (United States)

Niţu, E. L.; Costea, A.; Iordache, M. D.; Rizea, A. D.; Babă, Al

2017-10-01

The modern concept for the evolution of manufacturing systems requires multi-criteria optimization of technological processes and equipments, prioritizing associated criteria according to their importance. Technological preparation of the manufacturing can be developed, depending on the volume of production, to the limit of favourable economical effects related to the recovery of the costs for the design and execution of the technological equipment. Devices, as subsystems of the technological system, in the general context of modernization and diversification of machines, tools, semi-finished products and drives, are made in a multitude of constructive variants, which in many cases do not allow their identification, study and improvement. This paper presents a case study in which the multi-criteria analysis of some structures, based on a general optimization method, of novelty character, is used in order to determine the optimal construction variant of a control device. The rational construction of the control device confirms that the optimization method and the proposed calculation methods are correct and determine a different system configuration, new features and functions, and a specific method of working to control inaccessible surfaces.

Feasibility Study and Optimization of An Hybrid System (Eolian ...

African Journals Online (AJOL)

Feasibility Study and Optimization of An Hybrid System (Eolian- Photovoltaic - Diesel) With Provision of Electric Energy Completely Independent. ... reducing emissions of greenhouse gas (CO2 rate = 16086 kg / year for a system using only the generator diesel and is 599 kg / year for the stand alone hybrid system studied).

Optimal dimensioning model of water distribution systems | Gomes ...

African Journals Online (AJOL)

This study is aimed at developing a pipe-sizing model for a water distribution system. The optimal solution minimises the system's total cost, which comprises the hydraulic network capital cost, plus the capitalised cost of pumping energy. The developed model, called Lenhsnet, may also be used for economical design when ...

Selection and optimization of extracellular lipase production using ...

African Journals Online (AJOL)

The aim of this study was to isolate and select lipase-producing microorganisms originated from different substrates, as well as to optimize the production of microbial lipase by submerged fermentation under different nutrient conditions. Of the 40 microorganisms isolated, 39 showed a halo around the colonies and 4 were ...

Oral bioavailability enhancement of raloxifene by developing microemulsion using D-optimal mixture design: optimization and in-vivo pharmacokinetic study.

Science.gov (United States)

Shah, Nirmal; Seth, Avinashkumar; Balaraman, R; Sailor, Girish; Javia, Ankur; Gohil, Dipti

2018-04-01

The objective of this work was to utilize a potential of microemulsion for the improvement in oral bioavailability of raloxifene hydrochloride, a BCS class-II drug with 2% bioavailability. Drug-loaded microemulsion was prepared by water titration method using Capmul MCM C8, Tween 20, and Polyethylene glycol 400 as oil, surfactant, and co-surfactant respectively. The pseudo-ternary phase diagram was constructed between oil and surfactants mixture to obtain appropriate components and their concentration ranges that result in large existence area of microemulsion. D-optimal mixture design was utilized as a statistical tool for optimization of microemulsion considering oil, S mix , and water as independent variables with percentage transmittance and globule size as dependent variables. The optimized formulation showed 100 ± 0.1% transmittance and 17.85 ± 2.78 nm globule size which was identically equal with the predicted values of dependent variables given by the design expert software. The optimized microemulsion showed pronounced enhancement in release rate compared to plain drug suspension following diffusion controlled release mechanism by the Higuchi model. The formulation showed zeta potential of value -5.88 ± 1.14 mV that imparts good stability to drug loaded microemulsion dispersion. Surface morphology study with transmission electron microscope showed discrete spherical nano sized globules with smooth surface. In-vivo pharmacokinetic study of optimized microemulsion formulation in Wistar rats showed 4.29-fold enhancements in bioavailability. Stability study showed adequate results for various parameters checked up to six months. These results reveal the potential of microemulsion for significant improvement in oral bioavailability of poorly soluble raloxifene hydrochloride.

Optimization of PCR Condition: The First Study of High Resolution Melting Technique for Screening of APOA1 Variance.

Science.gov (United States)

Wahyuningsih, Hesty; K Cayami, Ferdy; Bahrudin, Udin; A Sobirin, Mochamad; Ep Mundhofir, Farmaditya; Mh Faradz, Sultana; Hisatome, Ichiro

2017-03-01

High resolution melting (HRM) is a post-PCR technique for variant screening and genotyping based on the different melting points of DNA fragments. The advantages of this technique are that it is fast, simple, and efficient and has a high output, particularly for screening of a large number of samples. APOA1 encodes apolipoprotein A1 (apoA1) which is a major component of high density lipoprotein cholesterol (HDL-C). This study aimed to obtain an optimal quantitative polymerase chain reaction (qPCR)-HRM condition for screening of APOA1 variance. Genomic DNA was isolated from a peripheral blood sample using the salting out method. APOA1 was amplified using the RotorGeneQ 5Plex HRM. The PCR product was visualized with the HRM amplification curve and confirmed using gel electrophoresis. The melting profile was confirmed by looking at the melting curve. Five sets of primers covering the translated region of APOA1 exons were designed with expected PCR product size of 100-400 bps. The amplified segments of DNA were amplicons 2, 3, 4A, 4B, and 4C. Amplicons 2, 3 and 4B were optimized at an annealing temperature of 60 °C at 40 PCR cycles. Amplicon 4A was optimized at an annealing temperature of 62 °C at 45 PCR cycles. Amplicon 4C was optimized at an annealing temperature of 63 °C at 50 PCR cycles. In addition to the suitable procedures of DNA isolation and quantification, primer design and an estimated PCR product size, the data of this study showed that appropriate annealing temperature and PCR cycles were important factors in optimization of HRM technique for variant screening in APOA1 .

Minimizing transient influence in WHPA delineation: An optimization approach for optimal pumping rate schemes

Science.gov (United States)

Rodriguez-Pretelin, A.; Nowak, W.

2017-12-01

For most groundwater protection management programs, Wellhead Protection Areas (WHPAs) have served as primarily protection measure. In their delineation, the influence of time-varying groundwater flow conditions is often underestimated because steady-state assumptions are commonly made. However, it has been demonstrated that temporary variations lead to significant changes in the required size and shape of WHPAs. Apart from natural transient groundwater drivers (e.g., changes in the regional angle of flow direction and seasonal natural groundwater recharge), anthropogenic causes such as transient pumping rates are of the most influential factors that require larger WHPAs. We hypothesize that WHPA programs that integrate adaptive and optimized pumping-injection management schemes can counter transient effects and thus reduce the additional areal demand in well protection under transient conditions. The main goal of this study is to present a novel management framework that optimizes pumping schemes dynamically, in order to minimize the impact triggered by transient conditions in WHPA delineation. For optimizing pumping schemes, we consider three objectives: 1) to minimize the risk of pumping water from outside a given WHPA, 2) to maximize the groundwater supply and 3) to minimize the involved operating costs. We solve transient groundwater flow through an available transient groundwater and Lagrangian particle tracking model. The optimization problem is formulated as a dynamic programming problem. Two different optimization approaches are explored: I) the first approach aims for single-objective optimization under objective (1) only. The second approach performs multiobjective optimization under all three objectives where compromise pumping rates are selected from the current Pareto front. Finally, we look for WHPA outlines that are as small as possible, yet allow the optimization problem to find the most suitable solutions.

Towards Optimal Diagnosis of Type II Germ Cell Tumors

NARCIS (Netherlands)

J.A. Stoop (Hans)

2011-01-01

textabstractThe aim of the work described in this thesis is to improve the understanding of the pathobiology of testicular cancer (type II Germ Cell Tumors) to create possibilities for optimalization of diagnosis for this type of malignancy in routine pathology laboratories. The different studies

Dynamic optimization of dead-end membrane filtration

NARCIS (Netherlands)

Blankert, B.; Betlem, Bernardus H.L.; Roffel, B.; Marquardt, Wolfgang; Pantelides, Costas

2006-01-01

An operating strategy aimed at minimizing the energy consumption during the filtration phase of dead-end membrane filtration has been formulated. A method allowing fast calculation of trajectories is used to allow incorporation in a hierarchical optimization scheme. The optimal trajectory can be

A Casting Yield Optimization Case Study: Forging Ram

DEFF Research Database (Denmark)

Kotas, Petr; Tutum, Cem Celal; Hattel, Jesper Henri

2010-01-01

This work summarizes the findings of multi-objective optimization of a gravity sand-cast steel part for which an increase of the casting yield via riser optimization was considered. This was accomplished by coupling a casting simulation software package with an optimization module. The benefits...... of this approach, recently adopted in foundry industry world wide and based on fully automated computer optimization, were demonstrated. First, analyses of filling and solidification of the original casting design were conducted in the standard simulation environment to determine potential flaws and inadequacies...

Relationships among hamstring muscle optimal length and hamstring flexibility and strength

OpenAIRE

Xianglin Wan; Feng Qu; William E. Garrett; Hui Liu; Bing Yu

2017-01-01

Background: Hamstring muscle strain injury (hamstring injury) due to excessive muscle strain is one of the most common injuries in sports. The relationships among hamstring muscle optimal lengths and hamstring flexibility and strength were unknown, which limited our understanding of risk factors for hamstring injury. This study was aimed at examining the relationships among hamstring muscle optimal length and flexibility and strength. Methods: Hamstring flexibility and isokinetic strength ...

Optimality study of a gust alleviation system for light wing-loading STOL aircraft

Science.gov (United States)

Komoda, M.

1976-01-01

An analytical study was made of an optimal gust alleviation system that employs a vertical gust sensor mounted forward of an aircraft's center of gravity. Frequency domain optimization techniques were employed to synthesize the optimal filters that process the corrective signals to the flaps and elevator actuators. Special attention was given to evaluating the effectiveness of lead time, that is, the time by which relative wind sensor information should lead the actual encounter of the gust. The resulting filter is expressed as an implicit function of the prescribed control cost. A numerical example for a light wing loading STOL aircraft is included in which the optimal trade-off between performance and control cost is systematically studied.

A study on a new algorithm to optimize ball mill system based on modeling and GA

International Nuclear Information System (INIS)

Wang Heng; Jia Minping; Huang Peng; Chen Zuoliang

2010-01-01

Aiming at the disadvantage of conventional optimization method for ball mill pulverizing system, a novel approach based on RBF neural network and genetic algorithm was proposed in the present paper. Firstly, the experiments and measurement for fill level based on vibration signals of mill shell was introduced. Then, main factors which affected the power consumption of ball mill pulverizing system were analyzed, and the input variables of RBF neural network were determined. RBF neural network was used to map the complex non-linear relationship between the electric consumption and process parameters and the non-linear model of power consumption was built. Finally, the model was optimized by genetic algorithm and the optimal work conditions of ball mill pulverizing system were determined. The results demonstrate that the method is reliable and practical, and can reduce the electric consumption obviously and effectively.

An Experimental Study of Structural Identification of Bridges Using the Kinetic Energy Optimization Technique and the Direct Matrix Updating Method

Directory of Open Access Journals (Sweden)

Gwanghee Heo

2016-01-01

Full Text Available This paper aims to develop an SI (structural identification technique using the KEOT and the DMUM to decide on optimal location of sensors and to update FE model, respectively, which ultimately contributes to a composition of more effective SHM. Owing to the characteristic structural flexing behavior of cable bridges (e.g., cable-stayed bridges and suspension bridges, which makes them vulnerable to any vibration, systematic and continuous structural health monitoring (SHM is pivotal for them. Since it is necessary to select optimal measurement locations with the fewest possible measurements and also to accurately assess the structural state of a bridge for the development of an effective SHM, an SI technique is as much important to accurately determine the modal parameters of the current structure based on the data optimally obtained. In this study, the kinetic energy optimization technique (KEOT was utilized to determine the optimal measurement locations, while the direct matrix updating method (DMUM was utilized for FE model updating. As a result of experiment, the required number of measurement locations derived from KEOT based on the target mode was reduced by approximately 80% compared to the initial number of measurement locations. Moreover, compared to the eigenvalue of the modal experiment, an improved FE model with a margin of error of less than 1% was derived from DMUM. Thus, the SI technique for cable-stayed bridges proposed in this study, which utilizes both KEOT and DMUM, is proven effective in minimizing the number of sensors while accurately determining the structural dynamic characteristics.

Towards Excellence in Asthma Management: final report of an eight-year program aimed at reducing care gaps in asthma management in Quebec.

Science.gov (United States)

Boulet, Louis-Philippe; Dorval, E; Labrecque, M; Turgeon, M; Montague, T; Thivierge, R L

2008-09-01

Asthma care in Canada and around the world persistently falls short of optimal treatment. To optimize care, a systematic approach to identifying such shortfalls or 'care gaps', in which all stakeholders of the health care system (including patients) are involved, was proposed. Several projects of a multipartner, multidisciplinary disease management program, developed to optimize asthma care in Quebec, was conducted in a period of eight years. First, two population maps were produced to identify regional variations in asthma-related morbidity and to prioritize interventions for improving treatment. Second, current care was evaluated in a physician-patient cohort, confirming the many care gaps in asthma management. Third, two series of peer-reviewed outcome studies, targeting high-risk populations and specific asthma care gaps, were conducted. Finally, a process to integrate the best interventions into the health care system and an agenda for further research on optimal asthma management were proposed. Key observations from these studies included the identification of specific patterns of noncompliance in using inhaled corticosteroids, the failure of increased access to spirometry in asthma education centres to increase the number of education referrals, the transient improvement in educational abilities of nurses involved with an asthma hotline telephone service, and the beneficial effects of practice tools aimed at facilitating the assessment of asthma control and treatment needs by general practitioners. Disease management programs such as Towards Excellence in Asthma Management can provide valuable information on optimal strategies for improving treatment of asthma and other chronic diseases by identifying care gaps, improving guidelines implementation and optimizing care.

PWR fuel management optimization

International Nuclear Information System (INIS)

Dumas, Michel.

1981-10-01

This report is aimed to the optimization of the refueling pattern of a nuclear reactor. At the beginning of a reactor cycle a batch of fuel assemblies is available: the physical properties of the assemblies are known: the mathematical problem is to determine the refueling pattern which maximizes the reactivity or which provides the flattest possible power distribution. The state of the core is mathematically characterized by a system of partial derivative equations, its smallest eigenvalue and the associated eigenvector. After a study of the convexity properties of the problem, two algorithms are proposed. The first one exhanges assemblies to improve the starting configurations. The enumeration of the exchanges is limited to the 2 by 2, 3 by 3, 4 by 4 permutations. The second one builds a solution in two steps: in the first step the discrete variables are replaced by continuous variables. The non linear optimization problem obtained is solved by ''the Method of Approximation Programming'' and in the second step, the refuelling pattern which provides the best approximation of the optimal power distribution is searched by a Branch an d Bound Method [fr

Optimization in the nuclear fuel cycle II: Surface contamination

International Nuclear Information System (INIS)

Pereira, W.S.; Silva, A.X.; Lopes, J.M.; Carmo, A.S.; Fernandes, T.S.; Mello, C.R.; Kelecom, A.

2017-01-01

Optimization is one of the bases of radioprotection and aims to move doses away from the dose limit that is the borderline of acceptable radiological risk. This work aims to use the monitoring of surface contamination as a tool of the optimization process. 53 surface contamination points were analyzed at a nuclear fuel cycle facility. Three sampling points were identified with monthly mean values of contamination higher than 1 Bq ∙ cm -2 , points 28, 42 and 47. These points were indicated for the beginning of the optimization process

Optimism in prolonged grief and depression following loss: A three-wave longitudinal study.

Science.gov (United States)

Boelen, Paul A

2015-06-30

There is considerable evidence that optimism, the predisposition to have generalized favorable expectancies for the future, is associated with numerous desirable outcomes. Few studies have examined the association of optimism with emotional distress following the death of a loved one. Doing so is important, because optimism may be an important target for interventions for post-loss psychopathology. In the current study, we examined the degree to which optimism, assessed in the first year post-loss (Time 1, T1), was associated with symptom levels of prolonged grief and depression six months (Time 2, T2) and fifteen months (Time 3, T3) later, controlling for baseline symptoms and also taking into account positive automatic cognitions at T1. Findings showed that higher optimism at T1 was associated with lower concurrent prolonged grief and depression severity. Higher optimism at T1 was also inversely related with depression symptom severity at T2 and T3, but not prolonged grief severity at T2 and T3. Implications of these findings are discussed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Optimism and recovery after acute coronary syndrome: a clinical cohort study.

Science.gov (United States)

Ronaldson, Amy; Molloy, Gerard J; Wikman, Anna; Poole, Lydia; Kaski, Juan-Carlos; Steptoe, Andrew

2015-04-01

Optimism is associated with reduced cardiovascular mortality, but its impact on recovery after acute coronary syndrome (ACS) is poorly understood. We hypothesized that greater optimism would lead to more effective physical and emotional adaptation after ACS and would buffer the impact of persistent depressive symptoms on clinical outcomes. This prospective observational clinical study took place in an urban general hospital and involved 369 patients admitted with a documented ACS. Optimism was assessed with a standardized questionnaire. The main outcomes were physical health status, depressive symptoms, smoking, physical activity, and fruit and vegetable consumption measured 12 months after ACS, and composite major adverse cardiac events (cardiovascular death, readmission with reinfarction or unstable angina, and coronary artery bypass graft surgery) assessed over an average of 45.7 months. We found that optimism predicted better physical health status 12 months after ACS independently of baseline physical health, age, sex, ethnicity, social deprivation, and clinical risk factors (B = 0.65, 95% confidence interval [CI] = 0.10-1.20). Greater optimism also predicted reduced risk of depressive symptoms (odds ratio = 0.82, 95% CI = 0.74-0.90), more smoking cessation, and more fruit and vegetable consumption at 12 months. Persistent depressive symptoms 12 months after ACS predicted major adverse cardiac events over subsequent years (odds ratio = 2.56, 95% CI = 1.16-5.67), but only among individuals low in optimism (optimism × depression interaction; p = .014). Optimism predicts better physical and emotional health after ACS. Measuring optimism may help identify individuals at risk. Pessimistic outlooks can be modified, potentially leading to improved recovery after major cardiac events.

On optimal development and becoming an optimiser

NARCIS (Netherlands)

de Ruyter, D.J.

2012-01-01

The article aims to provide a justification for the claim that optimal development and becoming an optimiser are educational ideals that parents should pursue in raising their children. Optimal development is conceptualised as enabling children to grow into flourishing persons, that is persons who

Optimization of imprintable nanostructured a-Si solar cells: FDTD study.

Science.gov (United States)

Fisker, Christian; Pedersen, Thomas Garm

2013-03-11

We present a finite-difference time-domain (FDTD) study of an amorphous silicon (a-Si) thin film solar cell, with nano scale patterns on the substrate surface. The patterns, based on the geometry of anisotropically etched silicon gratings, are optimized with respect to the period and anti-reflection (AR) coating thickness for maximal absorption in the range of the solar spectrum. The structure is shown to increase the cell efficiency by 10.2% compared to a similar flat solar cell with an optimized AR coating thickness. An increased back reflection can be obtained with a 50 nm zinc oxide layer on the back reflector, which gives an additional efficiency increase, leading to a total of 14.9%. In addition, the patterned cells are shown to be up to 3.8% more efficient than an optimized textured reference cell based on the Asahi U-type glass surface. The effects of variations of the optimized solar cell structure due to the manufacturing process are investigated, and shown to be negligible for variations below ±10%.

Optimal inflation for the U.S.

OpenAIRE

Roberto M. Billi

2007-01-01

What is the correctly measured inflation rate that monetary policy should aim for in the long-run? This paper characterizes the optimal inflation rate for the U.S. economy in a New Keynesian sticky-price model with an occasionally binding zero lower bound on the nominal interest rate. Real-rate and mark-up shocks jointly determine the optimal inflation rate to be positive but not large. Even allowing for the possibility of extreme model misspecification, the optimal inflation rate is robustly...

An optimal control approach to manpower planning problem

Directory of Open Access Journals (Sweden)

H. W. J. Lee

2001-01-01

Full Text Available A manpower planning problem is studied in this paper. The model includes scheduling different types of workers over different tasks, employing and terminating different types of workers, and assigning different types of workers to various trainning programmes. The aim is to find an optimal way to do all these while keeping the time-varying demand for minimum number of workers working on each different tasks satisfied. The problem is posed as an optimal discrete-valued control problem in discrete time. A novel numerical scheme is proposed to solve the problem, and an illustrative example is provided.

Topology Optimization of Nanophotonic Devices

DEFF Research Database (Denmark)

Yang, Lirong

This thesis explores the various aspects of utilizing topology optimization in designing nanophotonic devices. Either frequency-domain or time-domain methods is used in combination with the optimization algorithms, depending on various aims of the designing problems. The frequency-domain methods...... lengthscale and flexible pulse delay are addressed to demonstrate time-domain based topology optimization’s potential in designing complicated photonic structures with specifications on the time characteristics of pulses....

The simplest formal argument for fitness optimization

Indian Academy of Sciences (India)

The Formal Darwinism Project aims to provide a formal argument linking population genetics to fitness optimization, which of necessity includes defining fitness. This bridges the gulf between those biologists who assume that natural selection leads to something close to fitness optimization and those biologists who believe ...

Aerodynamic reconfiguration and multicriterial optimization of centrifugal compressors – a case study

Directory of Open Access Journals (Sweden)

Valeriu DRAGAN

2014-12-01

Full Text Available This paper continues the recent research of the author, with application to 3D computational fluid dynamics multicriterial optimization of turbomachinery parts. Computational Fluid Dynamics has been an ubicuous tool for compressor design for decades, helping the designers to test the aerodynamic parameters of their machines with great accuracy. Due to advances of multigrid methods and the improved robustness of structured solvers, CFD can nowadays be part of an optimization loop with artificial neural networks or evolutive algorithms. This paper presents a case study of an air centrifugal compressor rotor optimized using Numeca's Design 3D CFD suite. The turbulence model used for the database generation and the optimization stage is Spalart Allmaras. Results indicate a fairly quick convergence time per individual as well as a good convergence of the artificial neural network optimizer.

Recent advances in stellarator optimization

Science.gov (United States)

Gates, D. A.; Boozer, A. H.; Brown, T.; Breslau, J.; Curreli, D.; Landreman, M.; Lazerson, S. A.; Lore, J.; Mynick, H.; Neilson, G. H.; Pomphrey, N.; Xanthopoulos, P.; Zolfaghari, A.

2017-12-01

Computational optimization has revolutionized the field of stellarator design. To date, optimizations have focused primarily on optimization of neoclassical confinement and ideal MHD stability, although limited optimization of other parameters has also been performed. The purpose of this paper is to outline a select set of new concepts for stellarator optimization that, when taken as a group, present a significant step forward in the stellarator concept. One of the criticisms that has been leveled at existing methods of design is the complexity of the resultant field coils. Recently, a new coil optimization code—COILOPT++, which uses a spline instead of a Fourier representation of the coils,—was written and included in the STELLOPT suite of codes. The advantage of this method is that it allows the addition of real space constraints on the locations of the coils. The code has been tested by generating coil designs for optimized quasi-axisymmetric stellarator plasma configurations of different aspect ratios. As an initial exercise, a constraint that the windings be vertical was placed on large major radius half of the non-planar coils. Further constraints were also imposed that guaranteed that sector blanket modules could be removed from between the coils, enabling a sector maintenance scheme. Results of this exercise will be presented. New ideas on methods for the optimization of turbulent transport have garnered much attention since these methods have led to design concepts that are calculated to have reduced turbulent heat loss. We have explored possibilities for generating an experimental database to test whether the reduction in transport that is predicted is consistent with experimental observations. To this end, a series of equilibria that can be made in the now latent QUASAR experiment have been identified that will test the predicted transport scalings. Fast particle confinement studies aimed at developing a generalized optimization algorithm are also

Dynamic optimization of a FCC converter unit: numerical analysis

Directory of Open Access Journals (Sweden)

E. Almeida Nt

2011-03-01

Full Text Available Fluidized-bed Catalytic Cracking (FCC is a process subject to frequent variations in the operating conditions (including feed quality and feed rate. The production objectives usually are the maximization of LPG and gasoline production. This fact makes the FCC converter unit an excellent opportunity for real-time optimization. The present work aims to apply a dynamic optimization in an industrial FCC converter unit, using a mechanistic dynamic model, and to carry out a numerical analysis of the solution procedure. A simultaneous approach was used to discretize the system of differential-algebraic equations and the resulting large-scale NLP problem was solved using the IPOPT solver. This study also does a short comparison between the results obtained by a potential dynamic real-time optimization (DRTO against a possible steady-state real-time optimization (RTO application. The results demonstrate that the application of dynamic real-time optimization of a FCC converter unit can bring significant benefits in production.

An optimization strategy for the control of small capacity heat pump integrated air-conditioning system

International Nuclear Information System (INIS)

Gao, Jiajia; Huang, Gongsheng; Xu, Xinhua

2016-01-01

Highlights: • An optimization strategy for a small-scale air-conditioning system is developed. • The optimization strategy aims at optimizing the overall system energy consumption. • The strategy may guarantee the robust control of the space air temperature. • The performance of the optimization strategy was tested on a simulation platform. - Abstract: This paper studies the optimization of a small-scale central air-conditioning system, in which the cooling is provided by a ground source heat pump (GSHP) equipped with an on/off capacity control. The optimization strategy aims to optimize the overall system energy consumption and simultaneously guarantee the robustness of the space air temperature control without violating the allowed GSHP maximum start-ups number per hour specified by customers. The set-point of the chilled water return temperature and the width of the water temperature control band are used as the decision variables for the optimization. The performance of the proposed strategy was tested on a simulation platform. Results show that the optimization strategy can save the energy consumption by 9.59% in a typical spring day and 2.97% in a typical summer day. Meanwhile it is able to enhance the space air temperature control robustness when compared with a basic control strategy without optimization.

Optimal design of a spherical parallel manipulator based on kinetostatic performance using evolutionary techniques

Energy Technology Data Exchange (ETDEWEB)

Daneshmand, Morteza [University of Tartu, Tartu (Estonia); Saadatzi, Mohammad Hossein [Colorado School of Mines, Golden (United States); Kaloorazi, Mohammad Hadi [École de Technologie Supérieur, Montréal (Canada); Masouleh, Mehdi Tale [University of Tehran, Tehran (Iran, Islamic Republic of); Anbarjafari, Gholamreza [Hasan Kalyoncu University, Gaziantep (Turkmenistan)

2016-03-15

This study aims to provide an optimal design for a Spherical parallel manipulator (SPM), namely, the Agile Eye. This aim is approached by investigating kinetostatic performance and workspace and searching for the most promising design. Previously recommended designs are examined to determine whether they provide acceptable kinetostatic performance and workspace. Optimal designs are provided according to different kinetostatic performance indices, especially kinematic sensitivity. The optimization process is launched based on the concept of the genetic algorithm. A single-objective process is implemented in accordance with the guidelines of an evolutionary algorithm called differential evolution. A multi-objective procedure is then provided following the reasoning of the nondominated sorting genetic algorithm-II. This process results in several sets of Pareto points for reconciliation between kinetostatic performance indices and workspace. The concept of numerous kinetostatic performance indices and the results of optimization algorithms are elaborated. The conclusions provide hints on the provided set of designs and their credibility to provide a well-conditioned workspace and acceptable kinetostatic performance for the SPM under study, which can be well extended to other types of SPMs.

Thermo economical optimization of sugar plants with environmental constraints

Energy Technology Data Exchange (ETDEWEB)

Colombo, Mauricio; Mele, Fernando Daniel; Hernandez, Maria Rosa [Universidad Nacional de Tucuman (UNT), Tucuman (Argentina). Facultad de Ciencias Exactas y Tecnologia], Email: macolombo@herrera.unt.edu.ar; Gatica, Jorge [Cleveland State University (CSU), Cleveland, OH (United States). Dept. of Chemical and Biomedical Engineering], Email: j.gatica@csuohio.edu; Silveira, Jose Luz [Universidade Estadual Paulista (FEG/UNESP), Guaratingueta, SP (Brazil). Faculdade de Engenharia. Dept. de Energia], Email: joseluz@feg.unesp.br

2009-07-01

This paper highlights the need for analysis and optimization techniques which can be applied to new energy systems and include considerations for environmental issues. These techniques have proven indispensable in dealing with the constrained optimization problem of finite natural resources and growing demands of energy. Within this framework, thermo economical optimization has gradually been brought to the forefront as a powerful tool in assisting the decision-making process. This work uses the technique of Life Cycle Analysis (LCA) as a means to include environmental indexes in the optimization process. While most of the environmental approaches formulate the optimization problem aiming to reduce residue generation without assessing the impact of this reduction on related processes, LCA considers environmental issues as an integral part of the optimization problem. A sugar cane processing plant located in Tucuman (Argentina) is selected as a case study. This example serves to highlight the importance of formulating solutions that ensure an efficient use of a common fuel to meet useful heat, shaft power, and electricity demands. (author)

Mirror hybrid reactor optimization studies

International Nuclear Information System (INIS)

Bender, D.J.

