1,030 research outputs found
Trust Based Participant Driven Privacy Control in Participatory Sensing
Widespread use of sensors and multisensory personal devices generate a lot of
personal information. Sharing this information with others could help in
various ways. However, this information may be misused when shared with all.
Sharing of information between trusted parties overcomes this problem. This
paper describes a model to share information based on interactions and opinions
to build trust among peers. It also considers institutional and other controls,
which influence the behaviour of the peers. The trust and control build
confidence. The computed confidence bespeaks whether to reveal information or
not thereby increasing trusted cooperation among peers.Comment: 14 page
ISAR Image Classification with Wavelet and Watershed Transforms
Inverse Synthetic Aperture Radar images are playing a significant role in classification of sea and air targets. First we acquire the ISAR images of targets using a sensor like radar and extract the characteristics of targets from the ISAR images in the form of feature vectors. The computed feature vectors are used for classification of targets. In this work, widely used and efficient segmentation tool Watershed transform and the multi resolution technique wavelet transform are explored to derive the target features. An artificial neural network based classifier is used for classification. The Wavelet analysis divides the information of an image into approximation and detail sub signals. The approximate and three detail sub signal values are taken as feature vectors and given as input to the classifier for ship ISAR image classification. The widely used segmentation technique, Watershed transform is applied to the ISAR images. The wavelet coefficients are computed for the segmented ISAR images and used as feature vectors for classification of the ISAR images. Also, the statistical moments mean and standard deviation are computed for the color ISAR images itself, taken in RGB format. These statistical color moments are used as feature vector. The classification accuracy is compared for the feature vectors
Luminance-Chrominance-Gradient Based Technique for High Dynamic Range Image Fusion
604-607The High Dynamic Range (HDR) technique involves capturing the same scene multiple times with different exposure values and produces an output image with more dynamic range. Instead of doing all processing in RGB color space, we proposed to do it in Luminance Chrominance Gradient colour space, which results the output images to be more natural and pleasant to perceive with less noise. This experiment was evaluated and analysed with BAR and AEE1 methods and the results are compared. We showed that, our LCGHDR method is computationally efficient and able to remove any colour distortions originated from the RGB color channel
Set-up of a multi wavelength polar photometer for off-line absorption coefficient measurements on 1-h resolved aerosol samples
In this paper, a polar photometer (PP_UniMI) was set up to measure the aerosol absorption
coefficient (\u3c3ap) at four wavelengths (\u3bb) on 1-h resolved aerosol samples collected using a
streaker sampler. Due to the characteristics of such samples (small deposit area, low aerosol load,
and limited substrate thickness 12 10 \u3bcm), the main technical developments aimed at reaching
suitable limits of detection (LODs). To this aim, multiple scattering between the sample and a
suitable substrate were exploited to amplify the system sensitivity to absorbing particle load. In
the paper, the development and test of this innovative approach is presented.
LODs for \u3c3ap in the range 5.0\u201311.6 Mm 121 were reached, depending on the wavelength. Such
values were suitable for the analysis of 1-hour resolved samples collected at an urban background
site in Milan (Italy) during a test campaign of 1-week carried out in winter 2015. The
methodology was validated comparing \u3c3ap measurements performed by PP_UniMI at
\u3bb=635 nm on the streaker sample to the data obtained by a Multi-Angle Absorption
Photometer (MAAP) operated in parallel. Agreement within 10% was found. To check the
results obtained at other wavelengths, \uc5ngstr\uf6m Absorption Exponent (AAE) was calculated from
\u3c3ap measurements at 4-\u3bb. The AAE values resulted in the range of expectations for aerosol
emitted by fossil fuel combustion (0.8\u20131.2) and wood burning (0.9\u20133.5), which are the main
sources contributing to absorbing aerosol in urban areas in winter.
The analytical methodology can be extended to samples collected with high time resolution
using other high-time resolution samplers (e.g. drum rotating impactors).
