943 resultados para supervised neighbor embedding


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Structures built by animals are a widespread and ecologically important 'extended phenotype'. While its taxonomic diversity has been well described, factors affecting short-term evolution of building behavior within a species have received little experimental attention. Here we describe how, given the opportunity, wandering Drosophila melanogaster larvae often build long tunnels in agar substrates and embed their pupae within them. These embedded larvae are characterized by a longer egg-to-pupariation developmental time than larvae that pupate on the surface. Assuming that such building behaviors are likely to be energetically costly and/or time consuming, we hypothesized that they should evolve to be less pronounced under resource or time limitation. In accord with this prediction, larvae from populations evolved for 160 generations under a regime that combines larval malnutrition with limited developmental time dug shorter tunnels than larvae from control unselected populations. However, the proportion of larvae that embedded before pupation did not differ between the malnutrition-adapted and control populations, suggesting that tunnel length and likelihood of embedding before pupation are controlled by different genetic loci. The behaviors exhibited by wandering larvae of Drosophila melanogaster prior to pupation offer a model system to study evolution of animal building behaviors because the tunneling and embedding phenotypes are simple, facultative and highly variable.

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This article reports on a lossless data hiding scheme for digital images where the data hiding capacity is either determined by minimum acceptable subjective quality or by the demanded capacity. In the proposed method data is hidden within the image prediction errors, where the most well-known prediction algorithms such as the median edge detector (MED), gradient adjacent prediction (GAP) and Jiang prediction are tested for this purpose. In this method, first the histogram of the prediction errors of images are computed and then based on the required capacity or desired image quality, the prediction error values of frequencies larger than this capacity are shifted. The empty space created by such a shift is used for embedding the data. Experimental results show distinct superiority of the image prediction error histogram over the conventional image histogram itself, due to much narrower spectrum of the former over the latter. We have also devised an adaptive method for hiding data, where subjective quality is traded for data hiding capacity. Here the positive and negative error values are chosen such that the sum of their frequencies on the histogram is just above the given capacity or above a certain quality.

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This paper proposes a novel high capacity robust audio watermarking algorithm by using the high frequency band of the wavelet decomposition at which the human auditory system (HAS) is not very sensitive to alteration. The main idea is to divide the high frequency band into frames and, for embedding, to change the wavelet samples depending on the average of relevant frame¿s samples. The experimental results show that the method has a very high capacity (about 11,000 bps), without significant perceptual distortion (ODG in [¿1 ,0] and SNR about 30dB), and provides robustness against common audio signal processing such as additive noise, filtering, echo and MPEG compression (MP3).

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Many audio watermarking schemes divide the audio signal into several blocks such that part of the watermark is embedded into each of them. One of the key issues in these block-oriented watermarking schemes is to preserve the synchronisation, i.e. to recover the exact position of each block in the mark recovery process. In this paper, a novel time domain synchronisation technique is presented together with a new blind watermarking scheme which works in the Discrete Fourier Transform (DFT or FFT) domain. The combined scheme provides excellent imperceptibility results whilst achieving robustness against typical attacks. Furthermore, the execution of the scheme is fast enough to be used in real-time applications. The excellent transparency of the embedding algorithm makes it particularly useful for professional applications, such as the embedding of monitoring information in broadcast signals. The scheme is also compared with some recent results of the literature.

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A new coding technique to be used in steganography is evaluated. The performanceof this new technique is computed and comparisons with the well-known theoreticalupper bound, Hamming upper bound and basic LSB are established.

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BACKGROUND: New methods of ultra-rapid opiate detoxification (URD) under intravenous sedation have been criticized because of limited data on safety and long-term follow-up. Premedication with buprenorphine has been advocated to improve safety by decreasing vomiting. Prior research has not explored URD in socially impaired patients. METHOD: Sixteen patients were detoxified with URD and prospectively evaluated over at least 30 months. Data of this procedure were compared with those of our previous study without buprenorphine preparation (Drug Alcohol Depend. 52(3) (1998) 243). The 16 patients were followed up by a general practitioner (GP) before and after URD. The GPs also supervised the 7-day course of buprenorphine treatment prescribed for the 16 patients prior to URD. RESULTS: During the procedure, only one episode of vomiting occurred instead of 13 out of 20 in our previous study. Post-procedure, only two patients experienced moderate withdrawal symptoms, such as persistent nausea, abdominal cramps and vomiting lasting from 24 to 48 h, in comparison with most patients in the previous study without buprenorphine. After a period of at least 30 months (36.0+/-6.38), the 16 patients were still alive and were regularly monitored by their GP. Only two of the 16 never relapsed after URD and reported total opiate abstinence. Fourteen patients relapsed; 12 of these were prescribed a licensed methadone substitution program and two were still using heroin. CONCLUSION: In this small sample, the data indicated that URD with buprenorphine preparation was safe and that it markedly decreased post-procedure morbidity. No patient died over a minimum 30-month follow-up period. Furthermore, the procedure was employed with socially impaired patients. In the long term, a few patients were still free of opiates, while the majority opted for a methadone maintenance program, showing that URD can serve as one possible step in a long-term treatment program.

