2,343 research outputs found

    Localizing Active Objects from Egocentric Vision with Symbolic World Knowledge

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    The ability to actively ground task instructions from an egocentric view is crucial for AI agents to accomplish tasks or assist humans virtually. One important step towards this goal is to localize and track key active objects that undergo major state change as a consequence of human actions/interactions to the environment without being told exactly what/where to ground (e.g., localizing and tracking the `sponge` in video from the instruction "Dip the `sponge` into the bucket."). While existing works approach this problem from a pure vision perspective, we investigate to which extent the textual modality (i.e., task instructions) and their interaction with visual modality can be beneficial. Specifically, we propose to improve phrase grounding models' ability on localizing the active objects by: (1) learning the role of `objects undergoing change` and extracting them accurately from the instructions, (2) leveraging pre- and post-conditions of the objects during actions, and (3) recognizing the objects more robustly with descriptional knowledge. We leverage large language models (LLMs) to extract the aforementioned action-object knowledge, and design a per-object aggregation masking technique to effectively perform joint inference on object phrases and symbolic knowledge. We evaluate our framework on Ego4D and Epic-Kitchens datasets. Extensive experiments demonstrate the effectiveness of our proposed framework, which leads to>54% improvements in all standard metrics on the TREK-150-OPE-Det localization + tracking task, >7% improvements in all standard metrics on the TREK-150-OPE tracking task, and >3% improvements in average precision (AP) on the Ego4D SCOD task.Comment: In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP

    Blind Source Separation of Hemodynamics from Magnetic Resonance Perfusion Brain Images Using Independent Factor Analysis

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    Perfusion magnetic resonance brain imaging induces temporal signal changes on brain tissues, manifesting distinct blood-supply patterns for the profound analysis of cerebral hemodynamics. We employed independent factor analysis to blindly separate such dynamic images into different maps, that is, artery, gray matter, white matter, vein and sinus, and choroid plexus, in conjunction with corresponding signal-time curves. The averaged signal-time curve on the segmented arterial area was further used to calculate the relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT). The averaged ratios for rCBV, rCBF, and MTT between gray and white matters for normal subjects were congruent with those in the literature

    On the Analysis of Product Appropriateness Principles

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    The purpose of this study is to explore appropriateness of the various products presented in the market and the application of appropriateness principles to the product design. To obtain appropriateness principles, this study compares and analyzes a variety of products available in the market. After obtaining preliminary principles, many times convergence and analysis are operated for getting more accurate principles. Then, AHP method is used for evaluating importance of every appropriateness principles and appropriateness principles are obtained. And, the appropriateness principles are used to construct the design process of appropriateness product. Finally, some design cases are operated and appropriateness principles are evaluated for the products of design cases. The results of this study are obtained 10 appropriateness principles: freedom, demand, environmental protection, effectiveness, intuition, compliance, simplicity, optimal performance, simplicity, fault tolerance. And, weights of appropriateness principles get in this paper

    ANALYSIS OF GRIP FORCE DURING GOLF PUTTING AT DIFFERENT DISTANCES - PILOT STUDY

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    The purpose of this study was to explore the grip force performance at different distances during putting stroke. Four golfers (2 professionals and 2 novices) as accurately as possible executed a putt to reach 1, 2 and 3 m target distance, respectively. Putting motions were recorded by JVC video and grip pressure measurement sensor placed on two hands, allowing the force output of all regions of the hands to be measured. The grip force trace among 1 to 3 m distance was repeatable across putting strokes for each golfer but between golfers was inconsistent. Dominant forces appear to arise primarily from the left hand. In this study, the grip force and force distribution were preliminarily discovered during putting stroke at different distances. This research has suggested a potentially important influence of grip force on the golf putting performance in long distance

    Pelvic skeletal metastasis of hepatocellular carcinoma with sarcomatous change: a case report

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    Sarcomatoid hepatocellular carcinoma (HCC) is a very rare histologic variant of HCC. The characteristic of skeletal metastatic sarcomatoid hepatocellular carcinoma has never been reported. We reported a patient with sarcomatoid hepatocellular carcinoma pelvic metastasis who presented with huge pelvic metastasis that had relatively small osteolytic lesion centrally located accompanied by huge bipeduncular invasive expansile lesions into surrounding soft tissue. The lesion showed almost non-isotope uptake in 99mTc-methylene diphosphonate bone scintigraphy study. He underwent radiotherapy and tumor excision but the tumor rapidly recurred. In addition, serum α-fetoprotein level was never elevated beyond normal limit (< 20 ng/mL) through the whole course of treatment. We considered sarcomatoid hepatocellular carcinoma bone metastasis a highly aggressive lesion with unusual metastatic pattern. Surgical treatment with adequate safe margin in such a huge tumor with hypervascularity and extensive invasion in the pelvis was difficult; and radiotherapy maybe refractory regarding the sarcomatous nature. Therefore, debulking operation with local symptoms control may provide a better quality of life. And the clinical course suggests sarcomatoid hepatocellular carcinoma is derived from the transition of an ordinary hepatocellular carcinoma
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