A compact triple-band coplanar waveguide (CPW)-fed antenna for WLAN/WiMAX applications is proposed. The radiation patch is fed by capacitive coupling of the top transmission line. By only using one metallic strip etched on the bottom of the substrate, tri-band resonances of the antenna are generated. The proposed antenna has a compact size of 30 × 27 mm 2 , which can provide stable omnidirectional radiation patterns in three bands. The measured − 10 dB impedance bandwidths are 150 MHz (2.39-2.54 GHz), 360 MHz (3.37-3.73 GHz) and 1170 MHz (5.02-6.19 GHz), which is suitable for WLAN/WiMAX applications.Introduction: The prodigious rate of development of wireless communication technology as a viable and cost-effective high-speed data connectivity solution demands high-performance multi-band antennas with good radiation characteristics. In view of the practical needs, many promising antennas have been proposed to cover the WLAN (2.4-2.484, 5.1-5.35 and 5.725-5.85 GHz) operation and WiMAX (3.4-3.69 and 5.25-5.85 GHz) standards. These include monopole antennas with several branches to generate low band and two upper bands [1, 2], a slot monopole antenna for dual-band [3], a monopole antenna with a split-ring [4] and a slot-monopole antenna with embedded rectangular parasitic elements [5]. However, these antennas either need large size or the shapes are too complex. In [6], dual-band was achieved by adding L-and E-elements together with a total area of only 8 × 11.3 mm 2 . However, it just covers the WLAN bands.In this Letter, a compact coplanar waveguide (CPW)-fed antenna for WLAN/WiMAX application is proposed. The patch on the bottom of the substrate could generate three resonant modes with an inverted L-shaped strip to further improve the impedance matching performance at 5.5 GHz. The measured impedance bandwidths can cover the 2.4/5.2/ 5.8 GHz WLAN bands and 3.5/5.5 GHz WiMAX bands. In addition, the proposed antenna has the advantages of small size, low profile, a simple structure and cheap production. Details of the antenna design and simulated and measured results are presented and discussed.
This paper presents a novel framework for simultaneously implementing localization and segmentation, which are two of the most important vision-based tasks for robotics. While the goals and techniques used for them were considered to be different previously, we show that by making use of the intermediate results of the two modules, their performance can be enhanced at the same time. Our framework is able to handle both the instantaneous motion and long-term changes of instances in localization with the help of the segmentation result, which also benefits from the refined 3D pose information.We conduct experiments on various datasets, and prove that our framework works effectively on improving the precision and robustness of the two tasks and outperforms existing localization and segmentation algorithms.
This paper presents a novel obstacle avoidance system for road robots equipped with RGB-D sensor that captures scenes of its way forward. The purpose of the system is to have road robots move around autonomously and constantly without any collision even with small obstacles, which are often missed by existing solutions. For each input RGB-D image, the system uses a new two-stage semantic segmentation network followed by the morphological processing to generate the accurate semantic map containing road and obstacles. Based on the map, the local path planning is applied to avoid possible collision. Additionally, optical flow supervision and motion blurring augmented training scheme is applied to improve temporal consistency between adjacent frames and overcome the disturbance caused by camera shake. Various experiments are conducted to show that the proposed architecture obtains high performance both in indoor and outdoor scenarios.
This paper presents a novel system that enables intelligent robots to exhibit realistic body gestures while communicating with humans. The proposed system consists of a listening model and a speaking model used in corresponding conversational phases. Both models are adapted from the sequence-to-sequence (seq2seq) architecture to synthesize body gestures represented by the movements of twelve upper-body keypoints. All the extracted 2D keypoints are firstly 3Dtransformed, then rotated and normalized to discard irrelevant information. Substantial videos of human conversations from Youtube are collected and preprocessed to train the listening and speaking models separately, after which the two models are evaluated using metrics of mean squared error (MSE) and cosine similarity on the test dataset. The tuned system is implemented to drive a virtual avatar as well as Pepper, a physical humanoid robot, to demonstrate the improvement on conversational interaction abilities of our method in practice.
A novel compact monopole antenna for WLAN and WiMAX applications is presented. By properly etching two openended inverted L-shaped slots on the radiation patch, three separated resonances with effective bandwidth enhancement can be obtained. The overall dimension of the proposed antenna is only 29 (L) × 10 (W) × 1.6 (H) mm 3 . Experimental results show that the antenna provides three impedance bandwidth of 80 MHz (2.4-2.48 GHz), 420 MHz (3.28-3.7 GHz) and 600 MHz (5.23-5.83 GHz). Good radiation patterns and applicable gains are also obtained across the operating bands. The proposed antenna is thus suitable for wireless communications systems.
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