Robust Independent Component Analysis via Minimum Divergence Estimation

Independent component analysis (ICA) has been shown to be useful in many applications. However, most ICA methods are sensitive to data contamination and outliers. In this article we introduce a general minimum U-divergence framework for ICA, which covers some standard ICA methods as special cases. Within the U-family we further focus on the gamma-divergence due to its desirable property of super robustness, which gives the proposed method gamma-ICA. Statistical properties and technical conditions for the consistency of gamma-ICA are rigorously studied. In the limiting case, it leads to a necessary and sufficient condition for the consistency of MLE-ICA. This necessary and sufficient condition is weaker than the condition known in the literature. Since the parameter of interest in ICA is an orthogonal matrix, a geometrical algorithm based on gradient flows on special orthogonal group is introduced to implement gamma-ICA. Furthermore, a data-driven selection for the gamma value, which is critical to the achievement of gamma-ICA, is developed. The performance, especially the robustness, of gamma-ICA in comparison with standard ICA methods is demonstrated through experimental studies using simulated data and image data.Comment: 7 figure

The Effect of Exhibitors' Brand Equity on Visitors' Purchase Decision: Moderating Role of Exhibition's Competitive Intensity

This study explores the effect of exhibitors' brand equity on visitors' purchase intention, purchase postponement, and switching intention in an international industrial fair, as well as examines the moderating effect of competitive intensity on the above relationships. This study surveyed visitors of the famous International Woodworking Machine Fair in Jakarta, Indonesia. Of the 200 surveys distributed, 138 valid questionnaires were returned, representing a response rate of 69.00%. Analytical results show that higher exhibitors' brand equity is associated with visitors' higher purchase intention, more prevalent purchase postponement, and stronger switching intention. Also, in a high competitive intensity environment, the level of visitors' purchase postponement and switching intention of high brand equity products is similar. In a low competitive intensity exhibition, visitors are unlikely to postpone purchase of low brand equity products but are more likely to postpone purchase of high brand equity products. Lastly, in a low competitive intensity environment, visitors are less inclined to switch low brand equity suppliers but more likely to switch high brand equity suppliers. According to the research results, recommendations and limitations of this study are proposed

3D Experiential Marketing in International Industrial Fair

This study explores the effect of buyers’ 3D experiences on their purchase intention, as well as the moderating effect of exhibitors’ corporate image on the above relationship. This study uses the purposive sampling method to survey buyers of the famous International Woodworking Machine Fair in China. Analytical results from 91 visitors are summarized as: the higher the international mechanical fair buyers’ feel experience, think experience and act experience, then the higher their purchase intention; buyers’ relate experience has a negative prediction effect on purchase intention; exhibitors’ corporate image has a moderating effect on the relationship between buyers’ feel experiences and purchase intention; exhibitors’ corporate image has a moderating effect on the relationship between buyers’ relate experience and purchase intention

A CMMI-based approach for medical software project life cycle study

In terms of medical techniques, Taiwan has gained international recognition in recent years. However, the medical information system industry in Taiwan is still at a developing stage compared with the software industries in other nations. In addition, systematic development processes are indispensable elements of software development. They can help developers increase their productivity and efficiency and also avoid unnecessary risks arising during the development process. Thus, this paper presents an application of Light-Weight Capability Maturity Model Integration (LW-CMMI) to Chang Gung Medical Research Project (CMRP) in the Nuclear medicine field. This application was intended to integrate user requirements, system design and testing of software development processes into three layers (Domain, Concept and Instance) model. Then, expressing in structural System Modeling Language (SysML) diagrams and converts part of the manual effort necessary for project management maintenance into computational effort, for example: (semi-) automatic delivery of traceability management. In this application, it supports establishing artifacts of “requirement specification document”, “project execution plan document”, “system design document” and “system test document”, and can deliver a prototype of lightweight project management tool on the Nuclear Medicine software project. The results of this application can be a reference for other medical institutions in developing medical information systems and support of project management to achieve the aim of patient safety. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/2193-1801-2-266) contains supplementary material, which is available to authorized users

Rapid identification of allergenic and pathogenic molds in environmental air by an oligonucleotide array

<p>Abstract</p> <p>Background</p> <p>Airborne fungi play an important role in causing allergy and infections in susceptible people. Identification of these fungi, based on morphological characteristics, is time-consuming, expertise-demanding, and could be inaccurate.</p> <p>Methods</p> <p>We developed an oligonucleotide array that could accurately identify 21 important airborne fungi (13 genera) that may cause adverse health problems. The method consisted of PCR amplification of the internal transcribed spacer (ITS) regions, hybridization of the PCR products to a panel of oligonucleotide probes immobilized on a nylon membrane, and detection of the hybridization signals with alkaline phosphatase-conjugated antibodies.</p> <p>Results</p> <p>A collection of 72 target and 66 nontarget reference strains were analyzed by the array. Both the sensitivity and specificity of the array were 100%, and the detection limit was 10 pg of genomic DNA per assay. Furthermore, 70 fungal isolates recovered from air samples were identified by the array and the identification results were confirmed by sequencing of the ITS and D1/D2 domain of the large-subunit RNA gene. The sensitivity and specificity of the array for identification of the air isolates was 100% (26/26) and 97.7% (43/44), respectively.</p> <p>Conclusions</p> <p>Identification of airborne fungi by the array was cheap and accurate. The current array may contribute to decipher the relationship between airborne fungi and adverse health effect.</p

