word number: 2927
Time: 2021-09-25 15:30:33 +0000
As the title suggest, the course is a collection of topics discussed by Professors in Kumamoto University which is compulsory for international students and optional for native Japanese students. Unfortunately I do not have all the materials and do not have the right to share them but I do have the right to share my assignments. Most the assignments are summaries or just my impressions about each sessions and not all of them survived since some are asked to be hand written. Either way, these assignments has never been published anywhere and I, as the author and copyright holder, license this assignment customized CC-BY-SA where anyone can share, copy, republish, and sell on condition to state my name as the author and notify that the original and open version available here.
The feedback control is one of the topics that is discussed in the subject of control system. It can be implemented in all fields but in my case, I mostly heard in field of Engineering usually in Electrical and Mechanical Engineering. The control system itself is the field of controlling a system where a simple control device can control the behaviour of another device, a remote controlled car for example. The remote controlled car is a user or manually controlled device which generally is not feeback controlled that tends to be automatic. A feedback control technology automatically controls the device with the general definition follows after Figure 1.
Figure 1. Feedback Control Block Diagram
Figure 1 above shows the block diagram of feedback control system where the desired output is controlled. The variable “input” itself is usually “desired output”, and “feedback” is the current “output”. The feedback system is a system where the current output is included into the calculation. For example an air conditioner is set an input of 250C, the current temperature is 270C will be the value of the feedback. The system will detect the difference in temperature that the room is still hot. The air condition will attempt to cool it down until it reaches 250C or lower, and once it reaches it the air condition will stop the cool down attempt. It will turn on again when the temperature rises.
Air conditioner is a good commonly known example in the first section. Another example is the refrigerator which should have the almost the same method as the air conditioner. There’s a block diagram thermoelectric cooler control on Figure 2.
Figure 2. Thermoelectric cooler control diagram
Another example of heat controlled device is the electric iron for ironing clothes. The heating process will stop if it reaches the desired temperature. There’s still more examples like oven, microwave, dispenser, and heater during summer. Those are common examples that can easily be explained and tends to be very crucial if feedback control is not implemented. If iron, oven, dispensers, and stuffs over heat it will burn the clothes, the foods, spill the water, in worst case it might explode, cause fire, and casualties. Now days even computers and laptops are equipped with cooling features. The hotter the computer the faster the fan spins, and on the other hand if it cools down, the fan will spin slower. Those are essential control example in daily live, another very crucial example is the balance of helicopter issue, air plane, train, rocket, which are very dangerous if feedback control is not implemented. They’re not daily lives thought.
There are other feedback control that can be implemented which is not necessary but could benefit greatly. On my undergraduate I made an automatic dimming light consist of light and photo-transistor as its sensor with micro-controller. Other than the automatically turning on the light when it’s night, turning it off when it’s day, it can automatically adjust the light intensity based on surrounding light intensity. It’s an automatic lighting system that could adjust to the desired brightness with the block diagram on Figure 3. This isn’t crucial but it could save energy if it’s implemented.
Figure 3. Automatic light dimmer block diagram
Today’s feedback control system purposes are for efficient, richer, and safer life. Electric vehicles such as the segways and scooters are feedback controlled on the balance issues where it tries to maintain the center of balance. As for the building demolisher prevents shaking of the demolisher (the pendulum iron ball) to prevent accident. The latest control system technology is on automatic cars and robots. Latest car can drive automatically using the GPS to find the way, using the road’s lines and signs to keep on track (line follower robot is the most basic), and few sensors to detect surroundings like other cars, bike, and people crossing the road. It’s not that far where vehicles can automatically be called to get us using remote control for example. If autopilot is already possible, then all we need is to send our GPS location to our car, and will automatically come. Lastly on Figure 5 is a compilation of feedback control applications.
Figure 4. Feedback control application compilation
First I would like to admit that my knowledge of chemistry and environment is still insufficient but I would like to give my comments and suggestion from the public point of view. The lecture consists of “Development of environmentally benign biomass utilization processes”, “producing functional polymers“, and “synthesizing bio-active peptides”.
