Predictor-corrector methods of Runge-Kutta type for stochastic differential equations

In this paper we construct predictor-corrector (PC) methods based on the trivial predictor and stochastic implicit Runge-Kutta (RK) correctors for solving stochastic differential equations. Using the colored rooted tree theory and stochastic B-series, the order condition theorem is derived for constructing stochastic RK methods based on PC implementations. We also present detailed order conditions of the PC methods using stochastic implicit RK correctors with strong global order 1.0 and 1.5. A two-stage implicit RK method with strong global order 1.0 and a four-stage implicit RK method with strong global order 1.5 used as the correctors are constructed in this paper. The mean-square stability properties and numerical results of the PC methods based on these two implicit RK correctors are reported.

An atomistic simulation of solid state sintering using Monte Carlo methods

This paper presents results on the simulation of the solid state sintering of copper wires using Monte Carlo techniques based on elements of lattice theory and cellular automata. The initial structure is superimposed onto a triangular, two-dimensional lattice, where each lattice site corresponds to either an atom or vacancy. The number of vacancies varies with the simulation temperature, while a cluster of vacancies is a pore. To simulate sintering, lattice sites are picked at random and reoriented in terms of an atomistic model governing mass transport. The probability that an atom has sufficient energy to jump to a vacant lattice site is related to the jump frequency, and hence the diffusion coefficient, while the probability that an atomic jump will be accepted is related to the change in energy of the system as a result of the jump, as determined by the change in the number of nearest neighbours. The jump frequency is also used to relate model time, measured in Monte Carlo Steps, to the actual sintering time. The model incorporates bulk, grain boundary and surface diffusion terms and includes vacancy annihilation on the grain boundaries. The predictions of the model were found to be consistent with experimental data, both in terms of the microstructural evolution and in terms of the sintering time. (C) 2002 Elsevier Science B.V. All rights reserved.

Estimation of total body water from bioelectrical impedance analysis in patients with pancreatic cancer - agreement between three methods of prediction

Introduction Bioelectrical impedance analysis (BIA) is a useful field measure to estimate total body water (TBW). No prediction formulae have been developed or validated against a reference method in patients with pancreatic cancer. The aim of this study was to assess the agreement between three prediction equations for the estimation of TBW in cachectic patients with pancreatic cancer. Methods Resistance was measured at frequencies of 50 and 200 kHz in 18 outpatients (10 males and eight females, age 70.2 +/- 11.8 years) with pancreatic cancer from two tertiary Australian hospitals. Three published prediction formulae were used to calculate TBW - TBWs developed in surgical patients, TBWca-uw and TBWca-nw developed in underweight and normal weight patients with end-stage cancer. Results There was no significant difference in the TBW estimated by the three prediction equations - TBWs 32.9 +/- 8.3 L, TBWca-nw 36.3 +/- 7.4 L, TBWca-uw 34.6 +/- 7.6 L. At a population level, there is agreement between prediction of TBW in patients with pancreatic cancer estimated from the three equations. The best combination of low bias and narrow limits of agreement was observed when TBW was estimated from the equation developed in the underweight cancer patients relative to the normal weight cancer patients. When no established BIA prediction equation exists, practitioners should utilize an equation developed in a population with similar critical characteristics such as diagnosis, weight loss, body mass index and/or age. Conclusions Further research is required to determine the accuracy of the BIA prediction technique against a reference method in patients with pancreatic cancer.

A subset-oriented algorithm for minimizing the number of steps required for synthesis of cyclic-peptide libraries

Libraries of cyclic peptides are being synthesized using combinatorial chemistry for high throughput screening in the drug discovery process. This paper describes the min_syn_steps.cpp program (available at http://www.imb.uq.edu.au/groups/smythe/tran), which after inputting a list of cyclic peptides to be synthesized, removes cyclic redundant sequences and calculates synthetic strategies which minimize the synthetic steps as well as the reagent requirements. The synthetic steps and reagent requirements could be minimized by finding common subsets within the sequences for block synthesis. Since a brute-force approach to search for optimum synthetic strategies is impractically large, a subset-orientated approach is utilized here to limit the size of the search. (C) 2002 Elsevier Science Ltd. All rights reserved.

