基于变压器的视觉细分:一项调查
概括
变压器正在彻底改变视觉细分,在自动驾驶和医疗分析等任务中表现优于旧方法. 这份调查详细介绍了它们的架构,应用以及未来的研究方向.
科学领域:
- 计算机视觉 计算机视觉
- 人工智能的人工智能
- 机器学习 机器学习
背景情况:
- 视觉细分将图像/视频分成有意义的组,用于自动驾驶和医学分析等应用.
- 在过去的十年里,深度学习方法已经大大提升了视觉细分.
- 最初用于NLP的变压器现在在视觉任务中表现出色,超过了卷积和循环网络.
研究的目的:
- 提供基于变压器的视觉细分方法的全面概述.
- 总结最近的进展,并在一个元架构下统一最近的基于变压器的方法.
- 探索特定的子领域,并确定未来的研究方向.
主要方法:
- 对背景的审查,包括问题定义,数据集和先前的卷积方法.
- 基于变压器的视觉细分的统一元架构的总结.
- 基于元架构的各种方法设计,修改和应用的检查.
主要成果:
- 变压器为各种细分任务提供了强大,统一和简单的解决方案.
- 具体子领域的详细检查:3D点云细分,基础模型调整,域意识,高效和医疗细分.
- 在已建立的数据集上重新评估已审查的方法.
结论:
- 基于变压器的方法代表了视觉细分的重大进步.
- 该调查强调了关键的挑战,并提出了这个快速发展的领域的未来研究途径.
相关概念视频
Transformers
A device that transforms voltages from one value to another using induction is called a transformer. A transformer consists of two separate coils, or windings, wrapped around the same soft iron core. However, they are electrically insulated from each other.
The iron core has a substantial relative permeability. Therefore, the magnetic field lines generated due to the current in one winding are almost entirely confined within the core, such that the same magnetic flux permeates each turn of both...
The iron core has a substantial relative permeability. Therefore, the magnetic field lines generated due to the current in one winding are almost entirely confined within the core, such that the same magnetic flux permeates each turn of both...
Types Of Transformers
Transformers can provide desired voltages to a circuit by modifying the number of turns in the secondary windings.
If the ratio of the number of turns in the secondary winding to that of the primary winding is greater than one, then the transformer is said to be a step-up transformer. In a step-up transformer, the voltage at the secondary winding is greater than the voltage applied at the primary winding.
However, if this ratio is less than one, the transformer is said to be a step-down...
If the ratio of the number of turns in the secondary winding to that of the primary winding is greater than one, then the transformer is said to be a step-up transformer. In a step-up transformer, the voltage at the secondary winding is greater than the voltage applied at the primary winding.
However, if this ratio is less than one, the transformer is said to be a step-down...
Energy Losses in Transformers
In an ideal transformer, it is assumed that there are no energy losses, and, hence, all the power at the primary winding is transferred to the secondary winding. However, in reality, the transformers always have some energy losses, and, hence, the output power obtained at the secondary winding is less than the input power at the primary winding due to energy losses.
There are four main reasons for energy losses in transformers.
The first cause can be the high resistance of the copper windings...
There are four main reasons for energy losses in transformers.
The first cause can be the high resistance of the copper windings...
The Ideal Transformer
In single-phase two-winding transformers, two windings are coiled around a magnetic core characterized by cross-sectional area A and magnetic permeability μ. A phasor current i1 enters the left winding while i2 exits the right winding, establishing the fundamental working of the transformer through electromagnetic principles.
Ampere's Law forms the basis of understanding the magnetic field within the transformer. It states that the integral of the magnetic field intensity's tangential component...
Ampere's Law forms the basis of understanding the magnetic field within the transformer. It states that the integral of the magnetic field intensity's tangential component...
Transformers in Distribution System
Transformers in distribution systems can be broadly categorized into distribution substation transformers and other distribution transformers. They are crucial for stepping down high transmission voltages to levels suitable for distribution and end-user applications.
Distribution substation transformers come in various ratings and typically use mineral oil for insulation and cooling. To prevent moisture and air from entering the oil, some transformers use an inert gas like nitrogen to fill the...
Distribution substation transformers come in various ratings and typically use mineral oil for insulation and cooling. To prevent moisture and air from entering the oil, some transformers use an inert gas like nitrogen to fill the...
Transformers with Off-Nominal Turns Ratios
In scenarios involving parallel transformers with disparate ratings, developing per-unit models requires accommodating off-nominal turns ratios. This situation arises when the selected base voltages are not proportional to the transformer’s voltage ratings. Consider a transformer where the rated voltages are related by the term a. If the chosen voltage bases satisfy a relationship involving term b, term c is defined as the ratio of these bases. This ratio is then substituted into the rated...


