4,051 research outputs found

    The prediction of wake wash in the towing tank

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    The wash or ship-generated waves from high speed craft has become a common subject in research and development of marine transportation. Since some time now the wake wash of high speed craft has become a problem in particular on inland or confined waterways. This wake wash has an impact on safety and environment such as bank/shoreline erosion, risk to people on shore and small boats in harbors and changes in the local ecology. This paper describes the results of model test of a high speed patrol, together with theoretical prediction of wake wash

    Oral Cancer Awareness and its Determinants among a Selected Malaysian Population

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    Objective: To assess oral cancer awareness, its associated factors and related sources of information among a selected group of Malaysians. Methods: A cross-sectional survey was conducted on all Malaysian ethnic groups aged >= 15 years old at eight strategically chosen shopping malls within a two week time period. Data were analysed using chi-square tests and multiple logistic regression. Significance level was set at alpha<0.05. Results: Most (84.2%) respondents had heard of oral cancer. Smoking was the most (92.4%) recognized high risk habit. Similar levels of awareness were seen for unhealed ulcers (57.3%) and red/white patches (58.0%) as signs of oral cancer. Age, gender, ethnicity, marital status, education, occupation and income were significantly associated with oral cancer awareness (p<0.05). Conclusions: There was a general lack of awareness regarding the risk habits, early signs and symptoms, and the benefits of detecting this disease at an early stage. Mass media and health campaigns were the main sources of information about oral cancer. In our Malaysian population, gender and age were significantly associated with the awareness of early signs and symptoms and prevention of oral cancer, respectively.Article Link: http://koreascience.or.kr/article/ArticleFullRecord.jsp?cn=POCPA9_2013_v14n3_195

    Insights from unifying modern approximations to infections on networks

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    Networks are increasingly central to modern science owing to their ability to conceptualize multiple interacting components of a complex system. As a specific example of this, understanding the implications of contact network structure for the transmission of infectious diseases remains a key issue in epidemiology. Three broad approaches to this problem exist: explicit simulation; derivation of exact results for special networks; and dynamical approximations. This paper focuses on the last of these approaches, and makes two main contributions. Firstly, formal mathematical links are demonstrated between several prima facie unrelated dynamical approximations. And secondly, these links are used to derive two novel dynamical models for network epidemiology, which are compared against explicit stochastic simulation. The success of these new models provides improved understanding about the interaction of network structure and transmission dynamics

    Antigen-driven T-cell turnover.

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    A mathematical model is developed to characterize the distribution of cell turnover rates within a population of T lymphocytes. Previous models of T-cell dynamics have assumed a constant uniform turnover rate; here we consider turnover in a cell pool subject to clonal proliferation in response to diverse and repeated antigenic stimulation. A basic framework is defined for T-cell proliferation in response to antigen, which explicitly describes the cell cycle during antigenic stimulation and subsequent cell division. The distribution of T-cell turnover rates is then calculated based on the history of random exposures to antigens. This distribution is found to be bimodal, with peaks in cell frequencies in the slow turnover (quiescent) and rapid turnover (activated) states. This distribution can be used to calculate the overall turnover for the cell pool, as well as individual contributions to turnover from quiescent and activated cells. The impact of heterogeneous turnover on the dynamics of CD4(+) T-cell infection by HIV is explored. We show that our model can resolve the paradox of high levels of viral replication occurring while only a small fraction of cells are infected

    Particle swarm optimization and spiral dynamic algorithm-based interval type-2 fuzzy logic control of triple-link inverted pendulum system: A comparative assessment

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    This paper presents investigations into the development of an interval type-2 fuzzy logic control (IT2FLC) mechanism integrated with particle swarm optimization and spiral dynamic algorithm. The particle swarm optimization and spiral dynamic algorithm are used for enhanced performance of the IT2FLC by finding optimised values for input and output controller gains and parameter values of IT2FLC membership function as comparison purpose in order to identify better solution for the system. A new model of triple-link inverted pendulum on two-wheels system, developed within SimWise 4D software environment and integrated with Matlab/Simulink for control purpose. Several tests comprising system stabilization, disturbance rejection and convergence accuracy of the algorithms are carried out to demonstrate the robustness of the control approach. It is shown that the particle swarm optimization-based control mechanism performs better than the spiral dynamic algorithm-based control in terms of system stability, disturbance rejection and reduce noise. Moreover, the particle swarm optimization-based IT2FLC shows better performance in comparison to previous research. It is envisaged that this system and control algorithm can be very useful for the development of a mobile robot with extended functionality