Control of Aedes vectors of dengue in three provinces of Vietnam by use of Mesocyclops (Copepoda) and community-based methods validated by entomologic, clinical, and serological surveillance

We describe remarkable success in controlling dengue vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), in 6 communes with 11,675 households and 49,647 people in the northern provinces of Haiphong, Hung Yen, and Nam Dinh in Vietnam. The communes were selected for high-frequency use of large outdoor concrete tanks and wells. These were found to be the source of 49.6-98.4% of Ae. aegypti larvae, which were amenable to treatment with local Mesocyclops, mainly M. woutersi Van der Velde, M. aspericornis (Daday) and M. thermocyclopoides Harada. Knowledge, attitude, and practice surveys were performed to determine whether the communities viewed dengue and dengue hemorrhagic fever as a serious health threat; to determine their knowledge of the etiology, attitudes, and practices regarding control methods including Mesocyclops; and to determine their receptivity to various information methods. On the basis of the knowledge, attitude, and practice data, the community-based dengue control program comprised a system of local leaders, health volunteer teachers, and schoolchildren, supported by health professionals. Recycling of discards for economic gain was enhanced, where appropriate, and this, plus 37 clean-up campaigns, removed small containers unsuitable for Mesocyclops treatment. A previously successful eradication at Phan Boi village (Hung Yen province) was extended to 7 other villages forming Di Su commune (1,750 households) in the current study. Complete control was also achieved in Nghia Hiep (Hung Yen province) and in Xuan Phong (Nam Dinh province); control efficacy was greater than or equal to 99.7% in the other 3 communes (Lac Vien in Haiphong, Nghia Dong, and Xuan Kien in Nam Dinh). Although tanks and wells were the key container types of Ae. aegypti productivity, discarded materials were the source of 51% of the standing crop of Ae. albopictus. Aedes albopictus larvae were eliminated from the 3 Nam Dinh communes, and 86-98% control was achieved in the other 3 communes. Variable dengue attack rates made the clinical and serological comparison of control and untreated communes problematic, but these data indicate that clinical surveillance by itself is inadequate to monitor dengue transmission.

Rock fracture mean trace length estimation and confidence interval calculation using maximum likelihood methods

There has been a resurgence of interest in the mean trace length estimator of Pahl for window sampling of traces. The estimator has been dealt with by Mauldon and Zhang and Einstein in recent publications. The estimator is a very useful one in that it is non-parametric. However, despite some discussion regarding the statistical distribution of the estimator, none of the recent works or the original work by Pahl provide a rigorous basis for the determination a confidence interval for the estimator or a confidence region for the estimator and the corresponding estimator of trace spatial intensity in the sampling window. This paper shows, by consideration of a simplified version of the problem but without loss of generality, that the estimator is in fact the maximum likelihood estimator (MLE) and that it can be considered essentially unbiased. As the MLE, it possesses the least variance of all estimators and confidence intervals or regions should therefore be available through application of classical ML theory. It is shown that valid confidence intervals can in fact be determined. The results of the work and the calculations of the confidence intervals are illustrated by example. (C) 2003 Elsevier Science Ltd. All rights reserved.

Stereological and other methods applied to rock joint size estimation - Does Crofton's theorem apply?

A number of authors concerned with the analysis of rock jointing have used the idea that the joint areal or diametral distribution can be linked to the trace length distribution through a theorem attributed to Crofton. This brief paper seeks to demonstrate why Crofton's theorem need not be used to link moments of the trace length distribution captured by scan line or areal mapping to the moments of the diametral distribution of joints represented as disks and that it is incorrect to do so. The valid relationships for areal or scan line mapping between all the moments of the trace length distribution and those of the joint size distribution for joints modeled as disks are recalled and compared with those that might be applied were Crofton's theorem assumed to apply. For areal mapping, the relationship is fortuitously correct but incorrect for scan line mapping.