The first comment I would like to give is about biorefinery with supercritical fluids. As the question that I asked on the previous lecture the idea is the cost of the refinery process in compare to the output whether they are fuels, power supply, or chemicals. If the input is larger than the output normally it’s a loss, but biorefinery is a special case. Since it is the process of recycling waste is not necessary a loss if the cost to do the refinery is larger than the output. Instead I suggest to compare the cost used using conventional method and supercritical fluid method, then compare the output of those two methods. Which one is better? Another opinion is, maybe you may mix using supercritical fluids and conventional method. As for Supercritical CO2 Extraction and Micronization of Carotenoids I think it may proceed to the manufacturing side for next research. How is it if it’s actually implemented in Industry?
On PNIPAM polymers synthesis topic using pulsed power, there’s a graphic of using pulsed power to produce with low frequencies and the conventional way. The conventional method produces on 5 minutes while using pulsed power can produce almost instantaneously. On the very low frequency the conventional method can produce higher yields when over 10 minutes pass. I propose, how about mixing the pulsed power method with the conventional method? Use the pulsed power method first, then continue with conventional method. Another thing is you may continue retrieving data for more frequencies. Again is it more expensive to use the pulsed power method? Are we ready to implement it?
On synthesis of peptides using the same method, how about doing the experiment on the larger scale of volumes? If not possible due to current equipment, then I think we can provide datas with different volumes. Then to perform on large scale the first step can be done through theoretical, calculation, or simulation. Another curiosity, what if we do the experiment in different room temperatures?
Lastly I would like to thank for your time for giving us lecture. With have another view of what is like in Pulsed Power department. I believed that learning many different things will widen our view, and make even more path possible. I prefer to learn a little of everything than just being closed to study one subject. One last advice, since some of us are not familiar on this field is very hard for us the grasp the lecture, so I suggest you may provide videos of your experiments. We find it harder to imagine based on the advance theory, but with videos we directly see your research.
This Lecture of Current Science and Technology on 18th and 25th January 2016 discusses about noise policy and later on to be implement in developing countries by Professor Takashi Yano from Department of Architecture and Environment Planning, Graduate School of Science and Technology, Kumamoto University. On the first lecture the very basics of what noises are, how can it occurs, and how the impact is to the environment. Then a policy was introduced for this noise including how the policy was created. Develop countries like Europe and Japan already studied early for these policies. The Professor states he would like to continue the research on implementing them on developing countries, on the second lecture his study of noise policy in Vietnam was introduced.
On this topic noise is defined as unwanted sounds that bothers, cause disturbance, or cause annoyance. We can perceive sound in terms of energy, frequency, and temporal characteristic. Energy is more like the intensity of the sound with the higher the intensity the louder the sound. For us loud sounds tends to be nuisance. Frequency can correlate with pitch, women in choirs tends to have high pitch or high frequency or soprano sound, while men tends to have low pitch or low frequency or bass sound. The study between intensity and frequency have been conduct and we can refer to the research usually in form of graphic. With certain level usually high level of intensity are treated as noise. Where does noise came from? It can come from aircrafts, cars, trains, industrial, and many more. What are the effects of noise? It could be noise-induced hearing impairment, interference with speech communication, sleep disturbance, cardiovascular and physiological effects, mental health effects, performance, and residential behavior and annoyance. How does noise policies are made? First of is to get the scientific data of the noise by calculating the sound level in decibel (dB), not to forget to include the factors of daytime, evening, and night times. For example calculating the sound intensity of trains. Then get a social data by conducting surveys on people of getting their opinion of how annoying the sound is. In English it is either extremely, very, moderately, slightly, or not annoying at all. Another way is to use numbers or metrics and ask the people to fill it in. Finally a correlation between the level of annoyance and sound level is made usually in form of graphs. From here we derive of what sound level of certain object is tolerable in our policy. Studies in Europe shows an aircraft is more annoying on the same sound level rather than road traffic followed by railway. It’s similar in Japan but railway is more annoying than road traffic, with these conditions bonus levels might be implemented in policies. These could be psychological issues and maybe others.
