Cluster-based active learning for compact image classification

In this paper, we consider active sampling to label pixels grouped with hierarchical clustering. The objective of the method is to match the data relationships discovered by the clustering algorithm with the user's desired class semantics. The first is represented as a complete tree to be pruned and the second is iteratively provided by the user. The active learning algorithm proposed searches the pruning of the tree that best matches the labels of the sampled points. By choosing the part of the tree to sample from according to current pruning's uncertainty, sampling is focused on most uncertain clusters. This way, large clusters for which the class membership is already fixed are no longer queried and sampling is focused on division of clusters showing mixed labels. The model is tested on a VHR image in a multiclass classification setting. The method clearly outperforms random sampling in a transductive setting, but cannot generalize to unseen data, since it aims at optimizing the classification of a given cluster structure.

Scenario method in anticipating future opportunities of e-business in the forest industry

Tutkimuksen tavoitteena on ennakoida liiketoimintaprosessien sähköistymisen kehittymistä käyttämällä skenaariomenetelmää, yhtä laajimmin käytetyistä tulevaisuuden tutkimisen menetelmistä. Tarkastelun kohteena ovat erityisesti tulevaisuuden e-business -ratkaisut metsäteollisuudessa. Tutkimuksessa selvitetään skenaariomenetelmän ominaisuuksia, skenaariosuunnittelun periaatteita sekä menetelmän sopivuutta teknologian ja toimialan muutosten tarkasteluun. Tutkimuksen teoriaosassa selvitetään teknologian muutoksen vaikutusta toimialojen kehitykseen. Todettiin, että teknologisella muutoksella on vahva vaikutus toimialojen muutoksiin, ja että jokainen toimiala seuraa tietynlaista kehitystrajektoria. Yritysten tulee olla tietoisia teknologisen muutoksen nopeudesta ja suunnasta, ja seurata toimialansa kehityksen sääntöjä. Metsäteollisuudessa muutosten radikaali luonne sekä ICT-teknologian nopea kehitys asettavat haasteita liiketoimintaprosessien sähköistämisen kentässä. Empiriaosuudessa luotiin kolme erilaista skenaariota e-busineksen tulevaisuudesta metsäteollisuudessa. Skenaariot perustuvat pääosin aiheen asiantuntijoiden tämän hetkisiin näkemyksiin, joita koottiin skenaariotyöpajassa. Skenaarioiden muodostamisessa yhdistettiin kvalitatiivisia ja kvantitatiivisia elementtejä. Muodostetut kolme skenaariota osoittavat, että e-busineksen vaikutukset tulevaisuudessa nähdään pääosin positiivisina, ja että yritysten tulee kehittyä aktiivisesti ja joustavasti pystyäkseen hyödyntämään sähköisiä ratkaisuja tehokkaasti liiketoiminnassaan.

Appropriateness of therapy for active Crohn's disease: results of a multidisciplinary international expert panel-EPACT II

The increasing number of trials testing management strategies for luminal Crohn's disease (CD) has not fitted all the gaps in our knowledge and thus, in clinical. practice, many decisions for CD patients have to be taken without the benefit of high-quality evidence. Methods: A multidisciplinary European expert panel used the RAND Appropriateness Method to develop and rate explicit criteria for the management of individual patients with active, steroid-dependent (ST-D) and steroid-refractory (ST-R) CD. Results: Overall., 296 indications pertaining to mild-to-moderate, severe, ST-D, and ST-R CD were rated. In anti-TNF naive patients, budesonide and prednisone were found to be appropriate for mild-moderate CD, and infliximab (IFX) was appropriate when these had previously failed or had not been tolerated. In patients with a prior successful treatment by IFX, this drug, with or without co-administration of a thiopurine analog, was favoured. Other anti-TNFs were appropriate in the presence of intolerance or resistance to IFX. High-dose steroids, IFX or adlimumab were appropriate in severe active CD. For the 105 indications for ST-D or ST-R disease, the panel considered the thiopurine analogs, methotrexate, IFX, adalimumab, and surgery for limited resection, to be appropriate, depending on the outcome of prior therapies. Anti-TNFs were generally considered appropriate in ST-R. Conclusion: Steroids, including budesonide for mild-to-moderate CD, remain the first-line therapy for active luminal CD. Anti-TNFs, in particular IFX as shown by the amount of available evidence, remain the second-line therapy for most indications. Thiopurine analogs, methotrexate and anti-TNFs are favoured in ST-D patients and ST-R patients. (C) 2009 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