1976-01-01

A system model of the mirror hybrid reactor has been developed. The major components of the model include (1) the reactor description, (2) a capital cost analysis, (3) various fuel management schemes, and (4) an economic analysis that includes the hybrid plus its associated fission burner reactors. The results presented describe the optimization of the mirror hybrid reactor, the objective being to minimize the cost of electricity from the hybrid fission-burner reactor complex. We have examined hybrid reactors with two types of blankets, one containing natural uranium, the other thorium. The major difference between the two optimized reactors is that the uranium hybrid is a significant net electrical power producer, whereas the thorium hybrid just about breaks even on electrical power. Our projected costs for fissile fuel production are approximately 50 $/g for 239 Pu and approximately 125 $/g for 233 U

Optimization of tax on corporate income

OpenAIRE

OBERTÍKOVÁ, Lucie

2017-01-01

My diploma thesis is focused on the optimization of corporate income tax. The thesis is divided into the theoretical and practical part. In the theoretical part are described terms such as taxpayers, subject of tax, tax base, tax calculation or when the tax is payable. The practical part begins with the characteristic of the company, followed by the calculation of the tax liability and the optimization of the corporate income tax. The aim of the thesis was to find the optimal variant of the c...

Study on integrated approach of Nuclear Accident Hazard Predicting, Warning, and Optimized Controlling System based on GIS

International Nuclear Information System (INIS)

Tang Lijuan; Huang Shunxiang; Wang Xinming

2012-01-01

The issue of nuclear safety becomes the attention focus of international society after the nuclear accident happened in Fukushima. Aiming at the requirements of the prevention and controlling of Nuclear Accident establishment of Nuclear Accident Hazard Predicting, Warning and optimized Controlling System (NAPWS) is a imperative project that our country and army are desiderating, which includes multiple fields of subject as nuclear physics, atmospheric science, security science, computer science and geographical information technology, etc. Multiplatform, multi-system and multi-mode are integrated effectively based on GIS, accordingly the Predicting, Warning, and Optimized Controlling technology System of Nuclear Accident Hazard is established. (authors)

Biogeography-inspired multiobjective optimization for helping MEMS synthesis

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Di Barba Paolo

2017-09-01

Full Text Available The aim of the paper is to assess the applicability of a multi-objective biogeography-based optimisation algorithm in MEMS synthesis. In order to test the performances of the proposed method in this research field, the optimal shape design of an electrostatic micromotor, and two different electro-thermo-elastic microactuators are considered as the case studies.

Numerical optimization with computational errors

CERN Document Server

Zaslavski, Alexander J

2016-01-01

This book studies the approximate solutions of optimization problems in the presence of computational errors. A number of results are presented on the convergence behavior of algorithms in a Hilbert space; these algorithms are examined taking into account computational errors. The author illustrates that algorithms generate a good approximate solution, if computational errors are bounded from above by a small positive constant. Known computational errors are examined with the aim of determining an approximate solution. Researchers and students interested in the optimization theory and its applications will find this book instructive and informative. This monograph contains 16 chapters; including a chapters devoted to the subgradient projection algorithm, the mirror descent algorithm, gradient projection algorithm, the Weiszfelds method, constrained convex minimization problems, the convergence of a proximal point method in a Hilbert space, the continuous subgradient method, penalty methods and Newton’s meth...

Does optimism act as a buffer against posttraumatic stress over time? A longitudinal study of the protective role of optimism after the 2011 Oslo bombing.

Science.gov (United States)

Birkeland, Marianne Skogbrott; Blix, Ines; Solberg, Øivind; Heir, Trond

2017-03-01

Cross-sectional studies have revealed that high levels of optimism can protect against high levels of posttraumatic stress after exposure to trauma. However, this is the first study to explore (a) the protective role of optimism in a longitudinal perspective and (b) optimism's protective effects on specific symptom clusters within the posttraumatic stress symptomatology. This study used prospective survey data from ministerial employees (n = 256) collected approximately 1, 2, and 3 years after the 2011 Oslo bombing. To examine relationships between optimism and development of posttraumatic stress, we applied a series of latent growth curve analyses of both overall posttraumatic stress and the 5 clusters within the posttraumatic stress symptomatology (intrusions, avoidance, numbing, dysphoric arousal, and anxious arousal) with predictors and interaction terms. The results showed that levels of exposure and optimism had main effects on starting levels of all clusters of posttraumatic stress. In addition, optimism had a protective-stabilizing effect on starting levels of avoidance, numbing, and dysphoric arousal. No associations between optimism and rate of change in symptoms clusters were found. These results suggest that optimism may help to neutralize the effects of high exposure on levels of symptoms of avoidance, numbing, and dysphoric arousal but not on the symptoms of intrusions and anxious arousal. Thus, individuals high in optimism still experience intrusions and anxious arousal after trauma, but may be better equipped to cope with these so they do not develop into avoidance, numbing and dyshorical arousal. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Study of the Optimal Planning Model for Reservoir Sustainable Management- A Case Study of Shihmen Reservoir

Science.gov (United States)

Chen, Y. Y.; Ho, C. C.; Chang, L. C.

2017-12-01

The reservoir management in Taiwan faces lots of challenge. Massive sediment caused by landslide were flushed into reservoir, which will decrease capacity, rise the turbidity, and increase supply risk. Sediment usually accompanies nutrition that will cause eutrophication problem. Moreover, the unevenly distribution of rainfall cause water supply instability. Hence, how to ensure sustainable use of reservoirs has become an important task in reservoir management. The purpose of the study is developing an optimal planning model for reservoir sustainable management to find out an optimal operation rules of reservoir flood control and sediment sluicing. The model applies Genetic Algorithms to combine with the artificial neural network of hydraulic analysis and reservoir sediment movement. The main objective of operation rules in this study is to prevent reservoir outflow caused downstream overflow, minimum the gap between initial and last water level of reservoir, and maximum sluicing sediment efficiency. A case of Shihmen reservoir was used to explore the different between optimal operating rule and the current operation of the reservoir. The results indicate optimal operating rules tended to open desilting tunnel early and extend open duration during flood discharge period. The results also show the sluicing sediment efficiency of optimal operating rule is 36%, 44%, 54% during Typhoon Jangmi, Typhoon Fung-Wong, and Typhoon Sinlaku respectively. The results demonstrate the optimal operation rules do play a role in extending the service life of Shihmen reservoir and protecting the safety of downstream. The study introduces a low cost strategy, alteration of operation reservoir rules, into reservoir sustainable management instead of pump dredger in order to improve the problem of elimination of reservoir sediment and high cost.

Optimization of the air cargo supply chain

Directory of Open Access Journals (Sweden)

María Pérez Bernal

2012-10-01

Full Text Available Purpose: This paper aims to evaluate and optimize the various operations within the air cargo chain. It pursues to improve the efficiency of the air cargo supply chain and to provide more information to the decision-makers to optimize their fields.Design/methodology/approach: The method used is a process simulation modelling software, WITNESS, which provides information to the decision-makers about the most relevant parameters subject to optimization. The input for the simulation is obtained from a qualitative analysis of the air cargo supply chain with the involved agents and from a study of the external trade by air mode, given that their behaviour depend on the location. The case study is focused on a particular location, the Case of Zaragoza Airport (Spain.Findings: This paper demonstrates that efficiency of the air cargo supply chain can increase by leveraging several parameters such as bottlenecks, resources or warehouses.Originality/value: It explores the use of a simulation modeling software originally intended for manufacturing processes and extended to support decision making processes in the area of air cargo.

MANAGERIAL OPTIMISM AND DEBT FINANCING: CASE STUDY ON INDONESIA MANUFACTURING LISTED FIRMS

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Gesti Memarista

2016-10-01

Full Text Available Managerial’s psychology can affect financial decision in the company. This paper analyzes the influence of managerial optimism on the debt financing by using regression analysis. The dependent variable in this paper is debt financing. The independent variable is managerial optimism and the control variable are firm value, firm size, and firm performance that are occurred in the previous period. The sample used in this study is manufacturing companies that listed in Indonesian stock exchange during 2010-2014. The result on this study shows that managerial optimism, firm value, and firm size that are occurred in the previous period have positive significantly impact on debt financing, whereas firm performance in the previous period has negative significantly impact on debt financing.

AIMES Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Katz, Daniel S [Univ. of Illinois, Urbana-Champaign, IL (United States). National Center for Supercomputing Applications (NCSA); Jha, Shantenu [Rutgers Univ., New Brunswick, NJ (United States); Weissman, Jon [Univ. of Minnesota, Minneapolis, MN (United States); Turilli, Matteo [Rutgers Univ., New Brunswick, NJ (United States)

2017-01-31

This is the final technical report for the AIMES project. Many important advances in science and engineering are due to large-scale distributed computing. Notwithstanding this reliance, we are still learning how to design and deploy large-scale production Distributed Computing Infrastructures (DCI). This is evidenced by missing design principles for DCI, and an absence of generally acceptable and usable distributed computing abstractions. The AIMES project was conceived against this backdrop, following on the heels of a comprehensive survey of scientific distributed applications. AIMES laid the foundations to address the tripartite challenge of dynamic resource management, integrating information, and portable and interoperable distributed applications. Four abstractions were defined and implemented: skeleton, resource bundle, pilot, and execution strategy. The four abstractions were implemented into software modules and then aggregated into the AIMES middleware. This middleware successfully integrates information across the application layer (skeletons) and resource layer (Bundles), derives a suitable execution strategy for the given skeleton and enacts its execution by means of pilots on one or more resources, depending on the application requirements, and resource availabilities and capabilities.

Aerothermodynamic shape optimization of hypersonic blunt bodies

Science.gov (United States)

Eyi, Sinan; Yumuşak, Mine

2015-07-01

The aim of this study is to develop a reliable and efficient design tool that can be used in hypersonic flows. The flow analysis is based on the axisymmetric Euler/Navier-Stokes and finite-rate chemical reaction equations. The equations are coupled simultaneously and solved implicitly using Newton's method. The Jacobian matrix is evaluated analytically. A gradient-based numerical optimization is used. The adjoint method is utilized for sensitivity calculations. The objective of the design is to generate a hypersonic blunt geometry that produces the minimum drag with low aerodynamic heating. Bezier curves are used for geometry parameterization. The performances of the design optimization method are demonstrated for different hypersonic flow conditions.

Study on transfer optimization of urban rail transit and conventional public transport

Science.gov (United States)

Wang, Jie; Sun, Quan Xin; Mao, Bao Hua

2018-04-01

This paper mainly studies the time optimization of feeder connection between rail transit and conventional bus in a shopping center. In order to achieve the goal of connecting rail transportation effectively and optimizing the convergence between the two transportations, the things had to be done are optimizing the departure intervals, shorting the passenger transfer time and improving the service level of public transit. Based on the goal that has the minimum of total waiting time of passengers and the number of start of classes, establish the optimizing model of bus connecting of departure time. This model has some constrains such as transfer time, load factor, and the convergence of public transportation grid spacing. It solves the problems by using genetic algorithms.

Pro-health role of optimism among people with mental disorders

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Karolina Potempa

2014-12-01

Full Text Available Aim: Many scientific reports indicate that optimism positively affects our psychophysical well-being. The main purpose of the conducted research was to verify whether optimism is a predictor of health-oriented resources also in patients with paranoid schizophrenia, depressive disorders and depressive schizoaffective disorders. The following health-oriented factors were evaluated in the study: health behaviour, life satisfaction, social functioning and coping with stress. Furthermore, we have verified whether there were any differences related to the level of optimism and health-oriented factors between individuals with mental disorders and a control group. Methods: The following tools were used in the study: Optimism Questionnaire, Health-Related Behaviour Inventory, Coping Inventory for Stressful Situations, Satisfaction with Life Scale, Social and Occupational Functioning Assessment Scale, Beck Depression Inventory. Results: Effects of optimism on some of the health-oriented factors were observed in patients with mental disorders as well as in healthy individuals. Significant differences in the level of health-oriented resources between the study population and controls were reported. Conclusions: The study suggests that generalisation of the conclusions regarding healthy population to individuals with mental disorders should be done with caution. Further research is needed to investigate the health behaviour determinants in patients with mental disorders.

Optimized Dose Distribution of Gammamed Plus Vaginal Cylinders

International Nuclear Information System (INIS)

Supe, Sanjay S.; Bijina, T.K.; Varatharaj, C.; Shwetha, B.; Arunkumar, T.; Sathiyan, S.; Ganesh, K.M.; Ravikumar, M.

2009-01-01

Endometrial carcinoma is the most common malignancy arising in the female genital tract. Intracavitary vaginal cuff irradiation may be given alone or with external beam irradiation in patients determined to be at risk for locoregional recurrence. Vaginal cylinders are often used to deliver a brachytherapy dose to the vaginal apex and upper vagina or the entire vaginal surface in the management of postoperative endometrial cancer or cervical cancer. The dose distributions of HDR vaginal cylinders must be evaluated carefully, so that clinical experiences with LDR techniques can be used in guiding optimal use of HDR techniques. The aim of this study was to optimize dose distribution for Gammamed plus vaginal cylinders. Placement of dose optimization points was evaluated for its effect on optimized dose distributions. Two different dose optimization point models were used in this study, namely non-apex (dose optimization points only on periphery of cylinder) and apex (dose optimization points on periphery and along the curvature including the apex points). Thirteen dwell positions were used for the HDR dosimetry to obtain a 6-cm active length. Thus 13 optimization points were available at the periphery of the cylinder. The coordinates of the points along the curvature depended on the cylinder diameters and were chosen for each cylinder so that four points were distributed evenly in the curvature portion of the cylinder. Diameter of vaginal cylinders varied from 2.0 to 4.0 cm. Iterative optimization routine was utilized for all optimizations. The effects of various optimization routines (iterative, geometric, equal times) was studied for the 3.0-cm diameter vaginal cylinder. The effect of source travel step size on the optimized dose distributions for vaginal cylinders was also evaluated. All optimizations in this study were carried for dose of 6 Gy at dose optimization points. For both non-apex and apex models of vaginal cylinders, doses for apex point and three dome

Technical and economic optimization study for HLW waste management

International Nuclear Information System (INIS)

Deffes, A.

1989-01-01

This study was conducted to assess the technical and economic aspects of high level waste (HLW) management with the objective of optimizing the interim storage duration and the dimensions of the underground repository site. The procedure consisted in optimizing the economic criterion under specified constraints. The results are intended to identify trends and guide the choice from among available options; simple and highly flexible models were therefore used in this study, and only nearfield thermal constraints were taken into consideration. Because of the present uncertainty on the physicochemical properties of the repository environment and on the unit cost figures, this study focused on developing a suitable method rather than on obtaining definitive results. With the physical and economic data bases used for the two media investigated (granite and salt) the optimum values found show that it is advisable to minimize the interim storage time, and that the geological repository should feature a high degree of spatial dilution. These results depend to a considerable extent on the assumption of high interim storage costs

Lower irritation microemulsion-based rotigotine gel: formulation optimization and in vitro and in vivo studies.

Science.gov (United States)

Wang, Zheng; Mu, Hong-Jie; Zhang, Xue-Mei; Ma, Peng-Kai; Lian, Sheng-Nan; Zhang, Feng-Pu; Chu, Sheng-Ying; Zhang, Wen-Wen; Wang, Ai-Ping; Wang, Wen-Yan; Sun, Kao-Xiang

2015-01-01

Rotigotine is a potent and selective D1, D2, and D3 dopaminergic receptor agonist. Due to an extensive first-pass effect, it has a very low oral bioavailability (approximately 0.5% in rats). The present investigation aimed to develop a microemulsion-based hydrogel for transdermal rotigotine delivery with lower application site reactions. Pseudoternary phase diagrams were constructed to determine the region of oil in water (o/w)-type microemulsion. Central composite design was used to support the pseudoternary phase diagrams and to select homogeneous and stable microemulsions with an optimal amount of rotigotine permeation within 24 hours. In vitro skin permeation experiments were performed, using Franz diffusion cells, to compare rotigotine-loaded microemulsions with rotigotine solutions in oil. The optimized formulation was used to prepare a microemulsion-based hydrogel, which was subjected to bioavailability and skin irritancy studies. The selected formulations of rotigotine-loaded microemulsions had enhanced flux and permeation coefficients compared with rotigotine in oil. The optimum microemulsion contained 68% water, 6.8% Labrafil(®), 13.44% Cremophor(®) RH40, 6.72% Labrasol(®), and 5.04% Transcutol(®) HP; the drug-loading rate was 2%. To form a microemulsion gel, 1% Carbomer 1342 was added to the microemulsion. The bioavailability of the rotigotine-loaded microemulsion gel was 105.76%±20.52% with respect to the marketed rotigotine patch (Neupro(®)). The microemulsion gel irritated the skin less than Neupro. A rotigotine microemulsion-based hydrogel was successfully developed, and an optimal formulation for drug delivery was identified. This product could improve patient compliance and have broad marketability.

A comparative study on stress and compliance based structural topology optimization

Science.gov (United States)

Hailu Shimels, G.; Dereje Engida, W.; Fakhruldin Mohd, H.

2017-10-01

Most of structural topology optimization problems have been formulated and solved to either minimize compliance or weight of a structure under volume or stress constraints, respectively. Even if, a lot of researches are conducted on these two formulation techniques separately, there is no clear comparative study between the two approaches. This paper intends to compare these formulation techniques, so that an end user or designer can choose the best one based on the problems they have. Benchmark problems under the same boundary and loading conditions are defined, solved and results are compared based on these formulations. Simulation results shows that the two formulation techniques are dependent on the type of loading and boundary conditions defined. Maximum stress induced in the design domain is higher when the design domains are formulated using compliance based formulations. Optimal layouts from compliance minimization formulation has complex layout than stress based ones which may lead the manufacturing of the optimal layouts to be challenging. Optimal layouts from compliance based formulations are dependent on the material to be distributed. On the other hand, optimal layouts from stress based formulation are dependent on the type of material used to define the design domain. High computational time for stress based topology optimization is still a challenge because of the definition of stress constraints at element level. Results also shows that adjustment of convergence criterions can be an alternative solution to minimize the maximum stress developed in optimal layouts. Therefore, a designer or end user should choose a method of formulation based on the design domain defined and boundary conditions considered.

Finite dimensional convexity and optimization

CERN Document Server

Florenzano, Monique

2001-01-01

The primary aim of this book is to present notions of convex analysis which constitute the basic underlying structure of argumentation in economic theory and which are common to optimization problems encountered in many applications. The intended readers are graduate students, and specialists of mathematical programming whose research fields are applied mathematics and economics. The text consists of a systematic development in eight chapters, with guided exercises containing sometimes significant and useful additional results. The book is appropriate as a class text, or for self-study.

Optimization and management of materials in earthwork construction : final report, April 2010.

Science.gov (United States)

2010-04-01

As a result of forensic investigations of problems across Iowa, a research study was developed aimed at providing solutions to identified : problems through better management and optimization of the available pavement geotechnical materials and throu...

THE MEDIATING ROLE OF ROMANTIC RELATIONSHIPS BETWEEN OPTIMISM AND DEPRESSION IN EMERGING ADULTS

Directory of Open Access Journals (Sweden)

Elena Cattelino

2014-04-01

Full Text Available The existing literature showed that higher depression is linked to less optimism and to poor quality of romantic relationship, but studies considering the role of both optimism and romantic relationship on depression among emerging adults are lacking. The aims of the study were: 1 to describe the quality of romantic relationship, optimism and depression in a group of Italian emerging adults; 2 to examine the relation between optimism and depression; 3 to investigate the possible mediating role of quality of romantic relationship on the relation between optimism and depression. The study involved 228 emerging adults (59% girls, aged from 18 to 22 (mean age= 19.5, standard deviation=1.2. Optimism was assessed through the Life Orientation Test-Revised (LOT-R; Scheier et al., 1994, depression through the Center for Epidemiologic Studies Short Depression Scale (CES-D 10; Andresen et al., 1994 and quality of romantic relationships through the Romance Qualities Scale (RQS; Ponti et al., 2010. Main results showed a partial mediating effect of quality of romantic relationship between optimism and depression: less optimistic emerging adults reported higher depression, but the effect of lack of optimism was mediated by a good relationship with the partner. Implications for theory and practice were discussed.

Dispositional Optimism

Science.gov (United States)

Carver, Charles S.; Scheier, Michael F.

2014-01-01

Optimism is a cognitive construct (expectancies regarding future outcomes) that also relates to motivation: optimistic people exert effort, whereas pessimistic people disengage from effort. Study of optimism began largely in health contexts, finding positive associations between optimism and markers of better psychological and physical health. Physical health effects likely occur through differences in both health-promoting behaviors and physiological concomitants of coping. Recently, the scientific study of optimism has extended to the realm of social relations: new evidence indicates that optimists have better social connections, partly because they work harder at them. In this review, we examine the myriad ways this trait can benefit an individual, and our current understanding of the biological basis of optimism. PMID:24630971

Authentic Leadership for Teacher's Academic Optimism: Moderating Effect of Training Comprehensiveness

Science.gov (United States)

Srivastava, Anugamini Priya; Dhar, Rajib Lochan

2016-01-01

Purpose: This study aims to analyse the impact of authentic leadership (AL) on academic optimism (AO) through the mediating role of affective commitment (AC). As this study also examines the moderating role of training comprehensiveness (TC) in strengthening the relation between AC and AO. Design/methodology/approach: Data were collected from…

Non-Viral Transfection Methods Optimized for Gene Delivery to a Lung Cancer Cell Line

OpenAIRE

Salimzadeh, Loghman; Jaberipour, Mansooreh; Hosseini, Ahmad; Ghaderi, Abbas

2013-01-01

Background Mehr-80 is a newly established adherent human large cell lung cancer cell line that has not been transfected until now. This study aims to define the optimal transfection conditions and effects of some critical elements for enhancing gene delivery to this cell line by utilizing different non-viral transfection Procedures. Methods In the current study, calcium phosphate (CaP), DEAE-dextran, superfect, electroporation and lipofection transfection methods were used to optimize deliver...

Optimization of prophylaxis for hemophilia A.

Directory of Open Access Journals (Sweden)

Robert D Herbert

Full Text Available Prophylactic injections of factor VIII reduce the incidence of bleeds and slow the development of joint damage in people with hemophilia. The aim of this study was to identify optimal person-specific prophylaxis regimens for children with hemophilia A.Analytic and numerical methods were used to identify prophylaxis regimens which maximize the time for which plasma factor VIII concentrations exceed a threshold, maximize the lowest plasma factor VIII concentrations, and minimize risk of bleeds.It was demonstrated analytically that, for any injection schedule, the regimen that maximizes the lowest factor VIII concentration involves sharing doses between injections so that all of the trough concentrations in a prophylaxis cycle are equal. Numerical methods were used to identify optimal prophylaxis schedules and explore the trade-offs between efficacy and acceptability of different prophylaxis regimens. The prophylaxis regimen which minimizes risk of bleeds depends on the person's pattern of physical activity and may differ greatly from prophylaxis regimens that optimize pharmacokinetic parameters. Prophylaxis regimens which minimize risk of bleeds also differ from prophylaxis regimens that are typically prescribed. Predictions about which regimen is optimal are sensitive to estimates of the effects on risk of bleeds of factor VIII concentration and physical activity.The methods described here can be used to identify optimal, person-specific prophylaxis regimens for children with hemophilia A.

Understanding Optimal Decision-making in Wargaming

OpenAIRE

Nesbitt, P; Kennedy, Q; Alt, JK; Fricker, RD; Whitaker, L; Yang, J; Appleget, JA; Huston, J; Patton, S

2013-01-01

Approved for public release; distribution is unlimited. This research aims to gain insight into optimal wargaming decision-making mechanisms using neurophysiological measures by investigating whether brain activation and visual scan patterns predict attention, perception, and/or decision-making errors through human-in-the-loop wargaming simulation experiments. We investigate whether brain activity and visual scan patterns can explain optimal wargaming decision making and its devel...

Design thinking for website optimization. A case study

DEFF Research Database (Denmark)

Somoza Sanchez, Vella Veronica; Andersen, Frederik; Schneider-Kamp, Peter

This paper presents results from a pilot study, which is part of a larger research project where we study the process innovation of website optimization as a service through the use of big data. Over a process of design thinking we investigate which type of website design best addresses the needs...... for observing the users in their native environment. Furthermore, we use the method of Digital Anthropology to complete the loop between the human-centric designs and the possibilities offered by the analysis of big data....

Dependability of self-optimizing mechatronic systems

CERN Document Server

Rammig, Franz; Schäfer, Wilhelm; Sextro, Walter

2014-01-01

Intelligent technical systems, which combine mechanical, electrical and software engineering with control engineering and advanced mathematics, go far beyond the state of the art in mechatronics and open up fascinating perspectives. Among these systems are so-called self-optimizing systems, which are able to adapt their behavior autonomously and flexibly to changing operating conditions. Self-optimizing systems create high value for example in terms of energy and resource efficiency as well as reliability. The Collaborative Research Center 614 "Self-optimizing Concepts and Structures in Mechanical Engineering" pursued the long-term aim to open up the active paradigm of self-optimization for mechanical engineering and to enable others to develop self-optimizing systems. This book is directed to researchers and practitioners alike. It provides a design methodology for the development of self-optimizing systems consisting of a reference process, methods, and tools. The reference process is divided into two phase...

Fuel management optimization for a PWR

International Nuclear Information System (INIS)

Dumas, M.; Robeau, D.

1981-04-01

This study is aimed to optimize the refueling pattern of a PWR. Two methods are developed, they are based on a linearized form of the optimization problem. The first method determines a feasible solution in two steps; in the first one the original problem is replaced by a relaxed one which is solved by the Method of Approximation Programming. The second step is based on the Branch and Bound method to find the feasible solution closest to the solution obtained in the first step. The second method starts from a given refueling pattern and tries to improve this pattern by the calculation of the effects of 2 by 2, 3 by 3 and 4 by 4 permutations on the objective function. Numerical results are given for a typical PWR refueling using the two methods

Computer models for optimizing radiation therapy

International Nuclear Information System (INIS)

Duechting, W.

1998-01-01

The aim of this contribution is to outline how methods of system analysis, control therapy and modelling can be applied to simulate normal and malignant cell growth and to optimize cancer treatment as for instance radiation therapy. Based on biological observations and cell kinetic data, several types of models have been developed describing the growth of tumor spheroids and the cell renewal of normal tissue. The irradiation model is represented by the so-called linear-quadratic model describing the survival fraction as a function of the dose. Based thereon, numerous simulation runs for different treatment schemes can be performed. Thus, it is possible to study the radiation effect on tumor and normal tissue separately. Finally, this method enables a computer-assisted recommendation for an optimal patient-specific treatment schedule prior to clinical therapy. (orig.) [de

A Shape Optimization Study for Tool Design in Resistance Welding

DEFF Research Database (Denmark)

Bogomolny, Michael; Bendsøe, Martin P.; Hattel, Jesper Henri

2009-01-01

The purpose of this study is to apply shape optimization tools for design of resistance welding electrodes. The numerical simulation of the welding process has been performed by a simplified FEM model implemented in COMSOL. The design process is formulated as an optimization problem where...... the objective is to prolong the life-time of the electrodes. Welding parameters like current, time and electrode shape parameters are selected to be the design variables while constraints are chosen to ensure a high quality of the welding. Surrogate models based on a Kriging approximation has been used in order...

Optimism in prolonged grief and depression following loss : A three-wave longitudinal study

NARCIS (Netherlands)

Boelen, Paul A

2015-01-01

There is considerable evidence that optimism, the predisposition to have generalized favorable expectancies for the future, is associated with numerous desirable outcomes. Few studies have examined the association of optimism with emotional distress following the death of a loved one. Doing so is

Do different methods of modeling statin treatment effectiveness influence the optimal decision?

NARCIS (Netherlands)

B.J.H. van Kempen (Bob); B.S. Ferket (Bart); A. Hofman (Albert); S. Spronk (Sandra); E.W. Steyerberg (Ewout); M.G.M. Hunink (Myriam)

2012-01-01

textabstractPurpose. Modeling studies that evaluate statin treatment for the prevention of cardiovascular disease (CVD) use different methods to model the effect of statins. The aim of this study was to evaluate the impact of using different modeling methods on the optimal decision found in such

Developing a simulation framework for safe and optimal trajectories considering drivers’ driving style

DEFF Research Database (Denmark)

Gruber, Thierry; Larue, Grégoire S.; Rakotonirainy, Andry

2017-01-01

drivers with the optimal trajectory considering the motorist's driving style in real time. Travel duration and safety are the main parameters used to find the optimal trajectory. A simulation framework to determine the optimal trajectory was developed in which the ego car travels in a highway environment......Advanced driving assistance systems (ADAS) have huge potential for improving road safety and travel times. However, their take-up in the market is very slow; and these systems should consider driver's preferences to increase adoption rates. The aim of this study is to develop a model providing...

