Improving Neural Radiance Field using Near-Surface Sampling with Point Cloud Generation

Neural radiance field (NeRF) is an emerging view synthesis method that samples points in a three-dimensional (3D) space and estimates their existence and color probabilities. The disadvantage of NeRF is that it requires a long training time since it samples many 3D points. In addition, if one samples points from occluded regions or in the space where an object is unlikely to exist, the rendering quality of NeRF can be degraded. These issues can be solved by estimating the geometry of 3D scene. This paper proposes a near-surface sampling framework to improve the rendering quality of NeRF. To this end, the proposed method estimates the surface of a 3D object using depth images of the training set and sampling is performed around there only. To obtain depth information on a novel view, the paper proposes a 3D point cloud generation method and a simple refining method for projected depth from a point cloud. Experimental results show that the proposed near-surface sampling NeRF framework can significantly improve the rendering quality, compared to the original NeRF and a state-of-the-art depth-based NeRF method. In addition, one can significantly accelerate the training time of a NeRF model with the proposed near-surface sampling framework.Comment: 13 figures, 2 table

Clinical Characteristics and Risk Factors for Nosocomial Candidemia in Medical Intensive Care Units: Experience in a Single Hospital in Korea for 6.6 Years

The aim of this study was to determine candidemia incidence among patients in a medical intensive-care unit (MICU) and the associated mortality rate and to identify risk factors associated with candidemia. We retrospectively performed a 1:3 matched case-control study of MICU patients with candidemia. Controls were matched for sex, age, and Acute Physiology and Chronic Health Evaluation (APACHE) II score. Candidemia incidence was 9.1 per 1,000 admissions. The most common pathogen was Candida albicans. Crude mortality was 96% among candidemia patients and 52% among controls (P<0.001). Mortality differed significantly between the groups according to Kaplan-Meier survival analysis (P=0.024). Multivariate analysis identified the following independent risk factors for candidemia: central venous catheterization (odds ratio [OR] = 3.2, 95% confidence interval [CI]=1.2-9.0), previous steroid therapy (OR=4.7, 95% CI=1.8-12.1), blood transfusion during the same admission period (OR=6.3, 95% CI=2.4-16.7), and hepatic failure upon MICU admission (OR=6.9, 95% CI=1.7-28.4). In conclusion, we identify an additional independent risk factor for candidemia, the presence of hepatic failure on MICU admission. Therefore, increased awareness of risk factors, including hepatic failure, is necessary for the management of candidemia

Perpendicular-bias-field-dependent vortex-gyration eigenfrequency

We found that the angular frequency ??0 of vortex-core gyrations is controllable by the application of static perpendicular bias fields Hp as studied by micromagnetic simulations and Thiele's-approach- based quantitative interpretation. The observed linear dependence of ??0 on Hp could be explained in terms of the dynamic variables of the vortex, the gyrovector constant G, and the potential stiffness constant , for cases of negligible damping. Here we calculated the values of G and ?? as a function of Hp directly from the simulation numerical data using Thiele's equivalent force equations, providing a more correct understanding of the remarkable change of ??0 with Hp. This micromagnetic-simulation-based quantitative analysis is a straightforward, accurate, and effective means of understanding vortex dynamics in nanoscale magnetic elements.open7

The submucosal fibrosis: what does it mean for colorectal endoscopic submucosal dissection?

Background/AimsEndoscopic submucosal dissection (ESD) allows removal of colorectal epithelial neoplasms en bloc regardless of size. Colorectal ESD is a difficult procedure because of technical difficulties and risks of complications. This study aimed to assess the relationship between ESD outcome and degree of submucosal fibrosis.MethodsPatients with colorectal tumors undergoing ESD and their medical records were reviewed retrospectively. The degree of submucosal fibrosis was classified into three types. The relationship between ESD outcome and degree of submucosal fibrosis was analyzed.ResultsESD was performed in 158 patients. Thirty-eight cases of F0 (no) fibrosis (24.1%) and 46 cases of F2 (severe) fibrosis (29.1%) were observed. Complete resection was achieved for 138 lesions (87.3%). Multivariate analysis demonstrated that submucosal invasion of tumor and histology of carcinoma were independent risk factors for F2 fibrosis. Severe fibrosis was an independent risk factor for incomplete resection.ConclusionsSevere fibrosis is an important factor related to incomplete resection during colorectal ESD. In cases of severe fibrosis, the rate of complete resection was low even when ESD was performed by an experienced operator. Evaluation of submucosal fibrosis may be helpful to predict the submucosal invasion of tumors and technical difficulties in ESD

Psychological Profile of Sasang Typology: A Systematic Review

A systematic review of studies related to the psychological characteristics of Sasang types was conducted with the goal of delineating generalizable psychological profiles based on Sasang typology, a traditional Korean medical typology with medical herbs and acupuncture that is characterized as personalized medicine. Journal articles pertaining to Sasang typology were collected using five electronic database systems in Korea and in the USA. As a result, 64 potentially relevant studies were identified and 21 peer-reviewed research articles that employed psychometric inventories were included. Beginning with the use of the Minnesota Multiphasic Personality Inventory in 1992, Myers-Briggs Type Indicator, NEO-Personality Inventory, Temperament and Character Inventory and other personality assessment tools were employed in the identified studies. Because data synthesis could not be carried out due to the heterogeneity of the studies, the present review article sought to delineate the mutual relevance of the studies based on research results pertaining to the correlation between the aforementioned psychological assessment instruments. Results of the review indicate that two super-factors, Extraversion and Neuroticism, serve as the foundation in regards to delineating personality constructs, such that the So-Yang type scored high on the Extraversion dimension and low on the Neuroticism dimension, while the So-Eum type scored low on the Extraversion dimension and high on the Neuroticism dimension. The present systematic review indicates that Sasang typology shares similarities with the Western psychological tradition

Translation and validation of the Korean confusion assessment method for the intensive care unit

<p>Abstract</p> <p>Background</p> <p>Delirium is a common problem and associated with poor outcomes in intensive care unit (ICU) patients. Diagnosis of delirium in ICU patients is limited and usually underdiagnosed by physicians. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is one of the most widely used screening methods for detection of ICU delirium. Our goal was to translate and validate the CAM-ICU for use in the Korean ICU setting.</p> <p>Methods</p> <p>Translation of the CAM-ICU was done according to the guidelines suggested by the Translation and Cultural Adaptation Group. For validation and interrater reliability assessment of the Korean CAM-ICU, two nurses independently assessed delirium in ICU patients and the results were compared with the reference evaluation, which was done by a psychiatrist using the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV).</p> <p>Results</p> <p>Twenty-two patients were evaluated by two nurses and one psychiatrist expert independently. During the study period, we have continuously educated study nurses. Based on DSM-IV criteria, 16 out of 22 (72.7%) patients developed delirium. The sensitivities of the two nurses' evaluations using the Korean CAM-ICU were 89.80% for nurse 1 and 77.40% for nurse 2. Their specificities were 72.40% and 75.80% and their overall accuracy was 83.33% and 88.37% respectively. The Korean CAM-ICU was done with reasonable interrater reliability between nurse 1 and nurse 2 (κ = 0.81, <it>p </it>< 0.001).</p> <p>Conclusions</p> <p>The Korean CAM-ICU showed good validity and could be incorporated into clinical practice in Korean ICUs.</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN50265663">ISRCTN50265663</a></p