Project for Active and Robot Vision Course

Tässä työssä raportoidaan harjoitustyön kehittäminen ja toteuttaminen Aktiivisen- ja robottinäön kurssille. Harjoitustyössä suunnitellaan ja toteutetaan järjestelmä joka liikuttaa kappaleita robottikäsivarrella kolmiuloitteisessa avaruudessa. Kappaleidenpaikkojen määrittämiseen järjestelmä käyttää digitaalisia kuvia. Tässä työssä esiteltävässä harjoitustyötoteutuksessa käytettiin raja-arvoistusta HSV-väriavaruudessa kappaleiden segmentointiin kuvasta niiden värien perusteella. Segmentoinnin tuloksena saatavaa binäärikuvaa suodatettiin mediaanisuotimella kuvan häiriöiden poistamiseksi. Kappaleen paikkabinäärikuvassa määritettiin nimeämällä yhtenäisiä pikseliryhmiä yhtenäisen alueen nimeämismenetelmällä. Kappaleen paikaksi määritettiin suurimman nimetyn pikseliryhmän paikka. Kappaleiden paikat kuvassa yhdistettiin kolmiuloitteisiin koordinaatteihin kalibroidun kameran avulla. Järjestelmä liikutti kappaleita niiden arvioitujen kolmiuloitteisten paikkojen perusteella.

Active Damping and Energy Recovery in a Hydraulic Boom Controlled by an Electric Drive

The aim of the study is to obtain a mathematical description for an alternative variant of controlling a hydraulic circuit with an electrical drive. The electrical and hydraulic systems are described by basic mathematical equations. The flexibilities of the load and boom is modeled with assumed mode method. The model is achieved and proven with simulations. The controller is constructed and proven to decrease oscillations and improve the dynamic response of the system.

Computed tomography angiography in patients with active gastrointestinal bleeding

Abstract Gastrointestinal bleeding represents a common medical emergency, with considerable morbidity and mortality rates, and a prompt diagnosis is essential for a better prognosis. In such a context, endoscopy is the main diagnostic tool; however, in cases where the gastrointestinal hemorrhage is massive, the exact bleeding site might go undetected. In addition, a trained professional is not always present to perform the procedure. In an emergency setting, optical colonoscopy presents limitations connected with the absence of bowel preparation, so most of the small bowel cannot be assessed. Scintigraphy cannot accurately demonstrate the anatomic location of the bleeding and is not available at emergency settings. The use of capsule endoscopy is inappropriate in the acute setting, particularly in the emergency department at night, and is a highly expensive method. Digital angiography, despite its high sensitivity, is invasive, presents catheterization-related risks, in addition to its low availability at emergency settings. On the other hand, computed tomography angiography is fast, widely available and minimally invasive, emerging as a promising method in the diagnostic algorithm of these patients, being capable of determining the location and cause of bleeding with high accuracy. Based on a critical literature review and on their own experience, the authors propose a computed tomography angiography protocol to assess the patient with gastrointestinal bleeding.

Active regions for colour texture segmentation integrating region and boundary information

In this paper a colour texture segmentation method, which unifies region and boundary information, is proposed. The algorithm uses a coarse detection of the perceptual (colour and texture) edges of the image to adequately place and initialise a set of active regions. Colour texture of regions is modelled by the conjunction of non-parametric techniques of kernel density estimation (which allow to estimate the colour behaviour) and classical co-occurrence matrix based texture features. Therefore, region information is defined and accurate boundary information can be extracted to guide the segmentation process. Regions concurrently compete for the image pixels in order to segment the whole image taking both information sources into account. Furthermore, experimental results are shown which prove the performance of the proposed method

Unsupervised active regions for multiresolution image segmentation

An unsupervised approach to image segmentation which fuses region and boundary information is presented. The proposed approach takes advantage of the combined use of 3 different strategies: the guidance of seed placement, the control of decision criterion, and the boundary refinement. The new algorithm uses the boundary information to initialize a set of active regions which compete for the pixels in order to segment the whole image. The method is implemented on a multiresolution representation which ensures noise robustness as well as computation efficiency. The accuracy of the segmentation results has been proven through an objective comparative evaluation of the method

Evaluation of potential breath biomarkers for active smoking: assessment of smoking habits

Different compounds have been reported as biomarkers of a smoking habit, but, to date, there is no appropriate biomarker for tobacco-related exposure because the proposed chemicals seem to be nonspecific or they are only appropriate for short-term exposure. Moreover, conventional sampling methodologies require an invasive method because blood or urine samples are required. The use of a microtrap system coupled to gas chromatography–mass spectrometry analysis has been found to be very effective for the noninvasive analysis of volatile organic compounds in breath samples. The levels of benzene, 2,5-dimethylfuran, toluene, o-xylene, and m- p-xylene have been analyzed in breath samples obtained from 204 volunteers (100 smokers, 104 nonsmokers; 147 females, 57 males; ages 16 to 53 years). 2,5-Dimethylfuran was always below the limit of detection (0.005 ppbv) in the nonsmoker population and always detected in smokers independently of the smoking habits. Benzene was only an effective biomarker for medium and heavy smokers, and its level was affected by smoking habits. Regarding the levels of xylenes and toluene, they were only different in heavy smokers and after short-term exposure. The results obtained suggest that 2,5-dimethylfuran is a specific breath biomarker of smoking status independently of the smoking habits (e.g., short- and long-term exposure, light and heavy consumption), and so this compound might be useful as a biomarker of smoking exposure

On Commutation and Conjugacy of Rational Languages and the Fixed Point Method

The research on language equations has been active during last decades. Compared to the equations on words the equations on languages are much more difficult to solve. Even very simple equations that are easy to solve for words can be very hard for languages. In this thesis we study two of such equations, namely commutation and conjugacy equations. We study these equations on some limited special cases and compare some of these results to the solutions of corresponding equations on words. For both equations we study the maximal solutions, the centralizer and the conjugator. We present a fixed point method that we can use to search these maximal solutions and analyze the reasons why this method is not successful for all languages. We give also several examples to illustrate the behaviour of this method.