A characteristic study of CCF modeling techniques and optimization of CCF defense strategies

International Nuclear Information System (INIS)

Kim, Min Chull

2000-02-01

Common Cause Failures (CCFs ) are among the major contributors to risk and core damage frequency (CDF ) from operating nuclear power plants (NPPs ). Our study on CCF focused on the following aspects : 1) a characteristic study on the CCF modeling techniques and 2) development of the optimal CCF defense strategy. Firstly, the characteristics of CCF modeling techniques were studied through sensitivity study of CCF occurrence probability upon system redundancy. The modeling techniques considered in this study include those most widely used worldwide, i.e., beta factor, MGL, alpha factor, and binomial failure rate models. We found that MGL and alpha factor models are essentially identical in terms of the CCF probability. Secondly, in the study for CCF defense, the various methods identified in the previous studies for defending against CCF were classified into five different categories. Based on these categories, we developed a generic method by which the optimal CCF defense strategy can be selected. The method is not only qualitative but also quantitative in nature: the selection of the optimal strategy among candidates is based on the use of analytic hierarchical process (AHP). We applied this method to two motor-driven valves for containment sump isolation in Ulchin 3 and 4 nuclear power plants. The result indicates that the method for developing an optimal CCF defense strategy is effective

Optimizing clozapine treatment

DEFF Research Database (Denmark)

Nielsen, Jimmi; Damkier, P; Lublin, Henrik

2011-01-01

Clozapine treatment remains the gold standard for treatment-resistant schizophrenia, but treatment with clozapine is associated with several side-effects that complicate the use of the drug. This clinical overview aims to provide psychiatrists with knowledge about how to optimize clozapine...... treatment. Relevant strategies for reducing side-effects and increasing the likelihood of response are discussed....

The FERMI (at) Elettra Technical Optimization Study: Preliminary Parameter Set and Initial Studies

International Nuclear Information System (INIS)

Byrd, John; Corlett, John; Doolittle, Larry; Fawley, William; Lidia, Steven; Penn, Gregory; Ratti, Alex; Staples, John; Wilcox, Russell; Wurtele, Jonathan; Zholents, Alexander

2005-01-01

The goal of the FERMI (at) Elettra Technical Optimization Study is to produce a machine design and layout consistent with user needs for radiation in the approximate ranges 100 nm to 40 nm, and 40 nm to 10 nm, using seeded FEL's. The Study will involve collaboration between Italian and US physicists and engineers, and will form the basis for the engineering design and the cost estimation

Optimal control approaches for aircraft conflict avoidance using speed regulation : a numerical study

OpenAIRE

Cellier , Loïc; Cafieri , Sonia; Messine , Frederic

2013-01-01

International audience; In this paper a numerical study is provided to solve the aircraft conflict avoidance problem through velocity regulation maneuvers. Starting from optimal controlbased model and approaches in which aircraft accelerations are the controls, and by applying the direct shooting technique, we propose to study two different largescale nonlinear optimization problems. In order to compare different possibilities of implementation, two environments (AMPL and MATLAB) and determin...

Optimal time policy for deteriorating items of two-warehouse

Indian Academy of Sciences (India)

... goods in which the first is rented warehouse and the second is own warehouse that deteriorates with two different rates. The aim of this study is to determine the optimal order quantity to maximize the profit of the projected model. Finally, some numerical examples and sensitivity analysis of parameters are made to validate ...

Optimization of in vitro culture and transfection condition of bovine ...

African Journals Online (AJOL)

The present study aimed to optimize the in vitro culture and transfection efficiency of bovine primary spermatogonial stem cells (SSCs). To this end, SSCs were obtained from newborn Holstein bull calves by two-step enzymatic digestion. After enrichment and culture, SSCs were characterized by using alkaline phosphatase ...

A Study on Development of a Cost Optimal and Energy Saving Building Model: Focused on Industrial Building

Directory of Open Access Journals (Sweden)

Hye Yeon Kim

2016-03-01

Full Text Available This study suggests an optimization method for the life cycle cost (LCC in an economic feasibility analysis when applying energy saving techniques in the early design stage of a building. Literature and previous studies were reviewed to select appropriate optimization and LCC analysis techniques. The energy simulation (Energy Plus and computational program (MATLAB were linked to provide an automated optimization process. From the results, it is suggested that this process could outline the cost optimization model with which it is possible to minimize the LCC. To aid in understanding the model, a case study on an industrial building was performed to outline the operations of the cost optimization model including energy savings. An energy optimization model was also presented to illustrate the need for the cost optimization model.

Transport Routes Optimization Model Through Application of Fuzzy Logic

Directory of Open Access Journals (Sweden)

Ivan Bortas

2018-03-01

Full Text Available The transport policy of the European Union is based on the mission of restructuring road traffic into other and energy-favourable transport modes which have not been sufficiently represented yet. Therefore, the development of the inland waterway and rail transport, and connectivity in the intermodal transport network are development planning priorities of the European transport strategy. The aim of this research study was to apply the scientific methodology and thus analyse the factors that affect the distribution of the goods flows and by using the fuzzy logic to make an optimization model, according to the criteria of minimizing the costs and negative impact on the environment, for the selection of the optimal transport route. Testing of the model by simulation, was performed on the basis of evaluating the criteria of the influential parameters with unprecise and indefinite input parameters. The testing results show that by the distribution of the goods flow from road transport network to inland waterways or rail transport, can be predicted in advance and determine the transport route with optimal characteristics. The results of the performed research study will be used to improve the process of planning the transport service, with the aim of reducing the transport costs and environmental pollution.

Nonlinear Dynamic Analysis and Optimization of Closed-Form Planetary Gear System

Directory of Open Access Journals (Sweden)

Qilin Huang

2013-01-01

Full Text Available A nonlinear purely rotational dynamic model of a multistage closed-form planetary gear set formed by two simple planetary stages is proposed in this study. The model includes time-varying mesh stiffness, excitation fluctuation and gear backlash nonlinearities. The nonlinear differential equations of motion are solved numerically using variable step-size Runge-Kutta. In order to obtain function expression of optimization objective, the nonlinear differential equations of motion are solved analytically using harmonic balance method (HBM. Based on the analytical solution of dynamic equations, the optimization mathematical model which aims at minimizing the vibration displacement of the low-speed carrier and the total mass of the gear transmission system is established. The optimization toolbox in MATLAB program is adopted to obtain the optimal solution. A case is studied to demonstrate the effectiveness of the dynamic model and the optimization method. The results show that the dynamic properties of the closed-form planetary gear transmission system have been improved and the total mass of the gear set has been decreased significantly.

Dispositional Optimism as a Correlate of Decision-Making Styles in Adolescence

Directory of Open Access Journals (Sweden)

Paola Magnano

2015-06-01

Full Text Available Despite the numerous psychological areas in which optimism has been studied, including career planning, only a small amount of research has been done to investigate the relationship between optimism and decision-making styles. Consequently, we have investigated the role of dispositional optimism as a correlate of different decision-making styles, in particular, positive for effective styles and negative for ineffective ones (doubtfulness, procrastination, and delegation. Data were gathered through questionnaires administered to 803 Italian adolescents in their last 2 years of high schools with different fields of study, each at the beginning stages of planning for their professional future. A paper questionnaire was completed containing measures of dispositional optimism and career-related decision styles, during a vocational guidance intervention conducted at school. Data were analyzed using stepwise multiple regression. Results supported the proposed model by showing optimism to be a strong correlate of decision-making styles, thereby offering important intervention guidelines aimed at modifying unrealistically negative expectations regarding their future and helping students learn adaptive decision-making skills.

Oyster Creek cycle 10 nodal model parameter optimization study using PSMS

International Nuclear Information System (INIS)

Dougher, J.D.

1987-01-01

The power shape monitoring system (PSMS) is an on-line core monitoring system that uses a three-dimensional nodal code (NODE-B) to perform nodal power calculations and compute thermal margins. The PSMS contains a parameter optimization function that improves the ability of NODE-B to accurately monitor core power distributions. This functions iterates on the model normalization parameters (albedos and mixing factors) to obtain the best agreement between predicted and measured traversing in-core probe (TIP) reading on a statepoint-by-statepoint basis. Following several statepoint optimization runs, an average set of optimized normalization parameters can be determined and can be implemented into the current or subsequent cycle core model for on-line core monitoring. A statistical analysis of 19 high-power steady-state state-points throughout Oyster Creek cycle 10 operation has shown a consistently poor virgin model performance. The normalization parameters used in the cycle 10 NODE-B model were based on a cycle 8 study, which evaluated only Exxon fuel types. The introduction of General Electric (GE) fuel into cycle 10 (172 assemblies) was a significant fuel/core design change that could have altered the optimum set of normalization parameters. Based on the need to evaluate a potential change in the model normalization parameters for cycle 11 and in an attempt to account for the poor cycle 10 model performance, a parameter optimization study was performed

Experimental Study On The Optimization Of Extraction Process Of ...

African Journals Online (AJOL)

The objective is to study the extraction process of garlic oil and its antibacterial effects. Materials and Methods: CO2 Supercritical extraction was used to investigate the optimal processing conditions for garlic oil extraction; filter paper test and suspension dilution test were applied to determine the bacteriostatic action of ...

Prolonged release matrix tablet of pyridostigmine bromide: formulation and optimization using statistical methods.

Science.gov (United States)

Bolourchian, Noushin; Rangchian, Maryam; Foroutan, Seyed Mohsen

2012-07-01

The aim of this study was to design and optimize a prolonged release matrix formulation of pyridostigmine bromide, an effective drug in myasthenia gravis and poisoning with nerve gas, using hydrophilic - hydrophobic polymers via D-optimal experimental design. HPMC and carnauba wax as retarding agents as well as tricalcium phosphate were used in matrix formulation and considered as independent variables. Tablets were prepared by wet granulation technique and the percentage of drug released at 1 (Y(1)), 4 (Y(2)) and 8 (Y(3)) hours were considered as dependent variables (responses) in this investigation. These experimental responses were best fitted for the cubic, cubic and linear models, respectively. The optimal formulation obtained in this study, consisted of 12.8 % HPMC, 24.4 % carnauba wax and 26.7 % tricalcium phosphate, had a suitable prolonged release behavior followed by Higuchi model in which observed and predicted values were very close. The study revealed that D-optimal design could facilitate the optimization of prolonged release matrix tablet containing pyridostigmine bromide. Accelerated stability studies confirmed that the optimized formulation remains unchanged after exposing in stability conditions for six months.

New Optimization Algorithms in Physics

CERN Document Server

Hartmann, Alexander K

2004-01-01

Many physicists are not aware of the fact that they can solve their problems by applying optimization algorithms. Since the number of such algorithms is steadily increasing, many new algorithms have not been presented comprehensively until now. This presentation of recently developed algorithms applied in physics, including demonstrations of how they work and related results, aims to encourage their application, and as such the algorithms selected cover concepts and methods from statistical physics to optimization problems emerging in theoretical computer science.

Ecological optimization and parametric study of irreversible Stirling and Ericsson heat pumps

International Nuclear Information System (INIS)

Tyagi, S.K.; Kaushik, S.C.; Salohtra, R.

2002-01-01

This communication presents the ecological optimization and parametric study of irreversible Stirling and Ericsson heat pump cycles, in which the external irreversibility is due to finite temperature difference between working fluid and external reservoirs while the internal irreversibilities are due to regenerative heat loss and other entropy generations within the cycle. The ecological function is defined as the heating load minus the irreversibility (power loss) which is ambient temperature times the entropy generation. The ecological function is optimized with respect to working fluid temperatures, and the expressions for various parameters at the optimal operating condition are obtained. The effects of different operating parameters on the performance of these cycles have been studied. It is found that the effect of internal irreversibility parameter is more pronounced than the other parameters on the performance of these cycles. (author)

Institutional Economic Reconstruction by Optimizing the Role of Middlemen

OpenAIRE

Sudrajat, Jajat; Arani, Norasari

2016-01-01

This study is aimed to analize the role of middlemen in rural economic institution and formulate the economic development model through optimalization the role of middlemen. This study was done by conducting literature research. Data were analized by using qualitative method. The results of study conclude that middlemen have strategic positions in rural economic development although their role has negative and positive side. In evolving the positive side, there must be other institution which...

Solution of optimal power flow using evolutionary-based algorithms

African Journals Online (AJOL)

It aims to estimate the optimal settings of real generator output power, bus voltage, ...... Lansey, K. E., 2003, Optimization of water distribution network design using ... Pandit, M., 2016, Economic load dispatch of wind-solar-thermal system using ...

Optimization and anti-optimization of structures under uncertainty

National Research Council Canada - National Science Library

Elishakoff, Isaac; Ohsaki, Makoto

2010-01-01

The volume presents a collaboration between internationally recognized experts on anti-optimization and structural optimization, and summarizes various novel ideas, methodologies and results studied over 20 years...

Optimal Power Flow in three-phase islanded microgrids with inverter interfaced units

DEFF Research Database (Denmark)

Sanseverino, Eleonora Riva; Quang, Ninh Nguyen; Di Silvestre, Maria Luisa

2015-01-01

In this paper, the solution of the Optimal Power Flow (OPF) problem for three phase islanded microgrids is studied, the OPF being one of the core functions of the tertiary regulation level for an AC islanded microgrid with a hierarchical control architecture. The study also aims at evaluating the...

Multiple energy supply risks, optimal reserves, and optimal domestic production capacities

International Nuclear Information System (INIS)

Zweifel, P.; Ferrari, M.

1992-01-01

This study starts from the observation that today's Western trading nations are exposed to multiple risks of energy supplies, e.g. simultaneous shortage of oil and electricity supplies. To cope with these risks, oil can be stockpiled as well as domestic capacity for power production built up. Adopting the viewpoint of a policy maker who aims at minimizing the expected cost of security of supply, optimal simultaneous adjustments of oil stocks and electric production capacities to exogenous changes such as economic growth are derived. Against this benchmark, one-dimensional rules such as 'oil reserves for 90 days' turn out to be not only suboptimal but also to foster adjustments that exacerbate suboptimality. 9 refs., 1 tabs

Optimization of the Single Staggered Wire and Tube Heat Exchanger

Directory of Open Access Journals (Sweden)

Arsana I Made

2016-01-01

Full Text Available Wire and tube heat exchanger consists of a coiled tube, and wire is welded on the two sides of it in normal direction of the tube. Generally,wire and tube heat exchanger uses inline wire arrangement between the two sides, whereas in this study, it used staggered wire arrangement that reduces the restriction of convection heat transfer. This study performed the optimization of single staggered wire and tube heat exchanger to increase the capacity and reduce the mass of the heat exchanger. Optimization was conducted with the Hooke-Jeeves method, which aims to optimize the geometry of the heat exchanger, especially on the diameter (dw and the distance between wires (pw. The model developed to present heat transfer correlations on single staggered wire and tube heat exchanger was valid. The maximum optimization factor obtained when the diameter wire was 0.9 mm and the distance between wires (pw was 11 mm with the fref value = 1.5837. It means that the optimized design only using mass of 59,10 % and could transfer heat about 98,5 % from the basis design.

Post-processing of Monte Carlo simulations for rapid BNCT source optimization studies

International Nuclear Information System (INIS)

Bleuel, D.L.; Chu, W.T.; Donahue, R.J.; Ludewigt, B.A.; Vujic, J.

2000-01-01

A great advantage of some neutron sources, such as accelerator-produced sources, is that they can be tuned to produce different spectra. Unfortunately, optimization studies are often time-consuming and difficult, as they require a lengthy Monte Carlo simulation for each source. When multiple characteristics, such as energy, angle, and spatial distribution of a neutron beam are allowed to vary, an overwhelming number of simulations may be required. Many optimization studies, therefore, suffer from a small number of datapoints, restrictive treatment conditions, or poor statistics. By scoring pertinent information from every particle tally in a Monte Carlo simulation, then applying appropriate source variable weight factors in a post-processing algorithm, a single simulation can be used to model any number of multiple sources. Through this method, the response to a new source can be modeled in minutes or seconds, rather than hours or days, allowing for the analysis of truly variable source conditions of much greater resolution than is normally possible when a new simulation must be run for each datapoint in a study. This method has been benchmarked and used to recreate optimization studies in a small fraction of the time spent in the original studies

Nuclear-thermal-coupled optimization code for the fusion breeding blanket conceptual design

International Nuclear Information System (INIS)

Li, Jia; Jiang, Kecheng; Zhang, Xiaokang; Nie, Xingchen; Zhu, Qinjun; Liu, Songlin

2016-01-01

Highlights: • A nuclear-thermal-coupled predesign code has been developed for optimizing the radial build arrangement of fusion breeding blanket. • Coupling module aims at speeding up the efficiency of design progress by coupling the neutronics calculation code with the thermal-hydraulic analysis code. • Radial build optimization algorithm aims at optimal arrangement of breeding blanket considering one or multiple specified objectives subject to the design criteria such as material temperature limit and available TBR. - Abstract: Fusion breeding blanket as one of the key in-vessel components performs the functions of breeding the tritium, removing the nuclear heat and heat flux from plasma chamber as well as acting as part of shielding system. The radial build design which determines the arrangement of function zones and material properties on the radial direction is the basis of the detailed design of fusion breeding blanket. For facilitating the radial build design, this study aims for developing a pre-design code to optimize the radial build of blanket with considering the performance of nuclear and thermal-hydraulic simultaneously. Two main features of this code are: (1) Coupling of the neutronics analysis with the thermal-hydraulic analysis to speed up the analysis progress; (2) preliminary optimization algorithm using one or multiple specified objectives subject to the design criteria in the form of constrains imposed on design variables and performance parameters within the possible engineering ranges. This pre-design code has been applied to the conceptual design of water-cooled ceramic breeding blanket in project of China fusion engineering testing reactor (CFETR).

Nuclear-thermal-coupled optimization code for the fusion breeding blanket conceptual design

Energy Technology Data Exchange (ETDEWEB)

Li, Jia, E-mail: lijia@ustc.edu.cn [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230027, Anhui (China); Jiang, Kecheng; Zhang, Xiaokang [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, Anhui (China); Nie, Xingchen [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230027, Anhui (China); Zhu, Qinjun; Liu, Songlin [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, Anhui (China)

2016-12-15

Highlights: • A nuclear-thermal-coupled predesign code has been developed for optimizing the radial build arrangement of fusion breeding blanket. • Coupling module aims at speeding up the efficiency of design progress by coupling the neutronics calculation code with the thermal-hydraulic analysis code. • Radial build optimization algorithm aims at optimal arrangement of breeding blanket considering one or multiple specified objectives subject to the design criteria such as material temperature limit and available TBR. - Abstract: Fusion breeding blanket as one of the key in-vessel components performs the functions of breeding the tritium, removing the nuclear heat and heat flux from plasma chamber as well as acting as part of shielding system. The radial build design which determines the arrangement of function zones and material properties on the radial direction is the basis of the detailed design of fusion breeding blanket. For facilitating the radial build design, this study aims for developing a pre-design code to optimize the radial build of blanket with considering the performance of nuclear and thermal-hydraulic simultaneously. Two main features of this code are: (1) Coupling of the neutronics analysis with the thermal-hydraulic analysis to speed up the analysis progress; (2) preliminary optimization algorithm using one or multiple specified objectives subject to the design criteria in the form of constrains imposed on design variables and performance parameters within the possible engineering ranges. This pre-design code has been applied to the conceptual design of water-cooled ceramic breeding blanket in project of China fusion engineering testing reactor (CFETR).

Optimal design method for magnetization directions of a permanent magnet array

Energy Technology Data Exchange (ETDEWEB)

Choi, Jae Seok [Center for Information Storage Device, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Yoo, Jeonghoon, E-mail: yoojh@yonsei.ac.k [School of Mechanical Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

2010-08-15

In many magnetic systems, the permanent magnet (PM) pattern has a great influence on their performance. This study proposes a systematic optimization method for designing discrete magnetization directions. While previous works have been mostly dependent on researchers' intuition, the developed method is systematic and can be applied to a two-dimensional PM-type eddy current brake model. The effectiveness of the method is confirmed, where the design's aim is to maximize the braking force on a moving conductor. The sensitivity analysis is accomplished by the adjoint variable method and the sequential linear programming is used as an optimizer. Several optimization results for various conditions through the proposed design method are compared to each other and the optimal magnet configuration for an eddy current brake is suggested.

Optimization bitumen-based upgrading and refining schemes

Energy Technology Data Exchange (ETDEWEB)

Munteanu, M.; Chen, J. [National Centre for Upgrading Technology, Devon, AB (Canada); Natural Resources Canada, Devon, AB (Canada). CanmetENERGY

2009-07-01

This poster highlighted the results of a study in which the entire refining scheme for Canadian bitumen as feedstocks was modelled and simulated under different process configurations, operating conditions and product structures. The aim of the study was to optimize the economic benefits, product quality and energy use under a range of operational scenarios. Optimal refining schemes were proposed along with process conditions for existing refinery configurations and objectives. The goal was to provide guidelines and information for upgrading and refining process design and retrofitting. Critical steps were identified with regards to the upgrading process. It was concluded that the information obtained from this study would lead to significant improvement in process performance and operations, and in reducing the capital cost for building new upgraders and refineries. The simulation results provided valuable information for increasing the marketability of bitumen, reducing greenhouse gas emissions and other environmental impacts associated with bitumen upgrading and refining. tabs., figs.

Taxing Strategies for Carbon Emissions: A Bilevel Optimization Approach

Directory of Open Access Journals (Sweden)

Wei Wei

2014-04-01

Full Text Available This paper presents a quantitative and computational method to determine the optimal tax rate among generating units. To strike a balance between the reduction of carbon emission and the profit of energy sectors, the proposed bilevel optimization model can be regarded as a Stackelberg game between the government agency and the generation companies. The upper-level, which represents the government agency, aims to limit total carbon emissions within a certain level by setting optimal tax rates among generators according to their emission performances. The lower-level, which represents decision behaviors of the grid operator, tries to minimize the total production cost under the tax rates set by the government. The bilevel optimization model is finally reformulated into a mixed integer linear program (MILP which can be solved by off-the-shelf MILP solvers. Case studies on a 10-unit system as well as a provincial power grid in China demonstrate the validity of the proposed method and its capability in practical applications.

Effects of Optimism and Gratitude on Physical Activity, Biomarkers, and Readmissions After an Acute Coronary Syndrome: The Gratitude Research in Acute Coronary Events Study.

Science.gov (United States)

Huffman, Jeff C; Beale, Eleanor E; Celano, Christopher M; Beach, Scott R; Belcher, Arianna M; Moore, Shannon V; Suarez, Laura; Motiwala, Shweta R; Gandhi, Parul U; Gaggin, Hanna K; Januzzi, James L

2016-01-01

Positive psychological constructs, such as optimism, are associated with beneficial health outcomes. However, no study has separately examined the effects of multiple positive psychological constructs on behavioral, biological, and clinical outcomes after an acute coronary syndrome (ACS). Accordingly, we aimed to investigate associations of baseline optimism and gratitude with subsequent physical activity, prognostic biomarkers, and cardiac rehospitalizations in post-ACS patients. Participants were enrolled during admission for ACS and underwent assessments at baseline (2 weeks post-ACS) and follow-up (6 months later). Associations between baseline positive psychological constructs and subsequent physical activity/biomarkers were analyzed using multivariable linear regression. Associations between baseline positive constructs and 6-month rehospitalizations were assessed via multivariable Cox regression. Overall, 164 participants enrolled and completed the baseline 2-week assessments. Baseline optimism was significantly associated with greater physical activity at 6 months (n=153; β=102.5; 95% confidence interval, 13.6-191.5; P=0.024), controlling for baseline activity and sociodemographic, medical, and negative psychological covariates. Baseline optimism was also associated with lower rates of cardiac readmissions at 6 months (n=164), controlling for age, sex, and medical comorbidity (hazard ratio, 0.92; 95% confidence interval, [0.86-0.98]; P=0.006). There were no significant relationships between optimism and biomarkers. Gratitude was minimally associated with post-ACS outcomes. Post-ACS optimism, but not gratitude, was prospectively and independently associated with superior physical activity and fewer cardiac readmissions. Whether interventions that target optimism can successfully increase optimism or improve cardiovascular outcomes in post-ACS patients is not yet known, but can be tested in future studies. URL: http://www.clinicaltrials.gov. Unique

A Study on Optimal Resource Allocation of Taxis

Directory of Open Access Journals (Sweden)

Lv Xiao Peng

2016-01-01

Full Text Available As taxis play an increasingly important role in urban traffic system, the research on the supply and demand of taxis and the design of an optimal model of taxis supply has an importantly practical significance. In this paper, we used the traffic bureau data of Guangzhou, and determined the rate of empty driving as the index to establish the model. Nonlinear programming method was uesd to establish the optimal model of taxis quantity to meet the maximum income and maximum passenger satisfaction. Finally we got the optimal number of taxis was 37537.59

Genetic algorithms used for PWRs refuel management automatic optimization: a new modelling

International Nuclear Information System (INIS)

Chapot, Jorge Luiz C.; Schirru, Roberto; Silva, Fernando Carvalho da

1996-01-01

A Genetic Algorithms-based system, linking the computer codes GENESIS 5.0 and ANC through the interface ALGER, has been developed aiming the PWRs fuel management optimization. An innovative codification, the Lists Model, has been incorporated to the genetic system, which avoids the use of variants of the standard crossover operator and generates only valid loading patterns in the core. The GENESIS/ALGER/ANC system has been successfully tested in an optimization study for Angra-1 second cycle. (author)

Efficient Output Solution for Nonlinear Stochastic Optimal Control Problem with Model-Reality Differences

Directory of Open Access Journals (Sweden)

Sie Long Kek

2015-01-01

Full Text Available A computational approach is proposed for solving the discrete time nonlinear stochastic optimal control problem. Our aim is to obtain the optimal output solution of the original optimal control problem through solving the simplified model-based optimal control problem iteratively. In our approach, the adjusted parameters are introduced into the model used such that the differences between the real system and the model used can be computed. Particularly, system optimization and parameter estimation are integrated interactively. On the other hand, the output is measured from the real plant and is fed back into the parameter estimation problem to establish a matching scheme. During the calculation procedure, the iterative solution is updated in order to approximate the true optimal solution of the original optimal control problem despite model-reality differences. For illustration, a wastewater treatment problem is studied and the results show the efficiency of the approach proposed.

Dispositional optimism, self-framing and medical decision-making.

Science.gov (United States)

Zhao, Xu; Huang, Chunlei; Li, Xuesong; Zhao, Xin; Peng, Jiaxi

2015-03-01

Self-framing is an important but underinvestigated area in risk communication and behavioural decision-making, especially in medical settings. The present study aimed to investigate the relationship among dispositional optimism, self-frame and decision-making. Participants (N = 500) responded to the Life Orientation Test-Revised and self-framing test of medical decision-making problem. The participants whose scores were higher than the middle value were regarded as highly optimistic individuals. The rest were regarded as low optimistic individuals. The results showed that compared to the high dispositional optimism group, participants from the low dispositional optimism group showed a greater tendency to use negative vocabulary to construct their self-frame, and tended to choose the radiation therapy with high treatment survival rate, but low 5-year survival rate. Based on the current findings, it can be concluded that self-framing effect still exists in medical situation and individual differences in dispositional optimism can influence the processing of information in a framed decision task, as well as risky decision-making. © 2014 International Union of Psychological Science.

Portfolio Implementation Risk Management Using Evolutionary Multiobjective Optimization

Directory of Open Access Journals (Sweden)

David Quintana

2017-10-01

Full Text Available Portfolio management based on mean-variance portfolio optimization is subject to different sources of uncertainty. In addition to those related to the quality of parameter estimates used in the optimization process, investors face a portfolio implementation risk. The potential temporary discrepancy between target and present portfolios, caused by trading strategies, may expose investors to undesired risks. This study proposes an evolutionary multiobjective optimization algorithm aiming at regions with solutions more tolerant to these deviations and, therefore, more reliable. The proposed approach incorporates a user’s preference and seeks a fine-grained approximation of the most relevant efficient region. The computational experiments performed in this study are based on a cardinality-constrained problem with investment limits for eight broad-category indexes and 15 years of data. The obtained results show the ability of the proposed approach to address the robustness issue and to support decision making by providing a preferred part of the efficient set. The results reveal that the obtained solutions also exhibit a higher tolerance to prediction errors in asset returns and variance–covariance matrix.

