A load scheduler for SIP proxy servers: design, implementation and evaluation of a history weighted window approach

Abstract In this paper, we developed a new navigation system, called ATCM, which detects obstacles in a sliding window with an adaptive threshold clustering algorithm, classifies the detected obstacles with a decision tree, heuristically predicts potential collision and finds optimal path with a simplified Morphin algorithm. This system has the merits of optimal free-collision path, small memory size and less computing complexity, compared with the state of the arts in robot navigation. The modular design of 6-steps navigation provides a holistic methodology to implement and verify the performance of a robot’s navigation system. The experiments on simulation and a physical robot for the eight scenarios demonstrate that the robot can effectively and efficiently avoid potential collisions with any static or dynamic obstacles in its surrounding environment. Compared with the particle swarm optimisation, the dynamic window approach and the traditional Morphin algorithm for the autonomous navigation of a mobile robot in a static environment, ATCM achieved the shortest path with higher efficiency.

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Formation Control and Obstacle Avoidance Algorithm of a Multi-USV System Based on Virtual Structure and Artificial Potential Field

Journal of Marine Science and Engineering ◽

10.3390/jmse9020161 ◽

2021 ◽

Vol 9 (2) ◽

pp. 161

Author(s):

Xun Yan ◽

Dapeng Jiang ◽

Runlong Miao ◽

Yulong Li

Keyword(s):

Obstacle Avoidance ◽

Potential Field ◽

Formation Control ◽

Shape Change ◽

Artificial Potential Field ◽

Generation Algorithm ◽

Time Performance ◽

Movement Ability ◽

Window Approach ◽

Avoidance Problem

This paper proposes a formation generation algorithm and formation obstacle avoidance strategy for multiple unmanned surface vehicles (USVs). The proposed formation generation algorithm implements an approach combining a virtual structure and artificial potential field (VSAPF), which provides a high accuracy of formation shape keeping and flexibility of formation shape change. To solve the obstacle avoidance problem of the multi-USV system, an improved dynamic window approach is applied to the formation reference point, which considers the movement ability of the USV. By applying this method, the USV formation can avoid obstacles while maintaining its shape. The combination of the virtual structure and artificial potential field has the advantage of less calculations, so that it can ensure the real-time performance of the algorithm and convenience for deployment on an actual USV. Various simulation results for a group of USVs are provided to demonstrate the effectiveness of the proposed algorithms.

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Sitsen: Passive sitting posture sensing based on wireless devices

International Journal of Distributed Sensor Networks ◽

10.1177/15501477211024846 ◽

2021 ◽

Vol 17 (7) ◽

pp. 155014772110248

Author(s):

Miaoyu Li ◽

Zhuohan Jiang ◽

Yutong Liu ◽

Shuheng Chen ◽

Marcin Wozniak ◽

...

Keyword(s):

Radio Frequency ◽

Radio Frequency Identification ◽

High Performance ◽

Learning Algorithm ◽

Low Cost ◽

Recognition System ◽

Sitting Posture ◽

Average Accuracy ◽

Phase Variations ◽

Window Approach

Physical health diseases caused by wrong sitting postures are becoming increasingly serious and widespread, especially for sedentary students and workers. Existing video-based approaches and sensor-based approaches can achieve high accuracy, while they have limitations like breaching privacy and relying on specific sensor devices. In this work, we propose Sitsen, a non-contact wireless-based sitting posture recognition system, just using radio frequency signals alone, which neither compromises the privacy nor requires using various specific sensors. We demonstrate that Sitsen can successfully recognize five habitual sitting postures with just one lightweight and low-cost radio frequency identification tag. The intuition is that different postures induce different phase variations. Due to the received phase readings are corrupted by the environmental noise and hardware imperfection, we employ series of signal processing schemes to obtain clean phase readings. Using the sliding window approach to extract effective features of the measured phase sequences and employing an appropriate machine learning algorithm, Sitsen can achieve robust and high performance. Extensive experiments are conducted in an office with 10 volunteers. The result shows that our system can recognize different sitting postures with an average accuracy of 97.02%.

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Global Dynamic Path Planning Fusion Algorithm Combining Jump-A* Algorithm and Dynamic Window Approach

IEEE Access ◽

10.1109/access.2021.3052865 ◽

2021 ◽

Vol 9 ◽

pp. 19632-19638

Author(s):

Lisang Liu ◽

Jinxin Yao ◽

Dongwei He ◽

Jian Chen ◽

Jing Huang ◽

...

Keyword(s):

Path Planning ◽

A Algorithm ◽

Fusion Algorithm ◽

Global Dynamic ◽

Dynamic Path Planning ◽

Dynamic Path ◽

Window Approach

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Surgical considerations during cochlear implantation: the utility of temporal bone computed tomography

The Journal of Laryngology & Otology ◽

10.1017/s0022215121000232 ◽

2021 ◽

pp. 1-8

Author(s):

Beomcho Jun ◽

Sunwha Song

Keyword(s):

Computed Tomography ◽

Temporal Bone ◽

Cochlear Implantation ◽

Round Window ◽

Three Dimensional ◽

Electrode Placement ◽

Posterior Tympanotomy ◽

Electrode Insertion ◽

Window Approach ◽

Bone Structures

Abstract Objective This paper describes the construction of portals for electrode placement during cochlear implantation and emphasises the utility of pre-operative temporal bone three-dimensional computed tomography. Methods Temporal bone three-dimensional computed tomography was used to plan portal creation for electrode insertion. Results Pre-operative temporal bone three-dimensional computed tomography can be used to determine the orientation of temporal bone structures, which is important for mastoidectomy, posterior tympanotomy and cochleostomy, and when using the round window approach. Conclusion It is essential to create appropriate portals (from the mastoid cortex to the cochlea) in a step-by-step manner, to ensure the safe insertion of electrodes into the scala tympani. Pre-operative three-dimensional temporal bone computed tomography is invaluable in this respect.

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