The attenuation of concentrations model: a new method for assessing mercury mobility in sediments

In this work we propose a new approach for the determination of the mobility of mercury in sediments based on spatial distribution of concentrations. We chose the Tainheiros Cove, located in the Todos os Santos Bay, Brazil, as the study area, for it has a history of mercury contamination due to a chloro-alkali plant that was active during 12 years. Twenty-six surface sediment samples were collected from the area and mercury concentrations were measured by cold vapour atomic absorption spectrophotometry. A contour map was constructed from the results, indicating that mercury accumulated in a "hot spot" where concentrations reach more than 1 µg g-1. The model is able to estimate mobility of mercury in the sediments based on the distances between iso-concentration contours that determines an attenuation of concentrations factor. Values of attenuation ranged between 0.0729 (East of the hot spot, indicating higher mobility) to 0.7727 (North of the hot spot, indicating lower mobility).

Active du/dt Filtering for Variable-Speed AC Drives

An oscillating overvoltage has become a common phenomenon at the motor terminal in inverter-fed variable-speed drives. The problem has emerged since modern insulated gate bipolar transistors have become the standard choice as the power switch component in lowvoltage frequency converter drives. Theovervoltage phenomenon is a consequence of the pulse shape of inverter output voltage and impedance mismatches between the inverter, motor cable, and motor. The overvoltages are harmful to the electric motor, and may cause, for instance, insulation failure in the motor. Several methods have been developed to mitigate the problem. However, most of them are based on filtering with lossy passive components, the drawbacks of which are typically their cost and size. In this doctoral dissertation, application of a new active du/dt filtering method based on a low-loss LC circuit and active control to eliminate the motor overvoltages is discussed. The main benefits of the method are the controllability of the output voltage du/dt within certain limits, considerably smaller inductances in the filter circuit resulting in a smaller physical component size, and excellent filtering performance when compared with typical traditional du/dt filtering solutions. Moreover, no additional components are required, since the active control of the filter circuit takes place in the process of the upper-level PWM modulation using the same power switches as the inverter output stage. Further, the active du/dt method will benefit from the development of semiconductor power switch modules, as new technologies and materials emerge, because the method requires additional switching in the output stage of the inverter and generation of narrow voltage pulses. Since additional switching is required in the output stage, additional losses are generated in the inverter as a result of the application of the method. Considerations on the application of the active du/dt filtering method in electric drives are presented together with experimental data in order to verify the potential of the method.

Development of a simple, rapid and validated spectrophotometric method for nitazoxanide in pharmaceutical formulations and comparison with HPLC

A rapid, economical, reproducible, and simple direct spectrophotometric method was developed and validated for the assay of nitazoxanide in pharmaceutical formulations. Nitazoxanide concentration was estimated in water at 345 nm and pH 4.5. The method was suitable and validated for specificity, linearity, precision, and accuracy. There was no interference of the excipients in the determination of the active pharmaceutical ingredient. The proposed method was successfully applied in the determination of nitazoxanide in coated tablets and in powders for oral suspension. This method was compared to a previously developed and validated method for liquid chromatography to the same drug. There was no significative difference between these methods for nitazoxanide quantitation.

Learning through role-playing games: an approach for active learning and teaching

This study evaluates the use of role-playing games (RPGs) as a methodological approach for teaching cellular biology, assessing student satisfaction, learning outcomes, and retention of acquired knowledge. First-year undergraduate medical students at two Brazilian public universities attended either an RPG-based class (RPG group) or a lecture (lecture-based group) on topics related to cellular biology. Pre- and post-RPG-based class questionnaires were compared to scores in regular exams and in an unannounced test one year later to assess students' attitudes and learning. From the 230 students that attended the RPG classes, 78.4% responded that the RPG-based classes were an effective tool for learning; 55.4% thought that such classes were better than lectures but did not replace them; and 81% responded that they would use this method. The lecture-based group achieved a higher grade in 1 of 14 regular exam questions. In the medium-term evaluation (one year later), the RPG group scored higher in 2 of 12 questions. RPG classes are thus quantitatively as effective as formal lectures, are well accepted by students, and may serve as educational tools, giving students the chance to learn actively and potentially retain the acquired knowledge more efficiently.