Optimism and Mortality in Older Men and Women: The Rancho Bernardo Study

Directory of Open Access Journals (Sweden)

Ericha G. Anthony

2016-01-01

Full Text Available Purpose. To examine the associations of optimism and pessimism with all-cause, cardiovascular disease (CVD, coronary heart disease (CHD, and cancer mortality in a population-based sample of older men and women followed ≤12 years. Methods. 367 men and 509 women aged ≥50 from the Rancho Bernardo Study attended a 1999–2002 research clinic visit when demographic, behavioral, and medical history were obtained and completed a 1999 mailed survey including the Life Orientation Test-Revised (LOT-R. Mortality outcomes were followed through 2012. Results. Average age at baseline was 74.1 years; during follow-up (mean = 8.1 years, 198 participants died, 62 from CVD, 22 from CHD, and 49 from cancer. Total LOT-R, optimism and pessimism scores were calculated. Participants with the highest optimism were younger and reported less alcohol use and smoking and more exercise. Cox proportional hazard models showed that higher total LOT-R and optimism, but not pessimism scores, were associated with reduced odds of CHD mortality after adjusting for age, sex, alcohol, smoking, obesity, physical exercise, and medication (HR = 0.86, 95% CI = 0.75, 0.99; HR = 0.77, 95% CI = 0.61, 0.99, resp.. No associations were found for all-cause, CVD, or cancer mortality. Conclusions. Optimism was associated with reduced CHD mortality in older men and women. The association of positive attitudes with mortality merits further study.

Study of optimal exposure windows using 320-Detector rows dynamic volume CT

Directory of Open Access Journals (Sweden)

Gang Sun

2010-12-01

Full Text Available Gang Sun1, Min Li1, Li Li1, Guo-ying Li1, Zhi-wei Jing21Departments of Medical Imaging, 2Medical Statistics, Jinan Military General Hospital, Shandong Province, ChinaAbstract: The purpose of this study was to determine the optimal electrocardiographic (ECG pulsing windows and evaluate the effect on reduced dose and accuracy using 320-detector rows dynamic volume computed tomography (DVCT. A total of 170 patients were prospectively studied. The optimal reconstruction windows were analyzed in 76 patients scanned using retrospective ECG gating. Forty-seven patients were scanned by the predicted triggering windows. The optimal positions of exposure intervals according to different heart rates were evaluated. Optimal image quality, radiation dose, and diagnostic accuracy were then investigated by applying optimal triggering windows. The optimal ECG pulsing windows were determined as follows: when heart rate was <70 beats per minute, the exposure windows should be preset at 60%–80%; for a heart rate 70–90 beats per minute at 70%–90%; and for a heart rate ≥90 beats per minute at 30%–50%. The radiation dose for patients scanned with prospective ECG gating was significantly lower (5.9 versus 12.9 mSv, P < 0.001. However, because two or three heart beats were needed when heart rate was >70 beats per minute, the radiation dose increased with increasing heart rate for both retrospective and prospective ECG gating (r = 0.64, P < 0.001 and r = 0.59, P < 0.001, respectively. On the basis of a per segment analysis, overall sensitivity was 98.0% (49/50, specificity was 99.2% (602/607, the positive predictive value was 90.7% (49/54, and the negative predictive value was 99.8% (602/603. In conclusion, DVCT has the potential to provide high image quality across a wide range of heart rates using an optimized ECG pulsing window. However, it is recommended to control heart rate below 70 beats per minute, if possible, to decrease the radiation dose

Framework for sequential approximate optimization

NARCIS (Netherlands)

Jacobs, J.H.; Etman, L.F.P.; Keulen, van F.; Rooda, J.E.

2004-01-01

An object-oriented framework for Sequential Approximate Optimization (SAO) isproposed. The framework aims to provide an open environment for thespecification and implementation of SAO strategies. The framework is based onthe Python programming language and contains a toolbox of Python

Optimization of foam-filled bitubal structures for crashworthiness criteria

International Nuclear Information System (INIS)

Zhang, Yong; Sun, Guangyong; Li, Guangyao; Luo, Zhen; Li, Qing

2012-01-01

Highlights: ► The paper aims to optimize foam-filled bitubal squared column for crashworthiness. ► It explores different formulations and configurations of design. ► The optimal foam-filled bitubal column is better than foam-filled monotubal column. ► The optimal foam-filled bitubal column is better than empty bitubal column. -- Abstract: Thin-walled structures have been widely used as key components in automobile and aerospace industry to improve the crashworthiness and safety of vehicles while maintaining overall light-weight. This paper aims to explore the design issue of thin-walled bitubal column structures filled with aluminum foam. As a relatively new filler material, aluminum foam can increase crashworthiness without sacrificing too much weight. To optimize crashworthiness of the foam-filled bitubal square column, the Kriging meta-modeling technique is adopted herein to formulate the objective and constraint functions. The genetic algorithm (GA) and Non-dominated Sorting Genetic Algorithm II (NSGA II) are used to seek the optimal solutions to the single and multiobjective optimization problems, respectively. To compare with other thin-walled configurations, the design optimization is also conducted for empty bitubal column and foam-filled monotubal column. The results demonstrate that the foam-filled bitubal configuration has more room to enhance the crashworthiness and can be an efficient energy absorber.

Optimization of inventory management in furniture manufacturing

OpenAIRE

Karkauskas, Justinas

2017-01-01

Aim of research - to present inventory management optimization guidelines for furniture manufacturing company, based on analysis of scientific literature and empirical research. Tasks of the Issue: • Disclose problems of inventory management in furniture manufacturing sector; • To analyze theoretical inventory management decisions; • To develop theoretical inventory management optimization model; • Do empirical research of inventory management and present offers for optimizatio...

Advanced Integrated Multi-Sensor Surveillance (AIMS. Operator Machine Interface (OMI) Definition Study

National Research Council Canada - National Science Library

Baker, Kevin; Youngson, Gord

2007-01-01

To enhance the capability of airborne search and rescue (SAR) and surveillance, particularly at night and in poor weather, a multi sensor electro optical imaging system, the Advanced Integrated Multi sensor Surveillance (AIMS...

Optimization study on inductive-resistive circuit for broadband piezoelectric energy harvesters

Directory of Open Access Journals (Sweden)

Ting Tan

2017-03-01

Full Text Available The performance of cantilever-beam piezoelectric energy harvester is usually analyzed with pure resistive circuit. The optimal performance of such a vibration-based energy harvesting system is limited by narrow bandwidth around its modified natural frequency. For broadband piezoelectric energy harvesting, series and parallel inductive-resistive circuits are introduced. The electromechanical coupled distributed parameter models for such systems under harmonic base excitations are decoupled with modified natural frequency and electrical damping to consider the coupling effect. Analytical solutions of the harvested power and tip displacement for the electromechanical decoupled model are confirmed with numerical solutions for the coupled model. The optimal performance of piezoelectric energy harvesting with inductive-resistive circuits is revealed theoretically as constant maximal power at any excitation frequency. This is achieved by the scenarios of matching the modified natural frequency with the excitation frequency and equating the electrical damping to the mechanical damping. The inductance and load resistance should be simultaneously tuned to their optimal values, which may not be applicable for very high electromechanical coupling systems when the excitation frequency is higher than their natural frequencies. With identical optimal performance, the series inductive-resistive circuit is recommended for relatively small load resistance, while the parallel inductive-resistive circuit is suggested for relatively large load resistance. This study provides a simplified optimization method for broadband piezoelectric energy harvesters with inductive-resistive circuits.

Optimization study on inductive-resistive circuit for broadband piezoelectric energy harvesters

Science.gov (United States)

Tan, Ting; Yan, Zhimiao

2017-03-01

The performance of cantilever-beam piezoelectric energy harvester is usually analyzed with pure resistive circuit. The optimal performance of such a vibration-based energy harvesting system is limited by narrow bandwidth around its modified natural frequency. For broadband piezoelectric energy harvesting, series and parallel inductive-resistive circuits are introduced. The electromechanical coupled distributed parameter models for such systems under harmonic base excitations are decoupled with modified natural frequency and electrical damping to consider the coupling effect. Analytical solutions of the harvested power and tip displacement for the electromechanical decoupled model are confirmed with numerical solutions for the coupled model. The optimal performance of piezoelectric energy harvesting with inductive-resistive circuits is revealed theoretically as constant maximal power at any excitation frequency. This is achieved by the scenarios of matching the modified natural frequency with the excitation frequency and equating the electrical damping to the mechanical damping. The inductance and load resistance should be simultaneously tuned to their optimal values, which may not be applicable for very high electromechanical coupling systems when the excitation frequency is higher than their natural frequencies. With identical optimal performance, the series inductive-resistive circuit is recommended for relatively small load resistance, while the parallel inductive-resistive circuit is suggested for relatively large load resistance. This study provides a simplified optimization method for broadband piezoelectric energy harvesters with inductive-resistive circuits.

Scalar top study: Detector optimization

Indian Academy of Sciences (India)

This scenario could for example occur if the vertex detector is exposed to a large dose of machine background from the accelerator. The optimization of the radius of the innermost layer is an important aspect in the design of a vertex detector for a linear collider. VX32: Five layers and double material thickness (0.128% X0 ...

The diverse aims of science.

Science.gov (United States)

Potochnik, Angela

2015-10-01

There is increasing attention to the centrality of idealization in science. One common view is that models and other idealized representations are important to science, but that they fall short in one or more ways. On this view, there must be an intermediary step between idealized representation and the traditional aims of science, including truth, explanation, and prediction. Here I develop an alternative interpretation of the relationship between idealized representation and the aims of science. I suggest that continuing, widespread idealization calls into question the idea that science aims for truth. If instead science aims to produce understanding, this would enable idealizations to directly contribute to science's epistemic success. I also use the fact of widespread idealization to motivate the idea that science's wide variety aims, epistemic and non-epistemic, are best served by different kinds of scientific products. Finally, I show how these diverse aims—most rather distant from truth—result in the expanded influence of social values on science. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of a standard methodology for optimizing remote visual display for nuclear-maintenance tasks

International Nuclear Information System (INIS)

Clarke, M.M.; Garin, J.; Preston-Anderson, A.

1981-01-01

The aim of the present study is to develop a methodology for optimizing remote viewing systems for a fuel recycle facility (HEF) being designed at Oak Ridge National Laboratory (ORNL). An important feature of this design involves the Remotex concept: advanced servo-controlled master/slave manipulators, with remote television viewing, will totally replace direct human contact with the radioactive environment. Therefore, the design of optimal viewing conditions is a critical component of the overall man/machine system. A methodology has been developed for optimizing remote visual displays for nuclear maintenance tasks. The usefulness of this approach has been demonstrated by preliminary specification of optimal closed circuit TV systems for such tasks

The orientation, principles, priorities and aims of the state environmental policy

International Nuclear Information System (INIS)

1998-01-01

This chapter contains: (A) The orientation and priorities of state environmental policy of the government of the Slovak Republic which were approved 18 November 1993 by the resolution No 339. On the basis of the Strategy, principles and priorities of state environmental policy 70 short-terminable aims up to 1996, next 59 middle-terminable of aims up to years 2000 - 2010 and 33 general and partial long-terminable aims up to 2030 and longer were formulated. The Strategy is determined by next 5 branches oriented priorities: (1) air protection before pollutants and the global environmental safety; (2) organization of sufficiency of drinking water and decreasing of pollution of other waters under permissible limits; (3) soil protection before degeneration and organization of non-defected food-stuffs and other wares; (4) minimization of formation, use and good waste liquidate; (5) preservation of bio-diversity, preservation and rational use of natural reserves and optimization of place structure and use of the country. (B) The principles and priorities of state environmental policy determinate implementation and observance of then principles of the state environmental policy. (C) Total 162 aims of the Strategy of the state environmental policy and next followed programs, projects and measures of the environmental policy of the Slovak Republic can be grouped into 4 blocks: (1) the environmental policy in the protection of air, water and before of risk factors, in the nuclear safety and waste economy (environmental safety; (2) the environmental policy in protection of the nature and the country, protection and use of mineral surroundings, soils and forest;; (3) the environmental policy in the economy; (4) the environmental policy in the guidance, education, public information, organization, control and coordination of the ministration on the environment. These aims are grouped into 10 sectors. (D) The government of the Slovak republic has first National environmental

Association between frequent cardiac resynchronization therapy optimization and long-term clinical response: a post hoc analysis of the Clinical Evaluation on Advanced Resynchronization (CLEAR) pilot study

Science.gov (United States)

Delnoy, Peter Paul; Ritter, Philippe; Naegele, Herbert; Orazi, Serafino; Szwed, Hanna; Zupan, Igor; Goscinska-Bis, Kinga; Anselme, Frederic; Martino, Maria; Padeletti, Luigi

2013-01-01

Aims The long-term clinical value of the optimization of atrioventricular (AVD) and interventricular (VVD) delays in cardiac resynchronization therapy (CRT) remains controversial. We studied retrospectively the association between the frequency of AVD and VVD optimization and 1-year clinical outcomes in the 199 CRT patients who completed the Clinical Evaluation on Advanced Resynchronization study. Methods and results From the 199 patients assigned to CRT-pacemaker (CRT-P) (New York Heart Association, NYHA, class III/IV, left ventricular ejection fraction failure-related hospitalization, NYHA functional class, and Quality of Life score, at 1 year. Systematic CRT optimization was associated with a higher percentage of improved patients based on the composite endpoint (85% in Group 1 vs. 61% in Group 2, P < 0.001), with fewer deaths (3% in Group 1 vs. 14% in Group 2, P = 0.014) and fewer hospitalizations (8% in Group 1 vs. 23% in Group 2, P = 0.007), at 1 year. Conclusion These results further suggest that AVD and VVD frequent optimization (at implant, at 3 and 6 months) is associated with improved long-term clinical response in CRT-P patients. PMID:23493410

Adaptive stimulus optimization for sensory systems neuroscience.

Science.gov (United States)

DiMattina, Christopher; Zhang, Kechen

2013-01-01

In this paper, we review several lines of recent work aimed at developing practical methods for adaptive on-line stimulus generation for sensory neurophysiology. We consider various experimental paradigms where on-line stimulus optimization is utilized, including the classical optimal stimulus paradigm where the goal of experiments is to identify a stimulus which maximizes neural responses, the iso-response paradigm which finds sets of stimuli giving rise to constant responses, and the system identification paradigm where the experimental goal is to estimate and possibly compare sensory processing models. We discuss various theoretical and practical aspects of adaptive firing rate optimization, including optimization with stimulus space constraints, firing rate adaptation, and possible network constraints on the optimal stimulus. We consider the problem of system identification, and show how accurate estimation of non-linear models can be highly dependent on the stimulus set used to probe the network. We suggest that optimizing stimuli for accurate model estimation may make it possible to successfully identify non-linear models which are otherwise intractable, and summarize several recent studies of this type. Finally, we present a two-stage stimulus design procedure which combines the dual goals of model estimation and model comparison and may be especially useful for system identification experiments where the appropriate model is unknown beforehand. We propose that fast, on-line stimulus optimization enabled by increasing computer power can make it practical to move sensory neuroscience away from a descriptive paradigm and toward a new paradigm of real-time model estimation and comparison.

An introduction to optimal control of FBSDE with incomplete information

CERN Document Server

Wang, Guangchen; Xiong, Jie

2018-01-01

This book focuses on maximum principle and verification theorem for incomplete information forward-backward stochastic differential equations (FBSDEs) and their applications in linear-quadratic optimal controls and mathematical finance. Lots of interesting phenomena arising from the area of mathematical finance can be described by FBSDEs. Optimal control problems of FBSDEs are theoretically important and practically relevant. A standard assumption in the literature is that the stochastic noises in the model are completely observed. However, this is rarely the case in real world situations. The optimal control problems under complete information are studied extensively. Nevertheless, very little is known about these problems when the information is not complete. The aim of this book is to fill this gap. This book is written in a style suitable for graduate students and researchers in mathematics and engineering with basic knowledge of stochastic process, optimal control and mathematical finance.

A tool for study of optimal decision trees

KAUST Repository

Alkhalid, Abdulaziz

2010-01-01

The paper describes a tool which allows us for relatively small decision tables to make consecutive optimization of decision trees relative to various complexity measures such as number of nodes, average depth, and depth, and to find parameters and the number of optimal decision trees. © 2010 Springer-Verlag Berlin Heidelberg.

Terminal Control Area Aircraft Scheduling and Trajectory Optimization Approaches

Directory of Open Access Journals (Sweden)

Samà Marcella

2017-01-01

Full Text Available Aviation authorities are seeking optimization methods to better use the available infrastructure and better manage aircraft movements. This paper deals with the realtime scheduling of take-off and landing aircraft at a busy terminal control area and with the optimization of aircraft trajectories during the landing procedures. The first problem aims to reduce the propagation of delays, while the second problem aims to either minimize the travel time or reduce the fuel consumption. Both problems are particularly complex, since the first one is NP-hard while the second one is nonlinear and a combined solution needs to be computed in a short-time during operations. This paper proposes a framework for the lexicographic optimization of the two problems. Computational experiments are performed for the Milano Malpensa airport and show the existing gaps between the performance indicators of the two problems when different lexicographic optimization approaches are considered.

Handbook on modelling for discrete optimization

CERN Document Server

Pitsoulis, Leonidas; Williams, H

2006-01-01

The primary objective underlying the Handbook on Modelling for Discrete Optimization is to demonstrate and detail the pervasive nature of Discrete Optimization. While its applications cut across an incredibly wide range of activities, many of the applications are only known to specialists. It is the aim of this handbook to correct this. It has long been recognized that "modelling" is a critically important mathematical activity in designing algorithms for solving these discrete optimization problems. Nevertheless solving the resultant models is also often far from straightforward. In recent years it has become possible to solve many large-scale discrete optimization problems. However, some problems remain a challenge, even though advances in mathematical methods, hardware, and software technology have pushed the frontiers forward. This handbook couples the difficult, critical-thinking aspects of mathematical modeling with the hot area of discrete optimization. It will be done in an academic handbook treatment...

Shape Optimization for Navier-Stokes Equations with Algebraic Turbulence Model: Existence Analysis

International Nuclear Information System (INIS)

Bulicek, Miroslav; Haslinger, Jaroslav; Malek, Josef; Stebel, Jan

2009-01-01

We study a shape optimization problem for the paper machine headbox which distributes a mixture of water and wood fibers in the paper making process. The aim is to find a shape which a priori ensures the given velocity profile on the outlet part. The mathematical formulation leads to an optimal control problem in which the control variable is the shape of the domain representing the header, the state problem is represented by a generalized stationary Navier-Stokes system with nontrivial mixed boundary conditions. In this paper we prove the existence of solutions both to the generalized Navier-Stokes system and to the shape optimization problem

Site specific optimization of wind turbines energy cost: Iterative approach

International Nuclear Information System (INIS)

Rezaei Mirghaed, Mohammad; Roshandel, Ramin

2013-01-01

Highlights: • Optimization model of wind turbine parameters plus rectangular farm layout is developed. • Results show that levelized cost for single turbine fluctuates between 46.6 and 54.5 $/MW h. • Modeling results for two specific farms reported optimal sizing and farm layout. • Results show that levelized cost of the wind farms fluctuates between 45.8 and 67.2 $/MW h. - Abstract: The present study was aimed at developing a model to optimize the sizing parameters and farm layout of wind turbines according to the wind resource and economic aspects. The proposed model, including aerodynamic, economic and optimization sub-models, is used to achieve minimum levelized cost of electricity. The blade element momentum theory is utilized for aerodynamic modeling of pitch-regulated horizontal axis wind turbines. Also, a comprehensive cost model including capital costs of all turbine components is considered. An iterative approach is used to develop the optimization model. The modeling results are presented for three potential regions in Iran: Khaf, Ahar and Manjil. The optimum configurations and sizing for a single turbine with minimum levelized cost of electricity are presented. The optimal cost of energy for one turbine is calculated about 46.7, 54.5 and 46.6 dollars per MW h in the studied sites, respectively. In addition, optimal size of turbines, annual electricity production, capital cost, and wind farm layout for two different rectangular and square shaped farms in the proposed areas have been recognized. According to the results, optimal system configuration corresponds to minimum levelized cost of electricity about 45.8 to 67.2 dollars per MW h in the studied wind farms

Numerical study of optimal equilibrium cycles for pressurized water reactors

International Nuclear Information System (INIS)

Mahlers, Y.P.

2003-01-01

An algorithm based on simulated annealing and successive linear programming is applied to solve equilibrium cycle optimization problems for pressurized water reactors. In these problems, the core reload scheme is represented by discrete variables, while the cycle length as well as uranium enrichment and loading of burnable poison in each feed fuel assembly are treated as continuous variables. The enrichments are considered to be distinct in all feed fuel assemblies. The number of batches and their sizes are not fixed and also determined by the algorithm. An important feature of the algorithm is that all the parameters are determined by the solution of one optimization problem including both discrete and continuous variables. To search for the best reload scheme, simulated annealing is used. The optimum cycle length as well as uranium enrichment and loading of burnable poison in each feed fuel assembly are determined for each reload pattern examined using successive linear programming. Numerical results of equilibrium cycle optimization for various values of the effective price of electricity and fuel reprocessing cost are studied

A Study of Joint Cost Inclusion in Linear Programming Optimization

Directory of Open Access Journals (Sweden)

P. Armaos

2013-08-01

Full Text Available The concept of Structural Optimization has been a topic or research over the past century. Linear Programming Optimization has proved being the most reliable method of structural optimization. Global advances in linear programming optimization have been recently powered by University of Sheffield researchers, to include joint cost, self-weight and buckling considerations. A joint cost inclusion scopes to reduce the number of joints existing in an optimized structural solution, transforming it to a practically viable solution. The topic of the current paper is to investigate the effects of joint cost inclusion, as this is currently implemented in the optimization code. An extended literature review on this subject was conducted prior to familiarization with small scale optimization software. Using IntelliFORM software, a structured series of problems were set and analyzed. The joint cost tests examined benchmark problems and their consequent changes in the member topology, as the design domain was expanding. The findings of the analyses were remarkable and are being commented further on. The distinct topologies of solutions created by optimization processes are also recognized. Finally an alternative strategy of penalizing joints is presented.

Doses optimization to patients in computed tomography studies

International Nuclear Information System (INIS)

Trujillo Z, F. E.

2010-09-01

in recent years the number of studies of computed tomography has been increased, as well as the technology and methodology of these, while the radiological protection to the patient has not advanced to the same step. The IAEA has implemented the Patients Radiation Protection projects, where one of the areas of more interest is the computed tomography. The present work is a brief summary of the actions to realize for the doses optimization imparted to the patients, obtaining an appropriate diagnostic quality in the images at the same time; as it was presented in the course of the project C-RLA/9/067-001. The results that were obtained between Image Quality and Dose by Radiation that is imparted to the patient are shown, as well s the exposition factors that influence in these, according to the project C-RLA/9/067-001. The main actions for the dose optimization are using tension optimized protocols (kV), of load (m As), of collimation/cut thickness, of inclination of the gantry, of the pitch/displacement by rotation, of the reconstruction algorithm (kernel), according to the diagnostic objective to reach and to the patient physical characteristics (like weight and age), as well as to use protections to shield the sensitive organs (mainly those that do not have clinical interest for the procedure). Conclusion: To establish or to begin to implement, insofar as possible, the IAEA recommendations, relating to the clinical practice of the hospitals in Mexico and to the available equipment s type. (Author)

Post-processing of Monte Carlo simulations for rapid BNCT source optimization studies

International Nuclear Information System (INIS)

Bleuel, D.L.; Chu, W.T.; Donahue, R.J.; Ludewigt, B.A.; Vujic, J.

2000-01-01

A great advantage of some neutron sources, such as accelerator-produced sources, is that they can be tuned to produce different spectra. Unfortunately, optimization studies are often time-consuming and difficult, as they require a lengthy Monte Carlo simulation for each source. When multiple characteristics, such as energy, angle, and spatial distribution of a neutron beam are allowed to vary, an overwhelming number of simulations may be required. Many optimization studies, therefore, suffer from a small number of data points, restrictive treatment conditions, or poor statistics. By scoring pertinent information from every particle tally in a Monte Carlo simulation, then applying appropriate source variable weight factors in a post-processing algorithm; a single simulation can be used to model any number of multiple sources. Through this method, the response to a new source can be modeled in minutes or seconds, rather than hours or days, allowing for the analysis of truly variable source conditions of much greater resolution than is normally possible when a new simulation must be run for each data point in a study. This method has been benchmarked and used to recreate optimization studies in a small fraction of the time spent in the original studies. (author)

In vitro placental model optimization for nanoparticle transport studies

Directory of Open Access Journals (Sweden)

Cartwright L

2012-01-01

Full Text Available Laura Cartwright1, Marie Sønnegaard Poulsen2, Hanne Mørck Nielsen3, Giulio Pojana4, Lisbeth E Knudsen2, Margaret Saunders1, Erik Rytting2,51Bristol Initiative for Research of Child Health (BIRCH, Biophysics Research Unit, St Michael's Hospital, UH Bristol NHS Foundation Trust, Bristol, UK; 2University of Copenhagen, Faculty of Health Sciences, Department of Public Health, 3University of Copenhagen, Faculty of Pharmaceutical Sciences, Department of Pharmaceutics and Analytical Chemistry, Copenhagen, Denmark; 4Department of Environmental Sciences, Informatics and Statistics, University Ca' Foscari Venice, Venice, Italy; 5Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas, USABackground: Advances in biomedical nanotechnology raise hopes in patient populations but may also raise questions regarding biodistribution and biocompatibility, especially during pregnancy. Special consideration must be given to the placenta as a biological barrier because a pregnant woman's exposure to nanoparticles could have significant effects on the fetus developing in the womb. Therefore, the purpose of this study is to optimize an in vitro model for characterizing the transport of nanoparticles across human placental trophoblast cells.Methods: The growth of BeWo (clone b30 human placental choriocarcinoma cells for nanoparticle transport studies was characterized in terms of optimized Transwell® insert type and pore size, the investigation of barrier properties by transmission electron microscopy, tight junction staining, transepithelial electrical resistance, and fluorescein sodium transport. Following the determination of nontoxic concentrations of fluorescent polystyrene nanoparticles, the cellular uptake and transport of 50 nm and 100 nm diameter particles was measured using the in vitro BeWo cell model.Results: Particle size measurements, fluorescence readings, and confocal microscopy indicated both cellular uptake of

Is Fitts' law continuous in discrete aiming?

Directory of Open Access Journals (Sweden)

Rita Sleimen-Malkoun

Full Text Available The lawful continuous linear relation between movement time and task difficulty (i.e., index of difficulty; ID in a goal-directed rapid aiming task (Fitts' law has been recently challenged in reciprocal performance. Specifically, a discontinuity was observed at critical ID and was attributed to a transition between two distinct dynamic regimes that occurs with increasing difficulty. In the present paper, we show that such a discontinuity is also present in discrete aiming when ID is manipulated via target width (experiment 1 but not via target distance (experiment 2. Fitts' law's discontinuity appears, therefore, to be a suitable indicator of the underlying functional adaptations of the neuro-muscular-skeletal system to task properties/requirements, independently of reciprocal or discrete nature of the task. These findings open new perspectives to the study of dynamic regimes involved in discrete aiming and sensori-motor mechanisms underlying the speed-accuracy trade-off.

KEY DRIVERS OF OPTIMAL SPECIAL EDUCATION NEEDS PROVISION: AN ENGLISH STUDY

Directory of Open Access Journals (Sweden)

Saneeya QURESHI

2015-11-01

Full Text Available Background: The aim of this paper is to argue that there are a number of key drivers for Special Educational Needs (SEN provision that have to be met by Special Educational Needs Coordinators (SENCOs and teaching professionals so as to ensure optimal provision and inclusion for children with SEN in mainstream primary schools. Although the research has been carried out in England, there is a significant European Dimension to the issue, as a similar role to that of SENCOs in respect of SEN management already exists in countries such as Finland and Ireland, and is being considered in Italy. Methods: This paper focuses on the data gathered for the purpose of the author’s doctoral research in England, through questionnaires and interviews with SENCOs, head teachers and teachers. Thematic analysis was used to explore key drivers of SEN provision by practitioners who support children with SEN. Results: Data illustrate that the key drivers of SEN provision include time; teacher openness to change; target setting; evidence of tried interventions; empowerment; decision-making and approachability. The implementation of such drivers depend largely on practitioner skills and competencies. Conclusion: The main conclusion within this paper is to develop points of reference for planning and practice, with illustrations of optimal provision by all practitioners who work with children with SEN.

Computational and experimental optimization of the exhaust air energy recovery wind turbine generator

International Nuclear Information System (INIS)

Tabatabaeikia, Seyedsaeed; Ghazali, Nik Nazri Bin Nik; Chong, Wen Tong; Shahizare, Behzad; Izadyar, Nima; Esmaeilzadeh, Alireza; Fazlizan, Ahmad

2016-01-01

Highlights: • Studying the viability of harvesting wasted energy by exhaust air recovery generator. • Optimizing the design using response surface methodology. • Validation of optimization and computation result by performing experimental tests. • Investigation of flow behaviour using computational fluid dynamic simulations. • Performing the technical and economic study of the exhaust air recovery generator. - Abstract: This paper studies the optimization of an innovative exhaust air recovery wind turbine generator through computational fluid dynamic (CFD) simulations. The optimization strategy aims to optimize the overall system energy generation and simultaneously guarantee that it does not violate the cooling tower performance in terms of decreasing airflow intake and increasing fan motor power consumption. The wind turbine rotor position, modifying diffuser plates, and introducing separator plates to the design are considered as the variable factors for the optimization. The generated power coefficient is selected as optimization objective. Unlike most of previous optimizations in field of wind turbines, in this study, response surface methodology (RSM) as a method of analytical procedures optimization has been utilised by using multivariate statistic techniques. A comprehensive study on CFD parameters including the mesh resolution, the turbulence model and transient time step values is presented. The system is simulated using SST K-ω turbulence model and then both computational and optimization results are validated by experimental data obtained in laboratory. Results show that the optimization strategy can improve the wind turbine generated power by 48.6% compared to baseline design. Meanwhile, it is able to enhance the fan intake airflow rate and decrease fan motor power consumption. The obtained optimization equations are also validated by both CFD and experimental results and a negligible deviation in range of 6–8.5% is observed.

