A digital holography technique for generating beams with arbitrary polarization and shape

A method for generating beams with arbitrary polarization and shape is proposed. Our design requires the use of a Mach-Zehnder set-up combined with translucent liquid crystal displays in each arm of the interferometer; in this way, independent manipulation of each transverse beam components is possible. The target of this communication is to develop a numerical procedure for calculating the holograms required for dynamically encode any amplitude value and polarization state in each point of the wavefront. Several examples demonstrating the capabilities of the method are provided.

Törmäysystävällisen valaisinpylvään tuotteistaminen

Euroopan unioni on tiukentanut teiden laitteiden ja tukirakenteiden törmäysturvallisuusvaatimuksia. Uuden standardoinnin tarkoituksena on lieventää ajoneuvon kuljettajan ja matkustajan vammojen vakavuutta ajoneuvon törmätessä tielaitteiden pysyviin rakenteisiin. Käytännössä rakenteiden tulee hidastaa ajoneuvon nopeutta hallitusti eri törmäysnopeuksilla, jolloin matkustajaan kohdistuvat kiihtyvyydet eivät aiheuta vakavaa loukkaantumisriskiä. Vuonna 2005 Mikkelin ammattikorkeakoulun YTI-tutkimuskeskus ja Tehomet Oy kehittivät ensimmäisen version törmäysystävällisestä valaisinpylväästä. Tässä diplomityössä tavoitteena oli kehittää aikaisemmin tehdystä versiosta helpommin valmistettava versio sekä parantaa pylvään törmäyskäyttäytymistä. Valmistusmenetelmistä valittiin pultruusio, kuitukelaus, alipaineinjektio ja RTM. Menetelmille suunniteltiin soveltuvat rakenteet ja laskettiin rakenteiden valmistuskustannukset. Pultruusiolla, alipaineinjektiolla ja RTM:11ä valmistettiin koe-erä esitörmäyskokeita varten. Esitörmäyskokeiden jälkeen valittiin valmistusmenetelmäksi RTM. TKK/Tielaboratorion virallisissa testeissä kehitetylle pylväälle myönnettiin HE2-turvaluokitus. Hanketta jatketaan kehittämällä valmistusprosessia tehokkaammaksi uudistamalla muottitekniikkaa sekä ottamalla käyttöön lujiteaihiot. Tavoitteena on käynnistää tuotanto keväällä 2008. Kehitetty pylväs esitellään kansainvälisillä "Sähkö, Tele, Valo- ja AV 2008"-messuilla Jyväskylän Paviljongissa 6.-8.2.2008.

Aortic Annulus Stabilization Technique for Rapid Deployment Aortic Valve Replacement.

NlmCategory="UNASSIGNED">Rapid deployment aortic valve replacement (RDAVR) with the use of rapid deployment valve systems represents a smart alternative to the use of standard aortic bioprosthesis for aortic valve replacement. Nevertheless, its use is still debatable in patients with pure aortic valve regurgitation or true bicuspid aortic valve because of the risk of postoperative paravalvular leak. To address this issue, an optimal annulus-valve size match seems to be the ideal surgical strategy. This article describes a new technique developed to stabilize the aortic annulus and prevent paravalvular leak after RDAVR. To confirm the feasibility, this technique was performed in six patients with severe symptomatic aortic stenosis who were scheduled to undergo aortic valve replacement at our center. All patients survived surgery and were discharged from the hospital. There were no new intracardiac conduction system disturbances observed, and a permanent pacemaker implantation was not required in any of the patients. The intraoperative and postoperative echocardiogram confirmed successful positioning of the valve, and no paravalvular leak was observed. In this preliminary experience, RDAVR through a full sternotomy or an upper hemisternotomy approach with the use of aortic annulus stabilization technique was safe, and no leak was observed. Future studies on large series of patients are necessary to confirm the safety and effectiveness of this technique in preventing paravalvular leak in patients with true bicuspid aortic valves or pure aortic regurgitation.

Parcours de vie, récit et moments forts : entre défis et ressources. Une recherche-intervention à l'Ecole Technique de Ste-Croix

