Localization Uncertainty Estimation for Anchor-Free Object Detection

Since many safety-critical systems, such as surgical robots and autonomous driving cars, are in unstable environments with sensor noise and incomplete data, it is desirable for object detectors to take into account the confidence of localization prediction. There are three limitations of the prior uncertainty estimation methods for anchor-based object detection. 1) They model the uncertainty based on object properties having different characteristics, such as location (center point) and scale (width, height). 2) they model a box offset and ground-truth as Gaussian distribution and Dirac delta distribution, which leads to the model misspecification problem. Because the Dirac delta distribution is not exactly represented as Gaussian, i.e., for any $\mu$ and $\Sigma$. 3) Since anchor-based methods are sensitive to hyper-parameters of anchor, the localization uncertainty modeling is also sensitive to these parameters. Therefore, we propose a new localization uncertainty estimation method called Gaussian-FCOS for anchor-free object detection. Our method captures the uncertainty based on four directions of box offsets~(left, right, top, bottom) that have similar properties, which enables to capture which direction is uncertain and provide a quantitative value in range~[0, 1]. To this end, we design a new uncertainty loss, negative power log-likelihood loss, to measure uncertainty by weighting IoU to the likelihood loss, which alleviates the model misspecification problem. Experiments on COCO datasets demonstrate that our Gaussian-FCOS reduces false positives and finds more missing-objects by mitigating over-confidence scores with the estimated uncertainty. We hope Gaussian-FCOS serves as a crucial component for the reliability-required task

Formation characteristics and photoluminescence of Ge nanocrystals in HfO[sub 2]

Genanocrystals (NCs) are shown to form within HfO₂ at relatively low annealing temperatures (600–700 °C) and to exhibit characteristic photoluminescence(PL) emission consistent with quantum confinement effects. After annealing at 600 °C, sample implanted with 8.4×10¹⁵ Ge cm⁻² show two major PL peaks, at 0.94 and 0.88 eV, which are attributed to no-phonon and transverse-optical phonon replica of Ge NCs, respectively. The intensity reaches a maximum for annealing temperatures around 700 °C and decreases at higher temperatures as the NC size continues to increase. The no-phonon emission also undergoes a significant redshift for temperatures above 800 °C. For fluences in the range from 8.4×1015 to 2.5×10¹⁶ cm⁻², the average NC size increases from ∼13.5±2.6 to ∼20.0±3.7 nm. These NC sizes are much larger than within amorphous SiO₂. Implanted Ge is shown to form Ge NCs within the matrix of monoclinic (m)-HfO₂ during thermal annealing with the orientation relationship of [101]m-HfO₂//[110]Ge NC.S.H.C. and R.G.E. acknowledge supports from the Korea Research Foundation Grant Grant No. KRF-2007-521- C00094 and from the Australian Research Council Discovery Project, respectively

Interstitial lung disease caused by TS-1: a case of long-term drug retention as a fatal adverse reaction

TS-1 is an oral anti-cancer agent for gastric cancer with a high response rate and low toxicity. We report a case of long-term drug retention of TS-1 causing interstitial lung disease (ILD) as a fatal adverse reaction. A 65-year-old woman underwent a total gastrectomy with pathologic confirmation of gastric adenocarcinoma. She received 6 cycles of TS-1 and low-dose cisplatin for post-operative adjuvant chemotherapy followed by single-agent maintenance therapy with TS-1. After 8 months, the patient complained of a productive cough with sputum and mild dyspnea. A pulmonary evaluation revealed diffuse ILD in the lung fields, bilaterally. In spite of discontinuing chemotherapy and the administration of corticosteroids, the pulmonary symptoms did not improve, and the patient died of pulmonary failure. TS-1-induced ILD can be caused by long-term drug retention that alters the lung parenchyma irreversibly, the outcome of which can be life-threatening. Pulmonary evaluation for early detection of disease is recommended

The Clinical Usefulness of the SD Bioline Influenza Antigen Test® for Detecting the 2009 Influenza A (H1N1) Virus

Though the 2009 worldwide influenza A (H1N1) pandemic has been declared to have ended, the influenza virus is expected to continue to circulate from some years as a seasonal influenza. A rapid antigen test (RAT) can aid in rapid diagnosis and allow for early antiviral treatment. We evaluated the clinical usefulness of RAT using SD Bioline Influenza Antigen Test® kit to detect the influenza virus, considering various factors. From August 1, 2009 to October 10, 2009, a total of 938 patients who visited the outpatient clinic at Korea University Guro Hospital with influenza-like illnesses were enrolled in the study. Throat or nasopharyngeal swab specimens were obtained from each of the patients. Using these specimens, we evaluated the influenza detection rate by rapid antigen test based on the real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) method. In comparison with rRT-PCR, the sensitivity and specificity of the RAT were 44.0% and 99.9%, respectively. The cyclic threshold values of RAT negative specimens were higher than RAT positive specimens (30.1±3.1 vs. 28.3±3.9, p=0.031). The sensitivity of the RAT kit was higher in patients who visited clinics within two days of symptom onset (60.4% vs. 11.1%, p=0.026). The results of this study show that the RAT cannot be recommended for general use in all patients with influenza-like illness because of its low sensitivity. The RAT may be used, only in the settings with limited diagnostic resources, for patients who visit a clinic within two days of symptom onset