The research aims to creates noise policies for all around the globe. The example above (noise policy in Europe and Japan) shows that each place might not be able to implement the same policies, because each place had their own characteristics. On the second lecture there was a survey conducted comparison of road traffic noise annoyance among Japanese, Vietnamese living in Kumamoto and Vietnamese living in Hanoi. The result was the Vietnamese living in Hanoi experience a certain sound level doesn’t find it annoying at all, while for Japanese is already annoying. This could be due to the situation Vietnam very crowded in traffic and they are used to such noises. These arouse a question for me that will the noise policy be fixed? For example if the noises are reducing in the future wouldn’t that change the opinion of the people on next generation?
If I can use an X-ray CT scan for my study, I would like to use them for examining and reverse engineering of electronic devices the non destructive way. The term reverse engineering means to break open the object to know how it works that later could be troubleshoot, revised, enhance, or duplicate. The normal way have a high chance of breaking the electronic device, or at least it can no longer return to the way it is. Reverse engineering on a phone for example will break the guarantee seal. Therefore it be nice if we can use X-ray CT scan to reconstruct the inside into 3D digital image. Furthermore I wanted to use this X-ray CT for education, if possible commercially available for everyone. So I hope a portable X-ray CT are to be developed as vision of the author of the paper I showed below.
In the field of computer science, electrical engineering, or alike is more likely that we develop an X-ray computed tomography (CT) scanner, although not limited to that. We can for example use CT to monitor battery condition for example, or see whether CT can be use for reverse engineering of an electronic device. But most research are on finding algorithms for fast CT scan, develop the image processing, or upgrade the hardware as now nano-technologies are aggressively advancing. Here I would like to show a paper of “Towards a Flexible and Portable CT Scanner” by Jeff Orchard and John Yeow from Waterloo University, Canada on 2008, which was 8 years ago today the prototype probably exist.
Even today we knew that X-ray CT scanner are very big and stationary, only available on the hospital, industries, or laboratories. It’s not a public equipment, it’s also high power consuming and produces high temperature. Like computers today can be portable (laptops, gadgets, PDA, etc) the thought came up of what if we can carry an X-ray CT scanner? To make this the author claimed that it is possible ever since the discovery of carbon nano tubes (CNT). CNT had the ability to project electrons when exposed to an electric field which is the one of the fundamental of X-ray CT. The author hadn’t realized the device yet but simulates it when using flexible arrays in conjunction with X-ray detectors. The work before integrates the tiny x-ray devices into a flexible array such that each emitter can be individually pulsed. Through the simulation the author states that the challenge is within the irregular geometry shape (usually perfect circle). For this we have to treat scan as collection of individual ray sum. Other challenges were stated like the need of CNT to be in vacuum, the degradation of CNT structure, the unclear value of x-ray photon flux which determines the quality of the image, and some X-ray photons undergoes Rayleigh and Compton scattering.
Mamiko Yada explained to me 2x at poster session and special seminar of her topic related to binaural hearing and bone conduction in determining the source of incoming sound.
Koshiro Hira explained to me in his poster session on unidirectional sound for where each has anti sound waves of its opposing speakers so that it doesn’t clash with each other, it’s for evacuation pursposes.
I too am a member of this Lab which my research continues Dynamic Synchronization of Learning Contents previously by Dr. Royyana. I do have an idea of audio distribution over wireless sensor network for emergency evacuation purposes on remote area.
From this I learned that the consequences of breaking the rule is more severe for foreigners than local citizen. Local citizen’s suspension is more to social punishment while for let’s say international student punishment must leave Japan.
Using vehicle carefully is very important, even bicycle is regarded as an official vehicle. Plagiarism must be avoided at any cost. Don’t save money if it relates to health and safety. For example buy thick clothes for Winter, becareful of disasters.
But there is something still bothering me, and I highly suggest to explain deeply of this one. It’s about copyright issues on The Internet. Back in Indonesia I don’t have to worry anything when surfing on The Internet. I understand that you have to pay when downloading copyright materials, and uploading them is very severe. But what about just accessing the content like watching Youtube or reading online materials? Some say that you’re not allow to download videos for example on Youtube, but what if there’s no copyright on the video? It’s the author’s original video, and on Youtube he/she says it’s free to distribute. Here P2P and file sharing software, it’s said to be illegal, but I usually use them not for pirating, for example use torrent to download Linux and other open source software. Instead we encourage to use torrent because we wanted to widely distribute this free open source software.