Selecting methods to solve multi-well master equations

There are several competing methods commonly used to solve energy grained master equations describing gas-phase reactive systems. When it comes to selecting an appropriate method for any particular problem, there is little guidance in the literature. In this paper we directly compare several variants of spectral and numerical integration methods from the point of view of computer time required to calculate the solution and the range of temperature and pressure conditions under which the methods are successful. The test case used in the comparison is an important reaction in combustion chemistry and incorporates reversible and irreversible bimolecular reaction steps as well as isomerizations between multiple unimolecular species. While the numerical integration of the ODE with a stiff ODE integrator is not the fastest method overall, it is the fastest method applicable to all conditions.

A comparison of two methods for the calculation of accumulated oxygen deficit

The aim of this study was to compare accumulated oxygen deficit data derived using two different exercise protocols with the aim of producing a less time-consuming test specifically for use with athletes. Six road and four track male endurance cyclists performed two series of cycle ergometer tests. The first series involved five 10 min sub-maximal cycle exercise bouts, a (V) over dotO(2peak) test and a 115% (V) over dotO(2peak) test. Data from these tests were used to estimate the accumulated oxygen deficit according to the calculations of Medbo et al. (1988). In the second series of tests, participants performed a 15 min incremental cycle ergometer test followed, 2 min later, by a 2 min variable resistance test in which they completed as much work as possible while pedalling at a constant rate. Analysis revealed that the accumulated oxygen deficit calculated from the first series of tests was higher (P< 0.02) than that calculated from the second series: 52.3 +/- 11.7 and 43.9 +/- 6.4 ml . kg(-1), respectively (mean +/- s). Other significant differences between the two protocols were observed for (V) over dot O-2peak, total work and maximal heart rate; all were higher during the modified protocol (P

Plano de implementa????o do projeto de desenvolvimento de capacidade de governan??a