This is \u2013 as far as we know \u2013 the first time that \u3c3ap measurements are performed on streaker
samples collected with 1-h resolution. Our results thus set PP_UniMI as an important tool for the
community performing high time resolved sampling to widen the characterisation of such
samples and to further develop source apportionment studies
Over-the-scope-clip closure of long lasting gastrocutaneous fistula after percutaneous endoscopic gastrostomy tube removal in immunocompromised patients: A single center case series
Over-the-scope-clips (OTSC(®)) have been shown to be an effective and safe endoscopic treatment option for the closure of gastrointestinal perforations, leakages and fistulae. Indications for endoscopic OTSC(®) treatment have grown in number and also include gastro cutaneous fistula (GCF) after percutaneous endoscopic gastrostomy (PEG) tube removal. Non-healing GCF is a rare complication after removal of PEG tubes and may especially develop in immunosuppressed patients with multiple comorbidities. There is growing evidence in the literature that OTSC(®) closure of GCF after PEG tube removal is emerging as an effective, simple and safe endoscopic treatment option. However current evidence is limited to the geriatric population and short standing GCF, while information on closure of long standing GCF after PEG tube removal in a younger population with significant comorbidities is lacking. In this retrospective single-center case-series we report on five patients undergoing OTSC(®) closure of chronic GCF after PEG tube removal. Four out of five patients were afflicted with long lasting, symptomatic fistulae. All five patients suffered from chronic disease associated with a catabolic metabolism (cystic fibrosis, chemotherapy for neoplasia, liver cirrhosis). The mean patient age was 43 years. The mean dwell time of PEG tubes in all five patients was 808 d. PEG tube dwell time was shortest in patient 5 (21 d). The mean duration from PEG tube removal to fistula closure in patients 1-4 was 360 d (range 144-850 d). The intervention was well tolerated by all patients and no adverse events occured. Successful immediate and long-term fistula closure was accomplished in all five patients. This single center case series is the first to show successful endoscopic OTSC(®) closure of long lasting GCF in five consecutive middle-aged patients with significant comorbidities. Endoscopic closure of chronic persistent GCF after PEG tube removal using an OTSC(®) was achieved in all patients with no immediate or long-term complications. OTSC(®) is a promising endoscopic treatment option for this condition with a potentially high immediate and long term success rate in patients with multiple comorbidities
Interplay between destructive quantum interference and symmetry-breaking phenomena in graphene quantum junctions
We study the role of electronic spin and valley symmetry in the quantum interference (QI) patterns of the transmission function in graphene quantum junctions. In particular, we link it to the position of the destructive QI antiresonances. When the spin or valley symmetry is preserved, electrons with opposite spin or valley display the same interference pattern. On the other hand, when a symmetry is lifted, the antiresonances are split, with a consequent dramatic differentiation of the transport properties in the respective channel. We demonstrate rigorously this link in terms of the analytical structure of the electronic Green function, which follows from the symmetries of the microscopic model, and we confirm the result with numerical calculations for graphene nanoflakes. We argue that this is a generic and robust feature that can be exploited in different ways for the realization of nanoelectronic QI devices, generalizing the recent proposal of a QI-assisted spin-filtering effect [A. Valli et al., Nano Lett. 18, 2158 (2018)10.1021/acs.nanolett.8b00453]
Cervical growth in a young woman: a case report
Genital tuberculosis, a silent killer of menstrual function and fertility potential is common in developing countries like India. Cervical TB is extremely rare and it accounts for 0.1-0.65% of all the cases of tuberculosis and 5-24% of all the genital tuberculosis cases. The clinical presentation of genitourinary tuberculosis is variable in nature and it can also be asymptomatic. Here, we are reporting a rare case of cervical tuberculosis clinically masquerading as cervical malignancy presenting with secondary amenorrhoea
Analysis of adnexal masses requiring reoperation following hysterectomy
