811 research outputs found

    Minority-Oriented Vicinity Expansion with Attentive Aggregation for Video Long-Tailed Recognition

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    A dramatic increase in real-world video volume with extremely diverse and emerging topics naturally forms a long-tailed video distribution in terms of their categories, and it spotlights the need for Video Long-Tailed Recognition (VLTR). In this work, we summarize the challenges in VLTR and explore how to overcome them. The challenges are: (1) it is impractical to re-train the whole model for high-quality features, (2) acquiring frame-wise labels requires extensive cost, and (3) long-tailed data triggers biased training. Yet, most existing works for VLTR unavoidably utilize image-level features extracted from pretrained models which are task-irrelevant, and learn by video-level labels. Therefore, to deal with such (1) task-irrelevant features and (2) video-level labels, we introduce two complementary learnable feature aggregators. Learnable layers in each aggregator are to produce task-relevant representations, and each aggregator is to assemble the snippet-wise knowledge into a video representative. Then, we propose Minority-Oriented Vicinity Expansion (MOVE) that explicitly leverages the class frequency into approximating the vicinity distributions to alleviate (3) biased training. By combining these solutions, our approach achieves state-of-the-art results on large-scale VideoLT and synthetically induced Imbalanced-MiniKinetics200. With VideoLT features from ResNet-50, it attains 18% and 58% relative improvements on head and tail classes over the previous state-of-the-art method, respectively.Comment: Accepted to AAAI 2023. Code is available at https://github.com/wjun0830/MOV

    Is Retroflexion Helpful in Detecting Adenomas in the Right Colon?: A Single Center Interim Analysis

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    Background/AimsColonoscopy is less effective at screening for colorectal cancer in the right side of the colon. Retroflexion during colonoscopy is expected to improve the detection rate of colorectal adenomas. The aim of the present study was to evaluate the usefulness of retroflexion in the right-sided colon.MethodsFrom April to November 2013, a total of 398 patients were enrolled in this study. For each patient, a cap-assisted colonoscopic examination was performed. After cecal intubation, a forward view examination from the cecum up to the hepatic flexure was performed and all identified polyps were removed. The colonoscope was reinserted to the cecum, and a careful second forward view examination of the cecum to the hepatic flexure was performed, with removal of additionally identified polyps. The colonoscope was then reinserted to the cecum and retroflexed; a third colonoscopic examination was then performed to the hepatic flexure in retroflexion with removal of additional polyps. Total polyp numbers and characteristics were compared between the two forward view examinations and the retroflexion examination.ResultsA successful retroflexion was performed in 90.2% of patients. A total of 213 polyps and 143 adenomas were detected in the right-sided colon using the routine method of examining the right colon twice in forward view. An additional 35 polyps and 24 adenomas were detected on retroflexion. Of these 35 polyps, 27 (77.1%) were small-sized polyps (≤5 mm) and 24 (71.4%) were adenomas. Finding additional adenomas using the retroflexion technique was associated with older age.ConclusionsColonoscopic retroflexion is helpful in the detection of cecum and ascending colon adenomas, especially small-sized adenomas (≤5 mm). It is particularly useful in older patients

    Leveraging Hidden Positives for Unsupervised Semantic Segmentation

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    Dramatic demand for manpower to label pixel-level annotations triggered the advent of unsupervised semantic segmentation. Although the recent work employing the vision transformer (ViT) backbone shows exceptional performance, there is still a lack of consideration for task-specific training guidance and local semantic consistency. To tackle these issues, we leverage contrastive learning by excavating hidden positives to learn rich semantic relationships and ensure semantic consistency in local regions. Specifically, we first discover two types of global hidden positives, task-agnostic and task-specific ones for each anchor based on the feature similarities defined by a fixed pre-trained backbone and a segmentation head-in-training, respectively. A gradual increase in the contribution of the latter induces the model to capture task-specific semantic features. In addition, we introduce a gradient propagation strategy to learn semantic consistency between adjacent patches, under the inherent premise that nearby patches are highly likely to possess the same semantics. Specifically, we add the loss propagating to local hidden positives, semantically similar nearby patches, in proportion to the predefined similarity scores. With these training schemes, our proposed method achieves new state-of-the-art (SOTA) results in COCO-stuff, Cityscapes, and Potsdam-3 datasets. Our code is available at: https://github.com/hynnsk/HP.Comment: Accepted to CVPR 202