Effects of upper body parameters on biped walking efficiency studied by dynamic optimization

Directory of Open Access Journals (Sweden)

Kang An

2016-12-01

Full Text Available Walking efficiency is one of the considerations for designing biped robots. This article uses the dynamic optimization method to study the effects of upper body parameters, including upper body length and mass, on walking efficiency. Two minimal actuations, hip joint torque and push-off impulse, are used in the walking model, and minimal constraints are set in a free search using the dynamic optimization. Results show that there is an optimal solution of upper body length for the efficient walking within a range of walking speed and step length. For short step length, walking with a lighter upper body mass is found to be more efficient and vice versa. It is also found that for higher speed locomotion, the increase of the upper body length and mass can make the walking gait optimal rather than other kind of gaits. In addition, the typical strategy of an optimal walking gait is that just actuating the swing leg at the beginning of the step.

Optimization Study of Shaft Tubular Turbine in a Bidirectional Tidal Power Station

Directory of Open Access Journals (Sweden)

Xinfeng Ge

2013-01-01

Full Text Available The shaft tubular turbine is a form of tidal power station which can provide bidirectional power. Efficiency is an important turbine performance indicator. To study the influence of runner design parameters on efficiency, a complete 3D flow-channel model of a shaft tubular turbine was developed, which contains the turbine runner, guide vanes, and flow passage and was integrated with hybrid grids calculated by steady-state calculation methods. Three aspects of the core component (turbine runner were optimized by numerical simulation. All the results were then verified by experiments. It was shown that curved-edge blades are much better than straight-edge blades; the optimal blade twist angle is 7°, and the optimal distance between the runner and the blades is 0.75–1.25 times the diameter of the runner. Moreover, the numerical simulation results matched the experimental data very well, which also verified the correctness of the optimal results.

Optimization of ultrasonic arrays design and setting using a differential evolution

International Nuclear Information System (INIS)

Puel, B.; Chatillon, S.; Calmon, P.; Lesselier, D.

2011-01-01

Optimization of both design and setting of phased arrays could be not so easy when they are performed manually via parametric studies. An optimization method based on an Evolutionary Algorithm and numerical simulation is proposed and evaluated. The Randomized Adaptive Differential Evolution has been adapted to meet the specificities of the non-destructive testing applications. In particular, the solution of multi-objective problems is aimed at with the implementation of the concept of pareto-optimal sets of solutions. The algorithm has been implemented and connected to the ultrasonic simulation modules of the CIVA software used as forward model. The efficiency of the method is illustrated on two realistic cases of application: optimization of the position and delay laws of a flexible array inspecting a nozzle, considered as a mono-objective problem; and optimization of the design of a surrounded array and its delay laws, considered as a constrained bi-objective problem. (authors)

Optimal control novel directions and applications

CERN Document Server

Aronna, Maria; Kalise, Dante

2017-01-01

Focusing on applications to science and engineering, this book presents the results of the ITN-FP7 SADCO network’s innovative research in optimization and control in the following interconnected topics: optimality conditions in optimal control, dynamic programming approaches to optimal feedback synthesis and reachability analysis, and computational developments in model predictive control. The novelty of the book resides in the fact that it has been developed by early career researchers, providing a good balance between clarity and scientific rigor. Each chapter features an introduction addressed to PhD students and some original contributions aimed at specialist researchers. Requiring only a graduate mathematical background, the book is self-contained. It will be of particular interest to graduate and advanced undergraduate students, industrial practitioners and to senior scientists wishing to update their knowledge.

Optimally Stopped Optimization

Science.gov (United States)

Vinci, Walter; Lidar, Daniel

We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known, and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time, optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark the performance of a D-Wave 2X quantum annealer and the HFS solver, a specialized classical heuristic algorithm designed for low tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N = 1098 variables, the D-Wave device is between one to two orders of magnitude faster than the HFS solver.

Optimization of Mangala Hydropower Station, Pakistan, using Optimization Techniques

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Zaman Muhammad

2017-01-01

Full Text Available Hydropower generation is one of the key element in the economy of a country. The present study focusses on the optimal electricity generation from the Mangla reservoir in Pakistan. A mathematical model has been developed for the Mangla hydropower station and particle swarm and genetic algorithm optimization techniques were applied at this model for optimal electricity generation. Results revealed that electricity production increases with the application of optimization techniques at the proposed mathematical model. Genetic Algorithm can produce maximum electricity than Particle swarm optimization but the time of execution of particle swarm optimization is much lesser than the Genetic algorithm. Mangla hydropower station can produce up to 59*109 kWh electricity by using the flows optimally than 47*108 kWh production from traditional methods.

The optimal design of UAV wing structure

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Długosz, Adam; Klimek, Wiktor

2018-01-01

The paper presents an optimal design of UAV wing, made of composite materials. The aim of the optimization is to improve strength and stiffness together with reduction of the weight of the structure. Three different types of functionals, which depend on stress, stiffness and the total mass are defined. The paper presents an application of the in-house implementation of the evolutionary multi-objective algorithm in optimization of the UAV wing structure. Values of the functionals are calculated on the basis of results obtained from numerical simulations. Numerical FEM model, consisting of different composite materials is created. Adequacy of the numerical model is verified by results obtained from the experiment, performed on a tensile testing machine. Examples of multi-objective optimization by means of Pareto-optimal set of solutions are presented.

The Effects of Optimism and Gratitude on Physical Activity, Biomarkers, and Readmissions Following an Acute Coronary Syndrome: The Gratitude Research in Acute Coronary Events (GRACE) Study

Science.gov (United States)

Huffman, Jeff C.; Beale, Eleanor E.; Celano, Christopher M.; Beach, Scott R.; Belcher, Arianna M.; Moore, Shannon V.; Suarez, Laura; Motiwala, Shweta R.; Gandhi, Parul U.; Gaggin, Hanna; Januzzi, James L.

2015-01-01

Background Positive psychological constructs, such as optimism, are associated with beneficial health outcomes. However, no study has separately examined the effects of multiple positive psychological constructs on behavioral, biological, and clinical outcomes after an acute coronary syndrome (ACS). Accordingly, we aimed to investigate associations of baseline optimism and gratitude with subsequent physical activity, prognostic biomarkers, and cardiac rehospitalizations in post-ACS patients. Methods and Results Participants were enrolled during admission for ACS and underwent assessments at baseline (2 weeks post-ACS) and follow-up (6 months later). Associations between baseline positive psychological constructs and subsequent physical activity/biomarkers were analyzed using multivariable linear regression. Associations between baseline positive constructs and 6-month rehospitalizations were assessed via multivariable Cox regression. Overall, 164 participants enrolled and completed the baseline 2-week assessments. Baseline optimism was significantly associated with greater physical activity at 6 months (n=153; β=102.5; 95% confidence interval [13.6-191.5]; p=.024), controlling for baseline activity and sociodemographic, medical, and negative psychological covariates. Baseline optimism was also associated with lower rates of cardiac readmissions at 6 months (N=164), controlling for age, gender, and medical comorbidity (hazard ratio=.92; 95% confidence interval [.86-.98]; p=.006). There were no significant relationships between optimism and biomarkers. Gratitude was minimally associated with post-ACS outcomes. Conclusions Post-ACS optimism, but not gratitude, was prospectively and independently associated with superior physical activity and fewer cardiac readmissions. Whether interventions that target optimism can successfully increase optimism or improve cardiovascular outcomes in post-ACS patients is not yet known, but can be tested in future studies. Clinical

TRADING-OFF CONSTRAINTS IN THE PUMP SCHEDULING OPTIMIZATION OF WATER DISTRIBUTION NETWORKS

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Gencer Genço\\u011Flu

2016-01-01

Full Text Available Pumps are one of the essential components of water supply systems. Depending of the topography, a water supply system may completely rely on pumping. They may consume non-negligible amount of water authorities' budgets during operation. Besides their energy costs, maintaining the healthiness of pumping systems is another concern for authorities. This study represents a multi-objective optimization method for pump scheduling problem. The optimization objective contains hydraulic and operational constraints. Switching of pumps and usage of electricity tariff are assumed to be key factors for operational reliability and energy consumption and costs of pumping systems. The local optimals for systems operational reliability, energy consumptions and energy costs are investigated resulting from trading-off pump switch and electricity tariff constraints within given set of boundary conditions. In the study, a custom made program is employed that combines genetic algorithm based optimization module with hydraulic network simulation software -EPANET. Developed method is applied on the case study network; N8-3 pressure zone of the Northern Supply of Ankara (Turkey Water Distribution Network. This work offers an efficient method for water authorities aiming to optimize pumping schedules considering expenditures and operational reliability mutually.

Intermediate levels of hippocampal activity appear optimal for associative memory formation.

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Xiao Liu

Full Text Available BACKGROUND: It is well established that hippocampal activity is positively related to effective associative memory formation. However, in biological systems often optimal levels of activity are contrasted by both sub- and supra-optimal levels. Sub-optimal levels of hippocampal activity are commonly attributed to unsuccessful memory formation, whereas the supra-optimal levels of hippocampal activity related to unsuccessful memory formation have been rarely studied. It is still unclear under what circumstances such supra-optimal levels of hippocampal activity occur. To clarify this issue, we aimed at creating a condition, in which supra-optimal hippocampal activity is associated with encoding failure. We assumed that such supra-optimal activity occurs when task-relevant information is embedded in task-irrelevant, distracting information, which can be considered as noise. METHODOLOGY/PRINCIPAL FINDINGS: In the present fMRI study, we probed neural correlates of associative memory formation in a full-factorial design with associative memory (subsequently remembered versus forgotten and noise (induced by high versus low distraction as factors. Results showed that encoding failure was associated with supra-optimal activity in the high-distraction condition and with sub-optimal activity in the low distraction condition. Thus, we revealed evidence for a bell-shape function relating hippocampal activity with associative encoding success. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that intermediate levels of hippocampal activity are optimal while both too low and too high levels appear detrimental for associative memory formation. Supra-optimal levels of hippocampal activity seem to occur when task-irrelevant information is added to task-relevant signal. If such task-irrelevant noise is reduced adequately, hippocampal activity is lower and thus optimal for associative memory formation.

Web malware spread modelling and optimal control strategies

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Liu, Wanping; Zhong, Shouming

2017-02-01

The popularity of the Web improves the growth of web threats. Formulating mathematical models for accurate prediction of malicious propagation over networks is of great importance. The aim of this paper is to understand the propagation mechanisms of web malware and the impact of human intervention on the spread of malicious hyperlinks. Considering the characteristics of web malware, a new differential epidemic model which extends the traditional SIR model by adding another delitescent compartment is proposed to address the spreading behavior of malicious links over networks. The spreading threshold of the model system is calculated, and the dynamics of the model is theoretically analyzed. Moreover, the optimal control theory is employed to study malware immunization strategies, aiming to keep the total economic loss of security investment and infection loss as low as possible. The existence and uniqueness of the results concerning the optimality system are confirmed. Finally, numerical simulations show that the spread of malware links can be controlled effectively with proper control strategy of specific parameter choice.

On the application of artificial bee colony (ABC algorithm for optimization of well placements in fractured reservoirs; efficiency comparison with the particle swarm optimization (PSO methodology

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Behzad Nozohour-leilabady

2016-03-01

Full Text Available The application of a recent optimization technique, the artificial bee colony (ABC, was investigated in the context of finding the optimal well locations. The ABC performance was compared with the corresponding results from the particle swarm optimization (PSO algorithm, under essentially similar conditions. Treatment of out-of-boundary solution vectors was accomplished via the Periodic boundary condition (PBC, which presumably accelerates convergence towards the global optimum. Stochastic searches were initiated from several random staring points, to minimize starting-point dependency in the established results. The optimizations were aimed at maximizing the Net Present Value (NPV objective function over the considered oilfield production durations. To deal with the issue of reservoir heterogeneity, random permeability was applied via normal/uniform distribution functions. In addition, the issue of increased number of optimization parameters was address, by considering scenarios with multiple injector and producer wells, and cases with deviated wells in a real reservoir model. The typical results prove ABC to excel PSO (in the cases studied after relatively short optimization cycles, indicating the great premise of ABC methodology to be used for well-optimization purposes.

An Optimization of the Risk Management using Derivatives

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Ovidiu ŞONTEA

2011-07-01

Full Text Available This article aims to provide a process that can be used in financial risk management by resolving problems of minimizing the risk measure (VaR using derivatives products, bonds and options. This optimization problem was formulated in the hedging situation of a portfolio formed by an active and a put option on this active, respectively a bond and an option on this bond. In the first optimization problem we will obtain the coverage ratio of the optimal price for the excertion of the option which is in fact the relative cost of the option’s value. In the second optimization problem we obtained optimal exercise price for a put option which is to support a bond.

Aims and tasks in parental caregiving for children receiving palliative care at home: a qualitative study.

Science.gov (United States)

Verberne, Lisa M; Kars, Marijke C; Schouten-van Meeteren, Antoinette Y N; Bosman, Diederik K; Colenbrander, Derk A; Grootenhuis, Martha A; van Delden, Johannes J M

2017-03-01

In paediatric palliative care (PPC), parents are confronted with increasing caregiving demands. More children are cared for at home, and the need for PPC of children is lengthened due to technical and medical improvements. Therefore, a clear understanding of the content of parental caregiving in PPC becomes increasingly important. The objective is to gain insight into parental caregiving based on the lived experience of parents with a child with a life-limiting disease. An interpretative qualitative study using thematic analysis was performed. Single or repeated interviews were undertaken with 42 parents of 24 children with a malignant or non-malignant disease, receiving PPC. Based on their ambition to be a 'good parent', parents caring for a child with a life-limiting disease strived for three aims: controlled symptoms and controlled disease, a life worth living for their ill child and family balance. These aims resulted in four tasks that parents performed: providing basic and complex care, organising good quality care and treatment, making sound decisions while managing risks and organising a good family life. Parents need early explanation from professionals about balancing between their aims and the related tasks to get a grip on their situation and to prevent becoming overburdened. What is Known: • In paediatric palliative care, parents are confronted with increasing caregiving demands. • Parenting is often approached from the perspective of stress. What is New: • Parents strive for three aims: controlled symptoms and controlled disease, a life worth living for their child and family balance. • Parents perform four tasks: providing basic and complex care, organising good quality care, making decisions while managing risks and organising a good family life. • Professionals need insight into the parents' aims and tasks from the parental perspective to strengthen parents' resilience.

Analysis and Optimization of Distributed Real-Time Embedded Systems

DEFF Research Database (Denmark)

Pop, Paul; Eles, Petru; Peng, Zebo

2006-01-01

and scheduling policies. In this context, the task of designing such systems is becoming increasingly difficult. The success of new adequate design methods depends on the availability of efficient analysis as well as optimization techniques. In this paper, we present both analysis and optimization approaches...... characteristic to this class of systems: mapping of functionality, the optimization of the access to the communication channel, and the assignment of scheduling policies to processes. Optimization heuristics aiming at producing a schedulable system, with a given amount of resources, are presented....

Multi-objective optimization under uncertainty for sheet metal forming

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Lafon Pascal

2016-01-01

Full Text Available Aleatory uncertainties in material properties, blank thickness and friction condition are inherent and irreducible variabilities in sheet metal forming. Optimal design configurations, which are obtained by conventional design optimization methods, are not always able to meet the desired targets due to the effect of uncertainties. This paper proposes a multi-objective robust design optimization that aims to tackle this problem. Results obtained on a U shape draw bending benchmark show that spring-back effect can be controlled by optimizing process parameters.

Radiation therapy for painful bone metastases. Aiming at optimal treatment schedules

International Nuclear Information System (INIS)

Murakami, Ryuji; Saito, Ryuichi; Miyazaki, Toshiyuki; Takahashi, Mutsumasa

2001-01-01

The purpose of this study is to evaluate the pain relief obtained by radiation therapy for painful bone metastases, with a special regard to general condition. Between June 1998 and May 2000, 54 patients with 86 painful bone metastases were treated with radiation therapy whose effects could be evaluated for a minimum period of 6 months or until death. Treatment schedules were 3 Gy/fraction/day (30-36 Gy/10-12 fractions) in usual cases (61 lesions), 4-8 Gy/fraction/day (8-20 Gy/1-5 fractions) in patients with a poor general condition (9 lesions), and 2 Gy/fraction/day (40-50 Gy/20-25 fractions) in lesions with a large radiation field (16 lesions). Complete pain relief without medication (CR) was achieved in 40 lesions (47%). Significant predictors for CR were primary site (p=0.0003), performance status (p=0.0060), pain score (p=00190), narcotic score (p<0.0001), and prognosis (p<0.0001), but no difference was found in CR among treatment schedules. No evidence of severe radiation-induced complication was seen. General condition (performance status and prognosis) has an influence on pain relief. Compared with the daily 2 Gy protocol, the daily 3 Gy protocol has the advantage of shorter treatment time. The treatment schedule should be assessed in patients with a large radiation field and/or poor general condition. Especially for the patients with poor general condition, combined pain medication should be considered. (author)

Determination of Optimal Flow Paths for Safety Injection According to Accident Conditions

Energy Technology Data Exchange (ETDEWEB)

Yoo, Kwae Hwan; Kim, Ju Hyun; Kim, Dong Yeong; Na, Man Gyun [Chosun Univ., Gwangju (Korea, Republic of); Hur, Seop; Kim, Changhwoi [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

In case severe accidents happen, major safety parameters of nuclear reactors are rapidly changed. Therefore, operators are unable to respond appropriately. This situation causes the human error of operators that led to serious accidents at Chernobyl. In this study, we aimed to develop an algorithm that can be used to select the optimal flow path for cold shutdown in serious accidents, and to recover an NPP quickly and efficiently from the severe accidents. In order to select the optimal flow path, we applied a Dijkstra algorithm. The Dijkstra algorithm is used to find the path of minimum total length between two given nodes and needs a weight (or length) matrix. In this study, the weight between nodes was calculated from frictional and minor losses inside pipes. That is, the optimal flow path is found so that the pressure drop between a starting node (water source) and a destination node (position that cooling water is injected) is minimized. In case a severe accident has happened, if we inject cooling water through the optimized flow path, then the nuclear reactor will be safely and effectively returned into the cold shutdown state. In this study, we have analyzed the optimal flow paths for safety injection as a preliminary study for developing an accident recovery system. After analyzing the optimal flow path using the Dijkstra algorithm, and the optimal flow paths were selected by calculating the head loss according to path conditions.

Dispositional optimism and coping strategies in patients with a kidney transplant.

Science.gov (United States)

Costa-Requena, Gemma; Cantarell-Aixendri, M Carmen; Parramon-Puig, Gemma; Serón-Micas, Daniel

2014-01-01

 Dispositional optimism is a personal resource that determines the coping style and adaptive response to chronic diseases. The aim of this study was to assess the correlations between dispositional optimism and coping strategies in patients with recent kidney transplantation and evaluate the differences in the use of coping strategies in accordance with the level of dispositional optimism.  Patients who were hospitalised in the nephrology department were selected consecutively after kidney transplantation was performed. The evaluation instruments were the Life Orientation Test-Revised, and the Coping Strategies Inventory. The data were analysed with central tendency measures, correlation analyses and means were compared using Student’s t-test.   66 patients with a kidney transplant participated in the study. The coping styles that characterised patients with a recent kidney transplantation were Social withdrawal and Problem avoidance. Correlations between dispositional optimism and coping strategies were significant in a positive direction in Problem-solving (p<.05) and Cognitive restructuring (p<.01), and inversely with Self-criticism (p<.05). Differences in dispositional optimism created significant differences in the Self-Criticism dimension (t=2.58; p<.01).  Dispositional optimism scores provide differences in coping responses after kidney transplantation. Moreover, coping strategies may influence the patient’s perception of emotional wellbeing after kidney transplantation.

Investigation of Cost and Energy Optimization of Drinking Water Distribution Systems.

Science.gov (United States)

Cherchi, Carla; Badruzzaman, Mohammad; Gordon, Matthew; Bunn, Simon; Jacangelo, Joseph G

2015-11-17

Holistic management of water and energy resources through energy and water quality management systems (EWQMSs) have traditionally aimed at energy cost reduction with limited or no emphasis on energy efficiency or greenhouse gas minimization. This study expanded the existing EWQMS framework and determined the impact of different management strategies for energy cost and energy consumption (e.g., carbon footprint) reduction on system performance at two drinking water utilities in California (United States). The results showed that optimizing for cost led to cost reductions of 4% (Utility B, summer) to 48% (Utility A, winter). The energy optimization strategy was successfully able to find the lowest energy use operation and achieved energy usage reductions of 3% (Utility B, summer) to 10% (Utility A, winter). The findings of this study revealed that there may be a trade-off between cost optimization (dollars) and energy use (kilowatt-hours), particularly in the summer, when optimizing the system for the reduction of energy use to a minimum incurred cost increases of 64% and 184% compared with the cost optimization scenario. Water age simulations through hydraulic modeling did not reveal any adverse effects on the water quality in the distribution system or in tanks from pump schedule optimization targeting either cost or energy minimization.

A two-parameter preliminary optimization study for a fluidized-bed boiler through a comprehensive mathematical simulator

Energy Technology Data Exchange (ETDEWEB)

Rabi, Jose A.; Souza-Santos, Marcio L. de [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mails: jrabi@fem.unicamp.br; dss@fem.unicamp.br

2000-07-01

Modeling and simulation of fluidized-bed equipment have demonstrated their importance as a tool for design and optimization of industrial equipment. Accordingly, this work carries on an optimization study of a fluidized-bed boiler with the aid of a comprehensive mathematical simulator. The configuration data of the boiler are based on a particular Babcock and Wilcox Co. (USA) test unit. Due to their importance, the number of tubes in the bed section and the air excess are chosen as the parameters upon which the optimization study is based. On their turn, the fixed-carbon conversion factor and the boiler efficiency are chosen as two distinct optimization objectives. The results from both preliminary searches are compared. The present work is intended to be just a study on possible routes for future optimization of larger boilers. Nonetheless, the present discussion might give some insight on the equipment behavior. (author)

A case study of optimization in the decision process: Siting groundwater monitoring wells

International Nuclear Information System (INIS)

Cardwell, H.; Huff, D.; Douthitt, J.; Sale, M.

1993-12-01

Optimization is one of the tools available to assist decision makers in balancing multiple objectives and concerns. In a case study of the siting decision for groundwater monitoring wells, we look at the influence of the optimization models on the decisions made by the responsible groundwater specialist. This paper presents a multi-objective integer programming model for determining the location of monitoring wells associated with a groundwater pump-and-treat remediation. After presenting the initial optimization results, we analyze the actual decision and revise the model to incorporate elements of the problem that were later identified as important in the decision-making process. The results of a revised model are compared to the actual siting plans, the recommendations from the initial optimization runs, and the initial monitoring network proposed by the decision maker

Optimization of Organic Rankine Cycles for Off-Shore Applications

DEFF Research Database (Denmark)

Pierobon, Leonardo; Larsen, Ulrik; Nguyen, Tuong-Van

2013-01-01

and the thermal efficiency of the cycle can be maximized. This paper is aimed at finding the most optimal ORC tailored for off-shore applications using an optimization procedure based on the genetic algorithm. Numerous working fluids are screened through, considering mainly thermal efficiency, but also other...

[Optimal solution and analysis of muscular force during standing balance].

Science.gov (United States)

Wang, Hongrui; Zheng, Hui; Liu, Kun

2015-02-01

The present study was aimed at the optimal solution of the main muscular force distribution in the lower extremity during standing balance of human. The movement musculoskeletal system of lower extremity was simplified to a physical model with 3 joints and 9 muscles. Then on the basis of this model, an optimum mathematical model was built up to solve the problem of redundant muscle forces. Particle swarm optimization (PSO) algorithm is used to calculate the single objective and multi-objective problem respectively. The numerical results indicated that the multi-objective optimization could be more reasonable to obtain the distribution and variation of the 9 muscular forces. Finally, the coordination of each muscle group during maintaining standing balance under the passive movement was qualitatively analyzed using the simulation results obtained.

Psychological distress, optimism and general health in breast cancer survivors: a data linkage study using the Scottish Health Survey.

Science.gov (United States)

Leung, Janni; Atherton, Iain; Kyle, Richard G; Hubbard, Gill; McLaughlin, Deirdre

2016-04-01

The aim of this study is to examine the association between optimism and psychological distress in women with breast cancer after taking into account their self-rated general health. Data were aggregated from the Scottish Health Survey (2008 to 2011) to derive a nationally representative sample of 12,255 women (11,960 cancer-free controls, and 295 breast cancer cases identified from linked cancer registry data). The explanatory variables were optimism and general health, and the outcome variable was symptoms of psychological distress. Logistic regression analyses were conducted, with optimism entered in step 1 and general health entered in step 2. In an unadjusted model, higher levels of optimism were associated with lower odds of psychological distress in both the control group (OR = 0. 57, 95 % CI = 0.51-0.60) and breast cancer group (OR = 0. 64, 95 % CI = 0.47-0.88). However, in a model adjusting for general health, optimism was associated with lower odds of psychological distress only in the control group (OR = 0.50, 95 % CI = 0.44-0.57), but not significantly in the breast cancer group (OR = 1.15, 95 % CI = 0.32-4.11). In the breast cancer group, poor general health was a stronger associate of psychological distress (OR = 4. 98, 95 % CI = 1.32-18.75). Results were consistent after adjusting for age, years since breast cancer diagnosis, survey year, socioeconomic status, education, marital status, body mass index, smoking status, and alcohol consumption. This research confirms the value of multicomponent supportive care interventions for women with breast cancer. Specifically, it suggests that following breast cancer diagnosis, health care professionals need to provide advice and signpost to services that assist women to maintain or improve both their psychological and general health.

Operation Characteristics Optimization of Low Power Three-Phase Asynchronous Motors

Directory of Open Access Journals (Sweden)

VLAD, I.

2014-02-01

Full Text Available Most published papers on low power asynchronous motors were aimed to achieve better operational performances in different operating conditions. The optimal design of the general-purpose motors requires searching and selecting an electric machine to meet minimum operating costs criterion and certain customer imposed restrictive conditions. In this paper, there are many significant simulations providing qualitative and quantitative information on reducing active and reactive energy losses in motors, and on parameters and constructive solution. The optimization study applied the minimal operating costs criterion, and it took into account the starting restrictive conditions. Thirteen variables regarding electromagnetic stresses and main constructive dimensions were considered. The operating costs of the optimized motor decreased with 25.6%, as compared to the existing solution. This paper can be a practical and theoretical support for the development and implementation of modern design methods, based on theoretical and experimental study of stationary and transient processes in low power motors, to increase efficiency and power factor.

Evaluating the optimal timing of surgical antimicrobial prophylaxis: study protocol for a randomized controlled trial.

Science.gov (United States)

Mujagic, Edin; Zwimpfer, Tibor; Marti, Walter R; Zwahlen, Marcel; Hoffmann, Henry; Kindler, Christoph; Fux, Christoph; Misteli, Heidi; Iselin, Lukas; Lugli, Andrea Kopp; Nebiker, Christian A; von Holzen, Urs; Vinzens, Fabrizio; von Strauss, Marco; Reck, Stefan; Kraljević, Marko; Widmer, Andreas F; Oertli, Daniel; Rosenthal, Rachel; Weber, Walter P

2014-05-24

Surgical site infections are the most common hospital-acquired infections among surgical patients. The administration of surgical antimicrobial prophylaxis reduces the risk of surgical site infections . The optimal timing of this procedure is still a matter of debate. While most studies suggest that it should be given as close to the incision time as possible, others conclude that this may be too late for optimal prevention of surgical site infections. A large observational study suggests that surgical antimicrobial prophylaxis should be administered 74 to 30 minutes before surgery. The aim of this article is to report the design and protocol of a randomized controlled trial investigating the optimal timing of surgical antimicrobial prophylaxis. In this bi-center randomized controlled trial conducted at two tertiary referral centers in Switzerland, we plan to include 5,000 patients undergoing general, oncologic, vascular and orthopedic trauma procedures. Patients are randomized in a 1:1 ratio into two groups: one receiving surgical antimicrobial prophylaxis in the anesthesia room (75 to 30 minutes before incision) and the other receiving surgical antimicrobial prophylaxis in the operating room (less than 30 minutes before incision). We expect a significantly lower rate of surgical site infections with surgical antimicrobial prophylaxis administered more than 30 minutes before the scheduled incision. The primary outcome is the occurrence of surgical site infections during a 30-day follow-up period (one year with an implant in place). When assuming a 5% surgical site infection risk with administration of surgical antimicrobial prophylaxis in the operating room, the planned sample size has an 80% power to detect a relative risk reduction for surgical site infections of 33% when administering surgical antimicrobial prophylaxis in the anesthesia room (with a two-sided type I error of 5%). We expect the study to be completed within three years. The results of this

An exploration of factors related to dissemination of and exposure to internet-delivered behavior change interventions aimed at adults: a Delphi study approach.

