3,883 research outputs found
Hybrid biomedical intelligent systems
"Copyright © 2012 Maysam Abbod et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited."The purpose of this special issue is to promote research and developments of the best work in the field of hybrid intelligent systems for biomedical applications
Optimization the initial weights of artificial neural networks via genetic algorithm applied to hip bone fracture prediction
This paper aims to find the optimal set of initial weights to enhance the accuracy of artificial neural networks (ANNs) by using genetic algorithms (GA). The sample in this study included 228 patients with first low-trauma hip fracture and 215 patients without hip fracture, both of them were interviewed with 78 questions. We used logistic regression to select 5 important factors (i.e., bone mineral density, experience of fracture, average hand grip strength, intake of coffee, and peak expiratory flow rate) for building artificial neural networks to predict the probabilities of hip fractures. Three-layer (one hidden layer) ANNs models with back-propagation training algorithms were adopted. The purpose in this paper is to find the optimal initial weights of neural networks via genetic algorithm to improve the predictability. Area under the ROC curve (AUC) was used to assess the performance of neural networks. The study results showed the genetic algorithm obtained an AUC of 0.858±0.00493 on modeling data and 0.802 ± 0.03318 on testing data. They were slightly better than the results of our previous study (0.868±0.00387 and 0.796±0.02559, resp.). Thus, the preliminary study for only using simple GA has been proved to be effective for improving the accuracy of artificial neural networks.This research was supported by the National Science Council (NSC) of Taiwan (Grant no. NSC98-2915-I-155-005), the Department of Education grant of Excellent Teaching Program of Yuan Ze University (Grant no. 217517) and the Center for Dynamical Biomarkers and Translational Medicine supported by National Science Council (Grant no. NSC 100- 2911-I-008-001)
Neutrally stable atmospheric flow over a two-dimensional rectangular block
The phenomena of atmospheric flow over a two dimensional surface obstruction such as a building modeled as a rectangular block are analyzed by an approach using the Navier-Stokes equations with a two equation model of turbulence. The partial differential equations for the vorticity, stream function, turbulence kinetic energy, and turbulence length scale are solved by a finite difference technique. The predicted results are in agreement with the limited experimental data available. Current computed results show that the separation bubble originates from the upper front corner of the block and extends approximately 11.5 block heights behind the block. The decay of the mean velocity along the wake center line coincides almost perfectly with the experimental data. The vertical profiles of the mean velocity defect are also in reasonable agreement with wind tunnel results. Velocity profiles in the mixing region are shown to agree with the error function profile typically found in the shear layer. Details of the behavior of the turbulence kinetic energy and the turbulence length scale are also discussed
Precise computer controlled positioning of robot end effectors using force sensors
A thorough study of combined position/force control using sensory feedback for a one-dimensional manipulator model, which may count for the spacecraft docking problem or be extended to the multi-joint robot manipulator problem, was performed. The additional degree of freedom introduced by the compliant force sensor is included in the system dynamics in the design of precise position control. State feedback based on the pole placement method and with integral control is used to design the position controller. A simple constant gain force controller is used as an example to illustrate the dependence of the stability and steady-state accuracy of the overall position/force control upon the design of the inner position controller. Supportive simulation results are also provided
Two-dimensional matrix algorithm using detrended fluctuation analysis to distinguish Burkitt and diffuse large B-cell lymphoma
Copyright © 2012 Rong-Guan Yeh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.A detrended fluctuation analysis (DFA) method is applied to image analysis. The 2-dimensional (2D) DFA algorithms is proposed
for recharacterizing images of lymph sections. Due to Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL), there
is a significant different 5-year survival rates after multiagent chemotherapy. Therefore, distinguishing the difference between BL
and DLBCL is very important. In this study, eighteen BL images were classified as group A, which have one to five cytogenetic
changes. Ten BL images were classified as group B, which have more than five cytogenetic changes. Both groups A and B BLs are
aggressive lymphomas, which grow very fast and require more intensive chemotherapy. Finally, ten DLBCL images were classified
as group C. The short-term correlation exponent α1 values of DFA of groups A, B, and C were 0.370 ± 0.033, 0.382 ± 0.022, and
0.435 ± 0.053, respectively. It was found that α1 value of BL image was significantly lower (P < 0.05) than DLBCL. However, there
is no difference between the groups A and B BLs. Hence, it can be concluded that α1 value based on DFA statistics concept can
clearly distinguish BL and DLBCL image.National Science Council (NSC) of Taiwan the Center for Dynamical Biomarkers and
Translational Medicine, National Central University, Taiwan (also sponsored by National Science Council)
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Densely distributed and real-time scour hole monitoring using piezoelectric rod sensors
This study aims to validate a piezoelectric driven-rod scour monitoring system that can sense changes in scour depth along the entire rod at its instrumented location. The proposed sensor is a polymeric slender rod with a thin strip of polyvinylidene fluoride that runs through its midline. Extraction of the fundamental frequency allows the direct calculation of the exposed length (or scour depth) of the slender rod undergoing fluid flow excitation. First, laboratory validation in dry conditions is presented. Second, hydrodynamic testing of the sensor system in a soil-bed flume is discussed. Each rod was installed using a three-dimensional-printed footing designed for ease of installation and stabilization during testing. The sensors were installed in a layout designed to capture symmetric scour conditions around a scaled pier. In order to analyze the system out of steady-state conditions, water velocity was increased in stages during testing to induce different degrees of scour. As ambient water flow excited the portion of the exposed rods, the embedded piezoelectric element outputted a time-varying voltage signal. Different methods were then employed to extract the fundamental frequency of each rod, and the results were compared. Further testing was also performed to characterize the relationship between frequency outputs and flow velocity, which were previously thought to be independent. In general, the proposed driven-rod scour monitoring system successfully captured changing frequencies under varied flow conditions
Hong Kong moves towards open access to authenticated legal information
Congress Theme: Future Libraries: Infinite PossibilitiesHong Kong SAR (Special Administrative Region)’s legal system has retained its common law system developed during its colonial days under UK rule. The combination of legislative law and judge made law has been made available online in various commercial, academic and government sources. Government sources though to date for legislation are not “official” but recent developments by the Department of Justice aim to address this issue and this paper will outline the various Government sources of Hong Kong law online and this new development towards authentication of online legislation. Part I outlines the bilingual legal system of Hong Kong and its sources of law. Part II describes the various sources in which legislation and court judgments are available. Part III discusses the recent Government initiative in moving towards digital authentication. Copyright © 2013 by John Bahrij & Irene Shiehpublished_or_final_versio
Permanent Deformation of Earth Dams Under Earthquakes
Assessment of dam embankment deformation by various methods such as those proposed by Newmark, Ambraseys and Seed was reviewed herewith. A simple method based on dynamic response spectrum analyses by step-by-step integration technique is proposed for independent permanent deformation evaluation. The proposed method assumes that failure occurs on a well-defined slip surface and that the material behaves elastically at stress level below failure but develops a perfectly plastic behavior above the yield acceleration. The results of the proposed method were compared with those obtained from other method for actual examples. Favorable agreement on the analytical results was achieved
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