La littérature sur les transitions, en particulier entre l'école obligatoire et l'école professionnelle ou l'école et la vie professionnelle, attire l'attention sur le fait que les parcours personnels sont aujourd'hui moins linéaires. Les transitions professionnelles sont alors décrites comme des moments de difficultés, de ruptures, de vulnérabilité pour les jeunes (Pagnossin & Armi, 2011 ; Rastoldo, Amos & Davaud, 2009). Dans notre domaine en psychologie « socioculturelle », si ces aspects ne sont pas négligés, l'accent est mis sur l'importance du travail de construction de sens par la personne : indépendamment des zigzags de sa vie, l'important est la mise en cohérence, les liens de sens qu'elle peut reconstruire entre les différentes sphères d'expériences qui constituent son identité. Et pour cela, les ressources sociales et institutionnelles (parents, enseignants, groupes de pairs, dispositifs de formation...) mais aussi matérielles et culturelles (chansons, poèmes, films, romans, récits, etc.) peuvent être très importantes (Masdonati & Zittoun, 2012 ; Zittoun, 2012). L'étude-intervention qui sera présentée dans ce document, réalisée auprès d'une classe d'apprentis de l'Ecole technique de Ste-Croix par un groupe d'étudiants en Master en psychologie (UniL), s'inscrit dans un mouvement plus large qui cherche à rendre compte du point de vue des acteurs (Muller Mirza & Perret-Clermont, 2015) liés à la question des transitions des jeunes : il s'agira ici de celui des apprentis eux-mêmes, de manière à explorer ce qu'ils vivent en termes de difficultés, de ressources utilisées et d'apprentissages réalisés, ainsi que celui des personnes qui les accompagnent dans ces processus, les enseignants. Cette étude visait non seulement à recueillir des informations auprès de ces personnes mais également à réaliser un travail de type réflexif, par la mise en place d'activités en classe destinées aux apprentis, basées sur le « récit de vie » comme outil psychologique.

Step-by-step of ultrasound-guided core-needle biopsy of the breast: review and technique

Ultrasound-guided core-needle biopsy has high sensitivity in the diagnosis of breast cancer. The present study is aimed at detailing the main steps of such procedure, including indications, advantages, limitations, follow-up and description of the technique, besides presenting a checklist including the critical steps required for an appropriate practice of the technique. In the recent years, an increasing number of patients have required breast biopsy, indicating the necessity of a proportional increase in the number of skilled professionals to carry out the procedures and histological diagnoses. A multidisciplinary approach involving the tripod clinical practice-radiology-pathology is responsible for the highest rate of accuracy of the technique and must always be adopted.

Labor Market Signaling and Self-Confidence: Wage Compression and the Gender Pay Gap

I extend Spence's signaling model by assuming that some workers are overconfident-they underestimate their marginal cost of acquiring education-and some are underconfident. Firms cannot observe workers' productive abilities and beliefs but know the fractions of high-ability, overconfident, and underconfident workers. I find that biased beliefs lower the wage spread and compress the wages of unbiased workers. I show that gender differences in self-confidence can contribute to the gender pay gap. If education raises productivity, men are overconfident, and women underconfident, then women will, on average, earn less than men. Finally, I show that biased beliefs can improve welfare.

Transabdominal-pelvic-perineal (TAPP) anterolateral thigh flap: A new reconstructive technique for complex defects following extended abdominoperineal resection.

BACKGROUND: Abdominoperineal resection (APR) following radiotherapy is associated with a high rate of perineal wound complications. The anterolateral thigh (ALT) flap, combined with the vastus lateralis (VL) muscle, can cover complex perineal and pelvic anteroposterior defects. This is used for the first time transabdominally through the pelvis and the perineum (TAPP) in the infero-posterior directions; this technique has been described and illustrated in this study. METHODS: Among over 90 patients who underwent perineal reconstruction between May 2004 and June 2011, six patients presented high-grade tumours invading perineum, pelvis and sacrum, thereby resulting in a continuous anteroposterior defect. ALT + VL TAPP reconstructions were performed after extended APR and, subsequently, sacrectomy. Patients were examined retrospectively to determine demographics, operative time, complications (general and flap-related), time to complete healing and length of hospital stay. Long-term flap coverage, flap volume stability and functional and aesthetic outcomes were assessed. RESULTS: Mean operating time of the reconstruction was 290 min. No deaths occurred. One patient presented partial flap necrosis. Another patient presented a novel wound dehiscence after flap healing, due to secondary skin dissemination of the primary tumour. Following volumetric flap analysis on serial post-operative CT scans, no significant flap atrophy was observed. All flaps fully covered the defects. No late complications such as fistulas or perineal hernias occurred. Donor-site recovery was uneventful with no functional deficits. CONCLUSIONS: The use of the ALT + VL flap transabdominally is an innovative method to reconstruct exceptionally complex perineal and pelvic defects extending up to the lower back. This flap guarantees superior bulk, obliterating all pelvic dead space, with the fascia lata (FL) supporting the pelvic floor.

