143 research outputs found

    YouTube AV 50K: An Annotated Corpus for Comments in Autonomous Vehicles

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    With one billion monthly viewers, and millions of users discussing and sharing opinions, comments below YouTube videos are rich sources of data for opinion mining and sentiment analysis. We introduce the YouTube AV 50K dataset, a freely-available collections of more than 50,000 YouTube comments and metadata below autonomous vehicle (AV)-related videos. We describe its creation process, its content and data format, and discuss its possible usages. Especially, we do a case study of the first self-driving car fatality to evaluate the dataset, and show how we can use this dataset to better understand public attitudes toward self-driving cars and public reactions to the accident. Future developments of the dataset are also discussed.Comment: in Proceedings of the Thirteenth International Joint Symposium on Artificial Intelligence and Natural Language Processing (iSAI-NLP 2018

    Generalized lock-in amplifier for precision measurement of high frequency signals

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    We herein formulate the concept of a generalized lock-in amplifier for the precision measurement of high frequency signals based on digital cavities. Accurate measurement of signals higher than 200 MHz using the generalized lock-in is demonstrated. The technique is compared with a traditional lock-in and its advantages and limitations are discussed. We also briefly point out how the generalized lock-in can be used for precision measurement of giga-hertz signals by using parallel processing of the digitized signals

    Spectrum Modeling of Out-of-Band Intermodulation for Dual-Band RF Amplifiers in OFDM Modulation

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    Dual-band RF amplifiers play increasingly important roles in next-generation mobile communication systems including 5G, and the out-of-band intermodulation products are often not negligible since they generate interference to adjacent channels. In this article, following our previous modeling of cross-modulation for amplified dual-band signals, an analytical expression of out-of-band intermodulation for dual-band orthogonal frequency-division multiplexing signals is derived using the third-order intercept points IP3. The experimental measurement results validate the proposed analytical expression

    MITIGATING THE GLASS-WEAVE EFFECT INSIDE A BGA

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    For a printed circuit board (PCB) that includes many high-speed differential pairs may be routed the signal integrity (SI) performance of the pairs is to be carefully considered. One factor that may lead to a poorer SI performance, on the PCB itself and within a ball grid array (BGA) that is mounted on the PCB, is the glass-weave effect. To mitigate the impact of the glass-weave effect inside of a BGA, techniques are presented herein that support rotating the BGA by a free angle. With such a BGA rotation, a pair\u27s traces will be rotated by the same angle and, consequently, the glass-weave effect on those traces can be mitigated

    Chain of Thought Prompt Tuning in Vision Language Models

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    Language-Image Pre-training has demonstrated promising results on zero-shot and few-shot downstream tasks by prompting visual models with natural language prompts. However, most recent studies only use a single prompt for tuning, neglecting the inherent step-to-step cognitive reasoning process that humans conduct in complex task settings, for example, when processing images from unfamiliar domains. Chain of Thought is a simple and effective approximation to human reasoning process and has been proven useful for natural language processing (NLP) tasks. Based on this cognitive intuition, we believe that conducting effective reasoning is also an important problem in visual tasks, and a chain of thought could be a solution to this problem. In this work, we propose a novel chain of thought prompt tuning for vision-language modeling. Extensive experiments show that our method not only generalizes better in image classification tasks, has greater transferability beyond a single dataset, and has stronger domain generalization performance, but also performs much better in imagetext retrieval and visual question answering, which require more reasoning capabilities. We are the first to successfully adapt chain-of-thought prompting that combines visual and textual embeddings. We will release our code

    High Precision Measurements Using High Frequency Signals

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    Generalized lock-in amplifiers use digital cavities with Q-factors as high as 5X10^8. In this letter, we show that generalized lock-in amplifiers can be used to analyze microwave (giga-hertz) signals with a precision of few tens of hertz. We propose that the physical changes in the medium of propagation can be measured precisely by the ultra-high precision measurement of the signal. We provide evidence to our proposition by verifying the Newton's law of cooling by measuring the effect of change in temperature on the phase and amplitude of the signals propagating through two calibrated cables. The technique could be used to precisely measure different physical properties of the propagation medium, for example length, resistance, etc. Real time implementation of the technique can open up new methodologies of in-situ virtual metrology in material design

    Kinematics analysis of a FLHL robot parallel-executed cylinder mechanical integration system with force/position hybrid control servo actuator

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    In this research subtopic, an electro-hydraulic servo four-legged heavy load (FLHL) robot has been designed and developed. This paper proposes an integration layout cylinder design scheme for a non-lightweight hydraulic servo four-legged robot with high loads and torques of hip joint, and derives the mathematical element analysis model for a parallel hydraulic servo cylinder system. The multiple inherent characteristics of the parallel-executed cylinder integration system model are further explored. Based on the controllable functional requirements of interconnected joints and weakening the influence of internal force coupling, a design idea of force/position hybrid control scheme for the parallel-executed cylinder is determined, and then the force/position signal module design unit is used to reversely solve the force/position hybrid control. Considering the inherent requirements of the servo-executed cylinder force control unit module, the implementation process of magnetic flux compensation and speed compensation is discussed in detail. The minimum amplitude controller is applied to the servo-executed cylinder force unit module, and the proportional integrated controller has been determined in the servo-executed cylinder position control unit module. A compound control strategy proposed in this paper is verified on a parallel hydraulic servo platform. The experimental verification results reveal that the values of position/force attenuation amplitude and lag phase are not greater than 9 % and 18°, respectively. In addition, the feasibility of the interconnected implementation of the hybrid control scheme proposed in this paper is further deepened. The effective conclusion of this research will be accepted in the application field of FLHL robot control system
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