    Generic Fibrational Induction

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    This paper provides an induction rule that can be used to prove properties of data structures whose types are inductive, i.e., are carriers of initial algebras of functors. Our results are semantic in nature and are inspired by Hermida and Jacobs' elegant algebraic formulation of induction for polynomial data types. Our contribution is to derive, under slightly different assumptions, a sound induction rule that is generic over all inductive types, polynomial or not. Our induction rule is generic over the kinds of properties to be proved as well: like Hermida and Jacobs, we work in a general fibrational setting and so can accommodate very general notions of properties on inductive types rather than just those of a particular syntactic form. We establish the soundness of our generic induction rule by reducing induction to iteration. We then show how our generic induction rule can be instantiated to give induction rules for the data types of rose trees, finite hereditary sets, and hyperfunctions. The first of these lies outside the scope of Hermida and Jacobs' work because it is not polynomial, and as far as we are aware, no induction rules have been known to exist for the second and third in a general fibrational framework. Our instantiation for hyperfunctions underscores the value of working in the general fibrational setting since this data type cannot be interpreted as a set.Comment: For Special Issue from CSL 201

    Hubungan Faktor Determinan dengan Kejadian Tifoid di Indonesia Tahun 2007

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    Typhoid is an abdominal infectious diseases caused by Salmonella typhii. The Typhus more popular name called Typhus Abdominalis, Typhoid fever or Enteric fever. The Profile of disease control and healthy environment in 2006 reported that typhoid was to be publich health\u27s problem. The cases of morbidity and mortality rate from typhoid was 500 per 100.000 people, and fatality rate was 65%. The objective of this study is to find prevalence of typhoid and the relatied with several determinants in Indonesia. This study used cross-sectional design with descriptive analysis on relation of determinant factors to typhoid prevalence in Indonesia in 2007. The research sample is all sample who answered quesioner about Typhus. Collected data with direct quesioner. Determinant factor in analisis are individual karacteristic, demografi status, economy status, and environment. The result shown prevalency of clinical Typhoid about 1,5%, with range prevalence (0,4% - 2,6%). Dominant factor in Typhoid morbidity has 13 variable, which are sex variable with OR = 1,142 on male group, in age group The highest OR higher was on 1-14 years that was 1,449 (1,164-1,804)). The education variable who unfinishes from elementary school have OR =1,746 , responden who have child under five 5 years more than five child in their home have OR = 3,368, variable area according to island in Indonesia, NTT and NTB were OR = 1,052, Variable area according to administration area have OR = 1,283 (1,169-1,410) on rural side. The length of time to acces proffesional health service have OR = 1,420 on group who have time to acces was long, and the length of time to acces community health service have OR =1,226 for time long to acces, and water sufficienty OR= 1,273 for responden have not water sufficient, variable of the soil source around drinking water resource OR = 1,097, and the variable of the water quality bad have OR = 1,401, variable of having a garbage place have OR= 1,180 on responden didn\u27t have a garbage place, and the last was variable of having the waste pipeline in responden home, group responden didn\u27t have waste pipeline in home have OR = 1,098 . The result shown prevalency of clinical typhoid about 1,5%, with range prevalency (0,4% -2,6%). Dominan factors on the typhoid morbidity there were 13 factors which are 1. sex variable, 2. age variable, 3. consist of Child under five years in family 4. education variable, 5. area\u27s according island 6. administration area variable 7. length of time to acces to profesional health service 8. length of time to acces to profesional health inter grated health care post, 9. variable with water sufficiency, 10. variable of soil source paround drinking water source, 11. variable of water quality, 12. variable with having a garbage place, 13. variable of having the waste pipeline in responden home

    A demand-driven approach for a multi-agent system in Supply Chain Management

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    This paper presents the architecture of a multi-agent decision support system for Supply Chain Management (SCM) which has been designed to compete in the TAC SCM game. The behaviour of the system is demand-driven and the agents plan, predict, and react dynamically to changes in the market. The main strength of the system lies in the ability of the Demand agent to predict customer winning bid prices - the highest prices the agent can offer customers and still obtain their orders. This paper investigates the effect of the ability to predict customer order prices on the overall performance of the system. Four strategies are proposed and compared for predicting such prices. The experimental results reveal which strategies are better and show that there is a correlation between the accuracy of the models' predictions and the overall system performance: the more accurate the prediction of customer order prices, the higher the profit. © 2010 Springer-Verlag Berlin Heidelberg