Background: Generally, we would like to preserve ovaries during hysterectomy for benign conditions. Many of them come back with ovarian cysts and pain abdomen. Recently there were ten cases of residual ovaries requiring surgery during a year period which made us analyze these cases.Methods: This retrospective descriptive analysis was conducted in SRM Medical College Hospital and Research Centre. Data about residual ovaries requiring surgery were retrieved from the medical records department and operation records and analyzed.Results: There were ten cases of residual ovaries from January 2015 to December 2015 requiring surgery. In 70% of patients, residual ovary syndrome occurred within 5 years of hysterectomy. Majority (80%) of them were following abdominal hysterectomy. The most common symptom among these patients was chronic pelvic pain. Pelvic adhesions were present in most of the cases. Follicular cyst and hemorrhagic corpus luteum were the commonest pathological findings in the residual ovaries (50%). There were two cases of endometriotic cyst and a case of secondary malignant ovarian tumor with primary growth from stomach in a 40 year old woman for whom hysterectomy was performed five years ago for adenomyosis.Conclusions: When the ovaries are preserved the woman should be properly counseled and should undergo periodic clinical and ultrasonographic follow-up
Development of a dual-wavelength thermo-optical transmittance analyser: characterization and first results
Carbonaceous aerosol (CA) plays an important role in many different issues ranging from human health to global climate change. It mainly consists of organic carbon (OC) and elemental carbon (EC) although a minor fraction of carbonate carbon could be also present. Thermal-optical methods (TOT/TOR) are presently the most widespread approach to OC/EC speciation. Despite their popularity, there is still a disagreement among the results, especially for what concerns EC as different thermal protocols can be used. In fact, the pyrolysis occurring during the analysis can heavily affect OC/EC separation, depending on PM composition in addition to the used protocol. The main hypothesis at the basis of the technique relies on the optical properties of EC and OC: while EC is strongly light absorbing, OC is generally transparent in the visible range. However, a fraction of light-absorbing OC exists: the Brown Carbon (BrC) (Andreae and Gelencs\ue9r, 2006). The presence in the sample of BrC can shift the split point since it is slightly absorbing also @ 635nm, the typical laser wavelength used in this technique (Chen et al., 2015). At the Physics Department of the University of Genoa, a Sunset EC/OC analyser unit has been modified in order to monitor the optical transmittance during the thermo-optical analysis at two different wavelengths: 635 nm (the original wavelength of the instrument) and 405 nm (Fig.1). The additional use of the 405 nm transmittance measurement provides valuable information about the composition of the sample as well as on the pyrolytic carbon formation, both able to affect the instrumental \u201csplit point\u201d (i.e. the moment of the analysis in which the laser transmittance is back to its starting value, thus defining EC/OC separation). We present here the new instrument set-up, providing its full characterization with \u201csynthetic\u201d samples (i.e. mixtures of sucrose, graphitic carbon, and pure scattering particles). Moreover, we show also the results obtained analysing at 2-\uf06c - with both NIOSH and EUSAAR_2 protocols - real PM samples collected in very different conditions (i.e. summer-winter) and sites (ranging from urban to rural/mountain). Furthermore, we have recently introduced a new possibility, based on the apportionment of the absorption coefficient (babs) of particle-loaded filters, for correcting the thermo-optical analysis of PM samples (Massab\uf2 et al, 2016), an example in Fig.2. The apportionment is based on the optical analysis performed by the Multi-Wavelength Absorbance Analyser (MWAA), an instrument developed at the Physics Department of the University of Genoa (Massab\uf2 et al., 2015). The apportionment method uses the information gathered at five different wavelengths in a renewed and upgraded version of the approach usually referred to as Aethalometer model (Sandradewi et al., 2008). We present here also the results of the thermo-optical analysis correction (Massab\uf2 et al., 2016) applied to the dual-\uf06c analysis, which lead to a better homogeneity between the results obtained with different thermal protocols
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