Do you know the electronics behind the app that provides real-time bus location information?

A useful smartphone application on Seoul’s public transportation is backed by complex electronics technology. Technologies such as telecommunications, semiconductors, automation, and the Internet of Things are combining to revolutionize our lives, and the possibilities for advances in electronics are endless.

 

An application that can tell you the location of the next bus to arrive at the stop you’re at in real time, and with a high degree of accuracy, is a very useful feature for anyone who uses Seoul’s public transportation. It may seem trivial to others, but I often think about how much technology is behind these small conveniences, and the more I study, the more I realize that there is a complex intertwining of invisible technologies, which I find very interesting.
With that in mind, I’d like to give you a brief introduction to electronics, which is revolutionizing our daily lives. As mentioned above, electronics is everywhere, enriching our lives, whether it’s communications technology that allows us to send and receive vast amounts of data on our smartphones, semiconductor technology that processes this data as fast as computers, automation systems that enable precise and complex processes without the need for humans, or the Internet of Things (IoT), which allows objects around us to collect the information they need and act on their own or inform us accordingly.
In order to realize these technologies, we are learning the basics one by one at the university. First of all, let’s take a quick look at some of the fields that are being applied in real life that are relevant to what we are learning. The field of signal processing, which takes in various signals from nature through sensors, processes them according to the purpose, and sends them back to us in a signal that we can understand, is actually based on math. For example, signals from nature are called analog signals, which can be thought of as a combination of trigonometric functions (sine, cosine, etc.) with frequency.
For example, this is what we mean when we talk about frequency in radio broadcasts; light is said to have different colors depending on its wavelength, which is inversely proportional to its frequency; sound is also related to frequency because the wavelength of light is inversely proportional to its frequency; and the pitch of a sound depends on its frequency, which is the inverse of its frequency. As you can see, most analog signals are closely related to frequency, so we can identify the signal by specifying what value it has at what frequency, and then convert it to a digital signal so that the computer can perform computational processing. And then we convert that processed digital signal back into an analog signal that we can recognize. The reason we can take a video with a camera and watch it on a TV is because of this process. This property can also be used to amplify the values of certain frequencies, making it easier to see things that would otherwise be indistinguishable to the naked eye. It will also allow machines to identify objects, understand their movements, and perform various tasks based on them.
A related signal transformation method is the Fourier Transform, which you’ll learn about in your engineering math course. You’ll build on this in Signals and Systems to learn about systems that convert and process signals in earnest, and you’ll go on to study more sophisticated and complex signal processing in Digital Signal Processing. Circuit theory and electromagnetism, the foundations of electronics, are also essential to understanding and developing these skills.
Most electronic devices have circuits and chips. Circuits transfer digital information back and forth between devices, and chips compute and process that information. Electronic circuits are becoming more ubiquitous in the future. Even in the case of driverless cars, which we learned about in class, sensors are used to accurately recognize surrounding objects and road conditions, computational processing is performed on the electronic circuits in each part to perform appropriate actions, and each circuit is organized through an Ethernet (local area network).
To use these advanced technologies, you first learn the most basic circuit theory. You will learn about current and voltage sources and the changes in current and voltage in circuits made up of basic elements such as resistors, inductors, capacitors, and amplifiers, and in later subjects such as electronic circuits and logic circuits, you will learn about complex elements such as diodes and logic gates, and later you will construct circuits that perform simple operations and processing.
The field of telecommunications is very complex, and although we are not learning anything directly about it yet, it is largely based on electromagnetism. You’re probably very familiar with the word electromagnetic waves, and in fact, communication is done through electromagnetic waves. In order to be able to communicate accurately and safely, we need to know the properties of electric and magnetic fields, and we are currently studying electromagnetism and, depending on our choices, we will study communication theory in earnest in the future. I think it is the field of communication that serves as a medium to construct advanced modern civilization, and you can easily experience it just by looking at the fact that the Internet, mobile communication, or 5G or the Internet of Things, which are currently in the spotlight, are communication fields.
If you look around you, there are more electronics technologies embedded in batteries, displays, electric vehicles, card readers, etc. than you might think. Just by looking at Samsung Electronics’ recently announced Galaxy S6 smartphone, we can see that a lot of electronics technology, such as faster memory, photography, fingerprint recognition, Samsung Pay, etc. are integrated into a small device. Electronics is a big part of the reason why things we have seen in science fiction movies and longed for are slowly becoming a reality. In fact, I chose this major with the vague idea that I would like to develop various technologies to make life more convenient and high quality, and although I have only been studying for about two years, I have realized that I am close to my dreams, and I think it is a major that is somewhat complex and difficult but more than rewarding.
The fascinating thing about electronics is that it never ends – many of the conveniences we enjoy in our daily lives are the result of a huge amount of research and technological advancement, and the possibilities for future developments are endless. Self-driving cars, smart homes, virtual reality (VR) and augmented reality (AR), and many other technologies that will make our future even more revolutionary all fall under the umbrella of electronics. We are fortunate to be able to study electronics and face new challenges and learning opportunities every day. It’s more than just an academic discipline, it’s an opportunity to change our lives and contribute to making the world a better place.