Science.gov (United States)

Brouwer, Wendy; Oenema, Anke; Crutzen, Rik; de Nooijer, Jascha; de Vries, Nanne K; Brug, Johannes

2008-04-16

The Internet is an attractive medium for delivering individualized, computer-tailored behavior change interventions to large numbers of people. However, the actual numbers of people reached seem to fall behind the high expectations. Insight into factors that determine use of and exposure to these Internet interventions is important to be able to increase the reach and improve exposure. The aim was to identify potentially important factors that determine whether adults visit an Internet-delivered behavior change intervention, extend their visit, and revisit the intervention. A systematic, three-round Delphi study was conducted among national and international experts from Internet intervention research and practice, e-marketing/e-commerce, Web design, and technical website development. In the first round, 30 experts completed a structured, open-ended online questionnaire assessing factors that were, in their opinion, important for a first visit, an extended visit, a revisit and for effective promotion strategies. Based on the responses in this first questionnaire, a closed-ended online questionnaire was developed for use in the second round. A total of 233 experts were invited to complete this questionnaire. Median and interquartile deviation (IQD) scores were computed to calculate agreement and consensus on the importance of the factors. The factors for which no consensus was obtained (IQD > 1) were included in the third-round questionnaire. Factors with a median score of six or higher and with an IQD word-of-mouth by family and friends, a publicity campaign with simultaneous use of various mass media, and recommendation by health professionals, were indicated as effective ways to encourage adults to visit an Internet intervention. This systematic study identified important factors related to the dissemination of and exposure to Internet interventions aimed at adults. In order to improve optimal use of and exposure to Internet interventions, potential users may

Studying medium effects with the optimized δ expansion

International Nuclear Information System (INIS)

Krein, G.; Menezes, D.P.; Nielsen, M.; Pinto, M.B.

1995-04-01

The possibility of using the optimized δ expansion for studying medium effects on hadronic properties in quark or nuclear matter is investigated. The δ expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclear matter. The results obtained with the δ expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the δ expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs

Studying medium effects with the optimized {delta} expansion

Energy Technology Data Exchange (ETDEWEB)

Krein, G [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Menezes, D P [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Fisica; Nielsen, M [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Pinto, M B [Montpellier-2 Univ., 34 (France). Lab. de Physique Mathematique

1995-04-01

The possibility of using the optimized {delta} expansion for studying medium effects on hadronic properties in quark or nuclear matter is investigated. The {delta} expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclear matter. The results obtained with the {delta} expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the {delta} expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs.

Early lactate clearance in septic patients with elevated lactate levels admitted from the emergency department to intensive care: time to aim higher?

Science.gov (United States)

Walker, Craig A; Griffith, David M; Gray, Alasdair J; Datta, Deepankar; Hay, Alasdair W

2013-10-01

Septic patients with hyperlactatemia have increased mortality rates, irrespective of hemodynamic and oxygen-derived variables. The aims of the study are the following: (1) to ascertain whether lactate clearance (LC) (percentage change in lactate over unit time) predicts mortality in septic patients admitted to intensive care directly from the emergency department and (2) to calculate the optimal "cut-off" value for mortality prediction. Three-year retrospective observational study of consecutive patients with severe sepsis and septic shock admitted to intensive care from the emergency department of a tertiary UK hospital. We calculated 6-hour LC, performed receiver operating characteristic analyses to calculate optimal cut-off values for initial lactate and LC, dichotomized patients according to the LC cut-off, and calculated hazard ratios using a Cox proportional hazards model. One hundred six patients were identified; 78, after exclusions. Lactate clearance was independently associated with 30-day mortality (P<.04); optimal cut-off, 36%. Mortality rates were 61.1% and 10.7% for patients with 6-hour LC 36% or less and greater than 36%, respectively. Hazard ratio for death with LC 36% or less was 7.33 (95% confidence interval, 2.17-24.73; P<.001). Six-hour LC was independently associated with mortality, and the optimal cut-off value was 36%, significantly higher than previously reported. We would support further research investigating this higher LC as a distinct resuscitation end point in patients with severe sepsis and septic shock. Copyright © 2013 Elsevier Inc. All rights reserved.

Biodiesel production from crude cottonseed oil: an optimization process using response surface methodology

Energy Technology Data Exchange (ETDEWEB)

Fan, Xiaohu; Wang, Xi; Chen, Feng

2011-07-01

As the depletion of fossil resources continues, the demand for environmentally friendly sources of energy as biodiesel is increasing. Biodiesel is the resulting fatty acid methyl ester (FAME) from an esterification reaction. The use of cottonseed oil to produce biodiesel has been investigated in recent years, but it is difficult to find the optimal conditions of this process since multiple factors are involved. The aim of this study was to optimize the transesterification of cottonseed oil with methanol to produce biodiesel. A response surface methodology (RSM), an experimental method to seek optimal conditions for a multivariable system and reverse phase HPLC was used to analyze the conversion of triglyceride into biodiesel. RSM was successfully applied and the optimal condition was found with a 97% yield.

Schedule optimization study implementation plan

International Nuclear Information System (INIS)

1993-11-01

This Implementation Plan is intended to provide a basis for improvements in the conduct of the Environmental Restoration (ER) Program at Hanford. The Plan is based on the findings of the Schedule Optimization Study (SOS) team which was convened for two weeks in September 1992 at the request of the U.S. Department of Energy (DOE) Richland Operations Office (RL). The need for the study arose out of a schedule dispute regarding the submission of the 1100-EM-1 Operable Unit (OU) Remedial Investigation/Feasibility Study (RI/FS) Work Plan. The SOS team was comprised of independent professionals from other federal agencies and the private sector experienced in environmental restoration within the federal system. The objective of the team was to examine reasons for the lengthy RI/FS process and recommend ways to expedite it. The SOS team issued their Final Report in December 1992. The report found the most serious impediments to cleanup relate to a series of management and policy issues which are within the control of the three parties managing and monitoring Hanford -- the DOE, U.S. Environmental Protection Agency (EPA), and the State of Washington Department of Ecology (Ecology). The SOS Report identified the following eight cross-cutting issues as the root of major impediments to the Hanford Site cleanup. Each of these eight issues is quoted from the SOS Report followed by a brief, general description of the proposed approach being developed

Binary Cockroach Swarm Optimization for Combinatorial Optimization Problem

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Ibidun Christiana Obagbuwa

2016-09-01

Full Text Available The Cockroach Swarm Optimization (CSO algorithm is inspired by cockroach social behavior. It is a simple and efficient meta-heuristic algorithm and has been applied to solve global optimization problems successfully. The original CSO algorithm and its variants operate mainly in continuous search space and cannot solve binary-coded optimization problems directly. Many optimization problems have their decision variables in binary. Binary Cockroach Swarm Optimization (BCSO is proposed in this paper to tackle such problems and was evaluated on the popular Traveling Salesman Problem (TSP, which is considered to be an NP-hard Combinatorial Optimization Problem (COP. A transfer function was employed to map a continuous search space CSO to binary search space. The performance of the proposed algorithm was tested firstly on benchmark functions through simulation studies and compared with the performance of existing binary particle swarm optimization and continuous space versions of CSO. The proposed BCSO was adapted to TSP and applied to a set of benchmark instances of symmetric TSP from the TSP library. The results of the proposed Binary Cockroach Swarm Optimization (BCSO algorithm on TSP were compared to other meta-heuristic algorithms.

A Novel Adaptive Particle Swarm Optimization Algorithm with Foraging Behavior in Optimization Design

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Liu Yan

2018-01-01

Full Text Available The method of repeated trial and proofreading is generally used to the convention reducer design, but these methods is low efficiency and the size of the reducer is often large. Aiming the problems, this paper presents an adaptive particle swarm optimization algorithm with foraging behavior, in this method, the bacterial foraging process is introduced into the adaptive particle swarm optimization algorithm, which can provide the function of particle chemotaxis, swarming, reproduction, elimination and dispersal, to improve the ability of local search and avoid premature behavior. By test verification through typical function and the application of the optimization design in the structure of the reducer with discrete and continuous variables, the results are shown that the new algorithm has the advantages of good reliability, strong searching ability and high accuracy. It can be used in engineering design, and has a strong applicability.

Process optimization for osmo-dehydrated carambola (Averrhoa carambola L) slices and its storage studies.

Science.gov (United States)

Roopa, N; Chauhan, O P; Raju, P S; Das Gupta, D K; Singh, R K R; Bawa, A S

2014-10-01

An osmotic-dehydration process protocol for Carambola (Averrhoacarambola L.,), an exotic star shaped tropical fruit, was developed. The process was optimized using Response Surface Methodology (RSM) following Central Composite Rotatable Design (CCRD). The experimental variables selected for the optimization were soak solution concentration (°Brix), soaking temperature (°C) and soaking time (min) with 6 experiments at central point. The effect of process variables was studied on solid gain and water loss during osmotic dehydration process. The data obtained were analyzed employing multiple regression technique to generate suitable mathematical models. Quadratic models were found to fit well (R(2), 95.58 - 98.64 %) in describing the effect of variables on the responses studied. The optimized levels of the process variables were achieved at 70°Brix, 48 °C and 144 min for soak solution concentration, soaking temperature and soaking time, respectively. The predicted and experimental results at optimized levels of variables showed high correlation. The osmo-dehydrated product prepared at optimized conditions showed a shelf-life of 10, 8 and 6 months at 5 °C, ambient (30 ± 2 °C) and 37 °C, respectively.

Power Minimization through Packet Retention in Cognitive Radio Sensor Networks under Interference and Delay Constraints: An Optimal Stopping Approach

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Amr Y. Elnakeeb

2016-04-01

Full Text Available The aim of this article is twofold: First, we study the problem of packets retention in a queue with the aim of minimizing transmission power in delay-tolerant applications. The problem is classified as an optimal stopping problem. The optimal stopping rule has been derived as well. Optimal number of released packets is determined in each round through an Integer Linear Programming (ILP optimization problem. This transmission paradigm is tested via simulations in an interference-free environment leading to a significant reduction in transmission power (at least 55%. Second, we address the problem of applying the scheme of packets retention through the Optimal Stopping Policy (OSP to underlay Cognitive Radio Sensor Networks (CRSNs where strict interference threshold does exist. Simulations proved that our scheme outperforms traditional transmission method as far as dropped packet rate and Average Power per Transmitted Packet (APTP are concerned.

Optimization of mass of plastic scintillator film for flow-cell based tritium monitoring: a Monte Carlo study

International Nuclear Information System (INIS)

Roy, Arup Singha; Palani Selvam, T.; Raman, Anand; Raja, V.; Chaudhury, Probal

2014-01-01

Over the years, various types of tritium-in-air monitors have been designed and developed based on different principles. Ionization chamber, proportional counter and scintillation detector systems are few among them. A plastic scintillator based, flow-cell type online tritium-in-air monitoring system was developed for online monitoring of tritium in air. The value of the scintillator mass inside the cell-volume, which maximizes the response of the detector system, should be obtained to get maximum efficiency. The present study is aimed to optimize the amount of mass of the plastic scintillator film for the flow-cell based tritium monitoring instrument so that maximum efficiency is achieved. The Monte Carlo based EGSnrc code system has been used for this purpose

Job Resources and Work Engagement: Optimism as Moderator Among Finnish Managers

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Stela Rumenova Salminen

2014-05-01

Full Text Available The aim of the present study was to investigate the moderating role of optimism in the relationship between job resources (organizational climate, job control and work engagement among Finnish young managers ('N' = 747. Hierarchical regression analyses showed that both job resources and optimism exerted a positive effect on work engagement and its three dimensions of vigor, dedication, and absorption. The moderation results showed that optimism can diminish the negative impact of low job resources on work engagement. These findings provide evidence to the importance of including personal resources in future research conducted on motivational process. Additionally, these findings provide significant suggestions for the utilization of these resources in organizational practice too, i.e., in staff recruitment, retention and development.

Optimal parameters uncoupling vibration modes of oscillators

Science.gov (United States)

Le, K. C.; Pieper, A.

2017-07-01

This paper proposes a novel optimization concept for an oscillator with two degrees of freedom. By using specially defined motion ratios, we control the action of springs to each degree of freedom of the oscillator. We aim at showing that, if the potential action of the springs in one period of vibration, used as the payoff function for the conservative oscillator, is maximized among all admissible parameters and motions satisfying Lagrange's equations, then the optimal motion ratios uncouple vibration modes. A similar result holds true for the dissipative oscillator having dampers. The application to optimal design of vehicle suspension is discussed.

SOCIAL NETWORK OPTIMIZATION A NEW METHAHEURISTIC FOR GENERAL OPTIMIZATION PROBLEMS

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Hassan Sherafat

2017-12-01

Full Text Available In the recent years metaheuristics were studied and developed as powerful technics for hard optimization problems. Some of well-known technics in this field are: Genetic Algorithms, Tabu Search, Simulated Annealing, Ant Colony Optimization, and Swarm Intelligence, which are applied successfully to many complex optimization problems. In this paper, we introduce a new metaheuristic for solving such problems based on social networks concept, named as Social Network Optimization – SNO. We show that a wide range of np-hard optimization problems may be solved by SNO.

Factors influencing the profitability of optimizing control systems

International Nuclear Information System (INIS)

Broussaud, A.; Guyot, O.

1999-01-01

Optimizing control systems supplement conventional Distributed Control Systems and Programmable Logic Controllers. They continuously implement set points, which aim at maximizing the profitability of plant operation. They are becoming an integral part of modern mineral processing plants. This trend is justified by economic considerations, optimizing control being among the most cost-effective methods of improving metallurgical plant performance. The paper successively analyzes three sets of factors, which influence the profitability of optimizing control systems, and provides guidelines for analyzing the potential value of an optimizing control system at a given operation: external factors, such as economic factors and factors related to plant feed; features of the optimizing control system; and subsequent maintenance of the optimizing control system. It is shown that pay back times for optimization control projects are typically measured in days. The OCS software used by the authors for their applications is described briefly. (author)

Effect of perceived social support and dispositional optimism on the depression of burn patients.

Science.gov (United States)

He, Fei; Zhou, Qin; Zhao, Zhijing; Zhang, Yuan; Guan, Hao

2016-06-01

Burn wounds have a significant impact on the mental health of patients. This study aimed to investigate the impact of perceived social support and dispositional optimism on depression of burn patients. A total of 246 burn patients accomplished the Multidimensional Scale of Perceived Social Support, the Revised Life Orientation Test, and Depression Scale. The results revealed that both perceived social support and optimism were significantly correlated with depression. Structural equation modeling indicated that optimism partially mediated the relationship between perceived social support and depression. Implications for prevention of depression in burn patients were discussed. © The Author(s) 2014.

Optimism and survival: does an optimistic outlook predict better survival at advanced ages? A twelve-year follow-up of Danish nonagenarians

DEFF Research Database (Denmark)

Engberg, Henriette; Jeune, Bernard; Andersen-Ranberg, Karen

2013-01-01

BACKGROUND AND AIMS: Studies examining predictors of survival among the oldest-old have primarily focused on objective measures, such as physical function and health status. Only a few studies have examined the effect of personality traits on survival, such as optimism. The aim of this study...... physical and cognitive functioning and disease were taken into account the association between optimism and survival weakened in both sexes, but the general pattern persisted. Optimistic women were still at lower risk of death compared to neutral women [HR 0.85, 95 % CI (0.74-0.97)]. The risk of death...

A new enhanced index tracking model in portfolio optimization with sum weighted approach

Science.gov (United States)

Siew, Lam Weng; Jaaman, Saiful Hafizah; Hoe, Lam Weng

2017-04-01

Index tracking is a portfolio management which aims to construct the optimal portfolio to achieve similar return with the benchmark index return at minimum tracking error without purchasing all the stocks that make up the index. Enhanced index tracking is an improved portfolio management which aims to generate higher portfolio return than the benchmark index return besides minimizing the tracking error. The objective of this paper is to propose a new enhanced index tracking model with sum weighted approach to improve the existing index tracking model for tracking the benchmark Technology Index in Malaysia. The optimal portfolio composition and performance of both models are determined and compared in terms of portfolio mean return, tracking error and information ratio. The results of this study show that the optimal portfolio of the proposed model is able to generate higher mean return than the benchmark index at minimum tracking error. Besides that, the proposed model is able to outperform the existing model in tracking the benchmark index. The significance of this study is to propose a new enhanced index tracking model with sum weighted apporach which contributes 67% improvement on the portfolio mean return as compared to the existing model.

A new optimal seam method for seamless image stitching

Science.gov (United States)

Xue, Jiale; Chen, Shengyong; Cheng, Xu; Han, Ying; Zhao, Meng

2017-07-01

A novel optimal seam method which aims to stitch those images with overlapping area more seamlessly has been propos ed. Considering the traditional gradient domain optimal seam method and fusion algorithm result in bad color difference measurement and taking a long time respectively, the input images would be converted to HSV space and a new energy function is designed to seek optimal stitching path. To smooth the optimal stitching path, a simplified pixel correction and weighted average method are utilized individually. The proposed methods exhibit performance in eliminating the stitching seam compared with the traditional gradient optimal seam and high efficiency with multi-band blending algorithm.

Aims and theoretical frameworks in nursing students' Bachelor's theses in Sweden: A descriptive study.

Science.gov (United States)

Silén, Marit; Johansson, Linda

2016-02-01

Nursing students' independent projects in Sweden not only provide an opportunity to receive a professional qualification as a nurse but also gain a Bachelor's degree in nursing. The aim of these projects is to demonstrate knowledge and understanding within the major field of the education. This study aimed to describe and analyze the topics as well as theoretical frameworks and concepts in nursing students' independent projects, which lead to a Bachelor's degree, in a Swedish context. A total of 491 independent projects, written by nursing students in Sweden, were included in the study. Topics together with theoretical frameworks and concepts in the projects were identified. Similar topics and theoretical frameworks and concepts, respectively, were grouped into subcategories, and similar subcategories were then merged into a main category. The number of entries in each category was counted for descriptive statistics in order to allow for the demonstration of magnitude. The most common topics concerned experiences and managing when having an illness, experiences of care and of being a caregiver, and healthcare staff's care and knowledge. The nursing theories/models that were most often used were Eriksson's Theory of Caritative Caring, Travelbee's Human-to-Human Relationship Model, and Orem's Self-care Theory. Among the non-nursing theories/models, perspectives and concepts lifeworld, ethical values and principles, existential concepts and quality of life/health-related quality of life, were most often used by these students. There may be some difficulty in finding a topic for the project that is relevant for both a professional qualification as a nurse, as well as for achieving the requirements of a Bachelor's degree in nursing. The study indicates that there is a need to widen the student's understanding of different nursing theories/perspectives/models/concepts during nursing education so that students are familiar with a broad range of these when conducting their

Optimizing data access in the LAMPF control system

International Nuclear Information System (INIS)

Schaller, S.C.; Corley, J.K.; Rose, P.A.

1985-01-01

The LAMPF control system data access software offers considerable power and flexibility to application programs through symbolic device naming and an emphasis on hardware independence. This paper discusses optimizations aimed at improving the performance of the data access software while retaining these capabilities. The only aspects of the optimizations visible to the application programs are ''vector devices'' and ''aggregate devices.'' A vector device accesses a set of hardware related data items through a single device name. Aggregate devices allow run-time optimization of references to groups of unrelated devices. Optimizations not visible on the application level include careful handling of: network message traffic; the sharing of global resources; and storage allocation

What Impact Do Chaplains Have? A Pilot Study of Spiritual AIM for Advanced Cancer Patients in Outpatient Palliative Care.

Science.gov (United States)

Kestenbaum, Allison; Shields, Michele; James, Jennifer; Hocker, Will; Morgan, Stefana; Karve, Shweta; Rabow, Michael W; Dunn, Laura B

2017-11-01

Spiritual care is integral to quality palliative care. Although chaplains are uniquely trained to provide spiritual care, studies evaluating chaplains' work in palliative care are scarce. The goals of this pre-post study, conducted among patients with advanced cancer receiving outpatient palliative care, were to evaluate the feasibility and acceptability of chaplain-delivered spiritual care, utilizing the Spiritual Assessment and Intervention Model ("Spiritual AIM"), and to gather pilot data on Spiritual AIM's effects on spiritual well-being, religious and cancer-specific coping, and physical and psychological symptoms. Patients with advanced cancer (N = 31) who were receiving outpatient palliative care were assigned based on chaplains' and patients' outpatient schedules, to one of three professional chaplains for three individual Spiritual AIM sessions, conducted over the course of approximately six to eight weeks. Patients completed the following measures at baseline and post-intervention: Edmonton Symptom Assessment Scale, Steinhauser Spirituality, Brief RCOPE, Functional Assessment of Chronic Illness Therapy-Spiritual (FACIT-Sp-12), Mini-Mental Adjustment to Cancer (Mini-MAC), Patient Dignity Inventory, Center for Epidemiological Studies-Depression (10 items), and Spielberger State Anxiety Inventory. From baseline to post-Spiritual AIM, significant increases were found on the FACIT-Sp-12 Faith subscale, the Mini-MAC Fighting Spirit subscale, and Mini-MAC Adaptive Coping factor. Two trends were observed, i.e., an increase in Positive religious coping on the Brief RCOPE and an increase in Fatalism (a subscale of the Mini-MAC). Spiritual AIM, a brief chaplain-led intervention, holds potential to address spiritual needs and religious and general coping in patients with serious illnesses. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

RFID protocol design, optimization, and security for the Internet of Things

CERN Document Server

Liu, Alex X; Liu, Xiulong; Li, Keqiu

2017-01-01

This book covers the topic of RFID protocol design and optimization and the authors aim to demystify complicated RFID protocols and explain in depth the principles, techniques, and practices in designing and optimizing them.

Optimization, ex vivo permeation, and stability study of lipid nanocarrier loaded gelatin capsules for treatment of intermittent claudication

Directory of Open Access Journals (Sweden)

Sallam MA

2015-07-01

Full Text Available Marwa Ahmed Sallam,1 María Teresa Marín Boscá21Department of Industrial Pharmacy, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt; 2Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Granada University, Granada, Spain Abstract: In this study, an optimized nanodispersible oral dosage form (containing a lactate ester was developed for cilostazol (CZL. CZL is a phosphodiesterase inhibitor used for intermittent claudication. We aimed to improve the dissolution rate and absorption of CZL giving it a better chance of oral bioavailability, and to evaluate its stability on storage. Suitable compositions of nanoemulsion preconcentrate formulations were screened via solubility and compatibility tests. Response surface methodology and a desirability approach were applied to optimize preconcentrates containing minimum amount of surfactant mixture, maximum amount of lipid, and possessing the smallest globule size, with the highest emulsification and dissolution rates and minimum risk of drug precipitation. As part of the optimization process, the main effect, interaction effects and quadratic effects of amounts of lipid, and surfactant/co-surfactant ratio on % transmittance, globule size, emulsification time, drug precipitation, and drug release were investigated. The optimized formulation consisting of 28.9% butyl lactate, 28.9% Capryol®, 27.82% Solubilisant Gamma® 2429, and 14.18% Transcutol® possessing a globule size of 60 nm was mixed with Aerosil® 200. This gave uniform free flowing granules, which were characterized for surface and powder properties. The self-nanoemulsifying granules (SNEGs filled into hard gelatin capsules showed two- and threefold increase in CZL released compared with conventional tablet and pure drug, respectively. The amount of drug permeated using non-everted sac technique from the SNEGs was twofold higher than that permeated from the tablet suspension. The shelf life was 526 days at

Sensitivity analysis and optimization algorithms for 3D forging process design

International Nuclear Information System (INIS)

Do, T.T.; Fourment, L.; Laroussi, M.

2004-01-01

This paper presents several approaches for preform shape optimization in 3D forging. The process simulation is carried out using the FORGE3 registered finite element software, and the optimization problem regards the shape of initial axisymmetrical preforms. Several objective functions are considered, like the forging energy, the forging force or a surface defect criterion. Both deterministic and stochastic optimization algorithms are tested for 3D applications. The deterministic approach uses the sensitivity analysis that provides the gradient of the objective function. It is obtained by the adjoint-state method and semi-analytical differentiation. The study of stochastic approaches aims at comparing genetic algorithms and evolution strategies. Numerical results show the feasibility of such approaches, i.e. the achieving of satisfactory solutions within a limited number of 3D simulations, less than fifty. For a more industrial problem, the forging of a gear, encouraging optimization results are obtained

AIM Data Services

Directory of Open Access Journals (Sweden)

Michael Scholz

2016-05-01

Full Text Available AIM Data Services as a virtual facility provides virtual 3D reference tracks for simulation applications in the domain of automotive and railway systems. It offers tools for management and analysis of experiment data and a platform for survey and processing of vehicle data in the public transport domain. Collected spatial data is bundled in a database cluster and published through common web mapping interfaces.

Study and optimization of the partial discharges in capacitor model ...

African Journals Online (AJOL)

Page 1 ... experiments methodology for the study of such processes, in view of their modeling and optimization. The obtained result is a mathematical model capable to identify the parameters and the interactions between .... 5mn; the next landing is situated in 200 V over the voltage of partial discharges appearance and.

[Content analysis of food adverts aimed at children].

Science.gov (United States)

Ponce-Blandón, José Antonio; Pabón-Carrasco, Manuel; Lomas-Campos, María de Las Mercedes

To determine the contents and persuasive techniques used in processed food adverts aimed at children in Andalusia, comparing them with those aimed at adults. Study based on advert content analysis with two phases: a descriptive design phase and an analytical observational design phase. A sample of adverts from 60hours of broadcasting from the two most watched television channels in Andalusia. A total of 416 food and non-alcoholic beverage adverts were obtained, for 91 different products. Approximately 42.9% (n=39) was aimed at children and 53.8% (n=49) were products classified as "unhealthy". Unhealthy foods were more common in adverts for children (p <0.001). Significant differences were found between the ads aimed at adults and those aimed at children. Emotional and irrational persuasive resources such as fantasy (p <0.001), cartoons (p <0.001) or offering gifts with the purchase of the product (p=0.003) were observed more frequently in adverts for children. Food advertising aimed at children in Andalusia is mainly based on offering products with a low nutritional value and using persuasive resources based on fantasy or gifts. The message is focused on the incentive and not the food. More effective measures than the current self-regulatory systems must be put in place to counter these distorted adverts. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

OPTIMAL PRICE OF ADMISSION BANTIMURUNG NATURAL PARK, SOUTH SULAWESI

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Wahyudi Isnan

2016-12-01

Full Text Available The number of visitors to the Bantimurung natural park fluctuated allegedly due to the increase of the price of admission ticket. The aim of the study is to analyze optimal price of admission ticket and willingness of visitors to pay admission ticket to the Park. The study was conducted in Bantimurung natural park, South Sulawsi, from January to April 2013.117 number of samples was taken by using convenience sampling method. Analysis of optimal prices and the willingness of visitors to pay for ecotourism to the Park were conducted by creating tourism demand function, which then simulated the price of admission, into the equation function of tourist demand. The results showed that the optimal price of the admission ticket was at the price of Rp75,000. At the optimal price of admission ticket of Rp75,000 the Park would earn revenues of Rp18,230,700,000. An average value of the visitor willingness to pay was Rp118,032, with price of admission ticket was Rp75,000, then, the average visitor will get consumer surplus of Rp43,032. If the management of Bantimurung natural park desiring to increase the total revenue, then the price of admission ticket can be increased to be Rp75,000.

Wind farm layout optimization in complex terrain: A preliminary study on a Gaussian hill

International Nuclear Information System (INIS)

Feng, J; Shen, W Z

2014-01-01

One of the crucial problems for wind farm (WF) development is wind farm layout optimization. It seeks to find the optimal positions of wind turbines (WTs) inside a WF, so as to maximize and/or minimize a single objective or multiple objectives, while satisfying certain constraints. Although this problem for WFs in flat terrain or offshore has been investigated in many studies, it is still a challenging problem for WFs in complex terrain. In this preliminary study, the wind flow conditions of complex terrain without WTs are first obtained from computational fluid dynamics (CFD) simulation, then an adapted Jensen wake model is developed by considering the terrain features and taking the inflow conditions as input. Using this combined method, the wake effects of WF in complex terrain are properly modelled. Besides, a random search (RS) algorithm proposed in previous study is improved by adding some adaptive mechanisms and applied to solve the layout optimization problem of a WF on a Gaussian shape hill. The layout of the WF with a certain number of WTs is optimized to maximize the total power output, which obtained steady improvements over expert guess layouts

Optimism, well-being, depressive symptoms, and perceived physical health: a study among Stroke survivors.

