41 research outputs found
Feature Selection with Evolving, Fast and Slow Using Two Parallel Genetic Algorithms
Feature selection is one of the most challenging issues in machine learning,
especially while working with high dimensional data. In this paper, we address
the problem of feature selection and propose a new approach called Evolving
Fast and Slow. This new approach is based on using two parallel genetic
algorithms having high and low mutation rates, respectively. Evolving Fast and
Slow requires a new parallel architecture combining an automatic system that
evolves fast and an effortful system that evolves slow. With this architecture,
exploration and exploitation can be done simultaneously and in unison. Evolving
fast, with high mutation rate, can be useful to explore new unknown places in
the search space with long jumps; and Evolving Slow, with low mutation rate,
can be useful to exploit previously known places in the search space with short
movements. Our experiments show that Evolving Fast and Slow achieves very good
results in terms of both accuracy and feature elimination
Continuous Separation of Colloidal Particles using Dielectrophoresis.
Dielectrophoresis is the movement of particles in nonuniform electric fields and has been of interest for application to manipulation and separation at and below the microscale. This technique has the advantages of being noninvasive, nondestructive, and noncontact, with the movement of particle achieved by means of electric fields generated by miniaturized electrodes and microfluidic systems. Although the majority of applications have been above the microscale, there is increasing interest in application to colloidal particles around a micron and smaller. This paper begins with a review of colloidal and nanoscale dielectrophoresis with specific attention paid to separation applications. An innovative design of integrated microelectrode array and its application to flow-through, continuous separation of colloidal particles is then presented. The details of the angled chevron microelectrode array and the test microfluidic system are then discussed. The variation in device operation with applied signal voltage is presented and discussed in terms of separation efficiency, demonstrating 99.9% separation of a mixture of colloidal latex spheres
Effects of prenatal food and micronutrient supplementation on child growth from birth to 54 months of age: a randomized trial in Bangladesh
<p>Abstract</p> <p>Background</p> <p>There is a lack of information on the optimal timing of food supplementation to malnourished pregnant women and possible combined effects of food and multiple micronutrient supplementations (MMS) on their offspring's growth. We evaluated the effects of prenatal food and micronutrient interventions on postnatal child growth. The hypothesis was that prenatal MMS and early invitation to food supplementation would increase physical growth in the offspring during 0-54 months and a combination of these interventions would further improve these outcomes.</p> <p>Methods</p> <p>In the large, randomized MINIMat trial (Maternal and Infant Nutrition Interventions in Matlab), Bangladesh, 4436 pregnant women were enrolled between November 2001 and October 2003 and their children were followed until March 2009. Participants were randomized into six groups comprising 30 mg Fe and 400 μg folic acid (Fe30F), 60 mg Fe and 400 μg folic acid (Fe60F) or MMS combined with either an early (immediately after identification of pregnancy) or a later usual (at the time of their choosing, i.e., usual care in this community) program invitation to food supplementation. The anthropometry of 3267 children was followed from birth to 54 months, and 2735 children were available for analysis at 54 months.</p> <p>Results</p> <p>There were no differences in characteristics of mothers and households among the different intervention groups. The average birth weight was 2694 g and birth length was 47.7 cm, with no difference among intervention groups. Early invitation to food supplementation (in comparison with usual invitation) reduced the proportion of stunting from early infancy up to 54 months for boys (p = 0.01), but not for girls (p = 0.31). MMS resulted in more stunting than standard Fe60F (p = 0.02). There was no interaction between the food and micronutrient supplementation on the growth outcome.</p> <p>Conclusions</p> <p>Early food supplementation in pregnancy reduced the occurrence of stunting during 0-54 months in boys, but not in girls, and prenatal MMS increased the proportion of stunting in boys. These effects on postnatal growth suggest programming effects in early fetal life.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN16581394">ISRCTN16581394</a></p
