Patient-specific bronchoscopy visualization through BRDF estimation and disocclusion correction

This paper presents an image-based method for virtual bronchoscope with photo-realistic rendering. The technique is based on recovering bidirectional reflectance distribution function (BRDF) parameters in an environment where the choice of viewing positions, directions, and illumination conditions are restricted. Video images of bronchoscopy examinations are combined with patient-specific three-dimensional (3-D) computed tomography data through two-dimensional (2-D)/3-D registration and shading model parameters are then recovered by exploiting the restricted lighting configurations imposed by the bronchoscope. With the proposed technique, the recovered BRDF is used to predict the expected shading intensity, allowing a texture map independent of lighting conditions to be extracted from each video frame. To correct for disocclusion artefacts, statistical texture synthesis was used to recreate the missing areas. New views not present in the original bronchoscopy video are rendered by evaluating the BRDF with different viewing and illumination parameters. This allows free navigation of the acquired 3-D model with enhanced photo-realism. To assess the practical value of the proposed technique, a detailed visual scoring that involves both real and rendered bronchoscope images is conducted.     

A protection strategy for inverter-interfaced islanded microgrids with looped configuration

Electrical Engineering - Development of an efficient protection strategy is one of the main barriers in paving the way for the implementation of inverter-based microgrids. The limited fault current...     

A study on corrosion‐fatigue behavior of AA7075‐T651 subjected to different surface modification treatments

Two corrosive media were used (3.5 wt% NaCl aqueous solution and distilled water) to examine the corrosion‐fatigue behavior of AA 7075‐T651, subjected to various surface modifications (wire‐EDM, blasting, and anodizing). An in‐situ corrosion‐fatigue device was used to test the corrosion‐fatigue durability. The apparatus is able to generate cyclic loads within a corrosive solution. The mechanical loading is simulated with the aid of finite element method (FEM). At both corrosive environments, a prolongation of the corrosion‐fatigue life was achieved by the blasting procedure, compared with the as‐machined specimens under same conditions. Anodizing had a deleterious impact in all examined cases.     

Finding Diachronic Like‐Minded Users

User communities in social networks are usually identified by considering explicit structural social connections between users. While such communities can reveal important information about their members such as family or friendship ties and geographical proximity, just to name a few, they do not necessarily succeed at pulling like‐minded users that share the same interests together. Therefore, researchers have explored the topical similarity of social content to build like‐minded communities of users. In this article, following the topic‐based approaches, we are interested in identifying communities of users that share similar topical interests with similar temporal behavior. More specifically, we tackle the problem of identifying temporal (diachronic) topic‐based communities, i.e., communities of users who have a similar temporal inclination toward emerging topics. To do so, we utilize multivariate time series analysis to model the contributions of each user toward emerging topics. Further, our modeling is completely agnostic to the underlying topic detection method. We extract topics of interest by employing seminal topic detection methods; one graph‐based and two latent Dirichlet allocation‐based methods. Through our experiments on Twitter data, we demonstrate the effectiveness of our proposed temporal topic‐based community detection method in the context of news recommendation, user prediction, and document timestamp prediction applications, compared with the nontemporal as well as the state‐of‐the‐art temporal approaches.     

Carotenoid pattern in Blakeslea trispora grown on oil‐enriched substrates with regard to triacylglycerol species accumulation

The carotenoid pattern in Blakeslea trispora grown on oil‐enriched substrates was investigated with regard to triacylglycerol (TAG) species accumulation, to assess the interrelationship between these two processes. Analysis of individual carotenoids and TAG was carried out by HPLC. β‐Carotene production was at the expense of lycopene and γ‐carotene formation in cells grown on crude olive pomace oil (COPO) and crude soybean oil (CSO) at two levels of addition (10.0 and 30.0 g/L culture medium). A shift to γ‐carotene synthesis was observed at increased oil level. Cellular lipids produced at the low COPO or CSO levels contained more unsaturated TAG compared with those obtained on glucose as the sole carbon source. With regard to the typical soybean or olive oil TAG profile, cellular TAG had profiles dependent on the type and the amount of the co‐substrates used. In the presence of CSO, the cellular TAG profile was similar to that of the respective oil for both levels of addition. A notable desaturase activity was observed only in the presence of low COPO addition. The present study can serve as a basis for a better understanding of TAG accumulation with regard to β‐carotene production in oil‐enriched substrates.     