Science.gov (United States)

Shifren, Kim; Anzaldi, Kristen

2018-01-01

The investigation of the relation of positive personality characteristics to mental and physical health among Stroke survivors has been a neglected area of research. The purpose of this study was to examine the relationship between optimism, well-being, depressive symptoms, and perceived physical health among Stroke survivors. It was hypothesized that Stroke survivors' optimism would explain variance in their physical health above and beyond the variance explained by demographic variables, diagnostic variables, and mental health. One hundred seventy-six Stroke survivors (97 females, 79 males) completed the Revised Life Orientation Test, the Center for Epidemiological Studies Depression Scale, two items on perceived physical health from the 36-item Short Form of the Medical Outcomes study, and the Identity scale of the Illness Perception Questionnaire. Pearson correlations, hierarchical regression analyses, and the PROCESS approach to determining mediators were used to assess hypothesized relations between variables. Stroke survivors' level of optimism explained additional variance in overall health in regression models controlling for demographic and diagnostic variables, and mental health. Analyses revealed that optimism played a partial mediator role between mental health (well-being, depressive symptoms and total score on CES-D) variables and overall health.

Benchmarking Investments in Advancement: Results of the Inaugural CASE Advancement Investment Metrics Study (AIMS). CASE White Paper

Science.gov (United States)

Kroll, Juidith A.

2012-01-01

The inaugural Advancement Investment Metrics Study, or AIMS, benchmarked investments and staffing in each of the advancement disciplines (advancement services, alumni relations, communications and marketing, fundraising and advancement management) as well as the return on the investment in fundraising specifically. This white paper reports on the…

Optimizing diffusion of an online computer tailored lifestyle program: a study protocol

Directory of Open Access Journals (Sweden)

Schulz Daniela N

2011-06-01

Full Text Available Abstract Background Although the Internet is a promising medium to offer lifestyle interventions to large amounts of people at relatively low costs and effort, actual exposure rates of these interventions fail to meet the high expectations. Since public health impact of interventions is determined by intervention efficacy and level of exposure to the intervention, it is imperative to put effort in optimal dissemination. The present project attempts to optimize the dissemination process of a new online computer tailored generic lifestyle program by carefully studying the adoption process and developing a strategy to achieve sustained use of the program. Methods/Design A prospective study will be conducted to yield relevant information concerning the adoption process by studying the level of adoption of the program, determinants involved in adoption and characteristics of adopters and non-adopters as well as satisfied and unsatisfied users. Furthermore, a randomized control trial will be conducted to the test the effectiveness of a proactive strategy using periodic e-mail prompts in optimizing sustained use of the new program. Discussion Closely mapping the adoption process will gain insight in characteristics of adopters and non-adopters and satisfied and unsatisfied users. This insight can be used to further optimize the program by making it more suitable for a wider range of users, or to develop adjusted interventions to attract subgroups of users that are not reached or satisfied with the initial intervention. Furthermore, by studying the effect of a proactive strategy using period prompts compared to a reactive strategy to stimulate sustained use of the intervention and, possibly, behaviour change, specific recommendations on the use and the application of prompts in online lifestyle interventions can be developed. Trial registration Dutch Trial Register NTR1786 and Medical Ethics Committee of Maastricht University and the University Hospital

Sizing Optimization and Strength Analysis for Spread-type Gear Reducers

Directory of Open Access Journals (Sweden)

Wei-Hsuan Hsu

2014-08-01

Full Text Available A reducer is now developed towards the trend of customization service and cost-saving. In this study, a sizing program for the reducer has been developed in order to replace the manual sizing process. We aim at the total center distance of the gear reducer for optimization to reduce gear volume and weight. Also, we checked constrains such as, tooth root bending, tooth contact strength, gear shaft endangered cross-section, bearing life, gear shaft deflection, and torsion angle deformation, etc., to obtain reliable drive strength. Comparisons of sizes and weights before and after optimization confirm that the purpose for reducing production cost is achieved.

An Optimal Turkish Private Pension Plan with a Guarantee Feature

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Ayşegül İşcanog̃lu-Çekiç

2016-06-01

Full Text Available The Turkish Private Pension System is an investment system which aims to generate income for future consumption. This is a volunteer system, and the contributions are held in individual portfolios. Therefore, management of the funds is an important issue for both the participants and the insurance company. In this study, we propose an optimal private pension plan with a guarantee feature that is based on Constant Proportion Portfolio Insurance (CPPI. We derive a closed form formula for the optimal strategy with the help of dynamic programming. Moreover, our model is evaluated with numerical examples, and we compare its performance by implementing a sensitivity analysis.

A Framework for Constrained Optimization Problems Based on a Modified Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

Biwei Tang

2016-01-01

Full Text Available This paper develops a particle swarm optimization (PSO based framework for constrained optimization problems (COPs. Aiming at enhancing the performance of PSO, a modified PSO algorithm, named SASPSO 2011, is proposed by adding a newly developed self-adaptive strategy to the standard particle swarm optimization 2011 (SPSO 2011 algorithm. Since the convergence of PSO is of great importance and significantly influences the performance of PSO, this paper first theoretically investigates the convergence of SASPSO 2011. Then, a parameter selection principle guaranteeing the convergence of SASPSO 2011 is provided. Subsequently, a SASPSO 2011-based framework is established to solve COPs. Attempting to increase the diversity of solutions and decrease optimization difficulties, the adaptive relaxation method, which is combined with the feasibility-based rule, is applied to handle constraints of COPs and evaluate candidate solutions in the developed framework. Finally, the proposed method is verified through 4 benchmark test functions and 2 real-world engineering problems against six PSO variants and some well-known methods proposed in the literature. Simulation results confirm that the proposed method is highly competitive in terms of the solution quality and can be considered as a vital alternative to solve COPs.

Adaptive stimulus optimization for sensory systems neuroscience

OpenAIRE

DiMattina, Christopher; Zhang, Kechen

2013-01-01

In this paper, we review several lines of recent work aimed at developing practical methods for adaptive on-line stimulus generation for sensory neurophysiology. We consider various experimental paradigms where on-line stimulus optimization is utilized, including the classical optimal stimulus paradigm where the goal of experiments is to identify a stimulus which maximizes neural responses, the iso-response paradigm which finds sets of stimuli giving rise to constant responses, and the system...

Optimization studies of photo-neutron production in high-Z metallic ...

Indian Academy of Sciences (India)

Monte Carlo calculations have been performed using MCNP code to study the optimization of photo-neutron yield for different electron beam energies impinging on Pb, W and Ta cylindrical targets of varying thickness. It is noticed that photo-neutron yield can be increased for electron beam energies ≥ 100 MeV for ...

Analysis and Optimization of Heterogeneous Real-Time Embedded Systems

DEFF Research Database (Denmark)

Pop, Paul; Eles, Petru; Peng, Zebo

2005-01-01

. The success of such new design methods depends on the availability of analysis and optimization techniques. In this paper, we present analysis and optimization techniques for heterogeneous real-time embedded systems. We address in more detail a particular class of such systems called multi-clusters, composed...... to frames. Optimization heuristics for frame packing aiming at producing a schedulable system are presented. Extensive experiments and a real-life example show the efficiency of the frame-packing approach....

ENTERPRISE RESTRUCTURING AIM AND TYPES

Directory of Open Access Journals (Sweden)

S. P. Baranenko

2011-01-01

Full Text Available Enterprise restructuring is aimed at adapting it to market conditions and improving its competitiveness through selection of most effective model of using material, technical, technological, organizational, commercial, economical, financial, tax-related and other resources with due account of the demand. Restructuring classification signs and types as well as restructuring aims specific for industrial enterprises are provided for.

Thermodynamic and economic optimization of a solar-powered Stirling engine for micro-cogeneration purposes

International Nuclear Information System (INIS)

Ferreira, Ana C.; Nunes, Manuel L.; Teixeira, José C.F.; Martins, Luís A.S.B.; Teixeira, Senhorinha F.C.F.

2016-01-01

Micro-cogeneration systems are a promising technology for improving the energy efficiency near the end user, allowing the optimal use of the primary energy sources and significant reductions in carbon emissions. Its use, still incipient, has a great potential for applications in the residential sector. This study aims to develop a methodology for the thermal-economic optimization of micro cogeneration units using Stirling engine as prime mover and concentrated solar energy as the heat source. The thermal-economic optimization was formulated considering the maximization of the annual worth from the system operation, subjected to the nonlinear thermodynamic and economic constraints. The physical model includes the limitations in the heat transfer processes and losses due to the pumping effects and the costing methodology was defined considering a purchase cost equation representative of each system component. Geometric and operational parameters were selected as decision variables. Numerical simulations were developed in MatLab"® programming language and the Generalized Pattern Search optimization algorithm with MADSPositiveBasis2N was used in the determination of the optimal solution. A positive annual worth for the defined input simulation conditions and the economic analysis disclosed a system, economically attractive, with a payback period of approximately 10 years. - Highlights: • Application of optimization methods to model a renewable powered Stirling engine. • The aim is to optimize design of each plant-component for the best economical outcome. • The objective function is the maximization of annual worth of micro-CHP system. • The optimal solution is sensitive to electricity feed-in-tariffs and fuel prices fluctuations. • The optimal solution is economically attractive, with a payback period of ≈10 years.

Load flow optimization and optimal power flow

CERN Document Server

Das, J C

2017-01-01

This book discusses the major aspects of load flow, optimization, optimal load flow, and culminates in modern heuristic optimization techniques and evolutionary programming. In the deregulated environment, the economic provision of electrical power to consumers requires knowledge of maintaining a certain power quality and load flow. Many case studies and practical examples are included to emphasize real-world applications. The problems at the end of each chapter can be solved by hand calculations without having to use computer software. The appendices are devoted to calculations of line and cable constants, and solutions to the problems are included throughout the book.

Enhancement of dissolution and oral bioavailability of lacidipine via pluronic P123/F127 mixed polymeric micelles: formulation, optimization using central composite design and in vivo bioavailability study.

Science.gov (United States)

Fares, Ahmed R; ElMeshad, Aliaa N; Kassem, Mohamed A A

2018-11-01

This study aims at preparing and optimizing lacidipine (LCDP) polymeric micelles using thin film hydration technique in order to overcome LCDP solubility-limited oral bioavailability. A two-factor three-level central composite face-centered design (CCFD) was employed to optimize the formulation variables to obtain LCDP polymeric micelles of high entrapment efficiency and small and uniform particle size (PS). Formulation variables were: Pluronic to drug ratio (A) and Pluronic P123 percentage (B). LCDP polymeric micelles were assessed for entrapment efficiency (EE%), PS and polydispersity index (PDI). The formula with the highest desirability (0.959) was chosen as the optimized formula. The values of the formulation variables (A and B) in the optimized polymeric micelles formula were 45% and 80%, respectively. Optimum LCDP polymeric micelles had entrapment efficiency of 99.23%, PS of 21.08 nm and PDI of 0.11. Optimum LCDP polymeric micelles formula was physically characterized using transmission electron microscopy. LCDP polymeric micelles showed saturation solubility approximately 450 times that of raw LCDP in addition to significantly enhanced dissolution rate. Bioavailability study of optimum LCDP polymeric micelles formula in rabbits revealed a 6.85-fold increase in LCDP bioavailability compared to LCDP oral suspension.

Deploying response surface methodology (RSM) and glowworm swarm optimization (GSO) in optimizing warpage on a mobile phone cover

Science.gov (United States)

Lee, X. N.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.; Shazzuan, S.

2017-09-01

Plastic injection moulding is a popular manufacturing method not only it is reliable, but also efficient and cost saving. It able to produce plastic part with detailed features and complex geometry. However, defects in injection moulding process degrades the quality and aesthetic of the injection moulded product. The most common defect occur in the process is warpage. Inappropriate process parameter setting of injection moulding machine is one of the reason that leads to the occurrence of warpage. The aims of this study were to improve the quality of injection moulded part by investigating the optimal parameters in minimizing warpage using Response Surface Methodology (RSM) and Glowworm Swarm Optimization (GSO). Subsequent to this, the most significant parameter was identified and recommended parameters setting was compared with the optimized parameter setting using RSM and GSO. In this research, the mobile phone case was selected as case study. The mould temperature, melt temperature, packing pressure, packing time and cooling time were selected as variables whereas warpage in y-direction was selected as responses in this research. The simulation was carried out by using Autodesk Moldflow Insight 2012. In addition, the RSM was performed by using Design Expert 7.0 whereas the GSO was utilized by using MATLAB. The warpage in y direction recommended by RSM were reduced by 70 %. The warpages recommended by GSO were decreased by 61 % in y direction. The resulting warpages under optimal parameter setting by RSM and GSO were validated by simulation in AMI 2012. RSM performed better than GSO in solving warpage issue.

Optimization of Parameters for Biosynthesis of Silver Nanoparticles Using Leaf Extract of Aegle marmelos

Directory of Open Access Journals (Sweden)

JohnSamuel Godwin Christopher

2015-10-01

Full Text Available ABSTRACTThe aim of this study was to optimize the biosynthesis of silver nanoparticles using leaves ofAegle marmelos as the primary source. The optimal reaction medium comprised 2:1 concentration of leaf extract and 6mM concentration of silver nitrate solution (pH 7. The biosynthesized silver nanoparticles were confirmed by UV-Vis spectroscopy at 420 nm, XRD and FTIR analysis. The antimicrobial properties of silver nanoparticles were confirmed withBacillus subtilis andPseudomonas aeruginosa.

Optimal design of marine steam turbine

International Nuclear Information System (INIS)

Liu Chengyang; Yan Changqi; Wang Jianjun

2012-01-01

The marine steam turbine is one of the key equipment in marine power plant, and it tends to using high power steam turbine, which makes the steam turbine to be heavier and larger, it causes difficulties to the design and arrangement of the steam turbine, and the marine maneuverability is seriously influenced. Therefore, it is necessary to apply optimization techniques to the design of the steam turbine in order to achieve the minimum weight or volume by means of finding the optimum combination of design parameters. The math model of the marine steam turbine design calculation was established. The sensitivities of condenser pressure, power ratio of HP turbine with LP turbine, and the ratio of diameter with height at the end stage of LP turbine, which influence the weight of the marine steam turbine, were analyzed. The optimal design of the marine steam turbine, aiming at the weight minimization while satisfying the structure and performance constraints, was carried out with the hybrid particle swarm optimization algorithm. The results show that, steam turbine weight is reduced by 3.13% with the optimization scheme. Finally, the optimization results were analyzed, and the steam turbine optimization design direction was indicated. (authors)

Analysis and optimal design of an underactuated finger mechanism for LARM hand

Science.gov (United States)

Yao, Shuangji; Ceccarelli, Marco; Carbone, Giuseppe; Zhan, Qiang; Lu, Zhen

2011-09-01

This paper aims to present general design considerations and optimality criteria for underactuated mechanisms in finger designs. Design issues related to grasping task of robotic fingers are discussed. Performance characteristics are outlined as referring to several aspects of finger mechanisms. Optimality criteria of the finger performances are formulated after careful analysis. A general design algorithm is summarized and formulated as a suitable multi-objective optimization problem. A numerical case of an underactuated robot finger design for Laboratory of Robotics and Mechatronics (LARM) hand is illustrated with the aim to show the practical feasibility of the proposed concepts and computations.

A study of data representation in Hadoop to optimize data storage and search performance for the ATLAS EventIndex

Science.gov (United States)

Baranowski, Z.; Canali, L.; Toebbicke, R.; Hrivnac, J.; Barberis, D.

2017-10-01

This paper reports on the activities aimed at improving the architecture and performance of the ATLAS EventIndex implementation in Hadoop. The EventIndex contains tens of billions of event records, each of which consists of ∼100 bytes, all having the same probability to be searched or counted. Data formats represent one important area for optimizing the performance and storage footprint of applications based on Hadoop. This work reports on the production usage and on tests using several data formats including Map Files, Apache Parquet, Avro, and various compression algorithms. The query engine plays also a critical role in the architecture. We report also on the use of HBase for the EventIndex, focussing on the optimizations performed in production and on the scalability tests. Additional engines that have been tested include Cloudera Impala, in particular for its SQL interface, and the optimizations for data warehouse workloads and reports.

A study of data representations in Hadoop to optimize data storage and search performance of the ATLAS EventIndex

CERN Document Server

Baranowski, Zbigniew; The ATLAS collaboration

2016-01-01

This paper reports on the activities aimed at improving the architecture and performance of the ATLAS EventIndex implementation in Hadoop. The EventIndex contains tens of billions event records, each of which consisting of ~100 bytes, all having the same probability to be searched or counted. Data formats represent one important area for optimizing the performance and storage footprint of applications based on Hadoop. This work reports on the production usage and on tests using several data formats including Map Files, Apache Parquet, Avro, and various compression algorithms. The query engine plays also a critical role in the architecture. This paper reports on the use of HBase for the EventIndex, focussing on the optimizations performed in production and on the scalability tests. Additional engines that have been tested include Cloudera Impala, in particular for its SQL interface, and the optimizations for data warehouse workloads and reports.

Optimal Balance Between Force and Velocity Differs Among World-Class Athletes.

Science.gov (United States)

Giroux, Caroline; Rabita, Giuseppe; Chollet, Didier; Guilhem, Gaël

2016-02-01

Performance during human movements is highly related to force and velocity muscle capacities. Those capacities are highly developed in elite athletes practicing power-oriented sports. However, it is still unclear whether the balance between their force and velocity-generating capacities constitutes an optimal profile. In this study, we aimed to determine the effect of elite sport background on the force-velocity relationship in the squat jump, and evaluate the level of optimization of these profiles. Ninety-five elite athletes in cycling, fencing, taekwondo, and athletic sprinting, and 15 control participants performed squat jumps in 7 loading conditions (range: 0%-60% of the maximal load they were able to lift). Theoretical maximal power (Pm), force (F0), and velocity (v0) were determined from the individual force-velocity relationships. Optimal profiles were assessed by calculating the optimal force (F0th) and velocity (v0th). Athletic sprinters and cyclists produced greater force than the other groups (P balanced force-velocity profiles. Moreover, the differences between measured and optimal force-velocity profiles raise potential sources of performance improvement in elite athletes.

Adsorption of lanthanides in aqueous solution aiming to study of nuclear wastes

International Nuclear Information System (INIS)

Belline, Jean de Brito

2009-01-01

The problem of radioactive wastes is a concern of world-wide scope, a time that does not still have a defined local for the construction of a repository for radioactive wastes of high level. One of the preliminary stages for the choice of the place more appropriate is the geologic study associated to the experimental studies of adsorption of the involved chemical species in the process. In this work, a sample of basaltic rock was used, of the South Region of the Formation Serra Geral, collected in Frederico Westphalen Town (RS), that it will be probably a candidate to the rock hostess for location of radioactive wastes. Two experiments have been carried out through, namely: 'Test Batch' and Percolating, both under atmospheric pressure, at the ambient temperature of 25 deg C, with the purpose to study the capacity of sorption of the rare earth elements - REE. The REE are used in this work in function of its analogy with the actinides, aiming at to investigate the chemistry behavior and the speciation of the same in natural waters, searching the possibility of geologic storage of radioactive wastes, a time that the adsorption of the REE depends on variables of the environment as pH, ionic strength, temperature and presence of ligands, as carbonates and constituent of surfaces of minerals. Experiment of percolating of the REE was carried through, 100ppb, in the basalt (with 80 mesh) in solutions with ionic strength 1= 0,025 M and 1=0,5 M of NaCl. pH was controlled in a range of 5,6 the 7,6 with HNO 3 addition. The concentrations were analyzed by ICP-MS. The 'Batch Test' is an efficient form of studying sorption/desorption isotherms, beyond values of the reason between the distributions solid/solution and estimation of the solubility. The percolating experiment, was carried through under pH controlled around 6, and allowed to verify the behaviour of heavy REE in comparison with the light REE. (author)

Multiobjective Optimization of Linear Cooperative Spectrum Sensing: Pareto Solutions and Refinement.

Science.gov (United States)

Yuan, Wei; You, Xinge; Xu, Jing; Leung, Henry; Zhang, Tianhang; Chen, Chun Lung Philip

2016-01-01

In linear cooperative spectrum sensing, the weights of secondary users and detection threshold should be optimally chosen to minimize missed detection probability and to maximize secondary network throughput. Since these two objectives are not completely compatible, we study this problem from the viewpoint of multiple-objective optimization. We aim to obtain a set of evenly distributed Pareto solutions. To this end, here, we introduce the normal constraint (NC) method to transform the problem into a set of single-objective optimization (SOO) problems. Each SOO problem usually results in a Pareto solution. However, NC does not provide any solution method to these SOO problems, nor any indication on the optimal number of Pareto solutions. Furthermore, NC has no preference over all Pareto solutions, while a designer may be only interested in some of them. In this paper, we employ a stochastic global optimization algorithm to solve the SOO problems, and then propose a simple method to determine the optimal number of Pareto solutions under a computational complexity constraint. In addition, we extend NC to refine the Pareto solutions and select the ones of interest. Finally, we verify the effectiveness and efficiency of the proposed methods through computer simulations.

Constrained optimization via simulation models for new product innovation

Science.gov (United States)

Pujowidianto, Nugroho A.

2017-11-01

We consider the problem of constrained optimization where the decision makers aim to optimize the primary performance measure while constraining the secondary performance measures. This paper provides a brief overview of stochastically constrained optimization via discrete event simulation. Most review papers tend to be methodology-based. This review attempts to be problem-based as decision makers may have already decided on the problem formulation. We consider constrained optimization models as there are usually constraints on secondary performance measures as trade-off in new product development. It starts by laying out different possible methods and the reasons using constrained optimization via simulation models. It is then followed by the review of different simulation optimization approach to address constrained optimization depending on the number of decision variables, the type of constraints, and the risk preferences of the decision makers in handling uncertainties.

Optimizing the Gating System for Steel Castings

Directory of Open Access Journals (Sweden)

Jan Jezierski

2018-04-01

Full Text Available The article presents the attempt to optimize a gating system to produce cast steel castings. It is based on John Campbell’s theory and presents the original results of computer modelling of typical and optimized gating systems for cast steel castings. The current state-of-the-art in cast steel casting foundry was compared with several proposals of optimization. The aim was to find a compromise between the best, theoretically proven gating system version, and a version that would be affordable in industrial conditions. The results show that it is possible to achieve a uniform and slow pouring process even for heavy castings to preserve their internal quality.

Big data optimization recent developments and challenges

CERN Document Server

2016-01-01

The main objective of this book is to provide the necessary background to work with big data by introducing some novel optimization algorithms and codes capable of working in the big data setting as well as introducing some applications in big data optimization for both academics and practitioners interested, and to benefit society, industry, academia, and government. Presenting applications in a variety of industries, this book will be useful for the researchers aiming to analyses large scale data. Several optimization algorithms for big data including convergent parallel algorithms, limited memory bundle algorithm, diagonal bundle method, convergent parallel algorithms, network analytics, and many more have been explored in this book.

PROPOSAL OF SPATIAL OPTIMIZATION OF PRODUCTION PROCESS IN PROCESS DESIGNER

Directory of Open Access Journals (Sweden)

Peter Malega

2015-03-01

Full Text Available This contribution is focused on optimizing the use of space in the production process using software Process Designer. The aim of this contribution is to suggest possible improvements to the existing layout of the selected production process. Production process was analysed in terms of inputs, outputs and course of actions. Nowadays there are many software solutions aimed at optimizing the use of space. One of these software products is the Process Designer, which belongs to the product line Tecnomatix. This software is primarily aimed at production planning. With Process Designer is possible to design the layout of production and subsequently to analyse the production or to change according to the current needs of the company.

Pragmatics and the aims of language evolution.

Science.gov (United States)

Scott-Phillips, Thomas C

2017-02-01

Pragmatics has historically played a relatively peripheral role in language evolution research. This is a profound mistake. Here I describe how a pragmatic perspective can inform language evolution in the most fundamental way: by making clear what the natural objects of study are, and hence what the aims of the field should be.

Optimization of Adhesive Pastes for Dental Caries Prevention.

Science.gov (United States)

Sodata, Patteera; Juntavee, Apa; Juntavee, Niwut; Peerapattana, Jomjai

2017-11-01

Dental caries prevention products available on the market contain only remineralizing agents or antibacterial agents. This study aimed to develop adhesive pastes containing calcium phosphate and α-mangostin for dental caries prevention using the optimization technique. Calcium phosphate was used as a remineralizing agent, and extracted α-mangostin was used as an antibacterial agent. The effect of the independent variables, which were fumed silica, Eudragit ® EPO, polyethylene glycol, and ethyl alcohol, on the responses was investigated. The drying time, erosion rate, calcium release rate, and α-mangostin release rate were established as the measured responses. An equation and a model of the relationship were constructed. An optimal formulation was obtained, and its effect on dental caries prevention was investigated using the pH-cycling model. The quadratic equation revealed that the drying time, calcium release rate, and α-mangostin release rate tended to decrease when increasing the fumed silica and decreasing other factors. The erosion rate tended to increase when decreasing Eudragit ® EPO and increasing other factors. The observed responses of the optimal adhesive pastes were not significantly different from the predicted responses. This result demonstrated that optimization is an efficient technique in the formulation development of the adhesive pastes. In addition, the optimal adhesive pastes could enhance acid resistance activity to the tooth enamel.

Parameters Optimization and Application to Glutamate Fermentation Model Using SVM

OpenAIRE

Zhang, Xiangsheng; Pan, Feng

2015-01-01

Aimed at the parameters optimization in support vector machine (SVM) for glutamate fermentation modelling, a new method is developed. It optimizes the SVM parameters via an improved particle swarm optimization (IPSO) algorithm which has better global searching ability. The algorithm includes detecting and handling the local convergence and exhibits strong ability to avoid being trapped in local minima. The material step of the method was shown. Simulation experiments demonstrate the effective...

Fog computing job scheduling optimization based on bees swarm

Science.gov (United States)

Bitam, Salim; Zeadally, Sherali; Mellouk, Abdelhamid

2018-04-01

Fog computing is a new computing architecture, composed of a set of near-user edge devices called fog nodes, which collaborate together in order to perform computational services such as running applications, storing an important amount of data, and transmitting messages. Fog computing extends cloud computing by deploying digital resources at the premise of mobile users. In this new paradigm, management and operating functions, such as job scheduling aim at providing high-performance, cost-effective services requested by mobile users and executed by fog nodes. We propose a new bio-inspired optimization approach called Bees Life Algorithm (BLA) aimed at addressing the job scheduling problem in the fog computing environment. Our proposed approach is based on the optimized distribution of a set of tasks among all the fog computing nodes. The objective is to find an optimal tradeoff between CPU execution time and allocated memory required by fog computing services established by mobile users. Our empirical performance evaluation results demonstrate that the proposal outperforms the traditional particle swarm optimization and genetic algorithm in terms of CPU execution time and allocated memory.

Study of integrated optimization design of wind farm in complex terrain

DEFF Research Database (Denmark)

Xu, Chang; Chen, Dandan; Han, Xingxing

2017-01-01

wind farm design in complex terrain and setting up integrated optimization mathematical model for micro-site selection, power lines and road maintenance design etc.. Based on the existing 1-year wind measurement data in the wind farm area, the genetic algorithm was used to optimize the micro......-site selection. On the basis of location optimization of wind turbine, the optimization algorithms such as single-source shortest path algorithm and minimum spanning tree algorithm were used to optimize electric lines and maintenance roads. The practice shows that the research results can provide important...

Optimal feeding rate for Nile tilapia (Oreochromis niloticus)

OpenAIRE

Chowdhury, Dilip Kumar

2011-01-01

The aim of this study was to define optimal feeding rates for Nile tilapia (Oreochromis niloticus). Four experiments were carried out to evaluate the effect of feeding rate on growth performance of larger and juvenile tilapia by means of estimating growth rates, apparent nutrient digestibilities, feed utilization, body compositions, and nutrient and energy retentions. One nutritionally balanced diet (crude protein 342, crude fat 67, ash 47, starch 251 (all values in g (kg dry matter)-1)) was ...

Look on the bright side: do the benefits of optimism depend on the social nature of the stressor?

Science.gov (United States)

Terrill, Alexandra L; Ruiz, John M; Garofalo, John P

2010-10-01

Growing evidence suggests that a number of personality traits associated with physical disease risk tend to be social in nature and selectively responsive to social as opposed to non-social stimuli. The current aim was to examine dispositional optimism within this framework. In Study 1, optimism was projected into the Interpersonal Circumplex and Five Factor Model revealing significant interpersonal representation characterized by high control and affiliation. Study 2 demonstrated that higher dispositional optimism attenuated cardiovascular responses to a social (speech) but not non-social stressor (cold pressor) task. Optimism-related attenuation of reactivity to the social vs. non-social stressor contributes further evidence to an emerging picture of psychosocial risk as largely reflecting person x social environment interactions.