    Occupational Factors Associated with Changes in the Body Mass Index of Korean Male Manual Workers

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    OBJECTIVES: This study was carried out to analyze and compare the occupational factors that could influence changes in body mass index (BMI) in male manual workers stratified into short-term and long-term work experience groups. METHODS: The subjects were 299 male manual workers (sampled systematically) from 27 workplaces, who had undergone travelling medical examinations at a university hospital between March 28 and May 10, 2013, and had also undergone medical examinations at the same hospital in 2012. Their general and occupational characteristics were investigated through a structured, self-administered questionnaire. The BMI at each point in time was calculated based on the anthropometric results of the medical examinations. Multiple regression analyses were conducted on outcomes of the BMI change and predictors composed of the general and occupational characteristics, with the subjects stratified into groups with 5 years or less (short-term) versus more than 5 years (long-term) of work experience at the present post. RESULTS: In the short-term work experience group, the BMI increases of 3-shift workers and groups reporting disagreement with feeling “insufficient job control” and “lack of reward” at work, two of the subscales of job stress, were significantly higher than those of daytime workers and high-stress groups, respectively. In the long-term work experience group, However, although the BMI increase for 3-shift workers was also significantly higher than that of daytime workers, none of the job stress factors were significantly associated with a BMI increase, whereas the social factors of education and marital status were significant, and some lifestyle factors (such as smoking and regular exercise) were also significant. CONCLUSION: This study showed that, except for 3-shift work, the factors associated with BMI increase could differ depending on the length of job experience. Consequently, different strategies may be needed for workers with short-term versus long-term job experience when designing interventions for preventing their obesity

    Effects of 12 Weeks of Continuous Exercise and Accumulation of Short-Duration Exercise on Body Composition, Physical Fitness, and Lifestyle Disease indices in Overweight Men in their 30s

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    PURPOSE This study aimed to investigate the effects of continuous exercise and the accumulation of short-duration exercise for 12 weeks on body composition, physical fitness, and lifestyle disease indices in overweight men in their 30s. METHODS Participants in the continuous exercise group (CE; n=13) performed a circuit exercise program of 30 min/session, 3 sessions/week for 12 weeks. Participants in the accumulation of short duration exercise group (ASE; n=12) performed the same exercise time of 30 min per day, divided into three sessions of 10 min. Body composition, physical fitness, and lifestyle disease indices were measured pre- and post-test and were compared by utilizing a repeated two-way ANOVA. RESULTS 1) Regarding body composition, body weight, body mass index, skeletal muscle mass, waist circumference, and fat mass decreased significantly, while hip circumference increased significantly in the CE group. Waist circumference and skeletal muscle mass decreased significantly, while hip circumference increased significantly in the ASE group. 2) Regarding physical fitness, right grip strength, sit and reach, sit up, and maximal oxygen uptake increased significantly in both groups. 3) Regarding hypertension indices, there were no significant differences in both groups, but they showed a tendency to improve. 4) Regarding hyperlipidemia indices, triglycerides (TG) decreased significantly in both groups, and total cholesterol (TC) decreased significantly in the CE group. 5) Regarding diabetes indices, there were no significant differences in both groups, but a tendency to improve was noticed. 6) Regarding arteriosclerosis indices: TG/high density lipoprotein-cholesterol ratio decreased significantly in both groups, and the TC/high density lipoprotein-cholesterol ratio decreased significantly in the CE group. CONCLUSIONS We concluded that both the accumulation of short duration exercise and continuous exercise can be effective in improving body composition, physical fitness, and lifestyle disease in overweight men

    Gastric Yolk Sac Tumor: A Case Report and Review of the Literature

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    Gastric yolk sac tumors are extremely rare and their prognosis is poor; most patients have widespread metastases at the time of diagnosis. The treatment of gastric yolk sac tumors consists of aggressive chemotherapy combined with radiotherapy and surgery. Here, we first report a case of gastric yolk sac tumor presenting as an early gastric cancer that was cured after a gastrectomy with lymphadenectomy