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The objective of this work was to evaluate the use of multispectral remote sensing for site-specific nitrogen fertilizer management. Satellite imagery from the advanced spaceborne thermal emission and reflection radiometer (Aster) was acquired in a 23 ha corn-planted area in Iran. For the collection of field samples, a total of 53 pixels were selected by systematic randomized sampling. The total nitrogen content in corn leaf tissues in these pixels was evaluated. To predict corn canopy nitrogen content, different vegetation indices, such as normalized difference vegetation index (NDVI), soil-adjusted vegetation index (Savi), optimized soil-adjusted vegetation index (Osavi), modified chlorophyll absorption ratio index 2 (MCARI2), and modified triangle vegetation index 2 (MTVI2), were investigated. The supervised classification technique using the spectral angle mapper classifier (SAM) was performed to generate a nitrogen fertilization map. The MTVI2 presented the highest correlation (R²=0.87) and is a good predictor of corn canopy nitrogen content in the V13 stage, at 60 days after cultivating. Aster imagery can be used to predict nitrogen status in corn canopy. Classification results indicate three levels of required nitrogen per pixel: low (0-2.5 kg), medium (2.5-3 kg), and high (3-3.3 kg).

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Enterprise architectures (EA) are considered promising approaches to reduce the complexities of growing information technology (IT) environments while keeping pace with an ever-changing business environment. However, the implementation of enterprise architecture management (EAM) has proven difficult in practice. Many EAM initiatives face severe challenges, as demonstrated by the low usage level of enterprise architecture documentation and enterprise architects' lack of authority regarding enforcing EAM standards and principles. These challenges motivate our research. Based on three field studies, we first analyze EAM implementation issues that arise when EAM is started as a dedicated and isolated initiative. Following a design-oriented paradigm, we then suggest a design theory for architecture-driven IT management (ADRIMA) that may guide organizations to successfully implement EAM. This theory summarizes prescriptive knowledge related to embedding EAM practices, artefacts and roles in the existing IT management processes and organization.

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Due to the power of genetics, the mouse has become a widely used animal model in vision research. However, its eyeball has an axial length of only about 2 mm. The present protocol describes how to easily dissect the small rodent eye post mortem. This allows collecting different tissues of the eye, i.e., cornea, lens, iris, retina, optic nerve, retinal pigment epithelium (RPE), and sclera. We further describe in detail how to process these eye samples in order to obtain high‐quality RNA for RNA expression profiling studies. Depending on the eye tissue to be analyzed, we present appropriate lysis buffers to prepare total protein lysates for immunoblot and immuno‐precipitation analyses. Fixation, inclusion, embedding, and cryosectioning of the globe for routine histological analyses (HE staining, DAPI staining, immunohistochemistry, in situ hybridization) is further presented. These basic protocols should allow novice investigators to obtain eye tissue samples rapidly for their experiments.

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Rehabilitation programs represent an important and valuable tool for patients suffering various diseases. Supervised exercise programs for patients with peripheral arterial diseases have been shown to be efficacious in ameliorating walking performances and quality of life of such patients. With this regards the angiology service of the CHUV in Lausanne has established a multidisciplinary supervised program of vascular rehabilitation. This article describes organisation and characteristics of such a program.

