**Introduction to Speech Recognition**
Speech recognition is a groundbreaking technology that allows machines to understand and interpret human speech. It's like giving a machine an "auditory system" so it can hear and respond to what you say. This concept has long been a dream for many, and now, with the rapid development of technology, it's becoming a reality. The China Internet of Things School and Enterprise Alliance, for example, has integrated speech recognition as a core component in its systems.
Speech recognition involves converting a spoken signal into text or commands through a process of analysis and understanding. It mainly consists of three key components: feature extraction, pattern matching, and model training. These technologies are now widely used in various applications, such as voice-controlled navigation systems in cars, where users can set their destination by simply speaking, making driving safer and more convenient.
As an interdisciplinary field, speech recognition combines elements from signal processing, artificial intelligence, probability theory, and more. Over the past two decades, it has evolved significantly, moving from research labs to real-world applications. Experts predict that within the next decade, this technology will be embedded in industries like healthcare, automotive, home automation, and consumer electronics. In 1997, the U.S. press even ranked speech recognition as one of the top ten events in computer development. Many consider it one of the most important technological advancements in information technology between 2000 and 2010.
**Speech Classification and Applications**
Speech recognition tasks can be categorized based on what they identify. These include isolated word recognition, keyword detection, and continuous speech recognition. Isolated word recognition identifies specific words like “start†or “stop,†while continuous speech recognition handles full sentences or paragraphs. Keyword detection, on the other hand, scans through speech to find specific words without recognizing every single one.
Additionally, speech recognition can be speaker-dependent or speaker-independent. Speaker-dependent systems are trained to recognize specific voices, while speaker-independent systems work for any user. Although the latter is more challenging, it’s more practical for general use.
Different devices also influence how speech is recognized. Desktop systems, phone-based systems, and embedded devices like smartphones each have unique acoustic characteristics, requiring tailored recognition models.
The applications of speech recognition are vast. From voice input systems that replace traditional keyboards to voice-controlled smart homes and industrial equipment, this technology enhances efficiency and convenience. Voice-activated customer service systems, medical assistance tools, and even interactive toys all benefit from this innovation.
**Principle of Speech Recognition**
At its core, speech recognition is a pattern recognition system. It typically includes three main parts: feature extraction, pattern matching, and a reference library of known patterns. The process starts when a microphone captures sound and converts it into an electrical signal. The system then performs preprocessing, extracts relevant features, and builds a model for comparison.
During recognition, the system compares the extracted features with stored templates using a matching algorithm to determine the best match. The accuracy of this process depends heavily on the quality of the features, the robustness of the model, and the precision of the templates. As this technology continues to evolve, its impact on daily life and industry will only grow.
DC Source System
APM DC source system is programmable DC Power Supply which can output high power. Users can set the output voltage,current arbitrarily .Measure all kinds of features and display on VFD. As for this DC source system,output voltage is up to 1200VDC max (recommend not to exceed 800V) by connecting the internal single unit in series.
High voltage dc power supply output current is up to 2000A max by connecting the internal single unit in parallel. Maximum power and height of the adjustable power supply is in 10.8kW, 21.6kW, 36kW and 6U, 12U ,20U high respectively.
Some features as below:
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With accurate voltage and current measurement capability.
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Coded Knob, multifunctional keyboard.
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Standard RS232/RS485/USB/LAN communication interfaces, GPIB is optional.
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Remote sensing line voltage drop compensation.
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Equips with LIST waveform editing function.
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Use the Standard Commands for Programmable Instrumentation(SCPI) communication protocol.
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Have obtained CE certification.
DC Source System,30V Power Supply,Digital DC Power Supply,Dc Constant Power Source
APM Technologies Ltd , https://www.apmpowersupply.com