Desde a d??cada de 1990, o Governo Federal brasileiro vem implementando uma agenda ambiciosa de reformas do Estado, centradas na redu????o da pobreza e na melhoria da efici??ncia dos servi??os p??blicos. As principais prioridades, conforme previstas no Plano Plurianual (PPA) para o per??odo 2003-2007, s??o as seguintes: inclus??o social e redu????o da desigualdade; crescimento econ??mico com gera????o de emprego; distribui????o de renda e respeito ao meio ambiente; promo????o e amplia????o dos direitos de cidadania; e fortalecimento da democracia. No in??cio de 2006, o Governo criou a Pol??tica Nacional de Desenvolvimento de Pessoal (Decreto 5.707), com o objetivo de melhorar e aumentar a efici??ncia e a efic??cia na presta????o de servi??os p??blicos. No marco dessa pol??tica recente, as escolas de administra????o p??blica desempenham um papel fundamental na identifica????o das compet??ncias que precisam ser desenvolvidas nas institui????es do governo, bem como na implementa????o de pol??ticas de capacita????o para os servidores p??blicos, diretamente e/ou em parceria com escolas de governo nos n??veis federal, estadual ou local. O Canad?? tamb??m est?? criando uma estrutura para levantar as compet??ncias necess??rias para os servidores p??blicos e desenvolv??-las como um componente da Renova????o do Servi??o P??blico em todo o governo. Como institui????es l??deres no desenvolvimento de compet??ncias de servidores p??blicos, a Canada School of Public Service (CSPS) e a Escola Nacional de Administra????o P??blica (ENAP) firmaram uma parceria para implementar o Projeto de Desenvolvimento de Capacidade de Governan??a no Brasil. A finalidade do Projeto ?? melhorar a capacidade de servidores p??blicos federais, estaduais e municipais do Brasil para desenvolver e implementar programas de capacita????o e gerenciar pol??ticas p??blicas descentralizadas. Espera-se que essa parceria e o resultante compartilhamento de experi??ncias em capacita????o para governan??a efetiva contribuam para a redu????o da pobreza e das desigualdades no Brasil, por meio do desenvolvimento de compet??ncias de servidores na presta????o de servi??os p??blicos eficazes e eficientes, voltados para o cidad??o. O Projeto re??ne, al??m das duas principais Escolas de Governo no Canad?? e no Brasil, seis Escolas Brasileiras de Administra????o P??blica regionais e duas renomadas Institui????es Acad??micas Canadenses ??? a Queen???s University e a Western Ontario University. O Minist??rio do Desenvolvimento Social e Combate ?? Fome (MDS) e tr??s Secretarias Especiais do Governo Federal ??? Ra??a (SEPPIR), Direitos Humanos (SEDH) e Pol??ticas para as Mulheres (SPM) ??? tamb??m se envolver??o nas atividades de compartilhamento de conhecimentos com o Human Resources and Skills Development Canada (HRSDC) e a Canada Public Service Agency (CPSA). A CIDA fornecer?? CND$1.700.000 por meio do Programa Brasil-Canad?? de Interc??mbio de Conhecimentos para a Promo????o da Equidade (PIPE). A contribui????o da ENAP ser?? de CND$1.069.707 em esp??cie. A CSPS contribuir?? com cursos, al??m de conhecimentos e suporte t??cnicos, avaliados em CND$1.000.000. Aproveitando a parceria entre a CSPS e a ENAP, que resultou na transfer??ncia e na adapta????o bem sucedidas de cursos e metodologias canadenses, o novo projeto extrapola o n??cleo do servi??o p??blico em Bras??lia, alcan??ando escolas de governo em regi??es brasileiras em situa????o de desvantagem. ?? semelhan??a do papel da CSPS no primeiro projeto, a ENAP fortalecer?? a capacidade das escolas parceiras regionais para capacitar servidores p??blicos envolvidos na presta????o de servi??os aos brasileiros. O interc??mbio estruturado entre Minist??rios dos Governos canadense e brasileiro tamb??m aplicar?? a aprendizagem mais diretamente a quest??es de pol??ticas e programas sociais do Brasil. O desafio assumido neste Projeto ?? a adapta????o de conhecimentos e aprendizagem, com vistas a melhorar a implementa????o de pol??ticas e programas sociais. Para tanto, a CSPS e a ENAP introduzir??o novos cursos nos curr??culos das escolas parceiras e incorporar??o novos m??todos e tecnologias de aprendizagem como, por exemplo, comunidades de pr??tica virtuais e um componente de tutoria (mentoring) envolvendo o Human Resources and Skills Development Canada e o Minist??rio do Desenvolvimento Social e Combate ?? Fome do Brasil. Seis institui????es da Rede Nacional de Escolas de Governo do Brasil e do Programa de Parceria da ENAP foram selecionadas e convidadas a se unir ?? CSPS e ?? ENAP nesse novo Projeto: a Universidade Federal do Par?? (UFPA), de Bel??m (estado do Par?? ??? regi??o Norte); a Funda????o Joaquim Nabuco (FUNDAJ), de Recife (Pernambuco ??? Nordeste); a Universidade Corporativa do Servi??o P??blico / Secretaria de Administra????o do Estado da Bahia (UCS/SAEB), Salvador (Bahia ??? Nordeste); a Escola de Governo do Mato Grosso do Sul (ESCOLAGOV), Campo Grande (estado do Mato Grosso do Sul ??? Centro-Oeste); a Escola Nacional de Ci??ncias Estat??sticas / Instituto Brasileiro de Geografia e Estat??stica (ENCE/IBGE), Rio de Janeiro (estado do Rio de Janeiro ??? Sudeste); e o Instituto Municipal de Administra????o P??blica (IMAP) de Curitiba (Paran?? ??? Sul). Essas escolas de refer??ncia foram escolhidas segundo sua capacidade de trabalhar como p??los de pr??ticas inovadoras em pol??ticas p??blicas e disseminar os benef??cios do Projeto para outras escolas em suas regi??es, por meio da Rede Nacional coordenada pela ENAP. O objetivo dessa parceria ?? fortalecer as escolas de governo locais, para que estas desenvolvam, por meio de eventos de aprendizagem, compet??ncias em servidores p??blicos, a fim de aumentar a capacidade do governo na implementa????o e gest??o de pol??ticas p??blicas. O Plano de Implementa????o do Projeto (PIP) descreve o trabalho a ser realizado por essas institui????es nos pr??ximos 30 meses, ao tempo em que serve de guia para os Parceiros do Projeto no que se refere ??s a????es e aos recursos necess??rios para a obten????o dos resultados acordados. Na medida em que o Projeto estiver em andamento e os parceiros iniciarem um interc??mbio produtivo de conhecimentos, o Plano de Trabalho Anual ser?? atualizado e revisto por meio de reuni??es anuais de avalia????o e encontros do Comit?? Diretor do Projeto, com vistas a assegurar que os resultados descritos no PIP sejam alcan??ados com sucesso