Computational Approaches for Studying the Granular Dynamics of Continuous Blending Processes, 2 – Population Balance and Data‐Based Methods

The application of computationally inexpensive modeling methods for a predictive study of powder mixing is discussed. A multidimensional population balance model is formulated to track the evolution of the distribution of a mixture of particle populations with respect to position and time. Integrating knowledge derived from a discrete element model, this method can be used to predict residence time distribution, mean and relative standard deviation of the API concentration in a continuous mixer. Low‐order statistical models, including response surface methods, kriging, and high‐dimensional model representations are also presented. Their efficiency for design optimization and process design space identification with respect to operating and design variables is illustrated.

     

Automated gaze-contingent objects elicit orientation following in 8-month-old infants.

The current study tested whether the purely amodal cue of contingency elicits orientation following behavior in 8-month-old infants. We presented 8-month-old infants with automated objects without human features that did or did not react contingently to the infants' fixations recorded by an eye tracker. We found that an object's occasional orientation toward peripheral targets was reciprocated by a congruent visual orientation following response by infants only when it had displayed gaze-contingent interactivity. Our finding demonstrates that infants' gaze-following behavior does not depend on the presence of a human being. The results are consistent with the idea that, in 8-month-old infants, the detection of contingent reactivity, like other communicative signals, can itself elicit the illusion of being addressed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Nonlinear variable selection algorithms for surrogate modeling

Having the ability to analyze, simulate, and optimize complex systems is becoming more important in all engineering disciplines. Decision-making using complex systems usually leads to nonlinear optimization problems, which rely on computationally expensive simulations. Therefore, it is often challenging to detect the actual structure of the optimization problem and formulate these problems with closed-form analytical expressions. Surrogate-based optimization of complex systems is a promising approach that is based on the concept of adaptively fitting and optimizing approximations of the input–output data. Standard surrogate-based optimization assumes the degrees of freedom are known a priori; however, in real applications the sparsity and the actual structure of the black-box formulation may not be known. In this work, we propose to select the correct variables contributing to each objective function and constraints of the black-box problem, by formulating the identification of the true sparsity of the formulation as a nonlinear feature selection problem. We compare three variable selection criteria based on Support Vector Regression and develop efficient algorithms to detect the sparsity of black-box formulations when only a limited amount of deterministic or noisy data is available.     

Prevention of Bone Destruction by Mechanical Loading Is Not Enhanced by the Bruton’s Tyrosine Kinase Inhibitor CC-292 in Myeloma Bone Disease

Limiting bone resorption and regenerating bone tissue are treatment goals in myeloma bone disease (MMBD). Physical stimuli such as mechanical loading prevent bone destruction and enhance bone mass in the MOPC315.BM.Luc model of MMBD. It is unknown whether treatment with the Bruton’s tyrosine kinase inhibitor CC-292 (spebrutinib), which regulates osteoclast differentiation and function, augments the anabolic effect of mechanical loading. CC-292 was administered alone and in combination with axial compressive tibial loading in the MOPC315.BM.Luc model for three weeks. However, neither CC-292 alone nor its use in combination with mechanical loading was more effective in reducing osteolytic bone disease or rescuing bone mass than mechanical stimuli alone, as evidenced by microcomputed tomography (microCT) and histomorphometric analysis. Further studies are needed to investigate novel anti-myeloma and anti-resorptive strategies in combination with physical stimuli to improve treatment of MMBD.