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Puhdastilojen suunnittelussa pyritään saamaan hallittu ja valvottu ilmanpuhtaus luokiteltuun tilaan.Luokittelu tapahtuu puhdastilastandardeilla, lisäksi lääkevalmisteita valmistettavassa tilassa GMP -säädösten mukaisin luokituksin. Puhdastilastandardi ISO 14644 käsittää seitsemän osaa, jossa on käsitelty puhdastilaa koskevia määräyksiä suunnittelusta käyttöön ja testaukseen. GMP-säädökset sisältävät yhdeksän kappaletta, joista kappale 3: 'Tilat ja laitteet' on keskeinen osa lääkeainevalmistuksen puhdastilasuunnittelua. Puhtaan ilman aikaansaamiseksi puhdastilaan merkittävimmät roolit ovat ilmanvaihdolla, puhdastilarakenteilla ja rakennusautomaatiolla. Ilma voidaan tuoda tilaan kolmella eri periaatteella. Ilmaa tuodaan tilaan yhdensuuntaisesti, turbulenttisesti tai sekavirtauksena HEPA -suodattimien kautta, joilla varmistetaan epäpuhtauksien korkea suodatusaste. Ilmapoistetaan rei'itettyjen, korotettujen lattioiden kautta tai tilan alaosassa olevien poistoilmasäleikköjen kautta, josta se johdetaan noin 75-90%:sti kierrätettynä takaisin tilaan. Lääketeollisuudessa rei'itettyjä, korotettuja lattioita eivoida käyttää kontaminaatiovaaran, vuoksi. Tilaan suunniteltuja olosuhteita ylläpidetään rakennusautomaation avulla ja monitorointijärjestelmällä valvotaan tilassa olevan ilman laatua. Kaikki GMP-luokituksen mukaiset puhdastilat tulee validoida. Validointiin kuuluu teknisten järjestelmien kvalifiointi ja koko prosessin validointi. Teknisten järjestel-mien kvalifiointi käsittää suunnitelmien tarkastuksen (DQ), asennus - ja käyttöönotto tarkastukset (IQ), toiminnan testauksen (OQ) ja suorituksen testauksen (PQ). Kvali-fiointi kuuluu yhtenä osa-alueena validointiin. Prosessin validointi on osa yrityksen laadunvarmistusta. Validoinnilla hankitaan dokumentoidut todisteet siitä, että tila tai prosessi todella täyttää annetut vaatimukset. Tässä työssä laadittiin esimerkinomainen kvalifiointisuunnitelma puhdastilan tekni-sille järjestelmille. Suunnitelma sisältää asennus- ja käyttöönoton mukaiset tarkastukset (IQ)ja toiminnan aikaiset testaukset (OQ).

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This paper presents a novel image classification scheme for benthic coral reef images that can be applied to both single image and composite mosaic datasets. The proposed method can be configured to the characteristics (e.g., the size of the dataset, number of classes, resolution of the samples, color information availability, class types, etc.) of individual datasets. The proposed method uses completed local binary pattern (CLBP), grey level co-occurrence matrix (GLCM), Gabor filter response, and opponent angle and hue channel color histograms as feature descriptors. For classification, either k-nearest neighbor (KNN), neural network (NN), support vector machine (SVM) or probability density weighted mean distance (PDWMD) is used. The combination of features and classifiers that attains the best results is presented together with the guidelines for selection. The accuracy and efficiency of our proposed method are compared with other state-of-the-art techniques using three benthic and three texture datasets. The proposed method achieves the highest overall classification accuracy of any of the tested methods and has moderate execution time. Finally, the proposed classification scheme is applied to a large-scale image mosaic of the Red Sea to create a completely classified thematic map of the reef benthos