Avaliação assistida informatizada : indicadores do potencial cognitivo de crianças com deficiência

A identificação e a avaliação de crianças com desenvolvimento atípico configuram um processo muito importante para subsidiar as estratégias de ensino voltadas para a promoção do potencial de aprendizagem. O interesse em relação ao prognóstico de crianças com deficiência tem impulsionado o desenvolvimento de novas tecnologias e pesquisas relacionadas à avaliação, prevenção e intervenção. Nesse contexto, torna-se relevante verificar com instrumentos adequados indicadores linguísticos, cognitivos e comportamentais, para assim traçar metas a partir daquilo que as crianças podem aprender. Dessa forma, esta pesquisa teve por objetivo verificar se a avaliação assistida informatizada se apresenta como uma modalidade de diagnóstico mais prescritivo do desenvolvimento cognitivo, quando comparada à avaliação psicométrica, na aplicação em crianças com deficiência. Na modalidade assistida há ajuda do examinador para conduzir a criança a um melhor nível de desempenho cognitivo. Participaram 11 crianças que frequentam uma instituição de atendimento clínico, em saúde, para crianças com deficiência, na Grande Vitória. Na avaliação psicométrica foram utilizados a Escala de Maturidade Mental Colúmbia computadorizada – Colúmbiacomp e o Teste de Vocabulário por Imagens Peabody - TVIPcomp. Na avaliação assistida informatizada foram aplicadas três provas voltadas para as habilidades de classificação e raciocínio analógico: Exclusão de Objetos, Exclusão de Figuras Geométricas e Jogo de Analogia de Figuras, no ambiente informatizado SINDAPSI. Protocolos de registro de fatores afetivo-motivacionais e de operações cognitivas foram utilizados durante as tarefas assistidas. Na avaliação do comportamento, o Child Behavior Checklist – CBCL foi respondido pelas mães. Dados documentais e dos instrumentos foram submetidos à análise estatística descritiva para verificar o desempenho das crianças nas duas formas de avaliação informatizada (psicométrica e assistida). Nos testes psicométricos, 64% das crianças alcançaram índice “abaixo da média” no TVIPcomp, e 55% “médio-inferior” no Colúmbiacomp. Em relação ao perfil de desempenho cognitivo, na Prova de Exclusão de Objetos computadorizada 55% das crianças foram avaliadas como “não-mantenedoras”. Na Prova de Exclusão de Figuras Geométricas computadorizada 55% da amostra foi classificada no perfil “alto-escore”, e no Jogo de Analogias de Figuras computadorizado 45% apresentou o perfil “ganhador”. A amostra demonstrou níveis de dificuldade na realização dos testes,tanto na modalidade psicométrica quanto assistida. Contudo, o desempenho nos testes assistidos foi relativamente melhor, evidenciando que o grupo se beneficiou da mediação,implementada na fase de assistência, para melhorar as habilidades cognitivas. Além disso, a apresentação informatizada dos testes apresentou-se como fator motivador para a realização e persistência nas tarefas.