Parallel and Cooperative Particle Swarm Optimizer for Multimodal Problems

Directory of Open Access Journals (Sweden)

Geng Zhang

2015-01-01

Full Text Available Although the original particle swarm optimizer (PSO method and its related variant methods show some effectiveness for solving optimization problems, it may easily get trapped into local optimum especially when solving complex multimodal problems. Aiming to solve this issue, this paper puts forward a novel method called parallel and cooperative particle swarm optimizer (PCPSO. In case that the interacting of the elements in D-dimensional function vector X=[x1,x2,…,xd,…,xD] is independent, cooperative particle swarm optimizer (CPSO is used. Based on this, the PCPSO is presented to solve real problems. Since the dimension cannot be split into several lower dimensional search spaces in real problems because of the interacting of the elements, PCPSO exploits the cooperation of two parallel CPSO algorithms by orthogonal experimental design (OED learning. Firstly, the CPSO algorithm is used to generate two locally optimal vectors separately; then the OED is used to learn the merits of these two vectors and creates a better combination of them to generate further search. Experimental studies on a set of test functions show that PCPSO exhibits better robustness and converges much closer to the global optimum than several other peer algorithms.

Genetic Algorithm and its Application in Optimal Sensor Layout

Directory of Open Access Journals (Sweden)

Xiang-Yang Chen

2015-05-01

Full Text Available This paper aims at the problem of multi sensor station distribution, based on multi- sensor systems of different types as the research object, in the analysis of various types of sensors with different application background, different indicators of demand, based on the different constraints, for all kinds of multi sensor station is studied, the application of genetic algorithms as a tool for the objective function of the models optimization, then the optimal various types of multi sensor station distribution plan, improve the performance of the system, and achieved good military effect. In the field of application of sensor radar, track measuring instrument, the satellite, passive positioning equipment of various types, specific problem, use care indicators and station arrangement between the mathematical model of geometry, using genetic algorithm to get the optimization results station distribution, to solve a variety of practical problems provides useful help, but also reflects the improved genetic algorithm in electronic weapon system based on multi sensor station distribution on the applicability and effectiveness of the optimization; finally the genetic algorithm for integrated optimization of multi sensor station distribution using the good to the training exercise tasks based on actual in, and have achieved good military effect.

Optimization of mechanical properties of structures from the point of aseismic design

International Nuclear Information System (INIS)

Model, N.; Dineva, P.; Hadjikov, L.

1987-01-01

The vibroinsulation problem is solved by passive and active dynamic systems control methods. The attacking of the problem by design of vibroisolators that passively extinguish the harmful vibration has begun historically earlier. Quite in the latest years some attention has been drawn on the possibility about dynamical system's active control. But the questions about the technical realization at the optimal and the modal regulators making the behaviour safe during earthquake remains open until now. The optimal control theory application to the aims of the dynamical systems stability motion (systems being described as rigid, nondeformable solids) by a passive vibroinsulation is done. Thus the optimal dynamic system properties are identified without one having to solve the problem about a technical realization of active control equipments. An aim of this paper is an application of an optimal control theory to obtaining optimal elastic and dissipative characteristics of the buildings at their aseismic design

Conventional treatment planning optimization using simulated annealing

International Nuclear Information System (INIS)

Morrill, S.M.; Langer, M.; Lane, R.G.

1995-01-01

Purpose: Simulated annealing (SA) allows for the implementation of realistic biological and clinical cost functions into treatment plan optimization. However, a drawback to the clinical implementation of SA optimization is that large numbers of beams appear in the final solution, some with insignificant weights, preventing the delivery of these optimized plans using conventional (limited to a few coplanar beams) radiation therapy. A preliminary study suggested two promising algorithms for restricting the number of beam weights. The purpose of this investigation was to compare these two algorithms using our current SA algorithm with the aim of producing a algorithm to allow clinically useful radiation therapy treatment planning optimization. Method: Our current SA algorithm, Variable Stepsize Generalized Simulated Annealing (VSGSA) was modified with two algorithms to restrict the number of beam weights in the final solution. The first algorithm selected combinations of a fixed number of beams from the complete solution space at each iterative step of the optimization process. The second reduced the allowed number of beams by a factor of two at periodic steps during the optimization process until only the specified number of beams remained. Results of optimization of beam weights and angles using these algorithms were compared using a standard cadre of abdominal cases. The solution space was defined as a set of 36 custom-shaped open and wedged-filtered fields at 10 deg. increments with a target constant target volume margin of 1.2 cm. For each case a clinically-accepted cost function, minimum tumor dose was maximized subject to a set of normal tissue binary dose-volume constraints. For this study, the optimized plan was restricted to four (4) fields suitable for delivery with conventional therapy equipment. Results: The table gives the mean value of the minimum target dose obtained for each algorithm averaged over 5 different runs and the comparable manual treatment

Optimization of directional elastic energy propagation

DEFF Research Database (Denmark)

Andreassen, Erik; Chang, Hannah R.; Ruzzene, Massimo

2016-01-01

The aim of this paper is to demonstrate how topology optimization can be used to design a periodically perforated plate, in order to obtain a tailored anisotropic group velocity profile. The main method is demonstrated on both low and high frequency bending wave propagation in an aluminum plate......, but is general in the sense that it could be used to design periodic structures with frequency dependent group velocity profiles for any kind of elastic wave propagation. With the proposed method the resulting design is manufacturable. Measurements on an optimized design compare excellently with the numerical...

A Comparative Study on Recently-Introduced Nature-Based Global Optimization Methods in Complex Mechanical System Design

Directory of Open Access Journals (Sweden)

Abdulbaset El Hadi Saad

2017-10-01

Full Text Available Advanced global optimization algorithms have been continuously introduced and improved to solve various complex design optimization problems for which the objective and constraint functions can only be evaluated through computation intensive numerical analyses or simulations with a large number of design variables. The often implicit, multimodal, and ill-shaped objective and constraint functions in high-dimensional and “black-box” forms demand the search to be carried out using low number of function evaluations with high search efficiency and good robustness. This work investigates the performance of six recently introduced, nature-inspired global optimization methods: Artificial Bee Colony (ABC, Firefly Algorithm (FFA, Cuckoo Search (CS, Bat Algorithm (BA, Flower Pollination Algorithm (FPA and Grey Wolf Optimizer (GWO. These approaches are compared in terms of search efficiency and robustness in solving a set of representative benchmark problems in smooth-unimodal, non-smooth unimodal, smooth multimodal, and non-smooth multimodal function forms. In addition, four classic engineering optimization examples and a real-life complex mechanical system design optimization problem, floating offshore wind turbines design optimization, are used as additional test cases representing computationally-expensive black-box global optimization problems. Results from this comparative study show that the ability of these global optimization methods to obtain a good solution diminishes as the dimension of the problem, or number of design variables increases. Although none of these methods is universally capable, the study finds that GWO and ABC are more efficient on average than the other four in obtaining high quality solutions efficiently and consistently, solving 86% and 80% of the tested benchmark problems, respectively. The research contributes to future improvements of global optimization methods.

Combustion optimization and HCCI modeling for ultra low emission

Energy Technology Data Exchange (ETDEWEB)

Koten, Hasan; Yilmaz, Mustafa; Zafer Gul, M. [Marmara University Mechanical Engineering Department (Turkey)], E-mail: hasan.koten@marmara.edu.tr

2011-07-01

With the coming shortage of fossil fuels and the rising concerns over the environment it is important to develop new technologies both to reduce energy consumption and pollution at the same time. In the transportation sector, new combustion processes are under development to provide clean diesel combustion with no particulate or NOx emissions. However, these processes have issues such as limited power output, high levels of unburned hydrocarbons, and carbon monoxide emissions. The aim of this paper is to present a methodology for optimizing combustion performance. The methodology consists of the use of a multi-objective genetic algorithm optimization tool; homogeneous charge compression ignition engine cases were studied with the ECFM-3Z combustion model. Results showed that injected fuel mass led to a decrease in power output, a finding which is in keeping with previous research. This paper presented on optimization tool which can be useful in improving the combustion process.

Design and Optimization of Domperidone Fast Dissolving Tablet Using Central Composite Design.

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Shailendra, Bhatt; Shailendra, Mandge; Manish, Jaimini; Singh, Tanwar Yuveraj; Priti, Trivedi

2015-01-01

The main aim present work was to optimize fast dissolving tablet (FDT) formulation using response surface approach. The variables studied were sodium bicarbonate (X1), citric acid (X2), and superdisintegrant, Ac-Di-Sol (X3). The main aspect of present work was to develop FDT of Domperidone which possesses fast disintegration and high mechanical strength. It was found that the response was affected by all the three factors studied. The statistical models were successfully used to prepare FDT of Domperidone with fast disintegration (31.08 seconds) and adequate hardness (4.1 kg/cm(2)). Pharmacokinetic studies in rats showed statistically insignificant difference (p>0.05) between Domperidone fast dissolving tablet (DFDT) and market product. This concluded that optimized FDT is bioequivalent with the marketed formulation. The values of Tmax were found to be 0.5 h and 0.75 h for DFDT and reference product, respectively. Conditioned place aversion study was performed on Swiss Albino mice and the study showed the better anti emetic potency of optimized FDT in nauseated condition over market product (pdisintegration and high mechanical strength.

Optimism on quality of life in Portuguese chronic patients: moderator/mediator?

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Vilhena, Estela; Pais-Ribeiro, José; Silva, Isabel; Pedro, Luísa; Meneses, Rute F; Cardoso, Helena; Silva, António Martins da; Mendonça, Denisa

2014-07-01

optimism is an important variable that has consistently been shown to affect adjustment to quality of life in chronic diseases. This study aims to clarify if dispositional optimism exerts a moderating or a mediating influence on the personality traits-quality of life association, in Portuguese chronic patients. multiple regression models were used to test the moderation and mediation effects of dispositional optimism in quality of life. A sample of 729 patients was recruited in Portugal's main hospitals and completed self-reported questionnaires assessing socio-demographic and clinical variables, personality, dispositional optimism, quality of life (QoL) and subjective well-being (SWB). the results of the regression models showed that dispositional optimism did not moderate the relationships between personality traits and quality of life. After controlling for gender, age, education level and severity of disease perception, the effects of personality traits on QoL and in SWB were mediated by dispositional optimism (partially and completely), except for the links between neuroticism/openness to experience and physical health. dispositional optimism is more likely to play a mediating, rather than a moderating role in personality traits-quality of life pathway in Portuguese chronic patients, suggesting that "the expectation that good things will happen" contributes to a better quality of life and subjective well-being.

Wavefront-guided versus wavefront-optimized laser in situ keratomileusis: contralateral comparative study.

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Padmanabhan, Prema; Mrochen, Michael; Basuthkar, Subam; Viswanathan, Deepa; Joseph, Roy

2008-03-01

To compare the outcomes of wavefront-guided and wavefront-optimized treatment in fellow eyes of patients having laser in situ keratomileusis (LASIK) for myopia. Medical and Vision Research Foundation, Tamil Nadu, India. This prospective comparative study comprised 27 patients who had wavefront-guided LASIK in 1 eye and wavefront-optimized LASIK in the fellow eye. The Hansatome (Bausch & Lomb) was used to create a superior-hinged flap and the Allegretto laser (WaveLight Laser Technologie AG), for photoablation. The Allegretto wave analyzer was used to measure ocular wavefront aberrations and the Functional Acuity Contrast Test chart, to measure contrast sensitivity before and 1 month after LASIK. The refractive and visual outcomes and the changes in aberrations and contrast sensitivity were compared between the 2 treatment modalities. One month postoperatively, 92% of eyes in the wavefront-guided group and 85% in the wavefront-optimized group had uncorrected visual acuity of 20/20 or better; 93% and 89%, respectively, had a postoperative spherical equivalent refraction of +/-0.50 diopter. The differences between groups were not statistically significant. Wavefront-guided LASIK induced less change in 18 of 22 higher-order Zernike terms than wavefront-optimized LASIK, with the change in positive spherical aberration the only statistically significant one (P= .01). Contrast sensitivity improved at the low and middle spatial frequencies (not statistically significant) and worsened significantly at high spatial frequencies after wavefront-guided LASIK; there was a statistically significant worsening at all spatial frequencies after wavefront-optimized LASIK. Although both wavefront-guided and wavefront-optimized LASIK gave excellent refractive correction results, the former induced less higher-order aberrations and was associated with better contrast sensitivity.

A model for optimizing the production of pharmaceutical products

Directory of Open Access Journals (Sweden)

Nevena Gospodinova

2017-05-01

Full Text Available The problem associated with the optimal production planning is especially relevant in modern industrial enterprises. The most commonly used optimality criteria in this context are: maximizing the total profit; minimizing the cost per unit of production; maximizing the capacity utilization; minimizing the total production costs. This article aims to explore the possibility for optimizing the production of pharmaceutical products through the construction of a mathematical model that can be viewed in two ways – as a single-product model and a multi-product model. As an optimality criterion it is set the minimization of the cost per unit of production for a given planning period. The author proposes an analytical method for solving the nonlinear optimization problem. An optimal production plan of Tylosin tartrate is found using the single-product model.

Continuous nonlinear optimization for engineering applications in GAMS technology

CERN Document Server

Andrei, Neculai

2017-01-01

This book presents the theoretical details and computational performances of algorithms used for solving continuous nonlinear optimization applications imbedded in GAMS. Aimed toward scientists and graduate students who utilize optimization methods to model and solve problems in mathematical programming, operations research, business, engineering, and industry, this book enables readers with a background in nonlinear optimization and linear algebra to use GAMS technology to understand and utilize its important capabilities to optimize algorithms for modeling and solving complex, large-scale, continuous nonlinear optimization problems or applications. Beginning with an overview of constrained nonlinear optimization methods, this book moves on to illustrate key aspects of mathematical modeling through modeling technologies based on algebraically oriented modeling languages. Next, the main feature of GAMS, an algebraically oriented language that allows for high-level algebraic representation of mathematical opti...

Optimization of the radiation protection in industrial field: study of some practical cases

International Nuclear Information System (INIS)

Muglioni, P.

1998-01-01

Two situations are studied: the case of stationary gauges where the situation is sure with little actions to do to optimize the radiation protection and the case of mobile sources where the sources can submit to important exposure. In these conditions, the best way to optimize the radiation protection is to integrate the constraints, to put in operation a dosimetry and to keep a correct level of radiation protection information. (N.C.)

Study on optimal performance and working temperatures of endoreversible forward and reverse Carnot cycles

Energy Technology Data Exchange (ETDEWEB)

Chen, W.Z.; Sun, F.R.; Cheng, S.M.; Chen, L.G. [Huazhong Univ. of Sceince and Technology, Wuhan (China). Dept. of Power Engineering

1995-12-01

The connection between the expressions of optimization performances of Carnot heat engines, refrigerators and heat pumps, which operate subject to irreversible heat flow, is studied. We consider the endoreversible forward and reverse. Carnot cycles and analyse the expressions which relate efficiency, refrigeration and heating coefficients to power, refrigeration and heating rates, respectively. It is found and proved that when one of the optimal relations is derived the others are also determined, and give the unified formulation of the related optimal working temperatures of the forward and reverse Carnot cycles by isentropic temperature ratio exponent. Finally, several new optimal performance relations are derived for forward and reverse Carnot cycles under nonlinear heat transfer, and some major results in the references are easily deduced and unified in this paper. (author)

An Enhanced Memetic Algorithm for Single-Objective Bilevel Optimization Problems.

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Islam, Md Monjurul; Singh, Hemant Kumar; Ray, Tapabrata; Sinha, Ankur

2017-01-01

Bilevel optimization, as the name reflects, deals with optimization at two interconnected hierarchical levels. The aim is to identify the optimum of an upper-level  leader problem, subject to the optimality of a lower-level follower problem. Several problems from the domain of engineering, logistics, economics, and transportation have an inherent nested structure which requires them to be modeled as bilevel optimization problems. Increasing size and complexity of such problems has prompted active theoretical and practical interest in the design of efficient algorithms for bilevel optimization. Given the nested nature of bilevel problems, the computational effort (number of function evaluations) required to solve them is often quite high. In this article, we explore the use of a Memetic Algorithm (MA) to solve bilevel optimization problems. While MAs have been quite successful in solving single-level optimization problems, there have been relatively few studies exploring their potential for solving bilevel optimization problems. MAs essentially attempt to combine advantages of global and local search strategies to identify optimum solutions with low computational cost (function evaluations). The approach introduced in this article is a nested Bilevel Memetic Algorithm (BLMA). At both upper and lower levels, either a global or a local search method is used during different phases of the search. The performance of BLMA is presented on twenty-five standard test problems and two real-life applications. The results are compared with other established algorithms to demonstrate the efficacy of the proposed approach.

Optimization analysis of propulsion motor control efficiency

Directory of Open Access Journals (Sweden)

CAI Qingnan

2017-12-01

Full Text Available [Objectives] This paper aims to strengthen the control effect of propulsion motors and decrease the energy used during actual control procedures.[Methods] Based on the traditional propulsion motor equivalence circuit, we increase the iron loss current component, introduce the definition of power matching ratio, calculate the highest efficiency of a motor at a given speed and discuss the flux corresponding to the power matching ratio with the highest efficiency. In the original motor vector efficiency optimization control module, an efficiency optimization control module is added so as to achieve motor efficiency optimization and energy conservation.[Results] MATLAB/Simulink simulation data shows that the efficiency optimization control method is suitable for most conditions. The operation efficiency of the improved motor model is significantly higher than that of the original motor model, and its dynamic performance is good.[Conclusions] Our motor efficiency optimization control method can be applied in engineering to achieve energy conservation.

Managing the Public Sector Research and Development Portfolio Selection Process: A Case Study of Quantitative Selection and Optimization

Science.gov (United States)

2016-09-01

PUBLIC SECTOR RESEARCH & DEVELOPMENT PORTFOLIO SELECTION PROCESS: A CASE STUDY OF QUANTITATIVE SELECTION AND OPTIMIZATION by Jason A. Schwartz...PUBLIC SECTOR RESEARCH & DEVELOPMENT PORTFOLIO SELECTION PROCESS: A CASE STUDY OF QUANTITATIVE SELECTION AND OPTIMIZATION 5. FUNDING NUMBERS 6...describing how public sector organizations can implement a research and development (R&D) portfolio optimization strategy to maximize the cost

A novel heuristic method for optimization of straight blade vertical axis wind turbine

International Nuclear Information System (INIS)

Tahani, Mojtaba; Babayan, Narek; Mehrnia, Seyedmajid; Shadmehri, Mehran

2016-01-01

Highlights: • A novel heuristic method has been proposed for optimization of VAWTs. • The proposed method is the combination of DMST model with heuristic algorithms. • A continuous/discrete optimization problem has been solved. • A novel continuous optimization algorithm has been developed. • The CFD simulation of the optimized geometry has been carried out. - Abstract: In this research study it is aimed to propose a novel heuristic method for optimizing the VAWT design. The method is the combination of continuous/discrete optimization algorithms with double multiple stream tube (DMST) theory. For this purpose a DMST code has been developed and is validated using available experimental data in literature. A novel continuous optimization algorithm is proposed which can be considered as the combination of three heuristic optimization algorithms namely elephant herding optimization, flower pollination algorithm and grey wolf optimizer. The continuous algorithm is combined with popular discrete ant colony optimization algorithm (ACO). The proposed method can be utilized for several engineering problems which are dealing with continuous and discrete variables. In this research study, chord and diameter of the turbine are selected as continuous decision variables and airfoil types and number of blades are selected as discrete decision variables. The average power coefficient between tip speed rations from 1.5 to 9.5 is considered as the objective function. The optimization results indicated that the optimized geometry can produce a maximum power coefficient, 44% higher than the maximum power coefficient of the original turbine. Also a CFD simulation of the optimized geometry is carried out. The CFD results indicated that the average vorticity magnitude around the optimized blade is larger than the original blade and this results greater momentum and power coefficient.

Optimization of time characteristics in activation analysis

International Nuclear Information System (INIS)

Gurvich, L.G.; Umaraliev, A.T.

2006-01-01

Full text: The activation analysis temporal characteristics optimization methods developed at present are aimed at determination of optimal values of the three important parameters - irradiation time, cooling time and measurement time. In the performed works, especially in [1-5] the activation analysis processes are described, the optimal values of optimization parameters are obtained from equations solved, and the computational results are given for these parameters for a number of elements. However, the equations presented in [2] were inaccurate, did not allow one to have optimization parameters results for one element content calculations, and it did not take into account background dependence of time. Therefore, we proposed modified equations to determine the optimal temporal parameters and iteration processes for the solution of these equations. It is well-known that the activity of studied sample during measurements does not change significantly, i.e. measurement time is much shorter than the half-life, thus the processes taking place can be described by the Poisson probability distribution, and in general case one can apply binomial distribution. The equation and iteration processes use in this research describe both probability distributions. Expectedly, the cooling time iteration expressions obtained for one element analysis case are similar for the both distribution types, as the optimised time values occurred to be of the same order as half-life values, whereas the cooling time, as we observed, depends on the ratio of the studied sample's peak value to the background peak, and can be significantly larger than the half-life value. This pattern is general, and can be derived from the optimized time expressions, which is supported by the experimental data on short-living isotopes [3,4]. For the isotopes with large half-lives, up to years, like cobalt-60, the cooling time values given in the above mentioned works are equal to months which, apparently

Optimal designs for population pharmacokinetic studies of oral artesunate in patients with uncomplicated falciparum malaria

Directory of Open Access Journals (Sweden)

Lindegardh Niklas

2011-07-01

Full Text Available Abstract Background Currently, population pharmacokinetic (PK studies of anti-malarial drugs are designed primarily by the logistical and ethical constraints of taking blood samples from patients, and the statistical models that are fitted to the data are not formally considered. This could lead to imprecise estimates of the target PK parameters, and/or designs insufficient to estimate all of the parameters. Optimal design methodology has been developed to determine blood sampling schedules that will yield precise parameter estimates within the practical constraints of sampling the study populations. In this work optimal design methods were used to determine sampling designs for typical future population PK studies of dihydroartemisinin, the principal biologically active metabolite of oral artesunate. Methods Optimal designs were derived using freely available software and were based on appropriate structural PK models from an analysis of data or the literature and key sampling constraints identified in a questionnaire sent to active malaria researchers (3-4 samples per patient, at least 15 minutes between samples. The derived optimal designs were then evaluated via simulation-estimation. Results The derived optimal sampling windows were 17 to 29 minutes, 30 to 57 minutes, 2.5 to 3.7 hours and 5.8 to 6.6 hours for non-pregnant adults; 16 to 29 minutes, 31 minutes to 1 hour, 2.0 to 3.4 hours and 5.5 to 6.6 hours for designs with non-pregnant adults and children and 35 to 59 minutes, 1.2 to 3.4 hours, 3.4 to 4.9 hours and 6.0 to 8.0 hours for pregnant women. The optimal designs resulted in acceptable precision of the PK parameters. Conclusions The proposed sampling designs in this paper are robust and efficient and should be considered in future PK studies of oral artesunate where only three or four blood samples can be collected.

Optimizing the Delivery of Short-Lived Alpha Particle-Emitting Isotopes to Solid Tumors

International Nuclear Information System (INIS)

Adams, Gregory P.

2004-01-01

The underlying hypothesis of this project was that optimal alpha emitter-based radioimmunotherapy (RAIT) could be achieved by pairing the physical half-life of the radioisotope to the biological half-life of the targeting vehicle. The project had two specific aims. The first aim was to create and optimize the therapeutic efficacy of 211At-SAPS-C6.5 diabody conjugates. The second aim was to develop bispecific-targeting strategies that increase the specificity and efficacy of alpha-emitter-based RAIT. In the performance of the first aim, we created 211At-SAPS-C6.5 diabody conjugates that specifically targeted the HER2 tumor associated antigen. In evaluating these immunoconjugates we determined that they were capable of efficient tumor targeting and therapeutic efficacy of established human tumor xenografts growing in immunodeficient mice. We also determined that therapeutic doses were associated with late renal toxicity, likely due to the role of the kidneys in the systemic elimination o f these agents. We are currently performing more studies focused on better understanding the observed toxicity. In the second aim, we successfully generated bispecific single-chain Fv (bs-scFv) molecules that co-targeted HER2 and HER3 or HER2 and HER4. The in vitro kinetics and in vivo tumor-targeting properties of these molecules were evaluated. These studies revealed that the bs-scFv molecules selectively localized in vitro on tumor cells that expressed both antigens and were capable of effective tumor localization in in vivo studies

Optimizing the Delivery of Short-Lived Alpha Particle-Emitting Isotopes to Solid Tumors

Energy Technology Data Exchange (ETDEWEB)

Adams, Gregory P.

2004-11-24

The underlying hypothesis of this project was that optimal alpha emitter-based radioimmunotherapy (RAIT) could be achieved by pairing the physical half-life of the radioisotope to the biological half-life of the targeting vehicle. The project had two specific aims. The first aim was to create and optimize the therapeutic efficacy of 211At-SAPS-C6.5 diabody conjugates. The second aim was to develop bispecific-targeting strategies that increase the specificity and efficacy of alpha-emitter-based RAIT. In the performance of the first aim, we created 211At-SAPS-C6.5 diabody conjugates that specifically targeted the HER2 tumor associated antigen. In evaluating these immunoconjugates we determined that they were capable of efficient tumor targeting and therapeutic efficacy of established human tumor xenografts growing in immunodeficient mice. We also determined that therapeutic doses were associated with late renal toxicity, likely due to the role of the kidneys in the systemic elimination o f these agents. We are currently performing more studies focused on better understanding the observed toxicity. In the second aim, we successfully generated bispecific single-chain Fv (bs-scFv) molecules that co-targeted HER2 and HER3 or HER2 and HER4. The in vitro kinetics and in vivo tumor-targeting properties of these molecules were evaluated. These studies revealed that the bs-scFv molecules selectively localized in vitro on tumor cells that expressed both antigens and were capable of effective tumor localization in in vivo studies.

Optimism and the brain: trait optimism mediates the protective role of the orbitofrontal cortex gray matter volume against anxiety.

Science.gov (United States)

Dolcos, Sanda; Hu, Yifan; Iordan, Alexandru D; Moore, Matthew; Dolcos, Florin

2016-02-01

Converging evidence identifies trait optimism and the orbitofrontal cortex (OFC) as personality and brain factors influencing anxiety, but the nature of their relationships remains unclear. Here, the mechanisms underlying the protective role of trait optimism and of increased OFC volume against symptoms of anxiety were investigated in 61 healthy subjects, who completed measures of trait optimism and anxiety, and underwent structural scanning using magnetic resonance imaging. First, the OFC gray matter volume (GMV) was associated with increased optimism, which in turn was associated with reduced anxiety. Second, trait optimism mediated the relation between the left OFC volume and anxiety, thus demonstrating that increased GMV in this brain region protects against symptoms of anxiety through increased optimism. These results provide novel evidence about the brain-personality mechanisms protecting against anxiety symptoms in healthy functioning, and identify potential targets for preventive and therapeutic interventions aimed at reducing susceptibility and increasing resilience against emotional disturbances. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Optimization of fermentation parameters to study the behavior of selected lactic cultures on soy solid state fermentation.

Science.gov (United States)

Rodríguez de Olmos, A; Bru, E; Garro, M S

2015-03-02

The use of solid fermentation substrate (SSF) has been appreciated by the demand for natural and healthy products. Lactic acid bacteria and bifidobacteria play a leading role in the production of novel functional foods and their behavior is practically unknown in these systems. Soy is an excellent substrate for the production of functional foods for their low cost and nutritional value. The aim of this work was to optimize different parameters involved in solid state fermentation (SSF) using selected lactic cultures to improve soybean substrate as a possible strategy for the elaboration of new soy food with enhanced functional and nutritional properties. Soy flour and selected lactic cultures were used under different conditions to optimize the soy SSF. The measured responses were bacterial growth, free amino acids and β-glucosidase activity, which were analyzed by applying response surface methodology. Based on the proposed statistical model, different fermentation conditions were raised by varying the moisture content (50-80%) of the soy substrate and temperature of incubation (31-43°C). The effect of inoculum amount was also investigated. These studies demonstrated the ability of selected strains (Lactobacillus paracasei subsp. paracasei and Bifidobacterium longum) to grow with strain-dependent behavior on the SSF system. β-Glucosidase activity was evident in both strains and L. paracasei subsp. paracasei was able to increase the free amino acids at the end of fermentation under assayed conditions. The used statistical model has allowed the optimization of fermentation parameters on soy SSF by selected lactic strains. Besides, the possibility to work with lower initial bacterial amounts to obtain results with significant technological impact was demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

Enhanced transdermal delivery of ondansetron using nanovesicular systems: Fabrication, characterization, optimization and ex-vivo permeation study-Box-Cox transformation practical example.