Beneficial Perturbation Network for Designing General Adaptive Artificial Intelligence Systems.

The human brain is the gold standard of adaptive learning. It not only can learn and benefit from experience, but also can adapt to new situations. In contrast, deep neural networks only learn one sophisticated but fixed mapping from inputs to outputs. This limits their applicability to more dynamic situations, where the input to output mapping may change with different contexts. A salient example is continual learning-learning new independent tasks sequentially without forgetting previous tasks. Continual learning of multiple tasks in artificial neural networks using gradient descent leads to catastrophic forgetting, whereby a previously learned mapping of an old task is erased when learning new mappings for new tasks. Herein, we propose a new biologically plausible type of deep neural network with extra, out-of-network, task-dependent biasing units to accommodate these dynamic situations. This allows, for the first time, a single network to learn potentially unlimited parallel input to output mappings, and to switch on the fly between them at runtime. Biasing units are programed by leveraging beneficial perturbations (opposite to well-known adversarial perturbations) for each task. Beneficial perturbations for a given task bias the network toward that task, essentially switching the network into a different mode to process that task. This largely eliminates catastrophic interference between tasks. Our approach is memory-efficient and parameter-efficient, can accommodate many tasks, and achieves the state-of-the-art performance across different tasks and domains.

Effect of mechanical error on dual-wedge laser scanning system and error correction.

Compared with the traditional mechanical beam deflector in a beam-scanning system, the dual-wedge scanning system has several advantages, for example, compact structure, fast scanning speed, and low power consumption. High accuracy is the most important factor in dual-wedge scanning, but mechanical errors caused by machining or assembly errors adversely affect this scanning accuracy. Horizontal and angular mechanical errors appear between the incident light and the dual-wedge central optical axes. By building a mathematical model of an ideal dual-wedge scanning trajectory and a trajectory affected by mechanical errors, this paper analyzes the types and degree of influence on the scanning process, as well as the sensitivity of scanned images to different errors. Results show that the angular error has the most significant influence on the scanning image accuracy, in terms of trajectory shape and coverage. To correct the angular error, the two degrees-of-freedom flexible fine-tuning mechanism is customized based on the principle of the cantilever beam type. After finite element analysis and experimental validations, the fine-tuning mechanism can guarantee that the angular error in the dual-wedge central optical axes will be lower than 0.05 deg, thus ensuring scanning trajectory accuracy.

Horner syndrome as a complication after thyroid microwave ablation: Case report and brief literature review.

RATIONALE: Horner's syndrome (HS) can present as a complication of thyroid surgery, particularly after thyroid microwave ablation (MWA). HS presents clinically with eyelid ptosis, miosis, enophthalmos, anhidrosis, and vascular dilatation, all of which result from a damaged oculosympathetic chain. We aimed to try to avoid such devastating symptoms in future cases by exploring reasons for the destruction of the cervical sympathetic trunk. PATIENT CONCERNS: HS has previously been reported in the literature as a complication of thyroid surgery. Here, we report the case of a 44-year-old female patient who presented with miosis and eyelid ptosis following thyroid MWA. DIAGNOSES: This patient was subsequently diagnosed with HS. INTERVENTIONS: Mecobalamin was administered immediately. OUTCOMES: After 5 months of follow up, the patient's miosis and ptosis was incompletely relieved. LESSONS: Although HS is a rare complication of thyroid MWA, surgeons must be aware of the anatomic relationship of the cervical sympathetic trunk and thyroid gland with adjacent structures. Moreover, we hope this case presentation enables surgeons to take measures to minimize the possibility of oculosympathetic damage. Long-term follow up and comprehensive assessments are important for the patient's prognosis.