Disseminated nocardiosis with thyroid involvement: A case report

Nocardiosis is a life-threatening infection that affects the lungs, skin, and central nervous system, particularly in immune-compromised patients. We report a case of disseminated nocardiosis with pneumonia, brain abscesses, meningitis, and thyroiditis, for an individual with recent steroid therapy. Recovery was uneventful with a 4-month course of sulfamethoxazole–trimethoprim

The Evaluation And Using Intention For Digital Teaching Materials Of Penghu Basalt

The Bureau of Culture of Penghu County produced the Penghu Basalt Digital Teaching Materials, which are supplementary teaching materials for local curriculums in elementary and middle schools in Penghu County. But just what are the teachers&rsquo; and students&rsquo; opinions of the said teaching materials? Are they willing to use them? Are they suitable? These questions are, indeed, worth further research. The questionnaire survey was conducted to gather the opinions of 142 teachers and 151 students of elementary and middle schools in Penghu County. In addition, using the quasi-experimental and experimental teaching methods, after comparing the pre-test and post-test results to the control group, the learning effectiveness was determined. The results indicate that teachers and students have the highest evaluation for the interface design aspect of this teaching material. The teachers&rsquo; evaluation for the teaching materials is significantly higher than the students&rsquo;. Furthermore, the teaching materials are evaluated highly in terms of attracting attention, generating interest and willingness to use, indicating that the digital teaching materials have potential for promotion in Penghu. After the experimental teaching, only the vocational high school students&rsquo; scores before and after the experiment showed significantly improvement, while the scores of the students in the other levels of schools did not. &nbsp

Factors Affecting Daughter Cells' Arrangement during the Early Bacterial Divisions

On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed to an elastic material that restricts apparently separated bacteria from being in string. We hypothesize that the interaction between bacteria and the underneath substratum may affect the arrangement of the daughter bacteria. To test this hypothesis, bacterial division on hyaluronic acid (HA) gel, as an alternative substratum, was examined. Consistent with our proposition, the HA gel differs from agar by suppressing the typical side-by-side alignments to a rare population. Examination of bacterial surface molecules that may contribute to the daughter cells' arrangement yielded an observation that, with disrupted lpp, the E. coli daughter cells increasingly formed non-typical patterns, i.e. neither sliding side-by-side in parallel nor forming elongated strings. Therefore, our results suggest strongly that the early cell patterning is affected by multiple interaction factors. With oscillatory optical tweezers, we further demonstrated that the interaction force decreased in bacteria without Lpp, a result substantiating our notion that the side-by-side sliding phenomenon directly reflects the strength of in-situ interaction between bacteria and substratum

Effects of Blue Light on Dynamic Vision

Dynamic vision is crucial to not only animals’ hunting behaviors but also human activities, and yet little is known about how to enhance it, except for extensive trainings like athletics do. Exposure to blue light has been shown to enhance human alertness (Chellappa et al., 2011), perhaps through intrinsically photosensitive retinal ganglion cells (ipRGCs), which are sensitive to motion perception as revealed by animal studies. However, it remains unknown whether blue light can enhance human dynamic vision, a motion-related ability. We conducted five experiments under blue or orange light to test three important components of dynamic vision: eye pursuit accuracy (EPA, Experiment 1), kinetic visual acuity (KVA, Experiment 1 and 2), and dynamic visual acuity (DVA, Experiment 3–5). EPA was measured by the distance between the position of the fixation and the position of the target when participants tracked a target dot. In the KVA task, participants reported three central target numbers (randomly chosen from 0 to 9) moving toward participants in the depth plane, with speed threshold calculated by a staircase procedure. In the DVA task, three numbers were presented along the meridian line on the same depth plane, with motion direction (Experiment 3) and difficulty level (Experiment 4) manipulated, and a blue light filter lens was used to test the ipRGCs contribution (Experiment 5). Results showed that blue light enhanced EPA and DVA, but reduced KVA. Further, DVA enhancement was modulated by difficulty level: blue light enhancement effect was found only with hard task in the downward motion in Experiment 3 and with the low contrast target in Experiment 4. However, this blue light enhancement effect was not caused by mechanism of the ipRGCs, at least not in the range we tested. In this first study demonstrating the relationship between different components of dynamic vision and blue light, our findings that DVA can be enhanced under blue light with hard but not easy task indicate that blue light can enhance dynamic visual discrimination when needed

Sampling Neural Radiance Fields for Refractive Objects

Recently, differentiable volume rendering in neural radiance fields (NeRF) has gained a lot of popularity, and its variants have attained many impressive results. However, existing methods usually assume the scene is a homogeneous volume so that a ray is cast along the straight path. In this work, the scene is instead a heterogeneous volume with a piecewise-constant refractive index, where the path will be curved if it intersects the different refractive indices. For novel view synthesis of refractive objects, our NeRF-based framework aims to optimize the radiance fields of bounded volume and boundary from multi-view posed images with refractive object silhouettes. To tackle this challenging problem, the refractive index of a scene is reconstructed from silhouettes. Given the refractive index, we extend the stratified and hierarchical sampling techniques in NeRF to allow drawing samples along a curved path tracked by the Eikonal equation. The results indicate that our framework outperforms the state-of-the-art method both quantitatively and qualitatively, demonstrating better performance on the perceptual similarity metric and an apparent improvement in the rendering quality on several synthetic and real scenes.Comment: SIGGRAPH Asia 2022 Technical Communications. 4 pages, 4 figures, 1 table. Project: https://alexkeroro86.github.io/SampleNeRFRO/ Code: https://github.com/alexkeroro86/SampleNeRFR