Determination of compression behaviour of coating layer

The strength properties of paper coating layer are very important in converting and printing operations. Too great or low strength of the coating can affect several problems in printing. One of the problems caused by the strength of coating is the cracking at the fold. After printing the paper is folded to final form and the pages are stapled together. In folding the paper coating can crack causing aesthetic damage over printed image or in the worst case the centre sheet can fall off in stapling. When folding the paper other side undergoes tensile stresses and the other side compressive stresses. If the difference between these stresses is too high, the coating can crack on the folding. To better predict and prevent cracking at the fold it is good to know the strength properties of coating layer. It has measured earlier the tensile strength of coating layer but not the compressive strength. In this study it was tried to find some way to measure the compressive strength of the coating layer and investigate how different coatings behave in compression. It was used the short span crush test, which is used to measure the in-plane compressive strength of paperboards, to measure the compressive strength of the coating layer. In this method the free span of the specimen is very small which prevent buckling. It was measured the compressive strength of free coating films as well as coated paper. It was also measured the tensile strength and the Bendtsen air permeance of the coating film. The results showed that the shape of pigment has a great effect to the strength of coating. Platy pigment gave much better strength than round or needle-like pigment. On the other hand calcined kaolin, which is also platy but the particles are aggregated, decreased the strength substantially. The difference in the strength can be explained with packing of the particles which is affecting to the porosity and thus to the strength. The platy kaolin packs up much better than others and creates less porous structure. The results also showed that the binder properties have a great effect to the compressive strength of coating layer. The amount of latex and the glass transition temperature, Tg, affect to the strength. As the amount of latex is increasing, the strength of coating is increasing also. Larger amount of latex is binding the pigment particles better together and decreasing the porosity. Compressive strength was increasing when the Tg was increasing because the hard latex gives a stiffer and less elastic film than soft latex.

Process variability-aware proactive reconfiguration technique for mitigating aging effects in nanos scale SRAM lifetime

Postprint (published version)

Secure logarithmic audio watermarking scheme based on the human auditory system

Peer-reviewed

New Distance Transforms for Gray Level Image Compression

This thesis deals with distance transforms which are a fundamental issue in image processing and computer vision. In this thesis, two new distance transforms for gray level images are presented. As a new application for distance transforms, they are applied to gray level image compression. The new distance transforms are both new extensions of the well known distance transform algorithm developed by Rosenfeld, Pfaltz and Lay. With some modification their algorithm which calculates a distance transform on binary images with a chosen kernel has been made to calculate a chessboard like distance transform with integer numbers (DTOCS) and a real value distance transform (EDTOCS) on gray level images. Both distance transforms, the DTOCS and EDTOCS, require only two passes over the graylevel image and are extremely simple to implement. Only two image buffers are needed: The original gray level image and the binary image which defines the region(s) of calculation. No other image buffers are needed even if more than one iteration round is performed. For large neighborhoods and complicated images the two pass distance algorithm has to be applied to the image more than once, typically 3 10 times. Different types of kernels can be adopted. It is important to notice that no other existing transform calculates the same kind of distance map as the DTOCS. All the other gray weighted distance function, GRAYMAT etc. algorithms find the minimum path joining two points by the smallest sum of gray levels or weighting the distance values directly by the gray levels in some manner. The DTOCS does not weight them that way. The DTOCS gives a weighted version of the chessboard distance map. The weights are not constant, but gray value differences of the original image. The difference between the DTOCS map and other distance transforms for gray level images is shown. The difference between the DTOCS and EDTOCS is that the EDTOCS calculates these gray level differences in a different way. It propagates local Euclidean distances inside a kernel. Analytical derivations of some results concerning the DTOCS and the EDTOCS are presented. Commonly distance transforms are used for feature extraction in pattern recognition and learning. Their use in image compression is very rare. This thesis introduces a new application area for distance transforms. Three new image compression algorithms based on the DTOCS and one based on the EDTOCS are presented. Control points, i.e. points that are considered fundamental for the reconstruction of the image, are selected from the gray level image using the DTOCS and the EDTOCS. The first group of methods select the maximas of the distance image to new control points and the second group of methods compare the DTOCS distance to binary image chessboard distance. The effect of applying threshold masks of different sizes along the threshold boundaries is studied. The time complexity of the compression algorithms is analyzed both analytically and experimentally. It is shown that the time complexity of the algorithms is independent of the number of control points, i.e. the compression ratio. Also a new morphological image decompression scheme is presented, the 8 kernels' method. Several decompressed images are presented. The best results are obtained using the Delaunay triangulation. The obtained image quality equals that of the DCT images with a 4 x 4

Use of the EPR technique to determine thermal stability of some humified organic substances found in soil organic-mineral fractions

In this work, using the EPR spectroscopy, we analysed the thermal stability of some organic-mineral compounds found in a Gleysoil from Rio Janeiro. It was observed a complete disappearance of the EPR signal around 600 °C for the < 2 µm fraction and a residual EPR signal of semiquinone free radical for the 2-20 µm and 20-53 µm fractions at the same temperature. Also, the experiments showed that the 2-20 µm fraction had a larger concentration of semiquinone free radical per g of carbon and a smaller line width indicated a larger humification of this fraction. This is an evidence that the soil organic matter of this fraction (2-20 µm) is more stable than the other ones.