166 research outputs found
Lesion detection and Grading of Diabetic Retinopathy via Two-stages Deep Convolutional Neural Networks
We propose an automatic diabetic retinopathy (DR) analysis algorithm based on
two-stages deep convolutional neural networks (DCNN). Compared to existing
DCNN-based DR detection methods, the proposed algorithm have the following
advantages: (1) Our method can point out the location and type of lesions in
the fundus images, as well as giving the severity grades of DR. Moreover, since
retina lesions and DR severity appear with different scales in fundus images,
the integration of both local and global networks learn more complete and
specific features for DR analysis. (2) By introducing imbalanced weighting map,
more attentions will be given to lesion patches for DR grading, which
significantly improve the performance of the proposed algorithm. In this study,
we label 12,206 lesion patches and re-annotate the DR grades of 23,595 fundus
images from Kaggle competition dataset. Under the guidance of clinical
ophthalmologists, the experimental results show that our local lesion detection
net achieve comparable performance with trained human observers, and the
proposed imbalanced weighted scheme also be proved to significantly improve the
capability of our DCNN-based DR grading algorithm
Time of Arrival Complementing Method for Cooperative Localization of a Target by Two-Node UWB Sensor Network
Recently, the detection, localization and tracking of moving persons in emergency situations using ultra-wideband (UWB) sensors have attracted the attention of researchers and final users as well. Experiences with single UWB sensors in real applications have shown that their reliability and accuracy in person detection and localization may be considerably reduced. In contrast, the improved performance of a UWB sensor-based localization system can be provided by a UWB sensor network, which benefits from cooperation among spatially distributed sensor nodes. This cooperation extends the coverage of the monitored area and improves detection capability and localization performance, especially in the case of complex environments and multiple targets. In this paper, we will introduce a new approach to cooperative localization of a target, referred to as the time of arrival complementing method (TOACOM). TOACOM, developed for a two-node UWB sensor network, is based on the time of arrival (TOA) complementing and combining algorithms in combination with the conventional direct calculation method (DC). Its properties will be analyzed for through-the-wall single moving person localization. The obtained results will show the superior performance of TOACOM as compared with person localization by a single UWB sensor, or by a two-node sensor network. In the conclusion, we will outline that the presented version of TOACOM can be further modified for a multiple target scenario and an N-node sensor network
Damage classification in reinforced concrete beam by acoustic emission signal analysis
Acoustic Emission (AE) is a non-destructive testing technique which can be used to identify both the damage level and the nature of that damage such as tensile cracks and shear movements at critical zones within a structure. In this work, the acoustic emission parameters of amplitude, rise time, average frequency and signal strength were used to classify the damage and to determine the damage level. Laboratory experiments were performed on a beam (150 x 250 x 1900 mm). The acoustic emission analysis was successfully used to determine crack movements and classify damage levels in accordance with the observations made during an increasing loading cycle
SpEYEders: Adults’ and children’s affective responses during immersive playful gaze interactions transforming virtual spiders
Specific phobias like spider phobia represent a frequent mental health problem in children and adolescents, demanding innovative prevention and treatment approaches. We therefore develop an eye tracking supported Virtual Reality serious game for school-aged children, realizing gaze interactions to promote attention towards, and positive experiences during exposure to spiders. Within pilot studies in adults (n=30) and children (n=14) without fear of spiders, we assessed positive and negative affect during prototype gaze feedback through five different variants: If gazed for few seconds, the virtual spider changed into a shrunk, a rainbow coloured, or dying spider, or morphed into a smileyball, or speaks friendly. We found the highest positive affect for the rainbow and smileyball variant, followed by the shrunk and friendly speaking variant. In contrast, the dying variant was excluded due to the possible induction of negative affect. Findings indicate eligible variants for the further development of the VR serious game
An engaged research study to assess the effect of a 'real-world' dietary intervention on urinary bisphenol A (BPA) levels in teenagers.
Bisphenol A (BPA) has been associated with adverse human health outcomes and exposure to this compound is near-ubiquitous in the Western world. We aimed to examine whether self-moderation of BPA exposure is possible by altering diet in a real-world setting
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Multiple outer-shell ionization effect in inner-shell x-ray production by light ions
This article discusses multiple outer-shell ionization effect in inner-shell x-ray production by light ions
Low back pain in pregnant wome
Pain of lumbosacral segment of the vertebral column and the pelvis concerns about 45% of all pregnant women. The change of the body posture during pregnancy is the result of gravity centre relocation, which affects the musculosceletal system. Development of the joint, ligament and myofascial dysfunctions, as well as the pain in the lumbosacral segment and the pelvis, are the most common reasons of spine pain. The aim of this review is to present the current state of knowledge about lumbar spine pain in pregnant women with special focus on the pain connected with muscular, joint and ligament disorders. Pregnancy is a serious burden for the female osteo-skeletal system. Lumbar pain with different location and intensification is the negative consequence of the position changes during pregnancy. Pharmacotherapy could be useful only in cases of intensive low back pain, with possible application of small spectrum of drugs that are safe during pregnancy. Physical therapy, including manual therapy, exercises, massage and techniques of local anesthesia are alternative methods in case of low back pain in pregnant women
Development of appropriateness explicit criteria for cataract extraction by phacoemulsification
BACKGROUND: Consensus development techniques were used in the late 1980s to create explicit criteria for the appropriateness of cataract extraction. We developed a new appropriateness of indications tool for cataract following the RAND method. We tested the validity of our panel results. METHODS: Criteria were developed using a modified Delphi panel judgment process. A panel of 12 ophthalmologists was assembled. Ratings were analyzed regarding the level of agreement among panelists. We studied the influence of all variables on the final panel score using linear and logistic regression models. The explicit criteria developed were summarized by classification and regression tree analysis. RESULTS: Of the 765 indications evaluated by the main panel in the second round, 32.9% were found appropriate, 30.1% uncertain, and 37% inappropriate. Agreement was found in 53% of the indications and disagreement in 0.9%. Seven variables were considered to create the indications and divided into three groups: simple cataract, with diabetic retinopathy, or with other ocular pathologies. The preoperative visual acuity in the cataractous eye and visual function were the variables that best explained the panel scoring. The panel results were synthesized and presented in three decision trees. Misclassification error in the decision trees, as compared with the panel original criteria, was 5.3%. CONCLUSION: The parameters tested showed acceptable validity for an evaluation tool. These results support the use of this indication algorithm as a screening tool for assessing the appropriateness of cataract extraction in field studies and for the development of practice guidelines
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L-shell x-ray production cross sections of Ni, Cu, Ge, As, Rb, Sr, Y, Zr, and Pd by (0.25-2.5)-MeV protons
Article discussing L-shell x-ray production cross sections of Ni, Cu, Ge, As, Rb, Sr, Y, Zr, and Pd by (0.25-2.5)-MeV protons
Paying for parking : improving stated-preference surveys
This article describes an experiment which introduced random ranges into the variables used for the design of a stated preference survey and its effects on willingness to pay for parking. User behaviour at the time of parking was modelled to determine their willingness to pay in order to get to their final destination more quickly. Calculating willingness to pay is fundamental during the social and economic assessment of projects. It is important to correctly model how car parks and their users interact in order to get values which represent reality as closely as possible. Willingness to pay is calculated using a stated preference survey and by calibrating multinomial logit models, taking variable tastes into account. It is shown that a value with a low variability can be obtained for willingness to pay by correctly establishing the context of the choice and randomly changing the variables around an average value
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