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Paperin pinnan karheus on yksi paperin laatukriteereistä. Sitä mitataan fyysisestipaperin pintaa mittaavien laitteiden ja optisten laitteiden avulla. Mittaukset vaativat laboratorioolosuhteita, mutta nopeammille, suoraan linjalla tapahtuville mittauksilla olisi tarvetta paperiteollisuudessa. Paperin pinnan karheus voidaan ilmaista yhtenä näytteelle kohdistuvana karheusarvona. Tässä työssä näyte on jaettu merkitseviin alueisiin, ja jokaiselle alueelle on laskettu erillinen karheusarvo. Karheuden mittaukseen on käytetty useita menetelmiä. Yleisesti hyväksyttyä tilastollista menetelmää on käytetty tässä työssä etäisyysmuunnoksen lisäksi. Paperin pinnan karheudenmittauksessa on ollut tarvetta jakaa analysoitava näyte karheuden perusteella alueisiin. Aluejaon avulla voidaan rajata näytteestä selvästi karheampana esiintyvät alueet. Etäisyysmuunnos tuottaa alueita, joita on analysoitu. Näistä alueista on muodostettu yhtenäisiä alueita erilaisilla segmentointimenetelmillä. PNN -menetelmään (Pairwise Nearest Neighbor) ja naapurialueiden yhdistämiseen perustuvia algoritmeja on käytetty.Alueiden jakamiseen ja yhdistämiseen perustuvaa lähestymistapaa on myös tarkasteltu. Segmentoitujen kuvien validointi on yleensä tapahtunut ihmisen tarkastelemana. Tämän työn lähestymistapa on verrata yleisesti hyväksyttyä tilastollista menetelmää segmentoinnin tuloksiin. Korkea korrelaatio näiden tulosten välillä osoittaa onnistunutta segmentointia. Eri kokeiden tuloksia on verrattu keskenään hypoteesin testauksella. Työssä on analysoitu kahta näytesarjaa, joidenmittaukset on suoritettu OptiTopolla ja profilometrillä. Etäisyysmuunnoksen aloitusparametrit, joita muutettiin kokeiden aikana, olivat aloituspisteiden määrä ja sijainti. Samat parametrimuutokset tehtiin kaikille algoritmeille, joita käytettiin alueiden yhdistämiseen. Etäisyysmuunnoksen jälkeen korrelaatio oli voimakkaampaa profilometrillä mitatuille näytteille kuin OptiTopolla mitatuille näytteille. Segmentoiduilla OptiTopo -näytteillä korrelaatio parantui voimakkaammin kuin profilometrinäytteillä. PNN -menetelmän tuottamilla tuloksilla korrelaatio oli paras.

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The main goal of this paper is to propose a convergent finite volume method for a reactionâeuro"diffusion system with cross-diffusion. First, we sketch an existence proof for a class of cross-diffusion systems. Then the standard two-point finite volume fluxes are used in combination with a nonlinear positivity-preserving approximation of the cross-diffusion coefficients. Existence and uniqueness of the approximate solution are addressed, and it is also shown that the scheme converges to the corresponding weak solution for the studied model. Furthermore, we provide a stability analysis to study pattern-formation phenomena, and we perform two-dimensional numerical examples which exhibit formation of nonuniform spatial patterns. From the simulations it is also found that experimental rates of convergence are slightly below second order. The convergence proof uses two ingredients of interest for various applications, namely the discrete Sobolev embedding inequalities with general boundary conditions and a space-time $L^1$ compactness argument that mimics the compactness lemma due to Kruzhkov. The proofs of these results are given in the Appendix.

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Introduction Our institution (University hospital) is encouraging physical activities for health through various popular sporting events in the city of Lausanne, the biggest of which is a road race of 2, 4, 10 and 20km. Objective To create an efficient and sustainable training program in preparation of the race for a group of motivated hospital employees without any prior experience with structured training and to identifying the benefits and limitations encountered.. Methods Subjects of various fitness levels were recruited by add and agreed to undergo lab and field testing before a 12-week 3 times/week running program, based on maximal aerobic speed (MAS-30/30 sec intervals), running technique exercises and endurance training. The interval session was the only one supervised. Their goal was the 10km (11 subjects) and the 20km (6 subjects). Results A group of 17 subjects (7 male and 10 female), mean age 36.6±7.3 years, VO2max 44.0±5.5 ml/kg/min, filed test interval MAS 15.1±2.4 km/h started the program. 2 were lost because of injury (while skiing). Adherence to interval sessions was excellent, although 3 weekly training sessions proved to be difficult for most of the subjects. Performance in the race was satisfying for all of them, 6/7 subjects having improved their running time from the previous year, the others participated for the first time and 7/8 completed the race satisfyingly, one DNF-ed because of sinusitis. Repeat MAS field test was available for 6 subjects, who improved by 5.9% (p<0.01). Subjectively, all of the participants were very satisfied with improvement, interaction with colleagues from various professions, and with self achievement and confidence. Conclusions Implementation of a structured training program for recreational or non-athletes can be very successful in creating a better self-confidence, a better working environment inside a hospital facility and obviously in improvement of physical fitness and athletic performance. Above all, it can only encourage health institutions to promote the health of their own employees through physical activity, which can allow people to connect through sports. As a result, subjects in this study tend to encourage other employees to be more active and are hungry for more advice and continued offers for physical activities benefiting both them and the institution through better efficiency at work and less absenteeism common to more active people.