PLC programming
Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersDiese Arbeit stellt einige der wichtigsten Fragen im Bereich der Speicherbarprogrammierbare Steuerung. Das ganze Prozess wurde beschrieben, wie eine S7-300 Station kann in Betrieb genommen werden. In jedem Kapitel werden verschiedene Schritte des Prozesses wurden erläutert anhand von einfachen Beispielen. Im ersten Kapitel, allgemeine Infos wurden über die SPS und Arbeitsweise gegeben. Die wichtigsten Vor-und Nachteile wurden mit Beginn der Verwendung von SPS-Steuerungen in der Automatisierung Prozesse erläutert. Auch nach den Anforderungen der Industrie, die Entwicklung der SPS wurde mit Angabe der wichtigsten Meilensteine in der Geschichte beschrieben.Im zweiten Kapitel, einen Überblick über die Simatic-Controller wurde gegeben und Simatic S7-Controller-Serie und ihre Eigenschaften beschrieben. Dieses Kapitel konzentriert sich vor allem auf S7-300 und seinen Komponenten.Step7 ist die Software zur Programmierung der Simatic-Controller. In Kapitel 3 die wichtigsten Merkmale der Step7 wurden erwähnt.Im Kapitel Installation, es wurde beschrieben, wie das Netzteil, CPU-und Signal-Module können verdrahtet. Dann wird die Station in der Software Step7 konfiguriert.S7-PLCSIM ist die Simulation Programm, mit dem die Beispiele simuliert werden ohne zusätzliche Hardware. Dieses Programm ist besonders wichtig für uns, da alle Beispiele wurden in den letzten Kapitel mit S7-PLCSIM simuliert.Die Zukunft wird zeigen, wie die SPS wird sich weiterentwickeln. Die wichtigsten Fragen und Herausforderungen im Bereich der Automatisierungs-Steuerungen wurden im Kapitel 7 erwähnt. Die Entwicklungen und Trends in der Automatisierungstechnik wurden erläutert, um zu verstehen, was die Zukunft bringen wird.Im letzten Kapitel, verschiedene SPS-Anwendungen wurden ausgewählt, programmiert und simuliert.This work presented some of the most important issues in the field of Programmable Logic Controller. A whole process was described, how a S7-300 station could be taken into operation. In each chapter, different steps of the process were explained and illustrated with simple examples. In the first chapter, general informations about PLCs and working principles were provided. The main advantages and disadvantages were mentioned with starting the use of PLCs in automation processes. Also according the demands of industrial manufacturers, the evolution of the PLC was described with mentioning the most important milestones in its history. In the second chapter, an overview of Simatic controllers was given and Simatic S7 controller series and their specifications were described.This chapter focused especially on S7-300 station and its components.Step7 is the software to program the Simatic controllers. Thus in the chapter 3 main features of Step7 were mentioned. The programming languages offered by Step7 are Ladder Logic Diagrams, Statement Lists, Function block Diagram and Structural Control Language. Advantages, disadvantages and the main differences between these languages are given in this chapter. The most used functions were explained with simple examples such as AND, OR, XOR, SR Flip Flop, On Delay Timer etc. In the chapter Installation, it was described how the power supply, CPU and signal modules can get wired. Then the station has to be configured in the software program Step7. S7-PLCSIM is used to simulate user programs without additional hardware.Chapter 6 was dedicated to introduce the simulation program S7-PLCSIM.This program is especially important for us, because all examples given in the last chapter were simulated with S7-PLCSIM.Future will show how the PLCs will evolve. The most important issues and challenges in the field of automation controllers were mentioned in the chapter 7. The developments and trends in automation systems were explained in order to understand what the future may bring.In the last chapter, different PLC applications were chosen, programmed and simulated.8
Investigation of methods regarding the effectiveness of ventilation strategies in an operating room on the removal of airborne germs using tracer particles
In this study contaminant distribution in an operating room is evaluated experimentally to be able to compare different ventilation concepts afterwards. Low-turbulent unidirectional ventilation (LAF) is used in this study. Heated dummies are positioned around the operating table, which release tracer particles that surrogate airborne germs and measured in critical areas for bacteria spread. Measurement results are evaluated and compared in terms of the degree of protection as well as the local air quality index. It is shown that realistic arrangements limit the usage of the degree of protection. Also, low local air quality indices show recirculation areas appearing at the operating table