    Successful management of heterotopic cornual pregnancy with laparoscopic cornual resection

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    AbstractObjectiveTo examine the feasibility of laparoscopic cornual resection for the treatment of heterotopic cornual pregnancy.Study designWomen who underwent laparoscopic cornual resection for heterotopic cornual pregnancy at our hospital between January 2003 and March 2015 were retrospectively analyzed. We evaluated significant parameters such as operative complications and postoperative pregnancy outcomes of concomitant pregnancy.ResultsThirteen patients with heterotopic cornual pregnancy were included in the study. All were pregnant through assisted reproductive technology, and the diagnosis was made at a median of 6+6 weeks (range 5+4–10+0). They were successfully treated with laparoscopic cornual resection and admitted for a median of 4 days (range, 2–7) postoperatively. The median operative time was 65min (range, 35–145min) and estimated blood loss was 200mL (range, 10–3000mL). There was a spontaneous abortion at 7+6 gestational weeks in a patient who received bilateral cornual resection. Seven patients delivered babies at term and 3 at preterm. All 10 women delivered without any maternal or neonatal complications. Two were lost to follow-up.ConclusionsLaparoscopic cornual resection is a feasible primary approach for the management of heterotopic cornual pregnancy

    Acute Symptoms after a Community Hydrogen Fluoride Spill

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    OBJECTIVES: This study was conducted to describe the demographic characteristics, and clinical signs and symptoms of patients who visited a general hospital because of the release of chemically hazardous hydrogen fluoride that occurred on September 27, 2012 in Gumi City, Korea. METHODS: The medical records at 1 general hospital 9 km from the accident site were reviewed using a standardized survey format. There were 1,890 non-hospitalized and 12 hospitalized patients exposed to hydrogen fluoride between September 27 and October 13 2012. RESULTS: Among the 12 hospitalized patients, 11 were discharged within 1 week and the other was hospitalized for 10 days. The chief complaints were respiratory symptoms such as hemoptysis and shortness of breath, gastrointestinal symptoms, neurologic symptoms, sore throat, and lip burn. The number of non-hospitalized patients exhibited a bimodal distribution, peaking on the first and twelfth days after the accident. Their chief complaints were sore throat (24.1%), headache (19.1%), cough (13.1%), and eye irritation (9.2%); some patients were asymptomatic (6.2%). Patients who visited the hospital within 3 days (early patients) of the spill more often had shortness of breath (27.0%) and nausea (6.3%) as the chief complaints than patients who visited after 3 days (late patients) (3.5% and 2.6%, respectively). However, cough and rhinorrhea were more common in the late patients (14.0% and 3.3%, respectively) than in the early patients (5.0% and 0.0%, respectively). Patients who were closer to the accident site more often had shortness of breath and sputum as the chief complaints than patients who were farther away. The mean serum calcium concentration was 9.37 mg/dL (range: 8.4–11.0 mg/dL); none of the patients had a decreased serum calcium level. Among 48 pulmonary function test results, 4 showed decreased lung function. None of the patients had abnormal urine fluoride levels on the eighth day after exposure. CONCLUSIONS: Patients hospitalized due to chemical hazard release of hydrogen fluoride had acute respiratory, gastrointestinal, and neurologic health problems. Non-hospitalized patients have acute symptoms mainly related to upper respiratory irritation

    Visible emission from Ce-doped ZnO nanorods grown by hydrothermal method without a post thermal annealing process

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    Visible light-emitting Ce-doped ZnO nanorods [NRs] without a post thermal annealing process were grown by hydrothermal method on a Si (100) substrate at a low temperature of 90°C. The structural investigations of Ce-doped ZnO NRs showed that the Ce3+ ions were successfully incorporated into the ZnO lattice sites without forming unwanted Ce-related compounds or precipitates. The optical investigation by photoluminescence spectra shows that the doped Ce3+ ions in the ZnO NRs act as an efficient luminescence center at 540 nm which corresponds to the optical transition of 5d → 4f orbitals in the Ce3+ ions. The photoluminescence intensity of the Ce-doped ZnO NRs increased with the increasing content of the Ce-doping agent because the energy transfer of the excited electrons in ZnO to the Ce3+ ions would be enhanced by increased Ce3+ ions
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