Particle dispersion and deposition in displacement ventilation systems combined with floor heating
CETIN, Yunus Emre/0000-0003-0165-2900;WOS: 000534900500001The aim of this study is to investigate dispersion and deposition characteristics of different particle diameters (0.5-5-10 mu m) for a displacement ventilated and floor heated environment, experimentally and numerically. the experiments are performed in a reduced scale model with the operating parameters determined regarding to the similarity. Results are used to validate simulation outputs obtained via Eulerian-Lagrangian method. Three different outlet opening configurations and particle source heights are considered. Results are compared in terms of air change efficiency (ACE), average concentration of the room and the breathing height, contaminant removal effectiveness (CRE) and deposition fraction. It is disclosed that contaminant distribution is highly related with the outlet opening configuration and particle source position. Moreover, it is figured out that for the best ventilation strategy with the operating parameters to be determined, related performance indices and area of concern to be protected from particles must be well defined.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [117M488]This study is supported by the Scientific and Technological Research Council of Turkey (TUBITAK) with project number of 117M488
Effect of Air Exchange Rate on Particle Decay in a Cleanroom: A Numerical Study
In this study, particle decay in a cleanroom is investigated numerically. A commercial CFD package, FLUENT, is used in the analysis. The governing equations are solved by using the k-å turbulence model. For particle dispersion, the discrete phase model (DPM) is applied. Four different air change rates (3-10-25-43 ACH) with three particle diameters (0,5-5-10 ìm) are considered. It is shown that 10 ACH satisfies the needs in terms of recovery time
Praktische Bedeutung von CO2 als Indikator für die Innenraumluftqualität und die relative inhalierte Dosis virenbeladener Partikel
Die CO2-Konzentration wird bereits seit mehr als 150 Jahren als Indikator für die Luftqualität verwendet und entsprechende Grenzwerte sind in der Gesetzgebung vorgeschrieben. Die CO2-Konzentration hängt mit der Personenanzahl, der Dauer des Aufenthalts und der dem Raum zugeführten Außenluftmenge zusammen. Neben CO2 geben infektiöse Personen auch virenbeladene Partikel ab, die von anderen Raumnutzern eingeatmet werden. Zusätzlich bieten die CO2-Konzentration sowie die inhalierte Dosis die Möglichkeit, verschiedene Situationen hinsichtlich eines relativen Infektionsrisikos durch luftgetragene Pathogene miteinander zu vergleichen
Evaluation of in-duct UV-C lamp array on air disinfection: A numerical analysis
CETIN, Yunus Emre/0000-0003-0165-2900WOS: 000547754600001In-duct ultraviolet germicidal irradiation systems are effective systems that are used in disinfection of pathogenic particles transported by air that moving through the ventilation systems. Proper design of these systems is quite important for energy consumption and disinfection performance. in this study, effect of four different lamp arrays within a square cross-section ventilation duct on the average UV dose, UV dose distribution and disinfection rate are examined by using computational fluid dynamics. the standard k-epsilon turbulence model and the discrete phase modeling are used to analyze airflow and particle distribution within the duct, respectively. Also, Discrete Ordinates (DO) radiation model is employed to obtain the irradiation field formed by each UV lamp. It is disclosed that UV lamp arrangement within duct significantly affects UV dose distribution
Influence of Ceiling Height on Airflow and Particle Distribution in an Operating Room
Bacteria-carrying particles released by surgical staff are the main factors leading to surgical site infections (SSI). Operating rooms must be designed to reduce risks of such infections. In this numerical study, the effect of different ceiling heights on particle dispersion and deposition are studied for an operating room with laminar airflow (LAF) system. Two different particle diameters (12 and 20 ìm) are tested under three different ceiling heights (2.43–2.8–3.0 m) at a constant air change rate (ACH=20). Numerical predictions are performed by using the commercial software ANSYS Fluent 16.0. The results reveal that decreasing of the ceiling height reduces the amount of particle deposited on the surgical table